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H V Jones

Publications and source records attributed to H V Jones.

9 recordsLinked to original sources
PubMed1994

Apolipoprotein E expression in aortic smooth muscle cells: the effect of beta VLDL.

The expression of apolipoprotein E in cultured neonatal rabbit aortic smooth muscle cells was examined. Northern blot analysis determined that there was a single RNA transcript of approximately 1.2 kb. Moreover, a polyclonal antibody against rabbit apolipoprotein E was prepared in a goat and used in immunoprecipitations to demonstrate that the cultured cells secreted apolipoprotein E into the media. A double band typical of apolipoprotein E migrated at apparent molecular masses of 37 and 39 kDa. Analysis of steady-state levels of apolipoprotein E mRNA demonstrated that expression increased as cell seeding density increased. When examined as a function of time in culture, there were two peaks of expression evident 1 day and 8 days after seeding. The addition of beta VLDL (beta-very low density lipoprotein) to smooth muscle cells increased both [3H]thymidine incorporation into DNA as well as cell number and these increases were accompanied by a decrease in the levels of apolipoprotein E mRNA in cells treated with the lipoprotein for 1 and 7 days. After incubation of the cultures with beta VLDL for 1 week, the cells were radiolabeled with [35S]methionine and the media was subjected to immunoprecipitation with anti-apolipoprotein E. The data revealed that the amount of apolipoprotein E secreted into the media decreased in the presence of beta VLDL. In summary, these results show that apolipoprotein E expression in aortic smooth muscle cells is regulated by cell density, time in culture, cell proliferative state, and beta VLDL addition. These observations may have relevance to the conditions that are known to accompany the development of the atherosclerotic lesion.

Animals↗
PubMed1992

Long-term treatment of neonatal aortic smooth muscle cells with beta VLDL induces cholesterol accumulation.

A model for smooth muscle derived foam cells was developed by treating smooth muscle cells isolated from the aortae of neonatal rabbits with beta VLDL for up to 1 month. Hyperlipidemic beta VLDL isolated from cholesterol fed rabbits induced proliferation of the cells that were maintained in lipid deficient serum. In addition, the lipoprotein fraction stimulated [14C]oleic acid incorporation into [14C]cholesteryl ester, even in cultures that had been chronically exposed to the lipoprotein. The accumulation of cholesterol was evaluated and small amounts of cholesteryl ester were demonstrated in cultures treated for 3 days with beta VLDL. However, continued exposure to the lipoprotein resulted in larger elevations in total cholesterol, approximately 65% of which was in the esterified form in cultures treated with 100 micrograms beta VLDL/ml for 24 days. When cholesterol levels were examined as a function of time, it was determined that both total cholesterol and cholesteryl ester levels increased. Approximately 2-3 weeks after lipoprotein was introduced to the culture, maximum levels were attained. Triglyceride levels were also measured and found to increase more than two-fold in cultures that had been incubated in the presence of beta VLDL for 24 days, when compared to cultures incubated in its absence. Examination of the cultures by electron microscopy revealed intracytoplasmic lipid droplets in beta VLDL treated cells. These results suggest that beta VLDL treatment of neonatal aortic smooth muscle cells provides an ideal model in which to study the lipid laden smooth muscle cells that characterize the atherosclerotic plaque.

Animals↗
PubMed1991

The effect of beta-aminopropionitrile on elastin gene expression in smooth muscle cell cultures.

When beta-aminopropionitrile (BAPN) is added to neonatal rat aortic smooth muscle cell cultures there is a decrease in insoluble elastin accumulation with a concomitant increase in tropoelastin and tropoelastin fragments in the culture medium. The experiments described here examine the biological significance of this fragmentation. BAPN, as well as purified tropoelastin fragments isolated from spent medium of cells grown in the presence of BAPN, were added to cultures. A decrease in elastin mRNA was observed in cultures grown in the presence of BAPN and also in those cultures to which the purified tropoelastin moieties were added. These studies indicate that the inhibition of lysyl oxidase by BAPN prevents elastin crosslinking which results in an increase in tropoelastin moieties, thus leading to a down regulation of the steady state levels of elastin mRNA.

Aminopropionitrile↗
PubMed1991

A controlled precursor add-back model of elastogenesis in smooth muscle cell cultures.

Neonatal rat aortic smooth muscle cell cultures are capable of synthesizing and accumulating relatively large amounts of insoluble elastin in the extracellular matrix. There are two major soluble elastin molecules in these cultures, one of 77 kDa (protropoelastin) and the other of 71 kDa (tropoelastin). We examined the ability of the cell culture system to insolubilize exogenously added soluble elastin precursor moieties into the elastin matrix. To accomplish this, cultures were allowed to develop an enriched elastic fiber matrix for approximately two weeks in first passage. This accumulated matrix then served as the "substrate" for the exogenously added precursor elastin molecules. Culture-derived radioactive soluble elastin was added to the "substrate" cultures and the presence of radioactivity in the insoluble elastin as well as in the lysine-derived crosslinks unique to elastin (desmosines) was measured. When purified [3H]-valine radiolabeled protropoelastin was used, more than 15% of the radioactivity added was detected in the alkali-resistant insoluble elastin within 24 hours. After an initial 4-hour incubation of the cells with [3H]-lysine-labelled soluble elastin, most of the radioactivity in the insoluble elastin was associated with the lysine and only a negligible amount was detected in the desmosines. However, during a 16-day chase period, the ratio of radioactive desmosines to lysine increased dramatically, suggesting that not only insolubilization, but crosslinking occurs as well. The add-back system described herein should provide a means to probe the molecular properties of protropoelastin and increase our understanding of the mechanisms of elastic fiber formation.

Animals↗
PubMed1974

Preoperation anxiety: a qualitative analysis.

Twenty-eight patients were investigated psychologically before surgery. The purposes of the study were (1) to discover the nature of preoperative anxiety, and (2) to compare direct questioning with an indirect method. The merits and shortcomings of the two types of assessment emerged. The findings suggest that, in addition to worries about the operation and the anaesthetic, there was concern about leaving the home and family, which was accentuated by lack of communication and contact with hospital staff, including the surgical team. Pain was found to have a variety of implications including loneliness. These and other findings are discussed in relation to psychological theories.

Anesthesia↗