ABSTRACT
Objective To identify the sequence of hepatitis B virus S gene"a"determinant in patients with positive HBsAg and anti-HBs.Methods Nested-PCR Was used to amplify the HBV S gene in 4 patients with positive HBsAg and anti-HBs,and the PCR products were sequenced directly or after cloning.The sequences of"a" determinants were then analyzed by sequence alignment.Results Direct sequencing of PCR products showed that there was one amino acid (aa)residue in"a"determinant less conserved region emerging polymorphism in all 4 patients.Clone sequencing showed that aa residue at 126 of "a"determinant in patient 1 miSht be Thr,Ile and Set,at 134 might be Phe and Set;the aa at 126 in patient 2 misht be Ala and Thr.and in patient 3 might be Ile and Asn;aa polymorphism was not found in patient 4.Conclusion The polymorphism of"a"determinant in HBV S gene might be associated with positivity of both HBsAg and anti-HBs in hepatitis B patients.
ABSTRACT
Objective To study the occurring regulation of antibody of Urbani sever acute respiratory syndrome (SARS)-associated coronavirus after onset of illness in patients with SARS and investigate the co-infection status of Chlamydiae pneumoniae (Chlamydiae P.) , Mycoplasma pneumoniae (Mycoplasma P.), Adenovirus, Respiratory Syncytia virus (RSV). Methods Serum Antibody IgM and IgG of Urbani SARS-associated coronavirus of 43 patients with SARS and 10 patients with other diseases except SARS at the two different phases of illnesses were detected with immune fluorescent technique. Antibody IgM and IgG of Chlamydiae P., Mycoplasma P., Adenovirus and RSV in the above samples were detected with enzyme-linked immunosorbent assay (ELISA). Results 40 cases' infection of were Urbani SARS-associated coronavirus were determined (93.02%) and 3 cases were negative (6.98%). 10 patients with other diseases except SARS have negative serum Antibody IgM and IgG of Urbani SARS-associated coronavirus. Recent infection rates of Chlamydiae P., Mycoplasma P., Adenovirus and RSV were 25.58%, 16.28%, 6.98% and 4.65% , respectively, and former infection rates of these pathogens were 39.53%, 34.88%, 27.91% and 0, respectively. Antibody IgM of Urbani SARS-associated coronavirus occurred at the same time of onset of fever. Positive rates of IgM were respectively 69.57% and 62.96% in 8～14 days and 15～33 days after onset of fever, and there were no remarkable difference between them, but they were re-markably higher than that in 1～7 days after onset of fever (16.67%). Antibody IgG of Urbani SARS-as-sociated coronavirus occurred at the 6th day after onset of fever. Positive rates of IgG were respectively 19.44%, 65.22% and 92.59% in 1～7 days, 8～14 days and 15～33 days after onset of fever, and there were remarkable difference among them. Conclusions Antibody IgM and IgG of Urbani SARS-associated coronavirus may occur at the early stage of illness in patientswith SARS, which positive cases may increase remarkably 2 weeks later after onset of fever. There may be recent infection and/or former infection of Chlamydiae P., Mycoplasma P., Adenovirus and RSV in some patients with infectious atypical pneumonia. Detection of Antibody IgM and IgG of Urbani SARS-associated coronavirus in sera with immune fluorescent technique can be used on the early diagnosis of SARS.