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Biomedical subjects

S Matern

Publications and source records attributed to S Matern.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Heterophile antibodies, lack of communication and the diagnostic dilemma].

BACKGROUND: Heterophilic antibodies represent a great danger to clinical care by producing false-positive values for certain markers. Too large confidence in specificity of laboratory markers together with lack of communication between clinicians and clinical chemists may lead to unnecessary interventional diagnostic and therapeutic procedures. The prevalence of heterophilic antibodies is probably much higher than assumed up till now and several markers can be affected. AIM: In this review for clinicians, we explain formation of heterophilic antibodies, mechanisms of interference and present clinical data about affected markers and "side effects" from the literature. Furthermore we discuss possible alternatives and measures against this phenomenon. We consider broad awareness of this problem among clinicians the most important action to avoid further harm to patients.

Antibodies, Heterophile↗
PubMed2001

Molecular cloning and expression of human bile acid beta-glucosidase.

A novel microsomal beta-glucosidase was recently purified and characterized from human liver that catalyzes the hydrolysis of bile acid 3-O-glucosides as endogenous compounds. The primary structure of this bile acid beta-glucosidase was deduced by cDNA cloning on the basis of the amino acid sequences of peptides obtained from the purified enzyme by proteinase digestion. The isolated cDNA comprises 3639 base pairs containing 524 nucleotides of 5'-untranslated and 334 nucleotides of 3'-untranslated sequences including the poly(A) tail. The open reading frame predicts a 927-amino acid protein with a calculated M(r) of 104,648 containing one putative transmembrane domain. Data base searches revealed no homology with any known glycosyl hydrolase or other functionally identified protein. The cDNA sequence was found with significant identity in the human chromosome 9 clone RP11-112J3 of the human genome project. The recombinant enzyme was expressed in a tagged form in COS-7 cells where it displayed bile acid beta-glucosidase activity. Northern blot analysis of various human tissues revealed high levels of expression of the bile acid beta-glucosidase mRNA (3.6-kilobase message) in brain, heart, skeletal muscle, kidney, and placenta and lower levels of expression in the liver and other organs.

Amino Acid Sequence↗
PubMed2001

[Benign metastasizing leiomyoma of the lung--a rare differential diagnosis of pulmonary space-occupying lesions].

HISTORY AND ADMISSION FINDINGS: A 45-year-old woman was refferred for diagnosis of an accidentally found symptomless space-occupying lesions in the central part of the right lung. She had undergone a hysterectomy 4 years before and reported smoking 15 cigarettes daily since the age of 17 years. Physical examination was normal. INVESTIGATIONS: As primary bronchial carcinoma or metastasis to the lung was suspected she underwent a series of diagnostic tests: sonography, computed tomography (CT), gastroscopy, coloscopy, bronchoscopy, skeletal scintigraphy, gynaecological examination and various laboratory tests, none of which indicated a primary extrapulmonary tumour. CT-guided fine-needle biopsy then suggested benign metastasizing pulmonary leiomyoma (BMPL). TREATMENT AND COURSE: The largest of the tumours were surgically removed, confirming BMPL. Hormone receptors (for oestrogen, progesterone) having been demonstrated, progesterone treatment was initiated as prophylaxis against recurrences. CT 6 months later revealed new intrapulmonary foci. Administration of luteinizing hormone-releasing hormone analog to stop completely any oestrogen effect, and CT of the thorax 6 months later showed that both tumour numbers and their size had been reduced. The patient remained asymptomatic and the findings had not changed in the subsequent 12 months. CONCLUSION: BMPL is a rare cause of a space-occupying pulmonary lesion, predominantly affecting middle-aged women after hysterectomy for uterine myoma. The pathogenesis remains unclear, hormone-dependent tumour growth being discussed as a possible mechanism. Anti-oestrogen administration is the treatment of choice to achieve remission and effective prevention of recurrences.

Biopsy↗
PubMed2001

Metabolism and effects on cholestasis of isoursodeoxycholic and ursodeoxycholic acids in bile duct ligated rats.

Isoursodeoxycholic acid (isoUDCA), the 3 beta-epimer of ursodeoxycholic acid (UDCA), may have pharmaceutical potential because of its similar hydrophilicity and in vitro cytoprotection as compared with UDCA. We compared metabolism and effects on cholestasis of UDCA and isoUDCA in experimental cholestasis in rats. Cholestasis was induced by bile duct ligation. For bile flow and biliary bile acid analysis, UDCA or isoUDCA were infused intraduodenally. For the study of chronic effects, chow was supplemented with 2.5 g/kg UDCA or isoUDCA for 3 weeks. Sham-operated animals served as controls. IsoUDCA became completely converted to UDCA in the liver. Choleresis and biliary bile acids were the same after the intraduodenal administration of either compound. Oral administration of UDCA or isoUDCA significantly improved liver biochemistry but not clinical and histological parameters in chronic cholestasis. The decrease of serum cholic acid in control animals was more pronounced after isoUDCA (-93%) than after UDCA (-76%). Only after UDCA, this decrease was compensated by increases of UDCA, beta-muricholic acid (MCA), and Delta(22)-beta-MCA. Our results show that isoUDCA has the same effect on choleresis and liver biochemistry as UDCA. IsoUDCA features pro-drug characteristics of UDCA and causes compared to the latter lower serum bile acid concentrations in non-cholestatic animals.

Animals↗
PubMed2001

[Solitary fibrous thoracic wall tumor. Progression with percutaneous radiotherapy].

HISTORY AND CLINICAL FINDINGS: A 81-year-old patient free of pain was referred to the university hospital for further evaluation and therapy of tumour masses in the right thorax. Clinical examination revealed dullness to percussion and reduced breathing in the right lower lung. INVESTIGATIONS: Computed tomography showed an enlarged solid tumour mass attached to the thoracic cavity and pleural effusion on the right side. Quantification of pulmonary perfusion presented significant defects in the right upper and middle lobe. DIAGNOSIS, TREATMENT AND COURSE: The pulmonary masses were biopsied under CT-guidance. Biopsy and immunohistochemical findings proved a malignant solitary fibrous tumour of the chest wall, a mesenchymal tumour of its own entity. Because of pain in the right arm and because of missing other reliable therapeutic options a palliative irradiation was performed. The tumour did increase in size due to radiotherapy and a severe right ventricular heart failure occurred. The patient died 5 months after diagnosis has been made. Autopsy revealed a transition of tumour cells to sarcomatic growth. CONCLUSION: In our case we conclude an accelerated progression of the solitary fibrous chest wall tumour in the course of irradiation. Whether the development of sarcomatic growth occurred as a result of radiotherapy remains speculative.

Aged↗
PubMed2001

[Matrix metalloproteinases: Promoters of tumor invasion and metastasis - A review with focus on gastrointestinal tumors].

Degradation of basement membrane and extracellular matrix is crucial for invasion and metastasis of tumor cells. Proteolysis occurs via matrix metalloproteinases and is tightly controlled by specific endogenous proteinase inhibitors. This review will summarize the current view on the role of matrix metalloproteinases in tumor growth, invasion and metastasis and focus on the importance of matrix metalloproteinases in gastrointestinal cancer.

Animals↗
PubMed2001

Cholesterol crystal binding of biliary immunoglobulin A: visualization by fluorescence light microscopy.

AIM: To assess potential contributions of biliary IgA for crystal agglomeration into gallstones, we visualized cholesterol crystal binding of biliary IgA. METHODS: Crystal binding biliary proteins were extracted from human gallbladder bile using lectin affinity chromatography.Biliary IgA was isolated from the bound protein fraction by immunoaffinity chromatography. Pure cholesterol monohydrate crystals were incubated with biliary IgA and fluoresceine isothiocyanate (FITC)conjugated anti IgA at 37 degree. Samples were examined under polarizing and fluorescence light microscopy with digital image processing. RESULTS: Binding of biliary IgA to cholesterol monohydrate crystals could be visualized with FITC conjugated anti IgA antibodies. Peak fluorescence occurred at crystal edges and dislocations. Controls without biliary IgA or with biliary IgG showed no significant fluorescence. CONCLUSION: Fluorescence light microscopy provided evidence for cholesterol crystal binding of biliary IgA. Cholesterol crystal binding proteins like IgA might be important mediators of crystal agglomeration and growth of cholesterol gallstones by modifying the evolving crystal structures in vivo.

Bile↗
PubMed2001

Isoursodeoxycholic acid: metabolism and therapeutic effects in primary biliary cirrhosis.

Significant amounts of ursodeoxycholic acid (UDCA) used for the treatment of patients with primary biliary cirrhosis (PBC) become epimerized at C-3 to isoUDCA. We investigated the metabolism of isoUDCA and a possible pharmacologic effect in five patients (51.4 +/- 5.8 years old; 3 females, 2 males) with PBC and persistent elevations of gamma-glutamyl transpeptidase (gamma-GT) and alkaline phosphatase despite treatment with UDCA for more than one year. Serum samples were analyzed for bile acid metabolites and surrogate markers of cholestasis in 4-week intervals after 1 g/d UDCA, wash-out, 0.5 g/d isoUDCA, 0.75 g/d isoUDCA, 0.75 g/d UDCA, and two further periods with 1 g/d UDCA. Bile acids in urine were analyzed after wash-out, 0.5 and 0.75 g/d isoUDCA, and 0.75 and 1 g/d UDCA. During wash-out, AST, AP, and gamma-GT rose significantly (P < 0.05) but reversed to previous levels during the first isoUDCA period, with 0.5 g/d only. No further improvements were observed after increasing the dose of isoUDCA or switching back to UDCA. In serum, the relative amounts of isoUDCA and UDCA were 8.1 +/- 7.4% and 16.2 +/- 6.4% during 0.5 g/d isoUDCA, 6.2 +/- 2.5% and 45.0 +/- 4.1% during 0.75 g/d isoUDCA, and 0.5;-3% and 56.4;-60.0%, respectively, during UDCA. In urine, UDCA was the predominant bile acid both during isoUDCA and UDCA medications. The similar serum enrichment and urinary excretion of UDCA during administration of either isoUDCA or UDCA together with low concentrations of the intermediate of isomerization, 3-dehydro-UDCA, indicate a first-pass epimerization of isoUDCA to UDCA in the liver. Approximately 25% of serum isoUDCA and 10% of serum UDCA were conjugated with either glucuronic acid or N-acetylglucosamine, indicating hepatic formation and systemic secretion of glycosidic conjugates. In PBC patients, isoUDCA becomes isomerized to UDCA and has similar effects on surrogate markers of cholestasis. Thus, isoUDCA has pro-drug characteristics.

Bile Acids and Salts↗