The evolution of host associations in the parasitic wasp genus Ichneumon (Hymenoptera: Ichneumonidae): convergent adaptations to host pupation sites

Background

The diversification of organisms with a parasitic lifestyle is often tightly linked to the evolution of their host associations. If a tight host association exists, closely related species tend to attack closely related hosts; host associations are less stable if associations are determined by more plastic traits like parasitoid searching and oviposition behaviour. The pupal-parasitoids of the genus Ichneumon attack a variety of macrolepidopteran hosts. They are either monophagous or polyphagous, and therefore offer a promissing system to investigate the evolution of host associations. Ichneumon was previously divided into two groups based on general body shape; however, a stout shape has been suggested as an adaptation to buried host pupation sites, and might thus not represent a reliable phylogenetic character.

Results

We here reconstruct the first molecular phylogeny of the genus Ichneumon using two mitochondrial (CO1 and NADH1) and one nuclear marker (28S). The resulting phylogeny only supports monophyly of Ichneumon when Ichneumon lugens Gravenhorst, 1829 (formerly in Chasmias, stat. rev.) and Ichneumon deliratorius Linnaeus, 1758 (formerly Coelichneumon) are included. Neither parasitoid species that attack hosts belonging to one family nor those attacking butterflies (Rhopalocera) form monophyletic clades. Ancestral state reconstructions suggest multiple transitions between searching for hosts above versus below ground and between a stout versus elongated body shape. A model assuming correlated evolution between the two characters was preferred over independent evolution of host-searching niche and body shape.

Conclusions

Host relations, both in terms of phylogeny and ecology, evolved at a high pace in the genus Ichneumon. Numerous switches between hosts of different lepidopteran families have occurred, a pattern that seems to be the rule among idiobiont parasitoids. A stout body and antennal shape in the parasitoid female is confirmed as an ecological adaptation to host pupation sites below ground and has evolved convergently several times. Morphological characters that might be involved in adaptation to hosts should be avoided as diagnostic characters for phylogeny and classification, as they can be expected to show high levels of homoplasy.

The early social environment affects social competence in a cooperative breeder

Social competence is defined as the ability of an animal to optimize the expression of social behaviour as a function of the available social information. The social environment encountered early in life can affect the expression of various social behaviours later in life. We investigated whether early social experience can affect social competence. In the cooperatively breeding cichlid Neolamprologus pulcher, we tested whether individuals reared with older brood-caring conspecifics persistently perform better in a series of tasks (1) simulating different social contexts, (2) assigning individuals different social roles and (3) exposing them to an unknown social situation. Fish that had been reared together with older conspecifics showed more appropriate behaviours both as winners (more aggressive displays) and as losers (more submissive displays) when aggressively competing with peers over a resource, and when trying to be accepted as subordinate group member and prospective brood care helper by an unfamiliar dominant pair (more submissive displays near shelters), a situation they had never encountered before. In both tasks fish that had grown up with older fish were tolerated better by conspecifics than fish reared with same-age siblings only. We detected effects of the early environment on social behaviour in the juvenile and adult stages of the test fish. Our results suggest that growing up in more complex social groups fosters a general social ability (i.e. social competence) in N. pulcher that improves their performance across different social roles and contexts, and which may provide fitness benefits.

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.

[Does geometry of the lumbosacral inclination have an effect on the etiology of isolated osteochondrosis of L5/S1?]

Men and women with isolated osteochondrosis L5/S1 (excluding transitional anomalies) were compared against a corresponding group of healthy volunteers to see whether there is any geometric or statistical evidence that might constitute predisposing factors for isolated osteochondrosis L5/S1. Arithmetic means, variances, standard deviations, and correlation coefficients were calculated for all the characteristics determined for the two groups. Multiple linear discriminant analysis was used to try to reproduce any classifications our groupings of the characteristic bearers on the basis of their characteristics. It was found that the position of the sacrum in the pelvis and the extent of lumbar lordosis play a major role. To detect a predisposition for isolated osteochondrosis L5/S1, it is thus necessary to evaluate: the position of the sacrum with regard to the pelvis and the degree of lumbar lordosis-excluding that of the fifth lumbar vertebra-in the angle system. This evaluation can be performed by measuring the dorsal inclination of the sacrum (the delta angle) and the Albrecht inclination.

[Corticosteroids in giant cell arteritis: primum nil nocere?]

BACKGROUND

Steroids are the treatment of choice for giant cell arteritis but bear the risk of serious side effects.

PATIENTS AND METHODS

We carried out a retrospective study on 34 patients with documented giant cell arteritis (24 with ocular involvement) by means of a questionnaire sent to the treating physicians.

RESULTS

After a mean follow-up of 48 months, side effects occurred in 90 % of the patients. The most frequent were weight gain (> 50 %) and osteoporosis (> 40 %, F >> M). Side effects were more common in patients with ocular involvement and in women. Severe complications were significantly more frequent in patients with ocular involvement.

CONCLUSIONS

Side effects are the rule and not the exception in the treatment of giant cell arteritis. They can affect quality of life. Physicians should bear them in mind as many are preventable and/or treatable.

[Forgoing life-sustaining measures in patients at the end of life in the German-speaking part of Switzerland: results of a death certificate study]

BACKGROUND AND OBJECTIVE

There have not been any comprehensive data from German-speaking countries on the medical practice of withholding or withdrawing treatment at the end of life. This study from the German-speaking part of Switzerland provides the first in-depth analysis in this field. This study is based on data from this region and is a contribution to a large empirical research project on medical end-of-life decisions in 6 European countries (EURELD).

METHODS

Continuous random samples (n = 4991) were taken from all deaths in the German-speaking part of Switzerland that had been reported to the Swiss Federal Office of Statistics between June and October 2001. Doctors who had been attending the deceased person were asked to complete mailed questionnaires, their replies being kept strictly anonymous.

RESULTS

The response rate was 67 %. Medications were withheld or withdrawn in 48 % of all treatments forgone: among these, antibiotics accounted for 17 %. Other potentially life-sustaining medical measures forgone included artificial hydration (12 %), surgery (7 %), artificial feeding (6 %), chemotherapy (6 %), diagnostic tests (4 %), hospital admissions (3 %), renal dialysis (2 %), blood product infusions (2 %), intubation (2 %), ventilation (2 %), resuscitation (2 %), and radiotherapy (1 %). 43 % of all treatments were forgone in patients who died in hospital, 42 % in nursing homes, and 15 % at home. In almost three-quarters (73 %) of the treatments forgone, a primary-care doctor had ordered the treatment to be withheld or withdrawn. On average, forgoing treatment led to a life-shortening effect of more than one month in 8 % of all cases. The proportion was higher for renal dialysis (25 %), blood products infusion (18 %), and diagnostic tests (16 %).

CONCLUSIONS

Forgoing life-sustaining medical treatment comprises a wide range of decisions taken in many different clinical settings. In most cases the likely lifespan is only slightly shortened.

Clara cell protein and surfactant protein�B in garbage collectors and in wastewater workers exposed to bioaerosols

OBJECTIVES

Inhalation of bioaerosols has been hypothesised to cause "toxic pneumonitis" that should increase lung epithelial permeability at the bronchioloalveolar level. Serum Clara cell protein (CC16) and serum surfactant protein B (SPB) have been proposed as sensitive markers of lung epithelial injury. This study was aimed at looking for increased lung epithelial permeability by determining CC16 and SPB in workers exposed to bioaerosols from wastewater or garbage.

METHODS

Subjects (778 wastewater, garbage and control workers; participation 61%) underwent a medical examination, lung function tests [American Thoracic Society (ATS) criteria], and determination of CC16 and SPB. Symptoms of endotoxin exposure and several potential confounders (age, gender, smoking, kidney function, obesity) were looked for. Results were examined with multiple linear or logistic regression.

RESULTS

Exposure to bioaerosols increased CC16 concentration in the wastewater workers. No effect of exposure on SPB was found. No clue to work-related respiratory diseases was found.

CONCLUSIONS

The increase in CC16 in serum supports the hypothesis that bioaerosols cause subclinical "toxic pneumonitis", even at low exposure.

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.

Prevention of cardiac allograft rejection by FK506 and rapamycin: assessment by histology and nuclear magnetic resonance

We assessed the effect of FK506 and rapamycin (RPM) in a heterotopic abdominal rat heart transplant model using a major histocompatibility mismatch (DA to LEW). The end-point of our study was the histologic grading of rejection (Stanford) and 31P magnetic resonance spectroscopy (MRS) at 1 week after transplantation. Two dosages of FK506 (2.0 and 8.0 mg/kg per os daily) and RPM (1.5 and 6.0 mg/kg intraperitoneally daily) were compared in allografts without and with cyclosporine (12.5 mg/kg per os daily) treatment. The results show: Weak heartbeat and full rejection at day 5 in all untreated allografts; severe rejection in groups on a low dose of FK506 and RPM; mild rejection in both high dose groups comparable to the results of the hearts treated with cyclosporine; MRS does not allow differentiation between no or mild forms of rejection. Energy-rich phosphates are near normal in the high dosage immunosuppression groups but show a significant reduction in the low dosage groups. We conclude that all three tested drugs can reduce the degree of rejection from severe (untreated allografts) to mild if given in an adequate dosage. MRS correlates well with the degree of histologic rejection but permits only the diagnosis of moderate or severe rejection.

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.

Effectiveness and tolerability of melatonin and zolpidem for the alleviation of jet lag

BACKGROUND

The aim of this study was to compare the effectiveness and tolerability of a chronobiotic (melatonin) with a hypnotic (zolpidem) and the combination of both substances to alleviate jet lag symptoms associated with eastward travel.

METHODS

This double-blind, randomized, placebo-controlled study is based on 137 volunteers flying from Switzerland to the American continent and back (6-9 time zones). The participants either received melatonin 5 mg (n = 35), zolpidem 10 mg (n = 34), a combination thereof (n = 29) or placebo (n = 39) on the eastbound flight back to Switzerland and once daily at bedtime on 4 consecutive days after the flight. The test battery included daily sleep logs, symptoms questionnaires, and the Profile of Mood States (POMS). Also, on the last treatment day, Visual Analog Scales (VAS) were completed to assess overall jet lag ratings and treatment effectiveness. Baseline data were collected on 4 consecutive days 2 wk after the flight. During post-flight treatment and baseline, motor activity was assessed in a subgroup of 49 subjects using wrist-worn ambulatory monitors.

RESULTS

The self-rated sleep quality was significantly improved by zolpidem, especially during the night flight. Subjects taking zolpidem reported significantly less jet lag and zolpidem was rated as the most effective jet lag medication. However, zolpidem and the combination melatonin/zolpidem were less well tolerated than melatonin alone; adverse event reports included nausea, vomiting, amnesia and somnambulia to the point of incapacitation. Confusion, morning sleepiness and nausea were highest in the combination group.

CONCLUSIONS

All active treatments led to a decrease of jet lag severity with zolpidem being the most effective treatment, particularly in facilitating sleep on night flights. Potential individual adverse reactions to this hypnotic have to be considered.

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.

[Recording of multiple sclerosis in Swiss cause of death statistics. A 10-year mortality follow-up of the Bern prevalence study]

Based on data from a multiple sclerosis (MS) prevalence study which had been carried out in 1986 in the canton of Berne, Switzerland, a follow-up was performed 10 years later to gather information on mortality in the original study population. The authors used information on residency and death as gathered from municipal offices and, additionally, by record-linkage with the Swiss cause of death statistics. Slightly more than 80% of the cases were identified unequivocally as of January 1996. Among them, 21% of the cases died during the ten-year period; 70% of them have an MS entry in the cause of death statistics, mostly as the main cause of death. A large proportion of the non-identifiable cases appear to be related to mortality; thus, the findings here do not provide a promising basis for certain further analyses. In conclusion, continuous updating of personal data is the only way to avoid loss to follow-up in the carefully assembled prevalence database.

[Prevention of gastrointestinal and lungworm infections in alpine calves: use of doramectin pour-on in before and after the alpine grazing season]

The effect of doramectin pour-on (Dectomax 0.5% pour-on, Pfizer) against gastrointestinal nematodes (GIN) and lungworms was investigated in calves grazed on alpine pastures in Switzerland. Doramectin pour-on (0.5 mg/kg body weight) was administered topically to calves (n = 57, Group D) before and after the alpine grazing season (mid-June to end of September) when the calves were kept on altitudes between 1800 and 2600 m together with 20 untreated calves (Group K). Calves of both groups were grazed together during the alpine season and were subsequently moved to prealpine and home pastures where they were kept until stabling (end of November). Faecal examinations, performed 4 to 5 weeks after anthelmintic treatment of Group D calves showed a marked reduction of the trichostrongyle egg output, which was also low in the untreated calves. Low numbers of Dictyocaulus-larvae were excreted by the calves at turnout to the alpine pastures. At the end of September the mean excretion of Dictyocaulus-larvae had increased markedly in both groups. After treatment of Group D calves the larval output remained negative until stabling. In contrast, the larval excretion of the untreated calves (Group K) reached highest levels at the end of October and 4 calves exhibited clinical signs of dictyocaulosis. The results indicate that the strategic use of doramectin pour-on in June and in late September provided good protection against severe infections with D. viviparus. The infection level with GIN confirmed that these parasites are of minor relevance under the extensive grazing conditions on high alpine pastures.

Comparative study to determine the optimal melatonin dosage form for the alleviation of jet lag

To compare the impact of various dosage forms of melatonin and placebo on jet lag symptoms, 320 volunteers who had flights over 6 to 8 time zones were recruited for a double-blind, randomized, placebo-controlled study. The volunteers received either melatonin 0.5-mg fast-release (FR) formulation, melatonin 5-mg FR formulation, melatonin 2-mg controlled-release (CR) formulation, or placebo. The study medication was taken once daily at bedtime during 4 days after an eastward flight. The volunteers completed the Profile of Mood States (POMS), sleep log, and symptoms questionnaires once daily and the Karolinska Sleepiness Scale (KSS) three times daily prior to departure and during the 4 days of medication intake postflight. A total of 234 (73.1%) participants were compliant and completed the study. The FR melatonin formulations were more effective than the slow-release formulation. The 5-mg FR formulation significantly improved the self-rated sleep quality (p < .05), shortened sleep latency (p < .05), and reduced fatigue and daytime sleepiness (p < .05) after intercontinental flight. The lower physiological dose of 0.5 mg was almost as effective as the pharmacological dose of 5.0 mg. Only the hypnotic properties of melatonin, sleep quality and sleep latency, were significantly greater with the 5.0-mg dose.

Impact of melatonin on driving performance

BACKGROUND

Because millions of people are self-prescribing melatonin for various indications, the safety aspects of this substance have become very important. The aim of our study was to determine whether or not melatonin impairs driving-related performance.

METHODS

Twenty healthy men and women aged 21-57 years volunteered for this randomized, placebo-controlled, double-blind, crossover study. The crossover arms were separated by an interval of at least 4 weeks. On each testing day, melatonin 5 mg or placebo was taken at 1630 h; 60 minutes later a test series was performed, consisting of a medical examination, body sway measurement, and a standardized driving computer test battery to assess attention, reaction time, power of concentration, and sensomotor coordination. Subjective sleepiness was measured on three occasions during the test session using the Stanford Sleepiness Scale questionnaire.

RESULTS

Just one of the 16 main variables of the driving computer test battery, the selective attention tested by signal-detection, was significantly affected by melatonin (p &lt; .05). However, even those values were still within the normal range. Subjective sleepiness was increased by melatonin, although the result was significant only after the prolonged concentration task (p &lt; .05). Neither the clinical examination nor the body sway test showed signs of any drug influence.

CONCLUSIONS

The overall result of the computer test battery showed no objective adverse impact of melatonin on driving performance. However, due to the increased subjective sleepiness after administration of this hormone, caution should be exercised when driving under the influence of melatonin.

Interleukin 1 alpha hematological examination in mechanics exposed to low benzene concentrations

OBJECT

To examine the hypothesis of Renz and Kalf relative to the involvement of interleukin 1 alpha (IL-1 alpha) in the development of anemia in benzene-exposed workers. According to this hypothesis, benzene inhibits the cleavage of the IL-1 alpha precursor (proIL-1 alpha) to mature IL-1 alpha and the lack of this cytokine is responsible for benzene-induced bone marrow suppression. This inhibition of the processing of proIL-1 alpha is attributed to an inhibition of calpain.

METHOD

Selection of a population of mechanics exposed to low levels of benzene from fuels, assessment of usual exposure and lifetime exposure duration, and measurements of concentrations of workplace-air benzene and urinary benzene metabolites. Determination of IL-1 alpha concentrations was done by a whole-blood assay after lipopolysaccharide stimulation and a hematological examination was carried out. Statistical analysis considered several possible confounding factors, particularly smoking and drinking habits.

DESIGN

Cross-sectional study.

RESULTS

The level of exposure of the mechanics to benzene from fuels was mostly well below 1 ppm. IL-1 alpha production was not decreased in mechanics exposed to benzene from fuels, and no correlation between IL-1 alpha concentrations and red blood cell counts appeared. With the exception of a slight decrease in red blood cell counts in mechanics, no hint of a toxic effect of exposure on hematological parameters was found.

CONCLUSIONS

The hypothesis of Renz and Kalf could not be confirmed. Although the low level exposure of the study population and methodological factors are possible explanations, it cannot be excluded that the hypothesis of Renz and Kalf is not generalizable to benzene-exposed humans. Presently, one cannot advise the measurement of IL-1 alpha production for biological effect monitoring of workers exposed to low concentrations of benzene.

Assessment for Subclinical Kidney Damage in Workers Exposed to Low Concentrations of Hydrocarbons

It has been suggested the risk of hydrocarbon-induced chronic nephropathy is negligible at low exposure levels. The first purpose of the study was to test this hypothesis by selecting a population slightly exposed to hydrocarbons. Moreover, as hypertension might be associated with an increased excretion of nephrotoxic mercapturates, the association between blood pressure and urinary concentration of S-phenylmercapturic acid (S-PMA) was also examined. Lifetime exposure assessment, main tests of subclinical kidney damage, and statistical approach were taken from a previous study that had included primarily moderately or heavily exposed workers and had found hydrocarbon-induced nephrotoxic effects. No nephrotoxic effect of exposure could be ascertained in the present study. S-PMA concentration was not increased in hypertensive workers. Thus, the risk of hydrocarbon-induced chronic nephropathy might be extremely low in workers slightly exposed to hydrocarbons. The negative results of some studies might be due to the low lifetime hydrocarbon exposures of the study populations.

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.

Biological monitoring of vehicle mechanics and other workers exposed to low concentrations of benzene

It has been suggested that the threshold limit value (TLV) for the time-weighted average (TWA), of benzene be lowered because of its possible leukemogenic effect at low exposure concentrations. This requires the development of new methods of biological monitoring. In this cross-sectional study the diagnostic power of blood and breath benzene and of urinary phenol, catechol, hydroquinone, S-phenylmercapturic acid, and muconic acid were compared in a population of 410 male workers exposed to benzene in garages, in two coke plants, and in a by-product plant. Benzene exposure was assessed by personal air sampling (charcoal tube and passive dosimeter). In all, 95% of the workers were exposed to less than 0.5 ppm benzene. According to the multiple regression equation, the muconic acid and S-phenylmercapturic acid concentrations detected in nonsmokers exposed to 0.5 ppm benzene were 0.3 mg/g and 6 micrograms/g, respectively (range 0.2-0.6 mg/g and 1.2-8.5 micrograms/g, respectively). With muconic acid very few false-positive test results were found, and this determination remained reliable even around a cutoff level of 0.1 ppm benzene. Moreover, the diagnostic power of this test proved to be good even when diluted or concentrated urine samples were not excluded. S-Phenylmercapturic acid (S-PMA) also performed fairly well. Blood and breath benzene as well as urinary phenol (PH) and hydroquinone (HQ) were clearly less suitable biomarkers than muconic acid (MA). Catechol (CA) was not associated with occupational benzene exposure. According to the results of biological monitoring, the skin resorption of benzene from gasoline or other fuels seems negligible. Correlation, multiple regression, and likelihood ratios consistently showed that MA and S-PMA concentrations were fairly good indicators of benzene exposure in the 0.1- to 1-ppm range, even in a population comprising both smokers and nonsmokers. PH, HQ, CA, and blood and breath benzene were less suitable, if at all, in the same exposure range.

Mefloquine tolerability during chemoprophylaxis: focus on adverse event assessments, stereochemistry and compliance

This longitudinal study of travellers to Africa taking mefloquine (MQ) chemoprophylaxis aimed to quantify and assess non-serious adverse events (AE) occurring during short-term prophylaxis and relate these to concentrations of racemic MQ, its enantiomers and metabolite. A total of 420 volunteers (52% F) participated. AEs with some impact on activities were reported by 11.2% of participants including 7.9% of neurological/psychiatric symptoms. Women were more likely to report AEs (P = 0.02). The standardized questionnaires used showed more pathological indicators in travellers who reported subjective AE with significantly more dizziness, distress, sleep disturbances and a high total mood disturbance (TMD) in the AE group. There was, however, no significant performance deficit in computerized psychomotor tests in those experiencing AE. Furthermore, no significant differences were observed in enantiomer ratios, metabolite concentrations, or racemic MQ levels in participants with or without AEs suggesting that these factors are not the main predictors of mefloquine intolerability.

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.

[Evaluation of the smoking cessation course (1984-1990) of the Cancer and Lung Society of canton Zurich]

The present study is to evaluate the smoking cessation therapy of the working team of the Cancer Association and Lung Association of the State of Zurich. Roughly 1/3 of all 913 participants of the therapy from 1984 to July 1990 have responded to the survey. Of these 1/3, more than a quarter did not smoke any more one year after the therapy. An antismoking program with a 1-year smoking cessation rate of 20 to 30% is considered successful in professional circles. The smoking cessation rate of all 913 therapy participants is probably below the 27% obtained in as much as the share of the successful ones among those replying, by experience is bigger than the share of those failling. Also the more precise inquiry in the first 7 therapies of 1990 confirms these findings. There the rate of success is barely 15% after 1 to 1 1/2 year. It cannot be ascertained whether the smoking cessation rate of all therapy courses is that high or only at the time after the program restructurations at the beginning of 1990. Only a precise achievement control can guarantee a consequent and continuous therapy evaluation within the next years.

Efficacy and tolerance of insoluble carob fraction in the treatment of travellers' diarrhoea

The water-insoluble carob fraction (fraction insoluble caroube, FIC, Nestlé) has been successfully used in the treatment of infantile diarrhoea. To investigate the efficacy and toxicity of FIC (1970 mg to be taken every 2 hours over a 48-hour period except during sleeping time) in the treatment of travellers' diarrhoea in adults, a double-blind, computer randomized, placebo-controlled study was conducted. Of the 755 volunteers recruited at the Zurich University Vaccination Centre, 628 (83.5%) returned their questionnaires. Among them, 164 (27.7%) had diarrhoea, but only 69 (42%) used the trial medication correctly; the others were rated non-complaint. No significant difference in efficacy (p = 0.12) or adverse effects were observed in the two study groups. In conclusion, FIC, although showed a positive trend, was not efficacious.

Behavioural aspects of travellers in their use of malaria presumptive treatment

The use of stand-by treatment for malaria by travellers depends on their knowledge, attitudes and behaviour. We examined the behavioural aspects of a cohort of travellers from Switzerland to low-risk malarial areas who, on recruitment, were provided with a kit containing medication for stand-by treatment, guidelines on the diagnosis of malaria, and materials for collection of blood samples for later confirmation of malaria. All subjects were urged to seek medical advice at the first signs of possible malarial symptoms. Illness (fever as the main indicator) was reported by 123 of the 1187 participants, often accompanied by shivering/chills (36.6%), headache (35.0%), gastrointestinal symptoms (69.9%), and myalgia and/or arthralgia (41.5%). Two-thirds of those ill failed to seek medical attention despite their symptoms and pretravel advice. Only 9 (7.3%) were actually beyond the reach of medical attention. The stand-by treatment was self-administered by 6 travellers, only one of whom had confirmed malaria. Two non-serious adverse events were reported. All users consulted a physician after administering the presumptive treatment. This stand-by approach is limited by inappropriate behaviour and poor malaria awareness among travellers. These negative factors can be mitigated by development of an improved kit containing a simple test for self-diagnosis.

Comparison of Seven Commonly Used Agents for Prophylaxis of Seasickness

The objective of the study was to compare the efficacy and tolerability of seven drugs frequently used for the prevention of seasickness: the drugs were namely cinnarizine, cinnarizine with domperidone, cyclizine, dimenhydrinate with caffeine, ginger root, meclozine with caffeine, and scopolamine. The design was a randomized, double-blind study with two arms. On ethical grounds, a placebo group was not included as in a previous study, in the same setting, 80% of the passengers not receiving prophylactic drugs were seasick. The setting was in Andenes (Norway) during a time period from July to September 1992. Subjects were 1741 tourist volunteers who were joining a whale safari. The main outcome measures were vomiting, malaise (modified Graybiel criteria), and subjective reports of adverse events. Follow up was possible in 1489 volunteers (85.5%). In each active treatment group, 4.1-10.2% experienced vomiting and 16.4-23.5% experienced malaise (not significant). Equally, there was no significant difference in the incidence and characteristics of adverse events reported in the various medication groups. Scopolamine Transdermal Therapeutic System (TTS) users exhibited slightly more visual problems and the agent tended to be less effective. Six of the seven medications may be recommended for prevention of seasickness; scopolamine TTS seems the least attractive.

[How well do condoms protect against HIV infection?]

A review of the literature shows that condoms offer good protection against HIV infection and other sexually transmitted diseases. A series of in vitro experiments demonstrate that quality condoms made of latex are impermeable to HIV. In addition, more than 30 in vivo studies confirm that condoms are highly effective in preventing the transmission of HIV. Condom breakage or slippage is relatively uncommon (1-5%). Most condom failure probably results from incorrect or inconsistent usage. Failures may be minimized by increasing experience, choice of quality condoms and by strictly following instructions for use.

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.

Smell or taste disturbances, neurological symptoms, and hydrocarbon exposure

A total of 264 workers participated in a cross-sectional study concerning the toxicity of hydrocarbons. The clinical examination shows an increased prevalence of smell and/or taste disturbances in the heavily exposed group. These symptoms appear to be generally transitory and reversible. They seem to be due to concentration peaks rather than to a long exposure duration. They are associated with acute depressor effects and not with symptoms which could belong to a hydrocarbon-induced chronic toxic encephalopathy.

Differentiation of cardiac ischemia and rejection by nuclear magnetic spectroscopy

Nuclear magnetic resonance (NMR) criteria of early cardiac rejection are similar to those seen in myocardial ischemia, that is, a reduction of high energy phosphatases (Pc; ATP) and an increase of inorganic phosphates (Pi). Our aim was to assess in vivo changes of phosphorous spectroscopy (31P) induced by cardiac rejection and myocardial ischemia in the same animal. Heterotopic heart isografts (n = 5) and untreated allografts (n = 5) were examined at seven days on a two tesla wide-bore magnet with a surface coil. Subtotal global ischemia was produced for sequential NMR measurements, followed by heart excision for histological rejection grading (Billingham). Results 1. Isograft served as controls and showed normal energy-rich phosphate compounds and pH. 2. Rejecting (moderate to severe) allografts showed a decrease of Pc/Pi and beta-ATP/Pi ratio compared with isografts. However no significant pH drop could be detected. 3. Induced ischemia was confirmed by marked ECG-ST elevation and showed a significant early global myocardial acidosis (pH less than 6.9) particularly in severe prolonged ischemia (p less than 0.05). 4. Using 31P NMR techniques, ischemically induced changes were similar in isografts and allografts with a trend towards a more pronounced extent in the latter groups. In conclusion, magnetic resonance spectroscopy (31P and pH) allows in vivo differentiation between cardiac rejection and acute myocardial ischemia.

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.

[Effects of jogging on mental well-being and seasonal mood variations: a randomized study with healthy women and men]

The long-term effect of jogging on mental well-being and seasonal mood variation was examined in a randomized, controlled intervention study with healthy, middle-aged, sedentary, non-smoking, white collar subjects. 17 women and 39 men were allocated to jog 2 h/week for 4 months, whereas 16 women and 22 men served as controls. After 4 months, there was a partial cross-over with the controls now taking up jogging. After 8 study months, all 38 subjects of the second jogging intervention as well as 10 women and 30 men of the first 4-month jogging period were re-examined for the second time. All participants in the second re-examination were mailed a survey questionnaire one year after beginning of the study (response rate 83%). Despite varying adherence for the exercise regimen, the 4-month "net effects" (i.e. effect in exercise group minus effect in control group) showed a significant improvement in physical fitness (endurance capacity, resting heart rate) in men, but not in women. Among the mood scales assessed, "anger" showed a marginally significant effect in men (relative decrease; p = 0.05) and "calmness" a significant effect in women (relative increase; p = 0.02); after exclusion of 4 non-compliers from analysis in women, also "vigor" (relative increase; p = 0.03) and "depressiveness" (relative decrease; p = 0.02) were significantly improved after jogging. In women, the number of kilometers run was significantly correlated with an improvement in mental well-being (Pearson's r = 0.32 with change in 4 "positive" mood scales and r = 0.57 with change in 4 "negative" mood scales). Changes in endurance capacity were not significantly related to changes in mental well-being. However, in both women and men these mental effects of jogging were superposed by clear seasonal variations in mood, i.e. by a deterioration of mental well-being during the winter months and by a slow "remission" during summer. Taking jogging-induced and seasonal effects on mood together, the magnitude of the 1-year variability in mental well-being was somewhat attenuated in those study groups jogging, with this "buffering" effect reaching statistical significance in women (p = 0.050). We conclude from this training study with normal subjects that regular jogging of approximately 10 to 15 km/week may help to diminish the deterioration of mood observed during winter months (e.g. increase in depressiveness), especially in women. Hereby, a training-induced increase in endurance capacity is apparently not a prerequisite for this long-term mental effect of jogging.

[Cardiovascular risk factors of visitors to a mass-screening booth]

The attitude towards mass screening of serum cholesterol is controversial. In order to characterize the volunteers of such screenings and to test the representativity of its findings, we compared the data of 1686 adult health-screening participants collected during a trade fair in the city of Basel, Switzerland, with the results of two population-based studies, the Basel City Risk Factor Survey and the MONICA Project in Western Switzerland. Among those screened, there was an over-representation of women and older persons. The age-specific medians of blood cholesterol and proportions of hypercholesterolemic persons were consistently higher in female screenees--and marginally so in males--than in the reference populations, whereas higher proportions of persons with ideal cholesterol level in those screened were also observed, especially in younger males. Higher systolic blood pressure, lower relative body weight and less regular smoking were found consistently among the screenees. This cross-sectional study shows that the participants of such mass screening actions are a selective group of older, more frequently female health-conscious persons with a specific risk-factor pattern. Mass screenings of self-selected volunteers can, therefore, not be used for a reliable prediction of risk-factor distributions in the general population. Moreover, suggested further steps for those screenees with both health-conscious behavior and elevated biological risk-factor levels, such as second measurement, medical consultation and counselling, cannot be assured in the setting of a trade fair. The objectives and intentions of such mass screening activities should be reconsidered and discussed.

Effects of self-monitored jogging on physical fitness, blood pressure and serum lipids: a controlled study in sedentary middle-aged men

To study the effects of long-term, home-based exercise on physical fitness and cardiovascular risk factors of middle-aged nonsmoking males, a controlled study was conducted in 61 sedentary Swiss men. Thirty-nine men were randomly allocated to jog 2 h/week for 4 months on an individually prescribed and heart-rate-controlled basis, whereas 22 men served as controls. Despite varying adherence to the exercise regimen, the 4-month net change (effect in exercise group minus effect in control group) in estimated endurance capacity was significant and positive. Net changes in arterial blood pressure, measured with a random-zero device, were nonsignificant, but after exclusion of low-normotensive men (n = 19) from analysis, a significant net effect of exercise on diastolic blood pressure was seen (-4.3 mmHg; p = .048). The following net changes in serum lipid levels occurred: HDL cholesterol + 0.12 mmol/l (p = .028), total triglycerides -0.21 mmol/l (ns), HDL-C/total cholesterol ratio +0.02 (p = .047). Exploratory analyses revealed that an increase in estimated endurance capacity was associated with a rise in systolic and diastolic blood pressure (r = 0.49 and 0.43, respectively; p less than 0.01 both). Changes in the waist-hip ratio were directly related to the change in diastolic blood pressure (r = 0.27; p less than 0.05). Multivariable analysis indicated that much of the beneficial effect of exercise on diastolic blood pressure was apparently mediated through a decrease in body fat. This study confirms that individually prescribed jogging can reduce cardiovascular risk factors in self-selected nonsmoking males.(ABSTRACT TRUNCATED AT 250 WORDS)

[Hypercholesterolemia in general practice--2 representative surveys in Switzerland]

Two representative surveys of general practitioners in 1987 and 1989 showed, that cigarette smoking and high blood pressure are considered the most important risk factors for coronary heart disease. Elevated blood cholesterol level rank third. Between the two surveys no significant changes took place. The blood cholesterol level is usually measured at a check-up visit or in presence of another risk factor. Routine measurement is not common. At what level do Swiss physicians initiate a therapy? The median range in 1989 for a diet therapy was 6.2-6.7 mmol/l (240-260 mg%) for a 30 years old person, and 6.7-7.2 mmol/l for a 60 years old person. Lipid-lowering drugs are used at about 1 mmol/l (40 mg%) higher levels and there is less agreement between the physicians. Within two years the levels of initiating therapy decreased significantly. Differences between the three Swiss language regions (german/french/italian) in initiating therapy can be seen. 90% of the physicians mentioned compliance problems with a diet therapy. In 1989 half of the surveyed doctors experienced insufficient results in both diet and drug treatment. Further, compliance problems and side effects of drug treatment are mentioned. Half of the physicians reported having tested their own cholesterol level in the last 12 months. Older physicians are considerably more conscious of high cholesterol levels than younger.

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.