A multiarm randomized field trial evaluating strategies for udder health improvement in Swiss dairy herds.

The aims of this study were to quantify the effectiveness of specialist advice about udder health in Swiss dairy herds and to compare 3 different udder health improvement strategies against a negative control group. In 2010, 100 Swiss dairy herds with a high (between 200,000 and 300,000 cells/mL) yield-corrected bulk milk somatic cell count (YCBMSCC) were recruited for a 1-yr multiarm randomized field trial. The herds were visited between September and December 2011 to evaluate udder health-management practices and then randomly allocated into 1 of 4 study arms containing 25 herds each. The negative control study arm received neither recommendations for improving udder health nor any active support. The remaining 75 farmers received a herd-specific report with recommendations to improve udder health management. The positive control study arm received no further active support during 2012. The veterinarian study arm received additional support in the form of monthly visits by their herd veterinarian. Finally, the study group study arm received support in the form of bimonthly study group meetings where different topics concerning udder health were discussed. One year later, implementation of recommendations and changes in udder health were assessed. Of the recommendations given, 44.3% were completely implemented, 23.1% partially, and 32.6% were not implemented. No differences in implementation of recommendations were noted between the 3 study arms. At study enrollment, farmers were asked for the study arm of their preference but were subsequently randomly assigned to 1 of the 4 study arms. Farmers that were assigned to the study arm of their preference implemented more recommendations than farmers assigned to a study arm not of their preference. No decrease in the within-herd prevalence of cows that had a high (≥200,000 cells/mL) composite somatic cell count was observed in herds that had a YCBMSCC ≥200,000 cells/mL at the start of intervention. However, the 3 study arms with intervention (positive control, the veterinarian, and the study groups) prevented an increase in the within-herd prevalence of cows that had a high somatic cell count in herds with a low YCBMSCC at the start of the intervention compared with the negative control study arm. In the year after sending the report, herds assigned to the study group study arm had a reduced incidence rate of treated mastitis cases in comparison with the year before sending the report.

Basal cell carcinomas in a tertiary referral centre: a systematic analysis.

BACKGROUND: Basal cell carcinoma (BCC) is the most frequent skin cancer with increasing incidence and generally high cure rates. BCC can be quite aggressive and is difficult to treat. OBJECTIVES: To investigate BCCs with a focus on histological subtypes, treatment procedures and correlation to clinical progress to collect further information on complex BCC cases. METHODS: In this retrospective single-centre analysis the dermatopathology database, a network of cooperating dermatological surgeons, was queried for BCC cases between January 2007 and December 2011. Of 14,423 samples from a total of 9652 patients initially identified, 2938 patients were treated at the University Hospital Zurich and had corresponding local electronic patient records. RESULTS: Patients (n = 2938) (with 4769 diagnoses, 2006 re-excisions with 1180 microscopically controlled surgeries) were classified based on severity estimations into 2240 simple, 640 moderate, and 58 severe cases, including one BCC-treatment-associated death and 11 patients with subsequent participation in a clinical trial. In moderate and severe cases (n = 698), there were significantly higher rates of unique histological diagnoses (n = 2·5; P < 0·0001), higher association with basosquamous carcinoma [odds ratio (OR) 3·6; P < 0·0001] and sclerosing BCC (OR 2·48; P < 0·0001). Of the patients with basosquamous carcinoma 82·6% had a previous history of BCC. CONCLUSIONS: This is the first study that analyses the frequency of complicated BCCs in a tertiary referral centre. There were 6·6% moderate (640 of 9652) and 0·6% (58 of 9652) severe cases. We found significantly more varying histological diagnoses and significant association with aggressive subtypes in moderate and severe cases. These patients might especially benefit from new therapeutic options.

[Cost-benefit analysis of an intervention to improve udder health in Swiss dairy farms]. / Kosten-Nutzen-Analyse einer Intervention zur Verbesserung der Eutergesundheit in Schweizer Milchviehbetrieben.

The objective of this study was to calculate the national costs associated with udder health in Switzerland and to estimate the cost effectiveness of an udder health intervention program. In 49 farms, yearly mastitis associated costs before and during an intervention were collected at herd level. Costs were calculated for each lactating cow being present in the herd. At the beginning of the intervention, 24 farms received a report with recommendations to improve the udder health. In the following year, those herds were followed-up by their veterinarian at a monthly basis. The other 25 farms were used as a negative control group and neither received any recommendations nor any follow-up. In the first year of analysis (2010), the median udder health associated costs were 209.- Swiss Francs for each lactating cow, regardless of the intervention group. During the intervention period (2012), mastitis associated costs were 191.- Swiss Francs for control farms and 396.- Swiss Francs for farms with veterinary intervention on a monthly basis. The median additional costs for herds with intervention were 159.- Swiss Francs per lactating cow. At the national level, mastitis associated costs were estimated at 129.4 millions of Swiss Francs per year. The cost effectiveness of future mastitis control programs can be evaluated with the help of the deterministic model developed during this study.

Le but du présent travail était de calculer les coûts de la santé de la mamelle dans des exploitations laitières suisses et d'estimer l'efficacité économique d'une intervention en vue de l'améliorer. Pour cela on a relevé les coûts liés aux mammites sur une année dans 49 exploitations, et cela durant l'année précédant l'intervention puis dans l'année de l'intervention et on l'a divisé par le nombre de vaches en lactation. Vingt-quatre exploitations ont reçu au début de l'étude des recommandations en vue d'améliorer la santé de la mamelle et ont ensuite été suivies mensuellement durant une année par leur vétérinaire d'exploitation. Les 25 autres exploitations n'ont reçu aucune recommandation et ont été utilisées comme groupe de contrôle. Dans la première année d'analyse (2 ans avant l'intervention, 2010), les coûts moyens de la santé de la mamelle, indépendamment du groupe s'élevaient à CHF 209.­ par vache en lactation. Durant l'année de l'intervention, ils se montaient à CHF 191.­ pour les exploitations de contrôle contre CHF 396.- pour les exploitations suivies. Les dépenses supplémentaires durant l'intervention s'élevaient en moyenne à CHF 159.­ par vache en lactation. Au niveau national, on estime les coûts liés aux mammites à CHF 129.4 millions. Les modèles de calcul utilisés dans la présente étude permettent de juger à l'avenir de la rentabilité des programmes de contrôle des mammites.

Missed epidemics and missing links: international birth cohort trends in multiple sclerosis.

BACKGROUND AND PURPOSE: Many hypotheses on the etiopathogenesis of multiple sclerosis (MS) focus on risk factors occurring early in life. This study examined the variability of birth cohort trends in international MS data by means of age-period-cohort (APC) analysis. METHODS: The data from 25 countries were taken from the WHO mortality database. Data were encoded according to the International Classification of Diseases and covered slightly varying periods between 1951 and 2009. The APC analyses were based on logit models applied to cohort tables with 5-year age- and period intervals. RESULTS: In most countries, the birth cohort estimates peaked in those born in the first half of the 20th century. In countries from Central and Western Europe, the peak concerned those born before and around 1920. A second group of countries (Denmark, Sweden, Italy, Ireland, Scotland) shared a later peak amongst cohorts born in the 1920s and 1930s. Group 3 included Commonwealth countries, the USA and Norway, with a double or extended peak starting in the 1910s or 1920s, and ending by the 1950s. The fourth group, consisting of Mediterranean countries and Finland, was characterized by a steady increase in the birth cohort estimates until the 1950s. The fifth group with countries from Eastern Europe and Japan showed no particular pattern. CONCLUSIONS: Birth cohort trends have influenced the change in MS risk across the 20th century in many Western countries. This silent epidemic points to a most important but unknown latent risk factor in MS.

Hodgkin's lymphoma in remission after first-line therapy: which patients need FDG-PET/CT for follow-up?

BACKGROUND: The purpose of the study was to evaluate the impact of 2-[fluorine-18]fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET)/computed tomography (CT) during follow-up of patients with Hodgkin's lymphoma. PATIENTS AND METHODS: Patients in complete remission or an unconfirmed complete remission after first-line therapy who received FDG-PET/CT during their follow-up were analyzed retrospectively. Confirmatory biopsy was mandatory in case of recurrence. RESULTS: Overall, 134 patients were analyzed. Forty-two (31.3%) patients had a recurrence. The positive predictive value of FDG-PET/CT was 0.98. Single-factor analysis identified morphological residual mass [P = 0.0005, hazard ratio (HR) 3.4, 95% confidence interval (CI) 1.7-6.6] and symptoms (P < 0.0001, HR 4.9, 95% CI 2.4-9.9) as significant risk factors for relapse. By multivariate analysis, morphological residual mass was the only significant risk factor for early follow-up (<24 months) (P = 0.0019, HR 7.6, 95% CI 2.1-27.3). Advanced stage (P = 0.0426, HR 3.6, 95% CI 1.1-12.3) and the presence of symptoms (P = 0.0009, HR = 14.6, 95% CI 3.0-69.7) were found to be significant risk factors for later follow-up (>24 months). CONCLUSIONS: Asymptomatic patients without morphological residues and an early stage of disease do not need a routine FDG-PET/CT for follow-up. Asymptomatic patients with morphological residues should receive routine follow-up FDG-PET/CT for the first 24 months. Only patients with advanced initial stage do need a routine follow-up FDG-PET/CT beyond 24 months.

Surfactant protein-D and exposure to bioaerosols in wastewater and garbage workers.

PURPOSE: Bioaerosols and their constituents, such as endotoxins, are capable of causing an inflammatory reaction at the level of the lung-blood barrier, which becomes more permeable. Thus, it was hypothesized that occupational exposure to bioaerosols can increase leakage of surfactant protein-D (SP-D), a lung-specific protein, into the bloodstream. METHODS: SP-D was determined by ELISA in 316 wastewater workers, 67 garbage collectors, and 395 control subjects. Exposure was assessed with four interview-based indicators and by preliminary endotoxin measurements using the Limulus amoebocyte lysate assay. Influence of exposure on serum SP-D was assessed by multiple linear regression considering smoking, glomerular function, lung diseases, obesity, and other confounders. RESULTS: Overall, mean exposure levels to endotoxins were below 100 EU/m(3). However, special tasks of wastewater workers caused higher endotoxin exposure. SP-D concentration was slightly increased in this occupational group and associated with the occurrence of splashes and contact to raw sewage. No effect was found in garbage collectors. Smoking increased serum SP-D. No clinically relevant correlation between spirometry results and SP-D concentrations appeared. CONCLUSIONS: These results support the hypothesis that inhalation of bioaerosols, even at low concentrations, has a subclinical effect on the lung-blood barrier, the permeability of which increases without associated spirometric changes.

Cell sensitivity to gravity.

Cultures of human lymphocytes exposed in microgravity to the mitogen concanavalin A showed less than 3 percent of the activation of ground controls. This result supports the hypothesis, based on simulations at low g and experiments at high g, that microgravity depresses whereas high gravity enhances cell proliferation rates. The effects of gravity are particularly strong in cells undergoing differentiation.

Hepatitis E, Helicobacter pylori and peptic ulcers in workers exposed to sewage: a prospective cohort study.

BACKGROUND: Workers exposed to sewage may have an increased risk of infection by Helicobacter pylori and hepatitis E virus (HEV). OBJECTIVES: To assess the incidence of clinical hepatitis E and peptic ulcers and the seroconversion rate of antibodies to H pylori and HEV in workers with and without sewage exposure. METHODS: 332 workers exposed to sewage and a control group of 446 municipal manual workers (61% participation rate) entered a prospective cohort study with clinical examination and determination of antibodies to H pylori and HEV (immunoglobulins G and A or G and M, respectively). Survival curves were examined with log rank tests and Cox regressions. Travelling to endemic areas, socioeconomic level, age, country of childhood, number of siblings, and personal protective equipment were considered as the main confounding factors. RESULTS: Incidence of clinical hepatitis E was not increased in sewage workers. One peptic ulcer and three eradications were recorded in sewage workers compared with no peptic ulcers and 12 eradications in control workers. Incidence rates of approximately 0.01, 0.10, and 0.15 seroconversion/person-year for hepatitis E, H pylori IgG and H pylori IgA, respectively, were found in both exposed and non-exposed workers. Survival curves did not show an increased risk in sewage workers and no association with any exposure indicator was found. Sensitivity analyses did not alter these results. CONCLUSIONS: Sewage does not appear to be a source of occupational infection by H pylori or HEV in trained sewage workers with personal protective equipment working in a region with good sanitation.

Economic evaluation of the eradication program for bovine viral diarrhea in the Swiss dairy sector.

Since 2008, the Swiss veterinary service has been running a mandatory eradication program for Bovine Viral Diarrhea (BVD) that is focused on detecting and eliminating persistently infected (PI) animals. Detection was initially based on antigen testing from ear tag samples of the entire cattle population, followed by antigen testing of all newborn calves until 2012. Since then, bulk milk serology (dairy herds) and blood sample serology (beef herds) have been used for the surveillance of disease-free herds. From 2008 to 2012, the proportion of newborn PI calves decreased from 1.4% to less than 0.02%. However, this success was associated with substantial expenditures. The aim of this study was to conduct an economic evaluation of the BVD eradication program in the Swiss dairy sector. The situation before the start of the program (herd-level prevalence: 20%) served as a baseline scenario. Production models for three dairy farm types were used to estimate gross margins as well as net production losses and expenditures caused by BVD. The total economic benefit was estimated as the difference in disease costs between the baseline scenario and the implemented eradication program and was compared to the total eradication costs in a benefit-cost analysis. Data on the impact of BVD virus (BVDV) infection on animal health, fertility and production parameters were obtained empirically in a retrospective epidemiological case-control study in Swiss dairy herds and complemented by literature. Economic and additional production parameters were based on benchmarking data and published agricultural statistics. The eradication costs comprised the cumulative expenses for sampling and diagnostics. The economic model consisted of a stochastic simulation in @Risk for Excel with 20,000 iterations and was conducted for a time period of 14 years (2008-2021). The estimated annual financial losses in BVDV infected herds were CHF 85-89 per dairy cow and CHF 1337-2535 for an average farm, depending on the production type. The median net present value (NPV) was estimated at CHF 44.9 million (90% central range: CHF 13.4 million-69.4 million) and the break-even point to have been reached in 2015. Overall, the outcomes demonstrate that the Swiss BVD eradication program results in a net benefit for the dairy sector. These findings are relevant for planning similar BVD control programs in other countries.

A matched case-control study comparing udder health, production and fertility parameters in dairy farms before and after the eradication of Bovine Virus Diarrhoea in Switzerland.

An obligatory eradication programme for Bovine Virus Diarrhoea (BVD) was implemented in Switzerland in 2008. Between 2008 and 2012, all bovines were tested for antigen or antibodies against BVDV. By the year 2012, eradication was completed in the majority of farms. A decrease of the prevalence of persistently infected (PI) newborn calves was observed from 1.4% in 2008 to <0.02% in 2012. The objective of the present study was to assess the effects of BVD eradication on different parameters of animal health, production and fertility in Swiss dairy herds which had completed the eradication programme. A matched case-control study was carried out using data from two periods, before (Period 1) and after (Period 2) the active phase of eradication. Case farms had at least two PI animals detected before or during the eradication; controls were BVD-free and matched for region, herd size and use of alpine pasture. A total of 110 farmers (55 pairs) were recruited. During a phone interview, a questionnaire about farm characteristics, animal health and appreciation of the BVD eradication programme was filled in. Breeding data and milk test day records were also analyzed. Parameters were first compared between (i) case and control herds before eradication, and (ii) Period 1 and Period 2 for case herds only. Milk yield (MY), bulk milk somatic cell count (BMSCC), prevalence of subclinical mastitis (SCM), and non-return rate (NRR) showed a p-value<0.25 in at least one of the univariable comparisons and were thus further analyzed with a multilevel mixed-effects model to account for repeated measures over time. In order to assess whether changes in health status over time were due to BVD eradication, an interaction variable between period and group (case-control) was created (IA). Except for MY, the IA was significant for all parameters modelled. Despite an overall p-value of 0.27, case herds tended to have a higher MY after eradication (ß=0.53, p=0.050). For BMSCC and SCM, case herds had higher values than controls in both periods; udder health was significantly improved in control herds and it remained stable in case herds, with a slight decrease of BMSCC (ß=-0.19, p=0.010). Finally, among fertility parameters, NRR showed a general improvement but it was significant only in control herds (ß=0.29, p=0.019). Even though the effects of the eradication programme measured in this study were less pronounced than expected, 73% of the participants of this study had a positive attitude towards the campaign.

Anthropometric and lifestyle correlates of serum lipoprotein and apolipoprotein levels among normal non-smoking men and women.

The relationship between serologic predictors of coronary risk and anthropometric as well as lifestyle characteristics was investigated in 61 men (37.5 +/- 8.5 yrs) and 33 women (40.1 +/- 9.0 yrs). All subjects were healthy non-smokers, mostly middle-class bank employees. In bivariate analysis, among both genders the ratio of waist-to-hip circumference (WHR) was the single best predictor of levels of serum LDL-cholesterol, apolipoprotein B, VLDL-cholesterol and triglycerides (positive association) as well as HDL-cholesterol and apolipoprotein A-I (inverse association). In men, body fat as estimated from bioelectrical impedance measurement was the second best predictor of lipoprotein and apoprotein concentrations, whereas in women it was the body mass index (BMI). The additional independent predictive power of WHR and body fat for the lipid profile was tested in multivariate analysis by adding WHR and body fat sequentially to regression models containing already BMI, endurance capacity, exercise, alcohol consumption and age. For example, explained variance of triglyceride distribution rose from 26.3 to 35.1% (P = 0.01 for increase) when body fat was entered into the regression equation, or inclusion of WHR into a model already containing age, the behavioral variables, BMI, and body fat increased the explained variance of LDL/HDL-cholesterol ratio from 20.9 to 27.6% (P = 0.04 for increase). In women, the same regression models were even slightly more predictive for the serum lipid profile. Endurance capacity was related to a low atherogenic risk lipid profile in bivariate analysis but lost much of its predictive power in multivariate analysis, which confirms that the effect of fitness on lipid levels is probably mediated in part by a low body fat content. It is concluded from this cross-sectional investigation that studies which focus on associations between lifestyle and serologic predictors of atherogenic risk should possibly include the WHR and a measure of body fat, since the latter two appear to be closer correlates of serum lipoprotein and apolipoprotein levels than BMI or single behavioral factors, at least among male non-smokers.

Effects of long-term, self-monitored exercise on the serum lipoprotein and apolipoprotein profile in middle-aged men.

To study the effects of long-term, self-monitored exercise on the serum lipid profile and body composition of middle-aged non-smoking males, a controlled study was conducted in 61 sedentary, middle-class Swiss men. Thirty-nine men were randomly allocated to jog 2 h/wk for 4 months on an individually prescribed, heart rate-controlled basis, whereas 22 men served as controls. Despite varying adherence to the exercise regimen, the following 4-month net changes (effect in exercise group minus effect in control group) in lipids were seen: HDL cholesterol (C) +0.12 mmol/l (95% CI 0.02, 0.22; P = 0.028), LDL-C +0.08 mmol/l (ns), VLDL-C -0.26 mmol/l (-0.45, -0.07; P = 0.009), total triglycerides (TT) -0.21 mmol/l (ns), HDL-C/total C +0.02 (0.001, 0.05; P = 0.047). The net changes in endurance capacity and resting heart rate in favour of exercisers were significant as well, whereas no significant changes in apolipoprotein levels were seen. Exploratory analyses revealed, for example, associations of the increase in total physical activity with an increase in the HDL-C/total C ratio (r = 0.46; P less than 0.001), and of the change in estimated body fat content with an opposed change in the HDL-C/total C ratio (r = -0.40; P less than 0.001), or an inverse relationship of the change in subcutaneous fat with a change in the HDL2-C level (r = -0.39; P less than 0.001). Multivariable regression analysis suggested that much of the effect of jogging on HDL-C was apparently mediated through a decrease in body fat content. A change in the waist/hip ratio was unrelated to lipoprotein changes but was related to the change of TT level (r = 0.22; P less than 0.05). This study confirms that individually prescribed, unsupervised jogging can increase HDL-C levels and improve the serum lipoprotein profile in self-selected nonsmoking males. Although the effect is modest, it may be relevant to preventive cardiology, given the evidence for a reduction in cardiovascular risk even after apparently small decreases in risk factor levels.

Safer sex behavior and alcohol consumption. Research Group of the Swiss HIV Prevention Study.

To test the hypothesis that safer sex procedures are less consistently observed by persons under the influence of alcohol, data from the Swiss human immunodeficiency virus (HIV) Prevention Study (HIPS) were evaluated. HIPS is a large prospective cohort study involving 724 HIV-negative and mainly heterosexual subjects who entertain casual sexual contacts. Of the 724 participants, 36% reported that they had had sex while under the influence of alcohol. Of this group, 31% indicated that safer sex procedures were neglected owing to the influence of alcohol. No significant differences with regard to unprotected sexual intercourse were found between subjects who combine sex and alcohol and those who do not. The same was found to be true among subjects with different levels of general alcohol consumption. However, a significant correlation was found between the intensity of alcohol consumption (i.e., the quantity of alcohol intake per sitting) and the incidence of unprotected sexual intercourse. These findings show that the relationship between alcohol consumption and safer sex is complex; they also emphasize the need for preventive efforts to reinforce safer sexual behavior, for example through individual counseling of persons at risk for HIV-infection.

Incidence and clinical features of traveler's diarrhea in infants and children.

To assess the incidence rate and the characteristics of traveler's diarrhea in small children ages 0 to 2 years, children ages 3 to 14 years, and adolescents ages 15 to 20 years a retrospective survey was conducted. Of the pretravel visitors to the Zurich University Vaccination Center, all those ages 0 to 20 years were selected between October, 1987, and May, 1988. They received a questionnaire within 2 weeks after returning home. Of the 446 young travelers who were recruited, 363 (81.3%) could be evaluated. Within 14 days in the tropics or subtropics, traveler's diarrhea occurred in 8 of 20 (40.0%) small children, in 4 of 47 (8.5%) children ages 3 to 6 years, in 10 of 46 (21.7%) children ages 7 to 14 years and in 90 of 250 (36.0%) adolescents (P = 0.0003). In small children the clinical course tended to be severe and prolonged (average duration, 29.5; median, 17.5 days) when compared with other age groups (3 to 5 days). In 40% of all the children the parents reported that they had consistently practiced dietary preventive measures. For self-treatment oral rehydration solutions were used in 5.0% and loperamide in 33.8%. In conclusion adults should be discouraged from taking small children to developing countries unless necessary. Parents should be instructed about how to prevent traveler's diarrhea and about the mainstay of self-therapy in pediatric patients by oral rehydration solutions.

Magnetic resonance spectroscopy for assessing myocardial rejection in the transplanted rat heart.

Traditionally, detection of heart rejection after heart transplantation is based on histologic grading of endomyocardial biopsy specimens. The value of magnetic resonance spectroscopy for determining heart rejection was assessed in rejecting and nonrejecting isografts and allografts using energy-rich phosphate spectroscopy. In 46 rats a heterotopic abdominal heart transplantation was performed, and animals were divided into the following groups: six isografts (no rejection), five untreated allografts (severe rejection), and 35 immunosuppressed allografts (mild to moderate rejection). One week after transplantation magnetic resonance spectroscopy was performed, and data were correlated to histologic findings (rejection grades according to Stanford and the New International Working Formulation classifications and relative volume of viable myocardium). Magnetic resonance spectroscopy allows detection of moderate to severe rejection with significant alterations in the energy-rich phosphates such as a decrease in the ratio of phosphocreatine/inorganic phosphate, phosphomonoester/inorganic phosphate, and beta-adenosine triphosphate/inorganic phosphate. A significant correlation was found between spectroscopic changes (phosphocreatine/inorganic phosphate) and histologic rejection (correlation coefficient r = 0.47, p < 0.005) and/or the amount of relative volume of viable myocardium and phosphocreatine/inorganic phosphate (r = 0.58) or beta-adenosine triphosphate/inorganic phosphate (r = 0.63), respectively. In conclusion magnetic resonance spectroscopy permits detection of moderate to severe degrees of heart rejection with a sensitivity of 85% and a specificity of 61%. Changes in the energy-rich phosphates correlate with the histologic grading of heart rejection and the relative volume of viable myocardium. Magnetic resonance spectroscopy appeared to be a valid technique for detecting myocardial rejection after heart transplantation in the reported experimental model.

Tolerance of mefloquine by SwissAir trainee pilots.

Due to presumed adverse performance impact, a World Health Organization clause currently restricts the use of mefloquine malaria chemoprophylaxis in individuals requiring fine coordination and spatial discrimination. We conducted a double-blind, placebo-controlled, cross-over study to quantitatively assess the effects of mefloquine at steady state on performance in 23 trainee airline pilots. Flying performance was assessed using a flight simulator, psychomotor function was evaluated, sleep and wake cycles were monitored, and symptoms and moods were assessed using standardized questionnaires. A simplified postural sway meter recorded sway in three test positions. In the mefloquine loading dose phase, there was one withdrawal due to dizziness, diarrhea, and flu-like symptoms, and three volunteers reported nonserious, sleep-related adverse events. There was no significant difference in flying performance, psychomotor functions, or mean sway for any test position. Nonsignificant reductions in mean total nocturnal sleep (mefloquine = 450 min versus placebo = 484 min) and poorer sleep quality were detected in the mefloquine phases. The mood findings indicated a predominance of positive states, with vigor the predominant mood in all phases. No significant performance deficit was documented under laboratory conditions during use of mefloquine at steady state.

Bioprocessing in space: human cells attach to beads in microgravity.

Attachment to a substrate and survival of human embryonic kidney (HEK) cells have been tested in an incubator installed in the flight-deck of the Space Shuttle 'Challenger' during its eighth mission. HEK cells are producing the enzyme urokinase and are presently investigated as candidates for electrophoretic separation in an apparatus developed and manufactured by McDonnell Douglas. Attachment of HEK cells to a substrate is mandatory for survival and production of urokinase after electrophoretic separation. Analysis of the samples shows that cells adhere, spread and survive in microgravity (< 10(-3) x g) conditions as well as the ground controls at 1 x g. This result represents an important step towards further bioprocessing in space.

Dynamic cell culture system: a new cell cultivation instrument for biological experiments in space.

The prototype of a miniaturized cell cultivation instrument for animal cell culture experiments aboard Spacelab is presented (Dynamic cell culture system: DCCS). The cell chamber is completely filled and has a working volume of 200 microliters. Medium exchange is achieved with a self-powered osmotic pump (flowrate 1 microliter h-1). The reservoir volume of culture medium is 230 microliters. The system is neither mechanically stirred nor equipped with sensors. Hamster kidney (Hak) cells growing on Cytodex 3 microcarriers were used to test the biological performance of the DCCS. Growth characteristics in the DCCS, as judged by maximal cell density, glucose consumption, lactic acid secretion and pH, were similar to those in cell culture tubes.

MalaQuick versus ParaSight F as a diagnostic aid in travellers' malaria.

In this study we assessed whether travellers can perform malaria rapid tests, following the provided information leaflet, and correctly interpret performed and pre-prepared test strips. Two Plasmodium falciparum testing systems, namely MalaQuick (ICT) and ParaSight F were used. Test performance and test interpretation of pre-prepared tests were compared. There was no significant difference in test performance between the 2 tests. Interpretation of prepared test strips in both test systems was very reliable in blood parasite densities between 0.1% and 2%, but major problems were encountered at low parasitaemia (< 0.1% blood parasites) and also in ParaSight F test strips showing high parasitaemia (> 2% blood parasites). Low parasitaemia ParaSight F test strips were correctly interpreted by 52.1% compared with 10.8% correct interpretations with MalaQuick (P < 0.0001). Correct interpretation of highly positive (> 2% blood parasites) pre-prepared test strips was higher with MalaQuick (96.8%) than with ParaSight F (33.8%), P < 0.0001. Both tests were associated with high levels of false-negative interpretations which render them unsuitable as self-diagnostic kits. Efforts must be made to assist lay individuals in test performance by technical test improvement, by equiping the test strips with an additional reading aid for interpretation, and by providing instruction by a skilled person.

Hepatitis E, Helicobacter pylori, and gastrointestinal symptoms in workers exposed to waste water.

BACKGROUND: Workers exposed to sewage may have an increased risk of infection by Helicobacter pylori and hepatitis E virus (HEV). AIMS: To assess the prevalence of clinical hepatitis E (HE) and peptic ulcer disease as well as the seroprevalence of antibodies to H pylori and HEV in workers with and without sewage exposure and to look for symptoms due to exposure to endotoxin. METHODS: In the first year of a prospective cohort study 349 sewage exposed workers and 429 municipal manual workers (participation: 61%) underwent a complete medical examination. Travelling to endemic areas, socioeconomic level, age, country in which childhood was spent, and number of siblings were considered as the main confounding factors. RESULTS: Peptic ulcer disease and clinical HE did not occur more often in workers exposed to sewage. Prevalence of antibodies to HEV was 3.3% and overall prevalence of IgG antibodies to H pylori was 42% with large differences between subgroups. Logistic regression did not show an increased risk of seropositivity or antibodies to parietal cells in sewage exposed workers, but disentangling the effect of exposure from that of confounders was extremely difficult. No increase of symptoms due to exposure to endotoxin was found in sewage workers, with the exception of diarrhoea. CONCLUSIONS: No clear increased risk of infection by H pylori or by HEV in workers exposed to sewage was found in this cross-sectional study, but these results need to be confirmed by follow up.