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Biomedical subjects

U Lehmann

Publications and source records attributed to U Lehmann.

At least 73 records · Page 4Linked to original sources
PubMed1985

[Dissolution processes and surface changes. 3. Determination of the surface with the BET process].

Two methods are demonstrated for the determination of the surfaces of solid substances by the BET-method. Using a newly constructed apparatus substances with high specific surfaces can be determined by the two-point-method with a good precision. For the determination of pulverous drugs we used the one-point-method proposed by Haul and Dümbgen [2] improving it in calibration und practicability.

Chemistry, Pharmaceutical↗
PubMed1984

Emergence of adaptable systems and evolution of a translation device.

An over-all organizational framework for the origin of life is outlined and attempts for realization are given. Evolution can be described as a process resulting in an increase of "knowledge" where knowledge is the number of carriers of genetic information discarded, on the average, until the evolutionary state under consideration is reached. A model for the evolution of a translation device, a crucial event in the origin of life, is described in detail. Aggregates of short polynucleotide strands in a hairpin conformation play a major role in this model. Experimental evidence for the selectivity of aggregation supports the idea of aggregates as error filters. Chromatographic separation as selection process during chemical evolution supports the model of the early translation device leading to the origin of the genetic code.

Amino Acids↗
PubMed1982

[Angiography after interventions on the pancreas].

The angiograms of 35 patients who had had surgery of the pancreas were evaluated. One must distinguish between the changes due to the procedure and those due to the original disease or to progress or recurrence of tumours. Out of four patients with recurrence of a pancreatic carcinoma, the angiogram failed to show any evidence in three. Angiography after pancreatic surgery is of value in planning further treatment, or if sonography and computer tomography are unable to clarify the problem.

Angiography↗
PubMed1982

[Value of sonography in the control of pancreatic cancer].

In 152 examinations, sonography was found to be a reliable screening method in the follow-up of curative and palliative surgery of carcinoma of the pancreas. By the effected changeover from compound scanning to the high-resolution real-time B-process, it has become possible to recognize at an early date even small locoregional recurring tumours (1.5 cm diameter), metastases of lymph nodes (1-1.5 cm diameter) and hepatic filiae (1.0 cm diameter); it has also been possible to detect typical changes, such as stenoses or thromboses, at the major vessels of the upper abdomen, well in time. If the findings are not clear, CT examination will be mandatory, if necessary in conjunction with bolus injection of a contrast medium. These methods have been able to largely replace the well-known invasive procedures, such as ERCP, angiography and laparoscopy in follow-up controls.

Aged↗
PubMed1981

[Hyperlipoproteinaemia during additional methenolone administration in the treatment of metastasizing carcinoma of the breast].

The effect of additive administration of methenolone oenanthate (Primobolan) on lipid metabolism was studied in 28 menopausal women with metastasizing carcinoma of the breast. In ten women hyperlipoproteinaemia type IIa was demonstrated in the course of treatment, while in two there was hyperlipoproteinaemia type IIb. One of the latter patients had a myocardial infarction in the course of treatment. There was no relationship between the level of hypercholesterolaemia and the methenolone dosage. Nor was it possible to classify the type of cholesterolaemia as a bile stasis syndrome. The hyperlipoproteinaemia regressed in every case once methenolone treatment was discontinued.

Bone Neoplasms↗
PubMed1980

[Dynamic blood glucose adjustment in diabetics in a closed loop system].

An automatic regulator aep (artificial endocrine pancreas) has been developed for the extracorporeal blood glucose regulation. After glucose monitoring, the maschine steers an insulin infusion pump by means of adequate algorithms to obtain a glucose balance in labile diabetic inpatients. This system, also called artificial beta-cell, is a closed loop regulatory system with impulses from the actual blood glucose that represents true feedback principles. So far it is preferably used during surgical operations of labile diabetics and for the intensive therapy of patients with pancreatic affections. The clear therapeutic advantages, that have been found in some special medical centres, give hope that technical ways will be found to master the narrow passes and the difficulties in the future.

Aged↗
PubMed1979

[Algorithm for extracorporal blood glucose regulation (author's transl)].

A control mechanism is described, based on a simple proportional/differential regulation. The calculation takes one minute and it takes into account glucose degradation, insulin half life in vivo, and the delay between blood sampling and insulin action on the blood glucose value. This is repeated continuously every minute (short time mode) or every 5 minutes or more (long time mode), depending on the rate of change of the blood glucose. Operator decision is based on digitally converted tables, which are analogous to the graph of proportional control, and on glucose equivalent tables, which give the insulin effect on glucose as a function of time.

Blood Glucose↗