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Biomedical subjects

S C Smith

Publications and source records attributed to S C Smith.

At least 253 records · Page 14Linked to original sources
PubMed1982

Impact of influenza A in a nursing home.

Outbreaks of influenza A in the institutionalized elderly have been reported only rarely. Such an outbreak occurred in a nursing home in the period Dec 12, 1980, through Jan 21, 1981. Thirty (25%) of the 120 residents had onset of influenza-like illness during the outbreak. Influenza A/Bangkok/79-like (H3N2) virus was isolated from throat swab specimens from five of eight acutely ill patients. Thirteen persons were hospitalized; nine persons died (case-fatality ratio, 30%). This outbreak documents that mortality associated with an influenza outbreak can be substantial in a closed population of the elderly. Because nursing home residents are an easily accessible high-risk population, control and prevention of influenza should be a high priority in nursing homes.

Acute Disease↗
PubMed1982

Effects of oral contraception on liver function tests and serum proteins in women with past viral hepatitis.

Forty-three women who had viral hepatitis one or more years ago and 35 healthy women who were age and parity matched were given an oral contraceptive containing 0.05mg ethinyl estradiol and 0.5mg levonorgestrel for six consecutive months. Liver function tests (serum bilirubin, SGOT, SGPT and serum alkaline phosphatase) and serum proteins (total, albumin, globulins, ceruloplasmin, haptoglobin and alpha-1 antitrypsin) were measured before beginning treatment and after three and six months of use. Past hepatitis women experienced increased unconjugated bilirubin, SGOT, SGPT and alkaline phosphatase levels throughout the six months while the control women showed less pronounced changes during the first three months with tendency to reversion to normal during the subsequent three months; the group X time of test interactions were significantly different between the two groups. Serum haptoglobin decreased significantly in both groups but the past-hepatitis group showed a more persistent change with time. Changes also occurred in serum albumin, alpha-1 and beta globulins, ceruloplasmin but without group effect or group X time interactions.

Adult↗
PubMed1982

Effects of oral contraception on liver function tests and serum proteins in women with active schistosomiasis.

Thirty-eight women with urinary or intestinal schistosomiasis but without clinical or laboratory evidence of hepatic involvement and 30 healthy control women were treated with an oral contraceptive containing 0.05mg ethinyl estradiol and 0.05mg levonorgestrel for six consecutive months. Liver function tests (serum bilirubin, SGOT, SGPT, serum alkaline phosphatase) and serum proteins (total, albumin, globulins, ceruloplasmin, haptoglobin and alpha-1 antitrypsin) were measured before beginning the treatment and after three and six months of use. Both group experienced significant increases in SGOT, SGPT and serum alkaline phosphatase during the first three months of treatment with tendencies to decrease during the subsequent 3 months. No change occurred in serum bilirubin. There was significant decreases in serum albumin and haptoglobin and increases in alpha-1 globulin, ceruloplasmin and alpha-1 globulin, there were no significant differences between schistosomiasis patients and the controls in terms of changes in any laboratory test as a result of the treatment, thus suggesting that patients with active schistosomiasis do not incur a higher risk of hepatic dysfunction while using oral contraception.

Adult↗
PubMed1982

Biochemical characterization of canavalin, the major storage protein of jack bean.

The structure of canavalin, a jack bean (Canavalis ensiformis) protein homologous to phaseolin, the major seed storage protein of Phaseolus vulgaris, has been investigated by x-ray crystallography and found to be a hexamer composed of three identical pairs of similar but nonidentical subunits related by a perfect 3-fold axis and pseudo dyad axes (strict C(3) and pseudo D(3)). One member of each pair of subunits is derived from the amino terminal half of a precursor polypeptide of molecular weight 49,000 and the other from its carboxy terminal half. Thus, the crystallographic evidence indicates that the precursor polypeptide is a tandem duplicate and is structurally redundant (McPherson A. 1982 J Biol Chem 255: 10472). A number of physical and chemical properties of the protein in both the uncleaved and the cleaved form were investigated. These included the native molecular weights, amino acid analyses, number of exposed sulfhydryl groups, carbohydrate content, metal ion analysis, crystallization behavior, and the fate of the protein in developing seeds. It was also found that the purified precursor protein possesses a substantial level of alpha-d-mannosidase activity and seems to share a number of other physical and chemical properties with that enzyme.

Journal Article↗
PubMed1980

Focal differences in bioenergetic metabolism of atherosclerosis-susceptible and -resistant pigeon aortas.

To test the hypothesis of altered energy production in aortic sites predisposed to lesion formation, both coupled oxidative phosphorylation (evaluated from P/O ratios) and control of the energy-linked (ATP) NADH transhydrogenase were examined in muscular cushions at the celiac artery bifurcation. Comparisons were made between atherosclerosis-susceptible White Carneau (WC) and atherosclerosis-resistant Show Racer (SR) pigeons at ages up to early atherogenesis in WC (1 day to 6 months of development). From 1 day to 12 weeks of age, mitochondria from cushions of both breeds tightly coupled phosphorylation to the oxidation of either beta-hydroxybutyrate or succinate. However, by 6 months of age, WC celiac cushions had significantly (P less than 0.05) lower P/O ratios than the SR cushions with either substrate, suggesting uncoupled respiratory-chain phosphorylation. Aortic submitochondrial A-particles from celiac cushions of susceptible pigeons showed no ATP regulation of NADH transhydrogenation at 6 weeks and subsequent ages. This defect is believed to enhance lipid biosynthesis and may be involved in exacerbation of the biochemical arteriopathy in WC. These findings are discussed in terms of relationships between oxidative energy production, lipid accumulation, hypoxic stress, and atherosclerotic involvement.

Adenosine Triphosphate↗
PubMed1980

Enzyme null alleles in natural populations of Drosophila melanogaster: Frequencies in a North Carolina population.

A Raleigh, NC, population of Drosophila melanogaster was sampled for the presence of enzyme null alleles at 25 loci. No nulls were found at any of five X-linked loci. Nulls were recovered at 13 of 20 autosomal loci; the weighted mean frequency for all 20 autosomal loci was estimated to be 0.0025. A consideration of the effects of these null alleles on viability strongly suggests that, although they may contribute to so-called polygenic variation, they are not representative of the entire genome.

Journal Article↗
PubMed1980

Lack of genic variation in the abundant proteins of human kidney.

Abundant proteins of 25 human kidneys were surveyed for genic variation by means of two-dimensional electrophoresis. Eighty-three (83) proteins were scored, and no genic variation was detected. This reduction in genic heterozygosity corroborates results determined with two-dimensional electrophoresis in mice and flies. These results suggest that previous estimates of electrophoretic variation may have been in error because of biased selection of loci.

Electrophoresis, Polyacrylamide Gel↗
PubMed1980

Lipid accumulation and ultrastructural change within the aortic wall during early spontaneous atherogenesis.

To identify the initial period and type of lipid accumulation during spontaneous atherosclerosis, quantitative chromatographic profiles of major lipid classes in upper thoracic aortas (non-lesion areas) and celiac artery cushions (lesion areas) were obtained from atherosclerosis-susceptible White Carneau (WC) and atherosclerosis-resistant Show Racer (SR) pigeons from 1 day to 6 months of age. Thoracic aortas of WC and SR pigeons contained similar amounts of cholesterol, nonesterified fatty acids, triacylglycerols, cholesteryl esters, phospholipids, and hydrocarbon at each age studied. However, celiac sites in WCs contained more total lipid than corresponding SR sites at 6 weeks and 6 months of age. This initial increase at 6 weeks in WCs was characterized by invreased concentrations of nonesterified saturated fatty acids. By 6 months of age, WC celiac cushions had greater concentrations of each lipid class except hydrocarbon than did SR cushions. This initial lipid accumulation was accompanied by ultrastructural changes within the arterial wall, which included the presence of extracellular, vesiclelike structures and extensive accumulation of basal lamina-like material between cells. This material was not present in aortic regions that are not predisposed to lesion formation. This material increased by 6 months of age in the enlarging WC fibromuscular intimal cushions. These morphologic changes paralleled the quantitative lipid increases and represented the first morphologic changes detectable at this site. Age-related changes in arterial lipid content and ultrastructure in SRs are different from those related to early spontaneous atherogenesis in WCs.

Age Factors↗
PubMed1979

Synthesis of all the stereoisomers of statine (4-amino-3-hydroxy-6-methylheptanoic acid). Inhibition of pepsin activity by N-carbobenzoxy-L-valyl-L-valyl-statine derived from the four stereoisomers.

Synthesis of all four stereoisomers of the novel amino acid statine, 4-amino-3-hydroxy-6-methylheptanoic acid, found in pepstatin, a potent acid protease inhibitor, has been accomplished. Carbobenzoxy-L-valyl-L-valyl-statine tripeptides derived from all four stereoisomers have been prepared and their effect on pepsin activity is compared to that of pepstatin.

Amino Acids↗
PubMed1979

Tumour markers in breast cancer.

The clinical usefulness of 8 potential tumour markers has been evaluated in 69 patients with Stage I and II breast cancer and 57 patients with Stage III and IV. Serum CEA concentrations were raised in 13% of patients with local and 65% of those with advanced breast cancer. In patients with clinical evidence of progression or regression of tumour, serum CEA levels changed appropriately in 83% of cases. Taking 4 of the markers (carcinoembryonic antigen (CEA), lactalbumin, alpha subunit and haptoglobin) serum concentrations of one or more were raised in 33% of patients with local disease and 81% of those with advanced breast cancer. However, marker concentrations were often only marginally raised, and are unlikely to provide sensitive guide to tumour burden. CEA, lactalbumin and alpha subunit were detectable in 68%, 43% and 40% respectively of extracts of primary breast cancers.

Breast Neoplasms↗