Fat1 deletion promotes hybrid EMT state, tumour stemness and metastasis.

FAT1, which encodes a protocadherin, is one of the most frequently mutated genes in human cancers1-5. However, the role and the molecular mechanisms by which FAT1 mutations control tumour initiation and progression are poorly understood. Here, using mouse models of skin squamous cell carcinoma and lung tumours, we found that deletion of Fat1 accelerates tumour initiation and malignant progression and promotes a hybrid epithelial-to-mesenchymal transition (EMT) phenotype. We also found this hybrid EMT state in FAT1-mutated human squamous cell carcinomas. Skin squamous cell carcinomas in which Fat1 was deleted presented increased tumour stemness and spontaneous metastasis. We performed transcriptional and chromatin profiling combined with proteomic analyses and mechanistic studies, which revealed that loss of function of FAT1 activates a CAMK2-CD44-SRC axis that promotes YAP1 nuclear translocation and ZEB1 expression that stimulates the mesenchymal state. This loss of function also inactivates EZH2, promoting SOX2 expression, which sustains the epithelial state. Our comprehensive analysis identified drug resistance and vulnerabilities in FAT1-deficient tumours, which have important implications for cancer therapy. Our studies reveal that, in mouse and human squamous cell carcinoma, loss of function of FAT1 promotes tumour initiation, progression, invasiveness, stemness and metastasis through the induction of a hybrid EMT state.

Clinical description, molecular delineation and genotype-phenotype correlation in 340 patients with KBG syndrome: addition of 67 new patients.

BACKGROUND: KBG syndrome is a highly variable neurodevelopmental disorder and clinical diagnostic criteria have changed as new patients have been reported. Both loss-of-function sequence variants and large deletions (copy number variations, CNVs) involving ANKRD11 cause KBG syndrome, but no genotype-phenotype correlation has been reported. METHODS: 67 patients with KBG syndrome were assessed using a custom phenotypical questionnaire. Manifestations present in >50% of the patients and a 'phenotypical score' were used to perform a genotype-phenotype correlation in 340 patients from our cohort and the literature. RESULTS: Neurodevelopmental delay, macrodontia, triangular face, characteristic ears, nose and eyebrows were the most prevalentf (eatures. 82.8% of the patients had at least one of seven main comorbidities: hearing loss and/or otitis media, visual problems, cryptorchidism, cardiopathy, feeding difficulties and/or seizures. Associations found included a higher phenotypical score in patients with sequence variants compared with CNVs and a higher frequency of triangular face (71.1% vs 42.5% in CNVs). Short stature was more frequent in patients with exon 9 variants (62.5% inside vs 27.8% outside exon 9), and the prevalence of intellectual disability/attention deficit hyperactivity disorder/autism spectrum disorder was lower in patients with the c.1903_1907del variant (70.4% vs 89.4% other variants). Presence of macrodontia and comorbidities were associated with larger deletion sizes and hand anomalies with smaller deletions. CONCLUSION: We present a detailed phenotypical description of KBG syndrome in the largest series reported to date of 67 patients, provide evidence of a genotype-phenotype correlation between some KBG features and specific ANKRD11 variants in 340 patients, and propose updated clinical diagnostic criteria based on our findings.

Causes of mortality among adults with Down syndrome before and after the COVID-19 pandemic in Spain.

BACKGROUND: The life expectancy of people with Down syndrome (DS) is limited by Alzheimer's disease (AD)-related deaths, mainly due to respiratory infections. The emergence of the COVID-19 pandemic could have changed known, past trends in mortality in this population. We analysed the differences in causes of mortality between individuals with DS deceased before and after the onset of the pandemic. METHOD: This is a cross-sectional study of adults with DS recruited at a tertiary, university outpatient clinic in Madrid, Spain. Demographic and clinical data were retrospectively collected from their medical records, including information on their deaths, if any. RESULTS: Five hundred seventy-two adults were included in the study, and 67 (11.7%) died. The main cause of death was respiratory infections, which occurred in 36 participants [9 (45.0%) before, and 27 (58.7%) after the appearance of COVID-19]. No significant differences were found in the determinants of pre-pandemic and post-pandemic death after adjusting for age and AD, except for an association between the use of psychotropic medication and death in the post-pandemic period (odds ratio: 2.24; 95% confidence interval: 1.04-4.82). Vaccination against COVID-19 showed a marked protective effect against mortality (odds ratio: 0.0002; 95% confidence interval: 6.7e10-6 to 0.004). CONCLUSIONS: The appearance of COVID-19 has not impacted the overall trend of increase in mean age of death of adults with DS in our milieu, probably thanks to the very important protective effect of vaccination, which supports prioritising people with DS in future immunisation campaigns. The association between psychotropic medication use and mortality requires further exploration.

Previous use of statins does not improve the outcome of bloodstream infection after kidney transplantation.

Previous studies have suggested that exposure to statins confers a protective effect in bloodstream infection (BSI) due to the anti-inflammatory and immunomodulatory properties attributed to these lipid-lowering drugs. Scarce evidence is available for the solid organ transplant population. Therefore, we compared the time to clinical cure (primary outcome) and the time to fever resolution, new requirement of intensive care unit admission or renal replacement therapy, and 30-day all-cause mortality (secondary outcomes) between kidney transplant (KT) recipients with post-transplant BSI that were receiving or not statin therapy for at least the previous 30 days. We included 80 KT recipients that developed 109 BSI episodes (43 [39.4%] and 66 [60.6%] episodes within the statin and non-statin groups, respectively). The median interval since the initial prescription to BSI was 512 days (interquartile range [IQR]: 172-1388). Most episodes were of urinary source and due to Enterobacterales. There were no differences in the median time to clinical cure in the statin and non-statin groups (3.4 [IQR: 3-6.8] versus 4 [IQR: 2-6] days; p-value = .112). The lack of effect was confirmed by multiple linear regression analysis adjusted for confounding factors (standardized ß coefficient = 0.040; p-value = .709). No significant differences were observed for any of the secondary outcomes either. Vital signs and laboratory values at BSI onset and after 72-96 h were similar in both groups. In conclusion, previous statin therapy had no apparent protective effect on the outcome of post-transplant BSI among KT recipients.

Improving the Implementation of Advance Directives in Spain.

Since 2002, legislation in Spain has allowed for the creation and documentation of end-of-life decisionmaking. Over the intervening years, the actual implementation of such documents is very low. Through extensive analysis of the literature, this article explores the current status of the use of and attitudes toward advance directives in Spain and then proposes strategies for improvement in their implementation.

IL-6/STAT3 signaling in tumor cells restricts the expression of frameshift-derived neoantigens by SMG1 induction.

BACKGROUND: The quality and quantity of tumor neoantigens derived from tumor mutations determines the fate of the immune response in cancer. Frameshift mutations elicit better tumor neoantigens, especially when they are not targeted by nonsense-mediated mRNA decay (NMD). For tumor progression, malignant cells need to counteract the immune response including the silencing of immunodominant neoantigens (antigen immunoediting) and promoting an immunosuppressive tumor microenvironment. Although NMD inhibition has been reported to induce tumor immunity and increase the expression of cryptic neoantigens, the possibility that NMD activity could be modulated by immune forces operating in the tumor microenvironment as a new immunoediting mechanism has not been addressed. METHODS: We study the effect of SMG1 expression (main kinase that initiates NMD) in the survival and the nature of the tumor immune infiltration using TCGA RNAseq and scRNAseq datasets of breast, lung and pancreatic cancer. Different murine tumor models were used to corroborate the antitumor immune dependencies of NMD. We evaluate whether changes of SMG1 expression in malignant cells impact the immune response elicited by cancer immunotherapy. To determine how NMD fluctuates in malignant cells we generated a luciferase reporter system to track NMD activity in vivo under different immune conditions. Cytokine screening, in silico studies and functional assays were conducted to determine the regulation of SMG1 via IL-6/STAT3 signaling. RESULTS: IL-6/STAT3 signaling induces SMG1, which limits the expression of potent frameshift neoantigens that are under NMD control compromising the outcome of the immune response. CONCLUSION: We revealed a new neoantigen immunoediting mechanism regulated by immune forces (IL-6/STAT3 signaling) responsible for silencing otherwise potent frameshift mutation-derived neoantigens.

Surgical Trainee Performance and Alignment With Surgical Program Director Expectations.

OBJECTIVE: To examine the alignment between graduating surgical trainee operative performance and a prior survey of surgical program director expectations. BACKGROUND: Surgical trainee operative training is expected to prepare residents to independently perform clinically important surgical procedures. METHODS: We conducted a cross-sectional observational study of US general surgery residents' rated operative performance for Core general surgery procedures. Residents' expected performance on those procedures at the time of graduation was compared to the current list of Core general surgery procedures ranked by their importance for clinical practice, as assessed via a previous national survey of general surgery program directors. We also examined the frequency of individual procedures logged by residents over the course of their training. RESULTS: Operative performance ratings for 29,885 procedures performed by 1861 surgical residents in 54 general surgery programs were analyzed. For each Core general surgery procedure, adjusted mean probability of a graduating resident being deemed practice-ready ranged from 0.59 to 0.99 (mean 0.90, standard deviation 0.08). There was weak correlation between the readiness of trainees to independently perform a procedure at the time of graduation and that procedure's historical importance to clinical practice ( p = 0.22, 95% confidence interval 0.01-0.41, P = 0.06). Residents also continue to have limited opportunities to learn many procedures that are important for clinical practice. CONCLUSION: The operative performance of graduating general surgery residents may not be well aligned with surgical program director expectations.

The vascular surgery in-training examination predicts performance on qualifying examination.

OBJECTIVE: Vascular surgery trainees participate in the vascular surgery in-training examination (VSITE) during each year of their training. Although the VSITE was developed as a low-stakes, formative examination, performance on that examination might correlate with the pass rates for the Vascular Surgery Board written qualifying examination (VQE) and oral certifying examination (VCE) and might, therefore, guide both trainees and program directors. The present study was designed to examine the ability of the VSITE to predict trainees' performance on the VQE and VCE. METHODS: All first-time candidates of the Vascular Surgery Board VQE and VCE were analyzed from 2016 to 2020, including those from both the integrated and independent training pathways. VSITE scores from the final year of training were associated with the VQE scores and the probability of passing the VQE and VCE both. Linear and logistic regression models were used to determine the ability of VSITE results to predict the VQE scores and the probability of passing each board examination. RESULTS: VSITE scores available for the 559 candidates (69.3% male; 30.7% female) who had completed the VQE and 369 candidates (66.7% male; 33.3% female) who had completed both the VQE and the VCE. The linear regression model results for the final year of training showed that the VSITE scores explained 34% of the variance in the VQE scores (29% for the integrated and 37% for the independent trainees). Logistic regression demonstrated that the final year VSITE scores were a significant predictor of passing the VQE for both integrated and independent trainees (P < .001). A VSITE score of 500 during the final year of training predicted a VQE passing probability of >90% for each group of candidates. The probability of passing the VQE decreased to 73% for candidates from integrated programs, 61% for candidates from independent programs, and 64% for the whole cohort when the score was 400. The VSITE scores were a significant predictor of passing the VCE only for the candidates from independent programs (odds ratio, 1.01; 95% confidence interval, 1.00-1.02; P < .01), for whom a VSITE score of 400 correlated with an 82% probability of passing the VCE. CONCLUSIONS: VSITE performance is predictive of passing the VQE for trainees from both integrated and independent training paradigms. Vascular surgery trainees and training programs should optimize their preparation and educational efforts to maximize performance on the VSITE during their final year of training to improve the likelihood of passing the VQE. Further analysis of the predictive value of VSITE scores during the earlier years of training might allow the board certification examinations to be administered earlier in the final year of training.

Association of chemokines IP-10/CXCL10 and I-TAC/CXCL11 with insulin resistance and enhance leukocyte endothelial arrest in obesity.

BACKGROUND AND AIMS: Obesity is a key contributing factor to incidental type 2 diabetes and cardiovascular disease. CXCR3 receptor and its ligands CXCL 10 and 11 are associated with atherosclerosis and cardiovascular disease. The aim of our study was to analyse the role of the CXCR3 ligands on insulin resistance (IR) and endothelial dysfunction in human obesity. METHODS AND RESULTS: We have studied 45 obese patients (mean age 44 ± 6 years, body mass index 45 ± 9 kg/m2) who were selected for Roux-Y-gastric bypass surgery and 21 non obese control subjects with similar age and gender distribution. We measured by ELISA the circulating levels of the CXCR3 ligands interferon-γ inducible protein 10 (IP-10/CXCL10) and interferon-γ-inducible T-cell alpha chemoattractant (I-TAC/CXCL11). Using an ex vivo procedure with the flow chamber assay, we have investigated the effect of such chemokines on endothelial leukocytes arrest under dynamic conditions. Peripheral blood levels of CXCL10 and CXCL11 were significantly higher in obese subjects than in controls (p < 0.001) and significantly correlated with BMI, waist circunference and HOMA-IR. Obese patients with HOMA-IR index above 75th percentile showed highest increase of circulating CXCL10 and CXCL11 values. Under dynamic flow conditions, the enhanced adhesion of patient leukocytes to TNFα-induced human arterial endothelial cells was partly dependent on CXCR3. CONCLUSIONS: The study demonstrates that CXCL10 and CXCL11 are associated with IR and enhance leukocyte endothelial arrest in obese subjects. Blockade of CXCR3 signaling might be a new therapeutic approach for the prevention of obesity-associated cardiovascular co-morbidities.

TOCSY, hydrogen decoupling and computational calculations to an unequivocal structural elucidation of a new sesquiterpene derivative and identification of other constituents from Praxelis sanctopaulensis.

INTRODUCTION: Praxelis genus comprises 24 species, however, only two species of this genus have been chemically investigated. Here we investigated Praxelis sanctopaulensis, a native plant from Brazil, that occurs mainly in Cerrado regions. OBJECTIVE: The goal was to identify the specialised metabolites from P. sanctopaulensis, and compare with those described from Praxelis and Chromolaena species. METHODS: The phytochemical study of P. sanctopaulensis was performed through different chromatography techniques, including high-performance liquid chromatography (HPLC), gas chromatography flame ionisation detector (GC-FID), and ultra-high-performance liquid chromatography high-resolution tandem mass spectrometry (UHPLC-HRMS/MS). The structures of the compounds were established based on spectroscopic analysis, total correlated spectroscopy (TOCSY), hydrogen decoupling and computational calculations was used to an unequivocal structural elucidation of a new sesquiterpene. The antioxidant activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP), and antimicrobial assay was performed by the microdilution method. Comparison of the flavonoids described P. sanctopaulensis was carried out using principal component analysis. RESULTS: The phytochemical investigation of P. sanctopaulensis led to the isolation of a pair of diastereomers, praxilone A and praxilone B. Seven known compounds were isolated from this species, another 14 fatty acids were detected in hexane fraction, and 26 compounds were identified from ethyl acetate fraction. All these compounds are being described for the first time in this species, with the exception of viridifloric acid. The ethyl acetate fraction showed potent antioxidant activity. CONCLUSIONS: Forty-seven compounds are described from P. sanctopaulensis. The combination of different techniques of nuclear magnetic resonance (NMR) spectroscopy and computational calculations allowed the unequivocal structure elucidation of a new cadinene. The clustering analysis showed similarities between the flavonoids identified in P. sanctopaulensis and in Chromolaena species.

Is Initial Board Certification Associated With Better Early Career Surgical Outcomes?

OBJECTIVE: To determine if initial American Board of Surgery certification in general surgery is associated with better risk-adjusted patient outcomes for Medicare patients undergoing partial colectomy by an early career surgeon. BACKGROUND: Board certification is a voluntary commitment to professionalism, continued learning, and delivery of high-quality patient care. Not all surgeons are certified, and some have questioned the value of certification due to limited evidence that board-certified surgeons have better patient outcomes. In response, we examined the outcomes of certified versus noncertified early career general surgeons. METHODS: We identified Medicare patients who underwent a partial colectomy between 2008 and 2016 and were operated on by a non-subspecialty trained surgeon within their first 5 years of practice. Surgeon certification status was determined using the American Board of Surgery data. Generalized linear mixed models were used to control for patient-, procedure-, and hospital-level effects. Primary outcomes were the occurrence of severe complications and occurrence of death within 30 days. RESULTS: We identified 69,325 patients who underwent a partial colectomy by an early career general surgeon. The adjusted rate of severe complications after partial colectomy by certified (n = 4239) versus noncertified (n = 191) early-career general surgeons was 9.1% versus 10.7% (odds ratio 0.83, P = 0.03). Adjusted mortality rate for certified versus noncertified early-career general surgeons was 4.9% versus 6.1% (odds ratio 0.79, P = 0.01). CONCLUSION: Patients undergoing partial colectomy by an early career general surgeon have decreased odds of severe complications and death when their surgeon is board certified.

The lower energy diffraction and scattering side-bounce beamline for materials science at the Canadian Light Source.

A new diffraction beamline for materials science has been built at the Canadian Light Source synchrotron. The X-ray source is an in-vacuum wiggler with a 2.5 T peak magnetic field at 5.2 mm gap. The optical configuration includes a toroidal mirror, a single side-bounce Bragg monochromator, and a cylindrical mirror, producing a sub-150 µm vertical × 500 µm horizontal focused beam with a photon energy range of 7-22 keV and a flux of 1012 photons per second at the sample position. Three endstations are currently open to general users, and the techniques available include high-resolution powder diffraction, small molecule crystallography, X-ray reflectivity, in situ rapid thermal annealing, and SAXS/WAXS. The beamline design parameters, calculated and measured performance, and initial experimental results are presented to demonstrate the capabilities for materials science.

Frontiers in human factors: integrating human factors and ergonomics to improve safety and quality in Latin American healthcare systems.

BACKGROUND: The importance of human factors/ergonomics (HFE) is well established in all high-reliability systems but only applied in the healthcare sector relatively recently. Across many sectors, low-/middle-income countries (LMICs) lag behind more economically developed countries in their application of this safety science, due to resource and, in some cases, awareness and expertise. Most previous applications of HFE related to occupational ergonomics rather than healthcare safety. METHODS: The paper details how the reputation of HFE is being developed within healthcare communities of Latin America (LatAm), through increasing awareness and understanding of its role as safety science in the healthcare sector. It starts by articulating the need for HFE and then provides examples from Mexico, Colombia and Peru. RESULTS: The practical examples for research and education illustrate a developing awareness of the relevance of HFE to the healthcare sectors in LatAm and an appreciation of its worth to improve health service quality and patient safety through healthcare community engagement. A new LatAm Network of HFE in Healthcare Systems (RELAESA) was formed in 2019, which has provided a platform for HFE advice during the COVID-19 pandemic. CONCLUSION: There is a real opportunity in LatAm and other LMIC health services to make more rapid and sustainable progress in healthcare-embedded HFE than has been experienced within healthcare services of more developed nations.

Pre-inoculation with arbuscular mycorrhizal fungi affects essential oil quality and the reproduction of root lesion nematode in Cymbopogon citratus.

Cymbopogon citratus (lemongrass) is an important medicinal and aromatic plant containing citral-rich essential oil, of which the quality and quantity may be affected by nematode infection. Research has shown that arbuscular mycorrhizal fungi (AMF) may act as nematode biocontrol agents and improve the chemical composition of plants. Three experiments were conducted to assess the effects of AMF inoculation on vegetative growth, essential oil composition, induction of defense-related proteins, and control of Pratylenchus brachyurus in C. citratus. Seedlings were transplanted into pots inoculated with one of two AMF species (Rhizophagus clarus or Claroideoglomus etunicatum). At 30 days after AMF inoculation, plants were inoculated with P. brachyurus. Evaluations were performed at 75 days after nematode inoculation. Although both AMF treatments led to effective root colonization (> 84%), fungus inoculation was not effective in reducing P. brachyurus population density. Nevertheless, C. etunicatum promoted an increase in shoot weight, and AMF treatments contributed to preserving essential oil composition in nematode-infected plants. In addition, both AMF treatments enhanced polyphenol oxidase activity and R. clarus increased peroxidase activity after nematode inoculation.

Diagnostic Accuracy of Interferon Gamma-Induced Protein 10 mRNA Release Assay for Tuberculosis.

Interferon gamma (IFN-γ) release assays (IGRAs) are increasingly used to test for latent tuberculosis (TB) infection. Although highly specific, IGRAs have a relatively high false-negative rate in active TB patients. A more sensitive assay is needed. IFN-γ-induced protein 10 (IP-10) is an alternative biomarker with a 100-fold-higher expression level than IFN-γ, allowing for different analysis platforms, including molecular detection. The PCR technique is already an integrated tool in most TB laboratories and, thus, an obvious platform to turn to. In this case-control study, we investigated the diagnostic sensitivity and specificity of a molecular assay detecting IP-10 mRNA expression following antigen stimulation of a blood sample. We included 89 TB patients and 99 healthy controls. Blood was drawn in QuantiFeron-TB gold in-tube (QFT) assay tubes. Eight hours poststimulation, IP-10 mRNA expression was analyzed, and 20 h poststimulation, IP-10 and IFN-γ protein plasma levels were analyzed using an in-house IP-10 enzyme-linked immunosorbent assay (ELISA) and the official QFT ELISA, respectively. The IP-10 mRNA assay provided high specificity (98%), sensitivity (80%), and area under the concentration-time curve (AUC) (0.97); however, the QFT assay provided a higher overall diagnostic potential, with specificity of 100%, sensitivity of 90%, and AUC of 0.99. The IP-10 protein assay performed on par with the QFT assay, with specificity of 98%, sensitivity of 87%, and AUC of 0.98. We have provided proof of high technical performance of a molecular assay detecting IP-10 mRNA expression. As a diagnostic tool, this assay would gain from further optimization, especially on the kinetics of IP-10 mRNA expression.

ICOS Costimulation at the Tumor Site in Combination with CTLA-4 Blockade Therapy Elicits Strong Tumor Immunity.

Cytotoxic T lymphocyte-associated protein 4 (CTLA-4) blockade therapy is able to induce long-lasting antitumor responses in a fraction of cancer patients. Nonetheless, there is still room for improvement in the quest for new therapeutic combinations. ICOS costimulation has been underscored as a possible target to include with CTLA-4 blocking treatment. Herein, we describe an ICOS agonistic aptamer that potentiates T cell activation and induces stronger antitumor responses when locally injected at the tumor site in combination with anti-CTLA-4 antibody in different tumor models. Furthermore, ICOS agonistic aptamer was engineered as a bi-specific tumor-targeting aptamer to reach any disseminated tumor lesions after systemic injection. Treatment with the bi-specific aptamer in combination with CTLA-4 blockade showed strong antitumor immunity, even in a melanoma tumor model where CTLA-4 treatment alone did not display any significant therapeutic benefit. Thus, this work provides strong support for the development of combinatorial therapies involving anti-CTLA-4 blockade and ICOS agonist tumor-targeting agents.

Chemical Characterization and Phytotoxic Effects of the Aerial Parts of Ruzigrass (Urochloa ruziziensis).

Studies of the phytotoxic effects between plants can be a crucial tool in the discovery of innovative compounds with herbicide potential. In this sense, we can highlight ruzigrass (Urochloa ruziziensis), which is traditionally used in the crop rotation system in order to reduce weed emergence. The aim of this work was to characterize the secondary metabolites of ruzigrass and to evaluate its phytotoxic effects. In total, eight compounds were isolated: friedelin, oleanolic acid, α-amyrin, 1-dehydrodiosgenone, sitosterol and stigmasterol glycosides, tricin and p-coumaric acid. Phytotoxic effects of the crude methanolic extract and fractions of ruzigrass were assessed using germination rate, initial seedling growth, and biomass of Bidens pilosa, Euphorbia heterophylla and Ipomoea grandifolia. Chemometric analysis discriminated the weed species into three groups, and B. pilosa was the most affected by fractions of ruzigrass. The phytotoxic activities of 1-dehydrodiosgenone, tricin, and p-coumaric acid are also reported, and p-coumaric acid and 1-dehydrodiosgenone were active against B. pilosa.

Effects of Microplastics Associated with Triclosan on the Oyster Crassostrea brasiliana: An Integrated Biomarker Approach.

Urban waste is a complex mixture of different substances, including microplastics and pharmaceuticals and personal care products. Microplastics have a high affinity for hydrophobic substances. One of these substances is triclosan, a bactericide used in a variety of hygiene products. Therefore, microplastics (MPs) may serve as a vector between triclosan and aquatic organisms. The current study sought to evaluate the effects of the interaction between microplastics and triclosan based on a mechanistic approach in which the oyster Crassostrea brasiliana was used as a model. The organisms were exposed to three conditions: the control, microplastic (MP), and microplastic contaminated with triclosan (MPT). The organisms were exposed for 3 or 7 days. After the exposure time, hemolymph was sampled for performing the neutral red retention time assay and, subsequently, the gills, digestive glands, and adductor muscles were dissected for measuring biomarkers responses (EROD, DBF, GST, GPx, GSH, lipid peroxidation, DNA strand breaks, and AChE). Our results demonstrate combined effects of MPs associated with triclosan on oyster physiology and biochemistry, as well as on lysosomal membrane stability. These results contribute to understanding the effects of contaminants of emerging concern and microplastics on aquatic organisms.

Anthrax edema toxin disrupts distinct steps in Rab11-dependent junctional transport.

Various bacterial toxins circumvent host defenses through overproduction of cAMP. In a previous study, we showed that edema factor (EF), an adenylate cyclase from Bacillus anthracis, disrupts endocytic recycling mediated by the small GTPase Rab11. As a result, cargo proteins such as cadherins fail to reach inter-cellular junctions. In the present study, we provide further mechanistic dissection of Rab11 inhibition by EF using a combination of Drosophila and mammalian systems. EF blocks Rab11 trafficking after the GTP-loading step, preventing a constitutively active form of Rab11 from delivering cargo vesicles to the plasma membrane. Both of the primary cAMP effector pathways -PKA and Epac/Rap1- contribute to inhibition of Rab11-mediated trafficking, but act at distinct steps of the delivery process. PKA acts early, preventing Rab11 from associating with its effectors Rip11 and Sec15. In contrast, Epac functions subsequently via the small GTPase Rap1 to block fusion of recycling endosomes with the plasma membrane, and appears to be the primary effector of EF toxicity in this process. Similarly, experiments conducted in mammalian systems reveal that Epac, but not PKA, mediates the activity of EF both in cell culture and in vivo. The small GTPase Arf6, which initiates endocytic retrieval of cell adhesion components, also contributes to junctional homeostasis by counteracting Rab11-dependent delivery of cargo proteins at sites of cell-cell contact. These studies have potentially significant practical implications, since chemical inhibition of either Arf6 or Epac blocks the effect of EF in cell culture and in vivo, opening new potential therapeutic avenues for treating symptoms caused by cAMP-inducing toxins or related barrier-disrupting pathologies.

Reducing classroom temperature in a tropical climate improved the thermal comfort and the performance of elementary school pupils.

A two-week-long intervention study was performed in two classrooms in an elementary school in Costa Rica. Split-cooling air-conditioning (AC) units were installed in both classrooms. During the first week, the air temperature was reduced in one classroom while in the other (placebo) classroom the fans were operated but no cooling was provided. During the second week, the conditions were exchanged to create a 2 × 2 crossover design in which each pupil was their own control. A total of 37 children performed tasks similar to school work and completed questionnaires reporting their thermal sensation and perceptions. Operating the AC units reduced classroom temperature by about 5 K, from about 30 to 25°C. Thermal sensations changed from hot to neutral and slightly cold, and the percentage of children rating the thermal conditions as acceptable increased significantly. Neutral temperature was estimated to be about 27°C. The 11-year-old children performed the language and logical-thinking tasks significantly better in terms of speed at the lower temperature, while the less able pupils performed better on all tasks at the lower temperature. There were no significant effects on accuracy. These results confirm published findings from moderate climates and extend their validity to the tropics. They indicate that acclimatization can increase the optimal temperature for learning.