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Biomedical subjects

H Lippert

Publications and source records attributed to H Lippert.

At least 235 records · Page 13Linked to original sources
PubMed1985

Morphological investigations in human islets of Langerhans isolated by the Velcro-technic.

The lower yield of viable, isolated islets from one donor pancreas and the immunogenicity are responsible for disappointing results in human islet transplantation. Our preliminary results in the application of Velcro-technic (Lacy, 1982) studied by morphological investigations demonstrate the feasibility of this technic in human islet isolation. If we compare the influence of Velcro-technic with regard to the first step of Velcro-technic, the duct perfusion, we can conclude that A-cell granules, stained by Grimelius, are reduced during the collagenase perfusion. On the other side, we recognized B-cell granules up to 60 min after duct perfusion. Connective tissue is reduced by the isolation technic and absent completely up to the Ficoll separation. The exocrine tissue of the pancreas is damaged continuously, and after Ficoll separation we detected singular acinar cells only. The yield from the used lienal human pancreas were about 80 000 islets. Islets after Ficoll separation, studied by electron microscopic investigation, showed non-damaged A and B cells with granules in the typical manner.

Cell Separation↗
PubMed1985

[Diagnosis and surgical therapy of organic hyperinsulinism].

The diagnosis of an insulin producing tumour can be confirmed by a minimum of biochemical investigations. Its preoperative localisation is more difficult. Sonogram, Computertomogram, selective angiography and percutaneous transhepatic collecting of blood samples for insulin analysis from the portal system were preoperative measured to localize the tumours in 32 of 37 patients of our series. In 2 patients intraoperative tumour localisation by measurement of incorporated p32 proved to be effective. In B-cell-carinomas pancreas resection is the adequate therapy. With regard to the therapeutic effects a high risk is involved in the 'blind' left or right sited resection of non-localized tumours.

Adenoma, Islet Cell↗
PubMed1985

[Experimental diabetes mellitus induced by total pancreatectomy with preservation of the duodenum in dogs].

The total pancreatectomy without duodenectomy was carried out in 16 dogs. The postoperative diabetes mellitus leads to death on average until the 11th postoperative day. A prolongation of the survival time was possible only by an insulin injection or by pancreas transplantation. Bleedings and circulatory disturbances of the duodenum occurred in 3 of 16 dogs as a complication of the operation. The diabetes mellitus was confirmed by the estimation of the fasting blood glucose and the glucose stimulated plasma insulin concentration. The irreversible hyperglycemia syndrome after pancreatectomy proved as a pattern for the pancreas segmental transplantation.

Animals↗
PubMed1985

[Allogeneic segmental heterotopic pancreas transplantation in the dog with reference to various drainage technics].

In 35 pancreatectomized dogs, the donor pancreatic tail was transplanted by end-to-side anastomoses between the portal vein and the celiac axis to the femoral vessels of the host. To influence the exocrine pancreas secretion of the graft we applied different methods of drainage of the pancreatic duct: open drainage to the abdominal cavity (Group I, n = 15), occlusion of the duct by Neoprene (Group II, n = 12) and by Ethibloc (Group III, n = 8). Main complications were rejection crisis and pancreatitis. Segmental pancreas allografts were rejected in group I within about 34 days, in group II within about 11 days, in group III within about 13 days. The fasting blood glucose levels in all 3 groups returned to normal 2 days after transplantation. Better results were achieved in the open-duct and Ethibloc-occluded grafts. 3 weeks after transplantation, a delayed and diminished increase of insulin concentration after glucose stimulation was observed compared to the dogs of the control group. Peak insulin values were significantly higher (p 0.01) in group I compared to group II. Histologically acinar atrophy with replacement by fibrous tissue occurred in all groups after 2 weeks. The least severe histological changes were observed in group II. The best results were achieved by the open-duct technique, whereas the occlusion groups showed a high rate of early complications like rejection, venous thrombosis and pancreatitis.

Animals↗
PubMed1984

Relationship between insulin secretion and pancreas morphology in subjects with chronic pancreatitis.

In order to investigate whether a relationship exists between in vivo insulin secretion and islet mass, 8 patients suffering from severe chronic relapsing pancreatitis were studied before and after pancreatectomy by glucose-glucagon-test (per os 1.75 g glucose; i.v. glucagon 0.01 mg/kg b.w.) and by intravenous glucose-tolerance-test (iGTT) (i.v. glucose 0.33 g/kg b.w.). Postoperative in vitro assessments of pancreatic insulin and alpha-amylase content were performed, and morphometric studies were carried out. Patients were characterized by reduced c-peptide secretion when compared with healthy subjects. The c-peptide response to the glucose-glucagon-test correlated well with the morphometrically estimated exocrine and islet tissue mass (P less than 0.05) and with the content of insulin and amylase in the tissue. The findings suggest that in subjects suffering from severe chronic relapsing pancreatitis the maximal insulin response might represent a parameter for the patient's islet mass.

Adult↗
PubMed1984

[Experiences with pancreas occlusion following cephalic duodenopancreatectomy].

68 patients suffering from complications of chronic pancreatitis or tumours of the periampullary region respectively underwent partial duodeno-pancreatectomy (modified Whipple procedure) with or without obstruction of the remaining duct of the pancreas. These patients were followed-up and examined for glucose tolerance, serum insulin and C peptide levels until 2 years after surgery. There were no significant differences in endocrine function between patients with or without pancreatic duct obliteration by acrylate glueing.

Adult↗
PubMed1984

[Variability of hand and foot arteries].

In the hand the superficial palmar arch is variable and the communication between the radial and the ulnar artery is open in only 42% of cases. In 58% there is no connection, and in most cases the common digital palmar arteries arise from the ulnar artery. In 10% the median artery participates in the vascularization of the hand: 5% joining the superficial palmar arch, and the other 5% when the superficial arch is open continue into the first or second palmar digital arteries. The deep palmar arch is constantly found closed (only 3% are open). The dorsum of the hand is usually supplied by the radial and the posterior interosseous arteries. They are joined by a branch of the ulnar artery in about 38%. In the foot there is great variation in the extent of the areas supplied by the posterior and the anterior tibial artery. A deep plantar branch connects the dorsalis pedis artery with the plantar arch. In more than 50% the main blood supply of the plantar side of the toes is derived from the anterior tibial artery. The dorsal side of the toes II to V is often supplied by branches of the plantar arch which pass through the intermetatarsal spaces.

Arm↗
PubMed1983

Allogeneic segmental pancreas transplantation in diabetic dogs with and without occlusion of the pancreatic duct.

Currently the rate of complications in segmental pancreas transplantation is very high. Reasons for this come from technical failures and from the site of immunology. To prove the cause of technical complications, several methods were used for the allogeneic segmental pancreas transplantation in diabetic dogs. To influence the exocrine pancreas secretion in grafts, we applied the intraductal injection of Ethibloc and Neoprene and the intraperitoneal drainage. By all these approaches it was possible to ameliorate an experimental diabetes in the recipients. Clearly better results were achieved in the Ethibloc-injected and open-duct grafts. The longest function time was about 6 months. Main complications, especially in the Neoprene-injected group, were venous thrombosis, pancreatitis and graft rejection.

Animals↗
PubMed1983

[Allogeneic transplantation of isolated islands of Langerhans into the liver of diabetic dogs with reference to its immunologic aspects].

By means of collagenase digestion and Ficoll gradient separation technique, viable islets of Langerhans were isolated from canine pancreases. These islets were transplanted into the liver of diabetic dogs. An experimental diabetes was induced by subtotal pancreatectomy and an application of 25 mg streptocotocin/kg bodyweight done twice. We performed the islet transplantation in several groups: 5 dogs differed from the donors by a strong histoincompatibility (EM-Test more than 15%). 5 dogs with a weak histoincompatibility and immunosuppression by Imuran and anti-thymocyte serum. The best results after transplantation were reached in the group with immunosuppression. There was an ameliorate effect on the hyperglycemia over a period of one year and we found significant differences in the glucose tolerance tests and in the immunoreactive insulin concentrations in contrast to the diabetic control dogs. No signs of portal hypertension and disturbance of the liver function were observed over the whole time of observations.

Animals↗
PubMed1982

Biomechanical changes in long limb bones of HAN-Wistar rats during postnatal development.

From a total of 648 male and 638 female HAN-Wistar rats the bones of 12 males and 12 females were examined at seven week intervals from the 35th to the 1129th day after birth. Biomechanical properties of the femora, tibiae and humeri were defined in a bending test using a tension testing machine. Load deflection diagrams in bending were produced, and the values of maximum bending load, bending breaking load, maximum deflection and ultimate deflection were correlated to age, body weight and bone length. The mean values of weight, bone length and biomechanical data are significantly higher in male rats. In both sexes biomechanical properties show a clear dependence on age. Up to the age of 330 days the tibia is more flexible than the femur or humerus. Values of partial correlation coefficients demonstrate that weight exerts more influence on the biomechanical properties of bones than age or bone length. With increasing weight, the loading capacity of bones rises in both sexes.

Animals↗
PubMed1982

[The role of gastrin in duodenal ulceration (author's transl)].

The role of gastrin as a cause of duodenal ulceration has been generally overestimated. The serum gastrin level cannot be used as a criterion for choosing either partial gastrectomy or non-resecting surgery. In the postoperative course the stimulated serum gastrin release differs significantly after selective proximal vagotomy plus pyloroplasty and without pyloroplasty. This fact demonstrates the influence of pyloroplasty on the serum gastrin concentration. In case of duodenal ulcer the stimulated serum gastrin test presents a reliable method to control the results obtained after performing a highly selective vagotomy. Compared with the Hollander-test it is without any complication however more efforts are required.

Adult↗
PubMed1982

The influence of selective pancreatic denervation on plasma insulin and glucose tolerance in dogs.

The mechanism of reflex plasma insulin responses after oral stimulation and the influence of autonomic control on glucose- and meal -induced insulin secretion needs to be elucidated. Dogs with chronic pancreatic fistulas were studied two months after selective pancreatic denervation or bilateral truncal vagotomy and compared with fistulated controls. The normal glucose- and amino acid-independent insulinogenic reflex after an oral glucose load or after a meal was inhibited in the experimental groups. Glucose-related insulin secretion (oral or intravenous loads) and glucose tolerance were clearly reduced after vagotomy, but only partly diminished in the denervated animals. The plasma insulin increase after meat ingestion was inhibited in both experimental groups. It is concluded that the B-cells work under integrated tonic control of both the vagal and the sympathetic systems. Independent of this control, a vago-vagal insulinogenic reflex is initiated by enteric stimuli. These two mechanisms might be considered as part of the gastroentero-pancreatic axis in a broader sense.

Animals↗
PubMed1982

[Intraperitoneal infections and immunosuppression (author's transl)].

The growing number of patients showing a restricted immune defence, also causes the surgeon to be faced with big problems; particularly in the case of intraperitoneal infections. In case of peritonitis the organism may dispose of various opportunities of immune defence involving the local limitation by adhesions, phagocyte activity, humoral and cellular immunity. Deficiencies in immune defence (congenital, acquired or iatrogenically induced) will change symptoms, diagnosis and therapy of intraperitoneal infections. Due to the lack of segmental granulocytes in patients with restricted immune defence there are frequently no symptoms of intraperitoneal infections, such as abdominal tenderness and pain. The diagnostic lavage of the abdominal cavity should be applied early. The therapy hardly differs from the general treatment of peritonitis in normal patients. The changed germ spectrum among them opportunistic germs, viruses, parasites amd mycetes, required a modified application of antibiotics. The prognosis of peritonitis in patients with restricted immune defence depends on the etiology of the infection and the degree of immunosuppression. At present a mortality rate of up to 70% is still registered.

Antibody Formation↗
PubMed1981

[Transplantation of the endocrine pancreas].

The transplantation of the endocrine pancreas has been investigated intensively as one way to optimize the therapy of diabetes mellitus. Starting with the free pancreas transplantation 1966 in diabetics, more recently research has been focused on transplantation of pancreatic islets or fetal pancreatic slices and the segmental pancreas transplantation. These forms of transplantation of the endocrine induced diabetes in various animals. Whereas the transplantation of a dispersed pancreatic preparation (islets or fetal pieces) is not connected with any acute or chronic alternation for the patient, the complication rate of the segmental pancreatic transplantation has to be reduced for a broader clinical application. In the case of islet transplantation the research efforts were concentrated on the improvement of tissue preparation and prolongation of the tissue survival.

Animals↗
PubMed1981

Reversal of diabetes by isogeneic transplantation of cultured pancreatic islets.

Pancreatic islets were isolated by collagenase digestion from female Wistar rats and cultured at 20 mmol/l glucose. The enhancement of Mg++ concentration from 0.8 mmol/l up to 5.3 mmol/l had a protecting effect on the glucose-induced insulin release in the subsequent short-time incubation and prevented the age-depending decrease of B-cell function. About 1,000 cultured islets injected into portal vein normalized the plasma glucose of streptozotocin-diabetic rats. The plasma glucose patterns during the glucose load were nearly identical to healthy controls. These findings suggest that the cultured islets maintain the ability to secrete insulin in response to glucose in vitro as well as in vitro and that such islets can reverse an experimentally induced diabetes.

Animals↗
PubMed1981

[Progress in transplantation of the pancreas (author's transl)].

In the field of pancreas transplantation great progress has been made in recent years. While the transplantation of the whole organ has lost importance, success could be reached with the transplantation of isolated islets of Langerhans and with the segmental pancreas transplantation in experiments and in clinical practice. The present-day research is focused particularly on influencing the antigenicity of the endocrine pancreas tissue and on methodical problems of segmental pancreas transplantation.

Animals↗
PubMed1981

[Transplantation register for pancreas and island of Langerhans].

A new registry for human pancreas and islet transplantation has been established (D. E. R. Sutherland). Between 17 December 1966 and 31 December 1980, 108 pancreas transplantations were performed. Six patients had grafts that functioned for more than 12 months. In most of the 68 islet allotransplants performed, little or no evidence of islet function has been obtained. Three diabetic patients were dependent on insulin for 2.5 to 8 months after the operation. One of these, however, still has a functioning graft. Autotransplants of dispersed pancreatic islet tissue have been performed on 59 patients after total or partial pancreatectomy for benign disease. The 28 patients who had 90% pancreatectomies did not require insulin. Information from the registry should be helpful to the various transplant teams attempting clinical application of these procedures.

Diabetes Mellitus↗