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Biomedical subjects

H G Beger

Publications and source records attributed to H G Beger.

At least 307 records · Page 17Linked to original sources
PubMed1994

Prophylaxis of complications after pancreatic surgery: results of a multicenter trial in Germany.

Major pancreatic resection still carries a considerable risk for morbidity and even mortality. Complications occurring after pancreatic surgery are chiefly linked with exocrine pancreatic secretion. Therefore to inhibit exocrine pancreatic secretion perioperatively seems to be a promising concept in the prevention of complications following pancreatic resection. The hormone somatostatin and its synthetic analogue octreotide have been demonstrated to inhibit exocrine pancreatic secretion profoundly, particularly the secretion of proteases is decreased. In a randomized placebo-controlled multicentric and double-blind trial we analyzed the role of octreotide in the prevention of post-operative complications after major pancreatic surgery. A significant reduction of complications (fistula, abscess, fluid collection, sepsis, pulmonary insufficiency, postoperative acute pancreatitis) could be demonstrated in patients receiving octreotide (3 x 100 micrograms/day s.c.). The effect of octreotide was particularly true in patients undergoing a Whipple resection for cancer.

Austria↗
PubMed1994

Role of octreotide in the treatment of pancreatic cancer.

Prognosis in patients with advanced pancreatic cancer is dismal. There has been no effective therapy for these patients so far. Somatostatin and its analogues have been proven to be potent inhibitors of experimental pancreatic cancer. Tumor inhibition is supposed to be mediated directly by somatostatin-binding sites or indirectly by suppression of growth factors. In two trials the value of the new somatostatin analogue octreotide in a low-dose (3 x 100 micrograms/day) and a high-dose (3 x 2,000 micrograms/day) protocol was evaluated in patients with advanced pancreatic cancer. Median survival of the patients with a low-dose protocol was 3 months. However, the treatment of pancreatic cancer with a high-dose protocol revealed a median survival of 6 months and stable disease in 4/10 patients. According to quality of life scoring 4 patients showed values comparable to healthy controls. Octreotide therapy with a high-dose protocol is a promising experimental therapeutic approach to advanced pancreatic cancer.

Female↗
PubMed1994

Increased expression of acidic and basic fibroblast growth factors in chronic pancreatitis.

Acidic fibroblast growth factor (aFGF) and basic fibroblast growth factor (bFGF) belong to a family of mitogenic polypeptides that are involved in cellular proliferation and differentiation. In this study we investigated the potential role of aFGF and bFGF in chronic pancreatitis (CP), a fibrotic condition associated with acinar cell dedifferentiation and atrophy, and fibroblastic proliferation. By immunohistochemistry, aFGF and bFGF were abundant in pancreatic ductal and acinar cells in pancreatic tissues from CP patients. Immunoblotting with the same highly specific monoclonal antibodies demonstrated a marked increase in aFGF and bFGF in pancreatic homogenates from CP patients by comparison with the normal pancreas. Northern blot analysis indicated that, by comparison with normal controls, 16 of 21 CP tissues exhibited a 14-fold increase in aFGF mRNA levels, and 19 of 21 CP tissues exhibited a 15-fold increase in bFGF mRNA levels. In situ hybridization confirmed that this overexpression occurred in ductal and acinar cells, and indicated that both mRNA moieties colocalized with their respective proteins. These findings suggest that aFGF and bFGF may either be involved in the pathobiological mechanisms that occur in CP, or that their overexpression may be the consequence of other perturbations that occur in this disorder.

Adult↗
PubMed1994

Oxygen radicals in experimental acute pancreatitis.

Oxygen free radicals mediate an important step in the initiation of experimental acute pancreatitis. These reactive oxygen metabolites are generated at an early stage of the disease. However, the source of the enhanced production of oxygen radicals still remains unclear. Experimentally, the effectiveness of scavenger treatment varied from one model to another, the differences depending on the experimental model and not on the form of pancreatitis that was induced. In most studies the experimental animals were pretreated before inducing acute pancreatitis. This does not mirror clinical reality, since patients are admitted to the hospital after the onset of the disease. It was shown in cerulein-induced pancreatitis, however, that scavenger treatment also mitigated the pancreatic tissue damage after induction of acute pancreatitis. Moreover, antioxidant treatment also attenuated the extrapancreatic complications, thus improving the final outcome of the disease. Initial indirect observations also suggest that in human acute recurrent and chronic pancreatitis oxygen free radicals are generated and add to the damage. Well-defined controlled clinical trials involving patients suffering from acute pancreatitis are therefore needed to validate the role of oxygen radicals in this disease.

Acute Disease↗
PubMed1994

Balance of expression of genes coding for extracellular matrix proteins and extracellular matrix degrading proteases in chronic pancreatitis.

Chronic pancreatitis is characterized by proliferation of the extracellular matrix and by increased deposition of interstitial extracellular matrix proteins (collagens type I and III, fibronectin). In this study we analyzed the balance of expression of mRNAs encoding extracellular matrix components (collagens I, III and IV, laminin, fibronectin), extracellular matrix degrading metalloproteinases (MMP-1, -2 and -3) and tissue inhibitors of metalloproteinases (TIMP-1 and -2) in chronic pancreatitis (n = 8) and control pancreas (n = 7) by northern blot analysis. Transcripts for MMP-1 (interstitial collagenase), MMP-3 (stromelysin) and TIMP-1 were not detectable in chronic pancreatitis and control tissues. Steady-state levels of transcripts encoding extracellular matrix proteins, MMP-2 (72 kDa collagenase IV) and TIMP-2 were enhanced in 7 out of 8 chronic pancreatitis tissue samples and showed a large degree of variation between individual patients. Transcript levels could not be correlated to the histologically detectable degree of inflammation and fibrosis or to the total amount of deposited collagen protein, which was high in all chronic pancreatitis tissue samples as determined by a standard colorimetric procedure. Increased steady state levels of transcripts encoding extracellular matrix proteins or extracellular matrix degrading proteases may thus reflect the activity of processes involved in the remodeling of the gland during chronic inflammation. The precise role of overexpression of MMP-2 and its inhibitor TIMP-2 will have to be elucidated in further studies.

Chronic Disease↗
PubMed1994

[Morbidity and mortality in surgical therapy of colorectal cancer].

Morbidity and mortality of various surgical therapy protocols for large bowel carcinoma were analysed in 1270 patients and compared to data from other working groups. We found a decline of mortality rates, especially after abdomino-perineal rectum extirpation. The infection rate of the sacral wound is, however, still as high as it used to be. The anastomotic insufficiency rate after anterior rectum resection is depending on location of the anastomoses, amounting to about 7-8% after manual suture as well as after stapled anastomosis. In colon surgery general complications are more frequent than surgical ones.

Adult↗
PubMed1993

Overexpression of acidic and basic fibroblast growth factors in human pancreatic cancer correlates with advanced tumor stage.

Acidic fibroblast growth factor (aFGF) and basic FGF (bFGF) are mitogenic polypeptides that may contribute to cancer cell proliferation. In the present study we examined aFGF and bFGF expression in human pancreatic cancer. Northern blot analysis of total RNA isolated from 12 pancreatic cancers revealed elevated aFGF and bFGF mRNA levels in 12 and 10 samples, respectively, by comparison with the normal human pancreas. Immunostaining demonstrated the presence of aFGF and bFGF in many cancer cells and in the atrophic acini and ducts adjacent to the cancer cells, but to a much lesser extent in the surrounding fibroblasts. By in situ hybridization, both mRNA moieties colocalized with their respective proteins and were abundant in many cancer cells. Immunoblotting confirmed that cancer tissues with increased aFGF and bFGF immunoreactivity contained elevated levels of both proteins. To determine the significance of aFGF and bFGF expression in the pancreatic cancer cells, immunohistochemical analysis of 78 human pancreatic carcinomas was performed. aFGF and bFGF immunoreactivity was present in the cancer cells in 47 (60%) and 44 (56%) of the tumors, respectively. There was a significant correlation between the presence of either aFGF or bFGF in the cancer cells and advanced tumor stage, and the presence of bFGF and shorter patient survival. These data suggest that aFGF and bFGF are overexpressed in a significant proportion of human pancreatic carcinoma cells and that this overexpression may contribute to disease progression.

Adult↗
PubMed1993

p53 mutations are common in pancreatic cancer and are absent in chronic pancreatitis.

Pancreatic expression of the p53 tumor suppressor gene was studied in pancreatic adenocarcinomas and chronic pancreatitis. By immunohistochemistry, 16 of 34 (47%) cancers and none of the 24 chronic pancreatitis samples revealed nuclear staining. Sequence analysis indicated that 8 of 24 (33%) cancers were mutated for the p53 gene. Point substitutions occurred at codons 35, 105, 133, 213, 213, 258, and 299. A three base-pair in-frame insertion was identified between codons 261 and 262. None of 8 chronic pancreatitis samples exhibited p53 gene mutations. These data support a role for p53 gene alterations in human pancreatic cancer, and suggest that loss of its regulatory functions may constitute one of the differences between pancreatic cancer and chronic pancreatitis.

Adenocarcinoma↗
PubMed1993

CA 494--a new tumor marker for the diagnosis of pancreatic cancer.

In 59 patients with ductal pancreatic cancer the monoclonal antibody (MAb) BW 494, which detects the CA 494 glycoprotein antigen, was analyzed in comparison with the reference tumor markers CA 19-9 and CEA. Eighty-one patients with non-pancreatic malignancies of the gastrointestinal (GI) tract, 95 with chronic pancreatitis, 124 with benign non-pancreatic GI diseases, 30 with diabetes mellitus (type I or type II) and 114 healthy blood donors served as controls. The sensitivity of pancreatic cancer was 90%, 44% and 90% for CA 19-9, CEA and CA 494, respectively. In chronic pancreatitis, as the most important control population for pancreatic cancer, the specificity was 85%, 72% and 94% for CA 19-9, CEA and CA 494, respectively.

Adolescent↗
PubMed1993

Is follow-up of colorectal cancer patients worthwhile?

Between 1978 and 1989, 1,045 of 1,399 patients (580 male and 474 female) underwent curative surgery for colorectal carcinoma. Of these patients, 350 (33 percent) had recurrences, another 16 (1.5 percent) developed a metachronous colorectal cancer, and 23 (2 percent) had cancers of other organs. An isolated locoregional recurrence was found in 75/350 (21 percent). The remaining 275/350 patients (79 percent) showed systemic dissemination of the carcinoma. Reoperations with curative intent were performed on 56/350 patients (16 percent). Only 21 of the 56 resected patients (38 percent), i.e., 21/350 (6 percent), were without recurrence at the end of the follow-up period on December 31, 1990. Despite a curative reoperation, 62 percent of the patients again developed recurrent growths. There is an imbalance between the efforts invested in tumor follow-up and the benefits gained. Further follow-up programs should be investigated in a controlled, prospective fashion.

Adolescent↗
PubMed1993

Gabexate mesilate in human acute pancreatitis. German Pancreatitis Study Group.

BACKGROUND: A multicenter controlled study was performed to evaluate the effect of high doses of the low molecular weight protease inhibitor gabexate mesilate on mortality and complications associated with moderate and severe acute pancreatitis. METHODS: Two hundred twenty-three patients from 29 hospitals were entered in the randomized, double-blind trial. Admission to the study was based on strict criteria excluding mild acute pancreatitis. The patients received placebo or 4 g gabexate mesilate per day intravenously for 7 days. All patients were followed up for 90 days after randomization. The analysis was based on 14 complications, including death. RESULTS: There was no statistical difference in either mortality or complications associated with acute pancreatitis between the placebo and gabexate mesilate groups. CONCLUSIONS: The results show that gabexate mesilate was not effective in preventing complications and mortality in acute pancreatitis.

Acute Disease↗
PubMed1993

Enhanced expression of transforming growth factor beta isoforms in pancreatic cancer correlates with decreased survival.

BACKGROUND: Transforming growth factor beta s (TGF-beta s) constitute a family of bifunctional polypeptide growth factors that either inhibit or stimulate cell proliferation. Perturbations in TGF-beta expression and function may lead to loss of negative constraints on cell growth. In this study, we examined TGF-beta expression in human pancreatic cancer. METHODS: The distribution of TGF-beta isoforms in 60 human pancreatic cancers was examined using immunohistochemical, Northern blot, and in situ hybridization techniques. RESULTS: Immunohistochemical analysis showed the presence of TGF-beta 1 (47% of tumors), TGF-beta 2 (42% of tumors), and TGF-beta 3 (40% of tumors) in the cancer cells. The presence of TGF-beta 2 was associated with advanced tumor stage (P < 0.05). Furthermore, there was a significant correlation between the absence of TGF-beta s in the tumors and longer postoperative survival. Northern blot analysis indicated that, by comparison with the normal pancreas, pancreatic adenocarcinomas showed 11- (P < 0.001), 7- (P < 0.05), and 9-fold (P < 0.001) increases in the messenger RNA (mRNA) levels encoding TGF-beta 1, TGF-beta 2, and TGF-beta 3, respectively. By in situ hybridization, these mRNA moieties colocalized with their respective proteins in the cancer cells. CONCLUSIONS: These findings show that human pancreatic cancers show increased levels of TGF-beta isoforms and enhanced TGF-beta mRNA expression and suggest that the presence of TGF-beta s in pancreatic cancer cells may contribute to disease progression.

Adenocarcinoma↗
PubMed1993

Overexpression of HER2/neu oncogene in human pancreatic carcinoma.

The HER2/neu oncogene encodes a transmembrane protein that possesses intrinsic tyrosine kinase activity. Its overexpression has been associated with the malignant phenotype. In this study we examined HER2/neu expression in the normal and cancerous human pancreas. In the normal pancreas HER2/neu immunostaining was observed in acinar and ductal cells. HER2/neu immunoreactivity was expressed in 34 of 76 (45%) pancreatic carcinomas. There was a significant correlation between tumors with well-differentiated histology and HER2/neu expression. Northern blot analysis demonstrated HER2/neu mRNA expression in the normal pancreas and in situ hybridization confirmed its distribution in both acinar and ductal cells. In cancer tissues Northern blot analysis indicated that HER2/neu mRNA levels were elevated in 13 of 25 (52%) of the tumors in comparison with the normal tissues. In addition, in situ hybridization demonstrated a strong but heterogenous distribution of mRNA grains in these tumors. Southern blot analysis did not demonstrate HER2/neu gene amplification in any of the tumors. These data indicate that the HER2/neu protein is synthesized in the normal exocrine pancreas and is frequently overexpressed in well-differentiated adenocarcinomas of the pancreas as a result of increased HER2/neu mRNA levels.

Adult↗
PubMed1993

Reperfusion injury after intestinal ischemia.

OBJECTIVE: Review the histologic and pathophysiologic alterations seen after intestinal ischemia and reperfusion. DATA SOURCE: Current literature review. STUDY SELECTION: The most pertinent, current, and representative articles describing results from both animal and human investigations are utilized and discussed. DATA SYNTHESIS: Postischemic intestinal tissue damage appears to be due to the formation of oxygen radicals and the activation of phospholipase A2. The initial source of oxygen radicals seems to be the hypoxanthine-xanthine oxidase system. Oxygen radicals react directly with poly-unsaturated fatty acids, leading to lipid peroxidation within the cell membranes. Indirectly, the radicals trigger the accumulation of neutrophils within the affected tissue initiating inflammatory processes that lead to severe mucosal lesions. Similarly, phospholipase A2 also initiates postischemic mucosal lesions. Phospholipase A2 is a hydrolytic enzyme capable of increasing formation of cytotoxic lysophospholipids within the tissue. Enhanced activity of phospholipase A2 also stimulates the production of prostaglandins and leukotrienes. Various substances (superoxide dismutase, catalase, dimethyl sulfoxide, allopurinol, and deferoxamine, etc.) are able to detoxify oxygen radicals or inhibit the mechanisms leading to their enhanced generation, thus attenuating the postischemic lesions of the mucosa. CONCLUSIONS: Oxygen radicals and the activation of phospholipase A2 during reperfusion seem to be instrumental for the development of hemorrhagic mucosal lesions after intestinal ischemia. Radical scavengers and phospholipase A2 inhibitors may prevent reperfusion damage of the intestine, even when the treatment starts during ischemia but before reperfusion.

Animals↗
PubMed1993

Low-dose octreotide treatment is not effective in patients with advanced pancreatic cancer.

Octreotide (SMS 201-995), a long-acting somatostatin analogue, has been shown to decelerate growth of human pancreatic cancer in vitro and in vivo. We analyzed the efficacy of octreotide treatment in 22 patients (14 men, 8 women) with histologically verified ductal pancreatic cancer. All patients had advanced tumor stages (stage III: 13 patients; stage IV: 9 patients). Octreotide was given by self-administered subcutaneous injection (3 x 100 micrograms/day). When there was evidence of tumor progression, the dose of octreotide was increased to 3 x 200 micrograms/day. A monthly follow-up, including clinical status, CT scan or ultrasonography, and tumor marker carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 determination was carried out. There were no severe side effects apart from slight burning sensation at the injection site. No partial or complete remission was seen. Eighteen patients showed tumor progression with a median survival time of 17 weeks (range 3-42 weeks). In three patients a "no change" evaluation with a median survival time of 46 weeks (range 40-68 weeks) was registered. In these three patients the serum tumor markers CA 19-9 and CEA did not show an increase to more than twice the baseline value during this time. One patient discontinued the octreotide treatment because of tumor progression. The results of the analysis indicate that low-dose octreotide treatment is not effective in patient suffering from advanced tumor stages of pancreatic cancer.

Adenocarcinoma↗
PubMed1993

Synthesis and expression of transforming growth factor beta-1, beta-2, and beta-3 in the endocrine and exocrine pancreas.

The actions of transforming growth factor-beta isoforms as potent regulators of growth and differentiation have led to the examination of their presence in the human pancreas. The cellular localization of TGF-beta 1, TGF-beta 2, and TGF-beta 3 was assessed in the normal human pancreas by using immunohistochemical and in situ hybridization techniques. Although cytoplasmic immunoreactivity for TGF-beta 1, TGF-beta 2, and TGF-beta 3 was found in islet cells, acinar cells, and ductal cells, a differential immunostaining pattern for TGF-beta isoforms was observed. In the endocrine pancreas, the islet cells demonstrated diffuse cytoplasmic immunostaining for TGF-beta 1, TGF-beta 2, and TGF-beta 3. However, only TGF-beta 2 and TGF-beta 3 exhibited an intense pattern of immunostaining in a few endocrine cells. Most of the positive islet cells coexpressed insulin. In contrast, in the exocrine pancreas, a greater number of acinar cells showed immunoreactivity for TGF-beta 1 than for TGF-beta 2 and TGF-beta 3. In the ductal cells, all three TGF-beta isoforms showed a similar intensity and pattern of immunostaining and were observed more frequently in the smaller distal ductules than in the larger pancreatic ducts. TGF-beta 1 and TGF-beta 3, but not TGF-beta 2, immunostaining was detected strongly in the smooth muscle cells and weakly in the endothelial cells of the blood vessels, whereas the fibroblasts of the interstitium were completely negative. In situ hybridization revealed that mRNA encoding all three TGF-beta isoforms colocalized with their respective proteins in islets, acinar cells, and ductal cells. In contrast, mRNA expression was absent in the smooth muscle cells and endothelium of the vessels. These results suggest that TGF-beta isoforms may act by both autocrine and paracrine mechanisms in the pancreas. The differential pattern of expression observed for each TGF-beta isoform implies unique roles for these proteins in the regulation of the endocrine and exocrine pancreas.

DNA Probes↗