OBJECTIVETo clone the prtH gene from Porphyromonas gingivalis (P.g) ATCC 33277 and analyze the polymorphism of prtH gene from 5 strains of P.g in order to explore the relationship between P.g and periodontitis.

METHODSUsing PCR, the prtH was amplified and cloned into pGEM-T vector. To illustrate the prtH polymorphism among P.g strains, the genomic DNAs were extracted and screened by PCR with three pairs of specific primers, dot blot and Southern blot hybridization using the biotin-labeled prtH sequence as probe.

RESULTSRecombinant DNA pGEM-T- prtH was verified by restriction endonuclease and sequence assay. Strain W 381 and ATCC 33277 showed the identical results in PCR and hybridization assays, whereas strain ATCC 49417 and 14-3-2 revealed individual hybridization patterns. Strain 47A-1 seemed even not to contain prtH gene.

CONCLUSIONSDifferent prtH gene sequences exist in different P.g strains. This polymorphism may indicate various potential virulent effects during the infection and pathogenesis. Established PCR protocol is sensitive for identification of prtH gene.

Bacterial Proteins ; Blotting, Southern ; Cloning, Molecular ; Cysteine Endopeptidases ; genetics ; DNA, Bacterial ; genetics ; metabolism ; Deoxyribonuclease BamHI ; metabolism ; Deoxyribonuclease HindIII ; metabolism ; Polymorphism, Genetic ; Porphyromonas gingivalis ; genetics ; Species Specificity

OBJECTIVETo investigate the genomic variation of Epstein-Barr virus (EBV) and its significance in nasopharyngeal carcinogenesis.

METHODSForty nasopharyngeal carcinoma (NPC) biopsy tissues were used for detection of EBV BamHI f variant and LMP1 XhoI-loss by polymerase chain reaction (PCR), nested PCR, and RFLP (restriction fragment length polymorphism). Forty-eight samples of peripheral blood mononuclear cells (PBMC) taken from apparently healthy adult individuals were used for detection of LMP1 XhoI-loss. Three samples of amplified LMP1 exon 1 DNA from B95-8 cell line and 2 NPC tissues (one having XhoI-loss and the other having Wt-XhoI/XhoI-loss) were sequenced.

RESULTSThirty out of the 40 NPC cases (30/40, 75%) harbored EBV BamHI f variant and the remaining 10 (10/40, 25%) harbored BamHI F prototype. Thirty out of the 39 NPCs (30/39, 76.9%) showed single EBV LMP1 XhoI-loss, 7 (7/39, 18.0%) showed single LMP1 Wt-XhoI (presence of a XhoI site in exon 1 of LMP1 gene, as in B95-8 cell line), and 2 (2/39, 5.1%) showed both LMP1 Wt-XhoI and XhoI-loss. Thirty-eight of the 39 NPCs (97.4%) showed EBV LMP1 XhoI-loss or/and BamHI F variant. In the NPC tissue (1 case only) showing the prototype of Wt-XhoI/BamHI "f", there were several base substitutions, including 5 missense mutations and 2 silent mutations present in LMP1 exon 3, on DNA sequencing. On the other hand, 10 out of the 48 samples of PBMC taken from apparently healthy individuals could be amplified successfully by nested PCR for detection of LMP1 XhoI site. All of these 10 samples carried the prototype of EBV LMP1 Wt-XhoI.

CONCLUSIONSThe majority of EBV present in neoplastic cells of NPC is of BamHI "f" variant and/or possesses LMP1 XhoI-loss, as compared with that in healthy individuals. This genomic variation of EBV may bear some roles in the development and progression of NPC.

Adult ; Aged ; Binding Sites ; genetics ; DNA, Viral ; genetics ; metabolism ; Deoxyribonuclease BamHI ; metabolism ; Deoxyribonucleases, Type II Site-Specific ; metabolism ; Female ; Herpesvirus 4, Human ; genetics ; isolation & purification ; Humans ; Male ; Middle Aged ; Mutation ; Nasopharyngeal Neoplasms ; virology ; Sequence Deletion ; Viral Matrix Proteins ; genetics

OBJECTIVETo explore the diagnostic value of serum levels of BamHI-W fragment, latent membrane protein-1 (LMP-1), BZLF1 and ZEBRA protein in patients with natural killer (NK)/T-cell lymphomas (NKTCLs), and to evaluate their relationship with clinical features.

METHODSA total of 144 cases were analyzed in this study, including 48 NKTCLs patients, 48 other types of non-Hodgkin's lymphomas (NHL) patients and 48 healthy individuals as controls. Fluorescent quantitative real-time polymerase chain reaction (RQ-PCR) was used to measure the copy number of BamHI-W, LMP-1 and BZLF1 in serum. Enzyme linked immunosorbent assay (ELISA) was applied to measure the serum levels of ZEBRA protein. The relative operating characteristic (ROC) curve was applied in the evaluation of the tested markers in diagnosis of NKTCL patients, and the correlations among the tested markers and clinical feature were analyzed.

RESULTSCompared with the controls, NKTCL group showed significantly higher levels of all the tested markers (P < 0.01). The median values of serum BamHI-W, LMP-1 and BZLF1 DNAs level were 1870, 394 and 499 copies/ml, respectively. And the median value of ZEBRA protein level was 73.3 µg/L. Furthermore, the ROC curves analysis revealed that all the area under curve (AUC) of LMP-1, BZLF1 and ZEBRA were more than 0.70, which were probably helpful in the diagnosis of NKTCL. To predict the presence of NKTCL, BamHI-W showed a high sensitivity of 81.3%, while BZLF1 showed a high specificity of 81.2%. Untreated patients seemed to have a significantly higher level of serum LMP1 DNA than that of treated patients (median value 898 copies/ml vs 0 copies/ml, P = 0.050). Correlation analysis showed that serum BamHI-W DNA level was correlated with the presence of B symptoms. All the three genes expressed in 94.4% of the untreated cases. On the other hand, none of them expressed in treated cases.

CONCLUSIONSIt suggested that combined measurements of BamHI W, LMP1 and BZLF1 DNA levels might be helpful to the diagnosis and therapeutic monitor of NKTCL.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Case-Control Studies ; Deoxyribonuclease BamHI ; blood ; Female ; Herpesvirus 4, Human ; Humans ; Lymphoma, T-Cell ; blood ; diagnosis ; Male ; Middle Aged ; Real-Time Polymerase Chain Reaction ; Sensitivity and Specificity ; Trans-Activators ; blood ; Viral Matrix Proteins ; blood ; Young Adult