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Aim: To conduct a study on the effect of random setup errors inpatient for dose delivery in Intensity Modulated Radiotherapy plans using Octavius 4D phantom. Materials and methods: 11 patients with cancer of H&N were selected for this study. An IMRT plan was created for each patient. The IMRT quality assurance plans were transferred to Mosaiq workstation in a linear accelerator. These plans were delivered at the reference treatment position. Subsequently, the QA plans were delivered on the Octavius 4D phantom after introducing errors in various translational and rotational directions. The setup inaccuracies introduced varied from 1 mm to 5 mm along X, Y. These setup uncertainties were then introduced along X and Y direction simultaneously in equal measures. Similarly, IMRT plans were delivered also after introducing roll and yaw rotation of 1, 2 and 3 degrees in phantom. The deviation of gamma indices at all these positions was analyzed with respect to the reference setup position. Results: The percentage of points passing the gamma acceptance criterion decrease as we increase the setup error. The change is found to be very insignificant with setup error up to 2 mm along X, Y or XY direction. Similarly, the rotational error of up to 3 degrees is found to be acceptable. Conclusions: Small setup (< 2 mm) correction in patients may not adversely affect the dose delivery. But an error of similar magnitude in 2 directions simultaneously has a much greater impact on IMRT dose delivery.

Late Na+ current (INaL) contributes to action potential (AP) duration and Ca2+ handling in cardiac cells. Augmented INaL was implicated in delayed repolarization and impaired Ca2+ handling in heart failure (HF). We tested if Na+ channel (Nav) neuronal isoforms contribute to INaL and Ca2+ cycling defects in HF in 17 dogs in which HF was achieved via sequential coronary artery embolizations. Six normal dogs served as control. Transient Na+ current (INaT) and INaL in left ventricular cardiomyocytes (VCMs) were recorded by patch clamp while Ca2+ dynamics was monitored using Fluo-4. Virally delivered short interfering RNA (siRNA) ensured Nav1.1 and Nav1.5 post-transcriptional silencing. The expression of six Navs was observed in failing VCMs as follows: Nav1.5 (57.3%) > Nav1.2 (15.3%) > Nav1.1 (11.6%) > Nav2.1 (10.7%) > Nav1.3 (4.6%) > Nav1.6 (0.5%). Failing VCMs showed up-regulation of Nav1.1 expression, but reduction of Nav1.6 mRNA. A similar Nav expression pattern was found in samples from human hearts with ischaemic HF. VCMs with silenced Nav1.5 exhibited residual INaT and INaL (∼30% of control) with rightwardly shifted steady-state activation and inactivation. These currents were tetrodotoxin sensitive but resistant to MTSEA, a specific Nav1.5 blocker. The amplitude of the tetrodotoxin-sensitive INaL was 0.1709 ± 0.0299 pA pF–1 (n = 7 cells) and the decay time constant was τ = 790 ± 76 ms (n = 5). This INaL component was lacking in VCMs with a silenced Nav1.1 gene, indicating that, among neuronal isoforms, Nav1.1 provides the largest contribution to INaL. At –10 mV this contribution is ∼60% of total INaL. Our further experimental and in silico examinations showed that this new Nav1.1 INaL component contributes to Ca2+ accumulation in failing VCMs and modulates AP shape and duration. In conclusion, we have discovered an Nav1.1-originated INaL component in dog heart ventricular cells. This component is physiologically relevant to controlling AP shape and duration, as well as to cell Ca2+ dynamics. Key points Late Na+ current (INaL) contributes to action potential remodelling and Ca2+/Na+ changes in heart failure. The molecular identity of INaL remains unclear. The contributions of different Na+ channel isoforms, apart from the cardiac isoform, remain unknown. We discovered and characterized a substantial contribution of neuronal isoform Nav1.1 to INaL. This new component is physiologically relevant to the control of action potential shape and duration, as well as to cell Ca2+ dynamics, especially in heart failure. Introduction A physiological role of neuronal isoforms of voltage-sensitive Na+ channels (Navs) in heart has been suggested many years ago by Corabeouf (Coraboeuf et al. 1979) based on their result that low concentrations (33 nm) of tetrodotoxin (TTX) significantly shortened action potential (AP) duration recorded in cardiac Purkinje fibres. At this low concentration TTX blocks only so-called ‘TTX-sensitive’ Navs which are neuronal isoforms (Haufe et al. 2005a2005a). Indeed, during the past decade, besides the dominating cardiac isoform main α-subunit, Nav1.5, different transcripts of highly TTX-sensitive neuronal Nav isoforms have been found in mouse (Nav1.1, 1.3, 1.6) and dog (Nav1.1, 1.2, 1.3) heart (Maier et al. 2004; Haufe et al. 2005a2005a,b). These neuronal Navs are responsible for 10% and 20% of the peak transient Na+ current, INaT, in dog myocardial and Purkinje cells, respectively (Haufe et al. 2005b2005b). The contribution of neuronal Navs to the late Na+ current, INaL, has not been studied in cardiac cells, therefore the molecular identity of INaL needs further careful consideration. This problem is especially important in HF where the gene expression profile changes dramatically. Thus an intriguing possibility could be that the differential expression of neuronal Navs can contribute, at least in part, to INaL alterations (augmentation) (Valdivia et al. 2005; Maltsev et al. 2007) and to INaL-related electrophysiological abnormalities observed in HF (for review see Maltsev & Undrovinas, 2008). In the present study we used a combination of molecular and pharmacological approaches, as well as numerical modelling, to test a hypothesis that neuronal Nav isoforms contribute to INaL in a physiologically significant manner in ventricular myocytes (VCMs) isolated from failing adult dog hearts. We performed post-transcriptional silencing of Nav1.1 and Nav1.5 genes by sequence-directed RNA using virally delivered short interfering RNA (siRNA). We found the expression of six Navs in both human heart and adult dog VCMs. Analysis of the expression revealed up-regulation of Nav1.1 and down-regulation of Nav1.6 in failing heart compared to normal heart. We took advantage of the method of culturing adult dog VCMs, established by our group, that preserves INaT and INaL over 5 days, i.e. sufficient time for gene silencing and membrane protein turnover (Maltsev et al. 2008a2008a; Mishra et al. 2011). In VCMs with silenced Nav1.5 we found a substantial residual INaT and INaL. Our biophysical and pharmacological examinations confirmed its neuronal isoform origin. Diastolic Ca2+ accumulation was reduced via blockade of the neuronal INaL component, indicating its physiological importance. Our numerical model simulations also demonstrated the physiological importance of the novel INaL component: the Nav1.1- associated INaL effectively modulates AP shape and duration, as well as intracellular Ca2+ homeostasis.

The emerging paradigm for Na+ current in heart failure (HF) is that its transient component ( INaT) responsible for the action potential (AP) upstroke is decreased, whereas the late component ( INaL) involved in AP plateau is augmented. Here we tested whether Navβ1- and Navβ2-subunits can modulate INaL parameters in normal and failing ventricular cardiomyocytes (VCMs). Chronic HF was produced in nine dogs by multiple sequential coronary artery microembolizations, and six dogs served as a control. INa and APs were measured by the whole cell and perforated patch-clamp in freshly isolated and cultured VCMs, respectively. INaL was augmented with slower decay in HF VCMs compared with normal heart VCMs, and these properties remained unchanged within 5 days of culture. Post-transcriptional silencing SCN1B and SCN2B were achieved by virally delivered short interfering RNA (siRNA) specific to Navβ1 and Navβ2. The delivery and efficiency of siRNA were evaluated by green fluorescent protein expression, by the real-time RT-PCR, and Western blots, respectively. Five days after infection, the levels of mRNA and protein for Navβ1 and Navβ2 were reduced by >80%, but mRNA and protein of Nav1.5, as well as INaT, remained unchanged in HF VCMs. Navβ1-siRNA reduced INaL density and accelerated INaL two-exponential decay, whereas Navβ2-siRNA produced an opposite effect in VCMs from both normal and failing hearts. Physiological importance of the discovered INaL modulation to affect AP shape and duration was illustrated both experimentally and by numerical simulations of a VCM excitation-contraction coupling model. We conclude that in myocytes of normal and failing dog hearts Navβ1 and Navβ2 exhibit oppositely directed modulation of INaL.

Introduction: Variation of doses due to positional uncertainties of applicators based on orthogonal radiograph has been evaluated by several researchers. The present study has analyzed the various possibilities of special alterations of applicator placements in intracavitary brachytherapy (ICBT) and its impact on the dose to target volume, rectum, and bladder. An innovative approach has been suggested to quantify and utilize the special coordinates for reproducibility of applicator based on the pelvic bone landmark. Materials and Methods: A total of 27 fractions of 9 (n = 9) cancer cervix patients treated with external beam radiotherapy followed by ICBT have been evaluated retrospectively. The first fraction of each patient was planned as per the International Commission on Radiation Units and Measurements report 38 guidelines and was considered reference for consecutive fractions regarding dwell positions, dose to target volume, bladder, and rectum points. For each fraction, positioning of applicators regarding their spatial orientations with respect to pelvic bone landmarks and their correlation with dose to bladder and rectum was recorded and analyzed. Results: It was found that mean angulations between (1) the two applicator points with respect to tip of central tandem (α), (2) the two applicator points with junction point situated on the sacrum bone (β) and (3) the angle between the line joining applicator points and a point defined on pelvic bone (γ) is 62.20° ± 5.74°, 37.13° ± 5.64° and 105.51° ± 6.58°, respectively. Bladder dose increased with increment in α but decreased with increase of β and γ. Dose to rectum remained unaffected for γ. Mean distance from couch top to tip of central tandem and two ovoids is, respectively, 11.17 cm and 8.70 cm. Conclusion: Optimal plans even with orthogonal radiographs may be generated by verifying the application based on the parameters mentioned in the present study and computed tomography-based plans could be utilized more effectively instead of doing automatic or manual optimization. Whereever orthogonal radiograph based or template based ICBT practices is performed this study may create a dataset to have an optimal treatment plan even without three-dimensional images.

Background Expression and phosphorylation of the cardiac Na + -Ca 2+ exchanger-1 (NCX-1) are up-regulated in heart failure (HF). We examined the effects of chronic cardiac contractility modulation (CCM) therapy on the expression and phosphorylation of NCX-1 and its regulators GATA-4 and FOG-2 in HF dogs. Methods and Results Studies were performed in LV tissue from 7 CCM-treated HF dogs, 7 untreated HF dogs, and 6 normal (NL) dogs. mRNA expression of NCX-1, GATA-4, and FOG-2 was measured using reverse transcriptase polymerase chain reaction, and protein level was determined by Western blotting. Phosphorylated NCX-1 (P-NCX) was determined using a phosphoprotein enrichment kit. Compared with NL dogs, NCX-1 mRNA and protein expression and GATA-4 mRNA and protein expression increased in untreated HF dogs, whereas FOG-2 expression decreased. Compared with NL dogs, the level of P-NCX-1 normalized to total NCX-1 increased in untreated HF dogs (0.80 ± 0.10 vs 0.37 ± 0.04; P 05). CCM therapy normalized NCX-1 expression, GATA-4, and FOG-2 expression, and the ratio of P-NCX-1 to total NCX-1 (0.62 ± 0.10). Conclusion Chronic monotherapy with CCM restores expression and phosphorylation of NCX-1. These findings are consistent with previous observations of improved LV function and normalized sarcoplasmic reticulum calcium cycling in the left ventricles of HF dogs treated with CCM therapy.

Objectives: β-Blockers are standard therapy for patients with heart failure (HF). This study compared the effects of chronic monotherapy with 2 different β1-selective adrenoceptor blockers, namely atenolol and metoprolol succinate, on left ventricular (LV) function and remodeling in dogs with coronary microembolization-induced HF [LV ejection fraction (EF) 30–40%]. Methods: Twenty HF dogs were randomized to 3 months of therapy with atenolol (50 mg once daily, n = 6), metoprolol succinate (100 mg, once daily, n = 7) or to no therapy (control, n = 7). LV EF and volumes were measured before initiating therapy and after 3 months of therapy. The change (Δ) in EF and volumes between measurements before and after therapy was calculated and compared among study groups. Results: In controls, EF decreased and end-systolic volume increased. Atenolol prevented the decrease in EF and the increase in ESV. In contrast, metoprolol succinate significantly increased EF and decreased end-systolic volume. ΔEF was significantly higher and Δend-systolic volume significantly lower in metoprolol succinate-treated dogs compared to atenolol-treated dogs (EF: 6.0 ± 0.86% vs. 0.8 ± 0.85%, p < 0.05; end-systolic volume: –4.3 ± 0.81 ml vs. –1 ± 0.52 ml, p Conclusions: In HF dogs, chronic therapy with atenolol does not elicit the same LV function and remodeling benefits as those achieved with metoprolol succinate.

Late Na+current ( INaL) is a major component of the action potential plateau in human and canine myocardium. Since INaLis increased in heart failure and ischemia, it represents a novel potential target for cardioprotection. However, the molecular identity of INaLremains unclear. We tested the hypothesis that the cardiac Na+channel isoform (Nav1.5) is a major contributor to INaLin adult dog ventricular cardiomyocytes (VCs). Cultured VCs were exposed to an antisense morpholino-based oligonucleotide (Nav1.5 asOligo) targeting the region around the start codon of Nav1.5 mRNA or a control nonsense oligonucleotide (nsOligo). Densities of both transient Na+current ( INaT) and INaL(both in pA/pF) were monitored by whole cell patch clamp. In HEK293 cells expressing Nav1.5 or Nav1.2, Nav1.5 asOligo specifically silenced functional expression of Nav1.5 (up to 60% of the initial INaT) but not Nav1.2. In both nsOligo-treated controls and untreated VCs, INaTand INaLremained unchanged for up to 5 days. However, both INaTand INaLdecreased exponentially with similar time courses (τ = 46 and 56 h, respectively) after VCs were treated with Nav1.5 asOligo without changes in 1) decay kinetics, 2) steady-state activation and inactivation, and 3) the ratio of INaLto INaT. Four days after exposure to Nav1.5 asOligo, INaTand INaLamounted to 68 ± 6% (mean ± SE; n = 20, P < 0.01) and 60 ± 7% ( n = 11, P < 0.018) of those in VCs treated by nsOligo, respectively. We conclude that in adult dog heart Nav1.5 sodium channels have a “functional half-life” of ∼35 h (0.69τ) and make a major contribution to INaL.

Long-term monotherapy with the aldosterone receptor blocker eplerenone in dogs with HF was previously shown to improve LV systolic and diastolic function. This study examined the effects of long-term monotherapy with the aldosterone receptor blocker eplerenone on mRNA and protein expression of the cytoskeletal proteins titin, tubulin, fibronectin and vimentin, the matrix metalloproteinases (MMPs)-1, -2 and -9, and the tissue inhibitors of MMPs (TIMPs)-1 and -2 in left ventricular (LV) myocardium of dogs with heart failure (HF). HF was produced in 12 dogs by intracoronary microembolizations. Dogs were randomized to 3 months oral therapy with eplerenone (10 mg/kg twice daily, n = 6) or to no therapy at all (HF-control, n = 6). LV tissue from six normal dogs was used for comparison. mRNA expression was measured using reverse-transcriptase polymerase chain reaction (RT-PCR) and protein expression using Western blots. Compared to NL dogs, control dogs showed upregulation of mRNA and protein expression for tubulin, fibronectin, MMP-1, -2 and -9, and down-regulation of mRNA and protein expression for total titin. Normalization of mRNA and protein expression for all these genes was seen after treatment with eplerenone. N2BA/N2B-titin mRNA expression ratio increased significantly in dogs with HF treated with eplerenone. No differences in expression for vimentin, TIMP-1 and -2 were observed among groups. In dogs with HF, long-term eplerenone therapy normalizes mRNA and protein expression of key cytoskeletal proteins and MMPs. Reversal of these molecular maladaptations may partly explain the improvement in LV diastolic function seen after long-term therapy with eplerenone.

Major advances have been made over the past two decades in the pharmacologic treatment of chronic heart failure (HF). Angiotensin-converting enzyme inhibitors, beta-blockers, and aldosterone antagonists have had a substantial impact on reducing mortality and morbidity in patients with HF and low left ventricular ejection fraction. These treatments delayed the progression toward advanced intractable HF but did not arrest progressive worsening of the disease. Patients on optimal medical therapy continued to deteriorate, albeit at a much slower pace, ultimately requiring further intervention. This gave rise to a host of device-based therapies that emerged in recent years to address this unmet need. Device therapies such as cardiac resynchronization, the CorCap cardiac support device (Acorn Cardiovascular, Inc., St. Paul, MN), and the OPTIMIZER System (Impulse Dynamics USA, Inc., Orangeburg, NY) are a few examples. This review addresses the progress made to date in the development and implementation of cardiac contractility modulation (CCM) as a device-based therapy for the treatment of patients with advanced HF. Treatment of patients with HF using CCM electrical signals is at present an investigational form of therapy.

Molecular biomarkers are emerging as the key indices for the management of patients with significant diseases. Motivated by the systematic effort to define the human genome, the creation of rapid analytic technologies for evaluating nucleic acids and proteins has provided the technological “boom” for the development of molecular biomarkers. Collaboration and cooperation between stakeholders involved in biomarker development, application, and regulation may be the most expeditious route toward the translation of laboratory discovery into patient management. In summary, intensive research has originated multiple factors or biomarkers that are likely to be helpful in diagnosis, characterization, and therapy selection of different patients. A thorough understanding of the relevance of each biomarker will be the key to efficiently diagnose a disease and direct the patients towards the drugs more likely to be of benefit based on their particular profile. The papers selected for this special issue represent an excellent panel for addressing the molecular biomarkers as the future tools of medicine. This special issue contains thirteen papers. In the paper entitled “Circulating microRNAs and kallikreins before and after radical prostatectomy: are they really prostate cancer markers?,” M. G. Egidi et al. presented 38 patients with prostate cancer. They suggested that two miRNAs (miR-21 and miR-141) could be involved in post surgical inflammatory processes. Postoperative serum kallikreins showed a significant decrease, highlighting the potential usefulness of kallikreins apart from PSA as potential prostate cancer markers. In the paper entitled “A novel differential predict model based on matrixx-assisted laser ionization time of flight mass spectrometry and serum ferritin for acute graft-versus-host disease,”. C.-Y. Zhang et al. investigated the possibility of pre warning the risk of an acute graft-versus-host disease (aGVHD) before and after allogeneic hematopoietic stem cell transplantation (allo-HSCT) by serum profiling combining with serum ferritinin. Their joint prewarning model could predict the risk of aGVHD, especially severe aGVHD before transplant which provide a reliable method to continuously monitor the condition of patients. In the paper entitled “The use of multidimensional data to identify the molecular biomarker for pancreatic ductal adenocarcinoma,” L. Zhuang et al. presented that they have adopted an integrative approach to simultaneously identify biomarker and generate testable hypothesis from multidimensional omics data. They have found that PER2 expression was highly associated with the survival data, thus representing a novel biomarker for earlier detection of pancreatic ductal adenocarcinoma (PDAC). In the paper entitled “Clinical evaluation and cost-effectiveness analysis of serum tumor markers in lung cancer,” R. Wang et al. showed that combinations of four tumor markers (SCCA, NSE, CEA, and CYFRA21-1) improved the sensitivity for lung cancer and different combination panels had their own usefulness. NSE, CEA, and CYFRA21-1 were the optimal combination panel with highest Youden's index (0.64), higher sensitivity (75.76%), and specificity (88.57%), which can aid in clinical diagnosis of lung cancer. In the paper entitled “Immune parameters in the prognosis and therapy monitoring of cutaneous melanoma patients: experience, role, and limitations,” M. Neagu et al. reported the follow-up for 36 months of the immune parameters of patients diagnosed in stages I–IV, namely, pre- and postsurgery immune circulating peripheral cells and circulating intercommunicating cytokines. In the paper entitled “Comparative gene expression profiling in human cumulus cells according to ovarian gonadotropin treatments,” S. Assou et al. provided an exclusive study characterizing gene expression profiles in cumulus cells (CCs) of periovulatory follicles from patients undergoing HP-hMG and rFSH gonadotropin treatments during in vitro fertilization cycles. This project has characterized the expression of these genes as biomarkers of in vitro embryo quality. In the paper entitled “Aptamers: novel molecules as diagnostic markers in bacterial and viral infections?,” F. M. Zimbres et al. urged an urgent need to discover novel diagnostic as well as therapeutic tools against infectious agents. They viewed that the systematic evolution of ligands by exponential enrichment (SELEX) represents a powerful technology to target selective pathogenic factors as well as entire bacteria or viruses. SELEX uses a large combinatorial oligonucleic acid library (DNA or RNA) which is processed by a high-flux in vitro screen of iterative cycles. In the paper entitled “Distribution of ABO blood group and major cardiovascular risk factors with coronary heart disease,” S. Biswas et al. viewed that the AB blood group decreases the risk of CHD in healthy controls; it might be due to the higher concentration of high density lipoprotein cholesterol (HDL-c), while the O blood group increases the risk of CHD due to lower HDL-c levels in Bengali population of eastern part of India. In the paper entitled “Immunomodulatory effect of continuous veno-venous hemofiltration during sepsis: preliminary data,” G. Servillo et al. reported that severe sepsis and septic shock are the primary causes of multiple organ dysfunction syndrome (MODS), which is the most frequent cause of death in intensive care unit patients. Many pro- and anti-inflammatory mediators, such as interleukin-6 (IL-6), play a key role in septic syndrome. Continuous renal replacement therapy (CRRT) removes in a nonselective way pro- and anti-inflammatory mediators. The authors investigate the effects of continuous venovenous hemofiltration (CVVH) as immunomodulatory treatment of sepsis in a prospective clinical study. In the paper entitled “Acetylcholinesterase as biomarker in environmental and occupational medicine: new insights and future perspectives,” M. G. Lionetto et al. viewed that Acetylcholinesterase (AChE) is a key enzyme in the nervous system (NS), since it terminates nerve impulses by catalyzing the hydrolysis of acetylcholine. As a specific molecular target of organophosphate and carbamate pesticides, AChE activity and inhibition are a human biological marker of pesticide poisoning. Thus, it is used to study the effects of the exposure to organophosphate and carbamate pesticides on NS in occupational and environmental medicine. This paper reviews and discusses the recent findings about AChE, including its sensitivity to other pollutants and expression of different splice variants. These insights open new perspectives for the use of this biomarker in environmental and occupational human health monitoring. In the paper entitled “Polyisoprenylated methylated protein methyl esterase is both sensitive to curcumin and overexpressed in colorectal cancer: implications for chemoprevention and treatment,” F. Amissah et al. discussed polyisoprenylated methylated protein methyl esterase (PMPMEase) which cocatalyzes the polyisoprenylation pathway required to process various monomeric G proteins. Mutation of these G proteins is considered to be responsible for 50% of colorectal cancers. This interesting finding suggests that elevated PMPMEase activity and its overexpression can be one of the candidate markers for early diagnosis of colorectal cancer. Susceptibility of this enzyme to curcumin also suggests that PMPMEase can be a potential candidate for targeted anticancer therapy. In the paper, entitled “Emerging therapeutic biomarkers in endometrial cancer,” P. Dong et al. reviewed the current status of molecular therapies tested in clinical trials and mainly discussed the potential therapeutic candidates that are possibly used to develop more effective and specific therapies against endometrial cancer progression and metastasis. In the paper entitled “Mouse prostate epithelial luminal cells lineages originate in the basal layer where the primitive stem/early progenitor cells reside: implications for identifying prostate cancer stem cells” J. Zhou et al. have developed an in vivo cell fate tracing mouse model and an in vivo slow-cycling cell label mouse model to provide further insight into this question. Through genetic manipulation in the animals, their findings indicate that the basal cell lineage can produce more differentiated luminal cells; the putative mouse prostate stem cells (which are slow-cycling and responsible for tissue maintenance) likely reside in the basal layer. Though the selected topics and papers are not an exhaustive representation of the entire area of molecular biomarkers and tools of medicine, yet they represent the rich and many-faceted knowledge that we have the privilege of sharing with the readers.

The Zika virus (ZIKV) is an arbovirus, meaning that it is insect vector-borne disease, most commonly transmitted through Aedes mosquitoes. ZIKV was first identified in Uganda in 1947 in monkeys through a network that monitored yellow fever. It was later identified in humans. ZIKV is endemic to parts of Africa and Asia, but over the past months, a large number of locally acquired cases have been discovered in Brazil. The number of cases and the locations of the outbreak qualify ZIKV as a rapidly growing epidemic threat. The ZIKV causes microcephaly, small heads and often damaged brains, which may not have developed properly during pregnancy or may have stopped growing in the first years of life. These children may experience a range of problems, like developmental delays, intellectual deficits or hearing loss. Until recently, Zika was not considered a major threat because its symptoms are relatively mild. There is no widely available test for Zika infection. Infection with Zika virus may be suspected based on symptoms and recent history of travel. A diagnosis of Zika virus infection can only be confirmed through laboratory tests on blood or other body fluids, such as urine, saliva or semen. Protection against mosquito bites is a key measure to prevent Zika virus infection. You can submit your Manuscripts at: https://symbiosisonlinepublishing.com/submitManuscript.php

Type 1 protein phosphatase (PP1) is a negative regulator of cardiac function. However, studies on the status and regulation of sarcoplasmic reticulum (SR)-associated PP1 activity in failing hearts are limited. We studied PP1 activity and protein and mRNA expression of the catalytic subunit of PP1 (PP1C) and protein levels of PP1-specific inhibitors [inhibitor 1 (Inh-1) and inhibitor 2 (Inh-2)] in the left ventricular (LV) myocardium of 6 dogs with heart failure (HF; LV ejection fraction, 23 ± 2%) and 6 normal dogs. In failing LV tissue, PP1 activity values (expressed as pmol32P · min–1· mg of noncollagen protein–1) in the homogenate, crude membranes, cytosol, and purified SR were increased by 52, 54, 55, and 72%, respectively. Trypsin treatment released PP1 but not type 2A protein phosphatase from the SR. In the supernatant of trypsin-treated SR, PP1 activity was ∼24% higher in failing hearts than in normal control hearts. A similar increase in protein expression of PP1C was observed in the nontrypsinized SR. Heat-denatured phosphorylated SR inhibited PP1 activity by 30%, which suggests the presence of Inh-1 or -2 or both in the SR. With the use of a specific antibody, both Inh-1 and -2 proteins were found in the SR; the former was decreased by 56% in the failing SR, whereas the latter did not change. These results suggest that protein phosphatase activity bound to the SR is increased and is predominantly type 1. Increased SR-associated PP1 activity in failing hearts appears to be due partly to increased expression of PP1C and partly to reduced levels of Inh-1 but not Inh-2 protein. Thus inhibition of PP1 activity in the SR appears to be a potential therapeutic target for improving LV function in failing hearts, because it may lead to increased SR Ca2+uptake, which is impaired in failing hearts.

Passive mechanical containment of failing left ventricle (LV) with the Acorn Cardiac Support Device (CSD) was shown to prevent progressive LV dilation in dogs with heart failure (HF) and increase ejection fraction. To examine possible mechanisms for improved LV function with the CSD, we examined the effect of CSD therapy on the expression of cardiac stretch response proteins, myocyte hypertrophy, sarcoplasmic reticulum Ca 2+ -ATPase activity and uptake, and mRNA gene expression for myosin heavy chain (MHC) isoforms. HF was produced in 12 dogs by intracoronary microembolization. Six dogs were implanted with the CSD and 6 served as concurrent controls. LV tissue from 6 normal dogs was used for comparison. Compared with normal dogs, untreated HF dogs showed reduced cardiomyocyte contraction and relaxation, upregulation of stretch response proteins (p21ras, c-fos, and p38 α/β mitogen-activated protein kinase), increased myocyte hypertrophy, reduced SERCA2a activity with unchanged affinity for calcium, reduced proportion of mRNA gene expression for α-MHC, and increased proportion of β-MHC. Therapy with the CSD was associated with improved cardiomyocyte contraction and relaxation, downregulation of stretch response proteins, attenuation of cardiomyocyte hypertrophy, increased affinity of the pump for calcium, and restoration of α- and β-MHC isoforms ratio. The results suggest that preventing LV dilation and stretch with the CSD promotes downregulation of stretch response proteins, attenuates myocyte hypertrophy and improves SR calcium cycling. These data offer possible mechanisms for improvement of LV function after CSD therapy.

Cardiac sarcoplasmic reticulum (SR) sequesters Ca(2+) and plays a crucial role in the regulation of intracellular Ca(2+). Its functional properties are central to the excitation-contraction cycle of cardiac muscle. In this study, we hypothesized that alterations in SR function occur during the development of left ventricular (LV) hypertrophy. LV hypertrophy was produced in Lewis rats by the one-kidney, one-clip (1K1C) procedure. LV tissues were obtained from 1K1C rats 1 week (mild, N=7), 4 weeks (moderate, N=7), and 8 weeks (severe, N=7) post-surgery and from the corresponding age-matched, sham-operated controls (N=7 at each stage). In all of these rats, the ratio of LV weight (g) to body weight (kg) was determined and considered as an index for LV hypertrophy. In addition, the ratio of lung weight (g) to body weight (kg) was determined and considered as an index for pulmonary congestion and heart failure. In each LV specimen, SR Ca(2+)-uptake and tissue Ca(2+)-ATPase (CAA) level were determined. In 1K1C rats, LV hypertrophy increased by 21, 40, and 90% at 1, 4, and 8 weeks post-surgery, respectively, compared to the age-matched, sham-operated rats, whereas pulmonary congestion did not occur at 1 and 4 weeks but increased significantly by about 21% at 8 weeks. Further, both SR Ca(2+)-uptake and immunodetectable CAA level did not change at 1 week, increased (54%) to the same extent at 4 weeks, and decreased (42%) by approximately the same extent at 8 weeks in 1K1C rats compared to the age-matched, sham-operated rats. In summary, as LV hypertrophy evolved, Ca(2+)-uptake and CAA expression did not change in the early, increased in the moderate, and then declined in the later stages of hypertrophy development. The increase in Ca(2+)-uptake and CAA expression suggests, at the cellular level, a compensatory response to LV hypertrophy, while the decline at later stages indicates the transition to heart failure.

September is sickle cell awareness month which dictated us to write an overview. The term Sickle Cell Disease (SCD) describes a group of inherited red blood cell (erythrocytes) disorders. People with SCD have abnormal haemoglobin, called haemoglobin S or sickle haemoglobin, in their red blood cells. SCD is a serious blood disorder that affects the red blood cells, which use a protein called haemoglobin to transport oxygen from the lungs to the rest of the body [1]. Mutations in the haemoglobin gene cause sickle cell disease. SCD is the most common genetic disorder in the United States with higher frequency in African Americans when compared to other populations. About one in 500 African American babies are born with sickle cell anemia and one in 12 African American people carry the gene for this trait or disease. About 100,000 Americans are thought to be living with SCD, and every year another 1,000 babies are born with the disease. Approximately 3 million Americans including 10% of African American population carry one gene for SCD (i.e. sickle cell trait). SCD has several recognized forms including sickle cell anaemia, sickle cell haemoglobin C disease and sickle cell thalassemia disease. The red blood cells of patients with SCD don’t live as long as healthy red blood cells. So people with this disorder often have low red blood cell counts (anemia), which is why this disease is commonly referred to as sickle cell anaemia. Affected patients characteristically are asymptomatic until approximately 4 to 6 months of age. The median age at death is approximately 42 years for men and 48 years for women [2,3].

Protein phosphatase 1 (PP1) is well known for their role in signal transduction and protein function. Together with its inhibitors 1 and 2, it regulates wide variety of cellular activities. We have amplified catalytic subunit of PP1 (PP1c) and its inhibitors 1 (I-1) and 2 (I-2) from dog cardiac mRNA by rt-PCR and cloned into bacterial expression vector pCRT7. Cloned genes were expressed in E. coli BL21 (DE3) pLysS by IPTG induction. Functional positive clones were identified by western blotting of bacterial lysate and polymerase chain reaction. Double transformed bacterial cells were also generated by transforming PP1c clone with either I-1 or I-2. Activity of PP1 was analyzed in whole bacterial lysate by measuring dephosphorylation of phos b. Activities of inhibitors were analyzed by their capability to inhibit PP1 from dephosphorylation of phos b. Our findings indicate differential regulation of PP1 by I-1 and I-2. Both expressed recombinant inhibitors 1 and 2 have high potency for inhibition of PP1 activity. Interestingly, I-2 co-expression caused increase in PP1c expression but no change in expression was observed when co-expressed with I-1.

Objective: The objective of this study was to investigate the potential pleiotropic effects of rosuvastatin (RSV) in the left ventricular (LV) myocardium of dogs with moderate heart failure (HF). Methods: LV tissue was obtained from HF dogs randomized to 3 months therapy with low-dose RSV (n = 7), high-dose RSV (n = 7) or to no therapy (Control, n = 7) and from 7 normal dogs. mRNA and protein expression of prohypertrophic mediator NGFI-A binding protein 1 (Nab1), phosphatase and tensin homolog (PTEN), phosphoinositide-3 kinase (PI3K) and mammalian target of rapamycin (mTOR) were measured, as well as that of proinflammatory cytokine interleukin-6 (IL-6), bone marrow-derived stem cell markers cKit and Sca1, vascular endothelial and fibroblast growth factors (VEGF and FGF) and nitric oxide synthase (NOS) isoforms. Results: Nab1, PTEN, PI3K, mTOR and IL-6 increased in the controls. High-dose RSV reduced expression of Nab1, PTEN, PI3K, mTOR and IL-6 to near-normal levels. cKit and Sca1 significantly increased, while VEGF and FGF decreased in the controls compared to the normal dogs. RSV therapy further increased expression of cKit, Sca1, VEGF and FGF. High-dose RSV normalized the expression of NOS isoforms. Conclusion: These pleiotropic effects of RSV may account, in part, for the observed beneficial effect of RSV on LV function and structural remodeling.

Smoking is a most common way of tobacco consumption that provides a pleasurable effect by modulating neurotransmitters in the brain. African Americans (AA) have shown higher susceptibility to nicotine consumption and highest rate of mortality due to cancer. In this study we have examined the levels of 6 neurotransmitters in AA smokers and compared them with nonsmokers of same population. We observed decrease in plasma levels of glutamate and increase in serotonin, epinephrine and dopamine. The level of gamma amino butyric acid (GABA) and norepinephrine was not changed significantly. The results, in part, explain the basis of higher nicotine susceptibility in AAs and will be helpful to develop population specific strategies for smoking cessation.

Background: In dogs with heart failure (HF), chronic therapy with cardiac contractility modulation (CCM) electrical signals delivered to left ventricular (LV) muscle during the absolute refractory period improves LV function. This study examined the effects of CCM therapy on the expression of calcium (Ca2+)-binding proteins (CBPs) in dogs with HF. Methods and Results: Studies were performed in LV tissue from seven CCM-treated HF dogs, seven untreated HF dogs, and six normal (NL) dogs. mRNA expression of S100A1, sorcin, presenillin-1 (PS1), PS2, histidine-rich Ca2+-binding protein (HRC), and 18S ribosomal RNA (18S), a housekeeping gene, was measured using RT-PCR. Protein levels of CBPs and calsequestrin (CSQ) were determined by Western blotting. No difference was observed in the expression of 18S and CSQ among study groups. Compared with NL, the expression of S100A1, sorcin, and HRC was decreased, whereas the expression of PS2 was increased in untreated HF dogs. CCM therapy normalized the expression of S100A1, sorcin, and PS2 but not of HRC. No change was seen in the expression of PS1 among study groups. Conclusion: CCM therapy restores LV expression of S100A1, PS2, and sorcin. Normalization of CBPs may partly contribute to improved LV function in HF following CCM therapy.

In anemic patients with heart failure (HF), erythropoietin-type drugs can elicit clinical improvement. This study examined the effects of chronic monotherapy with darbepoetin-alpha (DARB) on left ventricular (LV) function and remodeling in nonanemic dogs with advanced HF. HF [LV ejection fraction (EF) approximately 25%] was produced in 14 dogs by intracoronary microembolizations. Dogs were randomized to once a week subcutaneous injection of DARB (1.0 microg/kg, n=7) or to no therapy (HF, n=7). All procedures were performed during cardiac catheterization under general anesthesia and under sterile conditions. LV end-diastolic volume (EDV), end-systolic volume (ESV), and EF were measured before the initiation of therapy and at the end of 3 mo of therapy. mRNA and protein expression of caspase-3, hypoxia inducible factor-1alpha, and the bone marrow-derived stem cell marker c-Kit were determined in LV tissue. In HF dogs, EDV and ESV increased and EF decreased after 3 mo of followup. Treatment with DARB prevented the increase in EDV, decreased ESV, and increased EF. DARB therapy also normalized the expression of HIF-1alpha and active caspase-3 and enhanced the expression of c-Kit. We conclude that chronic monotherapy with DARB prevents progressive LV dysfunction and dilation in nonanemic dogs with advanced HF. These results suggest that DARB elicits beneficial effects in HF that are independent of the presence of anemia.

Acute intravenous infusion of ranolazine (Ran), an anti-ischemic/antiangina drug, was previously shown to improve left ventricular (LV) ejection fraction (EF) without a concomitant increase in myocardial oxygen consumption in dogs with chronic heart failure (HF). This study examined the effects of treatment with Ran alone and in combination with metoprolol (Met) or enalapril (Ena) on LV function and remodeling in dogs with HF. Dogs ( n = 28) with microembolization-induced HF were randomized to 3 mo oral treatment with Ran alone [375 mg twice daily (bid); n = 7], Ran (375 mg bid) in combination with Met tartrate (25 mg bid; n = 7), Ran (375 mg bid) in combination with Ena (10 mg bid; n = 7), or placebo (PL; Ran vehicle bid; n = 7). Ventriculographic measurements of LV end-diastolic volume (EDV) and end-systolic volume (ESV) and LV EF were obtained before treatment and after 3 mo of treatment. In PL-treated dogs, EDV and ESV increased significantly. Ran alone prevented the increase in EDV and ESV seen in the PL group and significantly increased EF, albeit modestly, from 35 ± 1% to 37 ± 2%. When combined with either Ena or Met, Ran prevented the increase in EDV, significantly decreased ESV, and markedly increased EF compared with those of PL. EF increased from 35 ± 1% to 40 ± 1% with Ran + Ena and from 34 ± 1% to 41 ± 1% with Ran + Met. Ran alone or in combination with Ena or Met was also associated with beneficial effects at the cellular level on histomorphometric parameters such as hypertrophy, fibrosis, and capillary density as well as the expression for pathological hypertrophy and Ca2+ cycling genes. In conclusion, Ran prevented progressive LV dysfunction and global and cellular myocardial remodeling, and Ran in combination with Ena or Met improved LV function beyond that observed with Ran alone.

Objectives: Therapy with cardiac contractility modulation (CCM) electrical signals delivered to left ventricular (LV) muscle during the absolute refractory period improves LV systolic and diastolic function in dogs with heart failure (HF). This study examined the effects of CCM therapy on mRNA and protein expression of cytoskeletal proteins, matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) in the LV myocardium of dogs with HF. Methods: HF was produced in 14 dogs by coronary microembolizations. Dogs were randomized to 3 months of CCM therapy (n = 7) or to sham-operated controls (n = 7). LV tissue from 6 normal (NL) dogs was used for comparison. mRNA expression was measured using reverse-transcriptase polymerase chain reaction and protein expression using Western blots. Results: Compared with NL dogs, controls showed upregulation of mRNA and protein expression of the cytoskeletal proteins tubulin and fibronectin and MMP-1, MMP-2 and MMP-9, and downregulation of the cytoskeletal protein titin. Normalized expression of all these genes and proteins was seen after CCM therapy. No differences in expression of TIMP-1 and TIMP-2 were observed among groups. Conclusions: CCM therapy normalizes expression of key cytoskeletal proteins and MMPs and may partly explain the improvement in LV function seen in HF following CCM therapy.

Population-based variations in frequency and distribution of dystrophin gene deletions have been recognized in Duchenne/Becker (DMD/BMD) muscular dystrophy patients. In the present study, DNA samples from 121 unrelated DMD/BMD patients from North India were analyzed for deletional studies with multiplex PCR and Southern hybridization. A total of 88 (73%) patients showed intragenic deletions in the dystrophin gene. The observed proportion of gene deletions is relatively high, particularly compared with that of Asian counterparts. However, the distribution of breakpoints across the gene does not show significant variations.

Progressive left ventricular (LV) dilation is a characteristic feature of heart failure and is associated with poor long-term prognosis. One of the characteristic changes that occur in the failing heart is a change in gene expression wherein fetal genes that were turned off shortly after birth are re-activated in heart failure and may play a key role in the progressive worsening of the heart failure state. This review discusses reversal of maladaptive gene expression in dogs with chronic heart failure treated long-term with the Acorn Cardiac Support Device (CSD); a passive mechanical device designed to prevent progressive LV enlargement and to restore normal LV chamber geometry. Studies in our laboratories have shown that, in addition to preventing LV dilation and improving LV ejection fraction, long-term therapy with the CSD reverses the maladaptive gene program observed in LV myocardium of dogs with heart failure. Therapy with the CSD was associated with up-regulated mRNA expression for alpha-myosin heavy chain and down-regulated mRNA expression of A- and B- type natriuretic peptides, cytokines and favorably modulated cytoskeletal proteins. These findings provide an explanation for mechanisms that may be partly responsible for the improvement in LV systolic and diastolic function seen in dogs with heart failure after long-term CSD therapy.

Abnormal Ca(2+)-homeostasis is a hall-marked characteristic of the failing heart. In the normal myocardium, the sarcoplasmic reticulum (SR) is a principal organelle that controls intracellular Ca(2+) concentration during the cardiac cycle. The SR consists of longitudinal and terminal cisternea regions. The former contains the Ca(2+)-ATPase pump or SERCA-2a whose function is to transport cytosolic Ca(2+) into the lumen of the SR during diastole and whose activity is regulated by reversible phosphorylation of the endogenously SR-bound phospholamban (PLB). The SR's terminal cisternea region contains ryanodine-sensitive Ca(2+)-release channels (RR), the activity of which is regulated by direct and indirect reversible phosphorylation. These channels release the SR-stored Ca(2+) during contraction. We have shown that in left ventricular (LV) myocardium from dogs with coronary microembolization-induced heart failure, ability of the SR to sequester and release Ca(2+) during the cardiac cycles is impaired. This abnormality was associated with reduced expression (protein and mRNA) levels of Ca(2+)-ATPase, PLB, and reduced PLB phosphorylation. Long-term therapy with the Acorn Cardiac Support Device (CSD) is associated with restoration of the ability of the SR to sequester Ca(2+). This improvement in SR function following chronic CSD therapy was due primarily to increased affinity of the SERCA-2a for calcium. The later was associated with (1) increased phosphorylation of PLB at serine 16 and threonine 17, (2) unchanged protein expression of PLB and (3) unchanged protein expression of SERCA-2a in LV myocardium of CSD-treated dogs compared to controls. This review summarizes our current understanding of the role of the CSD in modulating SR calcium cycling in an experimental canine model of chronic heart failure produced by multiple sequential intracoronary microembolizations.

In failing hearts, although protein phosphatase type 1 (PP1) activity has increased, information about the regulation and status of PP1 inhibitor-1 (INH-1) and inhibitor-2 (INH-2) is limited. In this study, we examined activity and protein expression of PP1, INH-1 and INH-2 and phosphorylation of sarcoplasmic reticulum (SR) phospholamban (PLB), a substrate of PP1 and modulator of SR Ca2+-ATPase activity, in failing and non-failing hearts. These studies were performed in LV myocardium of seven rats with chronic renal hypertension produced by Goldblatt’s one-kidney, one-clip procedure and seven age-matched sham-operated normal controls (CTR). Eight weeks after surgery, LV ejection fraction, LV hypertrophy, and pulmonary congestion were determined in all rats. PP1 activity (nmol 32P/min/mg non-collagen protein) was assessed in LV homogenates using 32P-labeled phosphorylase a as substrate. INH-1 and INH-2 activity was determined in the immunoprecipitate of LV homogenates and expressed as percentage inhibitory activity. Using a specific antibody, LV tissue levels of PP1C and calsequestrin (CSQ), a SR calcium binding protein, which is not altered in failing hearts, were also determined. Further, total and phosphorylated PLB, INH-1 and INH-2 protein levels were determined in the LV homogenate and phosphoprotein-enriched fraction, respectively. The band density of each protein was quantified in densitometric units and normalized to CSQ. Results: rats with chronic renal hypertension exhibited significantly reduced LV ejection fraction and increased LV hypertrophy and pulmonary congestion, characteristics of chronic heart failure (CHF). We found that compared to CTR, (1) both INH-1 (10.2 ± 2 versus 57.5 ± 1; p

Background Passive mechanical containment of the failing left ventricle with the Acorn Cardiac Support Device (CSD) was shown to prevent progressive left ventricular dilation in dogs with heart failure and increase left ventricular ejection fraction. To examine possible mechanisms for improved cardiac function with a CSD, we examined the effect of CSD therapy on the mRNA gene expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), matrix metalloproteinases (MMP) 2 and 9, and tissue inhibitors of metalloproteinases (TIMP) 1 and 2. Methods Heart failure was produced in 12 dogs by multiple sequential intracoronary microembolizations. Six dogs were implanted with the CSD and 6 served as concurrent controls. Left ventricular tissue from 6 normal dogs was used for comparison. Results Compared with normal dogs, dogs with untreated heart failure showed downregulation of mRNA expression for VEGF and bFGF, whereas upregulation of mRNA expression for MMP-2 and MMP-9 was observed. Normalization of mRNA expression for all these genes was seen after treatment with the CSD. Conclusions This study shows that preventing left ventricular dilation and myocardial stretch with the CSD promotes normalization of growth factor and MMP gene expression. These results suggest that modulation of gene activity may, in part, contribute to the improvement of left ventricular function observed with CSD therapy.

Alteration of intracellular Ca(2+) homeostasis in failing cardiomyocytes is associated with changes in regulatory proteins located in the sarcoplasmic reticulum (SR) and sarcolemma, which participate in Ca(2+) fluxes across the membrane during the cardiac cycle. These regulatory proteins include Ca(2+)-ATPase (SERCA 2A), phospholamban (PLB), ryanodine-sensitive Ca(2+) release channels (RR), and the sarcolemmal Na(+)-Ca(2+) exchanger (NCX). Although their status is known in failed myocardium, it is poorly understood during the progression of heart failure (HF), particularly in large animals. We studied the left ventricular (LV) myocardium of six dogs with moderate HF and six with severe HF produced by multiple intracoronary microembolizations, compared with six normal dogs (NL). Oxalate-dependent SR Ca(2+) uptake and expression of SERCA 2A, PLB, phosphorylated PLB at serine 16 (PLB-Ser) and threonine 17 (PLB-Thr), RR, and NCX were determined. Percent LV ejection fraction declined by 47% compared with NL (34.1% +/- 1% vs 64% +/- 2%) in dogs with moderate HF (HF-2W) 2 weeks after the last embolization and by 42% (20.5% +/- 1% vs 34.1% +/- 1%) in dogs with severe HF (HF-4M) at 4 months compared with HF-2W. Left ventricular pressure during isovolumic contraction (+dP/dt, mmHg/s) and relaxation (-dP/dt, mmHg/s) was significantly reduced in severe compared with moderate HF. Oxalate-dependent SR Ca(2+) uptake (nmol (45)Ca(2+) accumulated/min per milligram noncollagen protein) declined by 25% (21.3 +/- 1 vs 28.5 +/- 2) in HF-2W and 49% in HF-4M. Protein expression of SERCA 2A and PLB decreased by 67% and 35%, respectively, in HF-2W compared with NL, whereas SERCA 2A expression increased by 167% and PLB decreased by 40% in HF-4M compared with HF-2W. However, SERCA 2A protein was still significantly lower in HF-4M compared with NL. PLB-Ser and PLB-Thr increased significantly in HF-2W but decreased in HF-4M compared with NL. Similar changes in mRNA encoding PLB and SERCA 2A were observed in dogs with moderate and severe HF. The RR protein level declined in dogs with moderate and severe HF, whereas NCX protein did not change with moderate HF but increased with sever HF. These results suggest that the regulatory proteins responsible for Ca(2+) uptake, Ca(2+) release, and Na(+)-Ca(2+) exchange are critically associated with the deterioration of LV function during the progression of HF.

Studies on the status of multifunctional Ca2+-calmodulin (CaM)-dependent protein kinase-II (CaMKII) in failing hearts are limited and controversial. The study was performed in the left ventricular (LV) myocardium of six dogs with heart failure (HF) (LV ejection fraction, 23 ± 2%) and six normal (NL) dogs. In the LV homogenate, CaMKII activity and its protein level were determined by using the CaMKII peptide and antibody, respectively. Furthermore, the protein level of CaM and phosphorylated phospholamban (PLB) at threonine-17 (PLB-Thr17) and serine-16 (PLB-Ser16) were also determined in the LV homogenate using a specific antibody. In addition, the level of zinc, which inhibits protein kinase A activity, was determined in the LV tissue by inductively coupled plasma mass spectrometry. CaMKII activity and phosphorylated PLB-Thr17 and PLB-Ser16 levels, but not CaM and Zn levels, were significantly reduced in the LV homogenate of dogs with HF compared with NL dogs. These results suggest that CaMKII activity is reduced in the failing LV myocardium, and this abnormality is associated with reduced protein expression level of the enzyme but not due to changes in CaM and zinc levels. In conclusion, reduced CaMKII activity and phosphorylated PLB level may be partly responsible for impaired sarcoplasmic reticulum function in HF.

Background: Human failing heart due to idiopathic dilated cardiomyopathy is associated with decreased sarcoplasmic reticulum Ca 2+ uptake. However, it is unknown as to which mechanism leads to this abnormality. Methods: Immunodetectable sarcoplasmic reticulum proteins (phospholamban [PLB], phosphorylated PLB at serine-16 or threonine-17, calsequestrin and Ca 2+ -ATPase levels), the activities of Ca 2+ -calmodulin-dependent protein kinase and protein phosphatase and Ca 2+ uptake at varying Ca 2+ concentrations were determined in left ventricular specimens from the same 7 failing hearts (ejection fraction 20 ± 2%) due to idiopathic dilated cardiomyopathy and 5 non-failing explanted control donor hearts. Results: In failing hearts, compared with control donors, decreased maximal velocity and affinity of Ca 2+ uptake for Ca 2+ were found to be associated with reduced expression levels of Ca 2+ -adenosine triphosphatase (ATPase), PLB and phosphorylated PLB at serine-16, but not of calsequestrin and phosphorylated PLB at threonine-17. In contrast, protein phosphatase activity increased significantly and the activity and protein expression level of the δ isoform of Ca 2+ -calmodulin-dependent protein kinase remained unchanged in failing hearts compared with control donors. Conclusions: The impaired maximal velocity of sarcoplasmic reticulum Ca 2+ uptake may be due in part to reduced protein expression level of Ca 2+ -ATPase, whereas the reduced affinity may be due in part to the reduced ratio of Ca 2+ -ATPase to PLB and reduced PLB phosphorylation at serine-16 in failing hearts. The latter abnormality may be due in part to increased protein phosphatase activity. These results suggest that selective enhancement of Ca 2+ uptake into the sarcoplasmic reticulum by pharmaceutical agents, or by molecular tools that inhibit phosphatase activity, would be a valuable therapeutic approach for treating, or at least retarding, the process of heart failure.

The purpose of this study was to examine the sarcoplasmic reticulum (SR) Ca(2+)-uptake and the expression of phospholamban (PLB) and Ca(2+)-ATPase (CAA) in left ventricular (LV) and right ventricular (RV) myocardium of 6 normal (NL) dogs and 6 dogs with chronic heart failure (HF). In addition, gene expression of PLB and CAA was also examined in LV myocardium of NL and HF dogs. HF (LV ejection fraction 23+/-2%) was produced by multiple sequential intracoronary microembolizations. Oxalate-dependent Ca(2+)-uptake was measured in isolated membrane vesicles. Using specific dog myocardial monoclonal antibody, the expression of CAA, PLB and calsequestrin (CSQ) were measured in sodium dodecyl sulfate extract prepared from LV and RV tissue. Steady-state mRNA levels were determined by Northern hybridization using specific cDNA clones of PLB, CAA, CSQ, and glyceraldehyde-3-phosphate dehydrogenase (GADPH), a house keeping gene. SR Ca(2+)-uptake of NL and HF dogs increased with increasing Ca(2+)concentrations and reached a plateau at 3 microm in both LV and RV. Total capacity (134+/-9 v 224+/-10 nmol(45)Ca/mg protein/10 min, P