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Find video protocols related to scientific articles indexed in Pubmed.
The 3rd Canadian Symposium on Hepatitis C Virus: Expanding care in the interferon-free era.
Can J Gastroenterol Hepatol
PUBLISHED: 10-15-2014
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Hepatitis C virus (HCV) currently infects approximately 250,000 individuals in Canada and causes more years of life lost than any other infectious disease in the country. In August 2011, new therapies were approved by Health Canada that have achieved higher response rates among those treated, but are poorly tolerated. By 2014?2015, short-course, well-tolerated treatments with cure rates >95% will be available. However, treatment uptake is poor due to structural, financial, geographical, cultural and social barriers. As such, 'Barriers to access to HCV care in Canada' is a crucial topic that must be addressed to decrease HCV disease burden and potentially eliminate HCV in Canada. Understanding how to better care for HCV-infected individuals requires integration across multiple disciplines including researchers, clinical services and policy makers to address the major populations affected by HCV including people who inject drugs, baby boomers, immigrants and Aboriginal and?or First Nations people. In 2012, the National CIHR Research Training Program in Hepatitis C organized the 1st Canadian Symposium on Hepatitis C Virus (CSHCV) in Montreal, Quebec. The 2nd CSHCV was held in 2013 in Victoria, British Columbia. Both symposia were highly successful, attracting leading international faculty with excellent attendance leading to dialogue and knowledge translation among attendees of diverse backgrounds. The current article summarizes the 3rd CSHCV, held February 2014, in Toronto, Ontario.
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Interferon lambda 3 genotype predicts hepatitis C virus RNA levels in early acute infection among people who inject drugs: The InC(3) Study.
J. Clin. Virol.
PUBLISHED: 07-18-2014
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Hepatitis C virus (HCV) RNA level in acute HCV infection is predictive of spontaneous clearance. This study assessed factors associated with HCV RNA levels during early acute infection among people who inject drugs with well-defined acute HCV infection.
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Defective anti-polysaccharide response and splenic marginal zone disorganization in ALPS patients.
Blood
PUBLISHED: 06-26-2014
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Autoimmune lymphoproliferative syndrome (ALPS) caused by impaired FAS-mediated apoptosis of lymphocytes is characterized by lymphoproliferation, autoimmunity, but also an increased risk of invasive bacterial infection, notably following splenectomy. We surveyed a cohort of 100 ALPS patients (including 33 splenectomized) and found that 12 (10 splenectomized) had experienced 23 invasive bacterial infections mainly caused by Streptococcus pneumoniae. This vulnerability was associated with evidence of defective B-cell function characterized by low serum immunoglobulin (Ig) M, low IgM antibody production in response to S pneumoniae following nonconjugated immunization, and low blood memory B-cells counts (including marginal zone [MZ] B-cell counts). This immunodeficiency strongly correlated with intensity of lymphoproliferation. Spleen sections from 9 ALPS patients revealed double-negative T-cell (DN-T) infiltration of the MZ, which was depleted of B cells. MZ in ALPS patients contained an abnormally thick layer of MAdCAM-1((+)) stromal cells and an excess of DN-Ts. DN-Ts were shown to express MAdCAM-1 ligand, the ?4?7 integrin. These observations suggest that accumulating DN-Ts are trapped within stromal cell meshwork and interfere with correct localization of MZ B cells. Similar observations were made in spleens of fas-deficient mice. Our data revealed an unexpected mechanism by which ALPS results in anti-polysaccharide IgM antibody production-specific defect. Splenectomy should be avoided.
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Signatures of protective memory immune responses during hepatitis C virus reinfection.
Gastroenterology
PUBLISHED: 06-12-2014
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Development of a vaccine against hepatitis C virus (HCV) has been hindered by our limited understanding of immune correlates of protection during real-life exposure to the virus. We studied the immune response during HCV reinfection.
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Portraying persons who inject drugs recently infected with hepatitis C accessing antiviral treatment: a cluster analysis.
Hepat Res Treat
PUBLISHED: 05-26-2014
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Objectives. To empirically determine a categorization of people who inject drug (PWIDs) recently infected with hepatitis C virus (HCV), in order to identify profiles most likely associated with early HCV treatment uptake. Methods. The study population was composed of HIV-negative PWIDs with a documented recent HCV infection. Eligibility criteria included being 18 years old or over, and having injected drugs in the previous 6 months preceding the estimated date of HCV exposure. Participant classification was carried out using a TwoStep cluster analysis. Results. From September 2007 to December 2011, 76 participants were included in the study. 60 participants were eligible for HCV treatment. Twenty-one participants initiated HCV treatment. The cluster analysis yielded 4 classes: class 1: Lukewarm health seekers dismissing HCV treatment offer; class 2: multisubstance users willing to shake off the hell; class 3: PWIDs unlinked to health service use; class 4: health seeker PWIDs willing to reverse the fate. Conclusion. Profiles generated by our analysis suggest that prior health care utilization, a key element for treatment uptake, differs between older and younger PWIDs. Such profiles could inform the development of targeted strategies to improve health outcomes and reduce HCV infection among PWIDs.
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Estimating the size of the population of persons who inject drugs in the island of Montréal, Canada, using a six-source capture-recapture model.
Drug Alcohol Depend
PUBLISHED: 03-27-2014
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To plan and implement services to persons who inject drugs (PWID), knowing their number is essential. For the island of Montréal, Canada, the only estimate, of 11,700 PWID, was obtained in 1996 through a capture-recapture method. Thirteen years later, this study was undertaken to produce a new estimate.
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Time to Seroconversion in HIV-Exposed Subjects Carrying Protective versus Non Protective KIR3DS1/L1 and HLA-B Genotypes.
PLoS ONE
PUBLISHED: 01-01-2014
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Natural killer (NK) cells play a role in the clearance of viral infections. Combinations of alleles at the polymorphic HLA-B locus and the NK cell surface killer immunoglobulin-like receptor locus KIR3DL1/S1 have been shown to influence time to AIDS in HIV-infected individuals and risk of seroconversion in HIV exposed seronegative (HESN) subjects. Here, we assessed time to seroconversion or duration of seronegative status in a group of 168 HIV exposed individuals, including 74 seroconverters and 94 HESN based on carriage or not of KIR3DL1/S1/HLA-B genotypes previously shown to be associated with protection from infection and/or slow time to AIDS. KIR3DL1/S1 genotyping was performed by sequence-specific primer polymerase chain reaction using two pairs of specific primers for each locus. The MHC class IB locus was typed to four-position resolution to resolve Bw4 and Bw6 alleles and the amino acid present at position 80. KIR3DL1/S1 heterozygotes became HIV infected significantly faster than KIR3DS1 homozygotes. Individuals who carried both KIR3DS1 and Bw4*80I did not remain HIV seronegative longer than those from a control group who were homozygous for HLA-Bw6 and carried no HLA-A locus Bw4 alleles Subjects who were *h/*y+B*57 showed a trend towards slower time to serconversion than those with other KIR3DL1 homozygous and KIR3DL1/S1 heterozygous genotypes. Thus, KIR3DS1 homozygosity is associated with protection from HIV infection while co-carriage of KIR3DS1 and Bw4*80I is not. The requirements for protection from HIV infection can differ from those that influence time to AIDS in HIV infected individuals.
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HIV protective KIR3DL1/S1-HLA-B genotypes influence NK cell-mediated inhibition of HIV replication in autologous CD4 targets.
PLoS Pathog.
PUBLISHED: 01-01-2014
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Carriage of the genetic combination encoding a high expression inhibitory Killer Immunoglobulin-like Receptor (KIR)3DL1 with its ligand, HLA-B*57 (*h/*y+B*57) is associated with slower time to AIDS and better HIV viral load control than being a Bw6 homozygote (Bw6hmz). Natural Killer (NK) cells from *h/*y+B*57 carriers receive potent educational signals through HLA-B*57 KIR3DL1 ligation leading to high functional potential. NK cells from Bw6hmz are not educated through KIR3DL1 because Bw6 antigens do not interact with this inhibitory receptor. To better understand the impact of KIR/HLA combinations on NK cell mediated anti-viral activity we measured NK cell mediated inhibition of HIV replication in autologous infected CD4 (iCD4) cells by assessing the frequency of p24 positive CD4 targets and supernatant levels of HIV p24 longitudinally in the presence versus absence of NK cells. Forty-seven HIV uninfected subjects were studied, including carriers of *h/*y+B*57, a low expression KIR3DL1 genotype with HLA-B*57 termed *l/*x+B*57, a genotype designated 3DS1+*80I and Bw6hmz. NK cells from *h/*y+B*57 carriers, like those from 3DS1+*80I subjects, inhibited HIV replication in autologous iCD4 cells better than those from Bw6hmz and *l/*x+B*57 carriers. Cell contact between NK and iCD4 cells activated NK cells to inhibit viral replication in a non-contact dependent fashion through secretion of CC-chemokines. iCD4 stimulated NK cells from *h/*y+B*57 and 3DS1+*80I carriers produced higher levels of CC-chemokines than those from Bw6hmz or *l/*x+B*57 carriers. Higher levels of CC-chemokines were produced by KIR3DL1(+) than KIR3DL1(-) NK cells. We conclude that NK-mediated inhibition of viral replication in autologous iCD4 cells is partially due to a block at the level of HIV entry into new targets by secreted CC-chemokines.
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Sustained drug use changes following hepatitis C screening and counseling among recently infected persons who inject drugs: a longitudinal study.
Clin. Infect. Dis.
PUBLISHED: 12-20-2013
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Background.?Notification of hepatitis C (HCV) positive status is known to have short-term impacts on subsequent alcohol, drug use and injection behaviors among persons who inject drugs (PWID). Whether post-screening behavioral changes extend over time for PWIDs, and whether screening test notification has behavioral impacts among HCV-negative PWIDs, remain to be established. This study sought to longitudinally assess substance use and injection behaviors after HCV status notification among HCV seroconverters and HCV-negative PWIDs. Methods.?Initially HCV-seronegative PWIDs (n=208) were followed prospectively between 2004 and 2011 in Montreal, Canada. Semi-annual screening visits included blood sampling and an interview-administered questionnaire assessing substance use and injection behaviors. Multivariable general estimating equations (GEE) analyses were conducted to assess substance use and behavior changes over time, and compare changes between HCV seroconverters and HCV-seronegative subjects while adjusting for baseline characteristics. Results.?Of the 208 participants (83% male; mean age 34.7 years, mean follow-up time 39 months), 69 (33.2%) seroconverted to HCV. A linear decrease in syringe sharing behavior was observed over time after HCV+ and HCV- status notification, whereas a 10% decrease for each additional 3-month follow-up was observed for injection cocaine and heroin use among HCV seroconverters, but not among HCV-seronegative PWIDs (p<0.05). No significant changes were observed in alcohol use. Conclusions.?Our results indicate that notification of HCV-positive status is associated with reduced injection drug use among seroconverters. Amongst PWIDs deemed seronegative after screening, there is no sustained trend for change in risk behavior.
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The Second Canadian Symposium on hepatitis C virus: a call to action.
Can. J. Gastroenterol.
PUBLISHED: 11-08-2013
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In Canada, hepatitis C virus (HCV) infection results in considerable morbidity, mortality and health-related costs. Within the next three to 10 years, it is expected that tolerable, short-duration (12 to 24 weeks) therapies capable of curing >90% of those who undergo treatment will be approved. Given that most of those already infected are aging and at risk for progressive liver disease, building research-based interdisciplinary prevention, care and treatment capacity is an urgent priority. In an effort to increase the dissemination of knowledge in Canada in this rapidly advancing field, the National CIHR Research Training Program in Hepatitis C (NCRTP-HepC) established an annual interdisciplinary Canadian Symposium on Hepatitis C Virus. The first symposium was held in Montreal, Quebec, in 2012, and the second symposium was held in Victoria, British Columbia, in 2013. The current article presents highlights from the 2013 meeting. It summarizes recent advances in HCV research in Canada and internationally, and presents the consensus of the meeting participants that Canada would benefit from having its own national HCV strategy to identify critical gaps in policies and programs to more effectively address the challenges of expanding HCV screening and treatment.
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A Mendelian predisposition to B-cell lymphoma caused by IL-10R deficiency.
Blood
PUBLISHED: 10-02-2013
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Monogenic interleukin-10 (IL-10) and IL-10 receptor (IL-10R) deficiencies cause very early onset severe inflammatory bowel disease. Here, we report that 5 patients with an IL-10R1 (n = 1) or IL-10R2 (n = 4) deficiency developed B-cell non-Hodgkin lymphoma between the ages of 5 and 6 years (which was recurrent in 1 patient). These lymphomas had some of the characteristics of diffuse large B-cell lymphomas and contained monoclonal, Epstein-Barr virus-negative germinal center B cells. The tumors displayed a remarkably homogeneous signature, with original activation of the nuclear factor ?B pathway and a decrease in intratumor T-cell infiltration. Hence, IL-10R deficiency is associated with a high risk of developing B-cell lymphoma. Our results revealed an unexpected role of the IL-10R pathway in lymphomagenesis.
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Galectin-9 and IL-21 mediate cross-regulation between Th17 and Treg cells during acute hepatitis C.
PLoS Pathog.
PUBLISHED: 06-01-2013
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Loss of CD4 T cell help correlates with virus persistence during acute hepatitis C virus (HCV) infection, but the underlying mechanism(s) remain unknown. We developed a combined proliferation/intracellular cytokine staining assay to monitor expansion of HCV-specific CD4 T cells and helper cytokines expression patterns during acute infections with different outcomes. We demonstrate that acute resolving HCV is characterized by strong Th1/Th17 responses with specific expansion of IL-21-producing CD4 T cells and increased IL-21 levels in plasma. In contrast, viral persistence was associated with lower frequencies of IL-21-producing CD4 T cells, reduced proliferation and increased expression of the inhibitory receptors T cell immunoglobulin and mucin-domain-containing-molecule-3 (Tim-3), programmed death 1 (PD-1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4) on HCV-specific CD8 T cells. Progression to persistent infection was accompanied by increased plasma levels of the Tim-3 ligand Galectin-9 (Gal-9) and expansion of Gal-9 expressing regulatory T cells (Tregs). In vitro supplementation of Tim-3(high) HCV-specific CD8 T cells with IL-21 enhanced their proliferation and prevented Gal-9 induced apoptosis. siRNA-mediated knockdown of Gal-9 in Treg cells rescued IL-21 production by HCV-specific CD4 T cells. We propose that failure of CD4 T cell help during acute HCV is partially due to an imbalance between Th17 and Treg cells whereby exhaustion of both CD4 and CD8 T cells through the Tim-3/Gal-9 pathway may be limited by IL-21 producing Th17 cells or enhanced by Gal-9 producing Tregs.
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Plasma interferon-gamma-inducible protein-10 (IP-10) levels during acute hepatitis C virus infection.
Hepatology
PUBLISHED: 05-08-2013
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Systemic levels of interferon-gamma-inducible protein-10 (IP-10) are predictive of treatment-induced clearance in chronic hepatitis C virus (HCV). In the present study, factors associated with plasma IP-10 levels at the time of acute HCV detection and the association between IP-10 levels and spontaneous clearance were assessed in three cohorts of acute HCV infection. Among 299 individuals, 245 (181 male, 47 human immunodeficiency virus-positive [HIV+]) were HCV RNA+ at acute HCV detection. In adjusted analysis, factors independently associated with IP-10 levels ?150 pg/mL (median level) included HCV RNA levels >6 log IU/mL, HIV coinfection and non-Aboriginal ethnicity. Among 245 HCV RNA+ at acute HCV detection, 214 were untreated (n = 137) or had persistent infection (infection duration ?26 weeks) at treatment initiation (n = 77). Spontaneous clearance occurred in 14% (29 of 214). Individuals without spontaneous clearance had significantly higher mean plasma IP-10 levels at the time of acute HCV detection than those with clearance (248 ± 32 versus 142 ± 22 pg/mL, P = 0.008). The proportion of individuals with spontaneous clearance was 0% (0 of 22, P = 0.048) and 16% (27 of 165) and in those with and without plasma IP-10 levels ?380 pg/mL. In adjusted analyses, favorable IL28B genotype was associated with spontaneous clearance, while higher HCV RNA level was independently associated with lower odds of spontaneous clearance. Conclusion: High IP-10 levels at acute HCV detection were associated with failure to spontaneously clear HCV. Patients with acute HCV and high baseline IP-10 levels, particularly >380 pg/mL, should be considered for early therapeutic intervention, and those with low levels should defer therapy for potential spontaneous clearance. (HEPATOLOGY 2013;).
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The effects of female sex, viral genotype, and IL28B genotype on spontaneous clearance of acute hepatitis C virus infection.
Hepatology
PUBLISHED: 04-19-2013
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Although 20%-40% of persons with acute hepatitis C virus (HCV) infection demonstrate spontaneous clearance, the time course and factors associated with clearance remain poorly understood. We investigated the time to spontaneous clearance and predictors among participants with acute HCV using Cox proportional hazards analyses. Data for this analysis were drawn from an international collaboration of nine prospective cohorts evaluating outcomes after acute HCV infection. Among 632 participants with acute HCV, 35% were female, 82% were Caucasian, 49% had interleukin-28 (IL28)B CC genotype (rs12979860), 96% had injected drugs ever, 47% were infected with HCV genotype 1, and 7% had human immunodeficiency virus (HIV) coinfection. Twenty-eight percent were HCV antibody negative/RNA positive at the time of acute HCV detection (early acute HCV). During follow-up, spontaneous clearance occurred in 173 of 632, and at 1 year after infection, 25% (95% confidence interval [CI]: 21, 29) had cleared virus. Among those with clearance, the median time to clearance was 16.5 weeks (IQR: 10.5, 33.4), with 34%, 67%, and 83% demonstrating clearance at 3, 6, and 12 months. Adjusting for age, factors independently associated with time to spontaneous clearance included female sex (adjusted hazards ratio [AHR]: 2.16; 95% CI: 1.48, 3.18), IL28B CC genotype (versus CT/TT; AHR, 2.26; 95% CI: 1.52, 3.34), and HCV genotype 1 (versus non-genotype 1; AHR: 1.56; 95% CI: 1.06, 2.30). The effect of IL28B genotype and HCV genotype on spontaneous clearance was greater among females, compared to males. Conclusions: Female sex, favorable IL28B genotype, and HCV genotype 1 are independent predictors of spontaneous clearance. Further research is required to elucidate the observed sex-based differences in HCV control. (Hepatology 2014;58:109-120).
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Leukocyte telomere length in mastocytosis: Correlations with depression and perceived stress.
Brain Behav. Immun.
PUBLISHED: 04-17-2013
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Mastocytosisis a rare disease associated with chronic symptoms related to mast cell mediator release. Patients with mastocytosis display high level of negative emotionality such as depression and stress sensibility. Brain mast cells are mainly localized in the diencephalon, which is linked to emotion regulatory systems. Negative emotionality has been shown to be associated with telomere shortening. Taken together these observations led us to hypothesize that mast cells activity could be involved in both negative emotionality and telomere shortening in mastocytosis.
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Sustained hyperresponsiveness of dendritic cells is associated with spontaneous resolution of acute hepatitis C.
J. Virol.
PUBLISHED: 04-10-2013
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Some studies have reported that dendritic cells (DCs) may be dysfunctional in a subset of patients with chronic hepatitis C virus (HCV) infection. However, the function of DCs during acute HCV infection and their role in determining infectious outcome remain elusive. Here, we examined the phenotype and function of myeloid DCs (mDCs) and plasmacytoid DCs (pDCs) during acute HCV infection. Three groups of injection drug users (IDUs) at high risk of HCV infection were studied: an uninfected group, a group with acute HCV infection with spontaneous resolution, and a group with acute infection with chronic evolution. We examined the frequency, maturation status, and cytokine production capacity of DCs in response to the Toll-like receptor 4 (TLR4) and TLR7/8 ligands lipopolysaccharide (LPS) and single-stranded RNA (ssRNA), respectively. Several observations could distinguish HCV-negative IDUs and acute HCV resolvers from patients with acute infection with chronic evolution. First, we observed a decrease in the frequency of mature CD86(+), programmed death-1 receptor ligand-positive (PDL1(+)), and PDL2(+) pDCs. This phenotype was associated with the increased sensitivity of pDCs from resolvers and HCV-negative IDUs versus the group with acute infection with chronic evolution to ssRNA stimulation in vitro. Second, LPS-stimulated mDCs from resolvers and HCV-negative IDUs produced higher levels of cytokines than mDCs from the group with acute infection with chronic evolution. Third, mDCs from all patients with acute HCV infection, irrespective of their outcomes, produced higher levels of cytokines during the early acute phase in response to ssRNA than mDCs from healthy controls. However, this hyperresponsiveness was sustained only in spontaneous resolvers. Altogether, our results suggest that the immature pDC phenotype and sustained pDC and mDC hyperresponsiveness are associated with spontaneous resolution of acute HCV infection.
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IL28B SNP screening and distribution in the French Canadian population using a rapid PCR-based test.
Immunogenetics
PUBLISHED: 02-14-2013
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Single nucleotide polymorphisms (SNPs) in the proximity of the interleukin-28B (IL28B) gene can predict spontaneous resolution of hepatitis C virus (HCV) infection and response to interferon therapy. Screening for this polymorphism has become part of the standard criteria for the management of HCV-infected patients, hence the need for a rapid, cost-effective screening method. Here, we describe a rapid PCR-based test to screen for two IL28B SNPs (rs12979860 and rs8099917). We used this test to investigate IL28B polymorphism and prevalence in a cohort of French Canadian injection drug users who are part of a unique population known to have a strong genetic founder effect. This population had lower linkage disequilibrium between the two tested SNPs as compared to other cohorts (|d| = 0.68, r = 0.59). The special genetic makeup should be considered in the management of HCV-infected patients within that population.
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Gastrointestinal manifestations in mastocytosis: a study of 83 patients.
J. Allergy Clin. Immunol.
PUBLISHED: 01-30-2013
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Mastocytosis is a heterogeneous disease characterized by mast cell accumulation in 1 or more organs. Gastrointestinal manifestations of systemic mastocytosis have been previously studied in small cohorts of patients, and no specific histologic description is available.
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Thalidomide in systemic mastocytosis: results from an open-label, multicentre, phase II study.
Br. J. Haematol.
PUBLISHED: 01-17-2013
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Mastocytosis can lead to organ failure as well as systemic symptoms that can be disabling, with considerable deterioration in quality of life. Beside symptomatic treatments, interferon-? and purine analogues have been shown to be effective but complete or long-term remission is rarely obtained with these drugs. We conducted a phase II, multicentre, study to investigate thalidomide in severely symptomatic indolent and aggressive systemic mastocytosis. Twenty patients were enrolled of whom 16 were analysed for response. The overall response rate was 56%. Responses were observed in the skin in 61% of patients with a significant decrease in the pruritus score. Mast cell mediator-related symptoms responded in 71% of cases and 25% of aggressive systemic mastocytosis patients had a response in terms of B/C findings (borderline/cytoreduction needed). Bone marrow mast cell infiltration decreased in five of the eight evaluable patients. There was no significant improvement in the AFIRMM (Association Française pour les Initiatives de Recherche sur le Mastocyte et Les Mastocytoses), Quality of Life or Hamilton scores. Grade 3-4 toxicities consisted of peripheral neuropathy (11%) and myelosuppression (neutropenia: 5%; thrombocytopenia: 11%). In conclusion, thalidomide might be useful in mastocytosis and in the treatment of mast cell-related symptoms. It might be considered in selected patients, taking into account the benefit/risk balance and the individual patient evaluation.
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Neuropilin-1 Expression Characterizes T Follicular Helper (Tfh) Cells Activated during B Cell Differentiation in Human Secondary Lymphoid Organs.
PLoS ONE
PUBLISHED: 01-01-2013
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T follicular helper (Tfh) cells play an essential role in the development of antigen-specific B cell immunity. Tfh cells regulate the differentiation and survival of activated B cells outside and inside germinal centers (GC) of secondary lymphoid organs. They act through cognate contacts with antigen-presenting B cells, but there is no current marker to specifically identify those Tfh cells which productively interact with B cells. Here we show that neuropilin 1 (Nrp1), a cell surface receptor, is selectively expressed by a subset of Tfh cells in human secondary lymphoid organs. Nrp1 expression on Tfh cells correlates with B cell differentiation in vivo and in vitro, is transient, and can be induced upon co-culture with autologous memory B cells in a cell contact-dependent manner. Comparative analysis of ex vivo Nrp1(+) and Nrp1(-) Tfh cells reveals gene expression modulation during activation. Finally, Nrp1 is expressed by malignant Tfh-like cells in a severe case of angioimmunoblastic T-cell lymphoma (AITL) associated with elevated terminal B cell differentiation. Thus, Nrp1 is a specific marker of Tfh cells cognate activation in humans, which may prove useful as a prognostic factor and a therapeutic target in neoplastic diseases associated with Tfh cells activity.
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[Integrated treatment of hepatitis C among people with concurrent mental health and substance abuse disorders: promoting change in an urban area].
Sante Ment Que
PUBLISHED: 12-28-2011
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In this article, the authors discuss the extent of HCV infections and the obstacles people with concurrent mental health and substance disorders face in terms of access to care in urban areas. The authors remind that HCV is associated with a reduced quality of life and an increased risk of cirrhosis, but that new treatments developed over the last decade can lead to the eradication of the virus and to the prevention of complications. The authors also describe the steps leading to the establishment of an HCV treatment program at the Centre hospitalier de lUniversité de Montréal (CHUM).
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Major histocompatibility complex class II expression deficiency caused by a RFXANK founder mutation: a survey of 35 patients.
Blood
PUBLISHED: 09-08-2011
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Inherited deficiency of major histocompatibility complex (MHC) class II molecules impairs antigen presentation to CD4(+) T cells and results in combined immunodeficiency (CID). Autosomal-recessive mutations in the RFXANK gene account for two-thirds of all cases of MHC class II deficiency. We describe here the genetic, clinical, and immunologic features of 35 patients from 30 unrelated kindreds from North Africa sharing the same RFXANK founder mutation, a 26-bp deletion called I5E6-25_I5E6 + 1), and date the founder event responsible for this mutation in this population to approximately 2250 years ago (95% confidence interval [CI]: 1750-3025 years). Ten of the 23 patients who underwent hematopoietic stem cell transplantation (HSCT) were cured, with the recovery of almost normal immune functions. Five of the patients from this cohort who did not undergo HSCT had a poor prognosis and eventually died (at ages of 1-17 years). However, 7 patients who did not undergo HSCT (at ages of 6-32 years) are still alive on Ig treatment and antibiotic prophylaxis. RFXANK deficiency is a severe, often fatal CID for which HSCT is the only curative treatment. However, some patients may survive for relatively long periods if multiple prophylactic measures are implemented.
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Blood CD34-c-Kit+ cell rate correlates with aggressive forms of systemic mastocytosis and behaves like a mast cell precursor.
Blood
PUBLISHED: 08-30-2011
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Mastocytosis is a heterogeneous disease characterized by the accumulation of mast cells in one or more organs. Our objective was to identify a peripheral mast cell precursor and assess its variation rate in mastocytosis. A peripheral blood phenotypic analysis was performed among 50 patients with mastocytosis who were enrolled in a prospective multicentric French study, and the phenotypic analysis results of the patients were compared with those of healthy donors. The rate of peripheral blood CD34(-)c-Kit(+) cells correlated with the severity of mastocytosis. This cellular population was isolated from healthy donors as well as from patients with systemic mastocytosis. After 30 days of culture, the CD34(-)c-Kit(+) cells gave birth to mature mast cells, indicating that this cellular population constitutes a mast cell circulating precursor. Monitoring peripheral CD34(-)c-Kit(+) cells by flow cytometry could be a useful and low-invasive tool to determine the disease severity and the relapses and to assess treatment efficiency.
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Loss of p19Arf in a Rag1(-/-) B-cell precursor population initiates acute B-lymphoblastic leukemia.
Blood
PUBLISHED: 05-26-2011
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In human B-acute lymphoblastic leukemia (B-ALL), RAG1-induced genomic alterations are important for disease progression. However, given that biallelic loss of the RAG1 locus is observed in a subset of cases, RAG1s role in the development of B-ALL remains unclear. We chose a p19Arf(-/-)Rag1(-/-) mouse model to confirm the previously published results concerning the contribution of CDKN2A (p19ARF /INK4a) and RAG1 copy number alterations in precursor B cells to the initiation and/or progression to B-acute lymphoblastic leukemia (B-ALL). In this murine model, we identified a new, Rag1-independent leukemia-initiating mechanism originating from a Sca1(+)CD19(+) precursor cell population and showed that Notch1 expression accelerates the cells self-renewal capacity in vitro. In human RAG1-deficient BM, a similar CD34(+)CD19(+) population expressed p19ARF. These findings suggest that combined loss of p19Arf and Rag1 results in B-cell precursor leukemia in mice and may contribute to the progression of precursor B-ALL in humans.
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Trends in human immunodeficiency virus incidence and risk behavior among injection drug users in montreal, Canada: a 16-year longitudinal study.
Am. J. Epidemiol.
PUBLISHED: 03-01-2011
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The authors sought to investigate trends in the incidence of human immunodeficiency virus (HIV) infection, evaluate changes in risk behavior, and assess associations between syringe access programs and HIV seroconversion among injection drug users (IDUs) in Montreal, Canada, who were recruited and followed for a prospective cohort study between 1992 and 2008. Methods included Kaplan-Meier survival analysis and time-varying Cox regression models. Of 2,137 HIV-seronegative IDUs at enrollment, 148 became HIV-positive within 4 years (incidence: 3.3 cases/100 person-years; 95% confidence interval: 2.8, 3.9). An annual HIV incidence decline of 0.06 cases/100 person-years prior to 2000 was followed by a more rapid annual decline of 0.24 cases/100 person-years during and after 2000. Behavioral trends included increasing cocaine and heroin use and decreasing proportions of IDUs reporting any syringe-sharing or sharing a syringe with an HIV-positive person. In multivariate analyses, HIV seroconversion was associated with male gender, unstable housing, intravenous cocaine use, and sharing syringes or having sex with an HIV-positive partner. Always acquiring syringes from safe sources conferred a reduced risk of HIV acquisition among participants recruited after 2004, but this association was not statistically significant for participants recruited earlier. In conclusion, HIV incidence has declined in this cohort, with an acceleration of the reduction in HIV transmission after 2000.
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A founder effect at the EPCAM locus in Congenital Tufting Enteropathy in the Arabic Gulf.
Eur J Med Genet
PUBLISHED: 01-25-2011
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Mutations of the EPCAM gene have been recently identified in Congenital Tufting Enteropathy (CTE), a severe autosomal recessive gastrointestinal insufficiency of childhood requiring parenteral nutrition and occasionally intestinal transplantation. Studying seven multiplex consanguineous families from the Arabic peninsula (Kuwait and Qatar) we found that most patients were homozygote for a c.498insC mutation in exon 5. The others carried a novel mutation IVS4-2A?G. Both mutations were predicted to truncate the C-terminal domain necessary to anchorage of EPCAM at the intercellular membrane. Consistently, immunohistochemistry of intestinal biopsies failed to detect the EPCAM protein at the intercellular membrane level. The c.498insC mutation was found on the background of a minimal common haplotype of 473kb suggesting a very old founder effect (5000-6000 yrs).
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Breakthrough Hormographiella aspergillata infections arising in neutropenic patients treated empirically with caspofungin.
J. Clin. Microbiol.
PUBLISHED: 11-10-2010
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Hormographiella aspergillata, a filamentous basidiomycete, has rarely been involved in human infections. We describe 2 febrile neutropenic patients who developed a severe pulmonary infection due to H. aspergillata while receiving empirical caspofungin therapy for presumed fungal pneumonia. After introduction of liposomal amphotericin B, one patient, who had neutrophil recovery, presented a favorable outcome, while the other, who remained neutropenic throughout the course of infection, died. Resistant fungi, including basidiomycetes, may emerge during empirical treatment with caspofungin in febrile neutropenic patients. A rapid switch to any other potent antifungal should be rapidly considered in case of failure of caspofungin in this setting.
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Mind the gap: lack of association between KIR3DL1*004/HLA?Bw4-induced natural killer cell function and protection from HIV infection.
J. Infect. Dis.
PUBLISHED: 10-05-2010
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Several combinations of genes encoding KIR3DL1 alleles and their HLA?Bw4 ligands have been linked with favorable outcomes upon exposure to or infection with human immunodeficiency virus (HIV). Some protective KIR3DL1/HLA?Bw4 combinations confer elevated natural killer (NK) cell functional potential. The K562?stimulated functionality of NK cells from KIR3DL1*004/HLA?Bw4 and control genotype carriers was assessed by flow cytometry and found to be higher in KIR3DL1*004/HLA?Bw4 carriers. However, a comparison of the frequency of this combined genotype among HIV?exposed uninfected and HIV?infected subjects revealed no between?group differences. Thus, despite its ability to license NK cells, KIR3DL1*004/HLA?Bw4 is not associated with a reduced risk of infection.
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Comparison of immune restoration in early versus late alpha interferon therapy against hepatitis C virus.
J. Virol.
PUBLISHED: 07-28-2010
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Early alpha interferon (IFN-alpha) therapy against hepatitis C virus (HCV) rescues polyfunctional, virus-specific memory CD8(+) T cells, but whether immune restoration is possible during late therapy remains controversial. We compared immune restoration of HCV-specific memory T cells in patients who cleared HCV infection spontaneously and following early or late IFN therapy. Multifunctional CD4(+) and CD8(+) memory T cells were detected in spontaneous resolvers and in individuals treated early following an acute infection. In contrast, limited responses were detected in patients treated during chronic infection, and the phenotype of HCV-specific cells was influenced by autologous viral sequences. Our data suggest that irreversible damage to the HCV-specific memory T-cell response is associated with chronic HCV infection.
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Regulatory T-cell depletion in angioimmunoblastic T-cell lymphoma.
Am. J. Pathol.
PUBLISHED: 06-21-2010
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Angioimmunoblastic T-cell lymphoma (AITL) is the most frequent nodal T-cell lymphoma and is characterized by a polymorphic lymph node infiltrate, various dysimmune disorders, and a poor prognosis. Regulatory T-cells (Treg) play an emerging role in the prognosis of non-Hodgkin B-cell lymphoma and mediate significant autoreactive T-cell suppression. In this report, we demonstrate that numbers of Treg are significantly decreased in AITL lymph nodes [n = 30, 91 (40-195) per high power fields] compared with follicular lymphoma [n = 19, 179 (86-355)] and reactive lymph nodes [n = 8, 186 (140-265)]. Moreover, the few Treg in lymph nodes of AITL are resting Treg (rTreg) and have a naive CD45RA+, PD1-, and ICOS- phenotype [n = 5, 57% of Treg are CD45RA+ (16-96)], in contrast to the Treg in follicular lymphomas [n = 5, 7.4% (1-13)] or reactive lymph nodes [n = 7, 18.6% (6-48)]. Interestingly, Treg depletion was not observed in AITL peripheral blood at diagnosis. Altogether, these data suggest that Treg depletion could contribute to the nodal neoplastic T(FH) expansion and dysimmune symptoms in AITL.
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Cannabis use correlates of syringe sharing among injection drug users.
Am J Addict
PUBLISHED: 06-08-2010
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This study examines whether the relation between acute cannabis use and syringe sharing during single injection days is similar among regular and nonregular users, participating in a cohort study of injection drug users in Montréal, Canada. 236 (36.6%) subjects were classified as regular cannabis users (RCUs), 227 (35.2%) as nonregular cannabis users (NRCUs), and 181 (28.1%) were abstinent. Cannabis use during a single injection day was associated with a fivefold increased risk of sharing (OR 4.92; 1.83-13.22) in NRCUs compared to RCUs. Our results indicate that cannabis use history should be considered when evaluating its potential effect on risk-taking behaviors.
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Increased degranulation of natural killer cells during acute HCV correlates with the magnitude of virus-specific T cell responses.
J. Hepatol.
PUBLISHED: 04-21-2010
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Natural killer (NK) cells provide early defense against viral infections by killing infected cells and producing cytokines that inhibit viral replication. NK cells also interact with dendritic cells (DCs) and this reciprocal interaction regulates both innate and adaptive immunity. Genetic studies have suggested that NK cell activity is a determinant of HCV infectious outcome but a functional correlation has not been established. We hypothesized that increased NK cell activity during acute HCV infection correlates with spontaneous viral clearance.
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Availability of body art facilities and body art piercing do not predict hepatitis C acquisition among injection drug users in Montreal, Canada: Results from a cohort study.
Int. J. Drug Policy
PUBLISHED: 02-06-2010
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Cross-sectional associations suggest that body art piercing (BAP) is a risk factor for hepatitis C (HCV) infection among injection drug users. The temporal basis of the relationship has not been established.
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Transient CD86 expression on hepatitis C virus-specific CD8+ T cells in acute infection is linked to sufficient IL-2 signaling.
J. Immunol.
PUBLISHED: 01-25-2010
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Costimulatory signals via B7/CD28 family molecules (signal 2) are critical for effective adaptive CD8(+) T cell immune responses. In addition to costimulatory signals, B7/CD28 family coinhibitory receptor/ligands that modulate immune responses have been identified. In acute hepatitis C virus (HCV) infection, programmed death receptor 1, an inhibitory receptor in the CD28 family, is highly expressed on virus-specific CD8(+) T cells, yet vigorous immune responses often develop. We hypothesized that other costimulatory signals present during the acute phase of HCV infection would be important to counter this negative signaling. In this study, we found that CD86 was highly expressed on HCV-specific CD8(+) T cells early in acute HCV infection and was lost on transition to chronic HCV infection; the expression of CD86 was different from other activation markers, because expression was delayed after in vitro TCR stimulation and required sufficient IL-2 signaling; and HCV-specific CD8(+) T cells in the liver of patients with chronic HCV infection were highly activated (CD69, CD38, and HLA-DR expression), but only a minority expressed CD86 or showed evidence of recent IL-2 signaling (low basal phosphorylated STAT5), despite persistent viremia. Our study identified B7 ligand expression on HCV-specific CD8(+) T cells as a distinct marker of effective T cell stimulation with IL-2 signaling in acute HCV infection. Expression of costimulatory molecules, such as CD86, early in HCV infection may be essential in overcoming inhibitory signals from the high level of programmed death receptor 1 expression also seen at this phase of infection.
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Programmed death-1-induced interleukin-10 production by monocytes impairs CD4+ T cell activation during HIV infection.
Nat. Med.
PUBLISHED: 01-22-2010
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Viral replication and microbial translocation from the gut to the blood during HIV infection lead to hyperimmune activation, which contributes to the decline in CD4+ T cell numbers during HIV infection. Programmed death-1 (PD-1) and interleukin-10 (IL-10) are both upregulated during HIV infection. Blocking interactions between PD-1 and programmed death ligand-1 (PD-L1) and between IL-10 and IL-10 receptor (IL-10R) results in viral clearance and improves T cell function in animal models of chronic viral infections. Here we show that high amounts of microbial products and inflammatory cytokines in the plasma of HIV-infected subjects lead to upregulation of PD-1 expression on monocytes that correlates with high plasma concentrations of IL-10. Triggering of PD-1 expressed on monocytes by PD-L1 expressed on various cell types induced IL-10 production and led to reversible CD4+ T cell dysfunction. We describe a new function for PD-1 whereby microbial products inhibit T cell expansion and function by upregulating PD-1 levels and IL-10 production by monocytes after binding of PD-1 by PD-L1.
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HIV protective KIR3DL1 and HLA-B genotypes influence NK cell function following stimulation with HLA-devoid cells.
J. Immunol.
PUBLISHED: 01-08-2010
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Epidemiological studies in humans have implicated carriage of combinations of genes encoding certain KIR3DL1 (killer Ig-like receptor 3DL1) alleles and their HLA-Bw4 ligands in slower progression to AIDS, lower viral load and protection from infection. Given that the KIR3DL1*h/*y/HLA-B*57 genetic combination is strongly associated with favorable HIV outcomes, we measured responses from NK cells isolated from these individuals by multiparametric flow cytometry for cytokine secretion and degranulation in response to stimulation with HLA-devoid cells to assess whether the KIR/HLA compound genotypes linked to better HIV outcome favor increased NK cell functional potential. Our results indicate that NK cells from these individuals had increased functional potential, particularly in the KIR3DL1(+) NK cell subset. These results support a link between KIR/HLA genotypes and NK cell function and could provide an explanation for the observation that some KIR/HLA combinations are associated protective phenotypes in the context of host-HIV interactions.
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Neuropilin-1 is not a marker of human Foxp3+ Treg.
Eur. J. Immunol.
PUBLISHED: 06-06-2009
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Treg are immune cells that play a critical role in the regulation of the immune response. Although the transcription factor Foxp3 is widely accepted as the standard marker of Treg, specific surface markers are needed to better characterize these cells and decipher their mechanisms of action. Neuropilin-1 (Nrp-1), a membrane protein primarily involved in the nervous system, was identified as a specific marker of murine Treg, but its expression has not been rigorously investigated in human Treg. Here we show that in contrast to murine Treg and regardless of their origins (blood, thymus, spleen, lymph node or tonsil), human Foxp3(+) Treg do not specifically express Nrp-1. However, a population of Foxp3(-) Nrp-1(+) T cells can be detected in human secondary lymphoid organs, and Nrp-1 expression is induced on peripheral blood T lymphocytes upon in vitro activation. We conclude that Nrp-1 cannot be used as a specific marker of human Treg, but might represent a novel activation marker of human T cells both in vitro and in vivo.
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Gender-specific situational correlates of syringe sharing during a single injection episode.
AIDS Behav
PUBLISHED: 02-02-2009
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Factors associated with syringe sharing differ between women and men; however, it is uncertain whether these hold within the setting of a single injection episode. A questionnaire eliciting information about the last injection episode with others present was administered to participants in a cohort of Montréal injection drug users (IDUs). Logistic regression was used to identify correlates of syringe sharing and to test potential gender differences in relation to syringe sharing. Data from 467 participants revealed significant differences between men and women with regard to situational factors; however, the relationships between situational factors and syringe sharing did not vary according to gender. In multivariate models including both genders, syringe sharing was associated with various attributes of other IDUs who were present as well as alcohol use during that specific episode. These results highlight the relevance of situational factors in injection drug use activity, regardless of gender.
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Association between neighbourhood socioeconomic characteristics and high-risk injection behaviour amongst injection drug users living in inner and other city areas in Montréal, Canada.
Int. J. Drug Policy
PUBLISHED: 01-22-2009
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Area-level socioeconomic conditions are associated with epidemic rates of viral hepatitis and HIV amongst urban injection drug users (IDUs), but whether specific socioeconomic markers are uniformly related to IDU outcomes across different urban environments is unclear. We evaluated whether injection behaviour is differentially related to neighbourhood socioeconomic characteristics for IDUs in inner city vs. surrounding urban areas.
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Cohort Profile: The International Collaboration of Incident HIV and Hepatitis C in Injecting Cohorts (InC3) Study.
Int J Epidemiol
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The International Collaboration of Incident HIV and Hepatitis C in Injecting Cohorts (InC(3)) Study is an international multi-cohort project of pooled biological and behavioural data from nine prospective cohorts of people who inject drugs (PWID). InC(3) brings together researchers from Australia, Canada, USA and the Netherlands with expertise in epidemiology, biostatistics, clinical and behavioural sciences, virology and immunology to investigate research questions relevant to hepatitis C virus (HCV) and HIV outcomes. InC(3) was established to: (i) create a merged multi-cohort study of pooled data from well-characterized cohorts of PWID with prospective data on HIV and HCV infections, with a particular focus on HCV; (ii) facilitate new studies not possible within individual cohorts; and (iii) bring together researchers across disciplines to answer a broad range of research questions. Study cohorts identify acute HCV cases through follow-up of high-risk HCV antibody-negative PWID or through clinical referral networks. To date, data from 1986 to 2010 have been received from all contributing cohorts, with 821 HCV-infected and 1216 HCV-uninfected participants (overall, n = 2037). Data collected include demographics, host genetics, HCV ribonucleic acid testing, alanine aminotransferase testing, HIV/hepatitis B virus testing, HCV therapy, loss to follow-up and mortality. Potential collaborators should contact the InC(3) PI Dr Kimberley Page (kPage@psg.ucsf.edu) for further information.
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Patterns of cocaine and opioid co-use and polyroutes of administration among street-based cocaine users in Montréal, Canada.
Int. J. Drug Policy
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Effective public health programs aimed at problematic cocaine users are challenged by the fact that they can have complex patterns of drug use with respect to polysubstance use and routes of drug administration. This study was carried out to explore the presence of subgroups of cocaine users on the basis of their concurrent use of opioids and their routes of cocaine and opioid administration, and to determine if subgroups could be differentiated in terms of sociodemographic factors and risk behaviours.
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Probing the binding sites of antibiotic drugs doxorubicin and N-(trifluoroacetyl) doxorubicin with human and bovine serum albumins.
PLoS ONE
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We located the binding sites of doxorubicin (DOX) and N-(trifluoroacetyl) doxorubicin (FDOX) with bovine serum albumin (BSA) and human serum albumins (HSA) at physiological conditions, using constant protein concentration and various drug contents. FTIR, CD and fluorescence spectroscopic methods as well as molecular modeling were used to analyse drug binding sites, the binding constant and the effect of drug complexation on BSA and HSA stability and conformations. Structural analysis showed that doxorubicin and N-(trifluoroacetyl) doxorubicin bind strongly to BSA and HSA via hydrophilic and hydrophobic contacts with overall binding constants of K(DOX-BSA) = 7.8 (± 0.7) × 10(3) M(-1), K(FDOX-BSA) = 4.8 (± 0.5)× 10(3) M(-1) and K(DOX-HSA) = 1.1 (± 0.3)× 10(4) M(-1), K(FDOX-HSA) = 8.3 (± 0.6)× 10(3) M(-1). The number of bound drug molecules per protein is 1.5 (DOX-BSA), 1.3 (FDOX-BSA) 1.5 (DOX-HSA), 0.9 (FDOX-HSA) in these drug-protein complexes. Docking studies showed the participation of several amino acids in drug-protein complexation, which stabilized by H-bonding systems. The order of drug-protein binding is DOX-HSA > FDOX-HSA > DOX-BSA > FDOX>BSA. Drug complexation alters protein conformation by a major reduction of ?-helix from 63% (free BSA) to 47-44% (drug-complex) and 57% (free HSA) to 51-40% (drug-complex) inducing a partial protein destabilization. Doxorubicin and its derivative can be transported by BSA and HSA in vitro.
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Injection of drug residue as a potential risk factor for HCV acquisition among Montréal young injection drug users.
Drug Alcohol Depend
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Preparing drugs or medications for injection may leave residues in containers and filters used by injection drug users (IDUs). Little is known about the specific practice of injecting someone elses drug residue as a possible route of HCV transmission.
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Altered thymic function during interferon therapy in HCV-infected patients.
PLoS ONE
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Interferon alpha (IFN?) therapy, despite good efficacy in curing HCV infection, leads to major side effects, in particular inducement of a strong peripheral T-cell lymphocytopenia. We here analyze the early consequences of IFN? therapy on both thymic function and peripheral T-cell homeostasis in patients in the acute or chronic phase of HCV-infection as well as in HIV/HCV co-infected patients. The evolution of T-cell subsets and T-cell homeostasis were estimated by flow cytometry while thymic function was measured through quantification of T-cell receptor excision circles (TREC) and estimation of intrathymic precursor T-cell proliferation during the first four months following the initiation of IFN? therapy. Beginning with the first month of therapy, a profound lymphocytopenia was observed for all T-cell subsets, including naïve T-cells and recent thymic emigrants (RTE), associated with inhibition of intrathymic precursor T-cell proliferation. Interleukin (IL)-7 plasma concentration rapidly dropped while lymphocytopenia progressed. This was neither a consequence of higher consumption of the cytokine nor due to its neutralization by soluble CD127. Decrease in IL-7 plasma concentration under IFN? therapy correlated with the decline in HCV viral load, thymic activity and RTE concentration in blood. These data demonstrate that IFN?-based therapy rapidly impacts on thymopoiesis and, consequently, perturbs T-cell homeostasis. Such a side effect might be detrimental for the continuation of IFN? therapy and may lead to an increased level of infectious risk, in particular in HIV/HCV co-infected patients. Altogether, this study suggests the therapeutic potential of IL-7 in the maintenance of peripheral T-cell homeostasis in IFN?-treated patients.
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Inhibitory Killer Immunoglobulin-like Receptors to self HLA-B and HLA-C ligands contribute differentially to Natural Killer cell functional potential in HIV infected slow progressors.
Clin. Immunol.
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Inhibitory Killer Immunoglobulin-like Receptors (iKIR) interact with their ligands, HLA molecules, to license Natural Killer (NK) cells for functional competence. Previous studies stimulating peripheral blood mononuclear cells (PBMCs) with the HLA-devoid K562 cell line revealed that NK cells from individuals with an iKIR encoded by the KIR3DL1 locus with self HLA-Bw4 as their ligands, had higher frequencies of tri-functional NK cells that expressed the degranulation marker CD107a and secreted Interferon-? and Tumor Necrosis Factor-? than those from individuals who were homozygous for HLA-Bw6 alleles, which are not ligands for these iKIR. To assess the effect of other iKIR to self-HLA (S-iKIR) on the NK cell response, we compared HIV-infected slow progressors (SP) carrying S-iKIR to HLA-C alleles with or without S-iKIR to HLA-Bw4. We show that S-iKIR to HLA-B and C alleles differ in their contribution to NK cell functional potential in HIV-infected SP upon stimulation with K562 targets.
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The rising prevalence of prescription opioid injection and its association with hepatitis C incidence among street-drug users.
Addiction
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? To examine trends in prescription opioid (PO) injection and to assess its association with hepatitis C virus (HCV) seroconversion among injection drug users (IDUs).
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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.