RESUMEN
Zika is caused by a flavivirus transmitted by mosquitoes of the Aedes species, mainly Aedes aegypti. It causes a mild self-limiting illness in people that it infects, leaving most people asymptomatic. However, the recent rise in the spread of Zika virus predominantly in Latin America has been accompanied by unprecedented rise in a number of children being born with abnormally small heads-identified as microcephaly. In addition several countries, including Brazil, which has experienced the world largest Zika outbreaks, reported a steep increase in Guillain Barre Syndrome- a neurological autoimmune disorder that could lead to paralysis and death. Although it has not been definitively proven, evidence is growing that Zika virus causes both microcephaly and Guillain Barre Syndrome. Obviously, these reports made the World Health Organization to declare Zika as a significant global public health concern. Apart from using insecticides to control the spread of mosquitoes, several other approaches are being implemented to prevent Zika virus infection. These include vaccine development and impairing egg-laying female mosquito’s ability to transmit infection and also genetic modification and sterilization of male Aedes aegypti.
RESUMEN
Stem cells derived from the embryo (embryonic stem cells), bone marrow or umbilical cord blood (adult stem cells) has the potential to differentiate into many cell types in the human body. The embryonic stem cell are called “pluripotent” because they can become any of the body‟s 220 cell types including bone, muscle, skin, nervous tissue as well as immune cells. Those derived from bone marrow and cord blood are considered “multipotent” because they can differentiate only to specific families of cell types such as those of muscle and bone and also replenish mature cells within tissue. Despite the potential that they have in repairing or regenerating human tissue damaged by injury or disease, embryonic stem cells have been under a lot of criticisms due to ethical, religious as well as political considerations. The development of induced pluripotent stem cells (iPSCs) from adult stem cells, derived from mouse and man by cellular reprogramming seems to have produced embryonic-like stem cells without destroying the embryo-which critics say it is a deliberate attempt to take away human life because it contains human DNA. As promising as they seem the iPSCs would still have to pass the test of skepticism by certain stem cell scientists and screening tests of functionality when subjected to the usual development and applications cues. These prerequisites are needed before they can be certified as truly pluripotential and therefore could be applied in the treatment of human diseases particularly those that have defied cure such as Parkinson‟s disease, multiple sclerosis and insulin-dependent diabetes mellitus. Applications of stem cells in rejuvenating diseased or destroyed human parts are largely experimental because of various constraints. However, neurons have been generated from iPSCs made from the skin cells of patients with Parkinson‟s disease. There are also other success stories in the treatment of degenerative diseases particularly in Germany where stem cells have been employed in treating many patients suffering from diverse diseases. Even if development of iPSCs has not offered much at this time towards repairing of tissues damaged by disease, it has at least circumvented the technical complexities of cloning thus avoiding most of the ethical and legal constraints associated with human embryo cell research. It has also refuted the old dogma that cells once differentiated cannot be dedifferentiated into primordial stage of development. Embryonic stem cells remain the gold standard in stem cell research while more studies are needed to gain better insight into the pluripotency of iPSCs. Whether derived from the embryo or adult cell, stem cells hold a huge promise in regenerative medicine in the near future.