Genetic variation at twentythree microsatellite loci in sixteen human populations

Artículo científico -- Universidad de Costa Rica, Instituto de Investigaciones en Salud. 1999We have analysed genetic variation at 23 microsatellite loci in a global sample of 16 ethnically and geographically diverse human populations. On the basis of their ancestral heritage and geographic locations, the studied populations can be divided into five major groups, viz. African, Caucasian, Asian Mongoloid, American Indian and Pacific Islander. With respect to the distribution of alleles at the 23 loci, large variability exists among the examined populations. However, with the exception of the American Indians and the Pacific Islanders, populations within a continental group show a greater degree of similarity. Phylogenetic analyses based on allele frequencies at the examined loci show that the first split of the present-day human populations had occurred between the Africans and all of the non-African populations, lending support to an African origin of modern human populations. Gene diversity analyses show that the coefficient of gene diversity estimated from the 23 loci is, in general, larger for populations that have remained isolated and probably of smaller effective sizes, such as the American Indians and the Pacific Islanders. These analyses also demonstrate that the component of total gene diversity, which is attributed to variation between groups of populations, is significantly larger than that among populations within each group. The empirical data presented in this work and their analyses reaffirm that evolutionary histories and the extent of genetic variation among human populations can be studied using microsatellite loci.Universidad de Costa Rica. Instituto de Investigaciones en SaludUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones en Salud (INISA

Curcumin in advancing treatment for gynecological cancers with developed drug- and radiotherapy-associated resistance

The development of resistance toward current cancer therapy modalities is an ongoing challenge in gynecological cancers, especially ovarian and cervical malignancies that require further investigations in the context of drug- and irradiation-induced resistance. In this regard, curcumin has demonstrated beneficial and highly pleiotropic actions and increased the therapeutic efficiency of radiochemotherapy. The antiproliferative, anti-metastatic, anti-angiogenic, and anti-inflammatory effects of curcumin have been extensively reported in the literature, and it could also act as a chemopreventive agent which mitigates the out-of-target harmful impact of chemotherapeutics on surrounding normal tissues. The current review discussed the modulating influences of curcumin on some cell and molecular features, including the cell signaling and molecular pathways altered upon curcumin treatment, the expression of target genes involved in the progression of gynecological cancers, as well as the expression of genes accountable for the development of resistance toward common chemotherapeutics and radiotherapy. The cell molecular targets implicated in curcumin�s resensitizing effect, when used together with cisplatin, paclitaxel, and irradiation in gynecological cancers, are also addressed. Finally, rational approaches for improving the therapeutic benefits of curcumin, including curcumin derivatives with enhanced therapeutic efficacy, using nanoformulations to advance curcumin stability in physiological media and improve bioavailability have been elucidated. © 2018, Springer International Publishing AG, part of Springer Nature

Patterns of donor-type microchimerism after heart transplantation

Allogeneic microchimerism of donor-type has been demonstrated in stable patients in the long-term after organ transplantation. We have analysed microchimerism in skin and blood of 47 heart-transplanted patients after transplantation with polymerase-chain-reaction amplification specific for donor HLA-DRB1. Microchimerism was detectable in 50% of the patients in the first 6 months, in 100% between 6 months and 2 years, and in 58% in the third postoperative year or later. The state of chimerism was not related to acute or chronic rejections. Patterns of microchimerism after heart transplantation may be dynamic, but any association with clinical and immunological variables remains to be elucidated