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Biomedical subjects

J Voigt

Publications and source records attributed to J Voigt.

At least 91 records · Page 5Linked to original sources
PubMed1983

No correlation between binding of glucocorticosteroids to specific cytoplasmic proteins in vivo and enzyme induction in the rat liver.

Time- and dose-dependence of the formation of the different cytoplasmic hormone-protein complexes were studied in the rat liver after administration in vivo of [3H]cortisol or [3H]dexamethasone and compared with the stimulation of RNA polymerase B and induction of tyrosine aminotransferase and tryptophan oxygenase. No correlation could be found between formation in vivo of any of the five cytoplasmic hormone-protein complexes found and stimulation of RNA polymerase B activity or enzyme induction. After administration of [3H]cortisol, different metabolites of cortisol could be demonstrated in the isolated hormone-protein complexes. No time- or dose-dependence of the metabolite patterns could be observed after application of hormone doses that were in the range of the biologically active doses. After administration of [3H]dexamethasone, the same hormone-protein complexes were observed, which contained, however, the injected steroid instead of metabolites. These results seem to indicate that the cytoplasmic binding components present in the rat liver are enzymes involved in the metabolism of the glucocorticosteroids and that dexamethasone binds to these enzymes as a substrate analogue.

Animals↗
PubMed1983

[Effect of the content of plant crude protein in the ration on the utilization of urea by the milk cow. 1. Nitrogen digestibility and utilization of urea for bacterial protein synthesis in the rumen].

The utilisation of feed urea in the rumen was tested in 2 experiments with a total of 4 newly lactating dairy cows (13 . . . 15 and 17 . . . 19 kg resp. milk/animal and day) with rumen and duodenal re-entrant cannulae. With the energy supply remaining constant in each case, the rations in experiment A contained 8.7, 12.4 and 14.6 and those of experiment B 10.7, 13,7 and 17.1% crude plant protein in the dry matter. After the supplementation with 120 and 150 g resp. urea/animal and day there were 11.9, 15.7 and 17.8 (A) and 13.8, 16.7 and 20.2 (B) % resp. crude protein in the dry matter. The rations consisted of maize silage and a pelleted mixture of straw and concentrated feed (A) resp. maize silage, alfalfa hay and concentrated feed (B). They contained 10.3 . . . 10.6 (A) and 13.6 (B) kg dry matter with 5.6 . . . 6.0 (A) and 8.2 (B). With the increase of the crude protein level of the ration to 16.7 . . . 17.8, the absolute amount of non-NH3-N (NAN) in the duodenum increased as well. Between N-intake (g/d, x) and NAN-passage corrected by the amount of the endogenous quota (g/d, y) the relation y = 87.3 + 0.55 x (r = 0.80) could be established. NAN-passage (y) as related to N-intake decreased with the N-concentration in the dry matter of the ration (x) according to the equation y = 0.35 + 1.22x-1 (r = 0.57). 70, 62 and 61% (experiment A) and 55, 61 and 51% (experiment B) of the consumed amount of N were apparently absorbed in the intestines as NAN (without endogenous quota). The bacterial N-yield of the rumen (g, y), determined with diamino pimelic acid as microbe marker, was dependent on the consumed digestible organic matter (g, x) as follows: y = 67.3 + 0.021x (r = 0.69). There was no connection with the level of N-supply. The measuring results of the bacterial N-yield show that the utilisation rate of the urea-N decreased rapidly when there was more than 11 . . . 12% crude plant protein in the dry matter of the ration. For the tested ration type (570 . . . 600 EFUcattle/kg dry matter) the urea utilisation potential in the rumen for crude plant protein concentrations of 8.7, 10.7, 12.4, 13.4, 13.7, 14.6 and 17.1% in the dry matter was 13.0, 6.9, 4.1, 2.6, 1.3 and -9.6 g urea/kg dry matter.

Animal Feed↗
PubMed1983

[Protein digestion in ruminant calves].

The influence of various protein sources on N-digestion in forestomachs was investigated with 10 calves of the average age of 12 weeks which were supplied with duodenal re-entrant cannulae. 50 and 100% resp. of the soybean coarse meal-N in the standard ration (A) were replaced by urea-N (B) and lucerne-N (C). The crude protein concentration in the test rations varied between 17 and 19%. In the rumen the average NH3-concentration for rations A, B and C amounted to 7.7, 18.9 and 4.5 mg/100 ml resp., the pH-value was 6.4, 6.8 and 6.3 resp. 2.2, 2.4 and 2.7 g bacteria-N were synthesised per 100 g fermented organic matter. There were significant differences as regards the flow of non-ammonia N measured at the duodenum. Related to N-intake, values of 90, 79 and 104% were registered. 3.7, 3.7 and 4.3 g resp. non-NH3-N per 100 g digested organic matter were found at the duodenum. Under consideration of the high protein level of more than 17% (in the dry matter of the ration) required for this phase of growth, a partial replacement of soybean coarse meal-N by urea-N is of little effectivity. In contrast to this, the complete replacement of soybean protein by lucerne protein could guarantee the protein supply of 12-week-old calves.

Animals↗
PubMed1983

Brain weight of Danish children. A forensic material.

Medico-legal data are presented on 995 child deaths, 361 girls and 634 boys aged 0-18 years, whose brains were weighed at the time of autopsy using a standardized weighing technique (the brains were weighed before fixation, immediately after entire removal; the medulla oblongata was divided in the foramen magnum). From the results it appears that the brain weights are greater than those reported in a previously published series. This may be ascribed to a higher degree of oedema and a shorter duration of illness, or an absence of illness; another explanation may be related to a difference in origin. It should be remembered that post-mortem brain weights exceed the ante-mortem weights by up to 9%. The greater part of brain growth is completed by the end of the 2nd year of life, and thereafter the brain weight in girls is on the average a little lower than that in boys. No significant differences in brain weights are found in the various groups of causes of death; the brain weights in the group of sudden, unexpected infant deaths especially do not deviate from those in the other groups.

Adolescent↗
PubMed1983

[Guides to ergotism, a too little recognized complication of trauma].

The authors present two cases of ergotism in polytraumatised patients after prophylactic treatment with the combination preparation heparin-dihydroergotamine. Attention is drawn to the severity of the possible complications. It seems that it would be quite appropriate to adopt a critical attitude towards routine therapy with combination preparations containing ergotamine for the prevention of thromboembolism in polytraumatised patients.

Adolescent↗
PubMed1982

Purification and characterization of two forms of rat plasma proangiotensin.

Two forms of rat plasma proangiotensin were purified by (NH4)2SO4 fractionation, chromatography on DEAE-cellulose at pH 6.5, DEAE-Sepharose at pH 8.9, Sephadex G-150, hydroxyapatite and hexyl-agarose. Both forms were finally separated by affinity chromatography on concanavalin-A--Sepharose. Presence or absence of carbohydrate side chains seems to be the only difference between these forms of proangiotensin. Both proteins consist of single polypeptide chains having apparent molecular weights of 52000 and 55000 and isoelectric points around 4.7 and 4.4, respectively. No significant difference between the proteins could be observed with respect to the amino-terminal amino acid sequence which was found to be the same (H2N-Asp-Arg-Val) as for angiotensin I and II. Furthermore, extensive digestion with renin, releasing the decapeptide angiotensin I, did not significantly reduce the molecular weights of both polypeptides. It can therefore be concluded that the angiotensin I peptide is located at the amino terminus of the prohormone. Kinetic constants measured for the release of angiotensin I by renin were found to be Km = 5.0 microM proangiotensin and V = 270 nmol of angiotensin I h-1 unit renin-1 for the concanavalin-A-binding form and Km = 5.6 microM proangiotensin and V = 250 nmol angiotensin I h-1 unit renin-1 for the prohormone which did not bind to concanavalin-A--Sepharose. The form of proangiotensin not bound to concanavalin-A--Sepharose was found to be more thermally labile (tm of 59.0 degrees C) than the form binding to concanavalin A (tm of 61.5 degrees C, where tm = temperature at which 50% reactivity is lost).

Amino Acid Sequence↗
PubMed1982

Influence of the adrenal gland on uptake, retention, metabolism and binding to cytoplasmic proteins of [3H] cortisol by the rat liver.

The effects of adrenalectomy on uptake, retention, metabolism and in vivo binding to cytoplasmic proteins of [3H]cortisol in the rat liver were studied. The same amount of radioactivity was accumulated in the different subcellular fractions of liver of adrenalectomized and normal male rats 30 min after intraperitoneal injection of a biologically active dose of [3H]-cortisol. However, the accumulated radioactivity, with exception of microsomes, was lost more rapidly from all subcellular fractions of normal than of adrenalectomized animals. The pattern of non-conjugated metabolites present in the cytosol also showed differences between adrenalectomized and normal rats. Analysis of the hormone-protein complexes formed in vivo after application of a biologically active dose of [3H]cortisol, revealed that the amount of hormone-protein complexes was lower in cytosol of adrenalectomized animals than in normal rats. Analysis of the individual hormone-protein complexes formed in vivo revealed that DE-1b, DE-2 and DE-3 were less prominent in adrenalectomized than in normal rats, whereas the level of DE-1 was found to be essentially independent from the adrenal state.

Adrenal Glands↗
PubMed1981

Absence of hydrocortisone from cytoplasmic hormone-protein complexes formed in vivo after administration of biologically active doses of [3H]hydrocortisone.

After administration of [3H]hydrocortisone to adrenalectomized rats, hormone-protein complexes were isolated from liver cytosol by DEAE-cellulose chromatography. After application of biologically active and inactive doses of hydrocortisone five binding components were detected eluting at the same salt concentrations as the hormone-protein complexes observed after incubation of cytosol with [3H]hydrocortisone in vitro. The isolated hormone-protein fractions were acidified and extracted with ethylacetate and the steroids were analyzed by thin-layer chromatography. No significant amount of hydrocortisone could be detected in any of the complexes formed in vivo 5-60 min after administration of biologically active doses of hydrocortisone. 3 xi, 11 beta, 17 alpha, 20 xi, 21-Pentahydroxypregnane, steroidal carboxy acids, glucuronides and a very polar conjugate of hydrocortisone were found in the different fractions. After an in vivo dose of hydrocortisone of about 1/5000th of the minimal dose required for enzyme induction, hydrocortisone could be found in all the cytoplasmic hormone-protein complexes formed. In contrast to the cytoplasmic hormone-protein complexes, hydrocortisone could be readily demonstrated in nuclei isolated after the administration of biologically active doses of hormone, although acid metabolites were found to represent the main part of the radioactive compounds present in the nuclei. These acid metabolites were located in the nuclear envelope. These results seem to contradict the generally accepted theory that hydrocortisone induces biosynthesis of proteins via a cytoplasmic hydrocortisone-receptor complex: after administration of biologically active doses of hydrocortisone, no such complex could be detected.

Adrenalectomy↗
PubMed1981

[Isobutylidene diurea as an NPN source for ruminants. 1. Rumen fermentation, digestibility of the nutrients and microbial protein synthesis in dairy cows].

In 3 experiments 2 lactating dairy cows received a mixed ration consisting of 10 kg maize silage, 2.5 kg hay, 2.0 kg barley, 1 kg dried sugar-beet pulp, 1.5 kg maize starch, 0.5 kg sugar, 0.2 kg of a mineral-vitamin mixture and 0.08 kg non-protein nitrogen (NPN) per animal and day. The ration contained 8.3 kg dry matter, 5.1 kEFU cattle and 1.18 kg crude protein, 0.5 kg of which from NPN, and was given in equal shares twice a day. Urea (I) or isobutylidene diurea (IBDU), to which the animals were not adapted (II) resp. adapted (III), were the sources of NPN.IBDU proved to a be a very slow source of NH3 in the rumen. 2 hours after the intake of NPN 48 . . . 75, 5 . . . 9 and 5 . . . 12 mg NH3/100 ml could be detected from I to III. Up to the third hour the concentration of IBDU and urea increased in III, which is due to the slow distribution of the slowly soluble IBDU in the fluid digestaphasis. 12 hours after the feeding the level of IBDU and urea in III still amounted to 25 mg urea/100 ml, in I to 1 mg/100 ml only. In the first 3 hours after supplying the NPN the pH-value of I was more than 1 unit higher than that of II and III. There were no significant differences in the fermentation models between the variants, the concentration of volatile fatty acids was 12.6, 12.3 and 11.1 mmol/100 ml. In the stomachs the digestibility of the organic matter was 52, 51 and 54%, that of the crude cellulose 64, 62 and 66% and that of the starch 91, 93 and 98%. At the duodenum the passage rate of N was 87 . . . 93, 107 . . . 126 and 96 . . . 130% of the N-intake, that of NH3-N 6, 43 and 22 g per day and that of bacteria-N 61 . . . 76, 78 . . . 100 and 76 . . . 96% of the N-intake. 2.3 . . . 2.8, 2.6 . . . 3.2 and 2.1 . . . 3.1 g bacteria-N were formed per 100 g dry matter fermented in the rumen. In the intestines 55 . . . 61, 57 . . . 64 and 48 . . . 71% of the feed-N were available as non-NH3-N. The conclusion is that in comparison to urea and concerning IBDU, the rumeno-hepatic circulation plays a definitely bigger role for the N-supply of the rumen microbes and that the possibility of the better N-utilisation can be derived from that.

Animals↗
PubMed1981

[Isobutylidene urea as NPN source for ruminants. 2. Digestion of 15N-labeled isobutylidene urea in lactating dairy cows].

Two cows with rumen cannulae and duodenal re-entrance cannulae received in the first experiment (Ia and IIa) a conventional diet on the basis of a mixture of maize silage, hay and concentrated feed and after a three-week adaptation to isobutylidene diurea (IBDU)--276 g per animal and day--138 g IBDU with 3.865 mg 15N-excess as a single supplementation to their first meal. In the second experiment (IIa and IIb) after a 6-week break the same cows served a repeated experiment without IBDU adaptation. Irrespective of the adaptation, a re-increase of the 15N-labelling in the TCA-soluble N in the rumen could be proved between the 6th and the 8th hour after the intake of the isotopes, which resulted from the backflow of 15N to the rumen. In the duodenal digesta the maximum labelling of the TCA--soluble N-fraction appeared 12 hours after the intake of the isotopes. At that moment a labelling plateau began in the protein fraction, which lasted to the 36th hour. On an average of all 4 cows approximately 30% of the 15N taken in the TCA-precipitable fraction and 55 and 60% in the TCA-soluble fraction had passed the duodenum up to the 72nd hour after the beginning of the experiment. Up to the 72nd hour after the beginning of the experiment, approximately 15% were excreted in urine, approximately 16% in feces and approximately 7% in the milk. This shows that roughly one half of the 90% 15N-amount measured at its passage in the re-entrance cannula (related to the intake) was metabolised in the rumen at least twice, resp. after the first passage through the duodenum it originated from the intermediary metabolism (e.g. as amino acids and their incorporation as digestion secretions). Negative correlations could be ascertained between the pH-value of the rumen fluid and the 15N incorporation in the rumen proteins as well as 15N-excretion through the TCA-soluble and -precipitable quota of feces. An adaptation to IBDU is obviously not necessary.

Animal Feed↗
PubMed1981

[Effect of crude protein on fertility and urea content of the body fluids of high-yielding cows].

A total of 36 high-yielding cows were -- post partum -- divided into two analogous groups. During the following 90 days they received rations containing 14.5 resp. 19.1% crude protein. The daily milk yield ranged between 27.8 and 28.8 kg resp. 29.4 and 31 kg FCM. The urea content of the milk reached 16.8 and 33.8, that in the blood plasma 19.7 and 38.8 mg/100 ml. The correlation between urea content in milk and blood serum was r = 0.94, between milk and urea content in urine r = 0.69. The period between gravidities of 82 days (14.4%) in contrast to 127 days (19.1%) was distinctly improved, and so was the insemination index (2.0 resp. 2.8). We consider 14.5% crude protein meet the requirement for yields of 30 kg milk, which is approximately 15% below the norm.

Animals↗
PubMed1980

Induction of tryptophan oxygenase and tyrosine aminotransferase by metabolites of hydrocortisone.

Metabolites of hydrocortisone were isolated from rat liver on a preparative scale, fractionated by column chromatography on Sephadex Lh-20 and silica gel and tested for biological activity. Apart from the well known neutral metabolites, steroid glucuronides and sulfates, we obtained metabolite fractions containing non-conjugated steroidal carboxy acids and acid metabolites of unknown structure. One of these fractions induced tyrosine aminotransferase (EC 2.6.1.5) in adrenalectomized female rats but not tryptophan oxygenase (EC 1.13.11.11), whereas another one mainly increased activity of tryptophan oxygenase. The doses necessary to significantly induce both enzymes were much lower in case of these metabolites than in the case of hydrocortisone itself. The active fractions eluting from silica gel column were analyzed by thin-layer chromatography in two different solvent systems. Absence of hydrocortisone in these fractions could be clearly demonstrated. Furthermore, the active fractions eluting from the silica gel column were characterized by treatment with an extract from Helix pomatia and/or diazomethane and subsequent analysis by thin-layer chromatography. We conclude, considering the biological activity of some synthesized derivatives of hydrocortisone, that the biologically active components are acid metabolites of hydrocortisone which are not identical to any of the known metabolites.

Adrenal Glands↗