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Die Malaria nimmt mit etwa 1000 jahrlich nach Deutschland importierten Fallen einen wesentlichen Stellenwert in der reisemedizinischen Beratung ein, insbesondere da es sich in ca. 80% der Falle um die gefahrliche Malaria tropica handelt, die ohne oder bei zu spater Behandlung beim Nichtimmunen todlich verlaufen kann. Die Malaria tropica wird meist bei Reisen in das tropische Afrika erworben. Die Schwierigkeiten bei der Beratung zur Malariaprophylaxe liegen in der zunehmenden Resistenzentwicklung der Plasmodien gegenuber den Malariamitteln, so das neben der Chemoprophylaxe auch die notfallmasige Selbstbehandlung vor der Reise besprochen und durch adaquate Medikamente abgedeckt werden mus. Es gilt insbesondere, die Malaria tropica zu verhindern bzw. rechtzeitig zu behandeln, notfalls durch den Reisenden selbst, wenn Malariaverdacht besteht und ein Arzt nicht kurzfristig erreichbar ist. Dies setzt aber voraus, das der Reisende weis, wann Malariaverdacht besteht. Jedes unklare Fieber in den Tropen und auch noch lange Zeit danach ist solange malariaverdachtig, bis das Gegenteil erwiesen ist.

An ion cyclotron range of frequencies (ICRF) heating experiment was performed on the Compact Helical System (CHS) device in order to identify the problems in establishing this as a reliable heating method. Radiofrequency heating was applied to plasmas with two ion species produced by ECH. Stored energy increased upto 2.2 kJ with the application of a 590 kW ICRF heating pulse, giving a heating efficiency comparable to that of NBI heating. More importantly, the `flat-top' of the stored energy was maintained during the pulse. Good heating was realized with 30% proton and 70% deuteron plasmas at high density (4*1019 m-3). It was found that the best discharges are dominated by electron ICRF heating, which seems to be the reason for the successful results. On the contrary, a flat-top in stored energy has never been obtained in discharges where ion heating dominates. The loss of high energy ions with large pitch angles produced by ion heating appears to degrade the performance and limit the duration of the heating. A similar degradation was encountered in previous ICRF heating experiments in helical systems. A newly designed detector was used to study the loss of the helically trapped particles

Aluminium (Al) exposure can result in Al accumulation in the liver and this metal can be toxic to the hepatic tissue at high concentrations. In the present study the model of the isolated perfused rat liver was used to investigate the hepatic handling of Al. Livers from male Wistar rats were perfused in a recirculating system for 240 min. The liver function remained unchanged at perfusate concentrations of Al ranging from 4.9 to 1530.0 micrograms/l. At higher Al levels of 6535.3-16694.9 micrograms/l signs of toxicity towards isolated perfused livers were observed as indicated by an increased release of the enzymes AST and ALT into the perfusate, a pronounced reduction of bile flow rate and a 50% suppression of oxygen consumption. The hepatic Al clearance was low and decreased with increasing concentrations of Al in the perfusate from 4.3 +/- 0.6 microliters/min per g liver at a nominal Al concentration of 9.1 micrograms/l in control perfusate to 0.04 +/- 0.02 microliter/min per g liver at the highest concentration group. There was almost a linear dose dependent retention of Al in the liver with 4.9-635.7 micrograms Al/l perfusate while at higher concentrations Al levels in this organ increased disproportionally. It is concluded that by using the isolated perfused rat changes of liver functions occur only at very high Al concentrations in the perfusate and that only negligible amounts of Al are eliminated by the liver.

An analytical method for the simultaneous determination of the pyrethroid metabolites cis and trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid, cis 3-(2,2-dibromovinyl)-2,2-dimethylcyclopropane carboxylic acid, 3-phenoxybenzoic acid and 4-fluoro-3-phenoxybenzoic acid in human urine samples is described. The urine is subjected to acid-induced hydrolysis followed by exhaustive solvent extraction, covering both conjugated and free acids, followed by a common derivatisation step yielding the corresponding methyl esters. Quantitation was by diastereomeric, capillary gas chromatography-mass spectrometry. It appears that 4-fluoro-3-phenoxybenzoic acid is a characteristic urinary marker for cyfluthrin exposure. The limits of determination are 0.5–1.0 μg L−1 urine depending on the metabolites concerned. The applicability of the method was tested on urine samples from pest control operators exposed occupationally to cypermethrin and cyfluthrin.

Bronchoalveolar lavage (BAL) has gained widespread use as a tool for investigating human lung diseases. In certain cases, it can be useful to obtain BAL material in a serial manner. There is convincing evidence from experimental and clinical studies that BAL can cause influx of neutrophils into the bronchoalveolar space. However, conflicting data have been reported on whether this side effect of BAL also affects previously nonlavaged lung areas. In addition, there is little information available on whether multiple repetitive BAL procedures cause damage to lung tissue. To reexamine the short-term effects of serial BAL procedures, the left lung of 10 cynomolgus monkeys was lavaged with five 20-ml aliquots of saline four times at 24-h intervals (Group A). 72 h after the initial BAL, the right lung was lavaged as a control. The percentage of neutrophils increased significantly (p0.05), with the greatest effect seen at 48 h (30.7 +/- 5.8 versus 0.8 +/- 0.3%, mean +/- SEM). No significant changes were observed in the control BAL of the right lung at 72 h. A multidisciplinary approach was used to assess the long-term effects of multiple BAL procedures. BAL was performed 14 times over 26 mo at 2-mo intervals (Group B, n = 5). The right lung was lavaged as a control 25 mo after the initial BAL. In addition to standard cellular BAL parameters, the concentrations of fibronectin, procollagen III amino-terminal peptide-related antigen, total phospholipids, and lactate dehydrogenase activity were measured.(ABSTRACT TRUNCATED AT 250 WORDS)

In this study the production of enterotoxin A-D and toxic shock syndrome toxin-1 (TSST-1) of 181 methicillin resistant (MRSA) and 100 methicillin sensitive (MSSA) Staphylococcus aureus first isolates from different patients was investigated. All the MRSA- and MSSA isolates in the study were collected in a period between 1993 and 1995 from specimens sent from 11 different acute care hospitals in the greater Düsseldorf area. As far as possible the isolates were matched according to ward and hospital. The isolates were collected in the same time period and matched for specimen from which isolated. Furthermore, only first isolates were analysed in both groups. No significant difference in the production of toxin of any type between MRSA and MSSA could be detected (51 and 40% respectively). When the individual toxins were analysed, again no significant difference between MRSA and MSSA was demonstrable (enterotoxin production by MRSA 40% and MSSA 36%, and TSST-1 16% and 8% respectively). Despite this, a slight tendency for MRSA to produce enterotoxin A and B and for MSSA to produce enterotoxin C was observed. In addition, generation of TSST-1 by both groups was independent of enterotoxin A-D production. Interestingly, no increase in the proportion of TSST-1- or enterotoxin-producing MRSA and MSSA isolates was observed in strains isolated from blood cultures from patients with a clinical diagnosis of sepsis. Genotypical pulsed-field-gel-electrophoresis (PFGE) and phenotypical (bacteriophage typing, lysotyping) characterization of the 181 MRSA isolates resulted in 28 different PFGE patterns (of which 19 were toxin producers) and 22 lysotyping groups (18 of which produced toxin). In summary, the investigated clinical S. aureus isolates showed no difference in their ability to produce toxin and this was independent of their sensitivity to methicillin.

Over a period of three years the incidence of methicillin resistant Staphylococcus aureus (MRSA) isolates in 11 hospitals in the greater Düsseldorf area was observed. From a total of 7,814 S. aureus isolates, 489 (6.3%) were methicillin resistant. From 198 different patients, MRSA first isolates and 291 second isolates could be cultured. Methicillin resistance among all S. aureus isolates from 11 hospitals in the greater Düsseldorf area, ranged from 0.5 to 7.8% dependant on the size of the hospital. The highest incidence (7.8%) was found in a 1,500 bed hospital and the lowest incidence in a smaller 200 bed hospital (0.5%). With respect to the distribution among clinical departments the highest incidence of MRSA isolates was found on intensive care units and surgical wards, 25.5% and 13.0% respectively. The commonest specimen from which the MRSA isolates were cultured were respiratory secretions (17.6%) followed by central venous catheter tips (12.8%). In terms of the drug resistance pattern: all isolates were resistant to the aminoglycosides and gyrase inhibitors, whereas between 80% and 90% were sensitive to fusidic acid, chloramphenicol and pyrimethamine-sulfamethoxazole. All the strains were sensitive to the glycopeptide antibiotics, vancomycin and teicoplanin. Strain typing of 181 available first isolates (from a total of 198 first isolates) by PFGE and phage lysotyping produced identical results in more than 90% of all cases. Twenty-eight different MRSA strain types were identified by PFGE and in total 23 lysotypes could be determined. During the period of investigation an increased incidence of MRSA on an intensive care unit was observed, in which a total of 204 MRSA (42% of the total number) were isolated. The strain typing using both methods showed that on that ICU eight different MRSA types were involved in this outbreak. A hygiene plan was implemented on the unit with considerable success in reducing the incidence and spread of MRSA.

Pneumoconiosis is a disease caused by chronic exposure to mineral dust such as coal mine dust, silica and asbestos. Current concepts in the pathogenesis of pneumoconiosis suggest that the alveolar macrophage plays a central role in the outcome of this disease. Upon stimulation with mineral dust the macrophages secrete a number of fibrogenic cytokines among them tumor necrosis factor a (TNFa) which is considered to play a key role in mineral dust induced pneumoconiosis (Dubois etal., 1989; Donaldson, 1992; Donaldson etal., 1992; Vanhee etal., 1995). Recently, naturally occurring inhibitors of TNFa activity have been identified showing high affinity binding to TNFa (Brockhaus et al., 1990). These inhibitors have been characterised as extracellular domains of the TNFa receptors types I and II, respectively. In response to inflammatory stimuli that cause enhanced TNFa levels, they are shed from the cell surface and appear as extracellular receptors in body fluids (Porteu and Nathan, 1990). Since such extracellular soluble receptors are suggested to intervene in the regulatory mechanism for modulation of excessive TNFa activity (van Zee et al., 1992; Spinas et al., 1992), enhanced serum TNF-receptor levels may reflect overexpression of TNFa in response to chronic exposure of mineral dust. In order to study the role of soluble TNF receptor as an individual factor in pneumoconiosis development we investigated serum levels of sTNFRII in groups exposed to silica containing dust or asbestos with normal chest radiographics and in groups of patients with silicosis and asbestosis.

Hair analysis comprises the determination of minerals, trace elements and drugs. It is applied in Germany with increasing frequency in the recently established field of environmental medicine for biological monitoring of the internal metal/metalloid exposure. Besides a number of advantages hair analysis is impaired by the difficulty-to distinguish between endogenous and exogenous sources of metals in hair. Except for methylmercury, there are no critical limit values for trace elements in hair available. However, valid reference values for some metals and for nicotine in hair have been recently presented in the German Environmental Survey. The significance of selected substances in hair are as follows: Aluminium in hair is of no value in environmental medicine. For assessment of cadmium and inorganic arsenic exposure hair analysis is only suitable as a screening method based on large populations. Monitoring of lead in hair is a valuable screening method also for small groups, especially for children. Based on toxicokinetics and under consideration of practicability the optimal biomarker of methylmercury exposure is the hair concentration. For other mercury compounds hair analysis is of lower significance. Nicotine and cotinine measurements in hair provide a practical and proper method for estimating environmental tobacco smoke exposure and to validate smoker status in epidemiological studies.

Es wurden die Bleikonzentrationen in den Milchschneidezahnen von 730 5–12jahrigen Schulkindern aus zwei unterschiedlich belasteten Gebieten in Nordwestdeutschland (Duisburg and Gummersbach) bestimmt. Duisburg ist ein stark industrialisiertes, hochbelastetes Gebiet, Gummersbach ein Gebiet von landlicher bis mittelstddtischer Struktur. Die Zahnbleikonzentrationen liegen im Bereich von 1,4–12,7 μg/g. Die Duisburger Kinder (N = 690) wiesen im Mittel Zahnbleikonzentrationen von 4,53 μg/g auf. Der Mittelwert der Kinder aus Gummersbach betrug 2,74 μg Pb/g. In Ubereinstimmung mit anderen Autoren wurde statistisch eine Zunahme des Zahnbleigehaltes mit dem Alter gefunden. Geschlechtsspezifische Unterschiede konnten nicht nachgewiesen wurden. Innerhalb des Stadtgebiets von Duisburg wurden die hochsten Durchschnittswerte (raumlich gleitende Mittelwerte) in der Umgebung and Hauptwindrichtung von zwei Betrieben der Bleiindustrie gefunden, wahrend die Zahnbleikonzentrationen in den ubrigen Stadtrandgebieten jedoch deutlich abnahmen. Der Zahnbleigehalt wird als Indikator der langfristigen and kumulativen Bleibelastung diskutiert, der deutlich die unterschiedlichen Expositionsbedingungen in den beiden untersuchten Gebieten reflektiert.

Sera of 72 lead workers and of 53 reference subjects were examined for levels of immunoglobulins IgM, IgG, and IgA, and complement C3 by radial immunodiffusion. Salivary IgA levels were determined in 33 lead workers and 40 reference subjects. On the average the lead workers had lower serum complement C3 and immunoglobulin levels, as well as lower salivary IgA levels, than the reference subjects. A significant negative correlation was found between blood lead concentrations (PbB) and the serum levels of complement C3 and IgG in the group of lead workers, as well as in the total population examined. However, a significant positive correlation was observed between PbB and serum IgA in the group of lead workers. The results obtained in this study are discussed in relation to numerous reports in the literature showing that lead exerts adverse effects on the immune system in animals.

Xenotransplants of human carcinomas were tested for consistency of the analytical data of tumor markers over several passages in nude mice and nude rats. The binding properties of antibodies against tumor-associated antigens present in sera from tumor-bearing patients were tested with aid of the anticomplement immunofluorescence. The best binding capacity was found when sera from patients with bronchogenic carcinomas reacted on xenotransplants of the digestive tract (70%). Because of the low values for controls as well as for inflammatory diseases, this test may be applicable in the early recognition of lung cancer.