Occult HCV infection has a predilection for specific populations such as haemodialysis (HD) patients.The exact natural course, epidemiology, pathogenesis and clinical importance of OCI are unknown. We investigated the existence of OCI among local patients undergoing routine HD at a referral hospital in Pahang, Malaysia. Methods:Serum andperipheral blood mononuclear cells (PMBCs) were collected from peripheral venous blood samples of seropositive (anti-HCV positive) and seronegative (anti-HCV negative) HD patients as well as healthy individuals (negative control group). Inclusion criteria for the seronegative patients included elevated liver enzymes. Both conventional PCR and strand-specific PCR were used to detect the viral RNA and to indicate active viral replication in PBMCs respectively. Direct DNA sequencing was done to confirm the viral HCV RNA and their genotypes. Results:In the majority (90-100%) of seropositive chronic hepatitis C patients, viral RNA was detected in both serum and PMBCs . Meanwhile, out of 22 seronegative patients, 6 (27%) showed active viral replication in PBMCs but no detectable viral RNA presence in the serum. None of the negative control group had detectable viral RNA. All seronegative patients with OCI were infected with HCV genotype 3 and two of them (2/6) had a slight elevation of their liver enzymes. Conclusion:Seronegative OCI does exist among local hemodialysis patients, with normal or persistently abnormal liver enzyme values. Further investigation is needed to study the mode of viral transmission and clinical significance of OCI in HD setting.
Carbon monoxide (CO) is a highly valuable component of syngas which could be used to synthesize various chemicals and fuels. Conventionally, syngas is derived from fossil-based natural gas and coal which are non-renewable. To curb the problem, CO2 gasification offers a win-win solution in which CO2 is converted with wastes to CO, achieving carbon emission mitigation and addressing waste disposal issue simultaneously. In this review, gasification of various wastes by CO2 with particular focus given to generation of CO-rich syngas is presented and critically discussed. This includes the effects of operating parameters (temperature, pressure and physicochemical properties of feedstocks) and advanced CO2 gasification techniques (catalytic CO2 gasification, CO2 co-gasification and microwave-driven CO2 gasification). Furthermore, associated technological challenges are highlighted and way forward in this field are proposed.