Iranian Journal of Basic Medical Sciences
Year:2013 | Volume:16 | Issue:9|Papers Count:12

Objective(s): The effect of maternal voluntary exercise on hippocampal BDNF level in rat offspring was studied. In addition, the possible role of hippocampal BDNF receptors in maternal exercise induced enhancement of learning in the rat pups was investigated.Materials and Methods: Pregnant rats have been randomly assigned to sedentary control or voluntary exercise groups. Each of the exercising pregnant rats was given access to a cage that was equipped with a running wheel until the end of their pregnancy. On post natal day (PND) 36, two groups consisted of 7 male rat pups in each group from sedentary or exercised mothers were sacrificed and the hippocampus was dissected for BDNF proteins level determination. Also, bilateral injection of K252a to the hippocampus was used to block the hippocampal BDNF action on PND59 in the rat pups.Results: Voluntary exercise during pregnancy significantly increased the level of BDNF protein in the hippocampus of the rat pups on PND36 compared to the control group (P=0.048). Inhibiting BDNF action abolished the exercise-induced improvement of learning acquisition in offspring in training trials (P=0.0001). No difference was observed in the platform location latency and the time spent in the target in the probe test between two groups.Conclusion: This study demonstrates that voluntary exercise during pregnancy via a TrkB-mediated mechanism enhances the spatial learning acquisition, however, not the retention of memory in the rat pups.

Objective(s): According to the occupationally risk of infection in staff workers who have direct contact with mycobacterium species, we investigated their immunological parameters and compared with healthy purified protein derivative (PPD) negative volunteers.Materials and Methods: We investigated 20 PPD positive volunteers working at Tuberculin Unit of Razi Vaccine and Serum Research Institute and PPD negative healthy controls with no exposure or history of active tuberculosis. The percentages of circulating lymphocyte subpopulations were detected by flowcytometry. IL-4 and IFN-g production levels were measured by ELISA in supernatants of PPD-stimulated peripheral blood mononuclear cells (PBMCs) culture.Results: Tuberculin workers showed an increase in IFN-g level and significant decrease of CD4+T cells percentage and CD4/CD8 ratio compared to PPD negative normal individuals. However the IL-4 production and percentage of other lymphocyte population has been unchanged.Discussion: These observations suggest that the immunological parameters of tuberculin workers with PPD positive reaction, who are occupationally exposed to mycobacterium antigens, could be changed. Future studies will be directed towards cytokine networking and regulatory lymphocytes, which will help us validate the significant data presented in this study.

Objective(s): Soluble Leishmania antigens (SLA) provide suitable protection against leishmaniasis in murine model when delivered by an appropriate delivery system. Liposomes have been shown to be suitable vaccine delivery systems against leishmaniasis, however, the phospholipase-A (PLA) activity of SLA is a drawback to prepare a stable liposomal SLA. One strategy to overcome this problem might be using a lipid which is resistant to PLA activity of SLA such as sphingomyelin (SM). The aim of this study was to evaluate the effect of stable SM liposomes containing SLA on the immune response induced against leishmaniasis in BALB/c mice.Materials and Methods: BALB/c mice were immunized subcutaneously, three times with 2-week intervals, with SLA, SM-liposome-SLA, empty liposome or buffer. As criteria for protection, footpads swelling at the site of challenge and foot parasite loads were assessed. The immune responses were also evaluated by determination of IgG subtypes and the level of IFN-g and IL-4 in cultured splenocytes.Results: The group of mice receiving SM-liposome-SLA, showed a significant large footpad swelling, higher parasite burden in foot and higher IL-4 level compared to the group immunized with buffer. In terms of IgG and IgG isotypes, there was no significant difference between the mice receiving SM-liposome-SLA and the mice that received buffer. Moreover, the immune response induced by SM-liposome-SLA showed no significant difference compared with the one caused by SLA alone.Conclusion: It is concluded that SM-liposome-SLA is not an appropriate strategy to induce Th1 immune response and protect the mice against Leishmaniasis; however, SM-liposomes could be suitable vaccine delivery systems when a Th2 response is needed.

Objective(s): siRNA may be a very promising tool for treatment of various diseases especially in cancer therapy due to high specificity. One of the main hurdles applications of siRNAs in vivo is optimization of the delivery strategy, especially the carrier systems. The aim of this study was to optimize siRNA delivery into suspended erythroleukemic cell line K562.Materials and Methods: We applied polyethyleneimine (PEI) and oligoethyleneimine (OEI) derivatives alone or their co-formulation with different agents such as chloroquine (a drug known to alter lysosomal pH and thus to inhibit lysosomal degradation of macromolecules), DOPE (lipophilic agent), succinic acid (introduction of negatively charged to polymer) and transferrin (the ligand of transferring receptor which is over-expressed in many types of tumors and hematopoietic cells).Results: In this study it was shown that utilizing a combination of 70% OEI-HA10 (ten hexyl acrylate residues per one OEI chain) plus 30% of transferin-PEI with Luc-siRNA was highly effective for transfecting K562 cell. This co-formulation silenced luciferase activity up to 70% after short time without any significant inhibition in the luciferase activity in siCONTROL wells.Conclusion: In conclusion, the combination of modified PEI with transferrin and OEI by hexyl acrylate may increase siRNA delivery and reduce toxicity in hematopoietic suspended cells.

Objective(s): Epilepsy is a neurodevelopmental disorder which is strongly influenced by genetic and environmental factors. Gestational stress has been shown to be an important factor for affecting seizure susceptibility. The present study was conducted to address whether gestational stress may affect pentylentetrazol (PTZ) -induced epileptic behavior in rat offspring in a sex- and age- dependent manner.Materials and Methods: Pregnant rats were divided into control and stressed groups (n=6 in each). In the stressed group, pregnant rats were under restraint stress and held immobile in the Plexiglas tube twice per day one hour per session for three consecutive days started on day 17 of pregnancy. To induce seizure, on postnatal days 15 (P15) and 25 (P25), PTZ (40-50 mg/kg, IP) was injected to rat offspring (n=12, one male and one female from any litter for each group/day). Then, epileptic behaviors of each rat were recorded.Results: Epileptic behaviors of stressed pups showed significant changes in comparison to control ones. The time to onset of the first epileptic behavior was shortened while mean duration and frequency of tonic-clonic attacks increased in stressed pups on both P15 and P25. Female offspring were different from male offspring in terms of epileptic behavior. Moreover, focal attacks were more obvious and significantly longer in the offspring of stressed group at the age of 25 days than those of 15 day old.Conclusion: Prenatal restraint stress potentiated PTZ-induced epileptic behavior, age and sex dependently, probably due to alteration of neural and endocrine pathways during developmental process. Male and younger rats were more sensitive to stress than female and older ones.

Objective(s): Streptokinase (SKa) is an antigenic protein which is secreted by Streptococcus pyogenes. Streptokinase induces inflammation by complement activation, which may play a role in post infectious diseases. In the present study, recombinant streptokinase from S. pyogenes was produced and showed that recombinant SKa protein was recognized by infected human sera using Western blot analysis.Materials and Methods: In this study, the ska gene from S. pyogenes was amplified and cloned into pET32a which is a prokaryotic expression vector. pET32a-ska was transformed to Escherichia coli BL21 (DE3) pLysS and gene expression was induced by IPTG. Protein production was improved by modification of composition of the bacterial culture media and altering the induction time by IPTG. The expressed protein was purified by affinity chromatography using the Ni-NTA resin. The integrity of the product was confirmed by Westernblot analysis using infected mice. Serum reactivity of five infected individuals was further analyzed against the recombinant SKa protein.Results: Data indicated that recombinant SKa protein from S. pyogenes can be recognized by patient and mice sera. The concentration of the purified recombinant protein was 3.2 mg/L of initial culture. The highest amount of the expressed protein after addition of IPTG was obtained in a bacterial culture without glucose with the culture optical density of 0.8 (OD600=0.8).Conclusion: Present data shows, recombinant SKa protein has same epitopes with natural form of this antigen. Recombinant SKa also seemed to be a promising antigen for the serologic diagnosis of S. pyogenes infections.

Objective (s): Non- Hodgkin lymphoma (NHL) and acute lymphoblastic leukemia (ALL) are two main hematological malignances which have been driven from lymphoid tissue. Genetic polymorphisms in tumor necrosis factor-a (TNF-a) -308 and lymphotoxin-a (LT-a) +252 may affect their transcription and expression which leads to their high plasma level. The frequency of the TNF-a (-308) and LT-a (+252) polymorphisms are different for NHL and ALL cases in various populations with different ethnicity. This research is designed to investigate the prevalence and association of TNF-a (-308) and LT-a (+252) polymorphisms from NHL and ALL in Azarian patients and healthy individuals from Northwestern part of Iran.Materials and Methods: Seventy subjects with ALL and 68 NHL, along with another 130 healthy subjects as control group took part in this study. Genomic DNA was extracted, then genetic polymorphisms in TNF-a and LT-a genes were analyzed with the PCR-RFLP and NCOI as restriction enzyme. A statistical analysis was performed by chi-square test using SPSS software. A P-value of<0.05 was considered statistically significant.Results: A statistically significant difference of LT-a polymorphism was in NHL patients and control (P-value=0.008) but there was not any association of TNF-a polymorphism between NHL patients and control group. A significant association for TNF-a variant was in ALL and control (P-value=0.005), however, there was no relationship about LT variant between ALL and control.Conclusion: The results show that there are significant differences between TNF-a (-308) and LT-a (+252) genetic polymorphisms respectively in ALL and NHL patients with control group from Northwestern part of Iran.

Objective(s): This study aimed to find out whether the chick cardiomyocyte micromass (MM) system could be employed to predict the teratogenecity of common environmental factors. Different multivitamins and over the counter drugs were used in this study.Materials and Methods: White Leghorn 5-day-old embryo hearts were dissected and trypsinized to produce a cardiomyocyte cell suspension in Dulbecco’s Modified Eagle's Medium. The cultures were incubated at 37oC in 5% CO2 in air, and observations were made at 24, 48 and 144 hr, for the detection of cell beating. Cellular viability was assessed using the resazurin assay and cell protein content was assessed by the kenacid blue assay. It was observed that while not affecting total cell number folic acid, vitamin C, sodium fluoride and ginseng did not significantly reduced cell activity and beating. However cadmium chloride significantly reduced the beating, cell viability and cell protein content in micromass cultures.Results: The results demonstrate the potential of the chick cardiomyocyte MM culture assay to identify teratogens/embryotoxins that alter morphology and function, which may result in either teratogenic outcome or cytotoxicity.Conclusion: This could form part of a screen for developmental toxicity related to cardiac function.

Objective(s): Cerebral hypoperfusion/ischemia (CHI) is a neurological disease where impaired hippocampus electrical activity and cognition caused by a serial pathophysiological events. This study aimed to evaluate the effects of chronic oral administration of grape seed extract (GSE) on passive avoidance memory and long-term potentiation (LTP) after permanent bilateral common carotid arteries occlusion (2CCAO) in male adult rats.Materials and Methods: Thirty-two adult male Wistar rats were randomly divided into: 1) Sham+Veh, 2) Isch+Veh, 3) Sham+GSE, 4) Isch+GSE. In order to make 2CCAO as an animal model of CHI, carotid arteries were ligatured and then cut bilaterally. To evaluation of passive avoidance memory, step-down latency (STL) was measured and LTP was recorded from hippocampal dentate gyrus (DG) after high frequency stimulation (HFS) in all rats.Results: We found that memory was significantly impaired in rats after CHI (P<0.001) concomitant with hippocampal LTP inhibition (P<0.05, P<0.01 for LTP1 and LTP48 respectively). GSE treatment significantly improved memory impairment and increased hippocampal LTP in rats with 2CCAO.Conclusion: Our results in present study suggest that GSE exhibits therapeutic potential for short-and long-term memories as well as LTP in DG, which is most likely related at least in part to its antioxidative and free radical scavenging actions.

Objective(s): Lupus nephritis (LN) is the main cause of mortality and disability in systemic lupus erythematosus (SLE) patients. Therefore, utilizing a reliable and non-invasive method for serial measurements of renal function seems to be necessary. The aim of this study was to evaluate the role of urinary lipocalin-2 as a biomarker of renal involvement in SLE patients.Materials and Methods: Fifty two lupus patients in this cross sectional study were divided into two groups: patients with and without nephritis. For each group, urinary lipocalin-2, values were measured and reported according to urinary lipocalin-2/creatinine. Urinary lipocalin-2/creatinine sensitivity and specificity for identifying biopsy-proven nephritis were calculated, and a receiver operating characteristic (ROC) curve was constructed.Results: The mean urinary lipocalin-2/creatinine value of patients with biopsy-proven LN was 2.99±4.1 ng/mg, and in non-LN patients was 1.16±1.27 ng/mg. Urinary lipocalin-2/creatinine levels in LN patients were significantly higher than those in non-LN patients (P- Value=0.03). In LN patients, urinary lipocalin-2/creatinine significantly correlated with proteinuria (r=0.68; P=0.0001). Using a cutoff value of 0.896 ng/mg, urinary lipocalin-2/creatinine had a sensitivity of 89.7% and a specificity of 39.1% for identifying SLE patients with biopsy-proven LN. The area under the ROC curve was 0.664 ± 0.076 with a 95% confidence interval of 0.52-0.81 (P=0.04). Analysis of variance showed that urinary lipocalin-2/creatinine is the same in different classes of LN (P-value=0.28).Conclusion: An important clinical conclusion is that measurement of urinary Lipocalin-2 may result in earlier diagnosis of LN.

Objective(s): Recently, phthalimide derivatives were designed based on ameltolide and thalidomide as they possess a similar degree of anticonvulsant potency due to their phenytoin-like profile. The ability of phthalimide pharmacophore to interact with neuronal voltage-dependent sodium channels was studied in the batrachotoxin affinity assay. Therefore, in the present study, a series of 19 compounds of phthalimide pharmacophore possessing a variety of substituents (NO2, NH2, Me, Cl, COOH, MeO) at 2-, 3-, and 4- position of the N-phenyl ring and N- (3-amino-2-methylphenyl) succinimide, were subjected to docking studies in order to inhibit voltage-gated sodium channels.Materials and Methods: Chemical structures of all compounds were designed using HYPERCHEM program and Conformational studies were performed through semi-empirical molecular orbital calculations method followed by PM3 force field. Total energy gradient calculated as a root mean square (RMS) value, until the RMS gradient was 0.01 kcal mol-1. Among all energy minima conformers, the global minimum of compounds was used in docking calculations. Using a model of the open pore of Na channels, docking study was performed by AUTODOCK4.2 program.Results: Docking studies have revealed that these types of ligands interacted mainly with II-S6 residues of NaV1.2 through making hydrogen bonds and have additional hydrophobic interactions with domain I, II, III and IV in the channel's inner pore.Conclusion: These computational studies have displayed that these compounds are capable of inhibiting Na channel, efficiently.

Objective(s): The effect of the extract of Crocus sativus and its constituent, safranal on inflammatory markers in sensitized guinea pigs was examined.Materials and Methods: Ovalbumin (OA) sensitized guinea pigs were given drinking water alone (group S), or drinking water containing three concentrations of safranal, three concentrations of extract and one concentration of dexamethasone, (n=6, for all groups) and serum levels of endotheline-1 (ET-1) and total protein (TP) were assessed.Results: Serum levels of ET-1 and TP in group S were significantly higher than control group (P<0.01 for ET-1 and P<0.001 TP). Treatment of S animals with dexamethasone, most concentrations of the extract and safranal significantly reduced serum levels of ET-1 and TP compared to group S (P<0.01 to P<0.001). The effects of one concentration of the extract and safranal were significantly higher than dexamethasone (P<0.05 to P<0.01).Conclusion: A preventive effect of the extract of C. sativus and its constituent safranal on serum inflammatory markers in sensitized guinea pigs was shown.