Devika Tayal

Paraoxonase: a multifaceted biomolecule.

BACKGROUND Paraoxonase enzyme was first identified as a protective barrier against organophosphorus poisoning. After painstaking research spanning the last three decades, the knowledge about this enzyme has increased immensely. The present review attempts to elaborate the role of paraoxonase enzyme in normal physiology as well as provide an overview of the various disorders in which the enzyme may have a role in etiopathogenesis. METHODS The literature was searched from the websites of the National Library of Medicine (http://www.ncbi.nlm.nih.gov/) and Pub Med Central, the U.S. National Library of Medicines digital archive of life sciences journal literature. RESULTS Paraoxonase acts as an important antioxidant enzyme against oxidative stress. The enzyme has been implicated in the pathogenesis of a number of disorders including cardiovascular disorders, cancers etc. CONCLUSIONS A better understanding of the molecular mechanism of the enzyme along with the regulatory circuits will help us to utilize agonists to potentiate the anti oxidant actions of the enzyme.

Identification of the Types of Preanalytical Errors in the Clinical Chemistry Laboratory: 1-Year Study at G.B. Pant Hospital

Objective: To evaluate the leading causes of preanalytical errors in a clinical chemistry laboratory. Methods: A retrospective analysis of the results obtained from the clinical chemistry laboratory for errors in the preanalytical phase has been carried out to summarize data regarding the frequency of the main factors affecting the preanalytical quality of results. Laboratory personnel were asked to register rejections, and causes for rejection of ward as well as out-patient samples collected in the laboratory. Results: Of the 96,328 tubes received during the data collection period, 1469 samples were found unsuitable for further processing. This accounted for 1.52% of all samples collected in the laboratory. Rejections arose as a result of the following reasons: 0.74% were rejected due to hemolysis; 0.47% were specimens without proper requisition slips; and 0.23% had insufficient sample quantity. Conclusion: Of all the samples received in the lab, the overall percentage of rejection is 1.52%.

Biochemical markers of liver and kidney function are influenced by thyroid function-a case-controlled follow up study in Indian hypothyroid subjects.

Thyroid hormones regulate the renal hemodynamics and basal metabolic rate of most cells. This hospital-based case-control study was done to evaluate the changes in biochemical markers of liver and kidney function in hypothyroid subjects before and after treatment. The study included 176 subjects randomly selected from Thyroid clinics. Serum T3, T4, TSH, Liver and Kidney Function tests were analysed using standard kits. Forty-six hypothyroid patients were re-evaluated 6 weeks after thyroxine substitution therapy. Hypothyroid subjects (n=80) showed significantly raised serum creatinine and uric acid levels as compared to euthyroid subjects (n=96). After 6 weeks of thyroxine replacement, serum creatinine and uric acid decreased significantly and were comparable to euthyroid group. A positive correlation of ALT, AST, uric acid, protein and albumin with TSH levels (p<0.05) and negative correlation of serum T4 levels with ALT, AST, proteins (p<0.05) was observed in the hypothyroid group. Hypothyroidism results in reversible impairment of hepatorenal function.

Pre-analytical factors that influence the interpretation of prothrombin time in the clinical laboratory: One year experience in a super speciality hospital in India

BACKGROUND Accuracy and precision of Laboratory results is a top most priority in a clinical laboratory. Errors in Laboratory results could be due to pre-analytical, analytical and postanalytical variables. Here, we have discussed about pre-analytical variables during estimation of prothrombin time. METHODS 15,335 PT (prothrombin time) samples received in the department of clinical biochemistry from June 2008 to May 2009 were evaluated for the prevalence of pre-analytical errors. The prothrombin time (PT) was analyzed on automated coagulometer-ACL 7000 with thromboplastin reagent supplied by Trinity Biotech, Ireland. RESULTS Out of the 15,335 samples received in one year for analysis by the department, 464 samples showed the presence of pre-analytical variables and therefore, could not be assayed. Among the pre-analytical variables, inappropriate proportion between blood and anticoagulant was the most common error with a frequency of approximately 60%. Clotted samples and illegible handwriting accounted for another 15% each of the rejections respectively. Around 6% of the samples were hemolysed and another 2% were rejected due to lipemia. CONCLUSION Appropriate knowledge of blood sample collection is a need of an hour to have accuracy in Laboratory results.

Association of Inflammatory Cytokines, Lipid Peroxidation End Products and Nitric Oxide with the Clinical Severity and Fetal Outcome in Preeclampsia in Indian Women

Preeclampsia is a multisystem disorder associated with maternal hypertension, placental abnormalities and adverse fetal outcomes. The various pathways involved in its etiology include endothelial dysfunction, inflammatory milieu, lipid peroxidation and immunological imbalance. The present study was conducted to evaluate the causative and predictive role of nitric oxide, lipid peroxidation end products (MDA) and inflammatory cytokines (IL-6, TNF-α) in clinical presentation, severity and fetal outcome in preeclampsia. The study population was divided into 3 groups- Non- pregnant females comprising the control population; G1 and G2 groups included normal pregnant and pregnant females with preeclampsia with 50 patients in each group. Nitric Oxide and MDA levels were found to be highest in the preeclamptic patients as compared to other two groups. ROC curve analysis shows the superiority of the inflammatory markers as determinants of severity of preeclampsia which suggests the emerging role of pro inflammatory markers in the various pathological changes in preeclampsia. TNF-α emerged as the best marker in multivariate analysis and thus, has the potential for being used as a marker for PIH. Our study illustrates the multifactorial etiology of preeclampsia involving oxidative stress, proinflammatory milieu and endothelial dysfunction.

Prevalence of metabolic syndrome in patients with angiographically proven coronary artery disease presenting to a tertiary care hospital in Delhi, India.

BACKGROUND Coronary artery disease is fast emerging as the major concern for afflicting people across the globe. The Indian subcontinent is highly predisposed to this condition due to distinctive risk factor profile of this population. This fact has led to a condition where the current preventative and management protocols that have worked well in the non-Asian Indian Caucasian populations, have failed to bring about the anticipated control over the incidence and progression of CAD in Asian Indians. Metabolic syndrome has been identified as a major determinant of CAD in this population. MATERIALS AND METHODS The prevalence of metabolic syndrome was determined in 431 patients undergoing coronary angiography through various diagnostic algorithms. The Asian modified diagnostic criteria were also implemented to estimate the metabolic syndrome prevalence in patients with different levels of stenosis. RESULTS We observed a high incidence of metabolic syndrome in the patients with coronary artery disease. The prevalence of MS increased with increase in severity of coronary artery involvement. The IDF guideline with Asian modification was the most successful diagnostic algorithm. CONCLUSIONS It is now imperative to acknowledge the unique pattern of CAD and risk factor profile prevalent among South Asians. This will facilitate more focused and individualized management protocols directed to this population. Metabolic syndrome is a major syndrome prevalent in this population. Hence, effective control of MS may help in reducing the morbidity and mortality due to CAD in a great way.