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Biomedical subjects

R Lück

Publications and source records attributed to R Lück.

16 recordsLinked to original sources
PubMed1991

Progressive deterioration of endocrine function after intraportal but not kidney subcapsular rat islet transplantation.

In inbred streptozocin-induced diabetic rats, the long-term function of different endocrine pancreatic isografts was compared. Isolated islets transplanted into the portal vein showed a progressive deterioration of function over time. In contrast, islets under the kidney capsule sustained a constant long-term function controlling all clinical signs of diabetes. Recipients of kidney subcapsular islets displayed normal growth rate, peripheral serum glucose and insulin levels, and metabolic parameters. However, their functional reserve was markedly reduced as revealed by diminished glucose tolerance and reduced insulin-secreting capacity after an intravenous glucose challenge. Vascularized whole-organ pancreatic grafts with portal venous drainage led to complete normalization of all parameters determined in this study. This study showed that the long-term function of islets transplanted under the kidney capsule is superior compared with islets transplanted into the portal vein.

Animals↗
PubMed1990

[Suppression of exocrine secretion does not lead to disruption of endocrine function of pancreas transplants].

The adequate management of the exocrine secretion of vascularized pancreas transplants is still controversial. Basically, the exocrine graft secretion may either be suppressed by obstruction of the pancreatic ducts or preserved by drainage into the recipient's enteric or urinary tract. In a model of isogenic pancreas transplantation in streptozotocin diabetic rats the impact of preserved versus suppressed exocrine secretion on the quality of endocrine graft function was investigated. Preservation of the exocrine secretion was accomplished by pancreaticoduodenal transplantation, while duct ligation was used to suppress the exocrine secretion. Endocrine graft function was monitored by determination of non-fasting blood glucose levels, intravenous glucose tolerance tests, peripheral insulin levels, water and food intake as well as urine and faeces production. Suppression of the exocrine graft secretion induced acinar atrophy, proliferation of pancreatic ducts, interstitial cell infiltration and fragmentation of islets of Langerhans, while drainage of the exocrine graft secretion completely preserved the architecture of the transplant. Despite the fundamental structural changes induces by exocrine suppression no deterioration of endocrine graft function was noted within the observation period of one year. Both techniques were equally effective in ameliorating the diabetic hyperglycemia, hypoinsulinemia, reduced glucose tolerance, polydipsia, polyphagia, polyuria and restored normal growth rate and general health of diabetic pancreas graft recipients. Thus it can be concluded that suppression of the exocrine secretion does not impair the quality of endocrine function of pancreas transplants.

Animals↗
PubMed1990

Comparison of graft morphology and endocrine function after vascularized whole-pancrease transplantation in the rat by different surgical techniques.

Graft morphology and endocrine function following vascularized pancreas transplantation by different surgical techniques were determined in streptozotocin-diabetic rats. Eight different surgical techniques were studied. Intestinal drainage of exocrine secretion was accomplished by pancreaticoduodenal transplantation or by utilizing only a patch of the donor duodenum for duodenojejunostomy. Following pancreaticoureterostomy and pancreaticocystostomy, the graft's exocrine secretion was drained to the recipient's urinary tract. The exocrine secretion was allowed to drain freely into the recipient's peritoneal cavity following transverse or longitudinal incision of the common bile duct. Exocrine secretion was suppressed either by duct ligation or by retrograde ductal injection of prolamine. Following enteric or urinary exocrine graft drainage, the architecture of both the endocrine and exocrine pancreas was perfectly preserved. Pancreatic juice had remarkably few adverse effects on the recipient's urinary tract. Obstruction of the exocrine secretion induced atrophy of the acinar cells, proliferation of small pancreatic ducts, and a typical fragmentation of the islets of Langerhans. Prolamine was biologically degraded within 28 days. Following free intraperitoneal drainage, spontaneous suppression of the exocrine graft function occurred early after transplantation. Metabolic signs of diabetes mellitus including hypoinsulinemia, hyperglycemia, polydipsia, polyuria, and impaired glucose tolerance were completely normalized by pancreas transplantation irrespective of the surgical technique used. Despite fundamental differences in graft architecture no alteration of endocrine graft function was noted following vascularized pancreas transplantation by different surgical techniques.

Animals↗
PubMed1990

Significance of portal venous drainage after whole-organ pancreas transplantation for endocrine graft function and prevention of diabetic nephropathy.

The significance of portal venous drainage after whole-pancreas transplantation both for metabolic control and development of diabetic nephropathy was investigated. Streptozotocin-diabetic inbred LEW rats received a duct-ligated pancreas graft with either systemic or portal venous drainage and were followed for up to one year. Normal and untreated diabetic rats (n=18 in each group) served as controls. Irrespective of the route of venous drainage pancreas transplants normalized the diabetic polyuria, polyphagia, and polydipsia. Growth rates and general health did not differ from normal rats. Pancreas transplantation with portal venous drainage furthermore normalized nonfasting blood glucose and peripheral insulin levels, and intravenous glucose tolerance. Pancreas transplantation with systemic venous drainage, however, was associated with peripheral hyperinsulinemia, slightly elevated nonfasting blood glucose levels, and supranormal K-values in intravenous glucose tolerance tests. Though portal venous drainage was associated with better metabolic control than systemic venous drainage, both techniques of pancreas transplantation proved equally effective to prevent the development of diabetic glomerular membrane thickening determined 6 and 12 months posttransplant.

Animals↗
PubMed1990

Gamma interferon treatment in vivo provokes accumulation of activated monocytes in the venous circulation of rats.

Activated monocytes forming intravascular clumps in the veins of most organs appeared in LEW rats after a 3-day intravenous treatment with recombinant rat gamma interferon. Phenotyping in situ and in cytospot preparations of perfusates revealed that the cells coexpressed the rat monocyte/macrophage antigen ED1 and class II MHC molecules. In addition, most cells reacted with a rat CD11b antibody and weakly expressed determinants detected by the W3/13 and Ox22 reagents. Minor fractions of the activated monocytes were positive for rat CD4 and the Ox2 and ED3 determinants. Cell proliferation was assessed by double staining for bromodeoxyuridine (BrdUrd) incorporation and phenotypic markers. Of the ED 1-positive class II-positive cells, 80% were labeled with BrdUrd after 3 days of combined infusion with gamma interferon. Pulse labeling for 30 minutes revealed 8% BrdUrd-positive intravascular ED 1-positive class II-positive monocytes in situ on day 3 of treatment, which contrasted with almost-absent labeling of this cell population in normal LEW rats. It is concluded that interferon not only promotes activation but also intravascular division of monocytes or their immediate precursors. Interestingly, cells of identical morphology and phenotype were observed in the vasculature of rats during lethal graft-versus-host reactions. Activated monocytes may thus contribute to the pathologic consequences of cytokine treatment and severe systemic immune reactions in vivo.

Animals↗
PubMed1989

Genetic control of rat heart allograft rejection: effect of different MHC and non-MHC incompatibilities.

We investigated the genetic control of heterotopic heart allograft rejection using a family of standard inbred, major histocompatibility complex (MHC)-congenic, and intra-MHC recombinant rat strains. Gene products of the various regions within the rat MHC differed markedly in their capacity to induce rejection. Isolated incompatibility at class I antigens encoded by the RTl.A and RTl.C regions failed to induce rejection within the observation period of 100 days, whereas class II antigens encoded by the RTl.B/D region provoked rapid rejection within 10 days. By comparison of the rejection times of isolated and combined incompatibilities a number of functional interactions could be demonstrated between individual MHC regions which either prolonged or shortened allograft survival. In contrast to rapid rejection of MHC-mismatched heart allografts, differences at non-MHC histocompatibility antigens were associated with graft survival beyond 100 days, although chronic rejection of variable severity was detected histologically. Disparity at non-MHC plus class I antigens, however, provoked acute heart allograft rejection.

Animals↗
PubMed1975

[Eosinophilic leukaemia with chloroacetate-esterase-positive granules in a child (author's transl)].

Eosinophilic leukaemia was diagnosed in a 13-year-old boy with clinical and haematological signs of acute leukaemia. A positive naphthol-AS-D-chloroacetate esterase reaction was present in 93% of bone marrow eosinophils. This confirms earlier findings for this sub-group of leukaemia in adultsmcharcot-Leyden's crystals were found in bone marrow, and the eosinophils were further characterized by other cytochemical and electronmicroscopic studies. Only short remission periods were achieved, the patient dying 53 weeks after diagnosis. Attacks of cardiac arrhythmias, thought to be due to adriamycin treatment, were probably related to thrombi in the coronary arteries as a result of disseminated intravascular coagulation. It is thought that eosinophilic leukaemia with a positive naphthol-AS-D-chloroacetate esterase reaction is a variant of acute myeloid leukaemia.

Acute Disease↗
PubMed1975

[Clinical, biochemical, morphological and electrophysiological studies of glycogenosis Type II in childhood with double deficiency of enzymes (author's transl)].

The clinical, biochemical, morphological and electrophysiological findings in a 13-month-old child, who died of glycogenosis type II, is presented. In addition to the deficiency of alpha-1,4-glucosidase, which is typical for the disease, a deficiency in hyaluronidase could be detected for the first time in the skeletal and heart muscles and in the liver. On the other hand, the beta-glucoronidase and beta-acetylglucosaminidase activity was highly increased. Deposits of a substance, most probably an acid mucopolysaccharide, which could be differentiated from glycogen by chromography and electronmicroscopy, could be detected in the muscle. A pathogenetical connection with the hyaluronidase defect is imminent.

Glucosidases↗