Advancing arbovirus diagnosis in Brazil: strengthening diagnostic strategies and public health data collection.

BACKGROUND: The last five decades have seen a surge in viral outbreaks, particularly in tropical and subtropical regions like Brazil, where endemic arboviruses such as Dengue (DENV), Zika (ZIKV), and Chikungunya (CHIKV) pose significant threats. However, current diagnostic strategies exhibit limitations, leading to gaps in infection screening, arbovirus differential diagnoses, DENV serotyping, and life-long infection tracking. This deficiency impedes critical information availability regarding an individual's current infection and past infection history, disease risk assessment, vaccination needs, and policy formulation. Additionally, the availability of point-of-care diagnostics and knowledge regarding immune profiles at the time of infection are crucial considerations. OBJECTIVES: This review underscores the urgent need to strengthen diagnostic methods for arboviruses in Brazil and emphasizes the importance of data collection to inform public health policies for improved diagnostics, surveillance, and policy formulation. METHODS: We evaluated the diagnostic landscape for arboviral infections in Brazil, focusing on tailored, validated methods. We assessed diagnostic methods available for sensitivity and specificity metrics in the context of Brazil. RESULTS: Our review identifies high-sensitivity, high-specificity diagnostic methods for arboviruses and co-infections. Grifols transcription-mediated amplification assays are recommended for DENV, CHIKV, and ZIKV screening, while IgG/IgM ELISA assays outperform Rapid Diagnostic Tests (RDTs). The Triplex real-time RT-PCR assay is recommended for molecular screening due to its sensitivity and specificity. CONCLUSION: Enhanced diagnostic methods, on-going screening, and tracking are urgently needed in Brazil to capture the complex landscape of arboviral infections in the country. Recommendations include nationwide arbovirus differential diagnosis for DENV, ZIKV, and CHIKV, along with increased DENV serotyping, and lifelong infection tracking to combat enduring viral threats and reduce severe presentations.

Cross-cultural adaptation of four instruments to measure stigma towards people with mental illness and substance use problems among primary care professionals in Chile.

Stigma toward people with mental illness and substance use problems is a significant global concern, and prevents people with these conditions from accessing treatment, particularly in primary health care (PHC) settings. Stigma is a cultural phenomenon that is influenced by particular contexts and can differ by country and region. The majority of stigma research focuses on Europe or North America leading to a lack of culturally relevant stigma research instruments for the Latin American context. The present study describes and discusses the methodology for cross-culturally adapting four stigma measurement scales to the Chilean context. The cross-cultural adaptation process included nine phases: (1) preparation; (2) independent translations; (3) synthesis 1 with expert committee; (4) focus groups and interviews with researchers, PHC professionals, and PHC users; (5) synthesis 2 with expert committee; (6) independent back translations; (7) synthesis 3 with expert committee; (8) pilot with PHC professionals; and (9) final revisions. The adaptation process included an array of diverse voices from the PHC context, and met three adaptation objectives defined prior to beginning the process (Understandability, Relevance, and Acceptability and Answer Options). The resulting, culturally adapted questionnaire is being validated and implemented within PHC settings across Chile to provide in-depth insight into stigma among PHC professionals in the country. The authors hope it will be useful for future research on mental illness and substance use stigma in similar settings across Latin America.

Comparative Evaluation of Rapid Isothermal Amplification and Antigen Assays for Screening Testing of SARS-CoV-2.

Human transmission of SARS-CoV-2 and emergent variants of concern continue to occur globally, despite mass vaccination campaigns. Public health strategies to reduce virus spread should therefore rely, in part, on frequent screening with rapid, inexpensive, and sensitive tests. We evaluated two digitally integrated rapid tests and assessed their performance using stored nasal swab specimens collected from individuals with or without COVID-19. An isothermal amplification assay combined with a lateral flow test had a limit of detection of 10 RNA copies per reaction, and a positive percent agreement (PPA)/negative percent agreement (NPA) during the asymptomatic and symptomatic phases of 100%/100% and 95.83/100%, respectively. Comparatively, an antigen-based lateral flow test had a limit of detection of 30,000 copies and a PPA/NPA during the asymptomatic and symptomatic phases of 82.86%/98.68% and 91.67/100%, respectively. Both the isothermal amplification and antigen-based lateral flow tests had optimized detection of SARS-CoV-2 during the peak period of transmission; however, the antigen-based test had reduced sensitivity in clinical samples with qPCR Ct values greater than 29.8. Low-cost, high-throughput screening enabled by isothermal amplification or antigen-based techniques have value for outbreak control.

A Health Technician-delivered Brief Intervention linked to AUDIT for reduction of alcohol use in Chilean primary care: a randomized controlled trial.

BACKGROUND: Because of the shortage of health professionals in Chilean primary care, Health Technicians (HT) are providing Brief Interventions (BI) for risky alcohol consumption. We compared the efficacy of two AUDIT-linked interventions provided by HTs: an informative leaflet and a BI plus leaflet. METHODS: This is a parallel-group randomized controlled trial with 1:1 randomization. Participants were identified through screening with the Alcohol Use Disorders Identification Test (AUDIT) at five primary care centers between March 2016 and July 2017. People older than 18 years at intermediate-risk (AUDIT score 8 to 15, inclusive) were randomized to receive either an HT-delivered BI (n = 174) or an informative leaflet (n = 168). Only data from participants (n = 294) who completed the 6-month assessment were analyzed. The leaflet was delivered without further advice. It contains alcohol consumption limits, a change planner, and strategies to decrease drinking. The BI was a 5-min discussion on the leaflet´s content plus normative feedback, tailored information on alcohol and health, and a change plan. The change in the AUDIT risk category six months after randomization (primary outcome) was compared among groups with a Chi-squared test. Changes in the secondary outcomes, which were scores on the AUDIT and the AUDIT´s consumption items (AUDIT-C), were compared with T-tests. Mixed-effects linear models adjusted for potential confounders. Outcome adjudicators were blinded to group assignment. RESULTS: At 6-month follow-up, low-risk alcohol consumption was observed in 119 (80%) participants in the BI group, and in 103 (71%) in the leaflet group, with no difference among groups ([Formula: see text] [1, N = 294] = 2.6, p = 0.1; adjusted odds ratio 0.6; 95% confidence interval [CI] 0.34, 1.05). The mean AUDIT score decreased by 5.76 points in the BI group, and by 5.07 in the leaflet group, which represents a 0.86 AUDIT point reduction attributable to the BI (secondary outcome) (T = 2.03, p = 0.043; adjusted mean difference 0.86 CI 0.06, 1.66). CONCLUSIONS: The AUDIT-linked BI delivered by HTs was not associated with a greater reduction of risky alcohol consumption than an informative leaflet. Delivering a leaflet could be more efficient than a BI when provided by HTs; however, more research on the effectiveness of the leaflet is needed. Trial registration ClinicalTrials.gov NCT02642757 (December 30, 2015) https://clinicaltrials.gov/ct2/show/NCT02642757 .

Neuropsychiatric Genetics of Psychosis in the Mexican Population: A Genome-Wide Association Study Protocol for Schizophrenia, Schizoaffective, and Bipolar Disorder Patients and Controls.

No large-scale genome-wide association studies (GWASs) of psychosis have been conducted in Mexico or Latin America to date. Schizophrenia and bipolar disorder in particular have been found to be highly heritable and genetically influenced. However, understanding of the biological basis of psychosis in Latin American populations is limited as previous genomic studies have almost exclusively relied on participants of Northern European ancestry. With the goal of expanding knowledge on the genomic basis of psychotic disorders within the Mexican population, the National Institute of Psychiatry Ramón de la Fuente Muñiz (INPRFM), the Harvard T.H. Chan School of Public Health, and the Broad Institute's Stanley Center for Psychiatric Research launched the Neuropsychiatric Genetics Research of Psychosis in Mexican Populations (NeuroMex) project to collect and analyze case-control psychosis samples from 5 states across Mexico. This article describes the planned sample collection and GWAS protocol for the NeuroMex study. The 4-year study will span from April 2018 to 2022 and aims to recruit 9,208 participants: 4,604 cases and 4,604 controls. Study sites across Mexico were selected to ensure collected samples capture the genomic diversity within the Mexican population. Blood samples and phenotypic data will be collected during the participant interview process and will contribute to the development of a local biobank in Mexico. DNA extraction will be done locally and genetic analysis will take place at the Broad Institute in Cambridge, MA. We will collect extensive phenotypic information using several clinical scales. All study materials including phenotypic instruments utilized are openly available in Spanish and English. The described study represents a long-term collaboration of a number of institutions from across Mexico and the Boston area, including clinical psychiatrists, clinical researchers, computational biologists, and managers at the 3 collaborating institutions. The development of relevant data management, quality assurance, and analysis plans are the primary considerations in this protocol article. Extensive management and analysis processes were developed for both the phenotypic and genetic data collected. Capacity building, partnerships, and training between and among the collaborating institutions are intrinsic components to this study and its long-term success.

Diversity matters: opportunities in the study of the genetics of psychotic disorders in low- and middle-income countries in Latin America.

Lack of diversity regarding genetic and environmental backgrounds weakens the generalization and clinical applicability of research findings on psychotic disorders. Notably, Latin Americans have been generally neglected in genetic studies, comprising less than 2% of genome-wide association study samples. But Latin American populations represent a unique opportunity for research, given the exceptionally high ethnic admixture of this group. Increasing genetic diversity is essential to improve the fine mapping of known regions associated with psychotic disorders, discover novel genetic associations, and replicate studies. Additionally, Latin America is characterized by massive social, political, and economic inequalities, all known risk factors for mental health issues, including psychotic disorders. This article aims to 1) discuss the challenges and advantages of studying Latin America's particular genetic makeup and environmental context; 2) review previous studies conducted in the region; and 3) describe three Latin American research initiatives in progress: the Neuropsychiatric Genetics of Psychosis in Mexican Populations (NeuroMEX), the Paisa, and the Latin American Network for the Study of Early Psychosis (ANDES) studies.

Does the nissen fundoplication procedure improve esophageal dysmotility in patients with barrett's esophagus?

OBJECTIVE: to evaluate esophageal dysmotility (ED) and the extent of Barrett's esophagus (BE) before and after laparoscopic Nissen fundoplication (LNF) in patients previously diagnosed with BE and ED. METHODS: twenty-two patients with BE diagnosed by upper gastrointestinal (GI) endoscopy with biopsies and ED diagnosed by conventional esophageal manometry (CEM) were submitted to a LNF, and followed up with clinical evaluations, upper GI endoscopy with biopsies and CEM, for a minimum of 12 months after the surgical procedure. RESULTS: : sixteen patients were male (72.7%) and six were females (27.3%). The mean age was 55.14 (± 15.52) years old. and the mean postoperative follow-up was 26.2 months. The upper GI endoscopy showed that the mean length of BE was 4.09 cm preoperatively and 3.91cm postoperatively (p=0.042). The evaluation of esophageal dysmotility through conventional manometry showed that: the preoperative median of the lower esophageal sphincter resting pressure (LESRP) was 9.15 mmHg and 13.2 mmHg postoperatively (p=0.006). The preoperative median of the esophageal contraction amplitude was 47.85 mmHg, and 57.50 mmHg postoperatively (p=0.408). Preoperative evaluation of esophageal peristalsis showed that 13.6% of the sample presented diffuse esophageal spasm and 9.1% ineffective esophageal motility. In the postoperative, 4.5% of patients had diffuse esophageal spasm, 13.6% of aperistalsis and 22.7% of ineffective motor activity (p=0.133). CONCLUSION: LNF decreased the BE extension, increased the LES resting pressure, and increased the amplitude of the distal esophageal contraction; however, it was unable to improve ED.

Potential pregnancy days lost: an innovative measure of gestational age.

In Brazil, the excess of interventions that anticipate childbirth, such as cesarean sections and labor inductions, has resulted in the shortening of pregnancy, with negative consequences on maternal-infant outcomes. This commentary presents a novel way to measure gestational age: the continuous variable "Potential pregnancy days lost." Using data from the Live Birth Information System (SINASC), we counted the missing days between the period until childbirth and the average duration of pregnancy (280 days), or the lost weeks. This measure can be used as an outcome variable (socioeconomic-demographic characteristics of the mother, type of childbirth, financing, etc.) or exposure variable (for neonatal, infant, and maternal outcomes). The indicator can be used in municipal and national cohorts and intervention studies to analyze hospitals and regions. We discuss the limits and scope of gestational age measures and, given their inaccuracies, the importance of studying their trends.

Potential pregnancy days lost: an innovative measure of gestational age / Dias potenciais de gravidez perdidos: uma medida inovadora da idade gestacional

ABSTRACT In Brazil, the excess of interventions that anticipate childbirth, such as cesarean sections and labor inductions, has resulted in the shortening of pregnancy, with negative consequences on maternal-infant outcomes. This commentary presents a novel way to measure gestational age: the continuous variable "Potential pregnancy days lost." Using data from the Live Birth Information System (SINASC), we counted the missing days between the period until childbirth and the average duration of pregnancy (280 days), or the lost weeks. This measure can be used as an outcome variable (socioeconomic-demographic characteristics of the mother, type of childbirth, financing, etc.) or exposure variable (for neonatal, infant, and maternal outcomes). The indicator can be used in municipal and national cohorts and intervention studies to analyze hospitals and regions. We discuss the limits and scope of gestational age measures and, given their inaccuracies, the importance of studying their trends.

RESUMO No Brasil, o excesso de intervenções que antecipam o parto, como cesarianas e induções, tem resultado no encurtamento da gestação, com consequências negativas nos desfechos materno-infantis. Neste comentário apresentamos uma medida inovadora da idade gestacional que estamos desenvolvendo: a variável contínua "dias potenciais de gravidez perdidos". Utilizando dados do Sistema de Informações de Nascidos Vivos, contamos, quando possível, os dias faltantes entre o período até o nascimento e a duração média da gestação (280 dias), ou então as semanas perdidas. Essa medida pode ser usada como variável desfecho (de características socioeconômico-demográficos da mãe, do tipo de parto, de financiamento etc.) ou de exposição (para desfechos neonatais, infantis e maternos). O indicador pode ser usado em coortes municipais e nacionais e em estudos de intervenção, para analisar hospitais e territórios. Discutimos os limites e alcances das medidas de idade gestacional e, diante de suas imprecisões, a importância de estudar suas tendências.

Does the nissen fundoplication procedure improve esophageal dysmotility in patients with barrett's esophagus? / A fundoplicatura a nissen melhora a dismotilidade esofágica em pacientes com esôfago de barrett?

ABSTRACT Objective: to evaluate esophageal dysmotility (ED) and the extent of Barrett's esophagus (BE) before and after laparoscopic Nissen fundoplication (LNF) in patients previously diagnosed with BE and ED. Methods: twenty-two patients with BE diagnosed by upper gastrointestinal (GI) endoscopy with biopsies and ED diagnosed by conventional esophageal manometry (CEM) were submitted to a LNF, and followed up with clinical evaluations, upper GI endoscopy with biopsies and CEM, for a minimum of 12 months after the surgical procedure. Results : sixteen patients were male (72.7%) and six were females (27.3%). The mean age was 55.14 (± 15.52) years old. and the mean postoperative follow-up was 26.2 months. The upper GI endoscopy showed that the mean length of BE was 4.09 cm preoperatively and 3.91cm postoperatively (p=0.042). The evaluation of esophageal dysmotility through conventional manometry showed that: the preoperative median of the lower esophageal sphincter resting pressure (LESRP) was 9.15 mmHg and 13.2 mmHg postoperatively (p=0.006). The preoperative median of the esophageal contraction amplitude was 47.85 mmHg, and 57.50 mmHg postoperatively (p=0.408). Preoperative evaluation of esophageal peristalsis showed that 13.6% of the sample presented diffuse esophageal spasm and 9.1% ineffective esophageal motility. In the postoperative, 4.5% of patients had diffuse esophageal spasm, 13.6% of aperistalsis and 22.7% of ineffective motor activity (p=0.133). Conclusion: LNF decreased the BE extension, increased the LES resting pressure, and increased the amplitude of the distal esophageal contraction; however, it was unable to improve ED.

RESUMO Objetivo: avaliar a dismotilidade esofágica (DE) e a extensão do esôfago de Barrett (EB) antes e depois da fundoplicatura laparoscópica a Nissen (FLN) em pacientes previamente diagnosticados com EB e DE. Método: vinte e dois pacientes com EB diagnosticada por endoscopia digestiva alta (EDA) com biópsias e DE diagnosticada por manometria esofágica convencional (MEC) foram submetidos a FLN, e acompanhados por avaliações clínicas, endoscopia digestiva alta com biópsias e MEC, por no mínimo 12 meses após o procedimento cirúrgico. Resultados: dezesseis pacientes eram do sexo masculino (72,7%) e seis do feminino (27,3%). A média de idade foi de 55,14 (± 15,52) anos e o seguimento pós-operatório médio foi de 26,2 meses. A endoscopia digestiva alta mostrou que o comprimento médio do EB foi de 4,09 cm no pré-operatório e 3,91 cm no pós-operatório (p = 0,042). A avaliação da dismotilidade esofágica por meio da manometria convencional mostrou que a mediana pré-operatória da pressão de repouso do esfíncter esofágico inferior (PREEI) foi de 9,15 mmHg, e de 13,2 mmHg no pós-operatório (p = 0,006). A mediana pré-operatória da amplitude de contração esofágica foi de 47,85 mmHg, e de 57,50 mmHg no pós-operatório (p = 0,408). A avaliação pré-operatória do peristaltismo esofágico mostrou que 13,6% da amostra apresentava espasmo esofágico difuso e 9,1%, motilidade esofágica ineficaz. No pós-operatório, 4,5% dos pacientes apresentaram espasmo esofágico difuso, 13,6% de aperistalse e 22,7% de atividade motora ineficaz (p = 0,133). Conclusões: a FLN diminuiu a extensão do EB, aumentou a pressão de repouso do EEI e aumentou a amplitude da contração esofágica distal; no entanto, não foi capaz de melhorar a DE.

The Effect of Sleeve Gastrectomy on the Hormonal Profile of Patients with Polycystic Ovary Syndrome.

PURPOSE: To prospectively evaluate the hormonal profile and weight loss of women with obesity and PCOS submitted to sleeve gastrectomy (SG). METHODS: A Prospective study carried out at the Hospital das Clínicas, Federal University of Pernambuco, Recife, Brazil, in 2018, where 18 patients with PCOS, whose age varied from 18 to 40 years, with an indication for bariatric surgery were evaluated. Plasma estradiol (E2), fasting insulin, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were measured prior to bariatric surgery and 3 months after surgery. The LH/FSH ratio and BMI of the study participants were also calculated. RESULTS: Postoperative E2 levels were higher (preoperative mean of 63.4 pg/dL versus postoperative mean of 91.0 pg/dL), with no statistical significance then (p = 0.139). It was observed, at the postoperative period, statistically significant decreases in mean fasting insulin levels (24.4 mIU/mL vs. 9.0 mIU/mL; p < 0.001), LH levels (7.2 vs. 4.5; p = 0.047), and an inverted LH/FSH ratio (1.5 vs. 0.9; p = 0.008); relevant weight loss occurred (mean BMI, 40.5 kg/m2 vs. 33.4 kg/m2; p < 0.001). CONCLUSION: Relevant changes in the hormone profile and significant alterations in the gonadotropic and insulin patterns were seen. In addition to satisfactory weight loss, the observed endocrine alterations revealed an internal environment that was more homeostatic and conducive to reproduction, indicating that SG was able to produce attractive physiological outcomes for women with PCOS.

Dedifferentiated liposarcoma of the gallbladder: first reported case.

BACKGROUND: Liposarcoma of the gallbladder is an extremely rare sarcoma, with only five cases reported in the literature according to our knowledge. CASE PRESENTATION: A 71-year-old woman was referred to the Surgical Oncology Division of Napoleão Laureano Hospital (João Pessoa, PB, Brazil) due to a solid mass at the right side of the abdomen and fever, with no signs of jaundice. Abdominal ultrasonography and computed tomography (CT) evidenced an extensive gallbladder lobular formation adhered to the inferior border of the right hepatic lobe and cholelithiasis. The CT report suggested gallbladder liposarcoma. A cholecystectomy associated with resection of segments IV-B and V of the liver were performed. Intraoperative frozen sections were compatible with gallbladder sarcoma. Anatomopathological examination and immunohistochemistry confirmed dedifferentiated liposarcoma with foci of heterologous leiomyosarcomatous differentiation and undifferentiated fusocellular areas of high histological grade. CONCLUSION: This is the first case of dedifferentiated liposarcoma of the gallbladder to be reported.

Stigma towards mental illness and substance use issues in primary health care: Challenges and opportunities for Latin America.

Stigma towards mental illness and addictive disorders is a global problem and one of the main obstacles in tackling this issue remains the effective integration of mental health services into primary health care (PHC). In Latin America, information has significantly increased on the existence of stigma; however, little is known about effective interventions to prevent stigma and promote recovery-oriented practices in PHC. The aim of this study is to understand the existing evidence regarding mental health stigma in PHC with a special focus on the Latin American region. A scoping review of the literature related to mental health stigma in PHC was conducted. Two hundred and seventeen articles were evaluated; 74 met inclusion criteria and 14 additional articles were selected from references of search results. Results were subdivided into five different perspectives: users, family members and significant others, health professionals, contextual factors, and potential effective interventions. Only nine studies were based in Latin America, and only one described an intervention to reduce stigma in mental health services, not specifically in PHC. We found an urgent need to develop interventions to understand and reduce stigma in PHC settings, especially in Latin America.

A randomized controlled trial of a brief intervention for alcohol and drugs linked to the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) in primary health care in Chile.

AIM: To study the effectiveness of a brief intervention (BI) associated with the ASSIST (Alcohol Smoking and Substance Involvement Screening Test) for alcohol and illicit drug use as part of a systematic screening program implemented in primary care. DESIGN: A multi-center randomized open-label trial stratified using the ASSIST-specific substance involvement score (for alcohol, scores ranged from 11 to 15 and 16 to 20; and for the other substances from 4 to 12 and 13 to 20). SETTING: A total of 19 primary care centers (n = 520), eight emergency rooms (n = 195) and five police stations (n = 91) were evaluated. PARTICIPANTS: A total of 12 217 people aged between 19 and 55 years were screened for moderate alcohol and drug use risk as defined by the ASSIST Chilean version. A total of 806 non-treatment-seekers were randomized. INTERVENTION AND COMPARISON: ASSIST-linked BI (n = 400) compared with an informational pamphlet on risk associated with substance use (n = 406). MEASUREMENTS: Total ASSIST alcohol and illicit involvement score (ASSIST-AI), and ASSIST-specific score for alcohol, cannabis and cocaine at baseline and at 3-month follow-up. FINDINGS: Sixty-two per cent of participants completed follow-up. An intention-to-treat analysis showed no difference between the two groups for the ASSIST-AI score [mean difference (MD) = - 0.17, confidence interval (CI) = -1.87, 2.20], either for specific scores alcohol (MD = 0.18, CI = -1.45, 1.10), cannabis (MD = -0.62, CI = -0.89, 2.14) or cocaine (MD = -0.79, CI = -2.89, 4.47). CONCLUSION: It is not clear whether a brief intervention associated with the Alcohol Smoking and Substance Involvement Screening Test is more effective than an informational pamphlet in reducing alcohol and illicit substance consumption in non-treatment-seeking, primary care users with moderate risk.

Cathepsin S As an Inhibitor of Cardiovascular Inflammation and Calcification in Chronic Kidney Disease.

Cardiovascular disease (CVD) is responsible for the majority of deaths in the developed world. Particularly, in patients with chronic kidney disease (CKD), the imbalance of calcium and phosphate may lead to the acceleration of both vascular and valve inflammation and calcification. One in two patients with CKD are reported as dying from cardiovascular causes due to the resulting acceleration in the development of atherosclerosis plaques. In addition, CKD patients on hemodialysis are prone to aortic valve calcification and often need valve replacement before kidney transplantation. The lysosomal proteases, cathepsins, are composed of 11 cysteine members (cathepsin B, C, F, H, K, L, O, S, V, W, and Z), as well as serine proteases cathepsin A and G, which cleave peptide bonds with serine as the amino acid, and aspartyl proteases D and E, which use an activated water molecule bound to aspartate to break peptide substrate. Cysteine proteases, also known as thiol proteases, degrade protein via the deprotonation of a thiol and have been found to play a significant role in autoimmune disease, atherosclerosis, aortic valve calcification, cardiac repair, and cardiomyopathy, operating within extracellular spaces. This review sought to evaluate recent findings in this field, highlighting how among cathepsins, the inhibition of cathepsin S in particular, could play a significant role in diminishing the effects of CVD, especially for patients with CKD.

Late Na(+) current and protracted electrical recovery are critical determinants of the aging myopathy.

The aging myopathy manifests itself with diastolic dysfunction and preserved ejection fraction. We raised the possibility that, in a mouse model of physiological aging, defects in electromechanical properties of cardiomyocytes are important determinants of the diastolic characteristics of the myocardium, independently from changes in structural composition of the muscle and collagen framework. Here we show that an increase in the late Na(+) current (INaL) in aging cardiomyocytes prolongs the action potential (AP) and influences temporal kinetics of Ca(2+) cycling and contractility. These alterations increase force development and passive tension. Inhibition of INaL shortens the AP and corrects dynamics of Ca(2+) transient, cell contraction and relaxation. Similarly, repolarization and diastolic tension of the senescent myocardium are partly restored. Thus, INaL offers inotropic support, but negatively interferes with cellular and ventricular compliance, providing a new perspective of the biology of myocardial aging and the aetiology of the defective cardiac performance in the elderly.

Silencing of CCR2 in myocarditis.

BACKGROUND: Myocarditis is characterized by inflammatory cell infiltration of the heart and subsequent deterioration of cardiac function. Monocytes are the most prominent population of accumulating leucocytes. We investigated whether in vivo administration of nanoparticle-encapsulated siRNA targeting chemokine (C-C motif) receptor 2 (CCR2)-a chemokine receptor crucial for leucocyte migration in humans and mice--reduces inflammation in autoimmune myocarditis. METHODS AND RESULTS: In myocardium of patients with myocarditis, CCL2 mRNA levels and CCR2(+) cells increased (P < 0.05), motivating us to pursue CCR2 silencing. Flow cytometric analysis showed that siRNA silencing of CCR2 (siCCR2) reduced the number of Ly6C(high) monocytes in hearts of mice with acute autoimmune myocarditis by 69% (P < 0.05), corroborated by histological assessment. The nanoparticle-delivered siRNA was not only active in monocytes but also in bone marrow haematopoietic progenitor cells. Treatment with siCCR2 reduced the migration of bone marrow granulocyte macrophage progenitors into the blood. Cellular magnetic resonance imaging (MRI) after injection of macrophage-avid magnetic nanoparticles detected myocarditis and therapeutic effects of RNAi non-invasively. Mice with acute myocarditis showed enhanced macrophage MRI contrast, which was prevented by siCCR2 (P < 0.05). Follow-up MRI volumetry revealed that siCCR2 treatment improved ejection fraction (P < 0.05 vs. control siRNA-treated mice). CONCLUSION: This study highlights the importance of CCR2 in the pathogenesis of myocarditis. In addition, we show that siCCR2 affects leucocyte progenitor trafficking. The data also point to a novel therapeutic strategy for the treatment of myocarditis.

Modified mRNA directs the fate of heart progenitor cells and induces vascular regeneration after myocardial infarction.

In a cell-free approach to regenerative therapeutics, transient application of paracrine factors in vivo could be used to alter the behavior and fate of progenitor cells to achieve sustained clinical benefits. Here we show that intramyocardial injection of synthetic modified RNA (modRNA) encoding human vascular endothelial growth factor-A (VEGF-A) results in the expansion and directed differentiation of endogenous heart progenitors in a mouse myocardial infarction model. VEGF-A modRNA markedly improved heart function and enhanced long-term survival of recipients. This improvement was in part due to mobilization of epicardial progenitor cells and redirection of their differentiation toward cardiovascular cell types. Direct in vivo comparison with DNA vectors and temporal control with VEGF inhibitors revealed the greatly increased efficacy of pulse-like delivery of VEGF-A. Our results suggest that modRNA is a versatile approach for expressing paracrine factors as cell fate switches to control progenitor cell fate and thereby enhance long-term organ repair.

Monocyte-directed RNAi targeting CCR2 improves infarct healing in atherosclerosis-prone mice.

BACKGROUND: Exaggerated and prolonged inflammation after myocardial infarction (MI) accelerates left ventricular remodeling. Inflammatory pathways may present a therapeutic target to prevent post-MI heart failure. However, the appropriate magnitude and timing of interventions are largely unknown, in part because noninvasive monitoring tools are lacking. Here, we used nanoparticle-facilitated silencing of CCR2, the chemokine receptor that governs inflammatory Ly-6C(high) monocyte subset traffic, to reduce infarct inflammation in apolipoprotein E-deficient (apoE(-/-)) mice after MI. We used dual-target positron emission tomography/magnetic resonance imaging of transglutaminase factor XIII (FXIII) and myeloperoxidase (MPO) activity to monitor how monocyte subset-targeted RNAi altered infarct inflammation and healing. METHODS AND RESULTS: Flow cytometry, gene expression analysis, and histology revealed reduced monocyte numbers and enhanced resolution of inflammation in infarcted hearts of apoE(-/-) mice that were treated with nanoparticle-encapsulated siRNA. To follow extracellular matrix cross-linking noninvasively, we developed a fluorine-18-labeled positron emission tomography agent ((18)F-FXIII). Recruitment of MPO-rich inflammatory leukocytes was imaged with a molecular magnetic resonance imaging sensor of MPO activity (MPO-Gd). Positron emission tomography/magnetic resonance imaging detected anti-inflammatory effects of intravenous nanoparticle-facilitated siRNA therapy (75% decrease of MPO-Gd signal; P<0.05), whereas (18)F-FXIII positron emission tomography reflected unimpeded matrix cross-linking in the infarct. Silencing of CCR2 during the first week after MI improved ejection fraction on day 21 after MI from 29% to 35% (P<0.05). CONCLUSION: CCR2-targeted RNAi reduced recruitment of Ly-6C(high) monocytes, attenuated infarct inflammation, and curbed post-MI left ventricular remodeling.