A systematic review of weight loss, physical activity and dietary interventions involving African American men.

When compared with men of other racial or ethnic groups, African American men are more likely to experience adverse health conditions. The systematic review objectives were to (i) determine the current evidence base concerning African American men's response to lifestyle behavioural interventions designed to promote weight loss, increase physical activity, and/or improve healthy eating and (ii) determine the next steps for research in these areas. The PubMed, Web of Science, Psych Info and Cochrane databases were searched to identify papers published before January 1, 2013 that reported change in weight, physical activity and/or dietary patterns in African American men aged 18 and older, as a result of behavioural change strategies. The titles and abstracts of 1,403 papers were screened; after removing duplicates, 141 papers were read to determine their eligibility. Seventeen publications from 14 studies reported outcomes for African American men. Eight large multi-centre trials and six community-based studies were identified. African American men were an exclusive sample in only four studies. Five studies showed statistically significant improvements. Although the available evidence appears to show that these interventions produce positive results, the relative and the long-term effectiveness of weight loss, dietary and/or physical activity interventions for this population are unknown.

Orientation and dynamics of an antimicrobial peptide in the lipid bilayer by solid-state NMR spectroscopy.

The orientation and dynamics of an 18-residue antimicrobial peptide, ovispirin, has been investigated using solid-state NMR spectroscopy. Ovispirin is a cathelicidin-like model peptide (NH(2)-KNLRRIIRKIIHIIKKYG-COOH) with potent, broad-spectrum bactericidal activity. (15)N NMR spectra of oriented ovispirin reconstituted into synthetic phospholipids show that the helical peptide is predominantly oriented in the plane of the lipid bilayer, except for a small portion of the helix, possibly at the C-terminus, which deviates from the surface orientation. This suggests differential insertion of the peptide backbone into the lipid bilayer. (15)N spectra of both oriented and unoriented peptides show a reduced (15)N chemical shift anisotropy at room temperature compared with that of rigid proteins, indicating that the peptide undergoes uniaxial rotational diffusion around the bilayer normal with correlation times shorter than 10(-4) s. This motion is frozen below the gel-to-liquid crystalline transition temperature of the lipids. Ovispirin interacts strongly with the lipid bilayer, as manifested by the significantly reduced (2)H quadrupolar splittings of perdeuterated palmitoyloleoylphosphatidylcholine acyl chains upon peptide binding. Therefore, ovispirin is a curved helix residing in the membrane-water interface that executes rapid uniaxial rotation. These structural and dynamic features are important for understanding the antimicrobial function of this peptide.

Analysis of opioid binding to UDP-glucuronosyltransferase 2B7 fusion proteins using nuclear magnetic resonance spectroscopy.

The UDP-glucuronosyltransferase UGT2B7 is an important human UGT isoform that catalyzes the conjugation of many endogenous and exogenous compounds, among them opioids, resulting in the formation of D-glucuronides. The binding site of the aglycone is located in the N-terminal half of the protein. In this study, we demonstrate that the opioid binding site in UGT2B7 is within the first 119 amino-terminal amino acids. Two maltose binding protein fusion proteins, 2B7F1 and 2B7F2, incorporating the first 157 or 119 amino acids, respectively, of UGT2B7 were expressed in Escherichia coli and purified by affinity chromatography. NMR spectroscopy using one-dimensional spectra, the inversion recovery method, and the transferred nuclear Overhauser effect spectroscopy was used to study the binding properties of opioids to the fusion proteins. Morphine was found to bind at a single site within the first 119 amino acids and to undergo a conformational change upon binding, as demonstrated by transferred nuclear Overhauser effect spectroscopy. Dissociation constants were obtained for morphine, naloxone, buprenorphine, and zidovudine, and the results were confirmed by equilibrium dialysis determinations. Two possible opioid binding sites, based on the nearest neighbors from opioid binding to the micro-receptor and to cytochrome 2D6, are proposed.

The NMR structure of human beta-defensin-2 reveals a novel alpha-helical segment.

Human beta-defensin-2 (HBD-2) is a member of the defensin family of antimicrobial peptides. HBD-2 was first isolated from inflamed skin where it is posited to participate in the killing of invasive bacteria and in the recruitment of cells of the adaptive immune response. Static light scattering and two-dimensional proton nuclear magnetic resonance spectroscopy have been used to assess the physical state and structure of HBD-2 in solution. At concentrations of < or = 2.4 mM, HBD-2 is monomeric. The structure is amphiphilic with a nonuniform surface distribution of positive charge and contains several key structural elements, including a triple-stranded, antiparallel beta-sheet with strands 2 and 3 in a beta-hairpin conformation. A beta-bulge in the second strand occurs at Gly28, a position conserved in the entire defensin family. In solution, HBD-2 exhibits an alpha-helical segment near the N-terminus that has not been previously ascribed to solution structures of alpha-defensins or to the beta-defensin BNBD-12. This novel structural element may be a factor contributing to the specific microbicidal or chemokine-like properties of HBD-2.

The osmolyte xylitol reduces the salt concentration of airway surface liquid and may enhance bacterial killing.

The thin layer of airway surface liquid (ASL) contains antimicrobial substances that kill the small numbers of bacteria that are constantly being deposited in the lungs. An increase in ASL salt concentration inhibits the activity of airway antimicrobial factors and may partially explain the pathogenesis of cystic fibrosis (CF). We tested the hypothesis that an osmolyte with a low transepithelial permeability may lower the ASL salt concentration, thereby enhancing innate immunity. We found that the five-carbon sugar xylitol has a low transepithelial permeability, is poorly metabolized by several bacteria, and can lower the ASL salt concentration in both CF and non-CF airway epithelia in vitro. Furthermore, in a double-blind, randomized, crossover study, xylitol sprayed for 4 days into each nostril of normal volunteers significantly decreased the number of nasal coagulase-negative Staphylococcus compared with saline control. Xylitol may be of value in decreasing ASL salt concentration and enhancing the innate antimicrobial defense at the airway surface.

Bonding of amalgam to dentine: microleakage and shear bond strength evaluation.

This study investigates the shear bond strengths (SBS) of different products used for bonding amalgam to dentine and the marginal seal provided by these materials. The SBS test was carried out by bonding cylinders of Dispersalloy amalgam to human dentine with an intermediate layer of Amalgambond Plus, All-Bond 2, Imperva Bond/Dual or Scotch Bond Multi-Purpose was first placed. Thereafter the samples were tested to failure in the shear mode. For the microleakage test, standardized class V cavities were prepared in human molars with one cavo margin abutting enamel and another dentine/cementum. Amalgam was condensed into the cavities, pretreated with one of the products mentioned above. In addition two further groups were prepared. One receiving treatment with Polyvar varnish and the other remained untreated as the control. Microleakage was assessed with a reflecting light microscope using I.S.O. criteria and the fracture sites and marginal gaps were examined in a scanning electron microscope. Results indicate that All-Bond 2 and Amalgambond Plus induced similar SBS and Scotchbond Multi-Purpose the weakest. At both enamel and dentine/cementum junctions resin bonding agents reduced microleakage. However, this reduction was greater at the enamel interface than at the other. Varnish allowed the greatest amount of marginal leakage and leakage was similar to the untreated control. Amalgam bonding agents are more effective at preventing marginal leakage at the enamel margin than at the dentine/cementum margin. Cavity varnish is not effective in preventing microleakage around amalgam restorations. There is a correlation between shear bond strength and marginal leakage. Materials giving the highest shear bond strength also exhibited the least marginal leakage. All-Bond 2, Amalgambond Plus and Imperva Bond/Dual are recommended to improve the seal around amalgam restorations.

Scientific and ethical concerns in neural fetal tissue transplantation.

This report presents a brief overview of the medical and ethical issues involved with the procurement, preparation, safety, efficacy, and subject protection of human fetal central nervous system tissue in the context of neural transplantation. The ethical perspectives from which to view the clinical use of fetal tissue include the following: 1) that fetal tissue from elective abortions is a surgical specimen; 2) that the use of such tissue involves fetal experimentation in which the fetus is a subject; and 3) that fetal tissue is considered as a cadaveric organ specimen, similar to other organs, but with special considerations compared with adult cadaveric tissue. The latter approach appears to be the most applicable and is parallel to the use of cadaveric organs and tissues after a declaration of brain death. Additional issues include the following: 1) the safety and quality of fetal tissue for implantation; 2) the hypothesis that "legitimization" and "redemption" (potentially positive effects of tissue donation in general) may lead to an increase in elective abortion rates; 3) the ethical issues of the validity and value of human experimentation involving neural grafting; and 4) the type of consent to be obtained and the appropriate timing. Elective abortions, however, probably will continue to be the primary source of fetal tissue for grafting for some time, until other tissue sources become available.

Are there really alternatives to the use of fetal tissue from elective abortions in transplantation research?

PIP: Researchers believe fetal tissue can be easily transplanted into and cure people with incurable debilitating diseases such as Parkinson's disease. In 1988, the Reagan Administration stopped funding transplantation research of fetal tissue from induced abortions. An advisory panel later decided that it is an acceptable public policy as long as certain conditions a re met. Yet the Bush Administration continued the ban. In 1992, it erroneously claimed that transplantation research could use alternative sources of fetal tissue. 1 alternative is fetal tissue obtained from ectopic pregnancies. Yet spontaneously aborted ectopic pregnancies tend not to produce recognizable or viable in culture fetal tissue and if they do the tissue has been ischemic for days. Ectopic pregnancies requiring surgical sterilization tend to be morphologically abnormal. The only likelihood of viable fetal tissue form ectopic pregnancies is a fetus with myocardial contractility before surgery. The administration also recommended use of fetal tissue from spontaneous abortions but these fetuses often have a major chromosomal or other fatal defect. Researchers cannot use chromosomally abnormal fetal tissue since it growth, development, and function are unreliable. Expulsion of the necrotic fetus tends to occur a couple of weeks after death. The Bush Administration also proposed use of tissue from stillbirths but their tissue tends to be nonviable and the tissue, even if it were viable, is generally not at the developmental stage needed for transplantation. The placenta and yolk sac were other suggested alternatives, but the placenta is likely to be less immunogenic than embryonic tissue. It can help develop certain cell lines which produce insulin or neurotransmitters like dopamine, however. The yolk sac could replace fetal liver cells in transplantation. Nevertheless the only advantage of using the suggested alternatives is the perception of them raising less ethical concern than fetal tissue from an induced abortion.^ieng

Fetal tissue research and the misread compromise.

The bill to restore federal funding for human fetal tissue research has been passed by the House and awaits Senate approval. But it requires women who are willing to donate fetal tissue to certify that they did not have an abortion with the intent to donate. It further requires researchers to keep the certifications on file and available for government audit. Both requirements spell trouble.

PIP: H.R. 2507 passed by the US House of Representatives, is an attempt to end the ban on fetal tissue research. However it signals a new era in government violation of privacy and ultimately will undermine its own stated purpose. The law provides that any woman wishing to donate the fetal tissue from an abortion must sign 2 ethical intent forms. The 1st stating that the decision to donate was made independently of the decision to abort. The 2nd stating that the reason for aborting was not to donate fetal tissue. These forms of ethical intent are to be kept on file by the researchers using the fetal tissue and are to be made available for audit to ensure compliance. The law does not have any provision for protecting the confidentiality of these forms, nor does it state whose property they become. It also does not state who allowed to audit the records or whose responsibility it is. The results of this law are that women fearing exposure of their name in a document open to public audit will not want to donate. Further, in many states this failure to sign the forms can be legally viewed as intent to abort for donation and thus the abortion could be denied. In addition, researchers will not want to cover the expense or controversy surrounding these records and as such will refuse to accept fetal tissue.