The TIRS trial: Enrollment procedures and baseline characterization of a pediatric cohort to quantify the epidemiologic impact of targeted indoor residual spraying on Aedes-borne viruses in Merida, Mexico.

Aedes mosquito-borne viruses (ABVs) place a substantial strain on public health resources in the Americas. Vector control of Aedes mosquitoes is an important public health strategy to decrease or prevent spread of ABVs. The ongoing Targeted Indoor Residual Spraying (TIRS) trial is an NIH-sponsored clinical trial to study the efficacy of a novel, proactive vector control technique to prevent dengue virus (DENV), Zika virus (ZIKV), and chikungunya virus (CHIKV) infections in the endemic city of Merida, Yucatan, Mexico. The primary outcome of the trial is laboratory-confirmed ABV infections in neighborhood clusters. Despite the difficulties caused by the COVID-19 pandemic, by early 2021 the TIRS trial completed enrollment of 4,792 children aged 2-15 years in 50 neighborhood clusters which were allocated to control or intervention arms via a covariate-constrained randomization algorithm. Here, we describe the makeup and ABV seroprevalence of participants and mosquito population characteristics in both arms before TIRS administration. Baseline surveys showed similar distribution of age, sex, and socio-economic factors between the arms. Serum samples from 1,399 children were tested by commercially available ELISAs for presence of anti-ABV antibodies. We found that 45.1% of children were seropositive for one or more flaviviruses and 24.0% were seropositive for CHIKV. Of the flavivirus-positive participants, most were positive for ZIKV-neutralizing antibodies by focus reduction neutralization testing which indicated a higher proportion of participants with previous ZIKV than DENV infections within the cohort. Both study arms had statistically similar seroprevalence for all viruses tested, similar socio-demographic compositions, similar levels of Ae. aegypti infestation, and similar observed mosquito susceptibility to insecticides. These findings describe a population with a high rate of previous exposure to ZIKV and lower titers of neutralizing antibodies against DENV serotypes, suggesting susceptibility to future outbreaks of flaviviruses is possible, but proactive vector control may mitigate these risks.

Vulnerability of Eastern Tropical Pacific chondrichthyan fish to climate change.

Climate change is an environmental emergency threatening species and ecosystems globally. Oceans have absorbed about 90% of anthropogenic heat and 20%-30% of the carbon emissions, resulting in ocean warming, acidification, deoxygenation, changes in ocean stratification and nutrient availability, and more severe extreme events. Given predictions of further changes, there is a critical need to understand how marine species will be affected. Here, we used an integrated risk assessment framework to evaluate the vulnerability of 132 chondrichthyans in the Eastern Tropical Pacific (ETP) to the impacts of climate change. Taking a precautionary view, we found that almost a quarter (23%) of the ETP chondrichthyan species evaluated were highly vulnerable to climate change, and much of the rest (76%) were moderately vulnerable. Most of the highly vulnerable species are batoids (77%), and a large proportion (90%) are coastal or pelagic species that use coastal habitats as nurseries. Six species of batoids were highly vulnerable in all three components of the assessment (exposure, sensitivity and adaptive capacity). This assessment indicates that coastal species, particularly those relying on inshore nursery areas are the most vulnerable to climate change. Ocean warming, in combination with acidification and potential deoxygenation, will likely have widespread effects on ETP chondrichthyan species, but coastal species may also contend with changes in freshwater inputs, salinity, and sea level rise. This climate-related vulnerability is compounded by other anthropogenic factors, such as overfishing and habitat degradation already occurring in the region. Mitigating the impacts of climate change on ETP chondrichthyans involves a range of approaches that include addressing habitat degradation, sustainability of exploitation, and species-specific actions may be required for species at higher risk. The assessment also highlighted the need to further understand climate change's impacts on key ETP habitats and processes and identified knowledge gaps on ETP chondrichthyan species.

El cambio climático es una emergencia medioambiental que amenaza a especies y ecosistemas en todo el mundo. Los océanos han absorbido alrededor del 90% del calor antropogénico y entre el 20% y el 30% de las emisiones de carbono, lo que ha provocado su calentamiento, acidificación, desoxigenación, cambios en la estratificación de los océanos y en la disponibilidad de nutrientes, así como fenómenos extremos más pronunciados. Dadas las predicciones de cambios, hay una importante necesidad de entender cómo las especies marinas se verán afectadas. En este estudio utilizamos una Evaluación Integrada de Riesgos para evaluar la vulnerabilidad de 132 condrictios del Pacífico Tropical Oriental (PTO) a los impactos del cambio climático. Adoptando un enfoque preventivo, estimamos que la vulnerabilidad general al cambio climático es Alta para casi una cuarta parte (23%) de las especies de condrictios del PTO evaluadas y Moderada para gran parte del resto (76%). La mayoría de las especies altamente vulnerables son batoideos (77%), y una gran proporción de éstas (90%) son especies costeras o especies pelágicas que utilizan los hábitats costeros como áreas de crianza. Seis especies de batoideos tuvieron una vulnerabilidad Alta en los tres componentes de la evaluación. Esta evaluación indica que las especies costeras, en particular las que dependen de áreas de crianza costeras, son las más vulnerables al cambio climático. Es probable que el calentamiento de los océanos, junto con la acidificación y la posible desoxigenación, tenga efectos generalizados sobre las especies de condrictios del PTO, pero las especies costeras se verán también afectadas por los cambios en los aportes de agua dulce, la salinidad y el aumento del nivel del mar. Esta vulnerabilidad relacionada con el clima se ve agravada por otros factores antropogénicos que ya se están produciendo en la región, como la sobrepesca y la degradación del hábitat. La mitigación de los impactos del cambio climático sobre los condrictios del PTO implica medidas que incluyan abordar la degradación del hábitat y la sostenibilidad de la explotación pesquera, y acciones para las especies de mayor riesgo son necesarias. Esta evaluación también destaca la necesidad de comprender mejor los impactos del cambio climático en los hábitats y procesos clave del PTO y las lagunas de conocimiento identificadas en relación con las especies de condrictios del PTO.

Reducing FKBP51 Expression in the Ventral Hippocampus Decreases Auditory Fear Conditioning in Male Rats.

Fear conditioning evokes a physiologic release of glucocorticoids that assists learning. As a cochaperone in the glucocorticoid receptor complex, FKBP51 modulates stress-induced glucocorticoid signaling and may influence conditioned fear responses. This study combines molecular and behavioral approaches to examine whether locally reducing FKBP51 expression in the ventral hippocampus is sufficient to affect fear-related behaviors. We hypothesized that reducing FKBP51 expression in the VH would increase glucocorticoid signaling to alter auditory fear conditioning. Adult male rats were injected with an adeno-associated virus (AAV) vector expressing short hairpin - RNAs (shRNA) targeting FKBP5 into the ventral hippocampus to reduce FKBP5 levels or a control AAV. Infusion of FKBP5-shRNA into the ventral hippocampus decreased auditory fear acquisition and recall. Although animals injected with FKBP5-shRNA showed less freezing during extinction recall, the difference was due to a reduced fear recall rather than improved extinction. Reducing ventral hippocampus FKBP51 did not affect exploratory behavior in either the open field test or the elevated zero maze test but did increase passive behavior in the forced swim test, suggesting that the reduction in auditory fear recall was not due to more active responses to acute stress. Furthermore, lower ventral hippocampus FKBP51 levels did not alter corticosterone release in response to restraint stress, suggesting that the reduced fear recall was not due to lower corticosterone release. Our findings suggest FKBP51 in the ventral hippocampus plays a selective role in modulating fear-learning processes and passive behavioral responses to acute stress rather than hypothalamic-pituitary-adrenal axis reactivity or exploratory responses.

Evidence of Ongoing Transmission of Zika Virus in Mérida, Mexico.

Since the Zika virus (ZIKV) pandemic in 2015-2017, there has been a near absence of reported cases in the Americas outside of Brazil. However, the conditions for Aedes-borne transmission persist in Latin America, and the threat of ZIKV transmission is increasing as population immunity wanes. Mexico has reported only 70 cases of laboratory-confirmed ZIKV infection since 2020, with no cases recorded in the Yucatán peninsula. Here, we provide evidence of active ZIKV transmission, despite the absence of official case reports, in the city of Mérida, Mexico, the capital of the state of Yucatán. Capitalizing on an existing cohort, we detected cases in participants with symptoms consistent with flavivirus infection from 2021 to 2022. Serum samples from suspected cases were tested for ZIKV RNA by polymerase chain reaction or ZIKV-reactive IgM by ELISA. To provide more specific evidence of exposure, focus reduction neutralization tests were performed on ELISA-positive samples. Overall, we observed 25 suspected ZIKV infections for an estimated incidence of 2.8 symptomatic cases per 1,000 persons per year. Our findings emphasize the continuing threat of ZIKV transmission in the setting of decreased surveillance and reporting.

Heavy metal and trace element concentrations in the blood of scalloped hammerhead sharks (Sphyrna lewini) from La Paz Bay, México.

Sharks are particularly susceptible to bioaccumulation due to their life history characteristics and trophic position within marine ecosystems. Despite this, studies of bioaccumulation cover only a small proportion of extant species. In this study we report concentrations of trace elements and heavy metals in blood samples of Sphyrna lewini for the first time. We report high concentrations of several trace elements and heavy metals, with concentrations of some elements exceeding the limit determined safe for human consumption. High elemental concentrations may reflect biochemical differences between blood plasma and other tissues; however, they may also be symptomatic of high levels of exposure triggered by anthropogenic activities. We also provide evidence of elemental accumulation through ontogeny, the nature of which differs from that previously reported. Ultimately, this baseline study increases our understanding of interspecific and intraspecific variation in bioaccumulation and ecotoxicology in elasmobranchs which may prove important in ensuring adequate management.

Promoting crucial team building, collaboration, and communication skills in graduate students through interactive retreats.

Biomedical graduate students receive intensive training in their scientific area of interest yet need additional skills for successful scientific careers. Our aim was to promote team building, improve collaborations and enhance communication skills. An off-site yearly retreat was organized for the graduate students in our NIH-funded Research Initiative for Scientific Enhancement (RISE) graduate training program. Retreat themes were addressed through short presentations, case studies, live podcasts, webinars, focus groups, role-play, and breakout sessions with various team building exercises to practice communication skills and identify abilities, knowledge, values, and behaviors. Trainees gave short presentations and served as discussion leaders on topics related to the central theme. Expert guest speakers participated in discussion sessions with the trainees. Trainees evaluated the retreats at the end. A total of 48 trainees, 12 RISE Program faculty and staff, and 26 external speakers from industry, academia, media/journalism, the arts, psychology, and holistic medical fields participated over 9 years. The overall average benefit of the in-person retreats was rated 4.80 on a Likert scale of 1-5 by trainees. Trainees particularly enjoyed the informal interactions with program faculty, staff, and fellow trainees. They appreciated the opportunity to learn soft skills, such as interpersonal communication, conflict resolution, and leadership. Two additional retreats conducted virtually because of the COVID-19 pandemic were perceived as less beneficial. We conclude that off-site interactive retreats are a valuable tool for enhancing soft skills and a sense of team identity in a biomedical sciences graduate program, while covering important issues related to scientific careers.NEW & NOTEWORTHY Off-site interactive science-related retreats are a valuable tool for enhancing soft skills and sense of team identity in a biomedical sciences graduate program, while covering important issues related to pursuing a career in science. There are many perceived benefits, so we encourage other training programs to include a similar type of regular activity in students' training with the goal of improving trainee well-being and supporting their academic and research productivity.

Sex-dependent effects of angiotensin II type 1 receptor blocker on molecular and behavioral changes induced by single prolonged stress.

Post-traumatic stress disorder (PTSD) is a neuropsychiatric disorder that not only entails alterations in fear behavior and anxiety but also includes neuroendocrine dysfunctions involving the hypothalamic pituitary adrenal (HPA) axis and the renin-angiotensin system. Recent preclinical studies demonstrate that activation of the angiotensin type 1 receptor (AT1R) in the paraventricular region of the hypothalamus (PVR) promotes anxiety-like behaviors and enables microglia proliferation. An increase in microglia and anxiety-like behavior also occurs in the PTSD animal model single-prolonged stress (SPS). In the present study, we tested whether AT1Rs contribute to the effects of SPS on behavior and microglia in brain structures important for HPA axis regulation and fear behavior. To test this, male and female animals were exposed to SPS and then given the oral AT1R antagonist candesartan beginning one week later. Candesartan did not alter auditory fear conditioning or extinction in SPS-exposed male or female animals. However, we found that the male animals exposed to SPS showed increased anxiety-like behavior, which was reversed by candesartan. In contrast, neither SPS nor candesartan altered anxiety-like behavior in the female animals. At the molecular level, SPS increased the cellular expression of AT1Rs in the PVR of male animals and candesartan reversed this effect, whereas AT1Rs in the PVR of females were unaltered by either SPS or candesartan. Iba1-expressing microglia increased in the PVR after SPS exposure and was reversed by candesartan in both sexes suggesting that SPS stimulates AT1Rs to increase microglia in the PVR. Collectively, these results suggest that the contribution of AT1Rs to the molecular and behavioral effects of SPS is sex-dependent.

Extracorporeal Membrane Oxygenation for Neonates With Congenital Diaphragmatic Hernia: Prevalence of Seizures and Outcomes.

OBJECTIVES: We aimed to determine the prevalence of electrographic seizures and associated odds of adverse outcomes of electrographic seizures in neonates with congenital diaphragmatic hernia (CDH) receiving extracorporeal membrane oxygenation (ECMO). DESIGN: Retrospective, descriptive case series. SETTING: Neonatal ICU (NICU) in a quaternary care institution. PATIENTS: All neonates with CDH receiving ECMO undergoing continuous electroencephalographic monitoring (CEEG) and follow-up between January 2012 and December 2019. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: All eligible neonates with CDH receiving ECMO underwent CEEG (n = 75). Electrographic seizures occurred in 14 of 75 (19%): they were exclusively electrographic-only in nine of 14, both electrographic-only and electroclinical in three of 14, and electroclinical only in two of 14. Two neonates developed status epilepticus. We identified an association between presence of seizures, rather than not, and longer duration of initial session of CEEG monitoring (55.7 hr [48.2-87.3 hr] vs 48.0 hr [43.0-48.3 hr]; p = 0.001). We also found an association between presence of seizures, rather than not, and greater odds of use of a second CEEG monitoring (12/14 vs 21/61; odds ratio [OR], 11.43 [95% CI, 2.34-55.90; p = 0.0026). Most neonates with seizures (10/14), experienced their onset of seizures more than 96 hours after the start of ECMO. Overall, the presence of electrographic seizures, compared with not, was associated with lower odds of survival to NICU discharge (4/14 vs 49/61; OR 0.10 [95% CI 0.03 to 0.37], p = 0.0006). Also, the presence of seizures-rather than not-was associated with greater odds of a composite of death and all abnormal outcomes on follow-up (13/14 vs 26/61; OR, 17.5; 95% CI, 2.15-142.39; p = 0.0074). CONCLUSIONS: Nearly one in five neonates with CDH receiving ECMO developed seizures during the ECMO course. Seizures were predominantly electrographic-only and when present were associated with great odds of adverse outcomes. The current study provides evidence to support standardized CEEG in this population.

Multistakeholder Perspectives on Interventions to Support Youth During Mental Health Boarding.

OBJECTIVE: To identify and prioritize opportunities to improve the psychiatric boarding experience for youth awaiting admission or transfer to inpatient psychiatric care. STUDY DESIGN: This study utilized an exploratory mixed methods design. The study team convened multidisciplinary stakeholder focus groups to discuss proposed hospital-based solutions to mental health boarding, potential psychosocial interventions deliverable during boarding, and outcomes measurement. Focus group responses were transcribed and analyzed to extract themes pertaining to these improvement opportunities. These results informed a follow-up survey which was then sent to the stakeholders to rate the feasibility and importance of modifications using a modified RAND-UCLA Appropriateness Method. RESULTS: Qualitative analyses revealed 9 themes across 2 domains related to psychiatric boarding care: in-hospital improvements and transitions of care. The follow-up survey identified 6 improvement opportunities rated as both feasible and important. Additionally, 6 psychosocial interventions, 2 delivery modalities, and 5 outcomes were rated as both feasible and important. CONCLUSIONS: Stakeholders concerned with the psychiatric boarding of youth identified numerous opportunities for improving the boarding process within 2 domains of in-hospital improvements and transitions of care. Most of the improvements were considered feasible and important with several serving as particularly viable strategies. These have the potential for implementation to improve the care of this vulnerable population and inform local and national quality improvement efforts.

A priority nursery area for the conservation of the scalloped hammerhead shark Sphyrna lewini in Mexico.

This study describes the genetic diversity and level of genetic differentiation of the scalloped hammerhead shark Sphyrna lewini from eight putative nursery areas in the Mexican Pacific Ocean, using the mtDNA control region. Genetic analyses revealed a particular spatial divergence between La Reforma and all the remaining sites, with five exclusive haplotypes and the highest genetic diversity. This pattern may be interpreted as the signature of regional female philopatry, relatively to a particular female-mediated gene flow for La Reforma, which shows a strong subdivision in the Gulf of California.

Infusion of C20:0 ceramide into ventral hippocampus triggers anhedonia-like behavior in female and male rats.

Increased long-chain C20:0 ceramides have been found in the serum of patients with depression. Moreover, ceramides are linked with increased microglia reactivity and inflammatory cytokine production, which are associated with depression. Since ceramides can readily cross the blood brain barrier, peripheral C20:0 ceramides could enter the brain, activate microglia, and induce depressive-like behavior. In this study, we determined whether localized infusion of C20:0 ceramides into the ventral hippocampus (VH) of rats is sufficient to activate microglia and induce depressive-like behaviors. Adult male and female rats received infusions of C20:0 ceramides or vehicle solution every other day for 2 weeks. After the third infusion, C20:0-infused animals showed reduced sucrose preference suggesting anhedonia-like behavior. In contrast, infusions of C20:0 ceramides did not affect immobility in the forced swim test or sucrose grooming suggesting that the behavioral effects of ceramides are task dependent. Furthermore, C20:0-infusions did not increase Iba-1 + microglia or inflammatory markers in the VH suggesting that localized increases in C20:0 ceramides in the VH are sufficient to induce anhedonia-like behavior without microglia activation.

Human IgG antibody responses to severe acute respiratory syndrome coronavirus 2 viral antigens receptor-binding domain, spike, and nucleocapsid, in vaccinated adults from Merida, Mexico.

Several vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been approved for controlling the coronavirus disease 2019 (COVID-19) pandemic worldwide. Antibody response is essential to understand the immune response to different viral targets after vaccination with different vaccine platforms. Thus, the main aim of this study was to describe how vaccination with two distinct SARS-CoV-2 vaccine preparations elicit IgG antibody specific responses against two antigenically relevant SARS-CoV-2 viral proteins: the receptor-binding domain (RBD) and the full-length spike (S). To do so, SARS-CoV-2 protein specific in-house enzyme-linked immunosorbent assays (ELISAs) were standardized and tested against serum samples collected from 89 adults, recipients of either a single-dose of the Spike-encoding mRNA-based Pfizer/BioNTech (Pf-BNT) (70%, 62/89) or the Spike-encoding-Adenovirus-5-based CanSino Biologics Inc. (CSBIO) (30%, 27/89) in Merida, Mexico. Overall, we identified an IgG seroconversion rate of 88% (68/78) in all vaccinees after more than 25 days post-vaccination (dpv). Anti-RBD IgG-specific responses ranged from 90% (46/51) in the Pf-BNT vaccine at 25 dpv to 74% (20/27) in the CSBIO vaccine at 42 dpv. Compared to the S, the RBD IgG reactivity was significantly higher in both Pf-BNT (p < 0.004) and CSBIO (p < 0.003) vaccinees. Interestingly, in more than 50% of vaccine recipients, with no history of COVID-19 infection, antibodies against the nucleocapsid (N) protein were detected. Thus, participants were grouped either as naïve or pre-exposed vaccinees. Seroconversion rates after 25 and more dpv varies between 100% in Pf-BNT (22/22) and 75% (9/12) in CSBIO pre-exposed vaccinees, and 89% (26/29) and 73% (11/15) in Pf-BNT and CSBIO naïve vaccine recipients, respectively. In summary, observed seroconversion rates varied depending on the type of vaccine, previous infection with SARS-CoV-2, and the target viral antigen. Our results indicate that both vaccine preparations can induce detectable levels of IgG against the RBD or Spike in both naïve and SARS-CoV-2 pre-exposed vaccinees. Our study provides valuable and novel information about the serodiagnosis and the antibody response to vaccines in Mexico.

The Association of Health Literacy with Health-Related Quality of Life in Youth and Young Adults with Spina Bifida: A Cross-Sectional Study.

OBJECTIVE: The objective of the study was to determine if health literacy is associated with health-related quality of life (HRQOL) in adolescents and young adults (AYAs) with spina bifida. STUDY DESIGN: Between June 2019 and March 2020, the Patient-Reported Outcome Measurement Information System Pediatric Global Health-7 (PGH-7), a measure of HRQOL, and the Brief Health Literacy Screening Tool (BRIEF) were administered to patients ≥12 years old with a diagnosis of spina bifida seen in our multidisciplinary spina bifida center. Questionnaires were completed at scheduled clinic visits. The primary outcome was the PGH-7 normalized T-score. The primary exposure was the BRIEF score. Demographic and clinical characteristics were obtained from the medical record. Nested, multivariable linear regression models assessed the association between health literacy and the PGH-7 score. RESULTS: Of 232 eligible patients who presented to clinic, 226 (97.4%) met inclusion criteria for this study. The median age was 17.0 years (range: 12-31). Most individuals were female (54.0%) and had myelomeningocele (61.5%). Inadequate, marginal, and adequate health literacy levels were reported by 35.0%, 28.3%, and 36.7% of individuals. In univariable analysis, higher health literacy levels were associated with higher PGH-7 scores. In nested, sequentially adjusted multivariable linear regression models, a higher health literacy level was associated with a stepwise increase in the PGH-7 score. In the fully adjusted model, adequate health literacy and marginal health literacy, compared with inadequate health literacy, were associated with increases in a PGH-7 score of 3.3 (95% CI: 0.2-6.3) and 1.1 (95% CI: -2.0 to 4.2), respectively. CONCLUSIONS: Health literacy was associated with HRQOL after adjusting for demographic and clinical factors. Strategies incorporating health literacy are needed to improve HRQOL in AYAs with spina bifida.

High-Fat Diet and Short-Term Unpredictable Stress Increase Long-Chain Ceramides Without Enhancing Behavioral Despair.

Clinical and preclinical studies suggest that increases in long-chain ceramides in blood may contribute to the development of depressive-like behavior. However, which factors contribute to these increases and whether the increases are sufficient to induce depressive-like behaviors is unclear. To begin to address this issue, we examined the effects of high fat diet (HFD) and short-term unpredictable (STU) stress on long-chain ceramides in the serum of male and female rats. We found that brief exposure to HFD or unpredictable stress was sufficient to induce selective increases in the serum concentrations of long-chain ceramides, associated with depression in people. Furthermore, combined exposure to HFD and unpredictable stress caused a synergistic increase in C16:0, C16:1, and C18:0 ceramides in both sexes and C18:1 and C24:1 in males. However, the increased peripheral long-chain ceramides were not associated with increases in depressive-like behaviors suggesting that increases in serum long-chain ceramides may not be associated with the development of depressive-like behaviors in rodents.

Prevalence of Secondary Hypertension in Otherwise Healthy Youths with a New Diagnosis of Hypertension: A Meta-Analysis.

OBJECTIVE: To estimate the prevalence of secondary hypertension among otherwise healthy children with hypertension diagnosed in the outpatient setting. STUDY DESIGN: The MEDLINE, PubMed Central, Embase, Web of Science, and Cochrane Library databases were systematically searched for observational studies reporting the prevalence of secondary hypertension in children who underwent evaluation for hypertension and had no known comorbidities associated with hypertension at the time of diagnosis. Two authors independently extracted the study-specific prevalence of secondary hypertension in children evaluated for hypertension. Prevalence estimates for secondary hypertension were pooled in a random-effects meta-analysis. RESULTS: Nineteen prospective studies and 7 retrospective studies including 2575 children with hypertension were analyzed, with a median of 65 participants (range, 9-486) in each study. Studies conducted in primary care or school settings reported a lower prevalence of secondary hypertension (3.7%; 95% CI, 1.2%-7.2%) compared with studies conducted in referral clinics (20.1%; 95% CI, 11.5%-30.3%). When stratified by study setting, there were no significant subgroup differences according to study design, country, participant age range, hypertension definition, blood pressure device, or study quality. Although the studies applied different approaches to diagnosing secondary hypertension, diagnostic evaluations were at least as involved as the limited testing recommended by current guidelines. CONCLUSIONS: The low prevalence of secondary hypertension among children with a new diagnosis of hypertension identified on screening reinforces clinical practice guidelines to avoid extensive testing in the primary care setting for secondary causes in most children with hypertension.

SARS-CoV-2 antibody prevalence in a pediatric cohort of unvaccinated children in Mérida, Yucatán, México.

The prevalence of SARS-CoV-2 exposure in children during the global COVID-19 pandemic has been underestimated due to lack of testing and the relatively mild symptoms in adolescents. Understanding the exposure rates in the pediatric population is essential as children are the last to receive vaccines and can act as a source for SARS-CoV-2 mutants that may threaten vaccine escape. This cross-sectional study aims to quantify the prevalence of anti-SARS-CoV-2 serum antibodies in children in a major city in México in the Spring of 2021 and determine if there are any demographic or socioeconomic correlating factors. We obtained socioeconomic information and blood samples from 1,005 children from 50 neighborhood clusters in Mérida, Yucatán, México. We then tested the sera of these participants for anti-SARS-CoV-2 IgG and IgM antibodies using lateral flow immunochromatography. We found that 25.5% of children in our cohort were positive for anti-SARS-CoV-2 antibodies and there was no correlation between age and antibody prevalence. Children that lived with large families were statistically more likely to have antibodies against SARS-CoV-2. Spatial analyses identified two hotspots of high SARS-CoV-2 seroprevalence in the west of the city. These results indicate that a large urban population of unvaccinated children has been exposed to SARS-CoV-2 and that a major correlating factor was the number of people within the child's household with a minor correlation with particular geographical hotspots. There is also a larger population of children that may be susceptible to future infection upon easing of social distancing measures. These findings suggest that in future pandemic scenarios, limited public health resources can be best utilized on children living in large households in urban areas.

Sex-dependent effects of microglial reduction on impaired fear extinction induced by single prolonged stress.

Single prolonged stress (SPS) is a preclinical rodent model for studying post-traumatic stress disorder (PTSD)-like behaviors. Previously we found that increased expression of the microglial marker Iba-1 in the ventral hippocampus after SPS exposure was associated with impaired fear extinction, suggesting that microglial activity contributed to the SPS-induced behavioral changes. To test this, we examined whether reducing microglia with the colony-stimulating factor 1 receptor blocker, PLX3397, in the diet would prevent the SPS-induced extinction impairment. Male rats exposed to SPS showed enhanced fear acquisition and impaired fear extinction memory. Adding PLX3397 to the diet prevented these behavioral changes. In contrast, PLX3397 did not prevent SPS from impairing fear extinction memory in the female rats. Despite the sex-dependent behavioral effects, we found a reduced number and area fraction of Iba-1+ microglia in both male and female rats suggesting that PLX3397 had similar effects on microglia in both sexes. Altogether, these results suggest that microglia contribute to the behavioral changes induced by SPS in male but not female rats.

A first assessment of the distribution and abundance of large pelagic species at Cocos Ridge seamounts (Eastern Tropical Pacific) using drifting pelagic baited remote cameras.

Understanding the link between seamounts and large pelagic species (LPS) may provide important insights for the conservation of these species in open water ecosystems. The seamounts along the Cocos Ridge in the Eastern Tropical Pacific (ETP) ocean are thought to be ecologically important aggregation sites for LPS when moving between Cocos Island (Costa Rica) and Galapagos Islands (Ecuador). However, to date, research efforts to quantify the abundance and distribution patterns of LPS beyond the borders of these two oceanic Marine Protected Areas (MPAs) have been limited. This study used drifting-pelagic baited remote underwater video stations (BRUVS) to investigate the distribution and relative abundance of LPS at Cocos Ridge seamounts. Our drifting-pelagic BRUVS recorded a total of 21 species including elasmobranchs, small and large teleosts, dolphins and one sea turtle; of which four species are currently threatened. Depth of seamount summit was the most significant driver for LPS richness and abundance which were significantly higher at shallow seamounts (< 400 m) compared to deeper ones (> 400m). Distance to nearest MPA was also a significant predictor for LPS abundance, which increased at increasing distances from the nearest MPA. Our results suggest that the Cocos Ridge seamounts, specifically Paramount and West Cocos which had the highest LPS richness and abundance, are important aggregation sites for LPS in the ETP. However, further research is still needed to demonstrate a positive association between LPS and Cocos Ridge seamounts. Our findings showed that drifting pelagic BRUVS are an effective tool to survey LPS in fully pelagic ecosystems of the ETP. This study represents the first step towards the standardization of this technique throughout the region.

Diving deeper into the underlying white shark behaviors at Guadalupe Island, Mexico.

Fine-scale movement patterns are driven by both biotic (hunting, physiological needs) and abiotic (environmental conditions) factors. The energy balance governs all movement-related strategic decisions.Marine environments can be better understood by considering the vertical component. From 24 acoustic trackings of 10 white sharks in Guadalupe Island, this study linked, for the first time, horizontal and vertical movement data and inferred six different behavioral states along with movement states, through the use of hidden Markov models, which allowed to draw a comprehensive picture of white shark behavior.Traveling was the most frequent state of behavior for white sharks, carried out mainly at night and twilight. In contrast, area-restricted searching was the least used, occurring primarily in daylight hours.Time of day, distance to shore, total shark length, and, to a lesser extent, tide phase affected behavioral states. Chumming activity reversed, in the short term and in a nonpermanent way, the behavioral pattern to a general diel vertical pattern.

Plasticity of GluN1 at Ventral Hippocampal Synapses in the Infralimbic Cortex.

Although the infralimbic cortex (IL) is not thought to play a role in fear acquisition, recent experiments found evidence that synaptic plasticity is occurring at ventral hippocampal (vHPC) synapses in IL during auditory fear acquisition as measured by changes in the N-methyl-D-aspartate (NMDA) receptor-mediated currents in male rats. These electrophysiological data suggest that fear conditioning changes the expression of NMDA receptors on vHPC-to-IL synapses. To further evaluate the plasticity of NMDA receptors at this specific synapse, we injected AAV particles expressing channelrhodopsin-EYFP into the vHPC of male and female rats to label vHPC projections with EYFP. To test for NMDA receptor changes in vHPC-to-IL synapses after fear learning, we used fluorescence-activated cell sorting (FACS) to quantify synaptosomes isolated from IL tissue punches that were positive for EYFP and the obligatory GluN1 subunit. More EYFP+/GluN1+ synaptosomes with greater average expression of GluN1 were isolated from male rats exposed to auditory fear conditioning (AFC) than those exposed to context and tones only or to contextual fear conditioning (CFC), suggesting that AFC increased NMDA receptor expression in males. In a second experiment, we found that pairing the tones and shocks was required to induce the molecular changes and that fear extinction did not reverse the changes. In contrast, females showed similar levels of EYFP+/GluN1+ synaptosomes in all behavioral groups. These findings suggest that AFC induces synaptic plasticity of NMDA receptors in the vHPC-to-IL projection in males, while female rats rely on different synaptic mechanisms.