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Biomedical subjects

M C Sutcliffe

Publications and source records attributed to M C Sutcliffe.

7 recordsLinked to original sources
PubMed1992

Comparison of elastin peptide concentrations in body fluids from healthy volunteers, smokers, and patients with chronic obstructive pulmonary disease.

Proteolysis of elastic fibers is central to the development of emphysema, and a simple, noninvasive assay of elastin degradation would be useful in diagnosis and in therapeutic monitoring. We have adapted an indirect enzyme-linked immunosorbent assay (ELISA) to determine plasma, urine, and bronchoalveolar lavage fluid (BALF) elastin peptide concentrations in nonsmokers, healthy smokers, and patients with chronic obstructive pulmonary disease (COPD). Plasma elastin peptide concentrations were significantly higher in subjects with COPD (66.8 +/- 5.8 ng/ml, n = 10) compared with nonsmokers (23.4 +/- 4.6 ng/ml, n = 12), and healthy smokers had intermediate values (36.0 +/- 6.8, n = 6), p less than 0.05. Urine values (both unadjusted and normalized to urine creatinine concentration) were approximately 10-fold higher than plasma in all subject groups, and the relative differences among groups were the same as for plasma with values of 910.8 +/- 105.6, 358.1 +/- 101.2, and 281.0 +/- 67.8 ng/ml for subjects with COPD (n = 10), healthy smokers (n = 6), and healthy nonsmokers (n = 12), respectively. Poor recovery of BALF in COPD subjects reduced differences in the BALF elastin peptide concentrations among subjects groups, although the healthy smokers and COPD subjects tended to have higher amounts. Assuming some dilution due to lavage technique, elastin peptide concentrations were estimated to be substantially higher in epithelial lining fluid than in plasma, suggesting lung as a significant source of elastin peptides in COPD. This is the first application of elastin peptide measurement to human urine or BALF, and we conclude that this assay in urine is useful in characterizing elastin turnover in patients with or at risk for emphysema.

Adult↗
PubMed1990

Effect of static stretching on elastin production by porcine aortic smooth muscle cells.

An in vitro model was developed to assay the effects of static stretching on soluble elastin (tropoelastin, TE) synthesis by porcine aorta smooth muscle cells (SMC). Culture dishes containing SMC adherent to the deformable bottoms were placed over hard convex templates. Stress was applied by placing a weight on the dish covers. Measurement of TE was accomplished by a specific ELISA assay. With this model we demonstrated reproducible stimulation of TE synthesis by stretched SMC. Significant results (161.4% of control; p = less than 0.003 by Student's t-test) were obtained by stretching passage 2 SMC for 3 days with a medium change after the first 18-24 hours, use of 5% newborn calf serum in cultures during stretching, and 50-g weight. DNA content in stretched cultures did not increase over control values. Thus, stretching alone did not cause hyperplasia or hyperploidy in these SMC and, in the absence of other vascular cell elements, was sufficient to increase production of this extracellular matrix protein. Transduction of mechanical force into elastin gene expression by SMC may contribute to the development of thickened arterial tunica media characteristic of hypertensive vessels.

Animals↗
PubMed1980

Transferrin-dependent growth inhibition of yeast-phase Histoplasma capsulatum by human serum and lymph.

Nonspecific host defense mechanisms that may limit growth of yeast-phase Histoplasma capsulatum in vivo were examined using an in vitro system of cell-free liquid culture. Native human transferrin in serum and lymph, or purified transferrin added to serum-free medium, inhibited yeast replication 10- to 50-fold. Supplementation of serum with iron to complete or almost complete saturation of total iron-binding capacity neutralized inhibition. Substitution of Zn++, Mn++, or Cu++ for Fe++ did not affect inhibition. Neither complement nor antibody was a relevant factor. Results of culture in medium with unsaturated transferrin followed by replenishment with iron indicated that iron deprivation was either fungistatic or fungicidal, depending on the yeast strain and, in serum-free medium, on the iron content of transferrin. Transferrin-dependent fungistasis was associated with morphologic alteration of yeasts as determined by electron microscopy. Thus, susceptibility of yeast-phase H. capsulatum to iron starvation by unsaturated transferrin may contribute to their low virulence in vivo.

Antifungal Agents↗
PubMed1974

The effect of 3',5'-adenosine monophosphate on granulocyte adhesion.

Human granulocyte adhesion to glass capillary tubes was tested in the presence of agents that increase intracellular levels of cyclic 3',5'-adenosine monophosphate (cAMP). Adhesion was significantly reduced by 10(-3)-10(-4) M dibutyryl cAMP, 10(-4)-10(-6) M prostaglandin E(1) (PGE(1)), 10(-4)-10(-6) M histamine, or 10(-3) M theophylline. Adhesion was not suppressed by 10(-4) M theophylline unless it was combined with PGE(1) or histamine. Eosinophil and basophil adhesion was especially sensitive to suppression by the above agents. These findings suggest that intracellular cAMP may play a role in regulation of adhesiveness of human basophils, eosinophils, and neutrophils.

Basophils↗