Implementation and assessment of personalized incentive measures for standardized residency training in department rotation / 中华医学教育探索杂志

Incentive system is an indispensable means in the process of standardized residency training, which plays an important role in improving the work efficiency and service quality of residents, teachers and other participants. Based on the analysis of the problems existing in the holistic incentive system, we have implemented a set of personalized incentive measures for the training of residents in department rotation and achieved preliminary results, which provides ideas for exploring personalized incentive system for standardized residency training.

CXCL10/CXCR3 Signaling in the DRG Exacerbates Neuropathic Pain in Mice / 神经科学通报·英文版

Chemokines and receptors have been implicated in the pathogenesis of chronic pain. Here, we report that spinal nerve ligation (SNL) increased CXCR3 expression in dorsal root ganglion (DRG) neurons, and intra-DRG injection of Cxcr3 shRNA attenuated the SNL-induced mechanical allodynia and heat hyperalgesia. SNL also increased the mRNA levels of CXCL9, CXCL10, and CXCL11, whereas only CXCL10 increased the number of action potentials (APs) in DRG neurons. Furthermore, in Cxcr3

Study on the contamination level and dietary exposure of 9,10-anthraquinone in different types of teas in Wuhan / 公共卫生与预防医学

Objective To investigate the pollution level of 9,10-anthraquinone in teas sold in Wuhan, and to assess the dietary exposure of 9,10-anthraquinone ingested through tea. Methods The content of 9,10-anthraquinone in teas collected from local tea markets in Wuhan was analyzed by GC-MS/MS. Results 9,10-anthraquinone was detected in all 36 tea samples with a concentration ranging from 0.0080 mg/kg to 0.137 mg/kg. The standard limit for 9,10-anthraquinone has not yet been set in China. Referring to EU standards, the total over-standard rate was 86.11% (31/36). Generally, the concentration of residual 9,10-anthraquinone was higher in highly fermented teas. The highest average concentration of residual 9,10-anthraquinone was found in fully/post-fermented tea (0.0762 mg/kg), and the over-standard rate was 100%. The second highest was in semi-fermented tea (0.0452 mg/kg), and the over-standard rate was 86.7%. The concentration of 9,10-anthraquinone in non-fermented tea was 0.0262 mg/kg, and the over-standard rate was 42.9%. According to people’s tea-drinking habits, tea samples were brewed with boiling water（1:50）for 5 minutes, and the concentration of 9,10-anthraquinone in tea soup was 0.0004 mg/kg～0.01 mg/kg, with an average leaching rate of 7.2%. The average daily intake exposure of tea for an adult was 0.0551μg/kg bw/day. Conclusion There was a certain degree of 9,10-anthraquinone pollution in the teas sold in Wuhan, and the rate exceeding the standard was high. Since the acceptable daily intake (ADI) for 9,10-anthraquinone has not been established, it is impossible to assess the health risks of 9,10-anthraquinone ingested through tea.

Long-term antibody persistence study (3 years after last dose) of the 7-valent pneumococcal conjugate vaccine in young children in China.

BACKGROUND: In a previous study, Chinese infants were vaccinated with 7-valent pneumococcal conjugate vaccine (PCV7) ⩾7days before routine diphtheria, tetanus, and acellular pertussis vaccine (DTaP); PCV7 administered concomitantly with DTaP (PCV7+DTaP); or DTaP alone. This study examined antibody persistence at a single time point 3years after the last vaccination. METHODS: Children who participated in the prior PCV7 study were eligible to participate. A single blood sample was drawn at enrollment. Immunoglobulin G (IgG) geometric mean concentrations (GMCs) specific to the PCV7 serotypes and percentages of subjects with IgG ⩾0.35µg/mL were compared for subjects receiving PCV7 versus PCV7+DTaP (concomitant) and for PCV7 or PCV7+DTaP (concomitant) versus DTaP alone. IgG concentrations at 3years after the last vaccination were also compared with those after the infant series and toddler dose. RESULTS: Three years after the last vaccination with PCV7 or PCV7+DTaP (concomitant), IgG GMCs for most PCV7 serotypes were lower than after the infant series or toddler dose but remained above prevaccination concentrations. IgG GMC were similar between the PCV7 and PCV7+DTaP (concomitant) groups for 5 out of 7 serotypes but serotypes 4 and 19F were significantly lower in the PCV7+DTaP (concomitant) recipients. Three years after the last vaccination, IgG GMCs were significantly higher for 6 of 7 PCV7 serotypes among those receiving PCV7 or PCV7+DTaP (concomitant) compared with recipients of DTaP alone. Among subjects receiving DTaP alone, serotype-specific antibody concentrations were significantly higher for all serotypes 3years after the last vaccination compared with after the infant series. CONCLUSION: Three years after PCV7 vaccination, serotype-specific antibodies were lower than after the primary infant series but higher than prevaccination levels and higher among subjects who received PCV7 compared with those who did not. The immune response was comparable in children who received PCV7 with and without concomitant DTaP. CLINICAL TRIAL REGISTRATION: NCT01298544.

The results of the epidemiological surveillance of severe fever with thrombocytopenia syndrome in Ningbo City / 预防医学

Objective To learn the epidemiological status of severe fever with thrombocytopenia syndrome (SFTS). Methods The surveillance sites were established in two county level hospitals and two township health centers in Ningbo city.Using the diagnostic criteria of the national ministry of health and questionnaire of epidemiological case survey,cases with SFTS were investigated.The SFTS virus was isolated with Vero cells from the positive serum and the gene sequence was analyzed.Results Eleven cases were reported during year 2012—2013,including one person died.A total of 156 ticks were detected negative.The positive rate of serum collected from healthy people in local area was 6.14% and increased with age(P <0.01).There were a close relationship between five isolates of Ningbo and isolates of Japan and Zhoushan,and the gene sequence similarity was more than 96%.Conclusion SFTS cases were reported in Ningbo City, and the surveillance system should be strengthened especially for the disease detection.

Characters of bone marrow mesenchymal stem cells of primary biliary cirrhosis / 中华风湿病学杂志

Objective To investigate the growth and exocrine function of BM-MSC derived from PBC patients.Methods To compare the growth patterns and cytokines secretions between PBC patients and healthy controls by student's t test.Results ① There was no difference in growth profile and speed between PBC patients and healthy controls.② The level of TGF-β1 was much lower in the supernatant of BM-MS from OBC patients than health controls [(2.6±1.9)vs (8.2±6.7)ng/ml,t=-3.641,P=0.001].There were no other differences between two groups' BM-MSC.③ The super natant concentration of interlukin-10 of the third BM-MSC subculture from healthy controls was lower than that of the primary subculture [(18.5±5.0) vs (12.4±3.1) pg/ml,t=2.368,P=0.045],and that of hepatic growth factor from the second subcuhure was higher than the primary subculture [(0.21±0.07) vs (0.35±0.08) ng/ml,t=-2.874,P=0.021].There were seldom discrepancies in other cytokines between different generations of BM-MSC.Conclusion BM-MSC from PBC patients may have almost the similar characters in growth pattern and cytokines secretion as,except the TGF-β1,which was much lower than those from healthy controls.The second subculture of BM-MSC might be more suitable for the treatment to patients with PBC.

Immunologic analysis of refractory primary biliary cirrhosis / 中华风湿病学杂志

Objective To describe the immunological characteristics of refractory primary biliary cirrhosis compared with the typical patients for more than 1 year's administration of UDCA.Methods Sixty patients treated with UDCA for more than 1 year in our clinic were enrolled into this study.According to the response to UDCA by Paris criteria,patients were divided into refractory group (23 patients) and typical groups (37 patients).The recent peripheral lymphocyte subsets and cytokines of the two groups were tested and analyzed.One-way ANOVA and t test were used for statistical analysis.Results ① One-year treatment after diagnosis,there were no differences between the two groups in the distribution of peripheral lymphocytic subsets,meanwhile,the two groups had higher percentage of B cells,CD4+T cells,CD4+CD28+T cells and CD8+ CD28-T cells than healthy controls respectively.② The serum levels of IL-6 [(0.8±0.9) pg/ml vs (0.3±0.4) pg/ml] and HGF were higher in the refractory group than other groups.Conclusion During the plateau phase,refractory PBC patients have higher serum levels of IL-6 and HGF,which probably suggest that the refractory PBC patients may have severe immunologic disturbance in vivo.

Influence of prenatal alcohol exposure on retinal development and cell differentiation / 生理学报

The aim of the present study was to investigate the effects of prenatal alcohol exposure (PAE) on the development and cell differentiation of retina in offspring. The mouse model of PAE was made. HE staining and immunofluorescent labeling were carried out to visualize the structure, development and cell differentiation of the retina from postnatal day 0 (P0)-P30 offspring. The results showed that PAE can lead to the retardation of retinal development, the reduction of number of bipolar cells and horizontal cells, the disorder of horizontal cells' polarity, as well as the retinal thickening in a dose-dependent manner. The data suggest that alcohol exposure during pregnancy can lead to the developmental retardation of retina and decreased number of bipolar cells and horizontal cells in the retina of offspring.

A complex hepatitis B virus (X/C) recombinant is common in Long An county, Guangxi and may have originated in southern China.

Recently, a complex (X/C) hepatitis B virus (HBV) recombinant, first reported in 2000, was proposed as a new genotype; although this was refuted immediately because the strains differ by less than 8 % in nucleotide distance from genotype C. Over 13.5 % (38/281) of HBV isolates from the Long An cohort in China were not assigned to a specific genotype, using current genotyping tools to analyse surface ORF sequences, and these have about 98 % similarity to the X/C recombinants. To determine whether this close identity extends to the full-length sequences and to investigate the evolutionary history of the Long An X/C recombinants, 17 complete genome sequences were determined. They are highly similar (96-99 %) to the Vietnamese strains and, although some reach or exceed 8 % nucleotide sequence difference from all known genotypes, they cluster together in the same clade, separating in a phylogenetic tree from the genotype C branch. Analysis of recombination reveals that all but one of the Long An isolates resembles the Vietnamese isolates in that they result from apparent recombination between genotype C and a parent of unknown genotype (X), which shows similarity in part to genotype G. The exception, isolate QL523, has a greater proportion of genotype C parent. Phylogeographic analysis reveals that these recombinants probably arose in southern China and spread later to Vietnam and Laos.

The clinical analysis of 35 patients with cutaneous sarcoidosis / 中华内科杂志

Objective To investigate clinical features of cutaneous sarcoidosis. Methods A retrospective analysis was carried out based on the clinic data of 35 patients with cutaneous sarcoidosis who were hospitalized in Peking Union Medical College Hospital during 1980-2009. They were divided into two groups, the group without systemic involvement (skin group )and the group with systemic involvement ( systemic group). Results ( 1 ) The ratio of men and women with cutaneous sarcoidosis was 1: 3. 38, and the average incident age was (47. 5 ± 10. 0) years old. The average incident age of skin group and systemic group were (41.8 ± 12.5 ) years old and ( 50. 5 ± 7. 1 ) years old, respectively. (2) The most common skin manifestation was subcutaneous nodule, followed by maculopapule and erythema nodosa. The most common involved sites were limbs. (3) The common involved systems extra-skin included the lung, joints and lymph nodes. The involvement rate of lung in cutaneous sarcoidosis of our present data was lower than those of foreign reports. However, the involvement rates of joints, lymph nodes, kidney, muscles and nervous system showed higher in our data. (4) The incidences of fatigue and weight loss in systemic group were higher than those in skin group ( P ＜ 0. 05 ). The indexes of erythrocyte sedimentation rate, C-reactive protein and rheumatoid factor in systemic group were higher than those in skin group ( P ＜ 0. 05 ). More patients in systemic group were treated with corticosteroid than that in skin group ( 95.7% vs 66.7%, P ＜ 0. 05 ).Conclusions Subcutaneous nodules are the most common and the involvement rate of lung is lower in cutaneous sarcoidosis of our present data. Compared to the patients without systemic involvement, the average incident age of systemic ones is older, the indexes of inflammation markers and the usage of corticosteroid are higher.

Study on the longevity related mitochondrial genome variation in Bama elderly population in Guangxi province / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the human mitochondrial DNA (mtDNA) variations associated with longevity in Bama elderly population from Guangxi.</p><p><b>METHODS</b>Mitochondrial genome of 20 individuals over 96 years of age was sequenced, and seven target single nucleotide polymorphism (SNPs) were observed by comparing with the standard rCRS sequence, and two were tested by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in a larger population including 208 individuals of 90-113 years old, and 586 unrelated control individuals from Guangxi.</p><p><b>RESULTS</b>The 4824G frequency of the mtDNA4824A/G locus increased with age both in the long-lived elderly and in controls. And it was significantly higher in controls than that in long-lived population (P<0.05).</p><p><b>CONCLUSION</b>The mtDNA4824 A/G is not only an age-related locus, its mutation is also negatively correlated with longevity.</p>

[A prospective study of the relationship between serum hepatitis B virus DNA and the risk of primary liver cancer].

OBJECTIVE: To determine the relationship between the serum hepatitis B virus (HBV) DNA and the risk of primary liver cancer (PLC). METHODS: Farmers aged 30 to 55 years in Long An county were recruited in this study Blood samples were collected and the sera were tested for HBsAg using Enzyme-Linked ImmunoSorbent Assay (ELISA), and the HBsAg-positive sera were further tested for viral DNA using nested polymerase chain reaction (nPCR). The study subjects were divided into three groups. The first group was positive for both HBsAg and HBV DNA. The second group was positive for HBsAg but negative for HBV DNA. Age-, sex-, residence-matched HBsAg negative controls for group 1 and group 2 were enrolled in the third group. The cohort was followed up for four years. RESULTS: The positive rate of HBsAg in these farmers was 14.52% (3975/27,379), and the HBV DNA positive rate in HBsAg positive subjects was 40.35% (1604/3975). The total PLC incidence rate in Group 1 and 2 was 672.45 /100,000 person-years (PY), significantly higher than that in Group3 (17.19 /100,000 PY). The relative risk (RR) was 39.123, and the 95% confidence interval (CI) was 9.018-159.146. The PLC incidence rate of Group 1 (984.03/100,000 PY) was significantly higher than that of Group2 (324.38 /100,000 PY). The RR was 3.034, and the 95% CI was 1.795-5.125. Multivariate analyses of Group1 and 2 with Cox model showed that sex, age, serum HBV DNA, and family history of PLC were independent risk factors of PLC. CONCLUSION: HBV DNA and HBsAg positive subjects have a higher chance to develop PLC than HBV DNA negative-, HBsAg positive subjects.

The association of HBV core promoter double mutations (A1762T and G1764A) with viral load differs between HBeAg positive and anti-HBe positive individuals: a longitudinal analysis.

BACKGROUND/AIMS: Although there have been a few reports regarding the effect of basal core promoter (BCP) double mutations (A1762T and G1764A) on hepatitis B viral loads, the association remains uncertain. We aim to determine the association after controlling for HBeAg - a strong confounding factor. METHODS: We selected randomly 190 individuals from a Chinese cohort of 2258 subjects for cross-sectional analysis and 56 of the 190 for longitudinal analysis of viral loads. RESULTS: In multivariable analysis of the cross-sectional data, BCP double mutations are significantly associated with lower viral loads in HBeAg positive subjects but no difference was found in anti-HBe positive subjects. Triple mutations at nucleotide (nt) 1753, 1762 and 1764 and mutations between nt 1809 and 1817, precore stop mutation (nt 1896) and genotype are not associated with viral loads in either HBeAg or anti-HBe positive subjects. Analysis of the longitudinal data yielded similar results to the cross-sectional data. Viral loads differ significantly between individuals infected with wild-type and BCP double mutations prior to HBeAg seroconversion but this difference is lost after seroconversion. CONCLUSIONS: BCP double mutations are associated with lower viral loads in HBeAg positive individuals but have no effect on the viral loads of anti-HBe positive individuals.

HBV A1762T, G1764A mutations are a valuable biomarker for identifying a subset of male HBsAg carriers at extremely high risk of hepatocellular carcinoma: a prospective study.

OBJECTIVES: Surveillance of hepatocellular carcinoma (HCC) can detect small tumors for resection but at a huge cost of health resources. The challenge is to reduce the surveillance population. We reported that 96% of HCC patients but only 24% of controls were infected with the hepatitis B virus (HBV) with A(1762)T, G(1764)A mutations in Guangxi, China. It is likely to be extremely beneficial in terms of cost and resources if a significant number of tumors can be detected early by screening this selected population. Our aim is to test this hypothesis. METHODS: A cohort of 2,258 hepatitis B surface antigen-positive subjects aged 30-55 yr was recruited in Guangxi. Following evaluation of virological parameters at baseline, HCC is diagnosed by 6-monthly measurements of serum alpha-fetoprotein levels and ultrasonographic examinations. RESULTS: Sixty-one cases of HCC were diagnosed after 36 months of follow-up. The HCC rate was higher in the mutant than wild-type group (P < 0.001, rate ratio [RR] 6.23, 95% confidence interval [CI] 2.83-13.68). The HCC rate in the male mutant group was higher than that in the male wild-type group (P < 0.001, RR 11.54, 95% CI 3.58-37.24). Specifically, 93.3% of male cases are infected with the mutant. Multivariate analyses showed that in men, increasing age and A(1762)T, G(1764)A double mutations are independently associated with developing HCC. CONCLUSIONS: HBV A(1762)T, G(1764)A mutations constitute a valuable biomarker to identify a subset of male HBsAg carriers aged >30 yr at extremely high risk of HCC in Guangxi, and likely elsewhere.

Hepatitis B virus pre-S deletion mutations are a risk factor for hepatocellular carcinoma: a matched nested case-control study.

A matched nested case-control study of 33 paired cases and controls was conducted, based on a study cohort in Long An county, Guangxi, China, to determine whether infection with hepatitis B virus (HBV) with pre-S deletions is independently associated with the development of hepatocellular carcinoma (HCC), without the confounding effects of basal core promoter (BCP) double mutations. The prevalence of pre-S deletions was significantly higher in HCC (45.5 %, 15 of 33) than the controls (18.2 %, 6 of 33) (P<0.01), under the control of the influence of BCP double mutations. Most of the pre-S deletions occurred in, or involved, the 5' half of the pre-S2 region and the difference between HCC (93.3 %, 14 of 15) and controls (66.7 %, four of six) was significant for this region (P=0.015). There was no significant difference in pre-S deletions between the BCP mutant group and BCP wild-type group (P>0.05), nor was the prevalence of pre-S deletions significantly different between genotypes B and C (P>0.1). These results suggest that pre-S deletions constitute an independent risk factor for HCC and their emergence and effect are independent of BCP mutations. The 5' terminus of pre-S2 is the favoured site for the deletion mutations, especially in HCC cases. Further prospective studies are required to confirm the role of these mutations in the development of HCC.

Safety and immunogenicity of a 7-valent pneumococcal conjugate vaccine (Prevenar): primary dosing series in healthy Chinese infants.

This was a randomized safety/immunogenicity evaluation of PCV7 primary series at 3, 4, 5 months in healthy Chinese infants. Eight hundred subjects were randomized to Group 1 (PCV7 > or =7 days before DTaP), or Group 2 (PCV7 with DTaP), or Group 3 (DTaP only). Erythema and induration/swelling were recorded at the PCV7 injection site at any individual dose in no more than 12% and 8% of subjects, respectively, and neither exceeded 2.5 cm in >1% of subjects. Fever >38.0 degrees C was observed in <13% of subjects at any individual dose. For each vaccine serotype, at least 90% of subjects (Groups 1 and 2) had IgG concentrations > or = 0.35 microg/mL after dose 3, except type 6B (Group 2) with 83.3%. PCV7 had an acceptable safety profile and was immunogenic in Chinese infants.

Expression of proliferation inducing ligand and its receptors in the peripheral blood mononuclear cells of patients with systemic lupus erythematosus / 中华风湿病学杂志

Objective To investigate the mRNA expression of a proliferation inducing ligand (APRIL) and its receptors including B cell maturation antigen (BCMA),transmembrane activator.calcium modulator and cyclophilin ligand interactor (TACI) in the peripheral blood mononuclear cells (PBMCs) of patients with systemic lupus erythematosus (SEE).Methods APRIL mRNA、BCMA mRNA and TACI mRNA in PBMCs were detected by real-time quantitative PCR in 66 SLE patients and 25 normal controls.Gene expression level was measured as 2-AACT.Results The expression levels of APRIL mRNA、BCMA mRNA and TACI-mRNA were significantly increased in both active SLE group and stable SLE group compared with those in the normal controls(P<0.01 for all).The expression levels of APRIL mRNA and TACI mRNA in active SLE group were significantly higher than those in stable SLE group(P<0.01,P<0.05,respectively).But there was no significant difierence in the expression levels of BCMA mRNA between the SLE stable and active groups-Beside,the expression levels of APRIL mRNA and TACI mRNA were significantly increased in patients with lupus nephritis (LN) compared to patients with non-LN (P<0.01 for all).Conclusion The expression levels of APRIL and its receptors are significantly elevated in SLE patients.It may suggest that APRIL and its receptors play an important role in the pathogenesis of SLE.

[Study on the variations of hepatitis B virus status among people having received hepatitis B vaccine].

OBJECTIVE: To study the epidemiological pattern and trends of hepatitis B virus (HBV) in the area where people had been immunized by HBV vaccine for long time. METHODS: Through cluster sampling and cross-sectional study, relative information and blood samples from people in Long-an county by families were collected. Signals of HBV infection were tested by solid-phase reverse immunosorbent test. RESULTS: (1) The average HBsAg positive rate was 7.5% with anti-HBs as 44.5 %, and anti-HBc as 47.8%. The positive rates of HBsAg and anti-HBc among 0-19 year-olds were lower than those of > or = 20 year-olds. (2) The positive rates of HBsAg, anti-HBc and HBV infection among HBV vaccine immunized group were 2.8%, 12.0% and 12.5% respectively, comparing with which among the un-immunized group as 10.2%, 69.8% and 71.2% respectively. (3) The HBsAg positive rate of male was higher than the female's but with no significant difference of anti-HBs and anti-HBc between different sexes. (4) The average HBsAg positive rate of 0-19 years old group was only 2.4%, while that of 20-30 years old group was 13.6%-17.7% and dropped from 60 years old group and on. The anti-HBs positive rate of 0-19 years old people started to drop significantly by age. The anti-HBs and anti-HBc positive rates of > or = 20 years people were showing a rising trend by ages. CONCLUSION: It seemed obviously that the HBV epidemiological patterns had changed after HBV vaccine had been universally used for long time in newborns. The age peak of infection had been pushed backward for nearly 20 years. It had been proved that the HBV vaccine immunization program had obtained excellent efficacy.

[Variations of hepatitis B virus infection epidemic pattern after long-term HBV vaccine immunization].

OBJECTIVE: To study the epidemic pattern and trend of HBV infection in the area where the people had been immunized by HBV vaccine for 20 years. METHODS: The whole sampling method was applied in combination with cross-sectional investigation. Blood samples were taken from every member of families. Markers of HBV infection were determined by using solid-phase radioimmunoassay (SPRIA). RESULTS: (1) The average HBsAg positive rate was 7.5%. The positive rate of markers for HBV infection of 0-19 years old subjects were lower than those of > or = 20 years old subjects. (2) The positive rate of HBsAg of 0-19 years old subjects in 1985 was higher than that in 2005. The anti-HBs positive rate in 1985 stemmed to be higher with age. It was 12.4% in 1- age group to 53.8% in >60 years age group. While the result of 2005 showed that the anti-HBs positive rate of 0-19 years old subjects dropped with age. The anti-HBc positive rate in 1985 also tended to be higher with age. But the result of 2005 showed that the rate of 0-19 years old subjects was just 1.4% to 16.8%. CONCLUSION: The epidemic patterns of HBV infection have had significant variations in the target population. HBV vaccine immunization has obtained excellent efficacy.

[Studies on the status of immune memory after completion of hepatitis B vaccination].

OBJECTIVE: To study the immune memory in vaccinees after the completion of a full schedule hepatitis B immunization. METHODS: One thousand and two hundred one infants born in 1987 -1989 were immunized with 3 doses of plasma derived hepatitis B vaccine, while 2484 newborn babies during 1996-1999 were injected with 3 doses of the yeast recombinant hepatitis B vaccine. All of the infants under observation were tested for HBsAg, anti-HBs and anti-HBc, in 2005. Of 959 individuals negative for anti-HBs (< 10 mIU/ml), HBsAg and anti-HBc, 228 were immunized with plasma-derived vaccine and 731 with yeast recombinant vaccine after birth. All of them were detected for anti-HBs 15 days after a booster of 10 Ipg yeast recombinant vaccine. In addition, interleukin-2 (IL-2) was detected in 11 non-responders and 22 responders after boostering, using an enzyme-linked immunospot (ELISPOT). The anti-HBs levels of 190 individuals (91 with plasma derived vaccine and 99 with yeast recombinant vaccine) who had had quantitative data on their antibody status after the primary hepatitis B vaccination, were compared with that after the boostering. RESULTS: Among the individuals who received plasma derived vaccine 16-18 years ago, 79.82% of them showed the signs of immune memory after one booster, with a geometric mean titer (GMT)of 325.69 mIU/ml. Of the individuals who received the yeast recombinant vaccine 6-9 years ago, 95.62% showed immune memory after one booster,with its GMT of 745.18 mIU/ml. Anti-HBs levels induced by the booster were associated with that after the primary immunization. The positive rate of IL-2 was 40.91% in subjects with good immune memory. However, IL-2 was not detected in non-responders after the booster (P < 0.01). CONCLUSION: Most of the individuals who had received a completed schedule of primary hepatitis B vaccination and seroconverted from anti-HBs positive to negative,showed the signs of having immune memory after the booster. Only a small proportion of the vaccinees had lost their immune memory during the long term follow-up period, suggesting that these individuals should receive a booster of hepatitis B vaccine in the highly endemic areas of hepatitis B. Hepatitis B virus; Immune memory; Booster immunization