Down-regulation of CatSper 1 and CatSper 2 genes by lead and mercury.

In the study of the expression of CatSper genes, consideration of the effects of environmental metal toxicity is very important. Therefore, in this study, the effects of lead acetate and mercury chloride exposure on expression of CatSper genes, sperm parameters, histology of testis and prooxidant antioxidant balance (PAB) values of serum were investigated. A total of 28 mice was divided into four groups. The control group did not receive injections. The sham group received normal saline intraperitoneally. Lead and mercury groups were injected 60 and 1.25 mg/kg/daily lead acetate and mercury chloride respectively intraperitoneally for 2 weeks. After 35 days, the sperm analysis and histology of left testis were performed. In addition, serum was obtained to measure the PAB values. The right testis was used for molecular analysis of real-time PCR. Administration with either lead acetate or mercury caused significant damage to the seminiferous tubules as well as a reduction in sperm parameters compared to the control group. The relative expression of CatSper 1 and CatSper 2 in the lead group was lower than that of the control group (-0.01 ±â€¯0.24, -0.007 ±â€¯0.52 vs. 1 ±â€¯0.50, P = 0.34). The relative expression of CatSper 1 and CatSper 2 was significantly lower in the mercury group compared to the control ones (-0.24 ±â€¯2.28, -4.49 ±â€¯4.86 vs. 1 ±â€¯0.50, P = 0.21). PAB values significantly increased in lead or mercury exposed- mice compared to the control ones (0.93 ±â€¯0.17, 1.54 ±â€¯0.17 vs. 0.51 ±â€¯0.11; P ≤ 0.000). The results of this study showed that administration with either lead acetate or mercury chloride caused degenerative damage in seminiferous tubules and reduction in sperm quality and expression of CatSper 1, 2 genes in mice. Therefore, it is possible in infertile men who have had exposure to lead acetate or mercury chloride. Owing to structural similarities, these metals are substitutes for calcium ions and have effects on calcium channels. These cause immobility in sperm by blocking CatSper-specific calcium channels. However, more studies are required to elucidate the mechanism underlying the impact of different doses of heavy metals on CatSper genes expression.

Preventive effects of garlic (Allium sativum) on oxidative stress and histopathology of cardiac tissue in streptozotocin-induced diabetic rats.

Since some complications of diabetes mellitus may be caused or exacerbated by an oxidative stress, the protective effects of garlic (Allium sativum) were investigated in the blood and heart of streptozotocin-induced diabetic rats. Twenty-eight male Wistar rats were randomly divided into four groups: control, garlic, diabetic, and diabetic+garlic. Diabetes was induced by intraperitoneal (i.p.) injection of streptozotocin (50 mg/kg) in male rats. Rats were fed with raw fresh garlic homogenate (250 mg/kg) six days a week by gavage for a period of 6 weeks. At the end of the 6th week blood samples and heart tissues were collected and used for determination of glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA) and histological evaluation. Induction of diabetes increased MDA levels in blood and homogenates of heart. In diabetic rats treated with garlic, MDA levels decreased in blood and heart homogenates. Treatment of diabetic rats with garlic increased SOD, GPX and CAT in blood and heart homogenates. Histopathological finding of the myocardial tissue confirmed a protective role for garlic in diabetic rats. Thus, the present study reveals that garlic may effectively modulate antioxidants status in the blood and heart of streptozotocin induced-diabetic rats.

The evaluation of Candida albicans biofilms formation on silicone catheter, PVC and glass coated with titanium dioxide nanoparticles by XTT method and ATPase assay.

Lots of Candida albicans infections involve in biofilm formation on medical devices. This kind of biofilm can impede antifungal therapy and complicates the treatment of infectious diseases particularly in field of chronic diseases associated with implanted devices. This study has investigated the influence of treating silicone catheter, PVC and glass coated with Titanium dioxide (TiO2) nanoparticles on attachment of C. albicans. In this study TiO2 nanoparticles were synthesized from precursor TiCl4 and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) which showed TiO2 nanoparticles are 70-100 nm in size. In the simplest model of biofilms formation, C. albicans isolates (ATCC10231) and (ATCC 76615) were grown on the surface of small disks of catheter, PVC and glass in a flat-bottomed 12-well plates and evaluated biofilm formation using ATP bioluminescence and tetrazolium salt (XTT) reduction assays. In addition, morphology of C. albicans biofilms after 48 h incubation was observed by SEM. Results indicated that there is a statistical difference between mean of coated samples especially catheter and glass before and after TiO2 nanoparticles coating (p<0.05). In SEM analysis, C. albicans biofilm was more aggregated on the surface of glass and catheter than PVC and control groups and after treatment by these nanoparticles, catheter and glass both showed most significant decrease of C. albicans attachment in comparison to the control groups (Fig. 4, Ref. 23).

Evaluation of DNA damage in the root cells of Allium cepa seeds growing in soil of high background radiation areas of Ramsar-Iran.

Plants are unique in their ability to serve as in situ monitors for environmental genotoxins. We have used the alkaline comet assay for detecting induced DNA damage in Allium cepa to estimate the impact of high levels of natural radiation in the soils of inhabited zones of Ramsar. The average specific activity of natural radionuclides measured in the soil samples for 226Ra was 12,766 Bq kg(-1) whereas in the control soils was in the range of 34-60 Bq kg(-1). A positive strong significant correlation of the DNA damage in nuclei of the root cells of A. cepa seeds germinated in the soil of high background radiation areas with 226Ra specific activity of the soil samples was observed. The results showed high genotoxicity of radioactively contaminated soils. Also the linear increase in the DNA damage indicates that activation of repair enzymes is not triggered by exposure to radiation in HBRA.

High background radiation areas of Ramsar in Iran: evaluation of DNA damage by alkaline single cell gel electrophoresis (SCGE).

The hot springs in special areas in Ramsar, a northern coastal town in Iran, contain (226)Ra and (222)Rn. The natural radiation effects, radiosensitivity or adaptive responses, on the inhabitants of high natural radiation in Ramsar were studied. The single cell gel electrophoresis was used to monitor DNA damages. Three groups of volunteers were selected, one from high natural background radiation areas as the case group and two from normal background radiation areas as controls (control 1 and control 2). The latter one had the similar living situation to case group while the other (control 2) had different living situation from the other groups. Peripheral blood mononuclear cells (PMNCs) were separated and irradiated by (60)Co source at five different gamma doses. It was found that the spontaneous level of DNA damage and the induced DNA damage in all challenging doses in case group was considerably higher than control groups (p < 0.05). On the other hand, the repair rate in those volunteers, who received less than 10.2 mSv/y was significantly more than the control groups. In the contrary, individuals who live in homes with more than 10.2 mSv/y had incomplete repair. Additionally the plasma and urinary levels of vitamin C were measured spectrophotometrically. Although the concentration of vitamin C of plasma was equal in case and control 1 groups, the urinary level of vitamin C was found to be lower in the case group.