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The promoter of p53 induced gene 3 (PIG3) contains a variable number of tandem repeats (VNTRs) of pentanucleotides (TGYCC)n that is known as a p53 binding site. In this study, we investigated whether other potential molecules could bind to this PIG3 promoter (TGYCC)n motif. Ligand-chromatography combined with liquid chromatography-tandem mass spectrometry analyses indicated direct interactions of prohibitin and/or prohibiton with the (TGYCC)15 motif, which was confirmed by electrophoretic mobility shift assay and super-gel shift analysis with anti-prohibitin and anti-prohibiton antibodies. Using the chromatin immunopercipipation assay, we further demonstrated that prohibitin and prohibiton associated with the (TGYCC)15 motif in vivo regardless of the p53 status and apoptotic stress. We also found that prohibitin and prohibiton up-regulated PIG3 transcription independent of p53, although p53 obviously enhanced this process, and that the knock-down of prohibitin and prohibiton inhibited camptothecin-induced apoptosis. Taken together, our findings suggest that prohibitin and prohibiton contribute to PIG3-mediated apoptosis by binding to the PIG3 promoter (TGYCC)15 motif., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: Regression and undertreatment after initial photorefractive keratectomy (PRK) in higher myopes is not unusual. Patients frequently desire 20/20 uncorrected vision, which necessitates retreatments or enhancements. However, the safest and most efficacious way to treat these patients has not yet been established. This study evaluates two techniques of PRK enhancements, comparing two different methods of laser epithelial removal., Design: Retrospective, nonrandomized, comparative trial., Participants: A total of 224 eyes., Methods: Eyes were identified that had 6-month follow-up after a PRK enhancement from February 1995 through February 1997. Two methods of treatment were identified. The same VISX 20/20B laser in the same clinic was used for all retreatments. Group I patients had a total removal of the epithelium in a mode phototherapeutic keratectomy (PTK) prior to the refractive ablation. Group II patients had a total laser epithelial removal in two steps prior to the refractive ablation. The first step was a PRK and then a PTK., Main Outcome Measure: The disappearance of epithelial fluorescence was the end point for the PTK ablation in groups I and II., Results: There were 131 eyes in group I and 93 eyes in group II. The mean spherical equivalent (SE) prior to the original PRK in group I was -7.5 diopters (D) +/- 3 D and in group II was -7.75 D +/- 2.34 D. The mean SE prior to the PRK retreatment in group I was -2.22 D +/- 1.29 D and in group II was -1.89 D +/- 0.83 D. The mean postoperative 6-month SE after the PRK enhancement in group I was -0.05 D +/- 0.80 D and in group II was 0.01 D +/- 1.08 D. A greater proportion of group I eyes (7.8%) had arcuate haze and a hyperopic shift from the 1- to 6-month postoperative visit (P = 0.03)., Conclusions: A two-step laser epithelial removal compared with a one-step PTK epithelial laser removal in PRK retreatments provides a more even and confluent epithelial removal, less risk of arcuate haze development, and less risk of a hyperopic shift from 1 to 6 months after the retreatment.

HIV-1 nucleocapsid protein (NCp7) is a double zinc-fingered protein that has been traditionally implicated in viral RNA recognition and packaging, in addition to its tight association with genomic RNA and tRNA primer within the virion nucleocapsid. The availability of large quantities of viral or recombinant wild-type NCp7 and mutant p7 has made possible the assignment of the different roles that structural motifs within the protein play during RNA binding. At low ionic strength binding to the homopolymeric fluorescent RNA, poly(epsilonA), is electrostatically driven and four sodium ions are displaced. Arg7 in the flanking N-terminal region, Lys20 and Lys26 in the first zinc finger and one positively charged residue (attributed to Lys41) in the second zinc finger are involved in electrostatic contacts with RNA. The p7 zinc fingers do not function independently but concomitantly. The first zinc finger (both isolated or in the context of the full-length protein) has a more prominent electrostatic interaction than the second one. The second zinc finger dominates the non-electrostatic stabilization of the binding to RNA due to stacking of its Trp residue with nucleic acid bases. Mutations in the highly conserved retroviral Zn-coordinating residues (CCHC) to steroid hormone receptor (CCCC) or transcription factor (CCHH) metal cluster types do not affect RNA binding. In spite of the limited impact in RNA binding affinity in vitro or RNA packaging in vivo that such mutations or structural alterations impart, they impair or abolish virus infectivity. It is likely that such an effect stems from the involvement of NCp7 in crucial steps of the virus life cycle other than RNA binding., (Copyright 1999 Academic Press.)

Purpose: The purpose of this study was to provide a description of the current dietary intake of a large sample of U.S. adolescents and to identify sociodemographic risk factors for nutrient intakes that did not meet recommended levels., Methods: The 1987-88 USDA Nationwide Food Consumption Survey was used to assess the nutrient intake of 933 adolescents aged 11 to 18 years. Analysis of covariance was used to determine the effect of the following on the nutrient intakes of males and females: household income and size, race, geographic region, degree of urbanization, and head of household status. Subject age was entered as a control variable., Results: Vitamin A, vitamin E, calcium, magnesium, and zinc were the nutrients most often consumed below recommended levels. In addition the females consumed low levels of phosphorus and iron. Percent calories from total fat and saturated fat and mean sodium intakes were above recommended levels for the majority of the sample. Females were more likely to meet cholesterol recommendations than males. Race and region affected the most nutrient intake variables. For the females, living in the south was a significant predictor for low intakes of several essential vitamins and minerals., Conclusions: On average, the adolescents consumed diets that were low in several essential vitamins and minerals and high in some nutrients related to increased incidence of chronic disease. There were groups of teens who had dietary patterns that placed them at especially high risk, in particular the black and Southern females.

In an effort to obtain highly potent glucagon antagonists, we have investigated glucagon (1) structure-function relationships utilizing the following design principles: (1) structural changes known to lead to partial agonist activities; (2) conformational restrictions; (3) changes in the conformational probabilities of the primary sequence; and (4) increased amphiphilicity. In this report we present the total synthesis, purification, receptor binding, adenylate cyclase activity, in vivo glycogenolytic activity and CD spectrum of the following four glucagon analogues: [Ahx17,18]glucagon (2), [D-Phe4,Tyr5, 3,5-diiodo-Tyr10,Arg12,Lys17,18,Glu21]glucagon (3), [Asp9,Lys12,Lys17,18,Glu21]glucagon 4, and [Glu15,Lys17,18]glucagon 5. Compound 2 binds exclusively to the high affinity receptor and compound 3 was a highly potent antagonist with respect to adenylate cyclase activity. Analog 4 showed distinct biphasic binding (IC50 5.6 nM and 630 nM), with only the low affinity binding leading to adenylate cyclase activity. Furthermore in analogue 5 receptor binding and adenylate cyclase activity were dissociated by a factor of 5. The results are consistent with a multistep binding mechanism in which glucagon interacts first nonspecifically with the anisotropic interphase of the cell membrane, followed by a conformational transition which occurs in the sequences 10-14 and 15-18 when the membrane bound peptide binds to its receptor.

Over 600 Howard University medical alumni of seven representative classes graduating from 1955 to 1975 were surveyed by questionnaire in 1975 and 1976. Replies of the 252 black respondents confirm that these graduates are providing substantial care to blacks, the economically disadvantaged, and residents of the inner city. Survey findings reaffirm the necessity to train more black physicians and to provide data on current and future practice patterns. Comparisons are made between the practice patterns of earlier (1955 to 1970) and later (1973 to 1975) black graduates. A general bibliography of publications relevant to the practice patterns of black physicians is included.

Serum levels of atrial natriuretic peptide (ANP) are elevated in chronic heart failure presumably due to dilatation of the left atrium resulting from increases in intracardiac pressures. To define the time course of changes in serum ANP levels and to determine the relationship to left ventricular end-diastolic pressure, rats were subjected to coronary artery ligation to produce myocardial infarction and left ventricular failure. Atrial natriuretic peptide levels were measured weekly for four weeks thereafter. In rats with myocardial infarction and elevation of left ventricular end-diastolic pressure there was no change in ANP levels at 7 and 14 days. However, at day 21 and 28, ANP levels were elevated more than 3 fold. There was a correlation between ANP levels and left ventricular end-diastolic pressures. There was no correlation between ANP levels and right atrial pressures or serum sodium concentrations. We conclude that the chronic elevation of left ventricular end-diastolic pressure is required to produce an increase in ANP after myocardial infarction which results in chronic heart failure.

The breakdown of proinsulin in the pancreatic beta cell yields insulin and C-peptide which are secreted in equimolar amounts. Unlike insulin, C-peptide is not degraded significantly by the liver, so that its measurement should give a better assessment of insulin secretion than estimation of peripheral insulin levels alone; particularly in the presence of hepatic dysfunction. Plasma C-peptide and insulin response to an oral glucose load have therefore been assessed in 14 cirrhotic and 7 normal subjects. Cirrhotic patients were divided into hyperinsulinaemic and normoinsulinaemic groups based on fasting plasma-insulin concentrations. Fasting blood-blucose and plasma-C-peptide concentrations were the same in normal and cirrhotic subjects, suggesting that basal pancreatic insulin secretion was the same in all subjects. Thus the C-peptide/insulin ratio was significantly decreased in hyperinsulinaemic subjects (2-13 +/- 0-31, compared with 4-63 +/- 0-48 in controls). After oral glucose, the two groups of cirrhotic patients showed the same glucose intolerance. C-peptide concentrations were also the same but insulin concentrations were markedly increased in the hyperinsulinaemic group. It is suggested that pancreatic insulin secretion is not increased in cirrhosis and that the peripheral hyperinsulinism is due solely to decreased hepatic insulin degradation secondary to either spontaneous portal-systemic shunting or to parenchymal damage.