精亏不育与锌锰

以临床典型精亏不育病案为例，探讨了中医中药传统和微量元素的关系，重点讨论了微量元素锌、锰、与精亏不育的病因病理和治疗的关系。     

Morus alba Prevented the Cyclophosphamide Induced Somatic and Germinal Cell Damage in Male Rats by Ameliorating the Antioxidant Enzyme Levels

Cytogenetic analysis is essential to determine the effect of mutagens and antimutagens on genetic material. This study was done to evaluate the protective effect of root bark extract of Morus alba (M. alba) against cyclophosphamide induced somatic and germinal cell damage in male rats. The ethanolic extract of M. alba (0.25, 0.5 and 1 g/kg, 2 weeks) was evaluated against cyclophosphamide (75 mg/kg, single dose) induced nuclear damage. The sampling was done after 48 h of the clastogen treatment. The somatic and germinal nuclear damage was studied by bone marrow micronucleus and sperm analysis, respectively. Serum superoxide and catalase levels were estimated to determine the antioxidant status in each group. The results were analyzed statistically to find the significant variation. The administration of M. alba for 2 weeks suppressed dose-dependently the changes induced by cyclophosphamide. M. alba (0.5 g/kg) decreased the frequency of micronucleated erythrocyte, sperm shape abnormality and enhanced the sperm count, sperm motility and polychromatic-normochromatic erythrocytes ratio significantly (p < 0.05) in comparison with the cyclophosphamide treated group. The highest tested dose of M. alba (1 g/kg) produced more prominent suppression (p < 0.01) in the cyclophosphamide-induced somatic and germinal cell defects. The results also showed significant (p < 0.05) improvement in the serum antioxidant enzymes levels with M. alba when compared with the challenge group. The lower dose of M. alba extract (0.25 g/kg) prevented the CP-induced changes but was found to be statistically insignificant. Therefore, antimutagenic potential of the high dose of the extract of M. alba is possibly due to its antioxidant nature. The ability of the M. alba extract to prevent the nuclear damage could play an important role in overcoming several mutational defects that are associated with anticancer chemotherapy.     

Sex promotes gamete selection: A quantitative comparative study of features favoring the evolution of sex

Explaining the maintenance of sexual reproduction remains one of the greatest challenges in biology. The theoretical oddity of sex is based on at least three advantages that asexual organisms have over sexual ones: (1) Asexuals, by not producing males, have a twofold advantage over sexuals, regarding the number of reproductive individuals; (2) sexuals have an evolutionary disadvantage over asexuals, in that a rare alleles that increases fitness of one parent, for example, is not necessarily transmitted to the offspring, due to segregation; and (3) asexuals do not have to find a mate in order to reproduce. Here I present the results of evolutionary tournaments performed using the agent‐based computer simulation Biodynamica. The tournaments explored the relative merits of various features that have been proposed to affect the putative advantages of sexual reproduction, including ploidy, mate selection, large reproductive variance of males, low mutation rates, gamete selection, reduced cost for the production of males, thelytoky vs. parthenogenesis, variable environments, and complex genomes. The model allowed for a quantitative comparison of the effect of these features on the adaptive value of sex. The results showed that the production of large number of gametes (for example “masting” in massive flowering of trees or spermatozoa of most animals) inducing gamete selection, together with nonrandom mate selection, increased variance in male reproductive success and/or low mutation rates, allowed sexual agents to out‐breed asexual ones, despite the three disadvantages for sex cited above. The wok suggests that gamete cycles and alloiogenesis, common to most sexual plants, fungi, and animals, should be viewed as a new level for natural selection to work. Mate and gamete selection are more efficient in the use of biomass, energy, and time than natural selection at the level of organisms, helping to make sexual reproduction an evolutionary success. © 2004 Wiley Periodicals, Inc. Complexity 9: 43–51, 2004