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Biomedical subjects

F Klebl

Publications and source records attributed to F Klebl.

At least 19 recordsLinked to original sources
PubMed2006

[Chronic diseases after gastrointestinal surgery].

Gastrointestinal surgery may not only lead to early postoperative complications but also chronic consequences. These have therapeutic implications for affected patients. The kind and extent of surgical intervention determines the spectrum of postsurgical phenomena which may occur. These chronic consequences are due to changes in gastrointestinal anatomy, the synchronization of digestive processes, or the ability to digest and absorb food. In case of transplantation surgery, adverse effects of immunosuppression have to be considered. Sometimes, chronic consequences of surgical procedures are difficult to recognize. The knowledge of typical problems associated with gastrointestinal surgery is necessary to enable early and timely diagnosis and treatment. Some negative effects can be avoided by early therapeutic interventions. This article summarizes typical chronic consequences of gastrointestinal surgery.

Bile Reflux↗
PubMed2005

Analysis of intestinal haem-oxygenase-1 (HO-1) in clinical and experimental colitis.

Haem-oxygenase-1 (HO-1) has been shown to exert anti-inflammatory, anti-apoptotic and anti-proliferative effects. We investigated HO-1 expression in patients with inflammatory bowel disease (IBD) and could demonstrate a scattered expression of HO-1 in the intestinal epithelium of severely inflamed colonic mucosa of patients with IBD compared to control specimens such as diverticulitis, suggesting dysregulated expression in IBD. To further analyse potential mechanisms of HO-1 induction in the intestine we employed an in vitro epithelial cell apoptosis model and an experimental colitis model. In vitro induction of HO-1 by the HO-1 inducer cobalt protoporphyrin (CoPP) resulted in a dose-dependent down-regulation of caspase-3 activation in HT-29 cells, indicating an anti-apoptotic function of HO-1 in the intestine. In vivo, preventive HO-1 induction by CoPP in acute dextran sodium sulphate (DSS)-induced colitis led to a significant down-regulation of colonic inflammation (P < 0.01) with a concomitant reduction in interferon (IFN)-gamma - but unaffected interleukin (IL)-10-secretion by isolated mesenteric lymph nodes (P < 0.01). Additionally, TUNEL staining of colonic sections demonstrated fewer apoptotic epithelial cells in the colon of CoPP treated animals. No beneficial effects were observed if HO-1 was induced by CoPP after the onset of acute colitis or in chronic DSS-induced colitis. In conclusion, the data suggest a protective role of HO-1 if it is induced before the onset of inflammation. However, as shown by the lack of effects in established acute or in chronic colitis, the induction of HO-1 may not be a promising approach for the treatment of IBD.

Acute Disease↗
PubMed2004

[Acute emesis].

Causes of acute vomiting are mostly harmless and readily amenable to treatment, so that the condition thus has a good prognosis. In more rare cases, however, it might also be a symptom accompanying a more serious--even life-threatening--illness. A meticulous diagnostic investigation and effective treatment is therefore mandatory.

Acute Disease↗
PubMed2004

[Hematemesis].

Explore the source record for details and available documents.

Diagnosis, Differential↗
PubMed2004

Contrast-enhanced ultrasound allows for interventions of hepatic lesions which are invisible on convential B-mode.

BACKGROUND AND AIMS: Contrast harmonic imaging significantly increases the detectability of liver lesions which are invisible on conventional B-mode sonography. With the introduction of contrast agents, which can be visualized at low mechanical index (low-MI), continuous real time observation of liver lesions under contrast conditions is possible. We addressed the question whether contrast-enhanced sonography allows for intervention of hepatic lesions impossible to detect on conventional B-mode imaging. PATIENTS AND METHODS: We evaluated twelve patients with hepatic tumors or abscesses, which could not be analyzed and punctured under fundamental B-mode guidance. The ultrasound contrast agent BRI was used for detection of the hepatic lesions under contrast harmonic imaging (CHI) conditions with phase inversion at low-MI. RESULTS: In eleven out of twelve patients interventions under CHI conditions were successful, as proven by histological, microbiological or tumor marker analysis. The puncture needles were visible in all cases. With an algorithm for optimizing the puncture conditions at low-MI CHI the biopsies can be performed in two steps. CONCLUSIONS: Our results show that biopsies of liver lesions under real-time continuous CHI at low-MI are feasible.

Biopsy, Needle↗
PubMed2004

[Evaluation of intestinal hyperaemia in inflamed bowel by high resolution Contrast Harmonic Imaging (CHI)].

AIM: Intestinal hyperaemia is a sign of active disease in the inflamed intestine which can be detected by Doppler sonography. This technique, however, can be jeopardized by tissue motion artefacts (peristalsis), and intramural enteric vessel perfusion may be below the detection threshold. Visualisation of vessels by Contrast Harmonic Imaging (CHI) at a low Mechanical Index (low MI) is not restricted by the limitations mentioned above. Contrast Harmonic Imaging at low MI of the intestinal wall has not yet been described with high frequency probes. We therefore evaluated the validity of this method for detecting hyperaemia of the intestinal wall. METHODS: CHI at low MI was performed with a 7.5 MHz ultrasound probe in 12 patients with signs of an inflamed intestine. The contrast agent BR 1 (4.8 ml) was injected intravenously. Contrast enhancement was quantified by analysing gray scale values before and after injection of BR 1 in regions of interest within the submucosal layer. RESULTS: At about 15 sec. after injection of BR 1, arterial inflow of the contrast agent with visualisation of the feeding mesenteric vessels and intense contrast of the submucosal lamina could be observed. An increase of the gray scale values within the ROI after contrast enhancement was detected in all patients. CONCLUSION: We have shown that CHI at low MI is technically feasible for the demonstration of increased intestinal perfusion in inflammatory bowel disease by using a high resolution ultrasound probe. One possible method of quantifying the contrast enhancement is the gray scale analysis of pixels in defined regions of interest within the submucosal layer.

Adult↗
PubMed2004

[Sonographic controlled drainage of a fluid formation of the spleen in combination with pancreatitis].

With regard to acute or chronic pancreatitis various complications involving the spleen can occur, hematoma of the spleen being a rare complication. We describe the case of a patient in reduced general condition with elevated pancreatic enzymes and signs of inflammation. During multiple examinations, hematoma of the spleen, as well as hematomas close to the left adrenal gland and a larger hematoma close to the gastric wall were detected. In computed tomography and due to the laboratory parameters a pancreatitis was diagnosed. After CT-controlled puncture a communication between both formations was considered possible which was in retrospect CT-assisted not successful. Subsequently an ultrasound controlled drainage was performed, finally resulting in a restitutio ad integrum, thereby avoiding splenectomy. The described percutaneous puncture of a fluid formation in the splenic area represents a non-surgical option in the therapy of intrasplenic pancreatic fluid formations.

Diagnosis, Differential↗
PubMed2004

Morphological characterisation of Crohn's disease fistulae.

BACKGROUND: Fistulae are a common complication in up to 35% of all patients with Crohn's disease. Their therapy is difficult and frequently unsatisfactory. To date, no histological comparison of Crohn's disease fistulae with non-inflammatory bowel disease fistulae has been performed. In addition, Crohn's disease fistulae have not been well characterised morphologically. METHODS: Eighty four fistulae from Crohn's disease patients were compared with 13 fistulae from controls. Haematoxylin-eosin staining, electron microscopy, and immunohistochemistry for panCytokeratin (epithelial cells), CD20 (B cells), CD45R0 (T cells), and CD68 (macrophages) were performed according to standard techniques. In addition, histopathological findings were compared with clinical and laboratory data. RESULTS: In 31.0% of controls and 27.4% of Crohn's disease specimens, fistulae had a lining of flattened intestinal epithelium without goblet cells or, in the case of cutaneous/perianal disease, narrow squamous epithelium. Non-epithelialised fistulae were covered by a thin layer of (myo)fibroblasts, focally forming a new basement membrane, as demonstrated by electron microscopy. All fistulae were surrounded by granulation tissue. Crohn's disease fistulae presented with central infiltration by CD45R0+ T cells, followed by a small band of CD68+ macrophages and dense accumulation of CD20+ B cells. In contrast, in controls, there was dense infiltration by CD68+ macrophages with only few CD20+ B cells and CD45R0+ T lymphocytes. CONCLUSIONS: Fistulae in Crohn's disease differ markedly from non-Crohn's disease fistulae with regard to their cellular composition. The presence of an epithelial lining in a subgroup of fistulae may be important for the therapeutic approach and healing process.

Adolescent↗
PubMed2003

Patients with refractory Crohn's disease or ulcerative colitis respond to dehydroepiandrosterone: a pilot study.

BACKGROUND: Dehydroepiandrosterone is a steroid hormone used as an 'over-the-counter' drug in the USA. Treatment with dehydroepiandrosterone was effective in randomized controlled trials in patients with systemic lupus erythematosus. Dehydroepiandrosterone sulphate concentrations are decreased in patients with inflammatory bowel disease. Dehydroepiandrosterone inhibits nuclear factor-kappaB and the secretion of interleukin-6 and interleukin-12 via the peroxisome proliferator-activated receptor alpha. AIM: A phase II pilot trial was started to evaluate the effect of dehydroepiandrosterone in active inflammatory bowel disease. METHODS: Twenty patients with chronic active inflammatory bowel disease [seven Crohn's disease (Crohn's disease activity index, 242 +/- 51; mean +/- s.d.); 13 ulcerative colitis (clinical activity index, 7.8 +/- 2.1)] took 200 mg dehydroepiandrosterone per day orally for 56 days. RESULTS: Six of the seven patients with Crohn's disease and eight of the 13 patients with ulcerative colitis responded to treatment, with a decrease in the Crohn's disease activity index of > 70 points and a decrease in the clinical activity index of > 4 points, respectively. Six Crohn's disease patients and six ulcerative colitis patients went into remission (Crohn's disease activity index < 150; clinical activity index <or= 4). No patient withdrew from the study because of side-effects. CONCLUSIONS: In a pilot study, dehydroepiandrosterone was effective and safe in patients with refractory Crohn's disease or ulcerative colitis. Adjustment of the dehydroepiandrosterone dosage may further improve the treatment success.

Adjuvants, Immunologic↗
PubMed2003

Alterations in p53 predict response to preoperative high dose chemotherapy in patients with gastric cancer.

AIMS: To evaluate the usefulness of molecular markers in predicting histopathological and clinical response to preoperative high dose chemotherapy (HDCT) and survival of patients with advanced gastric cancer. METHODS: In a phase II trial, 25 patients with metastatic gastric cancer received preoperative tandem HDCT consisting of etoposide, cisplatin, and mitomycin, followed by autologous bone marrow transplantation to achieve surgical resectability. Samples before and after treatment, from normal and tumour tissue, were characterised histopathologically, and both p53 and BAX expression was analysed by immunohistochemistry. Pretreatment formalin fixed, paraffin wax embedded samples from normal and tumour tissue were microdissected, and the extracted DNA was preamplified using improved primer extension preamplification polymerase chain reaction. Detection of microsatellite instability (MSI) or loss of heterozygosity (LOH) was performed using markers for p53, BAX, BAT25, BAT26, D2S123, D17S250, and APC. Exons 5-9 of the p53 gene were sequenced directly on ABI 373. RESULTS: Four parameters were significantly associated with response to chemotherapy and prolonged overall survival: positive p53 immunostaining, positive p53 mutation status before chemotherapy, strong histological regression induced by preoperative HDCT, and surgical treatment. Patients's sex or age, tumour location or stage, lymph node status, Lauren classification, MSI, or LOH did not influence duration of survival significantly in this high risk population. CONCLUSION: Positive p53 immunostaining and p53 mutation status in pretreatment tumour biopsies might be useful molecular predictors of response and prognosis in patients with advanced gastric cancer treated by preoperative HDCT.

Adult↗
PubMed2002

[Evaluation of a new, portable ultrasound system in routine clinical use].

AIM: Evaluation of a new, hand-carried ultrasound system (SonoSite 180) for routine use at a university hospital. METHODS: 101 routine ultrasound examinations were performed as bedside examinations on the wards or in the ultrasound centre by three experienced sonographers. The quality and results of examinations using the SonoSite 180 were evaluated in a standardized questionnaire. RESULTS: in 89 % of the ultrasound examinations, results were at least satisfactory. Even though the examiners felt some uncertainty due to the small screen, especially while performing abdominal scans, small lesions which were located far from the scanner were readily identified. CONCLUSION: Routine ultrasound examinations yield satisfactory results when performed with the new, hand-carried ultrasound system. The low size and weight of this ultrasound system and its good image quality makes it a very usefull tool, especially for examinations of patients at intensive care units and on hospital wards.

Equipment Design↗
PubMed1999

[Giant fecaliths in habitual constipation].

HISTORY AND FINDINGS: A 17-year old adolescent with chronic constipation developed fecal incontinence with liquid, fetid stool. He had had variable bowel symptoms since early childhood, but not in his infancy. Since several years he had undergone psychotherapeutic treatment for depression due to a familial conflict situation. Abdominal palpation revealed the presence of a large, hard mass in the lower abdomen, measuring about 20 cm in diameter. INVESTIGATIONS: A defecography verified the presence of a huge obstructing fecalith in the rectum, with massive dilation and elongation of the antecedent rectum and colon (megarectum and megacolon). Neither endoscopy nor radiological imaging revealed a narrow bowel segment. In sequential biopsies, no indication of aberrant innervation was found. The recto-anal inhibitory reflex could be elicited. TREATMENT AND COURSE: Restoration of the rectal passage was achieved by manual disimpaction in numerous sessions, supported by repeated rectal enemas. Subsequently, the patient had normal daily bowel movements for a few days. However, he had to be readmitted three weeks later because again a fecalith had formed, measuring 15 cm in diameter. A few days after discharge the patient hat not followed the exhortation to void ad least once per day. After renewed disimpaction he was referred to a psychosomatic clinic. CONCLUSION: Voluntary withholding of defecation can eventuate massive coprostasis and the development of megacolon and megarectum. In theses instances the major complaint may not be constipation but paradoxical diarrhea. A number of conditions have to be excluded before the diagnosis idiopathic megacolon can be confirmed. Treatment ist difficult and often necessitates prolonged and repetitious interventions.

Adolescent↗
PubMed1994

Cloning and analysis of the Saccharomyces cerevisiae MNN9 and MNN1 genes required for complex glycosylation of secreted proteins.

Proteins secreted by the yeast Saccharomyces cerevisiae are usually modified by the addition at asparagine-linked glycosylation sites of large heterogeneous mannan units that are highly immunogenic. Secreted proteins from mnn1 mnn9 mutant strains, in contrast, have homogeneous Man10GlcNAc2 oligosaccharides that lack the immunogenic alpha 1,3-mannose linkages. We have cloned and sequenced the MNN9 and MNN1 genes, both of which encode proteins with the characteristics of type II membrane proteins. Mnn9p is a membrane-associated protein with unknown function that is required for the addition of the long alpha 1,6-mannose backbone of the complex mannan, whereas Mnn1p is most likely the alpha 1,3-mannosyltransferase located in the Golgi apparatus.

Amino Acid Sequence↗
PubMed1993

Purification and characterization of the Saccharomyces cerevisiae BGL2 gene product, a cell wall endo-beta-1,3-glucanase.

One of the major proteins of the Saccharomyces cerevisiae cell wall, a beta-glucanase (BGL2 gene product), has been isolated and purified to homogeneity under conditions for preserving enzyme activity. The study of enzyme properties of the protein revealed that it is an endo-beta-1,3-glucanase and not an exoglucanase as reported previously (F. Klebl and W. Tanner, J. Bacteriol. 171:6259-6264, 1989). The examination of the glucanase structure showed that the lower apparent molecular mass of the protein (29 kDa) compared with what was calculated from the amino acid sequence of the enzyme (33.5 kDa) is due to anomalous migration in sodium dodecyl sulfate gels and not to posttranslational processing of the polypeptide chain. Of two potential N glycosylation sites at Asn-202 and Asn-284, only the latter site is glycosylated. The overproduction of the beta-glucanase from the high-copy-number plasmid brought about a significant decrease in the growth rate of transformed yeast cells.

Amino Acid Sequence↗
PubMed1990

Molecular cloning and heterologous expression of N-glycosidase F from Flavobacterium meningosepticum.

N-Glycosidase F (peptide-N4-(N-acetyl-beta-glycosaminyl)asparagine amidase; EC 3.5.1.52) catalyzes the cleavage of N-glycosidically linked carbohydrate chains between N-acetylglucosamine and asparagine. The structural gene was isolated by screening a Flavobacterium meningosepticum genomic DNA library in lambda gt10 with oligonucleotides, deduced from partial amino acid sequences of the protein. A clone with an open reading frame of 1062 bases was obtained. The amino acid sequence reveals a 42-residue-long leader peptide, which shows similarities to the endoglycosidase H-leader with respect to the cleavage site of the signal peptide, but is distinct from the ones known from other Gram-positive or -negative bacteria. The molecular weight of the native protein, derived from the DNA sequence, is in agreement with the molecular weight of the purified protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (35,000). Escherichia coli, transformed with a plasmid containing this DNA sequence, expresses N-glycosidase F activity. The enzyme with its natural Flavobacterium promoter and leader peptide is not secreted in E. coli but seems to be associated with cell membranes.

Amidohydrolases↗
PubMed1990

Functional expression of the Chlorella hexose transporter in Schizosaccharomyces pombe.

Schizosaccharomyces pombe cells were transformed with an S. pombe expression vector containing a full-length cDNA of the Chlorella hexose transporter. The transformed cells accumulated 3-O-methylglucose up to 10-fold, whereas wild-type S. pombe and control transformants could only equilibrate this sugar analogue. In a pH-jump experiment, in which extracellular pH was lowered by 1.9 units, the accumulation ratio was increased in transformed cells but not in control cells. This result indicates that the gene product, Chlorella H+/glucose-symporter protein, and a pH gradient suffice for active sugar uptake. Km values for glucose, 6-deoxyglucose, and 3-O-methylglucose of 1.5 x 10(-5) M, 2.7 x 10(-4) M, and 1.0 x 10(-3) M, respectively, were identical in Chlorella and in S. pombe cells transformed with Chlorella cDNA and approximately 100-fold lower than those of the endogenous transport system of S. pombe.

Journal Article↗
PubMed1989

Molecular cloning of a cell wall exo-beta-1,3-glucanase from Saccharomyces cerevisiae.

A major protein of Saccharomyces cerevisiae cell walls is a 29-kilodalton glycoprotein which shows lectinlike binding to beta-1,3-glucan and chitin. It was solubilized by heating isolated cell walls at 90 degrees C and purified to homogeneity by running two high-pressure liquid chromatography columns. With the sequence information of the N terminus and seven peptides, two oligonucleotides were synthesized and the gene was cloned. Its sequence is similar to those of two plant beta-glucanases, and the protein was shown to possess beta-1,3-exoglucanase activity with laminarin as substrate. Haploid yeast cells contained one copy of the gene (BGL2). Gene disruption did not result in a phenotype.

Amino Acid Sequence↗