Iranian Journal of Basic Medical Sciences
Year:2013 | Volume:16 | Issue:6|Papers Count:12

Objective(s): The dopamine level of the nucleus accumbens changes during some stereotyped behaviors. To study dopamine level of the nucleus accumbens in intra infralimbic apomorphine-induced climbing, microdialysis probes were implanted into the nucleus accumbens shell of male Sprague Dawley rats weighting 275–400 g.Materials and Methods: The rats were divided into two groups (apomorphine and control) of least eleven rats in each group. Apomorphine at dose of 5 mg/0.5 ml or its vehicle was microinjected into the infralimbic in apomorphine and control groups respectively. Then, changes in dopamine levels in the nucleus accumbens shell were monitored. The concentration of dopamine was measured by High-Performance Liquid Chromatography-Electochemical (HPLC-ECD). Finally, the stereotyped behaviors were recorded.Results: The mean of dopamine levels for all of after microinjection period in control and drug groups were 450% and 150% respectively compared to those of before microinjection period. However, there was no significant difference between groups of apomorphine and control. In addition, the return of dopamine level to the baseline was faster in apomorphine group than the control group.Conclusion: The intra infralimbic apomorphine -induced climbing at dose of 5 mg/0.5 ml was not modulated via the increase of dopamine level in the nucleus accumbens area.

Objective(s): Drug resistant Acinetobacter baumannii have emerged as a major problem in many hospitals and intensive care units. Various types of extended spectrum beta-lactamases (ESBLs) are responsible for resistance to beta-lactam antibiotics in different parts of the world. The objective of this study was to determine the prevalence of integron class1 (INT 1) and ESBL types PER-1, PER-2 and VEB-1 among A. baumannii strains isolated from Tabriz, North-West of Iran.Material and Methods: A total of 100 A. baumannii isolates collected from different clinical samples were included in the study. Antimicrobial susceptibility profiles were determined using the Kirby Bauer disk diffusion method. Production of ESBL was investigated by testing resistance against ceftazidime, cefotaxime, ceftriaxone and verified by Double Disk Synergy Test. DNA was extracted from the isolates and the frequency of INT 1 and ESBL types PER-1, PER-2 and VEB-1 were determined by PCR using specific primers.Results: Among 100 A. baumannii isolates screened, 80 isolates were multidrug-resistant and 70 isolates were positive for ESBL production. PCR screening revealed that 74 % of the isolates contained class 1 integron, 51% were positive for PER-1 gene, 10% positive for VEB1 whereas none of the isolates were positive for PER2 type gene.Conclusion: This is the first report of ESBL types VEB and PER in A. baumannii from North West of Iran. The results of this study demonstrated high prevalence of PER-1 and VEB-1 type ESBLs among A. baumannii isolates in the study region and reminded the necessity of appropriate infection control strategy to prevent further spread of infection by these organisms.

Objective(s): Erythropoiesis is regulated by some extrinsic and intrinsic factors as microRNAs (miRNAs). miRNAs are endogenously small non-coding regulatory RNAs which play vital roles in the variety of cellular fate, critical processes; growth, apoptosis, metabolism, survival of the cells and specially differentiation. Several miRNAs such as miR-16 and miR-451 have been shown to be correlated with erythroid differentiation. Taking into account the importance of miRNAs in cellular differentiation, the goal of the present study was to examine the role of miRNAs in hematopoietic stem cells (HSC) differentiation into the erythroid cells in the absence of growth factors and stimulatory cytokines.Materials and Methods: CD133+ stem cells were infected with lentiviruses containing miR-451/miR-16 precursor sequence, erythroid differentiation was evaluated using RT-PCR for hemoglobin chains and surface antigens, also by banzidine staining.Results: MiR-451up-regulation, but not miR-16, could induce a, b and g-globin expression in CD133+ cells and have strong correlation with appearance of CD71 and CD235a markers in these cells. Moreover, miR-451 up-regulation increases the banzidine positive cells to ~ %40.Conclusion: Our results provide strong evidence that miR-451 up-regulation strongly induces erythroid differentiation and maturation of CD133+ stem cells. Hence, this method may provide a useful technique for the production of artificial blood RBC and be used as a new strategy for gene therapy of hemoglobinopathies, such as b-thalassemias and sickle cell anemia.

Objective(s): Osteoarthritis is one of the most common diseases in middle-aged population in the world. Cartilage tissue engineering (TE) has been presented as an effort to introduce the best combination of cells, biomaterial scaffolds and stimulating growth factors to produce a cartilage tissue similar to the natural articular cartilage. In this study, the chondrogenic potent ial of adipose derived stem cells (ADSCs) was compared with natural articular chondrocytes cultured in alginate scaffold.Materials and Methods: Human ADSCs were obtained from subcutaneous adipose tissue and human articular chondrocytes from non-weight bearing areas of knee joints. Cells were seeded in 1.5% alginate and cultured in chondrogenic media for three weeks with and without TGFb3. The genes expression of types II and X collagens was assessed by Real Time PCR and the amount of aggrecan (AGC) and type I collagen measured by ELISA and the content of glycosaminoglycan evaluated by GAG assay.Results: Our findings showed that type II collagen, GAG and AGC were expressed, in differentiated ADSCs. Meanwhile, they produced a lesser amount of types II and X collagens but more AGC, GAG and type I collagen in comparison with natural chondrocytes (NCs).Conclusion: Further attempt should be carried out to optimize achieving type II collagen in DCs, as much as, natural articular chondrocytes and decline of the production of type I collagen in order to provide efficient hyaline cartilage after chondrogenic induction, prior to the usage of harvested tissues in clinical trials.

Objective(s): Incidence of neurocognitive and psychological disorders may be related to serum homocystein (Hcy), cobalamin (vitamin B12) and folate levels in old people. The aim of this study was to assess the relation between Hcy, cobalamin, folate and neurocognitive and/or psychological disorders in the elderly.Materials and Methods: In this cross-sectional study, 280 subjects with ³ 65 years old, were evaluated. The subjects were selected from 12 regions of Mashhad, Iran, over March to October 2009. After blood sampling, data were collected by questionnaire, face to face interview and performing neurocognitive and psychological tests. The sera of 250 persons were analyzed for cobalamin and folate by RIA method. Amongst the aforementioned samples, 78 cases with cobalamin <300 pg/ml and folate <6.5 ng/ml were analyzed for Hcy by ELISA method.Results: Amongst the people, 126 (45%) were male and 154 (55%) were female. The prevalence of hyperhomocysteinemia (HHcy) was 59.5% and 37.1% in male and female respectively (P -value =0.049). Hcy inversely correlated to cobalamin (r=-0.282, P=0.014) and to folate (r=-0.203, P=0.014). Hcy, cobalamin and folate correlations to neurocognitive and psychological impairments were not statically significant.Conclusion: Hyper Hcy or low cobalamin and folate in the elderly, are prevalent but their relationships with neurocognitive and psychological impairments is controversial. If these relationships had been confirmed, performing a single serum Hcy or cobalamin test would have been enough to diagnose and prevent neurocognitive impairments and inversely, neurocognitive-psychological sign and symptoms could have meant probable tissue vitamin deficiencies. However methods of assessing neurocognitive and psychological markers with validity and reliability of clinical and laboratory tests for finding aforementioned relationships should be revised.

Objective(s): Sertoli cells support in vivo germ cell production; but, its exact mechanism has not been well understood. The present study was designed to analyze the effect of Sertoli cells in differentiation of mouse embryonic stem cells (mESCs) to germ cells.Materials and Methods: A fusion construct composed of a Stra8 gene promoter and the coding region of enhanced green fluorescence protein was produced to select differentiated mESCs. To analyze sertoli cells’ effect in differentiation process, mESCs were separated into two groups: the first group was cultured on gelatin with retinoic acid treatment and the second group was co-cultured with sertoli cell feeder without retinoic acid induction. Expressions of pre-meiotic (Stra8), meiotic (Dazl and Sycp3) and post-meiotic (Prm1) genes were evaluated at different differentiation stages (+7, +12 and +18 days of culture).Results: In the first group, expressions of meiotic and post-meiotic genes started 12 and 18 days after induction with retinoic acid, respectively. In the second group, 7 days after co-culturing with Sertoli cells, expression of meiotic and post-meiotic genes was observed.Conclusion: These results show that differentiation process to germ cells is supported by Sertoli cells. Our findings provide a novel effective approach for generation of germ cell in vitro and studying the interaction of germ cells with their niche.

Objective(s): Recently we reported that the soybean 15-lipoxygenase (SLO) inhibitory activity of pyrimido[4,5-b][l,4]benzothiazines largely depends on the orientation of sulfur atom of thiazine core towards FeIII-OH in the active site pocket of the enzyme with subsequent oxidation of sulfur to sulfoxide. In this paper the results of a comparative study on the SLO inhibitory activities of the mentioned compounds using ab initio calculations and docking analyses has been reported.Materials and Methods: Structure optimization and docking analyses were performed using HyperChem 7.5 and AutoDock Tools 4.0 respectively. Enzyme assessment was reduced using spectrophotometric MBTH-DMAB method.Results: The inhibitory activity of synthetic 2-substituted pyrimido[4,5-b][l,4]benzothiazines against soybean 15-lipoxygenase (SLO) was evaluated and structure activity relationships and binding modes of their 4-H and 4-methyl analogs were studied using docking analysis and ab initio calculations.Discussion: The results of these studies showed that the lack of 4-methyl substituent in the pyrimido[4,5-b][1,4]benzothiazine molecules greatly reduces their lipoxygenase inhibitory activities and it was also found that the HOMO energy difference between the 4-H and 4-Methyl analogs can be responsible for the observed inhibitory activity reduction.Conclusion: Our molecular modeling studies shows that by using more flexible amino acids during the docking process, more rational results can be obtained. The method of measuring the lipoxygenase activity is also of prime importance for the study of structure activity relationship.

Objective(s): Gastroesophageal Reflux Disease (GERD) is one of the most common digestive disorders that frequently lead to pulmonary complications due to gastric fluid aspiration. In the present experimental study, chronic aspiration of gastric fluid, its components and bile salts in rat lung was performed to find out the main factor(s) causing pulmonary complications of gastric fluid aspiration.Materials and Methods: Forty eight male rats weighted 250-300 g were selected in six groups. After anesthesia and tracheal cannulation, the animals received 0.5 ml/kg normal saline, 0.5 ml/kg of whole gastric fluid, 0.5 ml/kg pepsin (2.5 mg/ml), 0.5 ml/kg hydrochloric acid (pH=1.5) or 0.5 ml/kg bile salts (2.5 mg/ml) by injection into their trachea and lungs. In sham group nothing was injected.Results: Parenchymal and airways inflammation and fibrosis of bronchi, bronchioles and parenchyma were significantly more in the test groups compared to saline and sham groups (P<0.001); also inflammation in pepsin and bile salts groups (histopathology scores: 2.87±0.35 and 3.0±0.0 for bronchial, 2.87±0.35 and 2.87±0.35 for bronchioles, 2.87±0.35 and 2.87±0.35 for parenchymal inflammation) were more than hydrochloric acid and gastric fluid groups (1.75±0.46 and 2.5±0.53 for bronchial, 2.0±0.0 and 2.0±0.0 for bronchioles, 2.0±0.0 and 2.0±0.0 for parenchymal inflammation) (P<0.05). The same results were found for fibrosis, so that the fibrosis in pepsin and bile salts groups were more than hydrochloric acid and gastric fluid groups (P<0.05).Conclusion: The present results suggested that pulmonary complications causing from bile salts and pepsin might be more than gastric juice and hydrochloric acid.

Objective(s): To investigate the expression of human papilloma virus (HPV) L1 capsid protein, and human telomerase RNA component (hTERC) in cervical cancer and the role of detection of both genes in screening of cervical cancer.Materials and Methods: A total of 309 patients were recruited and cervical exfoliated cells were collected. Immunocytochemistry was employed to detect HPV L1 capsid protein, and fluorescent in situ hybridization (FISH) was performed to detect the hTERC.Results: The expression of HPV L1 capsid protein reduced with the increase of the histological grade of cervical cells and was negatively related to the grade of cervical lesions. However, the expression of hTERC increased with the increase of the histological grade and positively associated with the grade of cervical lesions. The proportion of patients with L1 (-)/hTERC (+) was higher in patients with histological grade of CIN2 or higher than that in those with histological grade of CIN1. The L1 (+)/hTERC (-) and L1 (-)/hTERC (-) were negatively related to the grade of cervical lesions. L1 (-)/hTERC(+) was positively associated with the grade of cervical lesions. The L1/hTERC ratio increased. The negative predictive value of both HPV L1 and hTERC was higher than that of HPV L1 or hTERC, but there was no marked difference in the screening efficacy of cervical cancer among HPV L1, hTERC and HPV L1+hTERC.Conclusion: HPV L1 capsid protein and hTERC gene may serve as markers for the early diagnosis and prediction of cervical lesions. The increase in L1/hTERC ratio reflects the progression of cervical lesions to a certain extent.

Objective(s): Reliability measures precision or the extent to which test results can be replicated. This is the first ever systematic review to identify statistical methods used to measure reliability of equipment measuring continuous variables. This studyalso aims to highlight the inappropriate statistical method used in the reliability analysis and its implication in the medical practice.Materials and Methods: In 2010, five electronic databases were searched between 2007 and 2009 to look for reliability studies. A total of 5,795 titles were initially identified. Only 282 titles were potentially related, and finally 42 fitted the inclusion criteria.Results: The Intra-class Correlation Coefficient (ICC) is the most popular method with 25 (60%) studies having used this method followed by the comparing means (8 or 19%). Out of 25 studies using the ICC, only 7 (28%) reported the confidence intervals and types of ICC used. Most studies (71%) also tested the agreement of instruments.Conclusion: This study finds that the Intra-class Correlation Coefficient is the most popular method used to assess the reliability of medical instruments measuring continuous outcomes. There are also inappropriate applications and interpretations of statistical methods in some studies. It is important for medical researchers to be aware of this issue, and be able to correctly perform analysis in reliability studies.

Objective(s): The purpose of the present study was to examine the effects of L-glutamine on electromyographic (EMG) activity of the quadriceps muscle injured by eccentric exercise (EE).Materials and Methods: Seventeen healthy men (age: 22.35±2.27 yr; body mass: 69.91±9.78 kg; height: 177.08±4.32 cm) were randomly and double-blind study with subjects assigned to either an L-glutamine supplementation (n=9) or placebo (n=8) group. The subjects in two groups were asked to take three times during a week for 4 weeks. Each subject was screened for dietary habits before inclusion into the study. Participants performed 6 set to exhaustion eccentric leg extensions at 75% of 1RM and rest intervals were 3 min among sets. Pain Assessment Scale (PAS), EMG activity and range of motion (ROM) measurements were taken before exercise protocol and 24 and 48 hr afterwards.Results: There was no statistically significant difference between groups in perceived muscle soreness (SOR), ROM and EMG activity (P<0.05).Conclusion: The results indicate that L-glutamine supplementation has no significant effect on muscle injury markers in between groups, although glutamine supplementation attenuated delayed onset muscle soreness (DOMS) effects in sup group.

Objective(s): Stem cell differentiation into different cell lineages depends upon several factors, cell cycle control elements and intracellular signaling elements, including P15INK4b and P16INK4a genes. Epigenetics may be regarded as a control mechanism which is affected by these factors with respect to their promoter structure.Materials and Methods: The CD34 + cord blood stem cells were purified, isolated and then expanded. The undifferentiated day genome was isolated from part of the cultured cells, and the seventh day differentiated genome was isolated from the other part after differentiation to erythroid lineage. The procedure was followed by a separate Real-Time PCR for the two genes using the obtained cDNA. The processed DNA of the former stages was used for MSP (Methylation Specific PCR) reaction. Finally, pre- and post-differentiation results were compared.Results: After performing MSP for each gene, it became clear that P15INK4b gene has undergone methylation and expression in predifferentiation stage. In addition, its status has not been changed after differentiation. P15INK4b gene expression was reduced after the differentiation. The other gene, P16INK4a, showed no predifferentiation methylation. Itwas completely expressed methylated and underwent reduced expression after differentiation.Conclusion: Specific predifferentiation expression of P15INK4b and P16INK4a genes along with reduction in their expression after erythroid differentiation indicated animportant role for these two genes in biology of CD34+ cells in primary stages and before differentiation. In addition, both genes are capable of epigenetic modifications due to the structure of their promoters.