In Cameroon, despite extensive control efforts against HIV/AIDS, the number of new HIV infections is still on the rise. The factors contributing to this are not clearly understood. We hypothesized that it may lie on p...In Cameroon, despite extensive control efforts against HIV/AIDS, the number of new HIV infections is still on the rise. The factors contributing to this are not clearly understood. We hypothesized that it may lie on people living with HIV (PLHIV). In a case-control descriptive study, we studied the characteristics and sexual risky behaviour of PLHIV in the North West Region of Cameroon which has the highest HIV prevalence. Participants were screened for HIV and a structured questionnaire was used in data collection. An equivalent number (350) of PLHIV and controls who did not differ with respect to age and sex participated. Relative to the control, PLHIV were generally less educated (P < 0.001), poorer and less privileged (P < 0.001) with no stable source of income. Among participants that were once married, a greater proportion of PLHIV were divorced (OR = 5.23, P = 0.007), and widows (OR = 2.73, P = 0.001). Among participants that were single, a relatively greater proportion of PLHIV practiced multi-partner sex (OR = 4.55, P< 0.001). History of STDs was higher in PLHIV than the control (OR = 1.88, P = 0.001). Out of 350 PLHIV, 280 (80%) admitted to having had sexual intercourse after being diagnosed of which only 127 (41.78%) admitted to using condoms and 132 (47.14%) admitted to concealing their HIV status from their sexual partner(s). These findings have implications in HIV control programs which should target the poor and the less educated, as well as the sexual behaviour of PLHIV, so as to reverse the current rising trend of new infections in the country.展开更多
AIM: To test the hypothesis to block VEGF expression of SMMC-7721 hepatoma cells may inhibit tumor growth using the rat hepatoma model. METHODS: Amplify the 200 VEGF cDNA fragment and insert it into human U6 gene cass...AIM: To test the hypothesis to block VEGF expression of SMMC-7721 hepatoma cells may inhibit tumor growth using the rat hepatoma model. METHODS: Amplify the 200 VEGF cDNA fragment and insert it into human U6 gene cassette in the reverse orientation transcribing small antisense RNA which could specifically interact with VEGF165, and VEGF121 mRNA. Construct the retroviral vector containing this antisense VEGF U6 cassette and package the replication-deficient recombinant retrovirus. SMMC-7721 cells were transduced with these virus and positive clones were selected with G418. PCR and Southern blot analysis were performed to determine if U6 cassette integrated into the genomic DNA of positive clone. Transfected tumor cells were evaluated for RNA expression by ribonuclease protection assays. The VEGF protein in the supernatant of parental tumor cells and genetically modified tumor cells was determined with ELISA. In vitro and in vivo growth properties of antisense VEGF cell clone in nude mice were analyzed. RESULTS: Restriction enzyme digestion and PCR sequencing verified that the antisense VEGF RNA retroviral vector was successfully constructed.After G418 selection, resistant SMMC-7721 cell clone was picked up. PCR and Southern blot analysis suggested that U6 cassette was integrated into the cell genomic DNA. Stable SMMC-7721 cell clone transduced with U6 antisense RNA cassette could express 200 bp small antisense VEGF RNA and secrete reduced levels of VEGF in culture condition. Production of VEGF by antisense transgene-expressing cells was 65+/-10 ng/L per 10(6) cells, 42045 ng/L per 10(6) cells in sense group and 485+/-30 ng/L per 10(6) cells in the negative control group, (P【 0.05). The antisense-VEGF cell clone appeared phenotypically indistinguishable from SMMC-7721 cells and SMMC-7721 cells transfected sense VEGF. The growth rate of the antisense-VEGF cell clone was the same as the control cells. When S.C. was implanted into nude mice, growth of antisense-VEGF cell lines was greatly inhibited compared with control cells. CONCLUSION: Expression of antisense VEGF RNA in SMMC-7721 cells could decrease the tumorigenicity, and antisense-VEGF gene therapy may be an adjuvant treatment for hepatoma.展开更多
文摘In Cameroon, despite extensive control efforts against HIV/AIDS, the number of new HIV infections is still on the rise. The factors contributing to this are not clearly understood. We hypothesized that it may lie on people living with HIV (PLHIV). In a case-control descriptive study, we studied the characteristics and sexual risky behaviour of PLHIV in the North West Region of Cameroon which has the highest HIV prevalence. Participants were screened for HIV and a structured questionnaire was used in data collection. An equivalent number (350) of PLHIV and controls who did not differ with respect to age and sex participated. Relative to the control, PLHIV were generally less educated (P < 0.001), poorer and less privileged (P < 0.001) with no stable source of income. Among participants that were once married, a greater proportion of PLHIV were divorced (OR = 5.23, P = 0.007), and widows (OR = 2.73, P = 0.001). Among participants that were single, a relatively greater proportion of PLHIV practiced multi-partner sex (OR = 4.55, P< 0.001). History of STDs was higher in PLHIV than the control (OR = 1.88, P = 0.001). Out of 350 PLHIV, 280 (80%) admitted to having had sexual intercourse after being diagnosed of which only 127 (41.78%) admitted to using condoms and 132 (47.14%) admitted to concealing their HIV status from their sexual partner(s). These findings have implications in HIV control programs which should target the poor and the less educated, as well as the sexual behaviour of PLHIV, so as to reverse the current rising trend of new infections in the country.
基金Project supported by National Natural Science Foundation of China,No.863 Z2001-04
文摘AIM: To test the hypothesis to block VEGF expression of SMMC-7721 hepatoma cells may inhibit tumor growth using the rat hepatoma model. METHODS: Amplify the 200 VEGF cDNA fragment and insert it into human U6 gene cassette in the reverse orientation transcribing small antisense RNA which could specifically interact with VEGF165, and VEGF121 mRNA. Construct the retroviral vector containing this antisense VEGF U6 cassette and package the replication-deficient recombinant retrovirus. SMMC-7721 cells were transduced with these virus and positive clones were selected with G418. PCR and Southern blot analysis were performed to determine if U6 cassette integrated into the genomic DNA of positive clone. Transfected tumor cells were evaluated for RNA expression by ribonuclease protection assays. The VEGF protein in the supernatant of parental tumor cells and genetically modified tumor cells was determined with ELISA. In vitro and in vivo growth properties of antisense VEGF cell clone in nude mice were analyzed. RESULTS: Restriction enzyme digestion and PCR sequencing verified that the antisense VEGF RNA retroviral vector was successfully constructed.After G418 selection, resistant SMMC-7721 cell clone was picked up. PCR and Southern blot analysis suggested that U6 cassette was integrated into the cell genomic DNA. Stable SMMC-7721 cell clone transduced with U6 antisense RNA cassette could express 200 bp small antisense VEGF RNA and secrete reduced levels of VEGF in culture condition. Production of VEGF by antisense transgene-expressing cells was 65+/-10 ng/L per 10(6) cells, 42045 ng/L per 10(6) cells in sense group and 485+/-30 ng/L per 10(6) cells in the negative control group, (P【 0.05). The antisense-VEGF cell clone appeared phenotypically indistinguishable from SMMC-7721 cells and SMMC-7721 cells transfected sense VEGF. The growth rate of the antisense-VEGF cell clone was the same as the control cells. When S.C. was implanted into nude mice, growth of antisense-VEGF cell lines was greatly inhibited compared with control cells. CONCLUSION: Expression of antisense VEGF RNA in SMMC-7721 cells could decrease the tumorigenicity, and antisense-VEGF gene therapy may be an adjuvant treatment for hepatoma.
