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Biomedical subjects

M Ulbrich

Publications and source records attributed to M Ulbrich.

At least 37 records · Page 2Linked to original sources
PubMed1986

[Urea utilization by growing lambs. 5. N-balance with half synthetic rations].

In experiment with 14-week-old lambs a combination of semisynthetic rations containing 1.2% or 0.7% resp. native crude protein an intraruminal infusion of urea clearly influenced the biologic processes in the rumen. The molar quotas of butyric and valeric acid in comparison with acetic were high. The lambs could cope with infused amounts of 0.67 g urea/kg body weight if they received the daily amount of 1.35 g/kg body weight in two parts. When more than 1.9 g/kg body weight were applied, feed intake decreased even though the daily amount was distributed over 4 doses. In 10 out of 16 lambs N retention was, in dependence on the urea amounts infused, higher than the N amount retained from native crude protein. The result indicates that urea is utilized by 14-week-old lambs. Growing energy and N intake had a positive influence on the N balance.

Animal Feed↗
PubMed1985

Determination of the number of exponential functions in pharmacokinetic models on the basis of concentration-time data by MUCOM1.

MUCOM1 is a new BASIC computer program which has been developed for automatically deriving the function terms of a pharmacokinetic model, operating on the best-approximation principle. The parameters of a poly-exponential model and their confidence intervals are computed from any available concentration-time data. The user neither needs to make an initial estimate of the number of terms, nor to find first approximations to the coefficients of the exponential functions. The approximation procedure is iterative, and is based on the RIP routine. MUCOM1 can be used on desk computers.

Computers↗
PubMed1982

[Clinical death-cap (Amanita phalloides) poisoning: prognostic factors and therapeutic measures. Analysis of 205 cases].

205 cases of clinical poisoning with the mushroom Amanita phalloides (death cap) in the period 1971 to 1980 have been studied retrospectively. The lethality was 22.4%. Age and latency between the ingestion of the mushrooms and the first clinical symptoms were of prognostic significance. The death rate was 51.3% in children below 10 years of age but only 16.5% in patients older than 10 years. The average latency period was 10.3 hours for the fatal cases and 12.6 hours for the surviving patients. Country, year, sex and time of hospitalization did not influence lethality. Prognostic relevance could also be attributed to the thromboplastin time (Quick). 84% of the patients with values below 10% died, while all patients with minimal values of more than 40% survived. The correlation with the outcome was weaker for the serum transaminases and nil for creatinine. The patients underwent on the average 8 therapeutic measures, but up to 20 therapies could be administered to the same patient. Eight of the 30 recorded treatments involved general support, 7 toxin elimination and the remaining 14 could be classified as pharmacotherapy. With the aid of multiple regression analysis taking into account age, latency period and the effects of all the other measures, penicillin and hyperbaric oxygenation were found to contribute independently to a higher survival rate. As compared to penicillin, the combination of penicillin with silybin was associated with still further increased survival. On the other hand, several measures, including exchange transfusion, thiocytic acid, sulfamethoxazole, plasma expanders, haemodialysis, treatment of the hemorrhagic diathesis and THAM/sodium bicarbonate were administered more often to patients who did not survive. For the remaining 20 therapeutic measures our analysis revealed neither a positive nor a negative correlation with the clinical outcome.

Adolescent↗
PubMed1981

[Activity of disaccharidases in growing sheep. 3. Fattening lambs 5 to 18 weeks of age].

Lambs at an age between 4 and 18 weeks were kept on perforated floor and received pelleted fattening feed for lambs as sole feed ad libitum. After the maltase activity in the duodenal mucosa resp. the contents of the duodenum at an age of 5 weeks was low, it amounted to 6.98 resp. 5.31 units per 0.1 g fresh weight at the end of the eighth week and in the duodenal mucosa it remained on this level to the age of 18 weeks. In the contents of the duodenum it decreased to 3.25 units in this period. The lactase activity in the duodenal mucosa resp. the contents of the duodenum decreased continuously from 30.5 resp. 25.7 to 13.6 resp. 14.8 units in the period investigated. The maltase activity in the pancreas remained constant in the period investigated (4 units per 0.1 g fresh weight). Saccharase activity could not be detected in both duodenal mucosa and contents of the duodenum.

Aging↗
PubMed1981

[Pancreatic lipase activity in growing sheep].

The development of the activity of pancreas lipase was observed at lambs reared with and without ewes from their birth to an age of four weeks and in a second series between five and 18 weeks. A statistically significant influence of the age on the level of activity of pancreas lipase could be observed. It was also influenced by the feeding regime, that is, the lambs reared without ewes which were fed restrictively with milk replacer showed a significantly higher activity of pancreas lipase on comparison with lambs reared with milk replacer ad libitum or those reared by ewes. 8-week-old lambs after a suckling period of four weeks and the subsequent sole feeding with pelleted mixed feed reached approximately the same activity of pancreas lipase as adult wethers.

Animal Feed↗
PubMed1980

[Investigations of the activity of disaccharidases in growing sheep. 1. Suckling lambs from birth to an age of 4 weeks].

Investigations of the course disaccharidases take in duodenum and pancreas were made with 20 suckling lambs (straw litter, supplementary feed from 3rd week onwards) at an age between 1 and 30 days. In the first week of the Lambs' lives the activity of lactase in the duodenal mucosa was highest. In the following weeks there was a slightly falling tendency. During the first four weeks of the lambs' lives there were no statistically significant differences concerning the maltase activities in the duodenal mucosa. At the beginning of the first and at the end of the fourth week of the lambs' lives the activity of lactase in the content of the duodenum was significantly lower than at the end of the first and up to the third week. The maltase in the contents of the duodenum showed a significantly higher activity at the end of the fourth week of life. Enzyme activities in the contents of the duodenum were significantly lower then those in the mucosa. After maltase activity in the pancreas had shown high values in the first two days of life, it decreased distinctly toward the end of the first week and than increased again up to the fourth week of life. In the period investigated, saccharase activity in the duodenal mucosa and in the contents of the duodenum could not be detected in any lamb.

Animals↗
PubMed1980

[Studies of the activity of disaccharides in growing sheep. 2. The influence of the feeding regime on the activity of disaccharidases in lambs up to the age of 4 weeks under various rearing conditions].

In two groups of 16 animals each lambs were fed restrictively resp. ad libitum withour ewes with a milk replacer up to the age of four weeks. Maltase activity in the contents of the duodenum and the pancreas homogenate increased with the increasing age of the lambs. The maltase activity of the restrictively fed lambs was higher. The maltase activity in the duodenal mucosa was not influenced by the age. Lactase activity in the duodenal mucosa showed a decreasing tendency up to the end of the four week of life; an increase of lactase activity in the contents of the duodenum could be ascertained up to the fourth week. In comparison with the suckling lambs reared by ewes (cf. 1.) the maltase activity in the duodenal mucosa of the lambs reared without ewes was lower and that in the contents of the duodenum was higher. Concerning lactase activity, there were not significant differences between the rearing and feeding regimens up to the age of three weeks. At the end of their fourth week of life the lactase activity in the suckling lambs was significantly lower than that in the lambs reared without ewes. The total maltase activity (= sum of the activities in the duodenal mucosa, the contents of the duodenum and in the pancreas) showed the highest values for the lambs reared without ewes and fed restrictively in the first three weeks of life. Saccharase activities in the duodenal mucosa or the contents of the duodenum could not be detected in any case.

Animals↗
PubMed1978

[Glucose content of lambs' blood. 1. Effect of administration of various carbohydrates].

After the oral administration of lactose or starch the blood sugar content was proofed as an indicator for the carbohydrate digestion and resorption of lambs at the age of 7 to 35 days. With increasing age the blood sugar level during fasting decreased, on an average of all lambs, from 65 to 50 mg glucose/100 ml blood. The administration of lactose resulted in an increase of the blood glucose content on all days. In contrast to this, the administration of starch only resulted in an increase of the blood glucose content of lambs that were at least three weeks old.

Aging↗
PubMed1978

[Glucose content of lambs' blood. 2. Blood glucose content during several hours after feeding].

During a 16-hour fasting period, the development of the blood glucose level of ewelessly reared lambs of 4 to 30 days of age was analysed. While the blood glucose level of lambs during their first week of life reacted with a considerable increase and a relatively quick decrease on the administration of milk substitutes, the course of this curve became smoother with increasing age. After a five-hour fasting period, the blood glucose level--after 4 days of the lambs' life--amounted to 101 mg, after 9 days to 96 mg, after 16 days to 91 mg, after 23 days to 64 mg, after 30 days to 71 mg per 100 ml blood. The significance of these results for the establishment of a suitable drinking technology is being discussed.

Aging↗
PubMed1976

Is the chemomechanical energy transformation reversible?

In glycerol-extracted insect fibrillar muscle suspended in ATP salt solution the incorporation of 32Pi into ATP was studied during the performance of positive or negative oscillatory work and under a variety of mechanical and ionic conditions. An increase in calcium ion concentration from 10(-8)--10(-5) M increased the incorporation rate in proportion to the increase in ATPase activity, mean tension and immediate stiffness, which is a measure of the extent of actin-myosin interaction. Sinusoidal stretches (at 1% Lo) performed at 5 Hz induced the fibres to perform optimal positive oscillatory work and it caused a doubling of the incorporation rate (ant ATPase activity). A decrease or increase of the frequency below or above the optimum of 5 Hz always decreased the power output as well as the incorporation rate which, however, was still noticeable even under conditions where work was done on the fibres. A similar frequency dependence was found when square-wave rather than sinusoidal stretches were applied and this effect could be related to the finding that the rate of stretch-induced incorporation was highest shortly after stretching and then declined to low values (after about 100 ms). These results suggest the formation of an energy-rich intermediate (actomyosin-ADP?) during the contraction process induced by stretching and this intermediate must be assumed to accumulate transiently after stretching.

Actomyosin↗
PubMed1975

The relevance of the osmolarity of the instillation fluid to the effectiveness and toxicity of drugs given by the intraduodenal route--solvent drug influence on the intestinal absorption of drugs.

The influence of movements of fluid from the blood into the bowel lumen (solvent drag) on absorption of drugs from the intestine was studied in conscious rats with surgically implanted duodenal tubes. The drugs were given to the rats by intraduodenal instillation either in isotonic saline or in solutions of mannite having twice or three times the osmotic pressure of the blood. The instillation of hypertonic mannite solutions leads to concentration-dependent exsorption of fluid. The drugs tested were atropine and azoniaspiro compound XVII (azoniaspiro[3alpha-benziloyloxy-nortropan-8,1'-pyrrolidine]-chloride), both of which are poorly absorbed, and phenobarbital and nicotine, both of which are well absorbed. The criteria used to assess the rate of entry of the drugs into the blood stream were "efficacy" and "toxicity". In the case of atropine, azoniaspiro compound XVII and nicotine mortality rate and survival time were measured, while in the case of phenobarbital the latent period between instillation of the solution and onset of the hypnotic effect was used. As the tonicity of the solution was raised, so the concentration-dependent "efficacy" and "toxicity" declined. This meant that the latent period after instillation of phenobarbital lengthened, while after instillation of atropine, azoniaspiro compound XVII and nicotine in solutions of increasing tonicity the mortality fell and survival was prolonged. The only exception to this generalization was found when azoniaspiro compound XVII was instilled in triple strength mannite solution. The reasons for this exception were not ascertained. From the results it is concluded that "solvent drag" is an important factor in the absorption of drugs from the intestine. A stream of fluid passing into the lumen interferes with absorption, and this is reflected in the diminished "efficacy" and "toxicity" of the drug. Another factor which may influence the absorption of the drugs tested is the fall in concentration resulting from the inflow of fluid into the bowel lumen. This tends to flatten the concentration gradient between the bowel lumen and the blood and therefore delays absorption.

Animals↗