OBJECTIVE To investigate the quasispecies diversity and the dynamics of quasispecies evolution in patients with chronic Hepatitis C virus(HCV) infection.METHODS Changes of HCV quasispecies before and after interferon(IFN) therapy were detected by heteroduplex mobility analysis(HMA) and by automatic sequencer.RESULTS We found that no changes in viral complexity were observed with therapy,but there were marked changes in viral divergence.The proportion of major pretreatment variants was different in HVR1 in all patients.During the treatment,HCV quasispecies changed significantly.CONCLUSIONS HMA is a simple,rapid and reliable method for detecting HCV quasispecies.Responsiveness to interferon may be related to the changes in viral divergence,but not related to the numbers of viral variants.

OBJECTIVE To investigate the distribution and resistance of bacteria of nosocomial infection in ICU.METHODS A total of 128 strains were detected by double-disc synergy test.RESULTS Among 128 strains from ICU,Gram-negative bacilli,accounted for 61 strains(47.65%),fungi for 48(37.5%),and Gram-positive cocci for 19(14.84%).Escherichia coli and Klebsiella pneumoniae were 73.00% and 55.13%.CONCLUSIONS The strains isolated from ICU are antibiotic-resistant.It is very impotant to select antibiotics correctly for infection of the patients in ICU according to the results of antibiotic susceptibility tests.

OBJECTIVE To study the dynamic changing rule and effective factors of in-door air quality of cleanliness in operating room.METHODS On-the-spot air sampling method was used to examine the efficacy in purifying bacteria in operating room.RESULTS The bacterial count in air of operation area was significantily higher than that of the peripheral area(P

OBJECTIVE To evaluate the clinical efficacy of lamivudine on prevention of liver injury in HBV carriers complicating tuberculous exudative pleurisy after use of antituberculosis drugs.METHODS Totally 120 HBV carriers complicating tuberculous exadative pleurisy after use of antituberculosis drugs were randomly divided into lamivudine group and control group.RESULTS The incidence rate of liver injury was 10.0% in lamivudine group vs 1.7% in control group(P0.05).CONCLUSIONS Lamivudine may be good for reducing liver injury in HBV carriers complicating tuberculous exadative pleurisy after use of antituberculosis drugs.

0.05).Genotype B with YMDD mutations in 10 samples were found,including 2 YIDD(M+I) mutations and 8 YVDD(M+V) mutations.Genotype C with YMDD mutations in 68 samples were found,including 44 mutations I(M+I) and 24 mutations V(M+V).There was significant difference in YMDD mutation types between genotypes B and C(?2=5.5,P