Risk factor profile of calcific aortic stenosis.

BACKGROUND: Calcific aortic stenosis and coronary artery disease share common risk factors. In some of the previous studies statins have been used to retard the progression of aortic stenosis, but the results were inconsistent. METHODS: One hundred and ten patients of CAS above the age of 40 years have undergone clinical, biochemical and echocardiographic evaluation. Coronary angiograms were done in 66% of them. RESULTS: Male to female ratio was 2:1. Patients of CAS with CAD showed higher prevalence of diabetes, hypertension, dyslipidemia, smoking and family history of CAD. Prevalence of obesity and bicuspid aortic valve by echocardiogram was high in those without CAD. CONCLUSIONS: On comparison of prevalence of risk factor in those with and without associated CAD, there was higher prevalence of diabetes (65% vs 30%), hypertension (52% vs 43%), dyslipidemia (69% vs 52%), smoking (24% vs 18%) and family history of CAD (34% vs 16%) in those with associated CAD. The incidence of obesity was higher in those without CAD (20% vs 30%). The difference observed in diabetes alone was found to be statistically significant.

Combination therapy of albumin-bound Paclitaxel and Carboplatin as first line therapy in a patient with ovarian cancer.

Background. Ovarian cancer is the ninth most common cancer among women and causes more deaths than any other type of female reproductive cancer. Albumin-bound paclitaxel is known to increase intratumoral concentration of the paclitaxel by a receptor-mediated transport process across the endothelial cell wall, thereby breaching the blood/tumor interface. We present below three cases in which nab-paclitaxel based chemotherapy has been used in different settings for patients with ovarian cancer. Case Presentation. In the first case nab-paclitaxel was used along with carboplatin in adjuvant setting, in the second case, nab-paclitaxel was used along with carboplatin and bevacizumab as second line chemotherapy in a relapsed ovarian cancer case, and the third case delineates the use of nab-paclitaxel along with cisplatin as third line chemotherapy. Conclusion. In all the three scenarios, patients tolerated the chemotherapy well, as well as responding well to nab-paclitaxel based chemotherapy. The patients are currently on long-term follow-up and have been having an uneventful postchemotherapy.

Immune responses to T-cell epitopes of SARS CoV-N protein are enhanced by N immunization with a chimera of lysosome-associated membrane protein.

In our previous study by Gupta et al, dominant T-cell epitopes of SARS CoV-N(N) protein were predicted by software. The spectrum of interferon (IFN)-gamma responses of Balb/c mice immunized against two different forms of SARS CoV-N plasmid was then analyzed. A cluster of dominant T-cell epitopes of SARS CoV-N protein was found in the N-terminus (amino acids 76-114). On the basis of this study, four different plasmids were constructed: (i) DNA encoding the unmodified N (p-N) or N(70-122) (p-N(70-122)) as an endogenous cytoplasmic protein or (ii) DNA encoding a lysosome-associated membrane protein (LAMP) chimera with N (p-LAMP/N) or N(70-122) (p-LAMP/N(70-122)). The immune responses of mice to these four constructs were evaluated. The results showed marked differences in the responses of the immunized mice. A single priming immunization with the p-LAMP/N construct was sufficient to elicit an antibody response. Enzyme-linked immunospot (ELISpot) assay indicated that p-LAMP/N(70-122) and p-LAMP/N plasmids both elicited a greater IFN-gamma response than p-N. p-N and p-N(70-122) constructs induced low or undetectable levels of cytokine secretion. We also found that the p-LAMP/N(70-122) construct promoted a long-lasting T-cell memory response without an additional boost 6 months after three immunizations. These findings show that DNA vaccines, even epitope-based DNA vaccines using LAMP as chimera, can elicit both humoral and cellular immune responses.

Long QT syndrome in children with congenital deafness.

The Jervell and Lange Nielson syndrome(JLN) is an infrequent form of long QT syndrome (LQTS) in which prolonged QT interval and congenital deafness exist together. We attempted to identify patients with LQTS among 127 children (age 1.2 to 10 years) with congenital hearing loss. The corrected QT interval was measured from 12 lead electrocardiogram(ECG) , using Bazettes and Friedricia formulae.The QT interval was considered prolonged when it exceeded the upper limit of 440ms and 450ms, respectively. Ten children with congenital deafness had a corrected QT interval longer than 440ms. Although these children did not meet the definite criteria according to Schwartz parameters, all the 10 children could be defined as having intermediate probability of LQTS according to revised criteria. We advise that children with congenital deafness be screened for long QT syndrome.

Left ventricular non compaction a tertiary care centre experience.

AIM: To analyse the clinical profile of consecutive cases of Left Ventricular Non Compaction (LVNC), a condition characterized by excessive and prominent Left Ventricular (LV) trabeculations which may be associated with LV systolic dysfunction. METHODS: Twenty six consecutive cases from January 2003 to December 2008 with echocardiographic evidence of hypertrabeculation of LV were evaluated by clinical examination, electrocardiographic (ECG) and echocardiographic features. Diagnosis was based on 3 published definitions. RESULTS: Out of 26 cases of LVNC (18 Males: 8 Females) aged between 1 day and 63 years, isolated LVNC was seen in 16 cases and rest of the cases were associated with congenital heart disease (CHD), Rheumatic Heart Disease (RHD) and Coronary Artery Disease (CAD). All patients were previously undiagnosed cases of LVNC. Left ventricular ejection Fraction ranged from 20-60% in these cases. CONCLUSIONS: This study demonstrates the increased detection of patients fulfilling echocardiographic criteria of LVNC and its association with other disorders. It also shows that milder phenotypes exist and the disease is detected incidentally in some cases.

Conservation and variability of dengue virus proteins: implications for vaccine design.

BACKGROUND: Genetic variation and rapid evolution are hallmarks of RNA viruses, the result of high mutation rates in RNA replication and selection of mutants that enhance viral adaptation, including the escape from host immune responses. Variability is uneven across the genome because mutations resulting in a deleterious effect on viral fitness are restricted. RNA viruses are thus marked by protein sites permissive to multiple mutations and sites critical to viral structure-function that are evolutionarily robust and highly conserved. Identification and characterization of the historical dynamics of the conserved sites have relevance to multiple applications, including potential targets for diagnosis, and prophylactic and therapeutic purposes. METHODOLOGY/PRINCIPAL FINDINGS: We describe a large-scale identification and analysis of evolutionarily highly conserved amino acid sequences of the entire dengue virus (DENV) proteome, with a focus on sequences of 9 amino acids or more, and thus immune-relevant as potential T-cell determinants. DENV protein sequence data were collected from the NCBI Entrez protein database in 2005 (9,512 sequences) and again in 2007 (12,404 sequences). Forty-four (44) sequences (pan-DENV sequences), mainly those of nonstructural proteins and representing approximately 15% of the DENV polyprotein length, were identical in 80% or more of all recorded DENV sequences. Of these 44 sequences, 34 ( approximately 77%) were present in >or=95% of sequences of each DENV type, and 27 ( approximately 61%) were conserved in other Flaviviruses. The frequencies of variants of the pan-DENV sequences were low (0 to approximately 5%), as compared to variant frequencies of approximately 60 to approximately 85% in the non pan-DENV sequence regions. We further showed that the majority of the conserved sequences were immunologically relevant: 34 contained numerous predicted human leukocyte antigen (HLA) supertype-restricted peptide sequences, and 26 contained T-cell determinants identified by studies with HLA-transgenic mice and/or reported to be immunogenic in humans. CONCLUSIONS/SIGNIFICANCE: Forty-four (44) pan-DENV sequences of at least 9 amino acids were highly conserved and identical in 80% or more of all recorded DENV sequences, and the majority were found to be immune-relevant by their correspondence to known or putative HLA-restricted T-cell determinants. The conservation of these sequences through the entire recorded DENV genetic history supports their possible value for diagnosis, prophylactic and/or therapeutic applications. The combination of bioinformatics and experimental approaches applied herein provides a framework for large-scale and systematic analysis of conserved and variable sequences of other pathogens, in particular, for rapidly mutating viruses, such as influenza A virus and HIV.

Efficacy and safety of tenecteplase in Indian patients with st-segment elevation myocardial infarction.

OBJECTIVE: To assess the efficacy and safety of tenecteplase in Indian patients with ST-segment elevation MI (STEMI). METHODS: Cardiologists/physicians who had used tenecteplase for management of STEMI, recorded safety and efficacy parameters from consecutively treated patients. Tenecteplase was administered as per the prescribing information. Adjunctive therapy which included clopidogrel and UFH/LMWH was administered as routinely practiced and indicated by guidelines. RESULTS: Five hundred and seven patients (male = 415, females = 92; mean age = 58.28 +/- 12.23 yrs; weight (kg) = 70.12 +/- 11.06) with STEMI were treated with weight-adjusted tenecteplase within median chest pain to drug interval of 120 minutes. Resolution of chest pain within median interval of 45 minutes occurred in 436 patients with median duration required for > or = 50% resolution of ST segment of 75 minutes. Clinically successful thrombolysis was reported in 80.67% patients. Five patients suffered intra-cranial hemorrhage (ICH), of which 3 patients had received Gp IIb/IIIa inhibitors. Incidence of intra-cranial hemorrhage attributable to tenecteplase was 0.39% (2 out of 507 patients). Incidence of myocardial re-infarction was 2.96% (15 out of 507 patients). There were 12 deaths (2.36%). CONCLUSION , This data shows that tenecteplase is safe and effective in Indian patients with STEMI and conforms to the international ASSENT-2 trial data.

A systematic bioinformatics approach for selection of epitope-based vaccine targets.

Epitope-based vaccines provide a new strategy for prophylactic and therapeutic application of pathogen-specific immunity. A critical requirement of this strategy is the identification and selection of T-cell epitopes that act as vaccine targets. This study describes current methodologies for the selection process, with dengue virus as a model system. A combination of publicly available bioinformatics algorithms and computational tools are used to screen and select antigen sequences as potential T-cell epitopes of supertype human leukocyte antigen (HLA) alleles. The selected sequences are tested for biological function by their activation of T-cells of HLA transgenic mice and of pathogen infected subjects. This approach provides an experimental basis for the design of pathogen specific, T-cell epitope-based vaccines that are targeted to majority of the genetic variants of the pathogen, and are effective for a broad range of differences in human leukocyte antigens among the global human population.

Large-scale analysis of antigenic diversity of T-cell epitopes in dengue virus.

BACKGROUND: Antigenic diversity in dengue virus strains has been studied, but large-scale and detailed systematic analyses have not been reported. In this study, we report a bioinformatics method for analyzing viral antigenic diversity in the context of T-cell mediated immune responses. We applied this method to study the relationship between short-peptide antigenic diversity and protein sequence diversity of dengue virus. We also studied the effects of sequence determinants on viral antigenic diversity. Short peptides, principally 9-mers were studied because they represent the predominant length of binding cores of T-cell epitopes, which are important for formulation of vaccines. RESULTS: Our analysis showed that the number of unique protein sequences required to represent complete antigenic diversity of short peptides in dengue virus is significantly smaller than that required to represent complete protein sequence diversity. Short-peptide antigenic diversity shows an asymptotic relationship to the number of unique protein sequences, indicating that for large sequence sets (approximately 200) the addition of new protein sequences has marginal effect to increasing antigenic diversity. A near-linear relationship was observed between the extent of antigenic diversity and the length of protein sequences, suggesting that, for the practical purpose of vaccine development, antigenic diversity of short peptides from dengue virus can be represented by short regions of sequences (approximately <100 aa) within viral antigens that are specific targets of immune responses (such as T-cell epitopes specific to particular human leukocyte antigen alleles). CONCLUSION: This study provides evidence that there are limited numbers of antigenic combinations in protein sequence variants of a viral species and that short regions of the viral protein are sufficient to capture antigenic diversity of T-cell epitopes. The approach described herein has direct application to the analysis of other viruses, in particular those that show high diversity and/or rapid evolution, such as influenza A virus and human immunodeficiency virus (HIV).

Accurate prediction of scorpion toxin functional properties from primary structures.

Scorpion toxins are common experimental tools for studies of biochemical and pharmacological properties of ion channels. The number of functionally annotated scorpion toxins is steadily growing, but the number of identified toxin sequences is increasing at much faster pace. With an estimated 100,000 different variants, bioinformatic analysis of scorpion toxins is becoming a necessary tool for their systematic functional analysis. Here, we report a bioinformatics-driven system involving scorpion toxin structural classification, functional annotation, database technology, sequence comparison, nearest neighbour analysis, and decision rules which produces highly accurate predictions of scorpion toxin functional properties.

Potential effects of tetrodotoxin exposure to human glial cells postulated using microarray approach.

Sodium channels play an important role in many neurological disorders and also in prostate cancer. Tetrodotoxin (TTX), a blocker of voltage-gated sodium channels has been chiefly used as a molecular probe for the study and characterization of these channels. The regulation of gene expression in response for the exposure of TTX to glial cells which are reported to be involved in neurodegenerative process is poorly understood. Therefore, the present study aims to develop a repository of genes and map it on a few pivotal neurodegenerative pathways to speculate the effect of TTX. Using Affymetrix GeneChip (HG-U133A), we have selected a subset of 692 differentially expressed genes, several of which are-cullin 4A (CUL4A), ubiquitin carrier protein (E2-EPF), proteasome (prosome, macropain) subunit, beta type, 8 (large multifunctional protease 7) (PSMB8), protein tyrosine phosphatase type IVA (PTP4A1), intercellular adhesion molecule 1 (ICAM1), prostaglandin-endoperoxide synthase 2 (PTGS2), and caspase 1 (CASP1). These genes, which facilitate some of the neurodegenerative pathways, such as ubiquitin, proteasome, inflammation and kinases, were identified to be up- or down-regulated for the TTX treatment. Thus, the selected genes were further examined on ubiquitin-proteasome mediated inflammatory responses pathway as ample evidence for the role of glial cell-mediated inflammation in the neurodegenerative process are available. In summary, our result provides a basic understanding of the differentially expressed genes along with one of the possible pathway which may have been modulated by the exposure of TTX.

Prediction of class I T-cell epitopes: evidence of presence of immunological hot spots inside antigens.

MOTIVATION: Processing and presentation of major histocompatibility complex class I antigens to cytotoxic T-lymphocytes is crucial for immune surveillance against intracellular bacteria, parasites, viruses and tumors. Identification of antigenic regions on pathogen proteins will play a pivotal role in designer vaccine immunotherapy. We have developed a system that not only identifies high binding T-cell antigenic epitopes, but also class I T-cell antigenic clusters termed immunological hot spots. METHODS: MULTIPRED, a computational system for promiscuous prediction of HLA class I binders, uses artificial neural networks (ANN) and hidden Markov models (HMM) as predictive engines. The models were rigorously trained, tested and validated using experimentally identified HLA class I T-cell epitopes from human melanoma related proteins and human papillomavirus proteins E6 and E7. We have developed a scoring scheme for identification of immunological hot spots for HLA class I molecules, which is the sum of the highest four predictions within a window of 30 amino acids. RESULTS: Our predictions against experimental data from four melanoma-related proteins showed that MULTIPRED ANN and HMM models could predict T-cell epitopes with high accuracy. The analysis of proteins E6 and E7 showed that ANN models appear to be more accurate for prediction of HLA-A3 hot spots and HMM models for HLA-A2 predictions. For illustration of its utility we applied MULTIPRED for prediction of promiscuous T-cell epitopes in all four SARS coronavirus structural proteins. MULTIPRED predicted HLA-A2 and HLA-A3 hot spots in each of these proteins.

Plasma melatonin, pinealocyte morphology, and surface receptors/antigen expression on macrophages/microglia in the pineal gland following a high-altitude exposure.

The present study examined the effects of high-altitude exposure on the pineal gland, the main source of production of melatonin. It was surmised that hypoxia experienced at high altitude, caused by decreased oxygen tension in the ambient air, might lead to some structural alterations in the pineal gland and, hence, affect its melatonin production. Adult Wistar rats were exposed to an altitude of 8,000 m for 2 hr in an altitude chamber and then sacrificed at various time intervals after the exposure. Normal rats kept at ground level were used as controls. Blood samples were collected at various time intervals for measurement of plasma melatonin level, and the pineal glands from both groups were processed for electron microscopy and immunohistochemistry. The plasma melatonin level showed a steady increase following altitude exposure peaking at 7 days and returned to control levels thereafter. Between 1 and 4 days after altitude exposure, the mitochondrial number and lipid droplets in the pinealocytes appeared to be reduced compared with those in control rats. At 7 days, however, the mitochondrial numbers and lipid droplets were noticeably increased. At the same time interval, the expression of complement type 3 receptors and major histocompatibility class II antigens as detected with the antibodies OX-42 and OX-6, respectively, in macrophages/microglia was up-regulated compared with that in the control rats and those killed at earlier times. This was attributed to the increased serum melatonin after the altitude exposure. By 14 and 21 days, the ultrastructure of pinealocytes and immunoreactivity of macrophages/microglia were comparable with those in the control rats. We conclude from this study that an altitude exposure in rats leads to an increase in melatonin production, which returned to control levels with passage of time.

SCORPION, a molecular database of scorpion toxins.

Increasing interest in the studies of toxins and the requirements for better structural and functional annotations have created a need for improved data management in the field of toxins. The molecular database, SCORPION, contains more than 200 entries of fully referenced scorpion toxin data including primary sequences, three-dimensional structures, structural and functional annotations of scorpion toxins along with relevant literature references. SCORPION has a set of search tools that allow users to extract data and perform specific queries. These entries have been compiled from public databases and literature, cleaned of errors and enriched with additional structural and functional information. The grouping of scorpion toxins provides a basis for extending and clarifying the existing structural and functional classifications. The bioinformatics modules in SCORPION facilitate analyses aimed at classification of scorpion toxins and identification of sequence patterns associated with specific structural or functional properties of scorpion toxins. The SCORPION database is accessible via the Internet at sdmc.krdl.org.sg:8080/scorpion.

Functional site of bukatoxin, an alpha-type sodium channel neurotoxin from the Chinese scorpion (Buthus martensi Karsch) venom: probable role of the (52)PDKVP(56) loop.

Alpha-toxins from scorpion venoms prolong the action potential of excitable cells by blocking sodium channel inactivation. We have purified bukatoxin, an alpha-toxin from scorpion (Buthus martensi Karsch) venom, to homogeneity. Bukatoxin produced marked relaxant responses in the carbachol-precontracted rat anococcygeus muscle (ACM), which were mediated through the L-arginine-nitric oxide synthase-nitric oxide pathway, consequent to a neuronal release of nitric oxide. Based on the presence of proline residues in the flanking segments of protein-protein interaction sites, we predicted the site between (52)PP(56) to be the potential interaction site of bukatoxin. A homology model of bukatoxin indicated the presence of this site on the surface. Buka11, a synthetic peptide designed based on this predicted site, produced a concentration-dependent nitric oxide-mediated relaxant response in ACM. Using alanine-substituted peptides, we have shown the importance (53)DKV(55) flanked by proline residues in the functional site of bukatoxin.

Effect of occupation on lipid peroxidation and antioxidants' status in masons.

Effect of occupation on haematological factors, lipid peroxidation and antioxidants' status was studied in masons and compared with normal subjects. Red blood corpuscles (RBC), haemoglobin (Hb), Vitamin C, Vitamin E, beta-carotene levels and glutathione peroxidase (GSHPx), superoxide dismutase (SOD) and catalase (CAT) activities decreased. Thiobarbituric acid reacting substances (TBARS) level increased. Occupational exposure to cement increased lipid peroxidation but decreased antioxidants' levels in masons. Increased lipid peroxidation seems to be responsible for the reduction in RBC and Hb.