Salman Akbar Malik

Water purification by electrical discharges

There is a continuing need for the development of effective, cheap and environmentally friendly processes for the disinfection and degradation of organic pollutants from water. Ozonation processes are now replacing conventional chlorination processes because ozone is a stronger oxidizing agent and a more effective disinfectant without any side effects. However, the fact that the cost of ozonation processes is higher than chlorination processes is their main disadvantage. In this paper recent developments targeted to make ozonation processes cheaper by improving the efficiency of ozone generation, for example, by incorporation of catalytic packing in the ozone generator, better dispersion of ozone in water and faster conversion of dissolved ozone to free radicals are described. The synthesis of ozone in electrical discharges is discussed. Furthermore, the generation and plasma chemical reactions of several chemically active species, such as H2O2, O•, OH•, HO2•, O3*, N2*, e-, O2-, O-, O2+, etc, which are produced in the electrical discharges are described. Most of these species are stronger oxidizers than ozone. Therefore, water treatment by direct electrical discharges may provide a means to utilize these species in addition to ozone. Much research and development activity has been devoted to achieve these targets in the recent past. An overview of these techniques and important developments that have taken place in this area are discussed. In particular, pulsed corona discharge, dielectric barrier discharge and contact glow discharge electrolysis techniques are being studied for the purpose of cleaning water. The units based on electrical discharges in water or close to the water level are being tested at industrial-scale water treatment plants.}

Evaluation of Pathogenic Potential of Avian Influenza Virus Serotype H9N2 in Chickens

Abstract Recently seven isolates of avian influenza virus (AIV) serotype H9N2 recovered from an outbreak of AI were analyzed on the basis of their biological and molecular characteristics. All the isolates belonged to the low-pathogenicity group of AIV. To further evaluate their pathogenic potential in association with other organisms, an isolate was inoculated experimentally in chickens using different routes and subsequently challenged with infectious bronchitis virus, Ornithobacterium rhinotracheale or Escherichia coli. The virus isolation and seromonitoring data revealed a significant role of Escherichia coli in aggravating the clinical condition of the birds earlier infected with AIV (H9N2). The AIV-antigen was detected in lung, trachea, kidney, and cloacal bursa among the infected birds, using immunofluorescent antibody technique. In another experiment, chickens that were immunosuppressed chemically showed high mortality when challenged with AIV H9N2. The results indicated that this low pathogenicity AIV (H9N2) isolate could produce severe infection depending on the type of secondary opportunistic pathogens present under field conditions. This may explain the severity of infection with the present H9N2 outbreak in the field. A prolonged antibacterial therapy in flocks infected with AIV H9N2 and use of oil-based vaccine at an early age in new flocks has helped to control this infection and the disease.

Investigation of trace metals in the blood plasma and scalp hair of gastrointestinal cancer patients in comparison with controls

BACKGROUND Gastrointestinal cancer is one of the most common types of cancer which is predominantly associated with the environmental factors. The carcinogenic processes are linked with the imbalances of trace metals in body fluid and tissues. METHODS Trace metals (Cd, Cr, Cu, Fe, Ni, Pb and Zn) are estimated in blood plasma and scalp hair of the cancer patients and controls employing nitric acid-perchloric acid based wet-digestion followed by atomic absorption spectrophotometric method. RESULTS The mean concentrations of Cd, Cr, Cu and Ni were found to be significantly higher in the plasma of patients compared with the controls, however, appreciably higher concentrations of Fe and Zn were observed in the plasma of controls. The average scalp hair concentrations of Zn, Fe, Pb, Cu and Cd were notably higher in the patients than controls. The correlation study revealed significantly different mutual variations of the trace metals in the plasma and scalp hair of the patients and controls. The apportionment of trace metals in the plasma and scalp hair of the patients and controls was also considerably different. CONCLUSIONS The study revealed that the carcinogenic processes are significantly affecting the trace metal burden and mutual variations in the cancerous patients compared with the controls.

Immunosuppressive Potential and Pathogenicity of an Avian Adenovirus Isolate Involved in Hydropericardium Syndrome in Broilers

The role of avian adenovirus isolate PARC-1 as an immunosuppressive agent was investigated using a Newcastle disease virus (NDV) vaccine immune response procedure. The immunosuppressive effect on the humoral immune response was investigated up to 21 days after inoculation with adenovirus. Infected chickens showed a serologic response to NDV that was reduced compared with that of the controls. To further investigate the effect of the virus on major lymphoid organs, the pattern of virus dissemination in various organs was studied at various time intervals after inoculation. Spleen, thymus, bursa of Fabricius, and cecal tonsils of broilers were examined using a dot-immunobinding assay. The virus was found to have a predilection for lymphoid organs, and virus from lymphoid organs was capable of producing disease when inoculated into healthy chickens. The relationship of virus predilection to its immunosuppressive effect also was studied.

Molecular epidemiology of Hepatitis B virus genotypes in Pakistan

BackgroundEight genotypes of Hepatitis B virus designated A-H, have been known but in Pakistan, no such data is available on the prevalent HBV genotypes. Therefore, the subject study was conducted to determine HBV genotypes in the indigenous Pakistani population.MethodsA total of 690 individuals were enrolled for HBV screening with EIA and nested PCR. Positive samples were further analyzed to determine HBV genotypes (A-F) by multiplex-PCR using type specific primers.Results110 (15.94%) individuals were positive for HBV, including 64% males and 36% females. Out of these, 66 samples (65.34%) were classified into genotype D, 27 (26.73%) were of genotype B while 5(4.95%) had genotype A. In 3 (2.98%) samples, multiple genotypes were detected (genotype A+B; 2(1.99%) and genotypes B+D; 1(0.99%). Nine (8.18%) samples remained untyable.ConclusionIn Asia, genotypes B and C are the most prevalent but our study reveals that genotype D is predominant and HBV infection constitutes a significant health problem in Pakistan.

ANTIMICROBIAL SUSCEPTIBILITY AND ESBL PREVALENCE IN PSEUDOMONAS AERUGINOSA ISOLATED FROM BURN PATIENTS IN THE NORTH WEST OF PAKISTAN

Pseudomonas aeruginosa is one of the most prevalent pathogen in burn infections. Infections with P. aeruginosa are associated with higher mortality rate and antibiotic costs in hospitalized patients. These bacteria also produce enzymes called Expanded Spectrum Beta-Lactamases (ESBL) which render penicillins and cephalosporins inactive. The aim of this study was to assess the antimicrobial susceptibility pattern and prevalence of ESBL in P. aeruginosa in Peshawar, North West of Pakistan. During 2005-2006, one hundred and six P. aeruginosa isolates were collected from burn patients at a tertiary care hospital. Antibiotic susceptibility testing and ESBL detection were carried out according to Clinical Laboratory and Standards Institute (CLSI) criteria. Eighteen antibiotics were tested in this study. A total of 38 (35.85%) isolates were found to be ESBL producers. Thirty one (29.24%) isolates were resistant to 3 or more antibiotics (multidrug resistance). Meropenem and imipenem showed high potency with 99% and 96% isolates being susceptible respectively. Susceptibility to amikacin was 70%; gentamicin 25%; ciprofloxacin 49%; enoxacin 47%; gatifloxacin 42%; doxycycline 21% and to co-trimoxazole only 16%. This study reveals that P. aeruginosa isolated from burns in this region are multidrug resistant and produce ESBL in large proportions.

Common genotypes of Hepatitis B virus prevalent in injecting drug abusers (addicts) of North West Frontier Province of Pakistan.

BackgroundThe epidemiological significance of Hepatitis B virus genotypes has been well established and becoming an essential concern day by day however, much little is known about the mixed infection with more than one Hepatitis B virus genotypes and their clinical relevance.MethodsIntravenous drug abusers are considered as a major risk group for the acquisition and transmission of blood borne infections like hepatitis B, however, in Pakistan, no such data has ever been reported about the epidemiology of HBV and its genotypes in Injecting Drug Users. 250 individuals were analyzed for hepatitis B virus genotypes after prior screening with serological assay for the detection of HBsAg.Results56 (22.4%) individuals were found positive on ELSIA for HBsAg. The genotype distribution was found to be as: genotype D, 62.5%; genotype A, 8.92% while 28.57% individuals were found to be infected with a mixture of genotype A and D.ConclusionThere is an urgent need of the time to develop public health care policies with special emphasis towards the control of HBV transmission through high risk groups especially Injecting Drug Users.

Determination of genetic variability of Asian rice ( Oryza sativa L. ) varieties using microsatellite markers

The microsatellite or simple sequence repeat (SSR) marker analysis was done to determine the allelic diversity and relationship among thirty five Asian cultivars of rice including 19 aromatic, 13 non-aromatic and 3 japonica type cultivars. A total of 144 alleles were detected at the 32 SSR loci, of which 141 (98%) were polymorphic. The number of alleles generated by each marker ranged from 2 to 13 with an anverage of 4.5 alleles per marker The size of smallest and largest allele ranged from 8(RM122) to as high as 71 (RM302). Polymorphism information content (PIC) values ranged between 0.157 (RM19, RM55) and 0.897 (RM70), with an average of 0.603 per marker. Basmati rice varieties amplified different alleles at 15 of the SSR loci than those in the japonica and/ or indica rice varieties. A number of SSRs were identified that could be utilized to differentiate between basmati and other non-basmati rice varieties. The RM252 and RM310 showed a clear differentiation of japonica cultivars from other ones. Pair-wise Nei and Lis similarity coefficients ranged from 0.19 to 0.90. The dendrogram based on the cluster analysis by microsatellite polymorphism, grouped 35 rice cultivars into two major groups effectively differentiating the tall, late maturing and slender aromatic cultivars from the short statured, early, short bold and long bold non-aromatic cultivars. These results could be useful for monitoring purity, genotype identification and for plant variety protection.

Synthesis and biodistribution of 99mTc-Vancomycin in a model of bacterial infection

Abstract Vancomycin Hydrochloride is an antibiotic produced by the growth of certain strains of Streptomyces orientalis. As Vancomycin Hydrochloride is poorly absorbed after oral administration; it is given intravenously for therapy of systemic infections. Vancomycin was labeled with technetium-99m pertechnetate using SnCl2·2H2O as reducing agent. The labeling efficiency depends on ligand/reductant ratio, pH, and volume of reaction mixture. Radiochemical purity and stability of 99mTc-Vancomycin was determined by thin layer chromatography. Biodistribution studies of 99mTc-Vancomycin were performed in a model of bacterial infection in Sprague–Dawley rats. A significantly higher accumulation of 99mTc-Vancomycin was seen at sites of S. aureus infected animals. Whereas uptake of 99mTc-Vancomycin in turpentine inflamed rats were quite low.

Genetic structure of Plasmodium vivax and Plasmodium falciparum in the Bannu district of Pakistan.

BackgroundPlasmodium vivax and Plasmodium falciparum are the major causative agents of malaria. While knowledge of the genetic structure of malaria parasites is useful for understanding the evolution of parasite virulence, designing anti-malarial vaccines and assessing the impact of malaria control measures, there is a paucity of information on genetic diversity of these two malaria parasites in Pakistan. This study sought to shed some light on the genetic structure of P. vivax and P. falciparum in this understudied region.MethodsThe genetic diversities of P. vivax and P. falciparum populations from the densely populated, malaria-endemic Bannu district of Pakistan were evaluated by analysis of their merozoite surface protein (msp) genes by PCR-RFLP. Specifically, the Pvmsp-3α and Pvmsp-3β genes of P. vivax and the Pfmsp-1 and Pfmsp-2 genes of P. falciparum were analysed.ResultsIn P. vivax, genotyping of Pvmsp-3α and Pvmsp-3β genes showed a high level of diversity at these loci. Four distinct allele groups: A (1.9 kb), B (1.5 kb), C (1.2 kb), and D (0.3 kb) were detected for Pvmsp-3α, type A being the most prevalent (82%). Conversely, amplification of the P. vivax msp-3β locus produced two allele groups: A (1.7-2.2 kb, 62%) and B (1.4-1.5 kb, 33%), with 5% mixed-strain infections. Restriction analysis of Pvmsp-3α and Pvmsp-3β yielded 12 and 8 distinct alleles, respectively, with a combined mixed genotype prevalence of 20%. In P. falciparum, all three known genotypes of Pfmsp-1 and two of Pfmsp-2 were observed, with MAD20 occurring in 67% and 3D7/IC in 65% of the isolates, respectively. Overall, 24% P. falciparum samples exhibited mixed-strain infections.ConclusionThese results indicate that both P. vivax and P. falciparum populations in Pakistan are highly diverse.