Iranian Biomedical Journal
Volume:11 Issue: 2, Apr 2007

Avian influenza virus (AIV) infection is a major cause of bird or human mortality and morbidity, therefore the rapid identification of the virus is of important clinical and epidemiological implication. A multiplex Reverse Transcriptase PCR (RT-PCR) was optimized for the detection of influenza A virus and the H5 and H9 subtypes. The influenza type A specific primers were directed to the region of the influenza A matrix gene that is conserved among most type A influenza viruses. The H5 and H9 primers were directed to H5 and H9 hemagglutinin (HA) gene regions that are conserved among H5 and H9 subtypes. The selected primer sets were used in the RT-PCR for simultaneous detection of matrix, H5 and H9 responding specific sequences in a multiplex format. Three reaction conditions were optimized which include: i) RT-PCR typing using matrix gene primers for five subtypes of flu A (H1, H3, H5, H7 and H9), ii) RT-PCR subtyping for H5 and H9 subtypes, and iii) multiplex subtyping of H5 and H9. In this study, the multiplex RT-PCR was applied to 147 cloacal and tracheal swabs of clinical poultry cases with similar influenza symptoms. These results suggest that multiplex RT-PCR assay can be a useful test for rapid detection and subtyping of AIV in clinical samples. Iran. Biomed.

The amygdala is a forebrain region, which is known as a modulator of pain sensation. The amygdala, particularly the central nucleus, has high concentrations of enkephalins relative to dynorphins and has high concentrations of opioid receptors. We here studied the role of central nuclei of amygdala in morphine antinociception. In this study, we used 130 male Wistar rats (200- 250g). Bilateral two guide cannula were inserted into central nuclei of amygdala. The drugs were administrated via intra central- amygdala and intraperitoneal. The antinociceptive effect was measured by formalin test. Bilateral microinjections of morphine (50 and 100 μg/rat) into the central nuclei of amygdala elicited powerful suppression of nociceptive behaviors in both phases of formalin test. The intraperitoneal administration of naloxone (1 and 2 mg/kg) decreased significantly the antinociception induced by the intra-amygdaloid injection of morphine. Our data also showed that microinjection of naloxone (50 and 100 μg/rat) into the central nuclei of amygdala could reduce the analgesic effects of systemic morphine (7 mg/kg). On the other hand, bilateral neurotoxic lesions of the central nuclei of amygdala attenuated the antinociception induced by subcutaneous or intra-amygdaloid injection of morphine. These findings suggest that morphine analgesia in the formalin test depends on ascending connections to the forebrain, probably the amygdala. Iran. Biomed

Linear alkylbenzene sulfonate (LABS) is an anionic surfactant widely used all over the world. They will eventually end-up and accumulate in household or industrial sewage. Due to their high foaming capabilities which can cause numerous problems in sewage treatment facilities as well as direct toxic effects on many different organisms in ecosystem; they are generally considered as serious pollutants. Many reports have indicated that common bacteria can readily degrade LABS. In this survey, two different bacteria were isolated from Tehran municipal active sludge that showed the ability to degrade LABS rapidly and actively upon using it as their sole source of carbon. Biochemical tests as well as 16S rRNA gene sequencing performed. Results have indicated the two isolates to be Acinetobacter johnsoni and Pseudomonas beteli. After experiments to optimize the pH and temperature for growth of the two bacterial isolates, the extent of LABS, utilization was evaluated by HPLC method. The Pseudomonas beteli and Acinetobacter johnsoni isolates were able to degrade 96.4% and 97.2% of the original LABS levels after 10 days of growth, respectively. Mixed culture of the two isolates did not significantly increase LABS utilization (97.6%). Our study showed the ability of two isolated steains to rapidly biodegrade LABS under aerobic conditions. Iran. Biomed.

The importance of extra cellular matrix (ECM) in development and function of different cells has been reported but little is known about its role in human endometrial epithelial cells. The aim of the present study was to examine effects of artificial ECM (Matrigel) and progesterone on the function and morphology of human endometrial epithelial cells in vitro. Endometrial samples were removed, with informed patients consent and Ethics Committee approval, from 17 previously fertile women undergoing total abdominal hysterectomy. The tissue was dissociated and centrifuged to provide an epithelial rich suspension which was cultured either on plastic or seeded into Matrigel to produce polarized cells and then supplemented with or without progesterone (10-6 M). The amount of nucleic acid content of the cells in both in vitro model systems was examined by DNA, RNA extraction methods. The DNA and RNA content were later measured by spectrophotometry. The amount of total RNA in cells grown on Matrigel (23 ± 1.5 pg/cell) was more than double that in cells grown on pl1astic (9.1 ± 1.4 pg/cell). Cells cultured on both in vitro model systems had RNA induced by steroid hormones, but the extent of induction was greater in cells grown on Matrigel (30 ± 2 pg/cell) than those on plastic (12 ± 1.9 pg/cell). Cells cultured on Matrigel were differentiated and became polarized but cells grown on plastic proliferated to full confluency. Cells grown on Matrigel with progesterone supplementation were highly polarized, euchromatic and had greater mitochondria and accumulation of glycogen, when compared to unsupplemented cultures. These results suggest that ECM plays an important role in gene expression, polarization and differentiation of human endometrial epithelial cells in vitro. Endometrial cells grown on ECM responded to steroid hormone in a manner to that reported in endometrial cells in vivo. Iran. Biomed.

Knowledge of antimicrobial resistance patterns in E. coli, the predominant pathogen associated with urinary tract infections (UTI) is important as a guide in selecting empirical antimicrobial therapy. To describe the antimicrobial susceptibility of E. coli associated with UTI in a major university hospital in Tehran (Iran), seventy-six clinical isolates of E. coli were studied for susceptibility to b-lactam antibiotics by the disc diffusion method and Minimal Inhibitory Concentrations determination. All isolates were resistant to ampicillin, amoxicillin and oxacillin. Resistance to the other tested antibiotics was shown to be 93.4% to cefradine, 76.3% to carbenicillin, 47.3% to cefazoline, 50% to cefalexin and 32.8% to cephalothin while 1.3% expressed resistance to cefoxitime, and 2.6% were resistant to ceftizoxime and ceftriaxone. Two isolates (2.4%) harbored extended spectrum b-lactamases (ESBL) shown by the double disc diffusion method. Substrate hydrolysis by ultra violet spectroscopy showed that 87.4% harbored penicillinases, 9% produced cephlosporinases and 3.6% degraded both substrates. Clavulanic acid inhibited enzyme activity in 82.9%, of which 78.95% was penicillinases (group IIa) and 3.95% was cephalosporinases (group IIb) of the Bush classification system. The rest of the isolates (6.58 %) were placed in group IV b-lactamases. No group III b-lactamase was found, as EDTA inhibited none of the enzymes. DNA amplification by polymerase chain reaction using specific primers for ampC, TEM and SHV type b-lactamases for all of the isolates showed that 47 organisms (60%) carried the TEM gene and 18 isolates (24%) harbored blaTEM and ampC genes. About 26% of the organisms harbored SHV type enzymes. These results indicate that E. coli can posses a variety of b-lactamases that are responsible for β-lactam resistance. Iran. Biomed

This study demonstrates the changes in six different pathophysiological parameters such as body weight, body temperature, fecal pellet count, blood-brain barrier (BBB) permeability, plasma corticosterone level and emergence of hemorrhagic peptic ulcer spots due to exposure to high environmental heat in three different age groups of freely moving rats. Each age group of rats was sub divided into three groups: (i) acute heat stress-subjected to a single exposure for four hours in the Biological Oxygen Demand incubator at 38°C; (ii) chronic heat stress-exposed for 21 days daily for one hour in the incubator at 38°C, and (iii) handling control groups. The data were recorded for the analyses of the changes in different parameters just after the heat exposure from acute stressed rats and on 1st, 3rd, 6th, 9th, 12th, 15th, 18th and 21st day on chronic stressed rats for body temperature, body weight, fecal pellets count. For the analysis of changes in three other parameters, BBB permeability, plasma corticosterone level and peptic ulcer spots following chronic exposure to high environmental heat, data were recorded on 22nd day for the analysis. Analysis of variance (ANOVA-1) of the observations demonstrates a significant increase in body temperature, fecal pellet count, BBB permeability (except in adult group), plasma corticosterone level and emergence of hemorrhagic peptic ulcer spots in all three different age group of rats due to exposure to acute heat stress. However, chronic heat was found responsible for the significant reduction in body weight in weaning and young rats, increase in body temperature, number of fecal pellets excreted (in early days of chronic stress) and number of peptic ulcer spots in all three age groups of rats. At the same time, BBB extravasations were not observed in rats except very mild in weaning group. The results of the present study indicate that the acute as well as chronic exposure to hot environment significantly alters the physiology of different organs of the body. Iran. Biomed.

Oxidation of low density lipoprotein (LDL) has been strongly implicated in the phathogenesis of atherosclerosis. The use of oxidants in dietary food stuff may lead to the production of oxidized LDL and may increase both the development and the progression of atherosclerosis. The present work investigated the effects of some elements including: copper (Cu), iron (Fe), vanadium (V) and titanium (Ti) on in vitro LDL oxidation quantitatively. The first LDL fraction was isolated from fresh plasma by single vertical discontinuous density gradient ultracentrifugation. The formation of conjugated dienes and thiobarbituric acid reactive substances and increase in electrophoretic mobility of LDL were monitored as markers of the oxidation of LDL. It was demonstrated that Cu, Fe, V and Ti exhibited strong oxidant activity in this respect (P<0.001). Oxidation of LDL in the presence of Cu was more and appeared to be in this order Cu>Fe> V>Ti. Cu, Fe, V and Ti are redox-active transition metals that may cause oxidative damage to lipids, proteins and DNA molecules. We suggest that these elements may also influence the oxidation of LDL in vivo, which could increase both the development and progression of atherosclerosis. Iran. Biomed

Signal regulatory proteins (SIRP) belong to immunoglobulin super family (IgSF) and relate to integrin signaling cascades. It has been shown that SIRPa is expressed in a variety of cells including myeloid cells and neurons. In the present study the expression of this IgSF member in articular chondrocytes was investigated. Using a panel of anti-SIRPa antibodies, immunohistochemistry, Western-blotting and electrophysiology methods, expression of SIRPa and its role in chondrocyte mechano-transduction were assessed. No identifiable positive signal was obtained by using immunohistochemistry methods on frozen and paraffin sections. SIRPa is expressed by both normal and osteoarthritis cultured chondrocytes. The electrophysiological response of chondrocytes in the presence of SE7C2 mAb was significantly inhibited whereas; SE5A5 did not show any modification in this response. It seems likely that SIRPa could be associated with other proteins such as integrins, CD47 and ion channels, which contribute to the electrophysiological response of human articular chondrocytes. In any case, this study has provided a specific functional role for SIRPa in chondrocyte mechano-transduction. Iran. Biomed.

The human leukocyte antigen G (HLA-G) molecule exhibits limited tissue distribution, low polymorphism and alternative splicings that generate seven HLA-G isoforms. HLA-G exerts multiple immunoregulatory functions. Recent studies indicate an ectopic up-regulation in tumor cells that may favor their escape from anti-tumor immune responses. This study it is an effort to clarify the presence of HLA-G in B-cell chronic lymphocytic leukemia (B-CLL) patients. HLA-G mRNA expression was studied in a pilot study in circulating B-CLL and also healthy controls by reverse transcription (RT)-PCR using a set of pan-HLA-G primers. RT-PCR was performed on B-cells from 74 B-CLL patients and 12 healthy controls. The data showed HLA-G gene expression in 20% of the B-CLL patients. No expression of HLA-G could be detected in the healthy control group. These data suggest that HLA-G is expressed at the gene level in B cells from B-CLL patients but not in B cells from healthy controls. Further study is required to clarify the role of HLA-G as a regulatory factor that could affect immune response in B-CLL patients. Iran. Biomed.

Amino acid dehydrogenases (L-amino acid: oxidoreductase deaminating; EC 1.4.1.X) are members of the wider superfamily of oxidoreductases that catalyze the reversible oxidative deamination of an amino acid to its keto acid and ammonia with the concomitant reduction of either NAD+, NADP+ or FAD. These enzymes have been received much attention as biocatalysts for use in biosensors or diagnostic kits to screen amino acid metabolism disorders such as phenylketonuria (PKU), maple syrup urine disease (MSUD), homocystinuria (HCY) and hyperprolinemia. This study was aimed to isolation and screening of novel amino acid dehydrogenases from soil bacteria. The enzyme producing bacteria were selected among L-methionine and L-phenylalanine utilizers isolated from soil by thin layer chromatography, activity staining and confirmed by enzyme assay. Bacterial strains were identified by phenotypic and biochemical characteristics. The steady-state kinetic studies of enzymes were also performed. In total of 230 tested strains, four of them were recognized as amino acid dehydrogenase producers that belong to species of Pseudomonas, Citrobacter and Proteus. They exhibited the desired NAD+-dependent dehydrogenase activities toward L-isoleucine, L-methionine, L-cysteine, L-serine and L-glutamine in oxidative deamination reaction. The specific activity of L-isoleucine dehydrogenase, L-methionine dehydrogenase and L-glutamine dehydrogenase for oxidative deamination of L-isoleucine, L-methionine and L-glutamine were 1.59, 1.2 and 0.73 U/mg, respectively. The Kcat /Km (s-1.mM -1) values in these strains were as follows: L-isoleucine, 113.6, L-methionine, 62.05 and L-glutamine, 95.83. This is the first report of occurrence a specific isoleucine dehydrogenase, glutamine dehydrogenase and methionine dehydrogenase in bacteria. Iran. Biomed.