Reduced pancreatic polypeptide response is associated with early alteration of glycemic control in chronic pancreatitis.

AIM: To study the incidence of glucose intolerance in CP patients without diabetes by performing oral glucose tolerance test (OGTT). METHODS: We screened consecutive Indian CP patients without diabetes over 6 months by performing OGTT and correlated with physical characteristics and glycated hemoglobin (HbA1c). We also compared c-peptide and pancreatic polypeptide response in different groups based on OGTT. Relevant statistical tests were performed. P < 0.05 was considered significant. RESULTS: Total of 171 patients were screened. Mean duration of CP was 5.03 ± 4.32 years. 55 were detected to have prediabetes and 40 DM on OGTT. CP patients with diabetes and prediabetes had significantly dilated pancreatic duct compared to non-diabetic CP (4.2 ± 2.7 mm, 3.6 ± 2.7 mm, 2.84 ± 2.25 mm; p = 0.018). Fasting blood glucose (FBS) and 2-hour OGTT were 109.35 ± 19.06, 97.47 ± 11.94, 85.24 ± 9.95 and 236.13 ± 31.42, 154.65 ± 19.53, 112.89 ± 16.32 in patients with DM, prediabetes and CP patients without diabetes (p < 0.0001). There was a good c-peptide response (p = 0.001) and reduced pancreatic polypeptide response (p = 0.003) in CP patients compared to controls. CONCLUSION: Early in the course of disease reduced pancreatic polypeptide response in the presence of good c-peptide response may result in development of DM.

Melatonin metabolite 6-Sulfatoxymelatonin, Cu/Zn superoxide dismutase, oxidized LDL and malondialdehyde in unstable angina.

BACKGROUND: Melatonin, a lypophylic antioxidant, was reported to be low in patients suffering from myocardial infarction, a disease due to coronary atherosclerosis associated with increased reactive oxygen species. Studies carried out till now have shown association of either melatonin or another antioxidant Cu/Zn SOD in patients suffering from coronary artery disease but not both together. Concurrent measurement of these two parameters will reveal the relationship if any in the probable causation of the disease. METHODS: We estimated the serum malondialdeheyde, oxidized LDL, lipid profile and activity of Cu/Zn superoxide dismutase and the concentration of urinary metabolite of melatonin, 6-Sulfatoxymelatonin in 24 h urine sample collected from 21 patients suffering from unstable angina and 30 control subjects. RESULTS: A statistically significant decrease in urinary melatonin levels (p <0.05), serum Cu/Zn SOD (p <0.001) along with significant increase in serum oxidized LDL (p <0.001), serum malondialdeheyde (p <0.01) were observed in patients compared to controls. CONCLUSION: Our observations indicate that a decreased excretion of 6-Sulfatoxymelatonin may be causally related to a decrease in serum Cu/Zn SOD, an antioxidant, with a consequent increase in serum oxidized LDL, malondialdehyde contributing to the occurrence of the disease.

Homology modeling of membrane proteins: a critical assessment.

Evaluation and validation of homology modeling protocols are indispensable for membrane proteins as experimental determination of their three-dimensional structure is an arduous task. The prediction ability of Modeller, MOE, InsightII-Homology and Swiss-PdbViewer (SPV) with different sequence alignments CLUSTALW, BLAST and 3D-JIGSAW have been assessed. The sequence identity of the target and template was chosen to be in the range of 25-35%. Validation protocols to assess the structure, fold and stereochemical quality, are employed by comparing with experimental structures. Two different ranking schemes are suggested to evaluate the performance of each methodology based on the validation scores. While unambiguous preference for any given procedure did not surface, statistically Modeller and the sequence alignment technique, 3D-JIGSAW, gave best results amongst the chosen protocols. The present study helps in selecting the right protocols when modeling membrane proteins, which form a major class of drug targets.

Non-Hodgkin's lymphoma in AIDS. A case report.

We are reporting the first clinical case of AIDS from South India. The disease was diagnosed in a patient of non-Hodgkin's lymphoma. The source of infection was blood transfusion. After the diagnosis of this case, we undertook routine screening of all patients of non-Hodgkin's lymphoma for evidence of HIV infection. Out of a total of 20 patients of non-Hodgkin's lymphoma screened 2 other patients showed evidence of HIV infection.