Student participation in governance of medical and veterinary education: experiences and perspectives of student representatives and program directors.

Student participation in governance of education is of growing interest. However, it remains unclear what factors render this participation in institutional governance a success or a failure. Another question is: what are the perceived benefits for schools and students? We empirically explored experiences and perspectives of student representatives and program directors of all (8) medical and (1) veterinary schools in the Netherlands on factors that influence student participation in institutional governance and its values and challenges for schools and student representatives.

Surviving in a marine desert: the sponge loop retains resources within coral reefs.

Ever since Darwin's early descriptions of coral reefs, scientists have debated how one of the world's most productive and diverse ecosystems can thrive in the marine equivalent of a desert. It is an enigma how the flux of dissolved organic matter (DOM), the largest resource produced on reefs, is transferred to higher trophic levels. Here we show that sponges make DOM available to fauna by rapidly expelling filter cells as detritus that is subsequently consumed by reef fauna.

Dietary heme iron and the risk of colorectal cancer with specific mutations in KRAS and APC.

Red meat intake has been linked to increased colorectal cancer (CRC) risk. Although the underlying mechanisms remain unclear, experimental studies suggest a role for dietary heme iron. Because heme iron was shown to promote specific mutations, it would be insightful to link heme iron data to CRC with mutations in key genes in an observational, population-based study.

Body size, physical activity and risk of colorectal cancer with or without the CpG island methylator phenotype (CIMP).

Background: We investigated how body size and physical activity influence the risk of the CpG island methylator phenotype (CIMP) in colorectal cancer (CRC).

Methods: In the Netherlands Cohort Study (n = 120,852), risk factors were self-reported at baseline in 1986. After 7.

Olfactomedin-4 regulation by estrogen in the human endometrium requires epidermal growth factor signaling.

Olfactomedin-4 (OLFM-4) is an extracellular matrix protein that is highly expressed in human endometrium. We have examined the regulation and function of OLFM-4 in normal endometrium and in cases of endometriosis and endometrial cancer. OLFM-4 expression levels are highest in proliferative-phase endometrium, and 17β-estradiol up-regulates OLFM-4 mRNA in endometrial explant cultures.

Dietary methyl donors, methyl metabolizing enzymes, and epigenetic regulators: diet-gene interactions and promoter CpG island hypermethylation in colorectal cancer.

Dietary methyl donors might influence DNA methylation during carcinogenesis of colorectal cancer (CRC). Among 609 CRC cases and 1,663 subcohort members of the Netherlands Cohort Study on diet and cancer (n = 120,852), we estimated CRC risk according to methyl donor intake across genotypes of folate metabolizing enzymes and methyltransferases.Although diet-gene interactions were not statistically significant, methionine intake was inversely associated with CRC among subjects having both common rs2424913 and rs406193 DNMT3B C > T genotypes (highest versus lowest tertile: RR = 0.

Childhood and adolescent energy restriction and subsequent colorectal cancer risk: results from the Netherlands Cohort Study.

Background: Energy restriction during childhood and adolescence is suggested to lower colorectal cancer (CRC) risk. We investigated this in the Netherlands Cohort Study.

Methods: Information on diet and other risk factors was collected by a baseline questionnaire in 1986 when cohort members were 55-69 years of age (n = 120 852).

Cell kinetics of the marine sponge Halisarca caerulea reveal rapid cell turnover and shedding.

This study reveals the peculiar in vivo cell kinetics and cell turnover of the marine sponge Halisarca caerulea under steady-state conditions. The tropical coral reef sponge shows an extremely high proliferation activity, a short cell cycle duration and massive cell shedding. Cell turnover is predominantly confined to a single cell population, i.

Genetic variants of methyl metabolizing enzymes and epigenetic regulators: associations with promoter CpG island hypermethylation in colorectal cancer.

Aberrant DNA methylation affects carcinogenesis of colorectal cancer. Folate metabolizing enzymes may influence the bioavailability of methyl groups, whereas DNA and histone methyltransferases are involved in epigenetic regulation of gene expression. We studied associations of genetic variants of folate metabolizing enzymes (MTHFR, MTR, and MTRR), DNA methyltransferase DNMT3b, and histone methyltransferases (EHMT1, EHMT2, and PRDM2), with colorectal cancers, with or without the CpG island methylator phenotype (CIMP), MLH1 hypermethylation, or microsatellite instability.

MGMT and MLH1 promoter methylation versus APC, KRAS and BRAF gene mutations in colorectal cancer: indications for distinct pathways and sequence of events.

Background: To study how caretaker gene silencing relates to gatekeeper mutations in colorectal cancer (CRC), we investigated whether O6-methylguanine DNA methyltransferase (MGMT) and Human Mut-L Homologue 1 (MLH1) promoter hypermethylation are associated with APC, KRAS and BRAF mutations among 734 CRC patients.

Methods: We compared MGMT hypermethylation with G:C > A:T mutations in APC and KRAS and with the occurrence of such mutations in CpG or non-CpG dinucleotides in APC. We also compared MLH1 hypermethylation with truncating APC mutations and activating KRAS and BRAF mutations.

Effects of selective oestrogen receptor modulators on proliferation in tissue cultures of pre- and postmenopausal human endometrium.

We characterised the effects of selective oestrogen receptor modulators (SERM) in explant cultures of human endometrium tissue. Endometrium tissues were cultured for 24h in Millicell-CM culture inserts in serum-free medium in the presence of vehicle, 17beta-estradiol (17beta-E2, 1nM), oestrogen receptor (ER) antagonist ICI 164.384 (40nM), and 4-OH-tamoxifen (40nM), raloxifene (4nM), lasofoxifene (4nM) and acolbifene (4nM).

Alcohol consumption, type of alcoholic beverage and risk of colorectal cancer at specific subsites.

Within the Netherlands Cohort Study on diet and cancer, we investigated associations between total alcohol consumption, specific alcoholic beverage consumption and risk of colorectal cancer (CRC) according to anatomical subsite. Hazard Ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards models. Analyses were performed on 2,323 CRC cases, available after 13.

Associations of dietary methyl donor intake with MLH1 promoter hypermethylation and related molecular phenotypes in sporadic colorectal cancer.

Intake of dietary factors that serve as methyl group donors may influence promoter hypermethylation in colorectal carcinogenesis. We investigated whether dietary folate, vitamin B2 and vitamin B6, methionine and alcohol were associated with mutL homologue 1 (MLH1) hypermethylation and the related molecular phenotypes of MLH1 protein expression, microsatellite instability (MSI) and BRAF mutations in patients with colorectal carcinomas. Within the Netherlands Cohort Study on diet and cancer (n = 120 852), 648 cases (367 men and 281 women) and 4059 subcohort members were available for data analyses from a follow-up period between 2.

Cigarette smoking and KRAS oncogene mutations in sporadic colorectal cancer: results from the Netherlands Cohort Study.

Since a KRAS oncogene mutation is an early event in colorectal cancer development and cigarette smoking is thought to have an effect on early stages of colorectal tumorigenesis, smoking, especially long-term smoking, may be associated with the risk for colorectal cancer with KRAS oncogene mutations. In the Netherlands Cohort Study on diet and cancer (n=120,852 men and women), using a case-cohort design, adjusted incidence rate ratios (RR) and 95% confidence intervals (CI) were computed for colorectal tumors with wild-type and with mutated KRAS gene, and with specific G:C-->T:A or G:C-->A:T point mutations in KRAS, according to cigarette smoking status, frequency, duration, pack years, age at first exposure, years since cessation, inhalation and filter usage. After 7.

Haemoglobin expression in human endometrium.

Background: The general concept that haemoglobin is only a carrier protein for oxygen and carbon dioxide is challenged since recent studies have shown haemoglobin expression in non-erythroid cells and the protection of haemoglobin against oxidative and nitrosative stress. Using microarrays, we previously showed expression of haemoglobins alpha, beta, delta and gamma and the haeme metabolizing enzyme, haeme oxygenase (HO)-1 in human endometrium.

Methods: Using real-time quantitative PCR, haemoglobin alpha, beta, delta and gamma, and HO-1 mRNA levels were assessed throughout the menstrual cycle (n = 30 women).

Dietary fat and risk of colon and rectal cancer with aberrant MLH1 expression, APC or KRAS genes.

Objective: To investigate baseline fat intake and the risk of colon and rectal tumors lacking MLH1 (mutL homolog 1, colon cancer, nonpolyposis type 2) repair gene expression and harboring mutations in the APC (adenomatous polyposis coli) tumor suppressor gene and in the KRAS (v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) oncogene.

Methods: After 7.3 years of follow-up of the Netherlands Cohort Study (n = 120,852), adjusted incidence rate ratios (RR) and 95% confidence intervals (CI) were computed, based on 401 colon and 130 rectal cancer patients.

Progesterone regulation of implantation-related genes: new insights into the role of oestrogen.

Genomic profiling was performed on explants of late proliferative phase human endometrium after 24-h treatment with progesterone (P) or oestradiol and progesterone (17beta-E(2)+P) and on explants of menstrual phase endometrium treated with 17beta-E(2)+P. Gene expression was validated with real-time PCR in the samples used for the arrays, in endometrium collected from early and mid-secretory phase endometrium, and in additional experiments performed on new samples collected in the menstrual and late proliferative phase. The results show that late proliferative phase human endometrium is more responsive to progestins than menstrual phase endometrium, that the expression of several genes associated with embryo implantation (i.

Alcohol consumption and distinct molecular pathways to colorectal cancer.

High alcohol consumption is related to colorectal cancer (CRC). Our objective was to study associations between alcohol consumption and risk of CRC according to characteristics of aetiological pathways: the chromosomal instability (CIN) and the microsatellite instability (MIN) pathway. We classified CIN+ tumours (tumours with either a truncating APC mutation, an activating K-ras mutation or overexpression of p53), MIN+ tumours (tumours lacking hMLH1 expression) and CIN- /MIN- tumours (tumours without these defects).

Dietary folate and APC mutations in sporadic colorectal cancer.

Folate deficiency has been associated with colorectal cancer risk and may be involved in colorectal carcinogenesis through increased chromosome instability, gene mutations, and aberrant DNA methylation. Within the Netherlands Cohort Study on diet and cancer, we investigated the associations between dietary folate intake and colorectal cancer risk with (APC(+)) and without (APC(-)) truncating APC mutations, accounting for hMLH1 expression and K-ras mutations. In total, 528 cases and 4200 subcohort members were available for data analyses of the study cohort (n = 120,852) from a follow-up period between 2.

Alcohol and the risk of colon and rectal cancer with mutations in the K-ras gene.

The first metabolite of alcohol, acetaldehyde, may trigger replication errors and mutations in DNA, which may predispose to developing colorectal cancer (CRC). In a prospective study on colon and rectal cancer, we investigated the following hypotheses: alcohol consumption is associated with an increased risk of mutations in the K-ras oncogene, and beer consumption is associated with an increased risk of G-->A mutations in this gene. Therefore, we studied the associations between consumption of alcohol and alcoholic beverages and the risk of CRC without and with specific K-ras gene mutations.

Tibolone and metabolites induce prolactin production in human endometrial stromal cells in vitro: evidence for cell-specific metabolism.

In this study, we assessed the effects of tibolone and its metabolites on the production of a progesterone sensitive parameter, prolactin, in human endometrium stroma cells in vitro. In addition, the metabolism of the compounds by isolated stromal and epithelial cells was evaluated. The reference compounds, progesterone, Org 2058, and DHT all induced prolactin production.

Expression and regulation of vascular endothelial growth factor ligands and receptors during menstruation and post-menstrual repair of human endometrium.

Regeneration and growth of the human endometrium after shedding of the functional layer during menstruation depends on an adequate angiogenic response. We analysed the mRNA expression levels of all known vascular endothelial growth factor (VEGF) ligands and receptors in human endometrium collected in the menstrual and proliferative phases of the menstrual cycle. In addition, we evaluated the expression of VEGF-A, VEGF-R2 and NRP-1 at the protein level.