The action of demineralized bovine bone matrix on bone neoformation in rats submitted to experimental alcoholism / Ação da matriz óssea bovina desmineralizada na neoformação óssea em ratos submetidos ao alcoolismo experimental

The objective of this study was to evaluate whether demineralized bovine bone (Gen-ox®) alters bone neoformation in rats submitted to alcoholism. Forty male rats were separated into two groups of 20 rats and distributed as follows: Group E1, which received 25% ethanol and a surgical cavity filled only by a blood clot, and Group E2, which received 25% ethanol and a surgical cavity filled with Gen-ox®. The animals were euthanized at 10, 20, 40 and 60 days after surgery and necropsy was performed. The histomorphological and histometric analyses of the area of connective tissue and bone neoformation showed that the reorganization of the bone marrow and full repair of the surgical cavity in Group E1 occurred more quickly than in Group E2. It was also noted that in the final period the animals in Group E2 showed areas of connective tissue and thick bone trabeculae around the particles of the implant. It can be concluded that the use of Gen-ox® delayed the process of bone repair in alcoholic rats, although it can be used as filling material because it shows osteoconductive activity, as evidenced by bone tissue formation around the graft particles.

O objetivo deste trabalho foi avaliar se a matriz óssea bovina desmineralizada (Gen-ox®) altera a neoformação óssea em ratos submetidos ao alcoolismo. Foram utilizados 40 ratos machos, separados em dois grupos de 20 animais cada, assim distribuídos: Grupo E1, que recebeu etanol a 25% e cavidade cirúrgica preenchida por coágulo sanguíneo, e Grupo E2, que recebeu etanol a 25% e cavidade cirúrgica preenchida por Gen-ox®. Os animais foram eutanasiados aos 10, 20, 40 e 60 dias após a cirurgia. Os estudos histomorfológico e histométrico da quantidade de tecido conjuntivo presente e a quantidade de tecido ósseo neoformado demostraram que a reorganização da medula óssea e a reparação total da cavidade cirúrgica no Grupo E1 ocorreram em menor espaço de tempo do que no Grupo E2. Observou-se também que, no período final do experimento, os animais do Grupo E2 apresentaram áreas de tecido conjuntivo e trabéculas ósseas espessas ao redor das partículas do material implantado. Concluiu-se que a utilização do Gen-ox® retardou o processo de reparação óssea em ratos alcoolizados, muito embora o Gen-ox® possa ser utilizado como material de preenchimento, pois demonstra atividade osteocondutiva, com a formação de tecido ósseo ao redor das partículas do enxerto.

Morphometry and histochemistry of the semitendinosus muscle of tufted capuchin monkeys (Cebus apella Linnaeus, 1758).

Considering monkeys are animals closely related to the human, and semitendinosus muscle has been used in many postural research experiments, we have decided to study its histochemical characteristics. Samples were removed from the proximal, middle and distal regions of the semitendinosus muscles of five adult male tufted capuchin monkeys and observed for reaction with m-ATPase (with alkaline and acid pre-incubation), nicotinamide adenine dinucleotide tetrazolium reductase, and haematoxylin and eosin. The muscle fibres were classified as fast glycolytic (FG), fast oxidative glycolytic (FOG) and slow oxidative (SO) and quantified in terms of frequency and area. The three regions of the semitendinosus muscle showed no significant differences in frequency or area of the respective fibre types, and therefore the muscle can be considered histoenzymologically homogeneous. FG fibres presented higher frequencies and larger areas. The sum of FOG and SO fibres was 57.5%, suggesting that the semitendinosus muscle of the tufted capuchin monkey is adapted to an action involved in posture maintenance and in long arboreal dislocation. The present data agrees with the notion of differentiated quadrupedalism in some primates, which support a lower percentage of their weight on the fore limbs.

Histoenzymology and morphometry of the masticatory muscles of tufted capuchin monkey (Cebus apella Linnaeus, 1758).

Samples of the anterior and posterior regions of the masseter and temporal muscles and of the anterior belly of the digastric muscle of 4 adult male tufted capuchin monkeys (Cebus apella) were removed and stained with HE and submitted to the m-ATPase reaction (with alkaline and acid preincubation) and to the NADH-TR and SDH reactions. The results of the histoenzymologic reactions were similar, except for acid reversal which did not occur in fibers of the fast glycolytic (FG) type in the mandibular locomotor muscles. FG fibers had a larger area and were more frequent in all regions studied. No significant differences in frequency or area of each fiber type were detected, considering the anterior and posterior regions of the masseter and temporal muscles. The frequency of fibers of the fast oxidative glycolytic (FOG) and slow oxidative (SO) types and of FOG area differed significantly between the anterior belly of the digastric muscle and the mandibular locomotor muscle. The predominance of fast twitch (FG and FOG) fibers and the multipenniform and bipenniform internal architecture of the masseter and temporal muscles, respectively, are characteristics that permit the powerful bite typical of tufted capuchin monkeys.

A pilot study of immigration status, homosexual self-acceptance, social support, and HIV reduction in high risk Asian and Pacific Islander men.

This article reports the results of a cross-sectional study that was conducted to describe the sexual behavior and HIV risk reduction behaviors of homosexual and bisexual Asian and Pacific Islander men and to relate immigration status, self-acceptance as a homosexual, and levels of social support to the adoption of safe sexual behaviors in this population. Thirty-one gay and bisexual Asian and Pacific Islander men in San Diego County, California, participated. Generally high levels of knowledge about HIV and transmission risks as well as self-acceptance and social support were found. While most (84%) reported some attempts to increase condom use in the previous 6 months, 42% reported engaging in unprotected intercourse during that same time period. An inverse relationship between self-acceptance and utilization of risk reduction strategies was found. No association was found between immigration status or self-reported HIV status and level of HIV knowledge, level of HIV risk behavior, or level of HIV risk reduction efforts. The findings are discussed within the context of other social network studies and HIV prevention programs for gay and bisexual Asian and Pacific Islander men.