Persistence of antibodies acquired by natural hepatitis E virus infection and effects of vaccination.

OBJECTIVE: Naturally acquired anti-hepatitis E virus (HEV) immunity can protect against new HEV infections. The aim of this study was to analyse the persistence of naturally acquired anti-HEV immunoglobulin (Ig) G and anti-HEV IgG concentrations after vaccination. METHODS: We examined the seropositivity rates of participants included in a phase 3 clinical efficacy trial (67 months' follow-up) for a HEV vaccine (Hecolin; Xiamen Innovax Biotech, China) and predicted long-term persistence using mixed-effect models. RESULTS: The analysis focused on 2242 baseline seropositive participants in a control group (placebo recipients) and 2031 baseline seropositive participants in an vaccine group (vaccine recipients) who received 1 to 3 doses of Hecolin. Naturally acquired anti-HEV IgG levels decreased steadily independent of the initial antibody level; 50% of the placebo recipients were expected to have undetectable antibody concentrations after 14.5 years. After immunization with Hecolin, the power-law model and the modified power-law model predicted that 82.1 and 99.4% of the participants, respectively, would remain seropositive for anti-HEV IgG for 30 years after vaccination. CONCLUSIONS: Whereas naturally acquired anti-HEV IgG levels decrease steadily, HEV vaccination induces long-lasting, high-level anti-HEV IgG concentrations.

[Research progress regarding the clinical evaluation on recombinant human papillomavirus vaccines].

Human papillomavirus (HPV) is the main cause for cervical cancer, anogenital cancers and genital warts. Three HPV vaccines have been licensed abroad. Data from clinical trials showed high efficacy of the HPV vaccines in young women with 90%-100% vaccine-related HPV diseases prevented. Though efficacy of the vaccine appears lower in older women, this population can still benefit from vaccination. Immunobriging trials show that the two-dose schedule in 9-14 years old girls elicits non-inferior immune response than the three-dose one in young adults. In addition, HPV vaccines can reduce the recurrent rates in CIN2+ patients after therapeutic surgery and the vaccines have cross-protection aganist diseases caused by non-vaccine type HPV. Safety data on HPV vaccines are assuring. Thus HPV vaccine should be widely used in adolescent girls and women of appropriate age groups.

Cell cycle-dependent expression and nucleolar localization of hCAP-H.

Condensin is a conserved 13S heteropentamer composed of two nonidentical structural maintenance of chromosome (SMC) family proteins, in Xenopus XCAP-C and XCAP-E, and three regulatory subunits, XCAP-D2, XCAP-G, and XCAP-H. Both biochemical and genetic analyses have demonstrated an essential role for the 13S condensin complex in mitotic chromosome condensation. Further, a potential requirement for condensin in completion of chromatid arm separation in early anaphase is demonstrated by the mutational phenotypes of the Drosophila homologues of XCAP-H, barren and XCAP-C, DmSMC4. In this study we have investigated the expression and subcellular distribution of hCAP-H, the human homolog of XCAP-H, in order to better understand its cellular functions. Transcription of hCAP-H was restricted to proliferating cells with highest expression during the G(2) phase of the cell cycle. In contrast, cellular hCAP-H protein levels were constant throughout the cell cycle. hCAP-H was found to be associated with mitotic chromosomes exhibiting a nonuniform but symmetric distribution along sister chromatids. The symmetry of hCAP-H association with sister chromatids suggests that there are sequence-dependent domains of condensin aggregation. During interphase hCAP-H, -C, and -E, have distinct punctate nucleolar localization, suggesting that condensin may associate with and modulate the conformation and function of rDNA. hCAP-H association with condensed chromatin was not observed in the early phase of chromosome condensation when histone H3 phosphorylation has already taken place. This finding is consistent with the hypothesis that histone H3 phosphorylation precedes condensin-mediated condensation.

[Whole embryo culture for detecting teratogen].

Whole embryo culture technique was used to study direct effects of Penicillin G, Thiadiazole, Actinomycin D and glucose solution of high concentration on the development and growth of rat embryos, without maternal and placental influence. Nine-and-a-half-day rat embryos were transplanted to culture flasks from the animal's wombs for in vitro culture, and the four chemicals were added to culture medium, respectively. Results showed all those chemicals could cause death and malformation of the embryos and retardation in embryonic development and growth cultured in vitro, with an apparent dose-effect relationship. The embryonic malformations caused by the chemicals were the same both in vitro culture and in vivo. Possible teratogenesis of the chemicals and survival of the malformed embryos were speculated based on the above dose-effect relationship.

[Effect of hyperglycemia on rat embryos in vitro].

Using whole embryo culture, the effect of hyperglycemia on the embryogenesis of rat was studied. Hyperglycemia could cause death, malformation and intrauterine growth retardation of embryos. The effect of hyperglycemia was more obvious in the early embryogenesis of rat in vitro, and showed a dose related effect. The results suggested that the blood glucose level of diabetic women should be controlled strictly during pregnancy, particularly in the first trimester of pregnancy. It may play an important role in preventing death, congenital malformation and intrauterine growth retardation of fetus in diabetic women.

Leukogenic effect of complex indigo powder.

Oral administration of complex indigo powder, an anti-scrofula powder, at a daily dose of 0.5 g/kg, raised the leukocyte count in rats injured by irradiation, but prophylactic administration could not prevent the leukopenia induced by irradiation. This dosage did not affect growth in rats and oral doses up to 6 g/kg did not induce any toxic reactions in mice.

Central nervous system congenital malformations, especially neural tube defects in 29 provinces, metropolitan cities and autonomous regions of China: Chinese Birth Defects Monitoring Program.

Data from the Chinese Birth Defects Monitoring Program (CBDMP) over the period of October 1986 to September 1987 were analysed to study the descriptive epidemiology of congenital malformations of the central nervous system (CNS), especially neural tube defects (NTDs) in China. A total of 4628 CNS congenital malformations were recorded within seven days of delivery among 1,243,284 live and stillbirths of 28 or more weeks gestation in 945 hospitals from all 29 provinces, metropolitan cities and autonomous regions of China. Neural tube defects account for 73.55% of these cases, hydrocephaly for 24.63% and microcephaly for 1.82%. The prevalence rates at birth of NTDs and congenital malformations of the CNS in China were 27.37 and 37.22 per 10,000 respectively. More NTDs were observed in females (35.68 per 10,000 female births) as compared to males (19.23 per 10,000 male births). The prevalence of NTDs in rural areas (51.69 per 10,000 births) was higher than that in urban areas (15.45 per 10,000 births).