Frequency of aberrant expression of CD markers in cases of acute leukemia

In the present study 100 patients of acute leukemia were studied to find out the frequency of aberrant antigens in AML, B-ALL and T-ALL of which 73% cases were of lymphoid lineage and 27% cases were of myeloid lineage. 74% cases showed expression of lineage specific markers and were considered as conventional immunophenotypes while 26% cases showed expression of CD antigens which were not of that lineage upon which they were expressing. Some myeloid lineage associated antigens were present on acute lymphoblastic leukemia cases and lymphoid associated antigens showed their expression on acute myeloid leukemia cases. These cases were considered as aberrant immunophenotypes. The cases of acute lymphoblastic leukemia were further subcategorized as B-cell and T-cell acute lymphoblastic leukemia. The data from this study suggested that either the commonly described myeloid, B-cell and T-cell differentiation pathways are incorrect or blasts from cases of acute leukemia do not represent their normal counterparts. To explain these mixed immunophenotypes it is suggested that leukemic cells may have aberrant markers because of their abnormal genetic programme resulting in lineage infidelity. In this scenario the precursor cells may retain features of one lineage that they should have lost during commitment to another cell line. As a result of the leukemic process cells with aberrant immunophenotypes are immortalized in a precommitment phase of differentiation resulting in lineage promiscuity. This study strengthens the theories of lineage infidelity and lineage promiscuity by taking a critical and comparative approach of frequencies of aberrant antigens in acute leukemia in population of Pakistan

Evaluation of lipopeptide [surfactin] production by bacillus subtilis

Lipopeptides are the bioactive peptides and some constituents of these compounds are surfactin, fengycin and Turing A, B and C, mycosubtilins and bacillomycins. Among these lipopeptides, surfactin is produced by Bacillus subtilis that has strong anti-microbial properties. Surfactin can be obtained by cultivation of bacteria and possesses various biological activities; anti-microbial, anti-viral, anti-tumour, haemolytic, blood anticoagulant and fibrinolytic activities. The present study was evaluated for optimisation of media components [Carbon source, N, P. and K] and environmental factors for the growth and production of lipopeptides by Bacillus subtilis. It was a quasi experimental study. Surfactin production was optimised with different factors including Mannitol, Phosphate, Nitrogen, Carbon, Potassium, and pH by inoculating B. subtilis on standard mineral salt [SMS] medium using fermentation technology. Showed that all the optimised factors have contributed their role in the production of lipopeptides by B. subtilis. The increasing concentrations of mannitol and nitrogen produced maximum lipopeptides with O.D 2.110 and 2.375 respectively. Production of surfactin by B. subtilis might be increased by using different factors optimised in medium and these compounds have potential applications both in medical and biotechnological fields

Significance of appropriate sampling in the diagnosis of tuberculosis [TB] - a comparison of different techniques

After years of decline, tuberculosis [TB] has re-emerged as a serious public health problem worldwide causing significant mortality and morbidity in developing countries like Pakistan, where the estimated incidence of TB is 181 per 10000. The present prospective study was conducted in Shalamar Hospital Lahore from January 2007 to October 2009. The objective was to compare the PCR results of specific site samples and blood of the same TB patient to see the validity of PCR results based on blood samples. Clinical samples obtained from 205 patients of suspected TB [pulmonary or extra-pulmonary] were subjected to ZN smear examination, LJ medium culture, and PCR test by amplifying 541 fragment of Mycobacterium tuberculosis complex genome. A highly significant difference was seen in the test results clone on samples obtained from specific site according to disease and blood samples of the same patient infected with pulmonary or extra-pulmonary tuberculosis. The sensitivity of different tests was found to be significantly different, which was 67.32 percent for PCR test, 27.81 percent for LJ medium culture and 12.20 percent for ZN smear examination. However, there was no significant difference between different tests as far as specificity was concerned. PCR test sensitivity in pulmonary and extra-pulmonary clinical samples was 77.15 and 61.6 percent respectively, being significantly higher, when compared with sensitivity of other tests. The mean detection time for M. tuberculosis was 24 days by LJ medium culture and less than 1 day by .smear examination and PCR test. We concluded that the PCR test is more sensitive than ZN smear examination and LJ medium culture for the diagnosis of TB in pulmonary and extra-pulmonary clinical samples. To get more accurate results PCR for TB diagnosis should be done on specific site samples. Blood samples are not appropriate for the diagnosis of TB by PCR when the PCR is clone on TB genomic DNA