Cathepsin F cysteine protease of the human liver fluke, Opisthorchis viverrini

The liver fluke Opisthorchis viverrini is classified as a class I carcinogen due to the association between cholangiocarcinoma and chronic O. viverrini infection. During its feeding activity within the bile duct, the parasite secretes several cathepsin F cysteine proteases that may induce or contribute to the pathologies associated with hepatobiliary abnormalities.

The importance of pH in regulating the function of the Fasciola hepatica cathepsin L1 cysteine protease

The helminth parasite Fasciola hepatica secretes cathepsin L cysteine proteases to invade its host, migrate through tissues and digest haemoglobin, its main source of amino acids. Here we investigated the importance of pH in regulating the activity and functions of the major cathepsin L protease FheCL1. The slightly acidic pH of the parasite gut facilitates the auto-catalytic activation of FheCL1 from its inactive proFheCL1 zymogen; this process was approximately 40-fold faster at pH 4.5 than at pH 7.0. Active mature FheCL1 is very stable at acidic and neutral conditions (the enzyme retained approximately 45% activity when incubated at 37 degrees C and pH 4.5 for 10 days) and displayed a broad pH range for activity peptide substrates and the protein ovalbumin, peaking between pH 5.5 and pH 7.0. This pH profile likely reflects the need for FheCL1 to function both in the parasite gut and in the host tissues. FheCL1, however, could not cleave its natural substrate Hb in the pH range pH 5.5 and pH 7.0; digestion occurred only at pH

Is the public healthcare sector a more strenuous working environment than the private sector for a physician?

<p>Aims: The present study examined the differences between physicians working in public and private health care in strenuous working environments (presence of occupational hazards, physical violence, and presenteeism) and health behaviours (alcohol consumption, body mass index, and physical activity). In addition, we examined whether gender or age moderated these potential differences. Methods: Cross-sectional survey data were compiled on 1422 female and 948 male randomly selected physicians aged 25-65 years from The Finnish Health Care Professionals Study. Logistic regression and linear regression analyses were used with adjustment for gender, age, specialisation status, working time, managerial position, and on-call duty. Results: Occupational hazards, physical violence, and presenteeism were more commonly reported by physicians working in the public sector than by their counterparts in the private sector. Among physicians aged 50 years or younger, those who worked in the public sector consumed more alcohol than those who worked in the private sector, whereas in those aged 50 or more the reverse was true. In addition, working in the private sector was most strongly associated with lower levels of physical violence in those who were older than 50 years, and with lower levels of presenteeism among those aged 40-50 years. Conclusions: The present study found evidence for the public sector being a more strenuous work environment for physicians than the private sector. Our results suggest that public healthcare organisations should pay more attention to the working conditions of their employees.</p>

Essential and toxic elements in infant foods from Spain, UK, China and USA

Spanish gluten-free rice, cereals with gluten, and pureed baby foods were analysed for essential macro-elements (Ca and Na), essential trace elements (Fe, Cu, Zn, Mn, Se, Cr, Co and Ni) and non-essential trace elements (As, Pb, Cd and Hg) using ICP-MS and AAS. Baby cereals were an excellent source of most of the essential elements (Ca, Fe, Cu, Mn and Zn). Sodium content was high in pureed foods to improve their flavour; fish products were also rich in Se. USA pure baby rice samples had the highest contents of all studied essential elements, showing a different nutrient pattern compared to those of other countries. Mineral fortification was not always properly stated in the labelling of infant foods. Complementary infant foods may also contain significant amounts of contaminants. The contents of Hg and Cd were low enough to guarantee the safety of these infant foods. However, it will be necessary to identify the source and reduce the levels of Pb, Cr and As in Spanish foods. Pure baby rice samples contained too much: Pb in Spain; As in UK; As, Cr and Ni in USA; and Cr and Cd in China.

The impact of a rice based diet on urinary arsenic

Rice is elevated in arsenic (As) compared to other staple grains. The Bangladeshi community living in the United Kingdom (UK) has a ca. 30-fold higher consumption of rice than white Caucasians. In order to assess the impact of this difference in rice consumption, urinary arsenicals of 49 volunteers in the UK (Bangladeshi n = 37; white Caucasians n = 12) were monitored along with dietary habits. Total urinary arsenic (As(t)) and speciation analysis for dimethylarsinic acid (DMA), monomethylarsonic acid (MA) and inorganic arsenic (iAs) was conducted. Although no significant difference was found for As(t) (median: Bangladeshis 28.4 µg L(-1)) and white Caucasians (20.6 µg L(-1)), the sum of medians of DMA, MA and iAs for the Bangladeshi group was found to be over 3-fold higher (17.9 µg L(-1)) than for the Caucasians (3.50 µg L(-1)). Urinary DMA was significantly higher (p &lt;0.001) in the UK Bangladeshis (median: 16.9 µg DMA L(-1)) than in the white Caucasians (3.16 µg DMA L(-1)) as well as iAs (p &lt;0.001) with a median of 0.630 µg iAs L(-1) for Bangladeshi and 0.250 µg iAs L(-1) for Caucasians. Cationic compounds were significantly lower in the Bangladeshis (2.93 µg L(-1)) than in Caucasians (14.9 µg L(-1)). The higher DMA and iAs levels in the Bangladeshis are mainly the result of higher rice consumption: arsenic is speciated in rice as both iAs and DMA, and iAs can be metabolized, through MA, to DMA by humans. This study shows that a higher dietary intake of DMA alters the DMA/MA ratio in urine. Consequently, DMA/MA ratio as an indication of methylation capacity in populations consuming large quantities of rice should be applied with caution since variation in the quantity and type of rice eaten may alter this ratio.

Identification of tetramethylarsonium in rice grains with elevated arsenic content

Tetramethylarsonium has for the first time been identified in a commercially grown food product, rice, constituting up to 5.8% of the total arsenic in the rice.

Arsenic speciation in Japanese rice drinks and condiments

Rice has been demonstrated to be one of the major contributors to inorganic arsenic (i-As) intake in humans. However, little is known about rice products as additional source of i-As exposure. In this study, misos, syrups and amazake (a fermented sweet rice drink) produced from rice, barley and millet were analysed for total arsenic (t-As) and a subset of samples were also analyzed for As speciation. Rice based products displayed a higher i-As content than those derived from barley and millet. Most of the t-As in the rice products studied was inorganic (63-83%), the remainder being dimethylarsinic acid. Those who regularly consume rice drinks and condiments, such as the Japanese population and those who follow health conscious diets based on the Japanese cuisine, could reach up to 23% of the World Health Organization's Provisional Tolerable Daily Intake of i-As, by only consuming these kinds of products. This study provides a wide appreciation of how i-As derived from rice based products enters the human diet and how this may be of concern to populations who are already exposed to high levels of i-As through consumption of foods such as rice and seaweed.

Cooking rice in a high water to rice ratio reduces inorganic arsenic content

Total arsenic and arsenic speciation was performed on different rice types (basmati, long-grain, polished ([white] and wholegrain [brown]) that had undergone various forms of cooking. The effect of rinse washing, low volume (2.5 : 1 water : rice) and high volume (6 : 1 water : rice) cooking, as well as steaming, were investigated. Rinse washing was effective at removing circa. 10% of the total and inorganic arsenic from basmati rice, but was less effective for other rice types. While steaming reduced total and inorganic arsenic rice content, it did not do so consistently across all rice types investigated. Low volume water cooking did not remove arsenic. High volume water : rice cooking did effectively remove both total and inorganic arsenic for the long-grain and basmati rice (parboiled was not investigated in high volume cooking water experiment), by 35% and 45% for total and inorganic arsenic content, respectively, compared to uncooked (raw) rice. To reduce arsenic content of cooked rice, specifically the inorganic component, rinse washing and high volume of cooking water are effective.

Metal levels in the bones and livers of globally threatened marbled teal and white-headed duck from El Hondo, Spain

El Hondo is a key area for marbled teal and white-headed duck. We present Pb, Cu, Zn, Se, and As data for bone and liver in birds found dead between 1996 and 2001. Several metals were higher in adult white-headed ducks than in marbled teal. They were higher in female than in male white-headed ducks, and did not differ with sex in marbled teal, but did by age. Lead in liver of adults was influenced by Pb shot ingestion, which was detected in 21% of marbled teal and in 71% of white-headed duck. No marbled teal had liver levels indicative of Pb poisoning, while 86% of white-headed ducks did. Selenium, Zn, and Cu were elevated in 13%, 7%, and 39% of birds, respectively. Whilst Pb shot poses the greatest threat to these species, further work should assess exposure via plants, invertebrates, water, and sediments for other metals, and investigate possible sub-lethal effects.

Arsenic behaviour from groundwater and soil to crops:impacts on agriculture and food safety

High levels of As in groundwater commonly found in Bangladesh and other parts of Asia not only pose a risk via drinking water consumption but also a risk in agricultural sustainability and food safety. This review attempts to provide an overview of current knowledge and gaps related to the assessment and management of these risks, including the behaviour of As in the soil-plant system, uptake, phytotoxicity, As speciation in foods, dietary habits, and human health risks. Special emphasis has been given to the situation in Bangladesh, where groundwater via shallow tube wells is the most important source of irrigation water in the dry season. Within the soil-plant system, there is a distinct difference in behaviour of As under flooded conditions, where arsenite (AsIII) predominates, and under nonflooded conditions, where arsenate (AsV) predominates. The former is regarded as most toxic to humans and plants. Limited data indicate that As-contaminated irrigation water can result in a slow buildup of As in the topsoil. In some cases the buildup is reflected by the As levels in crops, in others not. It is not yet possible to predict As uptake and toxicity in plants based on soil parameters. It is unknown under what conditions and in what time frame As is building up in the soil. Representative phytotoxicity data necessary to evaluate current and future soil concentrations are not yet available. Although there are no indications that crop production is currently inhibited by As, long-term risks are clearly present. Therefore, with concurrent assessments of the risks, management options to further prevent As accumulation in the topsoil should already have been explored. With regard to human health, data on As speciation in foods in combination with food consumption data are needed to assess dietary exposure, and these data should include spatial and seasonal variability. It is important to control confounding factors in assessing the risks. In a country where malnutrition is prevalent, levels of inorganic As in foods should be balanced against the nutritional value of the foods. Regarding agriculture, As is only one of the many factors that may pose a risk to the sustainability of crop production. Other risk factors such as nutrient depletion and loss of organic matter also must be taken into account to set priorities in terms of research, management, and overall strategy.

Ecotoxicological screening of Kenyan tannery dust using a luminescent-based bacterial biosensor

Ecotoxicological screening of dust sampled throughout a Kenyan tannery was conducted using a luminescence (lux)-based bacterial biosensor for both solid and liquid assays. This was complemented by chemical analysis in an attempt to identify possible causative toxic components. The biosensor results showed a highly significant (p &lt;0.001) difference in both solid and liquid phase toxicity in samples collected from various identified sampling points in the tannery. A positive correlation was observed between results of the solid and liquid phase techniques, for most of the sampling points indicating that the toxic contaminants were bioavailable both in the solid and liquid state. However, the results generally indicated toxicity associated with liquid phase except certain areas in solid phase such as chemical handling, buffing area and weighing. The most toxic tannery area identified was the weighing area (p &lt;0.001), showing the lowest bioluminescence for both the solid (0.38 +/- 2.21) and liquid phases (0.01 +/- 0.001). Chromium was the metal present in the highest concentration indicating levels higher than the stipulated regulatory requirement of 0.5 mg Cr/m3 for total Cr (highest Cr concentration was at chemical handling at 209.24 mg l(-1)) in all dust samples. The weighing area had the highest Ni concentration (1.87 mg l(-1)) and the chemical handling area showed the highest Zn concentration (31.9 mg l(-1)). These results raise environmental health concerns, as occupational exposure to dust samples from this site has been shown to give rise to elevated concentrations (above the stipulated levels) of chromium in blood, urine and some body tissues, with inhalation being the main route. Health and Safety Executive (HSE), UK, and American Conference of Governmental Industrial Hygienist (ACGIH) and National Institute for Occupational Safety and Health (NIOSH), USA stipulates an occupational exposure limit of 0.5 mg Cr/m3 (8 h TWA) for total chromium. However, schedule 1 of Controls of substances hazardous to health (COSHH) regulations developed by HSE, indicate 0.05 mg m3 (8 h TWA reference periods) to be the limit for Cr (VI) exposure. The exposure limit for individual (e.g., Cr, Zn, Ni etc.) contaminants (homogeneity) was not exceeded, but potential impact of heterogeneity (multi-element synergistic effect) on toxicity requires application of the precautionary principle.

The influence of evidence-based medicine training on decision-making in relation to over-the-counter medicines: a qualitative study

Objectives<br/>To explore the role of evidence of effectiveness when making decisions about over-the-counter (OTC) medication and to ascertain whether evidence-based medicine training raised awareness in decision-making. Additionally, this work aimed to complement the findings of a previous study because all participants in this current study had received training in evidence-based medicine (unlike the previous participants).<br/> <br/>Methods<br/>Following ethical approval and an e-mailed invitation, face-to-face, semi-structured interviews were conducted with newly registered pharmacists (who had received training in evidence-based medicine as part of their MPharm degree) to discuss the role of evidence of effectiveness with OTC medicines. Interviews were recorded and transcribed verbatim. Following transcription, all data were entered into the NVivo software package (version 8). Data were coded and analysed using a constant comparison approach.<br/> <br/>Key findings<br/>Twenty-five pharmacists (7 males and 18 females; registered for less than 4 months) were recruited and all participated in the study. Their primary focus with OTC medicines was safety; sales of products (including those that lack evidence of effectiveness) were justified provided they did no harm. Meeting patient expectation was also an important consideration and often superseded evidence. Despite knowledge of the concept, and an awareness of ethical requirements, an evidence-based approach was not routinely implemented by these pharmacists. Pharmacists did not routinely utilize evidence-based resources when making decisions about OTC medicines and some felt uncomfortable discussing the evidence-base for OTC products with patients.<br/> <br/>Conclusions<br/>The evidence-based medicine training that these pharmacists received appeared to have limited influence on OTC decision-making. More work could be conducted to ensure that an evidence-based approach is routinely implemented in practice<br/>

A pilot survey for Fusarium mycotoxin biomarkers in women from Golestan, northern Iran

<p>Fusarium mycotoxins are frequent contaminants of cereals in many world regions, and are suggested risk factors for various acute and chronic human diseases. To date a lack of exposure tools has restricted epidemiological studies of the potential health effects. Recently established exposure biomarkers for deoxynivalenol (DON) and fumonisins are now available and here a pilot biomarker survey of 110 women (aged 39 to 72 years) from Golestan, northern Iran was conducted on samples collected at one time point during August-September 2007. Urinary DON and DON-glucuronide combined were detected frequently (79/110, 72%), mean 1.3 ng DON/ml urine, range not detected (nd)-6.5 ng/ml; mean creatinine adjusted levels were 1.5 ng DON/mg creatinine, range nd-7.1 ng/mg). Neither urinary de-epoxy DON (DOM-1) and DOM-1 glucuronide combined, nor urinary fumonisin B-1 were detected. This study is the first reported biomarker based exposure assessment of DON and fumonisins in this region. Overall DON exposure at this time point appears modest compared to other world regions where data are available.</p>

Preferences for a third-trimester ultrasound scan in a low-risk obstetric population: a discrete choice experiment

Objective: Establish maternal preferences for a third-trimester ultrasound scan in a healthy, low-risk pregnant population. <br/><br/>Design: Cross-sectional study incorporating a discrete choice experiment. <br/><br/>Setting: A large, urban maternity hospital in Northern Ireland. <br/><br/>Participants: One hundred and forty-six women in their second trimester of pregnancy. <br/><br/>Methods: A discrete choice experiment was designed to elicit preferences for four attributes of a third-trimester ultrasound scan: health-care professional conducting the scan, detection rate for abnormal foetal growth, provision of non-medical information, cost. Additional data collected included age, marital status, socio-economic status, obstetric history, pregnancy-specific stress levels, perceived health and whether pregnancy was planned. Analysis was undertaken using a mixed logit model with interaction effects. <br/><br/>Main outcome measures: Women's preferences for, and trade-offs between, the attributes of a hypothetical scan and indirect willingness-to-pay estimates. <br/><br/>Results: Women had significant positive preference for higher rate of detection, lower cost and provision of non-medical information, with no significant value placed on scan operator. Interaction effects revealed subgroups that valued the scan most: women experiencing their first pregnancy, women reporting higher levels of stress, an adverse obstetric history and older women. <br/><br/>Conclusions: Women were able to trade on aspects of care and place relative importance on clinical, non-clinical outcomes and processes of service delivery, thus highlighting the potential of using health utilities in the development of services from a clinical, economic and social perspective. Specifically, maternal preferences exhibited provide valuable information for designing a randomized trial of effectiveness and insight for clinical and policy decision makers to inform woman-centred care.