11 research outputs found
Recommended from our members
A novel approach for increasing sensitivity and correcting saturation artifacts of radioactively labeled cDNA arrays
The radioactivity labeled DNA array platform is a robust and accurate way for a high-throughput measurement of gene expression levels in biological samples. Despite its high degree of sensitivity and reproducibility, this platform has several sources of variation. These are related to the presence of saturation effects in the array images and impede the degree of accuracy at which gene expression levels are determined.
Here we describe a simple, but effective, approach for combining expression data from a series of autoradiographic exposures of variable length. This technique increases the sensitivity of this array platform by detecting low-expressed genes at longer exposures. It also improves the measurement accuracy of highly abundant genes by considering only values from the linear portion of dependency between the exposure times and gene intensities. As a result, the described approach improves the outcome of the subsequent steps of array data normalization and mining
Normalization of single-channel DNA array data by principal component analysis
Motivation: Detailed comparison and analysis of the output of DNA gene expression arrays from multiple samples require global normalization of the measured individual gene intensities from the different hybridizations. This is needed for accounting for variations in array preparation and sample hybridization conditions. Results: Here, we present a simple, robust and accurate procedure for the global normalization of datasets generated with single-channel DNA arrays based on principal component analysis. The procedure makes minimal assumptions about the data and performs well in cases where other standard procedures produced biased estimates. It is also insensitive to data transformation, filtering (thresholding) and pre-screening
High impact of quadrivalent human papillomavirus vaccine across racial/ethnic groups: National Health and Nutrition Examination Survey, 2003–2006 and 2015–2018
ABSTRACTHuman papillomavirus (HPV) causes cervical as well as other cancers. Racial and ethnic disparities in cervical cancer incidence and mortality in the United States are well documented. HPV vaccination has been recommended in the United States since 2006 and is expected to prevent HPV-attributable cancers in all racial/ethnic groups. Quadrivalent HPV vaccine-type (HPV6/11/16/18) and nonvaccine-type cervicovaginal HPV prevalences were estimated from National Health and Nutrition Examination Surveys in 2015–2018 (vaccine era) and 2003–2006 (prevaccine era) data. Prevalence ratios comparing 2015–2018 to 2003–2006 were calculated among sexually experienced Non-Hispanic White (NHW), Non-Hispanic Black (NHB), and Mexican American (MA) females aged 14–24 years. Quadrivalent HPV vaccine-type prevalence declined 82% (CI: 60%–92%) among NHW, 86% (CI: 64%–95%) among NHB, and 100% among MA females, forecasting future reductions in cervical cancer across racial/ethnic groups
Human Papillomavirus Persistence and Association With Recurrent Cervical Intraepithelial Neoplasia After Cryotherapy vs Loop Electrosurgical Excision Procedure Among HIV-Positive Women: A Secondary Analysis of a Randomized Clinical Trial
Importance: Persistence of cervical high-risk human papillomavirus (hrHPV) after treatment for cervical intraepithelial neoplasia grade 2 or higher (CIN2+) has not been compared between cryotherapy and loop electrosurgical excision procedure (LEEP) among HIV-positive women.
Objective: To evaluate whether cryotherapy or LEEP is more effective at clearing hrHPV and whether persistent hrHPV is associated with CIN2+ recurrence among HIV-positive women.
Design, Setting, and Participants: This is a secondary analysis of a randomized clinical trial conducted among women with HIV, hrHPV, and CIN2+ in Nairobi, Kenya. From June 2011 to September 2016, 354 HIV-positive women with CIN2+ disease had hrHPV cervical samples collected before and after treatment with cryotherapy or LEEP. Data were analyzed from September 2018 to January 2021.
Interventions: Women were randomized 1:1 to receive cryotherapy or LEEP and were followed up every 6 months for 24 months with hrHPV cervical swab and Papanicolaou test with confirmatory biopsy.
Main Outcomes and Measures: The main outcomes of this analysis were hrHPV positivity defined as having 1 of 12 hrHPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59) and disease recurrence defined as CIN grade 2 or higher as determined with cervical biopsy.
Results: A total of 354 HIV-positive women with CIN2+ were included in the study; mean (SD) age was 37 (8) years in the cryotherapy arm and 38 (9) years in the LEEP arm. Baseline hrHPV prevalence was 90% (160 of 177) in the cryotherapy arm and 94% (166 of 177) in the LEEP arm (P = .24), and the most common hrHPV types detected were 16 (87 of 326 [27%]), 58 (87 of 326 [27%]), 35 (86 of 326 [26%]), 52 (66 of 326 [20%]), and 18 (56 of 325 [17%]). Over 24 months, clearance of hrHPV was significantly higher among those who underwent LEEP compared with cryotherapy (hazard ratio, 1.40; 95% CI, 1.03-1.90; P = .03). In multivariable analysis, hrHPV type-specific persistence at 12-month follow-up was significantly associated with CIN2+ recurrence from 12 months to 24 months (adjusted hazard ratio, 4.70; 95% CI, 2.47-8.95; P \u3c .001). Performance of hrHPV testing at 12 months for recurrent CIN2+ was 93% sensitivity, 46% specificity, 38% positive predictive value, and 95% negative predictive value.
Conclusions and Relevance: In this secondary analysis of a randomized clinical trial, HIV-positive women who received LEEP were more likely to clear hrHPV infection compared with those undergoing cryotherapy, reinforcing the efficacy of LEEP in this population. Persistent hrHPV was significantly associated with recurrent CIN2+, suggesting that LEEP’s benefits may be related in part to its ability to clear hrHPV infection. Screening for hrHPV infection after treatment among HIV-positive women may be used to rule out recurrent CIN disease given its high sensitivity and negative predictive value
Human papillomavirus persistence and association with recurrent cervical intraepithelial neoplasia after cryotherapy vs loop electrosurgical excision procedure among HIV-positive women : a secondary analysis of a randomized clinical trial
IMPORTANCE Persistence of cervical high-risk human papillomavirus (hrHPV) after treatment for cervical intraepithelial neoplasia grade 2 or higher (CIN2+) has not been compared between cryotherapy and loop electrosurgical excision procedure (LEEP) among HIV-positive women.
OBJECTIVE To evaluate whether cryotherapy or LEEP is more effective at clearing hrHPV and whether persistent hrHPV is associated with CIN2+ recurrence among HIV-positive women.
DESIGN, SETTING, AND PARTICIPANTS This is a secondary analysis of a randomized clinical trial conducted among women with HIV, hrHPV, and CIN2+ in Nairobi, Kenya. From June 2011 to September 2016, 354 HIV-positive women with CIN2+ disease had hrHPV cervical samples collected before and after treatment with cryotherapy or LEEP. Data were analyzed from September 2018 to January 2021.
INTERVENTIONS Women were randomized 1:1 to receive cryotherapy or LEEP and were followed up every 6 months for 24 months with hrHPV cervical swab and Papanicolaou test with confirmatory biopsy.
MAIN OUTCOMES AND MEASURES The main outcomes of this analysis were hrHPV positivity defined as having 1 of 12 hrHPV types (16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59) and disease recurrence defined as CIN grade 2 or higher as determined with cervical biopsy.
RESULTS A total of 354 HIV-positive women with CIN2+ were included in the study; mean (SD) age was 37 (8) years in the cryotherapy arm and 38 (9) years in the LEEP arm. Baseline hrHPV prevalence was 90% (160 of 177) in the cryotherapy arm and 94% (166 of 177) in the LEEP arm (P = .24), and the most common hrHPV types detected were 16 (87 of 326 [27%]), 58 (87 of 326 [27%]), 35 (86 of 326 [26%]), 52 (66 of 326 [20%]), and 18 (56 of 325 [17%]). Over 24 months, clearance of hrHPV was significantly higher among those who underwent LEEP compared with cryotherapy (hazard ratio, 1.40; 95% CI, 1.03-1.90; P = .03). In multivariable analysis, hrHPV type-specific persistence at 12-month follow-up was significantly associated with CIN2+ recurrence from 12 months to 24 months (adjusted hazard ratio, 4.70; 95% CI, 2.47-8.95; P < .001). Performance of hrHPV testing at 12 months for recurrent CIN2+ was 93% sensitivity, 46% specificity, 38% positive predictive value, and 95% negative predictive value.
CONCLUSIONS AND RELEVANCE In this secondary analysis of a randomized clinical trial, HIV-positive women who received LEEP were more likely to clear hrHPV infection compared with those undergoing cryotherapy, reinforcing the efficacy of LEEP in this population. Persistent hrHPV was significantly associated with recurrent CIN2+, suggesting that LEEP's benefits may be related in part to its ability to clear hrHPV infection. Screening for hrHPV infection after treatment among HIV-positive women may be used to rule out recurrent CIN disease given its high sensitivity and negative predictive value.
This secondary analysis of a randomized clinical trial evaluates the efficacy of cryotherapy vs loop electrosurgical excision procedure in clearing high-risk HPV infection and whether persistent detection is associated with cervical intraepithelial neoplasia recurrence among HIV-positive women.
Question Among HIV-positive women, is cryotherapy or loop electrosurgical excision procedure (LEEP) more effective at clearing cervical high-risk human papillomavirus (hrHPV) infection, and is persistent hrHPV detection associated with recurrent cervical intraepithelial neoplasia (CIN)?
Findings In this secondary analysis of a randomized clinical trial that included 354 HIV-positive women in Kenya, LEEP was 40% more likely to clear hrHPV infection compared with cryotherapy, and persistent hrHPV detection was 5 times more likely to be associated with recurrent CIN than no HPV.
Meaning LEEP may be more likely to clear hrHPV infection than cryotherapy, and persistent detection of hrHPV was associated with recurrent CIN among HIV-positive women
Natural killer cytotoxicity in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS): a multi-site clinical assessment of ME/CFS (MCAM) sub-study
Abstract Background Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a multisystem illness characterized by substantial reduction in function accompanied by profound unexplained fatigue not significantly relieved by rest, post-exertional malaise, and other symptoms. Reduced natural killer (NK) cell count and cytotoxicity has been investigated as a biomarker for ME/CFS, but few clinical laboratories offer the test and multi-site verification studies have not been conducted. Methods We determined NK cell counts and cytotoxicity in 174 (65%) ME/CFS, 86 (32%) healthy control (HC) and 10 (3.7%) participants with other fatigue associated conditions (ill control [IC]) from the Multi-Site Clinical Assessment of ME/CFS (MCAM) study using an assay validated for samples shipped overnight instead of testing on day of venipuncture. Results We found a large variation in percent cytotoxicity [mean and (IQR) for ME/CFS and HC respectively, 34.1% (IQR 22.4–44.3%) and 33.6% (IQR 22.9–43.7%)] and no statistically significant differences between patients with ME/CFS and HC (p-value = 0.79). Analysis stratified on illness domain measured with standardized questionnaires did not identify an association of NK cytotoxicity with domain scores. Among all participants, NK cytotoxicity was not associated with survey results of physical and mental well-being, or health factors such as history of infection, obesity, smoking, and co-morbid conditions. Conclusion These results indicate this assay is not ready for clinical implementation and studies are needed to further explore immune parameters that may be involved in the pathophysiology of ME/CFS
Recommended from our members
Vaccine Effectiveness Against Prevalent Anal and Oral Human Papillomavirus Infection Among Men Who Have Sex With Men-United States, 2016-2018.
BackgroundIn the United States, human papillomavirus (HPV) vaccination has been recommended for young adult men who have sex with men (MSM) since 2011.MethodsThe Vaccine Impact in Men study surveyed MSM and transgender women aged 18-26 years in 3 US cities during 2016-2018. Self-collected anal swab and oral rinse specimens were assessed for 37 types of HPV. We compared HPV prevalence among vaccinated and unvaccinated participants and determined adjusted prevalence ratios (aPR) and 95% confidence intervals (CI).ResultsAmong 1767 participants, 704 (39.8%) self-reported receiving HPV vaccine. Median age at vaccination (18.7 years) was older than age at first sex (15.7 years). Quadrivalent vaccine-type HPV was detected in anal or oral specimens from 475 (26.9%) participants. Vaccine-type HPV prevalence was lower among vaccinated (22.9%) compared with unvaccinated (31.6%) participants; aPR for those who initiated vaccination at age ≤18 years was 0.41 (CI, 0.24-0.57) and at age >18 years was 0.82 (CI, 0.67-0.98). Vaccine effectiveness of at least 1 HPV vaccine dose at age ≤18 years or >18 years was 59% and 18%, respectively.ConclusionsFindings suggest real-world effectiveness of HPV vaccination among young adult MSM. This effect was stronger with younger age at vaccination