Zahedan Journal of Research in Medical Sciences
Year:2013 | Volume:15 | Issue:5|Papers Count:12

Background: Recent studies have shown that normobaric hyperoxia compared with normobaric normoxia can reduce the damages resulting from the stroke. The purpose of this study is to investigate the effects of oxygen radicals in reduction of cerebral edema caused by normobaric hyperoxia in rat stroke models.Materials and Methods: Wistar rats were divided into two main experimental groups and were exposed to 90% oxygen (HO) for 4 hours/day during 6 days, the main control group was placed inside a special chamber and exposed to room 21% oxygen at 1 atmosphere pressure (RA). Then, each group was divided into three subgroups half an hour before placing and treatment in the oxygen chamber, the first, second and third subgroups of both groups were received no substance (RA and HO), saline (RA-S and HO-S), and dimethylthiourea (RA-MT and HO-MT), respectively in order to evaluate the role of oxygen radicals. Then after 24 hours, they were exposed to ischemia through surgically occlusion of middle cerebral artery in order to create brain edema After 60 minutes of ischemia, the perfusion was reestablished for 24 hours. Then the neurological deficit scores and cerebral edema were analyzed.Results: Based on Mann–Whitney U test, the median of recovery effect of neurological deficit was significant (p<0.05). The extent of cerebral edema, based on one-way ANOVA test, was also significant (p<0.05). This effect disappeared largely by consumption of dimethylthiourea.Conclusion: The reduction of cerebral edema resulting from normobaric hyperoxia treatment is largely mediated through oxygen radicals.

Background: The human amniotic membrane is the inner most layer of placenta and has antimicrobial effect, due to the presence of human beta-defensins and elafins. The purpose of this study is to investigate the effect of dilution reduction of 0.5 McFarland prepared from standard bacterial strains of Salmonella enterica BAA-708, Escherichia coli ATCC25922, Pseudomonas aeruginosa ATCC27853, Klebsiella pneumoniae ATCC7881, and Enterococcus faecalis ATCC29212 on antibacterial effect of human amniotic membranes in vitroMaterials and Methods: The amniotic membranes were obtained from the bank of organ transplantation in Imam Khomeini hospital, of women with elective cesarean section whose HIV, HBV, HCV and VDRL serological tests were negative. They were cut to 1.5×1.5 cm pieces. Then 0.5 McFarland suspensions of 1.5×108, 0.5×107 and 1.5×106 dilutions were prepared from bacteria which then were spread on Mueller Hinton medium agar and a piece of membrane was put in the center of each plate. After 24 hours incubation at 37oC, the results were observed.Results: In 0.5 McFarland standard dilution an inhibition zone was created in three standard strains of Pseudomonas aeruginosa, Escherichia coli, and Salmonella enterica unlike the other two strains. There was no change in the above results with two other dilutions and inhibition zone of sensitive strains was not created.Conclusion: Dilution reduction of microbial strains does not affect the antibacterial impact of amniotic membrane and dilution reduction does not yield to a false positive response and the conversion of resistant to sensitive strains.

Background: Buthionine sulfoximine is an agent that reduces intracellular glutathione and anti-oxidant enzymes and by this means is involved in pathology of some disease. Since low glutathione level may affect embryonic development, the aim of the present study is to investigate glutathione reduction in pregnant and non-pregnant mice.Materials and Methods: In the present study, the mice were divided into 4 groups (10 in each group). The groups included pregnant and non-pregnant, each one consisting of a control and an experimental subgroup. The experimental groups received 2 mMol/kg buthionine sulfoximine (in the pregnant group on the 10th day of pregnancy), then 12 hours after buthionine sulfoximine injection, the mice in all control and experimental groups were killed and the blood obtained from their heart, and the glutathione level were determined and compared with each other.Results: Glutathione level in experimental pregnant group was reduced significantly (p<0.05) in comparison with control pregnant group. In non-pregnant group, also the level of glutathione were reduced significantly (p<0.05) in comparison to control group.Conclusion: The results indicated that buthionine sulfoximine injection could reduce glutathione level both in the pregnant and non-pregnant mice. Also the effect of buthionine sulfoximine in the pregnant group was more extensive than that of non-pregnant group.

Background: Noise is a known physical stress in workplace, which induces alterations of various physiological responses in exposed individuals. Aim of this study was to explore the status of oxidant and antioxidant parameters in blood and liver tissue of rats exposed to noise.Materials and Methods: Twenty-one adult albino wistar male rats seven in each of the following groups were used (N=7): 1- Control group, 2- Noise exposure (100 dB, 700-5700 Hz, 8 h/day, 8 days), 3- Noise exposure (100 dB,700-5700 Hz, 8 h/day, 14 days). The animals were anesthetized by CO2 and after decapitation, blood and liver samples were collected and processed for estimation of biochemical parameters (MDA and GSH levels) in control and exposed groups.Results: The present research findings showed significant decrease in liver weight and liver/body weight ratio in noise exposed groups compared to the control group (p<0.05). Fourteen days noise exposure caused a statistically significant increase in MDA level in serum and liver tissue and also statistically significant decrease in GSH level in serum (p<0.05), however, the level of GSH in the liver tissue showed no significant change. 8-days exposure just caused a statistically significant increase in MDA level in serum, and there was no significant change in the other parameters. Moreover, the levels of changes in biochemical parameters in noise exposed groups were exposure time-dependent.Conclusion: the results of present study showed that exposure to noise is toxic to blood and liver tissue. Further research for exploring the toxicity of noise in occupationally exposed groups is recommended.

Background: Clostridium tetani or Nicolaier's bacillus is an obligatory anaerobic, Gram-positive, movable with terminal or sub terminal spore. The chromosome of C. tetani contains 2,799,250 bp with a G+C content of 28.6%. The aim of this study was identification and genomic fingerprinting of the vaccine strain of C. tetani.Materials and Methods: The vaccine strain of C. tetani was provided by Razi Vaccine and Serum Research Institute. The seeds were inoculated into Columbia blood agar and grown for 72 h and transferred to the thioglycolate broth medium for further 36 h culturing. The cultures were incubated at 35oC in anaerobic conditions. DNA extraction with phenol/ chloroform method was performed. After extraction, the consistency of DNA was assayed. Next, the vaccine strain was digested using pvuII enzyme and incubated at 37oC for overnight. The digested DNA was gel-electrophoresed by 1% agarose for a short time. Then, the gel was studied with Gel Doc system and transferred to Hybond N+membrane using standard DNA blotting techniques.Results: The vaccine strain of C. tetani genome was fingerprinted by RFLP technique. Our preliminary results showed no divergence exists in the vaccine strain used for the production tetanus toxoid during the periods of 1990-2011.Conclusion: Observation suggests that there is lack of significant changes in RFLP genomic fingerprinting profile of the vaccine strain. Therefore, this strain did not lose its efficiency in tetanus vaccine production. RFLP analysis is worthwhile in investigating the nature of the vaccine strain C. tetani.

Background: 5-Bromo-2-deoxyuridine (BrdU) has been a principal marker for mitotic cells in studies of adult neurogenesis. The method consists of a pulse injection of BrdU into the intraperitoneal cavity followed by a variable survival time allowing for tracking the divided cells and their progeny. However, such exogenous markers may produce toxic effects. Aim of this study was determined the effects of Brdu on spatial memory in the adult rat.Materials and Methods: 16 Wistar rats were used in this experimental study. The rats were randomly divided into 2 groups (N=8 in each group), as follows: control and Brdu (50 mg/kg). Brdu was administered intraperitoneally for 6 weeks and then animals were used for behavioral testing in the Morris water maze. The data were analyzed with repeated measure's ANOVA.Results: Our present findings show that there were no differences in the path length, escape latency and swim speed between control and Brdu-administrated groups.Conclusion: This study show that Brdu (exogenic proliferation marker) did not has side effects on spatial memory in the adult rats.

Background: Hyperglycemia is the principal factor responsible for microvascular complications of diabetes. Diabetic nephropathy is a serious and common complication leading to end stage renal disease. The exact molecular mechanisms of high glucose-induced toxicity on renal cells are still incompletely understood. Therefore in the present study, glucose-induced toxicity was studied in HEK (human embryonic kidney) cells as an in vitro model for diabetic nephropathy.Materials and Methods: First, the viability of HEK 293 cells exposed to glucose was measured by MTT (Methyl Thiazolyl Tetra-zolium) assay. Caspase-3 activity was determined spectrophotometrically using enzyme specific substrate. Moreover, the alteration in expression of Bax, Bcl2 and caspase-3 were measured by Western blotting.Results: The results showed that high glucose significantly reduced cell viability after 48 h (p<0.05). In Western blot analysis, the ratio of Bax/Bcl-2 protein expression in cells treated with high glucose was significantly increased compared to controls (p<0.001). The activity of caspase-3 was significantly increased in treated cells compared to control (p<0.01). Moreover, high glucose exposure induced a significant decrease in protein level of procaspase-3 (p<0.01), indicating conversion of pro-form into the mature caspase.Conclusion: On the current data, it could be concluded that high glucose can cause HEK cell death, in which apoptosis plays an important role possibly by the mitochondrial pathway through higher expression of Bax pro-apoptotic protein and also by activation of caspase-3 related pathways.

Background: Since melatonin has been effective in some studies to improve liver failure and yet its effect in reducing liver toxicity of amphotericin B was not evaluated, in the present study the effects of melatonin and vitamin E were compared in reducing liver toxicity caused by amphotericin B in rabbits.Materials and Methods: The study was performed on five groups of rabbits, one control group, and 4 amphotericin (1 mg/kg) receiving groups (2 to 5), group 3 received melatonin (1 mg/kg), group 4 received vitamin E (80 mg/kg), and group 5 received melatonin together with vitamin E. Alterations in enzyme activity of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and lactate dehydrogenase in serum and liver tissue were evaluated.Results: Results showed that administration of amphotericin had significantly increased the activity level of liver function related enzymes. But consumption of vitamin E and melatonin prevented this increase, while the combination of vitamin E and melatonin had a more significant effect on lactate dehydrogenase. Also compared with the control group, liver tissue damage and cellular damage were significant after amphotericin consumption and these changes were decreased by melatonin and vitamin E.Conclusion: Melatonin and vitamin E may prevent liver damage caused by amphotericin through their antioxidant properties.

Background: Tuberculosis (TB) is a disease caused by a bacterium called Mycobacterium tuberculosis. M. tuberculosis has different molecular weight secreted antigens. Low molecular weight proteins secreted into the culture medium by M. tuberculosis are thought to play an important role in the development new TB diagnostic tests and new vaccines against tuberculosis. In this report, we describe isolation and purification of low-molecular-weight proteins secreted by M. tuberculosis.Materials and Methods: Initially by biphasic medium, bacteria from Lowenstein-Jensen solid medium transferred to a Dorset-Henley liquid medium and After 6 weeks of growth, the bacteria with a 0.22 micron filters of liquid medium containing secreted proteins were isolated and the secreted proteins was precipitated by ammonium sulfate. Protein concentrations were determined by using the lowry protein assay. Then low molecular weight proteins were purified by Sephadex-G75 gel chromatography and we studied purification of low molecular weight proteins by Coomassie-Blue stained SDS-PAGE.Results: The results showed that low molecular weight secreted proteins purified from M. tuberculosis strain DT. Also, low molecular weight proteins made up approximately 65.3% of total proteins.Conclusion: this study demonstrated that without break down of bacteria bodies can be purified low molecular weight secreted proteins from M. tuberculosis liquid medium by Sephadex-G75 gel chromatography.

Background: Amyloid Beta (1-42) is derived from amyloid precursor protein and plays a critical role in AD pathogenesis. The purpose of this study was to investigate the effect of 6 weeks of voluntary wheel running on brain Amyloid beta (1-42) in the diabetic rats induced with alloxan.Materials and Methods: 28 male rats weight 185±1 were assigned randomly to 4 groups (N=7): normal control (C), training (T), control-diabetic (CD) and diabetic-training (DT).Diabetes was induced with injecting Alloxan (120 mg/kg dissolved in saline) intraperitoneal.Results: 6 weeks of voluntary wheel running decreased the cortex Ab1-42 in T and DT groups. Ab1-42 levels significantly decreased in the T and DT in compare with C and CD (p<0.001), respectively. Also Ab1-42 levels significantly increased in the CD in compare with C (p<0.001).Conclusion: voluntary exercise had positive effects on decreasing of Ab1-42 levels during 6 weeks. Therefore it can be recommended as therapeutic strategy for diabetes.

Background: Albendazole is utilized as an anthelmentic agent. One its side effect is teratogenicity. This effect apparently is related to its metabolites especially albendazole sulfoxid. The aim of present study was evaluation effect of erythromycin (as enzyme inhibitor in biotransformation) on albendazole biotransformation and consequently fetal malformation.Materials and Methods: Four groups of female pregnant wistar rats (8 rats each group) were used. First group received normal saline (as control group). A single oral dose 30 mg/kg of albendazole was administered to rats on day 10 of gestation in group 2. Rats in group 3 received albendazole similar group 2 and erythromycin at dose 60 mg/kg. Rats in group 4 received only erythromycin on day 10 of gestation. The rats were euthanatized on day 20 of gestation. The skeletal malformation of fetus was studied by stereomicroscope after staining by Alizarin red-Alcian blue.Results: The length and weight of fetuses were significantly decreased by albendazole but erythromycin did not prevent this effect. In group that received only erythromycin, the length and weight of fetuses was similar to control group. Erythromycin decreased albendazole effect on weight of placenta. There was an increase in resorption by erythromycin when co-administrated with albendazole. The incidence of skeletal malformations (mostly of the limbs, vertebrae and palate) decreased significantly by erythromycin when co-administrated with albendazole.Conclusion: Thus, erythromycin may inhibit albendazole biotransformation and decrease teratogenicity of it metabolites, but this subject needs more detailed evaluation.

Background: The purpose of this study was to investigate the effects of three sessions of running on a negative slope (eccentric contraction) on changes of the serum levels of aspartate aminotransferase (AST) and alanin aminotransferaze (ALT) in adult male rats.Materials and Methods: 20 adult male rats were divided randomly into two equal groups (exercise and control). Levels of AST and ALT in both groups were measured in a fasting state, 24 hours before and 24 hours after the last session of training.Results: Exercise increased the levels of serum AST and ALT enzymes, significantly (p<0.05).Conclusion: Eccentric exercise, without allowing enough time for returning to the pre-exercise state, leads to the damage of some body organs such as the liver.