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Several etiologies may contribute to the development of excessive gingival display (EGD). However, little, if any, consideration has been given to the potentially significant role of prominent buccal maxillary exostoses (BMEs) in EGD etiology. Therefore, the aim of this report was to highlight the contribution of BMEs to EGD. Two patients complaining of EGD were evaluated, and BMEs were found associated with a hypermobile upper lip, vertical maxillary excess, and altered passive eruption. Both patients received esthetic crown lengthening (ECL) as the first surgical intervention. The BMEs were removed by osteoplasty performed during ECL. The resulting smile and EGD changes were evaluated 3 to 6 months postoperatively. An extraordinary amount of gingival display reduction was found in both patients (8 mm and 6 mm), a highly atypical outcome for ECL alone. BME removal on its own represented 75% and 67% of the EGD decrease, respectively. The exostoses removal-associated EGD decreases corresponded to observed reductions in lip mobility during smile. Sizeable BMEs can contribute significantly to the etiology of EGD, in part through an effect on lip mobility during smile. Proper management of such BMEs through osteoplasty provides meaningful EGD reduction, resulting in improvements of smile esthetics and patient satisfaction.
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Understanding how emerging infectious diseases spread within and between countries is essential to contain future pandemics. Spread to new areas requires connectivity between one or more sources and a suitable local environment, but how these two factors interact at different stages of disease emergence remains largely unknown. Further, no analytical framework exists to examine their roles. Here we develop a dynamic modelling approach for infectious diseases that explicitly models both connectivity via human movement and environmental suitability interactions. We apply it to better understand recently observed (1995-2019) patterns as well as predict past unobserved (1983-2000) and future (2020-2039) spread of dengue in Mexico and Brazil. We find that these models can accurately reconstruct long-term spread pathways, determine historical origins, and identify specific routes of invasion. We find early dengue invasion is more heavily influenced by environmental factors, resulting in patchy non-contiguous spread, while short and long-distance connectivity becomes more important in later stages. Our results have immediate practical applications for forecasting and containing the spread of dengue and emergence of new serotypes. Given current and future trends in human mobility, climate, and zoonotic spillover, understanding the interplay between connectivity and environmental suitability will be increasingly necessary to contain emerging and re-emerging pathogens.
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Dengue , Dengue/epidemiología , Dengue/transmisión , Dengue/virología , Humanos , Brasil/epidemiología , México/epidemiología , Animales , Virus del Dengue/fisiología , Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/virología , Enfermedades Transmisibles Emergentes/transmisión , Ambiente , Migración Humana , Aedes/virologíaRESUMEN
BACKGROUND: Iatrogenic blood contamination during cerebrospinal fluid (CSF) centesis is common, which can limit the diagnostic usefulness of the sample. A novel ultrasound-guided CSF collection technique is described in horses, by which CSF is obtained from the atlantoaxial (AA) space. HYPOTHESIS/OBJECTIVES: To compare ultrasound-guided AA centesis with lumbosacral (LS) centesis in South American camelids (SAC). The hypotheses were that AA centesis would yield samples with less blood contamination although being technically more challenging than LS centesis. ANIMALS: Eight clinically healthy adult SAC from a university-owned teaching herd. METHODS: Single-blinded, randomized, 4-way, 4-period crossover study in which 2 veterinarians each performed both centesis techniques on each animal once. Cytological sample analysis was performed, and the technical difficulty of sample acquisition was assessed. RESULTS: The CSF was collected successfully and without complications by either technique during all collection attempts. Aspects of technical difficulty and concentrations of CSF analytes did not vary significantly between techniques. Median total nucleated cell and red blood cell counts were 1/µL and 0.5/µL and 167.5/µL and 155/µL for AA and LS techniques, respectively. The median total protein concentration was 32.9 mg/dL and 38 mg/dL for AA and LS centeses. A median of 1 attempt was necessary for both centesis techniques and the median number of needle repositioning events was 1 for AA and 0 for LS. CONCLUSION AND CLINICAL IMPORTANCE: Depending on clinical circumstances, ultrasound-guided AA centesis appears to be an acceptable alternative to other techniques for collection of CSF from SAC.
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Líquido Cefalorraquídeo , Paracentesis , Humanos , Caballos , Animales , Paracentesis/veterinaria , Estudios Cruzados , Ultrasonografía , Recuento de Eritrocitos/veterinaria , América del SurRESUMEN
Alzheimer's Disease (AD) continues to be a leading cause of death in the US. As the US aging population (ages 65 +) expands, the impact will disproportionately affect vulnerable populations, e.g., Hispanic/Latino population, due to their AD-related health disparities. Age-related regression in mitochondrial activity and ethnic-specific differences in metabolic burden could potentially explain in part the racial/ethnic distinctions in etiology that exist for AD. Oxidation of guanine (G) to 8-oxo-guanine (8oxoG) is a prevalent lesion and an indicator of oxidative stress and mitochondrial dysfunction. Damaged mtDNA (8oxoG) can serve as an important marker of age-related systemic metabolic dysfunction and upon release into peripheral circulation may exacerbate pathophysiology contributing to AD development and/or progression. Analyzing blood samples from Mexican American (MA) and non-Hispanic White (NHW) participants enrolled in the Texas Alzheimer's Research & Care Consortium, we used blood-based measurements of 8oxoG from both buffy coat PBMCs and plasma to determine associations with population, sex, type-2 diabetes, and AD risk. Our results show that 8oxoG levels in both buffy coat and plasma were significantly associated with population, sex, years of education, and reveal a potential association with AD. Furthermore, MAs are significantly burdened by mtDNA oxidative damage in both blood fractions, which may contribute to their metabolic vulnerability to developing AD.
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Enfermedad de Alzheimer , Daño del ADN , ADN Mitocondrial , Mitocondrias , Estrés Oxidativo , Anciano , Humanos , Enfermedad de Alzheimer/genética , ADN Mitocondrial/genética , Guanina , Americanos Mexicanos/genética , Mitocondrias/genética , Estrés Oxidativo/genética , Daño del ADN/genética , Blanco/genéticaRESUMEN
Coralsnakes of the genus Micrurus are a diverse group of venomous snakes ranging from the southern United States to southern South America. Much uncertainty remains over the genus diversity, and understanding Micrurus systematics is of medical importance. In particular, the widespread Micrurus nigrocinctus spans from Mexico throughout Central America and into Colombia, with a number of described subspecies. This study provides new insights into the phylogenetic relationships within M. nigrocinctus by examining sequence data from a broad sampling of specimens from Mexico, Guatemala, Honduras, Nicaragua, Costa Rica, and Panama. The recovered phylogenetic relationships suggest that M. nigrocinctus is a species complex originating in the Pliocene and composed of at least three distinct species-level lineages. In addition, recovery of highly divergent clades supports the elevation of some currently recognized subspecies to the full species rank while others may require synonymization.
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Ponzoñas , Estados Unidos , Filogenia , América Central , Panamá , MéxicoRESUMEN
Alzheimer's disease (AD) is characterized by neurodegeneration, memory loss, and social withdrawal. Brain inflammation has emerged as a key pathogenic mechanism in AD. We hypothesized that oxytocin, a pro-social hypothalamic neuropeptide with anti-inflammatory properties, could have therapeutic actions in AD. Here, we investigated oxytocin expression in experimental models of AD, and evaluated the therapeutic potential of treatment with oxytocin. Amyloid-ß peptide oligomers (AßOs) reduced oxytocin expression in vitro and in vivo, and treatment with oxytocin prevented microglial activation induced by AßOs in purified microglial cultures. Treatment of aged APP/PS1 mice, a mouse model of AD, with intranasal oxytocin attenuated microglial activation and favored deposition of Aß in dense core plaques, a potentially neuroprotective mechanism. Remarkably, treatment with oxytocin alleviated social and non-social memory impairments in aged APP/PS1 mice. Our findings point to oxytocin as a potential therapeutic target to reduce brain inflammation and correct memory deficits in AD.
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CRISPR/Cas9 gene editing technology is an indispensable and powerful tool in the field of cancer biology. To conduct successful CRISPR-based experiments, it is crucial that sgRNAs generate their designed alterations. Here, we describe a simple and efficient sgRNA screening method for validating sgRNAs that generate oncogenic gene rearrangements. We used IL3-independence in Ba/F3 cells as an assay to identify sgRNA pairs that generate fusion oncogenes involving the Ret and Ntrk1 tyrosine kinases. We confirmed these rearrangements with PCR or RT-PCR as well as sequencing. Ba/F3 cells harboring Ret or Ntrk1 rearrangements acquired sensitivity to RET and TRK inhibitors, respectively. Adenoviruses encoding Cas9 and sgRNAs that catalyze the Kif5b-Ret and Trim24-Ret rearrangements were intratracheally instilled into mice and yielded lung adenocarcinomas. A cell line (TR.1) was established from a Trim24-Ret positive tumor that exhibited high in vitro sensitivity to RET-specific TKIs. Moreover, orthotopic transplantation of TR.1 cells into the left lung yielded well-defined tumors that shrank in response to LOXO-292 treatment. The method offers an efficient means to validate sgRNAs that successfully target their intended loci for the generation of novel murine oncogene-driven tumor models.
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Alzheimer's Disease (AD) continues to be a leading cause of death in the US. As the US aging population (ages 65+) expands, the impact will disproportionately affect vulnerable populations, e.g., Hispanic/Latinx population, due to their AD-related health disparities. Age-related regression in mitochondrial activity and ethnic-specific differences in metabolic burden could potentially explain in part the racial/ethnic distinctions in etiology that exist for AD. Oxidation of guanine (G) to 8-oxo-guanine (8oxoG) is a prevalent lesion and an indicator of oxidative stress and mitochondrial dysfunction. Damaged mtDNA (8oxoG) can serve as an important marker of age-related systemic metabolic dysfunction and upon release into peripheral circulation may exacerbate pathophysiology contributing to AD development and/or progression. Analyzing blood samples from Mexican American (MA) and non-Hispanic White (NHW) participants enrolled in the Texas Alzheimer's Research & Care Consortium, we used blood-based measurements of 8oxoG from both buffy coat PBMCs and plasma to determine associations with population, sex, type-2 diabetes, and AD risk. Our results show that 8oxoG levels in both buffy coat and plasma were significantly associated with population, sex, years of education, and reveal a potential association with AD. Furthermore, MAs are significantly burdened by mtDNA oxidative damage in both blood fractions, which may contribute to their metabolic vulnerability to developing AD.
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Current knowledge of dengue virus (DENV) transmission provides only a partial understanding of a complex and dynamic system yielding a public health track record that has more failures than successes. An important part of the problem is that the foundation for contemporary interventions includes a series of longstanding, but untested, assumptions based on a relatively small portion of the human population; i.e., people who are convenient to study because they manifest clinically apparent disease. Approaching dengue from the perspective of people with overt illness has produced an extensive body of useful literature. It has not, however, fully embraced heterogeneities in virus transmission dynamics that are increasingly recognized as key information still missing in the struggle to control the most important insect-transmitted viral infection of humans. Only in the last 20 years have there been significant efforts to carry out comprehensive longitudinal dengue studies. This manuscript provides the rationale and comprehensive, integrated description of the methodology for a five-year longitudinal cohort study based in the tropical city of Iquitos, in the heart of the Peruvian Amazon. Primary data collection for this study was completed in 2019. Although some manuscripts have been published to date, our principal objective here is to support subsequent publications by describing in detail the structure, methodology, and significance of a specific research program. Our project was designed to study people across the entire continuum of disease, with the ultimate goal of quantifying heterogeneities in human variables that affect DENV transmission dynamics and prevention. Because our study design is applicable to other Aedes transmitted viruses, we used it to gain insights into Zika virus (ZIKV) transmission when during the project period ZIKV was introduced and circulated in Iquitos. Our prospective contact cluster investigation design was initiated by detecttion of a person with a symptomatic DENV infection and then followed that person's immediate contacts. This allowed us to monitor individuals at high risk of DENV infection, including people with clinically inapparent and mild infections that are otherwise difficult to detect. We aimed to fill knowledge gaps by defining the contribution to DENV transmission dynamics of (1) the understudied majority of DENV-infected people with inapparent and mild infections and (2) epidemiological, entomological, and socio-behavioral sources of heterogeneity. By accounting for factors underlying variation in each person's contribution to transmission we sought to better determine the type and extent of effort needed to better prevent virus transmission and disease.
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Arbovirus , Virus del Dengue , Dengue , Infección por el Virus Zika , Virus Zika , Humanos , Estudios Longitudinales , Estudios Prospectivos , Perú/epidemiología , Infección por el Virus Zika/epidemiologíaRESUMEN
OBJECTIVE: To address the challenge in urology in recruiting physicians from backgrounds racially and ethnically underrepresented in medicine (URiM), we sought to design, implement, and evaluate methods for recruiting URiM candidates to our urology residency program. METHODS: We developed a 3-pronged approach aimed at increasing the number of interviewed applicants, and subsequently number of URiM residents recruited to our program. The 3 facets included: (1) funded visiting student rotation, (2) holistic evaluation of applications, (3) implemented targeted outreach. Statistical analysis of the applicants interviewed and matched into our residency program, as well as traditional metrics used for residency recruitment, were performed from 2015 to 2022. RESULTS: The number of URiM interviewees significantly increased from 6.1% in 2015 to its peak, 40%, in 2020. In 2015, there were no URiM residents in our urology residency program. By 2022, the total URiM complement increased to 35%. In evaluating traditional metrics of residency recruitment, there was no significant difference in mean USMLE Step 1 score before compared with after the implementation of our recruitment approach. The maximum rank number reached to fill the urology residency positions also remained relatively stable throughout the study period, with a range from 5 to 38. CONCLUSION: We demonstrate that the implementation of our innovative and intentional 3-pronged recruitment approach effectively increased the number of URiM interviewees and residents in our residency program. The diversification of our urology workforce depends on the implementation of such efforts, and we encourage urologists to lead the way on such initiatives.
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Internado y Residencia , Urología , Humanos , Urología/educación , Recursos Humanos , Benchmarking , UrólogosRESUMEN
BACKGROUND: Developmental cardiac tissue holds remarkable capacity to regenerate after injury and consists of regenerative mononuclear diploid cardiomyocytes. On maturation, mononuclear diploid cardiomyocytes become binucleated or polyploid and exit the cell cycle. Cardiomyocyte metabolism undergoes a profound shift that coincides with cessation of regeneration in the postnatal heart. However, whether reprogramming metabolism promotes persistence of regenerative mononuclear diploid cardiomyocytes enhancing cardiac function and repair after injury is unknown. Here, we identify a novel role for RNA-binding protein LIN28a, a master regulator of cellular metabolism in cardiac repair after injury. METHODS: LIN28a overexpression was tested using mouse transgenesis on postnatal cardiomyocyte numbers, cell cycle, and response to apical resection injury. With the use of neonatal and adult cell culture systems and adult and Mosaic Analysis with Double Markers myocardial injury models in mice, the effect of LIN28a overexpression on cardiomyocyte cell cycle and metabolism was tested. Last, isolated adult cardiomyocytes from LIN28a and wild-type mice 4 days after myocardial injury were used for RNA-immunoprecipitation sequencing. RESULTS: LIN28a was found to be active primarily during cardiac development and rapidly decreases after birth. LIN28a reintroduction at postnatal day (P) 1, P3, P5, and P7 decreased maturation-associated polyploidization, nucleation, and cell size, enhancing cardiomyocyte cell cycle activity in LIN28a transgenic pups compared with wild-type littermates. Moreover, LIN28a overexpression extended cardiomyocyte cell cycle activity beyond P7 concurrent with increased cardiac function 30 days after apical resection. In the adult heart, LIN28a overexpression attenuated cardiomyocyte apoptosis, enhanced cell cycle activity, cardiac function, and survival in mice 12 weeks after myocardial infarction compared with wild-type littermate controls. Instead, LIN28a small molecule inhibitor attenuated the proreparative effects of LIN28a on the heart. Neonatal rat ventricular myocytes overexpressing LIN28a mechanistically showed increased glycolysis, ATP production, and levels of metabolic enzymes compared with control. LIN28a immunoprecipitation followed by RNA-immunoprecipitation sequencing in cardiomyocytes isolated from LIN28a-overexpressing hearts after injury identified long noncoding RNA-H19 as its most significantly altered target. Ablation of long noncoding RNA-H19 blunted LIN28a-induced enhancement on cardiomyocyte metabolism and cell cycle activity. CONCLUSIONS: Collectively, LIN28a reprograms cardiomyocyte metabolism and promotes persistence of mononuclear diploid cardiomyocytes in the injured heart, enhancing proreparative processes, thereby linking cardiomyocyte metabolism to regulation of ploidy/nucleation and repair in the heart.
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Infarto del Miocardio , ARN Largo no Codificante , Proteínas de Unión al ARN , Animales , Ratones , Ratas , Animales Recién Nacidos , Ciclo Celular , Proliferación Celular , Corazón/fisiología , Miocitos Cardíacos/metabolismo , Regeneración/fisiología , ARN Largo no Codificante/metabolismo , Proteínas de Unión al ARN/metabolismoRESUMEN
The present study examined how the dosage and quality of the federal preschool program "Head Start" (HS) in the US related to children's self-regulation skills in kindergarten. Using Propensity Score Matching and multiple regression (OLS), this study explored how the number of years and hours a week of HS were related to self-regulation among 2,383 children, who entered the program either at 3 or 4 years old. An additional year in HS was significantly positively associated with self-regulation in kindergarten, while the number of hours a week in HS was not. However, the quality of teacher-child interactions moderated the relation between hours a week in HS and self-regulation. Findings contribute to the growing body of evidence about how dosage and quality of early childhood education experiences relate to children's development.
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OBJECTIVES: To validate a computational phenotype that identifies acute brain dysfunction (ABD) based on clinician concern for neurologic or behavioral changes in pediatric sepsis. DESIGN: Retrospective observational study. SETTING: Single academic children's hospital. PATIENTS: Four thousand two hundred eighty-nine index sepsis episodes. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: An existing computational phenotype of ABD was optimized to include routinely collected variables indicative of clinician concern for acute neurologic or behavioral change (completion of CT or MRI, electroencephalogram, or new antipsychotic administration). First, the computational phenotype was compared with an ABD reference standard established from chart review of 527 random sepsis episodes to determine criterion validity. Next, the computational phenotype was compared with a separate validation cohort of 3,762 index sepsis episodes to determine content and construct validity. Criterion validity for the final phenotype had sensitivity 83% (95% CI, 76-89%), specificity 93% (90-95%), positive predictive value 84% (77-89%), and negative predictive value 93% (90-96%). In the validation cohort, the computational phenotype identified ABD in 35% (95% CI 33-36%). Content validity was demonstrated as those with the ABD computational phenotype were more likely to have characteristics of neurologic dysfunction and severe illness than those without the ABD phenotype, including nonreactive pupils (15% vs 1%; p < 0.001), Glasgow Coma Scale less than 5 (44% vs 12%; p < 0.001), greater than or equal to two nonneurologic organ dysfunctions (50% vs 25%; p < 0.001), and need for intensive care (81% vs 65%; p < 0.001). Construct validity was demonstrated by higher odds for mortality (odds ratio [OR], 6.9; 95% CI, 5.3-9.1) and discharge to rehabilitation (OR, 11.4; 95% CI 7.4-17.5) in patients with, versus without, the ABD computational phenotype. CONCLUSIONS: A computational phenotype of ABD indicative of clinician concern for new neurologic or behavioral change offers a valid retrospective measure to identify episodes of sepsis that involved ABD. This computational phenotype provides a feasible and efficient way to study risk factors for and outcomes from ABD using routinely collected clinical data.
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Encefalopatías , Sepsis , Humanos , Estudios Retrospectivos , Mortalidad Hospitalaria , Sepsis/diagnóstico , Encefalopatías/diagnóstico , Encefalopatías/etiología , Fenotipo , Encéfalo/diagnóstico por imagenRESUMEN
Mexican Americans (MAs) are the fastest-growing Hispanic population segment in the US; as this population increases in age, so will the societal burden of age-related diseases such as Alzheimer's disease (AD). Mitochondrial DNA (mtDNA) damage may be implicated in MA AD risk since metabolic comorbidities are more prevalent in this group. Oxidative damage to guanosine (8oxoG) is one of the most prevalent DNA lesions and a putative indicator of mitochondrial dysfunction. Testing blood samples from participants of the Texas Alzheimer's Research and Care Consortium, we found mtDNA 8oxoG mutational load to be significantly higher in MAs compared to non-Hispanic whites and that MA females are differentially affected. Furthermore, we identified specific mtDNA haplotypes that confer increased risk for oxidative damage and suggestive evidence that cognitive function may be related to 8oxoG burden. Our understanding of these phenomena will elucidate population- and sex-specific mechanisms of AD pathogenesis, informing the development of more precise interventions and therapeutic approaches for MAs with AD in the future.
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Imaging plays an essential role in diagnosing and managing musculoskeletal soft tissue masses. It provides anatomic details and aids in the characterization and prognostication of tumors. Advanced imaging is also essential for assessing treatment response and post-treatment surveillance. Several novel imaging techniques are now available that provide additional functional and metabolic information about these tumors. This additional information may be used to predict the biological behavior of the tumors and effectively assess the treatment response for optimizing their management. This article focuses on multiparametric imaging evaluation of soft tissue masses with a discussion of advancements in the domains of ultrasound, MRI, and CT imaging and how these may be helpful in pre- and post-treatment assessment of soft tissue tumors. Current perspectives on the role of diffusion imaging, perfusion imaging, and MR spectroscopy have been highlighted, and future directions of metabolic imaging are briefly outlined. As these advances hold a promising role in the multidisciplinary management of soft tissue sarcomas, it is important for the radiologist to be familiar with the latest advances and developments in imaging soft tissue tumors.
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Sistema Musculoesquelético , Sarcoma , Neoplasias de los Tejidos Blandos , Humanos , Imagen por Resonancia Magnética/métodos , Sistema Musculoesquelético/patología , Sarcoma/diagnóstico por imagen , Sarcoma/patología , Sarcoma/terapia , Neoplasias de los Tejidos Blandos/diagnóstico por imagenRESUMEN
Over half the world's population is at risk for viruses transmitted by Aedes mosquitoes, such as dengue and Zika. The primary vector, Aedes aegypti, thrives in urban environments. Despite decades of effort, cases and geographic range of Aedes-borne viruses (ABVs) continue to expand. Rigorously proven vector control interventions that measure protective efficacy against ABV diseases are limited to Wolbachia in a single trial in Indonesia and do not include any chemical intervention. Spatial repellents, a new option for efficient deployment, are designed to decrease human exposure to ABVs by releasing active ingredients into the air that disrupt mosquito-human contact. A parallel, cluster-randomized controlled trial was conducted in Iquitos, Peru, to quantify the impact of a transfluthrin-based spatial repellent on human ABV infection. From 2,907 households across 26 clusters (13 per arm), 1,578 participants were assessed for seroconversion (primary endpoint) by survival analysis. Incidence of acute disease was calculated among 16,683 participants (secondary endpoint). Adult mosquito collections were conducted to compare Ae. aegypti abundance, blood-fed rate, and parity status through mixed-effect difference-in-difference analyses. The spatial repellent significantly reduced ABV infection by 34.1% (one-sided 95% CI lower limit, 6.9%; one-sided P value = 0.0236, z = 1.98). Aedes aegypti abundance and blood-fed rates were significantly reduced by 28.6 (95% CI 24.1%, ∞); z = -9.11) and 12.4% (95% CI 4.2%, ∞); z = -2.43), respectively. Our trial provides conclusive statistical evidence from an appropriately powered, preplanned cluster-randomized controlled clinical trial of the impact of a chemical intervention, in this case a spatial repellent, to reduce the risk of ABV transmission compared to a placebo.
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Aedes , Repelentes de Insectos , Control de Mosquitos , Mosquitos Vectores , Enfermedades Transmitidas por Vectores , Adulto , Animales , Dengue/epidemiología , Dengue/prevención & control , Humanos , Control de Mosquitos/normas , Perú/epidemiología , Enfermedades Transmitidas por Vectores/epidemiología , Enfermedades Transmitidas por Vectores/prevención & control , Enfermedades Transmitidas por Vectores/transmisión , Virus Zika , Infección por el Virus ZikaRESUMEN
Objective: To assess the prevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in selected health clinics in the three largest urban areas in Nicaragua, where data regarding coronavirus disease 2019 (COVID-19) testing, morbidity and mortality is severely limited. Methods: In this cross-sectional study, participants were tested for SARS-CoV-2 RNA by loop-mediated isothermal amplification (LAMP), and were tested for antibodies using immunoassays. A questionnaire recorded subjects' COVID-19-associated symptoms and risk factors. Data were collected from 22 February to 19 March 2021, 1 year after the first confirmed cases of SARS-CoV-2 in Nicaragua. Study participants were enrolled while attending routine check-ups or seeking care unrelated to COVID-19. Study participation was random and voluntary. All patients were eligible to participate. Symptom history was not part of the eligibility criteria. Results: The prevalence of current SARS-CoV-2 infection was high (14%, LAMP-positive/seronegative). Antibody testing showed higher overall seroprevalence (38%). Cough was the symptom most strongly associated with being LAMP-positive (odds ratio 3.57, 95% confidence interval 2.65-4.81). Loss of smell had the highest positive predictive value, and was significantly associated with being LAMP-positive. Conclusion: The prevalence of current SARS-CoV-2 infection and seropositivity were fairly high. More than half of the sample population had evidence of current or past infection. Knowledge of this previously unknown elevated level of infection is crucial for healthcare providers and policy makers.
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Acid-sensing ion channels (ASICs) are sensitized to activation by inflammatory mediators such as the polyunsaturated fatty acid (PUFA) arachidonic acid (AA). Previous work has shown that AA can potentiate ASIC currents at subsaturating proton concentrations, but the structural mechanisms of this change in gating are not understood. Here we show that PUFAs cause multiple gating changes in ASIC3, including shifting the pH dependence of activation, slowing the rate of desensitization, and increasing the current even at a saturating pH. The impact on gating depends on the nature of both the head and tail of the lipid, with the head group structure primarily determining the magnitude of the effect on the channel. An N-acyl amino acid (NAAA), arachidonyl glycine (AG), is such a strong regulator that it can act as a ligand at neutral pH. Mutation of an arginine in the outer segment of TM1 (R64) eliminated the effect of docosahexaenoic acid (DHA) even at high concentrations, suggesting a potential interaction site for the lipid on the channel. Our results suggest a model in which PUFAs bind to ASICs via both their tail group and an electrostatic interaction between the negatively charged PUFA head group and the positively charged arginine side chain. These data provide the first look at the structural features of lipids that are important for modulating ASICs and suggest a potential binding site for PUFAs on the channel.