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Biomedical subjects

H G Beger

Publications and source records attributed to H G Beger.

At least 289 records · Page 16Linked to original sources
PubMed1995

[Surgical therapy of short bowel syndrome].

Advances in medical and surgical technique and the development of home parenteral nutrition have led to an increasing number of patients with short-bowel syndrome. Many patients could benefit from definite surgical therapy as long-term parenteral nutrition besides being expensive frequently causes severe complications. Various techniques to prolongate intestinal transit and increase the absorptive area of the remaining small bowel have been experimentally developed and some have been successfully employed in humans. The recent discovery of new potent immunosuppressive agents has initiated clinical endeavours at intestinal transplantation. The various techniques for the surgical therapy of short-bowel syndrome with their indications and potential risks are reviewed.

Gastrointestinal Transit↗
PubMed1995

[Oxygen radicals and nitrogen monoxide in sepsis].

Accumulation and stimulation of PMN-leukocytes, enhanced prostaglandin metabolism and tissue hypoxia lead to high concentrations of oxygen radicals and their metabolites in septic shock. Synchroneously, excessive high concentrations of nitric oxide are found, most likely due to the stimulation of its inducible synthetase. Oxygen radicals seem to be attributable for the irreversible tissue damage leading to multiple organ failure in sepsis. High concentrations of nitric oxide induce the typical macro- and microcirculatory derangements normally seen in sepsis. Both mediators are present in the early phase of sepsis and seem to influence the course of disease. Therapeutic interventions such as scavenger therapy or inhibition of the inducible NO-synthetase are promising. The results of the first clinical therapeutic studies, however, were not always conclusive. It is still unclear which scavenger and which inhibitor should be given when and in which dosage in order to improve the outcome of sepsis and septic shock. Furthermore, it remains unclear to which extend oxygen radicals and nitric oxide react with each other, thus possibly potentiating their effects. The open questions still warrant further research and may lead to new therapeutic options improving the morbidity and mortality of this severe disease.

Animals↗
PubMed1995

Addition of interleukin 12 to low dose interleukin 2 treatment improves antitumor efficacy in vivo.

Interleukin 12 (IL-12) enhances lysis mediated by NK- and lymphokine activated killer (LAK) cells. It also causes proliferation of IL-2 stimulated T and NK cells in vitro. For these IL-2 complementing properties murine pulmonary metastases of a coloncarcinoma line were treated with IL-12 and IL-2 or with the individual agents. Results were compared to sham treated controls. IL-2 alone mediated significant tumor reduction but provoked pulmonary edema and concomittand toxicity, graded in three steps. IL-12 combined with an IL-2 dose reduced by 81% still resulted in significant antitumoral activity. Toxicity, however, was not discernable from sham treated controls. IL-12 thus appears as an attractive cytokine for combination with IL-2 in antitumor therapy. Particularly treatment of tumors, like gastrointestinal tract cancers, so far mainly resistant to cell mediated antitumor therapy, might profit from this approach.

Animals↗
PubMed1995

[Photodynamic therapy of small adenocarcinomas with methylene blue].

Photodynamic therapy (PDT) is a new method in the treatment of small/early malignancies. It is based on the interaction of a photosensitiser, light and cellular oxygen. A new therapeutic concept with locally applied 1% of methylene blue into the tumour and subsequent radiation (argon laser pumped dye laser, 665 nm, 100 mW/cm2, 100 J/cm2) was first tested in xeno-transplanted carcinomas and then clinically applied. The animal experiments showed a tumour volume reduction of 1:12, as compared to a control group, two weeks after the first PDT-application. After the second PDT-treatment 6 out of 10 tumours were destroyed. Four carcinomas showed inhibited growth after the treatment. The method was clinically applied in 3 patients with local tumour recurrence in the area of the anastomosis after oesophagus resection. 72 hours after PDT-treatment 4-5 mm tumour necrosis could be proven experimentally. PDT was repeated at the same site within 2 weeks. There were no experimental or clinical complications during or after PDT. The treated tumour areas showed no local tumour growth within 6 months after PDT-treatment.

Adenocarcinoma↗
PubMed1994

Carcinoid of the ampulla of Vater. Clinical characteristics and morphologic features.

BACKGROUND: Carcinoid tumors of the gastrointestinal tract are most common localized in the appendix, followed by the small intestine, the rectum, and the stomach. The localization of these tumors at the ampulla of Vater is extremely seldom. METHODS: In the present study the authors describe two patients with carcinoid tumors of the ampulla Vater and review 71 previously published cases. RESULTS: Most patients presented with jaundice, but without carcinoid syndrome. Because the tumor grows submucosally, preoperative diagnosis was correct only in 15%. Most tumors were around 2 cm in size. Metastasis to lymph nodes and/or liver was present in 45%. Standard treatment is Whipple resection or local excision in small tumors. CONCLUSIONS: Carcinoid tumors of the ampulla of Vater are an extremely rare clinical entity. Generally, the prognosis is good with a 5-year survival period of 90%.

Adult↗
PubMed1994

Differential expression of heat shock proteins in pancreatic carcinoma.

In the present study we sought to determine by Northern blot analysis and mRNA in situ hybridization whether gene expression of heat shock proteins (HSPs) (HSP 89 alpha, HSP 89 beta, HSP 70, and ubiquitin) is altered in pancreatic carcinoma, compared to control tissues (normal pancreas and chronic pancreatitis tissue). HSP 89 alpha was selectively overexpressed in pancreatic carcinoma, and tumor cells were shown to contain the largest amount of HSP 89 alpha mRNA. Steady state levels of HSP 70 mRNA were increased in pancreatic carcinoma (tumor and connective tissue cells) and in chronic pancreatitis (connective tissue cells and residues of exocrine acinar cells). HSP 89 beta and ubiquitin B were constitutively expressed at high levels in pancreatic tissue from all three groups; HSP 89 beta mRNA was found in cells of parenchymal and stromal origin. A strong correlation was found between the expression of HSP 70 and the expression of transforming growth factor beta 1. The finding that HSPs are differentially expressed in pancreatic cancer, compared to normal pancreas and chronic pancreatitis tissue, and the cancer specificity of HSP 89 alpha suggest that HSPs play a specific role in the pathogenesis of pancreatic cancer, e.g., by participating in regulatory processes or in tumor immunity, as proposed previously.

Blotting, Northern↗
PubMed1994

Effect of antioxidant treatment in rats with acute hemorrhagic pancreatitis.

The purpose of this study was to evaluate the effect of free radical ablation therapy in acute hemorrhagic pancreatitis. Acute pancreatitis was induced in 64 rats by retrograde injection of 5% sodium taurocholate. Thirty animals were pretreated with 100,000 units/kg/hr of superoxide dismutase (SOD) and 400,000 units/kg catalase within the first 3 hr. After 0.5, 3.5, and 12 hr of observation time, serum enzymes and the tissue content of conjugated dienes, malondialdehyde, reduced and oxidized glutathione, as well as ATP, ADP and AMP were measured. In addition, tissue samples were examined by light microscopy. Untreated rats (N = 34) developed within 12 hr an acute hemorrhagic necrotizing pancreatitis with a concomitant increase in serum enzyme levels and a decrease in reduced glutathione and ATP. Within the 12-hr observation period, 57% of the animals died. Scavenger treatment improved the tissue damage and attenuated the increase of the serum enzyme levels and the decrease in reduced glutathione and ATP. Moreover, the lethality rate was significantly lower. Oxygen radicals seem to be instrumental for the development of acute hemorrhagic pancreatitis. Thereby, antioxidant treatment reduces tissue damage, biochemical alterations and extrapancreatic complications, thus improving the final outcome.

Acute Disease↗
PubMed1994

Interaction of pancreatic ductal carcinoma with nerves leads to nerve damage.

BACKGROUND/AIMS: Perineural extension of pancreatic adenocarcinoma has been explained as a mechanical extension along planes of least resistance. This study tests whether the cancer is limited to following these planes and if substances involved in cell signaling are involved in the interaction of cancer cells with nerves. METHODS: Samples of tissue from patients undergoing resection of pancreatic cancer were studied by electron microscopy and light microscopy. Transforming growth factor alpha (TGF-alpha) and epidermal growth factor receptor (EGFR) were localized in sections. RESULTS: The adenocarcinoma is not confined to the periphery of nerves. It penetrates the perineurium and becomes intimately associated with Schwann cells and axons in the endoneurium. Neural elements are damaged. Neural invasion likely is a factor in associated pain. TGF-alpha is abundant in nerves in the pancreas. EGFR is prominent in the cells of the adenocarcinoma. CONCLUSIONS: The interaction of pancreatic cancer with nerves involves more than the cancer following a perineural space. Interaction of TGF-alpha in nerves with EGFR on cancer cells constitutes a possible paracrine mechanism that provides a growth advantage for pancreatic adenocarcinoma and serves as an example of potential interactions that might be active in biological interaction of cancer with nerves.

Adenocarcinoma↗
PubMed1994

Free radicals and pathogenesis during ischemia and reperfusion of the cat small intestine.

BACKGROUND/AIM: In spite of the interest in free radicals as mediators of ischemic damage, most information on these species in biological systems is derived from indirect measurements. Our aim was to obtain more direct information concerning sources of free radical production during ischemia and reperfusion. METHODS: We have performed simultaneous measurement of radical generation, purine metabolites, reduced glutathione, neutrophil infiltration and morphological appearance in the cat small intestine in vivo during 60 minutes of ischemia followed by 60 minutes of reperfusion. RESULTS: Radical formation increased abruptly on reperfusion and remained elevated in untreated animals. Inhibition by a monoclonal antibody (IB4) against the neutrophil and by allopurinol treatment was paralleled by improvement of biochemical and morphological parameters. The radicals detected during reperfusion could be divided into one component arising directly from the neutrophils, one due to the xanthine oxidase reaction, and one unknown source. CONCLUSIONS: Neutrophils are a major source of radical production during reperfusion after ischemia. Radicals formed in the xanthine oxidase reaction seem to function as a primer for the neutrophils. The nonsignificant linear correlation between radical formation and morphological appearance suggests that factors other than free radicals are important for the development of intestinal damage after a period of ischemia.

Allopurinol↗
PubMed1994

Growth-associated protein-43 and protein gene-product 9.5 innervation in human pancreas: changes in chronic pancreatitis.

Growth-associated protein-43, an established marker of neuronal plasticity during development and in injury, was used to characterize innervation in the normal human pancreas and changes in chronic alcohol-induced pancreatitis by using light microscopic immunocytochemistry and computer-assisted image analysis. Immunostaining for the pan-neuronal marker protein gene-product 9.5 served as a reference for the characterization of total innervation in both groups. In normal human pancreas, strong protein gene-product 9.5 immunostaining revealed all nerve fibres in nerve trunks, all neuronal cell bodies and the entire parenchymal innervation. In contrast, growth-associated protein-43 immunoreactivity was restricted to a few nerve fibres in interlobular nerve trunks and to fine varicose nerve fibres supplying the parenchyma, blood vessels, pancreatic ducts and intrinsic ganglia. In cell bodies of intrinsic neurons, growth-associated protein-43 immunoreactivity was absent or extremely faint. In chronic pancreatitis, the protein gene-product 9.5 innervation exhibited region-specific changes. In areas with reduced parenchyma, the protein gene-product 9.5 innervation was sparse. In fibrotic regions, which are characteristic for advanced stages of chronic pancreatitis, enlarged nerve trunks showing neuroma-like formations were heavily stained for protein gene-product 9.5. In fibrotic tissue, protein gene-product 9.5-containing nerve fibres were extremely rare. The growth-associated protein-43 innervation in chronic pancreatitis was characterized by a dramatic increase, which was most pronounced in the enlarged nerve trunks. Such nerve trunks were frequently surrounded by infiltrates of immune cells, which in some cases formed follicle-like structures. Digital image analysis of adjacent sections and double fluorescence immunocytochemistry revealed that growth-associated protein-43 immunoreactivity was present in the vast majority of protein gene-product 9.5-immunoreactive nerve fibres. In contrast to the normal pancreas, a major subpopulation of intrinsic neurons immunostained for growth-associated protein-43. The expression of growth-associated protein-43 in the terminal fields of pancreatic nerve suggests that the innervation of the normal human pancreas undergoes continual and toposelective remodelling. The increase in the density of growth-associated protein-43 immunoreactive nerve fibres in enlarged nerve trunks paralleled by augmented expression of growth-associated protein-43 in intrinsic neurons and reduced parenchymal growth-associated protein-43-immunoreactive innervation underline the dramatic plasticity of pancreatic innervation in chronic pancreatitis.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1994

[The early recognition of infected fluid collections in acute pancreatitis in computed tomography].

UNLABELLED: Infected accumulations of abdominal fluid are a severe complication and the major cause of death (mortality rate between 20 and 60%) in patients suffering from acute pancreatitis. In 93 patients with confirmed acute pancreatitis including 28 with surgically confirmed pancreatic abscess CT findings (volume of pancreatic and extrapancreatic necrosis, capsular enhancement, gas bubble formation and contact between fluid collection and intestinum) were retrospectively correlated with clinical and operative data to assess abscess formation. This revealed a sensitivity of 0.57 in respect of pancreatic necrosis; for extrapancreatic necrosis the sensitivity was 0.39, for capsular enhancement 0.5, for gas bubble formation 0.46 and for intestinal contact 0.93. The specificity was high for gas bubbles (1.0) and intestinal contact (0.91) and low for the other criteria. IN CONCLUSION: There is a strong relationship between fluid accumulations in direct contact with intestinal structures and the occurrence of abscess. This parameter enhances the reliability of CT in the early detection of extrapancreatic infection.

Abdominal Abscess↗
PubMed1994

A subgroup of patients with chronic pancreatitis overexpress the c-erb B-2 protooncogene.

OBJECTIVE: Chronic pancreatitis (CP) is a chronic condition associated with pancreatic fibrosis. A small subgroup of patients with CP develop enlargement of the head of the pancreas (EHP). This study examined some of the mechanisms that may lead to the development of EHP. SUMMARY BACKGROUND: The c-erb B-2 protooncogene encodes a 185-kDa transmembrane growth factor receptor (p185) that regulates cell growth and differentiation. METHODS: The authors analyzed c-erb B-2 expression in samples obtained from the head of the pancreas from 26 patients with CP (5 women, 21 men) using immunohistochemical and molecular technique. A diagnosis of CP with EHP was made when the vertical pancreatic head diameter was greater than 4 cm (14 patients), as determined by contrast-enhanced computed axial tomography scan. Pancreatic tissues from 15 healthy organ donors served as control subjects. RESULTS: In all patients without EHP and in the healthy control subjects, p185 immunoreactivity was present at low levels. In contrast, strong p185 immunoreactivity was observed in acinar and ductal cells in all patients with EHP. By in situ hybridization, c-erb B-2 messenger ribonucleic acid (mRNA) grains were expressed at high levels in patients with CP with EHP in both ductal and acinar cells. Northern blot analysis demonstrated a 4.5-fold increase (p < 0.001) in c-erb B-2 mRNA levels in patients with EHP compared with patients without EHP and healthy control subjects. Southern blot analysis did not reveal c-erb B-2 gene amplification or rearrangement. CONCLUSIONS: These findings indicate the c-erb B-2 is not overexpressed in most patients with CP. However, its overexpression in patients with CP with EHP suggest that c-erb B-2 may contribute to the pathophysiologic processes that lead to pancreatic head enlargement.

Adolescent↗
PubMed1994

Glucose homeostasis and endocrine pancreatic function in patients with chronic pancreatitis before and after surgical therapy.

In a prospective clinical-experimental study, 15 consecutive patients with chronic pancreatitis, operated on because of severe pain, were examined for the effects of a duodenum-preserving resection of the pancreas head on endocrine pancreas function. This was done by means of oral and intravenous glucose tolerance testing before the operation, on the 10th or 11th day postoperatively, and 3 months after the operation. In addition to glucose levels in the peripheral venous blood, levels of insulin, C-peptide, glucagon, and pancreatic polypeptide were determined. As indicated by the k value, glucose tolerance improved postoperatively in 10 patients (66.6%); three patients (19.9%) showed no change, and one patient (6.6%) was worse. Only one patient (6.6%) developed evident diabetes mellitus immediately postoperatively. Pre- and postoperative levels of insulin and C-peptide showed no significant differences. The fasting levels of glucagon were significantly lower postoperatively than before the operation (p < 0.01). The stimulation of pancreatic polypeptide after oral glucose was significantly lower postoperatively (p < 0.01). Duodenum-preserving pancreas head resection does not lead to an impairment of glucose tolerance in the majority of patients; a deterioration was observed only in few cases (13.3%).

Adult↗
PubMed1994

Is the elimination of endotoxin and cytokines with continuous lavage an alternative procedure in necrotizing enterocolitis?

Ascites fluid was obtained intraoperatively in 12 consecutively treated neonates (6M, 6F, mean weight 940 g, mean gestational age 27th week, lethality 3/12) suffering from necrotizing enterocolitis (NEC). The concentrations of endotoxin and cytokines (IL-1, IL-6, TNF) were determined. Endotoxin and interleukins were excessively elevated in all patients, TNF only in those who survived. Postoperative treatment included the use of a continuous abdominal lavage system. This therapeutical procedure allows the elimination of endotoxin and cytokines out of the abdominal cavity in order to reduce their adverse biological effect.

Ascites↗
PubMed1994

Chronic pancreatitis is associated with increased concentrations of epidermal growth factor receptor, transforming growth factor alpha, and phospholipase C gamma.

The epidermal growth factor (EGF) receptor is a transmembrane protein that binds EGF and transforming growth factor alpha (TGF alpha), and that stimulates phospholipase C gamma 1 (PLC gamma 1) activity. In this study the role of the EGF receptor in chronic pancreatitis was studied. By immunohistochemistry, the EGF receptor, TGF alpha, and PLC gamma 1 were found to be expressed at high concentrations in pancreatic ductal and acinar cells from chronic pancreatitis patients. Northern blot analysis showed that, by comparison with normal controls, 19 of 27 chronic pancreatitis tissues exhibited a 5.7-fold increase in EGF receptor mRNA concentrations, and 20 of 27 chronic pancreatitis tissues exhibited a sixfold increase in TGF alpha mRNA concentrations. In situ hybridisation confirmed that overexpression occurred in ductal and acinar cells, and showed that both mRNA moieties colocalised with their respective proteins. These findings suggest that TGF alpha may act through autocrine and paracrine mechanisms to excessively activate the overexpressed EGF receptor in the two major cell types of the exocrine pancreas, thereby contributing to the pathobiology of this disorder.

Adult↗