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Biomedical subjects

B Poch

Publications and source records attributed to B Poch.

At least 19 recordsLinked to original sources
PubMed2005

Antibiotic prophylaxis in severe acute pancreatitis.

Severe acute pancreatitis is considered to be a subgroup of acute pancreatitis with the development of local and/or systemic complications. A significant correlation exists between the development of pancreatic necrosis, the frequency of bacterial contamination of necrosis and the evolution of systemic complications. Bacterial infection and the extent of necrosis are determinants for the outcome of severe acute pancreatitis. The late course of necrotizing pancreatitis is determined by bacterial infection of pancreatic and peripancreatic necroses. Mortality increases from 5-25% in patients with sterile necrosis to 15-28% when infection has occurred. The use of prophylactic antibiotics has been recommended in patients with necrotizing pancreatitis. Several controlled clinical trials demonstrated a significant reduction in pancreatic infections or a significant reduction of hospital mortality. However, the results of these clinical trials are controversial and not convincing. Recently, the largest randomized placebo-controlled, double-blind trial has been able to demonstrate that antibiotic prophylaxis with ciprofloxacin and metronidazole has no beneficial effects with regard to the reduction of pancreatic infection and the decrease of hospital mortality. The clinical data from this placebo-controlled trial do not support antibiotic prophylaxis in all patients with necrotizing pancreatitis, but in specific subgroups of patients with pancreatic necrosis and a complicated course.

Acute Disease↗
PubMed2003

[Pancreatic cancer. The relative importance of neoadjuvant therapy].

Neoadjuvant radiochemotherapy in patients suffering from pancreatic cancer is presently not well established. Neoadjuvant radiochemotherapy is recommended to be applied in 5-8 weeks. The full dose of radiotherapy is between 50 and 54 Gy with 5FU used as radiosensitator. In patients with resectable pancreatic cancer, particularly in UICC-stage II neoadjuvant radiochemotherapy, this results in an improvement in survival: the median survival is between 15 and 30 months. In about 15% of the patients with resectable pancreatic cancer (UICC I-III), neoadjuvant radiochemotherapy results in downstaging. In combination with a R0-resection,neoadjuvant radiochemotherapy effects a reduction of local recurrence. Results from controlled clinical trials are necessary to objectify the benefits of neoadjuvant radiochemotherapy.

Adult↗
PubMed2001

Modulation of endogenous nitric oxide synthase in experimental acute pancreatitis: role of anti-ICAM-1 and oxygen free radical scavengers.

OBJECTIVE: To evaluate, in an experimental model of acute pancreatitis, the impact of nitric oxide on the disease process and the interaction between nitric oxide and oxygen free radicals. SUMMARY BACKGROUND DATA: Nitric oxide and oxygen free radicals are involved in the pathophysiology of acute pancreatitis. It is well established that oxygen free radicals play an important role in the development of pancreatic cell damage and remote organ failure, but the impact of nitric oxide on the disease process and the interactions between the two radical species remain controversial. METHODS: Necrotizing pancreatitis (NP) was induced in Wistar rats by intraductal sodium taurocholate infusion after pretreatment with isotonic saline (NP-S), superoxide dismutase/catalase (NP-SOD/CAT), or an anti-ICAM-1 antibody (aICAM-1). Sham-operated rats received isotonic saline (SHX). After an observation period of 5 minutes and 24 hours, the pancreas was removed for microscopy, glutathione, and myeloperoxidase (MPO) analysis. The inducible NO synthase (NOS-2) was detected by Western blotting or RT-PCR. Serum was analyzed for nitrite/nitrate (NO2-/NO3-) and S-nitrosothioles (RSNO), while plasma was used to assay for trypsinogen activation peptides (TAP). RESULTS: NP-S animals showed a significant decrease in GSH levels after NP-induction as compared with animals under therapy. Increased MPO levels in the NP-S group were significantly reduced by aICAM-1 while SOD/CAT injection showed no changes. Serum NO-derivatives peaked at 12 hours while TAP levels had a maximum at 6 hours after NP induction, and were lower after aICAM-1 application SOD/CAT treatment increased both parameters. Extended acinar cell damage and inflammatory infiltrate developed in NP-S animals and was significantly improved by SOD/CAT and aICAM-1 treatment. RT-PCR and Western-blot analysis revealed NOS-2 expression in the NP-S group, which was reduced by radical scavengers and aICAM-1. CONCLUSION: Enhanced nitric oxide synthase expression and increased nitric oxide derivatives are found during severe acute pancreatitis. Oxygen free radicals and neutrophils seem to be potent and important regulation mechanisms for nitric oxide synthase activity and nitric oxide-mediated toxicity but imply only a secondary role for nitric oxide in the local pathologic mechanism of this disease.

Animals↗
PubMed2001

Anti-ICAM-1 antibody modulates late onset of acinar cell apoptosis and early necrosis in taurocholate-induced experimental acute pancreatitis.

The hallmark of severe acute pancreatitis (SAP) is massive acinar cell death by necrosis. However, programmed, apoptotic acinar cell death has also been observed. Little is known about the dynamics, localization, and inductive factors of acinar cell apoptosis in SAP. We therefore induced SAP in rats by retrograde infusion of 3% sodium taurocholate. Starting as early as 5 minutes after taurocholate administration, small scattered groups of acinar cells showed zymogen degranulation, loss of cell polarity, cytoplasmic microvacuolization, and nuclear shrinkage, but no DNA degradation, thus featuring necrosis. The areas of necrotic acini extended at later time points giving rise to larger areas of complete parenchymal breakdown after 6 hours. Parenchymal degradation was paralleled by neutrophil infiltration and significant tumor necrosis factor (TNF)-alpha mRNA up-regulation. Up to the 12-hour interval, apoptotic acinar cells detected by TUNEL were as rare as in healthy pancreata. At 24 hours, however, the acinar apoptotic rate in nonnecrotic parenchyma had dramatically increased. Pretreatment of rats with anti-ICAM-1 antibody prior to pancreatitis induction led to a significant reduction of neutrophil infiltration along with decreased TNF-alpha mRNA expression throughout the 24-hour observation period without affecting the presence and dynamics of necrosis. However, anti-ICAM-1 pretreatment decreased the extent of acinar cell damage by necrosis and extensively suppressed acinar cell apoptosis. We conclude that taurocholate induces two sequential patterns of acinar cell death in terms of very early necrosis followed by late apoptosis during the postacute phase of SAP. The progression of necrosis and the late apoptotic acinar cell death seem to be influenced by the local presence of neutrophils via a TNF-alpha-dependent mechanism. In addition to augmenting necrosis, neutrophils might have an apoptosis-inducing potential in SAP.

Acute Disease↗
PubMed2001

Epidermal growth factor induces cyclin D1 in human pancreatic carcinoma: evidence for a cyclin D1-dependent cell cycle progression.

INTRODUCTION: We recently showed that cyclin D1 is overexpressed in human pancreatic carcinoma cells, and that this overexpression correlates significantly with a poor prognosis. AIMS: To assess the interrelations of epidermal growth factor (EGF), EGF receptor (EGFR), and cyclin D1 in human pancreatic carcinoma. METHODOLOGY AND RESULTS: In pancreatic carcinoma cell lines (BxPC-3, AsPC-1), cell cycle analysis revealed an increase in cells in the S/G1 phase between 18 and 30 hours after stimulation with 50 ng/mL EGF. Cyclin D1 mRNA increased after 2 hours, corresponding to an increase in cyclin D1 protein, with the maximum level between 7.5 and 10 hours after stimulation, as demonstrated by Western blot analysis. We performed immunohistochemical analysis on 61 adenocarcinoma tissues for the expression of EGF, EGFR, and cyclin D1 and demonstrated an overexpression in the tumor cells in 51%, 54%, and 62.3%, respectively, whereas normal human pancreas stained negative for all of the three factors. Interestingly, EGF and EGFR expression correlated significantly with the cyclin D1 expression in human pancreatic tumor cells (p < 0.001 and p < 0.01, respectively). CONCLUSION: These results demonstrate that cyclin D1 overexpression in the tumor cells of pancreatic carcinoma tissue is at least partly dependent on the mitogenic effects of EGF signaling through the EGFR.

Blotting, Western↗
PubMed2000

Pathophysiologic role of oxygen free radicals in acute pancreatitis: initiating event or mediator of tissue damage?

BACKGROUND AND OBJECTIVE: Oxidative stress is an important factor in the pathogenesis of acute pancreatitis, as shown in vivo by the beneficial effects of scavenger treatment and in vitro by the potential of free radicals to induce acinar cell damage. However, it is still unclear whether oxygen free radicals (OFR) act only as mediators of tissue damage or represent the initiating event in acute pancreatitis in vivo as well. In the present study the authors aimed to address this issue in an experimental set-up. MATERIALS AND METHODS: Two hundred male Wistar rats were randomly assigned to one of the following experimental groups. In two groups, acute necrotizing pancreatitis was induced by retrograde intraductal infusion of 3% sodium taurocholate. Through the abdominal aorta, a catheter was advanced to the origin of the celiac artery for continuous regional arterial (CRA) pretreatment with isotonic saline (NP-S group) or superoxide dismutase/catalase (NP-SOD/CAT group). In another group, oxidative stress was generated by CRA administration of xanthine oxidase and intravenous administration of hypoxanthine (HX/XOD group). Sham-operated rats received isotonic saline both arterially and intraductally. After observation periods of 5 and 30 minutes and 3 and 6 hours, the pancreas was removed for light microscopy and determination of reduced glutathione (GSH), oxidized glutathione (GSSG), conjugated dienes (CD), and malondialdehyde as a marker for OFR-induced lipid peroxidation as well as myeloperoxidase as a parameter for polymorphonuclear leukocyte accumulation. RESULTS: A significant decrease of GSH was paralleled by an increased ratio of GSSG per total glutathione and elevated CD levels after 5 minutes in the NP-S group versus the sham-operated group. Thereafter, the percentage of GSSG and GSH returned to normal levels until the 6-hour time point. After a temporary decrease after 30 minutes, CD levels increased again at 3 hours and were significantly higher at 6 hours in contrast to sham-operated rats. Myeloperoxidase levels were significantly elevated at 3 and 6 hours after pancreatitis induction. In contrast to NP-S rats, treatment with SOD/CAT significantly attenuated the changes in glutathione metabolism within the first 30 minutes and the increase of CDs after 6 hours. HX/XOD administration lead to changes in levels of GSH, GSSG, and CDs at 5 minutes as well as to increased myeloperoxidase levels at 3 hours; these changes were similar to those observed in NP-S rats. Acinar cell damage including necrosis was present after 5 minutes in both NP groups, but did not develop in HX/XOD rats. In addition, serum amylase and lipase levels did not increase in the latter group. SOD/CAT treatment significantly attenuated acinar cell damage and inflammatory infiltrate compared with NP-S animals during the later time intervals. CONCLUSION: OFRs are important mediators of tissue damage. However, extracellular OFR generation alone does not induce the typical enzymatic and morphologic changes of acute pancreatitis. Factors other than OFRs must be involved for triggering acute pancreatitis in vivo.

Animals↗
PubMed1999

The role of polymorphonuclear leukocytes and oxygen-derived free radicals in experimental acute pancreatitis: mediators of local destruction and activators of inflammation.

Using a retrograde infusion sodium taurocholate pancreatitis model in the rat treatment with oxygen radical scavengers or monoclonal anti-ICAM-1 antibody decreased tissue damage and polymorphonuclear leukocytes (PMN) infiltration. Scavengers or anti-ICAM-1 treatment attenuated the activating capacity of blood PMNs following zymosan stimulation. The local production of oxygen free radicals in the pancreas by systemic infusion of hypoxanthine and regional infusion of xanthine oxidase did not induce acute pancreatitis, although an increase of infiltrating PMNs was observed. Our data suggest that oxygen free radicals and infiltrating PMNs aggravate acute pancreatitis and that both are important mediators of local destruction and systemic activation of PMNs.

Acute Disease↗
PubMed1999

[Surgical management of liver rupture].

The management of 178 patients with liver trauma (132 male, 46 female; mean age 34 years (range 3-88) presenting from January 1979 to August 1996 is reviewed. There were 165 cases of blunt trauma and 13 cases of penetrating injury. 110 cases were classified as simple injuries (grade I or II) and 68 cases as complex injuries (grade III to V). The overall mortality was 32% (57 patients). The mortality for true hepatic injury was 15.7%. None of the patients with penetrating injuries died. Mortality was influenced by the type of liver injury and the number of associated injuries. The postoperative complication rate was 55%. The most-frequent postoperative complications related to the hepatic injury were intrahepatic or subcapsular hematoma (12.9%) and postoperative bleeding (9.6%). Intraabdominal abscess formation was seen in 2.8%. Operative therapy for liver injuries depends on the grade of the injury. The majority of liver injuries can be managed by simple techniques, including electrocautery and application of hemostatic agents. In complex injuries hepatotomy, direct vessel ligation, and debridement of necrotic tissue is the method of choice (Pachter's procedure). In non-controlled bleeding, perihepatic picking is a standard method.

Adolescent↗
PubMed1999

["No-puncture-laparoscopy" in hernia management in childhood--reliable complement to established therapy concepts].

BACKGROUND: Approximately 50% of children with a clinical unilateral inguinal hernia display a patent processus vaginalis on the contralateral side; half of these children subsequently develop an inguinal hernia. The management of this problem is still controversial. The purpose of this study was to evaluate the usefulness of intraoperative laparoscopy in a non-puncture technique through the opened hernia sack. METHOD: In 112 children (age 6 months to 7 years) with clinical unilateral hernia laparoscopy (5 mm laparoscope, 30 degrees and 70 degrees). In cases of a wide-open contralateral internal inguinal ring (type III) open surgical exploration was performed. RESULTS: Nineteen patients (17%) fulfilled the laparoscopic criteria of a type III ring; the diagnose was confirmed during open contralateral exploration. Fourteen of these patients were younger than two years. The median time for laparoscopy was 6 min (3-11 min). No complications associated with the laparoscopy were observed. CONCLUSIONS: Intraoperative laparoscopy during unilateral hernia repair allows the identification of patients who profit from bilateral open surgery during the same operation with little additional operating time and so far with no resulting complications. Application of this method may avoid a second hospitalization and operation, as well as an unnecessary routine bilateral open exploration. As an additional source of information through excellent visualization of the abdominal cavity, this method proved helpful to examine incarcerated bowel after repositioning.

Child↗
PubMed1999

The surgical management of chronic pancreatitis: duodenum-preserving pancreatectomy.

Duodenum-preserving pancreas resection for chronic pancreatitis results in a subtotal resection of the pancreatic head. Of 488 patients suffering from chronic pancreatitis with an inflammatory mass in the head, 48% had a common bile duct stenosis in the ERCP, 63% had a pancreatic main duct stenosis, 25% had a duodenum stenosis, and 17% showed vascular obstruction--mainly compression or occlusion of the portal vein. Hospital mortality after duodenum-preserving head resection was 0.9%. In the late follow-up, 88% of patients were free of pain and 60% were professionally rehabilitated. The incidence of diabetes mellitus in the late follow-up was 14%; however, 6% of the patients had a lasting improvement of endocrine function. Late mortality after a median follow-up of 6 years (1-22 years after surgical treatment) was 9%. Only 10% of the patients needed further hospitalization due to recurrent attacks of acute pancreatitis. Duodenum-preserving head resection should be the surgical procedure of choice in chronic pancreatitis with an inflammatory mass in the head of the pancreas and in cases with pancreas divisum after failure of medical and interventional treatment. Duodenum-preserving total pancreatectomy is a last-resort surgical treatment after failure of left resection for pain in chronic pancreatitis.

Chronic Disease↗
PubMed1998

The value of intraoperative laparoscopic examination of the contralateral inguinal ring during hernia repair in children.

Approximately 40% of children with a clinical unilateral inguinal hernia display a patent processus vaginalis on the contralateral side; half of these children subsequently develop an inguinal hernia. The management of this problem is still controversial. Different strategies to identify patients who profit from an open contralateral exploration have been applied (diagnostic pneumoperitoneum, herniography, ultrasound). The purpose of this study was to evaluate the usefulness of intraoperative laparoscopy in a no-puncture technique through the opened hernia sack. In 75 children (age 6 months to 7 years) with clinical unilateral hernia laparoscopy (5-mm Laparoscope, 30 degrees and 70 degrees ), in cases of wide-open contralateral internal inguinal ring (Type III) an open surgical exploration was performed. Twelve patients (17%) fulfilled the laparoscopic criteria of a Type III ring. The diagnose was confirmed during open contralateral exploration. Seven children (8%) showed a patent but small processus vaginalis with a shallow internal ring. These patients were treated conservatively. In the follow-up period (median 6 months) one subsequent hernia developed. There was no technical failure, and no associated complications were seen. The median time for laparoscopy was 6 minutes. Intraoperative laparoscopy during unilateral hernia repair allows the identification of patients who profit from bilateral open surgery during the same operation with little additional operating time, and so far with no resulting complications. Application of this method may avoid a second hospitalization and operation as well as unnecessary routine bilateral open exploration. As an additional source of information through excellent visualization of the abdominal cavity, this method proved helpful to examine the incarcerated bowel after repositioning.

Child↗
PubMed1997

Low serum levels of soluble CD44 variant 6 are significantly associated with poor prognosis in patients with pancreatic carcinoma.

BACKGROUND: Variant CD44 splice products, especially CD44 variant 6 (CD44v6), are expressed on activated lymphocytes and tumor cells. The soluble forms of CD44 standard (CD44s) and CD44v6 are present in the serum of normal individuals. The aim of the current study was to evaluate the concentrations and the prognostic potential of soluble CD44s and CD44v6 in patients with pancreatic carcinoma. METHODS: The serum CD44s and CD44v6 levels were determined quantitatively by enzyme-linked immunosorbent assay. The molecular mass of CD44v6 isoforms was determined by immunoprecipitation and Western blot analysis. CD44 mRNAs were analyzed by reverse transcriptase polymerase chain reaction followed by exon specific analysis. RESULTS: Both serum CD44s and serum CD44v6 were significantly reduced in patients with pancreatic carcinoma (n = 93, P < 0.001 and P < 0.00005). The median survival in the group with CD44v6 serum concentrations below 100 ng/mL was significantly decreased compared with that in the group with serum concentrations higher than 100 ng/mL (6.7 vs. 15.1 months, P < 0.0005). The isoforms containing soluble CD44v6 (sCD44v6) that were detected in the sera of pancreatic carcinoma patients showed molecular masses comparable to the sCD44v6 isoforms detected in the supernatant of lymphocytes activated by phorbol myestral acetate, whereas the sCD44v6 isoforms detected in the supernatant of pancreatic carcinoma cell lines exhibited higher molecular masses. CONCLUSIONS: These results suggest that serum CD44v6 is significantly reduced in pancreatic carcinoma patients and could serve as a good prognostic marker for patients with this disease.

Adenocarcinoma↗
PubMed1997

Exogenous, but not endogenous, nitric oxide increases proliferation rates in senescent human fibroblasts.

We investigated the effects of endogenously produced and exogenously applied nitric oxide (NO) on cell proliferation rates and cell cycle regulation in senescent human fibroblasts (WI38). Induction of inducible nitric oxide synthase by tumor necrosis factor-alpha, interferon-gamma and interleukin-1beta inhibited cell proliferation and led to a G1 arrest. These effects were partially reversible by N(G)-monomethyl-arginine (NMA). Addition of the NO donors sodium nitroprusside (SNP) or S-nitroso-N-acetylpenicillamine (SNAP) increased cell proliferation rates as well as the S/G2 fraction. This points to a functional role of NO in cell cycle regulation and cell proliferation in human fibroblasts which depends on the mode of NO generation as well as the culture conditions used.

Apoptosis↗
PubMed1997

The induction of apoptosis in proliferating human fibroblasts by oxygen radicals is associated with a p53- and p21WAF1CIP1 induction.

The role of reactive oxygen species (ROS) generated by hypoxanthine/xanthine oxidase (HX/XO) in the induction of apoptosis was studied in the human fibroblast cell line WI38. Apoptosis but not necrosis was observed in proliferating fibroblasts after 48 h incubation with 1 mM HX and 0.05 U/ml XO. Induction of apoptosis was hindered by catalase. Cell-cycle analysis revealed a reduction of cells in the S/G2 phase 24 and 48 h after stimulation, suggesting that ROS induce a G1 arrest in proliferating fibroblasts. This was supported by an accumulation of p53 and the cdk inhibitor p21WAF1/CIP1. Since apoptosis was not inducible in senescent fibroblasts our data indicate that ROS mainly induces apoptosis in proliferating cells.

Apoptosis↗
PubMed1996

Release of histamine in whole blood by oxygen radicals: division between specific and unspecific processes.

Oxygen derived free radicals are involved in many pathological processes such as postischemic reperfusion injuries, hepatotoxicity of drugs and inflammatory processes. Thereby these oxygen radicals induce lipid peroxidation and perturbation of cellular membranes. The aim of our present study was to determine whether oxygen radicals generated by the xanthine oxidase/ hypoxanthine system cause a release of histamine in human blood cell cultures. Stimulation of blood cell cultures with oxygen radicals induced a histamine liberation which was mainly due to calcium independent processes during the first 30 min, whereas then calcium requiring processes took part in the release of histamine. The regulation of the leukocyte selection LECAM-1 was altered by oxygen radicals whereas histamine, which is known to modulate vascular selectin expression, did not affect the expression of LECAM-1. Our data indicate that oxygen radicals induce a direct calcium independent release of histamine which is due to membrane pertubating processes during the first phase but also induce a specific reaction leading to a further indirect histamine liberation which is probably mediated by PAF.

Cell Adhesion Molecules↗
PubMed1996

The role of anti-p53-autoantibodies in pancreatic disorders.

CONCLUSION: Anti-p53-autoantibodies (a-p53-aabs) may suppress the development of distant metastases, but not lymph node metastases. This could explain the significantly prolonged survival of patients with UICC stage III tumors who have a-p53-aabs compared to those without a-p53-aabs. BACKGROUND: Mutation within the tumor suppressor gene p53 leads to increased intracellular p53 protein levels and an increased antibody formation against this molecule. Altered p53 has been proposed to be associated with poor prognosis, and the present study investigated whether the detection of a humoral response to p53 gives evidence for a prognostic or diagnostic parameter in pancreatic disorders. METHODS: We screened 145 patients with pancreatic cancer and 95 patients with chronic pancreatitis for the development of a-p53-aab via ELISA and Western-blotting. p53 expression was examined by immunohistochemistry. RESULTS: We found that 41% of the tissues of patients suffering from pancreatic carcinoma overexpressed p53, and 15.9% of the patients suffering from pancreatic cancer developed a-p53-aab. In pancreatic cancer, we could exhibit a significant correlation between grading, p53-overexpression, survival, and antibody response against p53. A-p53-aabs were significantly more frequent in patients with stage III tumors (tumors with lymph node metastases, but not distant metastases, p < 0.02).

Adult↗
PubMed1996

CAM 17.1--a new diagnostic marker in pancreatic cancer.

CAM 17.1-Ab is a recently described monoclonal antibody that detects a mucus glycoprotein with high specificity for intestinal mucus, particularly in the colon, small intestine, biliary tract and pancreas. We investigated the expression and release of CAM 17.1 in pancreatic carcinoma cell lines and tissue specimens of normal pancreas, chronic pancreatitis and pancreatic cancer. CAM 17.1 was weakly expressed on normal ductal cells and chronic pancreatitis, whereas it was overexpressed in pancreatic cancer. Serum analysis using a new enzyme-linked antibody sandwich assay (CAM 17.1/WGA) of patients with chronic pancreatitis, pancreatic cancer or other gastrointestinal cancer and of healthy blood donors revealed a high sensitivity (67%) and excellent specificity (90%) of CAM 17.1/WGA assay in pancreatic cancer. In comparison with the tumour marker CA19-9, the sensitivity of the CAM 17.1/WGA assay was similar to the sensitivity of CA 19-9 (67% and 76%, P = 0.22), whereas the specificity of CAM 17.1/WGA assay was higher than in CA 19-9 (90% compared with 78% in chronic pancreatitis, P > 0.05).

Adult↗