Search PubMed⌕ Search

Biomedical subjects

B Luther

Publications and source records attributed to B Luther.

At least 55 records · Page 3Linked to original sources
PubMed1991

Superoxide dismutase promotes ATP and GTP restoration of rat small intestine during postischaemic reperfusion.

The small intestine of rats was prepared according to a procedure which is taken for preservation and transplantation in clinical practice. The blood supply of the rat intestine was completely interrupted for 30 min in situ. During this period the lumen of the intestine was rinsed with Ringer-lactate solution. This ischaemic period was followed by 10 min of reperfusion. As a result a decrease in ATP, and GTP concentrations, and of the total adenine nucleotide content during the preservation period occurred. In animals pretreated with superoxide dismutase (i.v. application; superoxide dismutase preparation from human erythrocytes) an accelerated restoration of nucleotide concentrations during the reperfusion period was observed. From the beneficial effect of superoxide dismutase it can be concluded, that there is a considerable formation of active species of oxygen which disturb the energy generation by the mitochondrial respiratory chain during ischaemia/re-oxygenation.

Adenine Nucleotides↗
PubMed1990

Antigenic cross-reactivity between Borrelia burgdorferi, Borrelia recurrentis, Treponema pallidum, and Treponema phagedenis.

The antigenic cross-reactivity between different Borrelia and Treponema species was determined by the indirect immunofluorescence antibody test and sodium dodecyl sulphate-polyacrylamide gel electrophoresis followed by immunoblotting. The protein profiles of Borrelia burgdorferi, Borrelia recurrentis, Treponema pallidum, and Treponema phagedenis revealed essential differences. Using immunoblotting, rabbit immune sera to B. burgdorferi and B. recurrentis exhibited strong cross-reactivities to heterologous borrelial antigens and, to a lesser extent, to treponemal antigens. Immune sera to T. pallidum and T. phagedenis reacted with heterologous treponemal antigens, but exhibited lesser cross-reactivities to borrelial antigens. Five B. burgdorferi and seven T. pallidum major antigens were not cross-reacting with antisera raised against T. pallidum and B. burgdorferi, respectively. However, absorption of the investigated antisera with a T. phagedenis ultrasonicate eliminated cross-reacting borrelial and treponemal antibodies.

Absorption↗
PubMed1990

[Changes in the motility of the small intestine after autologous and allogenic transplantation in the dog].

The early and the late motility of the donor organ was measured after 13 allogeneic and 4 autologous small bowel transplantations in mongrel dogs. The postoperative motility indices were increased in contrast to the preoperative values. The activity of allogeneic transplants were greater than these of autologous intestinal segments. The basal tonus of the intestinum obtains a higher level because inhibiting central nervous influences are omitted after the denervation of the mesenteric radix. The contraction frequency remained constant. Disturbances of the motility model with irregular contractions and decrease of the frequency become evident in case of ischemia and rejection of the transplant still before the clinical signs.

Animals↗
PubMed1990

[Biochemical serum parameter changes during and after autologous small intestine transplantation in animal experiments. I. Intra- and immediate postoperative period].

Biochemical parameters sodium, potassium, lactate, alkaline phosphatase, ASAT, and ALAT were examined at the beginning of the operation, before, and 0, 2, 4, 6 hours after implantation of a small bowel autograft in an autologous model of intestinal transplantation in dogs. By the way of these early biochemical studies we have got information about metabolic situation during organ transplantation, efficiency of preservation and vitality of the graft. Using the given method safe preservation of small bowel can be guaranteed. Postoperatively only little changes of laboratory parameters occur.

Alanine Transaminase↗
PubMed1989

Effects of alpha 1-adrenoceptor blocker prazosin on microcirculation in terminal rabbit ileum.

The influence of the specific alpha 1-blocker prazosin on the microcirculation of the terminal ileum was examined in 10 rabbits. For this purpose an isotope clearance test was carried out by administering 133-Xenon solution into the intestinal wall before and after the intra-arterial injection of prazosin (1.0 mg) via the superior mesenteric artery. These experiments were supplemented by haemodynamic and thermographic measurements in a further group of 5 rabbits. Due to the systemic circulatory effect of prazosin, i.e. the drug-induced hypotension, the bowel segment exhibited, contrary to expectations, significantly delayed values for isotope elimination indicating a reduced local tissue clearance and blood supply. Thermographic observations also confirmed the impairment of mesenteric blood flow after prazosin. Therapeutic applicability of alpha 1-adrenoceptor blockers to treat intestinal circulatory disturbances in diseases of vascular genesis thus remains dubious.

Adrenergic alpha-Antagonists↗
PubMed1989

Motility, haemodynamics and responsibility to vasoactive agents after revascularization of autotransplanted small intestine segments in the dog.

Functional and haemodynamic changes occurring after revascularization of an autotransplanted small intestine segment were studied in acute experiments performed in 10 dogs under pentobarbital anaesthesia. Intestinal motility and mesenteric blood flow of the segment were measured with intraluminal pressurized balloon and electromagnetic flowmeter, respectively. The time-course of observations was divided, according to the findings, into three main periods (phases 1 to 3). In the initial phase (1) the bowel exhibited very slight spontaneous motility which was found to increase moderately but significantly after denervation and isolation of the graft still left in situ before transplantation (phase 2). After declamping of anastomoses of the retransplanted graft (which was protected by cooling to 4 degrees C after being removed from the body) a short period (approximately 2 min) of reactive hyperaemic flow increase was observed in association of vigorous bowel movements lasting for a more prolonged (approximately 15 min) period of time (phase 3a and 3b). Reactivity of the retransplanted vasculature as compared to the denervated control revealed a marked relative shift in adrenergic balance, tested by dopamine, to the vasoconstrictor range, but it showed no change in responses to general haemodynamic or haemorheologic interventions, tested by veratrine and pentoxifylline, respectively. However, the basic levels of blood supply (controlled also by thermography) and systemic blood pressure remained unaltered after transplantation. Regarding the critical role of functional changes immediately after transplantation in determining the survival of bowel grafts, these observations may contribute to a more effective monitoring of surgical interventions.

Animals↗
PubMed1989

[Cellulose implants--biostability and tissue reaction].

In order to test blood detoxication systems on cellulose basis (hollow fibers as separation material) histomorphological examinations were performed after incorporation in 10 rabbits. Already after 12 days granulation tissue around the cellulose fibers was found as foreign body reaction, but the implants remain uninjured up to 86 days. The lateral stability of the hollow fibers was unchanged. Further investigations are necessary on the radial stability and the transport properties of the cellulose fibers.

Animals↗