Prevalence and specificity of some rare red cell pan-reactive alloantibodies against high frequency red cell antigens among hospitalized Saudi patients

Some patients'' sera react with all available donors'' red cells and a compatible donor is difficult or impossible to be found. These may either be due to a complex mixture of antibodies or the presence of alloantibodies against high-frequency antigens (HFAs). The aim of this study is to identify the prevalence and characteristics of antibodies to HFAs in Saudi Arabian patients. A total of 23 out of 172 000 patients who received blood transfusions had rare alloantibodies to HFAs at an incidence of 0.013%. Twenty-three patients suspected with pan-reactive alloantibodies against HFAs had their red cells tested using antisera to HFAs, while their plasma was tested against a selected panel of red blood cells with rare phenotypes. Anti-Ge2 antibody was found in the highest number of patients (56.5%), whereas anti-U, anti JK3, anti H, anti-RH 29, anti-hr^s, anti-Kn^a, anti-Ch, anti-Rg, anti-Yt^a, and anti-Cr^a antibodies were found in the remaining patients (43.5%). This study suggests that although antibodies such as anti-Ge2, anti- Kn^a, anti-Ch, anti-Rg, anti-Yt^a , and anti-Cr^a are not clinically significant, they cause a delay in the provision of compatible blood. Whereas, anti-U, anti JK3, anti H, anti-RH29 and anti-hr^s are clinically significant antibodies. An understanding of antibody characteristics to HFAs and the widespread use of the extended red cell phenotype and antibody identification panel will both be helpful for the diagnosis of these HFAs.     

Membrane-associated proteins of adriamycin sensitive and resistant murine leukemic P388 cells

We have isolated an 84-fold adriamycin resistant subline, P388/R84, from mouse leukemia P388 cells by serial cultivation in methylcellulose in the presence of increasing drug concentrations. Electrophoresis of detergent soluble fractions of radiolabeled sensitive and resistant cells suggested marked alterations in the protein fractions of 160, 100, 60, 45, and 30 kd. In resistant clones labeled with 125I an increase in 160 and 100 kd proteins was accompanied by concomitant reduction in the 60, 45, and 30 kd proteins. In 35S methionine-labeled resistant cells, similar increases in the 160 and 100 kd components were observed but in contrast to 125I-labeled cells the 30 kd component was also higher. Alterations in surface proteins were confirmed in experiments where the cell extracts were adsorbed to concanavalin A polymers and extracted with 0.26 M methyl-alpha-D-mannopyranoside. Our data confirm earlier reported observations on cell-surface protein changes in cells resistant to anthracyclines and alkaloids.     

Punica granatum waste to ethanol valorisation employing optimized levels of saccharification and fermentation

Pomegranate peels (PPW) as municipal waste is inexpensive biomass that could be a renewable source of sugars particularly rich in hemicellulosic contents. The subsequent conversion of available sugars in PPW can provide prospective strategy for cost-effective bioenergy production. In this study, an experimental setup based on CCD was implemented with the aim of bioconversion of biomass into bioethanol. The factors considered were Hydrochloric acid concentration (X₁), the hydrolysis temperature (X₂) and time (X₃) for optimization with dilute Hydrochloric acid (HCl) saccharification. The present study investigates the optimised level of bioethanol synthesis from acid pre-treated PPW explained by RSM. Subsequently, three yeasts viz. Saccharomyces cerevisiae K7, Metschnikowia sp. Y31 and M. cibodasensis Y34 were utilized for fermentation of acid hydrolysed and detoxified feed stocks. Optimum values of reducing sugars 48.02 ± 0.02 (gL^?1) and total carbohydrates 205.88 ± 0.13 (gL^?1) were found when PPW was hydrolyzed with 1% HCl concentration at 100?C of temperature for 30 min. Later on, fermentation of PPWH after detoxification with 2.5% activated charcoal. The significant ethanol (g ethanol/g of reducing sugars) yields after fermentation with Metschnikowia sp. Y31 and M. cibodasensis Y34 found to be 0.40 ± 0.03 on day 5 and 0.41 ± 0.02 on last day of experiment correspondingly. Saccharomyces cerevisiae K7 also produce maximum ethanol 0.40 ± 0.00 on last day of incubation utilizing the PPWH. The bioconversion of commonly available PPW into bioethanol as emphasize in this study could be a hopeful expectation and also cost-effective to meet today energy crisis.     

C-phycocyanin as a storage protein in the blue-green alga Spirulina platensis

The possibility that c-phycocyanin serves as a nitrogen source in Spirulina platensis during nitrogen starvation was studied. The following evidence was obtained in support of this idea. 1. Under favourable conditions for growth, c-phycocyanin existed in large excess in the algal cells. 2. When the supply of nitrogen was low, about 30–50% of the c-phycocyanin disappeared without any effect on the maximal growth rate. 3. A culture which was deprived of nitrogen continued to grow unaffectedly for a period, the duration of which depended on the c-phycocyanin content in the cell before nitrogen starvation was initiated. 4. c-phycocyanin was the only nitrogenous compound that was depleted during the course of nitrogen starvation when growth was yet unaffected. 5. When protein synthesis was inhibited either by nitrogen starvation or by methionine sulfoximine (MSO), phycocyanin content began to decline immediately and growth continued at normal rates as long as c-phycocyanin did not decline below 50%. 6. The decrease in c-phycocyanin content during nitrogen starvation was accompanied by an increase in proteolytic activity.