نشریه دانشور پزشکی
پیاپی 106 (شهریور1392)

Melanoma is the most deadly type of skin cancer that has a high potency and rapid metastasis to other organs. It appears that cancer stem cells (CSCs) are responsible for invasion and metastasis. The aim of this study was to investigate the expression of cancer stem cells candidate markers and their association with stemness features in melanoma cell lines. The expression levels of CD133، CD44 and ABCG2 were measured in melanoma cell lines (WM115، NA8، SK-MEL، Me67، A375 and D10) by flow cytometry. Then، selected cell line was sorted up on the expression of selected stem cell marker into positive and negative populations. Afterward، The potential of cologenic، spheroid formation and expression of stem genes including NANOG، SOX2، OCT4 and KLF4 was estimated in positive، negative and unsorted cells. Our results demonstrated that 28. 65 ± 1. 85% of D10 cell line expressed CD133. However، CD44 and ABCG2 were or (not) expressed in all cell lines. The CD133+ sorted cells showed an increase in colony formation about 1. 64 fold (p<0. 05) and melanospheres about 2. 2 fold (p=000) as compared to CD133-. The evaluation of stemness genes expression determined the significance of up-regulation of NANOG and OCT4 in CD133+ and SOX2 in CD133- respectively. There was no difference in KLF4 expression between the two groups. Findings of this research showed that CD133 can be considered as stem-like cells marker in D10 cell line and other melanoma cells which expressed CD133.

Harnessing immune system and its powerful arm، T lymphocytes، against tumor cells are yielding promising results in cancer immunotherapy. Using two arms of immune system in the designing of engineered T cells expressing chimeric receptors with anti-HER2 nanobody (camelid single domain antibody) seems to be an effective strategy in the targeted cancer therapy. HER2 specific nanobodies were used as a recognition site for constructing chimeric receptors NbHER2-HHIgG3-CD28-OX40-CD3ζ (elongated) and NbHER2-HIgG3-CD28-OX40-CD3ζ (short) on the membrane of T cells. Expression of chimeric receptors was evaluated by RT-PCR. Function of engineered T cells against cancer cells was assessed by the secretion of interleukin 2 and LDH cytotoxicity assay. Elongated chimeric receptors with nanobodies RR6 and RR16 that target juxtamembranal domain of HER2 antigen functioned better than elongated constructs containing nanobodies RR4 and RR10. In contrast، nanobodies RR4 and RR10 used in the short chimeric receptors showed substantial results. Based on binding properties of nanobody، functional chimeric receptors can be designed and engineered T lymphocytes containing the mentioned receptors can be generated that substantially recognize and kill breast cancer cells.

Lactobacilli are one of the major microorganisms in the probiotic yoghurt. The therapeutic potentials of these microorganisms are due to their variations and rates of survival during the shelf life of probiotic yoghurt. This study aimed to assess the total colony counts of lactobacillus strains in some examples of typical commercial probiotic yoghurt. In this cross-sectional survey، 50 samples of probiotic yoghurts (10 samples derived from 5 dairy brands) were collected and coded. The variations of all lactobacilli strains were counted after the preparation of surface cultures in 2 stages (1: Mid–day of shelf-life، and 2:1 day before the expiration date of yoghurt); additionally، the pH of all samples was measured in the latter stage. Data were analyzed using the SPSS program. The average lactobacilli colony count was lower in the second culture as compared to the first one in 4 out of 5 probiotic yoghurt brands (p≤ 0. 002). Amongst all estimated samples، the highest number of colony counts was less than the minimum recommended dose (2. 9×105 vs. 106، p<0. 0001). The mean pH of samples was significantly lower than the optimum pH at the end of the shelf life (p<0. 0001). Underrated total colony counts of lactobacilli strains during shelf life، and increased acidity of samples at the end of storage period would exacerbate the potential efficacy and clinical merits of evaluated commercial probiotic yoghurts. Implementing regular quality controls in accordance with national standardized protocols، as well as further extended research are warranted.

Increased production and industrial application of manganese oxide (MnO2) nano and microparticles have led to increased human contact with these particles. In this study، the biodistribution of manganese in rat liver was studied after chronic administration of two MnO2 particles. Also، the effect of these particles was studied on body weight gain and liver function tests of rats. Male wistar rats were weighted and subcutaneously treated with 100 (μg/kg) nano- or micro-particles of MnO2 every two weeks for 14 weeks. Blood samples are taken directly from the heart of the rats (n=5) at the same times. The Mn level in samples of rat hepatic tissue was determined by ICP-MS. Serum levels of total protein، albumin، bilirubin، activities of transaminases، lactate dehdrogenase and alkaline phosphatase were measured by autoanalyzer. Rate of body weight gain in rats of nano group was significantly faster and in micro group rats was slower than control (p<0. 05). The hepatic Mn biodistribution، accumulation and bioclearance in nanoparticles group were different from microparticles group. The levels of total protein، albumin، bilirubin and alkaline phosphatase activity increased، while transaminease enzymes and lactate dehyrogenase activities decreased in serum of both groups (p<0. 05). The chronic administration of MnO2 nano- and microparticles casued manganese accumulation in hepatic tissue. The strong oxidizing property of both MnO2 particles and their binding with some hepatic enzymes can be main causes of liver dysfunction.

Preeclampsia is potentially life-threatening and as a dangerous complication of pregnancy. This study was performed to assess the relationship between serum zinc level and preeclampsia. This analytical and prospective study was conducted on 1033 pregnant women who referred to prenatal clinics of Tehran city. Demographic questionnaire and reproductive history was completed and also a venous blood sample was taken from all the pregnant women upon entry. Preeclampsia was defined as blood pressure equal or more than 140/90 mmHg along with proteinuria after 20th week of pregnancy. Data was analyzed using SPSS16 software and independent samples t-test. The incidence of preeclampsia was 1. 9 %. Mean serum zinc level was 116. 6±95. 7 µg/dl. In 27. 4% of samples، the zinc serum level was lower than 51µg/dl and the zinc serum level of 72. 6% of samples was at normal range. The independent samples t-test showed that there was a significant relationship between maternal serum zinc level and preeclampsia as the mean serum zinc level in pregnant women with preeclampsia was lower than normal pregnant women. The results showed that serum zinc level is associated with preeclampsia.

The multinational tobacco industry has made targeting of youth for increased tobacco use a priority، and adolescent smoking remains an important public health issue around the world. The purpose of this paper was to evaluate the impact of training programs based on Kemp model on smoking refusal ability in the male adolescents. The present study was a Quasi-experimental study that carried out on 150 male adolescent students (high school) that were randomly selected and assigned to case (n=75) and control (n=75) groups. The sampling method was multi-stage Sampling. Data collection tool that was a questionnaire that its validity and reliability confirmed by experts and Cornbrash’s alpha coefficient. After primary data collection، educational intervention was performed and 6 months later data was collected again and analyzed in SPSS16 software using descriptive and analytical statistics. Before intervention، the mean scores of knowledge، perceived benefits and threat، smoking refusal ability and tobacco use were not significantly different in two studied groups. After intervention، mean score of all mentioned variables increased significantly in case group but it was not different in control group. Also، cigarette smoking rate decreased significantly among the intervention group after intervention (p<0. 001) (before intervention 17%، after intervention 8% in the case group). This study showed that training based on Kemp model was useful in promotion of smoking refusal ability and decreased the tobacco use in the male adolescents.

Studies have shown that alteration in photoperiod influences secretion of many hormones. The aim of this study was to investigate the effect of different periods of darkness on serum level of T3، T4 and TSH in male rats.

In this experimental study، 30 male Wistar rats were randomly divided into control group (exposed to 12 h light-12 h dark)، and groups exposed to 13، 15، 21 or 21 h of darkness/day of 6 rats in each group. After 8 weeks، blood samples were collected using cardiac puncture method and following serum collection، the levels of T3، T4 and TSH were measured by radioimmunoassay. The data were statistically analyzed using ANOVA.

Serum T3 and T4 levels did not significantly change in rats exposed to darkness for 13 and 15 h/day as compared to control animals; however، significantly decreased in rats exposed to darkness for 18 and 21 h/day (p<0. 05). Serum level of TSH did not significantly change in experimental groups as compared to control animals.

The findings suggest that prolonged periods of artificial darkness at least up to 50% over the standard scale can reduce thyroid activity and serum levels of thyroid hormone. It is suggested that darkness can be considered as a probable factor in hypothyroidism occurrence.

The aim of this study was to identify the effect of acute caffeine intake on total antioxidant capacity (TAC) and oxidative stress indices (MDA) in male volleyball players following one-session resistance exhaustive exercise. Twenty male volleyball players (mean age 21. 20±1. 10 years، fat 10. 75±2. 78% and BMI 22. 95±0. 99 kg. m2) participated in a randomized، quasi-experimental، double-blind and repeated measured (three stages) design. Then، all subjects were allocated to two homogeneous groups (in order: 9 mg. kg-1. day caffeine or dextrose). All subjects participated in a single-session resistance weight-exercise (7 stations in 3 sets per station with 80% of 1-RM until exhausted). Blood samples were taken at three stages (baseline and 45 min after supplementation، and immediately after the exercise) were determined for changes in serum TAC and MDA. The results showed that the acute caffeine intake has no significant effect on the basal serum TAC and MDA (p≥0. 05). Moreover، one-session resistance exhaustive exercise significantly reduced TAC (P≤0. 05) and significantly increased MDA (p≤0. 05). However، no significant differences in any of the measured variables between the groups were found immediately after resistance exercise (p≥0. 05). The present results show that acute caffeine consumption does not increase basal TAC and could not decrease the undesirable alterations of serum MDA induced by one-session of resistance exhaustive exercise in male volleyball players.