Cell Journal (Yakhteh)
Year:2002 | Volume:4 | Issue:15|Papers Count:12

Introduction: Some dental sealers have neurotoxic effects on neuronaltissues. These effects appear to be mediated through the inhibition of ionic channels.Intracellular recording was performed on neuronal cells tocharacterize the underlying ionic mechanisms of neurotoxicity induced by Roth 801. Materials and Methods: Experiments were carried out on F1 neuronal soma membrane located in the right parietal ganglion of snail, Helix aspersa. The properties of action potential were analyzed using singl eelectrode current clamp method. Roth 801 was applied to the bathing solution in invasive and gradual forms. Results: In the current clamp experiments, several parameters, including, resting membrane potential (RMP), the peak amplitude of action potential, spike width, frequency, the peak amplitude of after hyperpolarization (AHP) were analyzed. In both invasive and gradual forms Roth 801 decreased the peak of amplitude and frequency of action potential and the peak amplitude of AHP. But the duration of spike was prolonged. After invasive application of Roth 801, membrane potential was depolarized. However in gradual method, it was initially hyperpolarized and subsequently shifted towards depolarized potential. Conclusion: These results suggest that Roth 801 affects shape and frequency of action potential through inhibition of ionic currents.

Introduction: Recently, a novel gene was cloned and characterized named CatSper, which codes for a unique Ca2+ channel that is expressed excludively in the testis. It has crucial role in sperm motility, sperm penetration into the ovum and ultimately male fertility. In the present study, we have evaluated the expression of this gene at different ages of mouse by Semi-quantitative RT-PCR. Material and Methods: Total RNA was extracted from testis of mouse using RNX plus solution. Reverse Transcription was done by oligo dT and MMLVenzyme.cDNAs were amplified in PCR reaction for both CatSper and β2m (as an internal control) genes. After gel electrophoresis, intensity of signa lfor each band was quantified by Labimage software. Results: 1) There was no d expression of CatSper gene in mouse testis of 1 day, 1 week and 2 weeks (pre-mature group) of age; 2) Expression of CatSper began with the age of three weeks with a gradual increase till two months of age and a gradual slight decrease in older age groups; however, the observed pattern of expression appeared not to be statistically significant (p=0.592). Conclusion: These results confirm previous data; that is there is a link between expression of CatSper and fertilization in mouse. The results further reveal a link between CatSper expression profile and the age of mouse in terms of sexual maturity.

Introduction: The aim of this study was to investigate the presence and distribution of cell surface terminal sugars in developing cartilage of the primordial vertebrae in rat embryo. Material and Methods: Fifty female and 25 male Wistar rats were chosenrandomly. After adaptation, mating was done. Vaginal plug observationwas performed on O-day of gestation. Specimens were collected from 9-18 days old embryos and were fixed in B4G solution. After routine histological processing and embedding in paraffin, blocks were cut into 4-micrometer thickness sections. Then sections were stained by PAS-Alcian blue and Lectin histochemistry methods (VVA-B4, MPA, WFA).On the basis of intensity of staining, sections were graded and nonparametric statistical test (Kruskal Wallis) was used to compare differences between samples. Results: The commencement of chondroblast differentiation in the centrum of future vertebrae was specified by appearance of D-Gal Terminal sugarin 13th day of embryonic period. On the 14th to 16th days of presence of Gal/GalNac, D-GalNac terminal sugars were detected in developing vertebrae. Reactions were first observed in centrum and then in pedicles and laminae of vertebrae. From the 17th day on ward, reaction with the above mentioned lectins showed a significant reductions (P<0.05). Conclusion: This study showed that changes in surface terminal sugars regulate morphologic changes and the fate of the cell, during tissue growth and development.

Introduction: To evaluate and compare efficiency of sil-select with Percoll to recover sperm with normal chromatin in morphology and also studyeffect of these parameters on fertilization, embryo quality and cleavagescore. Materials and Methods: Assessment of semen parameters, protamine deficiency (CMA3) and excessive histone (aniline blue staining) were carried out before and after sperm processing on 46 semen samples from IVF patients referring to Isfahan fertility and infertility center. Results: Both Sil-Select and percoll were efficient in elimination of sperms with chromatin and morphologic anomalies. Significant correlatis were obtained between sperm morphology (strict criteria), protamine deficiencyand excessive histone with in vitro fertilization rate. Among these parameters only sperm morphology showed a significant correlation with embryo quality and cleavage score. Conclusion: Sil-select is a suitable alternative for Percoll to recover sperm with normal chromatin and morphology. Furthermore density gradient techniques are recommended for sperm processing for IVF and especially for ICSI.

Introduction: This investigation was undertaken to examine the effect of 4ºC temperature on development and implantation rate of mouse embryos. Materials and Methods: Femal mice (4-6 week old) were induced to superovulate and were mated. Two cell embryos were flushed from excited oviducts, 46 – 48 h after the infection of HCG, and were cultured to eight – cell stage in M16 medium, thereafter the embryos were stored at 4ºC for 0 to 48 h in M2 Medium. After cold storage, embryos were allowed to develop to expanded blastocysts. To examine the implantation rate, blastocysts which were morphologically normal were transferred into the uterine horn of pseudopregnant recipients on Day 4. Results: Statistical analysis indicated that, there was no significant difference (P=0.19 & P=0.17) between experimental and control groups during storage at 4ºC for 0 to 24 h, regarding the development to expanding blastocysts in culture. But the survival rate tended to decrease with increased storage time In addition, considering the implantation rate, no significant difference was observed between the experimental groups stored for 18 – 24 h and control groups (P=0.79 & P=0.74). Conclusion: The results of this study indicate that nonfreezing technique is a useful method for short – term storage of mouse embryos.

Introduction: Nucleolar organizer region associated proteins are a group of non histone proteins which act in r-DNA transcription and r-RNA processing. The amount of these proteins increase in transition from G1 to S phase in cell cycle. Hence these proteins can show the proliferative index of the cells. Material & Methods: For this purpose 40 patients (30 gastritis, 10 carcinoma) with average age of 45 years were chosen from pathology file of Khatam AL Anbia of Zahedan and Shiraz Namazi Hospitals during the years 1999-2001. Paraffin blocks were cut with 3-5 um thickness andstained with H-E and colloidal silver nitrate. The number of NOR were counted blindly by two persons. Results: Pearson correlation test showed significant correlation of NOR counting (P< 0.001, r = 96) by two persons. Mann-Whitney test showed significant difference of NOR between gastritis and carcinoma.The shape and distribution of NOR in gastritis looked like diffuse black dots in nuclei,but in neoplastic cells the number of NOR were increased and theirdistribution differed extensively. Conclusion: It seems that NOR number is a reliable indicator of cellular proliferation in carcinoma of the stomach.

Introduction: Tuberculosis remains as an important socioeconomical and medical problem throughout the world and especially in Iran. Early and timely diagnosis of pulmonary and extrapulmonary tuberculosis is very vital to initiate prompt treatment. Current diagnostic methods are either slow or lack enough sensitivity or specificity. Several mycobacterial antigens are involved in the complex interaction with the immune system of the host. Their identification is important for both diagnosis and protection against mycobacteria. Antigen 60 (A60) is a thermostable antigen found in the cytosol of M.bovis and M.tuberculosis. Performing ELISA test using A60 for diagnosis of tuberculosis has shown goos results . In previous researches A60 also showed a protective effect against experimental infections and useful immuno therapeutic effects in prevention and treatment of cancer. Materials and Methods: A60 was purified by size exclusion chromatography using sephrose 4B. A60 was recognized by bidimentional immunoelectrophoresis with anti BCG and Anti A60 antiserum. Double diffusion – precipitation test was performed using purified antigen and anti BCG antiserum. Purified A60 was fractionated in SDS – PAGE and transferred to nitrocellulose membrane and western blotting was performed using anti A60 antiserum as primary antibody and anti human immunoglobulin as secondary antibody. Results: A60 appeared as the less mobile component in Crossed Immuno Electrophoresis. In agarose electrophoresis, A60 formed only one band and in immunodiffusion A60 formed two immunopercipitinogen line with anti BCG. In analyzing with dot blotting, both cytoplasm and cell wall of BCG showed positive reaction with anti A60 anti serum. When A60 was fractionated by SDS – PAGE and transferred to nitrocellulose membrane and analyzed in western blotting with anti A60, proteins of 65, 46, 40, 38 and 35 KD were identified. Conclusion: It is concluded that A60 is a macro molecular antigen of BCG with molecular weight of 106 – 107 Da and has several proteins. A60 can easily be purified from BCG vaccine which is produced in Iran, by size exclusionchromatography using sepharose 4B.

Introduction: During early neural tube formation, the notochord is essential for the induction of ectoderm and for the subsequent differentiation of the neuroepithelium forming diverse cell types in the neural tube. Due to the key role of the glycoconjugates in many developmental events, the early distribution of these molecules in early notochordal interaction with adjacent tissues were studied. Material and Methods: Paraffin fixed 5µm sections of days 10 to 14 of mouse embryo were processed for histochemical studies by using horse radish peroxidase labelled DBA, VVA-B4, WFA, UEA-1 and OFA lectins.These lectins have binding specificity for D-GalNac and a-fucose sidechains of the glycoconjugates. Results: Histochemical analysis revealed that notochord and its intermediate extracellular fluid show extensive reaction with the floor plate of neural tube on 10th day, using OFA. This reaction was absent in the next day but a sever reaction was observed in the floor plate region. The results revealed a reaction in venteral portion of notochord with VVA-B4 and it expanded in to gut tube. Furthermore, a WFA-reaction was observed in the notochord and some of adjacent mesenchymal cells, but UEA-1 and DBA, don,t showed any reaction. Conclusion: The expression of the GalNac and also fucosilated glycoconjugates is stage-dependent and thus probably genetically regulated. The timing and distribution of lectin reactions suggest that these molecules (GalNac and fucose) may play a role(s) in notochordal interactions and subsequent formation of the adjacent tissues.