Epidemic of mesothelioma in Egypt.

Asbestos has been recognized in Egypt since a long time as ancient Egyptians were using it in mummification. Mesothelioma in Egypt is mainly attributed to environmental origin with a high incidence of women and young adults affected. The incidence of mesothelioma is rising in Egypt. Epidemiological data for 635 malignant mesothelioma (MM) patients over 4 years in the third Millennium were collected from the National Cancer Institute (NCI), Cairo University and Abbassia Chest hospital. This number is more than four times the number diagnosed in the previous 11 years at NCI. A clinicopathological study was done for 100 malignant pleural mesothelioma (MPM) patients and showed that asbestos exposure and SV40 positivity were evident in 67% and 60% of cases, respectively. The median survival was 14.3 months and the 1 and 2 year survival rates were 60% and 27%, respectively. Evaluation of p53 and pRb immunohistochemically showed that pRb alteration was related to poor survival. Other biological prognostic factors such as EGFR, HER-2, glutathione S transferase (GST) and MDR were evaluated in 50 cases. Overexpression of EGFR was correlated with lack of clinical benefit and poor survival. GST potentiated the effect of EGFR on survival. The use of EGFR inhibitors may have a role in the treatment of MM. Asbestos in Cairo is a silent killer and measures toward eliminating it entirely or at least strictly controlling human contact with this dangerous carcinogen have to be taken in order to combat the coming epidemic of mesothelioma in Egypt.

Bacterial artificial chromosome-derived molecular markers for early bolting in sugar beet.

Early bolting in sugar beet (Beta vulgaris L.) is controlled by the dominant gene B. From an incomplete physical map around the B gene, 18 bacterial artificial chromosomes (BACs) were selected for marker development. Three BACs were shotgun-sequenced, and 61 open reading frames (ORFs) were identified. Together with 104 BAC ends from 54 BACs, a total number of 55,464 nucleotides were sequenced. Of these, 37 BAC ends and 12 ORFs were selected for marker development. Thirty-one percent of the sequences were found to be single copy and 24%, low copy. From these sequences, 15 markers from ten different BACs were developed. Ten polymorphisms were determined by simple agarose gel electrophoresis of either restricted or non-restricted PCR products. Another five markers were determined by tetra-primer amplification refractory mutation system-PCR. In order to select candidate BACs for cloning the gene, genetic linkage between seven markers and the bolting gene was calculated using 1,617 plants from an F2 population segregating for early bolting. The recombination values ranged between 0.0033 and 0.0201. In addition, a set of 41 wild and cultivated Beta accessions differing in their early bolting character was genotyped with seven markers. A common haplotype encompassing two marker loci and the b allele was found in all sugar beet varieties, indicating complete linkage disequilibrium between these loci. This suggests that the bolting gene is located in close vicinity to these markers, and the corresponding BACs can be used for cloning the gene.

A bacterial artificial chromosome (BAC) library of sugar beet and a physical map of the region encompassing the bolting gene B.

In sugar beet (Beta vulgaris L.), early bolting is caused by a single dominant gene, designated B. Twenty AFLP markers selected from a 7.8-cM segment of the B region on chromosome 2 were used to screen a YAC library, and a first-generation physical map including the B gene, made up of 11 YACs, was established. Because the genome coverage of the YAC library was low, a BAC library was constructed in the vector pBeloBAC11. This library consists of 57,600 clones with an average insert size of 116 kb, corresponding to 8.8 genome equivalents. Screening of the BAC library with chloroplast and mitochondrial DNA probes indicated that less than 0.1% of the clones contained organelle-derived DNA. To fill the gaps in the physical map around the B gene, the BAC library was screened with four AFLP markers and 10 YAC-derived probes. In total, 54 different BACs were identified. Overlaps between BACs were detected by using BAC termini amplified by PCR as probes, and by RFLP fingerprinting. In this way, a minimal tiling path of the central 4.6-cM region was constructed, which consists of 14 BACs. The B locus was localized to a 360-kb contig, a size which makes positional cloning of the gene feasible.