Quantitative evaluation of insulin resistance markers in Pakistani patients suffering from HCV-associated type 2 diabetes mellitus.

The current study was designed to determine the role of the host genes involved in the development of chronic hepatitis C-associated type 2 diabetes mellitus. This study was carried out in patients in four different stages of chronic hepatitis C virus (HCV) infection, including treatment-naïve HCV patients, HCV-positive patients with type 2 diabetes mellitus (T2DM), non-responders and responders. The mRNA expression level of host genes, such as glucose-6-phosphatase (G6Pase), tumor necrosis factor α (TNF-α) and different adipokines including adiponectin, leptin and resistin, was quantified and compared to healthy controls. HCV infection was found to be associated with insulin resistance, a step towards type 2 diabetes mellitus (T2DM). The results also suggest the potential role of adipokines in chronic HCV (CHC)-associated T2DM. The upregulation of gluconeogenic genes, such as G6Pase and resistin, and a decreased mRNA expression level of adiponectin suggest the potential role of selected markers in the CHC-associated T2DM in Pakistani population. Based on these results, it is concluded that upregulation of TNF-α, G6Pase and resistin in chronic HCV patients leads to gluconeogenesis, eventually favoring T2DM. Collectively, these findings suggest that CHC patients are more prone to T2DM.

Trends in human immunodeficiency virus seroprevalence in blood donors in northern Pakistan.

OBJECTIVE: To study trends in human immunodeficiency virus (HIV) seroprevalence in blood donors in northern Pakistan. STUDY DESIGN: Analysis of annual data from blood transfusion centre. PLACE AND DURATION OF STUDY: Data records from people who had donated blood at the Armed Forces Institute of Transfusion (AFIT) between 1998 and 2013 were retrieved and analysed. METHODS: All blood donations were tested for the presence of HIV antibodies using Abbott Inc's AxSYM from 1998 to 2006, and Abbott Inc's Architect 2000i with chemiluminescence microplate immunoassay from 2007 to 2013. RESULTS: Over the 16-year study period, 66 donors tested positive for HIV antibodies out of 626,413 donations (0.01%, i.e. 10 per 100,000 donations). From 1998 to 2006, 16 HIV-positive cases were detected out of 280,245 donations (0.0057%, i.e. 5.7 per 100,000 donations). However, from 2007 to 2013, 50 HIV-positive cases were detected out of 346,168 donations (0.0144%, i.e. 14 per 100,000 donations). The difference in HIV positivity between the two groups was found to be significant (0.0057% vs 0.0144%, χ(2) = 10.4, P = 0.008). CONCLUSION: A gradual and persistent increase in the number of HIV-positive cases among blood donors in northern Pakistan was seen over the study period. The HIV-positive cases reported one or more high-risk activities in the past which predisposed them to HIV infection.

Expression of NOX5 in human teratozoospermia compared to normozoospermia.

Spermatozoa are capable of producing small amounts of reactive oxygen species (ROS), and sperm in teratozoospermia generate more ROS than sperm in normozoospermia. The source of ROS production in ejaculated human sperm has not been fully clarified. Recently, NADPH oxidase 5 (NOX5) was detected in human sperm, and ROS generation by this enzyme was reported. We investigated the magnitude of NOX5 expression in normozoospermic (n = 12) and teratozoospermic (n = 13) semen samples with different percentages of abnormal sperm. The existence of NOX5 enzymes in sperm was analysed by immunocytochemistry and flow cytometry and correlated with morphological abnormalities. Immunofluorescent studies identified NOX5 in acrosomal, equatorial, post-acrosomal regions, the body and the tail of both normal and abnormal sperm. Teratozoospermic semen samples had higher percentages of NOX5-positive sperm and expressed more NOX5 (based on higher mean fluorescent intensity) than normal semen samples. Positive correlations were observed between abnormal sperm morphology and both the percentage of NOX5-positive sperm and the magnitude of NOX5 expression. Based on these findings, we can assume that there is a positive correlation between ROS generation in teratozoospermia and that in NOX5 expression.

Escherichia coli Nissle 1917 facilitates tumor detection by positron emission tomography and optical imaging.

PURPOSE: Bacteria-based tumor-targeted therapy is a modality of growing interest in anticancer strategies. Imaging bacteria specifically targeting and replicating within tumors using radiotracer techniques and optical imaging can provide confirmation of successful colonization of malignant tissue. EXPERIMENTAL DESIGN: The uptake of radiolabeled pyrimidine nucleoside analogues and [18F]FDG by Escherichia coli Nissle 1917 (EcN) was assessed both in vitro and in vivo. The targeting of EcN to 4T1 breast tumors was monitored by positron emission tomography (PET) and optical imaging. The accumulation of radiotracer in the tumors was correlated with the number of bacteria. Optical imaging based on bioluminescence was done using EcN bacteria that encode luciferase genes under the control of an l-arabinose-inducible P(BAD) promoter system. RESULTS: We showed that EcN can be detected using radiolabeled pyrimidine nucleoside analogues, [18F]FDG and PET. Importantly, this imaging paradigm does not require transformation of the bacterium with a reporter gene. Imaging with [18F]FDG provided lower contrast than [18F]FEAU due to high FDG accumulation in control (nontreated) tumors and surrounding tissues. A linear correlation was shown between the number of viable bacteria in tumors and the accumulation of [18F]FEAU, but not [18F]FDG. The presence of EcN was also confirmed by bioluminescence imaging. CONCLUSION: EcN can be imaged by PET, based on the expression of endogenous E. coli thymidine kinase, and this imaging paradigm could be translated to patient studies for the detection of solid tumors. Bioluminescence imaging provides a low-cost alternative to PET imaging in small animals.

Subacute sclerosing panencephalitis--a Pakistan perspective.

Subacute sclerosing panencephalitis (SSPE) remains a problem in areas of the world where measles virus is prevalent because of a lack of commitment to universal vaccination. We recently studied 89 cases compatible with a clinical diagnosis of SSPE and tested for antibody in serum or cerebrospinal fluid for measles virus. Eleven cases were confirmed to be SSPE on the basis of strongly supportive laboratory data.

Streptolysin O: inhibition of the conformational change during membrane binding of the monomer prevents oligomerization and pore formation.

Streptolysin O is a four-domain protein toxin that permeabilizes animal cell membranes. The toxin first binds as a monomer to membrane cholesterol and subsequently assembles into oligomeric transmembrane pores. Binding is mediated by a C-terminally located tryptophan-rich motif. In a previous study, conformational effects of membrane binding were characterized by introducing single mutant cysteine residues that were then thiol-specifically derivatized with the environmentally sensitive fluorophoracrylodan. Membrane binding of the labeled proteins was accompanied by spectral shifts of the probe fluorescence, suggesting that the toxin molecule had undergone a conformational change. Here we provide evidence that this change corresponds to an allosteric transition of the toxin monomer that is required for the subsequent oligomerization and pore formation. The conformational change is reversible with reversal of binding, and it is related to temperature in a fashion that closely parallels the temperature-dependency of oligomerization. Furthermore, we describe a point mutation (N402E) that, while compatible with membrane binding, abrogates the accompanying conformational change. At the same time, the N402E mutation also abolishes oligomerization. These findings corroborate the contention that the target membrane acts as an allosteric effector to activate the oligomerizing and pore-forming capability of streptolysin O.

Demographic aspects of hepatitis C in northern Pakistan.

OBJECTIVE: To find out the prevalence of hepatitis C in various, age, sex and ethnic groups in Pakistan. SETTING: Specimens obtained from military/civil hospitals and General Practitioners of Rawalpindi Islamabad, region and other areas of Northern Pakistan, in vicinity. SUBJECTS: Serum of 1710 patients of hepatitis C, diagnosed at Armed Forces Institute of Pathology (AFIP), Rawalpindi between 1st July 1996 and Dec 31, 1997, tested for Anti HCV by 3rd generation Murex Elisa. Required information was collected on a proforma filled for each patient. RESULTS AND CONCLUSION: The majority of the cases were between 30-60 years of age. There was male preponderance. The infection was more common in Urdu speaking fraction of the patients as compared with others.

Physostigmine, galanthamine and codeine act as 'noncompetitive nicotinic receptor agonists' on clonal rat pheochromocytoma cells.

The acetylcholine esterase inhibitor (-)-physostigmine has been shown to act as agonist on nicotinic acetylcholine receptors from muscle and brain, by binding to sites on the alpha-polypeptide that are distinct from those for the natural transmitter acetylcholine (Schröder et al., 1994). In the present report we show that (-)-physostigmine, galanthamine, and the morphine derivative codeine activate single-channel currents in outside-out patches excised from clonal rat pheochromocytoma (PC12) cells. Although several lines of evidence demonstrate that the three alkaloids act on the same channels as acetylcholine, the competitive nicotinic antagonist methyllycaconitine only inhibited channel activation by acetylcholine but not by (-)-physostigmine, galanthamine or codeine. In contrast, the monoclonal antibody FK1, which competitively inhibits (-)-physostigmine binding to nicotinic acetylcholine receptors, did not affect channel activation by acetylcholine but inhibited activation by (-)-physostigmine, galanthamine and codeine. The three alkaloids therefore act via binding sites distinct from those for acetylcholine, in a 'noncompetitive' fashion. The potency of (-)-physostigmine and related compounds to act as a noncompetitive agonist is unrelated to the level of acetylcholine esterase inhibition induced by these drugs. (-)-Physostigmine, galanthamine and codeine do not evoke sizable whole-cell currents, which is due to the combined effects of low open-channel probability, slow onset and slow inactivation of response. In contrast, they sensitize PC12 cell nicotinic receptors in their submaximal response to acetylcholine. While the abundance of nicotinic acetylcholine receptor isoforms expressed in PC12 cells excludes identification of specific nicotinic acetylcholine receptor subtypes that interact with noncompetitive agonists, the identical patterns of single-channel current amplitudes observed with acetylcholine and with noncompetitive agonists suggested that all PC12 cell nicotinic acetylcholine receptor subtypes that respond to acetylcholine also respond to noncompetitive agonist. The action of noncompetitive agonists therefore seems to be highly conserved between nicotinic acetylcholine receptor subtypes, in agreement with the high level of structural conservation in the sequence region harboring major elements of this site.