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Biomedical subjects

S M Bailey

Publications and source records attributed to S M Bailey.

98 records · Page 6Linked to original sources
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Improved homogenization of recombinant Escherichia coli following pretreatment with guanidine hydrochloride.

Pretreatment of recombinant Escherichia coli, expressing human growth hormone inclusion bodies, with guanidine hydrochloride and Triton X-100 prior to high-pressure homogenization has been investigated. Homogenates were analyzed for protein release, viscosity, and particle size. We were able to reduce the number of passes required for cell disruption and the number of downstream processing steps required for the recovery of protein from inclusion bodies by pretreating cells with guanidine HCl and Triton X-100. Pretreatment of exponential growth phase cells with 1.5 M guanidine HCl and 1.5% Triton X-100 gave adequate disruption after one pass at 41 MPa with a particle size distribution similar to that for untreated cells disrupted after one pass at 62 MPa. This combination of guanidine HCl and Triton X-100 was also selected so as to wash the inclusion bodies without solubilization of the human growth hormone. Pretreatment of cells with 4 M guanidine HCl produced cell debris that was substantially smaller than the debris from untreated cells and partially solubilized the inclusion bodies. Cells harvested in the stationary growth phase were more resistant to high-pressure homogenization and pretreatment.

Bacterial Proteins↗
PubMedDate not supplied

The measurement of body fat distribution using somatotype photographs and computer-assisted imaging techniques.

A computer-assisted image analysis technique has been devised which allows the measurement of body fat distribution from archived somatotype photographs. This report describes the technique, which enables useful measurements to be extracted from somatotype photographs which were taken over 50 years ago. This paper describes the process of digitization of photographs, the measurement of body diameters using computer-assisted edge detection, the quantitative analysis of measurement error in this procedure, and validation techniques employed.

Adipose Tissue↗
PubMedDate not supplied

The distribution of body fat from childhood to adulthood in a longitudinal study population.

Body fat distribution, its continuity from childhood (4-6 years) to 30 years of age, and its link to that of parents is described in a longitudinal study population. A computer-assisted image analysis technique was used to measure body fat distribution (as measured by waist and hip diameters) from somatotype photographs. Pearson correlation coefficients were used to assess the association between the waist/hip diameter ratio (WHDR) and the body mass index (BMI) at all ages and between the WHDR of parents and offspring. Both Pearson correlation coefficients and the Foulkes-Davis tracking index were used to assess tracking of the WHDR from childhood to age 30 years. Stepwise regression analyses were performed to determine the predictability of the WHDR at age 30 years from WHDRs in childhood and adolescence. Among both sexes the WHDR decreased and BMIs increased with age from childhood to 18 years, then both increased from age 18 to 30 years. The correlation between the WHDR and BMI was significant only at 30 years for males (r = 0.37; p < 0.05) and during all stages of adolescence in females (p < 0.05). Age-to-age correlations were high for both sexes (p < 0.0001), and remained significant over a span of up to 25 years. Using the Foulkes-Davis tracking index, tracking from the year of peak height velocity to 30 years (a span of approximately 20 years) was strong for both sexes. Parent and child WHDRs were correlated and differed by sex. Father-son correlations were not significant in childhood, but reached significance in early adolescence (2 years before the year of peak velocity) and remained significant to 30 years (p < 0.05). Mother-daughter correlations were significant at all ages (p < 0.05). The level of the WHDR at the peak of the pubertal growth spurt (year of peak height velocity) predicted up to 58% of the variance in males and 51% of the variance in females of the WHDR at 30 years. We conclude that the adult WHDR (a proxy for the waist/hip ratio) becomes evident by the year of the pubertal growth spurt in height.

Adipose Tissue↗
PubMedDate not supplied

Ethanol consumption and liver mitochondria function.

The mitochondrion is the subcellular organelle affected earliest during the development of alcoholic liver disease. As a result of chronic ethanol consumption mitochondrial protein synthesis is decreased significantly due to a depression in the functioning of the mitochondrial ribosome. This causes a significant decrease in the concentrations of the thirteen mitochondria gene products, all of which are components of the oxidative phosphorylation system. Consequently, there is a depression in the rate at which ATP is synthesized in hepatic mitochondria. In addition to this loss in function, hepatic mitochondria either acutely or chronically exposed to ethanol generate increased levels of reactive oxygen species (ROS). This elevation in ROS has been demonstrated in both isolated mitochondria and hepatocytes. The increase in mitochondrial ROS production accompanying acute ethanol exposure is due to mitochondrial associated reoxidation of NADH produced during ethanol and acetaldehyde metabolism. The elevation in ROS generation observed in mitochondria from chronic ethanol consumers is likely due to decreases in mitochondrial-derived electron transport components, which in turn results in higher levels of the semiquinone forms of flavin mononucleotide and ubiquinone. Both these semiquinones readily donate electrons to molecular oxygen to form superoxide.

Alcohol Drinking↗
PubMedDate not supplied

Relations of body habitus, fitness level, and cardiovascular risk factors including lipoproteins and apolipoproteins in a rural and urban Costa Rican population.

Increased general and abdominal obesity has been independently associated with diabetes, increased risk of stroke, and coronary artery disease (CAD). It is more prevalent in developed countries and in urban areas of nonindustrialized nations than in less developed and rural areas. To evaluate the associations between general and abdominal obesity (as determined by total body fat, waist to hip ratio, umbilical to triceps ratio, and umbilical to subscapular ratio) with glucose, plasma lipoproteins, apolipoprotein (apo) A-I and B concentrations, and low density lipoprotein (LDL) particle size (LDL 1-7), we randomly selected 222 men and 243 women from rural and urban areas of Puriscal, Costa Rica. Abdominal obesity, as assessed by the waist to hip ratio, was independently and significantly associated with higher triglyceride levels (p less than 0.01) and with lower high density lipoprotein cholesterol levels (p less than 0.05) in men and women and with higher glucose levels (p less than 0.05) and smaller LDL particle size (p less than 0.01) in women. Abdominal obesity, as assessed by the umbilical to subscapular ratio, was independently and significantly associated with higher total cholesterol (p less than 0.005) and apo B (p less than 0.01) levels. Umbilical to triceps ratio was positively associated with blood pressure in men. Urban men had increased general and abdominal obesity (p less than 0.0001), number of cigarettes smoked per day (p less than 0.0001), and diastolic blood pressure (p less than 0.05) and had a decreased fitness level (p less than 0.0001) as well as higher (p less than 0.05) plasma glucose, triglyceride, and total cholesterol concentrations and lower (p less than 0.05) apo A-I and HDL cholesterol levels compared with rural men. The differences between rural and urban women were not as striking. Urban women had increased general and abdominal obesity, glucose, and apo B levels (p less than 0.05) and a decreased fitness level (p less than 0.0001). Our data indicate that general and abdominal obesity, increased cigarette smoking, diastolic blood pressure, and decreased fitness level are more prevalent in an urban than in a rural area in Costa Rica, particularly in men. The higher prevalence of such risk factors in the urban area is associated with a more atherogenic plasma lipoprotein profile.

Adult↗
PubMedDate not supplied

Nutrient intake comparisons between Framingham and rural and Urban Puriscal, Costa Rica. Associations with lipoproteins, apolipoproteins, and low density lipoprotein particle size.

To assess cross-cultural relations between dietary intake and plasma lipoproteins, we randomly selected 222 men and 243 women from the urban and rural areas of Puriscal, Costa Rica; related their dietary composition (assessed by a food-frequency questionnaire), fitness level, and body fat to plasma lipids, apolipoproteins, and low density lipoprotein (LDL) particle size; and compared these data with those from a subsample of 280 adults from the Framingham Offspring Study. Total cholesterol and LDL cholesterol levels were significantly (p less than 0.0001) higher in Framingham (207 and 137 mg/dl, respectively) than in Puriscal (184 and 114 mg/dl, respectively) residents. Elevated triglyceride and apolipoprotein (apo) B levels (25% and 16% higher), low HDL cholesterol and apo A-I levels (12% and 29% lower), and smaller LDL particles (17%) were more frequent in Puriscal than in Framingham residents. Urban Puriscal residents had a significantly lower fitness level; increased body fat, total cholesterol, and triglyceride levels; decreased HDL cholesterol in men; and higher apo B levels in women compared with rural Puriscal residents. Body fat, animal fat, and saturated fat intakes were significantly correlated with total cholesterol, LDL cholesterol, and apo B levels in both men and women in Puriscal. Intakes of protein and animal fat were higher among urban (10.7% and 14.1%, respectively) compared with rural (8.9% and 9.9%, respectively) Puriscal residents and in Framingham (16.0% and 20.8%, respectively) compared with Puriscal residents. No significant differences were found in dietary cholesterol. Saturated fat (largely from palm oil in Puriscal) intakes were significantly different among the three groups: rural Puriscal, 10.7% of calories; urban Puriscal, 11.6%; and Framingham residents, 12.9%. These data indicate that the more atherogenic plasma lipid profile among urban compared with Puriscal residents was largely explained by increased adiposity, decreased fitness level, and higher saturated fatty acid intake. Puriscal residents consumed less animal fat and more carbohydrate than did Framingham residents, and these differences were associated with a 21% lower LDL cholesterol level, a 12% lower HDL cholesterol level, a 29% lower apo A-I level, a 25% higher triglyceride level, a 16% higher apo B level, and a 17% smaller LDL particle size. Some of these cross-cultural differences may be due to differences in ethnic background and physical activity as well.

Adipose Tissue↗
PubMedDate not supplied

Preparing health care assistants.

In the fourth part of this series on issues in ward management facing charge nurses, Sheila Mackie Bailey looks at the charge nurse's role in preparing and educating the health care assistant or support worker. The imminent adjustment of student nurses' clinical status makes the development of a skilled and educated assistant for the trained nurse an urgent necessity. Of all those involved in defining and delimiting this role, the charge nurse assumes the key responsibility, but it is a responsibility which requires proper preparation and support before it can be adequately exercised.

Humans↗