Randomised controlled trial of a secondary prevention program for myocardial infarction patients ('ProActive Heart'): study protocol. Secondary prevention program for myocardial infarction patients

Background: Coronary heart disease (CHD) is a significant cause of health and economic burden. Secondary prevention programs play a pivotal role in the treatment and management of those affected by CHD although participation rates are poor due to patient, provider, health system and societal-level barriers. As such, there is a need to develop innovative secondary prevention programs to address the treatment gap. Telephone-delivered care is convenient, flexible and has been shown to improve behavioural and clinical outcomes following myocardial infarction (MI). This paper presents the design of a randomised controlled trial to evaluate the efficacy of a six-month telephone-delivered secondary prevention program for MI patients (ProActive Heart). Methods: 550 adult MI patients have been recruited over a 14 month period (December 2007 to January 2009) through two Brisbane metropolitan hospitals, and randomised to an intervention or control group (n = 225 per group). The intervention commences within two weeks of hospital discharge delivered by study-trained health professionals ('health coaches') during up to 10 × 30 minute scripted telephone health coaching sessions. Participants also receive a ProActive Heart handbook and an educational resource to use during the health coaching sessions. The intervention focuses on appropriate modification of CHD risk factors, compliance with pharmacological management, and management of psychosocial issues. Data collection occurs at baseline or prior to commencement of the intervention (Time 1), six months follow-up or the completion of the intervention (Time 2), and at 12 months follow-up for longer term outcomes (Time 3). Primary outcome measures include quality of life (Short Form-36) and physical activity (Active Australia Survey). A cost-effective analysis of the costs and outcomes for patients in the intervention and control groups is being conducted from the perspective of health care costs to the government. Discussion: The results of this study will provide valuable new information about an innovative telephone-delivered cost-effective secondary prevention program for MI patients

K-ras oncogene mutations in sporadic colorectal cancer in The Netherlands Cohort Study

K-ras oncogene mutations in sporadic colorectal cancer in The Netherlands Cohort Study. Brink M, de Goeij AF, Weijenberg MP, Roemen GM, Lentjes MH, Pachen MM, Smits KM, de Bruine AP, Goldbohm RA, van den Brandt PA. Nutrition and Toxicology Research Institute Maastricht (NUTRIM), Department of Epidemiology, Maastricht University, PO Box 616, The Netherlands. [email protected] Activation of K-ras oncogene has been implicated in colorectal carcinogenesis, being mutated in 30-60% of the adenocarcinomas. In this study, 737 incident colorectal cancer (CRC) patients, originating from 120 852 men and women (55-69 years at baseline) participating in the Netherlands Cohort Study (NLCS), were studied in order to evaluate subgroups with respect to K-ras mutation status. Mutation analysis of the exon 1 fragment of the K-ras oncogene, spanning codons 8-29, was performed on archival colorectal adenocarcinoma samples of all patients using macrodissection, nested PCR and direct sequencing of purified fragments. The method of mutation detection was validated by the confirmation of reported K-ras status in CRC cell lines, a good correlation between fresh-frozen and routinely fixed, paraffin-embedded tissue, a detection limit of 5% mutated DNA and a good reproducibility. Various types of K-ras mutations were evaluated with respect to tumour sub-localization, Dukes' stage and tumour differentiation. In 37% (271/737) of the patients, the exon 1 fragment of K-ras gene was found to be mutated. The predominant mutations are G>A transitions and G>T transversions, and codons 12 and 13 are the most frequently affected codons. Patients with a rectal tumour were found to have the highest frequency of G>T transversions as compared with patients with a colon or rectosigmoid tumour. This difference appeared to be confined to women with a rectal tumour harbouring G>T transversions. No significant differences were observed for Dukes' stage with respect to types of K-ras mutation, which does not support direct involvement of the K-ras oncogene in adenocarcinoma progression. The equal distribution of K-ras mutations among cases with or without a family history of colorectal cancer argues against an important role for this mutation in familial colorectal cancer, and could imply that K-ras mutations are more probably involved in environmental mechanisms of colorectal carcinogenesis

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. This “sponge loop” was confirmed in aquarium and in situ food web experiments, using 13C- and 15N-enriched DOM. The DOM-sponge-fauna pathway explains why biological hot spots such as coral reefs persist in oligotrophic seas-the reef’s paradox-and has implications for reef ecosystem functioning and conservation strategie

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.e. the choanocytes, and in this process apoptosis only plays a minor role. To our knowledge, such fast cell kinetics under steady-state conditions, with high turnover by shedding in the absence of apoptosis, has not been observed previously in any other multicellular organism. The duration of the cell cycle in vivo resembles that of unicellular organisms in culture. Morphological and histochemical studies demonstrate compartmentalization of choanocytes in the sponge tissue, which corresponds well with its remarkable cellular kinetics. Coral reef cavity sponges, like H. caerulea, inhabit low nutrient tropical waters, forcing these organisms to filter large volumes of water and to capture the few nutrients efficiently. Under these oligotrophic conditions, a high cell turnover may be considered as a very useful strategy, preventing permanent damage to the sponge by environmental stress. Halisarca caerulea maintains its body mass and keeps its food uptake system up to date by constantly renewing its filter system. We conclude that studies on cell kinetics and functional morphology provide new and essential information on the growth characteristics and the regulation of sponge growth in vivo as well as in vitro and the role of choanocytes in tissue homeostasi

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.e. the choanocytes, and in this process apoptosis only plays a minor role. To our knowledge, such fast cell kinetics under steady-state conditions, with high turnover by shedding in the absence of apoptosis, has not been observed previously in any other multicellular organism. The duration of the cell cycle in vivo resembles that of unicellular organisms in culture. Morphological and histochemical studies demonstrate compartmentalization of choanocytes in the sponge tissue, which corresponds well with its remarkable cellular kinetics. Coral reef cavity sponges, like H. caerulea, inhabit low nutrient tropical waters, forcing these organisms to filter large volumes of water and to capture the few nutrients efficiently. Under these oligotrophic conditions, a high cell turnover may be considered as a very useful strategy, preventing permanent damage to the sponge by environmental stress. Halisarca caerulea maintains its body mass and keeps its food uptake system up to date by constantly renewing its filter system. We conclude that studies on cell kinetics and functional morphology provide new and essential information on the growth characteristics and the regulation of sponge growth in vivo as well as in vitro and the role of choanocytes in tissue homeostasi

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 13.3 years of follow-up. Compared to abstaining, alcohol consumption of ≥30.0 g/day (∼3 alcoholic drinks) was positively associated with the risk of CRC (HR: 1.32, 95% CI: 1.06-1.65). Analyses restricted to subjects who reported to have consumed equal amounts of alcohol 5 years before baseline compared to baseline, showed elevated risk estimates for consumers of ≥30.0 g of total alcohol per day as well (HR: 1.53, 95% CI: 1.16-2.01). Suggestive of a subsite-specific effect, cancer risk seemed to increase from proximal colon through rectum; HR: 1.29, 95% CI: 0.85-1.96 for proximal colon cancer, HR: 1.41, 95% CI: 0.94-2.11 for distal colon cancer, HR: 2.07, 95% CI: 1.03-4.18 for rectosigmoid cancer and HR: 1.69, 95% CI: 1.08-2.64 for rectal cancer. No associations were observed between consumption of alcoholic beverages and CRC risk when compared with the non-drinkers of the specific beverage and after adjustment for total alcohol intake. No evidence was found for sex-specific effects of alcohol and alcoholic beverages. In conclusion, our data showed a positive association between alcohol consumption and risk of CRC, which seemed to be mainly explained by the alcoholic content of alcoholic beverages, rather than other constituents. Also, cancer risk may vary according to anatomical subsite. © 2008 Wiley-Liss, Inc