51 research outputs found

    Plasma and testicular testosterone levels, volume density and number of Leydig cells and spermatogenic efficiency of rabbits

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    Plasma and tissue testosterone concentrations were determined by radioimmunoassay in 12 eight-month-old sexually mature New Zealand White rabbits and evaluated for possible associations with spermatogenic efficiency as well as with volume density and number of Leydig cells. Testicular tissue was processed histologically and histometry was performed in order to quantify germ cells, Sertoli cells and Leydig cells. Spermatogenic efficiency, reported as the ratios among germ cells (spermatogonia, primary spermatocytes and round spermatids) and by the ratio of germ cells to Sertoli cells, was not associated with testosterone levels. However, Leydig cell parameters such as number of Leydig cells per gram of testis, total number of Leydig cells per testis and percent cell volume of Leydig cell nuclei were correlated significantly with testosterone levels. The statistically significant correlation (r = 0.82, P\u3c0.05) observed between testosterone levels and the number of Leydig cells per gram of testis suggests that, in the rabbit, the latter parameter can serve as a criterion for monitoring testosterone levels in this species under normal conditions

    A pre formulation study of tetracaine loaded in optimized nanostructured lipid carriers

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    Tetracaine TTC is a local anesthetic broadly used for topical and spinal blockade, despite its systemic toxicity. Encapsulation in nanostructured lipid carriers NLC may prolong TTC delivery at the site of injection, reducing such toxicity. This work reports the development of NLC loading 4 TTC. Structural properties and encapsulation efficiency EE amp; 8201; gt; amp; 8201;63 guided the selection of three pre formulations of different lipid composition, through a 23 factorial design of experiments DOE . DLS and TEM analyses revealed average sizes 193 220 nm , polydispersity lt; amp; 8201;0.2 , zeta potential amp; 8722; amp; 8201;21.8 to amp; 8722; amp; 8201;30.1 mV and spherical shape of the nanoparticles, while FTIR ATR, NTA, DSC, XRD and SANS provided details on their structure and physicochemical stability over time. Interestingly, one optimized pre formulation CP TRANS TTC showed phase separation after 4 months, as predicted by Raman imaging that detected lack of miscibility between its solid cetyl palmitate and liquid Transcutol lipids. SANS analyses identified lamellar arrangements inside such nanoparticles, the thickness of the lamellae been decreased by TTC. As a result of this combined approach DOE and biophysical techniques two optimized pre formulations were rationally selected, both with great potential as drug delivery systems, extending the release of the anesthetic gt; amp; 8201;48 h and reducing TTC cytotoxicity against Balb c 3T3 cell

    Atividade biológica de extratos acetato de etila, etanólico e aquoso de timbó (Lonchocarpus floribundus) sobre carrapato bovino

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    Os extratos acetato de etila, etanólico e aquoso de raízes de Lonchocarpus floribundus foram utilizados, a fim de avaliar a atividade biológica sobre carrapato bovino. Carrapatos adultos foram coletados em bovinos infestados artificialmente, separados em grupos de dez indivíduos, pesados e imersos, separadamente, nos extratos de raízes de L. Floribundus, nas concentrações de 5, 25, 50, 75 e 100 mg mL-1. Para a avaliação em larvas, foram utilizados indivíduos de 14 a 21 dias, os quais foram imersos nos extratos nas concentrações de 1, 5, 10, 15 e 20 mg mL-1. Após o tratamento, cada grupo foi colocado em placa de Petri e incubado a 27 ± 1 ºC e umidade relativa de 80 ± 5%. Os extratos avaliados não foram eficazes para induzir, acima de 50%, a mortalidade de fêmeas ingurgitadas. Os extratos acetato de etila e etanólico induziram 100% de mortalidade de larvas. Entretanto, quanto aos valores de concentração letal mediana (CL50), o extrato etanólico (CL50 = 2,1 mg mL-1) foi mais tóxico que o extrato acetato de etila (CL50 = 4,1 mg mL-1). O extrato etanólico estimou concentração inibitória mediana (CI50) de 3,0 mg mL-1 e foi mais tóxico que os demais extratos quanto a este parâmetro de avaliação. Entre os três extratos avaliados, os extratos acetato de etila e etanólico apresentaram os melhores resultados quanto ao controle de reprodução de R. (B.) microplus, atingindo 100% na concentração de 5 mg mL-1. Os extratos de raízes de L. Floribundus apresentaram atividade biológica sobre carrapato bovino

    Body appreciation around the world: Measurement invariance of the Body Appreciation Scale-2 (BAS-2) across 65 nations, 40 languages, gender identities, and age.

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    The Body Appreciation Scale-2 (BAS-2) is a widely used measure of a core facet of the positive body image construct. However, extant research concerning measurement invariance of the BAS-2 across a large number of nations remains limited. Here, we utilised the Body Image in Nature (BINS) dataset - with data collected between 2020 and 2022 - to assess measurement invariance of the BAS-2 across 65 nations, 40 languages, gender identities, and age groups. Multi-group confirmatory factor analysis indicated that full scalar invariance was upheld across all nations, languages, gender identities, and age groups, suggesting that the unidimensional BAS-2 model has widespread applicability. There were large differences across nations and languages in latent body appreciation, while differences across gender identities and age groups were negligible-to-small. Additionally, greater body appreciation was significantly associated with higher life satisfaction, being single (versus being married or in a committed relationship), and greater rurality (versus urbanicity). Across a subset of nations where nation-level data were available, greater body appreciation was also significantly associated with greater cultural distance from the United States and greater relative income inequality. These findings suggest that the BAS-2 likely captures a near-universal conceptualisation of the body appreciation construct, which should facilitate further cross-cultural research. [Abstract copyright: Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.
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