Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.343
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Nature ; 589(7841): 270-275, 2021 01.
Artículo en Inglés | MEDLINE | ID: mdl-33116299

RESUMEN

There is an urgent need to create novel models using human disease-relevant cells to study severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) biology and to facilitate drug screening. Here, as SARS-CoV-2 primarily infects the respiratory tract, we developed a lung organoid model using human pluripotent stem cells (hPSC-LOs). The hPSC-LOs (particularly alveolar type-II-like cells) are permissive to SARS-CoV-2 infection, and showed robust induction of chemokines following SARS-CoV-2 infection, similar to what is seen in patients with COVID-19. Nearly 25% of these patients also have gastrointestinal manifestations, which are associated with worse COVID-19 outcomes1. We therefore also generated complementary hPSC-derived colonic organoids (hPSC-COs) to explore the response of colonic cells to SARS-CoV-2 infection. We found that multiple colonic cell types, especially enterocytes, express ACE2 and are permissive to SARS-CoV-2 infection. Using hPSC-LOs, we performed a high-throughput screen of drugs approved by the FDA (US Food and Drug Administration) and identified entry inhibitors of SARS-CoV-2, including imatinib, mycophenolic acid and quinacrine dihydrochloride. Treatment at physiologically relevant levels of these drugs significantly inhibited SARS-CoV-2 infection of both hPSC-LOs and hPSC-COs. Together, these data demonstrate that hPSC-LOs and hPSC-COs infected by SARS-CoV-2 can serve as disease models to study SARS-CoV-2 infection and provide a valuable resource for drug screening to identify candidate COVID-19 therapeutics.


Asunto(s)
Antivirales/farmacología , COVID-19/virología , Colon/citología , Evaluación Preclínica de Medicamentos/métodos , Pulmón/citología , Organoides/efectos de los fármacos , Organoides/virología , SARS-CoV-2/efectos de los fármacos , Animales , COVID-19/prevención & control , Colon/efectos de los fármacos , Colon/virología , Aprobación de Drogas , Femenino , Xenoinjertos/efectos de los fármacos , Humanos , Técnicas In Vitro , Pulmón/efectos de los fármacos , Pulmón/virología , Masculino , Ratones , Organoides/citología , Organoides/metabolismo , SARS-CoV-2/genética , Estados Unidos , United States Food and Drug Administration , Tropismo Viral , Internalización del Virus/efectos de los fármacos , Tratamiento Farmacológico de COVID-19
2.
Proc Natl Acad Sci U S A ; 121(17): e2315018121, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38625940

RESUMEN

Heterotrimeric G proteins can be regulated by posttranslational modifications, including ubiquitylation. KCTD5, a pentameric substrate receptor protein consisting of an N-terminal BTB domain and a C-terminal domain, engages CUL3 to form the central scaffold of a cullin-RING E3 ligase complex (CRL3KCTD5) that ubiquitylates Gßγ and reduces Gßγ protein levels in cells. The cryo-EM structure of a 5:5:5 KCTD5/CUL3NTD/Gß1γ2 assembly reveals a highly dynamic complex with rotations of over 60° between the KCTD5BTB/CUL3NTD and KCTD5CTD/Gßγ moieties of the structure. CRL3KCTD5 engages the E3 ligase ARIH1 to ubiquitylate Gßγ in an E3-E3 superassembly, and extension of the structure to include full-length CUL3 with RBX1 and an ARIH1~ubiquitin conjugate reveals that some conformational states position the ARIH1~ubiquitin thioester bond to within 10 Å of lysine-23 of Gß and likely represent priming complexes. Most previously described CRL/substrate structures have consisted of monovalent complexes and have involved flexible peptide substrates. The structure of the KCTD5/CUL3NTD/Gßγ complex shows that the oligomerization of a substrate receptor can generate a polyvalent E3 ligase complex and that the internal dynamics of the substrate receptor can position a structured target for ubiquitylation in a CRL3 complex.


Asunto(s)
Proteínas Portadoras , Ubiquitina-Proteína Ligasas , Unión Proteica , Ubiquitinación , Ubiquitina-Proteína Ligasas/metabolismo , Proteínas Portadoras/metabolismo , Ubiquitina/metabolismo , Proteínas Cullin/genética , Proteínas Cullin/metabolismo
3.
Nature ; 585(7825): 426-432, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32908310

RESUMEN

Endothelial cells adopt tissue-specific characteristics to instruct organ development and regeneration1,2. This adaptability is lost in cultured adult endothelial cells, which do not vascularize tissues in an organotypic manner. Here, we show that transient reactivation of the embryonic-restricted ETS variant transcription factor 2 (ETV2)3 in mature human endothelial cells cultured in a serum-free three-dimensional matrix composed of a mixture of laminin, entactin and type-IV collagen (LEC matrix) 'resets' these endothelial cells to adaptable, vasculogenic cells, which form perfusable and plastic vascular plexi. Through chromatin remodelling, ETV2 induces tubulogenic pathways, including the activation of RAP1, which promotes the formation of durable lumens4,5. In three-dimensional matrices-which do not have the constraints of bioprinted scaffolds-the 'reset' vascular endothelial cells (R-VECs) self-assemble into stable, multilayered and branching vascular networks within scalable microfluidic chambers, which are capable of transporting human blood. In vivo, R-VECs implanted subcutaneously in mice self-organize into durable pericyte-coated vessels that functionally anastomose to the host circulation and exhibit long-lasting patterning, with no evidence of malformations or angiomas. R-VECs directly interact with cells within three-dimensional co-cultured organoids, removing the need for the restrictive synthetic semipermeable membranes that are required for organ-on-chip systems, therefore providing a physiological platform for vascularization, which we call 'Organ-On-VascularNet'. R-VECs enable perfusion of glucose-responsive insulin-secreting human pancreatic islets, vascularize decellularized rat intestines and arborize healthy or cancerous human colon organoids. Using single-cell RNA sequencing and epigenetic profiling, we demonstrate that R-VECs establish an adaptive vascular niche that differentially adjusts and conforms to organoids and tumoroids in a tissue-specific manner. Our Organ-On-VascularNet model will permit metabolic, immunological and physiochemical studies and screens to decipher the crosstalk between organotypic endothelial cells and parenchymal cells for identification of determinants of endothelial cell heterogeneity, and could lead to advances in therapeutic organ repair and tumour targeting.


Asunto(s)
Vasos Sanguíneos/citología , Carcinogénesis , Células Endoteliales/citología , Hemodinámica , Neoplasias/irrigación sanguínea , Organogénesis , Organoides/irrigación sanguínea , Vasos Sanguíneos/crecimiento & desarrollo , Técnicas de Cultivo de Célula/instrumentación , Técnicas de Cultivo de Célula/métodos , Cromatina/metabolismo , Epigénesis Genética , Epigenómica , Células Endoteliales de la Vena Umbilical Humana , Humanos , Técnicas In Vitro , Islotes Pancreáticos/irrigación sanguínea , Modelos Biológicos , Especificidad de Órganos , RNA-Seq , Análisis de la Célula Individual , Factores de Transcripción , Transcriptoma
4.
Proc Natl Acad Sci U S A ; 120(41): e2308941120, 2023 10 10.
Artículo en Inglés | MEDLINE | ID: mdl-37782785

RESUMEN

Impaired lymphatic drainage and lymphedema are major morbidities whose mechanisms have remained obscure. To study lymphatic drainage and its impairment, we engineered a microfluidic culture model of lymphatic vessels draining interstitial fluid. This lymphatic drainage-on-chip revealed that inflammatory cytokines that are known to disrupt blood vessel junctions instead tightened lymphatic cell-cell junctions and impeded lymphatic drainage. This opposing response was further demonstrated when inhibition of rho-associated protein kinase (ROCK) was found to normalize fluid drainage under cytokine challenge by simultaneously loosening lymphatic junctions and tightening blood vessel junctions. Studies also revealed a previously undescribed shift in ROCK isoforms in lymphatic endothelial cells, wherein a ROCK2/junctional adhesion molecule-A (JAM-A) complex emerges that is responsible for the cytokine-induced lymphatic junction zippering. To validate these in vitro findings, we further demonstrated in a genetic mouse model that lymphatic-specific knockout of ROCK2 reversed lymphedema in vivo. These studies provide a unique platform to generate interstitial fluid pressure and measure the drainage of interstitial fluid into lymphatics and reveal a previously unappreciated ROCK2-mediated mechanism in regulating lymphatic drainage.


Asunto(s)
Molécula A de Adhesión de Unión , Vasos Linfáticos , Linfedema , Quinasas Asociadas a rho , Animales , Ratones , Biomimética , Citocinas/metabolismo , Células Endoteliales/metabolismo , Uniones Intercelulares , Molécula A de Adhesión de Unión/metabolismo , Vasos Linfáticos/metabolismo , Linfedema/genética , Linfedema/metabolismo , Quinasas Asociadas a rho/metabolismo
5.
Lancet ; 403(10437): 1671-1680, 2024 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-38588689

RESUMEN

BACKGROUND: Mental disorders are the leading global cause of health burden among adolescents. However, prevalence data for mental disorders among adolescents in low-income and middle-income countries are scarce with often limited generalisability. This study aimed to generate nationally representative prevalence estimates for mental disorders in adolescents in Kenya, Indonesia, and Viet Nam. METHODS: As part of the National Adolescent Mental Health Surveys (NAMHS), a multinational cross-sectional study, nationally representative household surveys were conducted in Kenya, Indonesia, and Viet Nam between March and December, 2021. Adolescents aged 10-17 years and their primary caregiver were interviewed from households selected randomly according to sampling frames specifically designed to elicit nationally representative results. Six mental disorders (social phobia, generalised anxiety disorder, major depressive disorder, post-traumatic stress disorder, conduct disorder, and attention-deficit hyperactivity disorder) were assessed with the Diagnostic Interview Schedule for Children, Version 5. Suicidal behaviours and self-harm in the past 12 months were also assessed. Prevalence in the past 12 months and past 4 weeks was calculated for each mental disorder and collectively for any mental disorder (ie, of the six mental disorders assessed). Prevalence of suicidal behaviours (ie, ideation, planning, and attempt) and self-harm in the past 12 months was calculated, along with adjusted odds ratios (aORs) to show the association with prevalence of any mental disorder in the past 12 months. Inverse probability weighting was applied to generate national estimates with corresponding 95% CIs. FINDINGS: Final samples consisted of 5155 households (ie, adolescent and primary caregiver pairs) from Kenya, 5664 households from Indonesia, and 5996 households from Viet Nam. In Kenya, 2416 (46·9%) adolescents were male and 2739 (53·1%) were female; in Indonesia, 2803 (49·5%) adolescents were male and 2861 (50·5%) were female; and in Viet Nam, 3151 (52·5%) were male and 2845 (47·4%) were female. Prevalence of any mental disorder in the past 12 months was 12·1% (95% CI 10·9-13·5) in Kenya, 5·5% (4·3-6·9) in Indonesia, and 3·3% (2·7-4·1) in Viet Nam. Prevalence in the past 4 weeks was 9·4% (8·3-10·6) in Kenya, 4·4% (3·4-5·6) in Indonesia, and 2·7% (2·2-3·3) in Viet Nam. The prevalence of suicidal behaviours in the past 12 months was low in all three countries, with suicide ideation ranging from 1·4% in Indonesia (1·0-2·0) and Viet Nam (1·0-1·9) to 4·6% (3·9-5·3) in Kenya, suicide planning ranging from 0·4% in Indonesia (0·3-0·8) and Viet Nam (0·2-0·6) to 2·4% (1·9-2·9) in Kenya, and suicide attempts ranging from 0·2% in Indonesia (0·1-0·4) and Viet Nam (0·1-0·3) to 1·0% (0·7-1·4) in Kenya. The prevalence of self-harm in the past 12 months was also low in all three countries, ranging from 0·9% (0·6-1·3) in Indonesia to 1·2% (0·9-1·7) in Kenya. However, the prevalence of suicidal behaviours and self-harm in the past 12 months was significantly higher among those with any mental disorder in the past 12 months than those without (eg, aORs for suicidal ideation ranged from 7·1 [3·1-15·9] in Indonesia to 14·7 [7·5-28·6] in Viet Nam). INTERPRETATION: NAMHS provides the first national adolescent mental disorders prevalence estimates for Kenya, Indonesia, and Viet Nam. These data can inform mental health and broader health policies in low-income and middle-income countries. FUNDING: The University of Queensland in America (TUQIA) through support from Pivotal Ventures, a Melinda French Gates company.


Asunto(s)
Trastornos Mentales , Humanos , Adolescente , Indonesia/epidemiología , Femenino , Estudios Transversales , Masculino , Kenia/epidemiología , Prevalencia , Vietnam/epidemiología , Niño , Trastornos Mentales/epidemiología , Encuestas Epidemiológicas
7.
J Infect Dis ; 230(2): e268-e278, 2024 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-38169323

RESUMEN

BACKGROUND: Tuberculous meningitis (TBM) is difficult to diagnose. We investigated whether a 3-gene host response signature in blood can distinguish TBM from other brain infections. METHODS: The expression of 3 genes (dual specificity phosphatase 3 [DUSP3], guanylate-binding protein [GBP5], krupple-like factor 2 [KLF2]) was analyzed by RNA sequencing of archived whole blood from 4 cohorts of Vietnamese adults: 281 with TBM, 279 with pulmonary tuberculosis, 50 with other brain infections, and 30 healthy controls. Tuberculosis scores (combined 3-gene expression) were calculated following published methodology and discriminatory performance compared using area under a receiver operator characteristic curve (AUC). RESULTS: GBP5 was upregulated in TBM compared to other brain infections (P < .001), with no difference in DUSP3 and KLF2 expression. The diagnostic performance of GBP5 alone (AUC, 0.74; 95% confidence interval [CI], .67-.81) was slightly better than the 3-gene tuberculosis score (AUC, 0.66; 95% CI, .58-.73) in TBM. Both GBP5 expression and tuberculosis score were higher in participants with human immunodeficiency virus (HIV; P < .001), with good diagnostic performance of GBP5 alone (AUC, 0.86; 95% CI, .80-.93). CONCLUSIONS: The 3-gene host signature in whole blood has the ability to discriminate TBM from other brain infections, including in individuals with HIV. Validation in large prospective diagnostic study is now required.


Asunto(s)
Tuberculosis Meníngea , Humanos , Tuberculosis Meníngea/diagnóstico , Tuberculosis Meníngea/sangre , Tuberculosis Meníngea/genética , Masculino , Femenino , Adulto , Persona de Mediana Edad , Proteínas de Unión al GTP/genética , Factores de Transcripción de Tipo Kruppel/genética , Diagnóstico Diferencial , Tuberculosis Pulmonar/diagnóstico , Tuberculosis Pulmonar/genética , Tuberculosis Pulmonar/sangre , Biomarcadores/sangre , Adulto Joven , Vietnam , Curva ROC
8.
J Biol Chem ; 299(10): 105188, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37625591

RESUMEN

Rapidly accelerated fibrosarcoma (ARAF, BRAF, CRAF) kinase is central to the MAPK pathway (RAS-RAF-MEK-ERK). Inactive RAF kinase is believed to be monomeric, autoinhibited, and cytosolic, while activated RAF is recruited to the membrane via RAS-GTP, leading to the relief of autoinhibition, phosphorylation of key regulatory sites, and dimerization of RAF protomers. Although it is well known that active and inactive BRAF have differential phosphorylation sites that play a crucial role in regulating BRAF, key details are still missing. In this study, we report the characterization of a novel phosphorylation site, BRAFS732 (equivalent in CRAFS624), located in proximity to the C-terminus binding motif for the 14-3-3 scaffolding protein. At the C terminus, 14-3-3 binds to BRAFpS729 (CRAFpS621) and enhances RAF dimerization. We conducted mutational analysis of BRAFS732A/E and CRAFS624A/E and revealed that the phosphomimetic S→E mutant decreases 14-3-3 association and RAF dimerization. In normal cell signaling, dimerized RAF phosphorylates MEK1/2, which is observed in the phospho-deficient S→A mutant. Our results suggest that phosphorylation and dephosphorylation of this site fine-tune the association of 14-3-3 and RAF dimerization, ultimately impacting MEK phosphorylation. We further characterized the BRAF homodimer and BRAF:CRAF heterodimer and identified a correlation between phosphorylation of this site with drug sensitivity. Our work reveals a novel negative regulatory role for phosphorylation of BRAFS732 and CRAFS624 in decreasing 14-3-3 association, dimerization, and MEK phosphorylation. These findings provide insight into the regulation of the MAPK pathway and may have implications for cancers driven by mutations in the pathway.

9.
Artículo en Inglés | MEDLINE | ID: mdl-39441241

RESUMEN

Several health beneficial effects are associated with intake of medium-chain triacylglycerol (MCT), however, the underlying mechanisms are unknown. Furthermore, it remains uncertain whether the acute metabolic effects of MCT differ between lean individuals and individuals with obesity - and whether these effects are sustained following chronic intake. This study aimed to elucidate the postprandial physiological and metabolic effects of MCT before and after eight days intake compared to intake of energy-matched triacylglycerol consisting of long-chain fatty acids (LCT) using a randomized cross-over design in lean individuals (n=8) and individuals with obesity (n=8). The study revealed that consumption of MCT increased ketogenesis and metabolic rate, while lowering blood glucose levels over five hours. The hypoglycemic action of MCT intake was accompanied by a concomitant transient increase in plasma insulin and glucagon levels. Interestingly, the effects on ketogenesis, metabolic rate, and glycemia were preserved in individuals with obesity and sustained after eight days of daily supplementation. Lipidomic plasma analysis in lean individuals (n=4) showed that a part of the ingested MCT bypasses the liver and entered the systemic circulation as medium-chain fatty acids (MCFA). The findings suggest that MCFA, along with ketone bodies from the liver, may act as signaling molecules and/or substrates in the peripheral tissues, thereby contributing to the effects of MCT intake. In summary, these findings underscore the health benefits of MCT in metabolically compromised individuals after daily supplementation. Moreover, we uncover novel aspects of MCFA biology, providing insights into how these fatty acids orchestrate physiological effects in humans.

10.
Emerg Infect Dis ; 30(11): 2385-2390, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-39322418

RESUMEN

We studied a community cluster of 25 mpox cases in Vietnam caused by emerging monkeypox virus sublineage C.1 and imported into Vietnam through 2 independent events; 1 major cluster carried a novel APOBEC3-like mutation. Three patients died; all had advanced HIV co-infection. Viral evolution and its potential consequences should be closely monitored.


Asunto(s)
Monkeypox virus , Mpox , Filogenia , Vietnam/epidemiología , Humanos , Mpox/epidemiología , Mpox/virología , Mpox/transmisión , Monkeypox virus/genética , Monkeypox virus/clasificación , Masculino , Femenino , Adulto , Persona de Mediana Edad , Enfermedades Transmisibles Emergentes/virología , Enfermedades Transmisibles Emergentes/transmisión , Enfermedades Transmisibles Emergentes/epidemiología , Infecciones por VIH/transmisión , Infecciones por VIH/virología , Infecciones por VIH/epidemiología , Historia del Siglo XXI , Mutación , Coinfección/virología
11.
Int J Cancer ; 2024 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-39301840

RESUMEN

Salivary carcinomas of minor salivary glands are very infrequent tumors. When located in the tongue, the therapeutic strategy may comprise upfront surgery, which may be debilitating, and/or (chemo-)radiotherapy. The aim of this study was to identify the prognostic factors of salivary carcinomas of the tongue in a population-based cohort. This retrospective multicentric study, based on the "Réseau d'Expertise Français sur les Cancers ORL Rares" (REFCOR), included all the patients with a salivary carcinoma of the tongue, diagnosed between January 2009 and December 2018. Dubious slides were reviewed by REFCOR expert pathologists to ensure diagnostic accuracy. Treatment was performed in accordance with national REFCOR recommendations. From 28 centers, 103 patients were included in this study. Median age at diagnosis was 63 years, and 60.2% were female. Tumors were adenoid cystic carcinomas (41.7%), mucoepidermoid carcinomas (30.1%), and other adenocarcinomas (28.2%). Primary treatment was surgical for 61.2% of them. Five-year overall survival (OS) and event-free survival (EFS) rates were 84.7% and 38.6%, respectively. In multivariable analysis, EFS was significantly worse in case of nonsurgical treatment, alcohol consumption, and glossotonsillar sulcus involvement. N-positive status was the only significant prognostic factor for OS in multivariable analysis. Salivary carcinomas of the tongue represent a heterogeneous group of rare tumors, with a high risk of recurrence. In this national cohort, surgery was associated with better EFS and N-status was the main independent prognostic factor for OS.

12.
Eur J Neurosci ; 59(12): 3162-3183, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38626924

RESUMEN

Musical engagement can be conceptualized through various activities, modes of listening and listener states. Recent research has reported that a state of focused engagement can be indexed by the inter-subject correlation (ISC) of audience responses to a shared naturalistic stimulus. While statistically significant ISC has been reported during music listening, we lack insight into the temporal dynamics of engagement over the course of musical works-such as those composed in the Western classical style-which involve the formulation of expectations that are realized or derailed at subsequent points of arrival. Here, we use the ISC of electroencephalographic (EEG) and continuous behavioural (CB) responses to investigate the time-varying dynamics of engagement with functional tonal music. From a sample of adult musicians who listened to a complete cello concerto movement, we found that ISC varied throughout the excerpt for both measures. In particular, significant EEG ISC was observed during periods of musical tension that built to climactic highpoints, while significant CB ISC corresponded more to declarative entrances and points of arrival. Moreover, we found that a control stimulus retaining envelope characteristics of the intact music, but little other temporal structure, also elicited significantly correlated EEG and CB responses, though to lesser extents than the original version. In sum, these findings shed light on the temporal dynamics of engagement during music listening and clarify specific aspects of musical engagement that may be indexed by each measure.


Asunto(s)
Percepción Auditiva , Electroencefalografía , Música , Humanos , Electroencefalografía/métodos , Masculino , Femenino , Adulto , Percepción Auditiva/fisiología , Adulto Joven , Estimulación Acústica/métodos , Encéfalo/fisiología
13.
Antimicrob Agents Chemother ; 68(9): e0004424, 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39046237

RESUMEN

The emergence and spread of chloroquine-resistant Plasmodium vivax have necessitated the assessment of alternative blood schizonticidal drugs. In Vietnam, chloroquine-resistant P. vivax malaria has been reported. In an open-label, single-arm trial, the safety, tolerability, and efficacy of pyronaridine-artesunate (Pyramax, PA) was evaluated in Dak Nong province, Vietnam. A 3-day course of PA was administered to adults and children (≥20 kg) infected with P. vivax. Patients also received primaquine (0.25 mg/kg daily for 14 days). PA was well tolerated with transient asymptomatic increases in liver transaminases. The per-protocol proportion of patients with day 42 PCR-unadjusted adequate clinical and parasitological response was 96.0% (95% CI, 84.9%-99.0%, n = 48/50). The median parasite clearance time was 12 h (range, 12-36 h), with a median fever clearance time of 24 h (range, 12-60 h). Single nucleotide polymorphisms (SNPs) as potential genetic markers of reduced drug susceptibility were analyzed in three putative drug resistance markers, Pvcrt-o, Pvmdr1, and PvK12. Insertion at position K10 of the Pvcrt-o gene was found in 74.6% (44/59) of isolates. Pvmdr1 SNPs at Y976F and F1076L were present in 61% (36/59) and 78% (46/59), respectively. Amplification of Pvmdr1 gene (two copies) was found in 5.1% (3/59) of parasite samples. Only 5.1% (3/59) of isolates had mutation 552I of the PvK12 gene. Overall, PA rapidly cleared P. vivax blood asexual stages and was highly efficacious in treating vivax malaria, with no evidence of artemisinin resistance found. PA provides an alternative to chloroquine treatment for vivax malaria in Vietnam. CLINICAL TRIALS: This study is registered with the Australian New Zealand Clinical Trials Registry as ACTRN12618001429246.


Asunto(s)
Antimaláricos , Artemisininas , Artesunato , Malaria Vivax , Naftiridinas , Plasmodium vivax , Humanos , Malaria Vivax/tratamiento farmacológico , Malaria Vivax/parasitología , Naftiridinas/uso terapéutico , Antimaláricos/uso terapéutico , Artesunato/uso terapéutico , Vietnam , Adulto , Plasmodium vivax/efectos de los fármacos , Plasmodium vivax/genética , Masculino , Artemisininas/uso terapéutico , Adolescente , Niño , Femenino , Persona de Mediana Edad , Adulto Joven , Primaquina/uso terapéutico , Polimorfismo de Nucleótido Simple/genética , Preescolar , Proteínas Protozoarias/genética , Resistencia a Medicamentos/genética , Proteínas de Transporte de Membrana
14.
J Clin Microbiol ; 62(4): e0128723, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38466092

RESUMEN

Mortality from tuberculous meningitis (TBM) remains around 30%, with most deaths occurring within 2 months of starting treatment. Mortality from drug-resistant strains is higher still, making early detection of drug resistance (DR) essential. Targeted next-generation sequencing (tNGS) produces high read depths, allowing the detection of DR-associated alleles with low frequencies. We applied Deeplex Myc-TB-a tNGS assay-to cerebrospinal fluid (CSF) samples from 72 adults with microbiologically confirmed TBM and compared its genomic drug susceptibility predictions to a composite reference standard of phenotypic susceptibility testing (pDST) and whole genome sequencing, as well as to clinical outcomes. Deeplex detected Mycobacterium tuberculosis complex DNA in 24/72 (33.3%) CSF samples and generated full DR reports for 22/24 (91.7%). The read depth generated by Deeplex correlated with semi-quantitative results from MTB/RIF Xpert. Alleles with <20% frequency were seen at canonical loci associated with first-line DR. Disregarding these low-frequency alleles, Deeplex had 100% concordance with the composite reference standard for all drugs except pyrazinamide and streptomycin. Three patients had positive CSF cultures after 30 days of treatment; reference tests and Deeplex identified isoniazid resistance in two, and Deeplex alone identified low-frequency rifampin resistance alleles in one. Five patients died, of whom one had pDST-identified pyrazinamide resistance. tNGS on CSF can rapidly and accurately detect drug-resistant TBM, but its application is limited to those with higher bacterial loads. In those with lower bacterial burdens, alternative approaches need to be developed for both diagnosis and resistance detection.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Meníngea , Tuberculosis Resistente a Múltiples Medicamentos , Adulto , Humanos , Tuberculosis Meníngea/diagnóstico , Tuberculosis Meníngea/tratamiento farmacológico , Tuberculosis Meníngea/líquido cefalorraquídeo , Mycobacterium tuberculosis/genética , Pirazinamida , Sensibilidad y Especificidad , Rifampin/farmacología , Rifampin/uso terapéutico , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Líquido Cefalorraquídeo , Pruebas de Sensibilidad Microbiana
15.
Microb Pathog ; 195: 106890, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39208960

RESUMEN

The toxicity of the contaminated powder contributed to toxic aflatoxins has been well-known in the literature. However, before this study, the specific fungal strain behind aflatoxin production remained unidentified. Our research aimed to isolate and identify fungi from the tainted sandwiches while also assessing the preservation of sandwiches in ambient conditions. The study pinpointed Aspergillus flavus as the fungus responsible for aflatoxin production. Analysis revealed that the sandwich samples contaminated with pure A. flavus exhibited a significant Aflatoxin B1 (AFB1) concentration of 55.2 ± 0.21 ng/g, accompanied by a spore count of 2 × 106 Colony-Forming Unit (CFU)/g after ten days. In contrast, sandwich samples contaminated with the unspecified fungi displayed a lower AFB1 content of 16.21 ± 0.42 ng/g, with a spore count of 2.2 × 102 CFU/g after the same duration. In the prevention study, the efficacy of the ethanol spray method for inhibiting aflatoxin from A. flavus was investigated. Results demonstrated that a 70 % ethanol concentration at a ratio of 2.0 % total weight of the sandwich proved highly effective, significantly impeding fungal growth. This method extended the preservation time by sevenfold compared to the control. Importantly, tests at 2.0 % ethanol of the sandwich weight did not detect aflatoxin presence.


Asunto(s)
Aflatoxina B1 , Aflatoxinas , Aspergillus flavus , Contaminación de Alimentos , Microbiología de Alimentos , Aspergillus flavus/metabolismo , Aspergillus flavus/crecimiento & desarrollo , Aflatoxina B1/metabolismo , Aflatoxina B1/análisis , Contaminación de Alimentos/análisis , Aflatoxinas/análisis , Aflatoxinas/metabolismo , Esporas Fúngicas/crecimiento & desarrollo , Etanol/metabolismo , Recuento de Colonia Microbiana , Hongos/metabolismo , Hongos/aislamiento & purificación , Hongos/efectos de los fármacos , Conservación de Alimentos/métodos
16.
Crit Rev Biotechnol ; 44(3): 477-494, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-36788704

RESUMEN

Plastic biodegradation has emerged as a sustainable approach and green alternative in handling the ever-increasing accumulation of plastic wastes in the environment. The complete biodegradation of polyethylene terephthalate is one of the most recent breakthroughs in the field of plastic biodegradation. Despite the success, the effective and complete biodegradation of a wide variety of plastics is still far from the practical implementation, and an on-going effort has been mainly devoted to the exploration of novel microorganisms and enzymes for plastic biodegradation. However, alternative strategies which enhance the existing biodegradation process should not be neglected in the continuous advancement of this field. Thus, this review highlights various strategies which have shown to improve the biodegradation of plastics, which include the pretreatment of plastics using UV irradiation, thermal, or chemical treatments to increase the susceptibility of plastics toward microbial action. Alternative pretreatment strategies are also suggested and compared with the existing techniques. Besides, the effects of additives such as pro-oxidants, natural polymers, and surfactants on plastic biodegradation are discussed. In addition, considerations governing the biodegradation performance, such as the formulation of biodegradation medium, cell-free biocatalysis, and physico-chemical properties of plastics, are addressed. Lastly, the challenges and future prospects for the advancement of plastic biodegradation are also highlighted.


Asunto(s)
Plásticos , Polímeros , Plásticos/química , Plásticos/metabolismo , Polímeros/metabolismo , Biodegradación Ambiental , Biocatálisis
17.
Neural Comput ; : 1-26, 2024 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-39312497

RESUMEN

In recent years, using orthogonal matrices has been shown to be a promising approach to improving recurrent neural networks (RNNs) with training, stability, and convergence, particularly to control gradients. While gated recurrent unit (GRU) and long short-term memory (LSTM) architectures address the vanishing gradient problem by using a variety of gates and memory cells, they are still prone to the exploding gradient problem. In this work, we analyze the gradients in GRU and propose the use of orthogonal matrices to prevent exploding gradient problems and enhance long-term memory. We study where to use orthogonal matrices and propose a Neumann series-based scaled Cayley transformation for training orthogonal matrices in GRU, which we call Neumann-Cayley orthogonal GRU (NC-GRU). We present detailed experiments of our model on several synthetic and real-world tasks, which show that NC-GRU significantly outperforms GRU and several other RNNs.

18.
Langmuir ; 40(43): 23033-23040, 2024 Oct 29.
Artículo en Inglés | MEDLINE | ID: mdl-39418218

RESUMEN

Inspired by iron gall ink (IGI), the Fe2+ ion is utilized for the continuous formation of Fe3+-tannic acid (TA) films through its in situ oxidation to the Fe3+ ion. Although several IGI-based strategies have been developed to meet different application requirements, there remains a need for the precise kinetic control for Fe2+ oxidation, along with one-step spatial controllability. This work demonstrates a visible light-induced method for oxidizing Fe2+ to Fe3+ ions, achieving the kinetic control over Fe3+-TA film formation. Photoexcitation of eosin Y leads to significantly accelerated film formation in a continuous manner, as shown by an 11-fold increase in film thickness compared with the air oxidation-based IGI method. Mechanistic studies reveal that the process is O2-dependent, and the kinetics of the film-forming process could be easily tuned by changing the light intensity or eosin Y concentration. Furthermore, the spatiotemporal controllability of the photoreaction allows for the pattern generation of Fe3+-TA complexes, proteins, and cells.

19.
Langmuir ; 40(26): 13573-13582, 2024 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-38885642

RESUMEN

Extensive removal of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) using titania (TiO2) nanoparticles by adsorption and photocatalysis with a surface coating by cetyltrimethylammonium bromide (CTAB) is reported. The CTAB-coated TiO2 nanoparticles (CCTN) were characterized by FT-IR, zeta-potential measurements, and UV-vis diffuse reflectance spectroscopy (UV-vis-DRS). 2,4,5-T removal increased significantly after surface modification with CTAB compared with bare TiO2 nanoparticles. Optimal parameters affecting 2,4,5-T removal were found to be pH 4, CCTN dosage 10 mg/mL, and adsorption time 180 min. The maximum adsorptive removal of 2,4,5-T using CCTN reached 96.2% while highest adsorption capacity was 13.4 mg/g. CCTN was also found to be an excellent photocatalyst that achieved degradation efficiency of 99.2% with an initial concentration of 25 mg/L. The removal mechanisms of 2,4,5-T using CCTN by both adsorption and photocatalysis are discussed in detail based on changes in functional group vibrations and surface charge. Our results indicate that CCTN is an excellent material for 2,4,5-T removal in water by both adsorption and photocatalysis.

20.
Pediatr Res ; 2024 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-38762663

RESUMEN

BACKGROUND: Preterm birth disrupts fetal kidney development, potentially leading to postnatal acute kidney injury. Preterm infants are deficient in insulin-like growth factor 1 (IGF-1), a growth factor that stimulates organ development. By utilizing a preterm pig model, this study investigated whether IGF-1 supplementation enhances preterm kidney maturation. METHODS: Cesarean-delivered preterm pigs were treated systemically IGF-1 or vehicle control for 5, 9 or 19 days after birth. Blood, urine, and kidney tissue were collected for biochemical, histological and gene expression analyses. Age-matched term-born pigs were sacrificed at similar postnatal ages and served as the reference group. RESULTS: Compared with term pigs, preterm pigs exhibited impaired kidney maturation, as indicated by analyses of renal morphology, histopathology, and inflammatory and injury markers. Supplementation with IGF-1 reduced signs of kidney immaturity, particularly in the first week of life, as indicated by improved morphology, upregulated expression of key developmental genes, reduced severity and incidence of microscopic lesions, and decreased levels of inflammatory and injury markers. No association was seen between the symptoms of necrotizing enterocolitis and kidney defects. CONCLUSION: Preterm birth in pigs impairs kidney maturation and exogenous IGF-1 treatment partially reverses this impairment. Early IGF-1 supplementation could support the development of preterm kidneys. IMPACT: Preterm birth may disrupt kidney development in newborns, potentially leading to morphological changes, injury, and inflammation. Preterm pigs have previously been used as models for preterm infants, but not for kidney development. IGF-1 supplementation promotes kidney maturation and alleviates renal impairments in the first week of life in preterm pigs. IGF-1 may hold potential as a supportive therapy for preterm infants sensitive to acute kidney injury.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA