Subbiah Vivekanandhan

Serial circulating vasopressin levels in children with septic shock.

Background: Septic shock is an important cause of death in pediatric intensive care units. Initial evaluations have shown that vasopressin may have a role in catecholamine refractory shock in adults. It is important to determine whether children with septic shock have deficiency of vasopressin. This will help in defining the role of vasopressin in septic shock. Design: Prospective cohort study. Setting: Pediatric intensive care unit of a tertiary care hospital in north India. Patients: Patients were children with septic shock, and controls were children with sepsis but no shock. Study Design: Vasopressin levels in plasma were determined by enzyme-linked immunosorbent assay for children with septic shock at diagnosis (baseline) and thereafter at 24, 48, and 96 hrs to determine the time trends. The baseline vasopressin values for children with septic shock were compared with those for children without shock. Results: The median (95% confidence interval) vasopressin level at baseline in children with septic shock was 116 (63.3–130.7) pg/mL, and in children with sepsis but no shock it was 106 (61.7–131.77) pg/mL. The median value for survivors was 76 (44.6–130.9) pg/mL, and for nonsurvivors, 118 (81.7–259) pg/mL (p = .16). The serial values also did not show any significant changes; the values at 24 hrs (n = 17), 48 hrs (n = 16), and 96 hrs (n = 15) were 105 (76.1–125.9), 105 (41.4–155.5), and 109.5 (54.9–154.8) pg/mL, respectively. Conclusions: The results of our study suggest that vasopressin levels are elevated in children with septic shock and that serial values up to 96 hrs do not show any decline.

Telomerase activity as an adjunct to high-risk human papillomavirus types 16 and 18 and cytology screening in cervical cancer.

Telomerase is a ribonucleoprotein comprising an RNA template, the telomerase-associated protein and its catalytic subunit, human telomerase reverse transcriptase (hTERT). Telomerase activation is a critical step in cellular immortalisation and development of cancer. Enhanced telomerase activity has been demonstrated in cervical cancer. In the present study telomerase activity and hTERT mRNA expression were evaluated and correlated with the presence of human papillomavirus (HPV) infection and cytological changes in the cervical lesions. Telomerase activity was assayed by telomeric repeat amplification protocol, hTERT mRNA expression by reverse transcriptase polymerase chain reaction and presence of high risk HPV (HR-HPV) infection by polymerase chain reaction. Out of 154 cervical samples of different cytology, 90 (58.44%) were positive for HR-HPV types 16/18, while among 55 normal cervical scrapes, 10 (18.18%) were HPV DNA positive. All 59 invasive cancer samples showed a very high telomerase activity. Among dysplasia, seven (63.6%) mild dysplasia, 18 (100%) of moderate, 20 (100%) of severe dysplasia and 6 (100%) carcinoma in situ (CIS) samples were positive with mild to moderate to high to very high telomerase activity respectively. Seven (12.7%) samples of apparently normal cervical scrapes were weakly positive for telomerase activity. We observed a good correlation (P<0.001) between telomerase activity and HR-HPV 16/18 positivity with a sensitivity of 88.1% for HPV and 100% for telomerase activity. It is suggested that telomerase activity may be used as an adjunct to cytology and HPV DNA testing in triaging women with cervical lesions.

Genetic polymorphism of drug metabolizing enzymes (GSTM1 and CYP1A1) as risk factors for oral premalignant lesions and oral cancer

AIMS Polymorphisms in the genes that code for metabolic enzymes involved in either the activation (Phase I) or detoxication (Phase II) of chemical carcinogens in tobacco, may alter expression or function of carcinogenic compounds and hence alter risk of oral cancer. The present study investigates whether polymorphisms at CYP1A1 and GSTM1 gene loci act as risk factors for oral precancerous lesions and cancer. METHODS For the present study, histopathologically confirmed cases of 90 oral precancerous lesions, 150 oral squamous cell carcinoma (SCC) and 150 control subjects were selected. Polymerase chain reaction and restriction fragment length polymorphism were performed using DNA from blood samples to determine the polymorphic genotypes at CYP1A1 and GSTM1 loci. RESULTS CYP1A1 C (m2/m2) genotype conferred a 12.0 fold-increased risk (OR=12.0; 95% CI, 2.40-60.05) to oral SCC. GSTM1 null showed no significant association but the frequency was higher in oral SCC cases. Patients with genotype C and/or GSTM1 deficiency developed carcinoma after less tobacco consumption than those of other genotypes though the difference was not statistically significant. The frequency of the combined genotypes C and GSTM1 null was found to be 14% among oral SCC patients. On comparing the susceptibility of intraoral sites it was found that in the majority of cases (64%) in the study groups they were the buccal mucosa. CONCLUSION Hence it was concluded that metabolic enzymes reported in the present study: CYP1A1 significantly alter oral cancer risk. GSTM1 null and CYP1A1 C (m2m2) show a predisposition to premalignant lesions and cancer of the buccal mucosa than other sites.

Identification of genetic contribution to ischemic stroke by screening of single nucleotide polymorphisms in stroke patients by using a case control study design

BackgroundStroke is the second most common cause of death and disability worldwide. It is a multi-factorial disease influenced by both environmental and genetic factors. Studies from the different ethnic regions of world have reported variable results on association of Apolioprotein E (APOE), Methylenetetrahydrofolate reductase (MTHFR), Endothelial Nitric Oxide Synthase (ENOS), Factor V Leiden (F5), Cytochrome P450 4F2 (CYP4F2), beta-fibrinogen and Phosphodiesterase 4D (PDE4D) gene in stroke. There has been substantial evidence from the European descent genetic studies showing that genetic risk of stroke varies as per specific subtypes of ischemic stroke.This study aims to test the hypothesis that above mentioned encoding gene polymorphisms are associated with stroke and to determine whether risk varies as per specific subtypes of stroke.Methods/DesignThe study design would be case–control study. Six hundred cases with diagnosis of stroke and 600 age and sex matched controls will be recruited. Controls will be matched in 1:1 ratio. Baseline and demographic data will be collected in standardized data collection form. Four ml of blood will be collected in EDTA coated vial and will be used for DNA isolation. Genotyping will be done by using PCR-RFLP method. For the reconfirmation of RFLP results, PCR product of each genotype in triplet for all the selected polymorphism will be sent for DNA sequencing. Data will be analyzed using conditional logistic regression to determine odds ratio associated with the above genes.DiscussionThis protocol will assess the association of above mentioned gene polymorphisms with ischemic stroke in North Indian Population. This study will also helpful to determine genetic component of stroke and whether variation in genetic risk as per different subtypes of stroke.

Mitochondrial Perturbance and Execution of Apoptosis in Platelet Mitochondria of Patients With Amyotrophic Lateral Sclerosis

ABSTRACT Role of platelets have been evinced as a systemic tool in a variety of neurological disorders. Oxidative phosphorylation contributes approximately 80% of total adenosine–tri-phosphate (ATP) production in resting platelets suggesting potential dependence of platelets on modest mitochondrial functioning. Since mitochondria play a pivotal role in regulating metabolic and apoptotic pathways in various neurodegenerative disorders including amyotrophic lateral sclerosis (ALS), we assessed mitochondrial membrane potential (MMP) associated alterations and apoptotic status of platelet mitochondria in ALS patients using case-control approach. Confocal microscopy reflected heterogeneous distribution of JC-1 aggregates and monomers indicating altered MMP in ALS platelets. Our flow cytometry results confirmed greater percentage of mitochondrial depolarization in ALS platelets. Greater exposure of phosphatidyl serine (PS) residue vindicated by annexin V binding and lesser accumulation of mitotracker red in mitochondrial matrix demonstrated initiation of apoptosis in ALS platelets. Our findings corroborate mitochondrial abnormalities such as perturbance of MMP, mitochondrial depolarization, and apoptosis in ALS platelet mitochondria. In conclusion, our study further evinces the involvement of mitochondrial dysfunction in the pathogenesis of ALS and suggests implication of cell death in peripheral tissues apart from motor neurons in ALS.

Thyroid function in children with sepsis and septic shock

Aim: A prospective study was conducted to determine thyroid hormone levels and their relationship to survival in children with septic shock and sepsis.

Val66Met polymorphism and BDNF levels in Alzheimer's disease patients in North Indian population

Analysis of serum brain-derived neurotrophic factor (BDNF) levels in Alzheimers disease (AD), amnestic mild cognitive impairment (aMCI) and controls with BDNF gene polymorphism and cognitive function were investigated. The study recruited 63 AD patients, 15 aMCI and 63 age- and sex-matched healthy controls from All India Institute of Medical Sciences, New Delhi, India. Patients with AD (12268.3 ± 7099.9 pg BDNF/ml) and aMCI (10780 ± 4184.2 pg BDNF/ml) had higher serum levels than had the controls (9362.833 ± 5883.32 pg BDNF/ml). Significant difference in BDNF levels was not found between the three groups. No significant difference was obtained between BDNF genotype and allele distribution between AD patients, aMCI versus controls; genotypic frequency: Chi-square = 3.21; p-value = 0.20 and allelic frequency: Chi-square = 0.412, p-value = 0.521, df = 1 (AD vs controls); Chi-square = 1.63, p-value = 0.201, df = 1 (aMCI vs controls). In conclusion, val66met polymorphism and BDNF serum level between the three groups and genotype did not significantly affect the serum BDNF level or age, Mini-Mental State Examination score in AD and aMCI. Further studies are necessary to elucidate the kinetics and the potential role of serum BDNF as a marker of disease progression in AD patients.

Ultrastructural Variations in Platelets and Platelet Mitochondria: A Novel Feature in Amyotrophic Lateral Sclerosis

Platelets are characterized as a systemic tool to elucidate mitochondria-allied perturbance in neurological diseases. The authors studied ultrastructural changes in platelets and platelet mitochondria using a case-control approach in amyotrophic lateral sclerosis (ALS). Subjects were sporadic ALS cases (n = 22) and age- and sex-matched controls (n = 16). Phlebotomy was performed, platelet concentrates (PCs) were prepared, and mitochondria were extracted. PCs and mitochondria were processed for ultrastructure study using transmission electron microscopy. Image analysis was done using Image-J. Transmission electron microscopy demonstrated both qualitative and quantitative variations in ALS platelets and platelet mitochondria. Heterogeneous distribution of granules, formation of vacuoles, blebs, pseudopodia, loose demarcation of cell membrane with a significant increase in area (20.3%), perimeter (17.82%), integrated density (21.44%), electron-lucent granules (41.79%), and vacuoles (36.58%) were observed in ALS platelets. Conversely, control platelets exhibited an increase of circularity (11.7%) and electron-dense granules (36.89%). In parallel, nonuniformity of matrix, faint cristae, greater lysosomal bodies, and lesser intramitochondrial granules were seen in ALS platelet mitochondria. Significantly greater area (26.88%), perimeter (15%), circularity (3.76%), and integrated density (25.18%) were observed in control platelet mitochondria. Ultastructural divergence in platelets of ALS patients underlines a potential dependence of platelets on modest mitochondrial functioning. These observations also support the view that systemic involvement might be a novel feature in ALS pathophysiology.

Risk factors of dementia in North India: a case–control study

Objective: The prevalence of dementia in northern India is among the lowest in the world but reasons are unclear. The aim of the study was to evaluate the risk and protective factors for dementia in North India. Methods: In a case–control study, we investigated demographic, medical, genetic, dietary, lifestyle, and sociocultural protective and risk factors associated with dementia. Results: 150 patients of dementia (118 males and 32 females) and 150 healthy controls (112 males and 38 females) were included in the study. Diabetes, depression, hyperhomocysteinemia, hyperlipidemia, APOE ε4 gene, BMI, use of saturated fatty acids, pickles in diet, urban living, and lack of exercise were associated with independent risk of dementia. Various dietary factors and sociocultural factors, like cognitively stimulating activities, active socialization, living in joint families, increased intake of polyunsaturated fats, fruits, and salads conferred protection against dementia. Conclusions: Dietary, lifestyle, and sociocultural interventions may be protective against dementia.

an insight into ultrastructural and Morphological alterations of Platelets in neurodegenerative Diseases

Platelets are evinced as a systemic tool in a variety of disorders, including neurodegenerative diseases. Evidence suggests that variations in the ultrastructure and morphology of platelets and related organelles are involved in the pathophysiology of diabetes, cancer, HIV/AIDS, cardiovascular and neurological diseases. Due to structural alterations of platelets in many diseases, it is informative to discuss the ultrastructural and morphological discrepancies of platelets in contemporary medical research. The present review reveals the usefulness of ultrastructural study in better understanding of the disease patterns and may help to improve the treatment regimes.