Search PubMed⌕ Search

Biomedical subjects

U Keller

Publications and source records attributed to U Keller.

At least 325 records · Page 18Linked to original sources
PubMed1977

[The importance of heterologous implants in cardiovascular surgery (author's transl)].

The importance of heterologous transplants in the substitution of heart valves in cardiac surgery and the substitution or bypassing of displaced arteries of the thigh in vascular surgery is discussed with reference to some results and developmental considerations. In addition to the alloplastic valve material, heterologous bioprosthesis from glutaraldehyde-fixed pig's valves has proved useful to an increasing extent for the substitution of diseased and functionally impaired heart valves. The results of followup examinations show equally favorable results in comparison with the alloplastic prosthesis. In vascular surgery, the calf collagen prosthesis has proved a real alternative to the alloplastic Dacron prosthesis at the level of the thigh.

Animals↗
PubMed1977

[Cis-polyenecarboxylic acids and other fat-metabolism parameters in carcinoma of the digestive tract].

In 24 patients with a neoplasm of the gastro-intestinal tract cis-poly-unsaturated fatty acids were determined in the serum together with cholesterol, free and total glycerin as well as with neutral fats. In the cis-polyene acids a statistically ascertained diminution occurs, all the other parameters remain practically unchanged. To what extent very low values of poly-unsaturated fatty acids are to be connected must still be tested. It cannot be judged about a correlation of cancer and values of neutral fats, since the breadth of the normal area of this parameter of fatty metabolism is very large and the number of test persons is relatively small. The content of cholesterol of patients with cancer is prettily constant and deviated only little from the normal.

Adult↗
PubMed1977

Evidence for an important role of glucagon in the regulation of hepatic glucose production in normal man.

To investigate the role of glucagon in regulating hepatic glucose production in man, selective glucagon deficiency was produced in four normal men by infusing somatostatin (0.9 mg/h) and regular pork insulin (150-muU/kg per min) for 2 h. Exogenous glucose was infused to maintain euglycemia. Arterial plasma glucagon levels fell by greater than 50% whereas plasma insulin levels were maintained in the range of 10-14 muU/ml. In response to these hormonal changes, net splanchnic glucose production (NSGP) fell by 75% and remained suppressed for the duration of the study. In contrast, when somatostatin alone was administered to normal men, resulting in combined insulin and glucagon deficiency (euglycemia again maintained), NSGP fell markedly but only transiently, reaching its nadir at 15 min. Thereafter, NSGP rose progressively, reaching the basal rate at 105 min. These data indicate that the induction of selective glucagon deficiency in man (with basal insulin levels maintained) is associated with a marked and sustained fall in hepatic glucose production. We conclude, therefore, that basal glucagon plays an important role in the maintenance of basal hepatic glucose production in normal man.

Adolescent↗
PubMed1976

The role of insulin and glucagon in the regulation of basal glucose production in the postabsorptive dog.

The aim of the present experiments was to determine the role of insulin and glucagon in the regulation of basal glucose production in dogs fasted overnight. A deficiency of either or both pancreatic hormones was achieved by infusin somatostatin (1 mug/kg per min), a potent inhibitor of both insulin and glucagon secretion, alone or in combination with intraportal replacement infusions of either pancreatic hormone. Infusion of somatostatin alone caused the arterial levels of insulin and glucagon to drop rapidly by 72+/-6 and 81+/-8%, respectively. Intraportal infusion of insulin and glucagon at rates of 400 muU/kg per min and 1 ng/kg per min, respectively, resulted in the maintenance of the basal levels of each hormone. Glucose production was measured using tracer (primed constant infusion of [3-3H]glucose) and arteriovenous difference techniques. Isolated glucagon deficiency resulted in a 35+/-5% (P less than 0.05) rapid and sustained decrease in glucose production which was abolished upon restoration of the plasma glucagon level. Isolated insulin deficiency resulted in a 52+/-16% (P less than 0.01) increase in the rate of glucose production which was abolished when the insulin level was restored. Somatostatin had no effect on glucose production when the changes in the pancreatic hormone levels which it normally induces were prevented by simultaneous intraportal infusion of both insulin and glucagon. In conclusion, in the anesthetized dog fasted overnight; (a) basal glucagon is responsible for at least one-third of basal glucose production, (b) basal insulin prevents the increased glucose production which would result from the unrestrained action of glucagon, and (c) somatostatin has no acute effects on glucose turnover other than those it induces through perturbation of pancreatic hormone secretion. This study indicates that the opposing actions of the two pancreatic hormones are important in the regulation of basal glucose production in the postabsorptive state.

Animals↗
PubMed1976

Investigation of urine transport in the ureter of the pig by x-ray videodensitometry. I. The effect of increasing diuresis on velocity and rhythm of contractions: relationship between pressure wave and urine bolus.

The flow rate is the decisive parameter of ureteric function. The frequency and the velocity of the contraction waves can be measured by X-ray videodensitometry without having to touch the ureter. The relationship between flow rate (milliliters per minute) and wave velocity (millimeters per second) is investigated in the pig ureter. It can be demonstrated that the wave velocity is a quadratic function of the perfusion. The graphic representation of this function corresponds ot a parabolic curve. The relationship between the bolus and the pressure wave is analyzed and it is shown that the time lag between the rear end of the bolus and the pressure peak is independent of the wave velocity. The theoretical ureter model of Weinberg is experimentally confirmed by simultaneous manometry and videodensitometry.

Absorptiometry, Photon↗
PubMed1976

Investigation of urine transport in the ureter of the pig by x-ray videodensitometry. II. The effect of an increasing obstruction on velocity, rhythm, and efficiency of the contraction waves.

The effect on an increasing acute obstruction on the motility of the ureter was analyzed by means of X-ray videodensitometry. The mean wave velocity decreases and the efficiency of the individual contraction is reduced. The lumen of the ureter is no longer closed completely and an increasing fraction of the urine bolus flows backward. The regurgitation can be seen cineradiographically and assessed semiquantitatively by densitometry.

Absorptiometry, Photon↗
PubMed1976

Taenia saginata cysticerci in muscles of beef cattle.

Minute dissection of carcasses infected with Taenia saginata cysts revealed that heart and masticatory muscles were more heavily and more frequently infected with Taenia saginata cysts than were any other muscle groups. Increasing the number of inspection cuts in the heart and masseter muscles, while omitting cuts in such sites as the diaphragm, during meat inspection would increase the efficiency in detecting beef cysticercosis. Complete dissection of cattle found to have a single viable or dead cyst by routine inspection revealed dead or viable cysts in portions of the carcass not routinely examined. These findings justify the recent change in routine meat inspection procedures whereby all carcasses with a single cyst (whether viable or dead) are now cooked or refrigerated, instead of having the offending cysts excised.

Animals↗
PubMed1975

Course and prognosis of 86 episodes of diabetic coma. A five year experience with a uniform schedule of treatment.

The admission data and the course of 58 episodes of severe diabetic ketoacidotic coma and of 28 episodes of non-ketotic coma are compared. The non-ketotic patients were older; initial blood glucose, osmolarity, blood urea and serum sodium concentration were higher than in the ketotic patients. Treatment in the first 24 hrs consisted of similar amounts of insulin in both coma forms, the presence of acidaemia did not increase the insulin needs. Acidaemia was corrected only when pH was below 7.20. The disadvantages of alkali therapy are emphasized. A comparison of the age groups of survivors and those patients who died within 72 hrs showed an increase in mortality with age. However, the mortality rates from ketotic and non-ketotic coma were similar in the age groups above 50 years. On admission, blood glucose, osmolarity and blood urea were higher in the fatal cases. Blood urea was the most important indicator of a fatal outcome. The response of blood glucose to insulin was impaired in the subsequently fatal cases. Insulin was given in "moderate" doses by constant infusion. The use of "small" doses is discussed. Early mortality was 14% in the ketotic and 29% in the non-ketotic cases. The most frequent causes of death were circulatory failure of undetermined origin, infections and thromboembolic complications.

Adult↗