Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 160
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
PLoS Genet ; 20(7): e1011344, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-39074161

RESUMEN

Deciphering the evolutionary forces controlling insecticide resistance in malaria vectors remains a prerequisite to designing molecular tools to detect and assess resistance impact on control tools. Here, we demonstrate that a 4.3kb transposon-containing structural variation is associated with pyrethroid resistance in central/eastern African populations of the malaria vector Anopheles funestus. In this study, we analysed Pooled template sequencing data and direct sequencing to identify an insertion of 4.3kb containing a putative retro-transposon in the intergenic region of two P450s CYP6P5-CYP6P9b in mosquitoes of the malaria vector Anopheles funestus from Uganda. We then designed a PCR assay to track its spread temporally and regionally and decipher its role in insecticide resistance. The insertion originates in or near Uganda in East Africa, where it is fixed and has spread to high frequencies in the Central African nation of Cameroon but is still at low frequency in West Africa and absent in Southern Africa. A marked and rapid selection was observed with the 4.3kb-SV frequency increasing from 3% in 2014 to 98% in 2021 in Cameroon. A strong association was established between this SV and pyrethroid resistance in field populations and is reducing pyrethroid-only nets' efficacy. Genetic crosses and qRT-PCR revealed that this SV enhances the expression of CYP6P9a/b but not CYP6P5. Within this structural variant (SV), we identified putative binding sites for transcription factors associated with the regulation of detoxification genes. An inverse correlation was observed between the 4.3kb SV and malaria parasite infection, indicating that mosquitoes lacking the 4.3kb SV were more frequently infected compared to those possessing it. Our findings highlight the underexplored role and rapid spread of SVs in the evolution of insecticide resistance and provide additional tools for molecular surveillance of insecticide resistance.


Asunto(s)
Anopheles , Sistema Enzimático del Citocromo P-450 , Elementos Transponibles de ADN , Resistencia a los Insecticidas , Insecticidas , Malaria , Mosquitos Vectores , Piretrinas , Animales , Anopheles/genética , Anopheles/parasitología , Anopheles/efectos de los fármacos , Piretrinas/farmacología , Resistencia a los Insecticidas/genética , Mosquitos Vectores/genética , Mosquitos Vectores/parasitología , Mosquitos Vectores/efectos de los fármacos , Malaria/transmisión , Malaria/parasitología , Malaria/genética , Elementos Transponibles de ADN/genética , Sistema Enzimático del Citocromo P-450/genética , Insecticidas/farmacología , Uganda , Humanos , Camerún
2.
PLoS Genet ; 19(3): e1010678, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36972302

RESUMEN

Cross-resistance to insecticides in multiple resistant malaria vectors is hampering resistance management. Understanding its underlying molecular basis is critical to implementation of suitable insecticide-based interventions. Here, we established that the tandemly duplicated cytochrome P450s, CYP6P9a/b are driving carbamate and pyrethroid cross-resistance in Southern African populations of the major malaria vector Anopheles funestus. Transcriptome sequencing revealed that cytochrome P450s are the most over-expressed genes in bendiocarb and permethrin-resistant An. funestus. The CYP6P9a and CYP6P9b genes are overexpressed in resistant An. funestus from Southern Africa (Malawi) versus susceptible An. funestus (Fold change (FC) is 53.4 and 17 respectively), while the CYP6P4a and CYP6P4b genes are overexpressed in resistant An. funestus in Ghana, West Africa, (FC is 41.1 and 17.2 respectively). Other up-regulated genes in resistant An. funestus include several additional cytochrome P450s (e.g. CYP9J5, CYP6P2, CYP6P5), glutathione-S transferases, ATP-binding cassette transporters, digestive enzymes, microRNA and transcription factors (FC<7). Targeted enrichment sequencing strongly linked a known major pyrethroid resistance locus (rp1) to carbamate resistance centering around CYP6P9a/b. In bendiocarb resistant An. funestus, this locus exhibits a reduced nucleotide diversity, significant p-values when comparing allele frequencies, and the most non-synonymous substitutions. Recombinant enzyme metabolism assays showed that both CYP6P9a/b metabolize carbamates. Transgenic expression of CYP6P9a/b in Drosophila melanogaster revealed that flies expressing both genes were significantly more resistant to carbamates than controls. Furthermore, a strong correlation was observed between carbamate resistance and CYP6P9a genotypes with homozygote resistant An. funestus (CYP6P9a and the 6.5kb enhancer structural variant) exhibiting a greater ability to withstand bendiocarb/propoxur exposure than homozygote CYP6P9a_susceptible (e.g Odds ratio = 20.8, P<0.0001 for bendiocarb) and heterozygotes (OR = 9.7, P<0.0001). Double homozygote resistant genotype (RR/RR) were even more able to survive than any other genotype combination showing an additive effect. This study highlights the risk that pyrethroid resistance escalation poses to the efficacy of other classes of insecticides. Available metabolic resistance DNA-based diagnostic assays should be used by control programs to monitor cross-resistance between insecticides before implementing new interventions.


Asunto(s)
Anopheles , Insecticidas , Malaria , Piretrinas , Animales , Insecticidas/farmacología , Carbamatos/metabolismo , Piretrinas/metabolismo , Anopheles/genética , Drosophila melanogaster , Resistencia a los Insecticidas/genética , Mosquitos Vectores/genética , Citocromos/metabolismo , Ghana
3.
Genomics ; 116(2): 110798, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38266739

RESUMEN

UDP-glycosyltransferases (UGTs) enzymes are pivotal in insecticide resistance by transforming hydrophobic substrates into more hydrophilic forms for efficient cell elimination. This study provides the first comprehensive investigation of Anopheles funestus UGT genes, their evolution, and their association with pyrethroid resistance. We employed a genome-wide association study using pooled sequencing (GWAS-PoolSeq) and transcriptomics on pyrethroid-resistant An. funestus, along with deep-targeted sequencing of UGTs in 80 mosquitoes Africa-wide. UGT310B2 was consistently overexpressed Africa-wide and significant gene-wise Fst differentiation was observed between resistant and susceptible populations: UGT301C2 and UGT302A3 in Malawi, and UGT306C2 in Uganda. Additionally, nonsynonymous mutations in UGT genes were identified. Gene-wise Tajima's D density curves provide insights into population structures within populations across these countries, supporting previous observations. These findings have important implications for current An. funestus control strategies facilitating the prediction of cross-resistance to other UGT-metabolised polar insecticides, thereby guiding more effective and targeted insecticide resistance management efforts.


Asunto(s)
Anopheles , Insecticidas , Piretrinas , Animales , Anopheles/genética , Glicosiltransferasas/genética , Estudio de Asociación del Genoma Completo , Insecticidas/farmacología , Piretrinas/farmacología , Mutación , Resistencia a los Insecticidas/genética
4.
Pediatr Blood Cancer ; 71(7): e31041, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38715224

RESUMEN

International and national oncofertility networks, including the US-led Oncofertility Consortium, FertiProtekt, and the Danish Network, have played pivotal roles in advancing the discipline of oncofertility over the last decade. Many other countries lack a shared approach to pediatric oncofertility health service delivery. This study aims to describe baseline oncofertility practices at Australian New Zealand Children's Haematology/Oncology Group centers in 2019-2021, describe binational priorities for care, and propose a 5-year action plan for best practice to be implemented by the newly formed Australian New Zealand Consortium in Children, Adolescents, and Young Adults (CAYA) Oncofertility (ANZCO).


Asunto(s)
Preservación de la Fertilidad , Neoplasias , Humanos , Adolescente , Nueva Zelanda , Preservación de la Fertilidad/métodos , Niño , Neoplasias/terapia , Neoplasias/complicaciones , Adulto Joven , Femenino , Australia , Masculino , Adulto
5.
BMC Biol ; 21(1): 125, 2023 05 24.
Artículo en Inglés | MEDLINE | ID: mdl-37226196

RESUMEN

BACKGROUND: Information on common markers of metabolic resistance in malaria vectors from countries sharing similar eco-climatic characteristics can facilitate coordination of malaria control. Here, we characterized populations of the major malaria vector Anopheles coluzzii from Sahel region, spanning four sub-Saharan African countries: Nigeria, Niger, Chad and Cameroon. RESULTS: Genome-wide transcriptional analysis identified major genes previously implicated in pyrethroid and/or cross-resistance to other insecticides, overexpressed across the Sahel, including CYP450s, glutathione S-transferases, carboxylesterases and cuticular proteins. Several, well-known markers of insecticide resistance were found in high frequencies-including in the voltage-gated sodium channel (V402L, I940T, L995F, I1527T and N1570Y), the acetylcholinesterase-1 gene (G280S) and the CYP4J5-L43F (which is fixed). High frequencies of the epidemiologically important chromosomal inversion polymorphisms, 2La, 2Rb and 2Rc, were observed (~80% for 2Rb and 2Rc). The 2La alternative arrangement is fixed across the Sahel. Low frequencies of these inversions (<10%) were observed in the fully insecticide susceptible laboratory colony of An. coluzzii (Ngoussou). Several of the most commonly overexpressed metabolic resistance genes sit in these three inversions. Two commonly overexpressed genes, GSTe2 and CYP6Z2, were functionally validated. Transgenic Drosophila melanogaster flies expressing GSTe2 exhibited extremely high DDT and permethrin resistance (mortalities <10% in 24h). Serial deletion of the 5' intergenic region, to identify putative nucleotide(s) associated with GSTe2 overexpression, revealed that simultaneous insertion of adenine nucleotide and a transition (T->C), between Forkhead box L1 and c-EST putative binding sites, were responsible for the high overexpression of GSTe2 in the resistant mosquitoes. Transgenic flies expressing CYP6Z2 exhibited marginal resistance towards 3-phenoxybenzylalcohol (a primary product of pyrethroid hydrolysis by carboxylesterases) and a type II pyrethroid, α-cypermethrin. However, significantly higher mortalities were observed in CYP6Z2 transgenic flies compared with controls, on exposure to the neonicotinoid, clothianidin. This suggests a possible bioactivation of clothianidin into a toxic intermediate, which may make it an ideal insecticide against populations of An. coluzzii overexpressing this P450. CONCLUSIONS: These findings will facilitate regional collaborations within the Sahel region and refine implementation strategies through re-focusing interventions, improving evidence-based, cross-border policies towards local and regional malaria pre-elimination.


Asunto(s)
Anopheles , Insecticidas , Malaria , Animales , Anopheles/genética , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , Acetilcolinesterasa/genética , Drosophila melanogaster , Malaria/prevención & control , Mosquitos Vectores/genética , Permetrina , Animales Modificados Genéticamente
6.
Int J Mol Sci ; 25(15)2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-39125661

RESUMEN

The versatility of cytochrome P450 reductase (CPR) in transferring electrons to P450s from other closely related species has been extensively exploited, e.g., by using An. gambiae CPR (AgCPR), as a homologous surrogate, to validate the role of An. funestus P450s in insecticide resistance. However, genomic variation between the AgCPR and An. funestus CPR (AfCPR) suggests that the full metabolism spectrum of An. funestus P450s might be missed when using AgCPR. To test this hypothesis, we expressed AgCPR and AfCPR side-by-side with CYP6P9a and CYP6P9b and functionally validated their role in the detoxification of insecticides from five different classes. Major variations were observed within the FAD- and NADP-binding domains of AgCPR and AfCPR, e.g., the coordinates of the second FAD stacking residue AfCPR-Y456 differ from that of AgCPR-His456. While no significant differences were observed in the cytochrome c reductase activities, when co-expressed with their endogenous AfCPR, the P450s significantly metabolized higher amounts of permethrin and deltamethrin, with CYP6P9b-AfCPR membrane metabolizing α-cypermethrin as well. Only the CYP6P9a-AfCPR membrane significantly metabolized DDT (producing dicofol), bendiocarb, clothianidin, and chlorfenapyr (bioactivation into tralopyril). This demonstrates the broad substrate specificity of An. funestus CYP6P9a/-b, capturing their role in conferring cross-resistance towards unrelated insecticide classes, which can complicate resistance management.


Asunto(s)
Anopheles , Resistencia a los Insecticidas , Insecticidas , NADPH-Ferrihemoproteína Reductasa , Piretrinas , Anopheles/genética , Anopheles/efectos de los fármacos , Anopheles/enzimología , Anopheles/metabolismo , Animales , Resistencia a los Insecticidas/genética , NADPH-Ferrihemoproteína Reductasa/metabolismo , NADPH-Ferrihemoproteína Reductasa/genética , Insecticidas/farmacología , Insecticidas/metabolismo , Piretrinas/farmacología , Piretrinas/metabolismo , Oxidación-Reducción , Proteínas de Insectos/metabolismo , Proteínas de Insectos/genética , Sistema Enzimático del Citocromo P-450/metabolismo , Sistema Enzimático del Citocromo P-450/genética , Especificidad por Sustrato , Nitrilos/metabolismo , Nitrilos/farmacología , Permetrina/farmacología
7.
Basic Res Cardiol ; 118(1): 39, 2023 09 29.
Artículo en Inglés | MEDLINE | ID: mdl-37775647

RESUMEN

Giant mitochondria are frequently observed in different disease models within the brain, kidney, and liver. In cardiac muscle, these enlarged organelles are present across diverse physiological and pathophysiological conditions including in ageing and exercise, and clinically in alcohol-induced heart disease and various cardiomyopathies. This mitochondrial aberration is widely considered an early structural hallmark of disease leading to adverse organ function. In this thematic paper, we discuss the current state-of-knowledge on the presence, structure and functional implications of giant mitochondria in heart muscle. Despite its demonstrated reoccurrence in different heart diseases, the literature on this pathophysiological phenomenon remains relatively sparse since its initial observations in the early 60s. We review historical and contemporary investigations from cultured cardiomyocytes to human tissue samples to address the role of giant mitochondria in cardiac health and disease. Finally, we discuss their significance for the future development of novel mitochondria-targeted therapies to improve cardiac metabolism and functionality.


Asunto(s)
Cardiomiopatías , Miocitos Cardíacos , Humanos , Miocitos Cardíacos/metabolismo , Dilatación Mitocondrial , Mitocondrias/metabolismo , Miocardio/metabolismo , Mitocondrias Cardíacas/metabolismo
8.
PLoS Genet ; 16(6): e1008822, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32497040

RESUMEN

Insecticide resistance in malaria vectors threatens to reverse recent gains in malaria control. Deciphering patterns of gene flow and resistance evolution in malaria vectors is crucial to improving control strategies and preventing malaria resurgence. A genome-wide survey of Anopheles funestus genetic diversity Africa-wide revealed evidences of a major division between southern Africa and elsewhere, associated with different population histories. Three genomic regions exhibited strong signatures of selective sweeps, each spanning major resistance loci (CYP6P9a/b, GSTe2 and CYP9K1). However, a sharp regional contrast was observed between populations correlating with gene flow barriers. Signatures of complex molecular evolution of resistance were detected with evidence of copy number variation, transposon insertion and a gene conversion between CYP6P9a/b paralog genes. Temporal analyses of samples before and after bed net scale up suggest that these genomic changes are driven by this control intervention. Multiple independent selective sweeps at the same locus in different parts of Africa suggests that local evolution of resistance in malaria vectors may be a greater threat than trans-regional spread of resistance haplotypes.


Asunto(s)
Anopheles/genética , Evolución Molecular , Genoma de los Insectos/genética , Resistencia a los Insecticidas/genética , Malaria/prevención & control , Mosquitos Vectores/genética , África , Alelos , Animales , Anopheles/parasitología , Familia 6 del Citocromo P450/genética , Variaciones en el Número de Copia de ADN , Elementos Transponibles de ADN/genética , Flujo Génico , Sitios Genéticos , Haplotipos , Humanos , Proteínas de Insectos/genética , Malaria/parasitología , Malaria/transmisión , Metagenómica , Control de Mosquitos/métodos , Polimorfismo Genético , Piretrinas , Secuenciación Completa del Genoma
9.
Int J Mol Sci ; 24(20)2023 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-37894788

RESUMEN

Microbial resistance to antibiotics poses a tremendous challenge. Bacteriophages may provide a useful alternative or adjunct to traditional antibiotics. To be used in therapy, bacteriophages need to be purified from endotoxins and tested for their effects on human immune cells. Interleukin-1 Receptor Associated Kinase-3 (IRAK3) is a negative regulator of inflammation and may play a role in the modulation of immune signalling upon bacteriophage exposure to immune cells. This study aimed to investigate the immune effects of crude and purified bacteriophage FNU1, a bacteriophage that targets the oral pathobiont Fusobacterium nucleatum, on wildtype and IRAK3 knockout THP-1 monocytic cell lines. The IRAK3 knockout cell line was also used to develop a novel endotoxin detection assay. Exposure to crude FNU1 increased the production of pro-inflammatory cytokines (Tumour necrosis factor - alpha (TNF-α) and Interleukin 6 (IL-6)) compared to purified FNU1 in wildtype and IRAK3 knockout THP-1 monocytes. In the IRAK3 knockout THP-1 cells, exposure to crude FNU1 induced a higher immune response than the wildtype monocytes, supporting the suggestion that the inhibitory protein IRAK3 regulates reactions to endotoxins and impurities in bacteriophage preparations. Finally, the novel endotoxin detection assay generated here provides a robust and accurate method for determining endotoxin concentrations.


Asunto(s)
Bacteriófagos , Citocinas , Humanos , Citocinas/metabolismo , Monocitos/metabolismo , Fusobacterium nucleatum/metabolismo , Endotoxinas/metabolismo , Bacteriófagos/genética , Bacteriófagos/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Antibacterianos/metabolismo , Quinasas Asociadas a Receptores de Interleucina-1/genética , Quinasas Asociadas a Receptores de Interleucina-1/metabolismo
10.
Int J Mol Sci ; 24(10)2023 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-37239919

RESUMEN

Interleukin-1 receptor-associated kinase 3 (IRAK3) modulates the magnitude of cellular responses to ligands perceived by interleukin-1 receptors (IL-1Rs) and Toll-like receptors (TLRs), leading to decreases in pro-inflammatory cytokines and suppressed inflammation. The molecular mechanism of IRAK3's action remains unknown. IRAK3 functions as a guanylate cyclase, and its cGMP product suppresses lipopolysaccharide (LPS)-induced nuclear factor kappa-light-chain-enhancer of activated B cell (NFκB) activity. To understand the implications of this phenomenon, we expanded the structure-function analyses of IRAK3 through site-directed mutagenesis of amino acids known or predicted to impact different activities of IRAK3. We verified the capacity of the mutated IRAK3 variants to generate cGMP in vitro and revealed residues in and in the vicinity of its GC catalytic center that impact the LPS-induced NFκB activity in immortalized cell lines in the absence or presence of an exogenous membrane-permeable cGMP analog. Mutant IRAK3 variants with reduced cGMP generating capacity and differential regulation of NFκB activity influence subcellular localization of IRAK3 in HEK293T cells and fail to rescue IRAK3 function in IRAK3 knock-out THP-1 monocytes stimulated with LPS unless the cGMP analog is present. Together, our results shed new light on the mechanism by which IRAK3 and its enzymatic product control the downstream signaling, affecting inflammatory responses in immortalized cell lines.


Asunto(s)
Guanilato Ciclasa , Quinasas Asociadas a Receptores de Interleucina-1 , Humanos , Guanilato Ciclasa/metabolismo , Quinasas Asociadas a Receptores de Interleucina-1/genética , Quinasas Asociadas a Receptores de Interleucina-1/metabolismo , Lipopolisacáridos/farmacología , Células HEK293 , Mutación , FN-kappa B/genética
11.
Int J Mol Sci ; 24(9)2023 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-37176009

RESUMEN

The 5-hydroxytryptamine 3 (5-HT3) receptor belongs to the pentameric ligand-gated cation channel superfamily. Humans have five different 5-HT3 receptor subunits: A to E. The 5-HT3 receptors are located on the cell membrane, but a previous study suggested that mitochondria could also contain A subunits. In this article, we explored the distribution of 5-HT3 receptor subunits in intracellular and cell-free mitochondria. Organelle prediction software supported the localization of the A and E subunits on the inner membrane of the mitochondria. We transiently transfected HEK293T cells that do not natively express the 5-HT3 receptor with an epitope and fluorescent protein-tagged 5HT3A and 5HT3E subunits. Fluorescence microscopy and cell fractionation indicated that both subunits, A and E, localized to the mitochondria, while transmission electron microscopy revealed the location of the subunits on the mitochondrial inner membrane, where they could form heteromeric complexes. Cell-free mitochondria isolated from cell culture media colocalized with the fluorescent signal for A subunits. The presence of A and E subunits influenced changes in the membrane potential and mitochondrial oxygen consumption rates upon exposure to serotonin; this was inhibited by pre-treatment with ondansetron. Therefore, it is likely that the 5-HT3 receptors present on mitochondria directly impact mitochondrial function and that this may have therapeutic implications.


Asunto(s)
Receptores de Serotonina 5-HT3 , Serotonina , Humanos , Serotonina/metabolismo , Receptores de Serotonina 5-HT3/genética , Receptores de Serotonina 5-HT3/metabolismo , Células HEK293 , Ondansetrón/farmacología , Mitocondrias/metabolismo
12.
Mol Ecol ; 31(13): 3642-3657, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35546741

RESUMEN

Metabolic resistance to pyrethroids is a menace to the continued effectiveness of malaria vector controls. Its molecular basis is complex and varies geographically across Africa. Here, we used a multi-omics approach, followed-up with functional validation to show that a directionally selected haplotype of a cytochrome P450, CYP9K1 is a major driver of resistance in Anopheles funestus. A PoolSeq GWAS using mosquitoes alive and dead after permethrin exposure, from Malawi and Cameroon, detected candidate genomic regions, but lacked consistency across replicates. Targeted sequencing of candidate resistance genes detected several SNPs associated with known pyrethroid resistance QTLs. The most significant SNPs were in the cytochrome P450 CYP304B1 (Cameroon), CYP315A1 (Uganda) and the ABC transporter gene ABCG4 (Malawi). However, when comparing field resistant mosquitoes to laboratory susceptible, the pyrethroid resistance locus rp1 and SNPs around the ABC transporter ABCG4 were consistently significant, except for Uganda where SNPs in the P450 CYP9K1 was markedly significant. In vitro heterologous metabolism assays with recombinant CYP9K1 revealed that it metabolises type II pyrethroid (deltamethrin; 64% depletion) but not type I (permethrin; 0%), while moderately metabolising DDT (17%). CYP9K1 exhibited reduced genetic diversity in Uganda underlying an extensive selective sweep. Furthermore, a glycine to alanine (G454A) amino acid change in CYP9K1 was fixed in Ugandan mosquitoes but not in other An. funestus populations. This study sheds further light on the evolution of metabolic resistance in a major malaria vector by implicating more genes and variants that can be used to design field-applicable markers to better track resistance Africa-wide.


Asunto(s)
Anopheles , Insecticidas , Malaria , Piretrinas , Transportadoras de Casetes de Unión a ATP/genética , Transportadoras de Casetes de Unión a ATP/metabolismo , Animales , Anopheles/genética , Sistema Enzimático del Citocromo P-450/genética , Haplotipos/genética , Resistencia a los Insecticidas/genética , Insecticidas/farmacología , Malaria/genética , Mosquitos Vectores/genética , Permetrina/metabolismo , Permetrina/farmacología , Piretrinas/farmacología , Uganda
13.
Pediatr Blood Cancer ; 69(6): e29621, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35293690

RESUMEN

OBJECTIVE: To synthesize existing qualitative research exploring the experiences of parents caring for children with cancer during the end-of-life phase, and the factors that influence parental decision-making when choosing the location of end-of-life care and death for their child. RESULTS: This review included 15 studies of 460 parents of 333 children and adolescents who died from progressive cancer. Where reported, the majority (58%) of children died at home or in a hospital (39%), with only a small fraction dying in a hospice. Factors impacting decision-making for the location of care included the quality of communication and the quality of care available. Themes related to choosing home for end-of-life care and death included honoring the child's wishes, the familiarity of home, and parents' desire to be their child's primary carer. Preference for the location of death in the hospital included trust in hospital staff, practical logistics, and the safety of the hospital environment.


Asunto(s)
Cuidados Paliativos al Final de la Vida , Neoplasias , Cuidado Terminal , Adolescente , Niño , Familia , Humanos , Neoplasias/terapia , Padres
14.
Pestic Biochem Physiol ; 183: 105061, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35430064

RESUMEN

Pyrethroid resistance in the malaria vector Anopheles albimanus presents an obstacle to malaria elimination in the Americas. Here, An. albimanus CYP6P5 (the most overexpressed P450 in a Peruvian population) was functionally characterized. Recombinant CYP6P5 metabolized the type II pyrethroids, deltamethrin and α-cypermethrin with comparable affinities (KM of 3.3 µM ± 0.4 and 3.6 µM ± 0.5, respectively), but exhibited a 2.7-fold higher catalytic rate for α-cypermethrin (kcat of 6.02 min-1 ± 0.2) versus deltamethrin (2.68 min-1 ± 0.09). Time-course assays revealed progressive depletion of the above pyrethroids with production of four HPLC-detectable metabolites. Low depletion was obtained with type I pyrethroid, permethrin. Transgenic expression in Drosophila melanogaster demonstrated that overexpression of CYP6P5 alone conferred type II pyrethroid resistance, with only 16% and 55.3% mortalities in flies exposed to 0.25% α-cypermethrin and 0.15% deltamethrin, respectively. Synergist bioassays using P450 inhibitor piperonylbutoxide significantly recovered susceptibility (mortality = 73.6%, p < 0.001) in synergized flies exposed to 4% piperonylbutoxide, plus 0.25% α-cypermethrin, compared to non-synergized flies (mortality = 4.9%). Moderate resistance was also observed towards 4% DDT. These findings established the preeminent role of CYP6P5 in metabolic resistance in An. albimanus, highlighting challenges associated with deployment of insecticide-based control tools in the Americas.


Asunto(s)
Anopheles , Insecticidas , Malaria , Piretrinas , Animales , Anopheles/genética , Sistema Enzimático del Citocromo P-450/genética , Sistema Enzimático del Citocromo P-450/metabolismo , Drosophila melanogaster/metabolismo , Resistencia a los Insecticidas/genética , Insecticidas/metabolismo , Insecticidas/farmacología , Control de Mosquitos , Mosquitos Vectores/genética , Piretrinas/metabolismo , Piretrinas/farmacología
15.
Int J Mol Sci ; 23(5)2022 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-35269704

RESUMEN

Interleukin-1 receptor-associated kinase-3 (IRAK3) is a critical checkpoint molecule of inflammatory responses in the innate immune system. The pseudokinase domain of IRAK3 contains a guanylate cyclase (GC) centre that generates small amounts of cyclic guanosine monophosphate (cGMP) associated with IRAK3 functions in inflammation. However, the mechanisms of IRAK3 actions are poorly understood. The effects of low cGMP levels on inflammation are unknown, therefore a dose-response effect of cGMP on inflammatory markers was assessed in THP-1 monocytes challenged with lipopolysaccharide (LPS). Sub-nanomolar concentrations of membrane permeable 8-Br-cGMP reduced LPS-induced NFκB activity, IL-6 and TNF-α cytokine levels. Pharmacologically upregulating cellular cGMP levels using a nitric oxide donor reduced cytokine secretion. Downregulating cellular cGMP using a soluble GC inhibitor increased cytokine levels. Knocking down IRAK3 in THP-1 cells revealed that unlike the wild type cells, 8-Br-cGMP did not suppress inflammatory responses. Complementation of IRAK3 knockdown cells with wild type IRAK3 suppressed cytokine production while complementation with an IRAK3 mutant at GC centre only partially restored this function. Together these findings indicate low levels of cGMP form a critical component in suppressing cytokine production and in mediating IRAK3 action, and this may be via a cGMP enriched nanodomain formed by IRAK3 itself.


Asunto(s)
Quinasas Asociadas a Receptores de Interleucina-1 , Monocitos , GMP Cíclico , Citocinas , Guanilato Ciclasa , Humanos , Inflamación , Quinasas Asociadas a Receptores de Interleucina-1/genética , Lipopolisacáridos , Óxido Nítrico
16.
BMC Cancer ; 21(1): 438, 2021 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-33879127

RESUMEN

BACKGROUND: Daunorubicin is used clinically in the treatment of myeloma, acute lymphatic and myelocytic leukaemia. The toxic lesions caused by daunorubicin induce various modes of cell death, including apoptosis. Apoptosis is highly regulated programmed cell death that can be initiated mainly via two pathways, through death receptors (extrinsic) or involvement of the mitochondria (intrinsic). Induction of apoptosis via these pathways has been alluded following treatment with daunorubicin, but never compared in acute lymphoblastic leukaemia over a time course. METHODS: This study investigated the mechanisms of daunorubicin induced apoptosis in the treatment of CCRF-CEM, MOLT-4 (acute T-lymphoblastic leukaemia) and SUP-B15 (acute B-lymphoblastic leukaemia) cells. Cells were treated with daunorubicin for 4 h, and then placed in recovery medium (without daunorubicin) for 4 h, 12 h and 24 h. Apoptotic response was analysing using annexin-V expression, caspase activity, mitochondrial membrane potential change and an array to detect 43 apoptotic proteins. RESULTS: Daunorubicin induced apoptosis in all leukemic cell lines, but with different levels and duration of response. Both apoptosis levels and caspase activity increased after four hours recovery then declined in CCRF-CEM and MOLT-4 cells. However, SUP-B15 cells displayed initially comparable levels but remained elevated over the 24 h assessment period. Changes in mitochondrial membrane potential occurred in both MOLT-4 and CCRF-CEM cells but not in SUP-B15 cells. Expression of apoptotic proteins, including Bcl-2, Bax, caspase 3 and FADD, indicated that daunorubicin potentially induced both extrinsic and intrinsic apoptosis in both CCRF-CEM and MOLT-4 cells, but only extrinsic apoptosis in SUP-B15 cells. CONCLUSIONS: This study describes variations in sensitivities and timing of apoptotic responses in different leukaemia cell lines. These differences could be attributed to the lack of functional p53 in coordinating the cells response following cytotoxic treatment with daunorubicin, which appears to delay apoptosis and utilises alternative signalling mechanisms that need to be further explored.


Asunto(s)
Antibióticos Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Daunorrubicina/farmacología , Anexina A5/genética , Anexina A5/metabolismo , Antibióticos Antineoplásicos/uso terapéutico , Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/genética , Proteínas Reguladoras de la Apoptosis/metabolismo , Caspasas/metabolismo , Línea Celular Tumoral , Daunorrubicina/uso terapéutico , Humanos , Leucemia/tratamiento farmacológico , Leucemia/genética , Leucemia/metabolismo , Potencial de la Membrana Mitocondrial/efectos de los fármacos
17.
J Med Ethics ; 2021 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-33431646

RESUMEN

Ethical climate (EC) has been broadly described as how well institutions respond to ethical issues. Developing a tool to study and evaluate EC that aims to achieve sustained improvements requires a contemporary framework with identified relevant drivers. An extensive literature review was performed, reviewing existing EC definitions, tools and areas where EC has been studied; ethical challenges and relevance of EC in contemporary paediatric intensive care (PIC); and relevant ethical theories. We surmised that existing EC definitions and tools designed to measure it fail to capture nuances of the PIC environment, and sought to address existing gaps by developing an EC framework for PIC founded on ethical theory. In this article, we propose a Paediatric Intensive Care Ethical Climate (PICEC) conceptual framework and four measurable domains to be captured by an assessment tool. We define PICEC as the collective felt experience of interdisciplinary team members arising from those factors that enable or constrain their ability to navigate ethical aspects of their work. PICEC both results from and is influenced by how well ethical issues are understood, identified, explored, reflected on, responded to and addressed in the workplace. PICEC encompasses four, core inter-related domains representing drivers of EC including: (1) organisational culture and leadership; (2) interdisciplinary team relationships and dynamics; (3) integrated child and family-centred care; and (4) ethics literacy. Future directions involve developing a PICEC measurement tool, with implications for benchmarking as well as guidance for, and evaluation of, targeted interventions to foster a healthy EC.

18.
Int J Mol Sci ; 22(3)2021 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-33573037

RESUMEN

Plants as sessile organisms face daily environmental challenges and have developed highly nuanced signaling systems to enable suitable growth, development, defense, or stalling responses. Moonlighting proteins have multiple tasks and contribute to cellular signaling cascades where they produce additional variables adding to the complexity or fuzziness of biological systems. Here we examine roles of moonlighting kinases that also generate 3',5'-cyclic guanosine monophosphate (cGMP) in plants. These proteins include receptor like kinases and lipid kinases. Their guanylate cyclase activity potentiates the development of localized cGMP-enriched nanodomains or niches surrounding the kinase and its interactome. These nanodomains contribute to allosteric regulation of kinase and other molecules in the immediate complex directly or indirectly modulating signal cascades. Effects include downregulation of kinase activity, modulation of other members of the protein complexes such as cyclic nucleotide gated channels and potential triggering of cGMP-dependent degradation cascades terminating signaling. The additional layers of information provided by the moonlighting kinases are discussed in terms of how they may be used to provide a layer of fuzziness to effectively modulate cellular signaling cascades.


Asunto(s)
GMP Cíclico/metabolismo , Proteínas de Plantas/metabolismo , Plantas/metabolismo , Proteínas Quinasas/metabolismo , Transducción de Señal , Guanilato Ciclasa/química , Guanilato Ciclasa/metabolismo , Modelos Moleculares , Proteínas de Plantas/química , Plantas/química , Proteínas Quinasas/química , Proteolisis
19.
Int J Mol Sci ; 22(21)2021 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-34769340

RESUMEN

5-hydroxytryptamine type 3 (5-HT3) receptors are ligand gated ion channels, which clearly distinguish their mode of action from the other G-protein coupled 5-HT or serotonin receptors. 5-HT3 receptors are well established targets for emesis and gastrointestinal mobility and are used as adjunct targets in treating schizophrenia. However, the distribution of these receptors is wider than the nervous system and there is potential that these additional sites can be targeted to modulate inflammatory and/or metabolic conditions. Recent progress in structural biology and pharmacology of 5-HT3 receptors have provided profound insights into mechanisms of their action. These advances, combined with insights into clinical relevance of mutations in genes encoding 5-HT3 subunits and increasing understanding of their implications in patient's predisposition to diseases and response to the treatment, open new avenues for personalized precision medicine. In this review, we recap on the current status of 5-HT3 receptor-based therapies using a biochemical and physiological perspective. We assess the potential for targeting 5-HT3 receptors in conditions involving metabolic or inflammatory disorders based on recent findings, underscoring the challenges and limitations of this approach.


Asunto(s)
Inmunidad/inmunología , Inflamación/tratamiento farmacológico , Enfermedades Metabólicas/tratamiento farmacológico , Receptores de Serotonina 5-HT3/química , Antagonistas del Receptor de Serotonina 5-HT3/farmacología , Animales , Humanos , Inflamación/metabolismo , Inflamación/patología , Enfermedades Metabólicas/metabolismo , Enfermedades Metabólicas/patología
20.
Am J Transplant ; 20(11): 3089-3093, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32568471

RESUMEN

LiveOnNY, the organ procurement organization (OPO) for the greater New York metropolitan area, suspended several best practices to manage the rising referrals of deaths from hospitals during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. On April 2, 2020 hospitals in the donor service area were notified that coronavirus disease 2019 (COVID-19) referrals should be deferred. Still, only 2% of referred patients to the OPO in April 2020 were on ventilators and considered possible organ donors, versus a baseline of 11% in 2019. Few of these deaths were unrelated to COVID-19. Accordingly, organ donors declined to 10 in April (from 26 in March). Despite the exclusion of marginal donors and organs, the implementation of COVID-19 donor testing, and the availability of local procurement surgeons, only 1 organ (a liver) was accepted by a transplant center outside of New York State and 8 organs (5 livers, 4 kidneys) were transplanted in state; 11 organs (1 liver, 10 kidneys) were discarded. Allocation was unsuccessful for 11 additional organs (1 liver, 4 kidneys, 4 hearts, 2 lungs). Despite the obstacles, organ donation remained an important model of collaboration and satisfaction for the health care community in the pandemic's US epicenter. Declining COVID-19 deaths led to the resumption of the comprehensive referral policy on May 6, 2020, with improvement to 18 donors in May.


Asunto(s)
COVID-19/epidemiología , Trasplante de Órganos/normas , Pandemias , SARS-CoV-2 , Donantes de Tejidos/provisión & distribución , Obtención de Tejidos y Órganos/organización & administración , Adulto , Anciano , Comorbilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estados Unidos/epidemiología , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA