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Biomedical subjects

E R Cole

Publications and source records attributed to E R Cole.

At least 19 recordsLinked to original sources
PubMed2001

Structure and solution equilibria of D-glucose and D-mannose sulfite adducts.

An X-ray crystallographic study has confirmed that the potassium bisulfite adducts of D-glucose and D-mannose have open-chain structures with R and S configurations respectively at C-1. NMR studies have shown that each sugar gives rise to two bisulfite compounds, and solution-state structures and conformations of these isomers have been deduced from analysis of (1)H NMR spectra. (13)C NMR data for the four adducts are given. Furanose forms of the D-glucose and D-mannose have been detected in the equilibrium solutions.

Carbohydrate Conformation↗
PubMed1996

Meanings of political participation among black and white women: political identity and social responsibility.

This study examined the correlates of midlife political participation among 64 Black and 107 White women of the college classes of 1967-1973. Compared with White women, Black women scored higher on political participation, generativity, power discontent, and politicization. Factor analysis of personality and political attitude variables yielded three factors labeled Political Identity, Power Discontent, and Social Responsibility. Adult political participation was regressed on level of student activism and index scores of political identity, power discontent, and social responsibility. For both racial groups, social responsibility was associated with midlife political participation. For White women, political identity was also related; for Black women, student activism bore a significant relationship. The findings suggest that Black and White women's historical and political contexts imbued their political activities with different meanings.

Adult↗
PubMed1987

Solvent influence on model oxidations of alpha-tocopherol.

(+/-)-alpha-Tocopherol has been oxidised with t-butyl hydroperoxide in chloroform in order to simulate in vivo oxidations due to lipid hydroperoxides. t-Butyl hydroperoxide proved to be a weak oxidant and failed to oxidise alpha-tocopherol in 3 h at 60 degrees C. Inclusion of a small amount of ethanol in the reaction mixture brought about immediate oxidation and the formation of a new product, 5-ethoxymethyl-7,8-dimethyltocol in addition to the spiro dimer and spiro trimer of alpha-tocopherol, alpha-tocopherylquinone and 5-formyl-7,8-dimethyltocol. Formation of 5-ethoxymethyl-7,8-dimethyltocol increased with increasing concentrations of ethanol, up to a maximum of 59% at 20% ethanol. Further increase in ethanol concentration brought about a decrease in the oxidation of alpha-tocopherol and in the formation of 5-ethoxymethyl-7,8-dimethyltocol. Oxidation of the tocopherol model compound 2,2,5,7,8-pentamethyl-6-hydroxychroman under similar conditions produced the analogous product, 5-ethoxymethyl-2,2,7,8-tetramethyl-6-hydroxychroman together with 5-formyl-2,2,7,8-tetramethyl-6-hydroxychroman and 2-(3'-hydroxy-3'-methylbutyl)-3,5,6-trimethylbenzo-1,4-quinone.

Catalysis↗
PubMed1987

A high-potency, single-donor cryoprecipitate of known factor VIII content dispensed in vials.

Current factor VIII products expose recipients to many donors and hence to a high risk of acquiring blood-borne infections. Plasma-exchange donation of cryoprecipitate can reduce donor exposure by repeatedly obtaining large yields of factor VIII from individual donors. In this study, donor factor VIII levels were stimulated with desmopressin before donation. Mean yield per donation increased from 1399 +/- 425 IU in controls to 3818 +/- 1350 IU in stimulated donations (p less than 0.001), and mean factor VIII concentration in the cryoprecipitate increased from 8.2 +/- 3 IU/mL to 24 +/- 12 IU/mL (p less than 0.001). A new packaging system dispenses assayed aliquots of stimulated cryoprecipitate in plastic vials. The direct cost of production for this material is $.065 per unit. The cryoprecipitate is hemostatically active and convenient to use, and the aggregate yields from sequential donations by stimulated persons are high enough to allow long-term, single-donor support of many adults with hemophilia.

Blood Component Removal↗
PubMed1984

The effect of spicules obtained from sickle red cells on clotting activity.

Spicules from sickle red cells were examined for their effects on the clotting activity of blood. The spicules were obtained from the sickle red cells after deoxygenation and oxygenation and were tested for clotting activity with Russell's viper venom assay. A marked increase in clotting activity was observed when spicules were added to the system. The increase was distinctly greater than that observed after the addition of sickle red cells while normal red cells had little effect. Vesicles prepared from sickle or normal red cells by incubation with the ionophore A-23187+Ca2+ also markedly increased clotting activity. The effect of spicules or vesicles on the clotting system may be related to reorganization of phospholipid in the spectrin-poor membrane of the spicules or vesicles. Because of these effects, the spicules from the sickle red cells may contribute to the hypercoagulable state in these patients and possibly to their vaso-occlusive crises since free spicules are present in their plasma. Vesicles from red cells from other types of anaemia with hypercoagulability may have a similar effect on coagulation.

Anemia, Sickle Cell↗
PubMed1984

The oestrogenicity of equol in sheep.

The effects of intramuscular injection of synthetic racemic equol (+/- 3-(4-hydroxyphenyl)-3,4-dihydro-2H-1-benzopyran-7-ol) into wethers have been examined with respect to maintenance of plasma level, teat growth rate and the activity of the respiratory enzyme glucose-6-phosphate dehydrogenase. At a dose rate of 1.03 mmol/day a steady rise in 'total' (free plus conjugated) equol in plasma occurred to 1.78 mumol/l in 4 days. A dose rate of 2.07 mmol/day produced only a further slight increase in plasma equol. At a lower dose rate of 0.52 mmol/day the plasma concentration reached 0.62 mumol/l in 2 days and this was not exceeded thereafter. At the dose rate of 1.03 mmol/day over 7 days significant increases in teat length and glucose-6-phosphate dehydrogenase activity occurred but no significant changes were observed at the dose rate of 0.52 mmol/day. It appears that threshold levels of intake of equol which maintain a plasma level of about 1.65 mumol/l are needed for oestrogenic effects to become apparent within a relatively short time. Administration of 1.03 mmol/day over 5 days to ovariectomized ewes produced significant increases in uterine weight equivalent to those produced by 92 nmol stilboestrol dipropionate. Thus stilboestrol was apparently 56 000 times more potent than racemic equol.

Animals↗
PubMed1982

Alkyl selenosulphates (seleno Bunte salts). A new class of thiol-blocking reagents.

Potassium benzyl selenosulphate and potassium p-nitrobenzyl selenosulphate were shown to be powerful inhibitors of the thiol-dependent enzymes glutathione reductase and papain, but to have no effect on the serine-dependent proteinase trypsin. By contrast, potassium benzyl thiosulphate and potassium p-nitrobenzyl thiosulphate, at much higher concentrations, have virtually no effect on any of the enzymes. The selenosulphates show characteristics of both reversible non-competitive and irreversible inhibition. On the basis of model reactions in which the selenosulphates react instantly with cysteine, it is suggested that they form labile selenosulphide derivatives with the enzymes, but that these derivatives may be broken down either by the normal functioning of the enzyme (in the case of glutathione reductase) or by the approaching substrate (in the case of papain). Continued inhibition of the enzymes requires a stoicheiometric excess of inhibitor over enzyme.

Chromatography, Gel↗
PubMed1980

Factor VIII collection by pheresis.

A new blood donation procedure for obtaining selectively the proteins in cryoprecipitate consists of sequential automated plasma exchanges, in which the donor's fresh plasma is replaced with the autologous cryoprecipitated supernatant from the previous exchange donation. Fresh plasma is processed into cryoprecipitate and supernatant, both of which are frozen and stored. Six donors have undergone a total of twenty-six exchange donations of 1.5 to 2 litres. No adverse effects have been encountered. The yield of factor VIII per unit of plasma processed decreases during a donation but remains substantial in the last unit of plasma obtained from a 2 litre exchange. The average total yield of factor VIII from a donation was 730 U. The increased yield of factor VIII per donor may reduce the donor exposure, and hence the hepatitis risk, associated with factor VIII replacement therapy.

Adult↗
PubMed1978

The hemostatic mechanism after open-heart surgery. III. Correlation between the appearance of an abnormal protein demonstrated by gel electrophoresis and of an inhibitor of the extrinsic coagulation system (PEC).

A prospective study in 13 patients undergoing open-heart surgery with extracorporeal circulation revealed a marked decrease of the mean one-stage prothrombin time activity from 88% to 54% (p less than 0.005) but lesser decreases of factors I, II, V, VII and X. This apparent discrepancy was due to the appearance of an inhibitor of the extrinsic coagulation system, termed PEC (Protein after Extracorporeal Circulation). The mean plasma PEC level rose from 0.05 U/ml pre-surgery to 0.65 U/ml post-surgery (p less than 0.0005), and was accompanied by the appearance of additional proteins as evidenced by disc polyacrylamide gel electrophoresis of plasma fractions (p less than 0.0005). The observed increases of PEC, appearance of abnormal protein bands and concomitant increases of LDH and SGOT suggest that the release of an inhibitor of the coagulation system (similar or identical to PIVKA) may be due to hypoxic liver damage during extracorporeal circulation.

Aspartate Aminotransferases↗
PubMed1977

Purification and properties of a plasminogen activator from pig heart.

An improved procedure is described for the purification of plasminogen activator from pig heart. The initial purification steps were similar to these described previously (Bachmann, F., Fletcher, A. P., Alkjaersig, N., and Sherry, S. (1964) Biochemistry 3, 1578--1585). Use of a novel extraction medium containing EDTA, cysteine, and 2,3-dimercaptopropanol-1 facilitated the removal of large amounts of inert proteins prior to gel filtration on Bio-Gel P-150. The final product had a specific activity of 120,000 to 160,000 CTA units/mg of protein (CTA, Committee on Thrombolytic Agents of the National Heart Institute). Total purification over pig heart was 25,000 to 30,000-fold, average recovery compared to the initial extract was 6 to 8%. Polyacrylamide gel electrophoresis revealed a major and two minor components. The molecular weight of the activator determined by gel filtration was 51,500 +/- 3,400 for the major activity component and 48,000 for a minor component which was partially separated from the major peak in eight of nine chromatography runs. A gamma-globulin fraction of antiserum against purified activator neutralized the biological activity of the activator on fibrin plates. Immunoelectrophoresis of gel-filtered activator revealed only one anodic component.

Animals↗