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Biomedical subjects

S Chu

Publications and source records attributed to S Chu.

At least 163 records · Page 9Linked to original sources
PubMed1987

A light and electron microscopic evaluation of Zyderm collagen and Zyplast implants in aging human facial skin. A pilot study.

Four patients received Zyderm collagen implant (ZCI) or Zyplast implant (ZI) in preauricular and infraauricular regions of facial skin periodically between one and nine months. Both materials were identified microscopically in the mid- to deep dermis at all points of the study and, in 60% to 70% of the injected sites, some material was also present subdermally. A slow, gradual colonization of ZCI by fibroblasts was noted compared with a delayed intense interaction of these cells with ZI. Also, there was some new collagen deposition associated with remodeling of the ZI, while no demonstrable synthetic activity occurred in relationship to ZCI. The results suggest that ZCI and ZI "migrate" deeper and eventually move into the subcutaneous plane. This movement could explain the loss of correction at six to nine months that is noted when this implant is used for age-related changes.

Aging↗
PubMed1984

Characteristics of adipose tissue growth in broiler-type chickens to 22 weeks of age and the effects of dietary protein and lipid.

Female broiler-type chickens were fed diets containing different concentrations of protein and fat in two experiments. The first experiment was for 4 weeks. The mean weights of the abdominal fat pads were inversely related to dietary concentrations of protein between 20 and 35%. Adipocyte size and cellularity of the fat pads were lower with 30 than 20% protein. Fat deposition in the abdominal pad was increased in 3-week-old chicks by isocaloric substitution of oil for starch in the diets. At 4 weeks of age the effect of oil was not significant with 30 or 20% dietary protein (no measurements were made in chicks fed 35 or 25% protein). In Experiment 2, the development of the abdominal fat pad in birds fed 18 to 33% protein was monitored for 22 weeks. By 7 weeks the distribution of adipocyte size was bimodal. The initial adipocyte population showed comparatively little increase in numbers after 12 weeks, but cell size continued to increase. The numbers of adippcytes in the second population of adipocytes was still increasing rapidly at 22 weeks, although the size of the cells in this population remained small. At 22 weeks the small cells constituted 62% of the total adipocyte population but contained only 2.4% of the lipid in the fat pad. Adipocyte cell size was significantly affected by dietary protein and energy until 9 weeks of age, but the effects subsequently declined.

Abdomen↗
PubMed1983

The dynamics of ingested methyl mercury in growing and laying chickens.

Growing and laying chickens were fed practical-type diets containing 0, .05, .15, .45, and 1.35 ppm of mercury as methyl mercuric chloride. Chicks that had been fed mercury throughout life retained 61, 82, 91, and 95% of the mercury ingested from the respective diets at 8 weeks of age. The half-retention times of mercury, following withdrawal of dietary mercury after the 8-week period, were 8.4 and 23.4 days, respectively, for liver and kidney in chicks fed 1.35 ppm of mercury. Half-retention times in kidney and liver decreased with lower mercury intake, i.e., with lower concentrations in the tissues at the time of mercury withdrawal. Adult laying birds, continuously fed diets containing methyl mercuric chloride, laid eggs with gradually increasing concentrations of mercury until plateau concentrations reflecting the respective dietary concentrations were reached. Upon withdrawal of mercury from the diet, mercury concentrations in the eggs laid by the birds fed .05, .15, .45 and 1.35 ppm declined to reach half of the concentrations at the time of withdrawal in 17, 13, 10, and 9 days, respectively. Likewise, the half-retention time of mercury in the liver, kidney, heart muscle, pectoral muscle, and brain tissue of the adult birds depended upon the tissue concentration at the time mercury was withdrawn from the diet and was inversely proportional to initial tissue concentration according to the equation: 1n y = 1.92 - .39 1n (7 x-5), where x is the initial tissue concentration in ppm and y is half-retention time in weeks, r = -.95.

Animals↗
PubMed1977

Estimation of the state of saturation of brushite and calcium oxalate in urine: a comparison of three methods.

The estimation of the degree of saturation of brushite and of calcium oxalate in urine of patients with disorders of calcium metabolism has been proved to be an effective tool in evaluating the patient's propensity to form renal stones. The methods used in three different laboratories have been compared and evaluated in 27 urine samples. Relative saturation ratio (ratio of activity product and thermodynamic solubility product of brushite) and activity product ratio (ratio of activity product of original sample and that obtained after incubation of sample with synthetic brushite) were determined. Similar studies were performed for calcium oxalate. The values for relative saturation ratio of brushite or calcium oxalate differed widely among the three techniques. However, nearly identical values for activity product ratio of brushite were obtained. The activity product ratios of calcium oxalate, obtained by different techniques, closely approximated each other except in sampels containing excessive amounts of calcium (greater than 5 mM) or oxalate (greater than 5 mM). The values for the relative saturation ratios for both brushite and calcium oxalate were usually higher than the corresponding values for activity product ratio. The results indicate that the use of activity product ratio provides a more simple and reliable estimate of the urinary state of saturation than does the relative saturation ratio.

Ammonia↗