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C Rabe

Publications and source records attributed to C Rabe.

18 recordsLinked to original sources
PubMed2006

Increased VEGF levels induced by anti-VEGF treatment are independent of tumor burden in colorectal carcinomas in mice.

Inhibition of vascular endothelial growth factor (VEGF) by gene transfer techniques was effectively applied to control experimental tumor growth, whereas effects on systemic VEGF levels had not been investigated. Therefore, we evaluated the effect of VEGF inhibition by adenoviral-mediated gene delivery of a dominant-negative soluble fragment of FLK-1 (sFlk-1) on systemic VEGF levels, organ-specific VEGF-RNA expression and antitumor efficacy in a murine colorectal cancer (CRC) tumor model. Vector function of AdsFlk-1 was shown by Western blot analysis and transgene expression was documented over a time period of 42 days in the serum of treated mice. Although cell supernatant of CT26 cells contained considerable levels of VEGF, systemic VEGF levels in the serum of tumor-bearing mice remained unaffected. Interestingly, mice that were systemically treated with AdsFlk-1 showed a strong upraise of circulating VEGF, whereas VEGF remained at background levels in the control. Vascular endothelial growth factor was increased not only in tumor bearing but also in healthy, tumor-free mice. Vascular endothelial growth factor determination in liver tissue homogenates showed a 16.5-fold upraise in AdsFlk-1-treated animals as compared to the AdLacZ control. Consecutively, systemic small interfering RNA injection targeted against VEGF reverted elevated VEGF levels almost back to normal levels. In spite of elevated VEGF levels, AdsFlk-1 administration showed significant antitumor effects in a subcutaneous metastatic CRC tumor model. There was no significant correlation between antitumour treatment response and VEGF levels in this model. Collectively, we conclude that the systemic administration of AdsFlk-1 had significant inhibitory effects on metastatic CRC tumor growth in spite of elevated systemic VEGF levels and that VEGF serum concentrations did not correlate to tumor burden and antitumor treatment response in this model.

Adenoviridae↗
PubMed2006

Biliary metal stents and air embolism: a note of caution.

Metal stents are a valuable treatment modality for patients with biliary obstruction. However, we present here two patients whose cases may serve as a warning about an unusual complication associated with these stents. We encountered this complication after endoscopic retrograde cholangiography for obstructed metal biliary stents. The first patient, an 87-year-old man with a benign biliary stricture, failed to regain consciousness after clearing of his stent using a Dormia basket and balloon catheter. Cerebral air embolism was diagnosed on cerebral computed tomography, and transesophageal echocardiography revealed a patent foramen ovale as a precipitating factor for paradoxical air embolism. He survived and was discharged with a residual hemiparesis. In the second patient, a 54-year-old man who had a history of a Billroth II operation and chronic pancreatitis and who had a portal cavernoma with biliary obstruction due to collateral veins, electromechanical dissociation complicated the balloon-catheter stent revision. Echocardiography performed during cardiopulmonary resuscitation showed major air embolism to the right heart. The patient died. These cases demonstrate that air may gain access to the venous system during therapeutic endoscopic procedures of this type. It is likely that the large diameter of metal stents and the potential for these stents to lacerate venous structures facilitate the entry of air into the venous circulation, an event which may have life-threatening consequences.

Aged, 80 and over↗
PubMed2006

Therapy of hepatocellular carcinoma with iodine-131-lipiodol. Results in a large German cohort.

AIM: To evaluate the efficacy and tolerance of iodine-131-lipiodol ((131)I-lipiodol) for hepatocellular carcinoma (HCC) in German long term patients and comparison with medically treated controls. PATIENTS, METHODS: 38 courses of intra-arterial (131)I-lipiodol therapy with a total activity up to 6.7 GBq were performed in 18 patients with HCC (6 with portal vein thrombosis). Liver and tumour volume and lipiodol deposition were measured by computed tomography and (131)I activity by scintigraphy. Therapeutic efficacy was determined by tumour volume change and matched-pairs analysis in comparison to medically (i.e. tamoxifen or medical support) treated patients. RESULTS: Tumour volume decreased in 20/32 index nodules (63%) after the first course. Repeated therapy frequently resulted in further tumour reduction. Overall response to treatment was partial in 11 nodules, minor response in 4 nodules, and disease was stable in 12 and progressive in 5. Significant response was associated with pretherapeutic nodule volume up to 150 ml (diameter of 6.6 cm). Survival rate after 3, 6, 9, 12, 24 and 36 months was 78, 61, 50, 39, 17, and 6%. Matched-pairs analysis of survival revealed (131)I-lipiodol to be superior to medical treatment. The most important side effect was a pancreatitis-like syndrome whereas overall tolerance was good. CONCLUSION: The long term results confirm that HCC therapy with (131)I-lipiodol is effective and probably superior to medical treatment. Tumour nodules of up to 6 cm diameter are well suited for this therapy even in the presence of portal vein thrombosis.

Aged↗
PubMed2006

The attributable risk in a multifactorial situation--evaluation of different methods of partitioning.

OBJECTIVES: Different approaches to partition the attributable risk into exposure-specific components are methodologically evaluated. METHODS: Two methods of partitioning the attributable risk in a multifactorial situation have been suggested. One is based on a solution adopted from game theory, the Shapley value, whereas the other recently suggested approach uses a heuristically motivated proportional weighting scheme. These two concepts are reviewed and compared in a situation with three exposure factors. A hypothetical numerical example is discussed illustrating differences in the case of complex interaction structures. RESULTS: The two methods are found to differ in two critical features that affect the outcome of partitioning: i) including or ignoring the full interaction structure between exposure factors involved in the partitioning, ii) using an equal or proportional weighting scheme for the marginal excess risks of the exposures. As a result, not only the individual partial attributable risks for the exposure factors may be quantitatively different between the methods, but also their ranking depends on the partitioning approach. CONCLUSIONS: The epidemiologic properties of the partitioning procedure based on the Shapley value are known and fit to the needs of epidemiologic applications. The alternative approach recently suggested can lead to considerably different results. As long as its epidemiologic properties are not fully understood, the traditional partitioning method should be given preference in practical applications.

Algorithms↗
PubMed2005

[Malaria in the emergency room. Results of the emergency treatment of 137 patients with symptomatic malaria].

OBJECTIVE: To assess characteristics and outcome of emergency patients with acute malaria. PATIENTS AND METHODS: We retrospectively assessed the clinical and laboratory parameters of 137 consecutive patients (87 males, 50 females; median age 37 years, range 17 - 67 years) presenting with acute malaria to our tertiary care center between 1992 and 2002. RESULTS: Falciparum malaria was diagnosed in 116/137 and tertian malaria in 19/137 patients; a single patient was infected with both parasites while in another case the type of parasite remained unclear. Infections were acquired in Africa (121), Asia , and in the Americas . One traveler visited multiple continents. Only 36 % (50/137) of patients had used malaria chemoprophylaxis. 128/137 patients were treated as in-patients; 22 of these had to be treated on an intensive care unit. According to the criteria of the German Society of Tropical Medicine, 44/137 (32 %; 95 % confidence interval (CI): 25 - 40 %) patients suffered from complicated malaria. The overall mortality rate was 2/137 (1.5 %; 95 % CI: 0,4 - 5.2 %); the mortality rate of complicated malaria tropica was 2/44 (4,5 %; 95 % CI 1,3 - 15 %). Patients with complicated malaria were significantly older than those with uncomplicated malaria. Median length of hospital stay was 4 days in uncomplicated and 9 days in complicated cases. Based on costs of EUR 2500 per case, an attack rate of > 3 % in East African travelers and a cost of EUR 55 for a chemoprophylaxis with mefloquine, chemoprophylaxis is cost-effective. CONCLUSION: In our retrospective analysis, complicated malaria tropica was associated with older age. Although malaria causes considerable morbidity, the overall mortality from severe malaria is low. Reinforcement of chemoprophylaxis especially in travelers to Africa could reduce malaria cases and is cost-effective.

Adolescent↗
PubMed2002

[Clinical outcome of a cohort of 63 patients with hepatocellular carcinoma treated with octreotide].

Unresectable hepatocellular carcinoma (HCC) are associated with a poor prognosis. Recently, one controlled study reported a strikingly prolonged survival of patients with HCC who were treated with octreotide. Until other randomised controlled trials become available, this multicentric retrospective study therefore assesses the outcome of HCC-patients who received octreotide treatment. 63 patients (53 males, 10 females) who had been treated with octreotide at 13 participating German centres were included in the analysis. In 54 cases liver cirrhosis was present (25 Child-Pugh A, 20 Child-Pugh B, 7 Child-Pugh C, 2 unknown). The liver disease was associated with alcohol abuse in 19 patients, alcohol and viral hepatitis in four patients, while 12 patients had only markers of past or present hepatitis B infection, 11 patients suffered of chronic hepatitis C infection, and four patients were seropositive for both hepatitis B and hepatitis C markers. The Okuda stage was stage I in 23, stage II in 33, and stage III in 7 patients. The patients initially received octreotide as a long-acting release formula (20-30 mg/month) in 43 cases or through subcutaneous injection (dose 3 x 50-3 x 300 ug/day) in the remaining cases. 11 of the patients receiving subcutaneous treatment were later converted to the long-acting release form of the drug. At three months, a partial remission was achieved in two patients, while 22 tumours showed no change and 26 tumours progressed. At six months, 11 tumours showed no change, while 15 tumours progressed. The patients' median survival was 9 months (Okuda stage I 16 months, stage II 9 months, stage III 4 months). In conclusion, octreotide treatment did not result in markedly prolonged survival in this retrospective series of 63 patients.

Adult↗
PubMed2002

Cirrhotic patients with or without hepatocellular carcinoma harbour AFP-specific T-lymphocytes that can be activated in vitro by human alpha-fetoprotein.

BACKGROUND: Alpha-fetoprotein (AFP) is re-expressed in 60%-70% of hepatocellular carcinomas (HCC) and may therefore be a potential target for a prophylactic or therapeutic tumour-specific vaccination. A prerequisite for this approach is the possibility to induce AFP-specific T-lymphocytes in patients with HCC and/or cirrhosis. METHODS: Peripheral blood was examined for the presence of AFP-specific T-lymphocytes using a FACS-based interferon-gamma secretion assay. RESULTS: In a group of healthy volunteers, the presence of AFP-specific CD4- and CD8-lymphocytes was demonstrated. Screening of blood of 14 cirrhotic patients without HCC and 23 cirrhotic patients with HCC showed that patients with liver diseases that represent targets for vaccination also harbour CD4-positive as well as CD8-positive AFP-specific Tlymphocytes. AFP reactivity in patients' lymphocytes was not significantly influenced by soluble serum AFP. The median stimulation factors for CD4-positive T-lymphocytes were significantly higher (P = 0.0365) in cirrhotic patients without HCC (median 2.08, range 0.50-4.40) compared to cirrhotic patients with HCC (median 1.15, range 0.24-8.50). CONCLUSION: AFP-specific T-lymphocytes that may be instrumental in HCC vaccination strategies are present in humans. This study suggests that immunopreventive vaccination of cirrhotic patients rather than immunotherapeutic vaccination of HCC patients may be preferable.

Adult↗
PubMed2001

Characterization of an evolutionarily conserved far-upstream enhancer in the human alpha 2(I) collagen (COL1A2) gene.

We have examined the chromatin structure around and upstream of the transcriptional start site of the human alpha2(I) collagen (COL1A2) gene. Four strong DNase I-hypersensitive sites (HS2-5) were only detected in fibroblasts, and a weaker one (HS1) was identified in type I collagen-negative cells. Another hypersensitive site potentially involved in COL1A2 silencing was found in intron 1 (HS(In)). HS1 and HS2 were mapped within conserved promoter sequences and at locations comparable to the mouse gene. HS3, HS4, and HS5 were likewise mapped approximately 20 kilobases upstream of COL1A2 at about the same position as the mouse far-upstream enhancer and within a remarkably homologous genomic segment. DNase I footprinting identified twelve areas of nuclease protection in the far-upstream region (FU1-12) and within stretches nearly identical to the mouse sequence. The region containing HS3-5 was found to confer high and tissue-specific expression in transgenic mice to the otherwise minimally active COL1A2 promoter. Characterization of the human element documented functional differences with the mouse counterpart. Enhancer activity substantially decreased without the segment containing FU1-7 and HS5, and inclusion of AluI repeats located 3' of HS3 augmented position-independent expression of the transgene. Hence, subtle differences may characterize the regulation of mammalian alpha2(I) collagen genes by evolutionarily conserved sequences.

Animals↗
PubMed2001

Molecular mechanisms of hepatitis B virus-associated liver cancer.

Hepatitis B infection is associated with an increased risk of hepatocellular carcinoma development. Hepatitis B proteins, such as the hepatitis B x protein, the large hepatitis B surface protein, or truncated middle hepatitis B surface proteins, regulate transcription of many candidate genes for liver carcinogenesis by trans-mechanisms. They also alter mechanisms of apoptosis and interfere with nucleotide excision repair of damaged DNA. Together with an influence on cellular signaling, these mechanisms may favor the cell's clonal expansion.

Antigens, Viral↗
PubMed2001

Intracellular accumulation of middle hepatitis B surface protein activates gene transcription.

While the natural intact protein does not possess any transactivator function, C-terminal truncation of the middle hepatitis B surface (MHBs) protein yields a novel transactivator function. We have previously found that the truncated transactivator protein, MHBs(t167), is not secreted but retained within the secretory pathway. Here, we provide evidence that when full-length MHBs is coexpressed with the truncated MHBs(t167) protein, the secretion of the full-length protein is inhibited and both proteins accumulate within the cell. We further show that MHBs, forcibly retained in the cell by C-terminal fusion to the endoplasmic reticulum retention signal KDEL (MHBsKDEL), mimics the effects of MHBs(t167) in enhancing the nuclear-binding activity of transcription factors NFkappaB and AP-1, and activation of NFkappaB- and AP-1-dependent transcription of reporter genes. As is the case for MHBs(t167), MHBsKDEL-dependent activation of NFkappaB is inhibited by the antioxidant N-acetyl-L-cysteine indicating the involvement of reactive oxygen intermediates and suggesting a similar mechanism of activation. This study suggests that the intracellular retention and accumulation of the normally secreted MHBs leads to oxidative stress and activation of transcription. This may be an important but not exclusive mechanism in hepatocarcinogenesis.

Carcinoma, Hepatocellular↗
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↗
PubMed2000

Interaction of Hepatitis B virus with cellular processes in liver carcinogenesis.

Hepatitis B infection is strongly linked epidemiologically to hepatocellular carcinoma development. This article reviews the molecular mechanisms by which hepatitis B encoded proteins such as hepatitis B x and hepatitis B surface transactivators may interact with gene transcription, tumor suppression, apoptosis, and signalling pathways of the liver cell with the possible consequence of tumor induction. Data on the interaction between hepatitis B proteins and cellular processes are often conflicting indicating a non-specific simultaneous interaction with antagonistic cellular processes that result in the formation of escape mutants that are not subject to these selective pressures.

Amino Acid Sequence↗
PubMed1996

Mood and the use of scripts: does a happy mood really lead to mindlessness?

The authors tested whether happy moods increase, and sad moods decrease, reliance on general knowledge structures. Participants in happy, neutral, or sad moods listened to a "going-out-for-dinner" story. Happy participants made more intrusion errors in recognition than did sad participants, with neutral mood participants falling in between (Experiments 1 and 2). Happy participants outperformed sad ones when they performed a secondary task while listening to the story (Experiment 2), but only when the amount of script-inconsistent information was small (Experiment 3). This pattern of findings indicates higher reliance on general knowledge structures under happy rather than sad moods. It is incompatible with the assumption that happy moods decrease either cognitive capacity or processing motivation in general, which would predict impaired secondary-task performance.

Attention↗