Biomedical subjects

Helmut Witzigmann

Publications and source records attributed to Helmut Witzigmann.

At least 19 recordsLinked to original sources

PubMed2007

Detection of disseminated pancreatic cells by amplification of cytokeratin-19 with quantitative RT-PCR in blood, bone marrow and peritoneal lavage of pancreatic carcinoma patients.

AIM: To evaluate the diagnostic potential of cytokeratin-19 (CK-19) mRNA for the detection of disseminated tumor cells in blood, bone marrow and peritoneal lavage in patients with ductal adenocarcinoma of the pancreas. METHODS: Sixty-eight patients with pancreatic cancer (n = 37), chronic pancreatitis (n = 16), and non-pancreatic benign surgical diseases (n = 15, control group) were included in the study. Venous blood was taken preoperatively, intraoperatively and at postoperative d 1 and 10. Preoperative bone marrow aspirates and peritoneal lavage taken before mobilization of the tumor were analyzed. All samples were evaluated for disseminated tumor cells by CK-19-specific nested-PCR and quantitative fluorogenic RT-PCR. RESULTS: CK-19 mRNA expression was increased in 24 (64%) blood samples and 11 (30%) of the peritoneal lavage samples in the patients with pancreatic cancer. In 15 (40%) of the patients with pancreatic cancer, disseminated tumor cells were detected in venous blood and bone marrow and/or peritoneal lavage. In the peritoneal lavage, the detection rates were correlated with the tumor size and the tumor differentiation. CK-19 levels were increased in pT3/T4 and moderately/poorly differentiated tumors (G2/G3). Pancreatic cancer patients with at least one CK-19 mRNA-positive sample showed a trend towards shorter survival. Pancreatic cancer patients showed significantly increased detection rates of disseminated tumor cells in blood and peritoneal lavage compared to the controls and the patients with chronic pancreatitis. CONCLUSION: Disseminated tumor cells can be detected in patients with pancreatic ductal adenocarcinoma by CK-19 fluorogenic RT-PCR. In peritoneal lavage, detection rate is correlated with tumor stage and differentiation. In the clinical use, CK-19 is suitable for the distinction between malignant and benign pancreatic disease in combination with other tumor-specific markers.

Biomarkers, Tumor↗

PubMed2006

Pathophysiological role of platelets in acute experimental pancreatitis: influence of endothelin A receptor blockade.

The potential pathophysiological role of platelet-endothelium interactions was investigated during ischemia/reperfusion (I/R), and the effect of a selective endothelin(A) receptor antagonist (ET(A)-RA) was evaluated in an acute pancreatitis model. Acute pancreatitis was induced by warm ischemia (60 min) in Wistar rats, and its effects with and without antagonist treatment were investigated. Equivalent sham-operated animals were also studied. Microcirculatory changes were assessed by in vivo microscopy, and serum levels for lipase/amylase and histological specimens were investigated. Capillary constriction to 83.7 +/- 6.7% of sham-operated diameters was observed after 60 min of ischemia. A capillary density of 56.8 +/- 9.3% of the sham-operated group (396.3 +/- 15.8 mm(-1)) was measured after reperfusion. Stagnant leukocytes (329.5 +/- 30.4%) and platelets (337.5 +/- 32.3%) increased in postcapillary venules (P < 0.05). Administration of the ET(A)-RA significantly reduced I/R injury. Capillary diameters were maintained (101.4 +/- 4.5%), and capillary density was improved to 73.3 +/- 7.6% of sham-operated animals (P < 0.05). Stagnant leukocytes (152.3 +/- 10.6%) and platelets (207.1 +/- 19.8%) in sinusoids and postcapillary venules were reduced (P < 0.05). The extent of acute pancreatitis was reduced in the therapy group as indicated by serum lipase/amylase values and histological tissue damage (P < 0.05). Thus, ET(A)-RA therapy was effective in reducing I/R-induced pancreatitis in this experimental model.

Acute Disease↗

PubMed2006

Leptin inhibits cell growth of human vascular smooth muscle cells.

Elevated leptin levels are thought to contribute to the individual cardiovascular risk, however, the role of leptin in the pathogenesis of atherosclerosis remains unclear. The aim of our study was to elucidate the effects of leptin on growth of human vascular smooth muscle cells (VSMC) and leptin receptor expression. By establishing a new quantitative real-time PCR for leptin receptor (ObR) isoforms we showed that the short isoforms of ObR were expressed in a 10- to 27-fold excess compared to the long isoform in cultured human VSMCs. Incubation of VSMCs with 100 ng/ml leptin downregulated the short isoforms significantly, whereas the long isoform was not influenced. Increasing leptin concentrations of 50 and 100 ng/ml significantly reduced the cell number of VSMCs compared to untreated controls. Our findings suggest a role for leptin in vascular smooth muscle cell growth, associated to a downregulation of leptin receptor isoforms.

Aged↗

PubMed2006

Ectopic Cushing' syndrome caused by a neuroendocrine carcinoma of the mesentery.

BACKGROUND: ACTH overproduction within the pituitary gland or ectopically leads to hypercortisolism. Here, we report the first case of Cushing' syndrome caused by an ectopic ACTH-secreting neuroendocrine carcinoma of the mesentery. Moreover, diagnostic procedures and pitfalls associated with ectopic ACTH-secreting tumors are demonstrated and discussed. CASE PRESENTATION: A 41 year-old man presented with clinical features and biochemical tests suggestive of ectopic Cushing's syndrome. First, subtotal thyroidectomy was performed without remission of hypercortisolism, because an octreotide scan showed increased activity in the left thyroid gland and an ultrasound revealed nodules in both thyroid lobes one of which was autonomous. In addition, the patient had a 3 mm hypoenhancing lesion of the neurohypophysis and a 1 cm large adrenal tumor. Surgical removal of the pituitary lesion within the posterior lobe did not improve hypercortisolism and we continued to treat the patient with metyrapone to block cortisol production. At 18-months follow-up from initial presentation, we detected an ACTH-producing neuroendocrine carcinoma of the mesentery by using a combination of octreotide scan, computed tomography scan, and positron emission tomography. Intraoperatively, use of a gamma probe after administration of radiolabeled (111)In-pentetreotide helped identify the mesenteric neuroendocrine tumor. After removal of this carcinoma, the patient improved clinically. Laboratory testing confirmed remission of hypercortisolism. An octreotide scan 7 months after surgery showed normal results. CONCLUSION: This case underscores the diagnostic challenge in identifying an ectopic ACTH-producing tumor and the pluripotency of cells, in this case of mesenteric cells that can start producing and secreting ACTH. It thereby helps elucidate the pathogenesis of neuroendocrine tumors. This case also suggests that patients with ectopic Cushing's syndrome and an octreotide scan positive in atypical locations may benefit from explorative radioguided surgery using (111)In-pentetreotide and a gamma probe.

Adrenocorticotropic Hormone↗

PubMed2006

Attenuation of proinflammatory gene expression and microcirculatory disturbances by endothelin A receptor blockade after orthotopic liver transplantation in pigs.

BACKGROUND: Endothelin-1 (ET-1), a very potent mediator of vasoconstriction, leads to microcirculatory disturbances and release of proinflammatory cytokines under pathophysiologic conditions. Our aim was to evaluate the effect of a selective ET(A)-receptor antagonist (ET(A)-RA) on cold ischemia/reperfusion (I/R) injury in a pig model. METHODS: Twenty pigs revealed orthotopic liver transplantation. The animals were randomized into 2 groups: control pigs received isotonic saline; the treated group received the selective ET(A)-RA BSF 208075 at the beginning of reperfusion. On postoperative days 4 and 7, animals were re-laparotomized to obtain tissue specimens. Liver tissue samples were collected and quantitative mRNA expression for prepro-ET-1, ET(A) receptor, pro-IL-1beta, pro-IL-6, pro-TNF-alpha, and endothelial nitric oxide synthase was analyzed using the TaqMan system. Additionally, immunohistochemical analysis for ET-1 was performed. Hepatic microcirculation was evaluated by laser Doppler flow measurement and partial pressure of oxygen and carbon dioxide measurements with the Paratrend sensor. Postischemic liver damage was monitored by measurement of liver enzymes and by histologic analysis using a semiquantitative scoring classification. RESULTS: Treatment with the ET(A)-RA significantly reduced the severity of I/R injury evidenced by lower serum AST, ALT and GLDH. Analysis of partial pressure of oxygen and blood flow revealed a significant improvement of capillary perfusion and blood flow in the treated group and was associated with a relevant reduction of tissue injury. One hour after reperfusion, quantitative RT-PCR revealed significantly lower expression of prepro-ET-1, ET(A) receptor, endothelial nitric oxide synthase, pro-TNF-alpha, pro-IL-1beta and pro-IL-6 in the therapy group. Immunohistochemical analysis demonstrated significantly reduced ET-1 immunostaining after therapy. Histologic investigation suggested less tissue damage in treated animals. CONCLUSIONS: Treatment with the selective ET(A)-RA BSF 208075 has protective effects on microcirculation after liver transplantation. ET(A)-RA not only affects the expression of vasoactive genes, but also decreases gene expression of proinflammatory cytokines such as TNF-alpha, IL-1beta and IL-6.

Animals↗

PubMed2006

Radiochemotherapy followed by gemcitabine and capecitabine in extrahepatic bile duct cancer: a phase I/II trial.

OBJECTIVE: Both radiotherapy and chemotherapy with gemcitabine and capecitabine have efficacy in biliary cancer. Our aim was to determine the toxicity and efficacy of a postoperative regimen combining both treatment modalities in extrahepatic bile duct cancer. METHODS: Patients were eligible after surgery for extrahepatic bile duct adenocarcinoma. Surgery included resection of lymph node positive cancer, incomplete resections and diagnostic laparotomy in unresectable tumors. Patients received a fractionated radiotherapy of 49.6 Gy accompanied by gemcitabine once a week. After a 2-week rest, patients were treated with gemcitabine and capecitabine on a 3-week cycle. The treatment continued for 6 cycles in nonmeasurable disease or until disease progression or intolerable toxicity. RESULTS: There were 18 patients (resection/laparotomy 7/11) enrolled between August 2003 and April 2005. Radiotherapy was completed in all patients and a total of 66 cycles of chemotherapy was applied. Fatigue and nausea were the most common mild adverse events. Grade 3 and 4 toxicity was rare after resection but frequent in unresectable disease and consisted of fatigue, nausea, duodenal ulcer, cachexia, and cholangitis in 1, 2, 2, 4, and 4 patients, respectively. We observed a 50% disease stabilization rate in patients with measurable disease. Median overall survival was 7.9 months in patients with unresectable tumors. Median overall survival in patients after resection has not been reached at a median follow-up of 19.5 months. CONCLUSIONS: Radiochemotherapy using gemcitabine followed by gemcitabine and capecitabine is an active regimen with manageable toxicity after resection of extrahepatic bile duct cancer but has significant toxicity in unresectable disease.

Adenocarcinoma↗

PubMed2006

Surgical and palliative management and outcome in 184 patients with hilar cholangiocarcinoma: palliative photodynamic therapy plus stenting is comparable to r1/r2 resection.

OBJECTIVE: First, to analyze the strategy for 184 patients with hilar cholangiocarcinoma seen and treated at a single interdisciplinary hepatobiliary center during a 10-year period. Second, to compare long-term outcome in patients undergoing surgical or palliative treatment, and third to evaluate the role of photodynamic therapy in this concept. SUMMARY BACKGROUND DATA: Tumor resection is attainable in a minority of patients (<30%). When resection is not possible, radiotherapy and/or chemotherapy have been found to be an ineffective palliative option. Recently, photodynamic therapy (PDT) has been evaluated as a palliative and neoadjuvant modality. METHODS: Treatment and outcome data of 184 patients with hilar cholangiocarcinoma were analyzed prospectively between 1994 and 2004. Sixty patients underwent resection (8 after neoadjuvant PDT); 68 had PDT in addition to stenting and 56 had stenting alone. RESULTS: The 30-day death rate after resection was 8.3%. Major complications occurred in 52%. The overall 1-, 3-, and 5-year survival rates were 69%, 30%, and 22%, respectively. R0, R1, and R2 resection resulted in 5-year survival rates of 27%, 10%, and 0%, respectively. Multivariate analysis identified R0 resection (P < 0.01), grading (P < 0.05), and on the limit to significance venous invasion (P = 0.06) as independent prognostic factors for survival. PDT and stenting resulted in longer median survival (12 vs. 6.4 months, P < 0.01), lower serum bilirubin levels (P < 0.05), and higher Karnofsky performance status (P < 0.01) as compared with stenting alone. Median survival after PDT and stenting, but not after stenting alone, did not differ from that after both R1 and R2 resection. CONCLUSION: Only complete tumor resection, including hepatic resection, enables long-term survival for patients with hilar cholangiocarcinoma. Palliative PDT and subsequent stenting resulted in longer survival than stenting alone and has a similar survival time compared with incomplete R1 and R2 resection. However, these improvements in palliative treatment by PDT will not change the concept of an aggressive resectional approach.

Adult↗

PubMed2006

E-cadherin and DAP kinase in pancreatic adenocarcinoma and corresponding lymph node metastases.

E-cadherin and DAP kinase have been implicated as 'invasion suppressor' genes in human cancer. The aim of this study was to analyze the methylation status of E-cadherin and DAP kinase and the expression of the protein in the metastatic lesions and to compare it with the expression in the primary tumor. Methylation-specific PCR of the DAP kinase and E-cadherin promoter was performed in 28 primary adenocarcinomas of the pancreas and in 13 corresponding regional lymph node metastases. The presence of E-cadherin and DAP kinase protein was assessed by immunohistochemistry. Metastatic lymph nodes showed a significant different expression profile from the primary tumor. E-cadherin methylation was observed in 8/28 (29%) and loss of protein expression was observed in 16/28 (57%) of pancreatic carcinomas. E-cadherin methylation was observed in 7/13 (54%) and loss of protein expression was observed in 11/13 (85%) lymph node metastases (p=0.047). DAP kinase methylation occurred in 11/28 (39%) pancreatic carcinomas and loss of protein expression was observed in 13/28 (46%). DAP kinase was methylated in 6/13 (46%) lymph node meta-stases and loss of protein expression was observed in 10/13 (77%) (p=0.039). Comparing primary tumor and corresponding lymph node metastases in 13 cases, the status of E-cadherin methylation was discordant in 2 cases. The protein expression pattern of E-cadherin and DAP kinase was discordant in 4 and 3 cases respectively. Unmethylated tumor samples did not express E-cadherin in 12 and DAP kinase protein in 6 cases. Our results demonstrate that reduction of E-cadherin and DAP kinase expression is more frequent in lymph node metastases than in the primary tumor and methylation of the promoter region contributes to this reduction; however, an alternative mechanism of inactivation seems to exist.

Adenocarcinoma↗

PubMed2005

Allele loss and epigenetic inactivation of 3p21.3 in malignant liver tumors.

Previously, the RASSF1A, BLU and SEMAPHORIN 3B (SEMA3B) candidate tumor suppressor genes on chromosome 3p21.3 were found to be inactivated and downregulated by genetic and epigenetic changes in lung cancer. We analyzed the methylation status of RASSF1A, BLU and SEMA3B in 35 hepatocellular carcinomas (HCCs) and 15 cholangiocarcinomas (CCs) by methylation-specific PCR and loss of heterozygosity (LOH) at 3p21.3 after microdissection. The presence of mRNA transcripts was confirmed by semiquantitative PCR. SEMA3B hypermethylation was found in 29/35 HCCs (83%) and in all (15/15) patients with CC. BLU promoter hypermethylation was detected in 7/35 (20%) HCCs and 3/15 (20%) CCs. In 2 corresponding specimens of hepatitis B virus-related liver cirrhosis, BLU methylation was also observed, but not in uninvolved normal liver tissue. RASSF1A was methylated in 21/35 HCCs (60%) and in 10/15 CCs (67%). LOH at 3p21.3 occurred in 8/35 (23%) HCCs and 3/15 (20%) CCs. The presence of hypermethylation was statistically associated with LOH of SEMA3B and correlated with downregulation of mRNA transcripts. SEMA3B transcripts increased upon treatment of HCC cell lines with the demethylation compound 5-aza-2-deoxycytidine. In conclusion, our data indicate that 2-hit gene silencing of SEMA3B through epigenetic changes and allele loss is a common and important event in the carcinogenesis of malignant liver tumors.

Aged↗

PubMed2005

TNP-470 fails to block the onset of angiogenesis and early tumor establishment in an intravital minimal disease model.

BACKGROUND AND AIMS: The angiogenesis inhibitor TNP-470 (AGM-1470) has shown encouraging results in animal models of established tumors. However, results of recent clinical trials using TNP-470 have been disappointing. Since little is known about the effects of TNP-470 at the minimal disease stage, we analyzed the effects of TNP-470 on the early stages of tumor establishment. METHODS: Twenty thousand green fluorescent protein (GFP)-transfected murine CT-26 (colonic carcinoma) or Panc-02-H0 (pancreatic adenocarcinoma) cells were inoculated in dorsal skin-fold chambers in BALB/c or C57BL6 mice. Tumor area and microvessel density (MVD) were quantified by intravital microscopy (IVM). Body weight was also monitored. Effects were compared with those in a conventional model involving subcutaneous (s.c.) inoculation of 10(6) tumor cells, followed by measurement of tumor volume, endogenous plasma VEGF/endostatin (ELISA) and proliferation/apoptosis/microvessel density (Ki-67/TUNEL/CD-34). TNP-470 was injected s.c. over the 10-day experimental period (30 mg/kg every 2 days [n=6] to 100 mg/kg/day [n=5 dorsal skin-fold chamber model, n=4 s.c. tumor model]). RESULTS: At 30 mg/kg/every second day neither CT-26 nor PANC-02-H0 tumors were inhibited in neither of the two models. TNP-470 dosage was escalated in CT-26-bearing animals until an antiangiogenic effect could be observed. In the IVM model, only TNP-470 100 mg/kg/day reduced MVD (P=0.006), but failed to block the onset of angiogenesis and tumor area increase. Body weight decreased by 25% (P<0.05). In the subcutaneous tumor model, tumor growth was reduced (P=0.045) but not blocked, while vascular endothelial growth factor (VEGF)/endostatin synthesis and Ki67/TUNEL/CD-34 were not significantly affected. CONCLUSION: While capable of reducing tumor growth in a conventional model, treatment with TNP-470 does not block the onset of angiogenesis and tumor establishment in a model of minimal disease. When used as a single agent TNP-470 does not control minimal tumor disease in experimental colonic carcinoma.

Angiogenesis Inhibitors↗

PubMed2005

Improvement of postischemic hepatic microcirculation after endothelinA receptor blockade--endothelin antagonism influences platelet-endothelium interactions.

Endothelin (ET) contributes to disturbances of hepatic microcirculation after ischemia/reperfusion (I/R) by causing vasoconstriction and enhancing leukocyte- and platelet-endothelium interactions. The aim of this study was to investigate a possible protective role of a selective endothelin(A) receptor antagonist (ET(A)-RA) in this setting. In a rat model, warm ischemia of the left lateral liver lobe was induced for 90 minutes under intraperitoneal anesthesia with xylazine and ketamine. Groups of rats consisted of sham-operated (SO, n=14), untreated ischemia (n=14), and treatment with BSF208075 (5 mg/kg body weight IV, n=14). The effect of the ET(A)-RA on I/R was assessed by in vivo microscopy 20 to 90 minutes after reperfusion; by measurement of local tissue Po(2), serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and glutathione S-transferase alpha levels, and by histologic investigation. In the untreated group, sinusoidal constriction to 69.4+/-6.7% of diameters of SO rats was observed, leading to a significant decrease in perfusion rate (74.3+/-2.1% of SO) and liver tissue Po(2) (43.5+/-3.2% of SO) (P < 0.05). In addition, we found an increased percentage of stagnant leukocytes (142.9+/-11.9%) and platelets (450.1+/-62.3%) in sinusoids and in postsinusoidal venules (P < 0.05). Hepatocellular damage (AST and ALT increase to 1330+/-157 U/L and 750+/-125 U/L respectively; previously, 27.1+/-3.5 U/L and 28.5+/-3.6 U/L) was detected 6 hours after reperfusion (P < 0.05). Administration of the ET(A)-RA before reperfusion significantly reduced I/R injury. Sinusoidal diameters were maintained (108.5+/-6.6%), and perfusion rate (93.1+/-1.8%) and tissue Po(2) (95.3+/-5.7%) were significantly increased (P < 0.05). According to reduced leukocyte-endothelium interactions after therapy, both platelet rolling and adhesion were significantly reduced (P < 0.05). The number of stagnant platelets in sinusoids was 199.5+/-12.3% of 50 (P < 0.05). After treatment, hepatocellular damage was decreased (AST and ALT levels after 6 hours of reperfusion: 513+/-106 U/L and 309+/-84 U/L, respectively; P < 0.05), and histologic changes were reduced in the long term. Our results provide evidence that the new therapeutic approach with an ET(A)-RA is effective in reducing hepatic I/R injury. In addition to reduced leukocyte-endothelium interactions, the number of stagnant and rolling platelets in sinusoids and venules was significantly reduced. The reduction in microcirculatory damages is responsible for better organ outcome.

Animals↗

PubMed2004

Rapid simultaneous quantification of immunosuppressants in transplant patients by turbulent flow chromatography combined with tandem mass spectrometry.

BACKGROUND: Immunosuppressant therapeutic drug monitoring (TDM) is an important requirement in the management of post-transplant patients. Our aim was to develop and evaluate a robust high-throughput method using turbulent flow chromatography (TFC) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the simultaneous quantification of cyclosporin A (CsA), tacrolimus (FK 506) and sirolimus. METHODS: A total of 1483 EDTA-blood pre-dosage samples from 147 kidney, 67 liver, 15 kidney/pancreas, and 48 bone marrow recipients were collected. After hemolysis and protein precipitation of 50 microl blood, fast and efficient on-line matrix elimination was achieved using turbulent flow chromatography. Tandem mass spectrometric detection and quantification was performed using multiple reaction monitoring (MRM). RESULTS: The total analysis time of the column switching method was 3 min. The method was linear from 4.5 to 1500 ng/ml for cyclosporin A, from 0.2 to 100 ng/ml for tacrolimus, and from 0.4 to 100 ng/ml for sirolimus. The accuracy was >95%. Within and between-run assay variation coefficients ranged from 2.4% to 9.3%. Excellent correlation with other standard methods (immunoassay, HPLC) was observed. CONCLUSIONS: The presented turbulent flow chromatography-tandem mass spectrometric platform offers a very fast, simple and economical method with an excellent validation profile and is well suited for daily pre- and post-dosage immunosuppressant monitoring.

Bone Marrow Transplantation↗

PubMed2004

Prevalence of familial pancreatic cancer in Germany.

Based on several case-control studies, it has been estimated that familial aggregation and genetic susceptibility play a role in up to 10% of patients with pancreatic cancer, although conclusive epidemiologic data are still lacking. Therefore, we evaluated the prevalence of familial pancreatic cancer and differences to its sporadic form in a prospective multicenter trial. A total of 479 consecutive patients with newly diagnosed, histologically confirmed adenocarcinoma of the pancreas were prospectively evaluated regarding medical and family history, treatment and pathology of the tumour. A family history for pancreatic cancer was confirmed whenever possible by reviewing the tumour specimens and medical reports. Statistical analysis was performed by calculating odds ratios, regression analysis with a logit-model and the Kaplan-Meier method. Twenty-three of 479 (prevalence 4.8%, 95% CI 3.1-7.1) patients reported at least 1 first-degree relative with pancreatic cancer. The familial aggregation could be confirmed by histology in 5 of 23 patients (1.1%, 95% CI 0.3-2.4), by medical records in 9 of 23 patients (1.9%, 95% CI 0.9-3.5) and by standardized interviews of first-degree relatives in 17 of 23 patients (3.5%, 95% CI 2.1-5.6), respectively. There were no statistical significant differences between familial and sporadic pancreatic cancer cases regarding sex ratio, age of onset, presence of diabetes mellitus and pancreatitis, tumour histology and stage, prognosis after palliative or curative treatment as well as associated tumours in index patients and families, respectively. The prevalence of familial pancreatic cancer in Germany is at most 3.5% (range 1.1-3.5%) depending on the mode of confirmation of the pancreatic carcinoma in relatives. This prevalence is lower than so far postulated in the literature. There were no significant clinical differences between the familial and sporadic form of pancreatic cancer.

Adult↗

PubMed2004

Interaction between trypsinogen isoforms in genetically determined pancreatitis: mutation E79K in cationic trypsin (PRSS1) causes increased transactivation of anionic trypsinogen (PRSS2).

The human pancreas secretes two major trypsinogen isoforms, cationic and anionic trypsinogen. To date, 19 genetic variants have been identified in the cationic trypsinogen gene (PRSS1) of patients with hereditary, familial, or sporadic chronic pancreatitis. A common feature of cationic trypsinogen mutants studied so far is an increased propensity for autocatalytic activation (autoactivation). This is thought to lead to premature intrapancreatic digestive protease activation. In contrast, no pancreatitis-associated mutations have been found in the anionic trypsinogen gene (PRSS2), suggesting that this isoform might play a relatively unimportant role in pancreatitis. To challenge this notion, here we describe the unique properties of the E79K cationic trypsinogen mutation (c.235G>A), which was identified in three European families affected by sporadic or familial pancreatitis cases. In vitro analysis of recombinant wild-type and mutant enzymes revealed that catalytic activity of E79K trypsin was normal, and its inhibition by pancreatic secretory trypsin inhibitor was unaffected. Although the E79K mutation introduces a potential new tryptic cleavage site, autocatalytic degradation (autolysis) of E79K-trypsin was also unchanged. Furthermore, in contrast to previously characterized disease-causing mutations, E79K markedly inhibited autoactivation of cationic trypsinogen. Remarkably, however, E79K trypsin activated anionic trypsinogen two-fold better than wild-type cationic trypsin did, while the common pancreatitis-associated mutants R122H or N29I had no such effect. The observations not only suggest a novel mechanism of action for pancreatitis-associated trypsinogen mutations, but also highlight the importance of interactions between the two major trypsinogen isoforms in the development of genetically determined chronic pancreatitis.

Adult↗

PubMed2004

Assessment of hepatic ischemia-reperfusion injury by simultaneous measurement of tissue pO2, pCO2, and pH.

INTRODUCTION: The objective of this study was to determine whether the simultaneous measurement of tissue pH, pCO(2), and pO(2) with a multiple-parameter fiberoptic sensor (Paratrend 7) can be used for continuous monitoring of hepatic microperfusion in a pig model of hepatic ischemia given endothelin(A) receptor antagonist (ET(A)-RA) or isotonic saline. METHODS: Fourteen anesthetized swine were subjected to 2 h of hepatic vascular exclusion. The animals were randomized into two groups: control group (n = 7, saline solution iv) and therapy group (n = 7, ET(A)-RA). For evaluation of ischemia-reperfusion injury, the data of the multiple-parameter sensor (pO(2para), pCO(2para), and pH(para)) were compared with partial oxygen pressure in tissue (p(ti)O(2)), laser Doppler flow, and systemic hemodynamic, metabolic data, and time course of transaminases. RESULTS: In the control group 30 and 60 min after reperfusion, the following values were measured: p(ti)O(2): 34.0 +/- 8.6 / 36.3 +/- 7.0 mm Hg (P < 0.05 vs. preop.: 49.8 +/- 12.1 mm Hg), laser Doppler area: 133.3 +/- 23.2 / 156.4 +/- 15.4 (P < 0.05 vs. preop.: 215.9 +/- 14.8). Animals in the therapy group revealed significantly improved values (p(ti)O(2): 54.0 +/- 8.6 / 58.1 +/- 7.8 mm Hg, laser Doppler: 210.2 +/- 38.5 / 225.2 +/- 21.3; P < 0.05). Using the Paratrend, also an improvement in the therapy group was seen 30 and 60 min after reperfusion. The values showed a strong correlation with p(ti)O(2) (r = 0.895; P < 0.05) and laser Doppler flow (r = 0.807; P < 0.05). In the treatment group, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and glutamate dehydrogenase (GLDH) were reduced 6 and 18 h after reperfusion, respectively, indicating hepatoprotection by the therapy (P < 0.05 vs. control). CONCLUSIONS: The Paratrend sensor offers the opportunity to study postischemic organ hemodynamics through the simultaneous measurement of interstitial pH, pCO(2), and pO(2) in a small tissue region. This method offers a prognostic tool for the study of the effects of experimental vasoactive therapy on liver microcirculation and perspectives for continuous monitoring of human liver microperfusion after liver surgery and trauma.

Alanine Transaminase↗

PubMed2004

Photodynamic therapy in patients with non-resectable hilar cholangiocarcinoma: 5-year follow-up of a prospective phase II study.

BACKGROUND: Median survival of patients with non-resectable hilar cholangiocarcinoma is 3 to 6 months, even after biliary drainage. Therefore, a single-arm phase II study was conducted (July 1996 to October 1998) to investigate the effect of local photodynamic therapy; a significant improvement in survival (74%) was noted at 6 months. The present study is an analysis of the long-term follow-up for patients enrolled in that phase II study. METHODS: Five-year follow-up data for the 23 patients enrolled in the original prospective study were analyzed by using Kaplan-Meier log-rank analysis. RESULTS: Median survival after treatment was 11.2 months for patients without distant metastases (M0) and 9.3 months for all patients (M0+M1). The 1-year, 2-year, 3-year, and 4-year survival rates were estimated to be 47%, 21%, 11% and 5%, respectively, for patients with stage M0 cholangiocarcinoma, and 39%, 17%, 9%, and 4%, respectively, for patients with stages M0 and M1. Of the patients who died, 73.9% (n=17) were because of tumor progression; 26.1% (n=6) died as a result of cholangitis (n=4), septic shock (n=1), or appendicitis/peritonitis (n=1). For all patients, except one with diffuse liver metastases, there was improvement in cholestasis, performance, and quality of life, which was maintained for an extended period. CONCLUSIONS: This 5-year follow-up study confirms that photodynamic therapy is safe and effective for non-resectable hilar cholangiocarcinoma, although it does not prevent progression of the disease.

Adult↗

PubMed2004

Combined percutaneous transhepatic biliary drainage with port implantation for management of patients with malignant biliary obstruction.

BACKGROUND: Endoscopic biliary stent insertion has become a standard palliative treatment for patients with obstructive jaundice caused by malignancies of the hepatobiliary system or metastases of other tumors, such as pancreatic or gastric cancer. Unfortunately, bacterial colonization and encrustation frequently leads to occlusion of plastic stents and, consequently, recurrent cholangitis. METHODS: An external-internal Yamakawa-type endoprosthesis was modified and combined with a titanium, subcutaneously implanted port. This technique was evaluated as a new approach to prolongation of stent patency and prevention of cholangitis. Two patients with obstructive jaundice, one with recurrent gastric carcinoma and the other with invasive gallbladder cancer, underwent treatment with this new method. RESULTS: Effective biliary drainage was established and cholangitis was prevented in both patients for 6 and 2 months, respectively. CONCLUSIONS: A new method of percutaneous transhepatic drainage combined with port implantation was effective and safe in two patients. This technique may be a reasonable treatment option for selected patients, but further evaluation in a larger series is required to establish efficacy and safety.

Aged↗

PubMed2004

Endothelin-A receptor blockade improves postischemic hepatic microhemodynamics.

The aim of this study was to investigate a possible protective role of a selective endothelin-A receptor antagonist on hepatic microcirculation after ischemia/reperfusion. In a rat model, warm ischemia of the left liver lobe was induced for 90 minutes under intraperitoneal anesthesia with xylazine and ketamine. Shamoperated and untreated ischemic groups and a group treated with BSF 208075 were investigated. The effect of the endothelin-A receptor antagonist on ischemia/reperfusion was assessed by in-vivo microscopy and measurement of aspartate aminotransferase and alanine aminotransferase levels. In the untreated group, sinusoidal constriction to 70% of basal diameters was observed, leading to a significant decrease in perfusion rate. In addition, we found an increased percentage of stagnant leukocytes and platelets in sinusoids and in postsinusoidal venules (P < 0.05). A significant increase in liver enzymes was detected 6 hours after reperfusion (P < 0.05). In the treatment group, sinusoidal diameters were maintained at 108%, and perfusion rate was significantly increased (P < 0.05). Hepatocellular damage was decreased and leukocyte and platelet-endothelium interactions were reduced (P < 0.05). Our results provide evidence that the new therapeutic approach using an endothelin-A receptor antagonist is effective in reducing hepatic ischemia/reperfusion injury. It could be shown for the first time that endothelin receptor blockade also influences platelet-endothelium interactions.

Alanine Transaminase↗