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Biomedical subjects

J Hartung

Publications and source records attributed to J Hartung.

At least 55 records · Page 3Linked to original sources
PubMed2000

Lung function and work-related exposure in pig farmers with respiratory symptoms.

The present study was conducted to evaluate characteristics of pig houses that are associated with the development of respiratory morbidity in 100 swine producers with work-related respiratory symptoms. A standardized questionnaire for farm characteristics was used, and lung function was assessed immediately before and after feeding the pigs. Exposure to dust and endotoxin was determined by personal sampling. Among these farmers, baseline lung function results were shown to be negatively associated with duration of employment, number of pigs on the farm, manual feeding, and ventilation. The decrease in forced vital capacity and forced expiratory volume in 1 second over the feeding period was negatively correlated with air velocity, whereas respirable dust concentrations were shown to be significant predictors of maximal midexpiratory flow (MMEF25/75) decline. In conclusion, among symptomatic pig farmers, those with higher numbers of pigs and longer duration of employment are at highest risk for developing functional impairment.

Adult↗
PubMed2000

N-hydroxy-4-(4-chlorophenyl)thiazole-2(3H)-thione as a photochemical hydroxyl-radical source: photochemistry and oxidative damage of DNA (strand breaks) and 2'-deoxyguanosine (8-oxodG formation).

On irradiation of N-hydroxythiazole-2(3H)-thione 3 at 300 nm, the photoproducts disulfide 4, bisthiazole 5 and thiazole 6 are formed. During this photolysis, hydroxyl radicals are released, which have been detected by spin trapping with 5,5-dimethyl-1-pyrroline N-oxide (DMPO), coupled with electron paramagnetic resonance spectroscopy. In the presence of supercoiled pBR322 DNA, irradiation of thiazolethione 3 induces strand breaks through the photogenerated hydroxyl-radicals, as confirmed by control experiment with the hydroxyl-radical scavenger isopropanol. Singlet oxygen appears not to be involved, as attested by the lack of a D2O isotope effect. During the photoreaction of thiazolethione 3 in the presence of 2'-deoxyguanosine (dG), the latter is photooxidized (ca 10% conversion after 2 h of irradiation) to the 7,8-dihydro-8-oxo-2'-deoxyguanosine as the main oxidation product. The dG conversion levels off after complete consumption of thiazolethione 3 and is suppressed by the addition of the hydroxyl-radical scavenger 2,6-di-tert-butylcresol or DMPO. Since the photoproducts 4-6 are ineffective as sensitizers for the photooxidation of dG and DNA, the hydroxyl radicals released in the photolysis of thiazolethione 3 are the oxidizing species of DNA and dG. These results suggest that the thiazolethione 3 may serve as a novel and effective photochemical hydroxyl-radical source for photobiological studies.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed2000

[Rules to control ddrinking water supply systems in livestock farming].

Water is regarded as one of the most important distributors of infectious diseases. Moreover it can carry chemical compounds and toxic substances. Presently there are no specific legal regulations which define the quality of the drinking water for animals in Germany. However, some rules and criteria exist which help to survey and secure the water supply of animals on farm level. When controlling the hygienic quality of water on the farm it is necessary to investigate not only the water itself but also the local facilities around the water well. If health problems occur in the stock the water tanks, the tubing system which distributes the water in the animal houses and the drinkers have to be checked carefully. Water samples for the analysis on microorganisms and chemical contaminants should be taken according to a strict protocol. The regulations of the German drinking water directive for humans can be used as an orientation to characterise the drinking water quality for the animals. Nevertheless it seems useful to elaborate animal species specific thresholds for water contaminants particularly for food producing animals. A proposal for some threshold values is reported.

Agriculture↗
PubMed2000

[Do we need regulation of drinking water for animals? Recommendations for the water supply of farm animals and pets].

The role of water as an essential nutrient for the animals, their health, performance and welfare is often underestimated. Presently there exists no specific legal regulation which defines the water quality for animal consumption. Some local recommendations make reference to the German regulation for the drinking water of humans. This seems to be useful in respect to food producing animals at a first glance. However, significant practical difficulties can occur. Therefore it is necessary to include in a possible regulation for the drinking water of animals additional animal and management specific aspects such as the type of animal, the keeping system, the water supply system, the distribution systems and the drinkers which are used. It may also be useful to define animal specific thresholds for certain groups of compounds and contaminants. As a first step towards a possible regulation 12 recommendations are given to improve and standardise the water supply of farm and pet animals.

Animal Husbandry↗
PubMed2000

[Aspects of animal welfare in livestock production].

The modern consumer is increasingly concerned about the welfare of farm animals which are kept in intensive systems on specialised farms where the health and well-being is almost completely dependent on the will, ability and care of the farmer. Further demands related to animal production are consumer health (quality and safety of food products), the protection of the environment and cheap food. The currently used husbandry systems are man made and emphasise automation which requires permanent critical observation of the welfare of the animals. Ethological indicators are equally important as health and performance to evaluate keeping systems. Future animal farming will be influenced by new technologies such as electronic animal identification and milking robots, and more important by biotechnology and genome analysis. Veterinary surgeons and farmers have to co-operate on the basis of scientifically sound animal welfare schemes which help to protect our farm animals in modern and intensive livestock production systems.

Animal Husbandry↗
PubMed2000

A new class of self-designing clinical trials.

A class of self-designing clinical trials is considered which according to an effective but simple, finite learning algorithm consists of automatically adaptively planned weighted group sequential trials with a decision about rejection of the null-hypothesis at each step, but the full level-alpha-test at the end of the study preserved.

Clinical Trials as Topic↗
PubMed2000

Combined test procedures in the meta-analysis of controlled clinical trials.

Concerning the actual significance level, we investigate the commonly used combined test procedures of meta-analysis, which contain the choice of the model, in which the analysis is carried out, and the commonly used tests for treatment effect in the fixed and random effects model, and some new combined test procedures, which use an alternative test statistic in the random effects model or the t-distribution as test distribution of the commonly used test statistics. A simulation study indicates that the new combined test procedures are better with respect to a prescribed significance level.

Clinical Trials as Topic↗
PubMed2000

Meta-analysis: different methods--different conclusions?

Different estimation methods for covariance parameters in meta-analyses can result in conflicting p-values concerning the test of treatment effect. We propose a valid method to overcome this problem at least partially by introducing a new estimator for the standard deviation of the common treatment difference.

Analysis of Variance↗
PubMed1999

[Prospective Epidemiologic Study of Epigastric Discomfort (PRESTO). Ground work and preliminary results].

BACKGROUND AND OBJECTIVE: Symptoms of dyspepsia (indigestion; upper abdominal discomfort) are one of the most frequent reasons for consulting a general practitioner or internist. Yet there are no up-to-date national data on the epidemiology and course of this symptom complex. PATIENTS AND METHODS: In an open, prospective, multicentre, epidemiological study (PRESTO) 3016 patients with the suspected diagnosis of "functional dyspepsia" (1228 males, 1788 females, mean age 50 +/- 15 years) were followed for 2 years by 983 physicians in private practice (general practitioners or specialists in internal medicine). Patients with proven gastro-oesophageal reflux or peptic ulcer were excluded. Treatment was at the discretion of the physician. Patients were seen after one month (if under treatment) and then at 6, 12, 18 and 24 months. In addition to personal data, (1) symptoms, diagnosis and treatment of the dyspepsia, (2) socioeconomic aspects and (3) any limitations and the quality of life of each patient were recorded in a standard manner. RESULTS: At the first interim analysis more than half the patients judged there situation to be one of "chronic stress" or having to cope with a stressful event; nearly 50% thought this to be the cause of the symptoms. Concomitant illnesses were present in 63% of patients. Oesophagogastroduodenoscopy with subsequent medication was performed in 20.6%, a trial of medication (usually drugs stimulating gastric motility) in 65%. No medication was initially given to 14.4% of patients. The most common symptoms were feeling of fullness (92.9%, epigastric pressure sensation (91.5%) and flatulence (87.4%). CONCLUSION: These preliminary results indicate that a large epidemiological study can be performed by general practitioners and has advantages over the more usual method of enquiry by telephone. Dyspepsia exerts an unusually high degree of stress and results in considerable demands on medical facilities.

Adolescent↗
PubMed1999

Prenatal diagnosis of congenital varicella syndrome and detection of varicella-zoster virus in the fetus: a case report.

Varicella syndrome (VS) specific malformations were sonographically seen at 22 weeks and 3 days of gestation. Fetal infection was demonstrated by detection of varicella-zoster virus (VZV) DNA in fetal blood and amniotic fluid by polymerase chain reaction (PCR). Following therapeutic abortion, fetal infection was confirmed by detection of VZV DNA in several fetal tissues and placenta, and by histopathological findings like miliary calcified necroses in fetal organs.

Abortion, Therapeutic↗
PubMed1999

Work-related respiratory disorders and farming characteristics among cattle farmers in Northern Germany.

BACKGROUND: The aim of this cross-sectional study was to investigate the prevalence of respiratory symptoms among Northern German farmers in relation to cattle farming characteristics. METHODS: 1735 farmers were visited on their farms and were interviewed using a standardized questionnaire on work-related respiratory symptoms and farming details. RESULTS: 84.6% of the farmers were cattle farmers. The prevalence of work-related respiratory symptoms was 40.3%. In a multiple logistic regression model adjusting for response rate, age, gender, and smoking habits, work-related respiratory symptoms were shown to be significantly associated with the ventilation of the cattle house (OR (ventilation via the wall): 0.57), feeding management (OR (feeding once daily): 0.53), and plant crop (OR: 0. 75). Farmers, living inland, showed a significant higher prevalence of work-related respiratory symptoms (OR: 1.34). CONCLUSIONS: The use of ventilation via the wall might be recommended for new cattle houses in regions with warm winters.

Age Factors↗
PubMed1999

[A re-analysis of the Blue Mountain eye study on the risk of cataracts from inhaled corticosteroids. A contribution to objectifying the discussion].

By a re-analysis of the Blue Mountains Eye Study of Cumming, Mitchell and Leeder, Published in N Engl J Med 1997 (337: 8-14), there is shown in the present article, that this study does not yield a contribution to clarify the question, whether the use of inhaled corticosteroids is associated with the development of cataracts. The conclusions of the study are revealed to lead to results contradicting known risk factors.

Administration, Inhalation↗
PubMed1999

Molecular basis, pharmacology and physiological role of cardiac K(ATP) channels.

ATP-dependent potassium (K(ATP)) channels exist in high density in the sarcolemmal membrane of heart muscle cells. Under normoxic conditions these channels are closed, but they become active when the intracellular ATP level falls. This leads to a shortening of the action potential duration, rendering the heart susceptible for life-threatening arrhythmias. Molecular biology has revealed that K(ATP) channels consist of heteromultimers of the inwardly rectifying channel Kir6.2 and the sulfonylurea receptor SUR. To date, three types of SURs were identified, representing the pancreatic (SUR1), the cardiac (SUR2A) and the smooth muscle (SUR2B) K(ATP) channel. In order to develop a novel therapeutic principle against ischemia-induced life-threatening arrhythmias leading to sudden cardiac death, the cardioselective K(ATP) channel blocker HMR 1883 was developed. This substance inhibits the sarcolemmal cardiac K(ATP) channel activated by the channel opener rilmakalim half-maximally at concentrations of 0.6-2.2 micromol/l, and substantially affects pancreatic K(ATP) channels at 9-50 times higher concentrations. K(ATP) channels of the coronary vascular system are only slightly blocked by HMR 1883 when activated by hypoxia. The substance was potently effective in preventing ventricular fibrillation in a conscious dog model, and thus can be considered to be a potential novel drug candidate against sudden cardiac death.

Adenosine Triphosphate↗
PubMed1999

[Reduction efficiencies of a biofilter and a bio-scrubber as bio-aerosols in two piggeries].

Biofilters and bioscrubbers are ultimate tools to control odour emissions from animal houses in pig and poultry production. Little is known about the efficiency of these devices to remove airborne particulate pollutants such as dust, microorganisms and endotoxins from the exhaust air of animal houses. Preliminary results of a one year field campaign in two piggeries show that the biofilter reduces the number of particles in the exhaust air by 79 to 96%. The efficiency of the bioscrubber was 22% only. The biofilter reduced the amount of mesophilic bacteria by 11% and 71%, respectively, the amount of thermotolerant fungi by 71%. The concentration of endotoxin and mesophilic fungi in the clean air after the bioscrubber was 3.8 times resp. 2.7 times higher than in the air of the piggery. The washing water which is regularly recirculated in both systems was highly contaminated with varying amounts of air contaminants. It seems that the quality of the washing water distinctly influences the reduction efficiency of both systems.

Air Pollution↗
PubMed1999

[Orienting endotoxin measurement in the atmosphere].

Airborne endotoxins are supposed to influence the respiratory health of animal and man in animal housings as well as at certain work places in agriculture. Little is known about the usual concentrations of endotoxin in the outdoor atmosphere. Therefore in a field study 30 air samples were taken, 22 samples in a rural region, and 8 in a more residential and industrial area. The samples were taken by impingement and filtration. The analysis was carried out by means of the chromogen-kinetic limulus amoebocyte lysate test (LAL-Test). The median concentration of all samples was 0.36 ng/m3. The highest median concentration of 0.49 ng/m3 was found in summer with a maximum value of 1.80 ng/m3 indicating large variations. In the other seasons the median concentrations (ng/m3) were distinctly lower (spring: 0.30, n = 11; autumn: 0.26, n = 5; winter: 0.19, n = 3). No significant differences were observed between farming and residential areas at this low concentration level. The concentrations of endotoxin found in this study were far below all threshold limits which are presently discussed for work places.

Air Pollutants↗
PubMed1999

["Microbial air pollutants--methods for detection of endotoxins, mycotoxins and MVOC"].

In the context of microbial emissions from composting facilities the methods for the detection and identification of the groups of substances released, i.e. endotoxins, mycotoxins and Microbial Volatile Compounds (MVOC) are discussed. With the aid of an overview of the different methods employed for the investigation of the single groups of compounds the current state of the art in this field is presented. In conclusion the enormous research needs, especially with regard to the mycotoxins and MVOC, are pointed out.

Air Microbiology↗