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Background and AimsPatients with primary sclerosing cholangitis and inflammatory bowel disease [termed PSC-IBD] have a higher risk of developing colorectal neoplasia than those with IBD alone. The mechanism by which concomitant PSC increases the risk of colorectal neoplasia remains unknown. Seven distinct non-conventional dysplastic subtypes have been recently described in IBD, including crypt cell dysplasia, hypermucinous dysplasia, goblet cell-deficient dysplasia, dysplasia with increased Paneth cell differentiation [DPD], sessile serrated lesion [SSL]-like dysplasia, traditional serrated adenoma [TSA]-like dysplasia, and serrated dysplasia, not otherwise specified [NOS]. Despite the lack of high-grade morphological features, crypt cell, hypermucinous, and goblet cell-deficient dysplasias often show molecular features characteristic of advanced neoplasia [i.e. aneuploidy and KRAS mutations] and are more frequently associated with advanced neoplasia than conventional dysplasia on follow-up. We aimed to characterise clinicopathological features of dysplasia found in PSC-IBD patients.MethodsA cohort of 173 PSC-IBD patients were analysed. All dysplastic lesions were subtyped as either conventional or non-conventional dysplasia. The clinicopathological features of PSC-IBD patients with neoplasia were also compared with those of non-PSC IBD patients with neoplasia.ResultsThere were 109 [63%] men and 64 [37%] women, with a mean age of 26 years at IBD diagnosis and a long history of IBD [mean duration: 14 years]. Ulcerative colitis was the most common IBD subtype [80%], and the majority of patients [92%] had a history of pancolitis. A total of 153 dysplastic lesions were detected in 54 [31%] patients, 35 [65%] of whom had multifocal dysplasia. One additional patient presented with colorectal cancer [CRC] without a history of dysplasia. Dysplasia was often non-conventional [n = 93; 61%], endoscopically/grossly invisible [n = 101; 66%], and right/proximal-sided [n = 90; 59%]. All seven non-conventional subtypes were identified, including 46 [30%] crypt cell dysplasia, 23 [15%] hypermucinous dysplasia, 12 [8%] goblet cell-deficient dysplasia, seven [5%] DPD, three [2%] TSA-like dysplasia, one [1%] SSL-like dysplasia, and one [1%] serrated dysplasia NOS. Follow-up information was available for 86 lesions, of which 32 [37%] were associated with subsequent detection of advanced neoplasia [high-grade dysplasia or CRC] within a mean follow-up time of 55 months. PSC-IBD patients with neoplasia were more likely to have pancolitis [98%, p = 0.039] and a longer IBD duration [mean: 17 years, p = 0.021] than those without neoplasia [89% and 12 years, respectively]. When compared with a cohort of non-PSC IBD patients with neoplasia, the PSC-IBD group with neoplasia was more often associated with non-conventional [61%, p ConclusionsNearly a third of PSC-IBD patients developed dysplasia, which is often associated with non-conventional dysplastic features, invisible endoscopic/gross appearance, right/proximal-sided colon, multifocality, and advanced neoplasia on follow-up. These findings underscore the importance of recognising these non-conventional subtypes by practising pathologists and the need for careful and frequent endoscopic surveillance, with random biopsies, in PSC-IBD patients.

Most gastric cancers (GCs) are thought to develop via gastric intestinal metaplasia (GIM)-dysplasia-carcinoma pathway. Patients with extensive and/or incomplete GIM have been reported to have a higher risk of GC. GIM can also display dysplasia-like cytoarchitectural atypia limited to the bases of gastric pits without surface involvement. However, only a small proportion of GIM patients will develop gastric neoplasia, and it remains questionable if GIM is a direct precursor. A cohort of 82 GC patients with GIM who underwent gastrectomy were analyzed. DNA flow cytometry was performed on 109 GIM samples (including 88 predominantly complete GIM and 21 predominantly incomplete GIM subclassified based on morphology) obtained from adjacent mucosa of the 82 GCs. Only 2 (2%) of the 109 GIM samples demonstrated aneuploidy, both from 2 minority patients (Asian and Hispanic) with limited and complete GIM and no cytoarchitectural atypia. The remaining 107 GIM samples showed mild to focally moderate basal gland (metaplastic) atypia limited to the bases of gastric pits, but they all demonstrated normal DNA content regardless of anatomic location, histologic GIM subtype, or varying degrees of basal gland atypia. In conclusion, the vast majority of the GIM samples (98%) lack the aneuploidy that is characteristic of gastric dysplasia or cancer. This indicates that aneuploidy usually occurs after the development of gastric dysplasia rather than at the stage of GIM. The finding also suggests that the presence of GIM alone may not be sufficient to suggest an increased risk for GC and that the inclusion of other high-risk features (ie, extensive GIM, dysplasia, racial minorities, and/or family history of GC in a first-degree relative) and/or aneuploidy ought to play a role in the selection of GIM patients who may warrant endoscopic surveillance. Finally, GIM with mild to focally moderate basal gland atypia is likely to represent metaplastic atypia in most cases.

Endoscopic therapy is currently the standard of care for the treatment of high-grade dysplasia (HGD) or intramucosal adenocarcinoma (IMC) in patients with Barrett’s esophagus (BE). Visible lesions are treated with endoscopic mucosal resection (EMR), which is often coupled with radiofrequency ablation (RFA). However, endoscopic therapy may require multiple sessions (one session every 2-3 months) and does not always assure complete eradication of neoplasia. Furthermore, despite complete eradication, recurrences are not uncommon. This study assesses which potential risk factors can predict a poor response after endoscopic sessions. Forty-five BE patients who underwent at least one endoscopic session (EMR alone or ablation with or without preceding EMR) for the treatment of HGD/IMC, low-grade dysplasia (LGD), or indefinite for dysplasia (IND) were analyzed. DNA flow cytometry was performed on 82 formalin-fixed paraffin-embedded samples from the 45 patients, including 78 HGD/IMC, 2 LGD, and 2 IND. Eight non-dysplastic BE samples were used as controls. Three to four 60-micron thick sections were cut from each tissue block, and the area of HGD/IMC, LGD, or IND was manually dissected. Potential associations between clinicopathologic risk factors and persistent/recurrent HGD/IMC following each endoscopic session were examined using univariate and multivariate Cox models with frailty terms. Sixty (73%) of the 82 specimens showed abnormal DNA content (aneuploidy or elevated 4N fraction). These were all specimens with HGD/IMC (representing 77% of that group). Of these 60 HGD/IMC samples with abnormal DNA content, 42 (70%) were associated with subsequent development of persistent/recurrent HGD/IMC (n = 41) or esophageal adenocarcinoma (EAC; n = 1) within a mean follow-up time of 16 months (range: 1 month to 9.4 years). In contrast, only 6 (27%, all HGD/IMC) of the 22 remaining samples (all with normal DNA content) were associated with persistent/recurrent HGD/IMC. For outcome analysis per patient, 11 (24%) of the 45 patients developed persistent/recurrent HGD/IMC or EAC, despite multiple endoscopic sessions (mean: 3.6, range: 1–11). In a univariate Cox model, the presence of abnormal DNA content (hazard ratio [HR] = 3.8, p = 0.007), long BE segment ≥ 3 cm (HR = 3.4, p = 0.002), endoscopic nodularity (HR = 2.5, p = 0.042), and treatment with EMR alone (HR = 2.9, p = 0.006) were significantly associated with an increased risk for persistent/recurrent HGD/IMC or EAC. However, only abnormal DNA content (HR = 6.0, p = 0.003) and treatment with EMR alone (HR = 2.7, p = 0.047) remained as significant risk factors in a multivariate analysis. Age ≥ 60 years, gender, ethnicity, body mass index (BMI) ≥ 30 kg/m2, presence of hiatal hernia, and positive EMR lateral margin for neoplasia were not significant risk factors for persistent/recurrent HGD/IMC or EAC (p > 0.05). Three-month, 6-month, 1-year, 3-year, and 6-year adjusted probabilities of persistent/recurrent HGD/IMC or EAC in the setting of abnormal DNA content were 31%, 56%, 67%, 79%, and 83%, respectively. The corresponding probabilities in the setting of normal DNA content were 10%, 21%, 28%, 38%, and 43%, respectively. In conclusion, in BE patients with baseline HGD/IMC, both DNA content abnormality and treatment with EMR alone were significantly associated with persistent/recurrent HGD/IMC or EAC following each endoscopic session. DNA content abnormality as detected by DNA flow cytometry identifies HGD/IMC patients at highest risk for persistent/recurrent HGD/IMC or EAC, and it also serves as a diagnostic marker of HGD/IMC with an estimated sensitivity of 77%. The diagnosis of HGD/IMC in the setting of abnormal DNA content may warrant alternative treatment strategies as well as long-term follow-up with shorter surveillance intervals.

The purpose of this study was to evaluate the efficacy, health care utilization, and safety of a same-day discharge protocol.Catheter ablation of atrial fibrillation (AF) is the most common ablation performed. Increasing volumes of AF ablation are placing demands on hospital resources. In response, our institutions developed a same-day discharge protocol for AF ablation.This was a multicenter cohort study of all patients undergoing AF ablation from 2010 to 2014 at 2 major centers. The primary efficacy outcome was the proportion of successful same-day discharges. The primary health care utilization outcome was 30-day hospital readmission for any reason. The primary safety outcome was a composite of 30-day death, stroke/transient ischemic attack or embolism, or bleeding requiring hospitalization.A total of 3,054 patients underwent AF ablation from 2010 to 2014 and met inclusion criteria. Same-day discharge was achieved in 79.2% (2,418 of 3,054). Hospital readmission at 30 days was 7.7% for the same-day discharge group, 10.2% for those who remained in the hospital overnight without complications (p = 0.055 for comparison with same-day discharge), and 19.5% (p 0.001) for those who remained in the hospital with procedural complications (7.7%). Complication rates from discharge to 30 days (excluding immediate procedural complications) were 0.37% for the same-day discharge group, 0.36% (p = 0.999) for those kept overnight without complications, and 2.5% (p = 0.044) for those with initial procedural complications.Same-day discharge after AF ablation is feasible in the majority of patients with use of a standardized protocol. This approach was not associated with higher hospital readmission or complication rates after discharge.

Objective To assess effectiveness of intravitreous bevacizumab in a cohort of patients with neovascular age-related macular degeneration (nAMD) in British Columbia, Canada. Design Retrospective cohort study. Participants Patients with new-onset AMD who completed 1 year of bevacizumab treatment. Methods A cohort of 4507 patients with nAMD (5174 eyes) aged 50 years and older treated on an as-needed basis with bevacizumab was followed from June 1, 2010, to May 31, 2014, and then evaluated after completing a follow-up treatment at 1 year. Descriptive statistics were used to characterize eyes treated with bevacizumab. Multivariable regression models were used to quantify visual acuity (VA) changes over time, adjusting for baseline prognostic variables. Results On average, patients received 8.6 injections (SD 2.4) per eye during the year of treatment. There was an average gain of 5.2 letters over the 1-year study period. Among eyes treated with bevacizumab, improvement in VA was greater for eyes with poorer baseline VA and for eyes receiving more injections. The odds ratio for VA at 1 year was 9.35 (95% CI 6.00−14.6) for eyes with VA 20/50−20/80 versus 20/20−20/40 and increased to 74.5 (95% CI 47.7−116.4) for eyes 20/400 or worse versus 20/20−20/40. Conclusion Intravitreous bevacizumab is effective in treating nAMD, especially for eyes with poor baseline VA. Gains in VA were greatest by month 3 and were generally maintained thereafter.

We examined the impact of crystal methamphetamine injection on HIV RNA suppression among a prospective cohort of HIV-positive injection drug users initiating antiretroviral therapy. A multivariate Cox regression analysis found crystal methamphetamine injection to be negatively associated with viral load suppression (RH = 0.63 [95% CI: 0.40 – 0.98]; p = 0.039). This study is the first to our knowledge to demonstrate an association between crystal methamphetamine use and HIV RNA suppression.

ObjectivesThis study sought to compare the 1-year survival of patients diagnosed with ST-segment elevation myocardial infarction (STEMI) and transferred via pre-hospital triage strategy for primary percutaneous coronary intervention (PCI) with those transferred via inter-hospital transfer within a large suburban region in Canada.BackgroundPrimary angioplasty is the preferred therapy for STEMI if it is done within 90 min of door-to-balloon time by an experienced team in a high-volume center.MethodsPatients identified to have STEMI on the ambulances equipped with electrocardiography bypassed the local hospitals and were sent directly to the PCI center, whereas other patients that were picked up by ambulances without electrocardiographic equipment were transported to the local hospitals where the diagnosis of STEMI was made and were re-routed to the PCI center. Patient demographic data, clinical presentation, procedural data, in-hospital course, and vital statistics were prospectively recorded in a provincial cardiac registry.ResultsA total of 167 patients were brought into the PCI center via pre-hospital triage strategy, and 427 patients were brought in via inter-hospital transfer during a 2-year study period. Baseline demographic data, infarct location, cardiovascular history, and hemodynamic status were similar between the 2 groups. When compared with the inter-hospital transfer group, a significantly higher proportion of pre-hospital triaged patients achieved the 90-min door-to-balloon time benchmark (80.4% vs. 8.7%, p < 0.001) and post-procedural Thrombolysis In Myocardial Infarction flow grade 3 after the emergency procedure (97.6% vs. 91.4%, p = 0.02). In addition, the pre-hospital triage strategy was associated with a significantly lower 30-day (5.4% vs. 13.3%, p = 0.006) and 1-year (6.6% vs. 17.5%, p = 0.019) mortality. Pre-hospital triage was an independent predictor for survival at 1 year (hazard ratio: 0.37, 95% confidence interval: 0.18 to 0.75, p = 0.006).ConclusionsPre-hospital triage strategy was associated with improved survival rate in patients undergoing primary PCI in a regional STEMI program.

Background Human immunodeficiency virus (HIV)-positive injection drug users (IDUs) are known to be at risk for multiple medical problems that may necessitate emergency department (ED) use; however, the relative contribution of HIV disease vs. injection-related complications has not been well described. Objectives We examined factors associated with ED use among a prospective cohort of HIV-positive IDUs in a Canadian setting. Methods We enrolled HIV-positive IDUs into a community-recruited prospective cohort study. We modeled factors associated with the time to first ED visit using Cox regression to determine factors independently associated with ED use. In sub-analyses, we examined ED diagnoses and subsequent hospital admission rates. Results Between December 5, 2005 and April 30, 2008, 428 HIV-positive IDUs were enrolled, among whom the cumulative incidence of ED use was 63.7% (95% confidence interval [CI] 59.1–68.3%) at 12 months after enrollment. Factors independently associated with time to first ED visit included: unstable housing (hazard ratio [HR] 1.5; 95% CI 1.1–2.0) and reporting being unable to obtain needed health care services (HR 2.2; 95% CI 1.2–4.1), whereas CD4 count and viral load were non-significant. Skin and soft tissue infections accounted for the greatest proportion of ED visits (17%). Of the 2461 visits to the ED, 419 (17%) were admitted to the hospital. Conclusions High rates of ED use were observed among HIV-positive IDUs, a behavior that was predicted by unstable housing and limited access to primary care. Factors other than HIV infection seem to be driving ED use among this population in the post-highly active antiretroviral therapy era.

Objectives Adherence to antiretroviral therapy (ART) among injecting drug users (IDUs) is often suboptimal, yet little is known about changes in patterns of adherence since the advent of highly active antiretroviral therapy in 1996. We sought to assess levels of optimal adherence to ART among IDUs in a setting of free and universal HIV care. Methods Data were collected through a prospective cohort study of HIV-positive IDUs in Vancouver, British Columbia. We calculated the proportion of individuals achieving at least 95% adherence in the year following initiation of ART from 1996 to 2009. Results Among 682 individuals who initiated ART, the median age was 37 years (interquartile range 31–44 years) and 248 participants (36.4%) were female. The proportion achieving at least 95% adherence increased over time, from 19.3% in 1996 to 65.9% in 2009 (Cochrane–Armitage test for trend: P

Previous studies of adherence to antiretroviral therapy (ART) for HIV among young injection drug users (IDU) have been limited because financial barriers to care disproportionately affect youth, thus confounding results. This study examines adherence among IDU in a unique setting where all medical care is provided free-of-charge. From May 1996 to April 2008, we followed a prospective cohort of 545 HIV-positive IDU of 18 years of age or older in Vancouver, Canada. Using generalized estimating equations (GEE), we studied the association between age and adherence (obtaining ART≥95% of the prescribed time), controlling for potential confounders. Using Cox proportional hazards regression, we also studied the effect of age on time to viral load suppression (

Background Crack cocaine pipe sharing is associated with various health-related harms, including hepatitis C transmission. Although difficulty accessing crack pipes has been found to predict pipe sharing, little is known about the factors that limit pipe access in settings where pipes are provided at no cost, albeit in limited capacity. Therefore, we investigated crack pipe access among people who use drugs in Vancouver, Canada.

Introduction: Cutaneous injection-related infections (CIRI) are a primary reason injection drug users (IDU) access the emergency department (ED). Methodology: Using Cox proportional hazard regression, we examined predictors of ED use for CIRI, stratified by sex, among 1083 supervised injection facility (SIF) users. Results: Over a four-year period, 289 (27%) visited the ED for CIRI, yielding an incidence density for females of 23.8 (95% confidence interval (CI): 19.3 - 29.0) and males of 19.2 per 100 person-years (95% CI: 16.7 - 22.1). Factors associated with ED use for CIRI among females included residing in the Downtown Eastside (DTES) (adjusted hazard ratio (AHR) = 2.06 (1.13 - 3.78)) and being referred to hospital by SIF nurses (AHR = 4.48 (2.76 - 7.30)). Among males, requiring assistance with injection (AHR = 1.38 (1.01 - 1.90)), being HIV-positive (AHR = 1.85 (1.34 - 2.55)), and being referred to hospital by SIF nurses (AHR = 2.97 (1.93 - 4.57)) were associated with an increased likelihood of an ED visit for CIRI. Conclusion: These results suggest SIF nurses have facilitated referral of hospital treatment for CIRI, highlighting the need for continued development of efficient and collaborative efforts to reduce the burden of CIRI.

Purpose Because of growing concerns regarding the heightened vulnerabilities and risk of human immunodeficiency virus infection among youth who exchange sex for survival, we investigated individual risk patterns and structural barriers among young (≤24 years) female sex workers (FSWs) in Vancouver, Canada. Methods Between 2005 and 2008, a total of 255 street-based FSWs (≥14 years) were enrolled into a community-based prospective cohort, and were asked to participate in baseline and biannual questionnaires administered through interviews and human immunodeficiency virus screening. We used contingency table analysis to compare individual and structural barrier results obtained at baseline for younger (≤24 years) FSWs with those of the older (>25 years) FSWs. For longitudinal data, we used generalized estimating equations throughout the follow-up period to determine factors associated with being a young FSW in the past 6 months. Results In comparison with older FSWs (n = 199), youth (n = 56) were more likely to spend fewer years engaging in sex exchange (median: 6.4 [interquartile range: 4.6–9.1] vs. 19.9 [interquartile range: 10.0–26.8]; p ≤ .001), belong to an aboriginal ancestry (59% vs. 44%; p = .052), and be homeless (68% vs. 36%; p ≤ .001). In the multivariate generalized estimating equations analysis, youth reported a significantly elevated proportional odds of being homeless (odds ratio [OR]: 1.26 [confidence interval {CI}: 1.08–1.48]), servicing clients in public places (OR: 1.28 [CI: 1.04–1.57]), injecting heroin on a daily basis (OR: 1.35 [CI: 1.06–1.74]), and a significantly reduced odds of accessing methadone maintenance therapy (OR: .76 [CI: .62–.93]). Conclusions This study demonstrates significant displacement of youth who engage in sex exchange to marginalized working and living spaces. The findings of this study bring to attention the critical need for targeted structural interventions including access to youth and gender-specific social housing, safe working spaces, reduction in the amount of harm caused to them, and addiction treatment services for youth engaged in survival sex work.

While the community impacts of drug-related street disorder have been well described, lesser attention has been given to the potential health and social implications of drug scene exposure on street-involved people who use illicit drugs. Therefore, we sought to assess the impacts of exposure to a street-based drug scene among injection drug users (IDU) in a Canadian setting. Data were derived from a prospective cohort study known as the Vancouver Injection Drug Users Study. Four categories of drug scene exposure were defined based on the numbers of hours spent on the street each day. Three generalized estimating equation (GEE) logistic regression models were constructed to identify factors associated with varying levels of drug scene exposure (2–6, 6–15, over 15 hours) during the period of December 2005 to March 2009. Among our sample of 1,486 IDU, at baseline, a total of 314 (21%) fit the criteria for high drug scene exposure (>15 hours per day). In multivariate GEE analysis, factors significantly and independently associated with high exposure included: unstable housing (adjusted odds ratio [AOR] = 9.50; 95% confidence interval [CI], 6.36–14.20); daily crack use (AOR = 2.70; 95% CI, 2.07–3.52); encounters with police (AOR = 2.11; 95% CI, 1.62–2.75); and being a victim of violence (AOR = 1.49; 95 % CI, 1.14–1.95). Regular employment (AOR = 0.50; 95% CI, 0.38–0.65), and engagement with addiction treatment (AOR = 0.58; 95% CI, 0.45–0.75) were negatively associated with high exposure. Our findings indicate that drug scene exposure is associated with markers of vulnerability and higher intensity addiction. Intensity of drug scene exposure was associated with indicators of vulnerability to harm in a dose-dependent fashion. These findings highlight opportunities for policy interventions to address exposure to street disorder in the areas of employment, housing, and addiction treatment.

Homelessness is prevalent among HIV-infected injection drug users (IDU) and may adversely affect access and adherence to antiretroviral therapy (ART). There are limited descriptions of the effect of homelessness on adherence to ART in long-term cohorts of HIV-infected IDU. We used data from a community-recruited prospective cohort of HIV-infected IDU, including comprehensive ART dispensation records, in a setting where HIV care is free. We examined the relationship between the homelessness measured longitudinally, and the odds of ≥95% adherence to ART using generalized estimating equations logistic regression modeling adjusting for sociodemographics, drug use, and clinical variables. Between May 1996 and September 2008, 545 HIV-infected IDU were recruited and eligible for the present study. The median follow-up duration was 23.8 months (IQR 8.5–91.6 months) contributing 2,197 person-years of follow-up. At baseline, homeless participants were slightly younger (35.8 vs. 37.9 years, p = 0.01) and more likely to inject heroin at least daily (37.1% vs. 24.6%. p = 0.004) than participants who had housing. The multivariate model revealed that homelessness (adjusted odds ratio [AOR] 0.66; 95% CI: 0.53–0.84) and frequent heroin use (AOR 0.40; 95% CI: 0.30–0.53) were significantly and negatively associated with ART adherence, whereas methadone maintenance was positively associated (AOR 2.33; 95% CI: 1.86–2.92). Sub-optimal ART adherence was associated with homelessness and daily injection heroin use among HIV-infected IDU. Given the survival benefit of ART, it is critical to develop and evaluate innovative strategies such as supportive housing and methadone maintenance to address these risk factors to improve adherence.

When optimizing cell culture media for therapeutic antibody production cell lines, it is very important to monitor parameters such as IgG concentration, glucose and lactate levels, and oxygen consumption in culture medium in an automated high-throughput manner to ensure the desirable growth conditions. In this report, assays for measuring human IgG, glucose, and lactate concentrations, and oxygen consumption were automated using the Biomek NXP Span-8 workstation, and analyzed on the PARADIGM Detection Platform. The human-IgG homogeneous time-resolved fluorescence (HTRF) (All trademarks are the property of their respective owners.) assay from Cisbio Inc. (Cisbio US, Bedford, MA) was automated in a 384-well plate format and detected on the PARADIGM with a HTRF Detection Cartridge. Glucose and lactate assays were automated in a 96-well plate format and detected on the PARADIGM with a Fluorescence Intensity Cartridge. Oxygen consumption was determined by the 96-well calibration-free OxoPlate (All trademarks are the property of their respective owners.) (PreSens Inc., PreSens - Precision Sensing GmbH, Regensburg, Germany) and detected by the PARADIGM with a MultiMode Detection Cartridge. The data for human IgG, glucose, lactate, and oxygen consumption assays automated on the Biomek NXP demonstrate the accuracy and precision obtained using the automated protocols on the PARADIGM Detection Platform, with the user-friendly and assay-specific cartridges for easy, quick, and accurate detection. Using this as a model, one would be able to adapt these approaches to high-throughput media optimization and cell monitoring.

Drug users engaged in survival sex work are at heightened risk for drug- and sexual-related harms. We examined factors associated with survival sex work among street-involved youth in Vancouver, Canada.From September 2005 to November 2007, baseline data were collected for the At-Risk Youth Study (ARYS), a prospective cohort of street-recruited youth aged 14-26 who use illicit drugs. Using multiple logistic regression, we compared youth who reported exchanging sex for money, drugs etc. with those who did not.The sample included 560 youth: median age 22; 179 (32%) female; 63 (11%) reporting recent survival sex work. Factors associated with survival sex work in multivariate analyses included non-injection crack use [adjusted odds ratio (AOR) = 3.45, 95% confidence interval (CI): 1.75-6.78], female gender (AOR = 3.02, 95% CI: 1.66-5.46), Aboriginal ethnicity (AOR = 2.35, 95% CI: 1.28-4.29) and crystal methamphetamine use (AOR = 2.02, 95% CI: 1.13-3.62). In subanalyses, the co-use of crack cocaine and methamphetamine was shown to be driving the association between methamphetamine and survival sex work.This study demonstrates a positive interactive effect of dual stimulant use in elevating the odds of survival sex work among street youth who use drugs. Novel approaches to reduce the harms associated with survival sex work among street youth who use stimulants are needed.

Introduction and Aims. Thailand's longstanding HIV epidemic among injection drug users (IDU) has been attributed, in part, to the Thai government's unwillingness to implement evidence-based HIV prevention interven- tions.This study was undertaken to examine risk factors for syringe borrowing among a community-recruited sample ofThai IDU.Design and Methods.We examined the prevalence of syringe borrowing among 238 IDU participating in the Mit Sampan Community Research Project, Bangkok. Multivariate logistic regression was used to identify independent predictors of syringe borrowing in the past 6 months. Results. A total of 238 IDU participated in this study; 66 (26.2%) were female, and the median age was 36.5 years. In total, 72 (30.3%) participants reported borrowing a used syringe in the past 6 months, with 47 (65.3%) of these individuals reporting multiple borrowing events. In multivariate analyses, syringe borrowing was positively associated with difficulty accessing syringes (adjusted odds ratio (AOR) = 2.46; 95% confidence interval (CI): 1.08-5.60) and injecting with other people on a frequent basis (AOR = 3.17; 95% CI: 1.73-5.83). Primary reasons offered for experiencing difficulty accessing syringes included being too far from syringe outlets (34.1%), pharmacies being closed (13.6%) and being refused syringes at pharmacies (9.1%). Discussion and Conclusions. We observed an alarmingly high rate of syringe borrowing among a community-recruited sample ofThai IDU.Various lines of evidence indicate that poor access to sterile syringes is driving the high rate of syringe borrowing observed in this study. Immediate action should be taken to increase access to sterile syringes amongThai IDU. (KerrT, Fairbairn N, Hayashi K, Suwannawong P, Kaplan K, Zhang R, Wood E. Difficulty accessing syringes and syringe borrowing among injection drug users in Bangkok, Thailand. Drug Alcohol Rev 2010;29;157-161)

Purpose To evaluate the factors associated with receiving cutaneous injection-related infection (CIRI) care among a representative cohort of supervised injecting facility (SIF) users. Methods Data were collected biannually as part of a prospective cohort, the Scientific Evaluation of Supervised Injection study. Kaplan-Meier methods and Cox proportional hazards regression with recurrent events were used to examine incidence and factors associated with CIRI care, respectively. Results One thousand eighty individuals were recruited between December 1, 2003 and January 31, 2008. The incidence density of participants receiving CIRI care was 22.0 per 100 person-years (95% confidence interval [CI]: 19.6–24.6). In the adjusted Cox proportional hazard model, female sex (adjusted hazard ratio [AHR] = 1.87 [95% CI: 1.32–2.64]), unstable housing (AHR = 1.39 [95% CI: 1.02–1.88]), and daily heroin injection (AHR = 1.52 [95% CI: 1.13–2.04]) were independently associated with receiving CIRI care at the SIF. Conclusions These results describe who is more likely to receive CIRI care, which is of use to those engaged with policy and practice of treatment regimens involving this population.

Objectives: Although supervised injecting facility (SIF) use has been associated with reductions in injection-related risk behaviours, the impact of SIFs on the sexual behaviour of injection drug users (IDUs) has not been thoroughly investigated. Therefore, we examined the patterns and predictors of condom use among SIF users in Vancouver, Canada. Methods: We performed a longitudinal analysis of the factors associated with consistent condom use among IDUs recruited from within a SIF. Results: Among 1090 individuals, 650 (59.6%) reported a sexual partner in the past 6 months at baseline. Consistent condom use was reported by 108 (25.3%) and 205 (61.6%) individuals reporting regular or casual partners, respectively. After 2 years of observation, these proportions increased to 32.9% and 69.8%, respectively. In multivariate analysis, predictors of consistent condom use with regular partners included HIV positivity (adjusted odds ratio (AOR) 2.23; 95% CI 1.51 to 3.31), injecting with a sex partner (AOR 0.50; 95% CI 0.37 to 0.68), enrollment in addiction treatment (AOR 0.68, 95% CI 0.52 to 0.89) and time since recruitment (AOR 1.29; 95% CI 1.06 to 1.55 per year). Predictors of consistent condom use with casual partners included HIV positivity (AOR 1.70; 95% CI 1.03 to 2.81), syringe borrowing (AOR 0.54; 95% CI 0.32 to 0.91) and syringe lending (AOR 0.52; 95% CI 0.32 to 0.84). Conclusions: Our results demonstrate that among SIF users, consistent condom use was more frequent among casual sex partners and among HIV positive individuals. Importantly, while the prevalence of consistent condom use was low at baseline, it increased over time. Our findings suggest a possible beneficial effect of the SIF on safer sexual practices.

Despite the widely noted increase in crystal methamphetamine (CM) use, there are few studies on circumstances of first CM use or correlates of use among high-risk populations (e.g. street-involved youth).Street-involved youth in Vancouver, Canada, were enrolled in the At-Risk Youth Study (ARYS) prospective cohort. Extensive outreach produced a representative sample of Vancouver street youth who use illicit drugs. We examined circumstances of first CM use and factors associated with CM use among the cohort.Among 478 participants, 339 (70.9%) had used CM previously. Despite intensive covariate adjustment, a history of CM use was associated independently with having initiated injection drug use [OR = 3.15 (95% CI: 1.89-5.2); p0.001]. Among those who had used CM, route of first administration included: 11 (3.2%) oral ingestion; 25 (7.4%) injected; 105 (31.0%) snorted; 231 (68.1%) smoked. The proportion of respondents reporting current CM injection was significantly greater than the proportion reporting injection as the route for first CM use (18.3% vs. 7.4%; McNemar's test p0.001). Ability to obtain CM the first time was reported as 'very easy' or 'easy' by 93.5% and 5.3% of participants, respectively.Crystal methamphetamine use was independently associated with injection drug use, and significant increases in injecting as the primary mode of administration were observed when patterns of use were considered longitudinally. The easy accessibility of CM and its common use during transition into injection drug use demonstrate the need for innovative drug policy to address this growing concern.

Objectives. We sought to examine whether there were differential rates of HIV incidence among Aboriginal and non-Aboriginal injection drug users in a Canadian setting. Methods. Data were derived from 2 prospective cohort studies of injection drug users in Vancouver, British Columbia. Using the Kaplan–Meier method and Cox proportional hazards regression, we compared HIV incidence among Aboriginal and non-Aboriginal participants. Results. Overall, 2496 individuals were recruited between May 1996 and December 2005. Compared with that of non-Aboriginal persons, the baseline HIV prevalence was higher among Aboriginal persons (16.0% vs 25.1%; P Conclusions. Aboriginal persons in Vancouver had a significantly elevated burden of HIV infection, which calls for a culturally sensitive and evidence-based response. Policymakers in other settings with at-risk Aboriginal populations should seek to avert similar public health emergencies by being proactive with evidence-based HIV-prevention programs.

Non-fatal overdose among injection drug users (IDU) is a source of significant morbidity. Since it has been suggested that supervised injecting facilities (SIF) may increase risk for overdose, we sought to evaluate patterns of non-fatal overdose among a cohort of SIF users. We examined recent non-fatal overdose experiences among participants enrolled in a prospective study of IDU recruited from within North America's first medically supervised safer injecting facility. Correlates of recent non-fatal overdoses were identified using generalized estimating equations (GEE). There were 1,090 individuals recruited during the study period of which 317 (29.08%) were female. At baseline, 638 (58.53%) reported a history of non-fatal overdose and 97 (8.90%) reported at least one non-fatal overdose in the last six months. This proportion remained approximately constant throughout the study period. In the multivariate GEE analysis, factors associated with recent non-fatal overdose included: sex-trade involvement (Adjusted Odds Ratio [AOR]: 1.45 [95% Confidence Interval [CI] 1.07-1.99], p = 0.02) and public drug use (AOR: 1.50 [95% CI 1.09-2.06]; p = 0.01). Using the SIF foror= 75% of injections was not associated with recent non-fatal overdose in univariate (Odds Ratio: 1.05, p = 0.73) or multivariate analyses (AOR: 1.01, p = 0.96). The proportion of individuals reporting recent non-fatal overdose did not change over the study period. Our findings indicate that a sub-population of IDU might benefit from overdose prevention interventions. Our findings refute the suggestion that the SIF may increase the likelihood of overdose.

Syringe sharing continues to play an integral part in HIV epidemics involving injection drug users around the world. We examined the prevalence of syringe sharing among Canadian street youth enrolled in a prospective cohort study known as the At-Risk Youth Study (ARYS), and used logistic regression to examine factors associated with syringe sharing. Among 509 participants, 154 (30%) had injected drugs in the last 6 months and of those 44 (29%) injectors had shared a syringe in the previous 6 months. In logistic regression, being female (adjusted odds ratio [AOR] = 2.31, [95%CI: 1.01–5.28]), binge drug use (AOR = 2.11 [95%CI: 0.99–4.51]) and injection cocaine use (AOR = 2.43 [95%CI: 1.05–5.60]) remained associated with syringe sharing. These data indicate that, in order to reduce the potential for an explosive HIV epidemic among this population, further interventions are urgently needed to address the high level of syringe sharing among street-involved youth.

Barrett esophagus is presently defined in the United States by the presence of intestinal metaplasia in columnar-lined esophagus based on the premise that the risk for adenocarcinoma depends on the presence of intestinal metaplasia. Recently, arguments have been made that nonintestinalized cardiac epithelium is also at risk and should be included in the definition of Barrett esophagus, as it is in England and Japan. One of these arguments is that residual intestinal metaplasia is frequently absent around early adenocarcinomas removed by endoscopic mucosal resection (EMR). We reviewed 27 EMRs performed in 21 patients. Residual intestinal metaplasia was absent in 10/27 (37%) EMR specimens. An in-depth study of these 10 cases showed that 3 had intestinal metaplasia in a concurrent second EMR specimen, 4 had intestinal metaplasia in prior biopsy material available in our unit, and 2 had intestinal metaplasia in an esophagectomy that followed the EMR. The single patient in whom no intestinal metaplasia was found, neither in biopsies nor in EMR, and who did not undergo an esophagectomy had been under surveillance for Barrett esophagus for over 20 years. We conclude that the frequent absence of residual intestinal metaplasia around an adenocarcinoma in an EMR specimen is the result of sampling error. When evaluated in depth by looking at history, biopsies preceding the EMR, and esophagectomy following the EMR, all of these patients with adenocarcinoma had intestinal metaplasia in their columnar-lined esophagus. This indicates that intestinal metaplasia is a necessary precursor to adenocarcinoma of the esophagus.

Although research has examined the impacts of childhood maltreatment among various marginalized populations, few studies have explored the relationship between child abuse and subsequent involvement in sex work among drug-using street-involved youth. In the present study, the relationships between the level of childhood maltreatment and involvement in sex work were examined using the Childhood Trauma Questionnaire (CTQ) as part of an extensive interview protocol in an ongoing prospective cohort study of street-involved youth in Vancouver, Canada. Between September 2005 and June 2006, 361 youth were recruited using extensive outreach methods and snowball sampling. The prevalence rates for abuse in the sample were 73% for physical abuse; 32.4% for sexual abuse; 86.8% for emotional abuse; 84.5% for physical neglect; and 93% for emotional neglect. Univariate and logistic regression analyses demonstrated that not only was sexual abuse independently associated with sex work, but emotional abuse was as well. These findings have implications for early intervention efforts aimed at vulnerable, high-risk youth populations as well as intervention strategies for active sex trade workers.

A method to functionalize single-walled carbon nanotubes (SWNTs) in a field-effect transistor (FET) device for the selective detection of heavy-metal ions is presented. In this method, peptide-modified polymers were electrochemically deposited onto SWNTs and the selective detection of metal ions was demonstrated by choosing appropriate peptide sequences. The signal transduction mechanism of the peptide-modified SWNT-FETs has also been studied.

We report an application of nanoarea electron diffraction for structure determination of double-wall carbon nanotubes (DWNT) grown by catalytic chemical vapor deposition. The structures of 30 tubes were determined from experimental diffraction patterns. Among these tubes, the inner and outer wall structure of 18 tubes was precisely determined by comparison with kinematic electron diffraction simulations. For the structure of the DWNTs, our experiment revealed a mixture of semiconducting-metallic (S-M), S-S and M-M tubes. The spacing between the two walls ranges from 0.335 nm to 0.384 nm. Most DWNTs are incommensurate and chiral.

Background North America's first government sanctioned supervised injection facility (SIF) was opened in Vancouver in response to the serious health and social consequences of injection drug use and the perseverance of committed advocates and drug user groups who demanded change. This analysis was conducted to describe the attendance, demographic characteristics, drug use patterns, and referrals made during the first 18 months of operation. Methods As part of the evaluation strategy for the SIF, information is collected through a comprehensive on-site database designed to track attendance and the daily activities within the facility. All users of the SIF must sign a waiver form and are then entered into a database using a unique identifier of their choice. This identifier is used at each subsequent visit to provide a prospective record of attendance, drug use, and interventions. Results From 10 March 2004 to 30 April 2005 inclusive, there were 4764 unique individuals who registered at the SIF. The facility successfully attracted a range of community injection drug users including women (23%) and members of the Aboriginal community (18%). Although heroin was used in 46% of all injections, cocaine was injected 37% of the time. There were 273 witnessed overdoses with no fatalities. During just 12 months of observation, 2171 individual referrals were made with the majority (37%) being referred for addiction counseling. Interpretation Vancouver's SIF has successfully been integrated into the community, has attracted a wide cross section of community injection drug users, has intervened in overdoses, and initiated over 2000 referrals to counseling and other support services. These findings should be useful for other settings considering SIF trials.

In 2003, the city of Vancouver, British Columbia, opened North America’s first government-sanctioned safer injecting facility, where injection drug users (IDUs) can inject preobtained illicit drugs under the supervision of nurses. Use of the service by IDUs was followed by measurable reductions in public drug use and syringe sharing. IDUs who are frequently using the program tend to be high-intensity cocaine and heroin injectors and homeless individuals. The facility has provided high-risk IDUs a hygienic space where syringe sharing can be eliminated and the risk of fatal overdose reduced. Ongoing evaluation will be required to assess its impact on overdose rates and HIV infection levels, as well as its ability to improve IDU contact with medical care and addiction treatment

The contrast mechanism for scanning electron microscopy images of single-walled carbon nanotubes (SWNTs) is studied for samples on various substrates using low voltage scanning electron microscopy (LVSEM). We show that the contrast of SWNT images is greatly affected by a charging effect, where the brightness strongly depends on the supply of charges available to the SWNTs and the charging characteristics of the substrate. We demonstrate that the charging effect in LVSEM can be utilized to obtain images of various SWNT device structures to provide rapid feedback for the device fabrication process.

Background: Requiring help injecting has recently been independently associated with syringe sharing and HIV incidence among injection drug users (IDUs) in Vancouver. We examined IDUs who were receiving safer injecting education within a supervised injecting facility (SIF) in Vancouver. Methods: The Scientific Evaluation of Supervised Injecting (SEOSI) cohort is based on a representative sample of SIF users. We examined the prevalence and correlates of receiving safer injecting education within the SIF using univariate and logistic regression analyses. Results: Between May 31, 2003 and Oct 22, 2004, 874 individuals of the SEOSI cohort have completed the baseline questionnaire, among whom 293 (33.5%) received safer injecting education. In multivariate analyses, requiring help with an injection in the last 6 months (OR=2.20 [95% CI: 1.62–2.98]) and sex-trade involvement in the last 6 months (OR=1.54 [1.09–2.16]) were independently associated with receiving safer injecting education within the SIF. Conclusions: Since requiring help injecting has previously been associated with HIV incidence, it is encouraging that this risk factor was associated with receiving safer injecting education within the SIF. Nevertheless, prospective evaluation is necessary to examine if receiving safer injecting education is associated with reduced HIV risk behaviour and blood-borne disease incidence.

Vancouver, Canada recently opened a medically supervised safer injecting facility (SIF) in an effort to reduce HIV and overdose risk and public injection drug use. We sought to examine factors associated with syringe sharing among SIF users. SIF users were randomly recruited into a prospective cohort of SIF users known as the Scientific Evaluation of Supervised Injecting (SEOSI) cohort. We examined the prevalence and correlates of used syringe borrowing among baseline HIV-negative participants and used syringe lending among baseline HIV-infected participants. Between 22 March 2004 and 22 October 2004, 479 baseline HIV-negative subjects (48 [10%] syringe borrowing events) and 103 baseline HIV-infected participants (17 [16.5%] syringe lending events) were recruited into the cohort. For baseline HIV negative participants, syringe borrowing was positively associated with public drug use (p

There is a vast amount of valuable information in HTML documents, widely distributed across the World Wide Web and across corporate intranets. Unfortunately, HTML is mainly presentation oriented and hard to query. In this paper, we develop a system to extract desired information (records) from thousands of HTML documents, starting from a small set of examples. Duplicates in the result are automatically detected and eliminated. We propose a novel method to estimate the current coverage of results by the system, based on capture-recapture models with unequal capture probabilities. We also propose techniques for estimating the error rate of the extracted information and an interactive the technique for enhancing information quality. To evaluate the method and ideas proposed in this paper, we conducted an extensive set of experiments. Our experimental results validate the effectiveness and utility of our system, and demonstrate interesting tradeoffs between running time of information extraction and coverage of results.

Growth of single-walled carbon nanotubes (SWNTs) via a chemical vapor deposition technique catalyzed by a thin Al/Ni stack is presented. Catalyst islands are defined by lithography, thin film evaporation and lift off technique. The process is fully compatible with conventional micro- and nanolithography techniques. Micrometer size semiconducting SWNT devices have been used to explore field-effect properties of the nanotubes at room temperature while smaller length semiconducting SWNT islands are used to study single-electron charging effects at low temperatures.

Chemical vapor deposition (CVD) of single-walled carbon nanotubes (SWNTs) catalyzed using a few nm thick Ni layer supported by a thin Al underlayer is reported. Analysis by transmission electron mi...

We report the growth of carbon nanotubes (CNTs) via reduced-pressure chemical vapor deposition (CVD), using a gas mixture of methane/hydrogen and iron/molybdenum catalyst supported by alumina nanoparticles. The CNTs are either single-walled or double-walled as characterized by transmission electron microscopy. Investigation of various growth parameters indicates that CNT growth is limited by the gas supply when CVD is performed in the temperature range of 750−900 °C, whereas the limiting factor for growth at 700 °C is the rate of carbon diffusion through the catalyst particles. The density of CNTs changes with CVD pressure as well as gas flow rates when growth is limited by gas supply. We also use a single-step lithographic approach to form catalyst islands on top of patterned electrodes and to selectively grow CNTs bridging neighboring electrodes. The process yields both semiconducting and metallic CNTs as characterized by current−voltage measurements.

We are developing a 'toolbox' containing organic molecules, nanoparticles and carbon nanotubes (CNTs) that can be self-arranged into a very advanced information processing system. Before we can assemble these 'tools' in complex systems, it is imperative that we determine their physical, chemical and electrical properties. Here, we describe the development of three techniques to aid in evaluating the electrical properties of these 'tools'. Firstly, via a conducting atomic force microscope, we will examine a method of measuring the electrical properties of a single (few) dithiolated electronic molecule(s) inserted into an 'insulating' self-assembled monolayer (SAM). Secondly, to expedite the transport measurements of electronic molecules, we will present a hybrid assembly technique that consists of forming a SAM of the investigated molecule on pre-patterned electrodes and then bridging the electrodes with Au nanoparticles using an alternating electric field. Finally, to integrate single-wall carbon nanotubes into a circuit, we will outline a single optical lithographic step approach to pattern catalyst islands on top of metal electrodes. Then, reduced pressure chemical vapour deposition is performed on the patterned substrates to form CNTs bridging neighbouring electrodes and produce a circuit which is ready to test.

In Canada, Indigenous women are over-represented among new HIV infections and street-based sex workers. Scholars suggest that Aboriginal women's HIV risk stems from intergenerational effects of colonisation and racial policies. This research examined generational sex work involvement among Aboriginal and non-Aboriginal women and the effect on risk for HIV acquisition. The sample included 225 women in street-based sex work and enrolled in a community-based prospective cohort, in partnership with local sex work and Aboriginal community partners. Bivariate and multivariate logistic regression modeled an independent relationship between Aboriginal ancestry and generational sex work and the impact of generational sex work on HIV infection among Aboriginal sex workers. Aboriginal women (48%) were more likely to be HIV-positive, with 34% living with HIV compared to 24% non-Aboriginal women. In multivariate logistic regression model, Aboriginal women remained three times more likely to experience generational sex work (AOR:2.97; 95%CI:1.5,5.8). Generational sex work was significantly associated with HIV (AOR = 3.01, 95%CI: 1.67-4.58) in a confounder model restricted to Aboriginal women. High prevalence of generational sex work among Aboriginal women and three-fold increased risk for HIV infection are concerning. Policy reforms and community-based, culturally safe and trauma informed HIV-prevention initiatives are required for Indigenous sex workers.

A variety of unique processing capabilities can be achieved if the use of photoresist can be avoided during wafer patterning. Two such processes are reported here, based on the resistless patterning technique in which ultra-violet light is used to modify the surface native oxide on GaAs into a more stable gallium oxide suitable for use as a mask. First, we report the easy, in situ removal of the masking gallium oxide after selective growth and then regrowth to form embedded structures without additional process steps. Second, a non-planar GaAs wafer was exposed to ultra-violet light at an angle so that the gallium oxide is formed everywhere except in the shadowed sidewall areas where the native oxide remains intact. Upon thermal desorption of the native oxide, selective growth of InAs was achieved on the previously shadowed sidewalls only.

We have studied the selective area epitaxy of GaAs by chemical beam epitaxy, using tri-isopropylgallium as the Ga source. The results show that GaAs can be selectively grown at a rate of up to ∼0.36 µm/h on patterned GaAs substrates at temperatures as low as 380°C. A low selective growth temperature allows us to utilize deep-ultraviolet radiation to modify the GaAs surface oxides for use as the masking material. We found that excess AsH3 over-pressure degrades the selectivity significantly, and the maximum selective growth thickness is limited by a critical total adatom coverage on the mask. In addition, the low selective growth temperature does not result in a very high C background concentration. Initial Hall measurements indicate that unintentional C doping levels are at least two orders of magnitude lower than those in GaAs layers grown under comparable conditions using trimethylgallium.

To the Editor: In September 2003, the first safer injecting facility in North America opened in Vancouver, Canada. Here, injection-drug users can inject preobtained illicit drugs under medical supervision.1 A concern regarding such facilities is that they may lessen the likelihood that injection-drug users will seek addiction-treatment services.2,3 Randomized trials are lacking to address this concern. We assessed factors associated with time to entry into a detoxification program at one of the city's three detoxification centers. We used data collected by means of a questionnaire as part of a cohort study (supported by Health Canada) of persons who use . . .

We examined the impact of methadone maintenance therapy (MMT) on subsequent antiretroviral therapy (ART) use in a prospective cohort of injection drug users. At 24 months after enrollment, the rate of ART use was 69.7% among those who were on MMT at baseline and 44.4% among those not on MMT (log-rank P = 0.001). In a Cox model, the use of MMT was independently associated with an elevated rate of ART use.