Nasir Ahmad

Investigating the concurrent presence of HCV in serum, oral fluid and urine samples from chronic HCV patients in Faisalabad, Pakistan

Hepatitis C virus (HCV) is normally present in the blood of infected patients; however, it can also be present in some other body fluids. Therefore, in this study, a concurrent presence of HCV-RNA was investigated in oral fluid and urine of 80 Pakistani chronic HCV patients. HCV-RNA was detected in 31 (38.8%) oral fluid and 10 (12.5%) urine samples using RT-PCR in all 80 of the patients whose sera tested positive for HCV-RNA. From this study, it is concluded that, in addition to the blood, HCV RNA can also be found in oral secretions as well as urine of chronic HCV patients.

Identification of hepatitis B virus core mutants by PCR-RFLP in chronic hepatitis B patients from Punjab, Pakistan.

SummaryChronic hepatitis B virus (HBV) infection remains a major health issue worldwide. Several factors including core gene variation are responsible for the development of chronicity of HBV infection. The present study was designed to identify the variations in the core region of the HBV genome in a local population of chronic hepatitis B patients (n = 57) using a PCR-based restriction fragment length polymorphism (PCR-RFLP) method. Fifty subjects were found to be positive for the presence of HBV DNA. For the core region genotyping, the Ava II and Msp I restriction enzymes were used. Mutations at nucleotide (nt) 2147 and nt 2362 in the HBV genome in the core region for Ava II (A4 type, 74%) and nt 2331 for Msp I (M1 type, 66%) were observed as the most common pattern. These results are different from those of previously reported studies on other populations and thus appear to be unique to the Pakistani population. This type of characterization of core mutants may be useful for the design of vaccines based on viral epitopes that are effective for the Pakistani population. Moreover, these unique genotypic patterns for the HBV core gene might be some of the main factors responsible for understanding the underlying mechanism by which HBV chronicity is developed in the Pakistani population.

Stable Isotope Techniques to Address Coastal Marine Pollution

Stable isotopes of carbon (δ13C), sulfur (δ34S), oxygen (δ18O), hydrogen (δ2H), nitrogen (δ15N), and radioactive isotope of hydrogen (tritium) have been applied in combina‐ tion with conventional techniques (chemical) to investigate Karachi coastal water pollution due to Layari and Malir rivers, which mainly carry the domestic and industrial wastewater of Karachi Metropolitan. Heavy metal contents of the Manora Channel and southeast coastal waters were higher than the Swedish guidelines for the quality of seawater. By contrast, heavy metal concentrations in coastal sediments were found to be significantly higher than that of seawater. Mn and Ni contents in sediments of entire coast (Manora Channel, southeast and northwest coast) were above USEPA guidelines except at Buleji site, whereas Cr, Zn, and Cu levels only in Manora Channel sediments were higher than USEPA guidelines. The higher heavy metal contents of Manora Channel water and sediments can be attributed to an influx of a major portion of untreated industrial and/or domestic wastewater. Layari and Malir river water was observed to be depleted in δC(TDIC)and δ34S, which showed heavy influx of sewage into these rivers. Manora Channel water was also depleted in δCTDIC and δ34S during low tide environment, showing a large-scale domestic wastewater mixing with seawater. Southeast coastal water was found to be slightly enriched in δC(TDIC) and δ34S and exhibited mixing of relatively small quantity of sewage with the seawater as compared to the Manora Channel. δC(TDIC) and δ34S contents of northwest coastal water were close to the values meant for normal seawater. δ13C and δ15N contents of Karachi coastal seaweed ranged from -31.1‰ to -4.9‰ PDB and from 6.1‰ to 17.8‰ air, respectively. The average δ15N values (10.2‰ air) of Ulva spp. collected from nonpolluted northwest coast was higher as compared to the average δ15N contents (8.0‰ air) of Ulva from the Manora Channel, suggesting that nitrogen isotopic ratios of Ulva spp. could be a good indicator of sewage pollution.