Cumulative effects of temperature on blood pressure during pregnancy: A cohort study of differing effects in three trimesters.

BACKGROUND: Little is known about the non-linear cumulative effects of temperature on blood pressure (BP) during pregnancy. We investigated the differing effects of daily ambient temperature on BP for up to 30 days in three trimesters. METHODS: The first, second, and third trimester analyses included 2547, 2299, and 2011 pregnant women, respectively, from a prospective cohort in Nanjing from January 2017 to January 2020. BP was measured at each follow-up visit. The individual daily temperature exposures were calculated for 30 days prior to the follow-up date. The Distributed Lag Non-linear Model was used to investigate the relationship between temperature and BP in each trimester. RESULTS: Temperatures under 15 °C elevate systolic, diastolic BP, and mean arterial pressure (SBP, DBP, and MAP) in the first trimester, while temperatures above 15 °C reduce SBP in the second and third trimesters. By using Distributed Lag Linear Models, we estimated that with a 1 °C decrease in daily temperature, the SBP and DBP increased by 0.32 (95 % CI: 0.12, 0.52) and 0.23 (95 % CI: 0.07, 0.39) mmHg, respectively, in the first trimester with a 20-day cumulative lag, while with a 1 °C increase in daily temperature, the SBP decreased by 0.23 (0.35, 0.10) mmHg in the third trimester with a 30-day cumulative lag. The significant effects of temperature mainly manifested between 2 and 4 weeks of exposure. CONCLUSIONS: Temperature has different effects on BP over three trimesters. Protective measures to reduce cold-related BP rise will help reduce the risk of hypertensive disorders of pregnancy.

The role of caesarean section and nonbreastfeeding in preventing mother-to-child transmission of hepatitis B virus in HBsAg-and HBeAg-positive mothers: results from a prospective cohort study and a meta-analysis.

The study aimed to assess whether caesarean section and nonbreastfeeding can prevent mother-to-child transmission (MTCT) in HBsAg- and HBeAg-positive mothers via a cohort study and a meta-analysis. (1) Pregnant women who were positive for HBsAg and HBeAg and did not receive antiviral treatment during pregnancy were recruited from the First Hospital of Jilin University, Maternal and Child Health Care Center of Jiangsu and Henan from August 2009 to June 2015. Infants received active and passive immunity. (2) In addition, a systematic literature search was performed in the PubMed, Embase, Cochrane, China National Knowledge Infrastructure and Wanfang Chinese databases. The retrieval strategy was [("HBV" or "hepatitis b" or "hepatitis b virus") and ("mother-to-infant transmission" or "vertical transmission")]. Studies were screened, and data were extracted. The fixed-effect model was used to analyse the studies. A total of 852 mothers and 857 newborns were enrolled. At the age of 7 months, 41 infants (4.78%) were positive for HBsAg. Multivariate analysis showed that mothers with higher HBV DNA levels (>108  IU/mL; RR = 3.03, 95% CI: 1.41-6.52) were associated with an increased risk of infection. Although there was no statistical significance, caesarean section (RR = 0.61) and nonbreastfeeding (RR = 0.88) showed a tendency to reduce the risk of infection. (2) A total of 5726 studies were identified. Together with our study, 13 were included in the analysis of delivery mode, and 12 were included in the analysis of feeding mode. The risk of infection in the caesarean section group was lower than that in the vaginal delivery group (RR = 0.58, 95% CI: 0.46-0.74). In the analysis of feeding mode, the risk in the nonbreastfeeding group was significantly lower (RR = 0.74, 95% CI: 0.56-0.98). In conclusion, caesarean section and nonbreastfeeding reduced the risk of MTCT in infants of HBsAg- and HBeAg-positive mothers who did not receive antiviral therapy during pregnancy.

The efficacy of two different dosages of hepatitis B immunoglobulin combined with hepatitis B vaccine in preventing mother-to-child transmission of hepatitis B virus: A prospective cohort study.

BACKGROUND/AIMS: A birth dose of hepatitis B immunoglobulin (HBIG), in combination with hepatitis B vaccine (HepB), is recommended for infants born to hepatitis B surface antigen (HBsAg)-positive mothers. However, the optimal dosage of HBIG remains to be resolved. This prospective cohort study aimed to compare the efficacy of two dosages of HBIG combined with HepB to prevent mother-to-child transmission (MTCT) of HBV. METHODS: From 2009 to 2011, we prospectively enrolled mother-infant pairs with positive maternal HBsAg in China. Infants were assigned to receive one dose of 100 IU or 200 IU HBIG within 12 h of birth according to maternal numbering, followed by completion of the 3-dose 10 µg HepB series. At 7 months, post-vaccination serologic testing (PVST) was performed in 545 and 632 infants in 100 IU and 200 IU HBIG groups, respectively, among whom, 451 and 529 were followed up to 12 months. RESULTS: Maternal and birth characteristics were comparable between infants in 100 IU and 200 IU HBIG groups. At 7 months, the rates of perinatal infection were 1.5% (8/545) and 1.9% (12/632) in 100 IU and 200 IU HBIG groups, respectively (p = .568). One non-responder infant in 200 IU HBIG group became newly infected at 12 months. The antibody to hepatitis B surface antigen (anti-HBs) positive rates were 98.5% (529/537) and 98.2% (609/620) in 100 IU and 200 IU HBIG groups at 7 months, respectively (p = .704), and the corresponding figures were 98.2% (431/439) and 97.1% (496/511) at 12 months (p = .266). The anti-HBs geometric mean concentrations were comparable between two groups at 7 months (707.95 mIU/mL vs. 602.56 mIU/mL, p = .062) and 12 months (245.47 mIU/mL vs. 229.09 mIU/mL, p = .407). CONCLUSIONS: One birth dose of 100 IU HBIG, combined with the HepB series, might be enough for preventing MTCT of HBV in infants born to HBsAg-positive mothers.

The maternal viral threshold for antiviral prophylaxis of perinatal hepatitis B virus transmission in settings with limited resources: A large prospective cohort study in China.

BACKGROUND: Antiviral therapy has been documented to reduce perinatal transmission of hepatitis B virus (HBV) in highly viremic mothers. This large prospective cohort study conducted in China aims to delineate the maternal viral threshold for consideration of antiviral prophylaxis in settings with limited resources. METHODS: A total of 1177 mother-infant pairs with positive maternal hepatitis B surface antigen (HBsAg) under current passive-active prophylaxis regimen were enrolled from community health centers in Jiangsu and Henan provinces, China. Maternal hepatitis B e antigen (HBeAg) status and viral load were tested at 36-40 weeks of gestation. Post-vaccination serologic testing was performed at 7 and 12 months of age. RESULTS: HBeAg-positive mothers (419/1177; 35.6%) had significantly higher viral loads, compared with HBeAg-negative mothers (758/1177; 64.4%) (8.12 vs. 2.69 log IU/mL, p < .0001). Twenty infants, born to HBeAg-positive mothers with high viral loads (median, 8.38; range: 7.82-9.22 log IU/mL), were infected at 7 months of age. In contrast, none of the HBeAg-negative mothers transmitted HBV to their offspring. After adjustment for the other risk factor, a higher maternal viral load was significantly associated with a higher risk of transmission (adjusted odds ratio, 3.78; 95% confidence interval: 1.46-9.81; p = .006). The rates of passive-active immunoprophylaxis failure were 0.0% (0/789), 0.0% (0/27), 0.0% (0/32) and 6.1% (20/329) at maternal viral loads of <5, 5-6, 6-7 and ≥7 log IU/mL, respectively. The antibody to hepatitis B surface antigen (anti-HBs) response rate was 98.4% (1138/1157) at 7 months of age. CONCLUSIONS: Results from this study indicate that the maternal viral threshold associated with perinatal transmission of HBV is 7 log IU/mL, which may be appropriate for consideration of antiviral prophylaxis in settings with limited resources.

Evaluation of GeneXpert MTB/RIF for detection of pulmonary tuberculosis at peripheral tuberculosis clinics.

Tuberculosis is one of the most common infectious diseases in China, while delayed patient finding obstructed disease control, especially for smear-negative patients. The current study was undertaken to evaluate the diagnostic accuracy of GeneXpert MTB/RIF compared with conventional methods in the detection of pulmonary tuberculosis patients. A total of 295 spot sputum samples from confirmed pulmonary tuberculosis patients were evaluated from September 2014 to June 2015. Each sample was examined by acid-fast bacillus smear microscopy, culture and GeneXpert MTB/RIF. The sputum culture on Löwenstein-Jensen (L-J) was considered as the gold-standard. After testing by smear, 68.81% (203/295) was negative and 31.19% (92/295) was positive. As the gold-standard, L-J culture detected 37.97% (112/295) positive of all specimens, while the positivity for GeneXpert MTB/RIF was 46.44% (137/295). Compared with L-J culture, the combined sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for GeneXpert MTB/RIF were 94.64%, 82.97%, 77.37% and 96.18% respectively. For smear-negative specimens, the sensitivity, specificity, PPV and NPV for GeneXpert MTB/RIF were 96.00%, 83.05%, 44.44% and 99.32%; while for smear-positive specimens, the corresponding accuracy values were 94.25%, 80.00%, 98.80% and 44.44%. The findings of study indicated that GeneXpert MTB/RIF assay demonstrated a high sensitivity in detecting Mycobacterium tuberculosis compared to smear method and a high NPV among smear negative patients.

Hepatitis B vaccine alone may be enough for preventing hepatitis B virus transmission in neonates of HBsAg (+)/HBeAg (-) mothers.

BACKGROUND AND AIM: To prospectively evaluate the efficacy of vaccine alone compared with vaccine plus HBIG for preventing HBV transmission in neonates of HBsAg (+)/HBeAg (-) mothers. METHODS: Combined immunization is currently recommended for neonates of HBsAg (+) mothers in China. As a result, a randomized design is infeasible due to ethical reasons. In practice, Guangxi Zhuang Autonomous Region and Jiangsu Province implement vaccine alone and vaccine plus HBIG strategies for neonates born to HBsAg (+)/HBeAg (-) mothers, respectively. We alternatively enrolled neonates of HBsAg (+)/HBeAg (-) mothers from these two regions. Three doses of a recombinant yeast-derived hepatitis B vaccine were given at 0, 1 and 6months with or without HBIG at birth. RESULTS: At 7months, sera were collected from 132 neonates in Guangxi Zhuang Autonomous Region and 752 neonates in Jiangsu Province. Baseline characteristics of both mothers and neonates were comparable in the two regions. No differences were revealed regarding the occurrence of perinatal HBV transmission with or without HBIG at birth [0.1% (1/752) vs. 0.0% (0/132), p=1.000]. The anti-HBs response rates were 97.7% (129/132) and 98.5% (740/751) for the neonates with vaccine alone and with HBIG (p=0.758), respectively. Vaccine alone induced a significantly higher anti-HBs GMC as compared to vaccine plus HBIG at 7months of age (1555.3mIU/mL vs. 654.9mIU/mL, p<0.0001). At 12months of age, protective levels of anti-HBs remained in 97.4% (596/612) and 98.3% (118/120) of the neonates receiving and not receiving HBIG, respectively (p=0.771). The neonates receiving combined prophylaxis had a markedly lower anti-HBs GMC (210.7mIU/mL vs. 297.0mIU/mL, p=0.011). Horizontal HBV transmission occurred in none of the successfully immunized neonates for both compared groups at 12months of age. CONCLUSIONS: Vaccine alone may be enough for preventing HBV transmission in neonates of HBsAg (+)/HBeAg (-) mothers.

Occult HBV Infection in Immunized Neonates Born to HBsAg-Positive Mothers: A Prospective and Follow-Up Study.

OBJECTIVE: Occult HBV infection (OBI) has been reported in infants born to HBsAg-positive mothers despite immunization. This study aims to determine the maintenance of this status in a prospective birth cohort. METHODS: A total of 158 neonates born to HBsAg-positive mothers were enrolled. All received passive-active immunization against HBV according to a 0-1-6 schedule. Sera were collected at 7 months of age. Those diagnosed with OBI were serially followed up at 12, 24 and 36 months of age. HBV serological markers were determined by Abbott i2000 system. HBV DNA was quantitated by Abbott m2000 system. Standard PCR followed by direct sequencing were applied for mother-child HBV pairs. Homology and phylogenetic comparisons were done by BLAST and Mega 5. RESULTS: All the 158 neonates were HBsAg-negative and anti-HBs-positive at 7 months of age, and 32 (20.3%) of them were diagnosed with OBI, with a median HBV DNA level of 1.97 (1.20-3.71) log IU/mL. Of them, HBV DNA was positive in 25.0%, 21.9% and 7.7% at 12, 24 and 36 months of age, respectively. HBV DNA disappeared at one of the follow-up points in 31 neonates, however, rebounded to low levels in 6 of them thereafter. HBV DNA persisted at low levels during follow-ups in the other one neonate apart from the above 31. All remained negative for HBsAg. Only two (6.3%) neonates were positive for anti-HBc after 24 months of age. HBV showed close homology and phylogenetic relationships for mother-child pairs. S-escape mutant, G145R, was not discovered. The first vaccine dose within 6 hours of birth significantly reduced the occurrence of OBI (59.4% vs. 83.3%, p = 0.003). CONCLUSIONS: HBV may be controlled in immunized neonates of HBsAg-positive mothers, after being diagnosed with OBI. Timely vaccination against HBV may provide the utmost protection. Long-term and close monitorings are needed.

Seroepidemiology of hepatitis B virus infection and impact of vaccination.

AIM: To investigate hepatitis B virus (HBV) prevalence in the general population in China. METHODS: A total of 148931 individuals were investigated by multistage random sampling in Eastern China. Data were collected on demographics and hepatitis B vaccination history, and serum was tested for hepatitis B surface antigen (HBsAg) by ELISA. RESULTS: A total of 11469 participants (7.70%, 95%CI: 7.57%-7.84%) were positive for HBsAg. HBsAg prevalence was 0.77% among children < 5 years old but increased progressively from adolescents (1.40%-2.55%) to adults (5.69%-11.22%). A decrease in HBsAg prevalence was strongly associated with vaccination and familial history of HBV among both children and adult groups. Meanwhile, HBsAg risk in adults was associated with invasive testing and sharing needles. The HBV immunization rate among participants aged < 20 years was 93.30% (95%CI: 93.01%-93.58%). Significant difference in HBsAg prevalence appeared between vaccinated and unvaccinated participants (3.59% vs 10.22%). CONCLUSION: Although the national goal of HBsAg prevalence < 1% among children < 5 years old has been reached, immunization programs should be maintained to prevent resurgence.

A predictive value of quantitative HBsAg for serum HBV DNA level among HBeAg-positive pregnant women.

BACKGROUND: The high maternal HBV DNA level is the most important factor contributing to HBV perinatal transmission. This study is to explore whether HBsAg can be used as a surrogate marker of serum HBV DNA for HBsAg-positive pregnant women. METHODS: A total of 975 HBsAg-positive pregnant women and their infants were enrolled in this study. All infants received three doses of a yeast-derived recombinant Hepatitis B vaccine at 0, 1 and 6 months. They were also given Hepatitis B immunoglobulin (HBIG) at birth. HBsAg and HBeAg were determined using Abbott Architect assays while serum HBV DNA level was detected by the Abbott Real Time HBV DNA assay. RESULTS: Of the 975 subjects, 367 (37.6%) were HBeAg-positive and 608 (62.4%) were HBeAg-negative. Among the HBeAg-positive group, the samples with HBV DNA levels of ≥7.0 logIU/mL were 76.6% (281/367), and it was only 0.7% (4/608) for the HBeAg-negative group. HBV DNA level was positively correlated with HBsAg in HBeAg-positive group (r=0.786, p<0.001) but not in HBeAg-negative group (r=0.022, p=0.593). Among HBeAg-positive group, the area under the receiver-operator curve (ROC) of HBsAg titer for high HBV DNA level (≥7.0 logIU/mL) was 0.961 (95% CI, 0.940-0.983, p<0.001). The optimum cut-off point HBsAg titer above 4.1 logIU/mL had a sensitivity of 85.1%, specificity of 96.5%, and accuracy of 87.5% to predict HBV DNA levels of ≥7.0 logIU/mL. Of 367 infants born to mothers with HBeAg-positive, perinatal transmission was detected in 24 infants (6.5%, 24/367). Their mothers all had serum HBV DNA levels of ≥7.0 logIU/mL, 23 (95.8%) had HBsAg titers of ≥4.1 logIU/mL and the other mother had HBsAg titer of 3.9 logIU/mL. Of 608 infants born to mothers with HBeAg-negative, only one (0.2%, 1/608) became HBsAg-positive at the age of 7 months, and the mother of the infant had serum HBV DNA level of 3.4 logIU/mL and HBsAg titer of 1.8 logIU/mL, respectively. CONCLUSION: Serum HBsAg titer may be used as a surrogate marker of serum HBV DNA for HBeAg-positive pregnant women.

[Comparison on the antibody response after primary immunization of 5 µg and 10 µg hepatitis B vaccine made by recombinant DNA techniques among newborns].

OBJECTIVE: To compare the antibody response induced by primary immunization with 5 µg and 10 µg hepatitis B vaccine made by recombinant DNA techniques among the newborns. METHODS: Healthy infants who had completed primary immunization with 5 µg hepatitis B vaccine made by recombinant dexyribonucleic acid techniques in Saccharomyces (Hep-SC) or 10 µg hepatitis B vaccine made by recombinant dexyribonucleic acid techniques in Hansenula polymorpha (HepB-HP) were included in the study. Kids under study were 7-12 months of age and had been on 0-1-6 schedule. Standardized questionnaire was used and blood samples were collected. The titer of antibody to hepatitis B surface antigen (anti-HBs) was detected by Chemiluminescence Microparticle Imunoassay (CMIA). If anti-HBs happened to be under 10 mIU/ml, HBV DNA was further detected by nested-PCR to distinguish occult hepatitis B virus infection. Sero-conversion rate and titer of anti-HBs were compared between the two kinds of hepatitis B vaccines. Multivariate analysis was used to find the relationship between the kind of hepatitis B vaccine as well as the antibody response after debugging the other influencing factors including month-age, gender, birth-weight, premature birth and mother's HBsAg status. RESULTS: 8947 infants vaccinated with 5 µg HepB-SC and 4576 infants vaccinated with 10 µg HepB-HP were investigated. In the 5 µg group, the rates of non-, low-, normal- and high-response were 1.88%, 15.18%, 61.42% and 21.52% respectively. In the 10 µg group, the corresponding rates were 0.15%, 2.16%, 29.42% and 68.26% respectively. The non-, low-, normal-response rates were all higher in 5 µg group than in 10 µg group (P<0.01), while the high-response rate was much higher in 10 µg group than in 5 µg group (P<0.01). The geometric mean concentration (GMC) of anti-HBs were 354.81 mIU/ml (95%CI: 338.84-363.08 mIU/ml) and 1778.28 mIU/ml (95%CI: 1698.24-1819.70 mIU/ml) in the 5 µg group and 10 µg group respectively. The GMC was statistically higher in the 10 µg group than in the 5 µg group (P<0.001). The sero-conversion rate and GMC were significantly different between the two groups even after debugging the other influencing factors. CONCLUSION: Better anti-HBs response could be achieved by primary immunization with 10 µg HepB-HP than with 5 µg HepB-SC among newborns.

[Multi-center matching study on antibody response between preterm and full-term infants after primary immunization of hepatitis B vaccine].

OBJECTIVE: To compare the antibody response between preterm and full-term infants after primary immunization of hepatitis B vaccine (HepB). METHODS: Infants who were aged 7 - 12 months and had completed primary immunization with 5 µg HepB made by recombinant deoxyribonucleic acid techniques in saccharomyces cerevisiae (HepB-SC) or 10 µg HepB made by recombinant deoxyribonucleic acid techniques in Hansenula polymorpha (HepB-HP) on 0-1-6 schedule were investigated in four provinces (municipality) including Beijing, Shandong, Jiangsu and Guangxi of China. Among them, all preterm infants were selected to form the preterm group and the 1:1 matching full-term infants with the same month-age, gender and residence were randomly selected to form the full-term group. Their HepB history was determined by immunization certificate and all of their parents were interviewed with standard questionnaire to get their birth information. Blood samples were obtained from all anticipants and were tested for Anti-HBs by chemiluminescence microparticle immuno-assay (CMIA). RESULTS: Total anticipants were 648 pairs of infants. The rates of non-response, low-response, normal-response and high-response after the primary immunization were 1.39%, 8.64%, 45.83% and 44.14% in the preterm group, respectively. The corresponding rates were 1.08%, 9.26%, 44.91% and 44.75% in the full-term group. The above four rates did not show significant differences between the two groups (P > 0.05). The geometric mean concentrations (GMC) of anti-HBs in the pre-term and full-term group were 755.14 and 799.47 mIU/ml respectively. There was no significantly difference in the GMCs between the two groups (P > 0.05). Results from multivariable conditional logistic analysis showed that preterm was not an influencing factor to the antibody response after HepB primary immunization among newborns even after debugging the other influencing factors. CONCLUSION: The antibody response after HepB primary immunization were similar among the preterm and full-term infants. The preterm newborns could be immunized under the same HepB immunization strategy.

A serological and molecular survey of hepatitis B in children 15 years after inception of the national hepatitis B vaccination program in eastern China.

The emergence of mutations in the hepatitis B virus (HBV) S gene has threatened the long-term success of vaccination programs since the worldwide introduction of effective vaccines against hepatitis B. This study was conducted on 5,407 children (0-8 years old) in eastern China in 2007. We analyzed the prevalence of HBsAg, anti-HBs, and "a"-determinant mutations in the HBV S gene by microparticle enzyme immunoassays, PCR, and DNASTAR software. The total HBsAg prevalence was 1.52% (82/5,407) in the children and increased with age. In contrast, the positive rate (65.42%, 2,374/3,629) and the titers of anti-HBs decreased with age. The predominant infection was HBV of genotype C and serotype adr (45/51; 88% of cases). Mutations of I126T, amino acid 137 (nt553T deletion mutation), G145A, G145R, and F158S were found in the children; the mutations of amino acid 137 and F158S have not been reported previously. The total prevalence of mutant strains was 14% (7/51). To investigate whether the infection resulted from maternal transmission, we compared the S gene sequences in 16 mother-child pairs. Fourteen mother-child pairs exhibited the same HBV genotype, with 99.5-100% sequence homology in the S gene, while two pairs exhibited different genotypes. This study suggested that the hepatitis B vaccination strategies in eastern China have been successful. Although the emergence of "a"-determinant mutations in the HBV S gene have resulted in HBV infection in immunized children, this does not pose a threat to the vaccination strategies. The HBV-infected children had contracted the infection via vertical transmission.

[Study on the kinesis of cellular immunity in adults vaccinated with recombinant hepatitis B vaccine].

OBJECTIVE: To evaluate the kinesis of cellular immunity in adults who were vaccinated with yeast recombinant hepatitis B(rHB) vaccine and the correlation between cellular and humoral immune responses induced by the vaccine. METHODS: Eight adults were vaccinated with rHB vaccine according to 0, 1,2 month schedule. The peripheral blood mononuclear cells(PBMCs) were collected at the 3, 8, 21, 34 and 65 days after the first dose. The high purity of CD4+ and CD8+ T cells obtained by sorting from PBMCs were restimulated with recombinant hepatitis B surface antigens (rHBsAg) or peptides. The spot forming cell (SFC) of IFN-gamma, IL-2 and IL-4 of CD4+ and CD8+ T cells were detected by enzyme-linked immunospot (ELISPOT). RESULTS: The characteristics of IFN-gamma, IL-2 and IL-4 of CD4+ and CD8+ T cells appeared different after immunization with rHB vaccine. IFN-gamma of CD8+ and CD4+ T cells could be detected early with stable SFC, while the IL-2 and IL-4 of CD4+ T cells appeared late but increased after the second and third dose of vaccination. The positive rate of IL-4 of CD4+ T cells were significantly correlated with the positive rate of anti-HBs, while the SFCs of IL-4 and IL-2 of CD4+ T cells were also significantly related to the titers of anti-FIBs. CONCLUSION: IFN-gamma could be detected early after rHB vaccination in adults, and the positive rates of IL-4 and IL-2 were correlated with that of anti-HBs.

[Study on the efficacy of hepatitis B virus vaccination and its influencing factors among children in rural area of Jiangsu province].

OBJECTIVE: To evaluate the efficacy of hepatitis B viruse (HBV) vaccination and its influencing factors among children in rural area of Jiangsu province. METHODS: Twenty-five hundred and twenty-two children born after 1998 in rural area were selected as the study population using multistage cluster sampling method. HBsAg and anti-HBs were detected by enzyme linked immunoassay (ELISA) and radio-immunoassay (RIA), respectively. Anti-HBs negative children were boosted using different hepatitis B vaccines and the efficacy was compared. Factors causing HBV infection in HBsAg positive children were also investigated. RESULTS: HBsAg positive rates in 1-7 year olds were 0.28%-1.28%, and the anti-HBs positive rates decreased from 76.7% to 45.5%. The HBsAg positive rate in children not timely vaccinated was significantly higher than those with HBV vaccine injection within 24 hours after birth (1.4% vs. 0.5%, P = 0.031). More than 90% of the anti-HBs negative children had protective level of anti-HBs after boosted with HBV vaccine. CONCLUSION: HBsAg positive rate in children born after 1998 in rural area of Jiangsu province decreased significantly, with an average of 0.8%. The reason for HBsAg carriage in children might be attributed to mother-to-infant transmission or not timely HBV vaccination.

Functional polymorphisms in the cyclooxygenase 2 (COX-2) gene and risk of breast cancer in a Chinese population.

Cyclooxygenase (COX), the rate-limiting enzyme in prostaglandins (PG) synthesis, exists in at least two isoforms, COX-1 and COX-2. COX-2 plays an important role in carcinogenesis, and overexpression may increase proliferation, inhibit apoptosis, and enhance the invasiveness of breast cancer cells. Polymorphisms in the regulatory regions of the COX-2 gene may influence function and/or expression and contribute to interindividual variability in susceptibility to cancer. In this study three variants (-1195G/A and -765G/C in the promoter and 8473C/T in 3'UTR) of COX-2 were examined for correlation with breast cancer risk. A case-control study of 615 histologically confirmed breast cancer patients and 643 cancer-free controls frequency-matched for age were selected. Logistic regression analyses revealed that no overall significant associations were detected in the single-locus analysis between three polymorphisms of COX-2 and the risk of breast cancer. However, a significantly increased risk of breast cancer was associated with the combined genotypes containing "more than 3 variant alleles"' (adjusted OR = 1.37, 95% CI 1.01-1.84) compared with the combined genotypes with "0-3 variant alleles." Haplotype analyses showed that haplotypes A-1195G-765T8473 and A-1195C-765T8473 were significantly associated with breast cancer risk (OR = 1.20, 95% CI 1.01-1.43 for A-1195G-765T8473; OR = 9.16, 95% CI 1.14-73.51 for A-1195C-765T8473) compared with the most common haplotype, G-1195G-765T8473. These findings indicate that these three variants in the regulatory regions of COX-2 may contribute to the etiology of breast cancer.

The association of polymorphisms of CDT1 and GMNN gene with the risk of breast cancer in Chinese women: a case-control analysis.

OBJECTIVE: To investigate the association of polymorphisms of CDT1 and GMNN gene, two important genes participating in DNA replication, with the risk of sporadic breast cancer. METHODS: Using polymerase chain reaction-restriction fragment length polymorphism (PCR - RFLP) and the primer-introduced restriction analysis (PIRA)-PCR assay to genotype the CDT1 838G/A and GMNN 387C/A polymorphisms in a case-control study of 427 breast cancer cases and 477 cancer-free controls in a Chinese population. RESULTS: No significant association of the CDT1 838G/A and GMNN 387C/A polymorphisms with the risk of breast cancer was found (adjusted OR:1.16, 95% CI:0.88-1.54 for CDT1 GA+AA genotypes and adjusted OR:0.90, 95% CI:0.67-1.21 for GMNN CA+AA genotypes). However, in the stratified analyses, a significant association of CDT1 GA+AA genotypes with breast cancer risk among subjects with family history of cancer was found (adjusted OR:2.21, 95% CI:1.20-4.09). CONCLUSION: These findings suggest that the CDT1 838G/A and GMNN 387C/A polymorphisms may not play a major role in the etiology of breast cancer, but CDT1 variant may have a potential role only in genetically susceptible women.