Gender differences in KAP related to HIV/AIDS among freshmen in Afghan universities.

This cross-sectional study aimed to describe the level of knowledge, perception/ attitude, and practices related to HIV among 1,054 freshmen students in four Afghan universities differences between genders. A probability, two stage sampling method was used. Data were collected by a self administered structured questionnaire. SPSS software was used for data analysis. Descriptive and inferential statistics were performed. Most of respondents were male (72.1%), their average age was 20.1 +/- 2 years, and most were unmarried (93.4%). The majority (90.8%) were aware of HIV but only 28.3% had a good level of knowledge. Around one-third (35.6%) had a positive level of attitude toward HIV. Approximately 30% had at least one risk practice; therefore, they were counted as high-risk behavior group members. Females were statistically more knowledgeable than males, and high-risk behaviors were significantly more prevalent among males; p = 0.01 and p = 0.001, respectively. However, general awareness, and attitude were not statistically different between genders. A considerable proportion of students (14.6%), as compared to peer-countries, were sexually active. A very high level of sharing injecting needles (4.5%) and shaving sets (20.8%) were also reported among informants.

Development of a combined air sampling and quantitative real-time PCR method for detection of Legionella spp.

The objective of this study was to develop and optimize the combined methods of air sampling and real time polymerase chain reaction (real-time PCR) for quantifying aerosol Legionella spp. Primers and TaqMan hydrolysis probe based on 5S rRNA gene specific for Legionella spp were used to amplify a specific DNA product of 84 bp. The impinger air sampler plus T-100 sampling pump was used to collect aerosol Legionella and as low as 10 fg of Legionella DNA per reaction could detected. Preliminary studies demonstrated that the developed method could detect aerosol Legionella spp 1.5-185 organisms /500 l of air within 5 hours, in contrast to culture method, that required a minimum of 7-10 days.

Preparation of in vivo cow control blood samples for cadmium analysis.

Quality control is essential for any analysis in the laboratory. The objective of this study was to prepare in vivo cow control blood samples. The experiment was performed by feeding cows with a single dose of cadmium in the form of cadmium chloride, withdrawing the blood at an appropriate time to get the highest level of cadmium and detecting the level of cadmium in the blood. It was found that feeding the cow a single dose of 0.06 mg cadmium per kg body weight resulted in the highest cadmium level of 3.622 microg/l 30-60 minutes after feeding. The samples were homogeneous because feeding the cows with single dose of cadmium let the cadmium be absorbed and distributed naturally. In addition, the samples were stable during transport. Therefore, they may be used as quality control samples to detect cadmium levels without using a lyophilized process. They could be used for proficiency testing and to evaluate whole blood analysis in the laboratory.

Mutations in the gyrA and gyrB genes of fluoroquinolone-resistant Mycobacterium tuberculosis from TB patients in Thailand.

Among fluoroquinolone-resistant Mycobacterium tuberculosis (FQr-MTB) isolates, mutation at positions 90, 91, and 94 in gyrA gene and at positions 495, 516, and 533 in gyrB gene have been frequently reported. In this study, 35 isolates of FQr-MTB were collected from Siriraj Hospital and Chest Disease Institute. The quinolone-resistance-determining regions (QRDR) of gyrA and gyrB genes in all 35 FQr-MTB isolates and from the H37Ra MTB strain were amplified using polymerase chain reaction (PCR). DNA-sequencing and single-strand conformation polymorphism (SSCP) were further utilized for characterization of the mutations in the QRDR of gyrA and gyrB genes and mutation screening, respectively. From DNA-sequencing, 21 of 35 (60%) exhibited single-point mutations in different positions, at Ala90Val, Ser91Pro, and Asp94(Gly/Ala/His/Asn); and one novel mutation position at Gly88Cys in the gyrA gene and Asp495Asn in the gyrB gene. These positions were previously frequently reported to be responsible for FQr-MTB. The other 14 FQr-MTB isolates (40%) had no mutation. This study is the first report of mutation occurring only in the QRDR of the gyrB gene, without prior mutation in the gyrA QRDR among FQr-MTB isolates. By SSCP analysis for screening of the mutant FQr-MTB, the SSCP patterns of mutated FQr-MTB isolates were clearly differentiated from the SSCP patterns of FQs-MTB.

Determination of lead toxicity in Culex quinquefasciatus mosquitoes in the laboratory.

Laboratory investigations were carried out to study the effects of lead toxicity and lead uptake on Culex quinquefasciatus mosquitoes. Three different concentrations of lead nitrate were used in laboratory tests (0.05, 0.1, and 0.2 mg/l). An atomic absorption spectrometer (AAS) was used to the determine lead concentrations. The results showed that lead significantly reduced hatching, egg-production, and emergence rates, compared with the unexposed group (p < 0.05). The ratio of female to male offspring was 3.64:1, which was observed in the second generation, after the parents were exposed to 0.2 mg/l lead. No effects were observed on oviposition preference, larval weight, or larval deformation. The LC50 of lead against Cx. quinquefasciatus larvae within 24 hours was 0.18 mg/l. There was a significant increase in lead uptake related to increased lead exposure in mosquito larvae (p < 0.05). The bioconcentration factor (BCF) showed that the lead concentration in the larvae was 62 times greater than in the water. The lead concentration from parents to offspring reduced in the first and second generations (p < 0.05). There was no significant difference between female and male mosquitoes in lead concentration (p > 0.05).

Development of multiplex PCR for the detection of total coliform bacteria for Escherichia coli and Clostridium perfringens in drinking water.

Multiplex PCR amplification of lacZ, uidA and plc genes was developed for the simultaneous detection of total coliform bacteria for Escherichia coli and Clostridium perfringens, in drinking water. Detection by agarose gel electrophoresis yielded a band of 876 bp for the lacZ gene of all coliform bacteria; a band of 147 bp for the uidA gene and a band of 876 bp for the lacZ gene of all strains of E. coli; a band of 280 bp for the p/c gene for all strains of C. perfringens; and a negative result for all three genes when tested with other bacteria. The detection limit was 100 pg for E. coli and C. perfringens, and 1 ng for coliform bacteria when measured with purified DNA. This assay was applied to the detection of these bacteria in spiked water samples. Spiked water samples with 0-1,000 CFU/ml of coliform bacteria and/or E. coli and/or C. perfringens were detected by this multiplex PCR after a pre-enrichment step to increase the sensitivity and to ensure that the detection was based on the presence of cultivable bacteria. The result of bacterial detection from the multiplex PCR was comparable with that of a standard plate count on selective medium (p=0.62). When using standard plate counts as a gold standard, the sensitivity for this test was 99.1% (95% CI 95.33, 99.98) and the specificity was 90.9 % (95% CI 75.67, 98.08). Multiplex PCR amplification with a pre-enrichment step was shown to be an effective, sensitive and rapid method for the simultaneous detection of these three microbiological parameters in drinking water.

Effect of antisense-SGTPs on the glucose uptake of the blood fluke Schistosoma mansoni: observations in adult worms and schistosomula.

AS-ODNs, complementary to Schistosoma mansoni glucose transporter proteins (SGTP1 and SGTP4), were chosen as potential therapeutic agents for schistosomiasis. AS-SGTP1 oligos lowered the glucose uptake of adult worms both in vitro and ex vivo. The most effective AS-ODN was that of 21 nucleotides complementary to the SGTP1 nucleotide sequence, including the initiation region of mRNA translation. This oligo was found to decrease glucose uptake in vitro by as much as 50% and at a concentration of 4.0 mg/ml, it killed all male worms within 24 hours. A significant decrease, up to 34%, in glucose uptake was also noted when 100 mg/kg x2 (with a 2 hours interval) of AS-ODN was administered ex vivo. Two out of six anti-SGTP4 oligos also decreased the glucose uptake of adult worms in vitro by 25-44%. Added to the culture of schistosomula, two AS-SGTP4 oligos were found to decrease glucose uptake by 20-43%.

Comparison of biological specimens for manganese determination among highly exposed welders.

This research aimed to determine if less invasive biological specimens (other than blood), such as feces and clipped toenails could be used to determine manganese concentrations among occupationally exposed human subjects. In addition to blood samples, which have routinely been used in determining manganese concentration, specimens were collected from welders working at the Electricity Generating Authority of Thailand, Mae Moh Thermal Power Plant, Lampang Province. Manganese concentrations in these three biological samples were determined by atomic absorption spectrophotometer. Correlations of manganese concentrations among these three biological samples were measured, and found to be rather poor (Pearson's r <+/-0.2, p > 0.1 for any pair-wise comparisons). Blood remains the recommended material for biomonitoring manganese concentrations in occupationally exposed subjects.

Simultaneous determination of trans, transmuconic acid and s-phenylmercapturic acid by high pressure liquid chromatography and its application.

The simultaneous determination of urinary trans,trans-muconic acid (t,t-MA) and S-phenylmercapturic acid (S-PMA) was performed by liquid extraction with ethyl acetate and reversed-phase high performance liquid chromatography (RP-HPLC) on a Hypersil-ODS column using the gradient mobile phase of methanol and 0.0012 N perchloric acid and diode array detection at 205 and 264 nm for S-PMA and t,t-MA, respectively. The retention times for t,t-MA and S-PMA were 3.8 and 12.3 minutes, respectively. The recoveries of t,t-MA and S-PMA were > 97%; between-day precisions were all within 8% RSD (100x SD/mean). The method was applied to analyze the urinary t,t-MA and S-PMA of 59 service station attendants exposed to average benzene concentrations in the air of 0.20+/-0.18 ppm. Significant differences in pre-shift and post-shift urinary t,t-MA between smokers and non-smokers were found.