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Biomedical subjects

G Albrecht

Publications and source records attributed to G Albrecht.

At least 109 records · Page 6Linked to original sources
PubMed1983

Kunitz-type proteinase inhibitors derived by limited proteolysis of the inter-alpha-trypsin inhibitor, VII. Characterization of the bovine inhibitor as double-headed trypsin-elastase inhibitor.

The acid-resistant 14-kDa inhibitor BI-14, released from bovine inter-alpha-trypsin inhibitor, consists of two tandem Kunitz-type domains, and is of a double-headed nature. The Arg-Thr bond connecting both domains was cleaved and the two inhibitory domains were separated. The N-terminal domain is an inhibitor of bovine chymotrypsin and elastases from porcine pancreases and human polymorphonuclear granulocytes, whereas the C-terminal domain interacts with trypsin, plasmin, and chymotrypsin. In the intact inhibitor BI-14 both domains interact independently with the proteinases.

Alpha-Globulins↗
PubMed1983

Studies on the clinical importance of the constants used in the algorithm of an artificial B-cell (Biostator).

The clinical importance of different constants used in the algorithm of a glucose-controlled insulin infusion system (Biostator) with respect to insulin requirement was studied in 9 insulin-dependent juvenile-onset type diabetics. After normalizing the fasting blood glucose level (around 4.5 mmol/l), 3 consecutive glucose infusions (12 mg . kg-1 . min-1) followed by a 1 h post-infusion period were carried out in all individuals. The blood glucose was controlled by the Biostator using three sets of constants: A (KR = 160, KF = 50, QI = 30, RI = 12), B (KR = 70, KF = 50, QI = 40, RI = 12) and C (KR = 20, KF = 50, QI = 50, RI = 20). The algorithm constants were changed in an arbitrary order before the start of each glucose infusion in the same patient. Mean blood glucose profiles were comparable whereas the mean total insulin dose infused by the Biostator amounted to 13 +/- 1.3 U/h, 7.8 +/- 1.2 U/h and 7.0 +/- 1.0 U/h when sets A, B and C were applied (A versus B and C p less than 0.01). The higher insulin amount during control of set A was mainly due to a high insulin infusion during the first 20 min. In summary, the results emphasize the clinical importance of appropriate algorithm constants of a glucose-controlled insulin infusion system for evaluation of the insulin requirement in insulin-dependent diabetics.

Adult↗
PubMed1983

Not the artificial beta cell algorithms but their parameter values are important in automated glucose control of insulin-dependent diabetes.

The blood glucose responses of diabetic dogs on the ABC are nearly identical if different algorithms, but equivalent sets of parameters are used to control the glucose-dependent insulin infusion. There are however some differences in the insulin doses applied, which obviously result from different response kinetics of the particular formula to the minor BG oscillations that always occur. In the practical application of closed-loop systems the control constants should be individually estimated on the basis of certain controlled plant characteristics. For use in patients the checking and modeling systems still have to be simplified. The limits of the study, i.e. the fact that normoglycemia was restored for a short time only using the IV instead of the physiological portal route, remain the subject of further investigation.

Animals↗
PubMed1981

[Circadian variations in insulin concentrations and blood glucose in non-diabetics as well as insulin requirements in insulin-dependent diabetics].

On the basis of the estimation of the plasma glucose and the insulin concentrations in 10-minute intervals during 24 hours by the mathematical analysis (multiple regression) over relations between the behaviour of plasma glucose and insulin concentration insulin secretion rates independent of plasma glucose can be calculated. In non-diabetics a circadian rhythm of the disposal of insulin - independent of food - is established. Thus the secretion rate increases in the early morning hours still before before the first meal and is maintained in different size up to nearly 18 o'clock. Then it established itself to the level of the nocturnal basal rate. Adequate changes of the insulin need during night are proved in diabetics without endogenic residual insulin secretion by means of the artificial B-cell Biostator. The circadian rhythm of the disposal of insulin take place parallel with adequate changes of other biological parameters and is of importance for the practice of the conventional insulin therapy as well as in the future use of non-measuring value-regulated insulin infusions (open-loop system).

Adult↗
PubMed1980

Assessment of an algorithm for the artificial B-cell using the normal insulin-glucose relationship in diabetic dogs and men.

Insulin secretion rates after glucose loading were calculated from peripheral venous IRI concentrations considering half life and distribution space of exogenous insulin in normal men and dogs. The coefficients of multiple linear regression analysis between insulin secretion rates and plasma glucose (level and order and rate of change) were used as algorithm parameters in glucose-controlled insulin infusions. These were carried out in each dog based on individual estimations before the induction of diabetes but in the diabetic patients based on values derived from a group of normal subjects. Using this formula, nearly normal patterns of glucose and of insulin were observed in diabetic men and dogs under basal conditions and after IV glucose loading but not after meals. This algorithm enables selection of the parameters prospectively. The effect of a parameter combination depends on insulin sensitivity and it should be appropriately adapted. In the diabetic patients there was no predictable influence of the brittle or stable characteristics of the disease nor of insulin antibodies on the glucose curves obtained with glucose controlled insulin infusions.

Adult↗
PubMed1979

[Experiences with fine needle aspiration biopsy of the thyroid gland].

It is reported on 155 fine needle aspiration biopsies of the thyroid gland which above all were performed in cold nodes. In 81.9% of the cases unconspicuous cell pictures or cystico-regressive changes were present. Of the 17 findings suspicuous of malignoma (11%) hitherto 2 could histologically be diagnosed as carcinomas and 3 as adenomas with considerable regressive changes. The additionally established frequency of nodular strumas and cold nodes in 547 scintigraphically examined patients had the results of 54% nodular strumas and 48.4% of cold nodes in the total material. In 90.2% the nodular strumas revealed cold nodes. The rate of malignomas of all preparations of operations of the thyroid gland was altogether at 2.9% subtracting the secondary malignant processes 2.4% were found. These findings as well as the positive data from literature give the fine needle aspiration biopsy an important role in supplementing the morphologic diagnostics and the early recognition of malignomas of the thyroid gland.

Adult↗
PubMed1979

[The development of child pathology within the framework of pathology and pediatrics. A medico-historical review].

1. The history of child pathology is derived from the description of the development of the an pathological anatomy and paediatry. 2. The pathological anatomy of infancy is basing on the research results of the general and special pathology, the pathological physiology and the clinical medicine by the help of the experiment and the knowledges of biology, chemistry, and physics. 3. Further decisive impulses are given by social medicine.

Allergy and Immunology↗
PubMed1978

Polymorphism of apolipoprotein E. I. Methodological aspects and diagnosis of hyperlipoproteinemia type III without ultracentrifugation.

Two methods for phenotyping apolipoprotein E are compared. One is based on preparation of VLDL by conventional ultracentrifugation, whereas the other uses heparin/Mg precipitation of VLDG. In principle, the same results were obtained by both methods. However, the group limits for the three different phenotypes Apo E-N, Apo E-ND and Apo E-D were slightly different by the two methods. Phenotype Apo E-D - the phenotype characterizing type III dyslipoproteinemia - is clearly definable by both methods. Hence the precipitation-I.E.F. method for Apo E phenotyping provides a simple tool for genetic and population genetic studies and also for the routine diagnosis of hyperlipoproteinemia type III, based on the only specific marker known for this disease.

Apolipoproteins↗
PubMed1978

Pancreatic and hepatic balances of endogenous insulin and of glucose in the anaesthetized dog during primed and non-primed infusions of glucose and of mannitol.

Simultaneous monitoring of pancreatic and hepatic blood flows and serial analyses of blood glucose and immunoreactive insulin activity in arterial, portal, intestinal and hepatic venous blood were performed in anaesthetized laparotomized dogs. Based on these measurements, the rates of pancreatic insulin secretion, of hepatic insulin uptake and the hepatic glucose balance were computed. Under basal conditions pancreatic output was about 40% of the total hepatic insulin input. 30% of hepatic insulin inflow were actually taken up in the liver. During a primed i.v. glucose infusion (steady blood glucose concentration about 330 mg/100 ml) pancreatic and hepatic blood flows increase rapidly and the insulin secretion exhibits a biphasic pattern. The relative part of hepatic insulin inflow taken up in the liver remained unchanged. A non-primed i.v. glucose infusion provoked a slow increase of blood flow and a rapid but monophasic increase of insulin release. Under these conditions the relative hepatic insulin uptake was transiently increased. During both loads hepatic glucose balance switched from release to uptake. However the non-primed infusion was more effective. When pancreatic and hepatic blood flows were increased without any blood glucose alteration by an infusion of mannitol, insulin secretion did not change; hepatic uptake of insulin decreased, but hepatic glucose output was clearly reduced. A correlation between the rates of insulin secretion, of hepatic insulin inflow and of insulin uptake was observed under all conditions. However, the hepatic glucose balance was correlated to the inflow of insulin or glucose and to the hepatic insulin uptake under certain conditions in individual experiments only.

Animals↗
PubMed1977

[Metastizing basalioma. A case contribution].

A case of a metastasizing basal cell carcinoma that began 24 years earlier as a rodent ulcer on the back is reported. Histologically there were strands of characteristic basal cell type cells and, in addition, areas of squamous cell differentiation. The problem of "epithelioma metatypique" is discussed. The autopsy showed pure basal cell metastases in the lungs, the paraaortal lymph nodes and penetration of the tumor masses into the vena cava inferior. The unsufficient treatment by X-ray seems to be a conditioning factor by injuring the surrounding stroma.

Aged↗
PubMed1976

The effect of tris(2-chloroethyl)amine on human hemoglobin.

The reaction of tris(2-chloroethyl)amine (TCEA) with purified hemoglobin and its effect on properties of hemoglobin was studied using 14C-labeled TCEA. Hemoglobin remained soluble after binding as much as 4 TCEA per heme. In concentrations which did not denature hemoglobin TCEA reacted only with a small proportion of the free SH groups; blockade of the SH groups with PMB did not noticeably affect the binding of TCEA to hemoglobin. Hydrolysis by trypsin or chymotrypsin of hemoglobin which had reacted with TCEA yielded radioactive peptides besides not radioactive peptides and radioactive compounds not reacting with ninhydrin. The reaction with TCEA caused a change in electrophoretic mobility of hemoglobin and prevented its complete disintegration by PMB into subunits. After reaction with TCEA the affinity of hemoglobin for oxygen was strongly increased and the heme-heme interaction strongly diminished. The Bohr effect and the effect of 2,3-diphosphoglycerate on oxygen affinity remained unchanged. The effect of TCEA on the properties of hemoglobin points to specificity in its reaction with functional groups of hemoglobin.

Binding Sites↗
PubMed1976

[Relations between portal and peripheral venous insulin, proinsulin and glucagon concentrations after oral glucose in man].

During cholecystectomy a catheter was inserted into the V. porta via V. umbilicalis. 7 or 8 days later an oral glucose tolerance test was performed (100 g). Blood glucose, insulin (IRI), proinsulin-like material (PLM), and pancreatic glucagon (IRG) concentrations were determined in portal as well as in peripheral venous blood. 5 out of 6 patients showed a disturbed carbohydrate tolerance in comparison to 53 healthy subjects. The IRI increased promptly after the oral glucose load. The portal IRI-concentrations are significantly enhanced in comparison to the peripheral levels, but between both a positive correlation exists (r = 0.9447; p less than 0.01). PLM was slightly increased in the first 10 minutes. The basal IRG levels were not enhanced. Significant differences between the portal and peripheral IRG concentrations could not be observed. The correlation coefficient was 0.8902. Thus, the peripheral venous concentrations of IRI, PLM and IRG can be used as a diagnostic tool of pancreatic hormone secretion in man.

Administration, Oral↗
PubMed1975

[Pulmonary fibrosis after busulfan therapy].

After a short review concerning the side-effect of busulfan (myleran) a case of a myleran lung in a 45-year-old male patient is described who received altogether 408.0 mg myleran, as he suffered from a chronic myeloic leucosis; the special literature is cited and the developmental mechanisms are discussed.

Busulfan↗
PubMed1975

[Diabetes and pregnancy - a clinical and statistical analysis of 1800 pregnancies and deliveries in the years 1952 - 1971. 3. Birth weights percent values of newborn infants of diabetic mothers and further studies on the birth weight].

Newborn babies of diabetic mothers have a higher birth weight in comparison with newborns of nondiabetic mothers in the same gestational age (35. to 39. week). Body weight percentiles were estimated for new borns of diabetics (excluding stillborn babies), it was to be shown that birth weight lower than 2750 gm in the 38. to 39. gestational week (less than 10. percentile) characterizes "small for gestational age babies". Not any influence of maternal blood glucose values during the second part of pregnancy was to be seen. Severe toxaemias and vascular-renal complications (WHITE-class F) were statistically significant correlated with underweight in newborns. The lowest perinatal mortality was found in the weight class 3500 to 3999 gm.

Birth Weight↗