94 results on '"David E. Schwartz"'
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2. From Printed Transistors to Printed Smart Systems.
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Robert A. Street, Tse Nga Tina Ng, David E. Schwartz, Gregory L. Whiting, J. P. Lu, R. D. Bringans, and Janos Veres
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- 2015
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3. Isoflurane promotes phagocytosis of apoptotic neutrophils through AMPK-mediated ADAM17/Mer signaling.
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Xueke Du, Chunling Jiang, Yang Lv, Randal O Dull, You-Yang Zhao, David E Schwartz, and Guochang Hu
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Medicine ,Science - Abstract
A patient's recovery from lung inflammatory injury or development of multi-system organ failure is determined by the host's ability to resolve inflammation and repair tissue damage, both of which require the clearance of apoptotic neutrophils by macrophages (efferocytosis). Here, we investigated the effects of isoflurane on macrophage efferocytosis and resolution of lung inflammatory injury. Treatment of murine bone marrow-derived macrophages (BMDMs) or alveolar macrophages with isoflurane dramatically enhanced phagocytosis of apoptotic neutrophils. Isoflurane significantly increased the surface expression of the receptor tyrosine kinase Mer in macrophages, but markedly decreased the levels of a soluble form of Mer protein in the medium. Isoflurane treatment also caused a decrease in a disintegrin and metalloproteinase 17 (ADAM17) on the cell surface and a concomitant increase in its cytoplasmic fraction. These responses induced by isoflurane were completely reversed by a pharmacological inhibitor or genetic deletion of AMP-activated protein kinase (AMPK). In a mouse model of lipopolysaccharide-induced lung injury, isoflurane accelerated the recovery of lung inflammation and injury that was coupled with an increase in the number of alveolar macrophages containing apoptotic bodies. In alveolar macrophage-depleted mice, administration of isoflurane-pretreated BMDMs facilitated resolution of lung inflammation following lipopolysaccharide challenge. Thus, isoflurane promoted resolution of lipopolysaccharide-induced lung inflammatory injury via enhancement of macrophage efferocytosis. Increased macrophage efferocytosis following isoflurane treatment correlates with upregulation of Mer surface expression through AMPK-mediated blockade of ADAM17 trafficking to the cell membrane.
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- 2017
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4. A Single-Photon Avalanche Diode Array for Fluorescence Lifetime Imaging Microscopy.
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David E. Schwartz, Edoardo Charbon, and Kenneth L. Shepard
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- 2008
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5. Tissue Specificity of Human Angiotensin I-Converting Enzyme.
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Olga V Kryukova, Victoria E Tikhomirova, Elena Z Golukhova, Valery V Evdokimov, Gavreel F Kalantarov, Ilya N Trakht, David E Schwartz, Randal O Dull, Alexander V Gusakov, Igor V Uporov, Olga A Kost, and Sergei M Danilov
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Medicine ,Science - Abstract
Angiotensin-converting enzyme (ACE), which metabolizes many peptides and plays a key role in blood pressure regulation and vascular remodeling, as well as in reproductive functions, is expressed as a type-1 membrane glycoprotein on the surface of endothelial and epithelial cells. ACE also presents as a soluble form in biological fluids, among which seminal fluid being the richest in ACE content - 50-fold more than that in blood.We performed conformational fingerprinting of lung and seminal fluid ACEs using a set of monoclonal antibodies (mAbs) to 17 epitopes of human ACE and determined the effects of potential ACE-binding partners on mAbs binding to these two different ACEs. Patterns of mAbs binding to ACEs from lung and from seminal fluid dramatically differed, which reflects difference in the local conformations of these ACEs, likely due to different patterns of ACE glycosylation in the lung endothelial cells and epithelial cells of epididymis/prostate (source of seminal fluid ACE), confirmed by mass-spectrometry of ACEs tryptic digests.Dramatic differences in the local conformations of seminal fluid and lung ACEs, as well as the effects of ACE-binding partners on mAbs binding to these ACEs, suggest different regulation of ACE functions and shedding from epithelial cells in epididymis and prostate and endothelial cells of lung capillaries. The differences in local conformation of ACE could be the base for the generation of mAbs distingushing tissue-specific ACEs.
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- 2015
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6. A novel angiotensin I-converting enzyme mutation (S333W) impairs N-domain enzymatic cleavage of the anti-fibrotic peptide, AcSDKP.
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Sergei M Danilov, Michael S Wade, Sylva L Schwager, Ross G Douglas, Andrew B Nesterovitch, Isolda A Popova, Kyle D Hogarth, Nakul Bhardwaj, David E Schwartz, Edward D Sturrock, and Joe G N Garcia
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Medicine ,Science - Abstract
BACKGROUND: Angiotensin I-converting enzyme (ACE) has two functional N- and C-domain active centers that display differences in the metabolism of biologically-active peptides including the hemoregulatory tetrapeptide, Ac-SDKP, hydrolysed preferentially by the N domain active center. Elevated Ac-SDKP concentrations are associated with reduced tissue fibrosis. RESULTS: We identified a patient of African descent exhibiting unusual blood ACE kinetics with reduced relative hydrolysis of two synthetic ACE substrates (ZPHL/HHL ratio) suggestive of the ACE N domain center inactivation. Inhibition of blood ACE activity by anti-catalytic mAbs and ACE inhibitors and conformational fingerprint of blood ACE suggested overall conformational changes in the ACE molecule and sequencing identified Ser333Trp substitution in the N domain of ACE. In silico analysis demonstrated S333W localized in the S1 pocket of the active site of the N domain with the bulky Trp adversely affecting binding of ACE substrates due to steric hindrance. Expression of mutant ACE (S333W) in CHO cells confirmed altered kinetic properties of mutant ACE and conformational changes in the N domain. Further, the S333W mutant displayed decreased ability (5-fold) to cleave the physiological substrate AcSDKP compared to wild-type ACE. CONCLUSIONS AND SIGNIFICANCE: A novel Ser333Trp ACE mutation results in dramatic changes in ACE kinetic properties and lowered clearance of Ac-SDKP. Individuals with this mutation (likely with significantly increased levels of the hemoregulatory tetrapeptide in blood and tissues), may confer protection against fibrosis.
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- 2014
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7. Intravenous application of a primary sevoflurane metabolite improves outcome in murine septic peritonitis: first results.
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Inge K Herrmann, Maricela Castellon, David E Schwartz, Melanie Hasler, Martin Urner, Guochang Hu, Richard D Minshall, and Beatrice Beck-Schimmer
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Medicine ,Science - Abstract
Volatile anesthetics are known to have immunomodulatory effects in conditions of organ injury. A recent study in an experimental sepsis model has shown remarkably improved survival when mice were exposed to volatile anesthetics. In the present study, we show that hexafluoroisopropanol - a water-soluble primary sevoflurane metabolite - has beneficial effects on the overall survival in a murine model of cecal ligation and puncture. Seven-day survival as well as tissue damage markers including transaminases and high mobility group box protein-1 were assessed as measures of end organ damage. In animals undergoing cecal ligation and puncture procedure hexafluoroisopropanol conditioning - but not late postconditioning 24 hours after sepsis induction - significantly increased survival rate (17% vs. 77%, p = 0.037) and attenuated secretion of organ damage markers. This study shows survival benefits by administration of the metabolite of a volatile anesthetic. If successfully translated, hexafluoroisopropanol might offer interesting therapeutic opportunities in the future treatment of abdominal sepsis.
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- 2013
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8. Conformational changes of blood ACE in chronic uremia.
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Maxim N Petrov, Valery Y Shilo, Alexandr V Tarasov, David E Schwartz, Joe G N Garcia, Olga A Kost, and Sergei M Danilov
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Medicine ,Science - Abstract
BACKGROUND: The pattern of binding of monoclonal antibodies (mAbs) to 16 epitopes on human angiotensin I-converting enzyme (ACE) comprise a conformational ACE fingerprint and is a sensitive marker of subtle protein conformational changes. HYPOTHESIS: Toxic substances in the blood of patients with uremia due to End Stage Renal Disease (ESRD) can induce local conformational changes in the ACE protein globule and alter the efficacy of ACE inhibitors. METHODOLOGY/PRINCIPAL FINDINGS: The recognition of ACE by 16 mAbs to the epitopes on the N and C domains of ACE was estimated using an immune-capture enzymatic plate precipitation assay. The precipitation pattern of blood ACE by a set of mAbs was substantially influenced by the presence of ACE inhibitors with the most dramatic local conformational change noted in the N-domain region recognized by mAb 1G12. The "short" ACE inhibitor enalaprilat (tripeptide analog) and "long" inhibitor teprotide (nonapeptide) produced strikingly different mAb 1G12 binding with enalaprilat strongly increasing mAb 1G12 binding and teprotide decreasing binding. Reduction in S-S bonds via glutathione and dithiothreitol treatment increased 1G12 binding to blood ACE in a manner comparable to enalaprilat. Some patients with uremia due to ESRD exhibited significantly increased mAb 1G12 binding to blood ACE and increased ACE activity towards angiotensin I accompanied by reduced ACE inhibition by inhibitory mAbs and ACE inhibitors. CONCLUSIONS/SIGNIFICANCE: The estimation of relative mAb 1G12 binding to blood ACE detects a subpopulation of ESRD patients with conformationally changed ACE, which activity is less suppressible by ACE inhibitors. This parameter may potentially serve as a biomarker for those patients who may need higher concentrations of ACE inhibitors upon anti-hypertensive therapy.
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- 2012
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9. ACE phenotyping in Gaucher disease
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Sergei M. Danilov, Tatiana M. Bukina, L M Samokhodskaya, Olga A. Kost, Irina A. Naperova, Nahid Tayebi, Nurshat M. Gayfullin, David E. Schwartz, Ellen Sidransky, Ozlem Goker-Alpan, Roman Metzger, and Victoria E. Tikhomirova
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0301 basic medicine ,medicine.medical_specialty ,Glycosylation ,medicine.drug_class ,Endocrinology, Diabetes and Metabolism ,Endogeny ,Spleen ,Peptidyl-Dipeptidase A ,Monoclonal antibody ,Biochemistry ,Article ,Epitope ,03 medical and health sciences ,chemistry.chemical_compound ,Endocrinology ,Internal medicine ,Genetics ,medicine ,Humans ,Molecular Biology ,Cells, Cultured ,chemistry.chemical_classification ,Gaucher Disease ,Granuloma ,business.industry ,Macrophages ,Dendritic Cells ,Phenotype ,030104 developmental biology ,Enzyme ,medicine.anatomical_structure ,Liver ,chemistry ,Immunohistochemistry ,Biomarker (medicine) ,business - Abstract
Background Gaucher disease is characterized by the activation of splenic and hepatic macrophages, accompanied by dramatically increased levels of angiotensin-converting enzyme (ACE). To evaluate the source of the elevated blood ACE, we performed complete ACE phenotyping using blood, spleen and liver samples from patients with Gaucher disease and controls. Methods ACE phenotyping included 1) immunohistochemical staining for ACE; 2) measuring ACE activity with two substrates (HHL and ZPHL); 3) calculating the ratio of the rates of substrate hydrolysis (ZPHL/HHL ratio); 4) assessing the conformational fingerprint of ACE by evaluating the pattern of binding of monoclonal antibodies to 16 different ACE epitopes. Results We show that in patients with Gaucher disease, the dramatically increased levels of ACE originate from activated splenic and/or hepatic macrophages (Gaucher cells), and that both its conformational fingerprint and kinetic characteristics (ZPHL/HHL ratio) differ from controls and from patients with sarcoid granulomas. Furthermore, normal spleen was found to produce high levels of endogenous ACE inhibitors and a novel, tightly-bound 10–30 kDa ACE effector which is deficient in Gaucher spleen. Conclusions The conformation of ACE is tissue-specific. In Gaucher disease, ACE produced by activated splenic macrophages differs from that in hepatic macrophages, as well as from macrophages and dendritic cells in sarcoid granulomas. The observed differences are likely due to altered ACE glycosylation or sialylation in these diseased organs. The conformational differences in ACE may serve as a specific biomarker for Gaucher disease.
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- 2018
10. An angiotensin I-converting enzyme mutation (Y465D) causes a dramatic increase in blood ACE via accelerated ACE shedding.
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Sergei M Danilov, Kerry Gordon, Andrew B Nesterovitch, Heinrich Lünsdorf, Zhenlong Chen, Maricela Castellon, Isolda A Popova, Sergey Kalinin, Emma Mendonca, Pavel A Petukhov, David E Schwartz, Richard D Minshall, and Edward D Sturrock
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Medicine ,Science - Abstract
Angiotensin I-converting enzyme (ACE) metabolizes a range of peptidic substrates and plays a key role in blood pressure regulation and vascular remodeling. Thus, elevated ACE levels may be associated with an increased risk for different cardiovascular or respiratory diseases. Previously, a striking familial elevation in blood ACE was explained by mutations in the ACE juxtamembrane region that enhanced the cleavage-secretion process. Recently, we found a family whose affected members had a 6-fold increase in blood ACE and a Tyr465Asp (Y465D) substitution, distal to the stalk region, in the N domain of ACE.HEK and CHO cells expressing mutant (Tyr465Asp) ACE demonstrate a 3- and 8-fold increase, respectively, in the rate of ACE shedding compared to wild-type ACE. Conformational fingerprinting of mutant ACE demonstrated dramatic changes in ACE conformation in several different epitopes of ACE. Cell ELISA carried out on CHO-ACE cells also demonstrated significant changes in local ACE conformation, particularly proximal to the stalk region. However, the cleavage site of the mutant ACE--between Arg1203 and Ser1204--was the same as that of WT ACE. The Y465D substitution is localized in the interface of the N-domain dimer (from the crystal structure) and abolishes a hydrogen bond between Tyr465 in one monomer and Asp462 in another.The Y465D substitution results in dramatic increase in the rate of ACE shedding and is associated with significant local conformational changes in ACE. These changes could result in increased ACE dimerization and accessibility of the stalk region or the entire sACE, thus increasing the rate of cleavage by the putative ACE secretase (sheddase).
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- 2011
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11. Angiotensin I-converting enzyme Gln1069Arg mutation impairs trafficking to the cell surface resulting in selective denaturation of the C-domain.
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Sergei M Danilov, Sergey Kalinin, Zhenlong Chen, Elena I Vinokour, Andrew B Nesterovitch, David E Schwartz, Olivier Gribouval, Marie-Claire Gubler, and Richard D Minshall
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Medicine ,Science - Abstract
BACKGROUND: Angiotensin-converting enzyme (ACE; Kininase II; CD143) hydrolyzes small peptides such as angiotensin I, bradykinin, substance P, LH-RH and several others and thus plays a key role in blood pressure regulation and vascular remodeling. Complete absence of ACE in humans leads to renal tubular dysgenesis (RTD), a severe disorder of renal tubule development characterized by persistent fetal anuria and perinatal death. METHODOLOGY/PRINCIPAL FINDINGS: Patient with RTD in Lisbon, Portugal, maintained by peritoneal dialysis since birth, was found to have a homozygous substitution of Arg for Glu at position 1069 in the C-terminal domain of ACE (Q1069R) resulting in absence of plasma ACE activity; both parents and a brother who are heterozygous carriers of this mutation had exactly half-normal plasma ACE activity compared to healthy individuals. We hypothesized that the Q1069R substitution impaired ACE trafficking to the cell surface and led to accumulation of catalytically inactive ACE in the cell cytoplasm. CHO cells expressing wild-type (WT) vs. Q1069R-ACE demonstrated the mutant accumulates intracellularly and also that it is significantly degraded by intracellular proteases. Q1069R-ACE retained catalytic and immunological characteristics of WT-ACE N domain whereas it had 10-20% of the nativity of the WT-ACE C domain. A combination of chemical (sodium butyrate) or pharmacological (ACE inhibitor) chaperones with proteasome inhibitors (MG 132 or bortezomib) significantly restored trafficking of Q1069R-ACE to the cell surface and increased ACE activity in the cell culture media 4-fold. CONCLUSIONS/SIGNIFICANCE: Homozygous Q1069R substitution results in an ACE trafficking and processing defect which can be rescued, at least in cell culture, by a combination of chaperones and proteasome inhibitors. Further studies are required to determine whether similar treatment of individuals with this ACE mutation would provide therapeutic benefits such as concentration of primary urine.
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- 2010
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12. Angiotensin I-converting enzyme mutation (Trp1197Stop) causes a dramatic increase in blood ACE.
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Andrew B Nesterovitch, Kyle D Hogarth, Vyacheslav A Adarichev, Elena I Vinokour, David E Schwartz, Julian Solway, and Sergei M Danilov
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Medicine ,Science - Abstract
BACKGROUND:Angiotensin-converting enzyme (ACE) metabolizes many peptides and plays a key role in blood pressure regulation and vascular remodeling. Elevated ACE levels may be associated with an increased risk for different cardiovascular or respiratory diseases, including asthma. Previously, a molecular mechanism underlying a 5-fold familial increase of blood ACE was discovered: Pro1199Leu substitution enhanced the cleavage-secretion process. Carriers of this mutation were Caucasians from Europe (mostly Dutch) or had European roots. METHODOLOGY/PRINCIPAL FINDINGS:We have found a family of African-American descent whose affected members' blood ACE level was increased 13-fold over normal. In affected family members, codon TGG coding for Trp1197 was substituted in one allele by TGA (stop codon). As a result, half of ACE expressed in these individuals had a length of 1196 amino acids and lacked a transmembrane anchor. This ACE mutant is not trafficked to the cell membrane and is directly secreted out of cells; this mechanism apparently accounts for the high serum ACE level seen in affected individuals. A haplotype of the mutant ACE allele was determined based on 12 polymorphisms, which may help to identify other carriers of this mutation. Some but not all carriers of this mutation demonstrated airflow obstruction, and some but not all have hypertension. CONCLUSIONS/SIGNIFICANCE:We have identified a novel Trp1197Stop mutation that results in dramatic elevation of serum ACE. Since blood ACE elevation is often taken as a marker of disease activity (sarcoidosis and Gaucher diseases), it is important for clinicians and medical scientists to be aware of alternative genetic causes of elevated blood ACE that are not apparently linked to disease.
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- 2009
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13. ACE Phenotyping as a Guide Toward Personalized Therapy With ACE Inhibitors
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Stan I. Tovsky, Sergei M. Danilov, Randal O. Dull, and David E. Schwartz
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0301 basic medicine ,Pharmacogenomic Variants ,Sodium Chloride Symporter Inhibitors ,Drug Resistance ,Tetrazoles ,Angiotensin-Converting Enzyme Inhibitors ,Blood Pressure ,030204 cardiovascular system & hematology ,Pharmacology ,0302 clinical medicine ,Hydrochlorothiazide ,Enalapril ,Medicine ,Pharmacology (medical) ,Precision Medicine ,Personalized therapy ,Cross-Over Studies ,biology ,Phenotype ,Treatment Outcome ,Hypertension ,Drug Therapy, Combination ,Drug Monitoring ,Cardiology and Cardiovascular Medicine ,medicine.drug ,Genotype ,Peptidyl-Dipeptidase A ,03 medical and health sciences ,Double-Blind Method ,Predictive Value of Tests ,Humans ,Ace activity ,Antihypertensive Agents ,business.industry ,Patient Selection ,Biphenyl Compounds ,Angiotensin-converting enzyme ,Pharmacogenomic Testing ,Candesartan ,030104 developmental biology ,Blood pressure ,Pharmacogenetics ,ACE inhibitor ,biology.protein ,Benzimidazoles ,business ,Angiotensin II Type 1 Receptor Blockers - Abstract
Background: Angiotensin-converting enzyme (ACE) inhibitors (ACEI) are widely used in the management of cardiovascular diseases but with significant interindividual variability in the patient’s response. Objectives: To investigate whether interindividual variability in the response to ACE inhibitors is explained by the “ACE phenotype”—for example, variability in plasma ACE concentration, activity, and conformation and/or the degree of ACE inhibition in each individual. Methods: The ACE phenotype was determined in plasma of 14 patients with hypertension treated chronically for 4 weeks with 40 mg enalapril (E) or 20 mg E + 16 mg candesartan (EC) and in 20 patients with hypertension treated acutely with a single dose (20 mg) of E with or without pretreatment with hydrochlorothiazide. The ACE phenotyping included (1) plasma ACE concentration; (2) ACE activity (with 2 substrates: Hip-His-Leu and Z-Phe-His-Leu and calculation of their ratio); (3) detection of ACE inhibitors in patient’s blood (indicator of patient compliance) and the degree of ACE inhibition (ie, adherence); and (4) ACE conformation. Results: Enalapril reduced systolic and diastolic blood pressure in most patients; however, 20% of patients were considered nonresponders. Chronic treatment results in 40% increase in serum ACE concentrations, with the exception of 1 patient. There was a trend toward better response to ACEI among patients who had a higher plasma ACE concentration. Conclusion: Due to the fact that “20% of patients do not respond to ACEI by blood pressure drop,” the initial blood ACE level could not be a predictor of blood pressure reduction in an individual patient. However, ACE phenotyping provides important information about conformational and kinetic changes in ACE of individual patients, and this could be a reason for resistance to ACE inhibitors in some nonresponders.
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- 2017
14. The Role of HMGB1 in Pial Arteriole Dilating Reactivity following Subarachnoid Hemorrhage in Rats
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Randal O. Dull, David E. Schwartz, Dale A. Pelligrino, Haoliang Xu, Tibor Valyi-Nagy, Zhao Zhong Chong, and Benjarat Changyaleket
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Male ,0301 basic medicine ,Time Factors ,Subarachnoid hemorrhage ,Physiology ,Vasodilator Agents ,Receptor for Advanced Glycation End Products ,chemical and pharmacologic phenomena ,HMGB1 ,Hypercapnia ,Rats, Sprague-Dawley ,03 medical and health sciences ,0302 clinical medicine ,Cerebral vasospasm ,medicine ,Animals ,cardiovascular diseases ,HMGB1 Protein ,Pial arteriole ,biology ,business.industry ,Vasospasm ,Subarachnoid Hemorrhage ,medicine.disease ,Sciatic Nerve ,Electric Stimulation ,nervous system diseases ,Vasodilation ,Arterioles ,Disease Models, Animal ,030104 developmental biology ,Anesthesia ,biology.protein ,Pia Mater ,Cardiology and Cardiovascular Medicine ,business ,030217 neurology & neurosurgery ,Signal Transduction - Abstract
High-mobility group box 1 protein (HMGB1) has been implicated in inflammatory responses, and is also associated with cerebral vasospasm after subarachnoid hemorrhage (SAH). However, there are no direct evident links between HMGB1 and cerebral vasospasm. We therefore investigated the effects of HMGB1 on pial arteriole reactivity following SAH in rats. We initially found that SAH induced a significant decrease in pial arteriole dilating responses to sciatic nerve stimulation (SNS), hypercapnia (CO2), and the topical suffusion of acetylcholine (ACh), adenosine (ADO), and s-nitroso-N-acetylpenicillamine (SNAP) over a 7-day period after SAH. The percent change of arteriolar diameter was decreased to the lowest point at 48 h after SAH, in response to dilating stimuli (i.e., it decreased from 41.0 ± 19.0% in the sham group to 11.00 ± 0.70% after SNS) (n = 5, p < 0.01). HMGB1 infusion in the lateral ventricle in normal rats for 48 h did not change the pial arteriole dilating response. In addition, inhibitors of HMGB1-receptor for advanced glycation end-product or HMGB1-toll-like receptor 2/4 interaction, or the HMBG1 antagonist did not improve pial arteriole reactivity 48 h after SAH. These findings suggest that HMGB1 may not be a major player in cerebral vascular dilating dysfunction after SAH.
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- 2016
15. Clinically relevant concentrations of lidocaine and ropivacaine inhibit TNFα-induced invasion of lung adenocarcinoma cells in vitro by blocking the activation of Akt and focal adhesion kinase
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Beatrice Beck-Schimmer, Randal O. Dull, Tobias Piegeler, Alain Borgeat, Martin Schläpfer, David E. Schwartz, and Richard D. Minshall
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Pathology ,medicine.medical_specialty ,Lung Neoplasms ,Caveolin 1 ,Drug Evaluation, Preclinical ,Adenocarcinoma of Lung ,Adenocarcinoma ,Proinflammatory cytokine ,Focal adhesion ,03 medical and health sciences ,0302 clinical medicine ,Cell Movement ,030202 anesthesiology ,Translational Research ,Tumor Cells, Cultured ,medicine ,Humans ,Neoplasm Invasiveness ,Ropivacaine ,Anesthetics, Local ,Phosphorylation ,Protein kinase B ,030304 developmental biology ,0303 health sciences ,Tumor Necrosis Factor-alpha ,business.industry ,Lidocaine ,Cell migration ,Amides ,Neoplasm Proteins ,3. Good health ,Enzyme Activation ,Anesthesiology and Pain Medicine ,Matrix Metalloproteinase 9 ,Focal Adhesion Protein-Tyrosine Kinases ,Cancer cell ,Cancer research ,Tumor necrosis factor alpha ,business ,Proto-Oncogene Proteins c-akt ,medicine.drug - Abstract
Background Matrix-metalloproteinases (MMP) and cancer cell invasion are crucial for solid tumour metastasis. Important signalling events triggered by inflammatory cytokines, such as tumour necrosis factor α (TNFα), include Src-kinase-dependent activation of Akt and focal adhesion kinase (FAK) and phosphorylation of caveolin-1. Based on previous studies where we demonstrated amide-type local anaesthetics block TNFα-induced Src activation in malignant cells, we hypothesized that local anaesthetics might also inhibit the activation and/or phosphorylation of Akt, FAK and caveolin-1, thus attenuating MMP release and invasion of malignant cells. Methods NCI-H838 lung adenocarcinoma cells were incubated with ropivacaine or lidocaine (1 nM-100 µM) in absence/presence of TNFα (20 ng ml−1) for 20 min or 4 h, respectively. Activation/phosphorylation of Akt, FAK and caveolin-1 were evaluated by Western blot, and MMP-9 secretion was determined by enzyme-linked immunosorbent assay. Tumour cell migration (electrical wound-healing assay) and invasion were also assessed. Results Ropivacaine (1 nM–100 μM) and lidocaine (1–100 µM) significantly reduced TNFα-induced activation/phosphorylation of Akt, FAK and caveolin-1 in NCI-H838 cells. MMP-9 secretion triggered by TNFα was significantly attenuated by both lidocaine and ropivacaine (half-maximal inhibitory concentration [IC50]=3.29×10−6 M for lidocaine; IC50=1.52×10−10 M for ropivacaine). The TNFα-induced increase in invasion was completely blocked by both lidocaine (10 µM) and ropivacaine (1 µM). Conclusions At clinically relevant concentrations both ropivacaine and lidocaine blocked tumour cell invasion and MMP-9 secretion by attenuating Src-dependent inflammatory signalling events. Although determined entirely in vitro, these findings provide significant insight into the potential mechanism by which local anaesthetics might diminish metastasis.
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- 2015
16. Multi-modal contributions to detoxification of acute pharmacotoxicity by a triglyceride micro-emulsion
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Richard Ripper, Adrian Pichurko, David E. Schwartz, Katarzyna Kowal, Kinga Lis, Michael R. Fettiplace, Israel Rubinstein, Belinda S. Akpa, Dominic Vitello, and Guy L. Weinberg
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Drug ,Cardiotoxicity ,Chemistry ,media_common.quotation_subject ,Pharmaceutical Science ,Pharmacology ,Cardiotoxins ,Cardiotonic Agents ,Mechanism of action ,In vivo ,Detoxification ,Toxicity ,medicine ,medicine.symptom ,media_common - Abstract
Triglyceride micro-emulsions such as Intralipid® have been used to reverse cardiac toxicity induced by a number of drugs but reservations about their broad-spectrum applicability remain because of the poorly understood mechanism of action. Herein we report an integrated mechanism of reversal of bupivacaine toxicity that includes both transient drug scavenging and a cardiotonic effect that couple to accelerate movement of the toxin away from sites of toxicity. We thus propose a multi-modal therapeutic paradigm for colloidal bio-detoxification whereby a micro-emulsion both improves cardiac output and rapidly ferries the drug away from organs subject to toxicity. In vivo and in silico models of toxicity were combined to test the contribution of individual mechanisms and reveal the multi-modal role played by the cardiotonic and scavenging actions of the triglyceride suspension. These results suggest a method to predict which drug toxicities are most amenable to treatment and inform the design of next-generation therapeutics for drug overdose.
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- 2015
17. Endothelial Barrier Protection by Local Anesthetics
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Graeme K. Carnegie, E. Gina Votta-Velis, Tobias Piegeler, Mao Mao, Alain Borgeat, David E. Schwartz, Beatrice Beck-Schimmer, Richard D. Minshall, Marcelo G. Bonini, and Farnaz R. Bakhshi
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ARDS ,Endothelium ,biology ,business.industry ,Lung injury ,Pharmacology ,medicine.disease ,Nitric oxide ,Proinflammatory cytokine ,Endothelial stem cell ,Nitric oxide synthase ,chemistry.chemical_compound ,Anesthesiology and Pain Medicine ,medicine.anatomical_structure ,chemistry ,Immunology ,medicine ,biology.protein ,business ,Proto-oncogene tyrosine-protein kinase Src - Abstract
Background: Pulmonary endothelial barrier dysfunction mediated in part by Src-kinase activation plays a crucial role in acute inflammatory disease. Proinflammatory cytokines, such as tumor necrosis factor-α (TNFα), activate Src via phosphatidylinositide 3-kinase/Akt-dependent nitric oxide generation, a process initiated by recruitment of phosphatidylinositide 3-kinase regulatory subunit p85 to TNF-receptor-1. Because amide-linked local anesthetics have well-established anti-inflammatory effects, the authors hypothesized that ropivacaine and lidocaine attenuate inflammatory Src signaling by disrupting the phosphatidylinositide 3-kinase–Akt–nitric oxide pathway, thus blocking Src-dependent neutrophil adhesion and endothelial hyperpermeability. Methods: Human lung microvascular endothelial cells, incubated with TNFα in the absence or presence of clinically relevant concentrations of ropivacaine and lidocaine, were analyzed by Western blot, probing for phosphorylated/activated Src, endothelial nitric oxide synthase, Akt, intercellular adhesion molecule-1, and caveolin-1. The effect of ropivacaine on TNFα-induced nitric oxide generation, co-immunoprecipitation of TNF-receptor-1 with p85, neutrophil adhesion, and endothelial barrier disruption were assessed. Results: Ropivacaine and lidocaine attenuated TNFα-induced Src activation (half-maximal inhibitory concentration [IC50] = 8.611 × 10−10 M for ropivacaine; IC50 = 5.864 × 10−10 M for lidocaine) and endothelial nitric oxide synthase phosphorylation (IC50 = 7.572 × 10−10 M for ropivacaine; IC50 = 6.377 × 10−10 M for lidocaine). Akt activation (n = 7; P = 0.006) and stimulus-dependent binding of TNF-receptor-1 and p85 (n = 6; P = 0.043) were blocked by 1 nM of ropivacaine. TNFα-induced neutrophil adhesion and disruption of endothelial monolayers via Src-dependent intercellular adhesion molecule-1- and caveolin-1-phosphorylation, respectively, were also attenuated. Conclusions: Ropivacaine and lidocaine effectively blocked inflammatory TNFα signaling in endothelial cells by attenuating p85 recruitment to TNF-receptor-1. The resultant decrease in Akt, endothelial nitric oxide synthase, and Src phosphorylation reduced neutrophil adhesion and endothelial hyperpermeability. This novel anti-inflammatory “side-effect” of ropivacaine and lidocaine may provide therapeutic benefit in acute inflammatory disease.
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- 2014
18. Regional anaesthesia and cancer metastases: the implication of local anaesthetics
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José Aguirre, Tobias Piegeler, Alain Borgeat, Effrossyni G. Votta-Velis, David E. Schwartz, Richard D. Minshall, and Beatrice Beck-Schimmer
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Basic science ,business.industry ,Cancer ,Inflammation ,Cell migration ,Regional anaesthesia ,General Medicine ,medicine.disease ,Bioinformatics ,Metastasis ,Fight-or-flight response ,Anesthesiology and Pain Medicine ,Mechanism of action ,Anesthesia ,medicine ,medicine.symptom ,business - Abstract
Clinical and basic science studies have demonstrated the anti-inflammatory properties of local anaesthetics. Recent studies have begun to unravel molecular pathways linking inflammation and cancer. Regional anaesthesia is associated in some retrospective clinical studies with reduced risk of metastasis and increased long-term survival. The potential beneficial effects of regional anaesthesia have been attributed mainly to the inhibition of the neuroendocrine stress response to surgery and to the reduction in the requirements of volatile anaesthetics and opioids. Because cancer is linked to inflammation and local anaesthetics have anti-inflammatory effects, these agents may participate in reducing the risk of metastasis, but their mechanism of action is unknown. We demonstrated in vitro that amide local anaesthetics attenuate tumour cell migration as well as signalling pathways enhancing tumour growth and metastasis. This has provided the first evidence of a molecular mechanism by which regional anaesthesia might inhibit or reduce cancer metastases.
- Published
- 2013
19. Activation of NLRP3 Inflammasome in Alveolar Macrophages Contributes to Mechanical Stretch-Induced Lung Inflammation and Injury
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Jianbo Wu, Guochang Hu, Asrar B. Malik, Zhibo Yan, David E. Schwartz, and Jingui Yu
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Male ,Inflammasomes ,Ventilator-Induced Lung Injury ,medicine.medical_treatment ,Interleukin-1beta ,Immunology ,Inflammation ,Lung injury ,Biology ,Article ,Proinflammatory cytokine ,Mice ,Macrophages, Alveolar ,NLR Family, Pyrin Domain-Containing 3 Protein ,medicine ,Animals ,Immunology and Allergy ,Mice, Knockout ,Lung ,Innate immune system ,Caspase 1 ,Interleukin-18 ,Inflammasome ,Pneumonia ,respiratory system ,Mitochondria ,Uric Acid ,Cell biology ,Toll-Like Receptor 4 ,Disease Models, Animal ,medicine.anatomical_structure ,Cytokine ,Alveolar macrophage ,medicine.symptom ,Carrier Proteins ,Reactive Oxygen Species ,Signal Transduction ,medicine.drug - Abstract
Mechanical ventilation of lungs is capable of activating the innate immune system and inducing sterile inflammatory response. The proinflammatory cytokine IL-1β is among the definitive markers for accurately identifying ventilator-induced lung inflammation. However, mechanisms of IL-1β release during mechanical ventilation are unknown. In this study, we show that cyclic stretch activates the nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasomes and induces the release of IL-1β in mouse alveolar macrophages via caspase-1– and TLR4-dependent mechanisms. We also observed that NADPH oxidase subunit gp91phox was dispensable for stretch-induced cytokine production, whereas mitochondrial generation of reactive oxygen species was required for stretch-induced NLRP3 inflammasome activation and IL-1β release. Further, mechanical ventilation activated the NLRP3 inflammasomes in mouse alveolar macrophages and increased the production of IL-1β in vivo. IL-1β neutralization significantly reduced mechanical ventilation-induced inflammatory lung injury. These findings suggest that the alveolar macrophage NLRP3 inflammasome may sense lung alveolar stretch to induce the release of IL-1β and hence may contribute to the mechanism of lung inflammatory injury during mechanical ventilation.
- Published
- 2013
20. Role of Caveolin‐1 Expression in the Pathogenesis of Pulmonary Edema in Ventilator‐Induced Lung Injury
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Maricela Castellon, Nikolaos A. Maniatis, Dan Hecimovich, Charalambos Roussos, David E. Schwartz, Eleftheria Letsiou, Matina Kardara, Vasily Shinin, E. Gina Votta-Vellis, and Richard D. Minshall
- Subjects
Pulmonary and Respiratory Medicine ,medicine.medical_specialty ,Pathology ,medicine.medical_treatment ,Vascular permeability ,030204 cardiovascular system & hematology ,Lung injury ,albumin permeability ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,medicine ,Tidal volume ,030304 developmental biology ,0303 health sciences ,Lung ,medicine.diagnostic_test ,business.industry ,lung inflammation ,respiratory system ,Pulmonary edema ,medicine.disease ,thrombin ,Neutrophilia ,high tidal volume mechanical ventilation ,respiratory tract diseases ,3. Good health ,Bronchoalveolar lavage ,medicine.anatomical_structure ,Endocrinology ,Cytokine ,caveolae ,medicine.symptom ,business ,Research Article - Abstract
Caveolin-1 is a key regulator of pulmonary endothelial barrier function. Here, we tested the hypothesis that caveolin-1 expression is required for ventilator-induced lung injury (VILI). Caveolin-1 gene-disrupted (Cav-1(-/-)) and age-, sex-, and strain-matched wild-type (WT) control mice were ventilated using two protocols: volume-controlled with protective (8 mL/kg) versus injurious (21 mL/Kg) tidal volume for up to 6 hours; and pressure-controlled with protective (airway pressure = 12 cm H(2)O) versus injurious (30 cm H(2)O) ventilation to induce lung injury. Lung microvascular permeability (whole-lung (125)I-albumin accumulation, lung capillary filtration coefficient [K(f, c)]) and inflammatory markers (bronchoalveolar lavage [BAL] cytokine levels and neutrophil counts) were measured. We also evaluated histologic sections from lungs, and the time course of Src kinase activation and caveolin-1 phosphorylation. VILI induced a 1.7-fold increase in lung (125)I-albumin accumulation, fourfold increase in K(f, c), significantly increased levels of cytokines CXCL1 and interleukin-6, and promoted BAL neutrophilia in WT mice. Lung injury by these criteria was significantly reduced in Cav-1(-/-) mice but fully restored by i.v. injection of liposome/Cav-1 cDNA complexes that rescued expression of Cav-1 in lung microvessels. As thrombin is known to play a significant role in mediating stretch-induced vascular injury, we observed in cultured mouse lung microvascular endothelial cells (MLECs) thrombin-induced albumin hyperpermeability and phosphorylation of p44/42 MAP kinase in WT but not in Cav-1(-/-) MLECs. Thus, caveolin-1 expression is required for mechanical stretch-induced lung inflammation and endothelial hyperpermeability in vitro and in vivo.
- Published
- 2012
21. Contents Vol. 53, 2016
- Author
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Yaqin Zheng, Anna Maidecchi, Manman Li, Songling Fu, Erika Pintér, Yuanyuan Xia, Wei Wang, Shuzhen Li, Martina Monti, András Garami, Haoliang Xu, Christopher D. Saunter, Christina Lund Kidholm, Xia Shang, David J.R. Fulton, Ping-Jin Gao, Mao Luo, Wen-Dong Chen, Dale A. Pelligrino, Chengzhong Yang, Ciprian B. Anea, Ling-Yun Wu, Giulia Antonini, Michela Burico, David E. Schwartz, Jiali Li, Francesca Marini, Ivan Ivic, Lamei Xiao, Tong Chen, Xiuling Zhang, Huafeng Wang, Xiao-Mao Zhou, Shu-Jie Guo, Lise Pedersen, Peng Zhang, Jianbo Wu, Xin Deng, Luisa Mattoli, Daling Zhu, Guan-Nan Zhang, Jing Tao, Ni Chen, Lucia Morbidelli, Satz Mengensatzproduktion, Yiying Zhang, Li-Dian Chen, Qing-Ping Su, Calum Wilson, Yongjie Li, Tangting Chen, Xiaoling Tan, Meiping Ren, Fangqi Gong, Liqun Wang, Rong Li, Lars Melholt Rasmussen, R. Daniel Rudic, Julie Bukh Madsen, John M. Girkin, Valerio Ciccone, Weiwei Yang, John G. McCarron, Benjarat Changyaleket, Randal O. Dull, Ningbo Pang, Lin Liao, Paramita Pati, Druckerei Stückle, Tibor Valyi-Nagy, Chunhong Xie, Margit Solymár, Zhao Zhong Chong, Eszter Pakai, Ting Chen, Wei Wei, Zoltan Rumbus, Xiaodong Zheng, Akos Koller, and Xie-Hua Xue
- Subjects
Physiology ,Cardiology and Cardiovascular Medicine - Published
- 2016
22. Antimetastatic Potential of Amide-linked Local Anesthetics
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Aaron T. Place, E. Gina Votta-Velis, Guoquan Liu, Tobias Piegeler, Alain Borgeat, Beatrice Beck-Schimmer, Richard D. Minshall, and David E. Schwartz
- Subjects
Ropivacaine ,business.industry ,Intercellular Adhesion Molecule-1 ,Cell migration ,Pharmacology ,Anesthesiology and Pain Medicine ,Sodium channel blocker ,Mechanism of action ,Immunology ,medicine ,Tumor necrosis factor alpha ,medicine.symptom ,business ,medicine.drug ,Proto-oncogene tyrosine-protein kinase Src ,Chloroprocaine - Abstract
Background Retrospective analysis of patients undergoing cancer surgery suggests the use of regional anesthesia may reduce cancer recurrence and improve survival. Amide-linked local anesthetics have antiinflammatory properties, although the mechanism of action in this regard is unclear. As inflammatory processes involving Src tyrosine protein kinase and intercellular adhesion molecule-1 are important in tumor growth and metastasis, we hypothesized that amide-linked local anesthetics may inhibit inflammatory Src-signaling involved in migration of adenocarcinoma cells. Methods NCI-H838 lung cancer cells were incubated with tumor necrosis factor-α in absence/presence of ropivacaine, lidocaine, or chloroprocaine (1 nM-100 μM). Cell migration and total cell lysate Src-activation and intercellular adhesion molecule-1 phosphorylation were assessed. The role of voltage-gated sodium-channels in the mechanism of local anesthetic effects was also evaluated. Results Ropivacaine treatment (100 μM) of H838 cells for 20 min decreased basal Src activity by 62% (P=0.003), and both ropivacaine and lidocaine coadministered with tumor necrosis factor-α statistically significantly decreased Src-activation and intercellular adhesion molecule-1 phosphorylation, whereas chloroprocaine had no such effect. Migration of these cells at 4 h was inhibited by 26% (P=0.005) in presence of 1 μM ropivacaine and 21% by 1 μM lidocaine (P=0.004). These effects of ropivacaine and lidocaine were independent of voltage-gated sodium-channel inhibition. Conclusions This study indicates that amide-, but not ester-linked, local anesthetics may provide beneficial antimetastatic effects. The observed inhibition of NCI-H838 cell migration by lidocaine and ropivacaine was associated with the inhibition of tumor necrosis factor-α-induced Src-activation and intercellular adhesion molecule-1 phosphorylation, providing the first evidence of a molecular mechanism that appears to be independent of their known role as sodium-channel blockers.
- Published
- 2012
23. Activation of calpains mediates early lung neutrophilic inflammation in ventilator-induced lung injury
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Yuguo Chen, Dejie Liu, David E. Schwartz, Guochang Hu, Richard D. Minshall, and Zhibo Yan
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Male ,Pulmonary and Respiratory Medicine ,Nitric Oxide Synthase Type III ,Physiology ,Ventilator-Induced Lung Injury ,medicine.medical_treatment ,Inflammation ,Biology ,Pharmacology ,Lung injury ,Nitric Oxide ,Nitric oxide ,Mice ,chemistry.chemical_compound ,Physiology (medical) ,medicine ,Animals ,Phosphorylation ,Lung ,Tidal volume ,Glycoproteins ,Mechanical ventilation ,Ventilators, Mechanical ,Calpain ,Articles ,Cell Biology ,respiratory system ,Intercellular Adhesion Molecule-1 ,Intercellular adhesion molecule ,Enzyme Activation ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Neutrophil Infiltration ,chemistry ,Gene Knockdown Techniques ,Immunology ,biology.protein ,RNA Interference ,medicine.symptom - Abstract
Lung inflammatory responses in the absence of infection are considered to be one of primary mechanisms of ventilator-induced lung injury. Here, we determined the role of calpain in the pathogenesis of lung inflammation attributable to mechanical ventilation. Male C57BL/6J mice were subjected to high (28 ml/kg) tidal volume ventilation for 2 h in the absence and presence of calpain inhibitor I (10 mg/kg). To address the isoform-specific functions of calpain 1 and calpain 2 during mechanical ventilation, we utilized a liposome-based delivery system to introduce small interfering RNAs targeting each isoform in pulmonary vasculature in vivo. Mechanical ventilation with high tidal volume induced rapid (within minutes) and persistent calpain activation and lung inflammation as evidenced by neutrophil recruitment, production of TNF-α and IL-6, pulmonary vascular hyperpermeability, and lung edema formation. Pharmaceutical calpain inhibition significantly attenuated these inflammatory responses caused by lung hyperinflation. Depletion of calpain 1 or calpain 2 had a protective effect against ventilator-induced lung inflammatory responses. Inhibition of calpain activity by means of siRNA silencing or pharmacological inhibition also reduced endothelial nitric oxide (NO) synthase (NOS-3)-mediated NO production and subsequent ICAM-1 phosphorylation following high tidal volume ventilation. These results suggest that calpain activation mediates early lung inflammation during ventilator-induced lung injury via NOS-3/NO-dependent ICAM-1 phosphorylation and neutrophil recruitment. Inhibition of calpain activation may therefore provide a novel and promising strategy for the prevention and treatment of ventilator-induced lung injury.
- Published
- 2012
24. Identifying S100B as a Biomarker and a Therapeutic Target For Brain Injury and Multiple Diseases
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Zhao Zhong Chong, Haoliang Xu, David E. Schwartz, Benjarat Changyaleket, and Randy O. Dull
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0301 basic medicine ,Cell signaling ,Disease ,S100 Calcium Binding Protein beta Subunit ,Bioinformatics ,Biochemistry ,03 medical and health sciences ,0302 clinical medicine ,Drug Discovery ,medicine ,Animals ,Humans ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Pharmacology ,Phosphoinositide 3-kinase ,biology ,Organic Chemistry ,Neurodegeneration ,medicine.disease ,030104 developmental biology ,Brain Injuries ,Immunology ,biology.protein ,Molecular Medicine ,Biomarker (medicine) ,Signal transduction ,030217 neurology & neurosurgery ,Biomarkers - Abstract
The calcium binding protein S100B has attracted great attention as a biomarker for a variety of diseases. S100B is mainly expressed in glial cells and functions through intracellular and extracellular signaling pathways. The biological roles of S100B have been closely associated with its concentrations and its physiological states. The released S100B can bind to the receptor of advanced glycation end products and induce the initiation of multiple cell signaling transductions. The regulation of S100B bioactivities has been suggested through phosphoinositide 3 kinase/Akt, p53, mitogen-activated protein kinases, transcriptional factors including nuclear factor-kappaB, and cyclic adenosine monophosphate. The levels of S100B in the blood may function to predict the progress or the prognosis of many kinds of diseases, such as cerebrovascular diseases, neurodegenerative diseases, motor neuron diseases, traumatic brain injury, schizophrenia, depression, diabetes mellitus, myocardial infarction, cancer, and infectious diseases. Given that the activity of S100B has been implicated in the pathological process of these diseases, S100B should not be simply regarded as a biomarker, it may also function as therapeutic target for these diseases. Further elucidation of the roles of S100B may formulate innovative therapeutic strategies for multiple diseases.
- Published
- 2015
25. Cyclic stretch induces alveolar epithelial barrier dysfunction via calpain-mediated degradation of p120-catenin
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Richard D. Minshall, Yuelan Wang, David E. Schwartz, and Guochang Hu
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Pulmonary and Respiratory Medicine ,Delta Catenin ,Small interfering RNA ,animal structures ,Physiology ,Blotting, Western ,Intracellular Space ,Fluorescent Antibody Technique ,Lung injury ,Transfection ,Epithelium ,Cell Line ,Adherens junction ,Mice ,Stress, Physiological ,Physiology (medical) ,medicine ,Animals ,RNA, Small Interfering ,Blood-Air Barrier ,Dose-Response Relationship, Drug ,Staining and Labeling ,biology ,Tight junction ,Calpain ,Catenins ,Epithelial Cells ,Blood–air barrier ,Articles ,Cell Biology ,Up-Regulation ,Cell biology ,Pulmonary Alveoli ,medicine.anatomical_structure ,Catenin ,embryonic structures ,biology.protein - Abstract
Lung hyperinflation is known to be an important contributing factor in the pathogenesis of ventilator-induced lung injury. Mechanical stretch causes epithelial barrier dysfunction and an increase in alveolar permeability, although the precise mechanisms have not been completely elucidated. p120-catenin is an adherens junction-associated protein that regulates cell-cell adhesion. In this study, we determined the role of p120-catenin in cyclic stretch-induced alveolar epithelial barrier dysfunction. Cultured alveolar epithelial cells (MLE-12) were subjected to uniform cyclic (0.5 Hz) biaxial stretch from 0 to 8 or 20% change in surface area for 0, 1, 2, or 4 h. At the end of the experiments, cells were lysed to determine p120-catenin expression by Western blot analysis. Immunofluorescence staining of p120-catenin and F-actin was performed to assess the integrity of monolayers and interepithelial gap formation. Compared with unstretched control cells, 20% stretch caused a significant loss in p120-catenin expression, which was coupled to interepithelial gap formation. p120-Catenin knockdown with small interfering RNA (siRNA) dose dependently increased stretch-induced gap formation, whereas overexpression of p120-catenin abolished stretch-induced gap formation. Furthermore, pharmacological calpain inhibition or depletion of calpain-1 with a specific siRNA prevented p120-catenin loss and subsequent stretch-induced gap formation. Our findings demonstrate that p120-catenin plays a critical protective role in cyclic stretch-induced alveolar barrier dysfunction, and, thus, maintenance of p120-catenin expression may be a novel therapeutic strategy for the prevention and treatment of ventilator-induced lung injury.
- Published
- 2011
26. Prolonged Transesophageal Echocardiography Use in the ICU
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Ramona Nicolau, Vijay Krishnamoorthy, David E. Schwartz, Leon Frazin, and Mehmet S. Ozcan
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medicine.medical_specialty ,Fulminant hepatic failure ,business.industry ,Intensive care ,Psychological intervention ,Medicine ,Hemodynamics ,Management Science and Operations Research ,Critical Care and Intensive Care Medicine ,Critical Care Nursing ,business ,Intensive care medicine ,human activities - Abstract
Transesophageal echocardiography (TEE) has gained increasing popularity in the operating room and intensive care settings. The use of TEE can often times diagnose pathology that is missed by transthoracic echocardiography (TTE); in addition, it can be used as a guide to continuously monitor a patient’s hemodynamics, along with observing the direct cardiac effects of fluid and vasopressor therapy. We present a case of acute fulminant hepatic failure in the ICU, where TEE allowed a rapid diagnosis. We performed prolonged TEE monitoring (72 hours) of the patient to monitor the patient’s response to therapeutic interventions. We also discuss the diagnostic and therapeutic implications of prolonged TEE placement in the ICU. In addition, particular strategies to optimize the benefit and minimize the risk of this exciting, yet underutilized, technology are discussed.
- Published
- 2011
27. Conformational Fingerprinting of the Angiotensin I-Converting Enzyme (ACE). 1. Application in Sarcoidosis
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Sergei M. Danilov, Sergei E. Borisov, Roman Metzger, Folker E. Franke, Irina A. Naperova, David E. Schwartz, Olga A. Kost, I. V. Gachok, Natalia E. Arablinskaya, Joe G.N. Garcia, Anastasia S. Danilova, Irina V. Balyasnikova, and Ilya Trakht
- Subjects
Glycosylation ,Sarcoidosis ,Protein Conformation ,medicine.drug_class ,Peptidyl-Dipeptidase A ,Monoclonal antibody ,Biochemistry ,Epitope ,Cell Line ,Epitopes ,chemistry.chemical_compound ,Renin–angiotensin system ,medicine ,Animals ,Humans ,Tissue Distribution ,chemistry.chemical_classification ,Antibodies, Monoclonal ,General Chemistry ,Angiotensin I converting enzyme ,medicine.disease ,Enzyme ,Epitope mapping ,chemistry ,Epitope Mapping - Abstract
Fine epitope mapping of monoclonal antibodies (mAbs) to 16 epitopes on human angiotensin I-converting enzyme (ACE) revealed that the epitopes of all mAbs contained putative glycosylation sites. ACE glycosylation is both cell- and tissue-specific and, therefore, the local conformation of ACE produced by different cells could be also unique. The pattern of ACE binding by a set of mAbs to 16 epitopes of human ACE - "conformational fingerprint of ACE" - is the most sensitive marker of ACE conformation and could be cell- and tissue-specific. The recognition of ACEs by mAbs to ACE was estimated using an immune-capture enzymatic plate precipitation assay. Precipitation patterns of soluble recombinant ACE released from Chinese hamster ovary (CHO)-ACE cells was influenced by conditions that alter ACE glycosylation. This pattern was also strongly cell type specific. Patients with sarcoidosis exhibited conformational fingerprints of tissue ACE (lungs and lymph nodes), as well as blood ACE, which were distinct from controls. Conformational fingerprinting of ACE may detect ACE originated from the cells other than endothelial cells in the blood and when combined with elevated blood ACE levels in patients with sarcoidosis may potentially reflect extrapulmonary sarcoidosis involvement (bone marrow, spleen, liver). If proven true, this would serve as a biomarker of enormous potential clinical significance.
- Published
- 2010
28. Reduced expression of angiotensin I-converting enzyme in Caveolin-1 knockout mouse lungs
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Sergei M. Danilov, Nikolaos A. Maniatis, Irina V. Balyasnikova, Richard D. Minshall, David E. Schwartz, Roman Metzger, Maricela Castellon, and David J. Visintine
- Subjects
medicine.medical_specialty ,Hypertension, Pulmonary ,Caveolin 1 ,Blood Pressure ,Peptidyl-Dipeptidase A ,Pulmonary Artery ,Biology ,Biochemistry ,Gene Expression Regulation, Enzymologic ,Article ,Mice ,Internal medicine ,Renin–angiotensin system ,medicine ,Animals ,Endothelial dysfunction ,Lung ,Mice, Knockout ,Angiotensin II ,Endothelial Cells ,Angiotensin-converting enzyme ,Cell Biology ,medicine.disease ,Immunohistochemistry ,Pulmonary hypertension ,Capillaries ,Perfusion ,Endothelial stem cell ,medicine.anatomical_structure ,Endocrinology ,Knockout mouse ,biology.protein ,Angiotensin I ,Cardiology and Cardiovascular Medicine ,Signal Transduction - Abstract
Reduced lung capillary expression of angiotensin I-converting enzyme (ACE), a key enzyme in cardiovascular pathophysiology, and of caveolin-1, an important regulator of endothelial cell signalling, has been demonstrated in various models of pulmonary arterial hypertension (PAH). We addressed the relationship between PAH and ACE expression in caveolin-1 knockout mice (Cav1(-/-)), which have moderate PAH. Tissue ACE activity was reduced by 50% in lungs from 3-month-old Cav1(-/-) mice compared to wild type (WT). A similar reduction in lung endothelial ACE expression was observed by measuring the lung uptake of (125)I-labeled monoclonal anti-ACE antibody and by quantitative immunohistochemistry. These alterations in ACE are limited to capillary segments of the pulmonary circulation. Functionally, the increase in pulmonary artery pressure (PAP) in response to ACE conversion of angiotensin I to angiotensin II in isolated, perfused mouse lungs was reduced significantly in Cav1(-/-) mice compared to WT. Thus, these complementary approaches demonstrate the dependence of lung microvascular endothelial cell ACE protein expression on caveolin-1 expression and underscore the vital role of caveolin-1-regulated pulmonary vascular homeostasis on endothelial ACE expression and activity. In summary, we have revealed a novel role of caveolin-1 in the regulation of ACE expression in pulmonary capillary endothelial cells. Further understanding of the mechanism by which reduced caveolin-1 expression leads altered pulmonary vascular development, PAH, and reduced ACE expression may have important clinical implications in patients with these severe lung diseases.
- Published
- 2010
29. Resuscitation with Lipid versus Epinephrine in a Rat Model of Bupivacaine Overdose
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Douglas L. Feinstein, Malek G. Massad, Richard Ripper, Sophie Zheng, Kemba Kelly, Nirali Shah, David E. Schwartz, Guido Di Gregorio, Guy L. Weinberg, and Lucas Edelman
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Male ,Resuscitation ,Epinephrine ,medicine.medical_treatment ,Hypoxemia ,Rats, Sprague-Dawley ,Bolus (medicine) ,Animals ,Medicine ,Anesthetics, Local ,Infusions, Intravenous ,Saline ,Bupivacaine ,business.industry ,Heart ,Lipids ,Rats ,Disease Models, Animal ,Anesthesiology and Pain Medicine ,Blood pressure ,Anesthesia ,Arterial blood ,Drug Overdose ,medicine.symptom ,business ,medicine.drug - Abstract
Background Lipid emulsion infusion reverses cardiovascular compromise due to local anesthetic overdose in laboratory and clinical settings. The authors compared resuscitation with lipid, epinephrine, and saline control in a rat model of bupivacaine-induced cardiac toxicity to determine whether lipid provides a benefit over epinephrine. Methods Bupivacaine, 20 mg/kg, was infused in rats anesthetized with isoflurane, producing asystole in all subjects. Ventilation with 100% oxygen and chest compressions were begun immediately, along with intravenous treatment with 30% lipid emulsion or saline (5-ml/kg bolus plus continuous infusion at 0.5 ml . kg . min) or epinephrine (30 microg/kg). Chest compressions were continued and boluses were repeated at 2.5 and 5 min until the native rate-pressure product was greater than 20% baseline. Electrocardiogram and arterial pressure were monitored continuously and at 10 min, arterial blood gas, central venous oxygen saturation, and blood lactate were measured. Effect size (Cohen d) was determined for comparisons at 10 min. Results Lipid infusion resulted in higher rate-pressure product (P < 0.001, d = 3.84), pH (P < 0.01, d = 3.78), arterial oxygen tension (P < 0.05, d = 2.8), and central venous oxygen saturation (P < 0.001, d = 4.9) at 10 min than did epinephrine. Epinephrine treatment caused higher lactate (P < 0.01, d = 1.48), persistent ventricular ectopy in all subjects, pulmonary edema in four of five rats, hypoxemia, and a mixed metabolic and respiratory acidosis by 10 min. Conclusions Hemodynamic and metabolic metrics during resuscitation with lipid surpassed those with epinephrine, which were no better than those seen in the saline control group. Further studies are required to optimize the clinical management of systemic local anesthetic toxicity.
- Published
- 2008
30. Cardiac Depression Induced by Cocaine or Cocaethylene are Alleviated by Lipid Emulsion More Effectively Than by Sulfobutylether β-Cyclodextrin
- Author
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Katarzyna Kowal, Guy L. Weinberg, Douglas L. Feinstein, Adrian Pichurko, Bocheng Lin, Israel Rubinstein, David E. Schwartz, Michael R. Fettiplace, Kinga Lis, and Richard Ripper
- Subjects
Male ,Fat Emulsions, Intravenous ,medicine.drug_class ,Beta-Cyclodextrins ,Pharmacology ,Article ,Rats, Sprague-Dawley ,chemistry.chemical_compound ,Cocaethylene ,Cocaine ,Heart Rate ,Coronary Circulation ,medicine ,Animals ,Cardiotoxicity ,Local anesthetic ,business.industry ,beta-Cyclodextrins ,Arrhythmias, Cardiac ,Heart ,General Medicine ,medicine.disease ,Bupivacaine ,Myocardial Contraction ,Rats ,chemistry ,Anesthesia ,Depression, Chemical ,Toxicity ,Emergency Medicine ,Benzoylecgonine ,Cocaine intoxication ,Ecgonine ,business ,medicine.drug - Abstract
Objectives Cocaine intoxication leads to over 500,000 emergency department visits annually in the United States and ethanol cointoxication occurs in 34% of those cases. Cardiotoxicity is an ominous complication of cocaine and cocaethylene overdose for which no specific antidote exists. Because infusion of lipid emulsion (Intralipid) can treat lipophilic local anesthetic toxicity and cocaine is an amphipathic local anesthetic, the authors tested whether lipid emulsion could attenuate cocaine cardiotoxicity in vivo. The effects of lipid emulsion were compared with the metabolically inert sulfobutylether-β-cyclodextrin (SBE-β-CD; Captisol) in an isolated heart model of cocaine and cocaethylene toxicity to determine if capture alone could exert similar benefit as lipid emulsion, which exhibits multimodal effects. The authors then tested if cocaine and cocaethylene, like bupivacaine, inhibit lipid-based metabolism in isolated cardiac mitochondria. Methods For whole animal experiments, Sprague-Dawley rats were anesthetized, instrumented, and pretreated with lipid emulsion followed by a continuous infusion of cocaine to assess time of onset of cocaine toxicity. For ex vivo experiments, rat hearts were placed onto a nonrecirculating Langendorff system perfused with Krebs-Henseleit solution. Heart rate, left ventricle maximum developed pressure (LVdevP), left ventricle diastolic pressure, maximum rate of contraction (+dP/dtmax), maximum rate of relaxation (–dP/dtmax), rate-pressure product (RPP = heart rate × LVdevP), and line pressure were monitored continuously during the experiment. A dose response to cocaine (10, 30, 50, and 100 μmol/L) and cocaethylene (10, 30, and 50 μmol/L) was generated in the absence or presence of either 0.25% lipid emulsion or SBE-β-CD. Substrate-specific rates of oxygen consumption were measured in interfibrillar cardiac mitochondria in the presence of cocaine, cocaethylene, ecgonine, and benzoylecgonine. Results Treatment with lipid emulsion delayed onset of hypotension (140 seconds vs. 279 seconds; p = 0.008) and asystole (369 seconds vs. 607 seconds; p = 0.02) in whole animals. Cocaine and cocaethylene induced dose-dependent decreases in RPP, +dP/dtmax, and –dP/dtmaxabs (p
- Published
- 2015
31. Tissue Specificity of Human Angiotensin I-Converting Enzyme
- Author
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Ilya Trakht, Alexander V. Gusakov, Randal O. Dull, Olga V. Kryukova, I. V. Uporov, V. V. Evdokimov, David E. Schwartz, Elena Z. Golukhova, Sergei M. Danilov, Olga A. Kost, Victoria E. Tikhomirova, and Gavreel Kalantarov
- Subjects
Male ,medicine.medical_specialty ,Glycosylation ,medicine.drug_class ,lcsh:Medicine ,Epithelial cells ,Peptidyl-Dipeptidase A ,Monoclonal antibody ,chemistry.chemical_compound ,Semen ,Internal medicine ,Blood plasma ,medicine ,Humans ,lcsh:Science ,Lung ,chemistry.chemical_classification ,Epididymis ,Multidisciplinary ,biology ,lcsh:R ,Prostate ,Antibodies, Monoclonal ,Endothelial Cells ,Angiotensin-converting enzyme ,Membrane glycoproteins ,Endocrinology ,Blood pressure ,Enzyme ,medicine.anatomical_structure ,chemistry ,Biochemistry ,biology.protein ,Medicine ,lcsh:Q ,Angiotensin converting enzyme ,Epitope Mapping ,Research Article - Abstract
Background: Angiotensin-converting enzyme (ACE), which metabolizes many peptides and plays a key role in blood pressure regulation and vascular remodeling, as well as in reproductive functions, is expressed as a type-1 membrane glycoprotein on the surface of endothelial and epithelial cells. ACE also presents as a soluble form in biological fluids, among which seminal fluid being the richest in ACE content - 50-fold more than that in blood. Methods/Principal Findings: We performed conformational fingerprinting of lung and seminal fluid ACEs using a set of monoclonal antibodies (mAbs) to 17 epitopes of human ACE and determined the effects of potential ACE-binding partners on mAbs binding to these two different ACEs. Patterns of mAbs binding to ACEs from lung and from seminal fluid dramatically differed, which reflects difference in the local conformations of these ACEs, likely due to different patterns of ACE glycosylation in the lung endothelial cells and epithelial cells of epididymis/prostate (source of seminal fluid ACE), confirmed by mass-spectrometry of ACEs tryptic digests. Conclusions: Dramatic differences in the local conformations of seminal fluid and lung ACEs, as well as the effects of ACE-binding partners on mAbs binding to these ACEs, suggest different regulation of ACE functions and shedding from epithelial cells in epididymis and prostate and endothelial cells of lung capillaries. The differences in local conformation of ACE could be the base for the generation of mAbs distinguishing tissue-specific ACEs.
- Published
- 2015
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32. Isoflurane, but Not Sevoflurane, Increases Transendothelial Albumin Permeability in the Isolated Rat Lung
- Author
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George J. Crystal, Richard D. Minshall, Guochang Hu, Stephen M. Vogel, David J. Visintine, M. Ramez Salem, Ronald F. Albrecht, David E. Schwartz, and Ayesha N. Shajahan
- Subjects
Minimum alveolar concentration ,Endothelium ,business.industry ,Albumin ,Pharmacology ,Sevoflurane ,Anesthesiology and Pain Medicine ,medicine.anatomical_structure ,Biochemistry ,Isoflurane ,Caveolae ,Caveolin 1 ,medicine ,Phosphorylation ,business ,medicine.drug - Abstract
Background Caveolae mediated transendothelial transport of albumin has recently been shown to be the primary mechanism regulating microvascular endothelial albumin permeability. The authors investigated the effects of isoflurane and sevoflurane on pulmonary endothelial albumin permeability and assessed the potential role of the caveolae scaffold protein, caveolin-1, in these effects. Methods Isolated rat lungs and cultured rat lung microvessel endothelial cells (RLMVECs) were exposed to 1.0 or 2.0 minimum alveolar concentration (MAC) isoflurane or sevoflurane for 30 min. I-albumin permeability-surface area product and capillary filtration coefficient were determined in the isolated lungs. In RLMVECs, uptake and transendothelial transport of I-albumin were measured in the absence and presence of pretreatment with 2 mm methyl-beta-cyclodextrin, a caveolae-disrupting agent. Uptake of fluorescent-labeled albumin, as well as phosphorylation of Src kinase and caveolin-1, was also determined. In Y14F-caveolin-1 mutant (nonphosphorylatable) expressing RLMVECs, uptake of I-albumin and phosphorylation of caveolin-1 were evaluated. Results In the isolated lungs, 2.0 MAC isoflurane increased I-albumin permeability-surface area product by 48% without affecting capillary filtration coefficient. In RLMVECs, isoflurane more than doubled the uptake of I-albumin and caused a 54% increase in the transendothelial transport of I-albumin. These effects were blocked by pretreatment with methyl-beta-cyclodextrin. The isoflurane-induced increase in uptake of I-albumin in wild-type RLMVECs was abolished in the Y14F-caveolin-1 mutant expressing cells. Isoflurane also caused a twofold increase in Src and caveolin-1 phosphorylation. Neither 1.0 MAC isoflurane nor 1.0 or 2.0 MAC sevoflurane affected any index of albumin transport or phosphorylation of caveolin-1. Conclusion Isoflurane, but not sevoflurane, increased lung transendothelial albumin permeability through enhancement of caveolae-mediated albumin uptake and transport in the isolated lung. This effect may involve an enhanced phosphorylation of caveolin-1.
- Published
- 2006
33. Fatal Acute Pancreatitis in a Patient Chronically Treated with Candesartan
- Author
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David E Schwartz, Jeffrey B Newton, Christopher J. Gill, and Anne E Jennings
- Subjects
medicine.medical_specialty ,Angiotensin receptor ,business.industry ,Pharmaceutical Science ,030204 cardiovascular system & hematology ,medicine.disease ,030226 pharmacology & pharmacy ,Gastroenterology ,03 medical and health sciences ,Candesartan ,0302 clinical medicine ,Internal medicine ,medicine ,Acute pancreatitis ,Intensive care medicine ,business ,medicine.drug - Abstract
Objective: To summarize a case of acute pancreatitis in a patient receiving the angiotensin II receptor blocker (ARB) candesartan. Case Summary: A previously healthy 75-year-old white man presented with acute pancreatitis complicated by anuric renal failure, respiratory failure, circulatory collapse, and died within 24 hours despite resuscitation efforts. He had been receiving candesartan 32 mg/day for more than one year with no apparent adverse effects. Discussion: In recent years, angiotensin-converting enzyme (ACE) inhibitors have been linked with sporadic cases of acute pancreatitis. Recent case reports suggest a similar association between pancreatitis and the related drug class of ARBs. Animal data indicate that the renin–angiotensin system plays an important role in pancreatic hemodynamics and exocrine function and is activated in the setting of acute pancreatitis. Because both ARBs and ACE inhibitors affect angiotensin II, we hypothesize that a common pathophysiologic mechanism might apply to both ARB- and ACE inhibitor–induced pancreatitis. Conclusions: Although acute pancreatitis appears to be a rare complication of both ARBs and ACE inhibitors, the catastrophic outcome in this case mandates that clinicians be aware of this adverse effect. Further research into the role of the renin–angiotensin system in the pathogenesis of acute pancreatitis appears warranted.
- Published
- 2005
34. Isoflurane promotes phagocytosis of apoptotic neutrophils through AMPK-mediated ADAM17/Mer signaling
- Author
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Chunling Jiang, Yang Lv, Xueke Du, David E. Schwartz, You Yang Zhao, Guochang Hu, and Randal O. Dull
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Lipopolysaccharides ,0301 basic medicine ,Neutrophils ,Physiology ,Protein Expression ,lcsh:Medicine ,Apoptosis ,AMP-Activated Protein Kinases ,Pathology and Laboratory Medicine ,Mice ,White Blood Cells ,Animal Cells ,Immune Physiology ,Medicine and Health Sciences ,Macrophage ,Receptors, Immunologic ,Alveolar Macrophages ,lcsh:Science ,Immune Response ,Cells, Cultured ,Innate Immune System ,Multidisciplinary ,Isoflurane ,Cell Death ,Chemistry ,Animal Models ,3. Good health ,Cell biology ,Experimental Organism Systems ,Cell Processes ,Gene Knockdown Techniques ,Cytokines ,Cellular Types ,medicine.symptom ,Signal Transduction ,Research Article ,medicine.drug ,Immune Cells ,Phagocytosis ,Acute Lung Injury ,Immunology ,Mouse Models ,Inflammation ,ADAM17 Protein ,Lung injury ,Research and Analysis Methods ,03 medical and health sciences ,Signs and Symptoms ,Model Organisms ,Diagnostic Medicine ,Gene Expression and Vector Techniques ,medicine ,Animals ,Molecular Biology Techniques ,Efferocytosis ,Molecular Biology ,Molecular Biology Assays and Analysis Techniques ,Blood Cells ,Macrophages ,lcsh:R ,Biology and Life Sciences ,AMPK ,Cell Biology ,Molecular Development ,Antigens, Differentiation, B-Lymphocyte ,Mice, Inbred C57BL ,030104 developmental biology ,Immune System ,lcsh:Q ,Developmental Biology - Abstract
A patient's recovery from lung inflammatory injury or development of multi-system organ failure is determined by the host's ability to resolve inflammation and repair tissue damage, both of which require the clearance of apoptotic neutrophils by macrophages (efferocytosis). Here, we investigated the effects of isoflurane on macrophage efferocytosis and resolution of lung inflammatory injury. Treatment of murine bone marrow-derived macrophages (BMDMs) or alveolar macrophages with isoflurane dramatically enhanced phagocytosis of apoptotic neutrophils. Isoflurane significantly increased the surface expression of the receptor tyrosine kinase Mer in macrophages, but markedly decreased the levels of a soluble form of Mer protein in the medium. Isoflurane treatment also caused a decrease in a disintegrin and metalloproteinase 17 (ADAM17) on the cell surface and a concomitant increase in its cytoplasmic fraction. These responses induced by isoflurane were completely reversed by a pharmacological inhibitor or genetic deletion of AMP-activated protein kinase (AMPK). In a mouse model of lipopolysaccharide-induced lung injury, isoflurane accelerated the recovery of lung inflammation and injury that was coupled with an increase in the number of alveolar macrophages containing apoptotic bodies. In alveolar macrophage-depleted mice, administration of isoflurane-pretreated BMDMs facilitated resolution of lung inflammation following lipopolysaccharide challenge. Thus, isoflurane promoted resolution of lipopolysaccharide-induced lung inflammatory injury via enhancement of macrophage efferocytosis. Increased macrophage efferocytosis following isoflurane treatment correlates with upregulation of Mer surface expression through AMPK-mediated blockade of ADAM17 trafficking to the cell membrane.
- Published
- 2017
35. Transesophageal Echocardiography–Guided Aortic Thrombectomy in a Patient With a Mobile Thoracic Aortic Thrombus
- Author
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Vijay Krishnamoorthy, David E. Schwartz, Ramona Nicolau, Kunal Bhatt, and Martin Borhani
- Subjects
medicine.medical_specialty ,Aorta ,Surgical approach ,business.industry ,Aortic Diseases ,Aorta, Thoracic ,Thrombosis ,Middle Aged ,medicine.disease ,Surgery ,Anesthesiology and Pain Medicine ,Cardiothoracic surgery ,Monitoring, Intraoperative ,medicine.artery ,cardiovascular system ,medicine ,Humans ,Female ,Radiology ,Cardiology and Cardiovascular Medicine ,business ,Echocardiography, Transesophageal ,Aortic thrombus ,Thrombectomy - Abstract
Thoracic aortic thrombi are a well-known cause of distal embolic phenomena. There is a paucity of case reports because of the rarity of this condition, and thus clear management guidelines are lacking. The authors present a case of a mobile thoracic aortic thrombus managed by a surgical approach. This report demonstrates how intraoperative transesophageal echocardiography (TEE) proved to be critical in guiding surgical management. The utility of TEE in the diagnosis and management of aortic thrombi is also discussed. In addition, currently reported management strategies for this complex condition are reviewed.
- Published
- 2011
36. Autophagy in pulmonary macrophages mediates lung inflammatory injury via NLRP3 inflammasome activation during mechanical ventilation
- Author
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David E. Schwartz, Gongjian Liu, Guochang Hu, Randal O. Dull, and Yang Zhang
- Subjects
Pulmonary and Respiratory Medicine ,Male ,Pathology ,medicine.medical_specialty ,Physiology ,Inflammasomes ,medicine.medical_treatment ,Ventilator-Induced Lung Injury ,Inflammation ,Pharmacology ,Biology ,Lung injury ,Hydroxamic Acids ,Autophagy-Related Protein 5 ,Mice ,Physiology (medical) ,Macrophages, Alveolar ,NLR Family, Pyrin Domain-Containing 3 Protein ,medicine ,Autophagy ,Animals ,Tidal volume ,Mechanical ventilation ,Lung ,Adenine ,Macrophages ,Inflammasome ,Cell Biology ,Pneumonia ,Articles ,respiratory system ,Respiration, Artificial ,Mice, Inbred C57BL ,medicine.anatomical_structure ,Breathing ,Stress, Mechanical ,medicine.symptom ,Carrier Proteins ,Reactive Oxygen Species ,Microtubule-Associated Proteins ,medicine.drug ,Signal Transduction - Abstract
The inflammatory response is a primary mechanism in the pathogenesis of ventilator-induced lung injury. Autophagy is an essential, homeostatic process by which cells break down their own components. We explored the role of autophagy in the mechanisms of mechanical ventilation-induced lung inflammatory injury. Mice were subjected to low (7 ml/kg) or high (28 ml/kg) tidal volume ventilation for 2 h. Bone marrow-derived macrophages transfected with a scrambled or autophagy-related protein 5 small interfering RNA were administered to alveolar macrophage-depleted mice via a jugular venous cannula 30 min before the start of the ventilation protocol. In some experiments, mice were ventilated in the absence and presence of autophagy inhibitors 3-methyladenine (15 mg/kg ip) or trichostatin A (1 mg/kg ip). Mechanical ventilation with a high tidal volume caused rapid (within minutes) activation of autophagy in the lung. Conventional transmission electron microscopic examination of lung sections showed that mechanical ventilation-induced autophagy activation mainly occurred in lung macrophages. Autophagy activation in the lungs during mechanical ventilation was dramatically attenuated in alveolar macrophage-depleted mice. Selective silencing of autophagy-related protein 5 in lung macrophages abolished mechanical ventilation-induced nucleotide-binding oligomerization domain-like receptor containing pyrin domain 3 (NLRP3) inflammasome activation and lung inflammatory injury. Pharmacological inhibition of autophagy also significantly attenuated the inflammatory responses caused by lung hyperinflation. The activation of autophagy in macrophages mediates early lung inflammation during mechanical ventilation via NLRP3 inflammasome signaling. Inhibition of autophagy activation in lung macrophages may therefore provide a novel and promising strategy for the prevention and treatment of ventilator-induced lung injury.
- Published
- 2014
37. Hepatectomy without endotracheal general anesthesia: a safe procedure?
- Author
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David E. Schwartz, Beatrice Beck-Schimmer, Frédérique Hovaguimian, Pierre-Alain Clavien, and University of Zurich
- Subjects
medicine.medical_specialty ,business.industry ,10216 Institute of Anesthesiology ,General surgery ,medicine.medical_treatment ,610 Medicine & health ,Surgery ,2746 Surgery ,Text mining ,Anesthesia ,medicine ,Hepatectomy ,business ,10217 Clinic for Visceral and Transplantation Surgery - Published
- 2014
38. Endothelial barrier protection by local anesthetics: ropivacaine and lidocaine block tumor necrosis factor-α-induced endothelial cell Src activation
- Author
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Tobias, Piegeler, E Gina, Votta-Velis, Farnaz R, Bakhshi, Mao, Mao, Graeme, Carnegie, Marcelo G, Bonini, David E, Schwartz, Alain, Borgeat, Beatrice, Beck-Schimmer, and Richard D, Minshall
- Subjects
Enzyme Activation ,src-Family Kinases ,Tumor Necrosis Factor-alpha ,Microcirculation ,Humans ,Lidocaine ,Ropivacaine ,Endothelium, Vascular ,Anesthetics, Local ,Amides ,Lung ,Cells, Cultured ,Article - Abstract
Pulmonary endothelial barrier dysfunction mediated in part by Src-kinase activation plays a crucial role in acute inflammatory disease. Proinflammatory cytokines, such as tumor necrosis factor-α (TNFα), activate Src via phosphatidylinositide 3-kinase/Akt-dependent nitric oxide generation, a process initiated by recruitment of phosphatidylinositide 3-kinase regulatory subunit p85 to TNF-receptor-1. Because amide-linked local anesthetics have well-established anti-inflammatory effects, the authors hypothesized that ropivacaine and lidocaine attenuate inflammatory Src signaling by disrupting the phosphatidylinositide 3-kinase-Akt-nitric oxide pathway, thus blocking Src-dependent neutrophil adhesion and endothelial hyperpermeability.Human lung microvascular endothelial cells, incubated with TNFα in the absence or presence of clinically relevant concentrations of ropivacaine and lidocaine, were analyzed by Western blot, probing for phosphorylated/activated Src, endothelial nitric oxide synthase, Akt, intercellular adhesion molecule-1, and caveolin-1. The effect of ropivacaine on TNFα-induced nitric oxide generation, co-immunoprecipitation of TNF-receptor-1 with p85, neutrophil adhesion, and endothelial barrier disruption were assessed.Ropivacaine and lidocaine attenuated TNFα-induced Src activation (half-maximal inhibitory concentration [IC50] = 8.611 × 10 M for ropivacaine; IC50 = 5.864 × 10 M for lidocaine) and endothelial nitric oxide synthase phosphorylation (IC50 = 7.572 × 10 M for ropivacaine; IC50 = 6.377 × 10 M for lidocaine). Akt activation (n = 7; P = 0.006) and stimulus-dependent binding of TNF-receptor-1 and p85 (n = 6; P = 0.043) were blocked by 1 nM of ropivacaine. TNFα-induced neutrophil adhesion and disruption of endothelial monolayers via Src-dependent intercellular adhesion molecule-1- and caveolin-1-phosphorylation, respectively, were also attenuated.Ropivacaine and lidocaine effectively blocked inflammatory TNFα signaling in endothelial cells by attenuating p85 recruitment to TNF-receptor-1. The resultant decrease in Akt, endothelial nitric oxide synthase, and Src phosphorylation reduced neutrophil adhesion and endothelial hyperpermeability. This novel anti-inflammatory "side-effect" of ropivacaine and lidocaine may provide therapeutic benefit in acute inflammatory disease.
- Published
- 2014
39. A novel angiotensin I-converting enzyme mutation (S333W) impairs N-domain enzymatic cleavage of the anti-fibrotic peptide, AcSDKP
- Author
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David E. Schwartz, Edward D. Sturrock, Kyle Hogarth, Ross G. Douglas, Sylva L. U. Schwager, Sergei M. Danilov, Isolda A. Popova, Michael S. Wade, Andrew B. Nesterovitch, Joe G.N. Garcia, Nakul Bhardwaj, Institute of Infectious Disease and Molecular Medicine, and Faculty of Health Sciences
- Subjects
ACE inhibitors ,Substitution mutation ,Mutant ,lcsh:Medicine ,Peptide ,Cardiovascular ,Biochemistry ,Membrane proteins ,lcsh:Science ,Peptide sequence ,chemistry.chemical_classification ,Multidisciplinary ,biology ,Immunochemistry ,Hydrolysis ,CHO cells ,Enzymes ,Mutation detection ,Blood ,Medicine ,Oligopeptides ,Research Article ,Molecular Sequence Data ,Peptidyl-Dipeptidase A ,Cell Line ,Cricetulus ,Genetic Mutation ,Renin–angiotensin system ,Genetics ,Animals ,Humans ,Amino Acid Sequence ,Biology ,Enzyme Kinetics ,Clinical Genetics ,Tetrapeptide ,Point mutation ,Crystal structure ,lcsh:R ,Personalized Medicine ,Active site ,Proteins ,Molecular biology ,Fibrosis ,Kinetics ,Enzyme ,Metabolism ,chemistry ,Mutation ,Enzyme Structure ,biology.protein ,lcsh:Q ,Peptides ,Sequence Alignment - Abstract
Background Angiotensin I-converting enzyme (ACE) has two functional N- and C-domain active centers that display differences in the metabolism of biologically-active peptides including the hemoregulatory tetrapeptide, Ac-SDKP, hydrolysed preferentially by the N domain active center. Elevated Ac-SDKP concentrations are associated with reduced tissue fibrosis. Results We identified a patient of African descent exhibiting unusual blood ACE kinetics with reduced relative hydrolysis of two synthetic ACE substrates (ZPHL/HHL ratio) suggestive of the ACE N domain center inactivation. Inhibition of blood ACE activity by anti-catalytic mAbs and ACE inhibitors and conformational fingerprint of blood ACE suggested overall conformational changes in the ACE molecule and sequencing identified Ser333Trp substitution in the N domain of ACE. In silico analysis demonstrated S333W localized in the S1 pocket of the active site of the N domain with the bulky Trp adversely affecting binding of ACE substrates due to steric hindrance. Expression of mutant ACE (S333W) in CHO cells confirmed altered kinetic properties of mutant ACE and conformational changes in the N domain. Further, the S333W mutant displayed decreased ability (5-fold) to cleave the physiological substrate AcSDKP compared to wild-type ACE. Conclusions and Significance A novel Ser333Trp ACE mutation results in dramatic changes in ACE kinetic properties and lowered clearance of Ac-SDKP. Individuals with this mutation (likely with significantly increased levels of the hemoregulatory tetrapeptide in blood and tissues), may confer protection against fibrosis.
- Published
- 2014
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40. Volatile anesthetics improve survival after cecal ligation and puncture
- Author
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Melanie Hasler, David E. Schwartz, Inge K. Herrmann, Guochang Hu, Richard D. Minshall, Beatrice Beck-Schimmer, Martin Urner, Maricela Castellon, University of Zurich, and Beck-Schimmer, Beatrice
- Subjects
Male ,Methyl Ethers ,10216 Institute of Anesthesiology ,Inflammation ,610 Medicine & health ,Wounds, Stab ,Lung injury ,Sevoflurane ,Article ,10052 Institute of Physiology ,Sepsis ,03 medical and health sciences ,Desflurane ,Mice ,0302 clinical medicine ,030202 anesthesiology ,Intensive care ,medicine ,Animals ,Cecum ,Ligation ,Isoflurane ,business.industry ,Septic shock ,medicine.disease ,3. Good health ,Mice, Inbred C57BL ,Disease Models, Animal ,Anesthesiology and Pain Medicine ,Anesthesia ,10076 Center for Integrative Human Physiology ,Anesthetics, Inhalation ,570 Life sciences ,biology ,2703 Anesthesiology and Pain Medicine ,medicine.symptom ,business ,030217 neurology & neurosurgery ,medicine.drug - Abstract
Sepsis and septic shock remain the leading causes of death in intensive care units worldwide.1 Complex pathophysiology together with heterogeneous disease patterns are key features making the treatment of sepsis extremely challenging.2–5 Numerous approaches have been undertaken to attenuate the harmful host response to infection, with a mostly unsuccessful translation into clinical outcome. Despite new pathophysiological insights and major efforts in developing goal-directed therapies, mortality in septic patients remains considerably high, and the treatment of late stage diagnosed patients is generally associated with bad outcome.6 Volatile anesthetics such as desflurane, isoflurane, and sevoflurane have been identified as effective modifiers of the inflammatory response in various states of tissue injury, exerting beneficial effects on organ function and overall outcome in both animals7–12 and patients.13–16 Potential benefits of the application of volatile anesthetics in in vivo models of experimental sepsis have not been systematically explored, and their effect on survival remains unclear. Previous studies elucidating the protective potential of volatile anesthetics have traditionally focused on ischemia–reperfusion injury and not on sepsis. In addition, biomarkers of organ injury were determined, but outcome parameters were not.17 In this study, we investigated in a model of severe murine sepsis with intraabdominal focus (peritonitis) whether the volatile anesthetics desflurane, isoflurane, and sevoflurane impact on overall survival of septic animals. The cecal ligation and puncture (CLP) model is considered the “gold standard” in sepsis research with a disease profile similar to that in human sepsis in that it encompasses more of the clinical features and drug responses of human sepsis, than, for example, the lipopolysaccharide model,18,19 despite the absence of some key features (e.g., kidney and lung injury). In this study, mice were exposed to desflurane, isoflurane, or sevoflurane during induction of sepsis (conditioning). To investigate the effect in a postconditioning setting, desflurane and sevoflurane were applied 24 h after the CLP procedure, when the mice showed pronounced symptoms of inflammation. Survival as well as markers of renal and hepatic organ function was compared with the CLP group without intervention. Being aware of the limitations of animal models of sepsis, the current study illustrates the beneficial effects of the volatile anesthetics desflurane and sevoflurane in states of severe inflammation leading to a remarkably improved 7-day survival and reduced end-organ damage.
- Published
- 2013
41. Contributors
- Author
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Ronda E. Alexander, Carlos A. Artime, Paul A. Baker, David R. Ball, Anis S. Baraka, Irving Z. Basañez, Elizabeth C. Behringer, Jacqueline A. Bello, Jonathan L. Benumof, Lauren C. Berkow, James M. Berry, Nasir I. Bhatti, Archie I.J. Brain, Ansgar M. Brambrink, Calvin A. Brown, Robert A. Caplan, Davide Cattano, Laura F. Cavallone, Erol Cavus, Jacques E. Chelly, T. Linda Chi, Chris C. Christodoulou, Rebecca E. Claure, Edmond Cohen, Neal H. Cohen, Lee Coleman, Tim M. Cook, Richard M. Cooper, Steven A. Deem, David A. Diaz Voss Varela, Pierre Auguste Diemunsch, Stephen F. Dierdorf, Volker Dörges, D. John Doyle, Lara Ferrario, David Z. Ferson, Lorraine J. Foley, Michael Frass, Michael A. Gibbs, Katherine S.L. Gil, Julian A. Gold, Steven B. Greenberg, John A. Griswold, Carin A. Hagberg, Gregory B. Hammer, Stephen Harvey, Alexander T. Hillel, Orlando R. Hung, Ranu R. Jain, Aaron M. Joffe, Girish P. Joshi, Jeffrey P. Keck, Sofia Khan, P. Allan Klock, Peter Krafft, Claude Krier, Michael Seltz Kristensen, Olivier Langeron, Richard M. Levitan, Brian L. Marasigan, Lynette J. Mark, Eric C. Matten, Barry E. McGuire, Joseph H. McIsaac, Leah Meisterling, Gabriel Mena, Nathan W. Mick, David M. Mirsky, Thomas C. Mort, Jessen Mukalel, Uma Munnur, Michael F. Murphy, Robert T. Naruse, Vladimir Nekhendzy, Kevin F. O’Grady, Babatunde Ogunnaike, Irene P. Osborn, Anil Patel, Bela Patel, Karen L. Posner, Mary F. Rabb, Ali S. Raja, Satya K. Ramachandran, Sivam Ramanathan, Allan P. Reed, William H. Rosenblatt, Soham Roy, Kurt Rützler, Sebastian G. Russo, M. Ramez Salem, Antonio Sanchez, Jan-Henrik Schiff, Bettina U. Schmitz, David E. Schwartz, Jeanette Scott, Torin Shear, Roy Sheinbaum, Edward R. Stapleton, Maya S. Suresh, Mark D. Tasch, Arnd Timmermann, Arthur J. Tokarczyk, Sonia Vaida, Jeffery S. Vender, Chandy Verghese, Ashutosh Wali, Andreas Walther, Mark T. Warner, William C. Wilson, Robert Wong, and Mark Zakowski
- Published
- 2013
42. Death and Other Complications of Emergency Airway Management in Critically Ill Adults
- Author
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David E. Schwartz, Michael A. Matthay, and Neal H. Cohen
- Subjects
medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Incidence (epidemiology) ,medicine.disease ,Anesthesiology and Pain Medicine ,Pneumothorax ,Intensive care ,Emergency medical services ,Medicine ,Intubation ,Airway management ,business ,Prospective cohort study ,Complication ,Intensive care medicine - Abstract
Background Hospitalized patients outside of the operating room frequently require emergency airway management. This study investigates complications of emergency airway management in critically ill adults, including: (1) the incidence of difficult and failed intubation; (2) the frequency of esophageal intubation; (3) the incidence of pneumothorax and pulmonary aspiration; (4) the hemodynamic consequences of emergent intubation, including death, during and immediately following intubation; and (5) the relationship, if any, between the occurrence of complications and supervision of the intubation by an attending physician. Methods Data were collected on consecutive tracheal intubations carried out by the intensive care unit team over a 10-month period. Non-anesthesia residents were supervised by anesthesia residents, critical care attending physicians, or anesthesia attending physicians. Results Two hundred ninety-seven consecutive intubations were carried out in 238 adult patients. Translaryngeal tracheal intubation was accomplished in all patients. Intubation was difficult in 8% of cases (requiring more than two attempts at laryngoscopy by a physician skilled in airway management). Esophageal intubation occurred in 25 (8%) of the attempts but all were recognized before any adverse sequelae resulted. New infiltrates suggestive of pulmonary aspiration were present on chest radiography after 4% of intubations. Seven patients (3%) died during or within 30 min of the procedure. Five of the seven patients had systemic hypotension (systolic blood pressure < or = 90 mmHg), and four of the five were receiving vasopressors to support systolic blood pressure. Patients with systolic hypotension were more likely to die after intubation than were normotensive patients (P < 0.001). There was no relationship between supervision by an attending physician and the occurrence of complications. Conclusions In critically ill patients, emergency tracheal intubation is associated with a significant frequency of major complications. In this study, complications were not increased when intubations were accomplished without the supervision of an attending physician as long as the intubation was carried out or supervised by an individual skilled in airway management. Mortality associated with emergent tracheal intubation is highest in patients who are hemodynamically unstable and receiving vasopressor therapy before intubation.
- Published
- 1995
43. Antimetastatic potential of amide-linked local anesthetics: inhibition of lung adenocarcinoma cell migration and inflammatory Src signaling independent of sodium channel blockade
- Author
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Tobias, Piegeler, E Gina, Votta-Velis, Guoquan, Liu, Aaron T, Place, David E, Schwartz, Beatrice, Beck-Schimmer, Richard D, Minshall, and Alain, Borgeat
- Subjects
Veratridine ,Lung Neoplasms ,Lidocaine ,Tetrodotoxin ,Adenocarcinoma ,Intercellular Adhesion Molecule-1 ,Amides ,Article ,src-Family Kinases ,Cell Movement ,Cell Line, Tumor ,Humans ,Ropivacaine ,Anesthetics, Local ,Neoplasm Metastasis ,Phosphorylation ,Procaine ,Retrospective Studies ,Signal Transduction ,Sodium Channel Blockers - Abstract
Retrospective analysis of patients undergoing cancer surgery suggests the use of regional anesthesia may reduce cancer recurrence and improve survival. Amide-linked local anesthetics have antiinflammatory properties, although the mechanism of action in this regard is unclear. As inflammatory processes involving Src tyrosine protein kinase and intercellular adhesion molecule-1 are important in tumor growth and metastasis, we hypothesized that amide-linked local anesthetics may inhibit inflammatory Src-signaling involved in migration of adenocarcinoma cells.NCI-H838 lung cancer cells were incubated with tumor necrosis factor-α in absence/presence of ropivacaine, lidocaine, or chloroprocaine (1 nM-100 μM). Cell migration and total cell lysate Src-activation and intercellular adhesion molecule-1 phosphorylation were assessed. The role of voltage-gated sodium-channels in the mechanism of local anesthetic effects was also evaluated.Ropivacaine treatment (100 μM) of H838 cells for 20 min decreased basal Src activity by 62% (P=0.003), and both ropivacaine and lidocaine coadministered with tumor necrosis factor-α statistically significantly decreased Src-activation and intercellular adhesion molecule-1 phosphorylation, whereas chloroprocaine had no such effect. Migration of these cells at 4 h was inhibited by 26% (P=0.005) in presence of 1 μM ropivacaine and 21% by 1 μM lidocaine (P=0.004). These effects of ropivacaine and lidocaine were independent of voltage-gated sodium-channel inhibition.This study indicates that amide-, but not ester-linked, local anesthetics may provide beneficial antimetastatic effects. The observed inhibition of NCI-H838 cell migration by lidocaine and ropivacaine was associated with the inhibition of tumor necrosis factor-α-induced Src-activation and intercellular adhesion molecule-1 phosphorylation, providing the first evidence of a molecular mechanism that appears to be independent of their known role as sodium-channel blockers.
- Published
- 2012
44. Conformational changes of blood ACE in chronic uremia
- Author
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Valery Y. Shilo, Olga A. Kost, Maxim N. Petrov, Joe G.N. Garcia, Sergei M. Danilov, David E. Schwartz, and Alexandr V. Tarasov
- Subjects
Models, Molecular ,Protein Conformation ,lcsh:Medicine ,Angiotensin-Converting Enzyme Inhibitors ,Cardiovascular ,Biochemistry ,chemistry.chemical_compound ,Epitopes ,Blood plasma ,Pathology ,lcsh:Science ,Multidisciplinary ,biology ,Chemistry ,Immunochemistry ,Antibodies, Monoclonal ,Clinical Laboratory Sciences ,Enalaprilat ,Blood Chemistry ,Medicine ,medicine.drug ,Protein Binding ,Research Article ,medicine.medical_specialty ,Immunology ,Peptidyl-Dipeptidase A ,Cardiovascular Pharmacology ,End stage renal disease ,Diagnostic Medicine ,Internal medicine ,Renin–angiotensin system ,medicine ,Humans ,Immunoprecipitation ,Teprotide ,Biology ,Uremia ,lcsh:R ,Proteins ,Angiotensin-converting enzyme ,medicine.disease ,Endocrinology ,ACE inhibitor ,biology.protein ,Kidney Failure, Chronic ,lcsh:Q ,Biomarkers ,General Pathology - Abstract
Background: The pattern of binding of monoclonal antibodies (mAbs) to 16 epitopes on human angiotensin I-converting enzyme (ACE) comprise a conformational ACE fingerprint and is a sensitive marker of subtle protein conformational changes. Hypothesis: Toxic substances in the blood of patients with uremia due to End Stage Renal Disease (ESRD) can induce local conformational changes in the ACE protein globule and alter the efficacy of ACE inhibitors. Methodology/Principal Findings: The recognition of ACE by 16 mAbs to the epitopes on the N and C domains of ACE was estimated using an immune-capture enzymatic plate precipitation assay. The precipitation pattern of blood ACE by a set of mAbs was substantially influenced by the presence of ACE inhibitors with the most dramatic local conformational change noted in the N-domain region recognized by mAb 1G12. The ‘‘short’’ ACE inhibitor enalaprilat (tripeptide analog) and ‘‘long’’ inhibitor teprotide (nonapeptide) produced strikingly different mAb 1G12 binding with enalaprilat strongly increasing mAb 1G12 binding and teprotide decreasing binding. Reduction in S-S bonds via glutathione and dithiothreitol treatment increased 1G12 binding to blood ACE in a manner comparable to enalaprilat. Some patients with uremia due to ESRD exhibited significantly increased mAb 1G12 binding to blood ACE and increased ACE activity towards angiotensin I accompanied by reduced ACE inhibition by inhibitory mAbs and ACE inhibitors. Conclusions/Significance: The estimation of relative mAb 1G12 binding to blood ACE detects a subpopulation of ESRD patients with conformationally changed ACE, which activity is less suppressible by ACE inhibitors. This parameter may potentially serve as a biomarker for those patients who may need higher concentrations of ACE inhibitors upon antihypertensive therapy.
- Published
- 2012
45. An angiotensin I-converting enzyme mutation (Y465D) causes a dramatic increase in blood ACE via accelerated ACE shedding
- Author
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Zhenlong Chen, Pavel A. Petukhov, Isolda A. Popova, Kerry Gordon, Edward D. Sturrock, Sergey Kalinin, Heinrich Lünsdorf, David E. Schwartz, Richard D. Minshall, Emma Mendonca, Sergei M. Danilov, Maricela Castellon, Andrew B. Nesterovitch, Division of Medical Biochemistry, and Faculty of Health Sciences
- Subjects
Models, Molecular ,Substitution mutation ,Mutant ,DNA Mutational Analysis ,lcsh:Medicine ,Molting ,Blood plasma ,Cardiovascular ,Biochemistry ,0302 clinical medicine ,Cricetinae ,Molecular Cell Biology ,lcsh:Science ,chemistry.chemical_classification ,0303 health sciences ,Multidisciplinary ,Genomics ,Blood ,030220 oncology & carcinogenesis ,Hypertension ,Medicine ,Dimerization ,Research Article ,Hydrogen bonding ,CHO Cells ,Peptidyl-Dipeptidase A ,03 medical and health sciences ,Cricetulus ,Diagnostic Medicine ,Renin–angiotensin system ,Endopeptidases ,Genetics ,Animals ,Humans ,Binding site ,Biology ,030304 developmental biology ,Binding Sites ,Point mutation ,HEK 293 cells ,Cell Membrane ,lcsh:R ,Computational Biology ,Sheddase ,Molecular biology ,Protein Structure, Tertiary ,Enzyme ,HEK293 Cells ,chemistry ,Mutation ,Proteolysis ,Mutagenesis, Site-Directed ,Mutant Proteins ,lcsh:Q ,Protein Multimerization - Abstract
BACKGROUND: Angiotensin I-converting enzyme (ACE) metabolizes a range of peptidic substrates and plays a key role in blood pressure regulation and vascular remodeling. Thus, elevated ACE levels may be associated with an increased risk for different cardiovascular or respiratory diseases. Previously, a striking familial elevation in blood ACE was explained by mutations in the ACE juxtamembrane region that enhanced the cleavage-secretion process. Recently, we found a family whose affected members had a 6-fold increase in blood ACE and a Tyr465Asp (Y465D) substitution, distal to the stalk region, in the N domain of ACE. METHODOLOGY/PRINCIPAL FINDINGS: HEK and CHO cells expressing mutant (Tyr465Asp) ACE demonstrate a 3- and 8-fold increase, respectively, in the rate of ACE shedding compared to wild-type ACE. Conformational fingerprinting of mutant ACE demonstrated dramatic changes in ACE conformation in several different epitopes of ACE. Cell ELISA carried out on CHO-ACE cells also demonstrated significant changes in local ACE conformation, particularly proximal to the stalk region. However, the cleavage site of the mutant ACE - between Arg1203 and Ser1204 - was the same as that of WT ACE. The Y465D substitution is localized in the interface of the N-domain dimer (from the crystal structure) and abolishes a hydrogen bond between Tyr465 in one monomer and Asp462 in another. Conclusions/Significance The Y465D substitution results in dramatic increase in the rate of ACE shedding and is associated with significant local conformational changes in ACE. These changes could result in increased ACE dimerization and accessibility of the stalk region or the entire sACE, thus increasing the rate of cleavage by the putative ACE secretase (sheddase).
- Published
- 2011
46. Angiotensin I-converting enzyme Gln1069Arg mutation impairs trafficking to the cell surface resulting in selective denaturation of the C-domain
- Author
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Olivier Gribouval, Zhenlong Chen, Sergey Kalinin, Richard D. Minshall, Sergei M. Danilov, Andrew B. Nesterovitch, E. Vinokour, David E. Schwartz, and Marie Claire Gubler
- Subjects
Male ,Models, Molecular ,Protein Denaturation ,Protein Conformation ,lcsh:Medicine ,Biochemistry/Protein Folding ,chemistry.chemical_compound ,lcsh:Science ,Genetics and Genomics/Genetics of Disease ,Nephrology/Hereditary, Genetic, and Development Nephrology ,Multidisciplinary ,biology ,Temperature ,Sodium butyrate ,Pathology/Molecular Pathology ,Recombinant Proteins ,Protein Transport ,Female ,Intracellular ,Research Article ,Protein Binding ,medicine.drug ,medicine.medical_specialty ,Proteases ,Bradykinin ,Peptidyl-Dipeptidase A ,Gene Expression Regulation, Enzymologic ,Cell Biology/Membranes and Sorting ,Internal medicine ,Renin–angiotensin system ,medicine ,Humans ,Family ,Pharmacology ,Cell Membrane ,lcsh:R ,Angiotensin-converting enzyme ,Molecular biology ,Protein Structure, Tertiary ,Endocrinology ,Amino Acid Substitution ,chemistry ,Proteasome ,Mutation ,ACE inhibitor ,Biocatalysis ,Mutagenesis, Site-Directed ,biology.protein ,Mutant Proteins ,lcsh:Q ,Molecular Chaperones - Abstract
Background Angiotensin-converting enzyme (ACE; Kininase II; CD143) hydrolyzes small peptides such as angiotensin I, bradykinin, substance P, LH-RH and several others and thus plays a key role in blood pressure regulation and vascular remodeling. Complete absence of ACE in humans leads to renal tubular dysgenesis (RTD), a severe disorder of renal tubule development characterized by persistent fetal anuria and perinatal death. Methodology/Principal Findings Patient with RTD in Lisbon, Portugal, maintained by peritoneal dialysis since birth, was found to have a homozygous substitution of Arg for Glu at position 1069 in the C-terminal domain of ACE (Q1069R) resulting in absence of plasma ACE activity; both parents and a brother who are heterozygous carriers of this mutation had exactly half-normal plasma ACE activity compared to healthy individuals. We hypothesized that the Q1069R substitution impaired ACE trafficking to the cell surface and led to accumulation of catalytically inactive ACE in the cell cytoplasm. CHO cells expressing wild-type (WT) vs. Q1069R-ACE demonstrated the mutant accumulates intracellularly and also that it is significantly degraded by intracellular proteases. Q1069R-ACE retained catalytic and immunological characteristics of WT-ACE N domain whereas it had 10–20% of the nativity of the WT-ACE C domain. A combination of chemical (sodium butyrate) or pharmacological (ACE inhibitor) chaperones with proteasome inhibitors (MG 132 or bortezomib) significantly restored trafficking of Q1069R-ACE to the cell surface and increased ACE activity in the cell culture media 4-fold. Conclusions/Significance Homozygous Q1069R substitution results in an ACE trafficking and processing defect which can be rescued, at least in cell culture, by a combination of chaperones and proteasome inhibitors. Further studies are required to determine whether similar treatment of individuals with this ACE mutation would provide therapeutic benefits such as concentration of primary urine.
- Published
- 2010
47. Angiotensin I-converting enzyme mutation (Trp1197Stop) causes a dramatic increase in blood ACE
- Author
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Vyacheslav A. Adarichev, Julian Solway, Kyle Hogarth, E. Vinokour, Andrew B. Nesterovitch, Sergei M. Danilov, and David E. Schwartz
- Subjects
Male ,Protein Conformation ,DNA Mutational Analysis ,Mutant ,Gene Dosage ,lcsh:Medicine ,030204 cardiovascular system & hematology ,medicine.disease_cause ,0302 clinical medicine ,Cricetinae ,Blood plasma ,Ethnicity ,Cluster Analysis ,lcsh:Science ,Genetics and Genomics/Genetics of Disease ,Genetics ,0303 health sciences ,Mutation ,Multidisciplinary ,Pathology/Molecular Pathology ,Recombinant Proteins ,Stop codon ,Pedigree ,3. Good health ,Female ,Research Article ,medicine.medical_specialty ,Cardiovascular Disorders ,Blotting, Western ,Molecular Sequence Data ,CHO Cells ,Peptidyl-Dipeptidase A ,Biology ,Transfection ,03 medical and health sciences ,Cricetulus ,Internal medicine ,medicine ,Animals ,Humans ,Allele ,030304 developmental biology ,Base Sequence ,Point mutation ,Haplotype ,lcsh:R ,Cell Biology ,Blood pressure ,Endocrinology ,Amino Acid Substitution ,Haplotypes ,Mutagenesis, Site-Directed ,Mutant Proteins ,lcsh:Q - Abstract
Background Angiotensin-converting enzyme (ACE) metabolizes many peptides and plays a key role in blood pressure regulation and vascular remodeling. Elevated ACE levels may be associated with an increased risk for different cardiovascular or respiratory diseases, including asthma. Previously, a molecular mechanism underlying a 5-fold familial increase of blood ACE was discovered: Pro1199Leu substitution enhanced the cleavage-secretion process. Carriers of this mutation were Caucasians from Europe (mostly Dutch) or had European roots. Methodology/Principal Findings We have found a family of African-American descent whose affected members' blood ACE level was increased 13-fold over normal. In affected family members, codon TGG coding for Trp1197 was substituted in one allele by TGA (stop codon). As a result, half of ACE expressed in these individuals had a length of 1196 amino acids and lacked a transmembrane anchor. This ACE mutant is not trafficked to the cell membrane and is directly secreted out of cells; this mechanism apparently accounts for the high serum ACE level seen in affected individuals. A haplotype of the mutant ACE allele was determined based on 12 polymorphisms, which may help to identify other carriers of this mutation. Some but not all carriers of this mutation demonstrated airflow obstruction, and some but not all have hypertension. Conclusions/Significance We have identified a novel Trp1197Stop mutation that results in dramatic elevation of serum ACE. Since blood ACE elevation is often taken as a marker of disease activity (sarcoidosis and Gaucher diseases), it is important for clinicians and medical scientists to be aware of alternative genetic causes of elevated blood ACE that are not apparently linked to disease.
- Published
- 2009
48. Lipid emulsion is superior to vasopressin in a rodent model of resuscitation from toxin-induced cardiac arrest
- Author
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Malek G. Massad, Douglas L. Feinstein, Richard D. Minshall, Carlo Ori, David E. Schwartz, Kemba Kelly, Guy L. Weinberg, Richard Ripper, and Guido Di Gregorio
- Subjects
Male ,Resuscitation ,Vasopressin ,Fat Emulsions, Intravenous ,Epinephrine ,medicine.drug_class ,Vasopressins ,Neuropeptide ,Critical Care and Intensive Care Medicine ,Rats, Sprague-Dawley ,Intensive care ,medicine ,Animals ,Vasoconstrictor Agents ,Asystole ,Local anesthetic ,business.industry ,medicine.disease ,Bupivacaine ,Heart Arrest ,Rats ,Disease Models, Animal ,Anesthesia ,Toxicity ,business ,medicine.drug - Abstract
Lipid emulsion infusion is an emerging antidotal therapy for toxin-induced cardiac arrest. To compare the efficacy of resuscitation from bupivacaine-induced asystole using lipid emulsion infusion vs. vasopressin, alone and with epinephrine.Prospective, randomized, animal study.University research laboratory.Adult, male Sprague-Dawley rats.Instrumented rats were given an intravenous bolus of 20 mg/kg bupivacaine to induce asystole (zero time). Rats (n = 6 for all groups) were ventilated with 100% oxygen, given chest compressions, and randomized to receive 30% lipid emulsion (L, 5 mL/kg bolus then 1.0 mL/kg/min infusion) and vasopressin 0.4 U/kg bolus alone (V) or combined with epinephrine, 30 microg/kg (V + E); boluses (L, V, or V + E) were repeated at 2.5 and 5 minutes for a rate-pressure product (RPP) less than 20% baseline.The arterial blood pressure and electrocardiogram were measured continuously for 10 minutes when blood was drawn for arterial blood gas analysis, lactate content, and central venous oxygen saturation (ScvpO2). Hemodynamic parameters of the L group at 10 minutes (30,615 +/- 4782 mm Hg/min; 151 +/- 19.1 mm Hg; 197 +/- 8.6 min; RPP, systolic blood pressure and heart rate, respectively) exceeded those of the V group (5395 +/- 1310 mm Hg/min; 85.8 +/- 12 mm Hg; 61 +/- 10.8 min) and the V + E group (11,183 +/- 1857 mm Hg/min; 75.5 +/- 12.9 min, RPP and heart rate, respectively; systolic blood pressure was not different). Metrics indicated better tissue perfusion in the L group (7.24 +/- 0.02; 83% +/- 3.5%; 2.2 +/- 0.36 mmol/L; pH, ScvpO2, lactate, respectively) than V (7.13 +/- 0.02; 29.9% +/- 4.4%; 7.5 +/- 0.6 mmol/L) and V + E groups (7.07 +/- 0.03; 26.2% +/- 8.9%; 7.7 +/- 1 mmol/L). Wet-to-dry lung ratios in V (8.3 +/- 0.6) and V + E (8.7 +/- 0.2) were greater than that in the L group (6.2 +/- 05) (mean +/- sem; p0.05 for all shown results).Lipid emulsion in this rat model provides superior hemodynamic and metabolic recovery from bupivacaine-induced cardiac arrest than do vasopressors. Systolic pressure was not a useful metric in the vasopressor groups. Vasopressin was associated with adverse outcomes.
- Published
- 2009
49. Management of the Difficult Airway
- Author
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David E. Schwartz and Jeanine P. Wiener-Kronish
- Subjects
Pulmonary and Respiratory Medicine ,Larynx ,medicine.medical_specialty ,medicine.diagnostic_test ,business.industry ,medicine.medical_treatment ,General surgery ,Laryngoscopy ,Tracheotomy ,medicine.anatomical_structure ,medicine ,Intubation ,Airway management ,Intensive care medicine ,Airway ,business ,Difficult airway ,Difficult intubation - Abstract
For clinicians involved in airway management, a plan of action for dealing with the difficult airway or a failed intubation should be developed well in advance of encountering a patient in whom intubation is not routine. When difficulty is anticipated, the equipment necessary for performing a difficult intubation should be immediately available. It also is prudent to have a surgeon skilled in performing a tracheotomy and a criothyroidotomy stand by. The intubation should be attempted in the awake state, preferably using the fiberoptic bronchoscope. The more challenging situation is when the difficult airway is confronted unexpectedly. After the first failed attempt at laryngoscopy, head position should be checked and the patient ventilated with oxygen by mask. A smaller styletted tube and possibly a different laryngoscope blade should be selected for a second attempt at intubation. The fiberoptic bronchoscope and other equipment for difficult intubation should be obtained. A second attempt should then be made. If this is unsuccessful, the patient should be reoxygenated, and assistance including a skilled anesthesiologist and surgeon should be summoned. On a third attempt, traction to the tongue can be applied by an assistant, a tube changer could be used to enter the larynx, or one of the other special techniques previously described can be used. If this third attempt fails, it may be helpful to have a physician more experienced in airway management attempt intubation after oxygen has been administered to the patient. If all attempts are unsuccessful, then invasive techniques to secure the airway will have to be performed.
- Published
- 1991
50. Epitope mapping of mAbs to denatured human testicular ACE (CD143)
- Author
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Roman Metzger, Sergei M. Danilov, David E. Schwartz, Folker E. Franke, N. Conrad, Edward D. Sturrock, Irina V. Balyasnikova, and Harry Towbin
- Subjects
Gene isoform ,Male ,Glycan ,Glycosylation ,Phage display ,medicine.drug_class ,Immunology ,Molecular Sequence Data ,Cross Reactions ,Peptidyl-Dipeptidase A ,Monoclonal antibody ,Biochemistry ,Epitope ,chemistry.chemical_compound ,Peptide Library ,Testis ,Genetics ,medicine ,Immunology and Allergy ,Animals ,Humans ,Amino Acid Sequence ,biology ,Antibodies, Monoclonal ,General Medicine ,Molecular biology ,Protein Structure, Tertiary ,Blot ,Epitope mapping ,chemistry ,biology.protein ,Sequence Alignment ,Epitope Mapping ,Protein Binding - Abstract
Angiotensin I-converting enzyme (ACE; CD143) has two homologous enzymatically active domains (N and C) and plays a crucial role in blood pressure regulation and vascular remodeling. A wide spectrum of monoclonal antibodies (mAbs) to different epitopes on the N and C domains of human ACE have been used to study different aspects of ACE biology. In this study, we characterized a set of nine mAbs, developed against the C domain of human ACE, which recognize the denatured forms of ACE and thus are suitable for the detection and quantification of somatic ACE (sACE) and testicular ACE (tACE) using Western blotting and immunohistochemistry on paraffin-embedded human tissues. The epitopes for these mAbs were defined using species cross-reactivity, phage display library screening, Western blotting and ACE mutagenesis. Most of the mAbs recognized common/overlapping region(s) on both somatic and testicular forms of human ACE, whereas mAb 4E10 was relatively specific for the testicular isoform and mAb 5B9 mainly recognized the glycan attached to Asn 731. This set of mAbs is useful for identifying even subtle changes in human ACE conformation because of denaturation. These mAbs are also sensitive tools for the detection of human sACE and tACE in biological fluids and tissues using proteomic approaches. Their high reactivity in paraffin-embedded tissues provides opportunities to study changes in the pattern of ACE expression and glycosylation (particularly with mAb 5B9) in different tissues and cells.
- Published
- 2008
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