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Biomedical subjects

J Hartung

Publications and source records attributed to J Hartung.

At least 19 recordsLinked to original sources
PubMed1992

[Environmental hygiene tasks of the veterinarian in practice].

Apart from his direct tasks like treating diseased animals, preservation of animal health, recognition of mal-feeding and failures, recognition of unsuitable keeping systems and acknowledgement of animal welfare the veterinary practitioner can be the environmental-hygienic consultant of the farmer in following areas in particular: management and technique of feeding; management and technique of water supply; management and technique of air quality and ventilation; management and technique of manure handling and hygiene; cleaning and disinfection; deratting and pest control. The aim of these tasks is to diminish the risks/hazards for food products (food control act), the air (emission control act), surface water (law on the water household), ground water (waste control act, law on the water household) and vegetation and soil (waste control act, nature conservation act). Some examples will be given and comments are made on how to run a practice in an environmentally friendly way.

Air Pollution, Indoor↗
PubMed1992

[Emission and control of gases and odorous substances from animal housing and manure depots].

Agricultural animal production in increasingly regarded as a source of gases which are both aggravating and ecologically harmful. An overview of the origin, number and quantity of trace gases emitted from animal housing and from manure stores is presented and possible means of preventing or reducing them are discussed. Of the 136 trace gases in the air of animal houses, odorous substances, ammonia and methane are most relevant to the environment. The role played by the remaining gases is largely unknown. Quantitative information is available for 23 gases. The gases are emitted principally from freshly deposited and stored faeces, from animal feed and from the animals themselves. Future work should determine sources and quantities of the gases emitted from animal housing more precisely and should aim to investigate the potential of these gases to cause damage in man, animals and environment. Odorous substances have an effect on the area immediately surrounding the animal housing. They can lead to considerable aggravation in humans. For years, VDI1 guidelines (3471/72), which prescribe distances between residential buildings and animal housing, have been valuable in preventing odour problems of this kind. Coverings are suitable for outside stores. The intensity of the odour from animal housing waste air increases from cattle through to hens and pigs; it is also further affected by the type of housing, the age of the animals and the purpose for which they are being kept. Methods of cleaning waste air (scrubbers/biofilters) are available for problematic cases. The need for guidelines to limit emissions from individual outside manure stores (lagoons) is recognised. Total ammonia emissions from animal production in the Federal Republic of Germany (up to 1989) are estimated at approximately 300,000 to 600,000 t/year. There is a shortage of satisfactory and precise research on the extent of emissions, in particular on those from naturally ventilated housing. It is calculated that between 12 and 21 kg/ha of nitrogen a year enter the soil via the air, the average of which is higher than the average "critical loads" for most natural habitats. Ammonia has a direct effect on the trees in the area surrounding animal housing and is transported long distances through the air causing eutrophication and acidification of water and vegetation. This frequently results in changes in plant sociology. Reduction measures must begin with the housing and manure removal systems and with feeding and management.(ABSTRACT TRUNCATED AT 400 WORDS)

Air Pollution↗
PubMed1992

[Emissions of airborne substances from stalls of domestic animals].

There is concern on recent reports indicating an increase of respiratory affections in humans in areas with high livestock production. A survey is presented on airborne emissions from livestock buildings. About 136 gaseous compounds are analysed in animal house air of which 22 are quantified, only. The most environment-related compounds are ammonia and methane. It is assumed that German animal husbandry emits more than 350,000 t ammonia per year. The content of airborne microorganisms in livestock buildings is between some 100 and several 1000 per liter. The greatest part, more than 80%, are Staphylococcae and Streptococcae. Fungi, moulds and yeasts can form more than 1%, and coli-like bacteria about 0.5% of the total amount. Moulds like Penicillium, Aspergillus, Cladosporium and Alternaria were identified which are known to have allergic properties. The average concentrations of dust in animal barns vary between 0.5 and 20 mg/m3. The dust contains high amounts of protein and carries endotoxins which both have an allergic potential. Preliminary results show that the germ content of the surrounding air in areas with high animal densities seems to be distinctly higher than in non-livestock regions.

Agricultural Workers' Diseases↗
PubMed1991

Paraben preservatives do not increase intracranial pressure in cats.

It has been hypothesized recently that succinylcholine-associated increases in intracranial pressure (ICP) are caused by the paraben preservatives contained in multidose vials. We tested that hypothesis in a standard feline model to determine the effects on ICP of equal-volume injections of preservative-free succinylcholine, succinylcholine with preservatives from multi-dose vials that contain both propylparaben and methylparaben, these preservatives alone at five times the dose contained in the succinylcholine, and normal saline. The preservatives alone increased ICP by 0.08 +/- 0.08 mmHg (+/- standard error; not significant). Normal saline had no effect on ICP. Preservative-free succinylcholine and succinylcholine with preservatives increased ICP by 4.2 +/- 0.10 and 3.8 +/- 0.07 mmHg respectively (P less than 0.01 compared to the preservatives alone and normal saline). The 99% upper confidence limit for the increase in ICP induced by the preservatives alone was 0.42 mmHg. This result suggests that parabens do not cause or substantially augment the ICP increase associated with succinylcholine administration.

Animals↗
PubMed1990

Incidence and clinical relevance of QT prolongation caused by the new selective serotonin antagonist ketanserin. Multicenter Ketanserin Research Group.

Efficacy and safety of ketanserin was studied prospectively in a randomized and double-blind trial involving 221 patients treated for hypertension and/or coronary artery disease. Since ketanserin has been suggested to cause QTc prolongation, we investigated the incidence and severity of this effect, as well as its influence on the incidence of malignant ventricular arrhythmias during Holter monitoring. After a 1-week run-in-period, all patients were examined, measuring blood pressure, electrocardiogram (ECG) and 24-hour Holter ECG. Two thirds of the patients (n = 147) were then randomized to ketanserin, 1 week 20 mg b.i.d. followed by 3 weeks 40 mg b.i.d.; one third of the patients (n = 74) received placebo b.i.d. for 4 weeks. After 4 weeks of treatment, blood pressure, ECG and 24-hour Holter ECG were performed. In hypertensive patients, ketanserin resulted in a significant reduction of systolic (mean reduction: -17 +/- 2 mm Hg; p less than 0.0001) and diastolic blood pressure (-12 +/- 1 mm Hg; p less than 0.0001) as compared to baseline, and to the placebo group (p less than 0.005 for systolic and diastolic blood pressure). The QTc interval was prolonged with ketanserin (mean value: 400 to 418 ms; p less than 0.01) but not with placebo (399 vs. 402 ms). In the ketanserin group 30% of patients and in the placebo group 8% of patients had QTc prolongation greater than 30 ms (p less than 0.01). QTc was not prolonged to greater than 500 ms in any patient. During Holter monitoring 128/147 patients (ketanserin group) and 61/74 patients (placebo group) had ventricular premature beats; in 42 (ketanserin group) and 13 patients (placebo group) ventricular pairs and tachycardia were documented. Incidence and severity of the ventricular arrhythmias after 4 weeks of treatment were not different between the ketanserin and placebo groups. No sustained ventricular tachycardia occurred in any patient after ketanserin treatment. Thus, though ketanserin prolonged QTc in one third of the patients, the drug was not arrhythmogenic or antiarrhythmic.

Aged↗
PubMed1990

[Occupational problems of patients with manic-depressive disease].

The paper deals with the professional rehabilitation of cyclothymic patients with the aid of a semi-standardized interview of patient and superior direct at the place of employment. Half the patients had considerable professional problems consisting in requirements too low or too high and in lack of understanding on the past of the fellow workers. There is a connection between professional dissatisfaction and the numbers of recidives. Nearly all chiefs and associates wished more information about social manners towards the patient and about questions of his working capability and maximum stress. The results underline the necessity to include in the process of rehabilitation. Individual communication of the physician coworkers and with the patient is recommended as the most efficient form.

Adult↗
PubMed1989

[Determination of volatile fatty acids in the blood plasma of cattle before and after an infusion of propionate and butyrate].

Before and after infusion of propionate and butyrate the concentrations of volatile fatty acids (VFA) in the blood of heifers were determined by gas chromatography, in order to indicate activity and regulation of the carbohydrate metabolism. 14 heifers were loaded after food deprivation with intravenous infusions of propionate and butyrate. Concentrations of acetate, propionate, isobutyrate, butyrate, and valerate were measured in blood samples which were taken later on. The methods used for clearance and extraction as well as for gas chromatographic analysis are described. Retention times and blood concentrations are given for each VFA. Concentrations prior to infusion were for: acetate 10.14 +/- 2.51 microliters/ml; propionate 0.42 +/- 0.35 microliters/ml; iso-butyrate 3.72 +/- 1.37 microliters/ml; butyrate 3.44 +/- 0.68 microliters/ml blood plasma. The concentrations of the infused VFA showed a 100 (butyrate) to 1000 (propionate) fold increase followed by a subsequent decrease to the initial values. These investigations on the profile of VFA elucidated criteria of the energy metabolism.

Animals↗
PubMed1989

Incidence and clinical relevance of QT prolongation caused by the new selective serotonin antagonist ketanserin.

Efficacy and safety of ketanserin were studied prospectively in a randomized, double-blind trial involving 221 patients treated for hypertension or coronary artery disease, or both. Since ketanserin has been suggested to cause QTc prolongation, the incidence and severity of this effect were investigated, as was the incidence of malignant ventricular arrhythmias during Holter monitoring. After a 1-week run-in period, all patients were examined: blood pressure was measured and electrocardiograms and 24-hour Holter electrocardiograms were obtained. Two thirds of the patients (n = 147) were then randomized to receive ketanserin for 1 week (20 mg twice daily) followed by 3 weeks of 40 mg twice daily; one third of the patients (n = 74) received placebo (twice daily) for 4 weeks. After 4 weeks of treatment, blood pressure, electrocardiograms and 24-hour Holter electrocardiograms were repeated. In hypertensive patients, ketanserin significantly reduced systolic (mean reduction 17 +/- 2 mm Hg, p less than 0.0001) and diastolic blood pressure (12 +/- 1 mm Hg, p less than 0.0001) compared to baseline, and to the placebo group (p less than 0.005 for systolic and diastolic blood pressure). The QTc interval was prolonged with ketanserin (mean 400 to 418 ms, p less than 0.01) but not with placebo (399 vs 402 ms). In the ketanserin group 30% of patients and in the placebo group 8% of patients had QTc prolongation greater than 30 ms (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1988

Rate of induction of hypotension with trimetaphan modifies the intracranial pressure response in cats.

An infusion of 0.1% trimetaphan was administered to eight cats with artificially increased intracranial pressure (ICP) in order to decrease their mean arterial pressure (MAP) from 121 +/- 9.5 (SEM) to 58 +/- 4.6 mm Hg in less than 1 min. All cats developed an increase in intracranial pressure (ICP) (from 16 +/- 1.4 to 23 +/- 3.2 mm Hg) accompanied by a partial rebound in MAP. Eight additional cats received 0.1% trimetaphan to decrease their MAP from 128 +/- 13.4 to 52 +/- 8.1 mm Hg over more than 2 min. Four of these cats followed the same pattern, with ICP increases from 19 +/- 1.1 to 31 +/- 3.9 mm Hg, while in the other four ICP did not change. In nine of the 12 cats with an ICP increase, that increase was initiated before the partial MAP rebound. We conclude that trimetaphan causes clinically significant ICP increases in cats with increased ICP, that partial rebound in MAP frequently exacerbates these increases in ICP, and that rapid induction of hypotension tends to increase the frequency with which trimetaphan increases ICP.

Animals↗
PubMed1986

Effect of vecuronium on intracranial pressure, mean arterial pressure and heart rate in cats.

The effect of vecuronium on intracranial pressure (ICP) was investigated in six cats with normal and increased ICP. Cats were anaesthetized with pentobarbitone 33 mg kg-1 i.p. and acepromazine 0.6 mg kg-1 i.p., the trachea was intubated, and the lungs ventilated with nitrous oxide in oxygen. Mean arterial pressure (MAP), heart rate (HR), twitch response and ICP were recorded continuously. After the effect of vecuronium had been ascertained under the condition of normal ICP, and after full recovery of twitch response, pH-adjusted Ringer's lactate solution was infused to the cisterna magna until an ICP baseline of 26 +/- 2 mm Hg was established, and had stabilized. Vecuronium was administered again to determine its effect under the condition of increased ICP. Complete ablation of twitch response was obtained in 68 +/- 15 s with vecuronium 80 micrograms kg-1, and there was no significant change in ICP, MAP, HR or cerebral perfusion pressure (CPP) under either ICP condition.

Animals↗
PubMed1986

Hemodynamic effects of metocurine during isoflurane anesthesia.

Anesthesia was induced in 42 adults with thiopentone 3-7 mg/kg i.v. and maintained with isoflurane at a constant inspired concentration of 1-2%. After 30 min of hemodynamic stabilization with continuous muscle relaxation and an absence of surgical stimulation, each patient was randomly assigned to one of four metocurine dosage groups: I - control (n = 11); II - 0.2 mg/kg (n = 10); III - 0.3 mg/kg (n = 10); and IV - 0.4 mg/kg (n = 11). There were no significant hemodynamic changes in Groups I or II. In Groups III and IV mean arterial pressure (MAP) decreased 32% and 26% respectively, and systemic vascular resistance (SVR) decreased 42% and 36%, respectively (P less than 0.01). In Group IV, an increase of 24% in cardiac output was also significant (P less than 0.05). These results, especially in Group IV patients, stand in marked contrast to the lack of hemodynamic effects produced by metocurine during balanced anesthesia.

Adult↗
PubMed1986

[Estimating the biological effect of detrimental substances on E. coli with flow microcalorimetry. II. Studies using 3 antibiotics].

The influence of three antibiotics (Penicillin G, Oxtetracycline, Polymyxin B), which show different modes of action against gram-negative bacteria, is tested on the growth of liquid E. coli cultures in a flow microcalorimeter. The antibiotics were added during the logarithmic growth phase of the culture when a heat flux of 40 mu W/ml was approached. A supply vessel and a reaction vessel were used for establishing of the baseline and for performing the test, respectively. When testing Oxytetracycline and Polymyxin B the germ content in the nutrient broth was determined, additionally. Some measurements of the optical density of the nutrient broth were carried out parallel to the microcalorimetric investigation on the effect of Polymyxin B. As was to be expected, Penicillin G shows an influence on E. coli at concentrations of about 50 microgram/ml medium, only. An influence of Oxytetracycline on the heat production can be observed at concentrations between 0.3 and 0.6 microgram/ml. Polymyxin B acts on the power-time-curve at 0.025 microgram/ml. The minimum doses of Oxytetracycline and Polymyxin B found by the microcalorimetric technique are distinctly lower than those found by bacterial count and by measuring the optical density. Microcalorimetric results are achieved within 2 hours after adding the test substance to the bacterial culture. Flow microcalorimetry seems to be a promising tool for testing antibacterial drugs.

Calorimetry↗
PubMed1986

[Estimating the biological effect of detrimental substances on E. coli with flow microcalorimetry. I. Flow microcalorimetric test systems using microorganisms for antibiotics and chemicals (literature review)].

Flow microcalorimetry has found increasing use in many rather different sections of biological science in order to investigate metabolic reactions accompanied by heat production during the last few years. The microcalorimetric technique seems to be adequate for investigating liquid microbial cultures, particularly. Flow microcalorimetry is preferentially used for testing the effect of antibiotics and to a smaller extend the effect of other chemical compounds on bacteria and yeasts. The test substances are usually added during the logarithmic growth phase of the microbial culture or to cultures of nongrowing cells in glucose buffer solution. There are less reports on the addition of the test substances during the steady heat plateau of a respiring or grown through culture. The received power-time-curves are compared to "control curves" recorded under identical conditions without test substances. Difficulties and errors can be caused by external influences (e.g. changes in room temperature) or by latent processes within the detector and tubes of the calorimeter (e.g. mixing reactions, ad- and desorption, adhesion to and growth on the walls of the tubes, obstruction by clots of cells). A substantial advantage of the microcalorimetric technique as compared to traditional bioassays is the continuous monitoring of the effect, an additional advantage is its quick and simple performance. The sensitivity is comparable to other bioassays of antibiotics.

Anti-Bacterial Agents↗
PubMed1986

[Estimating the biological effect of detrimental substances on E. coli with flow microcalorimetry. III. Studies using m-cresol in glucose phosphate buffer].

Investigations are carried out to characterize the influence of the phenolic compound m-cresol on the heat production of glucose-respiring E. coli cells suspended in glucose phosphate buffer in a flow microcalorimeter according to the method of Perry et al. (5) The results are usually obtained within one hour. When testing m-cresol by this method thermic irritations occurred. A modified test procedure which largely avoids these troubles is described. The height (Q = heat flow) of the power-time-curves is evaluated 30 min and 60 min after the addition of the test substance. These values are compared to the values obtained from control-curves without any test substance. The 60 min-values seem less variable than the 30 min-values. The minimum effective m-cresol concentrations come to 7.50 mmol/l after 30 min and to 9.37 mmol/l after 60 min. The coefficients of variation are distinctly lower than +/- 10% at concentrations of less than 11.25 mmol/l. The coefficients of variation from 3 to 5 tests can extend +/- 20% both for the 30 min-values and the 60 min-values at higher concentrations (e.g. 15 mmol/l). Under the influence of increasing m-cresol concentrations the germ content in the solution and the heat flow decrease in a similar way. The results indicate that the used flow microcalorimetric technique is suitable to check the effect of a test substance on a test culture within only one hour's time. Possibly, the method can be helpful for pretesting disinfectants. The gathering of further experience with this system seems advisable.

Buffers↗