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Biomedical subjects

D Häussinger

Publications and source records attributed to D Häussinger.

At least 91 records · Page 5Linked to original sources

Abdominal three-dimensional power Doppler imaging.

Three-dimensional ultrasonic angiography is a new power Doppler ultrasonographic imaging mode that appears to improve the visualization of vascular anatomy in abdominal sonography. This study illustrates the utility of three-dimensional ultrasonic angiography in the abdomen, especially with respect to liver and portal vein anatomy, vascularization of the kidney, and vessels localized in the retroperitoneum.

Abdomen↗

[Constrictive pericarditis--a differential diagnosis in therapy refractory ascites].

HISTORY AND FINDINGS: A 62-year-old woman with refractory ascites and histologically proven liver cirrhosis was admitted for implantation of a transjugular intrahepatic portosystemic stent shunt (TIPSS). Another 44-year-old man presented for evaluation of a liver disease of unknown origin with refractory ascites. DIAGNOSIS, TREATMENT AND COURSE: In both patients abdominal ultrasound showed a dilatation of the inferior caval vein and the liver veins. There was no splenomegaly present. In the side projection of the chest X-ray major calcifications of the pericardium were found pointing to the diagnosis of constrictive pericarditis. Diagnosis was proven by combined left and right heart catheterization demonstrating diastolic dip-plateau-phenomenon. The women was treated successfully by pericardiectomy. CONCLUSIONS: In patients with refractory ascites, dilated jugular veins and dilated liver veins constrictive pericarditis must be suspected. Pericardial calcifications in chest X-ray often given further evidence for the diagnosis which helps to avoid further evaluation of a primary liver disease. The treatment of choice is early surgical pericardiectomy, whereas shunt procedures are not indicated.

Adult↗

Phosphoinositide 3-kinase-dependent Ras activation by tauroursodesoxycholate in rat liver.

Ursodesoxycholic acid, widely used for the treatment of cholestatic liver disease, causes choleretic, anti-apoptotic and immunomodulatory effects. Here the effects on choleresis of its taurine conjugate tauroursodesoxycholate (TUDC), which is present in the enterohepatic circulation, were correlated with the activation of important elements of intracellular signal transduction in cultured rat hepatocytes and perfused rat liver. TUDC induced a time- and concentration-dependent activation of the small GTP-binding protein Ras and of phosphoinositide 3-kinase (PI 3-kinase) in cultured hepatocytes. Ras activation was dependent on PI 3-kinase activity, without the involvement of protein kinase C- and genistein-sensitive tyrosine kinases. Ras activation by TUDC was followed by an activation of the mitogen-activated protein kinases extracellular-signal-regulated kinase-1 (Erk-1) and Erk-2. In perfused rat liver, PI 3-kinase inhibitors largely abolished the stimulatory effect of TUDC on taurocholate excretion, suggesting an important role for a PI 3-kinase/Ras/Erk pathway in the choleretic effect of TUDC.

Animals↗

Taurine attenuates cold ischemia-reoxygenation injury in rat liver.

BACKGROUND: Taurine, betaine, and inositol were recently identified as osmolytes in liver cells interfering with cell volume regulation and cell function. In this study, the effect of osmolytes on cold ischemia-reoxygenation injury was investigated in rat liver. METHODS AND RESULTS: Isolated rat livers were flushed for 15 min with Krebs-Henseleit buffer (KHB), then stored for 16 hr in KHB at 4 degrees C, and thereafter reperfused with oxygenated KHB for 180 min. When taurine, betaine, and inositol (2 mmol/L, each) were added to the preperfusion and storage buffer, lactate dehydrogenase, aspartate amino transferase, and glutathione S-transferase leakage into the effluent perfusate during the reoxygenation period were less than half compared to controls without osmolytes and bile flow was higher. The effect of taurine (2 mmol/L) was similar to a mixture of all three osmolytes, indicating that taurine is the most important constituent. When livers were stored for 24 hr in University of Wisconsin solution, osmolyte addition to the storage solution also decreased lactate dehydrogenase and aspartate aminotransferase leakage during reoxygenation. Increasing liver taurine content by a 7-day taurine supplementation of drinking water attenuated reoxygenation injury in cold and warm ischemia in rat livers, whereas taurine depletion by beta-alanine feeding had the opposite effect. CONCLUSIONS: The data show that taurine protects livers from ischemia-reoxygenation. Taurine addition to perfusion and storage solutions in low millimolar concentrations or taurine supplementation of the donor may be useful to protect transplanted organs.

Animals↗

Electron-microscopic demonstration of multidrug resistance protein 2 (Mrp2) retrieval from the canalicular membrane in response to hyperosmolarity and lipopolysaccharide.

Immunohistochemical studies suggest that canalicular secretion via multidrug resistance protein 2 (Mrp2), a conjugate export pump encoded by the Mrp2 gene, is regulated by rapid transporter retrieval from/insertion into the canalicular membrane. The present study was undertaken in order to investigate this suggestion by means of immunogold electron microscopy. Therefore the effects of lipopolysaccharide (LPS) and osmolarity on Mrp2 localization were studied following immunogold labelling in the perfused rat liver by quantitative electron microscopy and morphometric analyses, and by confocal laser scanning microscopy. Mrp2 activity was assessed in the isolated perfused rat liver by measuring the excretion of dinitrophenyl-S-glutathione as a substrate of Mrp2. Both LPS and hyperosmolarity resulted in a statistically significant decrease in immunogold-labelled Mrp2 in the canalicular membrane and canalicular villi, and an increase in labelling in the pericanalicular cytoplasm. Canalicular morphometric parameters were unchanged under these conditions compared with controls. Under hyperosmolar perfusion Mrp2, but not the canalicular protein dipeptidylpeptidase IV, was found inside the cells, as shown by double immunofluorescence and confocal laser scanning microscopy. The findings suggest a selective retrieval of Mrp2 from the canalicular membrane under the influence of hyperosmolarity and LPS, whereas canalicular morphology remains unchanged.

Animals↗

Hypoosmolarity influences the activity of transcription factor NF-kappaB in rat H4IIE hepatoma cells.

The influence of anisoosmolarity on NF-kappaB binding activity was studied in H4IIE rat hepatoma cells. Hypoosmolarity induced a sustained NF-kappaB binding activity whereas the hyperosmotic NF-kappaB response was only minor. Hypoosmotic NF-kappaB activation was accompanied by degradation of the inhibitory IkappaB-alpha. Protein kinase C, PI(3)-kinase, reactive oxygen intermediates and the proteasome apparently participate in mediating the hypoosmotic effect on NF-kappaB. Hypoosmolarity plus PMA induced, amplified and prolonged IkappaB-alpha degradation and NF-kappaB binding activity. Transforming growth factor beta-induced apoptosis was diminished by hypoosmolarity. However, this anti-apoptotic effect was probably not related to NF-kappaB activation.

Animals↗

Changes in free amino acid synthesis in the perfused liver of an air-breathing walking catfish, Clarias batrachus infused with ammonium chloride: a strategy to adapt under hyperammonia stress.

The changes in the free amino acid (FAA) levels, the rate of efflux of FAAs from the perfused liver, and the activity of some enzymes related to amino acid metabolism such as glutamate dehydrogenase (GDH, both reductive amination and oxidative deamination), glutamine synthetase (GS), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were studied in the liver of a freshwater air-breathing teleost, the walking catfish, Clarias batrachus, perfused with 5 and 10 mM NH(4)Cl. The level of the various non-essential FAAs increased significantly, with a total increase of about 150%, which was accompanied by a significant increase of both ammonia and urea-N in the perfused liver both with 5 and 10 mM NH(4)Cl. The rate of efflux of these non-essential FAAs from the perfused liver also increased significantly with a total increase of about 115% and 160% at 5 and 10 mM NH(4)Cl, respectively. The activity of the mentioned amino acid metabolism-related enzymes in the perfused liver also got stimulated, except for GDH in the ammonia forming direction and ALT, under a higher ammonia load. The activity (both tissue and specific) of GDH in the glutamate forming direction increased maximally, followed by AST and GS in a decreasing order. Owing to these physiological adaptive strategies related to amino acid metabolism along with the presence of a functional and regulatory urea cycle (reported earlier), it is believed that this catfish is able to survive in very high ambient ammonia or in the air or in the mud during habitat drying.

Adaptation, Physiological↗

Color Doppler sonographic evaluation of spontaneous portosystemic shunts and inversion of portal venous flow in patients with cirrhosis.

PURPOSE: The aim of the study was to evaluate the usefulness of color Doppler sonography in the detection of spontaneous portosystemic shunts and abnormal blood flow direction in the portal vein in patients with cirrhosis. METHODS: Patients were 67 men and 42 women (mean age, 53 +/- 14 years) with cirrhosis confirmed by liver biopsy. All patients underwent abdominal gray-scale and color Doppler sonographic evaluations to detect the presence of spontaneous portosystemic shunts and to analyze portal vein blood flow direction. RESULTS: Spontaneous portosystemic shunts were found in 41 patients (38%), most often as splenorenal shunts (21%) and patent umbilical veins (14%). Less frequent were gastric collaterals, gallbladder varices, collaterals to thrombotic portal veins, mesoiliac shunts, and portorenal shunts to the right kidney. The presence of shunts was associated with that of esophageal varices (p < 0.01), ascites (p < 0.01), and inversion of portal flow (p < 0. 001) but not with splenomegaly. The direction of portal venous flow was normal (hepatopetal) in 80 patients (73%), hepatofugal in 10 (9%), and bidirectional in 7 (6%); 12 patients (11%) had partial portal vein thrombosis. CONCLUSIONS: Portosystemic shunts and the direction of portal venous flow are important features in the sonographic diagnosis of portal hypertension.

Adult↗

Mutations of the core promoter and response to interferon treatment in chronic replicative hepatitis B.

In chronic replicative hepatitis B the significance of mutations in the basic core promoter (BCP), core upstream regulatory sequences (CURS) and negative regulatory element (NRE) for response to interferon (IFN) is unknown. A sequence analysis of the NRE, CURS, BCP, and precore region was performed from sera of 96 patients with chronic replicative hepatitis B (64 hepatitis B e antigen [HBeAg]-positive patients and 32 HBeAg-negative patients) treated with alfa-IFN (IFN-alpha). The overall sustained response (SR) rate to IFN was 30% with no significant difference between HBeAg-positive and HBeAg-negative patients. IFN responsiveness correlated to hepatitis B virus (HBV)-DNA levels, hepatitis B surface antigen (HBsAg) levels, the number of mutations in the complete BCP, especially nucleotide (nt) region 1753 to 1766 and mutations at nt 1762 and 1764. In HBeAg-positive hepatitis, SR to IFN was associated with a high number of mutations in the BCP (P <.04) and nucleotide region 1753 to 1766 (P <.015) as well as mutations at nucleotide 1764 (P <.007). In HBeAg-negative hepatitis, SR to IFN correlated with a low number of mutations in the BCP (P <.04) and nucleotide region 1753 to 1766 (P <.02) and a wild-type sequence at nt 1764 (P <.003). Prediction of IFN response was possible on the basis of nt 1764 in 77% of HBeAg-positive patients and 78% of HBeAg-negative patients. IFN response did not correlate with the occurrence of the 1896 mutation, mutations in the CURS or NRE, disease duration, ethnic origin of the patient, alanine transaminase (ALT) levels and HBV genotype. Our data suggest that HBV genome mutations located within the BCP are determinants of a response to IFN therapy.

Adult↗

Type I gaucher disease: extraosseous extension of skeletal disease.

OBJECTIVE: To investigate the frequency and morphology of extraosseous extension in patients with Gaucher disease type I. DESIGN AND PATIENTS: MRI examinations of the lower extremities were analyzed in 70 patients with Gaucher disease type I. Additionally, the thoracic spine and the midface were investigated on MRI in two patients. RESULTS: Four cases are presented in which patients with Gaucher disease type I and severe skeletal involvement developed destruction or protrusion of the cortex with extraosseous extension into soft tissues. In one patient, Gaucher cell deposits destroyed the cortex of the mandible and extended into the masseter muscle. In the second patient, multiple paravertebral masses with localized destruction of the cortex were apparent in the thoracic spine. In the third and fourth patient, cortical destruction with extraosseous tissue extending into soft tissues was seen in the lower limbs. CONCLUSIONS: Extraosseous extension is a rare manifestation of Gaucher bone disease. While an increased risk of cancer, especially hematopoietic in origin, is known in patients with Gaucher disease, these extraosseous benign manifestations that may mimic malignant processes should be considered in the differential diagnosis of extraosseous extension into soft tissues. A narrow neck of tissue was apparent in all cases connecting bone and extraosseous extensions.

Adult↗

Extraosseous manifestation of Gaucher's disease type I: MR and histological appearance.

Gaucher's disease type I is the most prevalent lysosomal storage disorder caused by an autosomal-recessive inherited deficiency of glucocerebrosidase activity with secondary accumulation of glucocerebrosides within the lysosomes of macrophages. The storage disorder produces a multisystem disease characterized by progressive visceral enlargement and gradual replacement of bone marrow with lipid-laden macrophages. Skeletal disease is a major source of disability in Gaucher's disease. Extraosseous extension of Gaucher cells is an extremely rare manifestation of skeletal Gaucher's disease. This is a report on the MRI and histopathological findings of an extraosseous Gaucher-cell extension into the midface in a patient with Gaucher's disease.

Biopsy↗

Decrease of plasma taurine in Gaucher disease and its sustained correction during enzyme replacement therapy.

Gaucher disease is caused by an autosomal-recessive deficiency of glucocerebrosidase. Cells of monocytic/macrophagic origin accumulate glucosylceramide. This leads to hepatosplenomegaly, bone destruction, thrombocytopenia and anemia. Enzyme replacement therapy (ERT) with macrophage-targeted glucocerebrosidase leads to normalization of these parameters. The way of macrophage activation in Gaucher disease is not known. Recently, the osmolytes taurine, betaine and inositol were identified as important regulators of macrophage function in liver. Therefore, the role of plasma taurine in Gaucher disease as a primarily macrophage-derived disease was studied. Fasting plasma levels were measured from blood samples of healthy control subjects (n = 29, m:f = 11:18, mean age 37 +/- 3 years), from untreated Gaucher patients (n = 16, m:f = 7:9, mean age 44 +/- 4 years) and those treated for 37 +/- 2 months (n = 54, m:f = 19:35, mean age 47 +/- 2 years). Amino acid analysis was carried out in a BioChrom amino acid analyzer. In the untreated patients, plasma taurine was 45 +/- 3 microM, as compared to the controls with a plasma taurine of 63 +/- 4 microM (p < 0.01). The average increase of plasma taurine during the first year of ERT was 18 +/- 8 microM (n = 10). Patients treated for an average of 37 months (range 1-9 years of ERT) had a plasma taurine of 65 +/- 4 microM (n = 54), which was not different from the controls. It is concluded that Gaucher patients show decreased plasma taurine levels and that therapy of Gaucher disease might correct this. It has to be established, whether decreased taurine availability is a cofactor of the permanent activation of glucosylceramide-storing monocytes/macrophages in this disease.

Adult↗

Glucagon-induced expression of the MAP kinase phosphatase MKP-1 in rat hepatocytes.

BACKGROUND & AIMS: Glucagon exerts pleiotropic effects on liver function, but the underlying signal transduction is incompletely understood. We investigated the effect of glucagon on the mitogen-activated protein (MAP) kinase phosphatase MKP-1 expression. METHODS: The effect of glucagon on MKP-1 expression was studied in cultured rat hepatocytes. RESULTS: Glucagon (10-100 nmol/L) and 8-CPT-cAMP (10 or 50 micromol/L) stimulated in rat hepatocytes the expression of MKP-1 messenger RNA and protein, which became maximal within 30 minutes and declined to nearly basal levels after 60 minutes. MKP-1 induction by glucagon was sensitive to inhibition of adenylate cyclase and protein kinase A. The protein kinases G and C, Ca(2+), MAP kinases, reactive oxygen intermediates, and cellular dehydration were not involved in the glucagon-induced signaling to MKP-1. MKP-1 expression correlated with glucagon-induced antagonization of MAP kinase phosphorylation by epidermal growth factor in hepatocytes. CONCLUSIONS: The MKP-1 response to glucagon produces an additional level of interaction with MAP kinase-dependent processes, which may contribute to the regulation of liver function by glucagon or other cAMP-elevating agents.

Animals↗

Successful treatment of hepatitis B virus associated polyarteritis nodosa with a combination of prednisolone, alpha-interferon and lamivudine.

Therapy of hepatitis B virus (HBV)-associated poly-arteritis nodosa is still evolving. Here we report a successful treatment with a short-term steroid administration in combination with a-interferon and lamivudine and a complete sequence analysis of the HBV genome. A 58-year-old man presented with the symptoms of mononeuritis multiplex associated in time with the onset of highly replicative hepatitis B. Polyarteritis nodosa was confirmed by biopsy. During an initial course with alpha-interferon and prednisolone no clinical improvement or hepatitis B virus seroconversion was observed. After addition of lamivudine to the protocol with fast tapering of prednisolone, HBV DNA fell to undetectable levels within 1 month and liver transaminases normalized. After 6 months of treatment HBeAg seroconversion took place, followed by HBsAg seroconversion 2 months later. Clinical symptoms of polyarteritis improved. No relapse of polyarteritis or hepatitis B was seen during the follow up of 9 months. Complete sequence analysis of the HBV genome revealed 6 nucleotide mutations but none in a relevant antigenic epitope. The present protocol of short-term prednisolone administration combined with alpha-interferon and lamivudine was effective for the treatment of HBV-related polyarteritis nodosa and may be a promising new therapeutic approach.

Antiviral Agents↗

[New developments in therapy of chronic hepatitis B. When are nucleoside analogs indicated?].

Nucleoside analogues are promising agents for the treatment of chronic hepatitis B infection (HBV-DNA-positive by hybridization assay). The drug being studied most intensively is Lamivudine (Zeffix) which has recently been approved in Germany. When given orally once daily (100 mg) Lamivudine is well-tolerated and suppresses HBV-DNA to undetectable levels in the majority of patients. Since relapse is frequent when medication is stopped long-term treatment (at least until seroconversion of HBeAg) is warranted. Indications for lamivudine monotherapy are patients with chronic hepatitis B in which interferon (IFN) is contraindicated or patients who did not respond to a previous course of interferon. Further indications are the HBV-DNA-positive cirrhosis prior to liver transplantation (OLT) and the HBV-reinfection after OLT. The main problem of long-term monotherapy with lamivudine is viral resistance. The clinical impact of the resistant mutants is often not clear. Withdrawal or even continuation of the medication may be acceptable approaches. Other nucleoside analogues like Entecavir or Adefovir are currently being tested in clinical studies. Famciclovir was investigated preferably in patients with decompensated liver disease or HBV-reinfection after OLT. Because of conflicting results the drug should only be used under study conditions. In IFN-naive patients with chronic hepatitis B (and compensated liver disease) alpha-interferon is still the first-line therapy. With a standard course of interferon 30-40% of the patients become seronegative for HBeAg as compared with 16-17% when treated with lamivudine for twelve months. Combination of lamivudine and interferon is not more effective than IFN alone. In the future combined antiviral treatment is likely to replace monotherapy.

Adenine↗