Activating nickel foam with trace titanium oxide for enhanced water oxidation.

Nickel-based electrocatalysts for water oxidation suffer from low activity and poor stability. In this work, 0.015 mg cm-2 TiO2 nanosheets anchored on Ni foam addressed these problems after electrochemical activation. In situ investigations, including Raman spectra, corroborated the enhanced generation of highly active Ni(III)-O-O species on Ni foam in the presence of trace TiO2.

Re-evaluation and modification of dehydrogenase activity tests in assessing microbial activity for wastewater treatment plant operation.

Reliable and cost-effective methods for monitoring microbial activity are critical for process control in wastewater treatment plants. The dehydrogenase activity (DHA) test has been recognized as an efficient measure of biological activity due to its simplicity and broad applicability. Nevertheless, the existing DHA test methods suffer from imperfections and are difficult to implement as routine monitoring techniques. In this work, an accurate and cost-effective modified DHA approach was developed and the procedure for the DHA test was critically evaluated with respect to the standard construction, sample pretreatment, incubation and extraction conditions. The feasibility of the modified DHA test was demonstrated by comparison with the oxygen uptake rate and adenosine triphosphate in a sequencing batch reactor. The sensitivities of the two typical tetrazolium salts to toxicant inhibition by heavy metals and antibiotics were compared, revealing that 2,3,5-triphenyltetrazolium chloride (TTC) exhibited a higher sensitivity. Furthermore, the sensitivity mechanism of the two DHA tests was elucidated through electrochemical experiments, theoretical analysis and molecular simulations. Both tetrazolium salts were found to be effective artificial electron acceptors due to their low redox potentials. Molecular docking simulations revealed that TTC could outperform other tetrazolium salts in accepting electrons and hydrogens from dehydrogenase. Overall, the modified DHA approach presents an accurate and cost-effective way to measure microbial activity, making it a practical tool for wastewater treatment plants.

Enhancing sulfate reduction and hydrogen sulfide removal through gas stripping in the acidogenesis phase of a two-phase anaerobic process.

This study aims at evaluating two-phase and single-phase reactors for treating sulfate wastewater with low COD/SO42- ratios. Additionally, a new process of gas stripping in an acidogenesis phase is proposed to reduce hydrogen sulfide (H2S) inhibition and enhance biomethanation. The two-phase performed better than the single-phase in terms of COD removal, CH4 production and H2S resistance. After 30 days of stripping, the COD and sulfate degradation rates increased from 85.16% to 91.09% and from 49.39% to 63.07% in the two-phase, respectively. In contrast, without stripping, they were from 79.21% to 64.37% and from 50.26% to 53.15% in the single-phase, respectively. The microbial biodiversity was augmented via stripping, including norank_f__Spirochaetaceae, Petrimonas, Desulfurella and Blvii28_wastewater-sludge_group. Stripping operation enhanced the dissimilatory sulfate reduction, amino acid metabolism and possibly sulfate-dependent anaerobic ammonia oxidation (S-ANAMMOX). This study provides a promising strategy to improve sulfate reduction and reduce H2S inhibition under a low COD/SO42- ratio.

Effect of Radiotherapy Alone vs Radiotherapy With Concurrent Chemoradiotherapy on Survival Without Disease Relapse in Patients With Low-risk Nasopharyngeal Carcinoma: A Randomized Clinical Trial.

Importance: Concurrent chemoradiotherapy has been the standard treatment for stage II nasopharyngeal carcinoma (NPC) based on data using 2-dimensional conventional radiotherapy. There is limited evidence for the role of chemotherapy with use of intensity-modulated radiation therapy (IMRT). Objective: To assess whether concurrent chemotherapy can be safely omitted for patients with low-risk stage II/T3N0 NPC treated with IMRT. Design, Setting, and Participants: This multicenter, open-label, randomized, phase 3, noninferiority clinical trial was conducted at 5 Chinese hospitals, including 341 adult patients with low-risk NPC, defined as stage II/T3N0M0 without adverse features (all nodes <3 cm, no level IV/Vb nodes; no extranodal extension; Epstein-Barr virus DNA <4000 copies/mL), with enrollment between November 2015 and August 2020. The final date of follow-up was March 15, 2022. Interventions: Patients were randomly assigned to receive IMRT alone (n = 172) or concurrent chemoradiotherapy (IMRT with cisplatin, 100 mg/m2 every 3 weeks for 3 cycles [n = 169]). Main Outcomes and Measures: The primary end point was 3-year failure-free survival (time from randomization to any disease relapse or death), with a noninferiority margin of 10%. Secondary end points comprised overall survival, locoregional relapse-free survival, distant metastasis-free survival, adverse events, and health-related quality of life (QOL) measured by the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (QLQ-C30; range, 0-100 points; minimum clinically important difference ≥10 for physical function, symptom control, or health-related QOL; higher score indicates better functioning and global health status or worse symptoms). Results: Among 341 randomized patients (mean [SD] age, 48 [10] years; 30% women), 334 (98.0%) completed the trial. Median follow-up was 46 months (IQR, 34-58). Three-year failure-free survival was 90.5% for the IMRT-alone group vs 91.9% for the concurrent chemoradiotherapy group (difference, -1.4%; 1-sided 95% CI, -7.4% to ∞; P value for noninferiority, <.001). No significant differences were observed between groups in overall survival, locoregional relapse, or distant metastasis. The IMRT-alone group experienced a significantly lower incidence of grade 3 to 4 adverse events (17% vs 46%; difference, -29% [95% CI, -39% to -20%]), including hematologic toxicities (leukopenia, neutropenia) and nonhematologic toxicities (nausea, vomiting, anorexia, weight loss, mucositis). The IMRT-alone group had significantly better QOL scores during radiotherapy including the domains of global health status, social functioning, fatigue, nausea and vomiting, pain, insomnia, appetite loss, and constipation. Conclusions and Relevance: Among patients with low-risk NPC, treatment with IMRT alone resulted in 3-year failure-free survival that was not inferior to concurrent chemoradiotherapy. Trial Registration: ClinicalTrials.gov Identifier: NCT02633202.

Autocrine INSL5 promotes tumor progression and glycolysis via activation of STAT5 signaling.

Metabolic reprogramming plays important roles in development and progression of nasopharyngeal carcinoma (NPC), but the underlying mechanism has not been completely defined. In this work, we found INSL5 was elevated in NPC tumor tissue and the plasma of NPC patients. Plasma INSL5 could serve as a novel diagnostic marker for NPC, especially for serum VCA-IgA-negative patients. Moreover, higher plasma INSL5 level was associated with poor disease outcome. Functionally, INSL5 overexpression increased, whereas knockdown of its receptor GPCR142 or inhibition of INSL5 reduced cell proliferation, colony formation, and cell invasion in vitro and tumorigenicity in vivo. Mechanistically, INSL5 enhanced phosphorylation and nuclear translocation of STAT5 and promoted glycolytic gene expression, leading to induced glycolysis in cancer cells. Pharmaceutical inhibition of glycolysis by 2-DG or blockade of INSL5 by a neutralizing antibody reversed INSL5-induced proliferation and invasion, indicating that INSL5 can be a potential therapeutic target in NPC. In conclusion, INSL5 enhances NPC progression by regulating cancer cell metabolic reprogramming and is a potential diagnostic and prognostic marker as well as a therapeutic target for NPC.

Electrospun spongy zero-valent iron as excellent electro-Fenton catalyst for enhanced sulfathiazole removal by a combination of adsorption and electro-catalytic oxidation.

In this study, a highly active electro-Fenton catalyst, spongy zero-valent iron (ZVI), has been developed at first via in-situ synthesis of ZVI nanoparticles (NPs) on an electrospun three-dimensional (3D) nanofiber network. The spongy ZVI effectively overcame the defects of easy aggregation of ZVI NPs and ferric sludge accumulation during the electro-catalytic process. Then, a three-dimensional electro-Fenton (3D-EF) system using the as-fabricated spongy ZVI as particle catalytic electrodes was designed, which presented a significant synergistic effect of adsorption and electro-catalytic oxidation on the enhanced removal of a widely used antibiotic, sulfathiazole (STZ) from water. Adsorption experiments demonstrated that the spongy ZVI had a relative high adsorption affinity towards STZ with about 50% of the total removal within 240 min, and the adsorption equilibrium was reached in 570 min. Hydroxyl radical (OH) was produced in the 3D-EF system with spongy ZVI catalyst, and almost 100% STZ was removed within 5 min. Reactive oxygen species analysis verified that OH was mainly responsible for the STZ degradation. Based on intermediates identified by a liquid chromatography-tandem mass spectrometry (LC-MS/MS), three pathways for the electro-Fenton oxidative degradation of STZ were proposed.

Enhanced adsorption of arsenite from aqueous solution by an iron-doped electrospun chitosan nanofiber mat: Preparation, characterization and performance.

A novel iron-doped chitosan electrospun nanofiber mat (Fe@CTS ENM) was synthesized, which was proven to be effective for the removal of arsenite (As(III)) from water at neutral pH condition. The physiochemical properties and adsorption mechanism were explored by SEM-EDS and X-ray photoelectron spectroscopy (XPS). Batch adsorption experiments were carried out to evaluate the As(III) adsorption performance of the Fe@CTS ENM with various process parameters, such as adsorbent dose, solution pH, initial As(III) concentration, contact time, ionic strength, coexisting anions, and natural organic matter. The experimental results indicated that the maximum adsorption capacity was up to 36.1 mg g-1. Especially, when the adsorbent dosage was higher than 0.3 g L-1, the As(III) concentration was reduced from 100 µg L-1 to less than 10 µg L-1, which indicated the Fe@CTS ENM could effectively remove trace As(III) from water over a wide pH range (from 3.3 to 7.5). Kinetics study demonstrated that the adsorption equilibrium was achieved within 2.0 h, corresponding to a fast uptake of As(III). The presence of common co-ions and humic acid had little effect on the As(III) adsorption. XPS analysis suggested that the FeO, COH, COC and CN groups on the adsorbent surface play dominant roles in the adsorption of As(III). Adsorption-desorption regeneration test further demonstrated that no appreciable loss in the adsorption capacities was observed, which confirmed that the Fe@CTS ENM maintained a desirable life cycle that was free of complex synthesis processes, expensive and toxic materials, qualifying it as an efficient and low-cost As(III) adsorbent.

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.

[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.

[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.

[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.

[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.

[Evaluation of detection of Epstein-Barr virus Rta/IgG in nasopharyngeal carcinoma].

OBJECTIVE: This study was aimed to investigate the clinical value of Epstein-Barr virus (EBV) Rta/IgG in the diagnosis of nasopharyngeal carcinoma (NPC). METHODS: Serum samples derived from 211 untreated patients with NPC, 413 subjects including 203 non-NPC ENT patients and 210 healthy volunteers as control were examined for the presence of antibodies directed against Rta/IgG by using enzyme-linked immnunosorbent assay (ELISA). Receiver operating characteristic (ROC) curve was applied to perform methodical evaluation of this tumor marker. RESULTS: The rA value median of Rta/IgG in NPC group was significantly higher than one in control group (P < 0.001). The area under ROC was 0.933. The sensitivity and specificity of this marker were 90.5% and 90.1%, respectively, when the best cutoff value was defined. CONCLUSION: Rta/IgG detected with ELISA method is a new target of EBV, and may be one of important marker for NPC diagnosis.

[Association study of chromosome 4 STRs polymorphisms with nasopharyngeal carcinoma].

Nasopharyngeal carcinoma (NPC) is a complex disease caused by an interaction of EBV chronic infection, environment and host genes, in a multi-step process of carcinogenesis. However, which genetic factors play an important role in the development of chronic EBV infection and NPC remain elusive. The objective of this study is to identify genetic variations associated with two key clinical stages of NPC development: persistent Epstein-Barr virus (EBV) infection of nasopharyngeal epithelia and progression to NPC. We inspected a NPC-associated region on the short arm of chromosome 4 previously implicated by a genome-wide linkage analysis of familial NPC. We determined genotypes for 319 alleles in 34 microsatellite markers spanning an 18 Mb region in 350 NPC cases, 288 individuals with IgA antibodies to EBV capsid antigen (IgA/VCA+) and 346 controls seronegative for IgA antibodies to EBV capsid antigen (IgA/VCA-). The cases and controls were Han Chinese from Wuzhou city and Cangwu County, Guangxi province where the incidence of NPC is as high as 25-50 per 100,000 individuals. Comparing NPC cases to IgA/VCA+ subjects, we found 9 alleles marginally associated with developing NPC from IgA+ status, 5 for risk (OR=1.51-5.36, P=0.01-0.03) and 4 for restrictive (OR=0.3-0.71, P=0.02-0.045). Comparing IgA/VCA+ subjects and IgA/VCA- controls, and comparing all IgA seropositives with and without NPC to IgA seronegatives revealed 12 significant and 3 highly significant (P<0.01) alleles associated with IgA+ serostatus in the two comparing groups. Alleles D4S3241-136 (P=0.004, OR=1.91, 95% CI=1.2-3.0) and D4S3347-213 (P=0.001, OR=1.6, 95% CI=1.2-2.1) were for risk. Allele D4S174-202 (P=0.001, OR=0.5, 95%CI=0.3-0.7) was restrictive. However, statistical significance was lost for all when corrected for multiple comparisons test. Our study could not affirm the genetic association within this region with NPC as did another pedigree study, but provide an opportunity for further gene discovery in this highly endemic NPC population and suggest that this region warrants further study.

[Sequence analysis of the deletion and mutation in carboxy terminal region of the Epstein-Barr virus latent membrane protein 1 derived from nasopharyngeal carcinoma patients].

BACKGROUND: To study the deletion and mutation in carboxy terminal region of LMP1 gene derived from nasopharyngeal carcinoma (NPC) in Guangdong and Guangxi, the high risk areas of nasopharyngeal carcinoma in China. METHODS: LMP1 gene carboxy terminal region was amplified from nasopharyngeal carcinoma tissues by PCR, and then cloned and sequenced. RESULTS: Of the 20 cases, 17 were LMP1 positive. In all positive cases, only 1 case did not show deletion. Four positive cases were chosen for DNA sequencing, The rusult showed that all the four cases had mutation and the 30bp deletion. CONCLUSIONS: High frequency of deletion and mutation in LMP1 gene of nasopharyngeal carcinoma tissues was found in Guangdong and Guangxi. Whether it related to the high incidence of NPC should be further studied.