فهرست مطالب نجمه جویان

Alzheimer's disease (AD) is a neurodegenerative disease characterized by the progressive loss of neurons leading to cognitive and memory decay. Accumulation of phosphorylated cis-tau inside neurons is considered a factor in AD's pathological features. This study investigated the effects of extremely low-frequency (EMF) and radiofrequency (RF) electromagnetic fields on the proliferation and expression of phosphorylated tau in SH-SY5Y neuroblastoma cells.

SH-SY5Y cells treated were exposed to 50 Hz, 20 mT EMF,  and 900 MHz for 24, 48, 72, and 96 hours, and the number of the viable cell were determined by MTT assay. Tau protein phosphorylation level was examined after exposure to EMF and RF at different time intervals.

Exposure to the EMF and RF alone had no significant effect on the viability of SH-SY5Y cells compared to sham-exposed cells. However, the expression of phosphorylated cis-tau was significantly increased after exposure.

This study suggests that exposure of human neuroblastoma cells to a 50 Hz electromagnetic field and 900 MHz radiofrequency might induce phosphorylated cis-tau and thus enhance the potency of AD.

Polymorphisms of the upstream transcription factor 1 (USF1) have been associated with familial combined hyperlipidemia (FCHL), type 2 diabetes and coronary heart diseases (CHD). In the current investigation, the association of USF1s2 variant of human USF1 gene with premature coronary artery disease (PCAD) was evaluated in a population from southern Iran. USF1s2 has the best potential as a functional variant. in the USF1 gene. In a case-control study USF1s2 variant of human USF1 gene was determined by polymerase chain reaction- restriction fragment length polymorphism (PCR-RFLP) technique using BsiHKA I restriction enzyme for 186 women under 55 years of age and 135 men less than 50 years of age who underwent diagnostic coronary angiography in Saadi, Nemazee and Kowsar Hospitals of Shiraz, between July 2009 and March 2012. Data on the history of familial myocardial infarction or other heart diseases, hypertension, and smoking habit were collected by a simple questionnaire. Blood sugar level and serum lipid profile of all participants were also obtained by measuring the levels of fasting blood sugar (FBS), total cholesterol (TC), triglycerides (TG), low density lipoprotein (LDL) and high-density lipoprotein cholesterol (HDL). Frequencies of the major (G) and minor (A) alleles of usf1s2 gene variant were 0.74 and 0.26 in the whole population, respectively. Meanwhile, the prevalence of the minor allele was significantly higher in PCAD patients compared with control subjects. This difference remained significant even after adjustment for confounding parameters. Indeed, subjects with mutant homozygous genotype (AA) were about 5 times more likely to suffer from early-onset CAD than those with wild-type homozygous genotype (GG). Moreover, the baseline characteristics of the control subjects and patients were statistically similar for almost all parameters except for the number of male individuals; there was no significant difference among various genotypes in the patient group for any of these investigated variables. It appears that the usf1s2 variant in upstream transcription factor 1 gene is an independent predictor of premature coronary artery disease in our population and applies its effects without affecting blood sugar and lipid levels.

Different types of first cousins marriage may variously affect the incidence of multifactorial disorders. Based on the pattern of X chromosome transmission, it seems that parallel and cross - cousin matrilateral marriages can have higher risks of multifactorial disorders with susceptibility genes on X chromosome in comparison to parallel and cross - cousin patrilateral marriages. In this study, the data of patients with 10 multifactorial disorders were extracted from the pedigrees of 9964 genetic counseling files. The frequency of different types of first cousins marriages among the parents of female patients with three disorders - cleft lip/palate, cleft palate, and systemic lupus erythematosus - was compared to the control group. No significant difference was observed in the frequency of different types of first cousins marriages among female patients’ parents and the control group. It seems that more studies are required to compare the effects of different types of first cousins marriages.

Methyl tetrahydrofolate reductase (MTHFR) plays a major role in the reduction of methyl tetrahydrofolate. Single nucleotide polymorphism C677T in the MTHFR gene is associated with elevated levels of homocysteine، which serves as a risk factor for cardiovascular disease since elevated homocysteine levels damage endothelial cells (coronary arteries). Lowering homocysteine levels with folic acid effectively prevents this condition. In this study، blood samples were collected from 400 individuals (200 patients with premature CAD and 200 controls without symptoms) and the levels of homocysteine and folic acid along with C677T polymorphism of the MTHFR gene were evaluated under chemical and genetic tests. The percentage distribution of CC، CT and TT genotypes (MTHFR gene) was 52. 7%، 42. 79% and 4. 51% in cases and 53. 3%، 42. 8% and 4% in controls، respectively. Mean homocysteine level was found to be 14. 36 in patients and 11. 97 in controls and mean folic acid level was assessed to be 11. 569 in controls and 10. 92 in patients. Then، logistic regression analysis was used to investigate the relationship between homocysteine and C677T polymorphism and early coronary artery disease but no relationship was found (p > 0. 05) No significant relationship was detected between blood levels of homocysteine and folic acid and MTHFR T allele of the gene with premature coronary artery disease (men under 45 and women under 55 years). It is suggested to conduct further studies on other cardiac genes in countries that are genetically close to the Iranian population. It is also suggested to evaluate polymorphism and HCY levels in patients with late-onset form of the disease.

Chromosome abnormality (CA) including Sex chromosomes abnormality (SCAs) is one of the most important causes of disordered sexual development and infertility. SCAs formed by numerical or structural alteration in X and Y chromosomes, are the most frequently CA encountered at both prenatal diagnosis and at birth. This study describes cytogenetic findings of cases suspected with CA referred for cytogenetic study. Blood samples of 4151 patients referred for cytogenetic analysis were cultured for chromosome preparation. Karyotypes were prepared for all samples and G-Banded chromosomes were analyzed using x100 objective lens. Sex chromosome aneuploidy cases were analyzed and categorized in two groups of Turners and Klinefelter’s syndrome (KFS). Out of 230 (5.54%) cases with chromosomally abnormal karyotype, 122 (30%) cases suspected of sexual disorder showed SCA including 46% Turner’s syndrome, 46% KFS and the remaining other sex chromosome abnormalities. The frequency of classic and mosaic form of Turner’s syndrome was 33% and 67%, this was 55% and 45% for KFS, respectively. This study shows a relatively high sex chromosome abnormality in this region and provides cytogenetic data to assist clinicians and genetic counselors to determine the priority of requesting cytogenetic study. Differences between results from various reports can be due to different genetic background or ethnicity.

Hybrid cells are made from fusion of two or more somatic cells. After formation chromosomes are located in one membrane. . So nucleic condition of each fused cell has changes and two genomes and chromosomes interact with each other. Locating the genes in new nucleic and cytoplasmic condition and great chromosomal rearrangement in these new formed cells can affect their chemotherapeutic drug sensitivity. In this study the effect of bleomycin sulfate (BML) on two hybridoma cell lines, F3B6 and HF2x653 was compared with two non-hybridoma WIL2 and NS1, their parent cells, focusing on chromosome aberrations in G1 phase of the cell cycle.

Four frozen cell lines, F3B6, NS1, HF2x653 and WIL2 were thawed and separately cultured in RPMI 1640 supplemented with 10-15 % FBS. Cells were treated with two concentrations of bleomycin sulfate (50 and 100 µg/ml) at G1 phase during logarithmic phase of growth. After harvesting, preparation of metaphase spreads and Gimsa staining, aberrant cells and chromosomal aberrations were scored.

Results showed that aberrations induced in hybridoma cells are similar to those induced in their parent cell lines. Cells with more chromosomes, ie. F3B6 and NS1, had more chromosomal damages in comparison with cells having less chromosomes, Study of the abundance of damages in comparison with chromosomes confirms this result. Frequency of chromosomal aberrations in lieu of in two similar cells (NS1&F3B6) were alike and more than the other two, WIL2 and HF2X653, Although sometimes hybrid cells showed more or less sensitivity than their parental cell lines, they also did not show dose-dependent response to bleomycin sulfate at G1 phase of the cell cycle.

Hybridoma cell lines studied in this study showed similar frequency of bleomycin induced chromosomal aberrations compared to one of the parent cell lines and had more or less chromosome aberrations (sensitivity) than the other parent.