Hospital-based screening outperforms primary care screening as a means of achieving hepatitis C virus micro-elimination.

AIM: To assess the respective performances of a HCV screening program in a hospital setting and a HCV screening model applied concomitantly in a primary care centre. METHODS: Adult patients consecutively admitted to hospital for ambulatory surgery were screened for anti-HCV antibodies (hospital screening cohort, HPSC), as were patients receiving blood tests for medical reasons in a primary care centre (primary care screening cohort, PCSC). Serum anti-HCV and HCV RNA levels were tested by ELISA and real-time PCR, respectively. RESULTS: Seroprevalence of HCV infection was 2.2 % in the HPSC and 1.4 % in the PCSC (p = 0.044). All viraemic patients (0.2 % in HPSC and 0.1 % in PCSC) were treated with direct-acting antivirals and 85.7 % experienced a sustained virological response. CONCLUSIONS: Hospital-based HCV screening outperformed primary care-centered screening, significantly increasing HCV case findings.

Novel frameshift variants expand the map of the genetic defects in IRF2BP2.

Background: At present, the knowledge about disease-causing mutations in IRF2BP2 is very limited because only a few patients affected by this condition have been reported. As previous studies have described, the haploinsufficiency of this interferon transcriptional corepressors leads to the development of CVID. Very recently, a more accurate phenotype produced by truncating variants in this gene has been defined, manifesting CVID with gastrointestinal inflammatory symptoms and autoimmune manifestations. Methods: We analyzed 5 index cases with suspected primary immunodeficiency by high throughput sequencing. They were submitted for a genetic test with a panel of genes associated with immune system diseases, including IRF2BP2. The screening of SNVs, indels and CNVs fulfilling the criteria with very low allelic frequency and high protein impact, revealed five novel variants in IRF2BP2. In addition, we isolated both wild-type and mutated allele of the cDNA from one of the families. Results: In this study, we report five novel loss-of-function (LoF) mutations in IRF2BP2 that likely cause primary immunodeficiency, with CVID as more frequent phenotype, variable expression of inflammatory gastrointestinal features, and one patient with predisposition of viral infection. All identified variants were frameshift changes, and one of them was a large deletion located on chromosome 1q42, which includes the whole sequence of IRF2BP2, among other genes. Both de novo and dominant modes of inheritance were observed in the families here presented, as well as incomplete penetrance. Conclusions: We describe novel variants in a delimited low-complex region, which may be considered a hotspot in IRF2BP2. Moreover, this is the first time that a large CNV in IRF2BP2 has been reported to cause CVID. The distinct mechanisms than LoF in IRF2BP2 could cause different phenotype compared with the mainly described. Further investigations are necessary to comprehend the regulatory mechanisms of IRF2BP2, which could be under variable expression of the disease.

Clinical relevance of viral codetection in infants with respiratory syncytial virus bronchiolitis.

INTRODUCTION: Respiratory syncytial virus (RSV) is the main cause of severe bronchiolitis, especially in infants. The aim of this study is to assess whether codetection of RSV and other respiratory viruses could affect the severity of this infection comparing with unique RSV detection. METHODS: A prospective study from 2016 to 2019 including children under 2 years who were admitted in the Emergency Service of the Hospital Universitari Arnau de Vilanova de Lleida (Spain) was performed. Nasopharyngeal samples from all patients were sent to the laboratory for RSV real-time PCR detection (GeneXpert®). A multiplex PCR that detects other respiratory viruses was done in all RSV-positive samples. Patients'medical records were checked to collect clinical data (hospital length of stay, BROSJOD score, ICU admission, need for ventilatory support or transfer to a reference hospital). Patients were divided in two groups: infants with unique RSV detection and infants with viral codetection. Bivariant analyses were performed to analyze the data obtained. RESULTS: During the period of study 437 RSV bronchiolitis were diagnosed. In 199 of them (177/437; 45,5%) another respiratory virus was detected concomitantly. Bivariant analyses do not show statistically significant differences between both groups. CONCLUSIONS: Viral codetection in infants with RSV bronchiolitis is frequent. However, it does not seems to affect the severity of this infection.

Accuracy of Xpert Ultra for the diagnosis of paediatric tuberculosis in a low TB burden country: a prospective multicentre study.

INTRODUCTION: Childhood pulmonary tuberculosis (TB) remains a diagnostic challenge. This study aimed to evaluate the performance of Xpert Ultra for the diagnosis of pulmonary TB in children in a low TB prevalence setting. METHODS: Prospective, multicentre, diagnostic accuracy study. Children with clinical or radiological suspicion of pulmonary TB were recruited at 11 paediatric units in Spain. Up to three gastric or sputum specimens were taken on 3 consecutive days, and analysed by Xpert MTB/RIF, Xpert Ultra and culture in parallel. RESULTS: 86 children were included (median age 4.9 years, IQR 2.0-10.0; 51.2% male). The final diagnosis was pulmonary TB in 75 patients (87.2%); 33 (44.0%) were microbiologically confirmed. A total of 219 specimens, comprising gastric aspirates (n=194; 88.6%) and sputum specimens (n=25; 11.4%), were analysed. Using culture as reference standard and comparing individual specimens, the sensitivity was 37.8% (14/37) for Xpert MTB/RIF and 81.1% (30/37) for Xpert Ultra (p<0.001); specificity was 98.4% (179/182) and 93.4% (170/182), respectively (p=0.02). In the per-patient analysis, considering positive results on any specimen, the sensitivity was 42.9% (9/21) for Xpert MTB/RIF and 81.0% for Xpert Ultra (17/21, p=0.01); specificity was 96.9% (63/65) and 87.7% (57/65, p=0.07), respectively. CONCLUSIONS: In children with pulmonary TB in a low burden setting, Xpert Ultra has significantly higher sensitivity than the previous generation of Xpert assay and only marginally lower specificity. Therefore, in children undergoing evaluation for suspected pulmonary TB, Xpert Ultra should be used in preference to Xpert MTB/RIF whenever possible.

Relevant SARS-CoV-2 viremia is associated with COVID-19 severity: Prospective cohort study and validation cohort.

Early kinetics of SARS-CoV-2 viral load (VL) in plasma determined by quantitative reverse-transcription polymerase chain reaction (RT-PCR) was evaluated as a predictor of poor clinical outcome in a prospective study and assessed in a retrospective validation cohort. Prospective observational single-center study including consecutive adult patients hospitalized with COVID-19 between November 2020 and January 2021. Serial plasma samples were obtained until discharge. Quantitative RT-PCR was performed to assess SARS-CoV-2 VL. The main outcomes were in-hospital mortality, admission to the Intensive Care Unit (ICU), and their combination (Poor Outcome). Relevant viremia (RV), established in the prospective study, was assessed in a retrospective cohort including hospitalized COVID-19 patients from April 2021 to May 2022, in which plasma samples were collected according to clinical criteria. Prospective cohort: 57 patients were included. RV was defined as at least a twofold increase in VL within ≤2 days or a VL > 300 copies/ml, in the first week. Patients with RV (N = 14; 24.6%) were more likely to die than those without RV (35.7% vs. 0%), needed ICU admission (57% vs. 0%) or had Poor Outcome (71.4% vs. 0%), (p < 0.001 for the three variables). Retrospective cohort: 326 patients were included, 18.7% presented RV. Patients with RV compared with patients without RV had higher rates of ICU-admission (odds ratio [OR]: 5.6 [95% confidence interval [CI]: 2.1-15.1); p = 0.001), mortality (OR: 13.5 [95% CI: 6.3-28.7]; p < 0.0001) and Poor Outcome (OR: 11.2 [95% CI: 5.8-22]; p < 0.0001). Relevant SARS-CoV-2 viremia in the first week of hospitalization was associated with higher in-hospital mortality, ICU admission, and Poor Outcome. Findings observed in the prospective cohort were confirmed in a larger validation cohort.

Usefulness of real-time RT-PCR to understand the kinetics of SARS-CoV-2 in blood: A prospective study.

BACKGROUND: SARS-CoV-2 viral load and kinetics assessed in serial blood samples from hospitalised COVID-19 patients by RT-PCR are poorly understood. METHODS: We conducted an observational, prospective case series study in hospitalised COVID-19 patients. Clinical outcome data (Intensive Care Unit admission and mortality) were collected from all patients until discharge. Viremia was determined longitudinally during hospitalisation, in plasma and serum samples collected sequentially, using two commercial and standardised RT-PCR techniques approved for use in diagnosis of SARS-CoV-2. Viral load (copies/mL and log10) was determined with quantitative TaqPath™COVID-19 test. Persistent viremia (PV) was defined as two or more consecutive quantifiable viral loads detected in blood samples (plasma/serum) during hospitalisation. RESULTS: SARS-CoV-2 viremia was studied in 57 hospitalised COVID-19 patients. PV was detected in 16 (28%) patients. All of them, except for one who rapidly progressed to death, cleared viremia during hospitalisation. Poor clinical outcome occurred in 62.5% of patients with PV, while none of the negative patients or those with sporadic viremia presented this outcome (p < 0.0001). Viral load was significantly higher in patients with PV than in those with Sporadic Viremia (p < 0.05). Patients presented PV for a short period of time: median time from admission was 5 days (Range = 2-12) and 4.5 days (Range = 2-8) for plasma and serum samples, respectively. Similar results were obtained with all RT-PCR assays for both types of samples. CONCLUSIONS: Detection of persistent SARS-CoV-2 viremia, by real time RT-PCR, expressed as viral load over time, could allow identifying hospitalised COVID-19 patients at risk of poor clinical outcome.

Impact of the implementation of a Sepsis Code Program in medical patient management: a cohort study in an Internal Medicine ward / Impacto de la implementación del Programa Código Sepsis en una planta de hospitalización médica: estudio de una cohorte de pacientes de Medicina Interna

Introduction. Sepsis is the main cause of death in hospitals and the implementation of diagnosis and treatment bundles has shown to improve its evolution. However, there is alack of evidence about patients attended in conventional units.Methods. A 3-year retrospective cohort study was conducted. Patients hospitalized in Internal Medicine units withsepsis were included and assigned to two cohorts according toSepsis Code (SC) activation (group A) or not (B). Baseline andevolution variables were collected.Results. A total of 653 patients were included. In 296 cases SC was activated. Mean age was 81.43 years, median Charlson comorbidity index (CCI) was 2 and 63.25% showed somefunctional disability. More bundles were completed in group A:blood cultures 95.2% vs 72.5% (p < 0.001), extended spectrumantibiotics 59.1% vs 41.4% (p < 0.001), fluid resuscitation96.62% vs 80.95% (p < 0.001). Infection control at 72 hourswas quite higher in group A (81.42% vs 55.18%, odds ratio3.55 [2.48-5.09]). Antibiotic was optimized more frequently ingroup A (60.77% vs 47.03%, p 0.008). Mean in-hospital staywas 10.63 days (11.44 vs 8.53 days, p < 0.001). Complicationsduring hospitalization appeared in 51.76% of patients, especially in group B (45.95% vs 56.58%, odds ratio 1.53 [1.12-2.09]). Hospital readmissions were higher in group A (40% vs24.76%, p < 0.001). 28-day mortality was significantly lower ingroup A (20.95% vs 42.86%, odds ratio 0.33 [0.23-0.47]).Conclusions. Implementation of SC seems to be effectivein improving short-term outcomes in IM patients, althoughtherapy should be tailored in an individual basis (AU)

Introducción. La sepsis es la principal causa de muerte enlos hospitales y la implantación de códigos para su manejo hademostrado mejorar su evolución. Sin embargo, es escasa laevidencia relativa a los pacientes atendidos en unidades médicas convencionales.Métodos. Se realizó un estudio de cohortes retrospectivode 3 años. Se incluyeron pacientes con sepsis hospitalizados enunidades de Medicina Interna y se asignaron a dos cohortessegún la activación del Código Sepsis (CS) (grupo A) o no (B).Se recogieron variables basales y de evolución.Resultados. Se incluyeron 653 pacientes. En 296 casos seactivó el SC. La edad media fue de 81,43 años, la mediana delíndice de comorbilidad de Charlson (ICC) fue de 2 y el 63,25%presentaba alguna limitación funcional. Se realizaron más acciones diagnósticas y terapéuticas en el grupo A: hemocultivos95,2% vs 72,5% (p < 0,001), antibióticos de espectro extendido59,1% vs 41,4% (p < 0,001), reanimación con líquidos 96,62%vs 80,95% (p < 0,001). El control de la infección a las 72 horasfue superior en el grupo A (81,42% vs 55,18%, odds ratio 3,55[2,48-5,09]). La optimización de los antibióticos fue más frecuente en el grupo A (60,77% vs 47,03%, p 0,008). La estanciamedia en el hospital fue de 10,63 días (11,44 vs 8,53 días, p <0,001). Aparecieron complicaciones durante la hospitalizaciónen el 51,76% de los pacientes, especialmente en el grupo B(45,95% vs 56,58%, odds ratio 1,53 [1,12-2,09]). Los pacientesdel grupo A reingresaron más (40% vs 24,76%, p < 0,001). Lamortalidad a los 28 días fue significativamente menor en elgrupo A (20,95% frente a 42,86%, odds ratio 0,33 [0,23-0,47]). (AU)

Evaluation of two RT-PCR techniques for SARS-CoV-2 RNA detection in serum for microbiological diagnosis.

Presence of SARS-CoV-2 RNA in serum (viremia) of COVID-19 patients has been related to poor prognosis and death. The aim of this study was to evaluate both the ability to detect viremia in COVID-19 patients of two commercial reverse real-time-PCR (rRT-PCR) tests, Cobas® and TaqPath™, comparing them with a gold standard method, and their implementation in microbiology laboratories. This retrospective cohort study included 303 adult patients (203 diagnosed with COVID-19 and 100 non-COVID-19 patients) admitted to a tertiary hospital, with at least one serum sample collected within the first 48 h from admission. A total of 365 serum samples were included: 100 from non-COVID patients (pre-pandemic and pandemic control groups) and 265 from COVID-19 patients. Serum samples were considered positive when at least one target was detected. All patients in control groups showed negative viremia. Cobas® and TaqPath™ tests showed specificity and Positive Predictive Value over 96%. Nevertheless, sensitivity (53.72 and 73.63, respectively) and Negative Predictive Value (64.78 and 75) were lower. Viremia difference between ICU and non-ICU patients was significant (p ≤ 0.001) for both techniques. Consequently, SARS-CoV-2 viremia detection by both rRT-PCR tests should be considered a good tool to stratify COVID-19 patients and could be implemented in microbiology laboratories.

Palaeoecological differences underlie rare co-occurrence of Miocene European primates.

BACKGROUND: The two main primate groups recorded throughout the European Miocene, hominoids and pliopithecoids, seldom co-occur. Due to both their rarity and insufficiently understood palaeoecology, it is currently unclear whether the infrequent co-occurrence of these groups is due to sampling bias or reflects different ecological preferences. Here we rely on the densely sampled primate-bearing sequence of Abocador de Can Mata (ACM) in Spain to test whether turnovers in primate assemblages are correlated with palaeoenvironmental changes. We reconstruct dietary evolution through time (ca. 12.6-11.4 Ma), and hence climate and habitat, using tooth-wear patterns and carbon and oxygen isotope compositions of enamel of the ubiquitous musk-deer Micromeryx. RESULTS: Our results reveal that primate species composition is strongly correlated with distinct environmental phases. Large-bodied hominoids (dryopithecines) are recorded in humid, densely-forested environments on the lowermost portion of the ACM sequence. In contrast, pliopithecoids inhabited less humid, patchy ecosystems, being replaced by dryopithecines and the small-bodied Pliobates toward the top of the series in gallery forests embedded in mosaic environments. CONCLUSIONS: These results support the view that pliopithecoid primates preferred less humid habitats than hominoids, and reveal that differences in behavioural ecology were the main factor underpinning their rare co-occurrence during the European Miocene. Our findings further support that ACM hominoids, like Miocene apes as a whole, inhabited more seasonal environments than extant apes. Finally, this study highlights the importance of high-resolution, local investigations to complement larger-scale analyses and illustrates that continuous and densely sampled fossiliferous sequences are essential for deciphering the complex interplay between biotic and abiotic factors that shaped past diversity.

Evaluation of diagnostic accuracy of 10 serological assays for detection of SARS-CoV-2 antibodies.

Antibody detection is essential to establish exposure, infection, and immunity to SARS-CoV-2, as well as to perform epidemiological studies. The worldwide urge for new diagnostic tools to control the pandemic has led to a quick incorporation in clinical practice of the recently developed serological assays. However, as only few comparative studies have been published, there is a lack of data about the diagnostic accuracy of currently available assays. We evaluated the diagnostic accuracy to detect Ig G, Ig M+A, and/or IgA anti SARS-CoV-2 of 10 different assays: lateral flow card immunoassays, 4 enzyme-linked immunosorbent assay (ELISA), and 3 chemiluminescent particle immunoassays (CMIA). Using reverse transcriptase polymerase chain reaction (RT-PCR) for COVID-19 as gold standard, sensitivity, specificity, PPV, and NPV were determined. Each assay was tested in 2 groups, namely, positive control, formed by 50 sera from 50 patients with SARS-CoV-2 pneumonia with positive RT-PCR; and negative control, formed by 50 sera from 50 patients with respiratory infection non-COVID-19. Sensitivity range of the 10 assays evaluated for patients with positive COVID-19 RT-PCR was 40-77% (65-81% considering IgG plus IgM). Specificity ranged 83-100%. VPP and VPN were respectively 81-100% and 61.6-81%. Among the lateral flow immunoassays, the highest sensitivity and specificity results were found in Wondfo® SARS-CoV-2 Antibody Test. ELISA IgG and IgA from EUROIMMUN® were the most sensitive ELISA. However, poor results were obtained for isolated detection of IgG. We found similar sensitivity for IgG with SARS-CoV-2 for Architect by Abbott® and ELISA by Vircell®. Results obtained varied widely among the assays evaluated. Due to a better specificity, overall diagnostic accuracy of the assays evaluated was higher in case of positive result. On the other side, lack of antibody detection should be taken with care because of the low sensitivity described. Highest diagnostic accuracy was obtained with ELISA and CMIAs, but they last much longer.

Gregariousness in the giant sloth Lestodon (Xenarthra): multi-proxy approach of a bonebed from the Last Maximum Glacial of Argentine Pampas.

Megamammals constituted an important component in the Pleistocene faunal communities of South America. Paleobiological and paleoecological studies involving different megamammal taxa have increased significantly in the last years, but there are still several poorly-known issues of its life history. In this work, we analyze an assemblage composed of 13 individuals of different ontogenetic stages, and possibly different sex, belonging to the giant ground sloth Lestodon armatus (Xenarthra, Folivora), recovered from Playa del Barco site (Pampean Region, Argentina). A dating of 19,849 years Cal BP allows assigning this assemblage to a period of the MIS (Marine Isotope Stage) 2 related to the end of the Last Glacial Maximum. Based on multiple lines of research (e.g. taphonomy, paleopathology, osteohistology, isotopy), we interpret the origin of the assemblage and diverse paleobiological and paleoecological aspects (e.g. social behavior, ontogenetic changes, sexual dimorphism, diseases, resource and habitat use, trophic relationships) of L. armatus. Evidence suggests that the assemblage was formed by a local single event of catastrophic mortality, which affected different members of a social group. This record represents the first accurate evidence of gregariousness for this ground sloth, providing new data on a poorly-known behavior among extinct Folivora.

The Great American Biotic Interchange revisited: a new perspective from the stable isotope record of Argentine Pampas fossil mammals.

This study aims at assessing resource and habitat use, niche occupation and trophic interactions from a stable isotope perspective on fossil mammals from the Argentine Pampas during the Great American Biotic Interchange (GABI). We present stable isotope data of more than 400 samples belonging to 10 mammalian orders and spanning a temporal range from ~9.5 Ma to ~12 ky. Rodents, notoungulates and pilosians record an increase in the consumption of C4 plants, whereas litopterns and cingulates show δ13C values that remain mostly within a C3-dominated diet. Our stable isotope data indicates that the expansion of C4 vegetation opened up new niche opportunities, probably alleviating resource competition among endemic taxa. Gomphothere, equid and camelid δ13C records show a broad variability pointing to consumption of C3 and mixed C3-C4 vegetation. This flexible dietary behavior may have facilitated the successful settlement of immigrant groups in South America. In the case of carnivorous taxa, Late Miocene pre-GABI endemic sparassodonts consumed prey from C3 environments, whereas immigrant carnivorans preferred prey from mixed C3-C4 areas. Our research contributes to the study of the GABI from a different perspective as stable isotope records permit to characterize, from a (semi)quantitative standpoint, ecological traits within extinct fauna.

Absceso periamigdalino producido por Actinomyces marseillensis / Peritonsillar abscess due to Actinomyces marseillensis

No disponible

An innovative quick solidifying technique for the forensic investigation of brain circulation using addition silicones.

Post-mortem study of the brain is extremely relevant to medico-legal autopsies. However, it can be difficult to handle due to its fragility. This article presents a study on the development of an arterial solidifying technique that can be applied to analyze arterial circulation, consequently easing the handling and later diagnosis of diseases in this anatomical site. Vinylpolysiloxane silicone is introduced into the internal carotid arteries until it completely fills the arterial tree, creating a detailed model of the arterial's internal anatomy. This technique is fast, easy to apply and requires no previous tissue fixation. In addition, it allows for further toxicological and pathological tests. In conclusion, this technique represents a simple, sensitive and efficient method to employ in conventional autopsies, which can help in the diagnosis of death.

PCR Multiplex for CMV Detection in Patients with Anterior Uveitis.

PURPOSE: Describing the utility of Polymerase Chain Reaction for Cytomegalovirus (CMV-PCR) in the diagnosis of suspected viral anterior uveitis (AU). PATIENTS AND METHODS: We analyzed aqueous humor (AH) CMV-PCR positivity and treatment modifications in 47 eyes of 46 patients with viral uveitis and its correlation with high intraocular pressure (HIOP), uveitis clinical characteristics and time intervals from samples to uveitis diagnosis and to relapse. RESULTS: CMV-PCR positive results occurred in 13 eyes (27.7%) of 12 patients. They were more frequent in HIOP eyes (34.2%, p = 0.047) and with Posner-Schlossman Syndrome (56.2%, p = 0.002). CMV-PCR positivity (p = 0.001) and HIOP (p = 0.038) increased the probability of treatment change. Although CMV-PCR positive results decreased over time (p = 0.002), they were not related to activity or proximity to inflammatory uveitis episode. CONCLUSION: HIOP AU eyes should be considered for CMV-PCR AH analysis due to possible treatment modifications.

Mycobacterium lentiflavum como causa principal de linfadenitis en población pediátrica / Mycobacterium lentiflavum as the main cause of lymphadenitis in pediatric population

INTRODUCCIÓN: La linfadenitis cervical es la infección más frecuente por micobacterias no tuberculosas (MNT) en niños inmunocompetentes, principalmente menores de 5 años. Durante años se ha considerado a Mycobacterium lentiflavum (M. lentiflavum) una inusual MNT causante de esta patología. MÉTODOS: Se realizó un estudio retrospectivo, observacional desde 2009 a 2016, que incluyó a pacientes pediátricos del Hospital Infantil Universitario Niño Jesús de Madrid, diagnosticados clínicamente y microbiológicamente de linfadenitis cervical por MNT. RESULTADOS: En el periodo estudiado se registraron 28 casos de linfadenitis cervical. En 23 (82,14%) pacientes se aisló M. lentiflavum y en 5 (17,85%), Mycobacterium avium. De los 23 pacientes con infección por M. lentiflavum, la localización más frecuente fue la submandibular (43,47%), 15 (65,21%) fueron niños, la media de edad global fue de 30,8 meses y todos los casos evolucionaron satisfactoriamente. CONCLUSIÓN: M. lentiflavum debe ser considerado como un importante patógeno emergente causante de linfadenitis cervical en población pediátrica

INTRODUCTION: Cervical lymphadenitis is the most common nontuberculous mycobacteria (NTM) infection in immunocompetent children, mainly in those under 5years. For many years Mycobacterium lentiflavum (M. lentiflavum) has been considered a rare NTM causing lymphadenitis. METHODS: A restrospective study was performed in pediatric patients with microbiologically confirmed NTM cervical lympahdenitis at the Niño Jesús Hospital in Madrid during 2009-2016. RESULTS: During the period studied, 28 cases of cervical lymphadenitis were recorded. In 23 (82.14%) and in 5 (17,85%) cases, M. lentiflavum and Mycobacterium avium were isolated, respectively. In those patients infected with M. lentiflavum, the most frequent location was sub-maxilar (43.47%); 15 (65.21%) were boys, global median age was 30,8 months and all cases showed a satisfactory evolution. CONCLUSION: We propose that M. lentiflavum should be considered an important emergent pathogen cause of cervical lymphadenitis in the pediatric population

Multi-scale interplays of biotic and abiotic drivers shape mammalian sub-continental diversity over millions of years.

The reconstruction of deep-time diversity trends is key to understanding current and future species richness. Studies that statistically evaluate potential factors affecting paleodiversity have focused on continental and global, clade-wide datasets, and thus we ignore how community species richness build-up to generate large-scale patterns over geological timescales. If community diversity is shaped by biotic interactions and continental and global diversities are governed by abiotic events, which are the modulators of diversity in subcontinental regions? To address this question, we model Iberian mammalian species richness over 13 million years (15 to 2 Ma) using exhaustive fossil evidence for subcontinental species' ecomorphology, environmental context, and biogeographic affinities, and quantitatively evaluate their impact on species richness. We find that the diversity of large Iberian mammals has been limited over time, with species richness showing marked fluctuations, undergoing substantial depletions as diversity surpasses a critical limit where a significant part of the niches is unviable. The strength of such diversity-dependence has also shifted. Large faunal dispersals and environmental heterogeneity increased the system's critical diversity limit. Diversity growth rate (net migration and diversification) also oscillated, mainly modulated by functional saturation, patchiness of canopy cover, and local temperature and aridity. Our study provides quantitative support for subcontinental species pools being complex and dynamic systems where diversity is perpetually imbalanced over geological timescales. Subcontinental diversity-dependence dynamics are mainly modulated by a multi-scale interplay of biotic and abiotic factors, with abiotic factors playing a more relevant role.

Correction: Body-size structure of Central Iberian mammal fauna reveals semidesertic conditions during the middle Miocene Global Cooling Event.

[This corrects the article DOI: 10.1371/journal.pone.0186762.].

Multiproxy evidence for leaf-browsing and closed habitats in extinct proboscideans (Mammalia, Proboscidea) from Central Chile.

Proboscideans are so-called ecosystem engineers and are considered key players in hypotheses about Late Pleistocene megafaunal extinctions. However, knowledge about the autoecology and chronology of the proboscideans in South America is still open to debate and raises controversial views. Here, we used a range of multiproxy approaches and new radiocarbon datings to study the autoecology of Chilean gomphotheres, the only group of proboscideans to reach South America during the Great American Biotic Interchange (∼3.1 to 2.7 million years before present). As part of this study, we analyzed stable isotopes, dental microwear, and dental calculus microfossils on gomphothere molars from 30 Late Pleistocene sites (31° to 42°S). These proxies provided different scales of temporal resolution, which were then combined to assess the dietary and habitat patterns of these proboscideans. The multiproxy study suggests that most foraging took place in relatively closed environments. In Central Chile, there is a positive correlation between lower δ13C values and an increasing consumption of arboreal/scrub elements. Analyses of dental microwear and calculus microfossils have verified these leaf-browsing feeding habits. From a comparative perspective, the dietary pattern of South American gomphotheres appears to be constrained more by resource availability than by the potential dietary range of the individual taxa. This multiproxy study is aimed at increasing knowledge of the life history of gomphotheres and thus follows an issue considered one of the greatest challenges for paleontology in South America, recently pointed out by the need to thoroughly understand the role of ecological engineers before making predictions about the consequences of ecosystem defaunation.