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1.
Nature ; 592(7852): 80-85, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33692543

RESUMEN

Placentas can exhibit chromosomal aberrations that are absent from the fetus1. The basis of this genetic segregation, which is known as confined placental mosaicism, remains unknown. Here we investigated the phylogeny of human placental cells as reconstructed from somatic mutations, using whole-genome sequencing of 86 bulk placental samples (with a median weight of 28 mg) and of 106 microdissections of placental tissue. We found that every bulk placental sample represents a clonal expansion that is genetically distinct, and exhibits a genomic landscape akin to that of childhood cancer in terms of mutation burden and mutational imprints. To our knowledge, unlike any other healthy human tissue studied so far, the placental genomes often contained changes in copy number. We reconstructed phylogenetic relationships between tissues from the same pregnancy, which revealed that developmental bottlenecks genetically isolate placental tissues by separating trophectodermal lineages from lineages derived from the inner cell mass. Notably, there were some cases with full segregation-within a few cell divisions of the zygote-of placental lineages and lineages derived from the inner cell mass. Such early embryonic bottlenecks may enable the normalization of zygotic aneuploidy. We observed direct evidence for this in a case of mosaic trisomic rescue. Our findings reveal extensive mutagenesis in placental tissues and suggest that mosaicism is a typical feature of placental development.


Asunto(s)
Mosaicismo , Mutagénesis , Mutación , Placenta/metabolismo , Biopsia , Masa Celular Interna del Blastocisto/citología , Femenino , Genoma Humano/genética , Humanos , Mesodermo/citología , Tasa de Mutación , Placenta/citología , Embarazo , Trisomía/genética , Trofoblastos/citología , Trofoblastos/metabolismo , Cigoto/citología
2.
Blood ; 2024 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-38949981

RESUMEN

-Thalassemia (AT) is one of the most commonly occurring inherited hematological diseases. However, few treatments are available, and allogeneic bone marrow transplantation (BMT) is the only available therapeutic option for patients with severe AT. Research into AT has remained limited due to a lack of adult mouse models, with severe AT typically resulting in in utero lethality. By using a lipid nanoparticle (LNP) targeting the receptor CD117 and delivering a Cre mRNA (mRNACreLNPCD117), we were able to delete floxed -globin genes at high efficiency in hematopoietic stem cells (HSC) ex vivo. These cells were then engrafted in the absence or presence of a novel α-globin expressing lentiviral vector (ALS20I). Myeloablated mice transplanted with mRNACreLNPCD117-treated HSC showed a complete knockout of -globin genes. They demonstrated a phenotype characterized by the synthesis of hemoglobin H (-tetramers,  or HbH), aberrant erythropoiesis, and abnormal organ morphology, culminating in lethality approximately eight weeks following engraftment. Mice receiving mRNACreLNPCD117-treated HSC with at least one copy of ALS20I survived long-term with normalization of erythropoiesis, decreased the production of HbH, and ameliorated the abnormal organ morphology. Furthermore, we tested ALS20I in erythroid progenitors derived from -globin-KO CD34+ and cells isolated from patients with both deletional and non-deletional HbH disease, demonstrating improvement in -globin/-globin mRNA ratio and reduction in the formation of HbH by HPLC. Our results demonstrate the broad applicability of LNP for disease modeling, characterization of a novel severe mouse model of AT, and the efficacy of ALS20I for treating AT.

3.
Nature ; 574(7778): E15, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31570886

RESUMEN

An Amendment to this paper has been published and can be accessed via a link at the top of the paper.

4.
Nature ; 572(7769): 329-334, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31367035

RESUMEN

We sought to determine whether pre-eclampsia, spontaneous preterm birth or the delivery of infants who are small for gestational age were associated with the presence of bacterial DNA in the human placenta. Here we show that there was no evidence for the presence of bacteria in the large majority of placental samples, from both complicated and uncomplicated pregnancies. Almost all signals were related either to the acquisition of bacteria during labour and delivery, or to contamination of laboratory reagents with bacterial DNA. The exception was Streptococcus agalactiae (group B Streptococcus), for which non-contaminant signals were detected in approximately 5% of samples collected before the onset of labour. We conclude that bacterial infection of the placenta is not a common cause of adverse pregnancy outcome and that the human placenta does not have a microbiome, but it does represent a potential site of perinatal acquisition of S. agalactiae, a major cause of neonatal sepsis.


Asunto(s)
Parto Obstétrico , Complicaciones del Trabajo de Parto/microbiología , Placenta/microbiología , Complicaciones Infecciosas del Embarazo/microbiología , Sepsis/congénito , Sepsis/microbiología , Streptococcus agalactiae/aislamiento & purificación , Streptococcus agalactiae/patogenicidad , Biopsia , Estudios de Cohortes , Contaminación de ADN , ADN Bacteriano/análisis , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Femenino , Humanos , Recién Nacido , Masculino , Metagenómica , Embarazo , Resultado del Embarazo , ARN Ribosómico 16S/análisis , ARN Ribosómico 16S/genética , Reproducibilidad de los Resultados , Análisis de Secuencia de ADN
5.
J Am Chem Soc ; 146(12): 7931-7935, 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38488290

RESUMEN

The oxygen reduction reaction (ORR) is important for alternative energy and industrial oxidation processes. Herein, an iminium-based organoelectrocatalyst (im+) for the ORR with trifluoroacetic acid as a proton source in acetonitrile solution under both electrochemical and spectrochemical conditions using decamethylferrocene as a chemical reductant is reported. Under spectrochemical conditions, H2O2 is the primary reaction product, while under electrochemical conditions H2O is produced. This difference in selectivity is attributed to the interception of the free superoxide intermediate under electrochemical conditions by the reduced catalyst, accessing an alternate inner-sphere pathway.

6.
Allergy ; 79(4): 977-989, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38433402

RESUMEN

BACKGROUND: IgE-mediated food allergy (FA) is a global health concern with substantial individual and societal implications. While diverse intervention strategies have been researched, inconsistencies in reported outcomes limit evaluations of FA treatments. To streamline evaluations and promote consistent reporting, the Core Outcome Measures for Food Allergy (COMFA) initiative aimed to establish a Core Outcome Set (COS) for FA clinical trials and observational studies of interventions. METHODS: The project involved a review of published clinical trials, trial protocols and qualitative literature. Outcomes found as a result of review were categorized and classified, informing a two-round online-modified Delphi process followed by hybrid consensus meeting to finalize the COS. RESULTS: The literature review, taxonomy mapping and iterative discussions with diverse COMFA group yielded an initial list of 39 outcomes. The iterative online and in-person meetings reduced the list to 13 outcomes for voting in the formal Delphi process. One more outcome was added based on participant suggestions after the first Delphi round. A total of 778 participants from 52 countries participated, with 442 participating in both Delphi rounds. No outcome met a priori criteria for inclusion, and one was excluded as a result of the Delphi. Thirteen outcomes were brought to the hybrid consensus meeting as a result of Delphi and two outcomes, 'allergic symptoms' and 'quality of life' achieved consensus for inclusion as 'core' outcomes. CONCLUSION: In addition to the mandatory reporting of adverse events for FA clinical trials or observational studies of interventions, allergic symptoms and quality of life should be measured as core outcomes. Future work by COMFA will define how best to measure these core outcomes.


Asunto(s)
Hipersensibilidad a los Alimentos , Calidad de Vida , Humanos , Técnica Delphi , Hipersensibilidad a los Alimentos/diagnóstico , Hipersensibilidad a los Alimentos/terapia , Inmunoglobulina E , Evaluación de Resultado en la Atención de Salud , Proyectos de Investigación , Resultado del Tratamiento , Ensayos Clínicos como Asunto , Estudios Observacionales como Asunto
7.
BJOG ; 131(6): 823-831, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-37822261

RESUMEN

OBJECTIVE: To determine the inter-relationships between five first-trimester biomarkers (pregnancy associated plasma protein A [PAPP-A], alpha-fetoprotein [AFP], beta human chorionic gonadotrophin [beta-hCG], placenta growth factor [PlGF] and soluble fms-like tyrosine kinase receptor-1 [sFlt-1]) and a range of adverse pregnancy outcomes (APOs). DESIGN: Prospective cohort study of nulliparous singleton pregnancy. SETTING: Cambridge, UK. POPULATION OR SAMPLE: 4056 pregnancy outcome prediction study participants. METHODS: The biomarker concentrations were measured in maternal serum at ~12 weeks of gestation. Univariable analysis of APOs was performed using logistic regression. Multivariable analysis used best subsets logistic regression with cross-validation. MAIN OUTCOME MEASURES: Pre-eclampsia (PE), small for gestational age (SGA), including severe SGA (birthweight <3rd), fetal growth restriction (FGR), preterm birth (PTB, both induced and spontaneous [iPTB and sPTB, respectively]), pre-viable loss and stillbirth, plus combinations of outcomes. RESULTS: Lower values of PAPP-A, PlGF and sFlt-1 and higher values of AFP were associated with FGR (OR for 1 SD higher value 0.59 [95% CI 0.48-0.74], OR 0.56 [95% CI 0.44-0.70], OR 0.68 [95% CI 0.54-0.87] and OR 1.53 [95% CI 1.25-1.88]), severe SGA (OR 0.59 [95% CI 0.49-0.72], OR 0.71 [95% CI 0.57-0.87], OR 0.74 [95% CI 0.60-0.91] and OR 1.41 [95% CI 1.17-1.71]), sPTB (OR 0.61 [95% CI 0.50-0.73], OR 0.79 [95% CI 0.66-0.96], OR 0.57 [95% CI 0.47-0.70] and OR 1.41 [95% CI 1.18-1.67]) and iPTB (OR 0.72 [95% CI 0.57-0.91], OR 0.62 [95% CI 0.49-0.78], OR 0.71 [95% CI 0.56-0.90] and OR 1.44 [95% CI 1.16-1.78]), respectively. When combinations of biomarkers were assessed, PAPP-A and AFP were independently associated with severe SGA; PAPP-A alone with PE + PTB; PlGF alone with severe PE; PlGF, beta-hCG, AFP and PAPP-A with the combination of PE and SGA; AFP and sFlt-1 with sPTB; and AFP and PlGF with iPTB. CONCLUSIONS: Combinations of first-trimester placental biomarkers are associated with APOs. However, the patterns vary for different types of APO, indicating heterogeneity in the underlying pathophysiological pathways.


Asunto(s)
Preeclampsia , Nacimiento Prematuro , Embarazo , Recién Nacido , Femenino , Humanos , Resultado del Embarazo , Primer Trimestre del Embarazo , alfa-Fetoproteínas , Proteína Plasmática A Asociada al Embarazo , Estudios Prospectivos , Placenta/metabolismo , Factor de Crecimiento Placentario , Gonadotropina Coriónica Humana de Subunidad beta , Biomarcadores , Retardo del Crecimiento Fetal/diagnóstico , Preeclampsia/diagnóstico , Receptor 1 de Factores de Crecimiento Endotelial Vascular
8.
Clin Exp Allergy ; 53(10): 989-1003, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37649424

RESUMEN

This review explores the anthropological and sociological literature on food allergy and identifies four primary areas of research to date. The first explores the relationality and management of risk, uncertainty and stigma among parents and sufferers of food allergies. The second analyses the influence of intersectionality, specifically the effects of class, gender, race/ethnicity and disability on experiences of food allergy. The third discusses diagnostic difficulties and the impact these have on legitimacy and believability, both in the context of clinician-patient relations and in managing food allergies in public spaces. The fourth explores the ethics and uncertainties in food allergy treatments and how scientific knowledge of emerging treatments is constructed. This body of research illustrates that although an individual disease, food allergy experiences are significantly affected by socio-cultural structures, institutions, ideologies and discourses. The review concludes with four primary recommendations. First, there should be more incorporation of anthropological or sociological methodologies and perspectives into studies of food allergy. Second, studies are needed from more countries exploring lived experience of food allergy. Third, research on food allergy needs to incorporate an analysis of intersectional factors such as gender, class and race/ethnicity, and should explore the experiences of minority populations. Fourth, more research is needed on the interactions between biomedicine and local systems of knowledge, as well as the factors that shape what treatments become available, for whom it becomes available, experiences of treatment and aspects (including biases) that influence patient-clinician interactions.


Asunto(s)
Hipersensibilidad a los Alimentos , Humanos , Hipersensibilidad a los Alimentos/diagnóstico , Hipersensibilidad a los Alimentos/epidemiología , Hipersensibilidad a los Alimentos/terapia , Padres , Alimentos , Etnicidad
9.
Rheumatology (Oxford) ; 62(9): 2979-2988, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-36645234

RESUMEN

OBJECTIVE: To describe the risks and predictors of coronavirus disease 2019 (COVID-19) hospitalization and mortality among patients with early inflammatory arthritis (EIA), recruited to the National Early Inflammatory Arthritis Audit (NEIAA). METHODS: NEIAA is an observational cohort. We included adults with EIA from Feb 2020 to May 2021. Outcomes of interest were hospitalization and death due to COVID-19, using NHS Digital linkage. Cox proportional hazards were used to calculate hazard ratios for outcomes according to initial treatment strategy, with adjustment for confounders. RESULTS: From 14 127 patients with EIA, there were 143 hospitalizations and 47 deaths due to COVID-19, with incidence rates per 100 person-years of 0.93 (95% CI 0.79, 1.10) for hospitalization and 0.30 (95% CI 0.23, 0.40) for death. Increasing age, male gender, comorbidities and ex-smoking were associated with increased risk of worse COVID-19 outcomes. Higher baseline DAS28 was not associated with COVID-19 admissions [confounder adjusted hazard ratio (aHR) 1.10; 95% CI 0.97, 1.24] or mortality (aHR 1.11; 95% CI 0.90, 1.37). Seropositivity was not associated with either outcome. Higher symptom burden on patient-reported measures predicted worse COVID-19 outcomes. In unadjusted models, CS associated with COVID-19 death (HR 2.29; 95% CI 1.02, 5.13), and SSZ monotherapy associated with COVID-19 admission (HR 1.92; 95% CI 1.04, 3.56). In adjusted models, associations for CS and SSZ were not statistically significant. CONCLUSION: Patient characteristics have stronger associations with COVID-19 than the initial treatment strategy in patients with EIA. An important limitation is that we have not looked at treatment changes over time.


Asunto(s)
Artritis Reumatoide , COVID-19 , Adulto , Humanos , Masculino , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/epidemiología , Artritis Reumatoide/complicaciones , Estudios de Cohortes , COVID-19/complicaciones , Hospitalización , Reino Unido/epidemiología , Femenino
10.
Artículo en Inglés | MEDLINE | ID: mdl-37725361

RESUMEN

OBJECTIVES: Inflammatory arthritis (IA) causes significant work disability. Studies frequently fail to report important contextual information such as employment type. Our objective was to explore work participation, by gender and occupation type in early IA. METHODS: Data are from the National Early Inflammatory Arthritis Audit between 2018 and 2020. At diagnosis, clinicians collected information on demographics, IA disease activity and working status. Participants completed patient-reported outcomes at baseline, 3- and 12-months, including occupation and Work Productivity Activity Impairment (WPAI). Descriptive analyses of work participation and WPAI scores by occupational class at all timepoints were performed. Regression models examined associations between WPAI score and occupation. FINDINGS: 12 473 people received a diagnosis of IA and reported employment status, amongst whom 5,999 (47%) were in paid-work at least 20-h/week. At diagnosis, the working cohort had statistically significant lower measures of disease activity (p< 0.001). Occupation data were available for 3,694 individuals. At diagnosis, 2,793 completed a WPAI; 200 (7.2%) had stopped work and 344 (12.3%) changed jobs because of IA symptoms. There was a high burden of absenteeism (30%) and presenteeism (40%). Compared with managerial or professional workers, the burden of work disability was greater amongst those in routine (manual) occupations. During follow-up, 9.4% of WPAI completers had stopped work and 14.6% had changed roles. Work dropout occurred almost entirely amongst people doing routine jobs. CONCLUSION: IA associates with work disability within 12 months of diagnosis. It is easier to retain work in certain employment sectors. Participation in routine jobs is more affected, which may widen health inequalities.

11.
Br J Dermatol ; 188(5): 610-617, 2023 04 20.
Artículo en Inglés | MEDLINE | ID: mdl-36763806

RESUMEN

BACKGROUND: Nonadherence to immune-modifying therapy is a complex behaviour which, before the COVID-19 pandemic, was shown to be associated with mental health disorders in people with immune-mediated diseases. The COVID-19 pandemic has led to a rise in the global prevalence of anxiety and depression, and limited data exist on the association between mental health and nonadherence to immune-modifying therapy during the pandemic. OBJECTIVES: To assess the extent of and reasons underlying nonadherence to systemic immune-modifying therapy during the COVID-19 pandemic in individuals with psoriasis, and the association between mental health and nonadherence. METHODS: Online self-report surveys (PsoProtectMe), including validated screens for anxiety and depression, were completed globally during the first year of the pandemic. We assessed the association between anxiety or depression and nonadherence to systemic immune-modifying therapy using binomial logistic regression, adjusting for potential cofounders (age, sex, ethnicity, comorbidity) and country of residence. RESULTS: Of 3980 participants from 77 countries, 1611 (40.5%) were prescribed a systemic immune-modifying therapy. Of these, 408 (25.3%) reported nonadherence during the pandemic, most commonly due to concerns about their immunity. In the unadjusted model, a positive anxiety screen was associated with nonadherence to systemic immune-modifying therapy [odds ratio (OR) 1.37, 95% confidence interval (CI) 1.07-1.76]. Specifically, anxiety was associated with nonadherence to targeted therapy (OR 1.41, 95% CI 1.01-1.96) but not standard systemic therapy (OR 1.16, 95% CI 0.81-1.67). In the adjusted model, although the directions of the effects remained, anxiety was not significantly associated with nonadherence to overall systemic (OR 1.20, 95% CI 0.92-1.56) or targeted (OR 1.33, 95% CI 0.94-1.89) immune-modifying therapy. A positive depression screen was not strongly associated with nonadherence to systemic immune-modifying therapy in the unadjusted (OR 1.22, 95% CI 0.94-1.57) or adjusted models (OR 1.14, 95% CI 0.87-1.49). CONCLUSIONS: These data indicate substantial nonadherence to immune-modifying therapy in people with psoriasis during the pandemic, with attenuation of the association with mental health after adjusting for confounders. Future research in larger populations should further explore pandemic-specific drivers of treatment nonadherence. Clear communication of the reassuring findings from population-based research regarding immune-modifying therapy-associated adverse COVID-19 risks to people with psoriasis is essential, to optimize adherence and disease outcomes.


Asunto(s)
COVID-19 , Psoriasis , Humanos , COVID-19/epidemiología , Estudios Transversales , Pandemias , Ansiedad/epidemiología , Ansiedad/psicología , Psoriasis/tratamiento farmacológico , Psoriasis/epidemiología , Depresión/epidemiología
12.
Am J Obstet Gynecol ; 229(2): 164.e1-164.e18, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-36758709

RESUMEN

BACKGROUND: Spontaneous preterm birth is the endpoint of multiple different pathophysiological pathways. Fetal growth restriction, assessed by serial ultrasonic fetal biometry, has been shown to predict both preterm and early-term spontaneous labor. The soluble fms-like tyrosine kinase-1 to placental growth factor ratio is predictive of early-term spontaneous labor, but its association with spontaneous preterm birth is unclear. OBJECTIVE: This study aimed to determine whether maternal serum levels of soluble fms-like tyrosine kinase-1, placental growth factor, and the soluble fms-like tyrosine kinase-1: placental growth factor ratio at 20 and 28 weeks' gestation, and the rate of change in these biomarkers between 20 and 28 weeks were predictive of risk of spontaneous preterm birth. STUDY DESIGN: The biomarkers were measured in maternal serum at 20- and 28-weeks' gestation in women recruited to a prospective cohort of unselected nulliparous women as part of the Pregnancy Outcome Prediction study in Cambridge, United Kingdom. The risk of spontaneous preterm birth was assessed using Cox regression and competing-risks regression. Associations from Cox regression were quantified by the adjusted hazard ratio for a 1 standard deviation higher level of a given biomarker or a 1 standard deviation increase in the marker between 20 and 28 weeks' gestation. A previously identified risk factor, slow femur length growth, was used as an additional predictor of spontaneous preterm birth for the purpose of risk stratification. RESULTS: Of the 3763 participants in the analysis, 95 (2.5%) had spontaneous preterm birth and 54 (1.4%) had medically indicated preterm birth. At 20 weeks' gestation, higher levels of soluble fms-like tyrosine kinase-1 and the soluble fms-like tyrosine kinase-1:placental growth factor ratio were associated with reduced risk of spontaneous preterm birth (adjusted hazard ratio [95% confidence interval], 0.75 [0.61-0.92]; P=.006 and 0.71 [0.59-0.87]; P=.0009, respectively). At 28 weeks' gestation, there was no association between either soluble fms-like tyrosine kinase-1 or placental growth factor and the risk of spontaneous preterm birth, but there was a U-shaped relation with the soluble fms-like tyrosine kinase-1:placental growth factor ratio. However, when the biomarkers were quantified as the rate of increase between 20 and 28 weeks' gestation, there were strong positive associations between spontaneous preterm birth and rate of increase in soluble fms-like tyrosine kinase-1 (1.36 [1.13-1.63]; P=.001) and the soluble fms-like tyrosine kinase-1:placental growth factor ratio (1.50 [1.30-1.73]; P<.0001), and a strong negative association with the rate of increase in placental growth factor (0.71 [0.61-0.82]; P<.0001). Women who were in the highest decile of increase in the soluble fms-like tyrosine kinase-1:placental growth factor ratio and the lowest decile of femur length growth between 20 and 28 weeks' gestation had approximately 9-fold risk of spontaneous preterm birth (9.27 [4.21-20.37]; P<.0001). Competing-risks regression yielded similar results. CONCLUSION: Changing levels of soluble fms-like tyrosine kinase-1 and placental growth factor are indicative of placental dysfunction and are strongly associated with the risk of spontaneous preterm birth, especially when combined with slower fetal femur length growth.


Asunto(s)
Preeclampsia , Nacimiento Prematuro , Embarazo , Femenino , Recién Nacido , Humanos , Factor de Crecimiento Placentario , Receptor 1 de Factores de Crecimiento Endotelial Vascular , Nacimiento Prematuro/epidemiología , Edad Gestacional , Estudios Prospectivos , Placenta , Biomarcadores
14.
Inorg Chem ; 61(22): 8387-8392, 2022 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-35594192

RESUMEN

We report a new terpyridine-based FeN3O catalyst, Fe(tpytbupho)Cl2, which reduces O2 to H2O. Variable concentration and variable temperature spectrochemical studies with decamethylferrocene as a chemical reductant in acetonitrile solution enabled the elucidation of key reaction parameters for the catalytic reduction of O2 to H2O by Fe(tpytbupho)Cl2. These mechanistic studies suggest that a 2 + 2 mechanism is operative, where hydrogen peroxide is produced as a discrete intermediate, prior to further reduction to H2O. Consistent with this proposal, the spectrochemically measured first-order rate constant k (s-1) value for H2O2 reduction is larger than that for O2 reduction. Further, significant H2O2 production is observed under hydrodynamic conditions in rotating ring-disk electrode measurements, where the product can be swept away from the cathode surface before further reduction occurs.


Asunto(s)
Peróxido de Hidrógeno , Catálisis , Oxidación-Reducción
15.
Angew Chem Int Ed Engl ; 61(1): e202109645, 2022 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-34695281

RESUMEN

The electrocatalytic reduction of CO2 is an appealing method for converting renewable energy sources into value-added chemical feedstocks. We report a co-electrocatalytic system for the reduction of CO2 to CO comprised of a molecular Cr complex and dibenzothiophene-5,5-dioxide (DBTD) as a redox mediator, which achieves high activity (TOF=1.51-2.84×105  s-1 ) and quantitative selectivity. Under aprotic or protic conditions, DBTD produces a co-electrocatalytic response with 1 by coordinating trans to the site of CO2 binding and mediating electron transfer from the electrode with quantitative efficiency for CO. This assembly is reliant on through-space electronic conjugation between the π frameworks of DBTD and the bpy fragment of the catalyst ligand, with contributions from dispersive interactions and weak sulfone coordination.

16.
J Am Chem Soc ; 143(40): 16411-16418, 2021 10 13.
Artículo en Inglés | MEDLINE | ID: mdl-34606274

RESUMEN

We report a bioinspired non-heme Fe complex with a tripodal [N3O]- ligand framework (Fe(PMG)(Cl)2) that is electrocatalytically active toward dioxygen reduction with acetic acid as a proton source in acetonitrile solution. Under electrochemical and chemical conditions, Fe(PMG)(Cl)2 selectively produces water via a 2+2 mechanism, where H2O2 is generated as a discrete intermediate species before further reduction to two equivalents of H2O. Mechanistic studies support a catalytic cycle for dioxygen reduction where an off-cycle peroxo dimer species is the resting state of the catalyst. Spectroscopic analysis of the reduced complex FeII(PMG)Cl shows the stoichiometric formation of an Fe(III)-hydroxide species following exposure to H2O2; no catalytic activity for H2O2 disproportionation is observed, although the complex is electrochemically active for H2O2 reduction to H2O. Electrochemical studies, spectrochemical experiments, and DFT calculations suggest that the carboxylate moiety of the ligand is sensitive to hydrogen-bonding interactions with the acetic acid proton donor upon reduction from Fe(III)/(II), favoring chloride loss trans to the tris-alkyl amine moiety of the ligand framework. These results offer insight into how mononuclear non-heme Fe active sites in metalloproteins distribute added charge and poise proton donors during reactions with dioxygen.


Asunto(s)
Compuestos Férricos
17.
J Am Chem Soc ; 143(33): 13065-13073, 2021 08 25.
Artículo en Inglés | MEDLINE | ID: mdl-34380313

RESUMEN

Generally, cobalt-N2O2 complexes show selectivity for hydrogen peroxide during electrochemical dioxygen (O2) reduction. We recently reported a Co(III)-N2O2 complex with a 2,2'-bipyridine-based ligand backbone which showed alternative selectivity: H2O was observed as the primary reduction product from O2 (71 ± 5%) with decamethylferrocene as a chemical reductant and acetic acid as a proton donor in methanol solution. We hypothesized that the key selectivity difference in this case arises in part from increased favorability of protonation at the distal O position of the key intermediate Co(III)-hydroperoxide species. To interrogate this hypothesis, we have prepared a new Co(III) compound that contains pendent -OMe groups poised to direct protonation toward the proximal O atom of this hydroperoxo intermediate. Mechanistic studies in acetonitrile (MeCN) solution reveal two regimes are possible in the catalytic response, dependent on added acid strength and the presence of the pendent proton donor relay. In the presence of stronger acids, the activity of the complex containing pendent relays becomes O2 dependent, implying a shift to Co(III)-superoxide protonation as the rate-determining step. Interestingly, the inclusion of the relay results in primarily H2O2 production in MeCN, despite minimal difference between the standard reduction potentials of the three complexes tested. EPR spectroscopic studies indicate the formation of Co(III)-superoxide species in the presence of exogenous base, with greater O2 reactivity observed in the presence of the pendent -OMe groups.


Asunto(s)
Cobalto/química , Complejos de Coordinación/química , Peróxido de Hidrógeno/química , Oxígeno/química , Piridinas/química , Estructura Molecular , Oxidación-Reducción
18.
Am J Obstet Gynecol ; 225(5): 520.e1-520.e10, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-33901486

RESUMEN

BACKGROUND: The physiological control of human parturition at term is unknown. OBJECTIVE: This study aimed to test the hypothesis that slowing of fetal growth or elevated maternal serum levels of markers of placental hypoxia in late gestation will be associated with earlier term labor. STUDY DESIGN: We observed 2208 women having first births and performed serial blinded ultrasonography and immunoassay of soluble fms-like tyrosine kinase-1 and placenta growth factor. We estimated the probability of spontaneous delivery from 37 weeks of gestational age concerning (1) fetal growth between 20 and 36 weeks of gestational age and (2) the maternal serum soluble fms-like tyrosine kinase-1-to-placenta growth factor ratio measured at approximately 36 weeks of gestational age. Data were analyzed using logistic regression and Cox regression. RESULTS: Fetal size at 36 weeks of gestational age was not independently associated with the timing of delivery at term. However, there was an inverse relationship between fetal growth between 20 weeks of gestational age and 36 weeks of gestational age and the probability of spontaneous labor at 37 to 38 weeks' gestation (hazard ratio [95% confidence interval] for a 50 percentile increase in abdominal circumference growth velocity, 0.60 [0.47-0.78]; P=.0001). This association was weaker at 39 to 40 weeks' gestation (0.83 [0.74-0.93]; P=.0013), and there was no association at ≥41 weeks' gestation. Very similar associations were observed for estimated fetal weight growth velocity. There was a positive relationship between soluble fms-like tyrosine kinase-1-to-placenta growth factor ratio and the probability of spontaneous labor at 37 to 38 weeks' gestation (hazard ratio [95% confidence interval] for a 50 percentile increase in soluble fms-like tyrosine kinase-1-to-placenta growth factor ratio, 3.05 [2.32-4.02]; P<.0001). This association was weaker at 39 to 40 weeks' gestation (1.46 [1.30-1.63]; P<.0001), and there was no association at ≥41 weeks' gestation. Adjustment for maternal characteristics was without material effect on any of these associations. CONCLUSION: Slowing of fetal growth and biomarkers of placental insufficiency were associated with an increased probability of early onset of spontaneous term labor. We speculated that progressive placental insufficiency may be a physiological phenomenon that occurs with advancing gestational age near and at term and promotes the initiation of labor.


Asunto(s)
Desarrollo Fetal , Trabajo de Parto , Factor de Crecimiento Placentario/sangre , Receptor 1 de Factores de Crecimiento Endotelial Vascular/sangre , Adulto , Biomarcadores/sangre , Estudios de Cohortes , Femenino , Edad Gestacional , Humanos , Insuficiencia Placentaria/metabolismo , Embarazo , Ultrasonografía Prenatal
19.
Cult Med Psychiatry ; 45(4): 544-564, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32975640

RESUMEN

"Food is relationships isn't it," Yamada san stated in 2017, neatly capturing the importance of food in social life. This article, drawing on the experiences of people with severe food allergies in Japan, illustrates the complexities of safely managing allergies when food-and the importance of sharing the same food-is so important to social life. In particular, I argue that individuals develop and practice skills of vigilance and situational awareness to mitigate physical and social risk which emerge through an affective imagination of what they feel could happen in the future, built on embodied memories of what has been experienced prior (e.g., severe allergic reactions and difficult social experiences with food). The development and enactment of these skills of vigilance happen through an 'education of attention' (Gibson in The ecological approach to visual perception, Psychology Press, New York, 1979; Ingold in The perception of the environment: essays on livelihood, dwelling and skill, Routledge, London, 2000) developed over time and in different social settings and constitute a somatic mode of attention (Csordas in Cult Anthropol 8:135-156, 1993) which shapes social interactions and aims to mitigate against any potential perceived social costs for not being able to eat everything.


Asunto(s)
Hipersensibilidad a los Alimentos , Imaginación , Emociones , Humanos , Japón , New York
20.
J Physiol ; 598(23): 5555-5571, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32886802

RESUMEN

KEY POINTS: Placental pathological abnormalities are more frequently observed in complicated pregnancies than in healthy pregnancies. Infiltration of CD8+ T-cells into the placental villous tissue occurred in both fetal growth restriction and pre-eclampsia, whereas CD79α+ B-cell infiltration was only apparent with reduced fetal growth. Vascularization, fibrin depositions, macrophage and neutrophil infiltration in the placenta did not differ between healthy and complicated pregnancies. ABSTRACT: Fetal growth restriction (FGR) and pre-eclampsia are severe, adverse pregnancy outcomes. Alterations in placental histology are frequently reported in these pregnancy complications and are often based upon scoring by pathologists. However, many alterations are also observed in placenta from uncomplicated pregnancies. Moreover, knowledge of disease state may bias assessment. We sought to perform an objective comparison of placental microscopic appearance in normal and complicated pregnancies. Placental villous tissue (n = 823) and edge biopsies (n = 488) from 871 individual, singleton pregnancies were collected after delivery. Cases of small-for-gestational age (SGA) or pre-eclampsia were matched with healthy controls. A subset of the SGA cases displayed signs of FGR. Cases of preterm delivery were also included. Tissue sections were stained with haematoxylin and eosin or antibodies for CD8, CD14, CD31, CD79α and elastase. Images were scored by two experienced pathologists for pathological features or analysed by image analysis and stereology. Analyses were performed blind to case-control status and gestational age. Volume fraction of T-cells increased in placentas from pregnancies complicated by pre-eclampsia (adjusted odds ratio (aOR) 1.46, 95% CI: 1.12-1.90) and FGR (aOR 1.64, 95% CI: 1.11-2.43), whereas B-cells only increased in FGR (aOR 1.65, 95% CI: 1.05-2.60). Pathological abnormalities in villous tissue were reported in 21.4% (88/411) of complicated pregnancies and 14.3% (52/363) of controls (OR 1.62, 95% CI: 1.12-2.37). There were no differences in the fractions of endothelial cells, fibrin deposition, macrophages and neutrophils when comparing normal and complicated pregnancies. In conclusion, FGR and pre-eclampsia are associated with T-cell infiltration of the placenta and placental pathological abnormalities.


Asunto(s)
Retardo del Crecimiento Fetal , Preeclampsia , Linfocitos T CD8-positivos , Células Endoteliales , Femenino , Humanos , Recién Nacido , Placenta , Embarazo
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