Clinical value of liquid biopsy in FGFR2 fusion-positive cholangiocarcinoma patients during targeted therapy.

PURPOSE: FGFR2 fusions occur in 10%-15% of intrahepatic cholangiocarcinoma (iCCA) patients, potentially benefiting from FGFR inhibitors (FGFRi). We aimed to assess the feasibility of detecting FGFR2 fusions in plasma and explore plasma biomarkers for managing FGFRi treatment. EXPERIMENTAL DESIGN: We conducted a retrospective study on 18 patients with iCCA and known FGFR2 fusions previously identified in tissue samples from prior FGFRi treatment. Both tissue and synchronous plasma samples were analyzed using a custom hybrid capture gene panel with next-generation sequencing (VHIO-iCCA panel) and validated against commercial vendor results. Longitudinal plasma analysis during FGFRi was performed. Subsequently, we explored the correlation between plasma biomarkers, liver enzymes, tumor volume, and clinical outcomes. RESULTS: Sixteen patients (88.9%) were positive for FGFR2 fusion events in plasma. Remarkably, the analysis of plasma suggests that lower levels of circulating tumor DNA (ctDNA) are linked to clinical benefits from targeted therapy and result in improved progression-free survival and (PFS) overall survival (OS). Higher concentrations of cell-free DNA (cfDNA) before FGFRi treatment were linked to worse OS, correlating with impaired liver function, and indicating compromised cfDNA removal by the liver. Additionally, increased ctDNA or the emergence of resistance mutations allowed earlier detection of disease progression compared to standard radiological imaging methods. CONCLUSIONS: VHIO-iCCA demonstrated accurate detection of FGFR2 fusions in plasma. The integration of information from various plasma biomarkers holds the potential to predict clinical outcomes and identify treatment failure prior to radiological progression, offering valuable guidance for the clinical management of patients with iCCA.

New Insights in ATP Synthesis as Therapeutic Target in Cancer and Angiogenic Ocular Diseases.

Lactate and ATP formation by aerobic glycolysis, the Warburg effect, is considered a hallmark of cancer. During angiogenesis in non-cancerous tissue, proliferating stalk endothelial cells (ECs) also produce lactate and ATP by aerobic glycolysis. In fact, all proliferating cells, both non-cancer and cancer cells, need lactate for the biosynthesis of building blocks for cell growth and tissue expansion. Moreover, both non-proliferating cancer stem cells in tumors and leader tip ECs during angiogenesis rely on glycolysis for pyruvate production, which is used for ATP synthesis in mitochondria through oxidative phosphorylation (OXPHOS). Therefore, aerobic glycolysis is not a specific hallmark of cancer but rather a hallmark of proliferating cells and limits its utility in cancer therapy. However, local treatment of angiogenic eye conditions with inhibitors of glycolysis may be a safe therapeutic option that warrants experimental investigation. Most types of cells in the eye such as photoreceptors and pericytes use OXPHOS for ATP production, whereas proliferating angiogenic stalk ECs rely on glycolysis for lactate and ATP production. (J Histochem Cytochem XX.XXX-XXX, XXXX).

Incidence of confusional syndrome (delirium) in a Latin American university hospital.

BACKGROUND: Little is known about the incidence of delirium and its subtypes in patients admitted to different departments of university hospitals in Latin America. OBJECTIVE: To determine the incidence of delirium and the frequency of its subtypes, as well as its associated factors, in patients admitted to different departments of a university hospital in Bogotá, Colombia. METHODS: A cohort of patients over 18 years of age admitted to the internal medicine (IM), geriatrics (GU), general surgery (GSU), orthopaedics (OU) and intensive care unit (ICU) services of a university hospital was followed up between January and June 2018. To detect the presence of delirium, we used the CAM (Confusion Assessment Method) and the CAM-ICU if the patient had decreased communication skills. The delirium subtype was characterised using the RASS (Richmond Agitation and Sedation Scale). Patients were assessed on their admission date and then every two days until discharged from the hospital. Those in whom delirium was identified were referred for specialised intra-institutional interdisciplinary management. RESULTS: A total of 531 patients admitted during the period were assessed. The overall incidence of delirium was 12% (95% CI, 0.3-14.8). They represented 31.8% of patients in the GU, 15.6% in the ICU, 8.7% in IM, 5.1% in the OU, and 3.9% in the GSU. The most frequent clinical display was the mixed subtype, at 60.9%, followed by the normoactive subtype (34.4%) and the hypoactive subtype (4.7%). The factors most associated with delirium were age (adjusted RR = 1.07; 95% CI, 1.05-1.09), the presence of four or more comorbidities (adjusted RR = 2.04; 95% CI, 1.31-3.20), and being a patient in the ICU (adjusted RR = 2.02; 95% CI, 1.22-3.35). CONCLUSIONS: The incidence of delirium is heterogeneous in the different departments of the university hospital. The highest incidence occurred in patients that were admitted to the GU. The mixed subtype was the most frequent one, and the main associated factors were age, the presence of four or more comorbidities, and being an ICU patient.

A Modified Delphi Consensus Approach to Define Entrustable Professional Activities for Neurocritical Care Advanced Practice Providers.

OBJECTIVES: To define consensus entrustable professional activities (EPAs) for neurocritical care (NCC) advanced practice providers (APPs), establish validity evidence for the EPAs, and evaluate factors that inform entrustment expectations of NCC APP supervisors. DESIGN: A three-round modified Delphi consensus process followed by application of the EQual rubric and assessment of generalizability by clinicians not affiliated with academic medical centers. SETTING: Electronic surveys. SUBJECTS: NCC APPs ( n = 18) and physicians ( n = 12) in the United States with experience in education scholarship or APP program leadership. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The steering committee generated an initial list of 61 possible EPAs. The panel proposed 30 additional EPAs. A total of 47 unique nested EPAs were retained by consensus opinion. The steering committee defined six core EPAs addressing medical knowledge, procedural competencies, and communication proficiency which encompassed the nested EPAs. All core EPAs were retained and subsequently met the previously described cut score for quality and structure using the EQual rubric. Most clinicians who were not affiliated with academic medical centers rated each of the six core EPAs as very important or mandatory. Entrustment expectations did not vary by prespecified groups. CONCLUSIONS: Expert consensus was used to create EPAs for NCC APPs that reached a predefined quality standard and were important to most clinicians in different practice settings. We did not identify variables that significantly predicted entrustment expectations. These EPAs may aid in curricular design for an EPA-based assessment of new NCC APPs and may inform the development of EPAs for APPs in other critical care subspecialties.

Estudio Histológico en Embriones de Cobayo (Cavia porcellus) y su Utilidad como Modelo para la Comprensión del Desarrollo Embrionario Humano / Histological Study in Guinea Pig Embryos (Cavia porcellus) and its Usefulness as a Model for Understanding Human Embryonic Development

El cobayo es un modelo animal ampliamente utilizado en la investigación biomédica debido a sus similitudes biológicas con los seres humanos. El objetivo de nuestro estudio es proporcionar sustento morfológico para utilizar preparados histológicos de embriones de cobayo como modelo de estudio para comprender los procesos del desarrollo embrionario humano. Nuestros resultados muestran que los embriones de cobayo presentan características morfológicas similares a las observadas en los embriones humanos, lo que sugiere que pueden utilizarse como un modelo efectivo para estudiar el desarrollo embrionario humano. Este hallazgo tiene importantes implicancias para la investigación y la docencia utilizando este modelo animal. Se analizaron preparados histológicos de embriones de cobayo teñidos con hematoxilina eosina, adquiridos por la Universidad Autónoma de Chile. Se tomaron microfotografías de preparados histológicos de cobayo en diferentes estadios del desarrollo y se seleccionaron las mejores imágenes para la descripción de estructuras y establecer estimados de la embriogénesis. Del análisis de los preparados se desprende que órganos como esófago, médula espinal y corazón presentan similitudes anatómicas e histológicas que hacen posible compararlas con el desarrollo embrionario humano y la edad de gestación en etapas tempranas. El uso de preparados de embriones de cobayo y su análisis desde un aspecto histológico resulta ser una estrategia metodológica factible debido a las similitudes en la embriogénesis de los mamíferos y las concordancias morfológicas con el desarrollo de los órganos entre humanos y roedores. Esto permite implementar este modelo animal como una herramienta para comprender el desarrollo embrionario humano.

SUMMARY: The guinea pig is an animal model widely used in biomedical research due to its biological similarities with humans. The objective of our study is to provide morphological support to use histological preparations of guinea pig embryos as a study model to understand the processes of human embryonic development. Our results show that guinea pig embryos present morphological characteristics similar to those observed in human embryos, suggesting that they can be used as an effective model to study human embryonic development. This finding has important implications for research and teaching using this animal model. Histological preparations of guinea pig embryos stained with hematoxylin eosin, acquired by the Autonomous University of Chile, were analyzed. Photomicrographs of histological preparations of guinea pigs at different stages of development were taken and the best images were selected to describe structures and establish estimates of embryogenesis. From the analysis of the preparations it is clear that organs such as the esophagus, spinal cord and heart present anatomical and histological similarities that make it possible to compare them with human embryonic development and gestation age in early stages. The use of guinea pig embryo preparations and their analysis from a histological aspect turns out to be a feasible methodological strategy due to the similarities in mammalian embryogenesis and the morphological concordances with the development of organs between humans and rodents. This allows this animal model to be implemented as a tool to understand human embryonic development.

Adaptation of the Recreovía During COVID-19 Lockdowns: Making Physical Activity Accessible to Older Adults in Bogotá, Colombia.

The community restrictions during the coronavirus disease 2019 pandemic adversely impacted older adults' physical activity levels. This convergent mixed-method study assessed the adaptation of the Recreovía, a community-based physical activity program in Bogotá, and characterized physical activity levels among older adult participants. Our results showed how the Recreovía adapted during the pandemic to continue promoting physical activity, through indoor and outdoor strategies, including virtual physical activity sessions and safety protocols. During this time, 72%-79% of the older adults attending the adapted program were physically active. A greater proportion of park users (84.2%) and more people involved in vigorous physical activity were observed during Recreovía days. Older adults had positive experiences and perceptions of the Recreovía program related to their health and social well-being. Even though the older adults prefer being outdoors, the adapted program allowed participants to continue with their physical activity routines as much as possible during the pandemic.

Early Versus Late Tracheostomy in Patients with Traumatic Brain Injury: A US Nationwide Analysis.

BACKGROUND: One of the most critical issues in patients suffering from traumatic brain injury (TBI) is protecting the airway and attempting to keep a secure airway. It is evident that tracheostomy in patients with TBI after 7-14 days can have favorable outcomes if the patient cannot be extubated; however, some clinicians have recommended early tracheostomy before 7 days. METHODS: A retrospective cohort of inpatient study participants was queried from the National Inpatient Sample to include patients with TBI between 2016 and 2020 undergoing tracheostomy and outcomes between the two groups of early tracheostomy (ET) (< 7 days from admission) and late tracheostomy (LT) (≥ 7 days from admission) were compared. RESULTS: We reviewed 219,005 patients with TBI, out of whom 3.04% had a tracheostomy. Patients in the ET group were younger than those in the LT group (45.02 ± 19.38 years old vs. 48.68 ± 20.50 years old, respectively, p < 0.001), mainly men (76.64% vs. 73.73%, respectively, p = 0.01), and mainly White race (59.88% vs. 57.53%, respectively, p = 0.33). The patients in the ET group had a significantly shorter length of stay as compared with those in the LT group (27.78 ± 25.96 days vs. 36.32 ± 29.30 days, respectively, p < 0.001) and had a significantly lower hospital charge ($502,502.436 ± 427,060.81 vs. $642,739.302 ± 516,078.94 per patient, respectively, p < 0.001). The whole TBI cohort mortality was reported at 7.04%, which was higher within the ET group compared with the LT group (8.69% vs. 6.07%, respectively, p < 0.001). Patients in the LT had higher odds of developing any infection (odds ratio [OR] 1.43 [1.22-1.68], p < 0.001), emerging sepsis (OR 1.61 [1.39-1.87], p < 0.001), pneumonia (OR 1.52 [1.36-1.69], p < 0.001), and respiratory failure (OR 1.30 [1.09-1.55], p = 0.004). CONCLUSIONS: This study shows that ET can provide notable and significant benefits for patients with TBI. Future high-quality prospective studies should be performed to investigate and shed more light on the ideal timing of tracheostomy in patients with TBI.

Differential roles of eNOS in late effects of VEGF-A on hyperpermeability in different types of endothelial cells.

Vascular endothelial growth factor (VEGF)-A induces endothelial hyperpermeability, but the molecular pathways remain incompletely understood. Endothelial nitric oxide synthase (eNOS) regulates acute effects of VEGF-A on permeability of endothelial cells (ECs), but it remains unknown whether and how eNOS regulates late effects of VEGF-A-induced hyperpermeability. Here we show that VEGF-A induces hyperpermeability via eNOS-dependent and eNOS-independent mechanisms at 2 days after VEGF-A stimulation. Silencing of expression of the eNOS gene (NOS3) reduced VEGF-A-induced permeability for dextran (70 kDa) and 766 Da-tracer in human dermal microvascular ECs (HDMVECs), but not in human retinal microvascular ECs (HRECs) and human umbilical vein ECs (HUVECs). However, silencing of NOS3 expression in HRECs increased permeability to dextran, BSA and 766 Da-tracer in the absence of VEGF-A stimulation, suggesting a barrier-protective function of eNOS. We also investigated how silencing of NOS3 expression regulates the expression of permeability-related transcripts, and found that NOS3 silencing downregulates the expression of PLVAP, a molecule associated with trans-endothelial transport via caveolae, in HDMVECs and HUVECs, but not in HRECs. Our findings underscore the complexity of VEGF-A-induced permeability pathways in ECs and the role of eNOS therein, and demonstrate that different pathways are activated depending on the EC phenotype.

Mass Mortality of Sea Lions Caused by Highly Pathogenic Avian Influenza A(H5N1) Virus.

We report a massive mortality of 5,224 sea lions (Otaria flavescens) in Peru that seemed to be associated with highly pathogenic avian influenza A(H5N1) virus infection. The transmission pathway may have been through the close contact of sea lions with infected wild birds. We recommend evaluating potential virus transmission among sea lions.

Durvalumab-induced Pure White Cell Aplasia.

Immune checkpoint inhibitors (ICI) have gained approval as a treatment for a wide array of cancers. Their mechanism of action prevents the inactivation of cytotoxic T-cells, allowing for its cytotoxic response. However, the upregulation of the immune system by ICI also leads to many undesired adverse events known as immune-related adverse events (irAEs), ranging from dermatologic manifestations, such as rashes, to inflammation of mucous membranes, to hematologic toxicities. Here, we report a case of ICI-induced pure white cell aplasia, secondary to the agent durvalumab, which responded to treatment with filgrastim, prednisone, and cyclosporine. ICI-neutropenia accounts for 0.6% of all irAEs or 17% of hematologic irAEs. Given the rarity of hematologic irAEs, the available treatment guidelines are based on expert consensus. As ICI becomes more widely used, we can expect an increase in the prevalence of rare irAEs as well. This case report aims to present a rare side effect of ICI and demonstrate its response to immunosuppressive therapy while providing guidance for future clinicians and further elucidating the mechanism behind these irAEs.

Risk factors associated with hemorrhagic cerebrovascular accident: A cross-sectional study in patients from a hospital in Peru.

In Peru, cardiovascular accidents (CVA) cause around 15% of premature death, with an increase in CVA due to the prevalence of risk factors for CVA in the Peruvian population. Hemorrhagic CVA presents higher mortality compared to ischemic. This research aimed to identify the risk factors associated with hemorrhagic CVA. We carried out a retrospective cross-sectional study using the medical records of patients with a diagnosis of CVA treated at the Regional Hospital of Ica during the years 2018 and 2019. Independent variables included age, sex, type 2 diabetes, dyslipidemia, hypertension, smoking, obesity, and intracranial carotid artery calcification. To identify factors associated with an increased probability for hemorrhagic CVA compared to ischemic CVA, a generalized linear model with logit link and binomial family, obtaining the odds ratio (OR) and its 95% confidence interval (CI). we evaluated the data from 132 patients. Of them, 46 (34.85%) had hemorrhagic CVA. Only systolic blood pressure (OR: 1.04; 95% CI: 1.02-1.06) and hypertension (OR: 0.29; 95% CI: 0.10-0.89) were significantly associated with hemorrhagic CVA compared to ischemic CVA. Hypertension is associated with hemorrhagic CVA compared to ischemic CVA. These results are consistent with the literature.

Neanderthal introgression in SCN9A impacts mechanical pain sensitivity.

The Nav1.7 voltage-gated sodium channel plays a key role in nociception. Three functional variants in the SCN9A gene (encoding M932L, V991L, and D1908G in Nav1.7), have recently been identified as stemming from Neanderthal introgression and to associate with pain symptomatology in UK BioBank data. In 1000 genomes data, these variants are absent in Europeans but common in Latin Americans. Analysing high-density genotype data from 7594 Latin Americans, we characterized Neanderthal introgression in SCN9A. We find that tracts of introgression occur on a Native American genomic background, have an average length of ~123 kb and overlap the M932L, V991L, and D1908G coding positions. Furthermore, we measured experimentally six pain thresholds in 1623 healthy Colombians. We found that Neanderthal ancestry in SCN9A is significantly associated with a lower mechanical pain threshold after sensitization with mustard oil and evidence of additivity of effects across Nav1.7 variants. Our findings support the reported association of Neanderthal Nav1.7 variants with clinical pain, define a specific sensory modality affected by archaic introgression in SCN9A and are consistent with independent effects of the Neanderthal variants on Nav1.7 function.

Dilatación idiopática de la aurícula derecha. Reporte de caso y revisión de la literatura / Idiopathic dilatation of the right atrium. Case report and literature review

Resumen La dilatación idiopática de la aurícula derecha (DIAD) es una malformación poco frecuente caracterizada por un crecimiento desproporcionado de la aurícula derecha en ausencia de una causa estructural o funcional que la justifique. Presentamos el caso de una paciente con DIAD con diagnóstico desde la etapa prenatal.

Abstract Idiopathic dilatation of the right atrium is a rare malformation characterized by disproportionate growth of the right atrium in the absence of a cause that justifies it. We present the case of a patient with idiopathic dilatation of the right atrium diagnosed since fetal life.

Idiopathic dilatation of the right atrium. Case report and literature review.

Idiopathic dilatation of the right atrium is a rare malformation characterized by disproportionate growth of the right atrium in the absence of a cause that justifies it. We present the case of a patient with idiopathic dilatation of the right atrium diagnosed since fetal life.

La dilatación idiopática de la aurícula derecha (DIAD) es una malformación poco frecuente caracterizada por un crecimiento desproporcionado de la aurícula derecha en ausencia de una causa estructural o funcional que la justifique. Presentamos el caso de una paciente con DIAD con diagnóstico desde la etapa prenatal.

Effects of an urban cable car intervention on physical activity: the TrUST natural experiment in Bogotá, Colombia.

BACKGROUND: Cable cars are part of the transport system in several cities in Latin America, but no evaluations of their effects on physical activity are available. TransMiCable is the first cable car in Bogotá, Colombia, and the wider intervention includes renovated parks and playgrounds. We assessed the effects of TransMiCable and the wider intervention on physical activity. METHODS: The Urban Transformations and Health natural experiment was a prospective quasi-experimental study conducted from Feb 1, 2018, to Dec 18, 2018 (baseline, pre-intervention) and from July 2, 2019, to March 15, 2020 (post-intervention follow-up) in the TransMiCable intervention area (Ciudad Bolívar settlement) and a control area without TransMiCable (San Cristóbal settlement). A multistage strategy was used to sample households in each area, with one adult (aged ≥18 years) per household invited to participate. Eligible participants had lived in the intervention or control areas for at least 2 years and were not planning to move within the next 2 years. Physical activity was assessed among participants in the intervention and control areas before and after the inauguration of TransMiCable in Ciudad Bolívar with the International Physical Activity Questionnaire (long form) and with wearable accelerometers. Complete cases (those with baseline and follow-up data) were included in analyses. Respondents were classed as being physically active if they met 2020 WHO guidelines (≥150 min per week of moderate activity, ≥75 min per week of vigorous activity, or equivalent combinations); and accelerometery data were classified with the Freedson cut-points for adults. Data were also gathered in zonal parks (area ≥10 000 m2) and neighbourhood parks (area <10 000 m2) in the intervention and control areas by direct observation with the System for Observing Play and Recreation in Communities, to assess levels of physical activity before and after the TransMiCable intervention. Multilevel regression models were used to assess changes in physical activity associated with the TransMiCable intervention. FINDINGS: Physical activity questionnaires were completed by 2052 adult participants (1289 [62·8%] women and 763 [37·2%] men; mean age 43·5 years [SD 17·7]) before the inauguration of TransMiCable. After the inauguration, the follow-up (final) questionnaire sample comprised 825 adults in the intervention group and 854 in the control group, including 357 adults in the intervention group and 334 in the control group with valid accelerometery data. 334 (40·5%) of 825 participants in the intervention group reported levels of physical activity that met the 2020 WHO guidelines during walking for transport before the intervention, and 426 (51·6%) afterwards (change 11·1 percentage points [95% CI 6·4 to 15·9]). A similar change was observed in the control group (change 8·0 percentage points [3·4 to 12·5]; adjusted odds ratio [OR] for the time-by-group interaction, intervention vs control group: 1·1 [95% CI 0·8 to 1·5], p=0·38). Time spent doing moderate-to-vigorous physical activity, measured with accelerometers, did not change in the intervention group after the inauguration of TransMiCable (change -0·8 min per day [-4·6 to 3·0]) and did not change compared with the control group (adjusted ß for the time-by-group interaction: 1·4 min per day [95% CI -2·0 to 4·9], p=0·41). Moderate-to-vigorous physical activity was 52·1 min per day (SD 24·7) before and 59·4 min per day (35·2) after the inauguration of TransMiCable in new regular users who reported using TransMiCable during mandatory trips for work or education (n=32; change 7·3 min per day [-22·5 to 7·9]). After the intervention, an increase in the proportion of male individuals engaging in moderate or vigorous physical activity was observed in a renovated zonal park (adjusted OR for the time-by-group interaction, intervention vs control park: 2·7 [1·1 to 6·8], p=0·033). Female users of a renovated neighbourhood park were less likely to become engaged in moderate or vigorous physical activity than female users of the control area neighbourhood park (adjusted OR for the time-by-group interaction: 0·4 [0·1 to 0·6], p=0·019). INTERPRETATION: It is encouraging that walking for transport remained high in the TransMiCable intervention area when the use of private motorised transport had increased elsewhere in Bogotá. In low-income urban areas, where transport-related walking is a necessity, transport interventions should be focused on efforts to maintain participation in active travel while improving conditions under which it occurs. FUNDING: Wellcome Trust (as part of the Urban Health in Latin America project); Bogotá Urban Planning Department; Ministry of Science, Technology, and Innovation of Colombia; Universidad de Los Andes; Fundación Santa Fe de Bogotá; and Universidad del Norte. TRANSLATION: For the Spanish translation of the abstract see Supplementary Materials section.

A new species of Dipsas (Serpentes, Dipsadidae) from central Panama.

A new species of Dipsas Laurenti, 1768, from Central Panama is described based on molecular analyses, hemipenial morphology, and external characters. This is the sixth species of Dipsas to be described for the country; the snake has been suspected to exist since 1977 and has not been thoroughly studied until now. Additionally, morphological comparations including scale counts are done with other species within the genus, and the current geographic distribution of Dipsastemporalis (Werner, 1909), the sister species, is updated. Finally, a key to the species of Dipsas currently known from Middle America is presented.

ResumenDescribimos una nueva especies de Dipsas Laurenti, 1768 de la región central de Panamá en base a análisis moleculares, morfología hemipenial y caracteres de morfología externa. Esta es la sexta especie del género Dipsas descrita para el país. Se sospechaba su existencia desde 1977 pero no había sido estudiada exhaustivamente hasta ahora. Adicionalmente, presentamos comparaciones morfológicas (incluyendo lepidosis) con otras especies del género y actualizamos la distribución geográfica de su especie hermana Dipsastemporalis (Werner, 1909). Finalmente, presentamos una clave para las especies de Dipsas distribuidas en Centroamérica.

Automatic landmarking identifies new loci associated with face morphology and implicates Neanderthal introgression in human nasal shape.

We report a genome-wide association study of facial features in >6000 Latin Americans based on automatic landmarking of 2D portraits and testing for association with inter-landmark distances. We detected significant associations (P-value <5 × 10-8) at 42 genome regions, nine of which have been previously reported. In follow-up analyses, 26 of the 33 novel regions replicate in East Asians, Europeans, or Africans, and one mouse homologous region influences craniofacial morphology in mice. The novel region in 1q32.3 shows introgression from Neanderthals and we find that the introgressed tract increases nasal height (consistent with the differentiation between Neanderthals and modern humans). Novel regions include candidate genes and genome regulatory elements previously implicated in craniofacial development, and show preferential transcription in cranial neural crest cells. The automated approach used here should simplify the collection of large study samples from across the world, facilitating a cosmopolitan characterization of the genetics of facial features.

Phylogenetic and morphological evidence reveals the association between diet and the evolution of the venom delivery system in Neotropical goo-eating snakes

Advanced endoglyptodont snakes share a complex but homologous venom delivery system associated with the upperjaw and its dentition. Recently, a remarkable novel lower jaw venom delivery system was described for the Neotropicaldipsadine radiation of goo-eating snakes. While most dipsadines are opistoglyphous and exhibit large, mainly serousvenom glands associated with the upper jaw and supralabial glands, goo-eating dipsadine snakes are aglyphous and lackserous upper labial venom glands. Here, we provide new morphological and histological information on the oral glandsand maxillary dentition of representatives of the major lineages of dipsadines that help trace the evolutionary steps thatshaped the venom delivery system of dipsadines. We performed a maximum likelihood analysis on a molecular datasetthat includes 443 terminals and seven loci. Our results show that goo-eating dipsadines form a monophyletic assemblagethat includes the genusAdelphicosfor the first time, along withGeophis,Atractus,Ninia,Chersodromus,Tropidodipsas,Sibon, andDipsas. We also provide the first evidence of a complete shift from an upper jaw to a lower jaw venomdelivery system associated with their specialized feeding behaviour. Unlike other dipsadines who exhibit typicalendoglyptodont anteroposteriorly ridged posterior maxillary teeth, goo-eating dipsadines have uniform lateromediallyridged teeth throughout their maxilla. Our results indicate that the loss of the endoglyptodont venom delivery systemoccurred in the most recent common ancestor of goo-eating dipsadines, probably resulting from the loss of theembryonic posterior maxillary lamina responsible for the development of the venom delivery system.

Healthy adult gut microbiota sustains its own vitamin B12 requirement in an in vitro batch fermentation model.

Vitamin B12 (cobalamin) is present in the human lower gastrointestinal tract either coming from the unabsorbed dietary fraction or from in situ production of the gut microbiota. However, it is unclear whether the gut microbial communities need exogenous B12 for growth and metabolism, or whether B12 in low and high levels could affect gut community composition and metabolite production. Here, we investigated in vitro B12 production of human fecal microbiota and the effects of different levels of B12 (as cyanocobalamin) on composition and activity. Eight fecal communities from healthy human adults distributed over three enterotypes, dominated by Firmicutes (n = 5), Bacteroides (n = 1) or Prevotella (n = 2) were used to perform batch fermentations in Macfarlane medium supplemented with low B12 medium (Control, 5 ng/ml, within the tested fecal range), no B12 addition (NB12), and high B12 addition (ExtraB12, 2500 ng/ml). The microbiota community composition (qPCR, 16S rRNA metabarcoding), metabolic activity (HPLC-RI), and B12 levels (UHPLC-DAD) were measured after 24 h incubation at 37°C under strict anaerobic conditions. All fecal microbial communities produced B12 in the NB12 condition after 24 h, in the range from 152 ± 4 to 564 ± 25 ng/ml. None of the B12 treatments had an impact on total bacterial growth, community richness, diversity and total metabolite production, compared to the low B12 control. However, a significant increase of propionate was measured in ExtraB12 compared to NB12. Most taxonomic and metabolite changes compared to control incubations were donor-dependent, implying donor-microbiota-specific changes upon B12 treatments. Our in vitro data suggest that healthy human adult gut microbial communities have the capacity to produce B12 at levels fulfilling their own requirements, independently of the initial B12 content tested in the donor's feces. Further, supplementation of exogenous dietary B12 may have limited impact on the healthy human gut microbial community composition and function.

Role of quiescent cells in the homeostatic maintenance of the adult submandibular salivary gland.

Stem/progenitor cells are required for maintenance of salivary gland (SG) function and serve as untapped reservoirs to create functional cells. Despite recent advancements in the identification of stem/progenitor pools, in the submandibular gland (SMG), a knowledge gap remains. Furthermore, the contribution to adult SMG homeostasis of stem/progenitor cells originating from embryonic development is unclear. Here, we employ an H2B-GFP embryonic and adult pulse-and-chase system to characterize potential SMG stem/progenitor cells (SGSCs) based on quiescence at different stages. Phenotypical profiling of quiescent cells in the SMG revealed that label-retaining cells (LRCs) of embryonic or adult origin co-localized with CK8+ ductal or vimentin + mesenchymal, but not with CK5+ or CK14 + stem/progenitor cells. These SMG LRCs failed to self-renew in vitro while non-label retaining cells displayed differentiation and long-term expansion potential as organoids. Collectively, our data suggest that an active cycling population of cells is responsible for SMG homeostasis with organoid forming potential.