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Biomedical subjects

W Brendel

Publications and source records attributed to W Brendel.

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

[Changes in microcirculation of various layers and regions of the stomach wall following selective proximal vagotomy. Animal experiments using radioactive-labeled plastic particles].

Changes of the blood flow in the different layers and regions were determined with radioactively labelled microspheres after proximal vagotomy. Under normal conditions and vagal stimulation a significant reduction of the flow in corpus and antrum up to 74% can be observed at least over the time of 3 weeks. This decrease of bloodflow in the stomach together with a reduction in secretion can possibly be responsible for the successful treatment of diffuse bleeding in erosive gastritis by selective vagotomy.

Animals↗
PubMed1982

Effects of prolonged cold injury on the subcutaneous microcirculation of the hamster. I. Technique, morphology and tissue oxygenation.

An animal model is described allowing for direct measurements of local tissue PO2, microhemodynamics and vascular density in the event of a prolonged non freezing cold injury. The model consists of implanting a transparent skin fold chamber in the dorsal skin fold in hamsters and of inserting two permanent indwelling catheters in jugular vein and carotid artery, respectively. The microcirculation was studied using a Wild Photomacroscope for photography and a platinum multiwire electrode for measurements of local PO2 in the conscious animal. After 72 h of recovery from anesthesia and surgery, the experimental was started with the animal immobilized. The decrease of local s.c. temperature was achieved by perfusing a heat exchanger with distilled H2O and Isopropanol 70% (1:1) at a rate of 81/min with the heat exchanger located directly beneath the aluminium frame of the chamber. With this technique, a decrease in local tissue temperature from 28 degrees C to 15 degrees C could be obtained within 15 min and was kept constant for 60 min. After photography of the microcirculation and local PO2-measurements, the local temperature was further reduced to 5 degrees C with 15 min. Sixty minutes later, the area exposed was slowly rewarmed from a level of 5 degrees C within 30 min. This procedure was repeated in intervals of 24 h over a period of five days. During the course of the experiments, local PO2 values shifted toward hypoxic or even anoxic values. Intravital microscopic observation revealed aggregate formation, stasis and obstruction of capillary flow associated with pronounced tissue anoxia after five cold exposures. This event resulted inevitably in tissue necrosis and scar formation after seven consecutive exposures to cold. It is concluded that this model can be used to study the effects of local non freezing cold injury in a precisely reproducible manner.

Animals↗
PubMed1982

First clinical experience with extracorporeally induced destruction of kidney stones by shock waves.

We performed extracorporeally induced destruction of kidney stones on 72 patients. No complications have resulted from the tissue exposure to high energy shock waves. Clearance studies before and after the shock wave treatment indicate no changes in renal function. The method was used successfully in all patients with stones in the renal pelvis. In none of these patients was an open operation required. Two patients with ureteral stones also were treated with shock waves but had to be operated upon because of insufficient destruction of the stone.

Electric Stimulation Therapy↗
PubMed1981

Direct proof of autoreactive T-lymphocytes in experimental allergical encephalomyelitis (EAE).

A microcytotoxicity assay to prove directly against myelin basic protein directed cytotoxic T cells has been developed. Spleen and lymph node cells of myelin basic protein immunized strain 13 guinea pigs were restimulated in vitro with basic protein for 5 days and used as attacking cells. Autologous spleen cells were coated with about 10(7) molecules basic protein by hydrophobic attachment, labelled with 51Cr and used as targets. Concentration dependent lysis (74% corrected lysis) was measured with attackers gained 12 days post immunization. Controls performed using unspecific (PHA) stimulated attackers and non BE coated target showed no lysis. Lysis was shown to be MHC restricted. The test may serve as a tool for the assay of human demyelinating diseases.

Animals↗
PubMed1981

[Detection of antitumor-antibodies in patients with tonsillar carcinoma (author's transl)].

48 patients with squamous cell carcinoma of the tonsil were tested for autologous and allogeneic antitumor-antibodies directed against squamous cell carcinoma cells. The use of autologous serum avoids the need of absorption. Antibodies detected at the time of tumor extirpation could also be used to label their specific antigen of cells from swabs of the oral cavity. Such a surface fluoreszens appeared in 5 patients between 3 and 6 months before recurrency and could be followed during the whole course of disease. Besides very low amounts of antibodies of the IgA- and IgM-class the main portion was IgG. While these antibodies reacted in a similar degree with allogeneic tonsillar carcinomas cross reaction with other allogeneic tumor cells (bladder--kidney carcinoma) could not be detected.

Antibodies, Neoplasm↗
PubMed1980

Extracorporeally induced destruction of kidney stones by shock waves.

High-energy shock waves were used to disintegrate kidney stones in dogs and man. In 96% of 60 dogs with surgically implanted renal pelvic stones, the fragments were discharged in the urine. The same effect was achieved in 20 out of 21 patients with renal pelvic stones. In the twenty-first patient, a staghorn calculus was broken up to facilitate surgical removal. 2 patients with upper ureteric stones also received shock waves, but their stones had to be removed surgically; in 1 of these the stone had been embedded in the ureteric wall by connective tissue. The procedure can in many cases be done under epidural instead of general anaesthesia. Side-effects consisted of slight haematuria and, occasionally, of easily treatable ureteric colic. They were probably due to passage of fragments down the ureter. Disintergration of kidney stones by shock waves seems to be a promising form of treatment that reduces the need for surgery.

Adult↗
PubMed1980

Are bloodflow changes after selective proximal vagotomy responsible for a necrosis in the gastric wall?

Animal experiments were performed to investigate bloodflow distribution before and after selective vagotomy to explain gastric mucosa necrosis found in some patients after vogtomy. Flow measurements were made using the microsphere technique. Changes in the microcirculation were determined under basal and stimulated conditions (250 mg 2-desoxy-D-glucose). After selective vagotomy a reduction in bloodflow of up to 50% could be observed in all layers of the stomach. There were no differences in the bloodflow along either the lesser or greater curvature under basal conditions. In the stimulated stomach, however, the increase in bloodflow along the lesser curvature was higher, although the vessels of this region were mostly altered by SPV operative procedure. From these results it can be concluded that a reducton of arterial input after selective proximal vagotomy is probably compensated for by intramucosal or submucosal anastomoses. Therefore, necrosis in the gastric wall is not due to SPV but probably to other accompanying diseases.

Animals↗
PubMed1980

Osmotic adaptation of the brains of scalded rats to chronic increase in plasma Na+. Effects of corticosteroids.

The effect of chronically increased plasma Na+ concentration, secondary to scalding, on the cerebral electrolyte and water content was studied in rats. In contrast to findings in acute hypernatremia, the water content of the brain remained constant in these experiments. Cerebral adjustment to chronic hypernatremia is supposed to be brought about by an increase of osmotically active solutes in the brain. Regression analyses of the Na+ concentration in brain water versus the plasma Na+ concentration indicate that accumulation of Na+ in brain tissue is responsible only for about 50--60% of the osmotic adjustment to increased plasma osmolality in chronic hypernatremia. Except for animals receiving prednisolone, the cerebral K+ content remained constant. Therefore, it may be concluded that except for this group, formation of idiogenic osmoles comprises about 40--50% of the extra osmolality in brain. Aldosterone and spirolactone do not seem to influence osmotic adaptation of the brain, or formation of idiogenic osmoles under these circumstances. Prednisolone, however, seems to enhance cerebral accumulation of K+ in chronic hypernatremia. This was concluded from the close correlation between the K+ concentration in brain water and the plasma Na+ concentration found in this group.

Adaptation, Physiological↗
PubMed1980

[Isolation and identification of antigen-specific T-cell-receptors (author's transl)].

Experimental allergic encephalomyelitis was induced by injection of myelin basic protein into guinea pigs strain 13. Specific antigen binding T-cell receptors were isolated by means of a nylon net coupled with antigen. A phage immunoassay was set up as an analytical tool for detection of the receptors. They were found not to be identical with common immunoglobulins and have a molecular weight of 71,000.

Animals↗
PubMed1980

[Assessment of lymphatic cells in natural and artificial allografts (author's transl)].

Transfer of "passenger lymphocytes" within a transplant initiates allogeneic rejection. As compared with peripheral lymphocytes, which show no different in vitro reaction, infiltrating cells from natural and artificial grafts are good stimulator, bad responder but powerful suppressor cells. These T-suppressor cells, which arose during rejection are enriched in the graft. The assumption is that the function of this relatively small number of lymphocytes is to suppress the local immunological rejection mechanisms. They cannot inhibit the proliferation of peripheral cytotoxic cells.

Animals↗
PubMed1979

Microcirculation and blood volume in rats before and after spinal cord injury.

Blood flow, cardiac output, blood pressure, indicator mixing time and blood volume were measured in rats before and after spinal cord injury. After cutting off the spinal cord blood flow decreases markedly in the paraplegic area but also in the main organs of the animals. Only the blood supply of the lung increases by this manipulation. As blood volume and the blood pressure is decreased and the indicator mixing time delayed the situation of the spinal cord injury can be compared with the situation after acute blood loss. Therefore it is proposed to include circulatory disturbances into the conception of the acute spinal shock situation.

Animals↗