Seroprevalences of antibodies against pertussis, diphtheria, tetanus, measles, mumps and rubella: A cross-sectional study in children following vaccination procedure in Guangzhou, China.

This study investigated the concentrations and seroprevalence of immunoglobulin G (IgG) antibodies against pertussis, diphtheria, tetanus, measles, mumps and rubella among children in Guangzhou, China. We conducted a cross-sectional study focusing on the post-vaccination immune statuses of children on scheduled immunisation. Human IgG antibody against six diseases were measured using commercial enzyme-linked immunosorbent assay kits. Of 620 subjects, the male-to-female ratio was 2.04 (416/204). Seroprevalence (81.97% vs 90.20%) and IgG concentrations (686.55 IU/mL vs 884.26 IU/mL, P < 0.05) for measles, tetanus (0.94 IU/mL vs 1.21 IU/mL) and rubella (34.33 IU/mL vs 47.37 IU/mL) were all higher in females. No differences based on sex were observed in the seroprevalence and IgG concentrations for anti-pertussis antibodies, anti-diphtheria antibodies and anti-mumps. Slight increase in seroprevalence and IgG concentration occurred with anti-pertussis antibodies after primary and booster vaccinations (from 0.00% [1 m], 5.45% [6 m], to 17.14% [1.5 yr]; and from 8.57% [5 yr] to 15.79% [6 yr]). Although no booster vaccination was given after age 6 yr, the seroprevalence and IgG concentration for anti-pertussis antibodies remained relatively stable. For diphtheria, tetanus, measles and rubella, seroprevalence reached their peaks after the primary and first booster vaccination. A plateau occurred after age 1.5 yr with a declining trend in subjects >8-10 yr. The IgG concentrations of these 4 pathogens showed a dramatic increase after primary vaccination, with steadily declining trends thereafter. For mumps, subjects showed increased seroprevalence and IgG concentration after the primary mumps-containing vaccination in 1.5-yr-olds (from 7.14% to 57.14%; 52.13 IU/mL to 214.18 IU/mL); however, following that low seroprevalence levels (from 42.86% to 80.00%) were observed. The post-vaccination immune statuses against diphtheria, tetanus, measles and rubella were relatively satisfactory, compared to those against pertussis and mumps. Booster vaccination against pertussis and mumps at appropriate time should be considered.

[Comparison of the anti-leukemia effect and mechanism of L-asparaginase between two different strains].

This study was purposed to compare the anti-leukemic effects of E.coli-L-Asp and Erwinia-L-Asp in vitro, and to investigate their mechanism. The cell apoptosis and proliferation inhibition rate were measured by CCK-8 kit, and IC50 of two drugs was calculated by using SPSS software. Pro-apoptosis effect of E.coli-L-Asp and Erwinia-L-Asp on REH and Jurkat cell lines was also determined by flow cytometry with Annexin V/PI double staining. Concentration changes of 4 amino acids (Asn, Aspa, Gln, and Glu) before and after medication were detected by using high pressure liquid chromatography (HPLC) assay. The results showed that both REH and Jurkat cell lines were sensitive to L-Asp drugs from two different strains, and E.coli-L-Asp and Erwinia-L-Asp displayed the inhibition effect on the proliferation of Jurkat and REH cell lines in dose-dependent and time-dependent manners. The inhibition cell of proliferation and cell apoptosis in Erwinia-L-Asp group were higher than those in E.coli-L-Asp group after 24 hours (P < 0.05) . However, after treatment of REN and Jurkat cells with 2 kind of L-Asp for 48 hours, the inhibition of cell proliferation and apoptosis rates were not significantly different between the 2 L-Asp drugs (P > 0.05). The Asn in medium could be depleted by two different L-Asp drugs with low concentration. Both the two L-Asp drugs had the same capability to deplete the Asn surrounding leukemia cells (P > 0.05). The Gln in medium could be depleted by two L-Asp drugs with high concentration. The hydrolysis effect of Erwinia-L-Asp on Gln was stronger than that of E.coli-L-Asp (P < 0.05). It is concluded that in a certain range of concentrations, E.coli-L-Asp and Erwinia-L-Asp exert anti-leukemia effect in dose-dependent manner. Depletion of Gln and Asn in surrounding environment and induction of cell apoptosis are two potential mechanisms, by which leukemia cells can be killed. Erwinia-L-Asp may be chosen as the first-line drug to treat childhood ALL for its fast action and stronger hydrolysis effect on Gln.