[Anti-HBs persistence following primary vaccination with three doses of hepatitis B vaccine among normal and high-responder adults: a 3-year follow-up study]

OBJECTIVE

To assess the 3-year anti-HBs persistence after primary vaccination with three-dose of hepatitis B vaccine (HepB) among normal and high-responder adults.

METHODS

A total of 24 237 healthy adults who had no histories of hepatitis B infection and hepatitis B vaccination, resided in local areas for more than six months and were aged 18-49 years were selected from 79 villages of Zhangqiu county, Shandong province, China in 2009. Blood samples were obtained and hepatitis B surface antigen (HBsAg), antibody against hepatitis B surface antigen (anti-HBs) and antibody against hepatitis B core antigen (anti-HBc) were detected using ELISA method. A total of 11 590 persons who were negative for all of these indicators were divided into four groups by cluster sampling method. Each group was vaccinated with one of the following four types of HepB at 0-1-6 months schedule: 20 μg HepB derived in Saccharomyces cerevisiae (HepB-SC), 20 μg HepB derived in Chinese hamster ovary cell (HepB-CHO), 10 μg HepB-SC and 10 μg HepB derived in Hansenula polymorpha (HepB-HP). Blood samples were collected one month after the third dose of primary immunization and tested for anti-HBs using chemiluminescence microparticle immunoassay (CMIA). During the follow-up to normal and high-responders, the following information was collected: the demographic characteristic (including age and gender), histories of hepatitis B infection, hepatitis B vaccination, smoking, drinking and chronic diseases. Blood samples were collected one month (T1) and three years after primary vaccination (T2) and anti-HBs, anti-HBc and HBsAg (if anti-HBs<10 mU/ml) were detected by CMIA. The risk factors associated with positive rate of anti-HBs and GMC of anti-HBs were identified by multiple logistic regression analysis and multifactor linear regression model analysis, respectively.

RESULTS

A total of 4 677 normal and high-responders were identified. Among 4 677 participants, 2 014 (43.06%) were males and 2 663 (56.94%) were females. The positive rate was 100% at T1 and it decreased to 80.99% (3 788/4 677) three years after vaccination. The corresponding GMC was decreased from 1 413.48 (95%CI: 1 358.86-1 470.30) mU/ml to 60.33 (95%CI: 56.97-63.90) mU/ml. When comparing with those vaccinated 20 μg HepB-CHO, the significantly lower positive rate of anti-HBs three years after vaccination was observed in those vaccinated 20 μg HepB-SC, 10 μg HepB-SC and 10 μg HepB-HP. The OR (95%CI) was 0.65 (0.50-0.84), 0.52 (0.41-0.67) and 0.31 (0.28-0.45), respectively. The GMC of anti-HBs was also significantly lower among those vaccinated 20 μg HepB-SC, 10 μg HepB-SC and 10 μg HepB-HP. The b (95%CI) was -0.33 (-0.47- -0.20), -0.41 (-0.55- -0.28) and -0.78 (-0.92- -0.65), respectively. The GMC of anti-HBs in those aged 30-39 years old and 40-49 years old were lower than that in 18-29 years. The b (95%CI) was -0.31 (-0.47- -0.15) and -0.24 (-0.39- -0.09), respectively. When comparing with those whose anti-HBs titer was less than 999 mU/ml at T1, the significantly higher positive rate of anti-HBs three years after vaccination was observed in those whose anti-HBs titer was 1 000-1 999 mU/ml, those whose anti-HBs titer was 2 000-9 999 mU/ml and those whose anti-HBs titer was ≥10 000 mU/ml. The OR (95%CI) was 4.97 (3.80-6.49), 7.87 (16.19-10.01) and 9.67 (6.47-14.44), respectively. When comparing with those whose anti-HBs titer was ≤999 mU/ml at T1, the GMC of anti-HBs three years after vaccination was also significantly higher among those whose anti-HBs titer at T1 was 1 000-1 999 mU/ml, those whose anti-HBs titer at T1 was 2 000-2 999 mU/ml and those whose anti-HBs titer at T1 was ≥10 000 mU/ml. The b (95%CI) was 1.00 (0.87-1.14), 1.85 (1.74-1.97) and 3.28 (3.12-3.44), respectively. Four subjects showed HBsAg seroconversion and anti-HBc conversion rate was 4.68% at T2.

CONCLUSIONS

Anti-HBs GMC decreased rapidly three years after primary vaccination among normal and high-responder adults, while the positive rate of anti-HBs still kept at a high level. The anti-HBs persistence after primary vaccination was associated with HepB type, age and GMC of anti-HBs one month after vaccination.

[Anti-HBs persistence after revaccination with three doses of hepatitis B vaccine among non-responsive adults: a 4-year of follow-up study]

OBJECTIVE

To explore anti-HBs persistence four years after revaccination with hepatitis B vaccine (HepB) among adults who were non-responsive to HepB primary immunization.

METHODS

A total of 24 237 healthy adults who had no history of hepatitis B infection and hepatitis B vaccination, resided in the local area for more than six months and aged 18-49 years were selected from 79 villages of Zhangqiu County, Shandong Province, China in 2009. Blood samples were obtained and hepatitis B surface antigen (HBsAg), antibody against hepatitis B surface antigen (anti-HBs) and antibody against hepatitis B core antigen (anti-HBc) were detected using ELISA method. A total of 11 590 persons who were negative for all of these indicators were divided into four groups by cluster sampling methods. Each group was vaccinated with one of the following four types of HepB at 0-1-6months schedule: 20 μg HepB derived in Saccharomyces cerevisiae (HepB-SC), 20 μg HepB derived in Chinese hamster ovary cell (HepB-CHO), 10 μg HepB-SC and 10 μg HepB derived in Hansenula polymorpha (HepB-HP). Blood samples were collected one month after the third dose of primary immunization and tested for anti-HBs using chemiluminescence microparticle immunoassay (CMIA). The non-responders were followed up and their basic information and the histories of hepatitis B infection, HepB vaccination, smoking and drinking were investigated. Then they were revaccinated with three doses of HepB with the same schedule as the primary immunization. Blood samples were collected from all of them one month (T1), two years and four years after revaccination and anti-HBs, anti-HBc and HBsAg were detected by CMIA. A total of 356 participants were followed up from 645 low-responders four years after revaccination, and the ratio was 55.2%. The risk factors associated with the positive rate and geometric mean concentration (GMC) of anti-HBs after four years of revaccination were analyzed using multivariate unconditional logistic regression model and multivariate linear regression model, respectively.

RESULTS

Among 356 participants, 172 (48.3%) were males and 184 (51.7%) were females. The anti-HBs positive rate was 90.4% (322 cases) at T1 and was 55.9% (199 cases) four years after revaccination. The GMC of anti-HBs was 240.5 (95% CI: 186.4-310.4)mU/ml at T1 and decreased to 15.0 (95%CI: 12.2-18.5) mU/ml four years after revaccination. The average annual decreasing rate of GMC was 50.63% from one month after revaccination to four years after revaccination. The corresponding rate was 64.89% in the first two years, which was 2.12 times the rate in the latter two years (30.57%). When compared with those whose anti-HBs titer was less than 99 mU/ml at T1, the significantly higher anti-HBs four years after revaccination was observed in those whose anti-HBs titer at T1 was 100-999 mU/ml and those whose anti-HBs titer at T1 was ≥1 000 mU/ml. The OR (95%CI) was 7.14 (3.90-13.05) and 28.40 (13.16-61.30) respectively. When compared with those whose anti-HBs titer was ≤99 mU/ml at T1, the GMC of anti-HBs four years after revaccination was also significantly higher among those whose anti-HBs titer at T1 was 100-999 mU/ml and those whose anti-HBs titer at T1 was ≥1 000 mU/ml. The b (95%CI) was 1.66 (1.26-2.05) and 3.16 (2.72-3.60), respectively.

CONCLUSION

The positive rate and GMC of anti-HBs decreased four years after revaccination among non-responsive adults, but still kept anti-HBs above protective level. The immunity durability after revaccination is mainly associated with anti-HBs titer one month after revaccination.

[Antibody persistence following primary vaccination with hepatitis B vaccine among normal and high-responder adults: a 5-year follow-up study]

OBJECTIVE

To evaluate the 5-year antibody persistence and the risk factors associated with the persistence after primary vaccination of hepatitis B vaccine (HepB) among normal or high-response adults.

METHODS

A total of 24 237 healthy adults who had no histories of hepatitis B infection and hepatitis B vaccination, resided in the local area for more than six months and were aged 18-49 years were selected from 79 villages in north of Zhangqiu county, Shandong province, China in 2009. Blood samples were obtained and hepatitis B surface antigen (HBsAg), antibody against hepatitis B surface antigen (anti-HBs) and antibody against hepatitis B core antigen (anti-HBc) were detected using ELISA method. A total of 11 590 persons who were negative for all of these indicators were divided into four groups by cluster sampling methods. Each group was vaccinated with one of the following four types of HepB at 0-1-6 months schedule: 20 μg HepB derived in Saccharomyces cerevisiae (HepB-SC), 20 μg HepB derived in Chinese hamster ovary cell (HepB-CHO), 10 μg HepB-SC and 10 μg HepB derived in Hansenula polymorpha (HepB-HP). The normal and high-responder was followed up and their demographic characteristic (including age, gender), histories of hepatitis B infection, hepatitis B vaccination, smoking, drinking and chronic diseases were investigated. Blood samples were collected one month (T1) and five years (T2) and anti-HBs, anti-HBc and HBsAg (if anti-HBs<10 mU/ml) were detected by CMIA. A total of 1 902 participants were followed up and the risk factors associated with positive rate of anti-HBs and GMC of anti-HBs were identified by multiple logistic regression analysis and multifactor linear regression model analysis, respectively.

RESULTS

Among 1 902 adults, 824 (43.32%) were male and 1 078 (56.68%) were female. The anti-HBs positive rate was 100% at T1 and it decreased to 73.29% (1 394 cases) at T2. The corresponding GMC was decreased from 1 527.15 (95%CI: 1 437.84-1 622.01) mU/ml at T1 to 35.07 (95%CI: 32.20-38.19) mU/ml at T2. When comparing with those vaccinated 20 μg HepB-SC, the significantly lower positive rate at T2 was observed in those vaccinated 10 μg HepB-SC group and 10 μg HepB-HP group. The OR (95% CI) was 0.41 (0.28-0.61) and 0.27 (0.18-0.39), respectively. The GMC of anti-HBs was also significantly lower among those vaccinated 10 μg HepB-SC and 10 μg HepB-HP. The b (95%CI) was -0.20 (-0.28- -0.12) and -0.36 (-0.44- -0.29) , respectively. When comparing with those occasionally drinking, the significantly lower positive rate at T2 was observed in those regular drinking. The OR(95%CI) was 0.51(0.30-0.87). The GMC of anti-HBs in age group of 18-29 was significantly higher than those in 40-49 age group; the b (95%CI) was -0.10(-0.18- -0.01). When comparing with those whose anti-HBs titer was less than 999 mU/ml at T1, the significantly higher positive rate of anti-HBs at T2 was observed in those whose anti-HBs titer was 1 000-1 999 mU/ml, those whose anti-HBs titer was 2 000-2 999 mU/ml and those whose anti-HBs titer was ≥10 000 mU/ml. The OR (95%CI) was 10.11 (6.90-14.82), 20.42 (13.98-29.82) and 54.58 (22.08-134.92), respectively. When comparing with those whose anti-HBs titer was ≤999 mU/ml at T1, the GMC of anti-HBs at T2 was also significantly higher among those whose anti-HBs titer at T1 was 1 000-1 999 mU/ml, those whose anti-HBs titer at T1 was 2 000-2 999 mU/ml and those whose anti-HBs titer at T1 was ≥10 000 mU/ml. The b (95%CI) was 0.55 (0.47-0.62), 0.94 (0.88-1.00) and 1.63 (1.54-1.72), respectively. Nobody was found positive to HBsAg at T2 and the conversion rate of anti-HBc was 3.89% (74/1 902) at T2.

CONCLUSION

Anti-HBs GMC decreased rapidly at T2 among normal and high-responder adults, while the positive rate of anti-HBs still kept at a high level. The antibody persistence among normal and high-responder adults at T2 was associated with HepB type, age, history of drinking and GMC of anti-HBs at T1.

[Anti-HBs persistence following revaccination with three doses of hepatitis B vaccine among low-responsive adults after primary vaccination: a 4-year follow-up study]

OBJECTIVE

To assess the 4-year anti-HBs persistence after revaccination with 3-dose of hepatitis B vaccine (HepB) among low-responsive adults.

METHODS

A total of 24 237 healthy adults who had no history of hepatitis B infection and hepatitis B vaccination, resided in the local area for more than six months and were aged 18-49 years were selected from 79 villages of Zhangqiu county, Shandong province, China in 2009. Blood samples were obtained and hepatitis B surface antigen (HBsAg), antibody against hepatitis B surface antigen (anti-HBs) and antibody against hepatitis B core antigen (anti-HBc) were detected using ELISA method. A total of 11 590 persons who were negative for all of these indicators were divided into four groups by cluster sampling method. Each group was vaccinated with one of the following four types of HepB at 0-1-6 months schedule: 20 μg HepB derived in Saccharomyces cerevisiae (HepB-SC), 20 μg HepB derived in Chinese hamster ovary cell (HepB-CHO), 10 μg HepB-SC and 10 μg HepB derived in Hansenula polymorpha (HepB-HP). Blood samples were collected one month after the third dose of primary immunization and tested for anti-HBs using chemiluminescence microparticle immunoassay (CMIA). The 892 low-responders were revaccinated with three doses of HepB at 0-1-6 months schedule and the type of HepB was the same as which was used for primary immunization. During the follow-up to low-responders, the following informations were collected: the demographic characteristics (including age, gender), histories of hepatitis B infection, hepatitis B vaccination, smoking, drinking and chronic diseases. Blood samples were collected one month (T1) and four years after revaccination and anti-HBs, anti-HBc and HBsAg (if anti-HBs <10 mU/ml) were detected by CMIA. The risk factors associated with positive rate of anti-HBs and GMC of anti-HBs were identified by multiple logistic regression analysis and multifactor linear regression model analysis respectively. Anti-HBs titer at T1 was grouped according to the level and was considered as the independent variable in the model analysis.

RESULTS

A total of 529 participants were identified from 892 low-responders. Among 529 participants, 276 (52.2%) were males and 253 (47.8%) were females. The positive rate was 82.6% (437/529) at T1 and it decreased to 28.2% (149/529) four years after revaccination. The corresponding GMC decreased from 542.06 (95% CI: 466.72-629.56) mU/ml to 27.69 (95% CI: 23.08-33.23) mU/ml. Multivariable analysis showed the positive rate of anti-HBs 4 years after revaccination was independently associated with anti-HBs titer at T1. The positive rate among those whose anti-HBs titer more than 1 000 mU/ml at T1 was significantly higher than those whose anti-HBs titer less than 100 mU/ml. The OR (95%CI) was 39.67 (13.81-114.01). The GMC was associated with HepB type for revaccination and anti-HBs titer at T1. The GMC among those revaccinated 20 μg HepB was significantly higher than those revaccinated 20 μg HepB-CHO, 10 μg HepB-SC and 10 μg HepB-HP. The b (95% CI) was -0.40 (-0.78--0.02), -0.57 (-1.01- -0.15) and -0.63 (-1.03- -0.23), respectively. The GMC among those whose anti-HBs titer 100-999 mU/ml and those whose anti-HBs titer ≥1 000 mU/ml at T1 were higher than those whose anti-HBs titer <100 mU/ml. The b (95% CI) was 0.93 (0.53-1.33) and 3.31 (2.88-3.73) respectively.

CONCLUSION

Anti-HBs GMC decreased rapidly 4 years after revaccination among low-responsive adults, but still kept good protecion. The anti-HBs persistence after revaccination was associated with HepB type for revaccination and anti-HBs level of titer one month after revaccination.

[A surveillance study on CRISPR/Cas molecular biomarker in Escherichia coli]

OBJECTIVE

A new method related to molecular biomarker with CRISPR/Cas (clustered regularly interspaced short palindromic repeats-cas) in Escherichia (E.) coli was developed and used for surveillance programs.

METHODS

CRISPR/Cas sequence that containing 135 strains with complete sequence and 203 strains with whole genome shotgun sequence of E. coli in GenBank by BLAST and 361 strains of E. coli (including 38 strains of E. coli O157∶H7) in laboratory were identified by PCR and analyzed with the CRISPR Finder. Spacers were compared with DANMAN and the phylogenetic trees of cas gene were constructed under Clustal Ⅹ and Mega 5.1.

RESULTS

With new perspective, a descriptive method was developed targeting on the position of CRISPR/cas in E. coli. The CRISPR1 was detected in 77.04%, 100.00% and 75.62% and the CRISPR2 was detected in 74.81%, 100.00% and 92.24% and the CRISPR3 and CRISPR4 were detected in 11.85%, 0 and 1.39% for 135 strains with complete sequence, 203 strains with whole genome shotgun sequence and 361 strains in the laboratory, respectively. One strain downloaded in GenBank with whole genome sequencing and 2 strains in the our laboratory were identified that containing four CRISPR locus. The other E. coli strain was with insertion sequence in downstream of the non-cas CRISPR1. The unique CRISPR was found in 8 strains of O55∶H7, in 180 strains of O157∶H7, in 8 strains of O157∶HNM, in 40 strains of O104∶H4, in 4 strains of O145∶H28, in all the 699 E. coli strains. The phylogenetic tree could be divided into two groups-cas with type I-E or type I-F.

CONCLUSIONS

CRISPR/Cas might be used as a valuable molecular biomarker in epidemiological surveillance studies to identify the high virulent strains or new strains of E. coli. Phage night be related to the missing or obtaining of spacers.

[Opportunity and challenge on molecular epidemiology]

Molecular epidemiology, a branch of epidemiology, combines the theories and methods, both in epidemiology and molecular biology. Molecular epidemiology mainly focuses on biological markers, describing the distribution, occurrence, development and prognosis of diseases at the molecular level. The completion of Human Genome Project and rapid development of Precision Medicine and Big Data not only offer the new development opportunities but also bring about a higher demand and new challenge for molecular epidemiology.

[Clinical value of contrast-enhanced ultrasound in evaluating portal hypertension in patients with decompensated liver cirrhosis]

OBJECTIVE

To investigate the correlation between contrast-enhanced ultrasound parameters and hepatic venous pressure gradient (HVPG), and to develop a new noninvasive method for the evaluation of portal hypertension in patients with decompensated liver cirrhosis.

METHODS

One-hundred patients with decompensated liver cirrhosis were examined by contrast-enhanced ultrasound, and the dynamic images were collected for offline analysis. The contrast arrival time was obtained in the hepatic artery (HA), portal vein (PV), and hepatic vein (HV), and HA-HV transit time (HA-HVTT) and PV-HV transit time (PV-HVTT) were calculated. At the same time, HVPG was measured within 24 hours after contrast-enhanced ultrasound, Pearson correlation analysis was performed between each parameter and HVPG, and the receiver operating characteristic (ROC) curve was also used for analysis.

RESULTS

HV arrival time (HVAT), HA-HVTT, and PV-HVTT were negatively correlated with HVPG (r = -0.385, -0.409, and -0.572, respectively). The area under the ROC curve (AUROC) was 0.903 for PV-HVTT < 2.5 s in judging HVPG≥ l0 mmHg in patients with decompensated liver cirrhosis, and the sensitivity and specificity were 74.4% and 89.5%, respectively. The AUROC was 0.861 for PV-HVTT < 1.5 s in judging HVPG≥l6 mmHg in these patients, and the sensitivity and specificity were 80.4% and 81.5%, respectively.

CONCLUSIONS

HVAT and intrahepatic transit time demonstrate negative linear correlations with HVPG in patients with decompensated liver cirrhosis, and among all parameters, PV-HVTT shows the strongest correlation with HVPG and can be used to determine and predict the severity of portal hypertension.

Progressive decrease of proinsulin secretion in sulphonylurea-treated type 2 diabetes

Progressive deterioration of beta-cell function is proposed as a disease-related factor of sulphonylurea (SU) failure in type 2 diabetes. If it gradually worsens over time then disease duration may mirror the progressive beta-cell deterioration. The aim of the present study is to assess whether or not disease duration is influential in remodelling the secretion pattern of insulin-like molecules and in glucose control of SU-treated type 2 diabetes. A research model is used to investigate proinsulin secreting capacity over time, using two groups of patients: i) disease duration <5 years (n=62), comprising SU responders (SUr; n=48) and SU failures (SUf; n=14); and ii) disease duration > or = 5 years (n= 37), comprising an SUr group (n=17) and an SUf group (n=20). Blood samples are taken at 0 h, 0.5 h 1 h, 2 h and 3 h during a standard oral glucose tolerance test and measured for glucose, total proinsulin (TPI), intact proinsulin (IPI) and specific insulin (SI) concentrations. Pairwise comparison of estimated marginal means of blood glucose, SI, IPI and TPI levels at each time point are carried out between groups and subgroups. (SUr vs. SUf). Homa insulin resistance index (IR index) is applied to analyse IR between the groups. It was found that patients with shorter disease duration had higher proinsulin (TPI and IPI) levels at all time points (P<0.05), together with a lower glucose level at 2 h and 3 h (P<0.05). Homa insulin index analysis showed no difference between the two groups (P=0.26). Results also showed that the SUr group had a significantly lower glucose level at Oh and 3h (P<0.05), although no significant difference in insulin and proinsulin levels was found between the SUr and SUf groups. In conclusion, proinsulin may play an important role in glucose control in SU-treated type 2 diabetes, but the effect is reduced in SUf patients.

[Clinicopathologic study of intractable epilepsy-related encephalitis]

OBJECTIVE

To investigate the clinicopathologic features of intractable epilepsy related encephalitis.

METHODS

The clinical and pathologic findings of 15 cases of intractable epilepsy after functional neurosurgical treatment were reviewed and analyzed retrospectively.

RESULTS

All patients, including four male and 11 female, had medically intractable epilepsy. The mean age of onset for seizure was 5.3 years (1-15 years) and the disease duration was 4.7 years (0.5-15 years). A definite past history was identified in 11 patients, including viral encephalitis in nine patients, anoxia in utero and head trauma in one patient respectively. The extent and sites of involvement were different, including single cerebral hemisphere diffusely in five cases, multiple lobes in seven cases, and single lobe in three cases. Temporal lobe was involved in 13 cases, frontal lobe in eight, parietal lobe in eight, occipital lobe in seven, and insular lobe in four. Microscopically, all cases were characterized by perivascular inflammatory cells infiltration in the subarachnoid space. The focal cerebral cortex showed obvious atrophy with various degrees of the neuronal loss and glial proliferation, eventually leading to glial scar formation. In addition, microglia nodules, lymphatic cuff and neuronophagia were also observed. Seven cases of focal cortical dysplasia were identified among the 11 cases with adequate perilesional cerebral cortex. Hippocampus sclerosis was found in two cases. Intranuclear inclusions were seen in six cases, and these were immunopositive of cytomegalovirus-late antigen, and three cases also showed multinucleated giant cells and calcifications.

CONCLUSION

Encephalitis is one of the common causes of refractory epilepsy, and may result in refractory epilepsy as a sequel.

Genetic background of Escherichia coli isolates from peritoneal dialysis patients with peritonitis and uninfected control subjects

Escherichia coli is the most common cause of Gram-negative peritonitis resulting in peritoneal function deterioration as well as poor clinical outcome in continuous ambulatory peritoneal dialysis (PD) patients. In this study, we analyzed the phylogenetic background and genetic profile of the E. coli isolates and sought to determine the characteristics of specific bacteria associated with peritonitis. E. coli isolates from 56 episodes of peritonitis in 46 PD patient cases and rectal isolates from 57 matched PD control patient cases were compared for both phylogenetic groups and the presence of virulence factors (VFs). There were no significant differences in terms of demographic data between the peritonitis and control groups. Peritonitis isolates exhibited a significantly greater prevalence of 8 VFs. In multivariate logistic regression analysis, kpsMT II (group 2 capsule synthesis) was the strongest VF predictor of peritonitis (OR = 8.02; 95%CI = 3.18-20.25; P < 0.001), followed by traT (serum-resistance-associated outer membrane protein) (OR = 3.83; 95%CI = 1.33-11.03; P = 0.013). The pathogenic groups of E. coli contained a higher concentration of individual VFs compared to the commensal groups. The prevalence of pathogenic E. coli was much higher in peritoneal isolates than rectal isolates (64.3 vs 31.6%, P = 0.001). Our results indicate that the E. coli peritonitis and rectal isolates are different in PD patients. The specific VFs associated with peritonitis isolates may directly contribute to the pathogenesis of peritonitis.

[Survival and prognostic evaluation of superficial esophageal cancer after surgery]

OBJECTIVE

To calculate the survival rate of patients with superficial esophageal squamous carcinoma who received esophageal resection and to explore factors that affect prognosis.

METHODS

There were 285 patients with pTis-T1 esophageal carcinoma who underwent esophagectomy during 2007-2011. Their cumulative survival rates were calculated using life tables. Nine factors that may have impact on postoperative survival of superficial esophageal carcinoma were selected. The Kaplan-Meier method and COX's regression model were used to select prognostic factors, estimate prognostic index, and establish risk stratification.

RESULTS

The 1-, 3- and 5-year overall survival rates of superficial esophageal carcinoma patients were 97%, 86%, and 82%, respectively. Tumor length, stenosis, depth of invasion, differentiation degree, lymph node metastasis, and vascular tumor thrombus were associated with prognosis according to univariate analysis. Depth of invasion (OR=2.065, P=0.029), lymph node metastasis (OR=2.049, P=0.041), differentiation degree (OR=3.828, P=0.000), stenosis(OR=2.129, P=0.048), and vascular tumor thrombus (OR=4.222, P=0.004) were independent prognostic factors in multivariate analysis. A prognostic models was thus established and all the patients were divided into low-risk, moderate-risk and high-risk group, with the 3-year survival rates being 95%, 84%, and 51%, and 5-year survival rates being 93%, 79%, and 44%, respectively.

CONCLUSIONS

Patients with superficial esophageal cancer have relatively favorable prognosis. Depth of invasion, differentiation degree, stenosis, lymph node metastasis, and vascular tumor thrombus may be independent factors of poor prognosis. Survival rate of moderate- and high-risk patients is yet to be improved.

NCRP Program Area Committee 5: Environmental Radiation and Radioactive Waste Issues

Program Area Committee 5 of the National Council on Radiation Protection and Measurements (NCRP) focuses its activities on environmental radiation and radioactive waste issues. The Committee completed a number of reports in these subject areas, most recently NCRP Report No. 175, Decision Making for Late-Phase Recovery from Major Nuclear or Radiological Incidents. Historically this Committee addressed emerging issues of the nation pertaining to radioactivity or radiation in the environment or radioactive waste issues due either to natural origins or to manmade activities.

Avian sarcoma and leukosis virus gag gene in the Anser anser domesticus genome

Endogenous retroviruses are regarded as ideal genetic markers for evolutionary analyses. Birds were some of the initial vertebrates found to contain endogenous retroviruses. However, few studies have investigated the presence and distribution of endogenous retroviruses in goose. In this study, we detected the avian sarcoma and leukosis virus gag gene in the genomic DNA of 8 Chinese native breeds using polymerase chain reaction method. The results indicated that a 1.2-kb avian sarcoma and leukosis virus gag sequence was integrated into all 8 goose breeds. The mean genetic pairwise distance was 0.918% among the investigated geese. To the best of our knowledge, this is the first report demonstrating the presence of the endogenous retroviruses in the domestic goose genome. The genetic structure should be further examined in the domestic goose.

Assessment of genetic diversity of bermudagrass germplasm from southwest China and Africa by using AFLP markers

Cynodon dactylon (L.) Pers. var. dactylon (common bermudagrass) is widely distributed geographically between approximately 45°N and 45°S latitude, penetrating to approximately 53°N latitude in Europe. The extensive variation of morphological and adaptive characteristics of the taxon has been substantially documented, but information is lacking on DNA molecular variation in geographically disparate forms. The genetic diversity of 51 wild accessions of bermudagrass from southwest China (Sichuan, Chongqing, Yunnan, Guizhou, and Tibet) and 8 African bermudagrass was analyzed using amplified fragment length polymorphism molecular markers. A total of 670 polymorphic bands were detected with 11 primer combinations, of which 663 (98.74%) bands were found to be polymorphic. The genetic similarity among the accessions ranged from 0.64-0.96 with an average of 0.78. All 59 wild accessions were clustered into 5 eco-geographic groups, and nearly all accessions from the same area were classified into the same group and were found to be associated with their geographical distributions. Therefore, complex geographical and ecological environments are important factors for the genetic structure and geographical distribution of C. dactylon.

Decision making for late-phase recovery from nuclear or radiological incidents: new guidance from NCRP

In 2010, the US National Council on Radiation Protection and Measurements (NCRP) established a scientific committee (SC5-1) to prepare a comprehensive report on the framework and approach for optimising decision making in late-phase recovery from nuclear or radiological incidents that lead to wide-area contamination. The NCRP report builds on recommendations from the International Commission on Radiological Protection's (ICRP) Publication 111 which specifically addresses the protection of people living in long-term contaminated areas. Based on this approach, the report addresses all relevant dimensions: health, environment, economic, psychological, cultural, ethical, and political. NCRP, like ICRP, considers optimisation to be the best approach to decision making for balancing these multiple risk factors in situations involving wide-area contamination where the conventional clean-up approach may encounter some serious constraints. The NCRP report describes optimisation as an iterative process that can be broken down into a series of steps, all of which involve deliberations with stakeholders as a necessary element for a community-focused recovery effort. The steps, elaborated on in the report, range from defining the situation to a series of actions involving assessing impacts, evaluating options, developing a strategy, and demonstrating its successful implementation. In conclusion, the NCRP report makes a series of recommendations aimed at enhancing and strengthening late-phase recovery following a major nuclear or radiological incident.

Decision making for late-phase recovery from nuclear or radiological incidents

Much of the effort on radiological emergency preparedness has focused on the initial responses to an event (e.g., rescuing or triaging missions), while guidance on the more complex issues (e.g., radiological remediation or population resettlement) of long-term recovery has been lacking. The recent major nuclear accidents at Chernobyl, Ukraine, in 1986 and Fukushima, Japan, in 2011 have clearly shown that radiological effects can spread over extended areas and last for a long period of time, thus making planning for long-term recovery an essential extension to the overall response. Similar challenges may be encountered in the aftermath of malicious acts involving devices such as radiological dispersal devices or improvised nuclear devices. Given the potentially unprecedented nature of the impact, the affected communities would have to face a series of daunting tasks in attempting to return to normality. To achieve this objective, a top priority is to conduct an effective and timely remediation of the contaminated areas. In contrast to emergency responses, the late-stage recovery effort is necessarily community focused and therefore will be driven by stakeholders. However, given the nature of the contamination and the widespread impact, cleanup in the aftermath of a major incident could involve a rather complex decision-making process for which the requisite experiences may not be readily available. To this end, the National Council on Radiation Protection and Measurements (NCRP) established a scientific committee to prepare a comprehensive study that develops a framework and recommends an approach to optimizing decision making in late-phase recovery in the wake of major nuclear or radiological incidents. This study, published as NCRP Report No. 175, addresses all relevant dimensions in decision making for long-term recovery. The report describes optimization as a flexible, graded, and iterative process that consists of a series of steps, all of which involve deliberations with stakeholders as central to the success of a community-focused recovery. Above all, it also presents a new paradigm that specifically addresses a long-term approach to managing the challenging radiological conditions that could be encountered by the communities. In conclusion, the report makes a series of recommendations aimed at enhancing and strengthening the effort toward long-term recovery following a major nuclear or radiological incident.

Single nucleotide polymorphism variants within tva and tvb receptor genes in Chinese chickens

Avian leukosis is an immunosuppressive neoplastic disease caused by avian leukosis viruses (ALV), which causes tremendous economic losses in the worldwide poultry industry. The susceptibility or resistance of chicken cells to subgroup A ALV and subgroup B, D, and E ALV are determined by the receptor genes tumor virus locus A (tva) and tumor virus locus B (tvb), respectively. Four genetic resistant loci (tva(r1), tva(r2), tva(r3), and tva(r4)) in tva receptor gene and a genetic resistant locus tvb(r) in the tvb receptor gene have been identified in inbred lines of White Leghorn. To evaluate the genetic resistance to subgroup A, B, D, and E ALV, genetic variations within resistant loci in tva and tvb genes were screened in Chinese local chicken breeds and commercial broiler lines. Here, the heterozygote tva(s1/r1) and the resistant genotype tva(r2/r2), tva(r3/r3), and tva(r4/r4) were detected in Chinese chickens by direct sequencing. The heterozygote tva(s1/r1) was detected in Huiyang Bearded chicken (HYBC), Rizhaoma chicken, and commercial broiler line 13 to 15 (CB13 to CB15), with the frequencies at 0.08, 0.18, 0.17, 0.25, and 0.15, respectively. The resistant genotype tva(r2/r2) was detected in Jiningbairi chicken (JNBRC), HYBC, and CB15, with the frequencies at 0.03, 0.08, and 0.06, respectively, whereas tva(r3/r3) and tva(r4/r4) were detected in 19 and 17 of the 25 Chinese chickens tested, with the average frequencies at 0.13 and 0.20, respectively. Furthermore, the resistant genotype tvb(r/r) was detected in JNBRC, CB07, CB12, CB14, and CB15 by pyrosequencing assay, with the frequencies at 0.03, 0.03, 0.11, 0.09, and 0.15, respectively. These results demonstrated that the potential for genetic improvement of resistance to subgroup A, B, D, and E ALV were great both in Chinese local chickens and commercial broilers. This study provides valuable insight into the selective breeding for chickens genetically resistant to ALV.

Effect of hybridization on carcass traits and meat quality of erlang mountainous chickens

Native chickens hold a significant share of the market in China. In response to the huge demand from the market, the productivity of Chinese native chickens needs to be improved. Cross breeding is an effective method to increase productivity, although it might affect meat quality. In this study, two pure lines (SD02 and SD03) of Erlang mountainous chickens were hybridized with a yellow feather and faster growing line (SD01). The effect of hybridization on carcass and meat quality (physiochemical and textural traits) was measured in the F1 population at d 91 of age. The hybrids exhibited higher body weight and dressed weight, and amount of semi-eviscerated, eviscerated, breast muscle and abdominal fat (p<0.05). Abdominal fat yield also increased (p<0.05) compared to the offspring of the two pure-lines. Meanwhile, there was no significant difference in meat quality traits except for the myofiber diameter and density and the shear force of the breast muscle. Overall, the offspring of cross-lines were similar to pure lines in meat color, pH value, inosinic acid, crude protein, crude fat, dry matter, moisture content and amino acid composition in the breast muscle. These results suggest that productivity can be improved via cross-breeding while maintaining meat quality of the Erlang mountainous chicken.

Comparison of NMOSFET and PMOSFET devices that combine CESL stressor and SiGe channel

Strained-Si technology could enhance the carrier mobility and improve the device performance. Contact-etch-stop-layer (CESL) structure with different stress and SiGe channel was fabricated with 90-nm technology. The electrical properties of N and PMOSFET devices combining CESL and SiGe channel were investigated. The short channel effects (SCE), such as drain-induced barrier lowering (DIBL), were also studied. Moreover, the stress contour in the SiGe channel has been simulated with TCAD to understand the relationship between stress distribution and device performance for different CESL structures. It is observed that the stress in the channel region was independent of the type of N or PMOSFET devices, but it was dependent on the CESL type and channel length. Based on the experimental and simulation results, it is confirmed that the device performance is associated with the stress in the channel, and the approach of CESL stressor and SiGe channel is shown to effectively improve the mobility of NMOSFETs and PMOSFETs.

Antioxidant effect of mogrosides against oxidative stress induced by palmitic acid in mouse insulinoma NIT-1 cells

Excessive oxidative stress in pancreatic β cells, caused by glucose and fatty acids, is associated with the pathogenesis of type 2 diabetes. Mogrosides have shown antioxidant and antidiabetic activities in animal models of diabetes, but the underlying mechanisms remain unclear. This study evaluated the antioxidant effect of mogrosides on insulinoma cells under oxidative stress caused by palmitic acid, and investigated the underlying molecular mechanisms. Mouse insulinoma NIT-1 cells were cultured in medium containing 0.75 mM palmitic acid, mimicking oxidative stress. The effects of 1 mM mogrosides were determined with the dichlorodihydrofluorescein diacetate assay for intracellular reactive oxygen species (ROS) and FITC-Annexin V/PI assay for cell apoptosis. Expression of glucose transporter-2 (GLUT2) and pyruvate kinase was determined by semi-quantitative reverse-transcription polymerase chain reaction. Palmitic acid significantly increased intracellular ROS concentration 2-fold (P<0.05), and decreased expression of GLUT2 (by 60%, P<0.05) and pyruvate kinase (by 80%, P<0.05) mRNAs in NIT-1 cells. Compared with palmitic acid, co-treatment with 1 mM mogrosides for 48 h significantly reduced intracellular ROS concentration and restored mRNA expression levels of GLUT2 and pyruvate kinase. However, mogrosides did not reverse palmitic acid-induced apoptosis in NIT-1 cells. Our results indicate that mogrosides might exert their antioxidant effect by reducing intracellular ROS and regulating expression of genes involved in glucose metabolism. Further research is needed to achieve a better understanding of the signaling pathway involved in the antioxidant effect of mogrosides.

Genetic diversity and relationships among accessions of five crested wheatgrass species (Poaceae: Agropyron) based on gliadin analysis

Agropyron Gaertn. is the most important genus in Triticeae (Poaceae), which includes many forage grasses with high economic value. The genetic diversity and relationships of 36 accessions from five crested wheatgrass species were analyzed by gliadin markers. A total of 54 product bands were detected after acid polyacrylamide gel electrophoresis (A-PAGE), of which 100% were polymorphic. The genetic similarity coefficient based on Nei-Li's method ranged from 0.065 to 0.755 with an average of 0.451. The Shannon diversity information index showed that there was a high level of genetic diversity among the accessions. An unweighted pair group method with arithmetic average (UPGMA) dendrogram was constructed based on the Nei-Li's genetic similarity coefficients, which showed the phylogenetic relationships among accessions of different species. Analysis of molecular variance (AMOVA) showed that the proportion of variance explained by inter- and intraspecific variance was 9.34 and 90.66%, respectively, which revealed that the genetic variations within species were higher than the variations among species. Based on pairwise genetic distances (ΦST) among species, the cluster analysis indicated that A. mongolicum had a low-affinity relationship with other species, while A. fragile showed a close relationship with A. cristatum ssp pectinatum. Finally, the implications of the results for the taxonomy of Agropyron were discussed.