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Biomedical subjects

R Fine

Publications and source records attributed to R Fine.

At least 55 records · Page 3Linked to original sources
PubMed1984

Elastolytic activity of peripheral blood monocytes.

Human peripheral blood monocytes have been purified by Ficoll-Hypaque density gradient centrifugation and adherence to plastic dishes, and assayed for elastolytic activity using insoluble [3H]elastin. Approximately 5-10 micrograms of elastin are solubilized at pH 7.5 per mg protein per h. The specific activity in monocytes varies between 3 and 15% of that of neutrophils obtained at the same time from the same subjects. The enzymatic activity derives principally from monocytes. Lymphocytes purified by Sephadex G-10 gel filtration chromatography exhibit only trace elastolytic activity, while neutrophils comprise 1% or less of the cell population. Monocyte elastolytic activity is inhibited by alpha-1-antitrypsin and Succinyl-Ala-Ala-Pro-Val-chloromethylketone indicating that it is a serine-type protease. When extracts of monocytes are analyzed by gel filtration, the elastolytic activity appears in large molecular weight forms; however, these forms are not observed when extracts of monocyte lysosomes are analyzed. Such variation in forms is also seen with neutrophil extracts. Monocytes are a source of elastolytic activity for various physiologic and pathologic actions in the lung and other organs.

Cell Fractionation↗
PubMed1982

The effect of theophylline on macrophage elastase secretion.

Theophylline increased the elastolytic activity in conditioned media from murine peritoneal macrophages maintained in a monolayer system. Continuing accumulation of enzyme activity with time required the continuing presence of the drug. Theophylline was active in the presence of a maximally stimulatory concentration of colchicine, a known enhancer of elastase secretion. The effect of theophylline was not due to interference with any elastase inhibitory activity in macrophage conditioned medium. The elastolytic activity from theophylline-stimulated cells exhibited an inhibitor profile similar to the profiles of colchicine-stimulated and unstimulated cells. The results demonstrate that theophylline regulates the amount of extracellular elastolytic activity from murine peritoneal macrophages differently from granulocytic elastase.

Animals↗
PubMed1981

The enzymatic digestion of elastin at acidic pH.

The enzymatic degradation of insoluble elastin has been studied at several pH values using purified pepsin and cathepsin D, and neutrophil extracts. Pepsin degraded elastin throughout the pH range of 1.2-4.0 with the optimum pH below 2.0. Molecular sieve chromatography and gel electrophoresis indicated that a spectrum of molecular weight degradation products was produced. The degradation by pepsin was inhibited by sodium dodecyl sulfate (SDS), NaCl and pepstatin. Cathepsin D, which, like pepsin, degrades hemoglobin at acid pH and is inhibited by pepstatin, had no activity against insoluble elastin in the pH range of 3.2-7.2. Extracts of neutrophils degraded elastin above pH 4.0. The pH profile of elastin degradation by neutrophil extracts generally followed that of purified human leukocyte elastase. Our results suggest that during alimentation or pulmonary aspiration of gastric contents, extracellular elastin may be digested by gastric juice at acid pH. Inflammatory cells would not appear to be capable of contributing to such actions until local pH approaches neutrality. Cathepsin D, a major constituent of inflammatory cells, does not digest all types of connective tissue proteins.

Anilides↗
PubMed1981

Effects of C5a on baboon alveolar macrophage migration.

The effect of C5a, a fragment of the fifth complement component, on alveolar macrophage migration was studied using a micropore method. Cells were obtained by broncho-pulmonary lavage, in vivo or in vitro, from control baboons and baboons taught to smoke cigarettes. Macrophage migration directly depended on the C5a concentration cells encountered. The highest C5a concentrations studied enhanced migration more than 20-fold. Cells from smokers exhibited greater migration than those from nonsmokers, and cells recovered in vivo exhibited greater migration than in vitro cells, but these differences were not significant. A gradient analysis suggested that C5a-induced migration was chemotactic, i.e., oriented; C5a enhanced migration more than N-formyl-methionyl-phenylalanine, and C5a without the C-terminal arginine lost over two thirds of its capacity to enhance migration. The observation that C5a induces alveolar macrophage chemotaxis established that alveolar macrophages are similar to other mononuclear phagocytes with respect to C5a-enhanced migratory responses, and demonstrated that complement components may participate in lung inflammatory reactions through effects on cells other than neutrophils.

Animals↗
PubMed1979

Lung elasticity in regional and diffuse pulmonary fibrosis.

Static deflation air and saline pressure-volume (PV) curves were performed on five normal excised baboon lungs, four with radiation-induced upper lobe fibrosis, and two with diffuse bleomycin-induced fibrosis. Curves were compared visually and using half-inflation pressures (h). When plotted as percent of observed vital capacity vs. transpulmonary pressure, the radiation-associated curves were similar in shape to control curves. Also, h values were not significantly different between the two groups. The bleomycin-associated curves, however, were shifted rightward and exhibited increased h values. PV curves were correlated with connective tissue data. Elastin concentration was increased in the irradiated upper lobes through loss of associated constituents. Elastin accumulated in the lower lobes of the irradiated animals through compensatory growth and in the bleomycin-associated lungs through excessive production. Collagen followed a similar but less dramatic trend. We conclude connective tissue accumulation may not lead to rightward shifted PV curves if accumulation is present in relatively noninflatable lung units, or as part of compensatory lung growth.

Animals↗
PubMed1978

Monocyte cellular function in asthmatic patients on alternate-day steroid therapy.

Monocyte cellular function in 15 asthmatics on alternate-day steroid therapy (mean dose of prednisone, 45.4 +/- 17.45 mg qod) was studied at 8 A.M. and noon after receiving an 8 A.M. steroid dose and at 8 A.M. the following day, and was contrasted to function in 16 healthy controls. Monocyte chemotaxis, bacterial killing and phagocytosis, and oil phagocytosis were not significantly altered by the steroid dose. On the other hand, all the patients experienced monocytopenia, lymphopenia, and neutrophilia 4 hr following the administration of steroid. The lack of functional impairment on this clinically relevant steroid regimen is consistent with the lack of serious infections seen in patients on such regimens. This study re-enforces the need to differentiate the effect of even small doses of steroid on circulating cell populations from direct effects on cell function which occur only with very high or frequent steroid dose regimens.

Asthma↗
PubMed1977

Acoustic neuroma causing subarachnoid haemorrhage.

The case reported in this paper appears to be the first example of spontaneous subarachnoid haemorrhage complicating an acoustic tumour. The only comparable case is one of a pontocerebellar angle tumour, but its histological nature is unstated. The excellent response to surgical management has been gratifying, and the patient has remained well over an extended period of surveillance.

Adult↗
PubMed1977

Effect of increased static lung recoil on ventilation distribution in excised human lungs.

The contour of a modified Fowler single-breath nitrogen washout was determined in 15 postmortem human lungs before and after static lung recoil had been increased by ventilation. Before ventilation, expiratory nitrogen versus volume curves exhibited the 4 phases similar to those seen in intact human lungs. The tests were repeated after ventilation with humidified air at room temperature for 3 hours at pleural pressures between -20 and +10 cm H2O at 15 breaths per min. After ventilation, the slope of the alveolar plateau (Phase III) decreased (P less than 0.01); the volume of Phase IV increased (P less than 0.01); and the closing capacity (Phase IV plus minimal volume) decreased (P less than 0.01). The data suggest that in the human lung the onset of Phase IV is not solely dependent on a pleural pressure gradient and that after ventilation, when static lung recoil is increased, the distribution of inspired gas in the excised human lung is more uniform, and at least some lung units empty more completely before zero transpulmonary pressure is reached.

Adult↗
PubMed1976

Successful renal allografts across a positive cross-match for donor B-lymphocyte alloantigens.

Seven patients received a renal allograft with negative standard and T-lymphocyte microlymphocytotoxicity cross-matches, but a positive B-lymphocyte cross-match using donor lymphocytes. In spite of this presensitisation, none underwent hyperacute rejection and all are functioning from one and a half to six months after transplantation. This procedure may help in the detection of false-positive cross-matches and possibly in detection of enhancing antibodies against a specific donor.

B-Lymphocytes↗