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1.  Changes in Sexual Behaviors among HIV-Infected Individuals after Their HIV Diagnosis in a Rural Prefecture of Eastern China 
PLoS ONE  2013;8(3):e59575.
To describe changes in sexual behaviors among HIV-infected individuals after their HIV diagnosis.
All HIV-infected individuals diagnosed by the end of 2009 in Taizhou Prefecture were invited to participate in this 12-month prospective study. Assessments including the total number and types of sexual contacts, and condom use details for up to their most familiar eight sexual contacts were collected both at enrollment and 12-month follow-up.
262 HIV-infected individuals were eligible for analysis. The total number of sexual contacts reported by participants was 4,017, 1,496 and 356 during the 12- month period prior to HIV diagnosis (T1), the 12-month period prior to the baseline survey (T2), and the 12-month follow-up period (T3), respectively. The difference in the number of sexual contacts between T2 and T1 was −5 in median (IQR −1, −14), and the difference between T3 and T2 was 0 in median (IQR: 0, −6). A larger proportion of spousal or long-term heterosexual contact was reported from T1(27.7%) to T2(42.5%) to T3(76.1%), whereas a smaller proportion of commercial heterosexual contacts was reported from T1 (48.6%) to T2 (33.2%) to T3 (7.0%) as well as a smaller proportion of non-commercial casual homosexual contacts was reported from T2 (8.4%) to T3 (3.8%).The proportion of consistent condom use increased significantly from T1 (9.3%) to T2 (35.3%) to T3 (91.5%).
Sexual behaviors did not change in a uniform manner for the participants in our study. Sexual behaviors and sexual networks vis-à-vis HIV diagnosis and follow-up were associated with the participant’s characteristics and HIV infection and treatment status. The overall lesson is that individuals who are unaware of their HIV infection are the main drivers of secondary transmission. Early identification of HIV infection and access to antiretroviral therapy (ART ) are both key strategies to the control and prevention.
PMCID: PMC3601103  PMID: 23527221
2.  Behavioral and Molecular Tracing of Risky Sexual Contacts in a Sample of Chinese HIV-infected Men Who Have Sex With Men 
American Journal of Epidemiology  2013;177(4):343-350.
Contact tracing, coupled with molecular epidemiologic investigation, is especially useful for identifying an infection with few cases in the population, such as human immunodeficiency virus (HIV) infection in China. No such research is available on Chinese men who have sex with men (MSM). From 2008 to 2010 in Taizhou Prefecture in China, every newly diagnosed HIV-infected MSM was invited to participate as an “index case” in a contact tracing survey by providing contact information for up to 8 sexual contacts, who themselves were approached to receive voluntary HIV counseling and testing. Those who tested HIV-positive were then subjected to another contact tracing survey. This process was repeated until no more sexual contacts were reported or tested positive. A total of 100 HIV-infected MSM served as “index cases,” including the initial 49 cases identified through routine surveillance programs and 51 cases from the present survey. Traced MSM exhibited little willingness to receive voluntary counseling and testing. CRF01_AE (HIV type 1) was the dominant subtype. Seven of 49 independent sexual networks were deemed HIV transmission clusters. Fear of stigma or discrimination may deter Chinese MSM from receiving voluntary counseling and testing. Nonetheless, the integration of behavioral network analysis and HIV phylogenetic analysis provides enhanced evidence for developing tailored prevention strategies for HIV-infected MSM.
PMCID: PMC3566707  PMID: 23348006
contact tracing; HIV; human immunodeficiency virus; men who have sex with men; molecular epidemiology; sexual behavior; sexual networks
3.  Tracing sexual contacts of HIV-infected individuals in a rural prefecture, Eastern China 
BMC Public Health  2012;12:533.
Contact tracing is especially useful for identifying an infection with few cases in the population, such as HIV in China. Little such research is available in China.
Every newly diagnosed HIV case from 2008–2010 in Taizhou Prefecture, Zhejiang Province in China, was invited to participate as an “index case” in a contact tracing survey by providing contact information for up to eight sexual contacts who themselves were approached for voluntary HIV counseling and testing (VCT). Those who tested HIV-positive were then subjected to another contact tracing survey. This process was repeated until no more sexual contacts were reported or tested positive.
A total of 463 HIV-infected individuals were newly identified during the study period, including 338 cases who were identified from routine surveillance programs and 125 cases who were identified from the present contact tracing survey. Among these 463 cases, 398 (86.0%) served as ‘index cases’ in the survey, including 290 (85.8%) out of the 338 cases identified from routine surveillance programs and 108 (86.4%) out of the 125 cases identified from the present survey. These 398 ‘index cases’ reported a total of 1,403 contactable sexual contacts, of whom 320 (22.8%) received HIV testing and 125 (39.1%) tested positive for HIV. Willingness to receive HIV testing was high among spouses and long term heterosexual or homosexual partners but extremely low among casual and commercial sex partners of ‘index cases’. Consistent condom use was rare for all participants. A total of 290 independent sexual network components were constructed, with high complexity.
Contact tracing is useful for identifying new HIV infections from spouses or long term sexual partners of HIV-infected individuals. The complicated sexual networks existing between and beyond HIV-infected persons provide opportunities for rapid spread of HIV in such areas.
PMCID: PMC3413611  PMID: 22818298
Contact tracing; Sexual behavior; Sexual networks; HIV testing; HIV infection
4.  PML-RARα and Dnmt3a1 Cooperate in vivo to Promote Acute Promyelocytic Leukemia 
Cancer research  2010;70(21):8792-8801.
The PML-RARα oncogene is the central effector of acute promyelocytic leukemia (APL). PML-RARα physically interacts with epigenetic-modifying enzymes including DNA methyltransferases (Dnmt) to suppress critical downstream targets. Here, we show that increased expression of Dnmt3a1 cooperates with PML-RARα in vivo to promote early lethality secondary to myeloid expansion and dysfunction in primary mice. Bone marrow cells from these mice cause leukemogenesis with a shortened latency and a higher penetrance on transplantation into irradiated recipients. Furthermore, leukemic cells overexpressing PML-RARα and Dnmt3a1 display increased methylation at a target promoter compared with PML-RARα or Dnmt3a1 controls. Our findings show a cooperation between the PML-RARα oncogene and the Dnmt3a1 enzyme in vivo and that Dnmt levels can be rate limiting in APL progression.
PMCID: PMC3021794  PMID: 20861188
5.  Mitochondrial DNA Damage and Repair in RPE Associated with Aging and Age-Related Macular Degeneration 
The authors show that macular-specific increases in mtDNA damage, heteroplasmic mutations, and diminished repair are associated with aging and with severity of age-related macular degeneration (AMD). Additionally, they link the accumulation of mtDNA damage to a decline in expression of the DNA repair enzyme OGG1 and speculate that this decline contributes to inefficient DNA repair capacity, especially in eyes with more advanced AMD.
Mitochondrial DNA (mtDNA) damage may be associated with age-related diseases, such as age-related macular degeneration (AMD). The present study was designed to test whether the frequency of mtDNA damage, heteroplasmic mtDNA mutations, and repair capacity correlate with progression of AMD.
Macular and peripheral RPE cells were isolated and cultured from human donor eyes with and without AMD. The stages of AMD were graded according to the Minnesota Grading System. Confluent primary RPE cells were used to test the frequency of endogenous mtDNA damage by quantitative PCR. Mutation detection kits were used to detect heteroplasmic mtDNA mutation. To test the mtDNA repair capacity, cultured RPE cells were allowed to recover for 3 and 6 hours after exposure to H2O2, and repair was assessed by quantitative PCR. The levels of human OGG1 protein, which is associated with mtDNA repair, were analyzed by Western blot.
This study showed that mtDNA damage increased with aging and that more lesions occurred in RPE cells from the macular region than the periphery. Furthermore, mtDNA repair capacity decreased with aging, with less mtDNA repair capacity in the macular region compared with the periphery in samples from aged subjects. Most interestingly, the mtDNA damage was positively correlated with the grading level of AMD, whereas repair capacity was negatively correlated. In addition, more mitochondrial heteroplasmic mutations were detected in eyes with AMD.
These data show macula-specific increases in mtDNA damage, heteroplasmic mutations, and diminished repair that are associated with aging and AMD severity.
PMCID: PMC3109040  PMID: 21273542
6.  Herpes simplex virus infections among rural residents in eastern China 
Herpes simplex virus (HSV) has two types: HSV-1 and HSV-2. Both infect epithelial cells and establish latent infections in neurons causing an infection that persists for life. Information on age- and gender-specific seroprevalence of HSV-1 and HSV-2 is valuable for understanding HSV transmission dynamics and designing population-based prevention and intervention programs for HSV. However, such information is not available for China.
Cryopreserved serum samples of all subjects aged 5 to 60 years from two randomly selected rural villages in Zhejiang province in Eastern China who had participated in the China national seroepidemiological survey of hepatitis B virus (HBV) infection conducted in 2006 were tested. Seroprevalence of HSV-1 and HSV-2 infections were determined by type-specific IgG antibody tests using an ELISA technique. Their 95% confidence intervals adjusted for the sampling fraction were calculated according to the Clopper-Pearson method.
A total of 2,141 residents participated in the survey, with a response rate of 82.3%. HSV-1 seroprevalence was 92.0% overall, 89.1% for males and 94.2% for females. HSV-1 seroprevalence was 61.6% among children aged 5-9 years, 90.3% among 25-29 years, and nearly 100% among those aged > = 40 years. HSV-2 seroprevalence was 13.2% overall, 10.5% for males and 15.3% for females. No children aged 5-14 years were HSV-2 positive, and HSV-2 seroprevalence was 7.1% among 15-19 years and peaked at 24.3% among those aged 45-49 years. Neither HSV-1 nor HSV-2 infections were significantly different by gender. About 11.8% of study subjects were co-infected with both types of HSV. Among 549 participating couples, 8.6% were HSV-1 serodiscordant and 11.8% were HSV-2 serodiscordant. No one tested positive for HIV. The overall prevalence of HBsAg was 16.2%, 16.9% for males and 15.4% for females.
HSV-1 was highly prevalent among all rural residents aged between 5-60 years in Eastern China, whereas HSV-2 was prevalent among sexually active people. HSV-1 and HSV-2 have different transmission modes and dynamics. Future HSV prevention and control programs in China should be type specific.
PMCID: PMC3068093  PMID: 21414231
Seroprevalence; Herpes simplex virus; Hepatitis B virus; Community residents; Eastern China
7.  Suppression of Intestinal Neoplasia by Deletion of Dnmt3b 
Molecular and Cellular Biology  2006;26(8):2976-2983.
Aberrant gene silencing accompanied by DNA methylation is associated with neoplastic progression in many tumors that also show global loss of DNA methylation. Using conditional inactivation of de novo methyltransferase Dnmt3b in ApcMin/+ mice, we demonstrate that the loss of Dnmt3b has no impact on microadenoma formation, which is considered the earliest stage of intestinal tumor formation. Nevertheless, we observed a significant decrease in the formation of macroscopic colonic adenomas. Interestingly, many large adenomas showed regions with Dnmt3b inactivation, indicating that Dnmt3b is required for initial outgrowth of macroscopic adenomas but is not required for their maintenance. These results support a role for Dnmt3b in the transition stage between microadenoma formation and macroscopic colonic tumor growth and further suggest that Dnmt3b, and by extension de novo methylation, is not required for maintaining tumor growth after this transition stage has occurred.
PMCID: PMC1446955  PMID: 16581773
8.  Polyploids require Bik1 for kinetochore–microtubule attachment 
The Journal of Cell Biology  2001;155(7):1173-1184.
The attachment of kinetochores to spindle microtubules (MTs) is essential for maintaining constant ploidy in eukaryotic cells. Here, biochemical and imaging data is presented demonstrating that the budding yeast CLIP-170 orthologue Bik1is a component of the kinetochore-MT binding interface. Strikingly, Bik1 is not required for viability in haploid cells, but becomes essential in polyploids. The ploidy-specific requirement for BIK1 enabled us to characterize BIK1 without eliminating nonhomologous genes, providing a new approach to circumventing the overlapping function that is a common feature of the cytoskeleton. In polyploid cells, Bik1 is required before anaphase to maintain kinetochore separation and therefore contributes to the force that opposes the elastic recoil of attached sister chromatids. The role of Bik1 in kinetochore separation appears to be independent of the role of Bik1 in regulating MT dynamics. The finding that a protein involved in kinetochore–MT attachment is required for the viability of polyploids has potential implications for cancer therapeutics.
PMCID: PMC2199317  PMID: 11756471
kinetechore; microtubule; ploidy; Bik1; plus end–tracking protein
10.  Divergent N-Terminal Sequences Target an Inducible Testis Deubiquitinating Enzyme to Distinct Subcellular Structures 
Molecular and Cellular Biology  2000;20(17):6568-6578.
Ubiquitin-specific processing proteases (UBPs) presently form the largest enzyme family in the ubiquitin system, characterized by a core region containing conserved motifs surrounded by divergent sequences, most commonly at the N-terminal end. The functions of these divergent sequences remain unclear. We identified two isoforms of a novel testis-specific UBP, UBP-t1 and UBP-t2, which contain identical core regions but distinct N termini, thereby permitting dissection of the functions of these two regions. Both isoforms were germ cell specific and developmentally regulated. Immunocytochemistry revealed that UBP-t1 was induced in step 16 to 19 spermatids while UBP-t2 was expressed in step 18 to 19 spermatids. Immunoelectron microscopy showed that UBP-t1 was found in the nucleus while UBP-t2 was extranuclear and was found in residual bodies. For the first time, we show that the differential subcellular localization was due to the distinct N-terminal sequences. When transfected into COS-7 cells, the core region was expressed throughout the cell but the UBP-t1 and UBP-t2 isoforms were concentrated in the nucleus and the perinuclear region, respectively. Fusions of each N-terminal end with green fluorescent protein yielded the same subcellular localization as the native proteins, indicating that the N-terminal ends were sufficient for determining differential localization. Interestingly, UBP-t2 colocalized with anti-γ-tubulin immunoreactivity, indicating that like several other components of the ubiquitin system, a deubiquitinating enzyme is associated with the centrosome. Regulated expression and alternative N termini can confer specificity of UBP function by restricting its temporal and spatial loci of action.
PMCID: PMC86134  PMID: 10938131

Results 1-10 (10)