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Biomedical subjects

W Lauchart

Publications and source records attributed to W Lauchart.

At least 19 recordsLinked to original sources

[The status of liver transplantation 1992].

Transplantation of the liver has progressed in recent years and has become universally accepted for numerous indications of end-stage liver diseases, predominantly cirrhosis induced by viral hepatitis (HBV/HCV), acute hepatic failure and primary biliary cirrhosis. Interdisciplinary research is devoted to prevention of recurrent disease: Risk groups have been defined, in which HBV recurrence can be prevented by immunoprophylaxis. The risk of tumor recurrence can be calculated, adjuvant chemotherapy might improve prognosis of patients with small incidental tumors.

Hepatitis, Viral, Human

[Acute liver failure: current hepatological-surgical therapy results].

For fulminant hepatic failure the prognosis is depending on the onset of severe encephalopathy (coma grade III to IV), cerebral oedema, renal and respiratory failure. Treatment strategies must be devoted to limit these complications and proceed with an urgent liver transplantation. Overall 1-year survival rates after hepatic transplantation in fulminant liver failure are as high as 80%.

Combined Modality Therapy

Noninvasive procedures for diagnosis of renovascular hypertension in renal transplant recipients--a prospective analysis.

The purpose of this study was to clarify the selectivity and specificity of noninvasive procedures for diagnosis of clinically suspected posttransplant renovascular hypertension. We prospectively investigated 25 renal transplant recipients with arterial hypertension and clinically suspected stenosis of the graft artery (8 female and 17 male patients; ages 45 +/- 15 years). We performed a captopril test with 25 mg captopril (n = 25), renography with technetium-99m diethylene triamine penta-acetic acid (99mTc-DTPA) before and after angiotensin-converting enzyme (ACE) inhibition with determination of glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) (n = 23) and color-coded duplex ultrasonography of the transplant kidney vessels (n = 24). Renal transplant artery stenosis (RTAS) was excluded by renal arteriography in 20 patients and by operative evaluation or clinical follow-up in 5 patients. We identified 4 patients with RTAS and renovascular hypertension. The noninvasive methods showed the following results (sensitivity/specificity): (1) captopril test: 75%/67%; (2) renography combined with ACE-inhibition: 75%/84%; and (3) color-coded duplex ultrasonography: 100%/75%. We conclude that in patients with clinical evidence of RTAS most noninvasive diagnostic procedures are not sufficiently accurate to exclude the diagnosis. Only color-coded duplex ultrasonography did not fail to detect all patients with RTAS and may act as a screening test. Intraarterial renal angiography remains the most reliable and as-yet indispensable diagnostic test for transplant recipients to rule out RTAS.

Adult

[Indications and results of liver transplantation].

More than 20,000 human liver transplantations have been performed world-wide. The procedure has become universally accepted by hepatologists and applied most broadly for numerous indications in end-stage liver disease. Most common indications for transplantation are benign liver diseases, leading to cirrhosis and/or liver failure. In non-resectable tumor stages liver transplantations have been less frequently performed. The main problem remains to define the "best timing" for the operation. The disease stage will influence the incidence of perioperative complications, postoperative mortality and survival after transplantation. Liver transplantation should be considered, before chronic liver disease reaches its final stage and extra-hepatic liver-related organ complications determine the course. "Ultima ratio" decisions in very late disease stages will leave the patient with only a small chance of surviving. High tumor recurrence rates and inferior survival figures after liver transplantation in malignant liver diseases necessitate a restrictive indication policy in such patients. Probably neoadjuvant chemotherapy in conjunction with liver transplantation will expand the therapeutic modalities in unresectable situations.

Humans

Human cytomegalovirus in rejected kidney grafts; detection by polymerase chain reaction.

Human cytomegalovirus (CMV) infections are frequently associated with graft rejection in the immunosuppressed patients following organ transplantation. Thirty-four tissue samples from rejected kidneys and 18 samples from normal adult kidneys obtained from autopsies were investigated for the presence of CMV-DNA by the polymerase chain reaction (PCR) and by immunohistochemistry. DNA extracted from renal tissues after proteinase K digestion was specifically amplified in 32 cycles using primers which flank a 147 bp DNA fragment of the immediate early CMV gene and analysed by slot-blot hybridization with digoxigenin-labelled detection oligonucleotides. CMV-DNA was detected by PCR in a range from 0.1 fg up to 100 fg in 14 (41%) rejected kidney transplants. Comparative immunohistological analysis revealed presence of CMV in only three biopsies of these rejected kidneys. Furthermore, CMV-DNA was also found in four of 18 (22%) normal donor kidneys. These results reveal that CMV is often present in rejected kidneys and that the infection can be transferred from the donor to the recipient, since the normal adult kidney appears to be a frequent site of latency for CMV. No differences in local immunological changes, characterized by interstitial mononuclear leukocyte infiltration as well as by aberrant expression of HLA-class II antigens and of ICAM1 on proximal tubular epithelial cells, could be detected by further immunohistological analysis between grafted kidneys at late stage of rejection with and without CMV infection.

Adolescent

[Primary hepatocyte cultures as a model of experimental study of liver preservation].

Primary hepatocyte cultures have been used to evaluate data concerning hypoxic liver cell injury. To show the suitability of this method in liver preservation studies hepatocyte cultures were incubated under different conditions: warm normoxia (37 degrees C, pO2 greater than 70 mm Hg), warm hypoxia (37 degrees C, pO2 less than 0.1 mm Hg), cold normoxia (4 degrees C, pO2 greater than 70 mm Hg) and cold hypoxia (4 degrees C, pO2 less than 0.1 mm Hg). Incubations were performed in Euro Collins solution (EC), University of Wisconsin solution of Belzer (UW) and histidine ketoglutarat tryptophan solution of Bretschneider (HTK) as well as in Krebs Henseleit buffer (KH) for control incubations. During 12 h of incubation hepatocyte cultures under warm normoxia lost viability continuously in EC, UW and HTK while in KH they remained stable. Under warm normoxia all cultures lost 50% of their viability during 12 h of incubation while in cold normoxia loss of viability was mild but significant. Under cold anoxia which is the standard condition of liver preservation the cultured hepatocytes remained unchanged for 12 h in KH, UW and HTK, while in EC most of the cells were dead after 6 h. It is concluded that incubations of primary hepatocyte cultures under different pO2 and temperatures are well suited to contribute to liver preservation studies on a preclinical level and thus may help to save animal experiments.

Animals

[Chemoembolization of primary liver cancer using epirubicin-lipiodol].

The double supply of the liver allows one to perform specific embolisation of liver carcinomas since these are mostly supplied arterially. According to their occlusion characteristics--central, peripheral, capillary--different embolising materials are suitable for tumour embolisation under varying conditions. Oily substances cause capillary occlusion and can be used in conjunction with chemotherapeutic agents. This study deals with the results from lipiodol-epirubicin embolisation in 25 patients with hepatocarcinomas and cholangiocarcinomas. In a three-and-a-half year follow-up period 16 of these 25 patients died, maximum survival time being 28.4 months. Survival varied from 9.2 to 28.4 months compared with a survival time of 2-8 months in untreated patients. In this case hypervascular tumours have a better prognosis than the rarer hypovascular tumours because of improved deposition and activity of the chemotherapeutic agent.

Adenoma, Bile Duct

[Chemo-embolization of inoperable hepatocellular cancer. A surgical-radiologic therapy concept].

The dual blood supply of the liver allows embolization therapy of malignant liver tumors nearly complete supplied by arterial vessels. The last three years we treated 25 patients with hepatocellular carcinoma by transcatheter arterial chemotherapy using iodized oil and anticancer agents suspension. The survival rate of untreated patients ranges between 1.6 and 2.5 months. Five patients died within two weeks to 9.7 months following embolization. Twenty of these patients are alive with survival rates of 1 to 22.9 months following the procedure. Because of the low procedural morbidity, transcatheter embolization is superior to surgical dearterialization or systemic chemotherapy.

Antineoplastic Agents

[Treatment of symptomatic non-parasitic liver cysts using percutaneous drainage and irrigation with hypertonic saline solution].

In 7 patients with a total of 20 symptomatic larger liver cysts an instillation therapy with 20% saline solution was performed via a sonographically placed sump drainage. No clinically relevant complications were observed. After a median follow-up period of 18 months in two patients with cystic livers asymptomatic residual cysts measuring less than 4 cm were found only. In comparison to the instillation therapy using a sclerosing agent the presented technique seems to be equally effective but less traumatizing. Surgical procedures are restricted to a few, otherwise not treatable patients.

Adult

Differences in glycolytic capacity and hypoxia tolerance between hepatoma cells and hepatocytes.

Viability, glycolytic capacity and energy metabolism under anaerobic conditions were studied in the hepatoma cell lines HTC, FU5 and HepG2 and in rat and human hepatocytes using glucose and fructose as glycolytic precursors. During 6 hr of anaerobic incubation without additional substrate, viability decreased rapidly in FU5 and HTC cells, whereas viability of HepG2 cells was not significantly affected. In all tumor cells, 10 mmol/L glucose prevented hypoxic cell injury almost completely. Lactate formation from glucose was about five times higher than in hepatocytes under these circumstances. ATP content of the tumor cells remained almost constant under anaerobic conditions in the presence of glucose. Ten millimoles per liter of fructose diminished glycolysis in the hepatoma cells compared with glucose, ranging from 87% reduction in HTC cells to 43% reduction in HepG2 cells. Accordingly, ATP content decreased rapidly in the FU5 and slowly in the HepG2 cells. Viability was strongly diminished in the HTC and FU5 cells in the presence of fructose, whereas in the HepG2 cells no effect of fructose on viability was detectable. In contrast to the hepatoma cells, rat and human hepatocytes exhibited higher rates of anaerobic glycolysis in the presence of fructose and thus were able to maintain their viability under these conditions. These differences in glycolytic capacity, energy metabolism and hypoxia tolerance of hepatoma cells compared with hepatocytes may be used for the treatment of liver cancer by isolated liver perfusion and ex situ revision of the organ.

Adenosine Diphosphate

[Postoperative monitoring of transplanted kidneys using color Doppler sonography].

In 52 renal transplant patients a prospective study was carried out to compare the validity of szintigraphy and color-duplex-sonography for demonstrating the renal blood flow. In 49 cases the questions bout intra-allograft blood flow could be answered. In two cases szintigraphy was unable to make a right evidence. Angiodynography is a non invasive method to demonstrate the blood flow in renal allografts and is able to replace the szintigraphy.

Blood Flow Velocity

[Pregnancy and labor following liver transplantation].

We report on pregnancy and delivery in a patient following hepatic transplantation. After an uneventful gestation at term, a child of normal body weight was born. To the best of our knowledge only 7 successful pregnancies following hepatic transplantation have been reported, one of them in the Federal Republic of Germany. Amongst the publications mentioned there are only two further reports on an immunosuppressive drug regimen utilising cyclosporine plus prednisolone. We stress the importance of the following items: peripartual immunosuppression, analgesia as well as the necessary control of the coagulation system.

Adult

The course of untreated acute rejection and effect of repeated anti-CD3 monoclonal antibody treatment in rhesus monkey liver transplantation.

The effect of single and repeated treatment of liver allograft rejection using an anti-CD3 monoclonal antibody (FN18) was studied in a rhesus monkey model. Eight RhLA-mismatched monkeys received initial postoperative immunosuppression with CsA/prednisolone for 28 days. After cessation, acute rejection occurred in all animals (days 28-50). Control animals (n = 3) receiving no rejection treatment developed a chronic progressive rejection and died at days 112-160. In the animals treated with FN18 (n = 5), the first acute rejection was successfully reversed. T lymphocytes were cleared from the peripheral blood and the graft. Increased class I and class II MHC-antigens on hepatocytes were reduced to normal levels within 5 days of treatment. The second rejection treatment remained ineffective in two animals with antiidiotypic antibodies to FN18 but was successful in two animals with a low antimouse response. These four animals survived 160-509 days. The results have a number of implications regarding the course of untreated rejection in human liver transplant recipients and repetitive rejection treatment with monoclonal antibodies.

Animals