Prevalence of the sickle cell gene in Yemen: a pilot study

To determine the prevalence of the sickle cell gene [[beta][S]] in Yemen and amongst people from different regions of the country living in the capital, Sana'a City, cord blood samples from 1,500 consenting mothers were collected from hospitals in Sana'a City between July and December 2001. The names and original homes of the parents were recorded .Cation exchange high performance liquid chromatography [HPLC] analysis was used for screening, while isoelectric focusing [IEF] and DNA polymerase chain reaction [PCR] were used to confirm Hb S [[beta]6 [A3] Glu Val] . Thirty-three samples were found to show Hb FAS, giving an overall likely [beta][S] gene frequency of 0.011. The [beta][S] gene frequency varied with the part of the country from which the parents came. Amongst people from Taiz and Haja in the west, the gene frequency was more than 0.04, but less than 0.004 amongst people from Ibb, adjacent to the governorate [administrative division] of Taiz. Of 66 chromosomes from babies carrying the Bs gene, only 1.5% also carried the - 158 [C-T] [G][gamma]-globin gene XmnI site compared with 16.1% of 168 chromosomes from babies without the [beta][S] gene from the same regions. The results of this study thus show a higher PS gene frequency in the western coastal part of Yemen than in the central mountainous and eastern desert areas. The incidence of affected homozygous births May therefore reach 20/10,000 in certain areas, although it is much lower than this overall. Limited health resources can best be invested in developing a program of education, screening and health care, initially prioritizing those communities residing in the western areas of Yemen with the highest [beta][S] gene frequency

Key regulatory gene expression in erythroleukemia differentiation

The characteristics of cellular and molecular mechanisms associated with cell proliferation and differentiation is important to understand malignancy. In this report we characterise a leukemic model, D5A1, to study the action of differentiation agent, cellular events and gene expression of the selected transcription factors. Cells induced with 4 mM hexamethylene bisacetamide [HMBA] caused signs of erythroid differentiation [changes in morphology and size, haemoglobinisation] and cessation of proliferation including accumulation of cells in G0/G1. Treatment with HMBA caused a time-related decrease of tumorigenicity detectable by 48 hour. Northern-blotting showed induction of -amino levulinic acid synthase-erythroid [ALAS-E] mRNA at 48 hours and appeared in a strong level subsequently. C-myc [myelocytomatosis] and c-myb [myeloblastoma] mRNA levels decreased transiently in early hours returning to control values by 24 hour and decreased again. Stem cell leukaemia [SCL] and GATA-1 mRNA were markedly down regulated in early hours and then returned back. A later time point, upregulation of GATA-1 and SCL was relevant to maturation phenotype. These data provide a useful model to study the cellular and molecular events in leukomogenesis and action of differentiation therapy in leukaemia