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Biomedical subjects

W Lauchart

Publications and source records attributed to W Lauchart.

At least 37 records · Page 2Linked to original sources
PubMed1994

The potential role of reactive oxygen species in liver ischemia/reperfusion injury following liver surgery.

Reperfusion of a previously ischemic tissue may lead to an aggravation of injury. The liver has been shown to be susceptible to this reperfusion injury in several experimental systems. Reactive oxygen species appear to play an important role in the development of such injury, as has been demonstrated by direct measurements of their release, and by the protective effects of antioxidants. Upon reperfusion, reactive oxygen species may be released by hepatocytes, Kupffer cells and neutrophils. The relative contribution of the various liver cell types to the release of reactive oxygen species depends on several factors, including the duration and condition of ischemia and the time elapsed after reperfusion. There is only limited evidence for the occurrence of reperfusion injury in humans following liver surgery. The role of reactive oxygen species in this injury in humans remains to be shown.

Animals↗
PubMed1994

[Liver transplantation in halothane-induced liver necrosis].

The risk for developing acute liver failure after halothane exposition was calculated between 1:8,000 and 1:36,000. The case report given on a 22 year old man with halothane-induced hepatic failure is unusual, because the typical risk factors as age over 40, female sex, obesity, and previous exposure to halothane were not present. Two days after exposure to halothane the patient suffered acute liver failure with severe coagulopathy (factor V = 5% activity), and encephalopathy grade IV complicated by renal failure and respiratory insufficiency. Maximal increases of enzymes in blood were AST 3900 U/L, ALT 2570 U/L, LDH 10600 U/L. After six days the patient underwent liver transplantation with complete anuria and instable circulation. Explanted liver showed massive necrosis (70% of parenchyma) and fatty changes. The liver transplant had immediately a good function and renal failure resolved within three days. In the follow-up of 3 1/2 years the patient suffered no further complications. Culturing the patient's lymphocytes in the lymphocyte transformation test a strong reaction could be detected with a stimulatory index of 20. Maximal proliferation was observed when lymphocytes were incubated with plasma metabolites of a volunteer drawn 120 minutes after anesthesia with halothane was started.

Adult↗
PubMed1994

[Diagnosis of fibrolamellar cancer].

A fibrolamellar carcinoma (FL-Ca) is a primary malignant tumor of the liver of unknown etiology, without cirrhosis and usually without an increase in tumor markers; it occurs mainly in young patients. As it can simulate malignant and benign tumors, particularly focal nodular hypoplasia (FNH), the diagnosis is difficult. Ultrasound and angiography show mostly uncharacteristic features, so ultrasound only has to ascertain that the tumor is there. Angiography can reveal vascular infiltrations and assess the resectability of the tumor, but diagnosis of FL-Ca is not always possible with angiography. CT has the highest specificity if calcifications are present, because calcifications in a tumor similar to FNH are pathognomonic for FL-Ca. By means of hepatobiliary functional scintigraphy FNH can be excluded. MRI seems to be important in differentiating the tumor from FNH, because the central scars of FL-Ca and FNH--if present--have a different signal intensity in T2-weighted images. The histological diagnosis of FL-Ca is also difficult. In patients with resectable tumors or prior to liver transplantation, an operative biopsy should be obtained to verify the diagnosis. In non-resectable tumors sonographic guided biopsy is justified.

Adult↗
PubMed1993

Injury to cultured liver endothelial cells during cold preservation: energy-dependent versus energy-deficiency injury.

Previously, we demonstrated an energy-dependent injury to cultured liver endothelial cells during cold incubation in University of Wisconsin (UW) solution. Here, the effects of Histidine-Tryptophan-Ketoglutarate (HTK) and Euro-Collins (EC) solutions on these cells were studied. In HTK solution, 83% +/- 4% of the cells had lost viability after 9 h of incubation at 4 degrees C. The addition of cyanide (1 mM) to simulate hypoxic conditions protected the cells to the extent that only 9% +/- 1% of the cells lost viability over the same period; the addition of glucose (10 mM) led to increased cell injury. ATP levels were highest in the incubations with the most rapid loss of viability. In Krebs-Henseleit buffer and EC solution, in contrast, cell injury increased upon addition of cyanide; the addition of glucose to Krebs-Henseleit buffer decreased injury. We conclude that the injury to cultured liver endothelial cells during cold incubation in HTK solution is energy-dependent, as it is in UW solution, whereas cells behave differently in EC solution and Krebs-Henseleit buffer.

Adenosine Triphosphate↗
PubMed1993

Posttransplant renal artery stenosis--outpatient intraarterial DSA versus color aided duplex Doppler sonography.

A prospective trial was conducted to assess the accuracy of color aided duplex Doppler (CADD) sonography to rule out transplant renal artery stenosis (TRAS) and to determine feasibility and safety of intraarterial digital subtraction angiography (DSA) in hypertensive renal allograft recipients on an outpatient basis. All patients were hypertensive (n = 18, mean age: 42 +/- 11 years) and underwent CADD and an i.a. DSA with 4F catheters. There was a 4 hour rest post DSA. Duplex Doppler measurements of maximum velocity were obtained. Absolute values of > or = 100 cm/s were considered indicative to suspect TRAS. DSA revealed severe TRAS in 4 patients (22%). The stenoses were located near the iliorenal anastomosis (n = 2) and at the bifurcation of the renal artery (n = 2). Duplex Doppler classified twelve (67%) renal artery pedicles normal (maximum velocity: 79 +/- 23 cm/s). TRAS was suspected in 6 patients with a maximum velocity of 159 +/- 48 cm/s (P < 0.01). False positive CADD diagnoses were due to tortuous graft vessels and a postbiopsy arteriovenous fistula. Sensitivity of CADD was 100%, specificity 86%. There were no DSA related complications. No impairment of graft function occurred. CADD allows renal angiography to be reserved to clarify an inconclusive ultrasound study and for definite diagnosis of angiomorphology and lesion classification. Intraarterial DSA of renal grafts in outpatients may be performed without an increased risk of procedure-related complications.

Adult↗
PubMed1993

Energy-dependent injury to cultured sinusoidal endothelial cells of the rat liver in UW solution.

The critical injury to liver during cold preservation is believed to occur to the sinusoidal endothelium. In this study the viability of cultured sinusoidal endothelial cells from rat liver was assessed during storage in University of Wisconsin solution at 4 degrees C. The vast majority of cells (83 +/- 12%) died within 24 hr of storage. Addition of KCN (1 mM) to the solution to simulate hypoxia markedly increased survival: only 3 +/- 2% of cells had lost viability after 24 hr in the presence of cyanide. Further experiments showed that other inhibitors of mitochondrial ATP formation (antimycin A 1 microM, rotenone 1 microM, oligomycin 10 microM, carbonyl cyanide m-chlorophenylhydrazone 1 microM) were protective as well, whereas glucose (10 mM) greatly diminished the protective effect of cyanide (loss of viability 38 +/- 7% after 24 hr). ATP measurements confirmed the correlation between the energy state of the cells and cell death: ATP levels after 6 hr of incubation were 19.9 +/- 4.0 nmol/10(6) cells in UW solution, 13.7 +/- 2.9 nmol/10(6) cells in UW + glucose, 6.9 +/- 1.9 nmol/10(6) cells in UW + KCN + glucose and 1.9 +/- 1.5 nmol/10(6) cells in UW + KCN. In contrast to the protective effect observed in UW solution, addition of KCN to Krebs-Henseleit buffer led to increased endothelial cell damage upon cold storage. We therefore conclude that in UW solution damage to the sinusoidal endothelium is energy-dependent.

Adenosine↗
PubMed1993

[Long-term results of chemoembolization of primary liver cancer with epirubicin-lipiodol].

This pilot study deals with the long-term results from lipiodol-epirubicin chemo-embolisation in 25 patients with hepatocellular or cholangiocellular carcinomas. 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 due to the improved deposition and activity of the chemotherapeutic agent inside the tumour itself.

Adenoma, Bile Duct↗
PubMed1992

[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↗
PubMed1992

[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↗
PubMed1992

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↗
PubMed1992

[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↗
PubMed1992

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↗