Protective Effects of Statins against Alzheimer Disease / 이화의대지

Alzheimer disease (AD) is a common neurodegenerative disorder, characterized by memory impairment, dementia, and diminished cognitive function. This disease affects more than 20 million people worldwide. Amyloid beta (Aβ) plaques and neurofibrillary tangles (NFTs) are important pathological markers of AD. Multiple studies have indicated a potential association between elevated cholesterol levels and increased risk of AD, suggesting that lowering the cholesterol level could be a viable strategy for AD treatment or prevention. Statins, potent inhibitors of cholesterol synthesis, are widely used in clinical practice to decrease the plasma levels of LDL cholesterol in patients with hyperlipidemia. Statins are known to play a neuroprotective role in limiting Aβ pathology through cholesterol-lowering therapies. In addition to Aβ plaques and neurofibrillary tangles, the brains of AD patients exhibit signs of oxidative stress, neuroinflammatory responses, and synaptic disruption.Consequently, compounds with antioxidant, anti-inflammatory, and/or neuroprotective properties could be beneficial components of AD treatment strategies. In addition to lowering LDL cholesterol, statins have demonstrated therapeutic efficacy in various forms, including antioxidant, anti-inflammatory, and neuroprotective effects. These properties of statins are potential mechanisms underlying their beneficial effects in treating neurodegenerative diseases. Therefore, this review was conducted to provide an overview of the protective effects of statins against AD.

Factors affecting the results of comprehensive pre-internship exam among medical students of Kermanshah University of Medical Sciences / 한국의학교육

PURPOSE: This study was aimed to evaluate the factors affecting the results of comprehensive pre-internship exam (CPIE) among medicals students of Kermanshah University of Medical Sciences. METHODS: In this descriptive-analytical study, all students (n=240) participating in CPIE over a 3-year period (2012–2014) were selected. Data were gathered by a questionnaire, including the CPIE results and educational and demographic data. Spearman correlation coefficient, Mann-Whitney U-test, and analysis of variance were used to analyze the association of students' success with study variables. Also, regression analysis was applied to determine the role of independent variables in students' success. RESULTS: The frequency of the failed units in apprenticeship course was one of the most important risk factors associated with failure in CPIE. Average scores of pre-internship course were the most important factors of success in CPIE. The CPIE score had the highest direct relationship with grade point average (GPA) of apprenticeship course, total GPA of all three courses, GPAs of physiopathology and basic sciences courses, and score of comprehensive basic sciences examination, respectively. CONCLUSION: CPIE showed the highest inverse correlation with the number of failed units in apprenticeship course. The most important factors influencing this exam were failure in apprenticeship course and GPA of previous educational stages.

Crab shell extract induces prostate cancer cell line [LNcap] apoptosis and decreases nitric oxide secretion

Objective: Prostate cancer is the second most common cancer worldwide. Chemotherapeutic agents have been shown to have adverse side-effects, and natural compounds have been recommended for cancer treatment, nowadays. Crab shell has been shown to have cancer preventative and suppressive effects in vivo and in vitro. The aim of present study was to investigate the effect of crab shell extract on prostate cancer cell line [LNcap] in vitro

Materials and Methods: In this in vitro experimental study, LNcap cells were treated with different concentrations [0, 100, 200, 400, 800 and 1000 micro g/ml] of crab shell hydroalcoholic extract in three different culture periods [24, 48 and 72 hours]. LNcap viability was evaluated by trypan blue staining and MTT assay. Cell apoptosis and nitric oxide [NO] secretion were determined by TUNEL and Griess assays, respectively. Data were analyzed by one-way ANOVA test and P<0.05 was considered significant

Results: LNcap viability was decreased dose- and time-dependently. Thus 400, 800, and 1000 micro g/ml doses showed significant differences compared to control group [P<0.001]. Dose-dependent increase in the apoptotic index was also observed in 800 and 1000 micro g/ml concentrations [P<0.001]. Nitric oxide secretion of LNcap cell was decreased time- and dose-dependently, while it was significant for 1000 micro g/ml [P<0.05]

Conclusion: Crab shell extract showed anti-prostate cancer effect, by inducing cell apoptosis and decreasing NO production

New Findings on Breast Cancer Stem Cells: A Review / 한국유방암학회지

Since the introduction of the "cancer stem cell" theory, significant developments have been made in the understanding of cancer and the heterogenic structure of tumors. In 2003, with the isolation of cancer stem cells from the first solid tumor, breast cancer, and recognition of the tumorigenicity of these cells, this theory suggested that the main reason for therapy failure might be the presence of cancer stem cells. This review article describes breast cancer stem cell origin, the related cellular and molecular characteristics, signaling pathways, and therapy resistance mechanisms. The databases PubMed, SCOPUS, and Embase were explored, and articles published on these topics between 1992 and 2015 were investigated. It appears that this small subpopulation of cells, with the capacity for self-renewal and a high proliferation rate, originate from normal stem cells, are identified by specific markers such as CD44+/CD24-/low, and enhance a tumor's capacity for metastasis, invasion, and therapy resistance. Cancer stem cell characteristics depend on their interactions with their microenvironment as well as on the inducing factors and elements. Although uncertainties about breast cancer stem cells exist, many of researchers believe that cancer stem cells should be considered as possible therapeutic targets.

Low doses of celecoxib stimulate human endometrium growth in a three-dimensional culture model

The endometrium plays a pivotal role in implantation and pregnancy. Cyclooxygenase II [COX-2] has an important function in biological processes such as cell proliferation and inflammation. Celecoxib is a selective inhibitor of COX-2 with numerous pharmacologic functions. The aim of present study is to investigate the effects of celecoxib on the human endometrium in a three-dimensional [3D] culture model. In this experimental study, normal human endometria [n=10] obtained from reproductive age women were cut into 1x1 mm sections. Endometrial explants were placed between two layers of fibrin gel. To create the fibrin gel, we poured a thin layer of fibrinogen solution [3 mg/ml in medium 199 [M199]] into each well of a 24-well culture dish and added thrombin enzyme. Endometrial fragments were placed in the center of each well and covered with a second layer of fibrinogen solution. M199 supplemented with L-glutamine, fetal bovine serum [FBS, 5%] and antibiotics were added to each well. The media in each experimental well contained either1, 10 or 50 micro M of celecoxib. At the end of the study, we calculated endometrial tissue growth changes by scoring methods and determined the percentage of angiogenesis. Data were analyzed by the Kruskal-Wallis method. P<0.05 was considered significant. The growth scores were as follows: control [1.37 +/- 0.16], 1 micro M [1.96 +/- 0.28], 10 micro M [2.01 +/- 0.25], and 50 micro M [1.17 +/- 0.14] celecoxib, all of which were significantly different. The angiogenesis percentages were: 25.56 +/- 6.72% [control], 31.98 +/- 6.18% [1 micro M], 42.67 +/- 7.27% [10 micro M] and 23.44 +/- 4.03% [50 micro M], which were not significantly different from each other. Lower celecoxib concentrations had stimulatory effects on the growth of normal endometrium

Study of Foeniculum vulgare effect on folliculogenesis in female mice

Foeniculum vulgare [FVE] is used in traditional medicine for its antiseptic, palliative and anti-inflammatory effects. Traditionally, FVE is utilized for treating female infertility. The present study aims to investigate the effects of FVE extract on folliculogenesis in female albino mice. In this experimental study, a total of 20 female albino mice were divided into four groups. Groups 1 and 2 [experimental] received FVE alcoholic extract at doses of 100 and 200 mg/kg body weight [BW]/day for five days. Group 3 [negative control] received ethanol and group 4 [positive control] was administered normal saline, in the same doses as the experimental groups. Animals in all groups were sacrificed on the sixth day of the study; their ovaries were dissected out and prepared for histological examinations. Hematoxylin and eosin [H and E] stained microscopic slides were evaluated and the numbers of ovarian follicles were compared between groups. Data were analyzed by one way ANOVA. The total follicle numbers were 26.5 +/- 5.24 for group 1 [100 mg/kg FVE], 27.2 +/- 4.1 for group 2 [200 mg/kg FVE], 10.1 +/- 2.53 for group 3 [ethanol control] and 17.2 +/- 3.9 for the saline control group [group 4]. The numbers of graffian, antral and multilaminar follicles increased significantly in both experimental groups when compared with the control groups [p<0.05], however there were no significant differences in follicle numbers among the experimental groups. The number of unilaminar primary follicles did not significantly change between all groups. GC-MS analysis of FVE extract identified the presence of diosgenin, an estrogenic compound. FVE induced folliculogenesis in female mice ovary and increased the number of growing ovarian follicles. The estrogenic component of FVE, diosgenin, may exert this effect