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Biomedical subjects

H Landmann

Publications and source records attributed to H Landmann.

At least 19 recordsLinked to original sources
PubMed1999

Biochemical characterization of a thrombin inhibitor from the bloodsucking bug Dipetalogaster maximus.

From the bloodsucking bug Dipetalogaster maximus, a protein with anticoagulant activity was isolated and biochemically characterized. The isolated protein, named dipetalogastin, possesses an average molecular mass of 11.8 kD. Its N-terminal sequence shows homology to rhodniin, a thrombin inhibitor isolated from the bug Rhodnius prolixus. The in vitro anticoagulant activity of dipetalogastin occurs via the inhibition of thrombin. The anticoagulant and thrombin inhibitory potency of dipetalogastin is comparable to that of recombinant hirudin. Its specific thrombin inhibitory activity is 9,300 antithrombin units/mg protein. Dipetalogastin forms only 1:1 molar complexes with thrombin. It is a tight-binding inhibitor of thrombin possessing a dissociation constant of 125 fM. It does not inhibit factor Xa or alpha-chymotrypsin and only weakly inhibits trypsin.

Amino Acid Sequence↗
PubMed1998

Electric toothbrush use. Attitudes and experience among dental practitioners in Germany.

PURPOSE: To evaluate the attitudes and experience of electric toothbrush use among dental practitioners in Germany. MATERIALS AND METHODS: A telephone survey of 399 dentists was conducted. RESULTS: Many dentists in Germany (41%) thought that between half and 70% of their patients do not clean their teeth correctly, and that this is the result of either poor brushing technique or insufficient brushing time coupled with insufficient visits to the dentist. Most dentists surveyed (61%) would recommend an electric toothbrush to their patients in order to improve oral hygiene control, and of these, 82% would recommend the Braun Oral-B Plaque Remover. When these dentists were asked if there had been any change in tooth and gum condition among those patients who switched from using a manual toothbrush to the Braun Oral-B Plaque Remover, 73% said that they had observed an improvement. None of the dentists interviewed had noted any deterioration. These views of German dentists are in agreement with laboratory and clinical studies that have shown an advantage for the Braun Oral-B Plaque Remover over a manual toothbrush. The results indicate that clinical trial results are a relevant way of assessing toothbrush performance, and that results may be extrapolated to normal home use.

Adult↗
PubMed1990

[Possibilities for increasing the elimination rate of Bonnecor].

Bonnecor is excreted in rats both via urine (3/4) and bile (1/4). It was the aim of this study to find out suitable methods for detoxication of a poisoning with this antiarrhytmic drug. In vivo methods intended to enhance the renal excretion of Bonnecor (forced diuresis, changes in urinary pH-values, peritoneal dialysis) are not qualified for therapeutically relevant increase of Bonnecor elimination. Relating to this Bonnecor is quite comparable with other antiarrhythmic drugs or dibenzazepine derivatives. The hemoperfusion can be recommended for the therapy of a Bonnecor overdosage as a propping up of symptomatic methods of intensive care, which are precendentally indicated. Therefore the therapy of a Bonnecor poisoning seems to be more promising compared to intoxications with other antiarrhythmics. Among the adsorbents tested, the resin Wofatit UH91 is most suitable to remove Bonnecor from the organism. If hemoperfusion equipments are not available, hemodialysis can also be used for acceleration of Bonnecor elimination, although its effectivity is only one third of that of hemoperfusion.

Animals↗
PubMed1989

[Recommendations for the therapy of atypical immunization courses and complications of BCG vaccination (Position: April, 1988)].

After introduction of the "direct" BCG-vaccination of the 16 years old youngsters in 1981 a small increase of atypical reactions and complications of the vaccination was probable. References and experiences about different therapy methods of these atypical reactions and complications gave rise to recommend uniform guide-lines for definition, diagnostic and therapy.

Adolescent↗
PubMed1986

[Cardiac effects of Cordemcura in vitro].

Cordemcura has a dose-dependent inotropic effect in the Langendorff-perfused guinea pig heart, in the isolated spontaneously active atria of the guinea pig as well as in the isolated electrically stimulated rabbit papillary muscle. Tachyphylaxy symptoms and arrhythmogene side-effects have not been observed. The dose-dependent coronardilatory effect caused by Cordemcura as observed at the isolated heart of a guinea-pig appears intensely. The positive inotropic effect by Cordemcura on an isolated electrically stimulated papillary muscle of a rabbit is linked with a significant decrease of the relaxation time t2, whereas there is no change in the time to peak force t1. Both mean velocity of force development S1 as well as the mean velocity of relaxation S2 are increased by Cordemcura.

Aminopyridines↗
PubMed1986

[The cardiovascular effect of Cordemcura on various animal models in vivo].

The cardiotonic activity of Cordemcura was investigated in anesthetized pigs, cats, and rats. Hemodynamic measurements were made under normal conditions and under drug-induced heart failure (hexobarbital, isoproterenol). Cordemcura caused significant positive inotropic effects with rapid onset and relatively short duration of action (0.2-3.2 mg/kg i. v.). In the pig dp/dtmax was increased by 31.4% (p less than 0.02) at 1.6 mg/kg, in the cat by 34.2% (p less than 0.05) at 0.5 mg/kg, and in the rat by 14.4% (ns) at 0.5 mg/kg. The inotropic response was associated with a significant reduction of total peripheral resistance (TPR) (pig: -21.4%, p less than 0.02; cat: -13.7), and relatively small changes in heart rate, cardiac output, and blood pressure. Under drug-induced heart failure there was no further increase in the cardiotonic activity of Cordemcura. The hemodynamic effects of Cordemcura were compared with the effects of dopamine (5-100 micrograms/kg i. v.) and ouabain (10-40 micrograms/kg i. v.).

Aminopyridines↗
PubMed1983

Effect of hexachlorobenzene on the activities of hepatic alcohol metabolizing enzymes.

To study the effect of experimental hepatic porphyria on the activities of hepatic alcohol metabolizing enzymes, female rats received a chow diet containing 0.05% hexachlorobenzene (HCB). After long-term HCB treatment for 60 days hepatic porphyria developed as evidenced by increased hepatic delta-aminolevulinic acid synthase activity and enhanced urinary excretion of delta-aminolevulinic acid, porphobilinogen and total porphyrins. Concomitantly, the activities of the hepatic microsomal ethanol oxidizing system (MEOS) were strikingly augmented by 213% (P less than 0.05) and 177% (P less than 0.01) when expressed per g of liver wet weight or per 100 g of body weight, respectively, whereas hepatic alcohol dehydrogenase activities remained virtually unchanged. Moreover, hepatic catalase showed only a trend for a slightly lower enzymic activity under these experimental conditions. The present data therefore show that experimental hepatic porphyria is associated with alterations of hepatic MEOS activities, which in turn may be a factor for the manifestation of human hepatic porphyrias in the course of alcohol consumption.

Animals↗