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Biomedical subjects

M Herrmann

Publications and source records attributed to M Herrmann.

At least 271 records · Page 15Linked to original sources
PubMed1981

[Interrelationships between pars intermedia and posterior pituitary with regard to corticotrophic and thyrotrophic partial function in rats].

Functional interrelationships between the pars intermedia and posterior pituitary were proved under different experimental conditions. After stimulation of the thyrotropical axis of rats by an acute intraperitoneal application of 50 microgram TRH/rat the nuclear sizes of the thyroid follicular and the anterior pituitary thyrotropical cells increased according to a monophasic time curve with maximal amplitude at the time of 30 minutes. Interestingly, the nuclear sizes of the posterior pituitary cells were also enhanced. Under the same experimental conditions the nuclear areas of the cells of the external layer of the adrenal zona fasciculata decreased as did the nuclei of the pars intermedia cells (without regard to the cell type or localization of the cells in the intermediate lobe). Stimulation of the adrenocorticotropical axis by an acute injection of 0.2 ml isotonic saline solution/rat was followed by a time-dependent increase of nuclear sizes of the fasciculata cells and pars intermedia, whereas the nuclear volumes of the thyroid follicular cells, the anterior pituitary thyrotropical cells and the posterior pituitary cells decreased. Thus the functional state of the pars intermedia was in accordance with that of the adrenal cortex. Also the posterior pituitary cells responded to stimuli applied to the thyrotropical axis at the same degree as the thyrotropic organs themselves. Between the nuclear sizes of the pars intermedia and posterior pituitary we established the same inverse functional relationships as between the adrenal cortex and the thyroid gland.

Adrenal Cortex↗
PubMed1980

[Morphology of the pig liver after Fluosol infusion].

About 500 ml of blood of young pigs weighing 20...25 mg were replaced by artificial blood substitute "Fluosol-DA 20%". Eight days after exchange the animals were sacrificed and the liver was fixed for electron microscopic investigation. The morphological studies showed Fluosol-droplets in the cytoplasma of parenchymal cells near the bile canaliculi and in the sinusoidal lining cells. Most Fluosol-droplets were found in the endothelial and Kupffer cells which both seemed to be completely filled. The ballooning of these cells often resulted in a partial occlusion of the sinusoids. The sinusoidal lining cells were saturated by Fluosol droplets to such an extent that they seemed to be unable to phagocytize further.

Animals↗
PubMed1980

[Oscillation in the energy metabolism of the insect host and symbiont. II. Analysis of possible endogenous rhythms in both systems].

The insect group which includes cicadas harbours intracellular bacterial symbionts (endocytobionts) which are passed on from generation to generation in the form of a symbiont ball inserted between the egg membrane and the rear pole of the egg cell. Bioluminiescence methods can be used to measure the oscillations in ATP, ADP and AMP levels in egg systems which have been separated into a host and a symbiont egg part (Euscelidius variegatus), and which are exposed to constant light at 26 degrees C, 70% relative humidity and 7,000 lux. Comparison of the energy charge curves of host and symbiont egg parts suggests an antagonistic relationship at high frequencies, and a synchronous relationship at low frequencies (length of period 23--27 h). These relationship can, however, only be reproduced as phase-shifted oscillation patterns. The most appearing interpretation of this data is that the oscillation pattern represent a basic circadian rhythm, and that the phase-shift is produced by an underlying endogenous yearly rhythm. This, however, indicates a regulative coupling between the energy metabolism of the host egg and that of the prokaryotic egg-symbiont. Regulated correlations in the energy charge were also observed between the mitochondria and the cytoplasms/nucleus system. It follows that endocytobiosis can serve as an experimental model for the biochemical analysis of eucyte systems.

Adenine Nucleotides↗
PubMed1979

About the relationship between adrenal cortex and thyroid gland of rats (shift-effect).

In the present paper the inverse quantitative relationships between the thyrotropical system and the adrenocorticotropical system should be demonstrated under different acute experimental conditions by caryometric investigations. In stimulating the adrenal cortex system by a single injection of 0.2 ml saline solution (0.9%)/rat the nuclear sizes of the thyroid follicular cells decreased timedependend whereas the nuclear parameters of adrenal cortex fasciculata cells increased. In inhibiting the adrenal cortex system and stimulating the thyrotropical system by a single injection of 50 micrograms TRH/rat the thyroid nuclear values increased timedependend biphasically and the adrenal cortex parameters decreased correspondingly. The inverse relationships of the histometric parameters of both endocrine organs proved to be highly significant (p less than or equal to 0.001). The mathematical relations could be expressed by the straight line y = 63.76 - 1.05 x.

Adrenal Cortex↗
PubMed1979

[Oscillations in the energy metabolism of the host and symbiont of a cicada. I. Analysis of possible metabolic and physiologic correlations of both systems].

The insect group which includes cicadas harbours intracellular bacterial symbionts which are passed on from generation to generation in the form of a 'symbiont ball' inserted between the egg membrane and the rear pole of the egg cell. Bioluminiscence methods can be used to measure the oscillations in ATP, ADP and AMP levels in egg systems which have been separated into a host and a symbiont part (Euscelidius variegatus, Euscelis incisus), and which are exposed to constant light or light-dark variations under otherwise constant conditions (26 degrees C, 70% relative humidity, 7000 lux). The energy charge can be calculated from the ATP, ADP and AMP concentrations. Comparisons of such curves suggest an 'antagonistic' relationship in the energy metabolism of the host and symbiont parts of the egg. The minima of oscilaltions in the host's energy metabolism generally occur at the same time as the maxima in the endocytobionts energy metabolism. Antagonistic correlations between the nucleus/cytoplasm and mitochondria/plastids were also observed in the eucyte system. Analogies between the two systems can be explained satisfactorily by the endosymbiont theory of the origin of eucytes. It follows that insect endocytobioses can serve as an experimental model for the biochemical analysis of the eucyte system.

Adenine Nucleotides↗
PubMed1978

Inhibitory effect of tyramine-induced release of catecholamines on renin secretion.

The effect of the indirect sympathomimetic agent tyramine on the isoprenaline-induced increase in plasma renin concentration was investigated in conscious rats. Tyramine caused a dose-dependent decrease in the isoprenaline-induced elevation of plasma renin concentration. Pretreatment of the rats with reserpine abolished this effect of tyramine, indicating that tyramine released catecholamines which acted on the inhibitory adrenoceptors. Pretreatment with phenoxybenzamine, an alpha-adrenoceptor antagonist, also abolished the inhibitory effect of tyramine on renin release, indicating that alpha-adrenoceptors mediated the observed inhibition of renin release. In rats with chronically denervated kidneys tyramine did not inhibit renin release. It is concluded that catecholamines which are released from renal sympathetic nerve endings can suppress renin release by activating alpha-adrenoceptors.

Animals↗
PubMed1978

[Bacteriostatic behavior of the tissue adhesive Fimomed (n-butyl-alpha-cyanoacrylate].

The tissue adhesive Fimomed (made in GDR), which is supplied in a non-sterilised form, was tested for its bacteriostatic behaviour. No such behaviour was found for Gram-negative bacteria, so that in view of the typical microorganisme occurring in hospitals sterilisation of the adhesive by means of gamma rays or an aseptic filling by the manufacturers is suggested.

Bacteria↗
PubMed1977

[Suprapubic puncture of the bladder within the scope of bacteriological urine diagnosis in gynecological-obstetrical patients].

Technology, evidence as well as indications and contraindications of the suprapubic bladder puncture are shown from a gynecological and obstetrical point of view. The bacteriological result of urine obtained by puncture from 476 women has been compared with that obtained subsequently by midstream voiding. It was proved statistically that bladder puncture yielded less positive results than midstream voiding. In 8.4 per cent of the cases there was a positive voided midstream urine culture with pathogenic bacteria while the samples of bladder puncture were sterile, thus 29.2 per cent of the positive voided midstream urine cultures proving to be "false-positive" concerning an infection of the bladder and of the upper urinary tract. The frequency of pathogenic bacteria, "apathogenic" bacteria and mixed cultures is given, divided into conforming and nonconforming culture results of puncture and midstream urines.

Bacteriuria↗
PubMed1977

[On the pharmacology of piprozoline (author's transl)].

Ethyl (Z)-(3-ethyl-4-oxo-5-piperidino-thiazolidin-2-ylidene)- acetate (piprozoline, Gö 919, Problin) is a new potent choleretic which can be classified as a true cholepoietic agent. Accordingly the substance increases bile fluid and solid content as well. A dose-dependent choleretic effect could be shown in all species investigated. The choleretic effect of piprozoline is long-lasting and superior to that of the other choleretics compared with. There was a significant inhibition of experimentally induced liver damage in animals by piprozoline given prophylactically. Our experiments did not reveal any pharmacological properties interfering with the use of piprozoline as a choleretic.

Amanitins↗
PubMed1977

[Method for direct measurement of choleresis and secretory function of the exocrine pancreaas demonstrated by sodium dehydrocholate and secretin (author's transl)].

A method has been described that enables to check secretory processes in animals directly. This has been demonstrated in dog exocrine pancreas stimulated by secretin and on bile secretion induced by sodium dehydrocholate. The design of this method permits to run experiments on pancreas and choleresis separately as well as simultaneously. The directly recorded absorption curves are in good agreement with the data obtained from the collected fractions. Based on the optical density curves, it is possible to determine the contents of the fractions more directly and more specifically. It is also possible to study kinetic problems and time dependent reactions by using this method and this design.

Animals↗