Author Correction: CCR5AS lncRNA variation differentially regulates CCR5, influencing HIV disease outcome.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

CCR5AS lncRNA variation differentially regulates CCR5, influencing HIV disease outcome.

Multiple genome-wide studies have identified associations between outcome of human immunodeficiency virus (HIV) infection and polymorphisms in and around the gene encoding the HIV co-receptor CCR5, but the functional basis for the strongest of these associations, rs1015164A/G, is unknown. We found that rs1015164 marks variation in an activating transcription factor 1 binding site that controls expression of the antisense long noncoding RNA (lncRNA) CCR5AS. Knockdown or enhancement of CCR5AS expression resulted in a corresponding change in CCR5 expression on CD4+ T cells. CCR5AS interfered with interactions between the RNA-binding protein Raly and the CCR5 3' untranslated region, protecting CCR5 messenger RNA from Raly-mediated degradation. Reduction in CCR5 expression through inhibition of CCR5AS diminished infection of CD4+ T cells with CCR5-tropic HIV in vitro. These data represent a rare determination of the functional importance of a genome-wide disease association where expression of a lncRNA affects HIV infection and disease progression.

Transcriptional Reprogramming during Effector-to-Memory Transition Renders CD4+ T Cells Permissive for Latent HIV-1 Infection.

The latent reservoir for HIV-1 in resting memory CD4+ T cells is the major barrier to curing HIV-1 infection. Studies of HIV-1 latency have focused on regulation of viral gene expression in cells in which latent infection is established. However, it remains unclear how infection initially becomes latent. Here we described a unique set of properties of CD4+ T cells undergoing effector-to-memory transition including temporary upregulation of CCR5 expression and rapid downregulation of cellular gene transcription. These cells allowed completion of steps in the HIV-1 life cycle through integration but suppressed HIV-1 gene transcription, thus allowing the establishment of latency. CD4+ T cells in this stage were substantially more permissive for HIV-1 latent infection than other CD4+ T cells. Establishment of latent HIV-1 infection in CD4+ T could be inhibited by viral-specific CD8+ T cells, a result with implications for elimination of latent HIV-1 infection by T cell-based vaccines.

Epigenetic therapy inhibits metastases by disrupting premetastatic niches.

Cancer recurrence after surgery remains an unresolved clinical problem1-3. Myeloid cells derived from bone marrow contribute to the formation of the premetastatic microenvironment, which is required for disseminating tumour cells to engraft distant sites4-6. There are currently no effective interventions that prevent the formation of the premetastatic microenvironment6,7. Here we show that, after surgical removal of primary lung, breast and oesophageal cancers, low-dose adjuvant epigenetic therapy disrupts the premetastatic microenvironment and inhibits both the formation and growth of lung metastases through its selective effect on myeloid-derived suppressor cells (MDSCs). In mouse models of pulmonary metastases, MDSCs are key factors in the formation of the premetastatic microenvironment after resection of primary tumours. Adjuvant epigenetic therapy that uses low-dose DNA methyltransferase and histone deacetylase inhibitors, 5-azacytidine and entinostat, disrupts the premetastatic niche by inhibiting the trafficking of MDSCs through the downregulation of CCR2 and CXCR2, and by promoting MDSC differentiation into a more-interstitial macrophage-like phenotype. A decreased accumulation of MDSCs in the premetastatic lung produces longer periods of disease-free survival and increased overall survival, compared with chemotherapy. Our data demonstrate that, even after removal of the primary tumour, MDSCs contribute to the development of premetastatic niches and settlement of residual tumour cells. A combination of low-dose adjuvant epigenetic modifiers that disrupts this premetastatic microenvironment and inhibits metastases may permit an adjuvant approach to cancer therapy.

A quantitative approach for measuring the reservoir of latent HIV-1 proviruses.

A stable latent reservoir for HIV-1 in resting CD4+ T cells is the principal barrier to a cure1-3. Curative strategies that target the reservoir are being tested4,5 and require accurate, scalable reservoir assays. The reservoir was defined with quantitative viral outgrowth assays for cells that release infectious virus after one round of T cell activation1. However, these quantitative outgrowth assays and newer assays for cells that produce viral RNA after activation6 may underestimate the reservoir size because one round of activation does not induce all proviruses7. Many studies rely on simple assays based on polymerase chain reaction to detect proviral DNA regardless of transcriptional status, but the clinical relevance of these assays is unclear, as the vast majority of proviruses are defective7-9. Here we describe a more accurate method of measuring the HIV-1 reservoir that separately quantifies intact and defective proviruses. We show that the dynamics of cells that carry intact and defective proviruses are different in vitro and in vivo. These findings have implications for targeting the intact proviruses that are a barrier to curing HIV infection.

Higher Doses of Calcium Associated With Survival in Trauma Patients.

INTRODUCTION: Calcium is required for coagulation, cardiac output, and peripheral vascular resistance. Between 85% and 94% of trauma patients treated with massive blood transfusion develop hypocalcemia.1 The aim of this study is to evaluate the relationship between increased intravenous calcium administration during massive transfusion and improved survival of trauma patients. METHODS: We performed a retrospective analysis of trauma patients who received massive transfusion over a 2-y period. Doses of elemental calcium administered per unit of blood product transfused were calculated by calcium to blood product ratio (CBR). Chi-square test evaluated association between coagulopathy and 30-d mortality. Two-sample t-test evaluated association between CBR and coagulopathy. Bivariate regression analysis evaluated association between CBR and blood products transfused per patient. Multivariable logistic regression analysis, controlling for age, sex, coagulopathy, and Injury Severity Score evaluated the association between CBR and mortality. RESULTS: The study included 77 patients. Coagulopathy was associated with increased 30-d mortality (P < 0.05). Patients who survived had higher CBR than those who died (P < 0.05). CBR was associated with a significant reduction in total blood products transfused per patient (P < 0.05). CBR was not associated with coagulopathy (P = 0.24). Multivariable logistic regression analysis demonstrated that Injury Severity Score ≥16, coagulopathy and decreased CBR were significant predictors of mortality (P < 0.05). CBR above 50 mg was a predictor of survival (P < 0.05). CONCLUSIONS: Higher doses of calcium given per blood product transfused were associated with improved 30-d survival and decreased blood product transfusions.

Microfluidic Isolation of Neuronal-Enriched Extracellular Vesicles Shows Distinct and Common Neurological Proteins in Long COVID, HIV Infection and Alzheimer's Disease.

Long COVID (LongC) is associated with a myriad of symptoms including cognitive impairment. We reported at the beginning of the COVID-19 pandemic that neuronal-enriched or L1CAM+ extracellular vesicles (nEVs) from people with LongC contained proteins associated with Alzheimer's disease (AD). Since that time, a subset of people with prior COVID infection continue to report neurological problems more than three months after infection. Blood markers to better characterize LongC are elusive. To further identify neuronal proteins associated with LongC, we maximized the number of nEVs isolated from plasma by developing a hybrid EV Microfluidic Affinity Purification (EV-MAP) technique. We isolated nEVs from people with LongC and neurological complaints, AD, and HIV infection with mild cognitive impairment. Using the OLINK platform that assesses 384 neurological proteins, we identified 11 significant proteins increased in LongC and 2 decreased (BST1, GGT1). Fourteen proteins were increased in AD and forty proteins associated with HIV cognitive impairment were elevated with one decreased (IVD). One common protein (BST1) was decreased in LongC and increased in HIV. Six proteins (MIF, ENO1, MESD, NUDT5, TNFSF14 and FYB1) were expressed in both LongC and AD and no proteins were common to HIV and AD. This study begins to identify differences and similarities in the neuronal response to LongC versus AD and HIV infection.

Circulating biomarker correlates of left atrial size and myocardial extracellular volume fraction among persons living with and without HIV.

BACKGROUND: Infection with human immunodeficiency virus (HIV) is associated with higher risk for myocardial disease despite modern combination antiretroviral therapy (cART). Factors contributing to this excess risk, however, remain poorly characterized. We aimed to assess cross-sectional relationships between elevations of left atrial volume index (LAVI) and myocardial extracellular volume (ECV) fraction that have been reported in persons living with HIV and levels of circulating biomarkers of inflammation, fibrosis, and myocyte stretch among persons living with and without HIV (PLWH, PLWOH). METHODS: Participants from three cohorts of PLWH and PLWOH underwent cardiovascular magnetic resonance imaging for measurement of LAVI and ECV. Levels of circulating proteins (IL-6, sCD14, galectin-3, NT-proBNP, GDF-15, TIMP-2, MMP-2, and hsTnI) were measured using immunoassays. Associations were assessed using logistic and linear regression, adjusting for demographics, substance use, and clinical characteristics. RESULTS: Among 381 participants with and without HIV, median age (IQR) was 55.1 (51.2, 58.4) years, 28% were female, 69% were Black, and 46% were current smokers. Sixty-two percent were PLWH (n = 235), of whom 88% were receiving cART and 72% were virally suppressed. PLWH had higher levels of sCD14 (p = < 0.001), GDF-15 (p = < 0.001), and NT-proBNP (p = 0.03) compared to PLWOH, while levels of other biomarkers did not differ by HIV serostatus, including IL-6 (p = 0.84). Among PLWH, higher sCD14, GDF-15, and NT-proBNP were also associated with lower CD4 + cell count, and higher NT-proBNP was associated with detectable HIV viral load. NT-proBNP was associated with elevated LAVI (OR: 1.79 [95% CI: 1.31, 2.44]; p < 0.001) with no evidence of effect measure modification by HIV serostatus. Other associations between HIV-associated biomarkers and LAVI or ECV were small or imprecise. CONCLUSIONS: Our findings suggest that elevated levels of sCD14, GDF-15, and NT-proBNP among PLWH compared to PLWOH observed in the current cART era may only minimally reflect HIV-associated elevations in LAVI and ECV. Future studies of excess risk of myocardial disease among contemporary cohorts of PLWH should investigate mechanisms other than those connoted by the studied biomarkers.

An Educational Module to Teach Interprofessional Learner Feedback Skills for Trauma Simulation Events.

BACKGROUND: Peer feedback, or feedback given by a learner to another learner, is an important active learning strategy. Hierarchy and stereotypes may affect interprofessional (IP) learner-to-learner feedback. The aim was to assess the efficacy of an educational module for IP learners in delivering effective feedback during trauma simulations. METHODS: Multiple simulation events designed to improve teamwork and leadership skills during trauma simulations included IP learners (residents and nurses). Participants completed a pre-course educational module on IP peer feedback. The Trauma Team Competence Assessment-24 tool structured feedback. Learners completed pre/post-assessments utilizing IP Collaborative Competencies Attainment Survey (ICCAS). RESULTS: Twenty-five learners participated in the trauma simulations (13 general surgery and 5 emergency residents, 3 medical students, 4 nurses). The majority of learners had either not received any previous training in how to effectively deliver peer feedback (40%) or had engaged in self-directed learning only (24%). Most learners (64%) had delivered peer feedback less than ten times. Learner knowledge and confidence in delivering feedback to fellow IP learners improved after simulations. All learners felt the feedback received was useful to their daily practice (68% agree, 32% strongly agree). All participants agreed that the simulation achieved each of the ICCAS competencies. CONCLUSIONS: Formal education on IP peer feedback is rare. This pilot work demonstrates educational modules with a foundation in validated tools can be effective in improving learner knowledge and confidence in the process. Engaging in IP peer feedback may also serve to flatten hierarchies that can challenge effective interprofessional teamwork.

HIV-infection and cocaine use regulate semen extracellular vesicles proteome and miRNAome in a manner that mediates strategic monocyte haptotaxis governed by miR-128 network.

BACKGROUND: Extracellular vesicles (EVs) are regulators of cell-cell interactions and mediators of horizontal transfer of bioactive molecules between cells. EV-mediated cell-cell interactions play roles in physiological and pathophysiological processes, which maybe modulated by exposure to pathogens and cocaine use. However, the effect of pathogens and cocaine use on EV composition and function are not fully understood. RESULTS: Here, we used systems biology and multi-omics analysis to show that HIV infection (HIV +) and cocaine (COC) use (COC +) promote the release of semen-derived EVs (SEV) with dysregulated extracellular proteome (exProtein), miRNAome (exmiR), and exmiR networks. Integrating SEV proteome and miRNAome revealed a significant decrease in the enrichment of disease-associated, brain-enriched, and HIV-associated miR-128-3p (miR-128) in HIV + COC + SEV with a concomitant increase in miR-128 targets-PEAK1 and RND3/RhoE. Using two-dimensional-substrate single cell haptotaxis, we observed that in the presence of HIV + COC + SEV, contact guidance provided by the extracellular matrix (ECM, collagen type 1) network facilitated far-ranging haptotactic cues that guided monocytes over longer distances. Functionalizing SEV with a miR-128 mimic revealed that the strategic changes in monocyte haptotaxis are in large part the result of SEV-associated miR-128. CONCLUSIONS: We propose that compositionally and functionally distinct HIV + COC + and HIV-COC- SEVs and their exmiR networks may provide cells relevant but divergent haptotactic guidance in the absence of chemotactic cues, under both physiological and pathophysiological conditions.

Longitudinal association of cytokine-producing CMV-specific T cells with frailty in HIV-infected and -uninfected men who have sex with men.

BACKGROUND: Chronic cytomegalovirus (CMV) infection has been postulated as a driver of chronic inflammation that has been associated with frailty and other age-related conditions in both HIV-infected (HIV+) and -uninfected (HIV-) people. METHODS: To study the T cell response to CMV as a predictor of onset and maintenance of frailty, baseline CMV-specific T cell responses of 42 men (20 HIV-, 22 HIV+; 21 frail, 21 nonfrail) in the Multicenter AIDS Cohort Study (MACS) were assessed by flow cytometric analysis of cytokine production (IFN-γ, TNF-⍺, and IL-2) in response to overlapping peptide pools spanning 19 CMV open reading frames. The Fried frailty phenotype was assessed at baseline and semiannually thereafter. Times to transition into or out of frailty were compared by tertiles of percentages of cytokine-producing T cells using Kaplan-Meier estimators and the exact log-rank test. RESULTS: Over a median follow-up of 6.5 (interquartile range: 2) years, faster onset of frailty was significantly predicted by higher (HIV- men) or lower (HIV+ men) percentages of CD4 T cells producing only IFN-γ (IFN-γ-single-producing (SP)), and by lower percentages of IFN-γ-, TNF-⍺-, and IL-2-triple-producing CD8 T cells (HIV- men). Greater maintenance of frailty was significantly predicted by lower percentages of both these T cell subsets in HIV- men, and by lower percentages of IFN-γ-SP CD4 T cells in HIV+ men. The antigenic specificity of IFN-γ-SP CD4 T cells was different between HIV- and HIV+ nonfrail men, as were the correlations between these cells and serum inflammatory markers. CONCLUSIONS: In this pilot study, percentages of CMV-specific T cells predicted the onset and maintenance of frailty in HIV- and HIV+ men. Predictive responses differed by HIV status, which may relate to differential control of CMV reactivation and inflammation by anti-CMV T cell responses.

Serological Responses to Toxoplasma gondii and Matrix Antigen 1 Predict the Risk of Subsequent Toxoplasmic Encephalitis in People Living With Human Immunodeficiency Virus (HIV).

BACKGROUND: Clinically useful predictors for fatal toxoplasmosis are lacking. We investigated the value of serological assays for antibodies to whole Toxoplasma antigens and to peptide antigens of the Toxoplasma cyst matrix antigen 1 (MAG1), for predicting incident toxoplasmic encephalitis (TE) in people living with human immunodeficiency virus (HIV; PLWH). METHODS: We performed a nested case control study, conducted within the Multicenter AIDS Cohort Study (MACS), using serum samples obtained 2 years prior to diagnosis of TE from 28 cases, and 37 HIV disease-matched Toxoplasma seropositive controls at matched time-points. Sera were tested for Toxoplasma antibodies using a commercial assay and for antibodies to MAG1_4.2 and MAG1_5.2 peptides in enzyme-linked immunosorbent assay (ELISA). RESULTS: Two years prior to clinical diagnosis, 68% of TE cases were MAG1_4.2 seropositive compared with 16% of controls (odds ratio [OR] 25.0, 95% confidence interval [CI] 3.14-199.18). Corresponding results for MAG1_5.2 seropositivity were 36% and 14% (OR 3.6, 95% CI .95-13.42). Higher levels of antibody to MAG1_4.2 (OR 18.5 per doubling of the optical density [OD] value, 95% CI 1.41-242) and to Toxoplasma (OR 2.91 for each OD unit increase, 95% CI 1.48-5.72) were also associated with the risk of TE. When seropositivity was defined as the presence of MAG1 antibody or relatively high levels of Toxoplasma antibody, the sensitivity was 89% and specificity was 68% for subsequent TE. CONCLUSIONS: Antibodies to MAG1 showed predictive value on the occurrence of TE in PLWH, and the predictive performance was further improved by adding the levels of Toxoplasma antibody. These measures could be clinically useful for predicting subsequent diseases in multiple at-risk populations.

Characteristics of the MACS/WIHS Combined Cohort Study: Opportunities for Research on Aging With HIV in the Longest US Observational Study of HIV.

In 2019, the National Institutes of Health combined the Multicenter AIDS Cohort Study (MACS) and the Women's Interagency HIV Study (WIHS) into the MACS/WIHS Combined Cohort Study (MWCCS). In this paper, participants who made a study visit during October 2018-September 2019 (targeted for MWCCS enrollment) are described by human immunodeficiency virus (HIV) serostatus and compared with people living with HIV (PLWH) in the United States. Participants include 2,115 women and 1,901 men with a median age of 56 years (interquartile range, 48-63); 62% are PLWH. Study sites encompass the South (18%), the Mid-Atlantic/Northeast (45%), the West Coast (22%), and the Midwest (15%). Participant race/ethnicity approximates that of PLWH throughout the United States. Longitudinal data and specimens collected for 35 years (men) and 25 years (women) were combined. Differences in data collection and coding were reviewed, and key risk factor and comorbidity data were harmonized. For example, recent use of alcohol (62%) and tobacco (28%) are common, as are dyslipidemia (64%), hypertension (56%), obesity (42%), mildly or severely impaired daily activities (31%), depressive symptoms (28%), and diabetes (22%). The MWCCS repository includes serum, plasma, peripheral blood mononuclear cells, cell pellets, urine, cervicovaginal lavage samples, oral samples, B-cell lines, stool, and semen specimens. Demographic differences between the MACS and WIHS can confound analyses by sex. The merged MWCCS is both an ongoing observational cohort study and a valuable resource for harmonized longitudinal data and specimens for HIV-related research.

Validation of Preamplification to Improve Quantification of Cytomegalovirus DNA Using Droplet Digital Polymerase Chain Reaction.

Subclinical cytomegalovirus (CMV) replication is associated with strong cellular immune response and chronic inflammation, which could contribute to aging-related conditions such as cardiovascular disease and frailty. However, because of very low levels of CMV DNA present in people with chronic CMV infection, it has been difficult to explore the virologic and immunologic mechanisms of chronic low-level CMV infection and a sensitive method to monitor CMV replication is needed. Droplet digital PCR (ddPCR) has been shown to have higher precision and reproducibility than real-time quantitative PCR (qPCR) in quantifying low levels of CMV DNA, but it is not always sensitive enough for this purpose. Through rigorous validation experiments, we demonstrated that sensitivity and precision of quantification of very low levels of CMV DNA by ddPCR can be significantly increased by preamplification of samples with 10-20 cycles of conventional PCR, especially when testing CMV DNA in the presence of cellular DNA. With preamplification, we could reliably quantify down to two copies of CMV DNA, as opposed to five copies without preamplification. Further studies are needed to determine if ddPCR with preamplification can facilitate mechanistic studies of the characteristics and consequences of chronic CMV infection in aging adults.

Stimulation of HIV-1-specific cytolytic T lymphocytes facilitates elimination of latent viral reservoir after virus reactivation.

Highly active antiretroviral therapy (HAART) suppresses HIV-1 replication but cannot eliminate the virus because HIV-1 establishes latent infection. Interruption of HAART leads to a rapid rebound of viremia, so life-long treatment is required. Efforts to purge the latent reservoir have focused on reactivating latent proviruses without inducing global T cell activation. However, the killing of the infected cells after virus reactivation, which is essential for elimination of the reservoir, has not been assessed. Here we show that after reversal of latency in an in vitro model, infected resting CD4(+) T cells survived despite viral cytopathic effects, even in the presence of autologous cytolytic T lymphocytes (CTLs) from most patients on HAART. Antigen-specific stimulation of patient CTLs led to efficient killing of infected cells. These results demonstrate that stimulating HIV-1-specific CTLs prior to reactivating latent HIV-1 may be essential for successful eradication efforts and should be considered in future clinical trials.

Broad CTL response is required to clear latent HIV-1 due to dominance of escape mutations.

Despite antiretroviral therapy (ART), human immunodeficiency virus (HIV)-1 persists in a stable latent reservoir, primarily in resting memory CD4(+) T cells. This reservoir presents a major barrier to the cure of HIV-1 infection. To purge the reservoir, pharmacological reactivation of latent HIV-1 has been proposed and tested both in vitro and in vivo. A key remaining question is whether virus-specific immune mechanisms, including cytotoxic T lymphocytes (CTLs), can clear infected cells in ART-treated patients after latency is reversed. Here we show that there is a striking all or none pattern for CTL escape mutations in HIV-1 Gag epitopes. Unless ART is started early, the vast majority (>98%) of latent viruses carry CTL escape mutations that render infected cells insensitive to CTLs directed at common epitopes. To solve this problem, we identified CTLs that could recognize epitopes from latent HIV-1 that were unmutated in every chronically infected patient tested. Upon stimulation, these CTLs eliminated target cells infected with autologous virus derived from the latent reservoir, both in vitro and in patient-derived humanized mice. The predominance of CTL-resistant viruses in the latent reservoir poses a major challenge to viral eradication. Our results demonstrate that chronically infected patients retain a broad-spectrum viral-specific CTL response and that appropriate boosting of this response may be required for the elimination of the latent reservoir.

A systematic review of global surgery partnerships and a proposed framework for sustainability.

Background: Building surgical capacity through global surgery partnerships (GSPs) between high and low- and middle-income countries (LMICs) is a rising global health focus. Our aim was to conduct a systematic review to characterize strategies employed by GSPs to build capacity and promote sustainability and to propose a novel reproducible model for sustainability. Methods: We conducted a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We searched PubMed, EMBASE, Medline and African Journals Online to identify all peer-reviewed articles published between 2000 and 2016 that described GSPs between partners from the United States or Canada or both and partners from LMICs. We excluded papers that described nonsurgical GSPs, unilateral GSPs (e.g., humanitarian missions) or military initiatives. Descriptive features were analyzed, with a focus on attributes that promote sustainability. We then proposed criteria for sustainability on the basis of the themes that emerged from our review. Results: Our search retrieved 3580 abstracts, which were then independently reviewed by 4 authors. A total of 128 papers (3.6%) met the inclusion criteria. They described GSPs in 68 countries on 5 continents. Among the GSPs, 21.9% demonstrated community engagement and 51.6% included multidisciplinary collaboration. Surgical training or education was provided in 81.3% of GSPs. Although 64.8% of GSPs collected data, only 53.1% reported project-related outcomes. A total of 55.5% had bilateral authorship for publications, and 28.9% had multisource funding. Only 1 GSP fulfilled all 6 of our criteria for sustainability. Conclusion: In this systematic review we identified 6 pillars that are indicators of sustainability: community engagement, multidisciplinary collaboration, education and training, outcomes reporting, bilateral authorship and multisource funding. We propose that future GSPs should build on a foundation of bilateral ideas and expertise exchange, that they should have defined and measurable objectives, that they should engage in continuous evaluation of program outcomes and that they should take a thoughtful and transparent approach to sustained capacity building.

Contexte: Le renforcement de la capacité chirurgicale au moyen de partenariats internationaux en chirurgie (PIC) entre les pays à revenu élevé et ceux à revenu faible ou intermédiaire (PRFI) prend de plus en plus de place en santé mondiale. Nous avons donc réalisé une revue systématique pour caractériser les stratégies de renforcement de la capacité et de promotion de la pérennité employées dans le cadre des PIC, ainsi que pour proposer un modèle de pérennité novateur et reproductible. Méthodes: Pour notre revue systématique, nous avons suivi le modèle Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Nous avons interrogé les bases de données PubMed, Embase, MEDLINE et African Journals Online pour trouver tous les articles évalués par des pairs publiés entre 2000 et 2016 présentant des PIC conclus entre des organismes des États-Unis ou du Canada (ou les 2) et des organismes de PRFI. Nous avons exclu les articles portant sur des partenariats internationaux dans un domaine autre que la chirurgie, les PIC unilatéraux (p. ex., missions humanitaires) et les initiatives militaires. Nous avons analysé les caractéristiques descriptives des partenariats, en particulier les attributs favorisant leur pérennité. Nous avons ensuite proposé des critères de pérennité en fonction des thèmes dégagés dans la revue systématique. Résultats: Les 3580 résumés recensés lors de la recherche initiale ont été évalués de façon indépendante par 4 auteurs. Au total, 128 articles (3,6 %) répondaient aux critères d'inclusion. Ces articles présentaient des PIC impliquant 68 pays de 5 continents. De ces PIC, 21,9 % comportaient une mobilisation communautaire, et 51,6 %, une collaboration multidisciplinaire. Une formation ou un enseignement relatif à la chirurgie était fourni dans 81,3 % des cas. Si 64,8 % des PIC comprenaient une collecte de données, seuls 53,1 % ont produit des rapports sur les issues du projet. En tout, 55,5 % des PIC avaient conclu une entente de paternité bilatérale pour la publication, et 28,9 % avaient bénéficié d'un financement multisource. Un seul PIC répondait aux 6 critères de pérennité établis. Conclusion: Six indicateurs de pérennité ont été dégagés dans le cadre de cette revue systématique : mobilisation communautaire, collaboration multidisciplinaire, éducation et formation, production de rapports sur les issues, entente de paternité bilatérale et financement multisource. Les futurs PIC devraient reposer sur un échange d'idées et de connaissances, avoir des objectifs définis et mesurables, évaluer sans cesse les issues du programme et adopter une approche réfléchie et transparente quant au renforcement continu de la capacité.

Aging, sex, inflammation, frailty, and CMV and HIV infections.

Aging is characterized by significant immune remodeling at both cellular and molecular levels, also known as immunosenescence. Older adults often manifest a chronic low-grade inflammatory phenotype. These age-related immune system changes have increasingly been recognized not only to lead to immune functional decline and increased vulnerability to infections, but also to play an important role in many chronic conditions such as frailty in older adults. In addition to sex as an important biological factor, chronic viral infections including that by human immunodeficiency virus (HIV) and cytomegalovirus (CMV) are all known to have major impact on the aging immune system. This article provides an overview of our current understanding of aging immunity, sex, inflammation, frailty, and HIV and CMV infections.

Associations between QT interval subcomponents, HIV serostatus, and inflammation.

BACKGROUND: The total QT interval comprises both ventricular depolarization and repolarization currents. Understanding how HIV serostatus and other risk factors influence specific QT interval subcomponents could improve our mechanistic understanding of arrhythmias. METHODS: Twelve-lead electrocardiograms (ECGs) were acquired in 774 HIV-infected (HIV+) and 652 HIV-uninfected (HIV-) men from the Multicenter AIDS Cohort Study. Individual QT subcomponent intervals were analyzed: R-onset to R-peak, R-peak to R-end, JT segment, T-onset to T-peak, and T-peak to T-end. Using multivariable linear regressions, we investigated associations between HIV serostatus and covariates, including serum concentrations of inflammatory biomarkers such as interleukin-6 (IL-6), and each QT subcomponent. RESULTS: After adjustment for demographics and risk factors, HIV+ versus HIV- men differed only in repolarization phase durations with longer T-onset to T-peak by 2.3 ms (95% CI 0-4.5, p < .05) and T-peak to T-end by 1.6 ms (95% CI 0.3-2.9, p < .05). Adjusting for inflammation attenuated the strength and significance of the relationship between HIV serostatus and repolarization. The highest tertile of IL-6 was associated with a 7.3 ms (95% CI 3.2-11.5, p < .01) longer T-onset to T-peak. Age, race, body mass index, alcohol use, and left ventricular hypertrophy were each associated with up to 2.2-12.5 ms longer T-wave subcomponents. CONCLUSIONS: HIV seropositivity, in combination with additional risk factors including increased systemic inflammation, is associated with longer T-wave subcomponents. These findings could suggest mechanisms by which the ventricular repolarization phase is lengthened and thereby contribute to increased arrhythmic risk in men living with HIV.

Acute care surgery, trauma and disaster relief: a clinical exchange between the University of British Columbia and the Mexican Red Cross.

Background: Our objective was to establish a sustainable educational partnership and clinical exchange between the trauma services at Vancouver General Hospital (VGH) and the Mexican Red Cross hospital in Mexico City (Hospital Central de la Cruz Roja [HCCR] Polanco). Methods: In 2017, a general surgery resident in postgraduate year 4 travelled from VGH to HCCR Polanco for the initial exchange, followed by a trauma fellow. The surgical case volumes in a month at VGH and a month at HCCR Polanco were compared. At the end of the exchange, a 36-item Likert style questionnaire was administered to the Mexican surgeons and residents who interacted with the Canadian resident and fellow during the exchange. Results: The most commonly performed procedures on the VGH acute care surgery service were laparoscopic cholecystectomy (35%) and laparoscopic appendectomy (17%). The most commonly performed procedures on the VGH trauma service were chest tube insertions (24%) and tracheostomies (24%). The most commonly performed procedures at HCCR Polanco were surgery for penetrating abdominal trauma (19%) and extremity trauma (13%). The survey results indicated that the costs of travel and accommodation were obstacles to future exchanges. All survey respondents wanted to continue collaborating with Canadians on clinical and research endeavours, felt that hosting Canadian residents was a valuable experience and felt that visiting VGH would also be valuable. Conclusion: Canadian surgical trainees gained valuable exposure to operative trauma during the exchange. The mix of operations performed at VGH and HCCR Polanco was vastly different; therefore, the exchange broadened the trainees' surgical experience. There was a unanimously positive response to the exchange among the Mexican survey respondents. This exchange is part of a long-term collaboration between our surgical centres.

Contexte: Notre objectif était d'établir un partenariat pédagogique et un échange clinique durables entre les services de traumatologie de l'Hôpital général de Vancouver (VGH) et de l'hôpital de la Croix-Rouge mexicaine à Mexico (Hospital Central de la Cruz Roja [HCCR] Polanco). Méthodes: En 2017, un résident R4 en chirurgie générale du VGH s'est rendu au HCCR Polanco pour l'échange inaugural; un fellow en traumatologie l'a suivi peu après. Les volumes de cas de chirurgie par mois dans les 2 hôpitaux ont été comparés. À la fin de l'échange, les chirurgiens et les résidents mexicains qui ont interagi avec le résident et le fellow canadiens ont répondu à un questionnaire en 36 points s'apparentant à l'échelle de Likert. Résultats: Les interventions les plus fréquemment effectuées au service chirurgical d'urgence du VGH étaient la cholécystectomie laparoscopique (35 %) et l'appendicectomie laparoscopique (17 %); au service de traumatologie, les plus fréquentes étaient l'insertion d'un drain thoracique (24 %) et la trachéotomie (24 %). Au HCCR Polanco, les interventions chirurgicales les plus courantes étaient la chirurgie pour un traumatisme abdominal pénétrant (19 %) et un traumatisme aux extrémités (13 %). Les résultats du questionnaire suggèrent que les coûts associés aux déplacements et à l'hébergement seraient un obstacle pour les échanges futurs. Cela dit, tous les répondants ont dit vouloir poursuivre leur collaboration avec les Canadiens dans des projets cliniques et de recherche, considérer que l'accueil de résidents canadiens était une expérience profitable et qu'ils gagneraient à se rendre eux-mêmes au VGH. Conclusion: Durant l'échange, les chirurgiens en formation canadiens ont reçu une exposition précieuse à la chirurgie traumatologique. Puisque la nature et la fréquence relative des opérations effectuées au VGH étaient très différentes de celles observées au HCCR Polanco, l'échange a contribué à diversifier l'expérience chirurgicale des apprenants. Tous les répondants mexicains au questionnaire avaient une expérience positive de l'échange. Le programme fait partie d'une collaboration à long terme entre les 2 centres chirurgicaux.