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Biomedical subjects

L S Phillips

Publications and source records attributed to L S Phillips.

141 records · Page 8Linked to original sources

Steroid hormone effects on sonatomedin. I. Somatomedin action in vitro.

The effects of cortisol, estradiol, and testosterone on somatomedin action on cartilage incubated in vitro have been examined. The addition of hormones in the absence of serum had no effect on the incorporation of sulfate by cartilage from hypophysectomized rats, embryonic chicks, or normal young pigs. Normal human serum provided a source of somatomedin which stimulated the incorporation of sulfate by cartilage in a dose-response relationship; the potency of serum with and without added steroid hormone was determined after formal parallel-line analysis. Moderately supraphysiologic levels of cortisol, 17 beta-estradiol, and testosterone generally had little effect on somatomedin action in the test systems. Very high levels of serum cortisol (100-1000 mug/100 ml) inhibited somatomedin action on pig cartilage, but had little effect on rat or chick cartilage. A 20 ng/100 ml increase in serum estradiol had no effect on somatomedin action on chick cartilage, but appeared to enhance somatomedin action on pig cartilage. A 5 mug/100 ml increase in serum testosterone did not affect somatomedin action on either chick or pig cartilage. These studies suggest that the alteration of somatomedin action is not a major mechanism in the effect of steroid hormones on growth. In addition, since modest increases in serum levels of cortisol, estradiol, and testosterone had little effect on somatomedin action in our assay systems, these systems should be satisfactory for the study of hormone effects on somatomedin generation.

Animals↗

Evaluation of methods used to purify acid-extracted group A streptococcal M protein.

The literature includes descriptions of both acid-soluble and acid-insoluble M protein in the preparation of "hot acid-extracted group A streptococcal M protein." We present evidence for the contamination of crude type 1 acid-insoluble M protein. The purification of preparations of crude and partially purified acid-soluble type 1 and type 12 M protein is described. Our quantitative criteria for purification were recovery of M precipitin activity, improvement in specific activity, and removal of carbohydrate. Exclusion of nucleic acid is also discussed. Greater purification in a single passage was found with a carboxymethylcellulose column (with acidic elution) than with hydroxyapatite, diethylaminoethyl-Sephadex, or carboxymethyl-cellulose (with neutral elution) columns or with ammonium sulfate fractional precipitation. Carboxymethylcellulose with acidic elution was found to be a satisfactory standard laboratory procedure for the preparation of purified acid-extracted (acid-soluble) group A streptococcal M protein.

Chemical Precipitation↗

Diabetes in urban African Americans: assessment of diabetes-specific locus of control in patients with type 2 diabetes.

PURPOSE: This study was conducted to examine the applicability and relationship to glycemic control of the Diabetes Locus of Control (DLC) Scales in a low-literacy, economically deprived, African American population with type 2 diabetes. METHODS: The DLC Scales were administered orally to African American patients with type 2 diabetes who had been referred to the diabetes unit of a large urban public hospital. Reliability, interscale correlations, and associations with patient characteristics were compared with those originally obtained for a better educated, predominately Caucasian population. RESULTS: The structure and correlates of the DLC Scales in the African American population were more similar than different from those originally obtained from a primarily well-educated, Caucasian population. However, comprehension of some items was difficult for up to 10% of the low-literacy population. A significant relationship was found between belief in chance and both glycemic control at the 6-month follow-up and the change in glycemic control over time. CONCLUSIONS: Although the DLC Scales operate similarly in an urban African American population with limited education, further modification is needed to enhance the prediction of glycemic control and provide direction for developing targeted interventions.

Black or African American↗

Diabetes in urban African Americans. V. Use of discussion groups to identify barriers to dietary therapy among low-income individuals with non-insulin-dependent diabetes mellitus.

Dietary therapy remains an integral part of diabetes management. The study objective was to identify potential barriers to dietary adherence among low-income, urban black patients with non-insulin-dependent diabetes. Forty-five patients participated in discussion group interviews that consisted of open-ended questions. Four problem areas were identified: habitual, economic, social, and conceptual. Most patients felt that the recommended meal plans were lacking in taste, and the cost of low-fat and sugar-free items was perceived as a major drawback. Lack of family support and family pressure to use fat-containing food seasoning were frequent problems. Participants had trouble following the food exchange system and analyzing food labels. Feedback suggested that dietary strategies may need to be revised to provide appropriate menus, identify low-cost foods, involve patients' families, and teach patients how to make healthy food choices. The discussion group approach was quick, simple, and could be easily translated to other settings.

Black or African American↗

Diabetes in urban African Americans. Body image, satisfaction with size, and weight change attempts.

We developed two gender specific sets of body-size silhouettes for evaluating body image in African Americans; 370 clinic-based adult participants with diabetes were queried on body image, perceptions, current efforts to change weight, and psychosocial variables. Comparisons were made by weight group and sex after classification as overweight or not overweight according to body mass index (BMI). Regardless of sex or weight category, perceived current body size was significantly related to BMI. Both men and women who were classified as overweight selected a desired body size that was significantly smaller than their perceived current size. Men, however, were more likely than women to select a larger desired size relative to their current size. Both men and women expected the dietician to favor a body size smaller than their own desired size and felt their designated important adult would choose the same desired size that they selected. Given the importance of cognitive perspectives in understanding weight management, it may be useful to incorporate body image measures into both observational and interventional studies.

Adult↗

Diabetes in urban African Americans: functional health literacy of municipal hospital outpatients with diabetes.

Functional health literacy was assessed in 63 patients from the diabetes outpatient clinic, 20 from the general medicine clinic, and a total of 48 from two satellite medical clinics. All patients received a demographic questionnaire, visual screening, and the Test of Functional Health Literacy in Adults, an instrument with good validity and internal consistency used to measure the ability to read and understand medical instructions. Functional health literacy was adequate in only 47% of new patients at the diabetes clinic and only 25% of established patients at all sites. There were no significant differences in functional health literacy among established patients across all sites. Overall, patients' mean functional health literacy level was inadequate to marginal. Of the patients with inadequate functional health literacy, 43% denied difficulty in reading. Patient education strategies and materials are needed to address this important barrier to healthcare delivery.

Adult↗

Postoperative management of diabetes mellitus: steady-state glucose control with bedside algorithm for insulin adjustment.

An algorithm was developed to determine whether an individualized insulin infusion could maintain plasma glucose in a desirable steady state after surgery. In 24 patients, insulin was provided according to a "glucose-feedback" formula to maintain plasma glucose between 120 and 180 mg/dl (6.7-10.0 mM). Initial plasma glucose was elevated, 218 +/- 16 mg/dl (mean +/- SE 12.1 +/- 0.9 mM), but reached the target range after 8 h and remained steady for the rest of the study period. Insulin requirements varied considerably, 0.5-5.0 U/h. Infusion rates were correlated with initial plasma glucose but not with previous insulin dose, HbA1c, or percent ideal body weight. Although insulin needs cannot be predicted, plasma glucose can be maintained in a desirable range after surgery via a simple formula suitable for implementation by general ward nurses.

Adult↗

Preliminary studies of diabetic decompensation assessed with bedside glucose-monitoring techniques.

Blood glucose-monitoring techniques originally developed to aid outpatient management of diabetic patients are now being used to facilitate hospital care. However, applications in hyperglycemic patients have been limited because many glucose-oxidase strips and meters respond only to glucose values less than or equal to 400 mg/dl. We asked if prior dilution of blood samples would permit reliable estimations. Ten consecutive decompensated diabetic patients (age 35-73, glucose 506-879, HCO3 12-28) had blood glucose determinations done simultaneously by the hospital laboratory and by Chemstrip bG after dilution of heparinized blood 1:2 in saline. Thirty-one samples were obtained before and during insulin therapy. Correlations with laboratory glucose values were 0.95 with strips read by Accu-Chek meter and 0.90 read visually, both P less than 0.001. Average deviations from laboratory values were 7.9% with Accu-Chek and 12.9% with visual readings. Accu-Chek deviations averaged 9.6% for glucose greater than 700 mg/dl, and 6.9% for glucose greater than 400 mg/dl. Over the first hour of insulin therapy, glucose fell 150 +/- 30 mg/dl by Accu-Chek, comparable to 168 +/- 29 by laboratory measurement; the decrement by visual reading was 107 +/- 32, not significantly different. We conclude that dilution of blood samples with glucose greater than 400 allows reliable estimation of elevated values by home glucose-monitoring techniques. This approach is cost-effective and provides the rapid feedback needed for the management of critically ill patients.

Adult↗

Nutritional intake, somatomedin activity and linear growth in children undergoing hemodialysis.

Reduced somatomedin activity was uniformly present pre-dialysis in 7 children with end-stage renal disease. Somatomedin activity improved in 6 of the 7 patients following a single 5 hr hemodialysis. Percent normal growth correlated with post-dialysis somatomedin activity in 6 of the 7 children. No correlation was present between percent normal growth and calorie or protein intake. Reduced somatomedin activity in children with end-stage renal disease appears to be due to a circulating uremic inhibitor(s). Somatomedin activity may be a useful in vitro test for adequacy of dialysis in children. Further efforts are necessary to identify the inhibitor(s) of somatomedin activity in uremia.

Body Height↗

Nateglinide (Starlix): update on a new antidiabetic agent.

Nateglinide is a new oral antidiabetic agent that stimulates insulin release promptly after its pre-meal administration in a strongly glucose-dependent fashion. Because its insulinotropic effects are short in duration, nateglinide specifically targets postprandial hyperglycaemia with a low potential to elicit hypoglycaemia or sustained hyperinsulinaemia. Nateglinide has an excellent safety and tolerability profile, and its efficacy in reducing HbA1c in monotherapy (120 mg before meals) is comparable to that of metformin, sulphonylureas, thiazolidinediones or acarbose (-0.5 to -1.5%). When combined with metformin, which primarily reduces fasting glucose levels, nateglinide's effects are additive. In our clinical experience, nateglinide is a particularly good therapeutic option in newly diagnosed, treatment-naive patients; elderly patients in whom hypoglycaemia is a concern; patients with kidney failure or mild hepatic impairment; patients taking low-dose sulphonylureas who encounter problems with hypoglycaemia; and patients failing to achieve adequate glycaemic control on metformin or thiazolidinedione monotherapy.

Blood Glucose↗