Stem cells in the light of evolution.

All organisms depend on stem cells for their survival. As a result, stem cells may be a prerequisite for the evolution of specific characteristics in organisms that include regeneration, multicellularity and coloniality. Stem cells have attracted the attention of biologists and medical scientists for a long time. These provide materials for regenerative medicine. We review in this paper, the link between modern stem cell research and early studies in ancient organisms. It also outlines details on stem cells in the light of evolution with an emphasis on their regeneration potential, coloniality and multicellularity. The information provided might be of use to molecular biologists, medical scientists and developmental biologists who are engaged in integrated research involving the stem cells.

Effect of caffeine, norfloxacin and nimesulide on heartbeat and VEGF expression of zebrafish larvae.

The use of pharmaceuticals during pregnancy may causes abnormalities to the embryo. Sometime the drug also effect to the new born if the drug transferred through lactation. We have used zebrafish model to see the effect of some pharmaceuticals on embryos and larvae. Three drugs, caffeine, norfloxacin and nimesulide, were used for this study to see the effect mainly the hatching rate of eggs, heart beat rate and the vascular endothelial growth factor (VEGF) expression of the larvae. VEGF is an important signaling protein that involved generating the new blood vessels during embryonic development. We have used 10, 20, 50, 100 Ag ml-1 concentrations of all the drugs to see the effect. No significant mortality or malformations were observed in zebrafish embryos. Hatching was stared from 60 hr. In control group, 91% hatching rate was observed. Lowest hatching rate was observed using highest concentration of norfloxacin (100 Ag ml-1) and nimesulide (100 Ag ml-1) i.e. 55 and 56% respectively. In control group, 110 to 115 heart beat rate was counted per minute. Significantly higher heart beat was observed in caffeine treated group which is 125 to140 min-1. Lower heart beat was noted in nimesulide treated group which is 100 min-1. We have tried to observe the possible effect of VEGF of the larvae by these three drugs. Expression of VEGF was very low in caffeine treated group. Almost no VGF expression was observe in 100 Ag ml-1 caffeine treated group. These studies suggest that there is a possibility that high dosage of caffeine can harm the unborn baby or new born babies, if the mothers use caffeine.

India's homosexual discrimination and health consequences

A large number of countries worldwide have legalized homosexual rights. But for 147 years, since when India was a British colony, Section 377 of the Indian Penal Code defines homosexuality as a crime, punishable by imprisonment. This outdated law violates the fundamental rights of homosexuals in India. Despite the fact that literature drawn from Hindu, Buddhist, Muslim, and modern fiction testify to the presence of same-sex love in various forms, homosexuality is still considered a taboo subject in India, by both the society and the government. In the present article, the continuation of the outdated colonial-era homosexuality law and its impact on the underprivileged homosexual society in India is discussed, as well as consequences to this group's health in relation to HIV infection.

Muitos países têm legalizado os direitos homossexuais. Mas há 147 anos, desde quando a índia ainda era colônia britânica, a Seção 377 do Código Penal indiano define a homossexualidade como crime passível de prisão. Esta lei antiga viola os direitos fundamentais de homossexuais na índia. Embora as literaturas hindu, budista, muçulmana, e a ficção moderna confirmem a presença de sentimento de amor entre pessoas do mesmo sexo, a homossexualidade ainda é considerada um tabu na índia, tanto pela sociedade como pelo governo. No presente artigo, discute-se a continuidade dessa lei da época colonial sobre homossexualidade e seu impacto na sociedade indiana desfavorecida, bem como as conseqüências para a saúde desse grupo quanto à infecção pelo HIV.