Iranian Journal of Basic Medical Sciences
Volume:15 Issue: 3, May-Jun 2012

Objective(s)Motility plays a major role in pathogenicity of Helicobacter pylori, yet there is scarce data regarding its chemotactic behaviour. The present study was designed to investigate the chemotactic responses of local isolates of H. pylori towards various sugars, amino acids, as well as some other chemical substances.Materials and MethodsChemotaxis was assayed by a modified Adler’s method. We used solutions of sugars, amino acids as well as urea, sodium chloride, sodium and potassium bicarbonate, sodium deoxycholate and keratin at 10 mM concentrations.ResultsDespite some small differences, tested H. pylori isolates generally had a positive chemotaxis towards the tested sugars (P< 0.05). Among amino acids, phenylalanine, aspartic acid, glutamic acid, isoleucine and leucine showed a positive chemotaxis (P< 0.05); however, tyrosine showed negative chemotaxis (repellent) (P< 0.15). Urea, sodium chloride, sodium and potassium bicarbonate showed to be attractants (P< 0.05), but sodium deoxycholate was repellent (P< 0.05). ConclusionIt seems that, sugars and many amino acids by their attraction for H.pylori, many amino acids, may enhance the activity of this bacterium and probably aggravate the symptoms of its infection. However, those like L-tyrosine, may possibly be employed as deterrents for H. pylori and thus can control its infections. However, we suggest that further investigations on chemotactic behaviour of many more strains of H. pylori should be carried out before a final conclusion.

Objective(s)Fatty acid is amide hydrolase which reduce endogenous anandamide. Transient receptor potential vanilloid-1 (TRPV1) channels have been reported to have a role in the modulation of anxiety-like behaviors in rodents. In the present study, the effects of either endocannabinoid system or TRPV1 channels and their possible interaction on anxiety-like behaviors of the rats were explored.Materials and MethodsElevated plus-maze test of anxiety was used to induce anxiety. Capsaicin and AMG 9810 as TRPV1 agonist and antagonist respectively were injected into the dorsal hippocampus. URB 597 as selective FAAH inhibitor and AM 251 as CB1 receptor selective antagonist were also injected into the dorsal hippocampus. The effect of AMG 9810 on the response of URB 597 was also examined. ResultsIntra-CA1 injection of URB 597 (0.001, 0.01 and 0.1 µg/rat) and AMG 9810 (0.003, 0.03 and 0.3 µg/rat) produced anxiolytic-like effects. Intra-CA1 infusion of capsaicin (0.003, 0.03 and 0.3 µg/rat) increased the anxiety-related behaviors and AM 251 (0.001, 0.01 and 0.1 µg/rat) did not significantly change the animals behavior. AMG 9810 at the dose of 0.003 µg/rat did not change the anxiolytic-like effect of URB 597. ConclusionThe results of the present study demonstrated that both endocannabinoid system and TRPV1 receptors may affect anxiety-like behaviors. In addition, it seems that TRPV1 receptors are not involved in the effects of anandamide on anxiety-related behaviors in the CA1 region.

Objective(s) Several lines of evidence indicate that neuropeptides exhibit protective properties against gastroduodenal ulcers. Neurotensin, a gut-brain neuropeptide, is implicated in a number of physiological processes in the central nervous system and peripheral tissues including gastrointestinal tract. In the present study, we aimed to investigate the gastroprotective potential of either peripherally or centrally administered neurotensin with a look at the role of the cannabinoid CB1 receptors which are located in brain areas implicated in the regulation of gastric functions. Materials and MethodsGastric mucosal damage was induced by intragastric administration of acidified ethanol in male Wistar rats. One hour later, gastric lesions were evaluated macroscopically. In gastroprotection study, neurotensin was administered either intravenously (1.5, 3, and 5 µM/kg) or intracerebroventricularly (0.5, 1, and 2.5 nM/rat) 30 min before the ethanol challenge. In order to evaluate the involvement of central CB1 receptors in the gastroprotective effect of neurotensin, the CB1 receptor antagonist AM251 (5, 10, and 15 nM/rat) was given i.c.v. 30 min prior to the administration of neurotensin. The effects of AM251 on the intact stomach and ethanol-induced gastric lesions were also evaluated.ResultsAcidified ethanol induced large areas of gastric lesions which were significantly reduced bythe highest dose of neurotensin in i.v. or i.c.v. application. The gastroprotective effect of neurotensin was prevented by pretreatment with 15 nM/rat AM251. AM251 had no effect by itself. Conclusion Peripherally or centrally given neurotensin protects gastric mucosa against damage induced by acidified ethanol through the activation of central cannabinoid CB1 receptors.

Objective(s)Fabaceae is the third largest family of flowering plants. Lack of essential oils in the plants of this family can be considered as an advantage and can favor them in search for safe and antiepileptic medicines. The effects of Fabacea family plants includingEbenus stellata (E. stellata), Sophora alopecuroides and Caesalpinia gilliiesii were evaluated in pentylenetetrazole (PTZ) and maximal electroshock (MES) seizure tests. Materials and MethodsThe hydroalcoholic extracts were obtained by percolation of 100 g aerial parts ofeach plant in 900 ml ethanol 80%. Acute toxicity of the extracts was assessed. Non-toxic doses of the extracts were injected to the mice intraperitoneally (i.p.) and occurrence of clonic seizures induced by PTZ (60 mg/kg, i.p.) or tonic seizures induced by MES (50 mA, 50 Hz, 1 sec), were monitored up to 30 min after each administration. The anticonvulsant extract was then fractionated by dichloromethane and water. Phytochemical screening of the effective extract was also carried out by thin layer chromatography to verify active constituents. ResultsAmong theextracts used, only E. stellata had no toxicity and inhibited clonic seizures in a significant and dose-dependent (3-7 g/kg) manner with ED50 of 4 g/kg. Fractionation of the extract resulted in dose-dependent (1-5 g/kg) anticonvulsant activity, which was observed in aqueous fraction with ED50 of 1.74 g/kg. Phytochemical screening revealed the presence of terpens/sterols, alkaloids, flavonoids, tannin and saponins in the extract. ConclusionThe presence of anticonvulsant compounds in E. stellata suggestsfurther activity-guided fractionation and analytical studies to find the potential of this plant as a source of anticonvulsant agents.

Objective(s)The purpose of the present study was to use the solid dispersion (SD) technique to improve the dissolution rates of indomethacin (IMC). Materials and MethodsIMC solid dispersions in PVP K30 and isomalt (GALEN IQ 990) were prepared using the solvent evaporation technique and a hot melt method in weight ratios of 2, 10 and 30% (IMC:PVP). Solid dispersions and physical mixtures were characterized by X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC) and dissolution test. Physical stability tests were also performed at different temperatures and humidity conditions. ResultsThe dissolution rates of all solid dispersions were faster than those of their physical mixtures. In samples containing 2% or 10% of IMC, there were no significant differences between the dissolution rates of IMC in PVP and isomalt solid dispersions, but in samples containing 30% of IMC, the dissolution rates were higher in isomalt dispersions. The XRPD analysis showed no crystalline peaks in solid dispersions, indicating that IMC was amorphous within the carrier. The DSC results showed that an interaction occurred between the drug and the carrier in PVP and isomalt dispersions. Physical stability tests at severe storage conditions showed that the dissolution rate of IMC in PVP solid dispersions decreased, while the dissolution profile of IMC in isomalt solid dispersions did not change significantly.ConclusionIt was shown that the dissolution rates of IMC in PVP and isomalt solid dispersions were substantially increased compared with their physical mixtures and pure IMC.

Objective(s)Extended-spectrum beta-lactamase (ESBL) producing bacteria have an important role in nosocomial infections. Due to the limited availability of information about the molecular epidemiology of ESBL producing bacteria in Mashhad, we decided to investigate about TEM, CTX and SHV ESBLs among urinary Escherichia coli isolates in Mashhad, a city in northeast Iran. Materials and Methods One hundred and eleven clinical isolates of E. coli were diagnosed from hospitalized patients in 2009. After performing antibiogram and phenotypic confirmation test, polymerase chain reaction (PCR) was performed by blaTEM, blaSHV and blaCTX primers and restriction digestion was carried out using PstI and TaqI (Fermentas-Lithuania) for confirmation. ResultsESBL producers of E. coli isolates were 33.3%. Among 37 ESBL-producing isolates, 35 (94.6%), 21 (56.8%) and 5 (13.5%) were shown to have blaCTX, blaTEM and blaSHV, genes respectively. Co-resistance to non-beta lactam antibiotics was observed more with ESBL producers (P < 0.05). Conclusion The results showed that the studied ESBL genes are found with high prevalence and among them blaCTX is more widespread in urine E. coli isolates in Mashhad.

Objective(s)Human papillomavirus (HPV) infections are related to the genesis of various benign lesions and some malignant tumors, but no clear relationship has been identified so far between the subtypes of HPV and skin tag. Materials and MethodsThe present case-control study was designed to detect the existence of low risk and high risk HPV types in lesions of 50 patients with skin tag (case group) and normal skin around the melanocytic nevus of 30 patients (control group), using PCR. ResultsAll of the samples were negative for HPV subtypes, except two samples in control group which were positive for high risk HPV. There was no significant relationship between the HPV subtypes and skin tag.ConclusionThere is no association between skin tag and low risk and high risk human papillomaviruses.

Objective(s)Lipocalin 2 (Lcn2) is a 25-kDa glycoprotein that has initially been extracted from neutrophil granules. Expression of Lcn2 is induced under various pathophysiological conditions. It is also known as an early marker of kidney and heart injury. High-level expression of recombinant Lcn2 neutrophil gelatinase-associated (NGAL) in insect cells was the aim of this study. Materials and MethodsLcn2 gene was isolated from HepG2 cell line. The PCR product was cloned into TOPO vector to construct TOPO-Lcn2. Then Lcn2 was transferred to Gateway adapted Baculovirus DNA by LR recombination reaction. The recombinant Baculovirus DNA was transfectedinto insect cell line. Expression of recombinant Lcn2 was detected by RT-PCR, ELISA and western blot analysis. ResultsInsertion of Lcn2 into pENTR/D-TOPO vector was confirmed by using PCR. The accuracy of the nucleotides sequence was verified by DNA sequencing. Transfer of the Lcn2 cDNA into the Baculovirus destination vector by LR recombination reaction was confirmed by amplification of a band of about 860 bp length by using forward Lcn2 primer and V5 reverse primer. Next, Lcn2 protein was detected as a prominent band with approximate molecular weight of 30 kDa in SDS-PAGE and western blot analysis. ELISA results revealed high-level expression of Lcn2 by Spodoptera frugiperda (Sf9) cells. ConclusionHigh-level expression of Lcn2 protein in insect cells is promising for future potential applications. Recombinant Lcn2 might be used for producing monoclonal or polyclonal antibodies and as potential therapeutic agent. Large scale expression and purification are next steps that are on the way.

IntroductionSulfur Mustard (SM) has been used as a chemical warfare agent, in the World War I and more recently during Iraq-Iran war in early 1980s’. Its biological poisoning effect could be local or systemic and its effect depends on environmental conditions, exposed organs, and the extent and duration of exposure. It is considered as a strong alkylating agent with known mutagenic, carcinogenic effects; although a few studies have been performed on its teratogenicity so far. Materials and Methods Mice were administered with SM intraperitoneally with a dose of 0.75 and 1.5 mg/kg in different periods of their gestation (gestational age of 11, 13 and 14 weeks). Control mice groups were included. Between 5 and 9 mice were used in each group. Dams underwent cesarean section on day 19 of their gestation. External examination was performed on the animals investigating craniofacial and septal defects and limb malformations such as adactyly and syndactyly. All data were analyzed by Chi-Square test and Fisher's exact test. The P- value less than 0.05 was considered significant.Results Craniofacial and septal defects as well as the limb malformations were the most common types of birth defects, displaying an extremely complex biomedical problem. ConclusionThis study confirms a significant correlation between SM exposure and its teratogenic effect. We postulated that the malformations could be caused by an uncontrolled migration of neural crest cells, causing developmental disorders. In addition to environmental factors, modifying genes could play an important role in the pathogenesis of the defects.

Objective(s)Human umbilical cord blood (HUCB) is now considered as a valuable source for stem cell–based therapies. Previous studies showed that intravascular injection of the HUCB significantly improves neurological functional recovery in a rat model of intracerebral hemorrhage (ICH). In the present study, we hypothesize transplanted HUCB derived mononuclear cells (UC-MCs) can decrease injured volume and also ameliorate neurological function in ICH rats.Materials and MethodsExperimental ICH was induced by intrastriatal administration of collagenase in rats. One day after surgery, the rats were divided into 3 groups to receive intravenously either BrdU positive human UC-MCs [(4×106 and 8×106 cells in 1 ml saline, n=10 respectively) as treated groups] or the same amount of saline [as lesion group (n=10)]. There was also one group (control) that received only vehicle solution of collagenase. The animals were evaluated for 14 days with behavioral tests. Transplanted UC-MCs were detected by immunohistochemistry. Histological data and scores of functional tests were analyzed using ANOVA. Cellular co-localization of BrdU+ cells in the histological slides was determined by software Image J.ResultsIntravenously transplanted UC-MCs migrated selectively to the hematomal area and reduce injured volume. The UC-MCs transplanted groups showed better performance on functional tests after 2 weeks compared with the lesion and control groups (P< 0.05). There was no difference in the functional recovery and injured volume improvement between the 2 treated groups.ConclusionIntravenously transplanted UC-MCs accelerate neurological function recovery of ICH rat and diminish the striatum lesion size. Thus these cells may provide a potential cell candidate for cell-based therapy in ICH.

Objective(s)The immunoadjuvant potential of cross-linked dextran microspheres (CDM) as absorption enhancer and Quillaja saponins (QS) as immunomodulator adjuvant was evaluated. Materials and MethodsCDM loaded or tetanus-mixed toxoid (TT) or Quillaja saponin (QS) were nasally administered to rabbits in dry powder form, three times in 2 weeks interval and serum IgG and nasal lavage sIgA titers were determined by ELISA.ResultsThe highest serum IgG titer was induced by parenteral immunization through alum adsorbed TT (P< 0.001). Among nasally immunized groups, the highest serum IgG titer was induced by (TT+QS)CDM (P< 0.01). Mixing of CDM with TT+QS powders (CDM+TT+QS), could not induce the high serum IgG titers as (TT+QS)CDM (P< 0.01). CDM loaded with TT+QS induced higher IgG titers than CDM loaded with TT alone (P< 0.01). No significant difference was observed in nasal lavage sIgA titers of various groups. ConclusionCDM microspheres loaded with TT+QS significantly increased serum anti-TT IgG titers, but mixing of CDM with TT+QS powder could not increase IgG titers. Both QS and CDM adjuvant could not significantly increase the lavage anti-TT IgA titers.

Objective(s)Cigarette and nicotine enhances embryogenesis, fertility, pregnancy loss and ultrastructure alterations of oocyte. This study was performed to determine the effect of daily supplementation of vitamin E on oocytes apoptosis in nicotine-treated mice.Materials and MethodsIn this experimental study, 24 NMARI adult female mice were randomly allocated into four experimental groups. For 30 days, animals in control group (C) were received saline through subcutaneous injection, group I received vitamin E (60 mg/kg/day orally), group II received nicotine (5 mg/kg/day, subcutaneous) and animals of group III received nicotine with vitamin E (60 mg/kg/day orally). After 30 days, the animals were superovulated with PSMG (10 Units) and HCG (10 Units). Next day animals were sacrificed and oocytes were flushed. Collected oocytes were examined through TUNEL assay for the determination of apoptosis through the use of fluorescent microscope. ResultsThe number of retrieved oocytes was 139, 148, 97 and 127 in control, experimental group I, II and III, respectively. Nicotine treatment increased apoptosis in oocytes up to 13.4% whereas oocytes apoptosis was 3.6% in controls. Supplementation with vitamin E in nicotine-treated mice reduced the oocytes apoptosis to 5.5%.ConclusionThis study showed that nicotine exposure (5 mg/kg/day for 30 days) can increase apoptosis in oocytes, and supplementation with vitamin E (60 mg/kg/day orally) can reduce the oocytes apoptosis in nicotine-treated mice.

Objective(s)Amongst the various antibiotic resistant elements in Vibrio. cholerae, SXT constin (SXT-C) is important. We were going to design a quick method for determination of antibiotic resistance gene pattern in SXT-C.Materials and MethodsNinety fourV. cholerae O1El Tor isolates were used in this study. Antibiotic susceptibility testing, multiplex PCR amplification of SXT-C containing dfrA1, sulII, strB and the int in a multiplex PCR were done. ResultsResults of our study showed that 92 (97.8%) out of 94 isolates were positive for all above genes. Multiplex PCR results correlated with the antibiotic susceptibility data obtained by using disc diffusion assay.ConclusionUsing this multiplex PCR, it would be easily possible to demonstrate the presence of antibiotic resistance in SXT-C which, in turn, allows for a suitable treatment in cholera patients causing reduction in the mortality and morbidity rate of the infected individuals.