Host genetic variants, Epstein-Barr virus subtypes, and the risk of nasopharyngeal carcinoma: Assessment of interaction and mediation.

Epstein-Barr virus (EBV) and human leukocyte antigen (HLA) polymorphisms are well-known risk factors for nasopharyngeal carcinoma (NPC). However, the combined effects between HLA and EBV on the risk of NPC are unknown. We applied a causal inference framework to disentangle interaction and mediation effects between two host HLA SNPs, rs2860580 and rs2894207, and EBV variant 163364 with a population-based case-control study in NPC-endemic southern China. We discovered the strong interaction effects between the high-risk EBV subtype and both HLA SNPs on NPC risk (rs2860580, relative excess risk due to interaction [RERI] = 4.08, 95% confidence interval [CI] = 2.03-6.14; rs2894207, RERI = 3.37, 95% CI = 1.59-5.15), accounting for the majority of genetic risk effects. These results indicate that HLA genes and the high-risk EBV have joint effects on NPC risk. Prevention strategies targeting the high-risk EBV subtype would largely reduce NPC risk associated with EBV and host genetic susceptibility.

[Association between human leukocyte antigen and nasopharyngeal-carcinoma].

Nasopharyngeal carcinoma (NPC) is characterized by its distinct racial and geographical distribution with a multifactorial etiology. It has been well accepted that NPC is related to Epstein-Barr(EB) virus infection but environmental and genetics factors also play critical roles. Among host genetic markers associated with NPC, the highly variable class I human leukocyte antigen (HLA) genes on chromosome 6 (6p21.3) have shown a strong and consistent association with NPC risk. As the consequence of new generation DNA sequencing technologies used in HLA genotyping, the number of the reported HLA new alleles is dramaticllyincreasing, and more full length sequences of HLA alleles have been reported. The significant association between HLA genes and NPC has been identifiedin a series of studies, including HLA association study, linkage disequilibrium study for microsatellite markers, and genome wide association study. In this review, we summarize association studies between HLA and NPC to evaluate the role of genetic polymorphisms in NPC development and illustrate the new clues of HLA association for deepexploration.

A comprehensive risk score for effective risk stratification and screening of nasopharyngeal carcinoma.

Using Epstein-Barr virus (EBV)-based markers to screen populations at high risk for nasopharyngeal carcinoma (NPC) is an attractive preventive approach. Here, we develop a comprehensive risk score (CRS) that combines risk effects of EBV and human genetics for NPC risk stratification and validate this CRS within an independent, population-based dataset. Comparing the top decile with the bottom quintile of CRSs, the odds ratio of developing NPC is 21 (95% confidence interval: 12-37) in the validation dataset. When combining the top quintile of CRS with EBV serology tests currently used for NPC screening in southern China, the positive prediction value of screening increases from 4.70% (serology test alone) to 43.24% (CRS plus serology test). By identifying individuals at a monogenic level of NPC risk, this CRS approach provides opportunities for personalized risk prediction and population screening in endemic areas for the early diagnosis and secondary prevention of NPC.

[Semen biochemical markers and their significance in the patients with premature ejaculation].

OBJECTIVE: To detect the changes of biochemical markers in the semen of premature ejaculation patients and investigate the correlation of the markers with premature ejaculation. METHODS: Fifty-six premature ejaculation patients and 60 males with normal sexual behavior were enrolled in this experiment. Acid phosphatase, alpha- glucosidase and fructose were assayed by the methods of glucose oxidase, disodium phenyl phosphate and disodium phenyl phosphate respectively. RESULTS: The contents of acid phosphatase, alpha-glucosidase and fructose were (36.37 +/- 31.33) U/ml, (39.97 +/- 22. 09) U/ml and (3.40 +/- 1.92) mg/ml in the premature ejaculation patients and (54. 27 +/- 20. 96) U/ml, (55.71 +/- 16.19) U/ml and (2.55 +/- 1.12) mg/ml in the normal control, respectively, with significant differences in the former two markers between the two groups. The rate of the abnormal content of both acid phosphatase and alpha- glucosidase was 31% and 13% (P < 0.05) , while that of the normal content of the three markers was 10% and 33% in premature ejaculation group and the control, respectively (P < 0. 05 ). CONCLUSION: The abnormality of both acid phosphatase and alpha-glucosidase is one of the causes of premature ejaculation. Because acid phosphatase and alpha- glucosidase reflect the functions of the prostate and epididymis, we should pay attention to the status of these two organs in the treatment of premature ejaculation.

Diagnostic significance of combined detection of Epstein-Barr virus antibodies, VCA/IgA, EA/IgA, Rta/IgG and EBNA1/IgA for nasopharyngeal carcinoma.

The objective of this study was to investigate the diagnostic significance of EBV antibody combined detection for nasopharyngeal carcinoma (NPC) in a high incidence region of southern China. Two hundred and eleven untreated NPC patients, 203 non-NPC ENT patients, and 210 healthy controls were recruited for the study. The titers of VCA/IgA and EA/IgA were assessed by immunoenzyme assay, and the levels of Rta/IgG and EBNA1/IgA were determined by enzyme-linked immunosorbent assay. The levels of VCA/IgA, EA/IgA, Rta/IgG and EBNA1/ IgA demonstrated no association with gender or age (p>0.05). The receiver operating characteristic curve and the area under the curve were used to evaluate the diagnostic value. The sensitivity of VCA/IgA (98.1%) and the specificity of EA/IgA (98.5%) were the highest. When a logistic regression model was used to combine the results from multiple antibodies to increase the accuracy, the combination of VCA/IgA+Rta/IgG, whose area under the curve was 0.99, had the highest diagnostic efficiency, and its sensitivity, specificity and Youden index were 94.8%, 98.0% and 0.93 respectively. The data suggest that the combination of VCA/IgA+Rta/IgG may be most suitable for NPC serodiagnosis.

Association between the RAD51 135 G>C polymorphism and risk of cancer: a meta-analysis of 19,068 cases and 22,630 controls.

BACKGROUND: RAD51 135G>C can modify promoter activity and the penetrance of BRCA1/2 mutations, which plays vital roles in the etiology of various cancer. To date, previous published data on the association between RAD51 135G>C polymorphism and cancer risk remained controversial. Recent meta-analysis only analyzed RAD51 135G>C polymorphism with breast cancer risk, but the results were also inconsistent. METHODS: A meta-analysis based on 39 case-control studies was performed to investigate the association between cancer susceptibility and RAD51 135G>C. Odds ratios (OR) with 95% confidence intervals (CIs) were used to assess the association in different inheritance models. Heterogeneity among studies was tested and sensitivity analysis was applied. RESULTS: Overall, no significant association was found between RAD51 135G>C polymorphism and cancer susceptibility in any genetic model. In further stratified analysis, significantly elevated breast cancer risk was observed in BRCA2 mutation carriers (recessive model: OR = 4.88, 95% CI = 1.10-21.67; additive model: OR = 4.92, 95% CI = 1.11-21.83). CONCLUSIONS: This meta-analysis suggests that RAD51 variant 135C homozygote is associated with elevated breast cancer risk among BRCA2 mutation carriers. Moreover, our work also points out the importance of new studies for RAD51 135G>C association in acute myeloid leukemia, especially in Caucasians, where at least some of the covariates responsible for heterogeneity could be controlled, to obtain a more conclusive understanding about the function of the RAD51 135G>C polymorphism in cancer development.

Expression of the Pokemon proto-oncogene in nasopharyngeal carcinoma cell lines and tissues.

To study the differentiated expression of the proto-oncogene Pokemon in nasopharyngeal carcinoma (NPC) cell lines and tissues, mRNA and protein expression levels of CNE1, CNE2, CNE3 and C666-1 were detected separately by reverse transcription polymerase chain reaction (RT-PCR), real-time PCR and Western-blotting. The immortalized nasopharyngeal epithelial cell line NP69 was used as a control. The Pokemon protein expression level in biopsy specimens from chronic rhinitis patients and undifferentiated non keratinizing NPC patients was determined by Western-blotting and arranged from high to low: C666-1>CNE1>CNE2> CNE3>NP69. The Pokemon mRNA expression level was also arranged from high to low: CNE1>CNE2>NP69>C666-1>CNE3. Pokemon expression of NP69 and C666-1 obviously varied from mRNA to protein. The Pokemon protein level of NPC biopsy specimens was obviously higher than in chronic rhinitis. The data suggest that high Pokemon protein expression is closely associated with undifferentiated non-keratinizing NPC and may provide useful information for NPC molecular target therapy.

[Prognostic significance of serum anti-Epstein-Barr virus antibodies in nasopharyngeal carcinoma].

OBJECTIVE: This study was aimed to investigate the association between serum against Epstein-Barr virus (EBV) antibodies levels and nasopharyngeal carcinoma (NPC) patients' prognosis. METHODS: Blood samples from 140 primary NPC patients without metastasis were collected before and after treatment. The titers of VCA/IgA and EA/IgA were detected by immunoenzyme assay, and the levels of NA1/IgA and Rta/IgG were detected by enzyme-linked immunosorbent assay (ELISA). All patients received consequent follow-up and long-term efficacy and survival assessment. RESULTS: Post-treatment serum levels of VCA/IgA, EA/IgA, NA1/IgA and Rta/IgG in NPC patients significantly decreased than those before treatment, while had significantly higher than those in control individuals (P < 0.05). Patients in remission had significantly lower pre-treatment serum levels of VCA/IgA and EA/IgA than patients with progression (P < 0.05). None of serum levels of VCA/IgA, EA/IgA, NA1/IgA and Rta/IgG was associated with the 3-year overall survival (P > 0.05). The progression-free survivals were significantly lower in patients with higher pre-treatment VCA/IgA (> or = 1 : 320) and EA/IgA (> or = 1:80) levels than in those with lower VCA/IgA ( < 1 : 320) and EA/IgA (< 1 : 80) levels, respectively (61.8% vs. 86.5% , 61.3% vs. 86.5%, P < 0.001). Cox regression model analysis demonstrated that pre-treatment serum VCA/IgA level was an independent risk factor for progression-free survival (HR = 3.80, P = 0.001). CONCLUSION: Anti-EBV VCA/IgA and EA/IgA might provide information regarding the prognosis of NPC patients.

[Relationship between HLA-A, B alleles and red blood cell parameters of patients with --(SEA/αα) subtype of α(0)-thalassemia of Han ethnic population of Wuzhou city].

This study was purposed to investigate the relationship between HLA-A, B allele polymorphisms and red blood cell parameters of patients with --(SEA/αα) subtype of α(0)-thalassemia in Han ethnic population of Wuzhou city. The HLA genetic polymorphisms were determined by polymerase chain reaction-sequence-based typing (PCR-SBT) in 57 patients with --(SEA/αα) subtype of α(0)-thalassemia of Han ethnic population in Wuzhou city, Guangxi province, China. Mean corpuscular volume (MCV), hemoglobin (Hb), mean corpuscular hemoglobin (MCH) and mean corpuscular hemoglobin concentration (MCHC) were detected by automatic blood analyzer system. HbA2 were detected by electrophoretic method. The statistical analysis was performed by ordinal polytomous logistic regression. The results showed that Hb and HbA2 levels were significantly lower in patients positive for HLA-A*33:03, B*15:01 or B*55:02, and were significantly higher in patients positive for B*15:02 (P < 0.05). It is concluded that several HLA alleles may be associated with Hb level of --(SEA/αα) subtype of α(0)-thalassemia of Han ethnic population in Wuzhou city. This result has the value for understanding phenotype-genotype relationships in thalassemia.

[Evaluation of computational methods for HLA three loci haplotype by compare with family-based data].

OBJECTIVE: We evaluated the accuracy and efficiency of computational inference methods for haplotype on estimate HLA-A-B-C haplotype frequencies by compared with the haplotypes manually defined in a family-base dataset. METHODS: 558 individuals with pedigree information were selected, and their haplotyps were compared with the data obtained by the following three method: the Expectation-Maximization (EM) and Excoffier-Laval-Balding (ELB)algorithms using the AELEQUIN software, and the SAS/Genetics PROC HAPLOTYPE method. RESULTS: After performing the SAS/Genetics method, and the Expectation-Maximization (EM) and Excoffier-Laval-Balding (ELB) algorithms using the AELEQUIN software, 248, 247, and 238 different haplotypes were obtained respectively. The accuracy rates of these three methods were 88.5%, 89.1%, and 90.3% respectively. There are no significant different in the accuracy and estimated haplotype frequency comparisons among any two of these computational inference methods. CONCLUSION: High accuracy haplotype frequency estimate rates could be obtained by these three computational inference methods, and there are no significant difference in the comparison of haplotypes estimated by SAS/Genetics, the EM and ELB algorithms using the AELEQUIN software. However, ELB algorithm shows better performance than EM algorithm and SAS/Genetics PROC HAPLOTYPE method for haplotype frequencies estimation in general.

[Effect of varying lingual traction forces on the space-closing speed in a typodont model].

OBJECTIVE: To investigate the influences of varying lingual traction forces on the space-closing speed in a typodont model. METHODS: Forty-two Angle Class I standard typodont models of bimaxillary teeth protrusion were divided into 7 equal groups. Four regions of the model were paired to groups, and in the odd-numbered models, the top left and bottom left regions served as the experimental group and the top right and bottom right regions as the control group; in the even-numbered models, the regions in the model were grouped oppositely. In the experimental group, the space was closed by niti wire extension spring in the buccal ridge combined with lingual elastic traction of 0, 5, 10, 15, 20, 25 and 30 g. In the control group, the space was closed by exclusive niti wire extension spring in the buccal ridge. The space-closing speed were analyzed in all the groups. RESULTS: The space-closing speed was significantly lower in the control group than in the experimental groups with lingual traction forces of 5, 10, 15, 20 and 25 g (P<0.05), but a traction force of 30 g resulted in a significantly lower speed than that in the control group (P<0.05). The space closing speed was the greatest in the experimental group with a traction force of 15 g (P<0.05). CONCLUSION: Niti wire extension spring in the buccal ridge combined with lingual elastic traction results in faster space-closing speed than traditional exclusive niti wire extension spring. The speed is the fastest by applying 15 g lingual traction, which is also associated with the lowest slip resistance.

[Combined detection of Epstein-Barr virus antibodies for serodiagnosis of nasopharyngeal carcinoma].

OBJECTIVE: To investigate the value of combined detection of Epstein-Barr virus (EBV) VCA/IgA, EA/IgA, Rta/IgG and EBNA1/IgA in serodiagnosis of nasopharyngeal carcinoma (NPC). METHODS: Serum samples obtained from 211 untreated patients with NPC and 203 non-NPC ENT patients were examined for the presence of VCA/IgA and EA/IgA by immunoenzymatic assay and for Rta/IgG and EBNA1/IgA by enzyme-linked immunosorbent assay (ELISA). The receiver operating characteristic (ROC) curve was generated to confirm the cutoff values of different antibodies. The evaluation indexes of combined detection of multiple antibodies used for serodiagnosis of NPC were calculated with compounded positive judgment method. RESULTS: Compared to a single antibody, combined detection achieved a higher sensitivity and specificity. The sensitivity of VCA/IgA + Rta/IgG + EBNA1/IgA (98.1%) was higher than the other 3 combinations with a specificity, accuracy, Youden index and positive predictive value (PPV) of 88.7%, 93.5%, 0.868 and 90.0%, respectively. The combination of EA/IgA+Rta/IgG+EBNA1/IgA had the highest specificity (95.1%), accuracy (94.9%), Youden index (0.899) and PPV (95.2%), with a sensitivity of 94.8%, suggesting its higher accuracy in the serodiagnosis of NPC. Combined detection of the 4 antibodies had the highest sensitivity (98.6%) with a specificity, accuracy, Youden index and PPV of 88.2%, 93.5%, 0.868 and 89.7%, respectively. CONCLUSIONS: Combined detection of Rta/IgG against immediate early antigens, EA/IgA against early antigens, VCA/IgA against late antigens, and EBNA1/IgA against latent antigens provides better understanding of the expression profiles of EBV lytic and latent antigens with excellent complementarity, and may serve as an optimal combination for NPC serodiagnosis.

[Relationship between clinical stages of nasopharyngeal carcinoma and Epstein-Barr virus antibodies Rta/IgG, EBNA1/IgA, VCA/IgA and EA/IgA].

OBJECTIVE: To evaluate the relationship between the clinical stages of nasopharyngeal carcinoma (NPC) and Epstein-Barr virus (EBV) antibodies Rta/IgG, EBNA1/IgA, VCA/IgA and EA/IgA. METHODS: Serum samples obtained from 211 untreated patients with NPC categorized by the project of 92' stage were examined for the presence of the EBV antibodies Rta/IgG and EBNA1/IgA by enzyme-linked immnunosorbent assay (ELISA) and for VCA/IgA and EA/IgA by immunoenzymatic assay. The positive rates and antibody levels in the NPC patients in different TNM stages and clinical stages were analyzed statistically. RESULTS: No significant difference in Rta/IgG rA value was found in the NPC patients in different TNM or clinical stages (P>0.05). The EBNA1/IgA rA value was significantly lower in stage T1, N0, and clinical stage I than in the other corresponding T stages, N stages and other clinical stage (P<0.05). The antibody titers of VCA/IgA and EA/IgA differed significantly between the N stages and the clinical stages (P<0.05). CONCLUSION: The expression of EBV Rta/IgG is not associated with NPC stage. The expression of EBNA1/IgA is relatively low in early NPC. The antibody level of VCA/IgA and EA/IgA are significantly correlated to the degree of neck lymph node metastasis, and might be helpful to classify the clinical stages of NPC.

[Evaluation of combined determinations of Epstein-Barr virus antibodies for nasopharyngeal carcinoma assessed with receiver operating characteristic curve based on logistic regression].

OBJECTIVE: This study was aimed to investigate the diagnostic value of combined determination of Epstein-Barr virus (EBV) antibodies for nasopharyngeal carcinoma (NPC), including immunoglobulin (Ig) A against EBV capsid antigens (VCA), IgA against early antigens (EA), IgG against BRLF1 transcription activator (Rta) and IgA against EBV nuclear antigen-1 (EBNA1), assessed with receiver operating characteristic (ROC) curve based on logistic regression. METHODS: Serum samples derived from 211 untreated patients with NPC and 203 non-NPC ENT patients were examined for the presence of VCA/IgA and EA/IgA by immunoenzymatic assay, Rta/IgG and EBNA1/IgA by enzyme-linked immnunosorbent assay (ELISA). The different Logistic regression models were established for various combined determinations of antibodies, respectively. Using the predicted probability as the analyzed variable, ROC curve was applied to evaluate the diagnostic accuracy of different combined determinations. RESULTS: The sensitivity of VCA/IgA (98.1%) and the specificity of EA/IgA (98.5%) were the highest while detecting solely. The results which were analyzed by ROC curve based on Logistic regression showed that the sensitivity and specificity were improved. In two-marker combinations, VCA/IgA + Rta/IgG whose area under ROC curve (AUC) was 0.991 had the highest diagnostic accuracy, and its sensitivity, specificity and Youden index were 94.8%, 98.0% and 0.928 respectively. No significant difference of AUC were found comparing VCA/IgA + Rta/IgG with VCA/IgA + Rta/IgG + EBNA1/IgA and four-marker combination( P > 0.05), of which sensitivity, specificity and Youden index were 94.8%, 98.5%, 0.933 and 96.7%, 97.0%, 0.937, respectively. CONCLUSION: The approach of ROC curve based on Logistic regression can improve synthetic efficiency for combined determination of multiple markers. The combined determination of VCA/IgA and Rta/IgG with a complementary effect is optimal for NPC serodiagnosis.

[Molecular detection and haematological analysis of heterozygotes in beta-thalassemia combining deletional alpha-thalassemia].

This study was aimed to investigate the prevalence and genotype distribution of heterozygotes in beta-thalassemia combining deletional alpha-thalassemia by using molecular detection and haematological methods. Three common deletions of alpha-thalassemia were detected by using gap-PCR. The mutations of beta-thalassemia were identified by using PCR with reverse dot blot hybridization. The routine analysis of blood cells was carried out. The results indicated that 15 cases from the 81 beta-thalassemia traits were found to be the compound heterozygosity for beta-thalassemia and alpha-thalassemia with 9 different types of gene defects with 18.52% detection rate. There were 6 cases (7.41%) of beta-thalassemia heterozygote combining alpha-thalassemia-1 gene (--(SEA)/alphaalpha), 8 cases (9.88%) combining with alpha-thalassemia-2 gene including 6 (7.41%) right ward deletion (-alpha(3.7)/alphaalpha) and 2 (2.47%) left ward deletion (-alpha(4.2)/alphaalpha), and 1 case (1.23%) combining deletional HbH gene (--(SEA)/-alpha(3.7)). No significant differences were found between beta-thalassemia heterozygotes combining deletional alpha-thalassemia and pure beta-thalassemia in all RBC parameters. It is concluded that the incidence of beta-thalassemia heterozygotes combining with deletional alpha-thalassemia is frequent in Wuzhou city. The hematological analysis can not give specificity for diagnosing these dual heterozygotes. Gap-PCR as a routine method for thalassemia screening has the advantages in reducing the possibility of failing to detect the combining heterozygosity for beta-thalassemia and alpha-thalassemia. It is more useful for genetic counselling and prenatal diagnosis of this disease.