Black heterosexual men's resilience in times of HIV adversity: findings from the "weSpeak" study.

BACKGROUND: In Canada, heterosexual African, Caribbean and Black (ACB) men tend to suffer a disproportionate burden of HIV. Consequently, studies have examined the underlying contributors to this disparity through the nexus of behavioral and structural factors. While findings from these studies have been helpful, their use of deficit and risk models only furthers our knowledge of why ACB men are more vulnerable to HIV infection. Thus far, there is a dearth of knowledge on how heterosexual ACB men mobilize protective assets to promote their resilience against HIV infection. METHODS: As part of a larger Ontario-based project called weSpeak, this study examined how ACB men acquire protective assets to build their resilience to reduce their HIV vulnerability. We analyzed three focus group discussions (n = 17) and 13 in-depth interviews conducted with ACB men using NVivo and a mixed inductive-deductive thematic analyses approach. RESULTS: The findings show that ACB men mostly relied on personal coping strategies, including sexual abstinence, to build resilience against HIV. Interpersonal resources such as family, friends, and religious communities also played an important role in constructing ACB men's resilience. ACB men bemoaned their lack of access to essential institutional resources, such as health services, that are important in managing HIV adversity. CONCLUSION: Based on these findings, there is an urgent need for HIV policy stakeholders, including service providers, to engage the ACB community in the design of intervention programs. Additionally, addressing the socioeconomic disadvantages faced by ACB communities will increase the capacity of ACB men to develop resilience against HIV.

Knowledge of sexual partner's HIV serostatus and the practice of safer sex among heterosexual men of African descent in London, Ontario.

Objective: Poor knowledge of sexual partners' HIV status is a major contributing factor in the heterosexual spread of HIV in Canada. This study examined knowledge of sexual partner's HIV serostatus and the practice of safer sex among self-identified heterosexual African, Caribbean and Black (ACB) men in London, Ontario.Design: A cross-sectional data was collected from 156 heterosexual ACB men in London. The negative log-log link function was fitted to estimate the relationship between knowledge of sexual partner's HIV status and condom use among ACB men.Results: Findings show that ACB men who know their sexual partner's HIV status are less likely to use condoms compared to men who do not know the serostatus of their sexual partner, controlling for other theoretically relevant covariates. In addition, the findings show that sexually active, single ACB men are less likely to use condoms. On the other hand, ACB men with higher education, employed and with income over 60 thousand dollars a year have a higher likelihood of using condoms.Conclusions: Heterosexual ACB men who used condoms even when they did not know their sexual partners' HIV status could be explained as a resilience-building strategy in response to their increasing HIV vulnerabilities. Heterosexual ACB men's use of condoms is further associated with socioeconomic factors including income, employment and education that need to be addressed for an improved safer sex.

Sexual Debut Among Heterosexual Men of African and Caribbean Descent: Are the Youth Initiating Sex Earlier than the Older Generation?

Although age at first sex is considered a measure of sexual risk and vulnerability for HIV infection, there is a dearth of literature on age at sexual debut in the Canadian context. This study examined time variations to first sex among heterosexual African, Caribbean, and Black (ACB) men in four Ontarian cities. A population-based retrospective survey (n = 879) on timing to first sexual intercourse was conducted between 2018 and 2019 among self-identified heterosexual ACB men 16 years or older and residing in London, Ottawa, Toronto or Windsor. We used the lognormal survival analysis technique to examine variations in time to first sexual intercourse among age cohorts and between cities. The findings showed a generational shift in the pattern of sexual initiation, with younger heterosexual ACB men initiating sexual intercourse earlier compared with those currently older than 50 years. We observed those between 16 and 19 years, 20 and 29 years, and 30 and 39 years of age to have significantly higher risk ratios of TR = 0.852, TR = 0.869, and TR = 0.855, respectively. At city level, the results show marked spatial variations, with youth in cities of Toronto, Ottawa, and London at the highest risk of early sexual debut relative to those in Windsor. Early initiation of first sexual intercourse among heterosexual ACB youth was observed with those in the larger cities being at a relatively higher risk. There is the need for programs aimed at delaying sexual debut among youth in general. It is, however, important to recognize the relative risk of those in the larger cities.

"I went in there, had a bit of an issue with those folks": everyday challenges of heterosexual African, Caribbean and black (ACB) men in accessing HIV/AIDS services in London, Ontario.

BACKGROUND: In Canada, heterosexual African, Caribbean, and Black (ACB) men's heightened risk of HIV infection has been linked to behavioral characteristics, including practices of hegemonic masculinity that discourage the use of HIV preventive services. However, this framing is bereft of the role of structural factors that may be contributing to new HIV infections. This paper examined the underlying factors limiting access to health services among heterosexual ACB men in London, Ontario Canada. METHODS: A convenient sampling technique was used to recruit thirty-seven (n = 37) self-identified heterosexual ACB men and service providers. Four focus groups (FG) were conducted; three with ACB participants of similar age category (i.e., 16-24; 25-38; 39+), and one with service providers. The FGs focused on the barriers to using health services and interrogated the ease of access to HIV intervention programs by ACB men respectively. Recurring themes from the FGs were probed further using in-depth interviews (n = 13). FGs and in-depth interviews complemented each other in reducing uneven power dynamics, fact checking, and allowing for detail discussion of the topic under study. Data analyses were done in NVivo using a mixed inductive-deductive thematic analyses approach. RESULTS: Most ACB men lacked information on HIV and were unaware of their increased risk of infection. Contrary to the notion that behavioral characteristics keep ACB men away from health services, we found that most ACB men were unaware of the availability of these services. Those that had some knowledge about the services reported that they were not appropriately tailored to their needs. In addition, stereotypes and stigma about the etiology of HIV among Blacks, and systemic neglect served as significant barriers to ACB men's use of services. CONCLUSION: The findings suggest that, to enhance preventive health service use among heterosexual ACB men, there is the need to remove structural barriers. Engaging ACB men in the design and implementation of policies may be useful at improving access to HIV information, testing, and treatment services. Increased information dissemination to ACB men would create awareness of the availability of HIV services. Finally, service providers should be conscious of ACB men's concern about experiences of discrimination and racism at service centers.

Proteins associated with pancreatic cancer survival in patients with resectable pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal disease with a dismal prognosis. However, while most patients die within the first year of diagnosis, very rarely, a few patients can survive for >10 years. Better understanding the molecular characteristics of the pancreatic adenocarcinomas from these very-long-term survivors (VLTS) may provide clues for personalized medicine and improve current pancreatic cancer treatment. To extend our previous investigation, we examined the proteomes of individual pancreas tumor tissues from a group of VLTS patients (survival ≥10 years) and short-term survival patients (STS, survival <14 months). With a given analytical sensitivity, the protein profile of each pancreatic tumor tissue was compared to reveal the proteome alterations that may be associated with pancreatic cancer survival. Pathway analysis of the differential proteins identified suggested that MYC, IGF1R and p53 were the top three upstream regulators for the STS-associated proteins, and VEGFA, APOE and TGFß-1 were the top three upstream regulators for the VLTS-associated proteins. Immunohistochemistry analysis using an independent cohort of 145 PDAC confirmed that the higher abundance of ribosomal protein S8 (RPS8) and prolargin (PRELP) were correlated with STS and VLTS, respectively. Multivariate Cox analysis indicated that 'High-RPS8 and Low-PRELP' was significantly associated with shorter survival time (HR=2.69, 95% CI 1.46-4.92, P=0.001). In addition, galectin-1, a previously identified protein with its abundance aversely associated with pancreatic cancer survival, was further evaluated for its significance in cancer-associated fibroblasts. Knockdown of galectin-1 in pancreatic cancer-associated fibroblasts dramatically reduced cell migration and invasion. The results from our study suggested that PRELP, LGALS1 and RPS8 might be significant prognostic factors, and RPS8 and LGALS1 could be potential therapeutic targets to improve pancreatic cancer survival if further validated.

Quantitative glycoproteomics analysis reveals changes in N-glycosylation level associated with pancreatic ductal adenocarcinoma.

Glycosylation plays an important role in epithelial cancers, including pancreatic ductal adenocarcinoma. However, little is known about the glycoproteome of the human pancreas or its alterations associated with pancreatic tumorigenesis. Using quantitative glycoproteomics approach, we investigated protein N-glycosylation in pancreatic tumor tissue in comparison with normal pancreas and chronic pancreatitis tissue. The study lead to the discovery of a roster of glycoproteins with aberrant N-glycosylation level associated with pancreatic cancer, including mucin-5AC (MUC5AC), carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5), insulin-like growth factor binding protein (IGFBP3), and galectin-3-binding protein (LGALS3BP). Pathway analysis of cancer-associated aberrant glycoproteins revealed an emerging phenomenon that increased activity of N-glycosylation was implicated in several pancreatic cancer pathways, including TGF-ß, TNF, NF-kappa-B, and TFEB-related lysosomal changes. In addition, the study provided evidence that specific N-glycosylation sites within certain individual proteins can have significantly altered glycosylation occupancy in pancreatic cancer, reflecting the complexity of the molecular mechanisms underlying cancer-associated glycosylation events.

Statistical inference from multiple iTRAQ experiments without using common reference standards.

Isobaric tags for relative and absolute quantitation (iTRAQ) is a prominent mass spectrometry technology for protein identification and quantification that is capable of analyzing multiple samples in a single experiment. Frequently, iTRAQ experiments are carried out using an aliquot from a pool of all samples, or "masterpool", in one of the channels as a reference sample standard to estimate protein relative abundances in the biological samples and to combine abundance estimates from multiple experiments. In this manuscript, we show that using a masterpool is counterproductive. We obtain more precise estimates of protein relative abundance by using the available biological data instead of the masterpool and do not need to occupy a channel that could otherwise be used for another biological sample. In addition, we introduce a simple statistical method to associate proteomic data from multiple iTRAQ experiments with a numeric response and show that this approach is more powerful than the conventionally employed masterpool-based approach. We illustrate our methods using data from four replicate iTRAQ experiments on aliquots of the same pool of plasma samples and from a 406-sample project designed to identify plasma proteins that covary with nutrient concentrations in chronically undernourished children from South Asia.

Significance of expression of ITGA5 and its splice variants in acute myeloid leukemia: a report from the Children's Oncology Group.

Acute myeloid leukemia (AML) encompasses a heterogeneous group of diseases, and novel biomarkers for risk refinement and stratification are needed to optimize patient care. To identify novel risk factors, we performed transcriptome sequencing on 68 diagnostic AML samples and identified 2 transcript variants (-E2 and -E2/3) of the α-subunit (ITGA5) of the very late antigen-5 integrin. We then quantified expression of ITGA5 and these splice variants in specimens from participants of the AAML03P1 trial. We found no association between ITGA5 expression and clinical outcome. In contrast, patients with the highest relative expression (Q4) of the -E2/3 ITGA5 splice variant less likely had low-risk disease than Q1-3 patients (21% vs. 38%, P = 0.027). Q4 patients had worse response to chemotherapy with a higher proportion having persistent minimal residual disease (50% vs. 23%, P = 0.003) and inferior overall survival (at 5 years: 48% vs. 67%, P = 0.015); the latter association was limited to low-risk patients (Q4 vs. Q1-3: 56% vs. 85%, P = 0.043) and was not seen in standard-risk (51% vs. 60%, P = 0.340) or high-risk (33% vs. 38%, P = 0.952) patients. Our exploratory studies indicate that transcriptome sequencing is useful for biomarker discovery, as exemplified by the identification of ITGA5 -E2/3 splice variant as potential novel adverse prognostic marker for low-risk AML that, if confirmed, could serve to further risk-stratify this patient subset.

Metabolomic profiling of urine: response to a randomised, controlled feeding study of select fruits and vegetables, and application to an observational study.

Metabolomic profiles were used to characterise the effects of consuming a high-phytochemical diet compared with a diet devoid of fruits and vegetables (F&V) in a randomised trial and cross-sectional study. In the trial, 8 h fasting urine from healthy men (n 5) and women (n 5) was collected after a 2-week randomised, controlled trial of two diet periods: a diet rich in cruciferous vegetables, citrus and soya (F&V), and a fruit- and vegetable-free (basal) diet. Among the ions found to differentiate the diets, 176 were putatively annotated with compound identifications, with forty-six supported by MS/MS fragment evidence. Metabolites more abundant in the F&V diet included markers of the dietary intervention (e.g. crucifers, citrus and soya), fatty acids and niacin metabolites. Ions more abundant in the basal diet included riboflavin, several acylcarnitines and amino acid metabolites. In the cross-sectional study, we compared the participants based on the tertiles of crucifers, citrus and soya from 3 d food records (n 36) and FFQ (n 57); intake was separately divided into the tertiles of total fruit and vegetable intake for FFQ. As a group, ions individually differential between the experimental diets differentiated the observational study participants. However, only four ions were significant individually, differentiating the third v. first tertile of crucifer, citrus and soya intake based on 3 d food records. One of these ions was putatively annotated: proline betaine, a marker of citrus consumption. There were no ions significantly distinguishing tertiles by FFQ. The metabolomic assessment of controlled dietary interventions provides a more accurate and stronger characterisation of the diet than observational data.

The case for early detection.

Early detection represents one of the most promising approaches to reducing the growing cancer burden. It already has a key role in the management of cervical and breast cancer, and is likely to become more important in the control of colorectal, prostate and lung cancer. Early-detection research has recently been revitalized by the advent of novel molecular technologies that can identify cellular changes at the level of the genome or proteome, but how can we harness these new technologies to develop effective and practical screening tests?

Integrative analysis of N-linked human glycoproteomic data sets reveals PTPRF ectodomain as a novel plasma biomarker candidate for prostate cancer.

In an attempt to identify prostate cancer biomarkers with greater diagnostic and prognostic capabilities, we have developed an integrative proteomic discovery workflow focused on N-linked glycoproteins that refines the target selection process. In this work, hydrazide-based chemistry was used to identify N-linked glycopeptides from 22Rv1 prostate cancer cells cultured in vitro, which were compared with glycopeptides identified from explanted 22Rv1 murine tumor xenografts. One hundred and four human glycoproteins were identified in the former analysis and 75 in the latter, with 40 proteins overlapping between data sets. Of the 40 overlapping proteins, 80% have multiple literature references to the neoplastic process and ∼40% to prostatic neoplasms. These include a number of well-known prostate cancer-associated biomarkers, such as prostate-specific membrane antigen (PSMA). By integrating gene expression data and available literature, we identified members of the overlap data set that deserve consideration as potential prostate cancer biomarkers. Specifically, the identification of the extracellular domain of protein tyrosine phosphatase receptor type F (PTPRF) was of particular interest due to the direct involvement of PTPRF in the control of ß-catenin signaling, as well as dramatically elevated gene expression levels in the prostate compared to other tissues. In this investigation, we demonstrate that the PTPRF E-subunit is more abundant in human prostate tumor tissue compared to normal control and also detectable in murine plasma by immunoblot and ELISA. Specifically, PTPRF distinguishes between animals xenografted with the 22Rv1 cells and control animals as early as 14 days after implantation. This result suggests that the ectodomain of PTPRF has the potential to function as a novel plasma or tissue-based biomarker for prostate cancer. The workflow described adds to the literature of potential biomarker candidates for prostate cancer and demonstrates a pathway to developing new diagnostic assays.

Discovery and preliminary confirmation of novel early detection biomarkers for triple-negative breast cancer using preclinical plasma samples from the Women's Health Initiative observational study.

Triple-negative breast cancer is a particularly aggressive and lethal breast cancer subtype that is more likely to be interval-detected rather than screen-detected. The purpose of this study is to discover and initially validate novel early detection biomarkers for triple-negative breast cancer using preclinical samples. Plasma samples collected up to 17 months before diagnosis from 28 triple-negative cases and 28 matched controls from the Women's Health Initiative Observational Study were equally divided into a training set and a test set and interrogated by a customized antibody array. Data were available on 889 antibodies; in the training set, statistically significant differences in case versus control signals were observed for 93 (10.5 %) antibodies at p < 0.05. Of these 93 candidates, 29 were confirmed in the test set at p < 0.05. Areas under the curve for these candidates ranged from 0.58 to 0.79. With specificity set at 98 %, sensitivity ranged from 4 to 68 % with 20 candidates having a sensitivity ≥ 20 % and 6 having a sensitivity ≥ 40 %. In an analysis of KEGG gene sets, the pyrimidine metabolism gene set was upregulated in cases compared to controls (p = 0.004 in the testing set) and the JAK/Stat signaling pathway gene set was downregulated (p = 0.003 in the testing set). Numerous potential early detection biomarkers specific to triple-negative breast cancer in multiple pathways were identified. Further research is required to followup on promising candidates in larger sample sizes and to better understand their potential biologic importance as our understanding of the etiology of triple-negative breast cancer continues to grow.

Use of a single-chain antibody library for ovarian cancer biomarker discovery.

The discovery of novel early detection biomarkers of disease could offer one of the best approaches to decrease the morbidity and mortality of ovarian and other cancers. We report on the use of a single-chain variable fragment antibody library for screening ovarian serum to find novel biomarkers for the detection of cancer. We alternately panned the library with ovarian cancer and disease-free control sera to make a sublibrary of antibodies that bind proteins differentially expressed in cancer. This sublibrary was printed on antibody microarrays that were incubated with labeled serum from multiple sets of cancer patients and controls. The antibodies that performed best at discriminating disease status were selected, and their cognate antigens were identified using a functional protein microarray. Overexpression of some of these antigens was observed in cancer serum, tumor proximal fluid, and cancer tissue via dot blot and immunohistochemical staining. Thus, our use of recombinant antibody microarrays for unbiased discovery found targets for ovarian cancer detection in multiple sample sets, supporting their further study for disease diagnosis.

Investigating neoplastic progression of ulcerative colitis with label-free comparative proteomics.

Patients with extensive ulcerative colitis (UC) have an increased risk of colorectal cancer. Although UC patients generally undergo lifelong colonoscopic surveillance to detect dysplasia or cancer in the colon, detection of cancer in this manner is expensive and invasive. An objective biomarker of dysplasia would vastly improve the clinical management of cancer risk in UC patients. In the current study, accurate mass and time methods with ion intensity-based label-free proteomics are applied to profile individual rectal and colon samples from UC patients with dysplasia or cancer (UC progressors) compared to rectal samples from patients that are dysplasia/cancer free (UC nonprogressors) to identify a set of proteins in the rectum mucosa that differentiate the two groups. In addition to the identification of proteins in UC dysplastic colon tissue, we for the first time identified differentially expressed proteins in nondysplastic rectal tissue from UC progressors. This provides a candidate pool of biomarkers for dysplasia/cancer that could be detected in a random nondysplastic rectal biopsy. Mitochondrial proteins, cytoskeletal proteins, RAS superfamily, proteins relating to apoptosis and metabolism were important protein clusters differentially expressed in the nondysplastic and dysplastic tissues of UC progressors, suggesting their importance in the early stages of UC neoplastic progression. Among the differentially expressed proteins, immunohistochemistry analysis confirmed that TRAP1 displayed increased IHC staining in UC progressors, in both dysplastic and nondysplastic tissue, and CPS1 showed a statistically significant difference in IHC staining between the nonprogressor and progressor groups. Furthermore, rectal CPS1 staining could be used to predict dysplasia or cancer in the colon with 87% sensitivity and 45% specificity, demonstrating the feasibility of using surrogate biomarkers in rectal biopsies to predict dysplasia and/or cancer in the colon.

Protein alterations associated with pancreatic cancer and chronic pancreatitis found in human plasma using global quantitative proteomics profiling.

Pancreatic cancer is a lethal disease that is difficult to diagnose at early stages when curable treatments are effective. Biomarkers that can improve current pancreatic cancer detection would have great value in improving patient management and survival rate. A large scale quantitative proteomics study was performed to search for the plasma protein alterations associated with pancreatic cancer. The enormous complexity of the plasma proteome and the vast dynamic range of protein concentration therein present major challenges for quantitative global profiling of plasma. To address these challenges, multidimensional fractionation at both protein and peptide levels was applied to enhance the depth of proteomics analysis. Employing stringent criteria, more than 1300 proteins total were identified in plasma across 8-orders of magnitude in protein concentration. Differential proteins associated with pancreatic cancer were identified, and their relationship with the proteome of pancreatic tissue and pancreatic juice from our previous studies was discussed. A subgroup of differentially expressed proteins was selected for biomarker testing using an independent cohort of plasma and serum samples from well-diagnosed patients with pancreatic cancer, chronic pancreatitis, and nonpancreatic disease controls. Using ELISA methodology, the performance of each of these protein candidates was benchmarked against CA19-9, the current gold standard for a pancreatic cancer blood test. A composite marker of TIMP1 and ICAM1 demonstrate significantly better performance than CA19-9 in distinguishing pancreatic cancer from the nonpancreatic disease controls and chronic pancreatitis controls. In addition, protein AZGP1 was identified as a biomarker candidate for chronic pancreatitis. The discovery and technical challenges associated with plasma-based quantitative proteomics are discussed and may benefit the development of plasma proteomics technology in general. The protein candidates identified in this study provide a biomarker candidate pool for future investigations.

Brain-specific proteins decline in the cerebrospinal fluid of humans with Huntington disease.

We integrated five sets of proteomics data profiling the constituents of cerebrospinal fluid (CSF) derived from Huntington disease (HD)-affected and -unaffected individuals with genomics data profiling various human and mouse tissues, including the human HD brain. Based on an integrated analysis, we found that brain-specific proteins are 1.8 times more likely to be observed in CSF than in plasma, that brain-specific proteins tend to decrease in HD CSF compared with unaffected CSF, and that 81% of brain-specific proteins have quantitative changes concordant with transcriptional changes identified in different regions of HD brain. The proteins found to increase in HD CSF tend to be liver-associated. These protein changes are consistent with neurodegeneration, microgliosis, and astrocytosis known to occur in HD. We also discuss concordance between laboratories and find that ratios of individual proteins can vary greatly, but the overall trends with respect to brain or liver specificity were consistent. Concordance is highest between the two laboratories observing the largest numbers of proteins.

Elevated level of anterior gradient-2 in pancreatic juice from patients with pre-malignant pancreatic neoplasia.

BACKGROUND: Pancreatic intraepithelial neoplasias (PanINs) are precursors of malignant pancreatic cancer, an ideal stage for early cancer detection. We applied quantitative proteomics to identify aberrantly elevated proteins in pancreatic juice samples derived from patients with PanIN3. RESULTS: Twenty proteins were found elevated in all three PanIN juices by at least two-fold. Among these proteins, anterior gradient-2 (AGR2) was found to be 2-10 fold elevated in PanIN3 juice samples analyzed by quantitative proteomics. An ELISA assay was developed to evaluate AGR2 levels in 51 pancreatic juice samples and 23 serum samples from patients with pancreatic cancer, pre-malignant lesions (including PanIN3, PanIN2, Intraductal Papillary Mucinous Neoplasms (IPMNs)) and benign disease controls (including chronic pancreatitis). AGR2 levels in the pancreatic juice samples were found significantly elevated in patients with pre-malignant conditions (PanINs and IPMNs) as well as pancreatic cancer compared to control samples (p < or = 0.03). By ROC analysis, the AGR2 ELISA achieved 67% sensitivity at 90% specificity in predicting PanIN3 juice samples from the benign disease controls. CONCLUSIONS: These results suggest that elevation of AGR2 levels in pancreatic juice occurs in early pancreatic cancer progression and could be further investigated as a potential candidate juice biomarker for early detection of pancreatic cancer.

MRMer, an interactive open source and cross-platform system for data extraction and visualization of multiple reaction monitoring experiments.

Multiple reaction monitoring (MRM) mass spectrometry identifies and quantifies specific peptides in a complex mixture with very high sensitivity and speed and thus has promise for the high throughput screening of clinical samples for candidate biomarkers. We have developed an interactive software platform, called MRMer, for managing highly complex MRM-MS experiments, including quantitative analyses using heavy/light isotopic peptide pairs. MRMer parses and extracts information from MS files encoded in the platform-independent mzXML data format. It extracts and infers precursor-product ion transition pairings, computes integrated ion intensities, and permits rapid visual curation for analyses exceeding 1000 precursor-product pairs. Results can be easily output for quantitative comparison of consecutive runs. Additionally MRMer incorporates features that permit the quantitative analysis experiments including heavy and light isotopic peptide pairs. MRMer is open source and provided under the Apache 2.0 license.

An Intersectional Approach to HIV Vulnerabilities and Testing Among Heterosexual African Caribbean and Black Men in London, Ontario: Results From the weSpeak Study.

Heterosexual African, Caribbean and Black (ACB) men are a vulnerable group to HIV infection in Canada, but little is known about their uptake of HIV testing services. Studies on ACB men HIV vulnerabilities have largely focused on behavioural factors. While these studies have contributed to the current HIV prevention success in Canada, little attention has been paid to structural factors that intersect with prevailing behaviours to reinforce vulnerabilities. Drawing insights from intersectionality theory, we examined healthcare access and HIV testing among heterosexual ACB men in London, Ontario. We fitted the negative log-log link function to 155 individuals' survey. Results show that participants, who had difficulty accessing healthcare, experienced discrimination, and were young, were all less likely to test for HIV. Even though the probability of testing for HIV increased after accounting for the effect of structural factors, the marginal impact was higher for those without any difficulty accessing healthcare than those with difficulty. Findings are discussed within the broader theory of intersectionality and recommendations made for public health policy.

Influence of ovarian cancer risk status on the diagnostic performance of the serum biomarkers mesothelin, HE4, and CA125.

OBJECTIVE: To evaluate the effect of ovarian cancer risk on the performance of the serum biomarkers mesothelin, human epididymis protein 4 (HE4), and CA125. METHODS: We measured mesothelin, HE4, and CA125 levels from women with invasive ovarian cancer (n = 143), benign gynecologic conditions (n = 124), and controls (n = 344). Demographic, epidemiologic, reproductive, medical, and family history data were collected using a standardized questionnaire. Pedigree and BRCA 1/2 test results were used to stratify women into average and high-risk groups. The diagnostic accuracy of each biomarker was characterized using receiver operating characteristic curve methods. RESULTS: Baseline characteristics did not vary by risk or case status. The distribution of stage and histology was similar in average and high-risk women. All three markers discriminated ovarian cancer cases from risk-matched healthy and benign controls. Marker performance did not vary by risk status. The sensitivity at 95% specificity for discriminating cases from risk-matched healthy control women in the average and high-risk groups, respectively, was 53.9% and 39.0% for mesothelin, 80.4% and 87.8% for HE4, and 79.4% and 82.9% for CA125. The performance of the markers was not as robust when cases were compared with benign controls. Area under the curve values for cases versus healthy and benign controls did not vary by risk status. CONCLUSIONS: The ability of serum mesothelin, HE4, and CA 125 levels to discriminate ovarian cancer cases from healthy and benign controls is not influenced by risk status. Our findings support the pursuit of additional studies evaluating the early detection potential of these markers in high-risk populations.