Eco-Physiological Study of the Effect of P Levels and Coated P Fertilizers on the Wheat Grain Yield (Triticum aestivum L.), Dirab, Riyadh, Saudi Arabia

The soils in the Kingdom of Saudi Arabia suffer from severe P deficiency. This is attributed to the high soil pH due to the presence of calcium carbonate. Under such conditions, the utilization of fertilizer P by plants is generally very low due to sorption of P by soils. The objectives of this study were to assess the suitability of coating of P fertilizer along with soil P application on available soil P content and wheat yield in calcareous soil. Soil application rates of P (0, 150, 300 and 450 kg ha-1) as di-Ammonium phosphate (DAP) applied just before sowing. Coating types included (No coated, humic acid with different %, bitumen emulsion and bitumen emulsion+ 5% clay). The results indicated that, application of different rates of soil P has a significant effect on the available P soil content. The available P reached 18.9, 31.0, 36.0 mg kg-1 under application of 150, 300 and 450 kg DAP ha-1, respectively. The results showed addition of 300 kg DAP ha-1 resulted in high content of available soil P and no need for further application of P fertilizer. The coated DAP fertilizer with HA, bitumen emulsion and bitumen emulsion+ clay did not increases the available P in soil compared with no coated. Under current experiment, coating of P fertilizer by HA, bitumen emulsion and bitumen emulsion+5% clay along with medium rates of soil P fertilizer may contribute to improve P fertilizer efficiency and increase wheat grain yield cultivated in calcareous soil

Antibacterial Activity of Three Medical Plant Extracts of Saudi Arabia on Isolated Bacteria

This study focuses the significant antibacterial activity of three medical plants (Salvadora persica, Alluim sativum and Tamarix aphylla) used in folk medicine in Saudi Arabia. The antibacterial activity of their ethanolic extracts were determined using the agar well diffusion technique. Two microorganisms were used, Gram positive Staphylococcus areus and Gram negative Escherichia coli, distilled water was used as the negative control. The result indicated that the ethanolic extracts of all tree plants exhibited antibacterial activity. The aqueous extract was not effective when compared to the ethanolic extract. The inhibition zone was higher against the Gram-negative bacteria than the Gram-positive bacteria. The antibacterial activity of the leaf extract of Salvadora persica demonstrated the highest activity (1

Lack of association of CTLA-4 +49 A/G polymorphism with predisposition to type 1 diabetes in a cohort of Egyptian families

Background: Type 1 diabetes is one of the most common chronic childhood illnesses. Interplay between genetic susceptibility and environmental factors is thought to provide the fundamental element for the disease. Apart from the Major Histocompatibility locus which is the main contributor to risk susceptibility, more than 40 loci are recognized. One among these is the CTLA-4, however data from the literature are controversial. The aim of our study was to investigate the role of CTLA4 49 A/G as a risk susceptibility factor for the development of type 1 diabetes in a cohort of Egyptian families. Subjects and methods: This is a case control study including 88 Egyptian families with one or more index cases (<18 years). The control group comprised 369 healthy unrelated subjects with no family history of diabetes or autoimmune disease. Using PCR-RFLP methodology, CTLA4 49 A/G was analyzed in 738 samples representing 88 families (88 patients, 125 siblings and 156 parents) and 369 control. Results: The age of onset was 6 days-12.5 years with a mean of 5.3 ± 3.6 and a median of 5 years. The mode of presentation was classic symptoms in 51 and diabetic ketoacidosis in 37 cases. Twenty-two cases had a history of viral infection or exanthematous disease and four had associated autoimmune diseases. No significant differences were encountered between the different groups with regard to CTLA4 +49 A/G genotype or allele frequencies. Neither was there a relation between the various genotypes and age of onset or the mode of presentation. Conclusions: CTLA4 49 A/G polymorphism was not recognized as a risk susceptibility factor in our cohort. This may be attributed to the low co-incidence of autoimmune diseases. Up to our best knowledge, this is the first study involving families. We recommend that all studies performed on risk susceptibility to type 1 diabetes should include proper investigation for other autoimmune diseases to exclude their confounding effect on data analysis

Rationale for an international consortium to study inherited genetic susceptibility to childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia is the major pediatric cancer in developed countries. To date most association studies of acute lymphoblastic leukemia have been based on the candidate gene approach and have evaluated a restricted number of polymorphisms. Such studies have served to highlight difficulties in conducting statistically and methodologically rigorous investigations into acute lymphoblastic leukemia risk. Recent genome-wide association studies of childhood acute lymphoblastic leukemia have provided robust evidence that common variation at four genetic loci confers a modest increase in risk. The accumulated experience to date and relative lack of success of initial efforts to identify novel acute lymphoblastic leukemia predisposition loci emphasize the need for alternative study designs and methods. The International Childhood Acute Lymphoblastic Leukaemia Genetics Consortium includes 12 research groups in Europe, Asia, the Middle East and the Americas engaged in studying the genetics of acute lymphoblastic leukemia. The initial goal of this consortium is to identify and characterize low-penetrance susceptibility variants for acute lymphoblastic leukemia through association-based analyses. Efforts to develop genome-wide association studies of acute lymphoblastic leukemia, in terms of both sample size and single nucleotide polymorphism coverage, and to increase the number of single nucleotide polymorphisms taken forward to large-scale replication should lead to the identification of additional novel risk variants for acute lymphoblastic leukemia. Ethnic differences in the risk of acute lymphoblastic leukemia are well recognized and thus in assessing the interplay between inherited and non-genetic risk factors, analyses using different population cohorts with different incidence rates are likely to be highly informative. Given that the frequency of many acute lymphoblastic leukemia subgroups is small, identifying differential effects will realistically only be possible through multi-center pooled analyses. Here, we review the rationale for identifying genetic risk variants for acute lymphoblastic leukemia and our proposed strategy for establishing the International Childhood Acute Lymphoblastic Leukaemia Genetics Consortium