Search PubMed⌕ Search

Biomedical subjects

B Villiger

Publications and source records attributed to B Villiger.

47 records · Page 3Linked to original sources
PubMed1983

[Fibronectin: an important component of bronchoalveolar defense?].

Fibronectin, an important nonimmune opsonin, was found in the bronchoalveolar lavage fluid (BAL) of 29 healthy volunteers using a sensitive radioimmunoassay. The mean FN content was 9.5 micrograms FN/mg albumin. The BAL FN was immunologically and functionally similar to plasma FN and showed opsonic activity which increased uptake of gelatin coated beads by human alveolar macrophages. Therefore, BAL contains a functionally intact FN which may serve as an opsonin for the clearance of particles and microorganisms in the terminal airways.

Bronchi↗
PubMed1981

Gelatin-binding domain-specific anti-human plasma fibronectin Fab' inhibits fibronectin-mediated gelatin binding but not cell spreading.

Antisera against a Mr = 60,000 peptide containing the gelatin-binding domain of human plasma fibronectin (McDonald, J. A., and Kelley, D. G. (1980) J. Biol. Chem. 255, 8848-8858) bound the Mr = 60,000 peptide and intact fibronectin but not three other fragments released by leukocyte elastase proteinolysis (the Mr = 25,000 amino-terminal sequence, Mr = 140,000 sequence containing cell adhesive activity, and a Mr = 31,000 fragment). Affinity-purified Fab' blocked Mr = 60,000 peptide binding to gelatin and inhibited plasma and cellular fibronectin gelatin binding without affecting fibronectin-mediated cell spreading. In contrast, antifibronectin Fab' absorbed with the gelatin-binding fragment completely blocked fibronectin-mediated cell spreading. These data indicate that the gelatin-binding domain of fibronectin is immunogenic, and antisera against this domain recognize cellular fibronectin gelatin-binding sites. Inhibition of gelatin binding but not cell spreading by anti-gelatin binding domain Fab' confirms the hypothesis that fibronectin has separate sites mediating these activities. Selective inhibition of fibronectin-collagen binding by domain-specific antisera may help elucidate the role of fibronectin in organization of the extracellular matrix.

Animals↗
PubMed1981

Human alveolar macrophage fibronectin: synthesis, secretion, and ultrastructural localization during gelatin-coated latex particle binding.

Human pulmonary alveolar macrophages synthesized and secreted several characteristic high molecular weight proteins for at least 7 d in vitro. Immunoprecipitates of medium and cell lysates from metabolically labeled cultures with specific anti-human plasma fibronectin IgG contained one major labeled polypeptide of molecular weight 440,000 (unreduced) or 220,000 (reduced). An identical polypeptide in conditioned medium from radiolabeled macrophages bound specifically to gelatin-Sepharose, demonstrating that alveolar macrophages synthesized and secreted a molecule immunologically and functionally similar to fibronectin. Fibronectin was the major newly synthesized and secreted polypeptide of freshly harvested alveolar macrophages. Pulse-chase experiments revealed that newly synthesized fibronectin was rapidly secreted into medium, approximately 50 percent appearing by 1 h and 80 percent by 8 h. Immunoperoxidase staining using antifibronectin F(ab')(2)-peroxidase conjugates revealed the majority of immunoreactive fibronectin to be intracellular, localized to endoplasmic reticulum and Golgi apparatus. No extracellular matrix fibronectin was visualized, and cell surface staining was rarely seen, usually appearing only at sites where cells were closely apposed and not at sites of macrophage-substrate attachment. Similar immunostaining of fibroblast cultures revealed cell surface-associated fibrillar fibronectin. Ultrastructural localization of fibronectin during binding and phagocytosis of gelatin-coated and plain latex particles revealed fibronectin only on gelatin-latex beads and at their cell binding sites. Neigher plain latex beads nor their cell membrane binding sites stained for fibronectin. These results demonstrate that fibronectin is a major product of human alveolar macrophages, is rapidly secreted, and is localized at cell membrane binding sites for gelatin-coated particles. In view of the known binding properties of fibronectin, it may serve as an endogenous opsonic factor promoting the binding of staphylococcus, denatured collagen, fibrin, or other macromolecules to macrophages in the lower respiratory tract.

Cell Membrane↗
PubMed1980

[Fiberoptical transbronchial lung biopsy. Results of 25 consecutive cases].

Transbronchial lung biopsy using fiberoptic bronchoscope under fluoroscopic guidance was performed in 25 consecutive patients. 13 patients had diffuse lung disease and 12 exhibited infiltrates or nodules without endobronchial lesions. Satisfactory specimens were obtained in 22 of 25 cases. Diagnosis was accurate in 84% of diffuse and 58% of localized lung disease cases. The over-all diagnostic accuracy was 72%. 11 patients had malignant and 7 patients non-malignant interstitial diseases. In 4 patients with abnormal chest radiographs, normal lung biopsies were obtained. There were no serious complications. The fiberoptic transbronchial biopsy technique can be recommended as a safe and well tolerated method with a good diagnostic yield and a low complication rate. The indication, technique, prophylaxis for complications and problems of interpreting small biopsy specimens are considered.

Biopsy↗
PubMed1977

[Myocardial function and metabolism during local coronary flow reduction].

In 6 open chest dogs, regional myocardial function und metabolic changes (ATP, creatine phosphate, lactate) were studied during coronary flow reduction in LAD by ultrasonic dimension gauges and transmural biopsies. After reduction of the perfusion pressure from 108 to 50 mm Hg the ischemic segment showed a marked dyskinesis: the enddiastolic segment length increased by 7%, and segment shortening and segment stroke work decreased by 22% and 63% respectively. Left ventricular (LV) enddiastolic pressure rose from 5 to 8 mm Hg (p less than 0.05). Heart rate, LV systolic pressure, LV max dP/dt and Vpm did not change significantly.

Adenosine Triphosphate↗
PubMed1976

[Effect of coronary flow reduction on the coronary flow distribution, the myocardial metabolism and left ventricular hemodynamics].

Myocardial blood flow, left ventricular performance, regional myocardial metabolites (ATP, CrP, lactate) and a-v differences of oxygen, lactate and pyruvate were determined in 6 open chest dogs with cannulated left coronary artery. A mean flow reduction from 92 to 43 ml/min/100 g heart weight resulted in marked heart failure accompanied by extensive flow reduction to the endocard with nearly 10 fold increase of lactate and a decrease of CrP content to 50% of control. In contrast, flow and metabolic parameters of the epicardial part changed only slightly. Furthermore, the DPTI/SPTI-ratio showed a good correlation with the subendocardial CrP content (r = 0.93, p less than 0.01).

Adenosine Triphosphate↗