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This study examined the relationship between adolescent smoking under stress, psychological distress, and social support. Sophomore and junior high school students, N=1,168, completed Derogatis' Brief Symptom Inventory, Spielberger's Anger Expression Scale, and revised version of Coppel's Index of Social Support. White students were more likely to engage in stress-related smoking than were black students (OR=5.74, 95% C.I. [4.00, 8.24]), as were adolescents with higher psychological distress and lower social-support scores. Adolescent smoking prevention and cessation programs should consider incorporating behavioral strategies aimed at coping with psychological distress and strengthening social support as students may smoke in response to stress. [ABSTRACT FROM AUTHOR]

Here, the hierarchical assembly of a collagen mimetic peptide (CMP) displaying four bipyridine moieties is described. The CMP was capable of forming triple helices followed by self-assembly into disks and domes. Treatment of these disks and domes with metal ions such as Fe(II), Cu(II), Zn(II), Co(II), and Ru(III) triggered the formation of microcages, and micron-sized cup-like structures. Mechanistic studies suggest that the formation of the microcages proceeds from the disks and domes in a metal-dependent fashion. Fluorescently-labeled dextrans were encapsulated within the cages and displayed a time-dependent release using thermal conditions.

Insulin-signaling requires conformational change: whereas the free hormone and its receptor each adopt autoinhibited conformations, their binding leads to structural reorganization. To test the functional coupling between insulin's "hinge opening" and receptor activation, we inserted an artificial ligand-dependent switch into the insulin molecule. Ligand-binding disrupts an internal tether designed to stabilize the hormone's native closed and inactive conformation, thereby enabling productive receptor engagement. This scheme exploited a diol sensor ( meta -fluoro-phenylboronic acid at Gly A1 ) and internal diol (3,4-dihydroxybenzoate at Lys B28 ). The sensor recognizes monosaccharides (fructose > glucose). Studies of insulin-signaling in human hepatoma-derived cells (HepG2) demonstrated fructose-dependent receptor autophosphorylation leading to appropriate downstream signaling events, including a specific kinase cascade and metabolic gene regulation (gluconeogenesis and lipogenesis). Addition of glucose (an isomeric ligand with negligible sensor affinity) did not activate the hormone. Similarly, metabolite-regulated signaling was not observed in control studies of 1) an unmodified insulin analog or 2) an analog containing a diol sensor without internal tethering. Although secondary structure (as probed by circular dichroism) was unaffected by ligand-binding, heteronuclear NMR studies revealed subtle local and nonlocal monosaccharide-dependent changes in structure. Insertion of a synthetic switch into insulin has thus demonstrated coupling between hinge-opening and allosteric holoreceptor signaling. In addition to this foundational finding, our results provide proof of principle for design of a mechanism-based metabolite-responsive insulin. In particular, replacement of the present fructose sensor by an analogous glucose sensor may enable translational development of a "smart" insulin analog to mitigate hypoglycemic risk in diabetes therapy., Competing Interests: Competing interest statement: M.A.W. has equity in Thermalin Inc. (Cleveland, OH) at which he serves as Chief Innovation Officer; he has also been a consultant to Merck Research Laboratories and DEKA Research and Development Corp. N.B.P. is a consultant to Thermalin Inc. M.C.L.'s laboratory has a Research Agreement with Eli Lilly and Company to conduct research not connected to this publication.

The hierarchical assembly of collagen-based triple helical peptides into disks, followed by metal-promoted assembly into microcages is described. The length of the triple helix was found to correlate to the height of the disks that formed, providing mechanistic insights into their formation. The encapsulation of fluorescently labeled dextrans within the peptide microcages, and their subsequent thermal release is detailed. The half-life for thermal release of the encapsulated cargo from the cages was found to increase as the peptide triple helix stability increased, providing a means to engineer cargo delivery rates through peptide design.

A 27 amino acid collagen-based peptide (Hbyp3) was designed to radially display nine hydrophobic bipyridine moieties from a triple helical scaffold. Self-assembly of such functionalized triple helices led to the formation of micrometer-scaled disks with a curved morphology, presumably mediated by aromatic interactions, with a height that is in the range of the length of the triple helical peptide. Higher order assembly of these curved disks into micrometer-sized hollow spheres was accomplished through metal-ligand interactions between bipyridine groups of the disks and metal ions such as Fe(II), Co(II), Zn(II) and Cu(II). The thickness of the shell of these hollow spheres corresponds well with the thickness of the collagen peptide-based triple helix and the corresponding self-assembled disks. Addition of a metal ion chelator was found to reverse the assembly of the hollow spheres back to the curved disk structures. These data support the formation of the hollow spheres from the self-assembled disks of Hbyp3 upon addition of metal ions.

This cross-sectional survey measured relationships among blood pressure and measures of psychologic distress, family structure, and economic status in a sample of adolescents exposed to Hurricane Hugo. Spielberger's Anger Scale and Derogatis' Brief Symptom Inventory were used. Data analysis revealed 5% of the 1079 adolescents were hypertensive. Multiple regression analyses revealed the following predictors of higher diastolic blood pressure: African-American race, recipient of subsidized lunch, exposure to Hurricane Hugo, and higher anger-in scores in males. The effects of a catastrophic event such as a hurricane on blood pressure and the effects of introjected anger have implications for both health care consumers and providers.

The recruitment and retention of highly qualified nurses present ongoing challenges to nursing service administrators throughout the world. Retention of nurses has been closely linked both to job satisfaction and selected demographic factors. Administrators must be aware of these demographic factors due to their importance to employees. The primary purpose of this study was to examine demographic correlates of job satisfiers and dissatisfiers among nurses in the West Bank of Palestine. Both the McCloskey/Mueller Satisfaction Scale (MMSS) and a single overall job satisfaction item were used to survey the entire population (n = 330) of nurses employed in 20 acute care hospitals. Significant relationships were found between job satisfaction and the demographic characteristics of marital status, distance traveled to work, number of years the nurse worked as an RN, and extended family responsibilities. This study of job satisfaction among nurses in a geographic location not previously studied provides nursing leaders in the West Bank with important information as they seek to retain and recruit nurses. The findings support the use of the MMSS in non-US countries and cultures. However, an argument is presented for further refinement of the instrument and the underlying conceptual framework of the instrument.

The purpose of this study was to assess the validity of the McCloskey/Mueller Satisfaction Scale (MMSS) in the West Bank, a dissimilar society and culture from the United States, where the instrument was developed. A second purpose was to measure the correlation between the MMSS total score and a single-item measure of job satisfaction. In contrast to the 31-item scale with eight factors of Mueller and McCloskey, four factors emerged in the current study: Interaction, Extrinsic Rewards, Control Over Work Environment, and Professional Participation. The resulting model is more similar to the original 1974 McCloskey conceptual framework than the 1990 eight-factor model.

Paroxysmal nocturnal haemoglobinuria (PNH) is a haemolytic disorder characterized by an increased sensitivity of peripheral blood cells including platelets to the lytic action of complement (C'). Previous studies have demonstrated that in PNH bone marrow erythroid colony and burst forming units, as well as granulocytic-monocytic colony forming units, have an increased sensitivity to complement-induced injury as compared with normal erythroid and myeloid progenitors. The purpose of this study was to investigate the effect of complement on PNH and normal marrow megakaryocytic progenitors (CFU-M). Bone marrow non-adherent and T-cell depleted light density mononuclear cells from three patients with PNH and six normal volunteers were exposed to fresh or heat-inactivated AB human serum in the presence of medium or isotonic aqueous sucrose solution for 30 min at 37 degrees C. After being washed the cells were assayed for CFU-M by the plasma clot method in a complement free medium containing 6% medium conditioned by T-lymphocytes stimulated by phytohaemagglutinin. The number of megakaryocytic colonies grown from PNH marrow cells exposed to isotonic sucrose and C' was reduced to one third of those grown from PNH cells exposed to isotonic sucrose and heat-inactivated C', or to medium with and without C'. In contrast, the number of megakaryocytic colonies grown from normal marrow cells exposed to isotonic sucrose and C' was unchanged. These findings indicate that PNH marrow CFU-M express an increased sensitivity to C'-mediated injury similar to that detected on PNH-erythrocytes by the sucrose haemolysis test, and support the hypothesis that the PNH defect is expressed at the level of pluripotent haematopoietic stem cell.

The suppressive role of platelets on the growth of human marrow megakaryocyte colony forming units (CFU-M) in vitro was investigated by the use of a plasma clot assay. An inverse correlation was established between the number of megakaryocytic colonies grown and the platelet concentration of the plasma or the resultant serum used in the culture system. The suppressive effect of platelets on megakaryocyte colony formation reached a plateau at normal human blood platelet concentration and was specific for CFU-M growth, since marrow cell erythroid burst formation (BFU-E) and granulocytic-monocytic colony formation (CFU-GM) remained unaffected. The inhibitory activity was detectable in the supernatants of platelet suspensions aggregated by thrombin or ADP, and the inhibitory activity released from ADP-stimulated platelets was blocked by pretreatment of platelets with monoclonal antibody HuPl-m1. Partial purification of this activity was achieved by diethylaminoethyl (DEAE)-ion exchange and phytohemagglutinin (PHA)-E agarose affinity chromatography. This inhibitor is a glycoprotein with a molecular weight of 12-17K daltons. This platelet released glycoprotein does not affect the early proliferative phase of CFU-M in vitro but acts on a day 6-8 CFU-M-derived cell by adversely affecting its maturation into recognizable megakaryocytes. These findings demonstrate that a glycoprotein released from platelets suppresses the maturation of CFU-M into megakaryocytes.

The effect of human recombinant erythropoietin (EP) on the growth of human marrow megakaryocyte colony forming units (CFU-M) in vitro was investigated by the use of a plasma clot assay. EP as a single stimulating factor or as an additional factor to optimal concentration of leucocyte conditioned medium (PHA-LCM) had no effect on the number of CFU-M derived colonies. However, addition of EP (0.5-1 U/ml) to cultures with suboptimal concentrations of PHA-LCM increased megakaryocytic colony formation by 50-90% but had no effect on the number of granulocytic-monocytic colonies (CFU-GM). Exposure of marrow cells to EP for 24-48 h in liquid suspension cultures, followed by removal of the hormone and assaying the cells for CFU-M in plasma clots, resulted in a 50-100% increase of megakaryocyte colony formation in vitro. The augmenting effect of EP on CFU-M growth in vitro was abolished when EP was added to the medium after the third day of culture. The presence of factors in human serum and in PHA-LCM was an absolute requirement for the hormone to exert its potentiating effect on human CFU-M growth in vitro. Recombinant EP potentiates the growth of human marrow CFU-M and this effect seems to be exerted during the early stages of CFU-M development in vitro.