Harmful cleats of football boots: a biomechanical evaluation.

BACKGROUND: Football players wear boots of varying cleat designs with some preferring the bladed cleats while others opting for the conventional studded cleats. The current study compares biomechanically the boots with differing cleat designs and their effect on feet, if any. METHODS: Twenty-nine healthy male volunteers were recruited from amateur football teams. They were asked to perform three trials each of two activities: a straight run and a run cutting at a 60° angle wearing bladed and studded Adidas®-F series boots on artificial turf. Plantar pressure values were recorded using the Pedar®-X in-shoe pressure measuring device. Peak pressure and pressure-time integral were analysed over 11 clinically relevant areas under the foot. RESULTS: While the in-shoe pressure and pressure-time integral were higher under the medial half of the foot with studded boots, they were higher under the lateral half of the foot with the bladed design. CONCLUSIONS: The studded boots can be considered safer as the pressure distribution across the foot and the pattern of centre of pressure progression mimicked the normal motif, whereas the bladed boots could potentially be deemed relatively more harmful due to the unnatural increased loading under the lateral half of the foot, predisposing the foot to injuries.

Structure, DNA minor groove binding, and base pair specificity of alkyl- and aryl-linked bis(amidinobenzimidazoles) and bis(amidinoindoles).

A series of bis(amidinobenzimidazoles) and bis(amidinoindoles) with varied linking chains connecting the aromatic groups and various modifications to the basic amidino groups have been prepared. The calf thymus (CT) DNA and nucleic acid homopolymer [poly(dA).poly(dT),poly(dA-dT).poly-(dA-dT), and poly(dG-dC).poly(dG-dC)] binding properties of these compounds have been studied by thermal denaturation (delta Tm) and viscosity. The compounds show a greater affinity for poly(dA).poly(dT) and poly(dA-dT).poly(dA-dT) than for poly(dG-dC).poly(dG-dC). Viscometric titrations indicate that the compounds do not bind by intercalation. Molecular modeling studies and the biophysical data suggest that the molecules bind to the minor groove of CT DNA and homopolymers. Analysis of the shape of the molecules is consistent with this mode of nucleic acid binding. Compounds with an even number of methylenes connecting the benzimidazole rings have a higher affinity for DNA than those with an odd number of methylenes. Molecular modeling calculations that determine the radius of curvature of four defined groups in the molecule show that the shape of the molecule, as a function of chain length, affects the strength of nucleic acid binding. Electronic effects from cationic substituents as well as hydrogen bonding from the imidazole nitrogens also contribute to the nucleic acid affinity. The bis(amidinoindoles) show no structurally associated differential in nucleic acid base pair specificity or affinity.

Inner-city older blacks have high levels of functional disability.

OBJECTIVES: To describe the frequency and severity of functional problems in two groups of noninstitutionalized inner-city blacks aged 70 years and older contrasted with results from appropriate groups of white and black older adults and with the goals of the Healthy People 2000 program. DESIGN: Cross-sectional descriptive study. SETTING: Community-based samples. PARTICIPANTS: A population-based sample of 416 older adults living in a 3.5-square mile catchment area in north St. Louis (NSL), Missouri, and a sample of 197 older residents living in public housing in East St. Louis (ESL), Illinois. MEASUREMENTS: Health status, preventive health activities, health services utilization, and risks for progressive frailty were assessed by self report and observation using well validated, standardized instruments. Whenever possible, comparison data were derived from national datasets, original samples used to validate the measures, and other useful comparison groups. RESULTS: The NSL sample had somewhat better health status and risk for progressive disability than the ESL sample. However, compared with national or regional reference groups using age-gender adjustments, both study groups demonstrated increased levels of dependence in intermediate activities of daily living, restricted activity days, inability to walk one-half mile without assistance, reported poor vision, living alone, and limited income compared with both older whites and blacks, and increased levels of worsening health, inability to perform heavy work around the house, never walking a mile or more, and currently unmarried versus whites with variable decrements versus blacks. Contrasted with other comparison groups, the two samples had increased body fat; consistent decrements in gait speed, timed chair stands, timed one-leg balance, and frequency of preventive exercise; and lower levels of dental care; results relative to physician visits and hospital days were mixed. They also had high levels of measured visual and hearing impairments, unmet needs for home delivered meals, and problems with false teeth. Deficiencies compared with the goals of Healthy People 2000 were large. CONCLUSIONS: The special attributes of inner-city blacks, including poverty and access to and acceptance of remedial programs, will have to be considered if the goals of Healthy People 2000 are to be met in this important and growing segment of older Americans. 44:0000-0000, 1996.

Nutritional risk in inner-city-dwelling older black Americans.

OBJECTIVE: To define the degree of nutritional risk in older inner-city black Americans and to identify important underlying factors associated with high nutritional risk. DESIGN: Cross-sectional descriptive study. SETTING AND PARTICIPANTS: A population-based sample of 400 noninstitutionalized persons older than 69 years of age in north St. Louis (NSL), Missouri, and a community-based sample of 115 residents aged 50 years and older living in public housing in East St. Louis (ESL), Illinois. Both study areas have high levels of poverty. MEASUREMENTS: Nutritional risk was measured using the Nutrition Screening Initiative Checklist. Demographic information, economic status, self-rated health, Geriatric Depression Scale score, and body mass index were assessed using established standardized instruments. MAIN RESULTS: Forty-eight percent of NSL and 66% of ESL subjects scored high on the Checklist. Compared with a mostly white (96%) comparison group from New England, both samples demonstrated particularly high prevalence for limited intake of fruits, vegetables, and milk; tooth and mouth problems; lack of money for food; eating alone; polypharmacy; and inability to shop, cook or feed on their own. High levels of depressive symptoms, fair or poor self-rated health, perceived inadequacy of income, and low income levels were associated with high risk, but even those subjects with no or few such predisposing factors were still high on the Checklist score compared with the New England sample. CONCLUSIONS: If confirmed, these results indicate that inner-city-dwelling older black Americans are at high nutritional risk. Attempts to reduce their nutritional risk should focus on improving nutritional content of their diet, oral health, polypharmacy, depressive symptoms, and poor general health; offering group meals; and providing assistance with shopping and cooking.

Differences in effect of 6-hydroxydopamine on the right and left atria from guinea-pig.

The effect of chemical sympathectomy by 6-hydroxydopamine (6-OHDA) treatment was studied on guinea-pig atria. 6-OHDA treatment significantly reduced the positive inotropic effect of nicotine and tyramine on the left atrium, while similar treatment on the intact atria and the right atrium showed a decreased response to tyramine but not to nicotine. After 6-OHDA treatment the left atrium but not the right atrium showed supersensitivity to noradrenaline. The 6-OHDA induced reduction of catecholamine content and noradrenaline uptake was less effective on the right atrium in comparison to the left atrium and ventricles. After 6-OHDA treatment, tissue catecholamine fluorescence disappeared from all tissue layers of the left atrium but the number of specific fluorescent nerve terminals of the right atrium was only slightly decreased. These results indicate that adrenergic mechanisms of the right atrium exhibit higher resistance to sympathectomy by 6-OHDA than the left atrium.

Molecular diversity in chemical databases: comparison of medicinal chemistry knowledge bases and databases of commercially available compounds.

A molecular descriptor space has been developed which describes structural diversity. Large databases of molecules have been mapped into it and compared. This analysis used five chemical databases, CMC and MDDR, which represent knowledge bases containing active medicinal agents, ACD and SPECS, two databases of commercially available compounds, and finally the Wellcome Registry. Together these databases contained more than 300,000 structures. Topological indices and the free energy of solvation were computed for each compound in the databases. Factor analysis was used to reduce the dimensionality of the descriptor space. Low density observations were deleted as a way of removing outliers, which allowed a further reduction in the descriptor space of interest. The five databases could then be compared on an efficient basis using a metric developed for this purpose. A Riemann gridding scheme was used to subdivide the factor space into subhypercubes to obtain accurate comparisons. Most of the 300,000 structures were highly clustered, but unique structures were found. An analysis of overlap between the biological and commercial databases was carried out. The metric provides a useful algorithm for choosing screening sets of diverse compounds from large databases.