No abstract available.
Genes, Neoplasm*

No abstract available.
Genes, Neoplasm*

Diseases caused by dioxine include mainly various types of cancers and p53 is one important gene in carcinogenesis-suppressing gene family. Objectives: This research's goal is detecting p53 gene's ratio in the high risk group of exposure to dioxine. Methods: In this study we detected p53 ratio in 50 cases in the group of high risk of exposure to dioxine and the control group of 30 cases. Gene p53 was detected by PCR technique. Results: The study showed that in the control group (no exposure to dioxine), p53 prevalence is 100% compared with 82% in high - risk group (p <0.05). Conclusions: p53 was not detected in 18% of the group of high risk exposure to dioxin, suggesting that there were serious damages in p53 gene (deletion...)
Genes, p53

The second step of immunoglobulin gene alteration consists of somatic hypermutation and class switch recombination. 80th are regulated by activation-induced cytidine deaminase (AID). Methods: Study on possible application of class switch recombination assays for immunoglobulin gene alteration via AID. Cell based assays using AID B lymphocyte and NIH3T3 cell carrying switch substrate; gene transfer using retrovirus system; FACS analysis; PCR and ELISA. Results: DNA sequencing for S region and gamma1CT are the most sensitive and accurate assays. However, gamma1CT assay seemed to be more reliable and applicable. Others are accurate assays but less applicable. Conclusion: gamma1CT determination is the best class switch recombination assay for immunoglobulin gene alteration via AID.
Immunoglobulins, Genes

BACKGROUND: Recently, genotypic identification of anaerobes is emerging as an alternative to the phenotypic method. In this study, we evaluated the performance of Vitek 2, API 20A and 16s rRNA gene sequencing for the identification of anaerobic bacteria. METHODS: A total of 35 anaerobe reference strains were identified using Vitek 2, API 20A and 16s rRNA gene sequencing. We evaluated the performance of three methods on the basis of the accurate identification rates. RESULTS: The Vitek 2, API 20A and 16s rRNA gene sequencing identified 54.3, 15.4, and 94.3% of test strains correctly at the species level and identified 77.1, 42.3, and 100% at the genus level, respectively. Results of the McNemar's test showed that there was a significant difference between each of the three identification methods in species level identification (P value<0.05). CONCLUSION: 16s rRNA gene sequencing showed better performance than Vitek 2 or API 20A for anaerobic bacteria. Considering its excellent performance, 16s rRNA gene sequencing may be useful for accurate identification of anaerobic bacteria that cannot be correctly identified by phenotypic methods.
Bacteria, Anaerobic* ; Genes, rRNA*

No abstract available.
Genes, ras* ; Humans*

Study used the methods of PCR-SSCP-sequencing to detect and identify point mutations in pbp1a gene, one of the genes involved in penicillin resistance of streptococcus pneuminiae. SSCP analysis result of PCR products from 19 clinical resistant and 1 susceptible strains allowed their classification into defferent groups depending on their electrophoretic pattern. This classification fits results obtained by sequencing. With improvement in the resolution capacity of SSCP, these methods could be used efficiently to investigate penicillin resistance in streptococcus pneuminiae
Streptococcus pneumoniae ; Mutation ; Genes

The study was performed on 20 couples samples of nasopharyngeal carcinoma patients in K hospital in Hanoi. The findings indicated that: the prevalence of LMP1-EBV gene in peripheral blood of healthy persons was 96.7% (29/30 positive cases); the prevalence of LMP1-EBV gene in 20 UCNT nasopharyngeal carcinoma patients was 100% (20/20 positive cases); the prevalence of LMP1-EBV gene in 20 patients with other head and neck tumors was 100% (5/5 positive cases). On electrophoresis, 90% biopsies of nasopharyngeal carcinoma patients had deletion in LMP1 gene, while LMP1-EBV gene in peripheral blood of these patients, there were only 10% having deletion mutations.
Neoplasms ; diagnosis ; Mutation ; Genes ;

Lymphomatoid papulosis is an enigmatic disease entity which is clinically benign and histologically malignant. Although sporadic cases have been reported, we could not find any comprehensive report on the combined clinical and histologic features of lymphomatoid papulosis in the literature. Perhaps the most controversial aspect of lymphomatoid papulosis is its pathogenesis and categorization as a benign versus a malignant entity. To date, there are no reports on p53 and bcl-2 protein expression in lymphomatoid papulosis. We analysed the clinico-pathological findings of 18 cases with lymphomatoid papulosis during the 10 year period from 1984 to 1995 and examined the prevalence of immunoreactivity for CD30(DAKO, Ber-H2), p53(DAKO, DO-7), and bcl-2(DAKO, 124) using an immunohistochemical(ABC) method. The results obtained are summarized as follows. 1) Age distribution ranged from 20 to 65, with a mean age of 45 years and a sex distribution which showed a male predominence(8:1). The lesions were located on the trunk and extremities(8cases), extremities (7cases), and trunk(3 cases). The morphology of the lesions were papules or plaques(12 cases), and nodules(6 cases). 2) Histopathologic types were classified into 3 types: type A(4 cases), type B(8 cases) and mixed type (6 cases). 3) Positive immunoreactivity for CD30 was seen in 17%(3 of 18cases): type A(2 of 3) and mixed type(1 of 3). 4) The positive immunoreactivity for p53 and bcl-2 was observed in 29%(5 of 18) and 11%(2 of 18), respectively. 5) Cases showing positive immunoreactivity for P53 were type A(1 of 5), type B(1 of 5), and mixed type(3 of 5). 6) Cases showing positive immunoreactivity for bcl-2 were mixed type(2 of 2). One case developed into Ki-1 lymphoma. These results support the idea that lymphomatoid papulosis and Ki-1 lymphoma represent a continuum. The role of p53 gene mutation and bcl-2 activation in the development of lymphomatoid papulosis is currently unknown. But, our results suggest that p53 gene mutation and bcl-2 activation are not a critical step in the development of lymphomatoid papulosis. Further studies are needed to elucidate the role of p53 gene mutation and bcl-2 activation in the development and progression of lymphomatoid papulosis.
Male ; Humans ; Genes, p53

BACKGROUND: Aberrant methylation of CpG islands in promoter regions is one of the major mechanisms for silencing of tumor suppressor genes in various types of human cancers including non-Hodgkin's lymphomas (NHL). In this study, we investigated the aberrant promoter methylation status of known or suspected tumor suppressor genes in NHLs and compared the methylation profiles between B-cell and T/NK-cell NHLs. METHODS: 54 cases of B-cell NHLs and 16 cases of T/NK-cell NHLs were examined for the methylation status of eight genes using methylation specific PCR. RESULTS: CpG islands methylation was variously found in eight genes as follows; DAPK (71%), MT1G (70%), p16 (53%), CDH1 (53%), THBS1 (56%), MGMT (27.1%), COX2 (13%), and RUNX3 (11.4%). In six cases (8 %), methylation was not observed in any of these genes. Overall methylation index of B-cell NHLs (0.48) was significantly higher than that of T/NK-cell NHLs (0.32). Of eight genes tested, THBS1 and CDH1 methylations were much more prominent in diffuse large B-cell lymphomas than in T/NK-cell NHLs or other B-cell NHLs. CONCLUSION: This study suggests that aberrant CpG island methylation is a frequent event in NHLs, and diffuse large B-cell lymphomas show overlapping but distinct methylation profiles.
Humans ; Genes, Tumor Suppressor