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Biomedical subjects

U Hofmann

Publications and source records attributed to U Hofmann.

At least 109 records · Page 6Linked to original sources
PubMed1987

[Autologous transfusion of blood deep frozen in the interim in childhood].

In the report we describe a method of reducing the number of transfusions of heterologous blood in patients with a surgical correction of chest walls. In 71 children between 2 and 17 years of age, 10-15% of total blood volume were withdrawn 3-4 weeks before the operation, deep frozen and thawed at the appropriate time to be ready for retransfusion. This arrangement reduced the need of heterologous blood significantly from 18.6% (prior to the introduction of the method) to 4.2%.

Adolescent↗
PubMed1987

[Therapeutic problems of pediatric tracheobronchial foreign bodies].

The report is based on 251 extractions of tracheo-bronchial foreign bodies performed since 1968. Bronchoscopy for foreign bodies, particularly chronic ones, is a high risk procedure in small children and even more in infants and should be limited to a skilled bronchologist. Progress in paediatric anaesthesiology and paediatric intensive care as well as bronchological devices designed specially for children facilitate the task. Technique of extraction, monitoring and pre- and postoperative management are described in detail. A recently developed method for the extraction of crumbly material, particularly peanuts, without forceps is presented.

Bronchi↗
PubMed1987

Antigen-gelonin conjugates. Preparation and application in experimental myasthenia gravis.

The antigen-specific immune suppression by gelonin-antigen conjugates was tested in two different systems: (i) the horseradish-peroxidase-stimulated T-cell proliferation in vitro and (ii) in vivo with experimental autoimmune myasthenia gravis (EAMG) in the rat. For this, the phytotoxin gelonin, a glycoprotein from Gelonium multiflorum, was purified and linked to the respective antigens. For the in-vitro assay a lymph node cell suspension from rats immunized with horseradish peroxidase was cultured in the presence of this protein and proliferation was measured by [3H]thymidine uptake. In-vitro proliferation was significantly inhibited by adding gelonin-horseradish peroxidase conjugates. The therapeutic effects of antigen-gelonin conjugates were tested in the rat model EAMG. For these experiments rats were immunized with purified nicotinic acetylcholine receptor from electric fish in order to develop EAMG. The success of the immunization was monitored by the change in physical performance tests, the change in anti-acetylcholine receptor antibody titer, and by the change in the number of ionic endplate channels using a novel electrophysiological method. The latter method permits a very accurate assay of functional damage of acetylcholine receptor at the endplate and correlates well with the clinical severity of the disease. Rats were conventionally immunized with acetylcholine receptor from electric fish. After the onset of EAMG as measured by physical performance tests and rise in antibody titer a group of the animals was injected with an acetylcholine receptor-gelonin conjugate and this treatment was repeated seven days later. The loss in functional acetylcholine receptor was significantly smaller in the therapy group than in the untreated EAMG group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Influence of thromboxane receptor-antagonists on the interaction of platelets with solid-phase immobilized human collagen.

The interaction of blood platelets with surfaces coated with human type I, III, IV, and V collagen (CI, CIII, CIV, and CV) has been studied. Using scanning electron microscopy it was demonstrated that the reactivity of the collagen substrates for platelets varies widely. In contrast to CV and CIV, on surfaces coated with CI and CIII, along with spreading, the formation of thrombi-like platelet aggregates occurs. Previously, it was demonstrated that this thrombogenesis in vitro correlates well with the synthesis of platelet prostanoids, and is sensitive to inhibitors of TXA2-synthesis. Therefore, we have investigated the influence of the TXA2/PGH2 receptor-antagonists, 13-azaprostanoic acid (13-APA) and the BM 13.177 compound, on the formation of thrombi-like platelet aggregates on CI and CIII-coated surfaces. It was demonstrated that both 13-APA and BM 13.177 cause a dose-dependent inhibition of the thrombogenesis without any effect on the initiation of the thrombogenesis without any effect on the initial attachment and the spreading of platelets on collagen-coated surfaces. The obtained data suggest that (1) the formation of platelet aggregates on CI and CIII-coated surfaces is triggered by platelet prostanoids; (2) TXA2/PGH2 receptor-antagonists may be useful as antithrombotic drugs.

Blood Platelets↗
PubMed1987

Cellular requirements of IgE-antibody regulation.

Regulation of IgE antibody response is T-cell dependent. It has been suggested that IL-4 (BSF-1) induces the expression of Fc epsilon RII on B-lymphocytes. Soluble molecules of the FC epsilon RII with various molecular weights represent IgE-binding factors which according to the current opinion either enhance or suppress the IgE-antibody response. In mice IgE suppressive factors were obtained, which inhibited IgE-synthesis in vitro and in vivo. IgE suppressive factors were also obtained by incubating MLN-cells with monoclonal IgE. In humans IgE binding factors are present within serum of normal donors. In atopics IgE-BF is apparently complexed with IgE. Thus, it becomes clear that the expression of IgE-bearing lymphocytes as well as the secretion of IgE is cytokine mediated.

Animals↗
PubMed1987

Comparison of verapamil and bepridil in the therapy of familiar cardiomyopathy of the Syrian hamster.

The effect of bepridil compared to verapamil on the cardiomyopathic hamster (Strain Bio 8262) was evaluated. Bepridil (10 mg/kg) was injected twice daily for 15 and 30 days. Verapamil (10 mg/kg) was injected twice daily for 30 days. Control animals were treated with NaCl. After life-day 30, large infarct-like lesions predominantly located in the central portion of the left ventricular walls were observed, while single cell necrosis occurred only in a few cases. In peripheral muscles, the necrotizing process started even before life-day 30. In the skeletal muscles, small foci of cell necrosis were the predominant type of lesion. Myocardial calcium accumulation and cell necrosis could be completely prevented by verapamil and were not influenced by bepridil. Both drugs were ineffective in the skeletal muscles. The infarct-like lesions of the myocardium demonstrate that a vascular component is involved in the pathogenesis of necrosis, in addition to the inherited disturbance of calcium metabolism. The results demonstrate that not all drugs with calcium antagonistic potencies have identical cardioprotective effects in the cardiomyopathic hamster.

Animals↗
PubMed1984

Chlorinated hydrocarbons in adipose tissue of infants and toddlers: inventory and studies on their association with intake of mothers' milk.

Chlorinated hydrocarbon and polychlorinated biphenyl (PCB) concentrations were determined in adipose tissue from 34 infants, 14 children in the 2nd year of life, and 2 older children. The highest mean concentration detected during the first 2 years of life was for PCBs (0.67 ppm), followed by DDT (0.57 ppm), HCB (0.23 ppm), and HCH (0.15 ppm). Concentrations of HCB and PCB, which are especially characteristic of highly industrialised countries, were considerably higher in children of German mothers than in those of Turkish mothers. All single investigated values were lower than the mean values for adults in the Federal Republic of Germany, but many were still higher than mean concentrations for adults in other parts of the world. A breakdown into children with high mothers' milk intake and those with low intake showed a highly significant association with the quantity of mothers' milk consumed: the concentration of organohalogens in adipose tissue of children with high intake was significantly higher than in those with low intake. Two tasks urgently demand our attention: the development of further ways to reduce environmental sources of organohalogen contamination and the study of the possible pathogenetic effect of these organohalogens on the health of our children.

Adipose Tissue↗
PubMed1984

Clinical aspects, diagnosis, and treatment of the Kaufman syndrome (hydrocolpos, hypospadias, polydactyly).

Three girls with the Kaufmann syndrome are reported. In these children the hydrocolpos was not caused by a vaginal atresia but by a stenosis of the vaginal introitus combined with female hypospadias. These children suffered from additional micrognathia. The parents of two of the children suffered from additional micrognathia. The parents of two of the children were related to each other. No such family history could be discovered in the third child. It is possible that this syndrome is autosomal recessive and sexlinked. As the associated malformations may endanger life and therefore necessitate immediate operation, the hydrocolpos should be treated at first conservatively. Later on, corrective operations should be performed.

Abnormalities, Multiple↗
PubMed1984

Platelet prostanoids in interaction of platelets with collagen substrates. I. Activation of platelets by surfaces coated with different types of human collagen.

We have studied the interaction of human platelets with surfaces coated with human type I, III, IV, and V collagen (CI, CIII, CIV, and CV). It was established using scanning electron microscopy that the reactivity of the collagen substrates for platelets varies widely. On CV, only the initial attachment of platelets takes place; spreading actively goes on CIV while on CI and CIII, along with spreading, the formation of multilayer thrombi-like platelet aggregates occurs. The production of malondialdehyde induced by the interaction of platelets with CI and CIII substantially exceeds that stimulated by CIV and CV. Indomethacin practically completely inhibits the formation of thrombi-like aggregates but only by 25% inhibits platelet spreading. An ADP-scavenger creatine phosphate/creatine phosphokinase inhibits the formation of thrombi-like aggregates and platelet spreading by 25-30%. The obtained data demonstrate that: (i) the formation of thrombi-like aggregates on CI and CIII is mediated mainly by the synthesis of platelet prostanoids, and not by the ADP release; (ii) the spreading of platelets on CIV, CIII, and CI is only partially mediated by prostanoid synthesis and ADP release which suggests a participation of other mechanisms in this process.

Blood Platelets↗
PubMed1983

[Results of lung perfusion and lung ventilation scintigraphy following surgery of diaphragmatic defects].

To elucidate the question whether congenital hernias of the diaphragm and diaphragmatic defects are often combined with primary hypoplasia of the pulmonary vascular bed, we performed lung scintigraphy in twenty children after operation of a diaphragmatic defect. We found in 66% of the cases persisting perfusion disorders of the operated side. However, this does not prove primary vascular hypoplasia, because a postoperative ventilation disorder with secondary perfusion disorder cannot be excluded. Ventilation scintigraphy with krypton-81m showed good results in all cases, so that the combination of good ventilation and restricted perfusion indicates primary vascular hypoplasia.

Age Factors↗
PubMed1982

[Special indications for the use of the Grüntzig balloon catheter in surgical problem cases].

The excellent experiences with the intravascular application of Grüntzig's double-lumen balloon catheter shows his potential use in thin-walled organs. We report our experiences with the dilatation of bile-duct stenoses (end-to-end anastomosis of the Ductus choledochus, sclerosis of the Papilla Vateri, intra- and extrahepatic fibrotic stenosis), stenosis of the esophagus after acid corrosion and stenosis of the ureter anastomosis after Anderson-Hynes operation. These results demonstrate, that in selected cases the balloon dilatation may be an alternative to surgical intervention.

Aged↗
PubMed1982

[Experiences with caudal anaesthesias in paediatric surgery (author's transl)].

The results of more than hundred caudal anaesthesias in surgical paediatric urology in children aged one to twelve years are reported. Modifying the method of Schulte-Steinberg, we used Bupivacain - CO2 0.5%, and attained sufficient analgesia in all cases for whatever surgery applied. There were no complications except in one case where an overdose had been applied. We feel that the postoperative period is easier to bear because of the longer lasting local analgesia. Earlier onset of oral food intake is possible.

Anesthesia, Caudal↗
PubMed1981

Renal fluoride excretion: experimental evaluation of the role of extracellular volume status during intact and impaired kidney function.

The renal disease of inorganic fluoride was studied in 5/6-nephrectomized and kidney-intact rats in order to evaluate the influence of the extracellular fluid volume status on net tubular fluoride reabsorption. Loss of renal functional mass impaired the ability of the hydropenic uremic rat to excrete fluoride, although tubular reabsorption of fluoride was depressed. Fractional fluoride excretion was closely correlated to urinary flow rate in hydropenic rats; no influence of urinary pH from 5.80 to 6.18 could be demonstrated. Acute, moderate expansion of the extracellular fluid volume by isotonic saline was followed by a significant rise in fractional fluoride excretion in uremic as well as in control rats, indicating that extracellular fluid volume is an important physiological determinant of passive tubular fluoride reabsorption.

Animals↗
PubMed1980

[Studies of iron level, Fe binding capacity, copper and protein in the blood plasma as well as hemoglobin in the blood of sows during the day].

The average iron level in the blood plasma of six gilts, weighting between 120 kg and 130 kg, was 103. 3 micrograms/100 ml, prior to early-morning feeding. The iron fixation capacity, measured at the time, was 673 micrograms/100 ml. Average iron levels went up to 121.3 micrograms/100 ml after 1.5 to two hours and to 130.3 micrograms/100 ml in the course of 3.5 to four hours. An average level of 124.3 micrograms/100 ml had been reached after another 1.5 to two hours. The iron fixation capacities first declined and then went up again. The average iron level recorded from eight adult sows, weighing between 180 kg and 210 kg, was 75 micrograms/100 ml, when measured seven weeks from piglet weaning. The average iron fixation capacity was 488.3 micrograms/100 ml at the same time and for the same animals. The iron level did not change throughout testing. The average copper level was 230.9 micrograms/100 ml, at the beginning, but individual differences in behaviour occurred during the day. No difference was recorded, at the beginning, between gilts and adult sows for blood plasma protein, levels being 7.73 or 7.81 g/100 ml, and for haemoglobin in the blood, levels being 12.8 or 12.5 g/100 ml. Individual variations, however, with no clear-cut direction, occurred over the testing period.

Age Factors↗
PubMed1980

[Iron, iron-binding capacity, copper and protein in blood plasma and hemoglobin in the blood of sows before and during pregnancy].

Blood tests were applied to five gilts and twelve adult sows, prior to insemination as well as in the sixth, ninth, twelfth, and 15th weeks of pregnancy. Average haemoglobin values in both groups dropped from 14.0 g/100 ml or 11.3 g/100 ml, at first measurement, to 9.5 g/100 ml in the ninth week of pregnancy. Then regrowth occurred to 12.6 g/100 ml or 12.2 g/100 ml up to the 15th week. The average blood plasma iron levels were 142 micrograms/100 ml or 117 micrograms/100 ml, at first measurement and went up in both groups, between the twelfth and 15th weeks, from 110 micrograms/100 ml to 161 micrograms/100 ml or from 105 micrograms/100 ml to 149 micrograms/100 ml. The original iron fixation capacity values for both groups were 673 micrograms/100 ml or 645 micrograms/100 ml and dropped to 524 micrograms/100 ml or 492 micrograms/100 ml by the 15th week of pregnancy. The copper levels grew from 221 micrograms/100 ml to 305 microgram/100 ml for gilts and from 200 micrograms/100 ml to 236 micrograms/100 ml for adult sows, from the twelfth to 15th weeks. The average blood plasma protein levels had been 7.7 g/100 ml or 8.1 g/100 ml, at the beginning, and went up to 8.5 g/100 ml in either group by the 15th week.

Animals↗
PubMed1975

Influence of chelation therapy on acute lead intoxication in rats.

The intraperitoneal administration of Pb acetate (5 x 20 mg Pb/kg per day) evokes a moderate and transient hypochromic anemia, a long-lasting enhanced urinary excretion of delta-aminolevulinic acid whereas the urinary excretion of alkaline phosphatase is not affected and that of lactic dehydrogenase only marginally. It is concluded that neither the hematologic response nor the slight nephrotoxicity are responsible for the lethal action of Pb. Chelate treatment started 3 days after the last Pb dose and was continued over 7 weeks. The daily intraperitoneal dose was 25, 50, and 100 mumol/kg, respectively. The efficacy in promoting the urinary excretion of Pb decreased in the following order: Ca diethylenetriaminepentaacetate greater than 2,3-dimercaptopropane-1-sulfonate greater than Zn diethylenetriaminepentaacetate greater than D-penicillamine. This effect was mainly due to the mobilization of skeletal Pb. The chelating agents also lowered the excretion of delta-aminolevulinic acid but failed to exert a beneficial influence on the anemia and the lethal action of Pb. These negative results raise questions about the usefulness of chelation therapy in cases of acute Pb poisoning.

Acute Disease↗