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Biomedical subjects

H Wright

Publications and source records attributed to H Wright.

At least 91 records · Page 5Linked to original sources
PubMed1981

Seasonal variation in serum 25-hydroxyvitamin D concentrations in sheep.

Seasonal changes in serum 25-hydroxyvitamin D were followed in pregnant and non-pregnant sheep kept indoors or at pasture. In housed sheep circulating levels depended on starting value, dietary intake and requirements. thus, in wethers given hay values declined steadily; in non-pregnant ewes on the standard diet values were constant; and in pregnant ewes given hay and nuts values were minimal at lambing. In sheep at pasture seasonal changes were aggravated by those changes due to pregnancy so that the lowest values were always observed at or near parturition.

Animals↗
PubMed1980

Some studies on the composition and surface properties of oil bodies from the seed cotyledons of safflower (Carthamus tinctorius) and linseed (Linum ustatissimum).

1. The average oil-body diameter in intact cells of developing linseed (Linum usitatissimum) and safflower (Carthamus tinctorius) cotyledons was similar (about 1.4 micrometer), and there was little change in size after oil bodies were isolated and repeatedly washed. 2. The glycerolipid composition of washed oil bodies from both developing and mature cotyledons of the two species was similar; oil bodies from ten different batches of cotyledons contained 4.3 +/- 0.16 mumol of 3-sn-phosphatidylcholine and 25.2 +/- 1.7 mumol of diacylglycerol per 1000 mumol of triacylglycerol. During four successive washings of a once-washed oil-body preparation, the proportion of diacylglycerol to triacylglycerol remained constant and that of 3-sn-phosphatidylcholine to triacylglycerol decreased by only 20%. 3. The protein content of thrice-washed oil bodies from the two species was similar, about 2.4% of the weight of glycerolipids, and appeared to be independent of the stage of cotyledon maturity. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis indicated that the protein of purified oil bodies from the two species consisted mainly of only four polypeptides and that two of the polypeptides from each species had apparent mol.wts. of 17500 and 15500. Similar patterns of polypeptides were obtained after the hydrolysis of the 15500-mol.wt. polypeptides from linseed and safflower oil bodies by Staphylococcus aureus V8 proteinase, whereas the proteolysis of the 17500-mol.wt. polypeptides from the two species produced different patterns of polypeptides. 4. The 3-sn-phosphatidylcholine in oil-body preparations was hydrolysed about 85% by bee-venom phospholipase A2 without any apparent coalescence of the oil bodies. Incubation with lipase from Rhizopus arrhizus caused rapid coalescence of the oil bodies, and this lipase appeared to initially hydrolyse diacylglycerols in preference to triacylglycerol. 5. Oil bodies from both species were almost completely dispersed in suspensions of pH between 7.1 and 8.3, but formed large aggregates at pH values between 6.7 and 3.9; pH-induced aggregation caused no coalescence. Aggregates formed under acidic conditions were dispersed by re-adjusting the pH of suspensions to 8.3. 6. A freeze-etch electron-microscopic examination of isolated oil bodies indicated that these organelles were bounded by some form of membrane with a particle-free outer surface.

Chemical Phenomena↗
PubMed1980

Hepatitis B infection in pediatric dialysis and transplant patients: significance of e antigen.

We examined the clinical significance of hepatitis Be antigenemia in 36 HBsAg positive pediatric dialysis and renal transplant patients. One hundred twenty-seven sera were tested for HBeAg and anti-HBe. Seventy-three sera (57%) from 29 patients (81%) contained HBeAg. The presence of HBeAg was associated with an increased titer of HBsAg (P < 0.005) and with the presence of the HBsAg carrier state (P < 0.001). HBeAg was found in 40% of specimens taken from dialysis patients, and in 70% of specimens from transplant patients (P < 0.001). No serum contained anti-HBe, although 28 of 29 sera (97%) tested had antibody to HBcAg. No association was found between the presence of HBeAg and serum aminoleucine transferase levels or the histologic evidence of chronic active hepatitis. Fifteen HBeAg negative sera from patients persistently positive for HBsAg were tested for HBV-specific DNA polymerase activity; 7 (47%) had significant activity. Since both HBeAg and DNA p are indicators of infectivity, many HBeAg negative sera from immunosuppressed HBsAg carriers may be infectious.

Adolescent↗
PubMed1980

The response of serum 25-hydroxyvitamin D concentrations to vitamin D intake and insolation in sheep.

1. Vitamin D-depleted, housed sheep were given diets providing fixed intakes of cholecalciferol ranging from 0.0 to 0.8 microgram/kg body-wt per d for 220 d. Thereafter they were shorn, deprived of dietary cholecalciferol and turned out from 30 June to 30 November. The concentration of 25-hydroxyvitamin D (25-OHD) in serum was determined at frequent intervals. 2. The serum concentrations of 25-OHD took approximately 10 weeks to stabilize after which they reflected dietary intake over 0.1--0.4 microgram/kg body-wt per d. For intakes of 0.4 and 0.8 microgram/kg body-wt per d the mean maximum concentrations were similar, but the rates of increase differed. The latter was proportional to the logarithm of intake over the range studied. 3. Changes in serum 25-OHD due to insolation were similar in all sheep regardless of their starting values, and consequently in some animals reached levels considerably greater than from the dietary source. 4. Although the response of serum 25-OHD to the higher dietary intakes appeared to be limited there was no evidence of any such control over the response ot endogenously-synthesized vitamin.

Animal Nutritional Physiological Phenomena↗
PubMed1980

Caring for old people in New York and London: the "nurses' aide' interviews.

As part of a comparative study of the institutionalized elderly in London and New York, random samples of nurses' aides, nursing assistants and care assistants were interviewed. It is shown that the two long-term care `systems' employ very similar people to provide basic care services, but far more in-service training is provided for New York staff. A detailed analysis of tasks performed suggests that New York staff may be more likely than their London counterparts to carry out technical `nursing' procedures and to be actively involved in physical rehabilitation. The preferences of staff in caring for more or less dependent people showed considerable cross-national agreement, almost half of the total respondents reporting that they preferred immobile patients. Some of the reasons they gave are presented and the implications of this finding discussed.

Aged↗
PubMed1979

A cross-national comparison of the institutionalized elderly in the cities of New York and London.

Two random samples, each constituting 0.5% of the institutionalized elderly (over 65) in the cities of New York and London have been compared. This preliminary report of a collaborative study demonstrates the similarity of the 2 samples. Institutions in the 2 cities are shown to differ in size, type of ownership and the frequency that skilled nursing is provided. Some implications of these 2 findings are raised now, and will be discussed later when the full data for the study are presented.

Aged↗
PubMed1976

Plasma thyroxine concentrations in ewes and their fetuses during the last six weeks of pregnancy.

Changes in plasma thyroxine (T4) concentrations were followed in 27 fetal sheep after surgical implantation of catheters. Fourteen days were required before stable concentrations of T4 were achieved, whether surgery was performed between 90 and 96 days or 109 and 120 days gestation. Twenty-three fetuses were followed to birth, and during the last four days the T4 concentrations showed no change in 11 fetuses and a significant decrease in the other 12. Birth occurred between 142 and 157 days gestation in both groups. There was a significant rise in T4 concentration during labour in all 23 fetuses. There were large differences among the plasma T4 concentrations of individual ewes which were not related to ambient temperature.

Animals↗
PubMed1975

Effect of dietary Mo on Cu metabolism. Evidence for the involvement of Mo in abnormal binding of Cu to plasma proteins.

The effects of feeding Mo at concentrations of 17 mug/g to sheep and 100 mug/g to guinea pigs in the presence of adequate dietary Cu, on the distribution of Cu within plasma have been studied. The creation of a fraction of plasma Cu which is insoluble in trichloroacetic acid has been confirmed and it has been shown that this fraction also contains Mo. Complete removal of Cu and Mo from this protein cannot be achieved under acid conditions without at least partial hydrolysis of the protein. The estimated atomic ratio of Cu:Mo in the fraction was 1.7. It is suggested that the formation of such a stable Cu-Mo-protein compound may explain the observed low tissue uptake of Cu in the presence of high plasma total and "direct-reacting" Cu concentrations.

Animals↗