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Biomedical subjects

J Voigt

Publications and source records attributed to J Voigt.

At least 109 records · Page 6Linked to original sources
PubMed1980

An unusual labeling index pattern of neutrophilic granulocytes after a 3H-thymidine flash labeling injection.

After flash labeling of neutrophilic granulocyte precursors with 3H-Thymidine in 3 hematologically normal subjects the postinjection labeling indices (LI) and the labeling intensities of venous blood neutrophils were determined. The LI pattern during 18 days after injection showed a reproducible triphasic course of the LI curves: (a) a low "plateau", (b) a steep rise, (c) an undulating decrease until the end of the experiments. On the basis of these findings a simultaneous "at random" and "first in--first out" release of neutrophils from the postmitotic bone marrow compartment to the blood was suggested. Moreover, the intravascular half-life time of the neutrophils was determined as 9.3 h, the corresponding mean circulation time was 14 h. From the undulating course of the LI curves and the labeling intensity curves the duration of the mean neutrophil precursor cell cycle time in the mitotic bone marrow compartment was estimated to range between 19 and 24 h.

Aged↗
PubMed1980

[Studies on the effect of phosphoric phenyl ester diamide as inhibitor of the rumen urease of dairy cows. 1. Influence on urea hydrolysis, ammonia release and fermentation in the rumen].

An amount of 0, 0.1, 0.5 and 1.0% (related to N) of phosphoric phenyl ester diamide (PPD) effective as urease blocking substance was applied to the surface of urea with oilbitumen and fed to cows with rumen cannulae over a period of 31 resp. 164 ... 167 days. (The ration essentially consisted of 4.5 kg dried roughage and 1.5 kg starch or 1.1 kg starch plus 0.4 kg sugar and contained 50 g urea). By treating the urea with PPD, the activity of urease, the hydrolysis rate of urea and the NH3-concentration in the rumen were significantly diminished 0.5 to 2 hours after feeding (alpha = 0.05). The effect of PPD was greatest in the first days and decreased with the advancing feeding period. In the variant with 0.5% PPD the examined parameters were significantly reduced after 142 to 164 days, too. This effect remained traceable in its diminished form even after the preparation was discontinued over a period of 35 days. The dynamics of the NH3-concentration was not altered by PPD after a longer feeding period. One can conclude that PPD inhibits the hydrolysis of urea but does not retard it. In conclusion one can say that, because of PPD, the toxicity of urea is lower without the utilisation of urea being better. Due to PPD the molar propionate level in volatile fatty acids decreases significantly and the acetate-propionate relation is expanded.

Ammonia↗
PubMed1980

[Studies on the effect of phosphoric phenyl ester diamide as inhibitor of the rumen urease of dairy cows. 2. The metabolism of 15N-urea].

Two lactating dairy cows supplied with rumen and duodenal re-entrance cannulae received with their rations containing 8.2% vegetable crude protein 180 g urea per day (I) or urea treated with the urease inhibitor phosphoric phenyl ester diamide (PPD, 1% of the N-quota). The cows, accustomed to urea, received the PPD-urea without adaptation (II) and after a 30-day adaptation (III) to PPD. On the first day of the experiment one half of the urea was given ruminally in its 15N-labelled form. 2 h after the isotope supplementation 62.5 and 24 mg NH3 and 6.58 and 21 mg urea/100 ml could be detected in the rumen juice of I to III. Within 72 h 16.6, 26.1 and 25.2% of the 15N-excess given (15N') passed the duodenum in TCA - soluble form and 31.2, 28.4 and 41.7% in TCA - precipitable form. 15.6, 24.4 and 21.5% of the total amount of 15N were excreted in urine and 4.5, 4.6 and 6.0% in the milk protein. The values for faeces were 14.4, 14,4 and 15.4%. The conclusion from these results and from the dynamics of the relative 15N' in the fractions of the rumen fluid is that with a limited inhibition of rumen urease by PPD as it develops after the adaptation, the utilisation of urea-N can be improved.

Animal Feed↗
PubMed1980

[Studies on the effect of phosphoric phenyl ester diamide as inhibitor of rumen urease in dairy cows. 3. Digestibility of the nutrients and bacterial protein synthesis].

Two lactating cows with duodenal re-entrance cannulae were fed with rations containing 180g urea (A) resp. urea modified with the urase inhibitor phosphoric phenyl ester diamide (PPD, 1 g PPD/100 g N). The cows, accustomed to urea, were not adapted to PPD (B) resp. had been adapted to PPD for 30 days (C). From A to C the digestibility of the organic matter in the stomachs amounted to 52, 47 and 52% and in the total tract to 78, 77 and 79%; the digestibility of crude cellulose amounted to 64, 50 and 62% resp. 69, 64 and 68% and that of starch to 91, 87 and 95% resp. 100% in each case. 71, 66 and 70% of the N were digested. The passage rate of N in the duodenum was 90, 102 and 106% of the N-intake. In the intestines 61, 68 and 76% of the N-intake were absorbed. The passage of bacteria-N in the duodenum was 67, 92 and 71% of the N-intake, that of the sum of NH3- and urea-N 6,8 and 8%. The conclusion is that, with unchanged digestibility of darbydrates, the N-supply of cows should be improved by the modification of urea with PPD after the adaptation of the cows. Cellulose fermentation is inhibited at the beginning of the adaptation to PPD.

Animal Feed↗
PubMed1980

Induction of plasma proangiotensin by steroid hormones in nephrectomized rats.

The response of plasma proangiotensin to various steroids was studied in bilaterally nephrectomized rats. In male animals, estradiol and testosterone increased the proangiotensin level up to 250% and 180% respectively. In female animals, both hormones lead to an increase of proangiotensin up to 220% of the controls, when given at optimal dose. The dose dependence on estradiol and testosterone was about the same in male rats, whereas in female animals the formation of proangiotensin was stimulated by much lower doses of estradiol as compared to testosterone. Adrenalectomy plus nephrectomy reduced the proangiotensin level to 20-30% of the value measured in animals nephrectomized only. Cortisol caused a rapid increase of plasma proangiotensin up to 1000% in adrenalectomized animals. Independent from the adrenal state, the amounts of cortisol necessary to induce proangiotensin were very low as compared to the dose response of other proteins, biosynthesis of which is regulated by cortisol. 21-Dehydrocortisol and aldosterone induced proangiotensin with the same efficiency as cortisol, whereas several other chemically related steroids were less active or inactive. Comparing the biological activity of the various steroids tested, it has to be concluded that the delta 4-ene-3-one structure of ring A, the 11 beta-OH group of ring C and the carbonyl group at C-20 of the ketol side-chain of cortisol are very important with respect to proangiotensin induction. The response of proangiotensin to cortisol, 21-dehydrocortisol and aldosterone could be inhibited by actinomocin D and cycloheximide, whereas the effects of estradiol and testosterone could be reversed by cycloheximide only.

Adrenalectomy↗
PubMed1978

[The effect of pelleting cereal straw with NaOH-addition on rumen fermentation in cows].

Experiments with rumen-fistulated dairy cows were performed to study the effect of NaOH-addition to cereal pellets. Compared to straw-concentrate rations in which the straw pellets were free of NaOH, cereal straw pellets containing 2.4 kg NaOH per 100 kg straw caused the rumenal pH to go up from 6.21 to 6.47, the cellulotlytic activity to rise by some 20%, and the passage turnover rate of dry matter to increase from 0,039 to 0,056. The concentrations of volatile fatty acids and the fermentation patterns were not influenced by the NaOH-content of the pellets. It is concluded that NaOH-addition during straw pelleting has a favourable effect on digestion in the bovine rumen.

Animals↗
PubMed1978

[Effect of the roughage sequence and concentrates in animal feed on carbohydrate digestion and bacterial protein synthesis in the rumen of dairy cows].

In experiments with dairy cows provided with rumen fistulas and duodenal re-entrant canulas, the order of feeding roughage (chopped forage and pellets) and concentrates (maize and barley) was found to influence carbohydrate digestion and bacterial protein synthesis in the rumen. Feeding the roughage 90 min. before the concentrate caused a wider C2:C3 ratio and a sustained course of the pH-value (greater than 6.5) than the ratio other way round. This favoured cellulose digestion in the rumen when feeding chopped roughage. When feeding roughage before concentrates, the nonbacterial N-proportion in the duodenal contents proved greater than in the reverse order and revealed the highest values for roughage fed in pelleted form. Feeding structured roughage as first component of the diet with concentrates given afterwards is, therefore, recommended for dairy cows.

Animal Feed↗
PubMed1978

Differences in inducibility by glucocorticoids of rat liver TO and TAT.

The modulation of tryptophan-oxygenase (TO) and tyrosine amino-transferase (TAT) in the rat liver after a single dose of hydrocortisone has been studied under various physiological conditions. Differences in the induction behavior of the two enzymes have been observed dependent on sex, age, amount of administered hormone, and presence or absence of the adrenals. Some of the results observed are the following: 1) TO reached its maximum induction level 3 h prior to TAT in normal male rats. This difference disappeared when adrenalectomized male rats or when female animals were tested. 2) The maximal induction values of both enzymes were 50--80% higher in adrenalectomized rats than in normal rats. This effect was independent of sex. 3) Higher doses of hydrocortisone were necessary for optimal induction of TO and TAT in normal than in adrenalectomized rats. 4) The minimum dose of hydrocortisone necessary for enzyme induction was significantly lower for TO than for TAT. 5) Actinomycin D caused a complete inhibition of the induction of TO and TAT when given simultaneously with the glucocorticoid. The inhibition was less complete the longer the interval between hormone and actinomycin D administration. The activity of TAT was suppressed to a larger extent than TO.

Adrenalectomy↗
PubMed1978

A simplified procedure for the purification of rat liver tyrosine aminotransferase.

Rat liver tyrosine aminotransferase was purified by chromatography on CM-Sephadex C-50 and DEAE-cellulose, (NH4)2SO4 fractionation and gel filtration on Sephadex G-200. Livers from 400 rats can be easily worked up by this procedure. Furthermore, this purification method has the advantage that hepatic tryptophan 2,3-dioxygenase, which, like tyrosine aminotransferase, is induced by glucocorticosteroids, can be purified from the same homogenate. Tyrosine aminotransferase purified by this method was shown to be specific for 2-oxoglutarate. Its subunits have a molecular weight of 45 000. The following "apparent" Michaelis constants were determined: L-tyrosine, 1.7 X 10(-3) M; 2-oxoglutarate, 5.9 X 10(-4) M; and pyridoxal 5'-phosphate, 2.1 X 10(-6) M. Tyrosine aminotransferase, depleted of its cofactors, binds 4 molecules of pyridoxal 5'-phosphate per 90 000 daltons with a KA of 2.2 X 10(5) M-1.

Animals↗
PubMed1977

[The effect of nutritional factors on the ruminal mucosa. 3. Condition of the mucosa after infusion of propionic acid, acetic acid and butyric acid].

Three non-lactating cows (Deutsches Schwarzbuntes Rind) with large ruminal fistulas were fed coarsely structured food. Within a trial period of 21 weeks infusion periods lasting 3 weeks alternated with equally long control periods (K). During the 3 infusion periods, 8.4 mMol of propionic acid (P), 14.8 mMol of acetic acid (E) and 4,5 mMol of butyric acid (B) per kg liveweight per day were administered through the fistula, the total quantity being 19 litres of solution. In the periods K1...4 the ruminal fluid contained an average of 68 Mol% E, 19 Mol% P, 13 Mol% B (maximum of 10.25 mMol free fatty acids (FFS) per 100 ml, minimum pH 6.4). In the course of the 10 hrs of infusion the Mol percentages of the particular acids infused increased to 27% P (maximum of 11.14 mMol FFS per 100 ml, minimum pH 6.4) or 79% E (maximum of 12,99 mMol FFS per 100 ml, minimum pH 6.0 (5.5)) or 25% B (maximum of 10.34 mMol FFS per 100 ml, minimum pH 6.0 (5.5)). Infusions of E and B had the most pronounced effect on the ruminal mucosa compared with the K periods. All fatty acids increased the process of keratinization and decreased the size of cell nuclei in the stratum basale. As specific effect, P infusions produced a thickening of the lamina propria; B infusions caused a thickening of the stratum germinativum (proliferative effect) while e infusions led to a drastically reduced thickness of villi (antiproliferative effect) due to reductions in the stratum germinativum and the lamina propria. According to the morphological situation high specific mucosal function is suggested during the B-period. The mucosa appeared quite normal during all periods investigated, with the exception of the E period, where hyperkeratosis, atrophy and necrosis were observed in 34% of the sample. Changes in the state of the mucosa appeared as early as 1 week after the beginning of the respective trial periods. Keratin consolidation was the primary cause for chemically induced keratosis. The development of hyperkeratosis seemed to be favoured if low pH values occurred in the rumen in combination with small amounts of metabolites inducing proliferation, both representing synergistic factors.

Acetates↗
PubMed1977

[The effect of physical shape of dried green feed and of various sources of starch on the site of digestion of carbohydrates and proteins and on the protein synthesis in the cow rumen].

The experiments were performed on cows with duodenal bridge fistulae to study the influence of the physical form of roughage (forage rye, chopped or pelleted) and of the starch source (barley or maize) on the place of carbohydrate digestion and on microbial protein synthesis. The organic matter digested in the stomachs contained more than 90% carbohydrates. Their digestibility was not found to be influenced by the physical form of the roughage and by the kind of starch source. Feeding pelleted roughage (30% crude fibre) as against chopped roughage increased the share of intestinal digestion of crude cellulose from 5 to 13%, whilst it remained relatively constant with starch (alpha-polymer bound glucose). Under high-starch feeding (some 2100 g/day) 710 g (maize) and 400 g (barley) of alpha-polmer bound glucose entered the duodenum. This corresponds to 29.6 and 17.6% of the starch consumed with maize and barley, respectively. When feeding the pelleted roughage (as compared to chopped roughage) a large amount of the non-bacterial N derived from feed protein and endogenous N (69.6 and 52.8 g/day) was available in the duodenum. Against this, the synthesis of bacterial N decreased (82.7 and 109.0 g/day). In the intestine, 107.1 and gN were absorbed daily from pelleted and chopped forage rye, respectively. In comparison with maize, barley was found to promote N availibility in the intestine (108.9 and 115.3 g N/day). Out of every 100 g of organic matter digested in the stomachs 28 and 21 g of bacterial protein were synthesized under chop and pellet feeding, respectively. Referred to the same amount, 6.6 g and 6.2 g N were found to enter the duodenum for chopped and pelleted roughage, respectively.

Animal Feed↗