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Tropical regions cover approximately 36% of the Earth’s landmass. These regions are home to 40% of the world’s population, which is projected to increase to over 50% by 2030 under a remarkable climate variability scenario often exacerbated by El Niño Southern Oscillation (ENSO) and other climate teleconnections. In the tropics, ecohydrological conditions are typically under the influence of complex land-ocean-atmosphere interactions that produce a dynamic cycling of mass and energy reflected in a clear partition of water fluxes. Here, we present a review of 7 years of a concerted and continuous water stable isotope monitoring across Costa Rica, including key insights learned, main methodological advances and limitations (both in experimental designs and data analysis), potential data gaps, and future research opportunities with a humid tropical perspective. The uniqueness of the geographic location of Costa Rica within the mountainous Central America Isthmus, receiving moisture inputs from the Caribbean Sea (windward) and the Pacific Ocean (complex leeward topography), and experiencing strong ENSO events, poses a clear advantage for the use of isotopic variations to underpin key drivers in ecohydrological responses. In a sequential approach, isotopic variations are analyzed from moisture transport, rainfall generation, and groundwater/surface connectivity to Bayesian and rainfall-runoff modeling. The overarching goal of this review is to provide a robust humid tropical example with a progressive escalation from common water isotope observations to more complex modeling outputs and applications to enhance water resource management in the tropics.

Background: Clinical features of SARS-CoV-2 infection vary, ranging from asymptomatic cases to pneumonia, and other serious complications. Some populations have been observed to be at higher risk for severe disease and death compared to other ethnical groups., Objective: To evaluate two parameters of the innate immune system, that play a significant role in viral immunity., Methods: In samples of peripheral blood from sixteen patients with severe COVID-19, ten with asymptomatic to mild illness, and fifteen healthy subjects, the percentage of NK and NKT cells, the expression of different NK cell receptors and the blood levels of pro-inflammatory cytokines were tested., Results: We observed that patients with severe COVID-19 showed significantly lower frequencies of both CD56dim and CD56bright NK cells compared to patients with mild illness or healthy controls. Furthermore, patients with severe manifestation of COVID-19 exhibited an aberrant expression of the natural cytotoxicity receptors NKp30, NKp44 and NKp46. Similarly, NK cells from these patients showed statistically significant differences in the expression of various killer immunoglobulin-like receptors (KIRs) in the two main cell subsets (CD56bright, CD56dim) compared to controls or patients with mild disease. Moreover, patients with severe illness displayed decreased frequency of NKT cells (defined as CD3+CD56+) and elevated blood levels of the cytokines IL-6 and IL-8., Conclusion: This study suggests that the abnormal features of NK and NKT cells observed in patients with severe SARS-CoV-2 infection may play an important role in the outcome of this infectious disease in various population groups.

Tropical cyclones (TCs) are one of the major natural hazards to island and coastal communities and ecosystems. However, isotopic compositions of TC-derived precipitation (P) in surface water (SW) and groundwater (GW) reservoirs are still lacking. We tested the three main assumptions of the isotope storm "spike" hypothesis (sudden spikes in isotopic ratios). Our database covers 40 TCs and is divided into recent (N = 778; 2012-2023) and archived (N = 236; 1984-1995) rainfall isotope observations and SW/GW isotope monitoring (N = 6013; 2014-2023). Seasonal rainfall contribution from TCs ranged from less than 1% to over 54% (4% on average) between 1984 and 2023. Mean δ 18 O compositions across TCs domains were significantly lower than the regional (noncyclonic) δ 18 O mean (-5.24 ± 4.27‰): maritime (-6.29 ± 3.28‰), coastal (-7.78 ± 4.28‰), and inland (-9.80 ± 5.18‰) values. Coastal and maritime TC convection resulted in large rainfall amounts with high isotope compositions. This could bias past climate reconstructions toward unrealistic drier conditions. Significant δ 18 O and d-excess differences were found between storm intensities. P/SW and P/GW isotope ratios revealed the rapid propagation of TC excursions in freshwater systems. Our findings highlight the potential of TC isotope observations for diagnosing intensity and frequency in paleoproxies beyond idealized TC models., (© 2024 The Author(s). Annals of the New York Academy of Sciences published by Wiley Periodicals LLC on behalf of The New York Academy of Sciences.)

Introduction and Objective: Peripheral and follicular helper T lymphocytes (Tph and Tfh, respectively) have an important role in B cell immune responses and the pathogenesis of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Although several studies on the number of Tph and Tfh cells in these conditions have been published, different phenotypes have been employed for their analysis. In this study, we assessed the levels and function of Tph and Tfh cells in blood samples from patients with RA and SLE by using an extended immunophenotype., Materials and Methods: In a cross-sectional pilot study, blood samples from twenty-seven patients with RA and fifteen with SLE, and twenty-six healthy controls were studied. The levels of Tph (CD4 + PD-1 + CXCR5 - CD38 + CD69 + ICOS + ) and Tfh (CD4 + PD-1 + CXCR5 + CD38 + CD69 + ICOS + ) cells were analyzed by flow cytometry. In addition, the function of Tph/Tfh cells was estimated by measuring the synthesis of IL-21 by these lymphocytes as well as the number of circulating plasmablasts (CD19 + CD27 + CD20 - CD38 hi )., Results: Increased percentages of Tph and Tfh lymphocytes were detected in patients with RA and SLE. Furthermore, the synthesis of IL-21 tended to be higher in both conditions, and higher levels of plasmablasts were detected in these patients, compared to controls. In patients with SLE, the number of Tph cells was associated with disease activity and with the levels of circulating plasmablasts, whereas in patients with RA a significant correlation between Tph cells and evolution time was observed., Discussion and Conclusions: Our data of Tph and Tfh lymphocytes, based in the analysis of an extended phenotype of these cells, provides further evidence on their involvement in the pathogenesis of RA and SLE., (Copyright © 2024 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.)

Purpose: Peripheral helper T (Tph) cells have an important role in the induction of humoral immune responses and autoantibody production. Accordingly, it is feasible that this lymphocyte subset has a relevant role in the pathogenesis of autoimmune thyroid diseases (AITD). In this study we aim to analyze the levels and function of Tph cells in blood samples from patients with AITD., Methods: We performed an observational study with cases and controls. Blood samples were obtained from nineteen patients with Hashimoto's thyroiditis (HT), twenty-four with Graves' disease (GD), and fifteen healthy controls. In addition, the levels of follicular T helper (Tfh) cells and Tph cells, the release of interleukin-21 (IL-21) by these lymphocytes and the number of plasmablasts were analyzed by multi-parametric flow cytometry analyses., Results: Increased percentages of Tfh and Tph lymphocytes were detected in patients with HT and GD. Furthermore, an enhanced synthesis of the cytokine IL-21 by these cells was observed. Accordingly, we detected significant higher percentages of plasmablasts in patients with GD, and these values tended to be also higher in HT patients. Moreover, significant positive associations were observed between the levels of Tfh or Tph and the number of plasmablast or anti-TSHR Ab titers in patients with AITD., Conclusion: Our data suggest that Tph lymphocytes may have a relevant role in the pathogenesis of AITD., (© 2024. The Author(s).)

Periapical lesions are common pathologies affecting the alveolar bone, often initiated by intraradicular lesions resulting from microbial exposure to dental pulp. These microorganisms trigger inflammatory and immune responses. When endodontic treatment fails to eliminate the infection, periapical lesions persist, leading to bone loss. The RANK/RANKL/OPG pathway plays a crucial role in both the formation and the destruction of the bone. In this study, the objective was to inhibit the RANK/RANKL pathway in vitro within exposed Thp-1 macrophages to endodontic microorganisms, specifically Enterococcus faecalis , which was isolated from root canals of 20 patients with endodontic secondary/persistent infection, symptomatic and asymptomatic, and utilizing an α-IRAK-4 inhibitor, we introduced endodontic microorganisms and/or lipoteichoic acid from Streptococcus spp. to cellular cultures in a culture plate, containing thp-1 cells and/or PBMC from patients with apical periodontitis. Subsequently, we assessed the percentages of RANK+, RANKL+, and OPG+ cells through flow cytometry and measured the levels of several inflammatory cytokines (IL-1β, TNF-α, IL-6, IL-8, IL-10, and IL-12p70) in the cellular culture supernatant through a CBA kit and performed analysis by flow cytometry. A significant difference was observed in the percentages of RANK+RANKL+, OPG+ RANKL+ cells in thp-1 cells and PBMCs from patients with apical periodontitis. The findings revealed significant differences in the percentages of the evaluated cells, highlighting the novel role of the IRAK-4 inhibitor in addressing this oral pathology, apical periodontitis, where bone destruction is observed.

We sought to evaluate the effect of endodontic-causative microorganisms of primary infections on mononuclear cells such as CD14 + , CD4 + , CD8 + , CD19 + and Tregs Foxp3 + . Facultative anaerobic microorganisms were isolated from radicular conducts and peripheral blood samples, which were taken from patients with primary infections. Cellular cultures were performed with peripheral blood mononuclear cells (PBMC) with and without Actinomyces spp. and Streptococcus spp. during 48, 72, and 96 h of contact in culture (concentration 5 × 10 5 cells/well) in a round plate bound with 48 wells. Later, PBMC was collected for analysis by flow cytometry, with the monoclonal antibodies αCD14, αCD4, αCD8, αCD19 and αFoxp3, and acquired using an FACSCanto II cytometer. The supernatant of cellular cultures was analyzed for the quantification of inflammatory cytokines. Data analysis was performed in FlowJo v10.8.2 and FCAPArray software, and statistical analysis was performed using GraphPad v5.0. software. We observed an increase in the percentage of CD14 + cells in patients at different hours of cellular culture in the presence of both Actinomyces spp. and Streptococcus spp. microorganisms, compared to healthy controls. This study demonstrates the role played by the innate immune system in the pathogeny of endodontic primary infections, explaining the effects that generate the more common microorganisms in this oral pathology.

A low-grade inflammatory phenomenon is a feature of overweight and metabolic syndrome. The involvement of a pro-inflammatory Th17 lymphocyte subset and the CD69+ T regulatory (Treg) cell subtype in patients with metabolic dysfunction associated with or without overweight has not been fully elucidated. The aim of this study was to perform a quantitative and functional analysis of pathogenic Th17 lymphocytes and CD69+ Treg cells in patients with metabolic dysfunction (insulin resistance and dyslipidemia). The number of pathogenic Th17 cells and the levels and function of CD69+ Treg cells were analyzed in blood samples from individuals with metabolic dysfunction, associated with or without overweight. Pathogenic and non-pathogenic Th17 lymphocytes as well as Th22 cells were determined by eight-color flow cytometry analysis, whereas the levels and suppressive function of CD69+ Treg cells were also analyzed by multiparametric flow cytometry. We detected increased levels of pro-inflammatory Th17 pathogenic cells and Th22 lymphocytes in overweight unhealthy individuals (P < 0.001, compared to normal weight healthy). Conversely, diminished numbers of CD69+ Treg lymphocytes were observed in metabolically unhealthy individuals, with or without overweight. Likewise, the immunosuppressive function of CD69+ Treg cells was also defective in these patients. The increased levels of pathogenic Th17 cells along with a diminished number and function of CD69+ Treg lymphocytes may significantly contribute to the low-grade inflammatory phenomenon of metabolically unhealthy patients., (© The Author(s) 2022. Published by Oxford University Press on behalf of the British Society for Immunology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Increasing energy consumption and food production worldwide results in anthropogenic emissions of reactive nitrogen into the atmosphere. To date, however, little information is available on tropical urban environments where inorganic nitrogen is vastly transported and deposited through precipitation on terrestrial and aquatic ecosystems. To fill this gap, we present compositions of water stable isotopes in precipitation and atmospheric nitrate (δ 18 O-H 2 O, δ 2 H-H 2 O, δ 15 N-NO 3 - , and δ 18 O-NO 3 - ) collected daily between August 2018 and November 2019 in a tropical urban atmosphere of central Costa Rica. Rainfall generation processes (convective and stratiform rainfall fractions) were identified using stable isotopes in precipitation coupled with air mass back trajectory analysis. A Bayesian isotope mixing model using δ 15 N-NO 3 - compositions and corrected for potential 15 N fractionation effects revealed the contribution of lightning (25.9 ± 7.1%), biomass burning (21.8 ± 6.6%), gasoline (19.1 ± 6.4%), diesel (18.4 ± 6.0%), and soil biogenic emissions (15.0 ± 2.6%) to nitrate wet deposition. δ 18 O-NO 3 - values reflect the oxidation of NO x sources via the ·OH + RO 2 pathways. These findings provide necessary baseline information about the combination of water and nitrogen stable isotopes with atmospheric chemistry and hydrometeorological techniques to better understand wet deposition processes and to characterize the origin and magnitude of inorganic nitrogen loadings in tropical regions., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Ingestion of high amounts of nitrite due processed meat consumption could produce negative effects in human health. Here, we investigate long-term residual sodium nitrite content in processed meat products in Costa Rica to provide the first estimations of nitrite daily intake. An extensively validated analytical procedure was applied for the long-term analysis of 1350 samples from 2014 to 2018. Mean residual sodium nitrite concentration was 76.5 mg kg -1 , ranging from < 11 to 278.0 mg kg -1 . Significant differences among product and meat types were found, but no temporal differences were observed. Nitrite daily intake was estimated in 0.0122 ± 0.0039 mg kg -1 bw -1 d -1 , which accounts for 17.4% of the acceptable daily intake (ADI). This information underlies the importance of studying residual nitrite kinetics in processed meat products as well as establishing long-term programs for the accurate estimation of nitrite daily intake rates., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Context: Natural killer (NK) cells have an important role in innate immunity and in the regulation of immune response. The role of NK cells expressing the programmed cell death protein-1 (PD-1) regulatory receptor has not been explored in patients with autoimmune thyroid disease (AITD)., Purpose: To analyze the levels and function of PD-1+ NK cells in samples from AITD patients., Design: Cases and controls, observational study., Setting: Hospital Universitario la Princesa, Spain., Patients: Forty patients with AITD, 16 with Hashimoto thyroiditis (HT), 24 with Graves' disease (GD), and 15 healthy controls., Intervention: Multiparametric flow cytometry analysis of peripheral blood NK cells. In vitro assays of cytotoxic activity of NK cells, and synthesis of cytokines., Main Outcome Measures: Levels and function of PD-1+ NK cells in blood samples from AITD patients and controls., Results: Increased levels of NK cells and the CD56dimPD-1+ subset were observed in GD patients. In HT, an enhanced expression of the regulatory receptors NKG2A and NKG2C by CD56brightPD-1+ NK cells was detected. AITD patients showed an increased synthesis of IL-10 by CD56brightPD-1- NK cells, whereas CD56dimPD-1+ cells from GD patients exhibited an enhanced production of interferon-γ. PD-1+ NK cells from patients with GD and HT showed an increased cytotoxic activity. Significant associations were observed in patients with GD or HT between the levels of PD-1+ NK cells and clinical laboratory parameters., Conclusions: The different abnormalities in NK cell subset levels, in the expression of PD-1 and its function in AITD patients' further support the complex role of these cells in this pathogenesis., (© Endocrine Society 2020. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

In the eastern region of central Costa Rica, land use in the sub-basins of the Maravilla-Chiz and Quebrada Honda rivers (47 km 2 ) is dominated by agricultural and livestock production, while groundwater resources constitute the main drinking water supply. This study aimed to (a) evaluate the location of groundwater recharge areas and groundwater flow paths, and (b) provide a characterization of the hydrochemistry and possible anthropic impacts. Groundwater was collected from 20 sites during the dry and rainy seasons and analysed for major ions, water stable isotopes and 222 Rn. Approximated recharge areas were estimated through a local altitudinal line based on isotopic compositions in springs. The hydrochemical and isotopic characterization of groundwater showed that the main recharge areas occur in the upper part of the basin, except for springs in the middle part of the basin probably due to a certain hydraulic disconnection from the upper part that facilitates local recharge processes. In the lower basin, groundwater exhibited greater transit times and longer flow paths. Low nitrate, chloride and sulphate concentrations found in groundwater indicate low leaching of fertilizers or urban wastewaters. Our results are focused to improve water resources and agricultural management plans in a dynamic tropical landscape.

Groundwater pollution in tropical and human-altered coastal landscapes is receiving novel attention due to decreasing in annual recharge as a consequence of recurrent droughts and overexploitation, whereby saline intrusion, point and diffuse source contamination, and water conflicts are common denominators. This study presents a detailed groundwater evaluation in a coastal aquifer within the central Pacific coast of Costa Rica. Three sampling campaigns including major ions, heavy metals, and fecal coliform analyses were conducted between July 2013 and March 2014 across 17 wells within the alluvial and fissured units of the Jacó aquifer. The groundwater system is classified as mixed HCO 3 - -Ca 2+ -Mg 2+ type. Coliforms presence was found in two wells, nearby Mona Creek headwaters and near the coastal line. Heavy metal concentrations were below quantification limits in most of the wells; however, chromium concentrations up to 6.56 μg/L were quantified within the coastal line and central portion of the alluvial aquifer in 20 out of the 48 samples. The spatial distribution of major ions (K + , Na + , Ca 2+ , Mg 2+ , Cl - , SO 4 2- , and HCO 3 - ) exhibited an increasing trend towards the central portion of the alluvial aquifer, which may be potentially associated with the large unregulated urban expansion, invoking a need of a continuous water quality monitoring program in this touristic hot spot. This study provides useful information for other similar coastal aquifers in Central America, whereby increasing population growth and unregulated touristic, industrial, and agricultural activities are posing a truly challenge to ensure water security and sustainability parallel to the economic development in a changing climate.

Tympanic paragangliomas usually present as a vascular middle ear mass, with the most common presenting symptoms being pulsatile tinnitus and hearing loss. We report an unusual case of a recurrent tympanic paraganglioma extending along the Eustachian tube and nasopharynx, presenting with recurrent epistaxis., (Copyright © 2010 Elsevier España, S.L. All rights reserved.)

The integrity of the paternal genome is of paramount importance in the initiation and maintenance of a viable pregnancy. Oxygen radicals (ROS) have been identified as one of the main factors responsible for the induction of sperm DNA damage. Spermatozoa are mainly protected against ROS-induced damage by seminal plasma. However, this protective effect disappears once spermatozoa enter the female genital tract. The fallopian tube mucosa may play a protective role against ROS-induced sperm damage. The main objective of this study was to determine whether human tubal explants and tubal fluid exert a protective effect on ROS-induced sperm DNA damage. Spermatozoa were exposed to tubal explants and/or tubal fluid in the presence of phorbol myristate acetate (PMA)-activated polymorphonuclear leucocytes or control medium and sperm DNA fragmentation was measured using the TdT-mediated dUTP-biotin nick end labelling (TUNEL) test. Exposure of human spermatozoa to PMA-activated leucocytes resulted in a 2-fold increase in sperm DNA fragmentation. Co-incubation of spermatozoa with tubal explants did not reduce this damage. However, pre-incubation of spermatozoa with tubal fluid resulted in a statistically significant reduction in sperm DNA fragmentation levels, comparable to those observed in control. In conclusion, tubal fluid appears to protect against activated leucocyte-induced sperm DNA fragmentation, thus preserving the integrity of the paternal genome.

The undernutrition rates observed in Cuban elders surveyed in three different geriatric scenarios: Community: coastal town of Cojímar (City of Havana); Geriatrics Service ("Hermanos Ameijeiras" Hospital, City of Havana); and Nursery Home (city of Cárdenas, province of Matanzas) by means of the Mini Nutritional Assessment (MNA) of the Elderly are presented. Undernutrition rates were 2.7% among elders surveyed in the coastal community of Cojímar, but increased to become 91.6% among those admitted to the hospital Geriatrics Service, and 95.3% for those institutionalized in the Nursery Home, respectively. The occurrence of undernutrition can be low among elders living freely in the community, but it might affect a vast number of those seeking medical assistance at the public health institutions. Extent of undernutrition among elders in geriatric assistance scenarios should lead to the adoption of the required measures for early identification, and timely treatment, of this health problem.

Objectives: To assess quality of life in patients diagnosed with epidermoid carcinoma of the larynx, after supracricoid partial laryngectomy (SCPL). To examine how quality-of-life may be associated to the treatment received., Patients and Method: A descriptive, observational, cross-sectional study was conducted involving 32 patients out of a group of 57. They were all males with an average age of 63.3 years at the time of the interview. We used the disease-specific quality of life questionnaire devised by the University of Michigan: the Head and Neck Cancer-specific Quality of life instrument (HNQOL)., Results: During an average follow-up period of 86 months, 3 patients (5.26%) suffered a recurrence. Estimated survival after 3, 5 and 10 years was 94.73%. Communication and overall bother caused by treatment were found to be the two quality-of-life domains mainly affected. Patients who had received CHP, radiotherapy, those who had not had their tracheal cannula removed or had undergone neck dissection were the most affected., Conclusions: SCPL as a surgical technique allows good control of the condition and has a low impact on the patient's quality of life.

We present one case of a 14 years old girl, diagnosed of fibrous displasia of the temporal bone, who developed a conductive hearing loss of progressive character. We analyse the clinic manifestations, radiologic and histopathologic study, and therapeutic indications of this disease.