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Biomedical subjects

C Park

Publications and source records attributed to C Park.

At least 289 records · Page 16Linked to original sources
PubMed1981

Surgical footwear in rheumatoid arthritis--a patient acceptability study.

One hundred patients wih rheumatoid arthritis were questioned about the acceptability of the surgical shoes that they had been prescribed for their foot problems. The approach was made from the records of a surgical supplies manufacturer. While 90 per cent experienced good alleviation of symptoms, 50 per cent had complaints regarding fit, comfort and styling. The implications of changes in the supply of shoes and the staffing of orthotic concerns are discussed, and suggestions are made for the direction of future research.

Adult↗
PubMed1981

Growth of human mammary epithelial cells on collagen gel surfaces.

We have developed a method for sustained growth of human mammary epithelial cells in monolayer cultures. Epithelial organoids derived from solid breast tissues were grown on the surface of thin (approximately 1 mm) collagen gel layers in an enriched growth medium supplemented with hormones, growth factors, fetal calf serum, and horse serum. To transfer the cultures, the collagen layers were dislodged and digested with collagenase. The monolayers of cells released into suspension were then dissociated into single cells using trypsin-ethylene-diaminetetraacetate. Dissociated single cells were repleted with 75 to 95% efficiency onto collagen layers or tissue culture plastic surfaces. The dissociated cells could also be cryopreserved and reactivated with greater than 80% plating efficiency on collagen layers. Normal human mammary epithelial cells grown under these conditions progressed through 12 to 15 population doublings. The population-doubling times for normal and malignant mammary cells on collagen layers were 34 and 65 hr, respectively. After reaching confluence, cells in some cultures, derived from either normal or malignant tissues, penetrated the gel surface and grew into the collagen. Within the gels, the cells became organized into three-dimensional tubular structures. The use of collagen layers eliminates a major problem in growth of human mammary epithelial cells in culture, difficulty in efficient dissociation, and cell transfer from monolayers.

Breast↗
PubMed1979

Pathophysiological studies on hypertension induced in rats by kidney extract and salt.

The renin-angiotensin-aldosterone system, electrolyte and water balance, body fluid, and neurogenic tone and reactivity of the vasculature were studied in hypertension induced in uninephrectomized rats by repeated injection of renin-rich kidney extract and 1% saline drinking. The control rats were injected with physiological saline. Various measurements were made in conscious rats on the 10th day of the treatment. As compared with the control, plasma renin concentration and serum sodium increased significantly, while plasma aldosterone and renal excretory function did not differ. Blood volume (BV) expressed as per body weight increased significantly, but absolute BV, absolute or body weight-related plasma volume and hematocrit were not significantly different. The hypotensive effect of 1-Sar-8-Ile-angiotensin II was negligible 12 hours after the preceding injection of kidney extract. It was small but significant 1 hour after the injection. Increase in water turn-over and fractional sodium excretion occurred during the development of hypertension. Spironolactone did not significantly modify the developmental course. We observed increased depressor response to hexamethonium and increased reactivities to noradrenaline and angiotensin II (A II); these response curves relatively resembled those of spontaneously hypertensive rats. Hypertensive vascular changes were seen in the kidney and heart by histology. Thus, it was suggested that a direct vascular action of A II played a partial role in this hypertensive process while aldosterone played little role. The significance of BV increase and possible contribution of A II's other actions were discussed.

1-Sarcosine-8-Isoleucine Angiotensin II↗
PubMed1975

Zymogram analyses of various organs, glands and tissues from spontaneously hypertensive rats (SHR) and DOCA hypertensive rats.

Esterase and Acid phosphatase isozymes were examined in a number of organs, glands and tissues from Spontaneously Hypertensive Rats (SHR) and kidney and liver from DOCA hypertensive rats at various stages in comparison with those of normotensive rats (CR). In SHR, the abnormalities in the patterns of esterase isozyme were demonstrated in endocrine glands and respiratory tracts as well as in the kidney, liver and digestive tracts throughout the whole life span, and abnormalities in the patterns of acid phosphatase isozyme was also demonstrated in the liver after seven days of age. Moreover, in DOCA hypertensive Rats, minute alterations in esterase isozyme were demonstrated in the kidney and liver after seventh month of the duration of hypertension.

Acid Phosphatase↗
PubMedDate not supplied

Facile macrocyclizations to beta-turn mimics with diverse structural, physical, and conformational properties.

On-resin S(N)Ar reactions were performed to prepare the macrocyclic beta-turn mimics 1a-n (Scheme 1 and Table 1). These reactions occurred more efficiently than completely analogous macrocyclization reactions that do not involve an iodinated aromatic electrophile. The synthesis was also modified to allow introduction of an alkyne via a solid-phase Sonogashira reaction (giving compound 2, Scheme 2) and an aryne via a solid-phase Suzuki reaction (giving compound 3, Scheme 2). Conformational analyses of three illustrative compounds, i.e., 1i, 2, and 3, were performed using a combination of NMR, circular dichroism, and computer-aided molecular simulation methods. Overall, the preferred conformations of all three molecules tended to be type-I-like beta-turns, but for compound 3 interaction of the electron cloud of the aryl substituent with the oxygen lone pairs seems to cause differences in the preferred orientation of the turn frameworks. This study illustrates how iodinated electrophiles can be used in solid-phase S(N)Ar reactions to increase the molecular and conformational diversity in a library.

Alkynes↗
PubMedDate not supplied

A male linkage map of the cattle (Bos taurus) genome.

A male linkage map of the cattle (Bos taurus) genome was constructed using nine large half-sib families. The map consists of 269 loci, of which 249 are microsatellites and 20 are structural genes. Among the 249 microsatellites, 140 are markers selected from other maps and 98 are new assignments. Chromosome assignment were established for 35 new markers by somatic cell hybrid analysis, of which 26 were confirmed by linkage analysis. Genome coverage is 1975 cM contained within terminal markers on all 29 autosomes. The average distance between adjacent loci is 9.7 cM, with 72.1% of the map intervals < or = 15 cM and 4.9% of the intervals > or = 25 cM. The inclusion of mapped markers permitted integration and comparisons with other maps, facilitating the identification of discrepancies in chromosome assignment, gene order, and map distance. The inclusion of Type I and blood group markers in the map was useful for comparative mapping, revealing possible blood group orthologies between humans and cattle. The map generated will serve as a useful tool for comparative mapping, mapping of quantitative trait loci and marker assisted selection.

Animals↗