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Biomedical subjects

T Schmid

Publications and source records attributed to T Schmid.

At least 73 records · Page 4Linked to original sources
PubMed1993

Increase in intraepithelial lymphocytes as an early marker of rejection in a fully allogeneic rat small bowel transplantation model.

In a model of fully allogeneic heterotopic rat small bowel transplantation, the changes in intraepithelial lymphocyte (IEL) number and subpopulations were analysed. During early phases of rejection (5th postoperative day) a 4-fold increase in the number of IEL was observed when compared with native small bowel (4.05 vs. 15.84 IEL/100 epithelial cells). When cyclosporine was given, counts were still as high as 11.4 and 12.58 on the 5th and 10th postoperative days, respectively. The percentage of CD8+ IEL, constituting a major population (84%) in the untreated small bowel, was significantly decreased (46.4%) during early phases of rejection. At that time, the majority of intraepithelial mononuclear cells were both CD8- and CD4-. In cyclosporine-treated animals, this was not observed until the 10th postoperative day. Some 23% of IEL in untreated animals expressed MHC class I antigens of the host; 17.2% (5th postoperative day) and 19.8% (10th postoperative day) did so in the cyclosporine-treated animals. Transmission electron microscopy revealed lymphocytes that bore cytoplasmic buds and pseudopods protruding between the enterocytes. There was no morphological difference between the IEL of rejected allografts and native small bowel. Due to the unspecific histologic changes associated with rejection, interpretation of histopathologic findings in mucosa biopsies of the allograft can be rather troublesome. An increase in the number of IEL is therefore a welcome additional marker of rejection.

Animals↗
PubMed1993

Regeneration of sympathetic activities in small bowel transplants.

In order to study the activity of noradrenergic nerve fibres along mesenteric arteries in small-intestinal grafts, the entire jejunoileum was transplanted heterotopically in an isogeneic rat model (group I, n = 12). To assess their influence on graft motility, 9 cm of jejunum were transplanted in an orthotopic position and three bipolar electrodes sutured to the seromuscular layer of the graft (group II, n = 10). Fasting motility was recorded up to postoperative day 42. Animals of group I were sacrificed from day 7 on at weekly intervals and mesenteries were analysed histochemically by fluorescence microscopy. After the 1st and 2nd week, grafts were found to be completely depleted of noradrenaline. At the end of the 3rd week, fluorescence became detectable along graft mesenteric arteries and showed normal intensity from the end of week 4. Migrating myoelectric complexes (MMCs) were present in all animals of group II. The variability of the MMC period (mean 12.6 min; SD 6.2 min) expressed as variation coefficient (median 36.5; 14.6-74) did not change during the observation period. From these findings it is concluded that there are no extrinsic noradrenergic activities in rat small-intestinal transplants for the first 3 postoperative weeks but they do recover there after. Their influence on graft function remains unclear: MMC periodicity, however, was no influenced.

Animals↗
PubMed1993

[Is selective use of intraoperative cholangiography in elective cholecystectomy justified?].

Operative cholangiography (IC) represents the most reliable investigation for common bile duct stones even during laparoscopic cholecystectomy (CHE). To reduce operating time, safety of selective IC was analysed in the last 308 consecutive patients undergoing conventional elective CHE. Obvious indication for common bile duct investigation excluded, IC was performed only in case of elevated liver function tests (n = 83, 26.9%), in 12 cases (14.5%) with positive in 2 cases (2.4%) with false positive result. In 255 (73.9%) patients IC was omitted. All patients were controlled after 4 months: no retained duct stone became evident in any case. Selective IC is safe and cuts time.

Adolescent↗
PubMed1993

[Blind loop of the large intestine--bypass enteropathy or diversion colitis?].

Investigating three patients with longstanding diarrhoea, severe abdominal bloating and cramps revealed an exclusion of the right hemicolon in all patients and additionally of the terminal ileum in one of them. The anastomosis of the ileo-colic bypass, performed decades ago due to complicated appendicitis, was stenotic in two of them. Because a classical blind-loop-syndrome could not be proven, the functional disorder is described as a clinical entity characterized by signs of bypass-enteropathy and diversion-colitis. The importance of the radiological examination for diagnosis and therapy-planing is emphasized, because endoscopically and histologically Crohn's disease might be suspected. The surgical reintegration of the bowel into the orthograde continuity of the intestinal tract is recommended as the causative treatment. Symptoms disappear completely and patients win normal health even after some decades, because the morphological signs of inflammation are reversible and bowel function is not lost during the exclusion.

Adult↗
PubMed1992

Endosonographic differentiation of mucosal and transmural nonspecific inflammatory bowel disease.

Thirty-seven patients with nonspecific inflammatory bowel disease were examined with an ultrasonic colonoscope and the inflammation classified as mucosal or transmural. Mucosal inflammation was characterized by preservation of the five-layer structure of the wall with thickening of the submucosa. Transmural inflammation was endosonographically defined as sectional interruption or loss of the five-layer structure. In 14 of the 37 patients a colectomy was performed. Examination of 3 of the 14 resected specimens revealed inflammation confined to the mucosa. This was consistent in all three cases with the preoperative endosonographic evaluation. Eleven of the 14 resected specimens showed sectional transmural inflammation. Ultrasonographically all of the 11 patients fulfilled the criteria for transmural inflammation, whereas endoscopic and microscopic signs were consistent with transmural inflammation in 9 of the 11. Endosonography of the colon enables definition of mucosal inflammation thus providing criteria for selection of patient for ileoanal pouch construction.

Colon↗
PubMed1991

[Ileostomy--stabilization by stapler technique].

In order to prevent nipple-sliding of the everted small bowel, conventional Brooke ileostomies in 26 patients were stabilized on both sides of the mesentery by longitudinal rows of staples. There were no early complications. With respect to historical controls with unstapled ileostomies, late complications (retraction, prolapse) could be reduced from about 16 to 0% in a median observation time of 2 years. The ileostomies were stable in size and form and therefore appliances were facilitated.

Crohn Disease↗
PubMed1991

Pancreatic transplantation with delayed duct occlusion versus bladder drainage: long-term results.

Between April 1985 and August 1990 a total of 51 combined pancreas kidney transplants and 6 single pancreas transplants were performed in 51 Type 1 (insulin - dependent) diabetic patients suffering from end-stage diabetic nephropathy and three patients with proliferative retinopathy. In 17 transplants the pancreatic duct was occluded with a mean delay of 53 days (Group 1). Because of a high incidence of local complications associated with a prolonged hospitalization this technique was abandoned despite favourable results: The actual survival rates for patients, pancreas and renal allografts at 1 year are 94%, 72% and 93%, respectively. From 1987 a total of 39 consecutive segmental pancreas grafts were anastomosed with the urinary bladder (Group 2). Pancreatic secretions were temporarily drained to the exterior in all patients via a duct catheter. Monitoring of the exocrine function including pancreatic secretion cytology and pancreatic secretion neopterin excretion proved to be reliable rejection markers. Survival rates at 1 year were calculated to be 90%, 74% and 89% for all patients, pancreas grafts and renal grafts. Apart from local complications in group I which did not cause any graft loss, the surgical complication rate was comparably low in both groups.

Adult↗
PubMed1991

The use of myocytes as a model for developing successful heart preservation solutions.

The development of a successful method to preserve the heart for relatively long periods (24-48 hr) requires demonstrating successful orthotopic transplantation and long-term survival after preservation. There are, however, multiple variables that may affect the quality of heart preservation, and it is nearly impossible to systematically study all the variables in this complicated model. One model that may be useful to study how preservation parameters affect heart cell preservation is the isolated myocyte preparation. In this study myocytes were isolated from the rabbit heart and the effects of up to 24 hr cold storage on viability measured to determine if this would be a suitable preservation model. Myocytes were stored in various preservation solutions including; EuroCollins (EC), two cardioplegic solutions (Stanford [ST] and Bretschneider solution [HTK]) and the University of Wisconsin solution (UW) with or without the addition of polyethylene glycol. The viability of myocytes was judged by measuring the effects of preservation and rewarming after preservation on cellular morphology (percent rod-shaped cells), ATP concentration, and LDH release. Myocytes preserved in the cardioplegic solutions were least well preserved after 12 and 24 hr storage, as judged by the loss of rod-shaped morphology and lower ATP concentration. Preservation in EC resulted in a decrease in the percent rod-shaped cells after 12 hr and 24 hr storage that was greater than obtained in the UW solutions. The best preservation of myocyte morphology and highest content of ATP was obtained in myocytes stored in the UW solutions, especially those containing PEG. The myocyte model of heart preservation shows a loss of cell integrity that is related to the preservation solution (HTK greater than ST greater than EC greater than UW-PEG) and these results are similar to what has been shown in the past with other models of heart preservation. Thus the myocyte model appears to be a useful method to test how many preservation solutions and preservation variables affect heart cell metabolism. In the future, results from these types of studies may find use in developing improved heart preservation solutions for testing in the orthotopic transplant model.

Adenosine↗
PubMed1991

In vitro susceptibilities of Mycoplasma pneumoniae, Mycoplasma hominis, and Ureaplasma urealyticum to sparfloxacin and PD 127391.

The in vitro activities of two investigational quinolones, sparfloxacin (previously designated AT 4140) and PD 127391, were determined for 30 strains each of Mycoplasma pneumoniae, Mycoplasma hominis, and Ureaplasma urealyticum and compared with those of ciprofloxacin, tetracycline, clindamycin, and erythromycin. Erythromycin was the most active compound against M. pneumoniae (maximum MIC, less than 0.008 microgram/ml). PD 127391 (MICs, less than 0.008 to 0.031 microgram/ml), sparfloxacin (MICs, less than 0.008 to 0.25 microgram/ml), clindamycin (MICs, less than 0.008 to 0.5 microgram/ml), and tetracycline (MICs, 0.063 to 0.25 microgram/ml) were superior to ciprofloxacin (MICs, 0.5 to 2 microgram/ml). Sparfloxacin and PD 127391 were active against M. hominis (MICs, less than 0.008 to 0.031 microgram/ml for each) at concentrations comparable to those of clindamycin (MICs, less than 0.008 to 0.063 microgram/ml) and at concentrations lower than those of ciprofloxacin (MICs, 0.125 to 0.5 microgram/ml). As expected, M. hominis was resistant to erythromycin (MICs, 32 to greater than or equal to 256 micrograms/ml). For U. urealyticum, PD 127391 (MICs, 0.031 to 0.5 microgram/ml) and sparfloxacin (MICs, 0.063 to 1 microgram/ml) were superior to erythromycin (MICs, 0.25 to 4 micrograms/ml), ciprofloxacin (MICs, 0.5 to 8 micrograms/ml), and clindamycin (MICs, 0.25 to 64 micrograms/ml. Both new quinolones were equally active against tetracycline-susceptible as well as resistant strains of M. hominis and U. urealyticum. The possible influence of medium components and/or pH on MICs was evaluated by testing a Staphylococcus aureus reference strain with each antibiotic in SP-4 broth and 10-B broth and comparing the results with published MICs for this strain. MICs determined in 10-B broth for erythromycin were affected most. This study shows that the activities of sparfloxacin and PD 127391 are similar to one another and comparable or superior to those of other drugs used to treat mycoplasmal infections. The MICs of both new quinolones were consistently 2 to several dilutions lower than those of ciprofloxacin for each species.

Anti-Infective Agents↗