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Biomedical subjects

G Baumann

Publications and source records attributed to G Baumann.

At least 361 records · Page 20Linked to original sources

[Vascular surgery in arterial occlusive disease. Possibilities and indications (author's transl)].

Besides amputation and resection of the sympathetic trunk, vascular reconstructive operations are among the most important surgical possibilities for the treatment of arterial occlusive disease. Disobliteration and bypass procedures come into consideration. Depending on the localization of the obstruction and the affected organ, one or the other method will be given preference. The indication for vascular reconstruction is principally governed by the disease complex, the danger to the organ due to the reduced blood supply and finally the extent of the arterial obstruction. The lethality of the intervention, the results, complications and follow-up are discussed in detail.

Amputation, Surgical↗

[Necrotizing enteritis in nursing piglets (Clostridium perfringens type C enterotoxemia) in industrialized swine breeding facilities].

Outbreaks of necrotising enteritis, caused by Clostridium perfringens, Type C, among piglets on five industrialised breeding units are reported in this paper. Original diagnosis was confirmed by clinical, pathologico-anatomic, histological, and bacteriological tests as well as by the detection of beta toxin from the intestinal matter of piglets after death. Cl. per fringens, Type C, was successfully isolated from 71.9 per cent of all animals that had died of necrotising enteritis. Three forms were differentiated by pathologico-anatomic findings: 1. haemorrhagic-necrotising enteritis with excessive bleeding of the intestinal wall and blood loss into the intestinal lumen; 2. necrotising enteritis with small scattered foci of bleeding; 3. necrotising enteritis without any bleeding. The first form usually developed concomitantly with peracute and acute disease in the first three days of age, whereas the third form was primarily recorded from piglets that had died, following subacute disease, between the fourth and ninth days after birth.

Animals↗

Adenosine as inhibitor of myocardial effects of catecholamines.

Infusion of adenosine into the coronary arteries of isolated guinea pig hearts produced a dose-dependent inhibition of dP/dtmax caused by bolus injections of isoproterenol (4 X 10(-11) moles). Threshold concentration of adenosine was 10(-7) M and maximal inhibition (90%) occurred at 10(-5) M. Coronary dilation induced by papaverine did not influence the contractile response to catecholamines. In addition to its influence on cardiac performance, adenosine (10(-5) M) effectively inhibited the isoproterenol (10(-7)M) induced initial rise in myocardial levels of cyclic 3'5'-AMP, glucose-1-phosphate and glucose-6-phosphate. Adenosine also antagonized the effect of isoproterenol on adenylate cyclase activity in a crude membrane preparation from guinea pig ventricles; it was without effect on the activity of the membrane phosphodiesterase. Theophylline inhibited the actions of adenosine both on adenylate cyclase activity and on contractile force development. Upon infusion of isoproterenol (3 X 10(-7)M) into the coronary arteries of the isolated heart (perfusion at constant pressure), the adenosine concentration in the effluent perfusate increased within 45 s from 10(-8) M to about 10(-6) M. It thus appears conceivable that in ventricular myocardium endogenously formed adenosine may serve 2 functions: dilation of the coronary arteries and limitation of the inotropic and metabolic effects of catecholamines.

Adenosine↗

[Cystic degeneration of the vessel walls. The differential diagnosis of obliterative angiopathies: (author's transl)].

Cystic degeneration of the vessel wall is a rare disease predominantly localized in the region of the popliteal artery. It appears in the frequent clinical picture of intermittent claudication. Two cases are presented. The etiology of this syndrome is not clear. The appearance of intermittent claudication, preferably in middle-aged men without risk factors is typical for an obliterative angiopathy. Angiophically there are smooth-walled stenoses or occlusions, especially of the popliteal artery, with an otherwise inconspicuous vascular system. The prognosis after surgical treatment by excision or resection is good.

Adult↗

[The revascularization of the profunda femoris artery (author's transl)].

The revascularization of the profunda femoris artery, the minimal vascular operation, is described in this paper. After the anatomic and pathological relations of the femoral arteries the indications and the position of the profunda-revascularization in vascular surgery of the thigh are reported. During a period of 15 years (1959-1974) a profundaplasty was performed in 357 cases on 308 patients in the Munich University Surgical Clinic. The result of the operation could be controlled in 320 cases. The lethality-rate of operation is 3,8%. The operation was successful after 5 years in 75,3%, after 10 years in 62,6% in the whole period in 60% of the living patients. If there is a vascular disease of the deep femoral artery, the profundaplasty proves to be a standard technique in the vascular surgery of the thigh.

Adult↗

[Change in indications for reconstruction of supraaortic extracranial arteries (author's transl)].

Analysis of 334 patients, operated upon from 1962 till 1976 because of obstructions of the extracranial cerebral vessels demonstrates a change in the indication for reconstruction during the last years. The aspect of prophylaxis of neurological damage by prompt reconstruction becomes increasingly important which is documented by an increase of patients which were operated upon a) in the asymptomatic stage, b) bilaterally, c) for internal carotid occlusion during the stage of increasing neurological symptoms after they were selected according to certain criteria.

Arterial Occlusive Diseases↗

The effect of osmotic stimuli on prolactin secretion and renal water excretion in normal man and in chronic hyperprolactinemia.

An osmoregulatory role for prolactin (PRL) in man has been postulated, and PRL secretion has been reported to be influenced by osmotic stimuli. Clinical observation, however, does not support this notion. The effects of water loading, hypertonic saline infusion and nicotine on serum PRL and on renal water metabolism were investigated in 6 normal subjects and in 8 patients with chronic hyperprolactinemia (four with and four without demonstrable pituitary tumors). None of the patients had thyroid, adrenal or vasopressin deficiency. Renal walter handling in these patients was indistinguishable from normal. Likewise, serum PRL was not affected by the stimuli employed in either the normal subjects or the patients. No correlation between degree or duration of hyperprolactinemia and renal water metabolism was found. It is concluded that PRL is not an important osmoregulatory hormone in man.

Adult↗

A catalogue of isohormones of human growth hormone based on quantitative polyacrylamide gel electrophoresis.

With the growing recognition that all polypeptide hormones exist in heterogeneous forms, i.e., isohormones, this study represents the initial development of a comprehensive catalogue of the various isohormone species of human growth hormone (hGH) in relation to molecular structure. The catalogue is based primarily on results obtained in quantitative polyacrylamide gel electrophoresis (PAGE) in a multiphasic buffer system optimized for characterization of hGH. Thus, hGH forms can be recognized in objective, numerical terms based on physicochemical parameters of molecular size and net charge. Isoelectric focusing in polyacrylamide gel; and PAGE in sodium dodecyl sulphate in the presence and absence of reducing agents supplement the quantitative PAGE criteria. Specific hGH immunoreactivity is necessary to completely distinguish hGH from hormones of similar size and charge properties (prolactin and chorionic somatomammotrophin). In the examination of eight standard hGH preparations obtained from four laboratories, all preparations exhibited multiple isohormone species, from two to five components per preparation. These identifiable components appear to represent the predominant species of a bidirectional continuum of hGH components, the continuum being in regard to both molecular size and charge. Within any given preparations, the continuum presents itself as a series of identifiable "charge isomers". Between preparations, in addition, there are size differences as well, which may relate to conformational changes (unfolding) in some preparations.

Electrophoresis, Polyacrylamide Gel↗

Myocardial injury associated with potassium arrest.

The relative efficacy of potassium-induced ischemic arrest using buffered, isosmotic potassium (25 mEq/liter) was compared with hypothermic arrest in an experimental protocol employing an intact canine heart preparation. Myocardial function (LVSW, dp/dt max), serum creatine phosphokinase levels, myocardial perfusion, and light and electron microscopical examination of the heart were assessed in five groups of 5 dogs each. There was one control group (90 minutes of bypass, no anoxia) and four experimental groups, each subjected to 1 hour of ischemic arrest and 30 minutes of reperfusion, comparing normothermic ischemic arrest (NIA), hypothermic ischemic arrest (myocardial temperature less than 25 degrees C) (HIA), normothermic potassium arrest (NKA), and hypothermic potassium arrest (HKA). Myocardial function decreased significantly following NIA and NKA but remained essentially equal in the control, HIA and HKA groups. Serum creatine phosphokinase analysis documented a significant increase in each group of animals: 2,250 mU after NIA, 1,778 mU after NKA, 1,388 mU after HIA, 1,220 mU after HKA, and 838 mU after control bypass. Left ventricular myocardial perfusion was unmeasurably low after NIA, reduced to 111 m/100 gm of tissue/min after NKA, and increased to 165 to 188 ml/100 gm/min in the control, HIA and HKA groups. Electron microscopical studies showed a range of myocardial changes, from probably irreversible damage after NIA to similar but less diffuse changes after NKA, and to potentially reversible changes after HKA and HIA with the least alteration from control after HIA. The results indicate that potassium arrest alone is not as effective as hypothermia in preventing ischemic injury, and the combination of hypothermia with a single 150 cc administration of potassium (25 mEq/liter) does not appear to provide significant additional protection.

Animals↗

Gram-preparative protein fractionation by isotachophoresis: isolation of human growth hormone isohormones.

Steady-state stacking (isotachophoresis) provides a preparative method in zone electrophoresis for the isolation of proteins in gram amounts. Up to four components were separated in 1000-fold larger quantities than those used in conventional electrophoresis. Separation occurs in order of free electrophoretic mobility. Recovery is nearly quantitative. The method was shown to be capable of resolving isohormones of human growth hormone. This fractionation is representative of difficult terminal isolations in biology. The best results are obtained when few components are fractionated at a high load. The method uses simple, small-scale apparatus. It does not utilize spacer ampholytes.

Buffers↗

Distribution, blood transport, and degradation of antidiuretic hormone in man.

The distribution, blood transport, and metabolic clearance of physiological concentrations of antidiuretic hormone were studied in 10 hydrated normal subjects with radioiodinated arginine vasopressin (125I-AVP). At 37 degrees C no binding of 125I-AVP to plasma proteins could be demonstrated, but some metabolites were associated with plasma proteins. 125I-AVP was rapidly distributed into a space approximating the extracellular fluid volume. Metabolic breakdown products became demonstrable within minutes after injection. The mean metabolic clearance rate of 125I-AVP was 4.1 ml/min/kg and the mean plasma half-life 24.1 min. Renal clearance had a mean value of 80 ml/min and accounted for 27% of the total metabolic clearance. It is concluded that in man antidiuretic hormone circulates as a free (non-protein bound) peptide, diffuses readily into the extracellular fluid space, and is metabolized within minutes. A plasma half-life of 24 min is consistent with the duration of antidiuresis after hormone administration or release.

Adult↗

Prolonged corticotropic action of synthetic human ACTH in man.

The corticotropic activities of synthetic human ACTH (revised structure), synthetic porcine ACTH (unrevised structure) and synthetic 1-24ACTH were compared in 8 normal men by measuring the magnitude and duration of the elevation of plasma 11-hydroxy-corticosteroids following the injection of 1 mg of the peptides. The duration of response was significantly longer after human ACTH than following porcine or 1-24ACTH, although the initial responses were identical. This difference was noted after both intramuscular and intravenous administration. The data suggest that the carboxyterminal of the ACTH peptide is of some importance for biological activity and that biological species specificity may exist.

11-Hydroxycorticosteroids↗

Corticotropic action of an intra-nasally applied synthetic ACTH derivative.

The corticotropic action of a synthetic ACTH derivative, D-Ser1 Lys17,18-1-18ACTH, after intranasal insufflation of 1 mg of the peptide was evaluated in 14 normal volunteers. Plasma cortisol and urinary 17-ketogenic steroids and 17-ketosteroids rose significantly over control values in all subjects (P less than 0.001). Plasma cortisol remained above the normal range for comparable clock times for 18 hr, but fell below 15 mug/100 ml after 12 hr. No evidence for suppression of the hypothalamo-pituitary axis was found the day after ACTH administration, as judged by normal plasma and urinary steroid values and normal diurnal variation. Intranasal administration of long-acting ACTH derivatives may provide a simple, painless and effective way to stimulate endogenous corticosteroid secretion.

17-Ketosteroids↗

Failure of endogenous plasmin to convert human growth hormone to its "activated" isohormones.

Human growth hormone B can be converted to its more acidic isohormones C, D, and E by limited enzymatic cleavage with purified plasmin in vitro. This process is accompanied by an increase of biological activity in the rat tibia line assay. A possible role of endogenous circulating plasmin in the in vivo formation of these isohormones was investigated. Human plasma, serum, glass-contact-activated serum, and serum extracts after the removal of protease inhibitors were incubated with ratioiodinated hGH-B and C for up to 24 h. Aliquots were analyzed at frequent intervals by polyacrylamide gel electrophoresis, followed by autoradiography and counting of radioactive bands. No evidence for interconversion or transformation to hGH-D and E was found. It is concluded that endogenous circulating plasmin does not play a major role in the conversion of hGH to its "activated" isohormones.

Adult↗