A baseline study of importance of bovines for human Schistosoma Japonicum infections around Poyang Lake, China: Villages studied and snail sampling strategy

An epidemiologic survey among four administrative villages around Poyang Lake, in Jiangxi Province, China (two experimental and two controls) is being conducted to determine if bovine infections are responsible for the persistence of human schistosomiasis transmission on Yangtze River marshlands. A previously published paper presented the experimental design and baseline data for humans and bovines. This paper presents basic data for the four villages using remote sensing, and baseline data for snails that includes geographic information systems and remote sensing technology to classify the areas of bovine grazing ranges and habitats suitable for snails. A new method for sampling Oncomelania snails in China is used to determine the distribution, density, and infection rates of snails throughout the grazing ranges from season to season over a four-year period. Hypothetically, treating bovines should reduce infection rates in snails to below the critical number necessary to maintain infections in man and bovines.

Genetic covariation of pelvic organ and elbow mobility in twins and their sisters

A range of environmental risk factors, with childbirth the most notable, have been associated with the development of pelvic organ prolapse and urinary incontinence. However, indications of genetic influence (positive family histories, ethnic differences) have prompted research into the heritability of measures of pelvic organ descent and joint mobility, which have also been associated with prolapse and incontinence. Genes appear to influence about half of the variation in these measures and, furthermore, the pelvic organ measures are associated with elbow hyperextension at a phenotypic level (r approximate to .2). We examined these measures in young, nulligravid women to determine if their association is due to a common genetic source. Data were collected from 178 Caucasian female co-twins and non-twin sisters, 50 of whom returned to be retested, which allowed reliability to be estimated and unreliable variance to be isolated in the multivariate analyses. Structural equation modeling was used to estimate genetic associations between latent elbow and bladder mobility factors for which heritabilities were estimated to be 0.80 and 0.64 respectively. The association between these factors appeared to be mediated by common genes (genetic r = .48, non-shared environmental r = -.06), with genes influencing latent elbow mobility accounting for 14% of the variation in latent bladder mobility. We speculate that genes influencing connective tissue structure may underlie this association.

The gender differences in health effects of environmental cadmium exposure and potential mechanisms

On a viewpoint of gender differences in Cd body burden and its health effects, we reviewed the population- based research including our own which conducted in Japan, Thailand, Australia, Poland, Belgium and Sweden to assess health effects of human exposure to environmental cadmium and their potential mechanisms. As a result, six risk factors in Cd health effects in women have been identified; ( 1) more serious type of renal tubular dysfunction, ( 2) difference in calcium metabolism and its regulatory hormones, ( 3) kidney sensitivity; difference in P450 phenotype, ( 4) pregnancy, ( 5) body iron store status, and ( 6) genetic factors. Further studies of Cd toxicity targeted to women would now appear necessary.

Adverse Health Effects of Chronic Exposure to Low-Level Cadmium in Foodstuffs and Cigarette Smoke

Cadmium is a cumulative nephrotoxicant that is absorbed into the body from dietary sources and cigarette smoking. The levels of Cd in organs such as liver and kidney cortex increase with age because of the lack of an active biochemical process for its elimination coupled with renal reabsorption. Recent research has provided evidence linking Cd-related kidney dysfunction and decreases in bone mineral density in nonoccupationally exposed populations who showed no signs of nutritional deficiency. This challenges the previous view that the concurrent kidney and bone damage seen in Japanese itai-itai disease patients was the result of Cd toxicity in combination with nutritional deficiencies, notably, of zinc and calcium. Further, such Cd-linked bone and kidney toxicities were observed in people whose dietary Cd intakes were well within the provisional tolerable weekly intake (PTWI) set by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives of 1 mug/kg body weight/day or 70 mug/day. This evidence points to the much-needed revision of the current PTWI for Cd. Also, evidence for the carcinogenic risk of chronic Cd exposure is accumulating and Cd effects on reproductive outcomes have begun to emerge.

Vertical handover supporting pervasive computing in future wireless networks

A variety of current and future wired and wireless networking technologies can be transformed into a seamless communication environments through application of context-based vertical handovers. Such seamless communication environments are needed for future pervasive/ubiquitous systems. Pervasive systems are context aware and need to adapt to context changes, including network disconnections and changes in network Quality of Service (QoS). Vertical handover is one of many possible adaptation methods. It allows users to roam freely between heterogeneous networks while maintaining the continuity of their applications. This paper proposes a vertical handover mechanism suitable for multimedia applications in pervasive systems. The paper focuses on the handover decision making process which uses context information regarding user devices, user location, network environment and requested QoS. (C) 2004 Elsevier B.V. All rights reserved.

Effects of chronic exposure to low-level cadmium on renal tubular function and CYP2A6-mediated coumarin metabolism in healthy human subjects

Relationships between cadmium (Cd) body burden, kidney function and coumarin metabolism were investigated using two groups of 197 and 200 healthy Thais with men and women in nearly equal numbers. A mean age of one group was 30.5 years and it was 39.3 years for the other group. Of 397, 20 subjects (5%) excreted urine Cd between 1.4 mug/g and 3.8 mug/g creatinine and these subjects faced 10-15% increase in the probability of having abnormal urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG-uria). The prevalence of NAG-uria varied with Cd body burden in a dose-dependent manner (chi(2) = 22, P < 0.008). Also NAG-nuria was one of the three kidney effect markers tested that showed the greatest strength of correlation with urine Cd in both men and women (r = 0.48 P < 0.001). In addition, urine Cd excretion of men and women showed a positive correlation (r = 0.46 to 0.54. P < 0.001) with urine 7-hydroxycoumarin (7-OHC) excretion which was used as a marker of liver cytochrome P450 2A6 (CYP2A6) enzyme activity. Urinary CA excretion accounted for 25% of the total variation in urine 7-OHC excretion (P < 0.001). These data suggest that Cd may increase the expression of CYP2A6 in liver, resulting in enhanced coumarin metabolism in subjects with high Cd body burden. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

Influence of body iron store status and cigarette smoking on cadmium body burden of healthy Thai women and men

The influence of cigarette smoking, body iron store status and gender on cadmium (Cd) body burden was examined in a group of 197 healthy Thais with overall mean age of 30.5 year (19-47 year). The lowest, geometric mean, and the highest urinary Cd excretion rate was 0.04, 0.46 and 3.84 mug/g creatinine, respectively. The prevalence of low iron stores (serum ferritin

A commentary on the impacts of metals and metalloids in the environment upon the metabolism of drugs and chemicals

The salient feature of metals is that unlike organic compounds they do not degrade in the environment and barely move from one environmental matrix to another. Human interventions take these compounds from their stable and non-bioavailable geological matrix into situations of biological accessibility. Studies in the 1970s and the 1980s of metal bioavailability and impacts of metals and metalloids were driven by the process of abatement of lead in the environment. Humans have clear and identifiable sources of exposure from fuels, food and leaded water pipes to lead. Interventions started at that time have dramatically lowered human lead exposure. Attention has now shifted to other metals, in particular, cadmium, which has seen increasing use. It is generally accepted that food crops grown on cadmium containing soils or soils naturally rich in this metal are the major source of exposure to humans other than exposure from smoking of cigarettes. This mini-review gives a summary and commentary on early studies on effects of lead on haem metabolism that provide us the clue to why investigations of the impacts of other toxic heavy metals and metalloids such as cadmium and arsenic on different human cytochrome P450 forms have become of great interest at the current time. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

Associations of location and perceived environmental attributes with walking in neighborhoods

Purpose. Ecological models highlight the importance of environmental influences. We examined associations of coastal versus noncoastal location and perceived environmental attributes with neighborhood walking, total walking, and total activity. Methods. Telephone interviews with 800 faculty and general staff of an Australian university. Results. Men were significantly more likely to walk in their neighborhood if they lived in a coastal location (odds ratio [OR] = 1.66), and they highly rated environmental aesthetics (OR = 1.91), convenience of facilities (OR = 2.20), and access to facilities (OR = 1.98). For women, neighborhood walking was associated with high ratings of convenience (OR = 3.78) but was significantly less likely if they had high ratings for access (OR = 0.48). For total walking and total physical activity, few significant associations emerged. Conclusions. Environmental attributes were related to walking in the neighborhood but not to more general activity indices. Understanding gender-specific environmental correlates of physical activity should be a priority.

Understanding environmental influences on walking - Review and research agenda

Background: Understanding how environmental attributes can influence particular physical activity behaviors is a public health research priority. Walking is the most common physical activity behavior of adults; environmental innovations may be able to influence rates of participation. Method: Review of studies on relationships of objectively assessed and perceived environmental attributes with walking. Associations with environmental attributes were examined separately for exercise and recreational walking, walking to get to and from places, and total walking. Results: Eighteen Studies were identified. Aesthetic attributes, convenience of facilities for walking (sidewalks, trails); accessibility of destinations (stores, park, beach); and perceptions about traffic and busy roads were found to be associated with walking for particular purposes. Attributes associated with walking for exercise were different front those associated with walking to get to and from places. Conclusions: While few studies have examined specific environment-walking relationships, early evidence is promising. Key elements of the research agenda are developing reliable and valid measures of environmental attributes and walking behaviors, determining whether environment-behavior relationships are causal, and developing theoretical models that account for environmental influences and their interactions with other determinants. (C) 2004 American Journal of Preventive Medicine.

Perceived environment attributes, residential location, and walking for particular purposes

Background: Identifying environmental factors that can influence physical activity is a public health priority. We examined associations of perceived environmental attributes with walking for four different purposes: general neighborhood walking, walking for exercise, walking for pleasure, and walking to get to and from places. Methods: Participants (n =399; 57% women) were surveyed by mail. They reported place of residence, walking behaviors, and perceptions of neighborhood environmental attributes. Results: Men with the most positive perceptions of neighborhood aesthetics were significantly more likely (odds ratio [OR] =7.4) to be in the highest category of neighborhood walking. Men who perceived the weather as not inhibiting their walking were much more likely (OR= 4.7) to be high exercise walkers. Women who perceived the weather as not inhibiting their walking were significantly more likely to be high neighborhood walkers (OR=3.8) and those with moderate perceptions of accessibility were much more likely to do more walking for pleasure (OR=3.5). Conclusions: Different environmental attributes were associated with different types of walking and these differed between men and women. Approaches to increasing physical activity might usefully focus on those attributes of the local environment that might influence particular subsets of walking behavior.

Knowledge beliefs and attitudes of squash venue operators relating to use of protective eyewear

Sports venues are in a position to potentially influence the safety practices of their patrons. This study examined the knowledge, beliefs and attitudes of venue operators that could influence the use of protective eyewear by squash players. A 50% random sample of all private and public squash venues affiliated with the Victorian Squash Federation in metropolitan Melbourne was selected. Face-to-face interviews were conducted with 15 squash venue operators during August 2001. Interviews were transcribed and content and thematic analyses were performed. The content of the interviews covered five topics: (1) overall injury risk perception, (2) eye injury occurrence, (3) knowledge, behaviors, attitudes and beliefs associated with protective eyewear, (4) compulsory protective eyewear and (5) availability of protective eyewear at venues. Venue operators were mainly concerned with the severe nature of eye injuries, rather than the relatively low incidence of these injuries. Some venue operators believed that players should wear any eyewear, rather than none at all, and believed that more players should use protective eyewear. Generally, they did not believe that players with higher levels of experience and expertise needed to wear protective eyewear when playing. Only six venues had at least one type of eyewear available for players to hire or borrow or to purchase. Operators expressed a desire to be informed about correct protective eyewear. Appropriate protective eyewear is not readily available at squash venues. Better-informed venue operators may be more likely to provide suitable protective eyewear.

Engagement and retention of participants in a physical activity website

Background. Websites have the potential to deliver enhanced versions of targeted and tailored physical activity programs to large numbers of participants. We describe participant engagement and retention with a stage-based physical activity website in a workplace setting. Methods. We analyzed data from participants in the website condition of a randomized trial designed to test the efficacy of a print- vs. website-delivered intervention. They received four stage-targeted e-mails over 8 weeks, with hyperlinks to the website. Both objective and self-reported website use data were collected and analyzed. Results. Overall, 327 were randomized to the website condition and 250 (76%) completed the follow-up survey. Forty-six percent (n = 152) visited the website over the trial period. A total of 4,114 hits to the website were recorded. Participants who entered the site spent on average 9 min per visit and viewed 18 pages. Website use declined over time; 77% of all visits followed the first e-mail. Conclusions. Limited website engagement, despite the perceived usefulness of the materials, demonstrates possible constraints on the use of e-mails and websites in delivering health behavior change programs. In the often-cluttered information environment of workplaces, issues of engagement and retention in website-delivered programs require attention. (C) 2004 The Institute For Cancer Prevention and Elsevier Inc. All rights reserved.