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Biomedical subjects

T Sauerbruch

Publications and source records attributed to T Sauerbruch.

At least 109 records · Page 6Linked to original sources
PubMed2001

Hemodynamic effects of the angiotensin II receptor antagonist irbesartan in patients with cirrhosis and portal hypertension.

BACKGROUND & AIMS: Angiotensin II receptor antagonists have been proposed as new drugs for portal hypertension. This randomized, placebo-controlled, double-blind study aimed to assess the effect of the angiotensin II receptor antagonist irbesartan on portal and systemic hemodynamics and renal function in patients with cirrhosis. METHODS: Thirty-six patients with cirrhosis and portal hypertension received 150 mg/d irbesartan or placebo for 1 week. Systemic hemodynamics, kidney and liver function parameters were recorded regularly; hepatic venous pressure gradient and plasma renin were assessed on days 0 and 7. RESULTS: Irbesartan reduced the hepatic venous pressure gradient by 12.2% +/- 6.6% (P < 0.05) and mean arterial pressure by 5.3% +/- 4.0% in 13 of 18 verum patients. In 4 (22%) verum patients, arterial hypotension, accompanied by significant renal impairment, required withdrawal of irbesartan. In these patients, baseline plasma renin (P < 0.002) and cystatin C (P < 0.001) levels were higher, and creatinine clearance (P < 0.02), serum sodium (P < 0.01), and albumin (P < 0.05) were lower than in patients who tolerated irbesartan. Four of five patients with baseline renin >900 microU/mL developed treatment-limiting hypotension. CONCLUSIONS: The angiotensin II receptor antagonist irbesartan is not advisable in patients with advanced cirrhosis and high plasma renin because it may induce arterial hypotension and only moderately reduces portal pressure.

Angiotensin Receptor Antagonists↗
PubMed2001

Contractile hyporesponsiveness of hepatic arteries in humans with cirrhosis: evidence for a receptor-specific mechanism.

Splanchnic vasodilatation and vascular hyporesponsiveness to vasopressors are characteristic features of patients with cirrhosis. Although the vascular response to different vasopressors has been shown to be attenuated in cirrhosis, alterations on the receptor level are discussed controversially. Thus, impaired postreceptor signaling has been postulated. However, so far this has not been studied in human splanchnic vessels. Therefore, we assessed the vascular response of human hepatic arteries after activating the G-protein-dependent signal transduction pathway by stimulation with angiotensin II, the thromboxane A(2) analog U46619, or by G-protein activation with NaF/AlCl(3). After endothelium denudation, cumulative isometric concentration contraction curves were obtained for hepatic arteries from 32 cirrhotic patients undergoing liver transplantation and from 40 organ donors after stimulation with either angiotensin II (10(-11)-10(-5) mol/L), U46619 (10(-10)-10(-6) mol/L) or AlCl(3) (30 micromol/L)/NaF (10(-4)-3 x 10(-2) mol/L). Hepatic arteries from cirrhotic patients were markedly less responsive to angiotensin II (P <.0001) than those from organ donors. Both stimulation of the G-protein phospholipase C pathway via the thromboxane A(2) receptor and receptor-independent G-protein stimulation with AlCl(3)/NaF, induced an intact contractile response. In conclusion, the G-protein-dependent signal transduction system itself is unaltered in cirrhosis. Hence, the cause of the hyporesponsiveness to some vasoconstrictors in cirrhosis appears to be a receptor-specific phenomenon localized upstream from the G-protein level.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed2001

Decrease of elevated N,N-dimethylglycine and N-methylglycine in human immunodeficiency virus infection during short-term highly active antiretroviral therapy.

This study investigates fasting serum levels of methionine and related metabolites, vitamin B6, and folate during highly active antiretroviral therapy in therapy-naive human immunodeficiency virus (HIV)-1-infected outpatients. The research design consisted of before and during therapy measurements with a median treatment period of 100 days (range, 50 to 188) in frozen samples. The subjects included 17 consecutive HIV-1-infected outpatients (15 men and 2 women; 25 to 65-years-old). Controls were 42 healthy individuals (28 men and 14 women; 24- to 82-years-old) without serologic evidence of HIV and/or hepatitis C infection and normal clinical chemistry. Subjects received treatment with the reverse transcriptase inhibitors, azidothymidine (AZT) or stavudine (D4T) plus lamivudine (3TC) and either the protease inhibitors, indinavir (IND), nelfinavir (NELF), ritonavir (RITV), or saquinavir (SAQ) at the standard dosage. Serum concentrations of methionine, total homocysteine (tHcy), cystathionine (CYSTA), N,N-dimethylglycine (DMG), N-methylglycine (MG), methylmalonic acid (MMA), and total cysteine, as well as vitamin B6, folate, and soluble tumor necrosis factor receptor p75 were taken at baseline and during highly active antiretroviral therapy. Baseline, serum tHcy, MMA, CYSTA, vitamin B6 concentrations were not significantly different from healthy controls. There was, however, a trend towards lower folate serum concentrations at baseline in HIV-infected patients as compared with healthy controls (P =.06). There were no significant correlations between tHcy and vitamin B6, folate, or MMA. Elevated baseline levels of DMG and MG decreased significantly during antiretroviral therapy (P =.0019 and.04, respectively), whereas no significant changes in serum concentrations of CYSTA, MMA, or methionine were detected. tHcy increased in 12 of 17 patients (P =.09). HIV-infected patients displayed significant alterations (elevated DMG and MG serum concentrations) in metabolite levels of the betaine pathway in methionine metabolism, which might be positively influenced by newly initiated antiretroviral combination therapy.

Adult↗
PubMed2001

Severe abdominal infections in neutropenic patients.

Abdominal infections are an important cause of morbidity and mortality in neutropenic patients. We present a retrospective series of 16 patients, mostly with acute leukemia, who developed severe abdominal infections during chemotherapy-induced neutropenia between 1991 and 1997. The frequency among patients with acute leukemia was 2.35% (13 of 553). Thirteen patients presented with enterocolitis and 3 patients presented with cholecystitis. Eight patients died. Bacteremia was present in 6 patients, 4 patients suffered from proven or strongly suspected fungal infections, and 1 patient suffered from cytomegalovirus infection. Early surgical management was required in a patient with intestinal obstruction, whereas other patients could be managed conservatively. Two patients with acute cholecystitis were treated with antibiotics until the end of neutropenia and then were resected. Severe abdominal injections in neutropenic patients, which are often fatal, were caused by nonbacterial microorganisms in one-fourth of the cases and could be managed conservatively in most instances.

Abdomen↗
PubMed2001

Virus-like particles in a case of acute hepatitis with human GB virus-C viraemia.

BACKGROUND/AIMS: It is still controversial whether the human GB virus-C can cause liver injury, as in situ demonstration of the virus is still inconclusive. METHODS: Here we describe the case report of a patient with two episodes of severe acute hepatitis, who had a meticulous clinical, immunological and microbiological work-up, including human GB virus-C RNA detection by in situ hybridization and electron microscopy. RESULTS: Human GB virus-C viraemia was found as the only potential cause of hepatitis in this patient. Furthermore, virus-like particles could be demonstrated in the cytoplasm of single hepatocytes by electron microscopy and human GB virus-C RNA was detected in the liver by in situ hybridization. CONCLUSION: The presence of human GB virus-C RNA in serum together with the demonstration of human GB virus-C RNA in the liver, favour acute human GB virus-C infection as the cause of liver injury in this patient. Thus virus-like particles and hepatic human GB virus-C RNA should be specifically looked for by electron microscopy and in situ hybridization, especially during the diagnostic work-up of patients with unexplained hepatitis.

Acute Disease↗
PubMed2001

Effects of different octreotide dosages on splanchnic hemodynamics and glucagon in patients with TIPS.

OBJECTIVE: The aim of this study was to evaluate the hemodynamic effects of octreotide in patients treated with transjugular intrahepatic portosystemic stent shunt in relation to plasma levels of octreotide and glucagon and the correlation between portal pressure and noninvasive Doppler parameters. METHODS: In 15 fasting patients, we i.v. administered isotonic sodium chloride followed by octreotide 25 microg/h and 100 microg/h, each over 1 h. We measured portal pressure (PP) directly and portal vein blood flow velocity by Doppler ultrasound simultaneously and calculated portal vascular resistance (PVR) and portal venous flow (PVF). Blood samples were taken for glucagon and octreotide (mean +/- SE). RESULTS: Octreotide reduced PP (120': -7.7+/-2.2%, p < 0.01 vs baseline; 180': - 11.4+/-2.1%, p < 0.01 vs baseline) and PVF (120': -21.7+/-31.7%, p < 0.01 vs baseline; 180': -11.6+/-18.1%, p < 0.05 vs baseline). Glucagon decreased with the increase in octreotide levels and showed a correlation with the decrease in PP and with PVF. In patients with a high PVR, we found a close inverse correlation between PP and portal vein blood flow velocity (r = -0.83, p = 0.03) as well as Cl (r = 0.81, p = 0.05), whereas poor correlation was found in patients with low PVR. CONCLUSIONS: Octreotide caused a dose-related, moderate but sustained reduction in PP in patients with transjugular intrahepatic portosystemic stent shunt. PVR seems to be an important parameter that influences the efficacy of octreotide and the relation between PP and noninvasive Doppler parameters.

Blood Flow Velocity↗
PubMed2001

Transient loss of T-cell reactivity in a patient with hepatitis C virus reinfection.

BACKGROUND/AIMS: Self-limited acute hepatitis C virus (HCV) infection with spontaneous recovery is only rarely observed in clinical practice. All existing studies correlate strong cellular immune responses to the recovery from HCV infection. CASE REPORT: Here, we present a 49-year-old haemophiliac, who had successfully recovered from an acute hepatitis, which was classified retrospectively as HCV infection based on his antibody profiles. This patient was reinfected with HCV 18 years later from an exogenous source, and successfully recovered from this reinfection within 2 months. After his first hepatitis the patient displayed strong cellular responses against recombinant HCV proteins. During reinfection, T-cell proliferation was markedly reduced, while HCV antibody titres increased. However, E2 antibodies were consistently not detectable. T-cell proliferation returned to the pre-reinfection level only several months after loss of viraemia. DISCUSSION: Our observations resulted in the unexpected finding that our patient cleared HCV reinfection despite an apparent loss of his pre-existing T-cell reactivity in the peripheral blood.

Hemophilia A↗
PubMed2001

Clinical characteristics and outcome of a cohort of 101 patients with hepatocellular carcinoma.

AIM: To conduct a cohort study of 101 patients with hepatocellular carcinoma (HCC) presenting to a tertiary care medical referral center in Germany between 1997 and 1999. METHODS AND RESULTS: Data were retrospectively analyzed by chart review. In 95 cases (72 males and 23 females) sufficient data were available for analysis. Twenty five (29%) of 85 patients were HBsAg or anti HBc positive, 21/85 (25%) were anti HCV positive, and 6/85 (7%) were positive for both HBV and HCV-markers. Age was significantly lower in HBV positive patients than in the other two groups. Thirty one (34%) of 90 patients had histories of alcohol abuse. In 79/94 (84%) patients, cirrhosis was diagnosed. Of these cirrhotic patients, 29/79 (37%) belonged to Child Pugh's group (CHILD) A, 32/79 (40%) to CHILD B, and 18/79 (23%) to CHILD C. AFP was elevated in 61/91 (67%) patients. A single tumor nodule was found in 38/94 (40%), more than one nodule in 31/94 (34%), and 25/94 (26%) had a diffusely infiltrating tumor, i.e. the tumor margins could not be seen on imaging procedures. Portal vein thrombosis was present in 19/94 (20%). Imaging data consistent with lymph node metastases were found in 10/92 (11%), while distant metastases were found in 8/93 (9%). According to Okuda 28/94 (30%) were grouped to stage I, 53/94 (56%) were grouped to stage II, and 13/94 (14%) were grouped to stage II. Survival data were available for 83 patients. The Kaplan-Meier estimate for median survival was 8 4 months. Factors influencing survival were the Okuda score, the presence of portal vein thrombosis, and the presence of ascites. The presence of non complicated liver cirrhosis by itself, distant metastases, or infection with hepatitis viruses did not influence survival. AFP positivity by itself did not influence survival, though patients with an AFP value greater than 100 microg/L did experience shortened survival. Treatment besides tamoxifen or supportive care was associated with prolonged survival. The influence of therapy on survival was most pronounced in Okuda stage II patients. There was longer survival in those Okuda stage II patients who were treated with percutaneous ethanol injection. CONCLUSION: Even in a low incidence area such as Germany, the majority of HCC is caused by viral hepatitis and therefore potentially preventable. Reflecting the high proportion of advanced stage tumors in our patients, the median survival was poor. Patients who received active therapy had a longer survival.

Adult↗
PubMed2001

Enhanced lytic activity of cytokine-induced killer cells against multiple myeloma cells after co-culture with idiotype-pulsed dendritic cells.

BACKGROUND AND OBJECTIVES: There are numerous reports of in vitro and in vivo usage of dendritic cells (DC) pulsed with idiotype, the tumor-specific antigen of multiple myeloma (MM), for immunotherapy of MM. Data suggest that not only T-cells, but also the innate immune system reacts against MM. Here, we examined the cytotoxic activity of cytokine-induced killer (CIK) cells against myeloma cells. This heterogeneous effector population consists of T-, NK- and NKT-cells. DESIGN AND METHODS: CIK cells generated from buffy coats or blood from patients with MM were co-cultured with autologous idiotype-pulsed DC. The cytotoxic activity was investigated in lactate dehydrogenase release assays against cell lines or autologous CD138 positive cells from bone marrow. RESULTS: CIK cells were able to lyse MM cells at low effector to target ratios. This effect was significantly enhanced by co-culturing with specifically pulsed DC (83.8% lysis at an effector to target ratio of 16:1). Using an interferon-g secreting MACS separation assay, the cytotoxic activity of CIK cells was enhanced to maximal lysis at the lower effector to target ratio of 5:1. High cytotoxic activity was also shown in a completely autologous setting against enriched CD138+ cells from a patient with MM (54.4% lysis at an effector to target ratio of 6:1). Interestingly, there was no cytotoxic activity against the CD138- fraction of the bone-marrow. INTERPRETATION AND CONCLUSIONS: Using a heterogeneous population of effector cells, we were able to activate the innate and the adoptive immune-system against myeloma cells. CIK cells showed high lytic activity against MM cells, which could be enhanced by co-culturing with antigen-specific pulsed DC.

Antigens, Neoplasm↗
PubMed2000

Flow cytometric analysis of peptide binding to major histocampatibility complex class I for hepatitis C virus core T-cell epitopes.

BACKGROUND/METHODS: To characterize the repertoire of T-cell epitopes on the hepatitis C virus (HCV) core protein, we studied major histocompatibility complex (MHC) class I binding of 75 decapeptides on 20 human B-cell lines and murine spleen cells using a flow cytometric assay. The results were compared with MHC class I stabilization on T2 cells, the SYFPEITHI algorithm, and known T-cell epitopes from the literature. RESULTS: Binding of peptides proved to be specific for MHC class I molecules. We observed peak fluorescence signals at positions amino acids (aa) 35-44, aa 87-96, aa 131-140, and aa 167-176 in virtually all HLA-A2-positive cell lines. These sites corresponded to T-cell epitopes predicted by SYFPEITHI and the positions of known T-cell epitopes, whereas T2 stabilization was at variance for two peptides. The assay was applied to HLA-A2-negative cells and murine spleen cells without further modification, and identified additional peptides, corresponding to known T-cell epitopes. CONCLUSIONS: Peptide binding to different MHC class I alleles can be mapped rapidly by a flow cytometric assay and enables a first orientation on the sites of possible T-cell epitopes. Application of this assay to HCV core suggests a rather limited repertoire of epitopes in the Caucasoid population.

Animals↗
PubMed2000

Parallel decrease in neurotoxin quinolinic acid and soluble tumor necrosis factor receptor p75 in serum during highly active antiretroviral therapy of HIV type 1 disease.

The chronic immune activation state in HIV disease leads to increased activity of the rate-limiting tryptophan-kynurenine pathway enzyme indoleamine 2,3-dioxygenase (2,3-IDO), thereby increasing the formation of neurotoxic tryptophan metabolites such as kynurenine and quinolinic acid. We investigated whether highly active antiretroviral therapy (HAART) (median duration, 100 days; range, 50-188 days) lowers serum levels of these metabolites in HIV-infected individuals and if so, whether this was paralleled by changes in a surrogate marker for immune activation, i.e., soluble tumor necrosis factor receptor p75 (sTNFR p75) concentrations. Baseline quinolinic acid (848 nM, 95% CI 567-1130 vs. 303 nM, 95% CI 267.1-339.5) and kynurenine (4.1 microM, 95% CI 3.3-4.9 vs. 2.7 microM, 95% CI 2.4-2.9) concentrations as well as the mean kynurenine-to-tryptophan ratio (108.2, 95% CI 76.1-140.4 vs. 51.4, 95% CI 47.6-55.3) in 17 HIV-1-infected outpatients (7 with AIDS) were significantly higher than those in 55 healthy age-matched controls (p < 0.01), respectively. Serum quinolinic acid concentrations in 14 of 17 patients decreased (mean, -44.4%) during HAART in comparison with baseline (471.2 nM, 95% CI 288-654.3; p = 0. 022). Thirteen of these 14 patients also had decreases in sTNFR p75 concentrations. Overall, the mean sTNFR p75 concentration decreased by 36.3% (13.5 ng/ml, 95% CI 9.3-17.8 vs. 8.6 ng/ml, 95% CI 5.9-11. 4; p = 0.01, n = 17). Reduction in viral load through HAART and subsequent mitigation of the pathological immune activation state in HIV disease may have reduced 2,3-IDO over activation. This eventually led to a decrease in quinolinic acid formation. The parallel reduction of the immune activation marker sTNFR p75 supports this hypothesis.

Adult↗
PubMed2000

Mechanism of cytotoxicity induced by chimeric mouse human monoclonal antibody IDEC-C2B8 in CD20-expressing lymphoma cell lines.

With a new flow cytometric cytotoxicity assay, we examined the mechanism of action of chimeric mouse human anti-CD20 monoclonal antibody IDEC-C2B8. IDEC-C2B8 alone induced direct cytotoxicity in four of eight examined CD20-expressing lymphoma cell lines (RAJI, DAUDI, JOK-1, and WT100) at a concentration above 100 ng/ml. Moreover, after 4 h incubation in human serum, only a moderate complement-dependent cellular cytotoxicity (CDCC) was observed, whereas cytotoxicity increased markedly after 3 days of culture, indicating that combined direct cytotoxicity and CDCC were responsible. IDEC-C2B8 induced an effective antibody-dependent cellular cytotoxicity (ADCC) in seven of eight tested lymphoma cell lines when peripheral blood mononuclear cells were used as effector cells. ADCC was moderately enhanced by cytokine interleukin-2, whereas interleukin-12, interferon-alpha, and GM-CSF had no influence. Interestingly, we could demonstrate a correlation between CD32 expression on lymphoma cell lines and IDEC-C2B8-induced direct cytotoxicity, indicating that crosslinking of CD20 with CD32 may be involved in the mechanism of cytotoxicity. We propose that direct cytotoxicity, CDCC, and ADCC result in the marked elimination of CD20-expressing tumor cells observed after treatment with IDEC-C2B8.

Animals↗
PubMed2000

Semi-quantification of human C-C chemokine mRNAs with reverse transcription/real-time PCR using multi-specific standards.

A reverse transcription/real-time polymerase chain reaction (PCR) assay was established to semi-quantify the mRNA levels of the human C-C chemokines RANTES, MIP-1beta and MCP-1 relative to the housekeeping gene beta-actin. The assay showed a high sensitivity (below 60 cDNA molecules/10 microl reaction) and dynamic range (8 log units); both within-assay and inter-assay variability were below 0.06 log units and the accuracy was +/-0.06 log units for all four chemokines. Moreover, it is demonstrated that a multi-specific DNA fragment, which had previously been constructed for competitive PCR, can be used as a reliable external standard. This allows a direct semi-quantitative comparison of different chemokine mRNA levels and is a convenient alternative to the use of different sets of homologous external standards. The method was successfully applied to the semi-quantification of chemokines in human liver specimens and should be useful in further studies on steady state mRNA levels of C-C chemokines from low cell numbers or small tissue specimens.

Chemokine CCL2↗
PubMed2000

Indication, outcome and follow up of intensive care in patients with HIV-infection.

BACKGROUND/AIM: The admission to intensive care is controversially discussed in patients with HIV infection, since life expectancy is limited. Therefore, we analyzed indications, outcomes and follow up of all patients with confirmed HIV-infection and Aids defining symptoms who had been admitted to the intensive care unit (ICU) of our department between 1985-1996. RESULTS: 49 patients were admitted to the ICU, 42 of them with CDC stage C of HIV infection before admission. The leading indications were pneumonia (n = 15; PCP: 10, bacterial: 5), acute bleedings (n = 14), acute neurological diseases (n = 6), and gastrointestinal perforation (n = 5). Overall mortality was 39% (19/49) with a higher mortality seen in patients with respiratory disorders (53%) compared to non-respiratory disorders (22%, n.s.). The only significant predictor of mortality was the serum creatinine (p = 0.001), while differences in the APACHE II score between survivors and non-survivors did not reach statistical significance (22 +/- 7, 16 +/- 5; p = 0.14). During follow up no difference was seen in the life expectancy of HIV-infected survivors of intensive care as compared to those patients with AIDS who had never been admitted to ICU (8.4 months versus 9 months). DISCUSSION: The need for intensive care in HIV infected patients does not accelerate the progression of HIV infection to death, if the complications requiring ICU intervention can be managed successfully. Respiratory infections and impaired renal function are risk factors for a fatal outcome. Thus, HIV infected patients benefit from intensive care therapy.

Adult↗