Our findings suggest that that administration of 1,000 mg of ascorbic acid together with 400 IU of alpha-tocopherol could be useful in preventing or aiding in the treatment of age-related osteoporosis.

Common indices for the assessment of nutritional status take height into account. Elderly individuals are frequently unable to assume the position needed for this measurement. Therefore, equations have been developed for predicting height in elderly American Whites, American Blacks, and Mexican Americans using knee height as a predictor. These equations may not be applicable for the elderly in other populations. A sample of 736 individuals was studied (186 males, 550 females) with a mean age of 74.7 +/- 8 years. Height and knee height (without shoes) were measured in millimeters. Multiple regression and cross-validation was performed. The correlation between knee height and standing height was similar in women (r = 0.86; P < 0.0001) and men (r = 0.83; P < 0.0001). The equations obtained were as follows: men (height in cm) = 52.6 + (2.17 x knee height in cm) and women (height in cm) = 73.7 + (1.99 x knee height in cm) - (0.23 x age in years). Cross-validation showed that the pure error was less than the root mean square error (RMSE) in both sexes. Mean heights, based on the equations of Chumlea et al. (1998) for Mexican Americans significantly differ from the reference values for females and males. Therefore, the equations developed by Chumlea et al. (1998) for elderly Mexican Americans do not appear to be applicable for elderly Mexicans.

RESUMENCoryphantha tiene entre 43 y 67 especies. Los patrones de variación morfológica del género se han interpretado de distintas formas y han conducido a una taxonomía inestable, de manera que aún no se ha establecido un consenso en la delimitación de las especies. Clasificaciones previas de Coryphantha se han basado en caracteres cualitativos. Para dilucidar y circunscribir especies de Coryphantha se emplearon diferentes técnicas de análisis multivariado. Se muestrearon un total de 1840 individuos, 467 ejemplares en campo y 1373 registros herborizados de 48 taxa del género. Se emplearon 28 caracteres vegetativos y reproductivos de los cuales 17 fueron cuantitativos y 11 cualitativos. El análisis de conglomerados indicó la presencia de dos grandes grupos organizados por la presencia o ausencia de glándulas extraflorales. Los análisis discriminantes para cada subgrupo formado por los análisis de conglomerados permitieron circunscribir con base en variables morfométricas a la mayoría de las especies analizadas. Con base en los caracteres morfológicos y los análisis multivariados se discute el reconocimiento de categorías taxonómicas a nivel de especie o subespecie. Se reconocen 45 especies y tres subespecies.Palabras clave: análisis de conglomerados, análisis discriminante, Cactaceae, Coryphantha, taxonomía. ABSTRACTCoryphantha consists of 43 to 67 species. This genus exhibit patterns of morphological variations that have been understood differently and have led to an unstable

Malaria is the most lethal parasitic disease worldwide; men exhibit higher mortality and more severe symptomatology than women; however, in most studies of immune response in malaria, sex is not considered a variable. Sex hormones 17β-oestradiol and testosterone are responsible for the main physiological differences between sexes. When interacting with their receptors on different immune cells, they modify the expression of genes that modulate cell proliferation, differentiation, and synthesis of cytokines. The immunosuppressive activity of testosterone is well accepted; however, its participation in the sexual dimorphism of the immune response to malaria has not been studied. In this work, we analysed whether altering the concentration of testosterone, through increasing the concentration of this hormone for exogenous administration for three weeks, or gonadectomy before infection with Plasmodium berghei ANKA affects different cells of the immune response necessary for parasite clearance. We also assessed the concentration of pro-and anti-inflammatory cytokines in male and female CBA/Ca mice infected or not with the parasite. Our results show that testosterone changes affect females more than males, resulting in sex-associated patterns. Testosterone administration increased parasitaemia in intact males while reducing it in intact females leading to a dimorphic pattern. In addition, gonadectomy increased parasitaemia in both sexes. Moreover, testosterone administration prevented both weight loss caused by the infection in females and hypothermia in gonadectomized mice of both sexes. Boosting testosterone concentration increased CD3+ and CD8+ populations but decreased the B220+ cells exclusively in females. Additionally, testosterone reduced IFN-γ concentration and increased IL-6 levels only in females, while in males, testosterone increased the number of NK cells. Finally, gonadectomy decreased TNF-α concentration in both sexes. Our results demonstrate that testosterone induces different patterns depending on sex and testosterone concentration. The results of this work contribute to understanding the impact of modifying testosterone concentration on the immune response specific against Plasmodium and the participation of this hormone in sexual dimorphism in malaria.

Malaria is the most lethal parasitic disease in the world. Mortality and severity in symptoms are higher in men than women, suggesting that oestrogens, which are in higher concentration in females than in males, may regulate the immune response against malaria. Tamoxifen, a selective oestrogen receptor modulator used in breast cancer treatment due to its antagonistic effect on oestrogen receptors α and β, is also studied because of its potential therapeutic use for several parasitic diseases. However, most studies, including one in malaria, have not addressed the immunomodulatory role of tamoxifen. In this work, we evaluated the effect of tamoxifen on the immune response of CBA/Ca mice against Plasmodium berghei ANKA. This study showed for the first time that tamoxifen increased parasite load, aggravated symptoms by decreasing body temperature and body weight, and worsened anaemia. Additionally, tamoxifen significantly increased the splenic index and the percentages of CD4+ and NK+ cells on day eight post-infection. By contrast, tamoxifen decreased both CD8+ and B220+ populations in the spleen and decreased the serum levels of IL-2, IL-6, and IL-17. Our findings support the notion that tamoxifen is a potent immunomodulator in malaria-infected mice and suggest caution when administering it to malaria-infected women with breast cancer.