PubMed Health⌕ Search

Biomedical subjects

Tilman Sauerbruch

Publications and source records attributed to Tilman Sauerbruch.

At least 73 records · Page 4Linked to original sources
PubMed2004

Chemokine mRNA levels in mononucleated cells of HIV-infected patients before and after initiation of PI- versus NNRTI-containing HAART.

To compare CC chemokine mRNA levels from native peripheral blood mononucleated cells (PBMCs) before and 6 months after the initiation of two different regimens of highly active antiretroviral therapy (HAART), we treated group 1 (n = 11) with two nucleoside analogues and the protease inhibitor (PI) indinavir boosted by ritonavir (800/100 mg b.i.d.); group 2 (n = 8) was treated with the non-nucleoside reverse transcriptase inhibitor (NNRTI) efavirenz instead of PI. CC chemokine mRNA levels (regulated upon T cell activation expressed secreted [RANTES], macrophage inhibitory protein [MIP]-1alpha, MIP-1beta, monocyte chemotactic protein [MCP]-1, MCP-2) were quantified from PBMCs before and 6 months after the initiation of HAART using a reverse transcription/real-time polymerase chain reaction (PCR) assay. The mRNA levels of MCP-1 and MCP-2 were significantly decreased in both groups (P < 0.05), while MIP-1alpha and MIP-1beta were decreased significantly only in the PI-treated group, but not in the NNRTI group. A moderate decrease of RANTES was observed in both treatment groups. The data suggest that HAART regimens containing either NNRTI or PI are not equivalent with regard to modification of CC chemokine mRNA profiles.

Adult↗
PubMed2004

Outcome of patients with acute myeloid leukemia and pulmonary infiltrates requiring invasive mechanical ventilation-a retrospective analysis.

PURPOSE: To assess the prognosis of patients with acute myeloid leukemia (AML) and pulmonary infiltrates requiring mechanical ventilation. DESIGN: A retrospective cohort study. SETTING: A medical intensive care unit (ICU) in an academic tertiary care center. PATIENTS AND METHODS: We identified 30 consecutive patients with acute myeloid leukemia and pulmonary infiltrates who received invasive mechanical ventilation and compared clinical and laboratory parameters between ICU survivors and ICU non-survivors using non-parametric statistics. RESULTS: The overall mortality rate was 87% (26/30). The survival was 40 % (4/10) for patients aged 50 years or less while none (0/20) of the patients older than 50 years survived (P <.02). The median time of mechanical ventilation in survivors was 23.5 (3-45) days. No differences between survivors and non-survivors were observed for the APACHE II score, oxygenation quotient, liver function tests, creatinine, blood urea nitrogen, or prognostic parameters of acute myeloid leukemia (presence of blasts on bone marrow aspirate, cytogenetic studies, and intensity of the chemotherapy regimen). CONCLUSIONS: Age seems to be an important prognostic parameter in our cohort of 30 consecutive patients with acute myeloid leukemia and pulmonary infiltrates requiring mechanical ventilation. Prolonged ventilation does not preclude survival.

Adolescent↗
PubMed2004

Establishment of an orthotopic tumour model for hepatocellular carcinoma and non-invasive in vivo tumour imaging by high resolution ultrasound in mice.

BACKGROUND/AIMS: In this study we established an orthotopic tumour model for hepatocellular carcinoma and evaluated a non-invasive high resolution ultrasound technique for diagnosis and follow-up of intrahepatic HCC. METHODS: Orthotopic liver tumours were induced by intrahepatic tumour cell injection of 10(5) Hepa129 hepatoma cells. Tumour establishment and growth were assessed by explorative laparotomy, ultrasound technique and hepatectomy one and two weeks after tumour cell implantation. Tumour establishment was confirmed histologically in liver sections. RESULTS: Our results show that the Hepa129 hepatoma cell line is suitable for orthotopic tumour establishment and that tumours can be diagnosed correctly by ultrasound imaging in all cases as confirmed by explorative laparotomy, hepatectomy and cross-sections. Tumour diameters obtained by explorative laparotomy correlated significantly with diameters assessed by ultrasound (r=0.7; P<0.0001). Tumour burden was slightly overestimated (1.2-fold) by ultrasound one week after tumour induction and relative tumour extensions increased 1.7-fold and 1.8-fold within one week as determined by subsequent explorative laparotomy or ultrasound imaging, respectively. CONCLUSIONS: These data demonstrate in a systematic study that ultrasound imaging can be used as a reliable tool to detect and to follow up orthotopic liver tumours in this tumour model in mice.

Animals↗
PubMed2004

Semiquantitative analysis of intrahepatic CC-chemokine mRNas in chronic hepatitis C.

BACKGROUND: The mechanisms leading to hepatic injury in chronic hepatitis C virus (HCV) infection are only incompletely understood. Recent data propose a correlation of the intrahepatic expression of the CC chemokine RANTES and the degree of periportal and portal inflammatory liver damage. AIM: Here, we have studied the intrahepatic mRNA levels of CC chemokines RANTES together with that of other members of this chemokine family (MIP-1beta, MCP-1, and MCP-2) in chronic hepatitis C as compared with healthy controls. METHODS: Liver samples from 22 HCV-infected patients, nine individuals with primary biliary cirrhosis and from 12 normal controls were included into this study. Intrahepatic mRNA levels of CC chemokines RANTES, MIP-1beta, MCP-1, and MCP-2 were analyzed by a semi-quantitative reverse transcription/real-time polymerase chain reaction assay. RESULTS: In chronic HCV infection, intrahepatic RANTES mRNA levels were significantly higher than in non-infected controls (7.2-fold, p < 0.001) or in the disease control group (2.8-fold, p < 0.001) and higher levels of RANTES mRNA levels were observed in livers with an advanced stage of liver cell injury (histologic activity index > or = 6), although this difference was not statistically significant (p = 0.08). In contrast, mRNA levels of MIP-1beta (p = 0.021) and MCP-1 (p = 0.021) were significantly lower in HCV liver samples while MCP-2 expression was similar in all groups analyzed. CONCLUSION: The data support the concept of chemokines as mediators of liver cell injury in chronic hepatitis C.

Adult↗
PubMed2004

Rapid determination of the Delta32 deletion in the human CC-chemokine receptor 5 (CCR5) gene without DNA extraction by lightcycler real-time polymerase chain reaction.

CCR5 is a major coreceptor for cellular entry of macrophage-tropic isolates of the human immunodeficiency virus (HIV). A 32-base pair deletion of the CCR5 gene (CCR5Delta32) protects against HIV infection because the frame shift leads to a truncated protein not expressed on the cell surface. CCR5Delta32 also delays progression in heterozygous HIV-infected patients and improves responses to antiretroviral therapy. Available methods for CCR5 genotyping, however, are cost expensive and/or time consuming. To improve CCR5 genotyping we studied four primer sets flanking the CCR5Delta32 deletion site using real-time polymerase chain reaction (PCR) on a LightCycler device. Primers amplified fragments of different length depending on the presence or absence of the Delta32 mutation. Next, melting curves of the amplified fragments were analyzed using SYBR green, a conventional double-strand DNA dye. To circumvent initial DNA extraction, we also studied serially diluted "interphase" leukocytes as PCR templates after centrifugation of EDTA blood. Finally, the validity of the new method was checked by analyzing 100 blood samples with known CCR5 genotypes. Amplicons of 82 bp:50 bp and 97 bp:65 bp fragment ratios could easily be discriminated due to the differences in their melting temperatures (3 degrees C and 2 degrees C, respectively). Furthermore, CCR5 genotyping was possible without initial DNA extraction and yielded optimal results at 1:400 to 1:600 dilution of the "interphase" leukocytes. Results of the new LightCycler PCR protocol were identical to conventional CCR5 genotyping but required considerably less time and expenditures. We have established a new real-time PCR protocol, which enables fast, cost-saving, and reliable CCR5 genotyping.

DNA Primers↗
PubMed2004

Retroviral IFN-alpha gene transfer combined with gemcitabine acts synergistically via cell cycle alteration in human pancreatic carcinoma cells implanted orthotopically in nude mice.

Standard chemotherapy for pancreatic carcinoma is based on the use of gemcitabine. The clinical benefit of interferon-alpha (IFN-alpha) in advanced pancreatic cancer has been shown. However, it has been demonstrated that to be effective, there is a need for a constant amount of IFN-alpha at the site of the tumor. Therefore, we examined transfection of the human pancreatic cancer cell line DAN-G with a retrovirus encoding for IFN-alpha and the effect of IFN-alpha gene expression alone or in combination with gemcitabine on growth inhibition of DAN-G pancreatic cancer cells in vitro and in vivo in orthotopically implanted DAN-G cells in nude mice. DAN-G cells could be efficiently transfected retrovirally by the human IFN-alpha gene and significantly enhanced the levels of IFN-alpha mRNA. In vitro gemcitabine led to an alteration of G1/S phase progression in transduced as well as untransduced cells, whereas IFN-alpha led to a significant decrease in cell viability in the transduced cells via delay in the progression of the S phase but no alteration of G1/S phase progression. In vivo, tumor volume in mice was reduced significantly with gemcitabine combined with IFN-alpha (76% +/- 8.3%) compared with gemcitabine alone (62.9% +/- 7.3%) or IFN-alpha alone (24.4% +/- 5.2%) compared with untreated animals. We conclude that gemcitabine and IFN-alpha concomitantly inhibited tumor cell proliferation significantly.

Animals↗
PubMed2004

Time course of low molecular weight proteins in the early kidney transplantation period--influence of corticosteroids.

BACKGROUND: Cystatin C (Cys C) is an established new marker of renal function in patients with various renal diseases and in kidney transplantation. However, few data are available for the early post-transplantation period. METHODS: Twenty-two patients who underwent renal transplantation (RTx) were evaluated for the kinetics of Cys C from day 0 to 14 in relation to creatinine and beta-2 microglobulin (B2MG). Blood samples were obtained immediately before and after transplantation and on a daily basis thereafter. Serum levels before transplantation (100%) were used to calculate reduction ratios. RESULTS: The decrease of the analytes differed considerably: immediately after RTx Cys C declined by 27.3% (P < 0.01). However, after 3 days, on average, all patients showed a significant increase in Cys C levels (15+/-2.5%; P < 0.01). B2MG levels fell quickly by 55.4 and 73.8% after days 1 and 7, respectively, and remained stable thereafter. In contrast, creatinine did not decrease immediately after RTx but fell slowly by 67.5% at the end of the study. Prior to rejection, all analytes showed a similar behaviour. Rejection treatment with high-dose methylprednisolone induced a significant increase in Cys C (+22.8+/-7.9%, P < 0.05), while in parallel, creatinine and B2MG decreased (-12.9+/-3.4 and -8.4+/-6.89%). CONCLUSIONS: Corticosteroid treatment for induction of immunosuppression or rejection therapy significantly induces Cys C, but decreases B2MG. Cys C and B2MG are not helpful in establishing the diagnosis of rejection earlier. Thus, our data indicate that Cys C and B2MG testing does not accurately reflect changes in the glomerular filtration rate early after transplantation.

Adult↗
PubMed2004

Dependence of oxalate absorption on the daily calcium intake.

Two to 20% of ingested oxalate is absorbed in the gastrointestinal tract of healthy humans with a daily 800 mg calcium intake. Calcium is the most potent modifier of the oxalate absorption. Although this has been found repeatedly, the exact correlation between calcium intake and oxalate absorption has not been assessed to date. Investigated was oxalate absorption in healthy volunteers applying 0.37 mmol of the soluble salt sodium [(13)C(2)]oxalate in the calcium intake range from 5 mmol (200 mg) calcium to 45 mmol (1800 mg) calcium. Within the range of 200 to 1200 mg calcium per day, oxalate absorption depended linearly on the calcium intake. With 200 mg calcium per day, the mean absorption (+/- SD) was 17% +/- 8.3%; with 1200 mg calcium per day, the mean absorption was 2.6% +/- 1.5%. Within this range, reduction of the calcium supply by 70 mg increased the oxalate absorption by 1% and vice versa. Calcium addition beyond 1200 mg/d reduced the oxalate absorption only one-tenth as effectively. With 1800 mg calcium per day, the mean absorption was 1.7% +/- 0.9%. The findings may explain why a low-calcium diet increases the risk of calcium oxalate stone formation.

Absorption↗
PubMed2003

Intratumoral immunization with tumor RNA-pulsed dendritic cells confers antitumor immunity in a C57BL/6 pancreatic murine tumor model.

Pancreatic tumors lack adequate recruitment of immunocompetent cells, especially dendritic cells (DCs). We have shown previously that coculturing of natural killer-like T cells with DCs transfected with pancreatic tumor cell line-derived RNA reverses pancreatic carcinoma cell resistance by directly triggering natural killer-like T lymphocytes in vitro. In the present study, we tested triggering of specific T lymphocytes in vivo by using an immunocompetent mouse strain (C57BL/6). Syngenic, bone marrow-derived DCs were pulsed with tumor RNA derived from the pancreatic cell line PANC02. This cell line is a ductal pancreatic adenocarcinoma and shows high resistance to every known class of clinically active antitumor agent. PANC02 cells were implanted orthotopically via ultrasound guidance and led to pancreatic tumor formation in all of the mice. Thereafter, tumor RNA-pulsed DCs were injected intratumorally. Intratumoral administration of tumor RNA-pulsed DCs induced significantly more potent protective immunity than s.c. or i.v. administration. It was significantly more effective than administration with unpulsed DCs or DCs pulsed with a control tumor RNA derived from a lymphomatous cell line (EL4). The antitumor effect was caused by induction of antigen-specific T lymphocytes as shown by additional in vitro studies. These results favor intratumoral injection of tumor RNA-pulsed DCs for immunotherapy of pancreatic cancer.

Animals↗
PubMed2003

[Life picture].

Explore the source record for details and available documents.

Gastroenterology↗
PubMed2003

Effect of antiretroviral therapy on liver-related mortality in patients with HIV and hepatitis C virus coinfection.

BACKGROUND: Highly active antiretroviral therapy (HAART) has improved the prognosis of HIV infection. However, replication of hepatitis C virus (HCV) is not inhibited by HAART, and treatment-related hepatotoxicity is common. To clarify the effect of HAART in HIV/HCV-coinfected patients, we studied liver-related mortality and overall mortality in 285 patients who were regularly treated during the period 1990-2002 at our department. METHODS: Survival was analysed retrospectively by Kaplan-Meier and Cox's regression analyses after patients (81% haemophiliacs) had been stratified into three groups according to their antiretroviral therapy (HAART n=93, available after 1995; treatment exclusively with nucleoside analogues n=55, available after 1992; or no treatment, n=137). FINDINGS: Liver-related mortality rates were 0.45, 0.69, and 1.70 per 100 person-years in the HAART, antiretroviral-treatment, and untreated groups. Kaplan-Meier analysis of liver-related mortality confirmed the significant survival benefit in patients with antiretroviral therapy (p=0.018), and regression analysis identified HAART (odds ratio 0.106 [95% CI 0.020-0.564]), antiretroviral treatment (0.283 [0.103-0.780]), CD4-positive T-cell count (0.746 [0.641-0.868] per 0.05x10(9) cells/L), serum cholinesterase (0.962 [0.938-0.986] per 100 U/L), and age (1.065 [1.027-1.105] per year) as independent predictors of liver-related survival. Severe drug-related hepatotoxicity was seen in five patients treated with nucleoside analogues alone and 13 treated with HAART. No patient died from drug-related hepatotoxicity. INTERPRETATION: In addition to improved overall survival, antiretroviral therapy significantly reduced long-term liver-related mortality in our patients. This survival benefit seems to outweigh by far the associated risks of severe hepatotoxicity.

Adult↗
PubMed2003

Regulation of CC chemokine receptor 5 in hepatitis G virus infection.

INTRODUCTION: Epidemiological data demonstrate an association between hepatitis G virus (HGV) co-infection and improved survival of HIV-positive individuals. However, the mechanism by which HGV affects progression of HIV disease remains unclear. As down-regulation of CC chemokine receptor 5 (CCR5) delays HIV progression, we investigated whether CCR5 expression is altered by exposure of lymphocytes to HGV proteins. METHODS: A cross-sectional analysis of CCR5 expression was carried out on CD4 and CD8 T lymphocytes of 11 HGV-positive and 12 HGV-negative persons, who were homozygous for the CCR5 wild-type gene. Binding of the HGV E2 protein to CD81 was analysed by flow cytometry. Lymphocytes were stimulated with immobilized HGV E2, anti-CD81 or serum proteins from HGV-infected subjects and changes in CCR5 expression and CC chemokine secretion were determined. RESULTS: We demonstrate that the HGV envelope protein E2 specifically binds to CD81 on T lymphocytes. This interaction induces a dose-dependent release of RANTES and down-regulation of CCR5 surface expression with concomitant intra-cellular accumulation of CCR5 proteins. This effect of HGV E2 on CCR5 expression was confirmed when lymphocytes were incubated with serum proteins from HGV-infected subjects. Finally, our cross-sectional analysis revealed CCR5 expression to be reduced by 53% and 36% on CD4 and CD8 lymphocytes of HGV-infected subjects, respectively (P < 0.01). CONCLUSIONS: Our results demonstrate that an interaction of HGV E2 with CD81 leads to increased RANTES secretion and decreased CCR5 surface expression. This mechanism might contribute to the delayed progression of HIV-infection in HGV-coinfected patients.

Antigens, CD↗
PubMed2003

Allogeneic dendritic cells fused with tumor cells: preclinical results and outcome of a clinical phase I/II trial in patients with metastatic renal cell carcinoma.

Therapeutic vaccination with dendritic cells (DC) can lead to tumor regression in animal models and has shown promising results in the first clinical trials of metastatic renal cell carcinoma and malignant melanoma. In vitro data and results of a clinical phase I/II trial using DC tumor fusions in patients with progressive metastatic renal cell carcinoma are presented here. In addition to toxicity and feasibility, complex immune monitoring was a point of interest. DC precursor cells were obtained from the peripheral blood mononuclear cells (PBMCs) of healthy donors and were fused with either allogeneic (8 patients) or autologous (4 patients) renal tumor cells. In total, 12 patients with progressive metastatic renal cell carcinoma were treated with an average of 2.8 x 10(7) tumor cells fused with 1.8 x 10(7) DC each administered on days 0, 28, and 56 intradermally. Fusion efficacy for the tumor cells used was 14.3% +/- 7.8%. Cell viability was 59.8% +/- 6.8% after fusion and irradiation. We observed no adverse effects and no difference in clinical outcome between the allogeneic and the autologous treatment. Eight patients remained in a progressive disease state and four patients in a stable disease state. T-cell immunity was carefully monitored before, during, and after treatment. Delayed-type hypersensitivity (DTH) reaction using tumor cells was positive after treatment in 7 of 12 patients, 2 of whom were found to have stable disease. An increase in the reactivity against recall antigens was seen in most patients. Interestingly, cytotoxicity of peripheral blood lymphocytes (PBLs) against renal cell carcinoma cells increased during treatment as well as the percentage of interferon-gamma-secreting cells. This effect was significantly enhanced within the group that had stable disease. The lack of adverse effects together with positive immunologic signs justifies further investigation of this novel therapeutic approach. Further studies are necessary to test for clinical effectiveness in patients with tumors, especially those with less advanced disease.

Adult↗
PubMed2003

Hepatitis C virus NS2 protein inhibits gene expression from different cellular and viral promoters in hepatic and nonhepatic cell lines.

The mechanisms leading to viral persistence and hepatocarcinogenesis in hepatitis C virus (HCV) infection are not fully understood. Recently, evidence has been accumulated that HCV viral proteins might interfere with gene expression of host cells. Here, we demonstrate that the amino-terminal portion of HCV NS2 protein inhibits the expression of reporter genes driven by different promoters or enhancer elements and also inhibits hepatitis B virus (HBV) gene expression and HBV DNA replication. The inhibitory effect of HCV NS2 on liver and non-liver-specific promoters and enhancer elements might be relevant for the pathogenesis of chronic HCV infection.

Cell Line↗
PubMed2003

Early up-regulation of chemokine expression in fulminant hepatic failure.

CC-chemokines recruit and activate macrophages and T lymphocytes, the major components of inflammatory infiltrates in fulminant hepatic failure (FHF). To analyse the role of CC-chemokines in the pathogenesis of FHF, this study examined serum levels and intrahepatic expression of MCP-1, MIP-1alpha, MIP-1beta, and RANTES in the livers and sera of patients with FHF and controls by ELISA, immunohistochemistry, and competitive RT-PCR. Serum levels and intrahepatic expression of all chemokines studied in FHF exceeded the levels in chronic liver diseases and normal controls. Distinct patterns of expression of each chemokine were noted on Kupffer cells, sinusoidal endothelial cells, hepatocytes, lymphocytes, and bile ducts. Intrahepatic chemokine expression correlated closely with the extent of infiltration by macrophages and T lymphocytes (r = 0.65-0.95, p < 0.001). The functional relationship between intrahepatic chemokine release and infiltration was confirmed in chemotaxis assays by inhibiting chemotaxis induced by homogenates of liver tissue obtained from FHF patients with neutralizing MCP-1, MIP-1alpha, MIP-1beta, and RANTES antibodies. The time course of CC-chemokine release was studied in the concanavalin A and the galactosamine/LPS mouse models of FHF. In both models, intrahepatic chemokine up-regulation occurred as an early event prior to hepatic infiltration and liver damage. The data indicate that an abundant intrahepatic release of CC-chemokines is an early and pivotal step in the pathogenesis of FHF.

Animals↗
PubMed2003

Phase II study of photodynamic therapy and metal stent as palliative treatment for nonresectable hilar cholangiocarcinoma.

BACKGROUND: The combination of photodynamic therapy and biliary drainage by plastic endoprosthesis insertion has produced promising results in the treatment of nonresectable hilar cholangiocarcinoma. The feasibility and efficacy of intraductal photodynamic therapy with subsequent biliary drainage by self-expandable metal stent insertion were evaluated in a prospective phase II study. METHODS: Twenty-four patients were treated with photodynamic therapy after sensitization with porfimer sodium. A plastic endoprosthesis was inserted immediately thereafter and replaced by a metal stent 4 weeks later. A retrospectively analyzed group of 20 patients treated only with biliary drainage served as a historical control group. RESULTS: In 19 of the 24 patients, insertion of a metal stent was technically feasible. The 30-day and 60-day mortality rates were 0%. A significant decrease in serum bilirubin was noted in all patients and quality of life remained stable throughout follow-up. Mean and median survival were, respectively, 15.9(3.1) and 9.9: 95% CI [6.4, 13.4] months after photodynamic therapy. In the control group, mean and median survival were, respectively, 12.5(3.4) and 5.6: 95% CI [3.7, 7.6] months, which was not statistically significantly different from the photodynamic therapy group. CONCLUSIONS: Photodynamic therapy with consecutive biliary drainage by insertion of a self-expandable metal stent is feasible. With respect to the small benefit in overall survival, randomized controlled trials are warranted.

Aged↗
PubMed2003

Effects of the CCR5-Delta32 mutation on antiviral treatment in chronic hepatitis C.

BACKGROUND/AIMS: The CC-chemokine receptor (CCR) 5-Delta32 mutation may predispose to chronic liver disease and high level viremia in hepatitis C. However, it is unclear whether CCR5-Delta32 also affects the response to antiviral treatment. METHODS: We determined CCR5 genotypes in patients with hepatitis C treated with either interferon-alpha (N=78) or interferon and ribavirin (N=78). In each group, rates of end of treatment responses (ETRs) and sustained virological responses (SVRs) were compared between CCR5-Delta32 carriers and homozygous CCR5 wildtype patients. RESULTS: ETR and SVR were achieved in 25 and 12 patients with interferon-alpha and in 52 and 45 patients with interferon/ribavirin treatment, respectively. CCR5-Delta32 carriers had significantly lower ETR rates than homozygous CCR5 wildtype patients (10.5 vs. 39.0%; P=0.02), whereas SVR rates only showed a non-significant trend (5.3 vs. 18.6%). Multivariate analysis confirmed CCR5-Delta32 carriage as an independent negative predictor for ETR in interferon-alpha monotherapy (odds ratio: 0.16; 95% confidence limits: 0.032-0.82; P=0.03). In interferon/ribavirin treated patients CCR-Delta32 carriers and CCR5 wildtype patients had similar ETR rates [19.2% vs. 23.1%] and SVR rates [20.0% vs. 21.2%]. CONCLUSIONS: Response rates to interferon-alpha monotherapy are reduced in hepatitis C virus (HCV)-infected patients carrying the CCR5-Delta32 mutation. However, interferon/ribavirin combination treatment may overcome this negative effect of CCR5-Delta32.

Adult↗