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R Schlemminger

Publications and source records attributed to R Schlemminger.

At least 19 recordsLinked to original sources
PubMed1999

[Laparoscopic stoma technique].

Laparoscopic stoma creation may be performed as an independent intervention, in combination with local anorectal procedures or as a part of complex laparoscopic intestinal operations. With the exception of specialized methods to preserve continence, every type of stoma formation can be performed laparoscopically. Indications for laparoscopic fecal diversion do not differ from open surgery. Apparent advantages are the limitation of the laparotomy to the location of the stoma, rapid return of bowel function and less postoperative discomfort and morbidity, especially when intestinal diversion is required as an independent procedure. Previous surgery is not a contraindication for the laparoscopic procedure. However, dense adhesions may compromise the ability to identify the bowel segment to be exteriorized and require adhesiolysis. Therefore, the risk of intra- and postoperative complications and the frequency of conversions (reported between 4.1 and 15.7%) is increased in patients with previous surgery. The overall rate of complications reviewed in the literature, including stoma-related problems, seems to be similar or superior to conventional laparotomy. Still, laparoscopic enterostomies are not routinely performed in most institutions. Presently available data are limited and randomized trials have not been performed. We recommend the use of laparoscopic techniques for fecal diversion in patients with intestinal obstruction requiring palliative treatment and in patients with high probability for future abdominal surgery, e.g. in Crohn's disease.

Colostomy↗
PubMed1998

Laminin localization in enterocytic basement membrane of rat small bowel grafts. A light and electron microscopic study.

In vitro laminins stimulate numerous biological effects, such as cell migration, proliferation, attachment and differentiation. In vitro laminins influence immunocompetent cells and in vivo possibly play an important role in graft rejection. To establish how laminins could be involved in the regulation of acute rejection of small bowel allografts (with and without immunosuppression), we investigated laminin distribution in rat small bowel allografts four days after transplantation, i.e., before the onset of histological signs of rejection, using antibodies against alpha1, beta1, gamma1 chain of laminin-1. In immunosuppressed allografts, the ultrastructure of the enterocytic basement membrane appeared normal, but no laminin staining was seen in this membrane, although basement membranes of intramural blood vessels and muscle cells were normally stained. In non-operated immunosuppressed rats, laminin staining was clearly reduced in the enterocytic basement membrane, demonstrating that cyclosporin A is able to affect this membrane. Since only rats in which laminin is altered survive, this laminin alteration in the enterocytic basement membrane presumably plays an important role in overcoming the acute rejection.

Animals↗
PubMed1997

Apoptosis in the small intestinal allograft of the rat.

BACKGROUND: Necrosis and apoptosis are different cell death mechanisms. Necrosis is a pathological process that occurs after destruction of the cell membrane. Apoptosis is a DNA-dependent cell death mechanism, which occurs under physiological and pathological conditions. Although necrosis is a well-defined phenomenon in an acute graft rejection, the occurrence and relevance of apoptosis during this process is largely unknown. METHODS: The enterocyte apoptosis rates in allografted (n=24) and isografted (n=24) small intestines of the rat were compared using the in situ end-labeling technique. RESULTS: In situ end-labeling showed a dramatically increased number of apoptotic enterocytes in allografted small intestines, whereas increased labeling could not be observed in isogeneic small intestinal grafts. CONCLUSIONS: We suggest that graft rejection-associated apoptosis, in addition to necrosis, plays an important role in the course of organ failure, and that the degree of apoptosis represents another reliable indicator for the diagnosis and prognosis of transplant rejection.

Animals↗
PubMed1997

Enrichment and characterization of dendritic cells from rat renal mesangium.

Dendritic cells (DC) initiate primary immune reactions and are distributed throughout most tissues. The most potent DC population of the kidney has long been suggested to reside within the glomerular mesangium. Using LEW.1A rats, we enriched and characterized such low-density cells. Mesangial DC generally exhibited round to oval cell bodies and cytoplasmic veils. Phenotypically, these cells were 100% OX-6++, 45% OX-42++, 35% ED1low, 10% OX-62low, and negative for ED2 and alpha-naphtylbutyrate esterase. Introducing a new monoclonal antibody, R3, which stains a subset of splenic DC, we showed strong antigen expression on 60% of mesangial DC. Correlating cell populations were detected immunohistochemically. Functionally, mesangial DC potently stimulated allogeneic mixed leucocyte reactions, but did not phagocytose opsonized Escherichia coli. In addition to their striking phenotypic similarity with autologous splenic DC, mesangial DC exhibited 88% of the allostimulatory activity of splenic DC. Calculation indicated approximately two mesangial DC per glomerulum. We suggest that these cells comprise different maturation-dependent subsets. The OX-62 integrin especially appears to be expressed only on mature mesangial DC, which may correlate to lymphoid veiled cells or interdigitating DC. An employment of mesangial DC in experimental models of acute allograft rejection or glomerulonephritis is discussed.

Animals↗
PubMed1996

Enhanced renal allograft rejection by inhibitors of nitric oxide synthase: a nonimmunologic influence on alloreactivity.

Clinical and experimental studies indicate that nonimmunologic factors may modulate the alloreactivity of a renal transplant. Nitric oxide (NO) is an essential modulator of endothelial function. It was postulated that, in renal allografts, inhibition of constitutive NO synthase may lead to an aggravation of immunologic damage to endothelia and therefore may enhance dysfunction of the graft. Male Lewis (RT1l) rats received syngeneic or allogeneic Brown Norway (RT1n) renal grafts and were treated with cyclosporin A (CyA) or with CyA and an NO synthase blocker (NOS-B): N omega-nitro-L-arginine (L-NNA) or NG-monomethyl-L-arginine (L-NMMA). CyA was given at a dose of 3.5 mg/kg body weight for 14 days and the NOS-B at a dose of 66 mg/L drinking water for up to 28 days postoperatively. Animals (N = 6/group) were studied at 4 to 7, 14, and 28 days posttransplantation. Four to 5 days posttransplantation, renal blood flow and glomerular filtration rate of allogeneic grafts did not differ between animals treated only with CyA and those treated with CyA and NOS-B. Mean arterial pressure was significantly elevated by NOS-B (CyA+L-NNA: 115 +/- 13 versus CyA: 78 +/- 16 mm Hg). Combined NOS-B and CyA administration led to a pronounced increase in vascular and tubulointerstitial damage. The number of mononuclear cells in vessels, glomeruli, and tubulointerstitium increased significantly in allografts upon treatment with NOS-B. During NOS-B administration, adhesion molecules (intracellular adhesion molecule-1; leukocyte-function-associated molecules-1 alpha and-beta) were strongly expressed in endothelial and leukocytic cells of the allograft. A pronounced positivity for mRNA and protein of cytokines tumor necrosis factor-alpha and transforming growth factor-beta could be demonstrated in the inflammatory infiltrate. With L-NNA treatment, the total vascular injury index was 10-fold higher (14 days posttransplantation, CyA+L-NNA: 59.8 +/- 11.7 versus CyA: 6.0 +/- 1.8; p < 0.05). The tubulointerstitial damage score rose more than 2.5-fold after CyA and L-NNA therapy (28 days posttransplantation: CyA+L-NNA: 83 +/- 1 versus CyA:29 +/- 1). L-NNA was more potent than L-NMMA at the dosages used. Thus, pronounced vascular leukostasis, vasculitis, and T-cell and monocyte infiltration of the tubulointerstitium led to a severe damage of the allograft under therapy with CyA and NOS-B. Inhibition of NO synthesis may aggravate alloreactive immunemediated injury in kidney transplants acting primarily by a disturbance of endothelial function.

Animals↗
PubMed1994

[The Chang mesocaval side-to-side shunt, an alternative shunt form after previous operations and portal vein thrombosis].

Over the time period from July 01, 1983 to June 01, 1993, 15 patients with portal hypertension and relapsing bleedings from esophageal varicosis were treated with Chang's mesocaval side-to-side shunt at the Department of General Surgery, University Hospital of Göttingen. All patients were pre-operated in the upper abdomen or exhibited thrombosis of the portal vein. While five cases revealed a prehepatic block, ten patients had an intrahepatic block, based on cirrhosis of the liver (Child classification A or B). The time required for operations was 180 +/- 32 minutes; the pressure in the portal circulation decreased by 56%. In three cases, patients suffered relapsing bleedings despite of regular shunt conditions. Complications which were due to the procedure were seen in two patients (one revealed intraabdominal posthemorrhage, followed by therapy-resistant coagulopathy; the other patient exhibited stenosis of the anastomosis). One patient developed encephalopathy. Given a rigid indication, we regard the procedure described herein an alternative to the mesocaval interposition shunt, and we consider the low rate of thrombosis (so far < 10%) without continued postoperative anticoagulant therapy as well as the avoidance of an interposition as important advantages of this technique.

Adolescent↗
PubMed1993

[Metabolic parameters and neurotensin liberation after resection of the small intestine, syngeneic and allogeneic segment transplantation the rat].

The aim of the following study was to gain some insight into the functional characteristics of different portions of the small intestine after either partial resection or syngeneic and allogeneic transplantation 3 months postoperatively. Nutritional parameters (serum albumin levels, serum triglyceride levels, maltose absorption, excretion of fecal fat) and fat-stimulated neurotensin release were determined in Lewis rats that underwent small-bowel resection (n = 21), syngeneic (Lewis-->Lewis, n = 21), or allogeneic transplantation (Brown Norway-->Lewis, n = 24). The length of the remnant, isograft, or allograft was 27 cm (i.e., one-third of the rat small intestine) and consisted of the proximal (n = 7), middle (n = 7), or distal (n = 7) portion. Three postoperative deaths were due to ileus or pneumonia. After allotransplantation cyclosporine (15 mg/kg body wt. s.c.) was administered for graft acceptance. The control group was not operated upon, but was composed of weight- and age-matched Lewis rats (n = 7). We found that resection of two-thirds of the small intestine led to significantly lower levels of albumin and triglycerides in all three portions investigated (P < 0.01), but did not affect maltose absorption. Excretion of fecal fat was elevated significantly only after distal resection (P < 0.05). When compared to resected animals, syngeneic transplantation did not affect the nutritional parameters, but caused a significantly higher hormone release (P < 0.05) in all three different intestinal grafts. Allogeneic transplantation was successful when the middle or distal portion was grafted. All recipients of proximal allografts showed a severe loss of body weight and died between day 8 and 10 after transplantation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

The role of pancreatic innervation and cholecystokinin in the intestinal phase of pancreatic polypeptide release in conscious dogs.

Besides vagal cholinergic mechanisms, pancreatic polypeptide (PP) secretion is thought to be mediated by hormones. This study was performed to delineate the role of extrinsic pancreatic innervation and cholecystokinin (CCK) in amino acid- and fat-stimulated PP secretion. In ten mongrel dogs, pancreatic denervation was performed by the method of Debas et al. [3]. Total denervation of the pancreas did not alter PP response to intraduodenal application of amino acids (integrated output 24,434 +/- 3260 pmol/1 x 120 min before vs 22,797 +/- 2470 pmol/1 x 120 min after operation) and to intraduodenal fat solution (19,595 +/- 2121 pmol/1 x 120 min vs 19,983 +/- 2031 pmol/1 x 120 min). Also, no significant differences were measured in CCK release (491 +/- 71 pmol/1 x 120 min vs 430 +/- 57 pmol/1 x 120 min for amino acids, 571 = 63 pmol/1 x 120 min vs 563 +/- 89 pmol/1 x 120 min for fat solution). Plasma PP and CCK levels were compared by linear regression analysis. Correlations between PP and CCK were high in the intact pancreas (amino acids, r = 0.92; fat, r = 0.99) as well as in the denervated pancreas (r = 0.93 amino acids and r = 0.98 fat). These results show that extrinsic pancreatic innervation does not influence PP and CCK release after intraduodenal amino acids or fat solution and that PP secretion seems to be mediated to some extent through the release of CCK.

Amino Acids↗
PubMed1993

The adaptive response of the rat small intestine after resection and segmental transplantation during the early postoperative phase.

Organ harvesting from a living donor or spatial constraints in the recipient's abdominal cavity are the main factors to be considered in the segmental transplantation of the small intestine. It was the aim of the following study to gain insight into the functional characteristics of different portions of the small intestine either after partial resection or syngeneic and allogeneic transplantation during the early postoperative period. Nutritional parameters (serum albumin levels, serum triglyceride levels, maltose absorption, excretion of fecal fat) and fat-stimulated neurotensin release were determined in Lewis rats that underwent small bowel resection (n = 21), syngeneic (Lewis-->Lewis, n = 21), or allogeneic transplantation (Brown Norway-->Lewis, n = 24). The length of the remnant, isograft, or allograft was 27 cm (i.e. one third of the rat small intestine) and consisted of the proximal (n = 7), middle (n = 7), or distal (n = 7) portion. Three postoperative deaths were due to ileus or pneumonia. After allotransplantation, cyclosporine (15 mg/kg BW s.c.) was administered for graft acceptance. Controls were unoperated, weight- and age-matched Lewis rats (n = 7). We found that resection of two-thirds of the small intestine led to significantly lower levels of albumin and triglycerides in all the three portions investigated (P < 0.01) but did not affect maltose absorption. Excretion of fecal fat was elevated after distal resection (P < 0.05). When compared to resected animals, syngeneic transplantation did not affect the nutritional parameters, but caused a significantly higher hormone release (P < 0.05) in all three different intestinal grafts. Allogeneic transplantation was successful when the middle or distal portion was grafted. All recipients of proximal allografts showed a severe loss of body weight and died between day 8 and 10 after transplantation. Postmortem examination revealed no signs of acute rejection. When transplantation of short intestinal segments is considered, it is of vital importance to take into account the functional differences and the influence of immunosuppressive drug therapy in the regulatory bowel function.

Adaptation, Physiological↗
PubMed1993

Fat-stimulated cholecystokinin release following transplantation of the entire small bowel or of different intestinal segments in rats.

This study presents data on the fat-stimulated release of cholecystokinin (CCK) in conscious rats 11 and 84 days after one-stage transplantation of the entire small bowel, or of jejunal, jejunoileal, or ileal segments, under syngeneic and allogenic conditions. After allotransplantation, ciclosporin (CsA) was administered for graft acceptance. The results were compared with those in unoperated controls and in animals that had undergone small-bowel resections leaving jejunal, jejunoileal, or ileal remnants. When the entire small bowel was grafted under syngeneic (92.5 +/- 8.3; 106.6 +/- 7.5) or allogeneic (110.5 +/- 5.5; 101.2 +/- 6.9) conditions, CCK release (pg/ml per 60 min) was similar (P > 0.05) to that of the controls (110.3 +/- 9.0; 94.7 +/- 6.8) at both measurement points. Recipients of jejunal or ileal segmental isografts showed a significantly elevated (P < 0.05) output of CCK (jejunal graft: 176.4 +/- 18.5; 125.5 +/- 10.1 -ileal graft: 55.9 +/- 9.0; 30.1 +/- 5.4) compared with corresponding small-bowel resections (jejunal remnant: 69.0 +/- 7.9; 93.5 +/- 3.9-ileal remnant: 16.7 +/- 3.7; 6.6 +/- 1.3). In contrast, the difference was not significant (P > 0.05) when jejunoileal segments were grafted (jejunoileal graft: 74.4 +/- 19.6; 47.0 +/- 10.4-jejunoileal remnant: 50.7 +/- 11.0; 47.0 +/- 11.9). All recipients of jejunal allografts died between day 8 and day 10 after transplantation, due to functional impairment. Two-stage segmental jejunal allotransplantation, with insertion of the graft into the continuation of the gastrointestinal tract in an accessory, non-functional position after 28 days was successful. Due to this technique, we could gather data on day 84. Recipients of jejunal (118.2 +/- 7.6), jejunoileal (87.1 +/- 19.7; 48.6 +/- 9.3), or ileal (48.1 +/- 6.7; 21.6 +/- 4.6) allografts showed no significant (P < 0.05) differences in CCK output compared with isografts, either on day 11 or on day 84. Our data indicate that transplantation of the entire small bowel affects the fat-stimulated CCK release neither in the early postoperative period nor 3 months after transplantation. In contrast, transplantation of jejunal or ileal segmental isografts caused a significantly elevated output of CCK compared with corresponding resection remnants. Immunosuppression with CsA did not affect CCK release after transplantation, but led to functional impairment with fatal outcome when a short jejunal segment was grafted. This could be prevented by applying the two-stage technique.

Animals↗