Search PubMed⌕ Search

Biomedical subjects

W Brendel

Publications and source records attributed to W Brendel.

At least 73 records · Page 4Linked to original sources

[Effectiveness of various immunoglobulin preparations administered by the intravenous route in peritonitis in the rat model].

Intraabdominal sepsis in rats was induced as a sublethal infection (mortality rate of controls: 60%-80%) and as a lethal infection (mortality rate of controls: 100%). The effectivity of different immunoglobulin (IgG) preparations alone or together with an antibiotic combination therapy (gentamicin + piperacillin) was then tested. In sublethal infection, 5 intravenous administrations of three 7S-IgG preparations and a plasmin-treated preparation at a dosage of 0.5 g/kg b.w. were able to reduce lethality only slightly, whereas a 5S-IgG preparation was able to reduce lethality by 30% significantly. Intraperitoneal administration of two 7S-IgG preparations (s-sulfitolysis, 42 degrees C/ammonium sulfate) and the 5S-IgG preparation reduced lethality to 27%, 37% and 47%, respectively, whereas another 7S-IgG (iodoacetamide/dithiothreitol) and a plasmin-treated preparation failed to reduce lethality significantly. The convincing results obtained with the 5S-IgG preparation are probably due to the fact that Fc-mediated side-effects could be avoided. The better effectivity of intraperitoneal compared to intravenous administration can be explained by much higher concentrations of specific antibodies at the site of infection. In the lethal infection model the mortality of animals treated with antibiotics only was 50%. The additional intravenous administration of 7S-IgG (42 degrees C/ammonium sulfate), a plasmin-treated preparation and a 5S-IgG was unable to reduce mortality any further. These findings are in contrast to several publications which postulate synergism of antibiotics and immunoglobulins.

Animals↗

Fragmentation of gallstones by extracorporeal shock waves.

We treated nine patients with functioning gallbladders containing one to three symptomatic radiolucent stones not larger than 25 mm in diameter, as well as five patients with stones in the common bile duct that were not removable by endoscopic procedures, by means of extracorporeally generated shock waves during general anesthesia. The patients with gallbladder stones received adjuvant treatment with a combination of ursodeoxycholic acid and chenodeoxycholic acid. All gallbladder stones were disintegrated into sludge or fragments with diameters of no more than 8 mm. In six of the nine patients the fragments disappeared completely within 1 to 25 weeks. No adverse effects were detected during a follow-up period of 10 to 34 weeks, except transient biliary pain in two patients, with mild pancreatitis in one. In four of the five patients with common-bile-duct stones, shock-wave treatment permitted stone disintegration and successful endoscopic extraction or spontaneous passage of fragments. We conclude that gallstone disease may be treated successfully and without serious adverse effects by extracorporeally generated shock waves in selected patients.

Adult↗

Sensitization against brain gangliosides after therapeutic swine brain implantation in a multiple sclerosis patient.

The case history is presented of a patient with multiple sclerosis who developed acute polyradiculoneuritis 11 days after subcutaneous implantation of a swine brain preparation. By means of lymphocyte transformation tests (LTT), sensitization against brain gangliosides could be demonstrated 16 days after the implantation. A second patient who underwent the same treatment showed neither clinical symptoms nor sensitization against brain gangliosides in the LTT. Patients did not show reactivity when tested with myelin basic protein. The polyradiculoneuritis was caused by the immune response to the implanted swine brain cross-reacting with human nervous system gangliosides.

Adult↗

Peripheral blood and intrarenal phagocytic chemiluminescence during acute kidney graft rejection.

During organ graft rejection, soluble mediators of inflammation are released into the polymorphs (PMNs) and monocytes recruited from the blood. One functional capacity of polymorphs and monocytes/macrophages is the production of cytotoxic activated oxygen species upon stimulation, which may contribute to the rejection process. Nothing is known about the influence of allograft rejection on this inflammatory cell property. Chemiluminescence (CL) allows measurement of respiratory burst capacity in small cell samples. Zymosan-induced and luminol-amplified CL of diluted whole blood, separated PMNs, and mononuclear cells from peripheral venous blood, as well as of intragraft phagocytes was measured after allogeneic and autologous kidney transplantation in untreated dogs. CL of separated PMNs, mononuclear cells, and intragraft phagocytes was significantly elevated during allograft rejection. In autologous kidneys transplanted to recipients of allografts, CL was also increased in the autologous grafts during rejection of the allogeneic ones, indicating a systemic alteration in phagocyte function.

Animals↗

[Effects and side effects of taurolin in experimental peritonitis in the rat].

Taurolin (2%) was tested in a peritonitis in the rat. In a control group without treatment the mortality was 63% 80 h after infection. Intraperitoneal application of taurolin did not change this mortality rate but delayed the mortality by 8 h. Intravenous administration of taurolin increased mortality to 87%. In a second experimental protocol the dosis of bacteria was increased and 100% of the animals died within 16 h. Gentamicin-Piperacillin therapy reduced the mortality to 50%. With taurolin this effect of antibiotics could not be improved. In both groups taurolin was not able to reduce toxic lung edema. With these results and the knowledge of the literature taurolin cannot be recommended for clinical use.

Animals↗

A new model for hetero-orthotopic heart-lung transplantation in the dog.

A method of hetero-orthotopic heart-lung transplantation is described in the dog. The model was developed to study patterns of rejection in the transplanted heart and lung, since the dog will not survive bilateral pneumonectomy and loss of the Hering-Breuer reflex. After removal of the recipient's left lung the donor heart and left lung are explanted en bloc. End-to-end connection is made of both left main bronchi, and the donor aorta is joined end-to-side with the recipient's descending aorta. An atrio-atrial anastomosis is performed between the recipient's left and the donor's right atrium. Four experiments were done to develop the surgical technique and 10 long-term studies were performed to investigate rejection patterns. The average survival rate of these animals was 28.5 +/- 8.3 days, ranging from 5 to 53 days. Causes of death were not due to operative complications. Heterotopic heart-lung transplantation is an uncomplicated surgical method which does not require cardiopulmonary bypass or anticoagulation and allows the investigator to study heart and lung grafts in dogs for long-term periods after surgery. Bronchoscopy, bronchoalveolar lavage, and heart and lung biopsies of both donor and recipient organs can be performed.

Animals↗

Prolonged reversal of diabetes in the rat by transplantation of allogeneic islets from a single donor and cyclosporine treatment.

Islets were isolated using neutral red as a dye to exclude lymphatic and acinar impurities in the transplant preparation. In a one donor-one recipient model, intraportally transplanted isogeneic islets survived indefinitely. Mean graft survival could be prolonged from 5 to 90 days, using a 3-dose rejection prophylaxis with CsA in allografts of (DA [RT1a]----Lew (RT 1l). Histological examination revealed intact islets in the grafted normoglycemic animals. Immunohistochemical staining of these islets showed B cells with insulin-rich cytoplasma. Blood glucose levels and the results of i.v. glucose tolerance tests 50 days after transplantation are presented. The different outcomes of our experiments are discussed.

Animals↗

Shock waves: a new physical principle in medicine.

Shock wave therapy of kidney- and gallstones, i.e. extracorporeal shock wave lithotripsy (ESWL), is a new, noninvasive technique to destroy concrements in the kidney, the gallbladder and in the ductus choledochus. This method was developed by the Dornier Company, Friedrichshafen, FRG, and tested in animal experiments at the Institute for Surgical Research of the University of Munich. In the meantime, kidney lithotripsy has gained world-wide acceptance. More than 60,000 patients suffering from urolithiasis have been treated successfully, what made surgical removal of their kidney stones obsolete. Gallstone lithotripsy is, however, still at the very beginning of clinical trial. Lithotripsy of gallbladder stones will have to be applied in combination with urso- or chenodesoxycholic acid in order to obtain complete dissolution of the fragments. Potential hazards to living tissues are briefly mentioned. Since the lung is particularly susceptible, shock waves must enter the body at an angle which ensures that lung tissue is not affected.

Cholelithiasis↗

Induction of oral tolerance in rats without Peyer's patches.

The induction of oral tolerance after ingestion of antigen has been reported in several animal models. The precise mechanisms responsible for this unresponsiveness are not well understood. As some investigations have suggested a key role of Peyer's patches suppressor T cells, an animal model was developed in which the PP were surgically removed. Using this model, the influence of the PP on the induction of oral tolerance against SRBC was investigated. In order to induce tolerance, the rats were fed SRBC on four consecutive days. On Day 5 they were i.p. challenged by injection of SRBC, and 5 days later the number of immunoglobulin-secreting cells against SRBC was determined within the spleen. Using this protocol, the oral tolerance induction could be shown very clearly in control animals as well as in rats without PP. Therefore, tolerance induction is possible in the absence of PP-T cells. Other mechanisms must be responsible for the tolerance induction in this model.

Animals↗

[Liver perfusion and oxygenation with isoflurane].

The influence of 0.7, 1.4 or 2.1 vol % isoflurane on hepatic blood flow and hepatic tissue oxygenation was studied in 12 dogs under basal anaesthesia with i.v. piritramid. Blood flow was measured by the microsphere method (phi = 15 micron). Tissue pO2 was determined by a platinum multiwire electrode and by measuring hepatic venous pO2. Isoflurane effected a marked fall in arterial blood pressure in these surgically not stimulated animals. However, cardiac output fell only moderately due to a considerable reduction in systemic vascular resistance. Both local tissue pO2 and venous pO2 were decreased with isoflurane. A potentially hazardous reduction in hepatic tissue pO2 was found predominantly with high isoflurane concentrations. The decrease in hepatic tissue pO2 results from disadvantageous effects on hepatic O2-balance: total hepatic blood flow decreases, whereas splanchnic O2 consumption increases. The lower blood flow is due to a reduction of portal blood flow whereas arterial perfusion remains unchanged. The increase in splanchnic O2 consumption possibly results from an elevated O2 consumption of the liver. Further studies have to clarify whether the disadvantageous effects of high isoflurane concentrations fail to appear when pain-induced stimulation of the sympathico-adrenergic system counteracts the fall in arterial blood pressure.

Animals↗

Monitoring immunocompetent cells in the peripheral blood of stomach cancer patients after splenectomy and gastrectomy.

The status of lymphocyte subpopulations in splenectomized (Sx) stomach cancer patients (SCa-patients), assessed by monoclonal antibodies, has not been evaluated so far. Therefore subsets of peripheral white blood cells were monitored prior to and following surgical treatment in gastrectomized (Gx) and Sx (n = 64) as well as in non-Sx patients (n = 39). Postoperative surgical complications were more frequent in the Sx group. However, the 2-year survival rate of this group was higher than in non-Sx patients. Lymphocytes were significantly decreased in both groups of patients during the early postoperative period. Monocytes and polymorphonuclear cells (PMN) increased correspondingly. A significant loss of lymphocytes and their subsets in Sx patients was observed during the 1st-3rd postoperative days as compared to the Gx only patients. The OKT4/OKT8 ratios did not differ in either group of patients, whereas the OKT3+anti-B-Ly2 ratio was significantly increased in Sx patients 1 to 3 days postoperatively.

Antibodies, Monoclonal↗

Hemodynamics and oxygen transport after partial and total blood exchange with pyridoxalated polyhemoglobin in dogs.

The effects of a pyridoxalated polyhemoglobin solution (SFH-PLP)n-solution) on cardiovascular hemodynamics and oxygen transport were investigated in a model of partial and total blood exchange in seven dogs. Cardiac output, mean arterial pressure and heart rate were essentially unchanged, even after total blood exchange, due to the long plasma half-disappearance time of (SFH-PLP)n (36 h) and due to the addition of albumin to the solution. The oxygen-binding capacity of (SFH-PLP)n was 1.1 to 1.2 ml O2/g hb. Oxygen availability was reduced to about 50%, resulting from the low hemoglobin concentration and the decreased oxygen-binding capacity of (SFH-PLP)n. Since cardiac output did not increase, O2-consumption was maintained by an increase in O2-extraction from 21 to about 50%. However the decrease in mixed venous PO2 to values not below 30 mmHg (4.00 kPa) proves the sufficient unloading capacity of (SFH-PLP)n. The adequate tissue oxygenation of (SFH-PLP)n could be demonstrated by the lack of a metabolic acidosis, the essentially unchanged PO2-histograms of the skeletal muscle and the only moderate decrease in mixed venous PO2. Four dogs survived for more than 3 days; three of them were long-term survivors. This suggests that oxygen supply was maintained by (SFH-PLP)n until red blood cells were restored.

Animals↗

Serial evaluation of absolute spleen cell numbers in Lewis lung tumor-bearing mice.

Subcutaneous (sc) transposition of the spleen followed by fine needle biopsies (FNB) from the organ allows the evaluation of relative numbers of splenic cells in Lewis lung tumor-bearing mice. Absolute cell numbers (N) can be calculated when the aspirated cells are weighed on a precision balance (m) and counted (c) after resuspension in a defined volume (v): N = C X V/m X M. The weight from the whole spleen (M) is derived from a calibration curve. Splenic nucleated cells and their subsets--as determined by the use of monoclonal antibodies--can thus probably be evaluated with a degree of accuracy which was not possible before. Shifts of splenic cells from and to the organ can be monitored.

Animals↗

[Revascularization of peripheral nerve transplants. Stereomicroangiographic evaluation of revascularization in allogeneic transplants, allogeneic transplants with cyclosporin A therapy and autologous transplants].

Allogeneic nerve grafts of the sciatic nerve longer than 3 cm were transplanted between August- and Wistar rats. One group of animals were treated with 17 mg/kg body weight Cyclosporine A from day 1-28. Autologous nerves served as controls. At various postoperative days contact microangiography, stereoangiography, microdensitometry and histology were performed. Allogeneic untreated grafts were rejected at day 7. Undisturbed neovascularisation was only seen in autografts. In Cyclosporine A treated rats a gradually reduced revascularisation could be observed until day 90.

Angiography↗