Search

Abstract Background Very little is known of the regulation of the function of human osteoclasts, largely due to the virtual impossibility of obtaining human osteoclasts ex vivo. It has recently become possible to generate human osteoclasts in vitro, by incubation of peripheral blood mononuclear cells (PBMCs) in macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-κB ligand (RANKL). However, the assays at present available do not distinguish clearly between the distinct effects of agents on differentiation and function. Materials and methods We developed a novel assay for resorptive function of human osteoclasts that minimizes inter-assay variability by using each culture as its own baseline, and that minimizes the confounding effects of agents on differentiation by assessing resorptive function over a short test period. In this assay, the development of resorptive activity is monitored in sample cultures. When resorption is underway, bone resorption (measured as the release of the C-terminal telopeptide degradation product of type I collagen (CTX-I) into the supernatant) is compared before vs after incubation for 1–24 h in test agent. Results Using this assay, we found that changes in bone resorption could be detected using substantially fewer cultures per variable. Moreover, we could detect effects of agents on resorption within 1 h of addition, a time sufficiently short that a change in release is likely to reflect an effect on function rather than on differentiation. Conclusion The assay makes it possible to distinguish the effects of agents on osteoclastic function, independent of their effects on differentiation.

Purpose: This phase 1 study (NCT03440437) evaluated the safety, tolerability, pharmacokinetics (PK), and activity of FS118, a bispecific antibody-targeting LAG-3 and PD-L1, in patients with advanced cancer resistant to anti-PD-(L)1 therapy., Patients and Methods: Patients with solid tumors, refractory to anti-PD-(L)1-based therapy, received intravenous FS118 weekly with an accelerated dose titration design (800 μg to 0.3 mg/kg) followed by 3+3 ascending dose expansion (1 to 20 mg/kg). Primary objectives were safety, tolerability, and PK. Additional endpoints included antitumor activity, immunogenicity, and pharmacodynamics., Results: Forty-three patients with a median of three prior regimens in the locally advanced/metastatic setting, including at least one anti-PD-(L)1 regimen, received FS118 monotherapy. FS118 was well tolerated, with no serious adverse events relating to FS118 reported. No dose-limiting toxicities (DLT) were observed, and an MTD was not reached. The recommended phase 2 dose of FS118 was established as 10 mg/kg weekly. The terminal half-life was 3.9 days. Immunogenicity was transient. Pharmacodynamic activity was prolonged throughout dosing as demonstrated by sustained elevation of soluble LAG-3 and increased peripheral effector cells. The overall disease control rate (DCR) was 46.5%; this disease control was observed as stable disease, except for one late partial response. Disease control of 54.8% was observed in patients receiving 1 mg/kg or greater who had acquired resistance to PD-(L)1-targeted therapy., Conclusions: FS118 was well tolerated with no DLTs observed up to and including 20 mg/kg QW. Further studies are warranted to determine clinical benefit in patients who have become refractory to anti-PD-(L)1 therapy. See related commentary by Karapetyan and Luke, p. 835., (©2022 American Association for Cancer Research.)

Galectin-3 (gal-3) is a fibrosis marker and may play a role in fibrosis of the left atrium (LA). Left atrial wall fibrosis may influence the transition from paroxysmal to non-paroxysmal atrial fibrillation (AF). In this study, we assessed the correlation of gal-3 concentration with the main echocardio-graphic parameters evaluating dimensions, volume, compliance, and left atrial contractility during AF and after successful electrical cardioversion (DCCV). The study included 63 patients with left atrial enlargement who qualified for DCCV due to persistent AF. The procedure recovered sinus rhythm in 43 (68.3%) patients. The concentration of gal-3 was negatively correlated with the echocardiographic parameters of LA including dimensions (LA length pre, rho = -0.38; p = 0.003), volume (LAV pre, rho = -0.39; p = 0.003), compliance (LASr mean post, rho = -0.33) and contractility (pLASRct mean post, rho = -0.33; p = 0.038). Negative correlations of gal-3 concentration were also observed in relation to the volume and contractility of the left ventricle. The concentration of gal-3 significantly negatively correlates with the size, systolic function, and compliance of the LA wall in patients with persistent AF. Determining gal-3 concentration in patients with persistent AF may help in the assessment of remodeling of the LA wall.

Aims: Soluble suppression of tumourigenicity 2 (sST2) and galectin-3 are involved in cardiac fibrosis, inflammation, and remodelling. However, the place of sST2 and galectin-3 in predicting the outcomes of electrical cardioversion of atrial fibrillation (AF) is uncertain. We evaluated whether these biomarkers could predict sinus rhythm (SR) maintenance after cardioversion of persistent AF in patients with normal left ventricular systolic function., Methods and Results: The study included 80 patients with persistent AF, who underwent cardioversion from February 2016 to August 2018. The blood concentrations of sST-2 and galectin-3 were measured with ELISA and the ASPECT-PLUS assays. Clinical and electrocardiographic follow-up was performed at months 1, 6, and 12. Patients who maintained SR at 12 months had significantly lower concentrations of sST2, measured by ELISA and ASPECT-PLUS assays, than the remaining patients (16.9 ± 9.8 vs. 28 ± 22.9 ng/mL; P < 0.001; 28.7 ± 13.4 vs. 40 ± 25.1 ng/mL; P = 0.003); the concentration of galectin-3 did not differ between these patients. Multivariable logistic regression showed that log-transformed sST2 ELISA was a significant predictor of SR maintenance at 12 months [odds ratio 0.14; 95% confidence interval (CI) 0.03-0.58; P = 0.006]. On receiver-operating characteristic curve analysis, the areas under the curve for the concentration of sST2 was 0.752 (95% CI 0.634-0.870; P < 0.001). The concentrations of sST2 measured with the two assays were strongly correlated (rho = 0.8; CI 95% 0.7-0.87; P = 0.001)., Conclusion: Soluble suppression of tumourigenicity 2, but not galectin-3, can be used to predict SR maintenance after cardioversion of AF in patients with normal left ventricular systolic function. The measurements of sST2 concentrations with the rapid lateral flow and enzyme-linked immunoassays were consistent., (Published on behalf of the European Society of Cardiology. All rights reserved. © The Author(s) 2020. For permissions, please email: journals.permissions@oup.com.)

Background: It was confirmed that during the inflammatory process development, granulocytes are among the main groups of cells responsible for the course of acute pancreatitis. One of these substances produced by them are extracellular matrix enzymesmetalloproteinases. In the presented study, we undertook an attempt to investigate whether they may be used as an instrument to predict the course of acute pancreatitis in previously healthy patients., Methods: The study included 72 patients with the first-time episode of acute pancreatitis. The 2012 Atlanta classification was used in order to divide them into 3 groups. The patients were assessed according to the most popular multifactor scoring systems and single laboratory markers. The levels of metalloproteinases 2 and 9 were determined by the ELISA method. The diagnostic value of the commonly applied scoring systems and single diagnostic markers was compared with the value of matrix metalloproteinases levels., Results: A mild form of AP developed in 42 patients, a moderate form in 16, and severe in 14. All multifactor prognostic systems have high specificity and rather low sensitivity. Single laboratory markers have higher sensitivity but lower specificity than multifactor tools. The determination of the level of MMP-2 shows specificity of 98.3%, while MMP-9-100%., Conclusion: The determination of a single laboratory marker, which is the level of metalloproteinase-2 or metalloproteinase-9, is characterized by sensitivity and specificity comparable to that of multifactor prognostic scoring systems., Competing Interests: The authors declare that they have no conflict of interest, (© Acta Gastro-Enterologica Belgica.)

A range of enantiomerically pure protected side-chain-fluorinated amino acids has been prepared (13 examples) by treatment of protected amino acids containing unsaturated side chains with a combination of Fe(III)/NaBH 4 and Selectfluor. The modification of the conditions by replacement of Selectfluor with NaN 3 allowed the preparation of side-chain azido-substituted amino acids (five examples), which upon catalytic hydrogenation gave the corresponding amines, isolated as lactams (four examples). Radical hydration of the unsaturated side chains leading to side-chain-hydroxylated protected amino acids has also been demonstrated., Competing Interests: The authors declare no competing financial interest.

Objectives: The term metabolic syndrome (MetS) refers to the coexistence of interlinked risk factors of metabolic origin, contributing to the development of arteriosclerotic cardiovascular diseases as well as type 2 diabetes and their cardiovascular complications. The aim of the study is the assessment of the prevalence of MetS among paramedics of the Świętokrzyskie Center of Emergency Medical Services, depending on the adopted diagnostic criteria., Material and Methods: The study included 140 paramedics (2 women and 138 men), aged 23–60 years old (median = 43 years, average age = 41.5 years, standard deviation = 10.8 years). The age distribution of the subjects was significantly different from the normal distribution (p-value < 0.0001). The oldest age group (50 years old and above) was overrepresented by nearly a half compared to the youngest group (up to 29 years old). Metabolic syndrome was defined on the basis of the International Diabetes Federation (IDF) criteria from 2005 and IDF in agreement with the American Heart Association/National Heart, Lung and Blood Institute (AHA/NHLBI) from 2009., Results: According to the IDF/2005 criteria, in which the necessary condition is the diagnosis of central obesity, MetS was recorded in 26.4% of the subjects (37 people). This is statistically significantly less often than the IDF/AHA/NHLBI/2009 definition of p = 0.001 – 35%. The frequency of the MetS occurrence was statistically significantly related to the age of the subjects and the age groups., Conclusions: The prevalence of the MetS in the subject group is evaluated to be significant. The prevalence of MetS is diversified by the applied diagnostic criteria with age being the factor increasing its frequency. The most common factor influencing the prevalence of MetS is blood pressure and waist circumference., (This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.)

Introduction: The mounting evidence that osteoclasts play an important role in osteoarthritis (OA) pain lead us to investigate the effects of L-006235, a potent and selective inhibitor of cathepsin K, on pain behaviour and joint pathology in a model of OA pain., Methods: Effects of preventative (30 and 100 mg/kg) and therapeutic (100 mg/kg) oral dosing with L-006235 on weight-bearing asymmetry, hind paw withdrawal thresholds, cartilage and bone pathology, synovial inflammation, and drug exposure were studied in the monosodium iodoacetate rat model of OA pain., Results: Preventative L-006235 inhibited weight-bearing asymmetry from day 14, with this measure nearly abolished by the higher dose. In the same treatment setting, L-006235 prevented lowering of hind paw withdrawal thresholds from day 7. Exposure to L-006235 in plasma was higher for the 100 mg/kg dose, compared with 30 mg/kg. Therapeutic dosing with L-006235 from day 14 significantly inhibited weight-bearing asymmetry, compared with monosodium iodoacetate vehicle rats. Regression analysis revealed a significant interaction coefficient of the effects of L-006235 on weight-bearing asymmetry and synovitis score, but not for cartilage damage nor osteophyte scores., Conclusion: Our novel finding that cathepsin K inhibition is analgesic in a clinically relevant model of OA pain provides new evidence for the therapeutic potential of this target., Competing Interests: Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article.

Background: Cathepsin K is an attractive therapeutic target for diseases in which bone resorption is excessive such as osteoporosis and osteoarthritis (OA). The current paper characterized the pharmacological profile of the potent and selective cathepsin K inhibitor, MIV-711, in vitro and in cynomolgus monkeys, and assessed translation to human based on a single dose clinical study in man., Methods: The potency and selectivity of MIV-711 were assessed in vitro using recombinant enzyme assays and differentiated human osteoclasts. MIV-711 was administered to healthy cynomolgus monkeys (3-30 µmol/kg, p.o.). Plasma levels of MIV-711 and the bone resorption biomarker CTX-I were measured after single dose experiments, and urine levels of CTX-I, NTX-I and CTX-II biomarkers were measured after repeat dose experiments. The safety, pharmacokinetics and pharmacodynamics (serum CTX-I) of MIV-711 were assessed in human healthy subjects after single ascending doses from 20 to 600 mg., Results: MIV-711 was a potent inhibitor of human cathepsin K (K i : 0.98 nmol/L) with > 1300-fold selectivity towards other human cathepsins. MIV-711 inhibited human osteoclast-mediated bone resorption with an IC 50 value of 43 nmol/L. Single oral doses of MIV-711 to monkeys reduced plasma levels of CTX-I in a dose-dependent fashion by up to 57% at trough. The effect on CTX-I was linearly correlated to the plasma exposure of MIV-711, while the efficacy duration outlasted plasma exposure. Repeat oral dosing with MIV-711 also reduced urinary levels of the bone resorption biomarkers CTX-I (by 93%) and NTX-I (by 71%) and the cartilage degradation biomarker CTX-II (by 71%). MIV-711 was safe and well-tolerated when given as single ascending doses to healthy subjects. MIV-711 reduced serum CTX-I levels in a dose-dependent manner by up to 79% at trough. The relationship between MIV-711 exposure and effects on these biomarkers in humans was virtually identical when compared to the corresponding monkey data., Conclusions: MIV-711 is a potent and selective cathepsin K inhibitor with dose-dependent effects on biomarkers of bone and cartilage degradation in monkey and human. Taken together, MIV-711 shows promise for the treatment of bone and cartilage related disorders in humans, such as OA. Trial Registration EudraCT number 2011-003024-12, registered on June 22nd 2011.

Background: MIV-711 is a highly potent and selective cathepsin K inhibitor. The current article summarizes the therapeutic effects of MIV-711 on joint pathology in rabbits subjected to anterior cruciate ligament transection (ACLT), and the prophylactic effects on joint pathology in dogs subjected to partial medial meniscectomy, two surgical models of osteoarthritis (OA)., Methods: Starting 1 week after surgery, rabbits were dosed daily via oral gavage with either MIV-711 or vehicle (n = 7/group) for 7 weeks. The four treatment groups were: (1) sham + vehicle; (2) ACLT + vehicle; (3) ACLT + MIV-711, 30 µmol/kg and (4) ACLT + MIV-711, 100 µmol/kg. Subchondral bone and articular cartilage structures were assessed by µCT, histomorphometry, and scoring. Dogs subjected to partial medial meniscectomy received either MIV-711 (30 µmol/kg) or vehicle (n = 15/group) via oral gavage once daily, starting 1 day before meniscectomy, for 28 days. Cartilage degradation was assessed at the macroscopic and microscopic levels. The exposures of MIV-711 were assessed in both studies and biomarkers reflecting bone resorption (HP-1 in rabbits, CTX-I in dogs) and cartilage degradation (CTX-II) were measured., Results: In ACLT rabbits, MIV-711 decreased HP-1 levels by up to 72% (p < 0.001) and CTX-II levels by up to 74% (p < 0.001) compared to ACLT vehicle controls. ACLT surgery significantly reduced the total thickness of the subchondral bone plate and reduced trabecular bone volume in the femur and tibia. These effects were reversed by MIV-711. ACLT resulted in cartilage thickening, which was attenuated by MIV-711. MIV-711 did not affect osteophyte formation or Mankin scores. In dogs, MIV-711 reduced CTX-I and CTX-II levels by 86% (p < 0.001) and 80% (p < 0.001), respectively. Synovial CTX-II levels were reduced by 55-57% (p < 0.001) compared to baseline. MIV-711-treated animals had 25-37% lower macroscopic scores in the femur condyles and 13-33% lower macroscopic scores in the tibial plateaus., Conclusions: MIV-711 prevents subchondral bone loss and partially attenuates cartilage pathology in two animal models of OA. These beneficial effects of MIV-711 on joint pathology are observed in conjunction with decreases in bone and cartilage biomarkers that have been shown to be clinically attainable in human. The data support the further development of MIV-711 for the treatment of OA.

In this study, we evaluated pancreatic morphology and function as well as nutritional status and quality of life among patients who experienced severe acute pancreatitis (SAP)., Materials and Methods: We enrolled 99 patients with SAP and 51 with mild acute pancreatitis (MAP). Computed tomography was performed one year following the disease. Endocrine function was evaluated by measuring hemoglobin A1c, insulin, and C peptide levels. Pancreatic exocrine insufficiency (PEI) was diagnosed by the concentration of fecal elastase-1. Nutritional status was assessed according to anthropometric parameters, albumin levels in blood serum, and the total number of lymphocytes. Quality of life was investigated using the Health Survey Questionnaire (SF-36)., Results: PEI was observed in 17.2% of patients after SAP vs. 7.8% of patients after MAP (p>0.05). Endocrine insufficiency was noted in 18.6% of patients after AP vs. 4.3% of patients after MAP (p<0.05). We observed changes in pancreatic morphology in 52.5% of patients after SAP and 9.8% of patients after MAP (p<0.0001). A medium risk of malnutrition was observed in 16.2% of patients after AP vs. 2% of patients after MAP (p=0.01). Patients with SAP described their mental health in more negative terms than patients with MAP (p<0.05)., Conclusions: One year after SAP, patients exhibited changes in pancreatic morphology and carbohydrate metabolism disorders, and exocrine insufficiency occurred with a similar frequency. The majority of quality of life domains did not differ between patient groups., Key Words: Acute pancreatitis, Pancreatic morphology, Pancreatic function.

Background: Thrombocytopenia is a possible side effect of routinely administered medical agents widely used in the management of patients with acute coronary syndromes (ACS). It is usually observed within 24 h after abciximab infusion. Differential diagnosis is challenging and the management controversial., Methods: We present a case of abciximab-induced thrombocytopenia which occurred after a standard treatment., Results: A 57-year-old male was admitted with ST-segment elevation ACS. Coronary angiography revealed an acute occlusion of the diagonal branch by massive thrombus. The patient was administered clopidogrel and acetylsalicylic acid followed by unfractionated heparin and abciximab according to the current guidelines. A rapid progression of thrombocytopenia up to 1 × 10(9)/L was observed. A total of 5 pooled platelet units were transfused and intravenous dexamethasone. Dual antiplatelet therapy was continued., Conclusion: Although specific mechanisms of abciximab-related thrombocytopenia are still unclear and the management is not well established, the patient responded well to the therapy and his recovery was uneventful., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Cathepsin S inhibitors attenuate mechanical allodynia in preclinical neuropathic pain models. The current study evaluated the effects when combining the selective cathepsin S inhibitor MIV-247 with gabapentin or pregabalin in a mouse model of neuropathic pain. Mice were rendered neuropathic by partial sciatic nerve ligation. MIV-247, gabapentin, or pregabalin were administered alone or in combination via oral gavage. Mechanical allodynia was assessed using von Frey hairs. Neurobehavioral side effects were evaluated by assessing beam walking. MIV-247, gabapentin, and pregabalin concentrations in various tissues were measured. Oral administration of MIV-247 (100-200 µmol/kg) dose-dependently attenuated mechanical allodynia by up to approximately 50% reversal when given as a single dose or when given twice daily for 5 days. No behavioral deficits were observed at any dose of MIV-247 tested. Gabapentin (58-350 µmol/kg) and pregabalin (63-377 µmol/kg) also inhibited mechanical allodynia with virtually complete reversal at the highest doses tested. The minimum effective dose of MIV-247 (100 µmol/kg) in combination with the minimum effective dose of pregabalin (75 µmol/kg) or gabapentin (146 µmol/kg) resulted in enhanced antiallodynic efficacy without augmenting side effects. A subeffective dose of MIV-247 (50 µmol/kg) in combination with a subeffective dose of pregabalin (38 µmol/kg) or gabapentin (73 µmol/kg) also resulted in substantial efficacy. Plasma levels of MIV-247, gabapentin, and pregabalin were similar when given in combination as to when given alone. Cathepsin S inhibition with MIV-247 exerts significant antiallodynic efficacy alone, and also enhances the effect of gabapentin and pregabalin without increasing side effects or inducing pharmacokinetic interactions., (Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.)

Introduction: Atrial fibrillation (AF) is the most common arrhythmia and leads to a five-fold increased risk of stroke compared to persons with sinus rhythm. A soluble form of thrombomodulin (sTM) is a recognized marker of endothelial dysfunction and may contribute to the hypercoagulable state in AF. The aim of the study was to evaluate plasma concentration of sTM in persistent AF patients before and after sinus rhythm recovery following direct current cardioversion (CV)., Material and Methods: In 45 effectively anticoagulated consecutive patients, with persistent non-valvular AF, and normal left ventricular function, CV was performed. Blood samples for sTM assessment were collected twice: 24 hours before and 24 hours after CV., Results: In 43 patients sinus rhythm was obtained. The mean plasma sTM level was significantly lower in AF patients compared to the control group with sinus rhythm and without anticoagulation (38.5 ±9.9 ng/ml vs. 44.1 ±9.1 ng/ml, p = 0.04). Plasma sTM levels did not change 24 hours after successful CV (36.7 ±9.5 ng/ml vs. 38.5 ±9.9 ng/ml, p = 0.16)., Conclusions: Plasma sTM concentration was lower in patients with persistent AF and normal left ventricle systolic function than in patients with sinus rhythm, presumably due to chronic oral anticoagulant therapy in the AF group. CV has no impact on sTM plasma level evaluated 24 hours after sinus rhythm restoration.

Background: Persistent atrial fibrillation (AF) leads to electrical, structural and neurohormonal remodelling of the atria, including increased plasma B-type natriuretic peptide (BNP) level., Aim: To assess the clinical value of plasma BNP or NT-proBNP concentrations in patients with persistent AF measured before and after sinus rhythm restoration following direct-current cardioversion., Methods: The study group consisted of 43 patients with persistent AF who underwent successful electrical cardioversion. The mean AF duration was 12.3 weeks. Patients in the study group had no symptoms of heart failure and they had preserved left ventricular systolic function. Blood samples were collected twice: 24 hours before and 24 hours after electrical cardioversion. Logistic regression analysis was used to assess the predictive value of BNP and NT-proBNP levels., Results: Baseline NT-proBNP and BNP levels were increased in patients with persistent AF (290.9 +/- 257.2 pg/mL and 148.4 +/- 111.4 pg/mL, respectively) compared to a matched control group without AF (47.8 +/- 80.6 pg/mL; p = 0.0001 and 74.9 +/- 81.7 pg/mL; p = 0.01). Plasma BNP level decreased 24 hours after cardioversion (from 148.4 +/- 111.4 to 106.4 +/- 74.7 pg/mL; p = 0.0045) whereas NT-proBNP level did not (from 290.9 +/- 257.2 to 262.7 +/- 185.6 pg/mL; NS). During an 18-month follow-up period, 21 (49%) patients remained in sinus rhythm. Neither baseline plasma BNP nor NT-proBNP level predicted sinus rhythm maintenance., Conclusions: NT-proBNP and BNP plasma levels are increased in patients with persistent AF. Conversion to sinus rhythm is associated with a significant decrease in plasma BNP but not NT-proBNP level. Baseline BNP and NT-proBNP levels do not predict long-term sinus rhythm maintenance.

In mice and humans, the effect of genetic deficiency of cathepsin K (catK) is impaired bone resorption, or osteopetrosis. Inhibition of catK is therefore a promising strategy for the treatment of osteoporosis. The enzyme acts in an acid environment. This provides a further potential opportunity: if the inhibitor is basic it is more likely to accumulate in membrane-bound acidic compartments (lysosomotropism), so minimizing off-target effects. However, the resorptive hemivacuole is not membrane-bound, and so might not retain lysosomotropic compounds. We therefore elected to determine whether the osteoclastic resorptive apparatus supports such accumulation. First, we attempted to compare the persistence of a lysosomotropic dye in the hemivacuole versus intracellular vesicles. To our surprise the dye could not be detected in the ruffled border region by confocal microscopy. We found that this could be explained by the tight packing of the folds of the ruffled border, and their close apposition to the bone surface. We also found that the dye persisted similarly in resorbing osteoclasts and macrophages, consistent with the notion that resorbing osteoclasts support lysosomotropism. Next, we compared the ability of basic and non-basic inhibitors of catK to suppress bone resorption by human osteoclasts. We found that basic compounds were considerably more potent than non-basic compounds at suppression of osteoclastic resorption than would be anticipated from their potency as enzyme inhibitors. Also consistent with osteoclastic lysosomotropism, basic inhibitors suppressed resorption for substantially longer than a non-basic inhibitor after washout from cell cultures. Furthermore, selectivity of basic inhibitors for inhibition of catK versus other cathepsins persisted: concentrations that inhibited catK in osteoclasts had no detectable effect on cathepsin S (catS) in a cell-based assay. This data is consistent with accumulation and enrichment of such basic inhibitors in the resorptive apparatus of the osteoclast, allowing for prolonged efficacy at the intended site of action. Our results suggest a major advantage for lysosomotropic compounds as inhibitors of bone resorption by osteoclasts in osteoporosis and other diseases caused by excessive osteoclastic activity., (Copyright (c) 2010 Elsevier Inc. All rights reserved.)

Background: Atrial fibrillation (AF) may result in endocardial endothelium dysfunction. The main objective of the study was to evaluate the plasma concentration of endothelin-1 (ET-1) during persistent AF and after sinus rhythm recovery following direct-current cardioversion and to assess the predictive value of ET-1 in AF patients., Methods: The study group consisted of 43 patients with persistent AF and normal left ventricle systolic function who had undergone successful cardioversion. Blood samples were collected twice: 24 hours before and 24 hours after cardioversion. All patients were also examined in terms of sinus rhythm maintenance on the 30th day after cardioversion., Results: There were no differences in ET-1 plasma concentration between the persistent AF group and the control group (2.6 ± 2.9 fmol/mL vs 2.3 ± 4.5 fmol/mL, NS). Plasma ET-1 levels did not change within 24 hours after successful cardioversion (2.5 ± 2.8 fmol/mL vs 2.6 ± 2.9 fmol/mL, NS). There was no correlation between the baseline plasma levels of ET-1 in patients with persistent AF and sinus rhythm maintenance 30 days after cardioversion., Conclusions: Persistent AF does not affect plasma ET-1 concentration in patients with normal left ventricle systolic function and with no symptoms of heart failure. There are no significant changes in plasma ET-1 level during the 24 hours after cardioversion.

Cathepsin K (EC 3.4.22.38) is expressed by osteoclasts and synovial fibroblasts and its proteolytic activity is hypothesized to play a role in the pathology of rheumatoid arthritis. This study explored the effects of the cathepsin K inhibitor N-(1-{[(Cyanomethyl)amino]carbonyl}cyclohexyl)-4-[2-(4-methylpiperazin-1-yl)-1,3-thiazol-4-yl]benzamide (L-006235) in murine collagen-induced arthritis. L-006235 is a potent inhibitor of recombinant human and murine cathepsin K, enzymes (K(i):0.073 nM and IC(50): 2.4 nM, respectively) and at the cellular level in human osteoclasts (IC(50): 28 nM) with ~1000-fold selectivity against cathepsin S. L-006235 did not result in splenic invariant chain p10 accumulation, a specific marker of cathepsin S inhibition. L-006235 was dosed daily (25 mg/kg, p.o.), either prophylactically (days 0-42) or therapeutically (14 days post onset of disease) to DBA/1J mice subjected to collagen-induced arthritis. Disease severity was scored during the course of the study. Histological evaluation of cartilage and bone degradation together with related biomarkers namely, deoxypyridinoline, cartilage oligomeric matrix protein and C-terminal telopeptide degradation product of type I collagen (CTX-I) were analyzed after the study. After prophylactic or therapeutic administration, L-006235 significantly reduced biomarkers reflecting bone and cartilage degradation. Pathological changes at the histological level were significantly reduced after prophylactic treatment (P<0.01), but not after therapeutic treatment. Prophylactic treatment with L-006235 delayed disease onset (P<0.01) and reduced the disease severity score (P<0.05). Inhibition of cathepsin K activity exerts beneficial effects on collagen-induced arthritis in mice and thus warrants further investigation as a therapeutic intervention in human rheumatoid arthritis.

Background: Postinfarction intraventricular conduction defects lead to asynchronous activation of the myocardium., Hypothesis: The aim of the current study is to evaluate contraction asynchrony in postinfarction patients with intraventricular conduction defects., Methods: A total of 158 patients 6 months postmyocardial infarction and 15 healthy subjects underwent echocardiography to evaluate atrioventricular, interventricular, intraventricular asynchrony, and myocardial performance index (MPI). A subgroup of 126 patients had intraventricular conduction defects in ECG, whereas 32 with normal QRS complex served as controls., Results: All patients postmyocardial infarction showed intraventricular asynchrony and markedly higher MPI. Comparing groups with and without intraventricular conduction defects postmyocardial infarction, those with left bundle branch block (BBB) had significantly higher parameters of all asynchrony types; those with right BBB and left posterior hemiblock (LPH) had significantly higher interventricular asynchrony parameters; those with left anterior hemiblock did not show significant differences in asynchrony parameters as compared with subjects without postinfarction conduction defects., Conclusions: (1) Patients 6 months postmyocardial infarction show intraventricular asynchrony and markedly higher MPI. (2) Postinfarction patients with LBBB have the highest parameters of atrioventricular, interventricular and intraventricular asynchrony as compared with postinfarction patients with other and without conduction defects. (3) In postinfarction patients with RBBB or LPH parameters of interventricular asynchrony are significantly higher as compared with postinfarction patients without intraventricular conduction defects.

Background: Very little is known of the regulation of the function of human osteoclasts, largely due to the virtual impossibility of obtaining human osteoclasts ex vivo. It has recently become possible to generate human osteoclasts in vitro, by incubation of peripheral blood mononuclear cells (PBMCs) in macrophage colony-stimulating factor (M-CSF) and receptor activator of nuclear factor-kappaB ligand (RANKL). However, the assays at present available do not distinguish clearly between the distinct effects of agents on differentiation and function., Materials and Methods: We developed a novel assay for resorptive function of human osteoclasts that minimizes inter-assay variability by using each culture as its own baseline, and that minimizes the confounding effects of agents on differentiation by assessing resorptive function over a short test period. In this assay, the development of resorptive activity is monitored in sample cultures. When resorption is underway, bone resorption (measured as the release of the C-terminal telopeptide degradation product of type I collagen (CTX-I) into the supernatant) is compared before vs after incubation for 1-24 h in test agent., Results: Using this assay, we found that changes in bone resorption could be detected using substantially fewer cultures per variable. Moreover, we could detect effects of agents on resorption within 1 h of addition, a time sufficiently short that a change in release is likely to reflect an effect on function rather than on differentiation., Conclusion: The assay makes it possible to distinguish the effects of agents on osteoclastic function, independent of their effects on differentiation.

Two distinct routes to beta-cycloalkylalanine derivatives have been developed. The first route employs the reaction of the iodoalanine-derived zinc-copper reagent 2 with cycloalk-1-en-3-yl phosphates, and the second uses the palladium-catalysed coupling of the iodoalanine-derived zinc reagent 1 with cycloalkenyl triflates; in each case, catalytic hydrogenation of the unsaturated product leads to the protected beta-cycloalkylalanine. The latter route allows access to a range of cycloalkyl derivatives, with ring sizes of 5-8. beta-(1-Methyl-1-cyclohexyl)alanine may be prepared using reaction of the zinc-copper reagent 2 with 3-methyl-2-cyclohexenyl chloride, followed by hydrogenation. The corresponding cyclopentyl derivative may be prepared by reaction of the same zinc-copper reagent 2 with diethyl geranylphosphate, followed by ring-closing metathesis and hydrogenation.

A scheme combining the preparation of building blocks in solution followed by solid-phase combinatorial chemistry has been developed to side-chain diversify 5-(hydroxymethyl)oxazole scaffold (1) into aryl ethers, thioethers, sulfones, sulfonamides, and carboxamides. Protected heterocyclic scaffolds 2 were linked to the solid phase and N-terminal derivatized using active ester chemistry, providing chemset 4¿1-4,1-4¿. The free side-chain hydroxyl of 4 was smoothly converted to aryl ethers 6 under Mitsunobu conditions, with a broad range of substituted phenols. Alternatively, quantitative conversion of hydroxyl to bromide followed by displacement with alkyl and aryl thiols gave thioethers 8. Thioethers were optionally oxidized to sulfones 9. Bromide displacement by azide, followed by reduction to amine and acylation with a range of carboxylic acids and sulfonyl chlorides gave carboxamides 11 and sulfonamides 13, respectively. Crude purity at typically >90% was observed for each of the five modifications detailed. A series of 20 compounds, exemplifying each modification, was reprepared, purified, and fully characterized.

The diastereoselectivity of the enzymatic hydrolyses of 4-nitrophenyl 6-deoxy-6-methyl-(R)- and (S)-sulfinyl-beta-D-galactopyranoside (1a,b), 4-nitrophenyl 7-deoxy-D- and L-glycero-beta-D-galacto-heptopyranoside (2a,b) and 4-nitrophenyl 6,7-anhydro-D- and L-glycero-beta-D-galacto-heptopyranoside (3a,b) was investigated using a range of crude glycosidase preparations. It was shown that the enzymes display a high degree of discrimination between diastereomers thereby demonstrating the utility of glycosidases for the diastereomeric resolution of unnatural 6-substituted monosaccharide derivatives.

In the present study the lowest p.o. doses of tin affecting heme biosynthesis in rabbits were determined and the protective effect of zinc on these disorders was evaluated. The experiment was performed on female rabbits who received per os single doses of SnCl2 x 2 H2O (10, 100, and 200 mg Sn/kg) and ZnSO4 (50 mg Zn/kg s.c.). The activities of delta-aminolevulinic acid dehydratase (ALA-D) in the whole blood, free erythrocyte propoporhyrins, urine delta-aminolevulinic acid, and coproporphyrins (CP-U) were determined. In animals administered tin at a dose of 100 mg Sn/kg, ALA-D activity decreased by about 80% and two- to threefold increases in the ALA and CP concentrations in urine were observed. A protective effect of zinc with respect to ALA-D activity was noticed in both groups (100 and 200 mg Sn/kg) after combined administration of both metals. Results of an interaction between zinc and tin were also observed to reduce ALA levels in urine, whereas zinc did not protect against an effect of tin on CP excretion.