University at Buffalo

About: University at Buffalo is a education organization based out in Buffalo, New York, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 33773 authors who have published 63840 publications receiving 2278954 citations. The organization is also known as: UB & State University of New York at Buffalo.

Ethnic differences in the presence of secondary sex characteristics and menarche among US girls: the Third National Health and Nutrition Examination Survey, 1988-1994.

Abstract: Objective To assess measures of puberty—presence of pubic hair, breast development, and menarche—for 3 racial/ethnic groups of girls in the United States Methods Using data from the Third National Health and Nutrition Examination Survey, this study sample was restricted to 1623 girls aged 8 to 16 years (466 non-Hispanic white, 589 non-Hispanic black, and 568 Mexican American) for whom information was available on Tanner stages of pubic hair and breast development Subsequently, the sample was restricted to 1168 girls aged 10 to 16 years (330 non-Hispanic white, 419 non-Hispanic black, and 419 Mexican American) for whom menarche data were available Tanner stage II or higher was used to define pubic hair and breast development; menarche status was self-reported The percentage of girls who had pubic hair and breast development and had achieved menarche was computed by age and race/ethnicity Probit and failure time models were applied to estimate mean ages at onset of pubic hair, breast development, and menarche The racial/ethnic differences also were examined after adjustment for social and economic variables and current body mass index Results Black and Mexican American girls had pubic hair and breast development and had achieved menarche at younger ages than white girls For example, 494% of black girls aged 9 years had breast development compared with 245% of Mexican American girls and 158% of white girls The mean age at onset of pubic hair, breast development, and menarche was 95, 95, and 121 year for black girls; 103, 98, and 122 years for Mexican American girls; and 105, 103, and 127 years for white girls These ethnic differences remained even after adjustment for current body mass index and several social and economic variables Conclusion Black girls on average enter puberty first, followed by Mexican American and then white girls

Surface properties determine bioadhesive outcomes: Methods and results

Abstract: This investigation developed experimental evidence for the influence of different surface energy states on tissue incorporation of biomedical materials. Implants of two smooth metals, each with three different surface energy states, were placed in the subdermal fascial plane of the backs of New Zealand White rabbits and were allowed healing times of 10 and 20 days. The implant surfaces were thoroughly characterized by physical-chemical criteria prior to surgical placement and again following removal from the tissue capsules generated by the host animals. Quantitative histopathologic analysis, using standard morphometric criteria, of the adjacent tissues revealed up to a threefold increase of fibroblastic-fibrocytic cells against the initially scrupulously cleaned, high-surface-energy materials. The cells were flattened and active, producing tenacious bonds through a thin pre-adsorbed protein-dominated "conditioning" film, that could be broken only by cohesive failure in the tissue itself. In contrast, the lower-surface-energy materials typical of standard dental implants were "walled off" by a cell-poor, nonadhesive capsule with a fibrous interface separated from a thicker "conditioning" film by a lipid-rich mucus zone. The advantages of proper surface treatment to favor the desired degree of biological adhesion are apparent.