Products of the colonic microbiota mediate the effects of diet on colon cancer risk

It is estimated that most colon cancers can be attributed to dietary causes. We have hypothesized that diet influences the health of the colonic mucosa through interaction with the microbiota and that it is the milieu interior that regulates mucosal proliferation and therefore cancer risk. To validate this further, we compared colonic contents from healthy 50- to 65-y-old people from populations with high and low risk, specifically low risk Native Africans (cancer incidence <1:100,000; n = 17), high risk African Americans (risk 65:100,000; n = 17), and Caucasian Americans (risk 50:100,000; n = 18). Americans typically consume a high-animal protein and -fat diet, whereas Africans consume a staple diet of maize meal, rich in resistant starch and low in animal products. Following overnight fasting, rapid colonic evacuation was performed with 2 L polyethylene glycol. Total colonic evacuants were analyzed for SCFA, vitamins, nitrogen, and minerals. Total SCFA and butyrate were significantly higher in Native Africans than in both American groups. Colonic folate and biotin content, measured by Lactobacillus rhamnoses and Lactobacillus plantarum ATCC 8014 bioassay, respectively, exceeded normal daily dietary intakes. Compared with Africans, calcium and iron contents were significantly higher in Caucasian Americans and zinc content was significantly higher in African Americans, but nitrogen content did not differ among the 3 groups. In conclusion, the results support our hypothesis that the microbiota mediates the effect diet has on colon cancer risk by their generation of butyrate, folate, and biotin, molecules known to play a key role in the regulation of epithelial proliferation.

Assessing capacity within a context of abuse or neglect

In 2000, with the implementation of Part III of the Adult Guardianship Act: Support and Assistance for Abused and Neglected Adults, British Columbia formally recognized the need to examine issues of decisional capacity of older adults within a context of abuse or neglect. Interestingly, however, although the test of capacity was clearly laid out under this piece of legislation, the potential influence that living in a situation of abuse or neglect may have on how the person makes decisions is not explicitly addressed. Similarly, this is a missing link throughout the literature discussing decisional capacity in older adults. This gap exists despite the fact that determining the "protection" needs of someone who is being abused and/or neglected often hinges directly on that person's decisional capacity. The purpose of this article is to examine the unique aspects associated with assessing and determining capacity for older adults who are living in a situation of abuse or neglect. The specific objectives are to: (a) examine how living in a situation of abuse or neglect may influence the determination of capacity and (b) explore the implications of conducting an assessment within a potentially abusive context. The legal notion of undue influence and the psychological concept of relational connection are introduced as potentially important for considering decision making within this context.

Use of tissue transglutaminase and fibronectin to influence osteoblast responses to tricalcium phosphate scaffolds

To explore the possibility of controlling cell interaction with biomaterials, tricalcium phosphate scaffolds were modified using the enzyme tissue transglutaminase (tTgase) in conjunction with fibronectin. Previous reports in the literature have highlighted a number of favourable responses that this protein-enzyme complex can stimulate, including enhancing both cell adhesion, and mineralisation. Fibronectin and tTgase alone were used as controls, and a series of different concentrations of tTgase and fibronectin in combination were assessed. Cell metabolic activity, alkaline phosphatase production, and collagen content were all measured in cultures up to 28 days. Using tetracycline labelling, calcium containing multilayered regions were imaged and quantified. Addition of 6 microg fibronectin resulted in increased alkaline phosphatase activity in all combinations, while increased transglutaminase resulted in more collagen in the cell lysates. Samples treated with fibronectin produced many small mineralised areas, those with 6 microg fibronectin and transglutaminase produced numerous large mineralised areas. The mixture of fibronectin and transglutaminase may prove to be a useful treatment for producing increased osteoblast differentiation on scaffolds.

Aldehyde oxidase and its contribution to the metabolism of a structurally novel, functionally selective GABAAα5-subtype inverse agonist

(3-Tert-butyl-7-(5-methylisoxazol-3-yl)-2-(1-methyl-1H-1,2,4-triazol-5-ylmethoxy)pyrazolo[1,5-d] [1,2,4]triazine was recently identified as a functionally selective, inverse agonist at the benzodiazepine site of GABA(A) alpha5-containing receptors, which enhances performance in animal models of cognition. The routes of metabolism of this compound in rat, dog, rhesus monkey and human in vitro systems, and in vivo in rat, dog and rhesus monkey have been characterized. The current study demonstrates that both a cytosolic oxidative reaction and cytochrome P450 play important roles in the metabolism of the compound. Chemical inhibition studies showed the oxidation in human cytosol to be catalysed predominantly by aldehyde oxidase rather than the related enzyme, xanthine oxidase. The aldehyde oxidase-mediated metabolites were present in vitro and in vivo in both rat and rhesus monkey, and also in vitro in man. They were absent both in vitro and in vivo in dog.

Guided plasmonic modes in nanorod assemblies: strong electromagnetic coupling regime

We demonstrate that the coupling between plasmonic modes of oriented metallic nanorods results in the formation of an extended (guided) plasmonic mode of the nanorod array. The electromagnetic field distribution associated to this mode is found to be concentrated between the nanorods within the assembly and propagates normally to the nanorod long axes, similar to a photonic mode waveguided by an anisotropic slab. This collective plasmonic mode determines the optical properties of nanorod assemblies and can be tuned in a wide spectral range by changing the nanorod array geometry. This geometry represents a unique opportunity for light guiding applications and manipulation at the nanoscale as well as sensing applications and development of molecular plasmonic devices.

Cold Water Recovery Reduces Anaerobic Performance

This study investigated the effects of cold water immersion on recovery from anaerobic cycling. Seventeen (13 male, 4 female) active subjects underwent a crossover, randomised design involving two testing sessions 2 - 6 d apart. Testing involved two 30-s maximal cycling efforts separated by a one-hour recovery period of 10-min cycling warm-down followed by either passive rest or 15-min cold water immersion (13 - 14 degrees C) with passive rest. Peak power, total work and postexercise blood lactate were significantly reduced following cold water immersion compared to the first exercise test and the control condition. These variables did not differ significantly between the control tests. Peak exercise heart rate was significantly lower after cold water immersion compared to the control. Time to peak power, rating of perceived exertion, and blood pH were not affected by cold water immersion compared to the control. Core temperature rose significantly (0.3 degrees C) during ice bath immersion but a similar increase also occurred in the control condition. Therefore, cold water immersion caused a significant decrease in sprint cycling performance with one-hour recovery between tests.

Screening for prostate cancer

BACKGROUND

Any form of screening aims to reduce mortality and increase a person's quality of life. Screening for prostate cancer has generated considerable debate within the medical community, as demonstrated by the varying recommendations made by medical organizations and governed by national policies. Much of this debate is due to the limited availability of high quality research and the influence of false-positive or false-negative results generated by use of the diagnostic techniques such as the digital rectal examination (DRE) and prostate specific antigen (PSA) blood test.

OBJECTIVES

To determine whether screening for prostate cancer reduces prostate cancer mortality and has an impact on quality of life.

SEARCH STRATEGY

Electronic databases (PROSTATE register, CENTRAL the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CANCERLIT and the NHS EED) were searched electronically in addition to hand searching of specific journals and bibliographies in an effort to identify both published and unpublished trials.

SELECTION CRITERIA

All randomised controlled trials of screening versus no screening or routine care for prostate cancer were eligible for inclusion in this review.

DATA COLLECTION AND ANALYSIS

The search identified 99 potentially relevant articles that were selected for full text review. From these 99 citations, two randomised controlled trials were identified as meeting the review's inclusion criteria. Data from the trials were independently extracted by two authors.

MAIN RESULTS

Two randomised controlled trials with a total of 55,512 participants were included; however, both trials had methodological weaknesses. Re-analysis using intention-to-screen and meta-analysis of results from the two randomised controlled trials indicated no statistically significant difference in prostate cancer mortality between men randomised for prostate cancer screening and controls (RR 1.01, 95% CI: 0.80-1.29). Neither study assessed the effect of prostate cancer screening on quality of life, all-cause mortality or cost effectiveness.

AUTHORS' CONCLUSIONS

Given that only two randomised controlled trials were included, and the high risk of bias of both trials, there is insufficient evidence to either support or refute the routine use of mass, selective or opportunistic screening compared to no screening for reducing prostate cancer mortality. Currently, no robust evidence from randomised controlled trials is available regarding the impact of screening on quality of life, harms of screening, or its economic value. Results from two ongoing large scale multicentre randomised controlled trials that will be available in the next several years are required to make evidence-based decisions regarding prostate cancer screening.

L. Radlin and G. Radlin. A Caregivers' Guide to Dementia: What If It's Not Alzheimer's?Amherst, NY: Prometheus, 2003

Dans cet ouvrage, Radlin et Radlin apportent une contribution importante à la littérature sur les soins familiaux. Centré sur les soins aux personnes atteintes de démence frontotemporale, ce livre met à la disposition des familles et des professionnels de la santé d'importantes informations biomédicales ainsi que de nouvelles perspectives professionnelles susceptibles de les aider à mieux comprendre les personnes qui souffrent de cette maladie, et ainsi mieux s'occuper d'elles. Chacun des chapitres aborde des questions centrées sur une explication de cette condition et fournit des conseils pratiques pour faire face aux problèmes quotidiens que les proches des malades doivent affronter. Dans une perspective canadienne, cependant, cet ouvrage s'avère un peu limité par son contexte de référence exclusivement américain. De plus, il risque par inadvertance d'accabler les familles en soulignant leur manque de qualifications formelles, sans leur communiquer une juste appréciation de la contribution inestimable que constituent leurs connaissances particulières. Il est par ailleurs décevant de voir que l'ouvrage ne souligne guère l'importance du fait que les proches des malades doivent aussi avoir soin d'eux-mêmes, et non seulement de la personne atteinte de démence frontotemporale.

A clinical audit of the quality of care of hypertension in general practice

Clinical audits monitor the use of particular interventions, or the care received by patients, against agreed standards. Any departures from "best practice" can then be examined, and causes can be determined and acted upon. The Ministry of Health (MOH), Jamaica, has recently published standards of care for hypertension. The medical records of a convenience sample of 125 hypertensive patients being managed by five current family medicine residents in their respective primary care practices were audited Initial results showed limited adherence to the MOH recommended hypertension management guidelines. The same practices were re-audited after an interval of six months, during which time the physicians were sensitized to the results of the preliminary audit. Marked improvements were noted in the second audit. Assessment for co-risk factors for hypertension-related diseases improved: nutritional advice (33% to 74%), smoking and alcohol intake history (40% to 65%) and history taking of physical activity (30% to 47%). Assessment for target organ damage also improved: fundoscopy done (11% to 54%), foot examination done (30% to 58%) and yearly electrolytes done (28% to 62%). There are clear gaps between current practice and standards that exist internationally and locally for management of hypertension. The MOH needs to disseminate and educate general practitioners about the standards of care guidelines.

A survey of the causes of sudden cardiac death in the under 35-year-age group

CRY (Cardiac Risk in the Young) is a registered Irish charity established by parents who are bereaved as a result of sudden cardiac death. The aim of this study is to establish the incidence and causes of sudden cardiac death in Dublin city in the 10-year period from 1st January 1993 to 31st December 2002. All sudden cardiac deaths in the under 35-year age group which were reported to the city coroner in the study period were examined. Details regarding age, sex, previous symptoms, investigations, circumstances of death and main pathological finding were recorded in each case. A total of 72 cases of sudden cardiac death in the under-35 year age group were reported. 52 were men. The median age was 26.5 years (range 12-34 years). The cause of death in 20 cases was reported as atherosclerotic Coronary Artery Disease. The second commonest cause of death (24% cases) was Hypertrophic Cardiomyopathy. Hypertrophic Cardiomyopathy was the commonest cause of death under the age of 25 years. Overall atherosclerotic coronary artery disease was the commonest cause of death in this group. The importance of Hypertrophic Cardiomyopathy is highlighted by the fact it was the commonest cause of death in the under 25-year age group. Screening those at high risk of sudden cardiac death especially the relatives of those affected by Hypertrophic Cardiomyopathy need to be discussed and implemented.