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1.
Nature ; 609(7926): 307-312, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36071188

RESUMEN

Monoterpenes (C10H16) are emitted in large quantities by vegetation to the atmosphere (>100 TgC year-1), where they readily react with hydroxyl radicals and ozone to form new particles and, hence, clouds, affecting the Earth's radiative budget and, thereby, climate change1-3. Although most monoterpenes exist in two chiral mirror-image forms termed enantiomers, these (+) and (-) forms are rarely distinguished in measurement or modelling studies4-6. Therefore, the individual formation pathways of monoterpene enantiomers in plants and their ecological functions are poorly understood. Here we present enantiomerically separated atmospheric monoterpene and isoprene data from an enclosed tropical rainforest ecosystem in the absence of ultraviolet light and atmospheric oxidation chemistry, during a four-month controlled drought and rewetting experiment7. Surprisingly, the emitted enantiomers showed distinct diel emission peaks, which responded differently to progressive drying. Isotopic labelling established that vegetation emitted mainly de novo-synthesized (-)-α-pinene, whereas (+)-α-pinene was emitted from storage pools. As drought progressed, the source of (-)-α-pinene emissions shifted to storage pools, favouring cloud formation. Pre-drought mixing ratios of both α-pinene enantiomers correlated better with other monoterpenes than with each other, indicating different enzymatic controls. These results show that enantiomeric distribution is key to understanding the underlying processes driving monoterpene emissions from forest ecosystems and predicting atmospheric feedbacks in response to climate change.


Asunto(s)
Sequías , Bosques , Monoterpenos , Árboles , Atmósfera/química , Cambio Climático , Monoterpenos/metabolismo , Árboles/metabolismo
2.
Proc Natl Acad Sci U S A ; 120(4): e2209831120, 2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36669112

RESUMEN

We recently reported transposon mutagenesis as a significant driver of spontaneous mutations in the human fungal pathogen Cryptococcus deneoformans during murine infection. Mutations caused by transposable element (TE) insertion into reporter genes were dramatically elevated at high temperatures (37° vs. 30°) in vitro, suggesting that heat stress stimulates TE mobility in the Cryptococcus genome. To explore the genome-wide impact of TE mobilization, we generated transposon accumulation lines by in vitro passage of C. deneoformans strain XL280α for multiple generations at both 30° and at the host-relevant temperature of 37°. Utilizing whole-genome sequencing, we identified native TE copies and mapped multiple de novo TE insertions in these lines. Movements of the T1 DNA transposon occurred at both temperatures with a strong bias for insertion between gene-coding regions. By contrast, the Tcn12 retrotransposon integrated primarily within genes and movement occurred exclusively at 37°. In addition, we observed a dramatic amplification in copy number of the Cnl1 (Cryptococcus neoformans LINE-1) retrotransposon in subtelomeric regions under heat-stress conditions. Comparing TE mutations to other sequence variations detected in passaged lines, the increase in genomic changes at elevated temperatures was primarily due to mobilization of the retroelements Tcn12 and Cnl1. Finally, we found multiple TE movements (T1, Tcn12, and Cnl1) in the genomes of single C. deneoformans isolates recovered from infected mice, providing evidence that mobile elements are likely to facilitate microevolution and rapid adaptation during infection.


Asunto(s)
Criptococosis , Cryptococcus neoformans , Humanos , Animales , Ratones , Retroelementos/genética , Cryptococcus neoformans/genética , Criptococosis/genética , Genoma , Respuesta al Choque Térmico/genética , Elementos Transponibles de ADN/genética
3.
Rep Prog Phys ; 87(7)2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38899367

RESUMEN

The aim of our paper is to investigate the properties of the classical phase-dispersion minimization (PDM), analysis of variance (AOV), string-length (SL), and Lomb-Scargle (LS) power statistics from a statistician's perspective. We confirm that when the data are perturbations of a constant function, i.e. under the null hypothesis of no period in the data, a scaled version of the PDM statistic follows a beta distribution, the AOV statistic follows an F distribution, and the LS power follows a chi-squared distribution with two degrees of freedom. However, the SL statistic does not have a closed-form distribution. We further verify these theoretical distributions through simulations and demonstrate that the extreme values of these statistics (over a range of trial periods), often used for period estimation and determination of the false alarm probability (FAP), follow different distributions than those derived for a single period. We emphasize that multiple-testing considerations are needed to correctly derive FAP bounds. Though, in fact, multiple-testing controls are built into the FAP bound for these extreme-value statistics, e.g. the FAP bound derived specifically for the maximum LS power statistic over a range of trial periods. Additionally, we find that all of these methods are robust to heteroscedastic noise aimed to mimic the degradation or miscalibration of an instrument over time. Finally, we examine the ability of these statistics to detect a non-constant periodic function via simulating data that mimics a well-detached binary system, and we find that the AOV statistic has the most power to detect the correct period, which agrees with what has been observed in practice.

4.
Lancet ; 402(10418): 2209-2222, 2023 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-37977169

RESUMEN

BACKGROUND: Umbilical cord clamping strategies at preterm birth have the potential to affect important health outcomes. The aim of this study was to compare the effectiveness of deferred cord clamping, umbilical cord milking, and immediate cord clamping in reducing neonatal mortality and morbidity at preterm birth. METHODS: We conducted a systematic review and individual participant data meta-analysis. We searched medical databases and trial registries (from database inception until Feb 24, 2022; updated June 6, 2023) for randomised controlled trials comparing deferred (also known as delayed) cord clamping, cord milking, and immediate cord clamping for preterm births (<37 weeks' gestation). Quasi-randomised or cluster-randomised trials were excluded. Authors of eligible studies were invited to join the iCOMP collaboration and share individual participant data. All data were checked, harmonised, re-coded, and assessed for risk of bias following prespecified criteria. The primary outcome was death before hospital discharge. We performed intention-to-treat one-stage individual participant data meta-analyses accounting for heterogeneity to examine treatment effects overall and in prespecified subgroup analyses. Certainty of evidence was assessed with Grading of Recommendations Assessment, Development, and Evaluation. This study is registered with PROSPERO, CRD42019136640. FINDINGS: We identified 2369 records, of which 48 randomised trials provided individual participant data and were eligible for our primary analysis. We included individual participant data on 6367 infants (3303 [55%] male, 2667 [45%] female, two intersex, and 395 missing data). Deferred cord clamping, compared with immediate cord clamping, reduced death before discharge (odds ratio [OR] 0·68 [95% CI 0·51-0·91], high-certainty evidence, 20 studies, n=3260, 232 deaths). For umbilical cord milking compared with immediate cord clamping, no clear evidence was found of a difference in death before discharge (OR 0·73 [0·44-1·20], low certainty, 18 studies, n=1561, 74 deaths). Similarly, for umbilical cord milking compared with deferred cord clamping, no clear evidence was found of a difference in death before discharge (0·95 [0·59-1·53], low certainty, 12 studies, n=1303, 93 deaths). We found no evidence of subgroup differences for the primary outcome, including by gestational age, type of delivery, multiple birth, study year, and perinatal mortality. INTERPRETATION: This study provides high-certainty evidence that deferred cord clamping, compared with immediate cord clamping, reduces death before discharge in preterm infants. This effect appears to be consistent across several participant-level and trial-level subgroups. These results will inform international treatment recommendations. FUNDING: Australian National Health and Medical Research Council.


Asunto(s)
Nacimiento Prematuro , Lactante , Embarazo , Recién Nacido , Humanos , Masculino , Femenino , Recien Nacido Prematuro , Clampeo del Cordón Umbilical , Constricción , Australia , Cordón Umbilical/cirugía
5.
Lancet ; 402(10418): 2223-2234, 2023 12 09.
Artículo en Inglés | MEDLINE | ID: mdl-37977170

RESUMEN

BACKGROUND: Deferred (also known as delayed) cord clamping can improve survival of infants born preterm (before 37 weeks of gestation), but the optimal duration of deferral remains unclear. We conducted a systematic review and individual participant data network meta-analysis with the aim of comparing the effectiveness of umbilical cord clamping strategies with different timings of clamping or with cord milking for preterm infants. METHODS: We searched medical databases and trial registries from inception until Feb 24, 2022 (updated June 6, 2023) for randomised controlled trials comparing cord clamping strategies for preterm infants. Individual participant data were harmonised and assessed for risk of bias and quality. Interventions were grouped into immediate clamping, short deferral (≥15 s to <45 s), medium deferral (≥45 s to <120 s), long deferral (≥120 s), and intact cord milking. The primary outcome was death before hospital discharge. We calculated one-stage, intention-to-treat Bayesian random-effects individual participant data network meta-analysis. This study was registered with PROSPERO, CRD42019136640. FINDINGS: We included individual participant data from 47 trials with 6094 participants. Of all interventions, long deferral reduced death before discharge the most (compared with immediate clamping; odds ratio 0·31 [95% credibility interval] 0·11-0·80; moderate certainty). The risk of bias was low for 10 (33%) of 30 trials, 14 (47%) had some concerns, and 6 (20%) were rated as having a high risk of bias. Heterogeneity was low, with no indication of inconsistency. INTERPRETATION: This study found that long deferral of clamping leads to reduced odds of death before discharge in preterm infants. In infants assessed as requiring immediate resuscitation, this finding might only be generalisable if there are provisions for such care with the cord intact. These results are based on thoroughly cleaned and checked individual participant data and can inform future guidelines and practice. FUNDING: Australian National Health and Medical Research Council.


Asunto(s)
Recien Nacido Prematuro , Nacimiento Prematuro , Lactante , Embarazo , Femenino , Recién Nacido , Humanos , Nacimiento Prematuro/prevención & control , Clampeo del Cordón Umbilical , Constricción , Teorema de Bayes , Metaanálisis en Red , Cordón Umbilical , Factores de Tiempo , Australia
6.
Plant Physiol ; 192(2): 767-788, 2023 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-36848194

RESUMEN

Dimethylallyl diphosphate (DMADP) and isopentenyl diphosphate (IDP) serves as the universal C5 precursors of isoprenoid biosynthesis in plants. These compounds are formed by the last step of the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway, catalyzed by (E)-4-hydroxy-3-methylbut-2-en-1-yl diphosphate reductase (HDR). In this study, we investigated the major HDR isoforms of two woody plant species, Norway spruce (Picea abies) and gray poplar (Populus × canescens), to determine how they regulate isoprenoid formation. Since each of these species has a distinct profile of isoprenoid compounds, they may require different proportions of DMADP and IDP with proportionally more IDP being needed to make larger isoprenoids. Norway spruce contained two major HDR isoforms differing in their occurrence and biochemical characteristics. PaHDR1 produced relatively more IDP than PaHDR2 and it encoding gene was expressed constitutively in leaves, likely serving to form substrate for production of carotenoids, chlorophylls, and other primary isoprenoids derived from a C20 precursor. On the other hand, Norway spruce PaHDR2 produced relatively more DMADP than PaHDR1 and its encoding gene was expressed in leaves, stems, and roots, both constitutively and after induction with the defense hormone methyl jasmonate. This second HDR enzyme likely forms a substrate for the specialized monoterpene (C10), sesquiterpene (C15), and diterpene (C20) metabolites of spruce oleoresin. Gray poplar contained only one dominant isoform (named PcHDR2) that produced relatively more DMADP and the gene of which was expressed in all organs. In leaves, where the requirement for IDP is high to make the major carotenoid and chlorophyll isoprenoids derived from C20 precursors, excess DMADP may accumulate, which could explain the high rate of isoprene (C5) emission. Our results provide new insights into the biosynthesis of isoprenoids in woody plants under conditions of differentially regulated biosynthesis of the precursors IDP and DMADP.


Asunto(s)
Plantas , Terpenos , Plantas/metabolismo , Terpenos/metabolismo , Carotenoides , Isoformas de Proteínas
7.
Mov Disord ; 39(1): 141-151, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37964426

RESUMEN

BACKGROUND: The ITPR1 gene encodes the inositol 1,4,5-trisphosphate (IP3 ) receptor type 1 (IP3 R1), a critical player in cerebellar intracellular calcium signaling. Pathogenic missense variants in ITPR1 cause congenital spinocerebellar ataxia type 29 (SCA29), Gillespie syndrome (GLSP), and severe pontine/cerebellar hypoplasia. The pathophysiological basis of the different phenotypes is poorly understood. OBJECTIVES: We aimed to identify novel SCA29 and GLSP cases to define core phenotypes, describe the spectrum of missense variation across ITPR1, standardize the ITPR1 variant nomenclature, and investigate disease progression in relation to cerebellar atrophy. METHODS: Cases were identified using next-generation sequencing through the Deciphering Developmental Disorders study, the 100,000 Genomes project, and clinical collaborations. ITPR1 alternative splicing in the human cerebellum was investigated by quantitative polymerase chain reaction. RESULTS: We report the largest, multinational case series of 46 patients with 28 unique ITPR1 missense variants. Variants clustered in functional domains of the protein, especially in the N-terminal IP3 -binding domain, the carbonic anhydrase 8 (CA8)-binding region, and the C-terminal transmembrane channel domain. Variants outside these domains were of questionable clinical significance. Standardized transcript annotation, based on our ITPR1 transcript expression data, greatly facilitated analysis. Genotype-phenotype associations were highly variable. Importantly, while cerebellar atrophy was common, cerebellar volume loss did not correlate with symptom progression. CONCLUSIONS: This dataset represents the largest cohort of patients with ITPR1 missense variants, expanding the clinical spectrum of SCA29 and GLSP. Standardized transcript annotation is essential for future reporting. Our findings will aid in diagnostic interpretation in the clinic and guide selection of variants for preclinical studies. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.


Asunto(s)
Aniridia , Anhidrasas Carbónicas , Ataxia Cerebelosa , Discapacidad Intelectual , Trastornos del Movimiento , Degeneraciones Espinocerebelosas , Humanos , Ataxia Cerebelosa/genética , Mutación Missense/genética , Trastornos del Movimiento/complicaciones , Atrofia , Receptores de Inositol 1,4,5-Trifosfato/química , Receptores de Inositol 1,4,5-Trifosfato/genética , Receptores de Inositol 1,4,5-Trifosfato/metabolismo , Anhidrasas Carbónicas/genética , Anhidrasas Carbónicas/metabolismo , Péptidos y Proteínas de Señalización Intracelular/genética
8.
Environ Sci Technol ; 58(22): 9750-9759, 2024 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-38780915

RESUMEN

Humans are known to be a continuous and potent indoor source of volatile organic compounds (VOCs). However, little is known about how personal hygiene, in terms of showering frequency, can influence these emissions and their impact on indoor air chemistry involving ozone. In this study, we characterized the VOC composition of the air in a controlled climate chamber (22.5 m3 with an air change rate at 3.2 h-1) occupied by four male volunteers on successive days under ozone-free (∼0 ppb) and ozone-present (37-40 ppb) conditions. The volunteers either showered the evening prior to the experiments or skipped showering for 24 and 48 h. Reduced shower frequency increased human emissions of gas-phase carboxylic acids, possibly originating from skin bacteria. With ozone present, increasing the number of no-shower days enhanced ozone-skin surface reactions, yielding higher levels of oxidation products. Wearing the same clothing over several days reduced the level of compounds generated from clothing-ozone reactions. When skin lotion was applied, the yield of the skin ozonolysis products decreased, while other compounds increased due to ozone reactions with lotion ingredients. These findings help determine the degree to which personal hygiene choices affect the indoor air composition and indoor air exposures.


Asunto(s)
Contaminación del Aire Interior , Ozono , Compuestos Orgánicos Volátiles , Humanos , Ozono/análisis , Compuestos Orgánicos Volátiles/análisis , Masculino , Higiene , Adulto
9.
Environ Sci Technol ; 58(4): 1986-1997, 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38237915

RESUMEN

Humans are the primary sources of CO2 and NH3 indoors. Their emission rates may be influenced by human physiological and psychological status. This study investigated the impact of physiological and psychological engagements on the human emissions of CO2 and NH3. In a climate chamber, we measured CO2 and NH3 emissions from participants performing physical activities (walking and running at metabolic rates of 2.5 and 5 met, respectively) and psychological stimuli (meditation and cognitive tasks). Participants' physiological responses were recorded, including the skin temperature, electrodermal activity (EDA), and heart rate, and then analyzed for their relationship with CO2 and NH3 emissions. The results showed that physiological engagement considerably elevated per-person CO2 emission rates from 19.6 (seated) to 46.9 (2.5 met) and 115.4 L/h (5 met) and NH3 emission rates from 2.7 to 5.1 and 8.3 mg/h, respectively. CO2 emissions reduced when participants stopped running, whereas NH3 emissions continued to increase owing to their distinct emission mechanisms. Psychological engagement did not significantly alter participants' emissions of CO2 and NH3. Regression analysis revealed that CO2 emissions were predominantly correlated with heart rate, whereas NH3 emissions were mainly associated with skin temperature and EDA. These findings contribute to a deeper understanding of human metabolic emissions of CO2 and NH3.


Asunto(s)
Amoníaco , Dióxido de Carbono , Humanos
10.
Environ Sci Technol ; 58(10): 4704-4715, 2024 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-38326946

RESUMEN

Ozone reaction with human surfaces is an important source of ultrafine particles indoors. However, 1-20 nm particles generated from ozone-human chemistry, which mark the first step of particle formation and growth, remain understudied. Ventilation and indoor air movement could have important implications for these processes. Therefore, in a controlled-climate chamber, we measured ultrafine particles initiated from ozone-human chemistry and their dependence on the air change rate (ACR, 0.5, 1.5, and 3 h-1) and operation of mixing fans (on and off). Concurrently, we measured volatile organic compounds (VOCs) and explored the correlation between particles and gas-phase products. At 25-30 ppb ozone levels, humans generated 0.2-7.7 × 1012 of 1-3 nm, 0-7.2 × 1012 of 3-10 nm, and 0-1.3 × 1012 of 10-20 nm particles per person per hour depending on the ACR and mixing fan operation. Size-dependent particle growth and formation rates increased with higher ACR. The operation of mixing fans suppressed the particle formation and growth, owing to enhanced surface deposition of the newly formed particles and their precursors. Correlation analyses revealed complex interactions between the particles and VOCs initiated by ozone-human chemistry. The results imply that ventilation and indoor air movement may have a more significant influence on particle dynamics and fate relative to indoor chemistry.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire Interior , Ozono , Compuestos Orgánicos Volátiles , Humanos , Tamaño de la Partícula , Ozono/análisis , Ventilación/métodos , Material Particulado/análisis , Compuestos Orgánicos Volátiles/análisis , Contaminación del Aire Interior/análisis , Contaminantes Atmosféricos/análisis
11.
Environ Sci Technol ; 58(15): 6693-6703, 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38577981

RESUMEN

A major component of human skin oil is squalene, a highly unsaturated hydrocarbon that protects the skin from atmospheric oxidants. Skin oil, and thus squalene, is continuously replenished on the skin surface. Squalene is also quickly consumed through reactions with ozone and other oxidants. This study examined the extent of squalene depletion in the skin oils of the forearm of human volunteers after exposure to ozone in a climate chamber. Temperature, relative humidity (RH), skin coverage by clothing, and participants' age were varied in a controlled manner. Concentrations of squalene were determined in skin wipe samples collected before and after ozone exposure. Exposures to ozone resulted in statistically significant decreases in post-exposure squalene concentrations compared to pre-exposure squalene concentrations in the skin wipes when squalene concentrations were normalized by concentrations of co-occurring cholesterol but not by co-occurring pyroglutamic acid (PGA). The rate of squalene loss due to ozonolysis was lower than its replenishment on the skin surface. Within the ranges examined, temperature and RH did not significantly affect the difference between normalized squalene levels in post-samples versus pre-samples. Although not statistically significant, skin coverage and age of the volunteers (three young adults, three seniors, and three teenagers) did appear to impact squalene depletion on the skin surfaces.


Asunto(s)
Contaminación del Aire Interior , Ozono , Humanos , Adolescente , Escualeno/análisis , Ozono/análisis , Contaminación del Aire Interior/análisis , Piel/química , Oxidantes
12.
J Immunol ; 208(2): 454-463, 2022 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-34930781

RESUMEN

Inflammation involves a delicate balance between pathogen clearance and limiting host tissue damage, and perturbations in this equilibrium promote disease. Patients suffering from autoimmune diseases, such as systemic lupus erythematosus (SLE), have higher levels of serum S100A9 protein and increased risk for infection. S100A9 is highly abundant within neutrophils and modulates antimicrobial activity in response to bacterial pathogens. We reasoned that increased serum S100A9 in SLE patients reflects accumulation of S100A9 protein in neutrophils and may indicate altered neutrophil function. In this study, we demonstrate elevated S100A9 protein within neutrophils from SLE patients, and MRL/lpr mice associates with lower mitochondrial superoxide, decreased suicidal neutrophil extracellular trap formation, and increased susceptibility to Staphylococcus aureus infection. Furthermore, increasing mitochondrial superoxide production restored the antibacterial activity of MRL/lpr neutrophils in response to S. aureus These results demonstrate that accumulation of intracellular S100A9 associates with impaired mitochondrial homeostasis, thereby rendering SLE neutrophils inherently less bactericidal.


Asunto(s)
Calgranulina B/sangre , Trampas Extracelulares/inmunología , Lupus Eritematoso Sistémico/sangre , Lupus Eritematoso Sistémico/inmunología , Mitocondrias/metabolismo , Staphylococcus aureus/inmunología , Animales , Susceptibilidad a Enfermedades/inmunología , Femenino , Homeostasis/fisiología , Humanos , Inflamación/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Neutrófilos/inmunología , Infecciones Estafilocócicas/inmunología , Staphylococcus aureus/crecimiento & desarrollo , Superóxidos/metabolismo
13.
Proc Natl Acad Sci U S A ; 118(18)2021 05 04.
Artículo en Inglés | MEDLINE | ID: mdl-33903234

RESUMEN

Amyloid fibril formation of α-synuclein (αS) is associated with multiple neurodegenerative diseases, including Parkinson's disease (PD). Growing evidence suggests that progression of PD is linked to cell-to-cell propagation of αS fibrils, which leads to seeding of endogenous intrinsically disordered monomer via templated elongation and secondary nucleation. A molecular understanding of the seeding mechanism and driving interactions is crucial to inhibit progression of amyloid formation. Here, using relaxation-based solution NMR experiments designed to probe large complexes, we probe weak interactions of intrinsically disordered acetylated-αS (Ac-αS) monomers with seeding-competent Ac-αS fibrils and seeding-incompetent off-pathway oligomers to identify Ac-αS monomer residues at the binding interface. Under conditions that favor fibril elongation, we determine that the first 11 N-terminal residues on the monomer form a common binding site for both fibrils and off-pathway oligomers. Additionally, the presence of off-pathway oligomers within a fibril seeding environment suppresses seeded amyloid formation, as observed through thioflavin-T fluorescence experiments. This highlights that off-pathway αS oligomers can act as an auto-inhibitor against αS fibril elongation. Based on these data taken together with previous results, we propose a model in which Ac-αS monomer recruitment to the fibril is driven by interactions between the intrinsically disordered monomer N terminus and the intrinsically disordered flanking regions (IDR) on the fibril surface. We suggest that this monomer recruitment may play a role in the elongation of amyloid fibrils and highlight the potential of the IDRs of the fibril as important therapeutic targets against seeded amyloid formation.


Asunto(s)
Amiloide/ultraestructura , Proteínas Intrínsecamente Desordenadas/ultraestructura , Enfermedad de Parkinson/genética , alfa-Sinucleína/ultraestructura , Amiloide/química , Amiloide/genética , Benzotiazoles/química , Benzotiazoles/metabolismo , Sitios de Unión/genética , Humanos , Proteínas Intrínsecamente Desordenadas/química , Proteínas Intrínsecamente Desordenadas/genética , Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética , Resonancia Magnética Nuclear Biomolecular , Enfermedad de Parkinson/patología , alfa-Sinucleína/química , alfa-Sinucleína/genética
14.
Transpl Infect Dis ; 25(3): e14059, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37005911

RESUMEN

BACKGROUND: The Centers for Disease Control and Prevention led an investigation to determine if Strongyloides infection in a right kidney recipient was an existing chronic infection, or if the infection was transmitted from an infected organ donor. METHODS: Evidence regarding the organ donor and organ recipients Strongyloides testing, treatment, and risk factors were gathered and evaluated. The case classification algorithm created by the Disease Transmission Advisory Committee was utilized. RESULTS: The organ donor had risk factors for Strongyloides infection; the banked donor specimen, submitted for serology testing 112 days post-donor death, was positive. The right kidney recipient was negative for Strongyloides infection pretransplant. Strongyloides infection was diagnosed via small bowel and stomach biopsies. The left kidney recipient had risk factors for Strongyloides infection. Two posttransplant Strongyloides antibody tests were negative at 59 and 116 days posttransplant; repeat antibody tests returned positive at 158 and 190 days posttransplant. Examination of bronchial alveolar lavage fluid collected 110 days posttransplant from the heart recipient showed a parasite morphologically consistent with Strongyloides species. She subsequently developed complications from Strongyloides infection, including hyperinfection syndrome and disseminated strongyloidiasis. Based on the evidence from our investigation, donor-derived strongyloidiasis was suspected in one recipient and proven in two recipients. CONCLUSION: The results of this investigation support the importance of preventing donor-derived Strongyloides infections by laboratory-based serology testing of solid organ donors. Donor positive testing results would direct the monitoring and treatment of recipients to avoid severe complications.


Asunto(s)
Trasplante de Órganos , Strongyloides stercoralis , Estrongiloidiasis , Animales , Femenino , Humanos , Estrongiloidiasis/diagnóstico , Estrongiloidiasis/tratamiento farmacológico , Estrongiloidiasis/parasitología , Michigan , Ohio , Donantes de Tejidos , California , Trasplante de Órganos/efectos adversos
15.
J Immunol ; 206(9): 2015-2028, 2021 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-33820855

RESUMEN

The cGAS-cyclic GMP-AMP (cGAMP)-stimulator of IFN genes (STING) pathway induces a powerful type I IFN (IFN-I) response and is a prime candidate for augmenting immunity in cancer immunotherapy and vaccines. IFN-I also has immune-regulatory functions manifested in several autoimmune diseases and is a first-line therapy for relapsing-remitting multiple sclerosis. However, it is only moderately effective and can induce adverse effects and neutralizing Abs in recipients. Targeting cGAMP in autoimmunity is unexplored and represents a challenge because of the intracellular location of its receptor, STING. We used microparticle (MP)-encapsulated cGAMP to increase cellular delivery, achieve dose sparing, and reduce potential toxicity. In the C57BL/6 experimental allergic encephalomyelitis (EAE) model, cGAMP encapsulated in MPs (cGAMP MPs) administered therapeutically protected mice from EAE in a STING-dependent fashion, whereas soluble cGAMP was ineffective. Protection was also observed in a relapsing-remitting model. Importantly, cGAMP MPs protected against EAE at the peak of disease and were more effective than rIFN-ß. Mechanistically, cGAMP MPs showed both IFN-I-dependent and -independent immunosuppressive effects. Furthermore, it induced the immunosuppressive cytokine IL-27 without requiring IFN-I. This augmented IL-10 expression through activated ERK and CREB. IL-27 and subsequent IL-10 were the most important cytokines to mitigate autoreactivity. Critically, cGAMP MPs promoted IFN-I as well as the immunoregulatory cytokines IL-27 and IL-10 in PBMCs from relapsing-remitting multiple sclerosis patients. Collectively, this study reveals a previously unappreciated immune-regulatory effect of cGAMP that can be harnessed to restrain T cell autoreactivity.


Asunto(s)
Micropartículas Derivadas de Células/inmunología , Encefalomielitis Autoinmune Experimental/inmunología , Interferón Tipo I/inmunología , Proteínas de la Membrana/inmunología , Nucleótidos Cíclicos/inmunología , Transducción de Señal/inmunología , Animales , Linfocitos T CD4-Positivos/efectos de los fármacos , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Micropartículas Derivadas de Células/metabolismo , Células Cultivadas , Citocinas/inmunología , Citocinas/metabolismo , Encefalomielitis Autoinmune Experimental/metabolismo , Encefalomielitis Autoinmune Experimental/prevención & control , Femenino , Humanos , Interferón Tipo I/metabolismo , Leucocitos Mononucleares/efectos de los fármacos , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/metabolismo , Proteínas de la Membrana/agonistas , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Ratones Endogámicos , Ratones Noqueados , Nucleótidos Cíclicos/administración & dosificación , Nucleótidos Cíclicos/metabolismo , Transducción de Señal/efectos de los fármacos
16.
Health Expect ; 2023 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-37751312

RESUMEN

BACKGROUND: Indiscriminate use of laboratory blood testing in hospitals contributes to patient discomfort and healthcare waste. Patient engagement in low-value healthcare can help reduce overuse. Understanding patient experience is necessary to identify opportunities to improve patient engagement with in-hospital laboratory testing. OBJECTIVES: To understand patient experience with the process of in-hospital laboratory blood testing. METHODS: We used a qualitative study design via semistructured interviews conducted online or over the phone. Participants were adult patients or family members/caregivers (≥18 years of age) with a recent (within 12 months of interview) experience of hospitalization in Alberta or British Columbia, Canada. We identified participants through convenience sampling and conducted interviews between May 2021 and June 2022. We analysed transcripts using thematic content analysis. Recruitment was continued until code saturation was reached. RESULTS: We interviewed 16 participants (13 patients, 1 family member and 2 caregivers). We identified four themes from patients' experiences of in-hospital laboratory blood testing: (i) patients need information from healthcare teams about expected blood testing processes, (ii) blood draw processes should consider patient comfort and preferences, (iii) patients want information from their healthcare teams about the rationale and frequency of blood testing and (iv) patients need information on how their testing results affect their medical care. CONCLUSION: Current laboratory testing processes in hospitals do not facilitate shared decision-making and patient engagement. Patient engagement with laboratory testing in hospitals requires an empathetic healthcare team that provides clear communication regarding testing procedures, rationale and results, while considering patient preferences and offering opportunities for involvement. PATIENT OR PUBLIC CONTRIBUTION: We interviewed 16 patients and/or family members/caregivers regarding their in-hospital laboratory blood testing experiences. Our findings show correlations between patient needs and patient recommendations to make testing processes more patient-centred. To bring a lived-experience lens to this study, we formed a Patient Advisory Council with 9-11 patient research partners. Our patient research partners informed the research design, co-developed participant recruitment strategies, co-conducted data collection and informed the data analysis. Some of our patient research partners are co-authors of this manuscript.

17.
Acta Paediatr ; 112(3): 372-382, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36484640

RESUMEN

BACKGROUND: Clinicians favour low oxygen concentrations when resuscitating preterm infants immediately after birth despite inconclusive evidence to support this practice. Prospective meta-analysis (PMA) is a novel approach where studies are identified as eligible for inclusion in the meta-analysis before their results are known. AIMS: To explore whether high (60%) or low (30%) oxygen is associated with greater efficacy and safety for the initial resuscitation (immediately after birth) of preterm infants born at <29 weeks' gestation. METHODS: We will conduct a prospective meta-analysis (PMA) with individual participant data (IPD). We will perform a systematic search to identify ongoing RCTs including infants <29 weeks' gestation randomised to high (60%) or low (30%) oxygen for initial resuscitation after birth. IPD will be sought for all infants randomised for the purpose of meta-analysis. We will employ a one-stage random-effects approach to IPD meta-analysis. Potential heterogeneity and the differential effect of high or low oxygen will be explored through subgroup and interaction analyses. The primary outcome of this study is all-cause mortality prior to hospital discharge. There will be a follow-up analysis of neurodevelopmental outcomes once available. RESULTS/CONCLUSION: The results of neonatal outcomes at hospital discharge are expected by 2025, and neurodevelopmental outcomes by 2027.


Asunto(s)
Recien Nacido Prematuro , Oxígeno , Lactante , Femenino , Recién Nacido , Humanos , Estudios Prospectivos , Resucitación/métodos , Edad Gestacional , Metaanálisis como Asunto
18.
Proc Natl Acad Sci U S A ; 117(18): 9973-9980, 2020 05 05.
Artículo en Inglés | MEDLINE | ID: mdl-32303657

RESUMEN

When transitioning from the environment, pathogenic microorganisms must adapt rapidly to survive in hostile host conditions. This is especially true for environmental fungi that cause opportunistic infections in immunocompromised patients since these microbes are not well adapted human pathogens. Cryptococcus species are yeastlike fungi that cause lethal infections, especially in HIV-infected patients. Using Cryptococcus deneoformans in a murine model of infection, we examined contributors to drug resistance and demonstrated that transposon mutagenesis drives the development of 5-fluoroorotic acid (5FOA) resistance. Inactivation of target genes URA3 or URA5 primarily reflected the insertion of two transposable elements (TEs): the T1 DNA transposon and the TCN12 retrotransposon. Consistent with in vivo results, increased rates of mutagenesis and resistance to 5FOA and the antifungal drugs rapamycin/FK506 (rap/FK506) and 5-fluorocytosine (5FC) were found when Cryptococcus was incubated at 37° compared to 30° in vitro, a condition that mimics the temperature shift that occurs during the environment-to-host transition. Inactivation of the RNA interference (RNAi) pathway, which suppresses TE movement in many organisms, was not sufficient to elevate TE movement at 30° to the level observed at 37°. We propose that temperature-dependent TE mobilization in Cryptococcus is an important mechanism that enhances microbial adaptation and promotes pathogenesis and drug resistance in the human host.


Asunto(s)
Antifúngicos/farmacología , Cryptococcus neoformans/efectos de los fármacos , Micosis/genética , Retroelementos/genética , Animales , Antifúngicos/efectos adversos , Cryptococcus neoformans/patogenicidad , Farmacorresistencia Fúngica/genética , Interacciones Huésped-Patógeno/genética , Humanos , Ratones , Mutagénesis/genética , Micosis/microbiología , Ácido Orótico/efectos adversos , Ácido Orótico/análogos & derivados , Ácido Orótico/farmacología , Sirolimus/farmacología , Tacrolimus/farmacología , Virulencia/genética
19.
Skeletal Radiol ; 52(1): 61-66, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35907017

RESUMEN

OBJECTIVE: To assess the validity and reliability of the calf injury classification system proposed by the Olympic Park group which focuses on connective tissue structure integrity on MRI. MATERIALS AND METHODS: A retrospective study analysing calf muscle group injuries in an English Premiership professional rugby union club using the MRI classification proposed by the Olympic Park group. Classification on MRI examinations of 28 calf injuries sustained over a 6-year period was performed by three independent musculoskeletal radiologists to determine the inter-observer variability and correlation of the grade of injury with return-to-full-training (RTFT) time. RESULTS: RTFT time ranged from 5 to 110 days (mean = 40.1, SD = 26.4) following calf muscle injury. The Olympic Park classification injury grade demonstrated moderate to strong correlation with RTFT time (Spearman's rank correlation coefficient, 0.661-0.715, p < 0.01). RTFT time was statistically different between different injury grades (one-way ANOVA, p < 0.01). Inter-observer agreement of the overall grade between radiologist pairs was fair to moderate (weighted kappa 0.406-0.583). CONCLUSION: The Olympic Park classification system demonstrates moderate to strong correlation with time to RTFT following calf injury. Inter-observer reliability is fair to moderate.


Asunto(s)
Traumatismos en Atletas , Traumatismos de la Pierna , Humanos , Volver al Deporte , Estudios Retrospectivos , Reproducibilidad de los Resultados , Rugby , Traumatismos de la Pierna/diagnóstico por imagen , Imagen por Resonancia Magnética , Traumatismos en Atletas/diagnóstico por imagen
20.
J Am Soc Nephrol ; 33(3): 565-582, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35091451

RESUMEN

BACKGROUND: Endothelial cell injury is a common nidus of renal injury in patients and consistent with the high prevalence of AKI reported during the coronavirus disease 2019 pandemic. This cell type expresses integrin α5 (ITGA5), which is essential to the Tie2 signaling pathway. The microRNA miR-218-5p is upregulated in endothelial progenitor cells (EPCs) after hypoxia, but microRNA regulation of Tie2 in the EPC lineage is unclear. METHODS: We isolated human kidney-derived EPCs (hkEPCs) and surveyed microRNA target transcripts. A preclinical model of ischemic kidney injury was used to evaluate the effect of hkEPCs on capillary repair. We used a genetic knockout model to evaluate the effect of deleting endogenous expression of miR-218 specifically in angioblasts. RESULTS: After ischemic in vitro preconditioning, miR-218-5p was elevated in hkEPCs. We found miR-218-5p bound to ITGA5 mRNA transcript and decreased ITGA5 protein expression. Phosphorylation of 42/44 MAPK decreased by 73.6% in hkEPCs treated with miR-218-5p. Cells supplemented with miR-218-5p downregulated ITGA5 synthesis and decreased 42/44 MAPK phosphorylation. In a CD309-Cre/miR-218-2-LoxP mammalian model (a conditional knockout mouse model designed to delete pre-miR-218-2 exclusively in CD309+ cells), homozygotes at e18.5 contained avascular glomeruli, whereas heterozygote adults showed susceptibility to kidney injury. Isolated EPCs from the mouse kidney contained high amounts of ITGA5 and showed decreased migratory capacity in three-dimensional cell culture. CONCLUSIONS: These results demonstrate the critical regulatory role of miR-218-5p in kidney EPC migration, a finding that may inform efforts to treat microvascular kidney injury via therapeutic cell delivery.


Asunto(s)
Lesión Renal Aguda/etiología , Lesión Renal Aguda/metabolismo , Células Progenitoras Endoteliales/metabolismo , Células Progenitoras Endoteliales/patología , Integrina alfa5/metabolismo , MicroARNs/fisiología , Lesión Renal Aguda/patología , Animales , Modelos Animales de Enfermedad , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Receptor TIE-2/fisiología , Transducción de Señal/fisiología
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