Biomedical subjects

R Guan

Publications and source records attributed to R Guan.

94 records · Page 6Linked to original sources

PubMedDate not supplied

Hepatitis B vaccination: half dose recombinant DNA hepatitis B vaccine (B-Hepavac II) is as immunogenic as the full recommended dose in healthy adults.

Sixty-seven healthy adult volunteers aged 20-40 years with no previous exposure to hepatitis B virus were randomized to receive either a 10 micrograms or 5 micrograms dose of recombinant DNA hepatitis B (HB) vaccine (B-Hepavac II) intramuscularly at 0, 1 and 6 months. Two months after the third injection 100% of subjects had seroconverted: 97% of the 10 micrograms group and 91% of the 5 micrograms group had antibody to HB surface antigen (anti-HBs) levels greater than 10 iu/L. The geometric mean titres (GMT) of anti-HBs levels at this time were 891 iu/L in the 10 micrograms dose group and 923 iu/L in the 5 micrograms dose group. These differences were not significant. Adverse effects included fever and mild pain at the injection site. The reduced dose of 5 micrograms was as effective as the standard 10 micrograms dose.

Alanine Transaminase↗

PubMedDate not supplied

Hepatocyte hepatitis B surface antigen expression in chronic hepatitis B virus carriers in Singapore: correlation with viral replication and liver pathology.

The hepatocyte hepatitis B surface antigen (HBsAg) expression in 149 liver biopsies from 124 chronic hepatitis B virus (HBV) carriers was correlated with serum HBV DNA status and histologic activity. Hepatocyte HBsAg was stained by the peroxidase-antiperoxidase method and serum HBV DNA was determined by dot blot hybridization. Sixty-five biopsies (44%) showed minimal changes (MC), 82 biopsies (55%) showed chronic liver disease (CLD) and 2 biopsies (1%) showed hepatocellular carcinoma. Hepatocyte HBsAg was found in 144 biopsies (97%). It was present in the cytoplasm of 141 specimens (95%) and/or plasma membrane of 48 specimens (32%). Approximately half (45%) of the cytoplasmic HBsAg-positive biopsies showed discrete distribution, while the other half (55%) were grouped. Fifty-five per cent (77 of 141) of cytoplasmic HbsAg-positive biopsies had CLD, while 44% (62 of 141) showed MC. There was no relationship between the presence of cytoplasmic HBsAg or its topographic distribution with disease activity. Membrane HBsAg distribution was similar for both groups of patients (MC vs CLD: 25 of 65 (38%) vs 23 of 82 (28%); P = NS). Serum HBV DNA was detected in 98 patients (66%) and was seen mostly in association with CLD (CLD vs MC: 61% vs 39%, P less than 0.001). It was also detected more often in the sera of patients with membrane HBsAg than in those with cytoplasmic HBsAg staining (41 of 48 (85%) vs 97 of 141 (67%); P less than 0.02). However, discrete distribution of cytoplasmic HBsAg was associated with positive serum HBV DNA when compared with grouped distribution (52 of 63 (83%) vs 43 of 78 vs (55%); P less than 0.005).

Carrier State↗

PubMedDate not supplied

Inflammatory bowel disease: an uncommon problem in Singapore.

Fifty patients with inflammatory bowel disease (ulcerative colitis, 40; Crohn's disease, seven; indeterminate colitis, three) treated in one gastroenterology unit in Singapore over a 10 year period were reviewed. Clinical features were similar to those described in Western patients. Of the three main races of Singapore it was found that Indians are more susceptible to these diseases than Chinese or Malays. A survey of all gastroenterologists in Singapore indicated a possible prevalence of 8.6 per 100,000 people for ulcerative colitis and 1.3 per 100,000 people for Crohn's disease. These prevalence rates are much lower than those reported for Western populations.

Adult↗

PubMedDate not supplied

Study on the comparative immunogenicity of a recombinant DNA hepatitis B vaccine containing pre-S components of the HBV coat protein with non pre-S containing vaccines.

A new recombinant hepatitis B vaccine (SCI-B-VAC), derived from Chinese hamster ovary (CHO) cells and consisting of both the major S protein and the minor pre-S1 and pre-S2 proteins of the viral coat were compared with two yeast-derived vaccines containing only S proteins (B-Hepavac II and Engerix-B) for immunogenicity in human volunteers in a randomized controlled study. Two hundred and ninety-five healthy subjects completed the 12 month follow up. There was no difference in the mean age and sex distribution among the three study groups. Seroconversion rates for all the three groups were similar at months 6, 9 and 12. However, hepatitis B surface antibody (anti-HBs) geometric mean titres (GMT) were significantly higher with 10 micrograms SCI-B-VAC and 20 micrograms Engerix-B than with 10 micrograms B-Hepavac-II at months 6, 9 and 12. SCI-B-VAC at month 6 also showed a significantly higher anti-HBs GMT than Engerix-B (295 vs 143 miu/mL, P < 0.02).

Adolescent↗