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Biomedical subjects

T Schmid

Publications and source records attributed to T Schmid.

At least 91 records · Page 5Linked to original sources
PubMed1991

Small bowel transplantation in the rat: impact of various immunosuppressive regimens on graft-versus-host reaction.

The effect of ciclosporin (CS) and methotrexate (MTX) on the development of graft-versus-host (GvH) disease was examined after small bowel allotransplantation in the rat. The drugs were tested either alone or in combination. Lewis small bowel allografts were transplantated into Brown Norway recipients in a heterotopic position. The native small bowel, spleen, liver, skin, mesenteric lymph nodes and the kidney of the recipients were examined histologically 5, 10 and 20 days after allotransplantation. Intraepithelial lymphocyte numbers were determined quantitatively in the native small bowel. The relative spleen weight of the host was determined after sacrifice for estimation of the severity of GvH disease. Grade I GvH reaction of the native small bowel occurred in the animals without immunosuppression, but graft rejection predominated in this group. Treatment with CS was effective in the early postoperative periods; after 10 and 20 days GvH lesions in the native small bowel were comparable to those observed in the allogeneic combinations. MTX had a detrimental effect on the allografts and the GvH reaction was augmented. When CS and MTX were combined, GvH lesions were comparable to those in the animals treated solely with CS. Animals, however, suffered from heavy side effects. The spleen, liver, lymph nodes and kidney exhibited only unspecific histologic changes, which could not unequivocally be recognized as a GvH reaction. This was true for all groups. As a conclusion it can be said that GvH reaction occurs in the early postoperative period in a fully allogeneic model and cannot be prevented by CS in the dosae used. MTX was not seen to be of any value in this regard.

Animals↗
PubMed1991

[Complete reconstruction of the natural anus in complicated rectal prolapse].

In a 44-year old woman a severe case of prolapse of the rectum was complicated by complete incontinence and rectal stenosis. Continence was restored by colo-anal anastomosis between an oral smooth-muscle-plasty and the anal skin introduced in a newly created anal canal by a distal voluntary muscle-plasty. The successfully applied one-stage technique in reestablishing non-voluntary and voluntary muscular continence is described in detail.

Adult↗
PubMed1990

[Respiration of patients with chronic lung disease at 500 and 1500 meter above sea level].

There is plentiful literature on respiration at high altitude (3000-8000 m above sea level) and its cardiopulmonary sequelae. But little is known about changes in ventilation and in pulmonary gas exchange at altitudes of 1,000-2,000 m above sea level. We studied 68 patients 500 and 1,500 m above sea level. On the arrival of the patients at 534 m above sea level we measured the arterial blood gases, pulse rate, respiratory rate and a breathing score. The same measurements were repeated on arrival at 1,500 m above sea level. A lung function test (FEV1, FVC, PEF, MEF 25-75) was also performed. The patients were divided into three groups: asthmatics, chronic bronchitics and restrictive patients. A control group was formed of patients without lung disease. Within all groups, the pO2 and the pCO2 diminishes significantly, no significant difference between the groups was found. In patients with lung disease oxygen saturation changes from 94.1% to 91.8% (COPD) and from 95.3% to 93.4% (restrictive patients). Age, smoking habits, lung function test and blood gases at 534 m are not predictors of the blood gases at altitude in COPD patients. But patients with restrictive lung disease show a positive correlation between age and change in pO2, as well as between severity of the restrictive disease and the change in oxygen saturation. The change of pO2 in COPD patients is not relevant clinically, as there is only minimal change in oxygen saturation. We conclude that patients of all degrees of COPD and patients with light to moderate restrictive lung disease can safely tolerate a difference in altitude from 534 to 1,500 m.

Aged↗
PubMed1990

[Intestinal angiodysplasia as a cause of severe intestinal hemorrhage--report of 4 cases].

Angiodysplasia of the small intestine alone cannot be differentiated histologically from hereditary hemorrhagic telangiectasia (Morbus Rendu-Osler-Weber). Isolated localisation in the small intestine is rare and requires surgery in the event of massive bleeding. Four cases of bleeding from angiodysplasias of the small intestine in patients having undergone surgery at our institution over a ten-year period are presented. In three patients the particular intestine was resected. Two of these patients had an uneventful follow-up of even and ten years, one patient relapsed and was rehospitalized for surgical treatment. The fourth patient, who showed angiodysplasias scattered over the entire small intestine, had no further bleeding over a three-year period after transmural ligations of the lesions found by intraoperative endoscopical diaphany.

Adult↗
PubMed1990

Altered distribution of MHC class II antigens on enterocytes during acute small bowel allograft rejection in rats.

Class II major histocompatibility complex (MHC) antigen induction was investigated on enterocytes of heterotopic rat small bowel allografts in the Lewis-Brown Norway strain combination and on isografts in the Lewis-Lewis strain combination. Ia antigens were detected with monoclonal antibodies using an immunoperoxidase technique. Generally, MHC class II antigens were not exhibited in the isografted group, with the exception of two long-term isografts that presented the same pattern as normal small bowel. In these cases, Ia was expressed in a patchy distribution predominantly in the villi, and only very few enterocytes stained positive in Lieberkühn's crypts. Allografted rats showed a typical pattern of Ia expression on the enterocytes during the rejection course. The initial expression was confined to the crypts, indicating a very early stage of rejection when compared to histological findings. More advanced stages of rejection were accompanied by increasing Ia biosynthesis in the crypts and Ia expression by the epithelium lining the villi. Cyclosporin (CyA) was not able to fully inhibit MHC class II antigen expression; however, the appearance of Ia was delayed.

Animals↗
PubMed1990

A new technique for venous anastomosis of pancreatic allografts.

Venous thrombosis is still a frequent cause of graft loss after pancreas transplantation where the portal vein is used for revascularisation. It is known that an increase in velocity of venous flow decreases the incidence of thrombosis. According to the equation of continuity, the flow velocity in the portal vein should decrease to 25% as compared with that in the splenic vein. Based on the rheological considerations we started to use the superior mesenteric vein, the diameter of which is similar to that of the splenic vein, for revascularisation of pancreas transplants after sewing the portal vein closed at its origin. This technique has been applied in 12 consecutive pancreatic transplants. Two patients died of a cerebrovascular accident and myocardial infarction, respectively. The only single pancreatic graft was lost due to rejection. The remaining 9 patients are alive and well between 2 and 23 months with normally functioning grafts. Another advantage of this technique is that a full-length portal vein can be left with the liver graft in the event of simultaneous liver and pancreas procurement.

Adult↗
PubMed1990

[Clinical experiences with 50 pancreas transplantations].

Between 1979 and December 1987 a total of 50 pancreas transplants were performed, 41 of them together with a kidney from the same donor. End-stage diabetic nephropathy was the indication for the combined procedure, and progressive pre-proliferative retinopathy for a single pancreas transplant. A segment consisting of body, tail but also major parts of the head of the gland was used. Technique-related complications or prolonged hospitalization prompted three changes in surgical technique. In the first five patients the pancreatic duct was occluded at the time of transplantation and in the subsequent eleven cases the graft was anastomosed to a Roux-Y-loop of jejunum. In a series of 17 patients thereafter the pancreatic duct was occluded after stabilization of graft function, and in the most recent 17 patients the pancreatic juice was drained into the urinary bladder. Prophylactic immunosuppression consisted of steroids and azathioprine for the first two patients. From 1981 to 1986 cyclosporin and prednisolone were given and from then on azathioprine was added as a third drug. Patient survival at one year was 25% in the first group, 80% in group II, 97% in group III and 88% in group IV. Cardiovascular and septic complications were the main causes of death. None of the group I transplants functioned at one year. Graft survival rates at one year for the pancreas and the kidney in groups II, III and IV were calculated at 30%, 70%, 58.8% and 77%, 86%, 72% respectively. In 16% of the long-term survivors significant amelioration and in another 50% stabilization of diabetic retinopathy occurred.

Adult↗