Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 301
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Development ; 147(19)2020 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-32907847

RESUMEN

Pattern formation is influenced by transcriptional regulation as well as by morphogenetic mechanisms that shape organ primordia, although factors that link these processes remain under-appreciated. Here we show that, apart from their established transcriptional roles in pattern formation, IRX3/5 help to shape the limb bud primordium by promoting the separation and intercalation of dividing mesodermal cells. Surprisingly, IRX3/5 are required for appropriate cell cycle progression and chromatid segregation during mitosis, possibly in a nontranscriptional manner. IRX3/5 associate with, promote the abundance of, and share overlapping functions with co-regulators of cell division such as the cohesin subunits SMC1, SMC3, NIPBL and CUX1. The findings imply that IRX3/5 coordinate early limb bud morphogenesis with skeletal pattern formation.


Asunto(s)
Cromátides/metabolismo , Proteínas de Homeodominio/metabolismo , Esbozos de los Miembros/embriología , Esbozos de los Miembros/metabolismo , Factores de Transcripción/metabolismo , Animales , Western Blotting , Segregación Cromosómica/genética , Segregación Cromosómica/fisiología , Femenino , Técnica del Anticuerpo Fluorescente , Células HEK293 , Proteínas de Homeodominio/genética , Humanos , Inmunoprecipitación , Espectrometría de Masas , Ratones , Mitosis/genética , Mitosis/fisiología , Embarazo , RNA-Seq , Reacción en Cadena en Tiempo Real de la Polimerasa , Factores de Transcripción/genética
2.
Biometals ; 36(2): 263-281, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-35167013

RESUMEN

The mammalian multicopper ferroxidases (MCFs) ceruloplasmin (CP), hephaestin (HEPH) and zyklopen (ZP) comprise a family of conserved enzymes that are essential for body iron homeostasis. Each of these enzymes contains six biosynthetically incorporated copper atoms which act as intermediate electron acceptors, and the oxidation of iron is associated with the four electron reduction of dioxygen to generate two water molecules. CP occurs in both a secreted and GPI-linked (membrane-bound) form, while HEPH and ZP each contain a single C-terminal transmembrane domain. These enzymes function to ensure the efficient oxidation of iron so that it can be effectively released from tissues via the iron export protein ferroportin and subsequently bound to the iron carrier protein transferrin in the blood. CP is particularly important in facilitating iron release from the liver and central nervous system, HEPH is the major MCF in the small intestine and is critical for dietary iron absorption, and ZP is important for normal hair development. CP and HEPH (and possibly ZP) function in multiple tissues. These proteins also play other (non-iron-related) physiological roles, but many of these are ill-defined. In addition to disrupting iron homeostasis, MCF dysfunction perturbs neurological and immune function, alters cancer susceptibility, and causes hair loss, but, despite their importance, how MCFs co-ordinately maintain body iron homeostasis and perform other functions remains incompletely understood.


Asunto(s)
Ceruloplasmina , Cobre , Animales , Ratones , Cobre/metabolismo , Ceruloplasmina/metabolismo , Ratones Noqueados , Oxidación-Reducción , Biología , Mamíferos/metabolismo
3.
Int J Mol Sci ; 24(18)2023 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-37762679

RESUMEN

In order to supply adequate iron during pregnancy, the levels of the iron regulatory hormone hepcidin in the maternal circulation are suppressed, thereby increasing dietary iron absorption and storage iron release. Whether this decrease in maternal hepcidin is caused by changes in factors known to regulate hepcidin expression, or by other unidentified pregnancy factors, is not known. To investigate this, we examined iron parameters during pregnancy in mice. We observed that hepatic iron stores and transferrin saturation, both established regulators of hepcidin production, were decreased in mid and late pregnancy in normal and iron loaded dams, indicating an increase in iron utilization. This can be explained by a significant increase in maternal erythropoiesis, a known suppressor of hepcidin production, by mid-pregnancy, as indicated by an elevation in circulating erythropoietin and an increase in spleen size and splenic iron uptake. Iron utilization increased further in late pregnancy due to elevated fetal iron demand. By increasing maternal iron levels in late gestation, we were able to stimulate the expression of the gene encoding hepcidin, suggesting that the iron status of the mother is the predominant factor influencing hepcidin levels during pregnancy. Our data indicate that pregnancy-induced hepcidin suppression likely occurs because of reductions in maternal iron reserves due to increased iron requirements, which predominantly reflect stimulated erythropoiesis in mid-gestation and increased fetal iron requirements in late gestation, and that there is no need to invoke other factors, including novel pregnancy factor(s), to explain these changes.


Asunto(s)
Hepcidinas , Deficiencias de Hierro , Femenino , Embarazo , Ratones , Animales , Hepcidinas/genética , Hepcidinas/metabolismo , Hierro/metabolismo , Hierro de la Dieta , Feto/metabolismo , Eritropoyesis
4.
Paediatr Child Health ; 28(2): 84-90, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37151930

RESUMEN

Objectives: Procalcitonin testing is recommended to discriminate febrile young infants at risk of serious bacterial infections (SBI). However, this test is not available in many clinical settings, limited largely by cost. This study sought to evaluate contemporary real-world costs associated with the usual care of febrile young infants, and estimate impact on clinical trajectory and costs when incorporating procalcitonin testing. Methods: We assessed hospital-level door-to-discharge costs of all well-appearing febrile infants aged ≤60 days, evaluated at a tertiary paediatric hospital between April/2016 and March/2019. Emergency Department and inpatient expense data for usual care were obtained from the institutional general ledger, validated by the provincial Ministry of Health. These costs were then incorporated into a probabilistic model of risk stratification for an equivalent simulated cohort, with the addition of procalcitonin. Results: During the 3-year study period, 1168 index visits were included for analysis. Real-world median costs-per-infant were the following: $3266 (IQR $2468 to $4317, n=93) for hospitalized infants with SBIs; $2476 (IQR $1974 to $3236, n=530) for hospitalized infants without SBIs; $323 (IQR $286 to $393, n=538) for discharged infants without SBIs; and, $3879 (IQR $3263 to $5297, n=7) for discharged infants subsequently hospitalized for missed SBIs. Overall median cost-per-infant of usual care was $1555 (IQR $1244 to $2025), compared to a modelled cost of $1389 (IQR $1118 to $1797) with the addition of procalcitonin (10.7% overall cost savings; $1,816,733 versus $1,622,483). Under pessimistic and optimistic model assumptions, savings were 5.9% and 14.9%, respectively. Conclusions: Usual care of febrile young infants is variable and resource intensive. Increased access to procalcitonin testing could improve risk stratification at lower overall costs.

5.
J Bacteriol ; 204(1): e0039821, 2022 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-34633868

RESUMEN

Stenotrophomonas maltophilia has recently arisen as a prominent nosocomial pathogen because of its high antimicrobial resistance and ability to cause chronic respiratory infections. Often the infections are worsened by biofilm formation which enhances antibiotic tolerance. We have previously found that mutation of the gpmA gene, encoding the glycolytic enzyme phosphoglycerate mutase, impacts the formation of this biofilm on biotic and abiotic surfaces at early time points. This finding, indicating an association between carbon source and biofilm formation, led us to hypothesize that metabolism would influence S. maltophilia biofilm formation and planktonic growth. In the present study, we tested the impact of various growth substrates on biofilm levels and growth kinetics to determine metabolic requirements for these processes. We found that S. maltophilia wild type preferred amino acids versus glucose for planktonic and biofilm growth and that gpmA deletion inhibited growth in amino acids. Furthermore, supplementation of the ΔgpmA strain by glucose or ribose phenotypically complemented growth defects. These results suggest that S. maltophilia shuttles amino acid carbon through gluconeogenesis to an undefined metabolic pathway supporting planktonic and biofilm growth. Further evaluation of these metabolic pathways might reveal novel metabolic activities of this pathogen. IMPORTANCE Stenotrophomonas maltophilia is a prominent opportunistic pathogen that often forms biofilms during infection. However, the molecular mechanisms of virulence and biofilm formation are poorly understood. The glycolytic enzyme phosphoglycerate mutase appears to play a role in biofilm formation, and we used a mutant in its gene (gpmA) to probe the metabolic circuitry potentially involved in biofilm development. The results of our study indicate that S. maltophilia displays unique metabolic activities, which could be exploited for inhibiting growth and biofilm formation of this pathogen.


Asunto(s)
Proteínas Bacterianas/metabolismo , Biopelículas/crecimiento & desarrollo , Regulación Bacteriana de la Expresión Génica/fisiología , Redes y Vías Metabólicas/fisiología , Stenotrophomonas maltophilia/fisiología , Aminoácidos/metabolismo , Aminoácidos/farmacología , Proteínas Bacterianas/genética , Medios de Cultivo , Ribosa/metabolismo , Ribosa/farmacología , Stenotrophomonas maltophilia/genética
6.
Mol Biol Evol ; 38(7): 2946-2957, 2021 06 25.
Artículo en Inglés | MEDLINE | ID: mdl-33769517

RESUMEN

Dissecting the genetic mechanisms underlying dioecy (i.e., separate female and male individuals) is critical for understanding the evolution of this pervasive reproductive strategy. Nonetheless, the genetic basis of sex determination remains unclear in many cases, especially in systems where dioecy has arisen recently. Within the economically important plant genus Solanum (∼2,000 species), dioecy is thought to have evolved independently at least 4 times across roughly 20 species. Here, we generate the first genome sequence of a dioecious Solanum and use it to ascertain the genetic basis of sex determination in this species. We de novo assembled and annotated the genome of Solanum appendiculatum (assembly size: ∼750 Mb scaffold N50: 0.92 Mb; ∼35,000 genes), identified sex-specific sequences and their locations in the genome, and inferred that males in this species are the heterogametic sex. We also analyzed gene expression patterns in floral tissues of males and females, finding approximately 100 genes that are differentially expressed between the sexes. These analyses, together with observed patterns of gene-family evolution specific to S. appendiculatum, consistently implicate a suite of genes from the regulatory network controlling pectin degradation and modification in the expression of sex. Furthermore, the genome of a species with a relatively young sex-determination system provides the foundational resources for future studies on the independent evolution of dioecy in this clade.


Asunto(s)
Evolución Biológica , Genoma de Planta , Procesos de Determinación del Sexo/genética , Solanum/genética , Regulación de la Expresión Génica de las Plantas , Familia de Multigenes , Pectinas/genética
7.
J Nutr ; 152(3): 714-722, 2022 03 03.
Artículo en Inglés | MEDLINE | ID: mdl-34625812

RESUMEN

BACKGROUND: Many women enter pregnancy with iron stores that are insufficient to maintain maternal iron balance and support fetal development and consequently, often require iron supplements. However, the side effects associated with many currently available iron supplements can limit compliance. OBJECTIVE: This study aimed to test the safety and efficacy of a novel nanoparticulate iron supplement, a dietary ferritin analog termed iron hydroxide adipate tartrate (IHAT), in pregnant mice. METHODS: Female C57BL/6 mice were maintained on either an iron-deficient or a control diet for 2 wk prior to timed mating to develop iron-deficient or iron-sufficient pregnancy models, respectively. Mice from each model were then gavaged daily with 10 mg iron/kg body weight as either IHAT or ferrous sulfate, or with water only, beginning on embryonic day (E) 4.5. Mice were killed on E18.5 and maternal iron and hematological parameters were measured. The expression of genes encoding iron transporters and oxidative stress markers in the duodenum and placenta were determined, along with hepatic expression of the gene encoding the iron regulatory hormone hepcidin and fetal iron. RESULTS: Oral IHAT and ferrous sulfate were equally effective at increasing maternal hemoglobin (20.2% and 16.9%, respectively) and hepatic iron (30.2% and 29.3%, respectively), as well as total fetal iron (99.7% and 83.8%, respectively), in iron-deficient pregnant mice compared with those gavaged with water only, with no change in oxidative stress markers seen with either treatment. However, there was a significant increase in the placental expression of the oxidative stress marker heme oxygenase 1 in iron-replete pregnant mice treated with ferrous sulfate when compared with iron-replete pregnant mice gavaged with IHAT (96.9%, P <0.05). CONCLUSIONS: IHAT has proved a safe and effective alternative to oral ferrous sulfate in mice, and it has potential for treating iron deficiency in human pregnancy.


Asunto(s)
Anemia Ferropénica , Deficiencias de Hierro , Anemia Ferropénica/tratamiento farmacológico , Animales , Femenino , Ferritinas/uso terapéutico , Compuestos Ferrosos/uso terapéutico , Hemoglobinas/análisis , Humanos , Hierro , Ratones , Ratones Endogámicos C57BL , Placenta/química , Embarazo , Agua
8.
J Periodontal Res ; 57(2): 294-304, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34855211

RESUMEN

OBJECTIVE: To investigate the effect of Hfe gene mutation on the distribution of iron and periodontal bone loss in periodontal tissues. BACKGROUND DATA: It remains unclear how tissue iron loading affects the periodontium architectures in a genetic animal model of hereditary haemochromatosis (HH). METHODS: Male C57BL/6 Hfe -/- (8 weeks old) and wild-type (WT) mice were utilized to examine the iron distribution in periodontal tissues, as well as periodontal tissues changes using micro-computed tomography and histomorphometric analysis. Furthermore, tissue inflammatory mediators, bone markers and periodontal pathogens were carried out in PFA-fixed paraffin-embedded tissues using ELISA, RT-qPCR and genomic DNA qPCR, respectively. RESULTS: Excessive iron deposition was found in the periodontal ligament, gingiva and alveolar bone in Hfe -/- mice relative to their WT counterparts. This, in turn, was associated with significant periodontal bone loss, increased cemento-enamel junction-alveolar bone crest distance and decreased expression of molecules involved in bone development and turnover. Furthermore, the pro-inflammatory cytokine - interleukin 6 and periodontal bacteria - Campylobacter rectus were significantly increased in Hfe -/- mice compared with WT controls. CONCLUSION: Our results suggest that the iron loading in a mouse model of HH decreases alveolar bone formation and leads to alterations in the inflammatory state in the periodontium. Periodontal health should be assessed during the clinical assessment of HFE-HH patients.


Asunto(s)
Hemocromatosis , Animales , Modelos Animales de Enfermedad , Hemocromatosis/complicaciones , Hemocromatosis/genética , Hemocromatosis/metabolismo , Proteína de la Hemocromatosis/genética , Proteína de la Hemocromatosis/metabolismo , Antígenos de Histocompatibilidad Clase I/genética , Antígenos de Histocompatibilidad Clase I/metabolismo , Humanos , Hierro/metabolismo , Hígado/metabolismo , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Microtomografía por Rayos X
9.
Biometals ; 35(1): 27-38, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34697758

RESUMEN

Iron deficiency is one of the most common nutritional deficiencies worldwide and is often treated with oral iron supplements. However, commonly used supplements, including those based on ferrous iron salts, are associated with gastrointestinal side effects and unfavorable changes in the intestinal microbiome. Sucrosomial® iron is a novel iron formulation that is effective at treating iron deficiency, and with fewer gastrointestinal side effects, yet its effect on the gut microbiome has not been examined previously. Thus, we treated mice for two weeks with diets containing either Sucrosomial® iron or ferrous sulfate as the sole iron source and examined bacterial communities in the intestine using 16S Microbial Profiling of DNA extracted from feces collected both prior to and following dietary treatment. Mice treated with Sucrosomial® iron showed an increase in Shannon diversity over the course of the study. This was associated with a decrease in the abundance of the phylum Proteobacteria, which contains many pathogenic species, and an increase in short chain fatty acid producing bacteria such as Lachnospiraceae, Oscillibacter and Faecalibaculum. None of these changes were observed in mice treated with ferrous sulfate. These results suggest that Sucrosomial® iron may have a beneficial effect on the intestinal microbiome when compared to ferrous sulfate and that this form of iron is a promising alternative to ferrous iron salts for the treatment of iron deficiency.


Asunto(s)
Anemia Ferropénica , Microbioma Gastrointestinal , Deficiencias de Hierro , Anemia Ferropénica/tratamiento farmacológico , Animales , Suplementos Dietéticos , Compuestos Ferrosos/farmacología , Hierro , Ratones , Sales (Química)/uso terapéutico
10.
PLoS Genet ; 15(5): e1008143, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-31125343

RESUMEN

Maintenance of the correct redox status of iron is functionally important for critical biological processes. Multicopper ferroxidases play an important role in oxidizing ferrous iron, released from the cells, into ferric iron, which is subsequently distributed by transferrin. Two well-characterized ferroxidases, ceruloplasmin (CP) and hephaestin (HEPH) facilitate this reaction in different tissues. Recently, a novel ferroxidase, Hephaestin like 1 (HEPHL1), also known as zyklopen, was identified. Here we report a child with compound heterozygous mutations in HEPHL1 (NM_001098672) who presented with abnormal hair (pili torti and trichorrhexis nodosa) and cognitive dysfunction. The maternal missense mutation affected mRNA splicing, leading to skipping of exon 5 and causing an in-frame deletion of 85 amino acids (c.809_1063del; p.Leu271_ala355del). The paternal mutation (c.3176T>C; p.Met1059Thr) changed a highly conserved methionine that is part of a typical type I copper binding site in HEPHL1. We demonstrated that HEPHL1 has ferroxidase activity and that the patient's two mutations exhibited loss of this ferroxidase activity. Consistent with these findings, the patient's fibroblasts accumulated intracellular iron and exhibited reduced activity of the copper-dependent enzyme, lysyl oxidase. These results suggest that the patient's biallelic variants are loss-of-function mutations. Hence, we generated a Hephl1 knockout mouse model that was viable and had curly whiskers, consistent with the hair phenotype in our patient. These results enhance our understanding of the function of HEPHL1 and implicate altered ferroxidase activity in hair growth and hair disorders.


Asunto(s)
Oxidorreductasas/genética , Oxidorreductasas/metabolismo , Adulto , Alelos , Animales , Sitios de Unión , Ceruloplasmina/metabolismo , Preescolar , Cobre/metabolismo , Femenino , Regulación de la Expresión Génica/genética , Variación Genética/genética , Células HEK293 , Cabello , Humanos , Hierro/metabolismo , Masculino , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Noqueados , Oxidación-Reducción , Fenotipo
11.
J Nutr ; 151(9): 2541-2550, 2021 09 04.
Artículo en Inglés | MEDLINE | ID: mdl-34114013

RESUMEN

BACKGROUND: The ferroxidase zyklopen (Zp) has been implicated in the placental transfer of iron to the fetus. However, the evidence for this is largely circumstantial. OBJECTIVES: This study aimed to determine whether Zp is essential for placental iron transfer. METHODS: A model was established using 8- to 12-wk-old pregnant C57BL/6 mice on standard rodent chow in which Zp was knocked out in the fetus and fetal components of the placenta. Zp was also disrupted in the entire placenta using global Zp knockout mice. Inductively coupled plasma MS was used to measure total fetal iron, an indicator of the amount of iron transferred by the placenta to the fetus, at embryonic day 18.5 of gestation. Iron transporter expression in the placenta was measured by Western blotting, and the expression of Hamp1, the gene encoding the iron regulatory hormone hepcidin, was determined in fetal liver by real-time PCR. RESULTS: There was no change in the amount of iron transferred to the fetus when Zp was disrupted in either the fetal component of the placenta or the entire placenta. No compensatory changes in the expression of the iron transport proteins transferrin receptor 1 or ferroportin were observed, nor was there any change in fetal liver Hamp1 mRNA. Hephl1, the gene encoding Zp, was expressed mainly in the maternal decidua of the placenta and not in the nutrient-transporting syncytiotrophoblast. Disruption of Zp in the whole placenta resulted in a 26% increase in placental size (P < 0.01). CONCLUSIONS: Our data indicate that Zp is not essential for the efficient transfer of iron to the fetus in mice and is localized predominantly in the maternal decidua. The increase in placental size observed when Zp is knocked out in the entire placenta suggests that this protein may play a role in placental development.


Asunto(s)
Ceruloplasmina , Placenta , Animales , Ceruloplasmina/genética , Femenino , Feto/metabolismo , Hierro/metabolismo , Ratones , Ratones Endogámicos C57BL , Placenta/metabolismo , Placentación , Embarazo
12.
Biol Res ; 54(1): 38, 2021 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-34903297

RESUMEN

BACKGROUND: Defective chloride transport in airway epithelial cells (AECs) and the associated lung disease are the main causes of morbidity and early mortality in cystic fibrosis (CF). Abnormal airway iron homeostasis and the presence of lipid peroxidation products, indicative of oxidative stress, are features of CF lung disease. RESULTS: Here, we report that CF AECs (IB3-1) are susceptible to ferroptosis, a type of cell death associated with iron accumulation and lipid peroxidation. Compared to isogenic CFTR corrected cells (C38), the IB3-1 cells showed increased susceptibility to cell death upon exposure to iron in the form of ferric ammonium citrate (FAC) and the ferroptosis inducer, erastin. This phenotype was accompanied by accumulation of intracellular ferrous iron and lipid peroxides and the extracellular release of malondialdehyde, all indicative of redox stress, and increased levels of lactate dehydrogenase in the culture supernatant, indicating enhanced cell injury. The ferric iron chelator deferoxamine (DFO) and the lipophilic antioxidant ferrostatin-1 inhibited FAC and erastin induced ferroptosis in IB3-1 cells. Glutathione peroxidase 4 (GPX4) expression was decreased in IB3-1 cells treated with FAC and erastin, but was unchanged in C38 AECs. Necroptosis appeared to be involved in the enhanced susceptibility of IB3-1 AECs to ferroptosis, as evidenced by partial cell death rescue with necroptosis inhibitors and enhanced mixed lineage kinase domain-like (MLKL) localisation to the plasma membrane. CONCLUSION: These studies suggest that the increased susceptibility of CF AECs to ferroptosis is linked to abnormal intracellular ferrous iron accumulation and reduced antioxidant defences. In addition, the process of ferroptotic cell death in CF AECs does not appear to be a single entity and for the first time we describe necroptosis as a potential contributory factor. Iron chelation and antioxidant treatments may be promising therapeutic interventions in cystic fibrosis.


Asunto(s)
Fibrosis Quística , Ferroptosis , Muerte Celular , Células Epiteliales , Humanos , Peroxidación de Lípido
13.
Nano Lett ; 20(1): 478-495, 2020 01 08.
Artículo en Inglés | MEDLINE | ID: mdl-31789044

RESUMEN

Microglia-mediated neuroinflammation is one of the most significant features in a variety of central nervous system (CNS) disorders such as traumatic brain injury, stroke, and many neurodegenerative diseases. Microglia become polarized upon stimulation. The two extremes of the polarization are the neuron-destructive proinflammatory M1-like and the neuron-regenerative M2-like phenotypes. Thus, manipulating microglial polarization toward the M2 phenotype is a promising therapeutic approach for CNS repair and regeneration. It has been reported that nanoparticles are potential tools for regulating microglial polarization. Gold nanoclusters (AuNCs) could penetrate the blood-brain barrier and have neuroprotective effects, suggesting the possibility of utilizing AuNCs to regulate microglial polarization and improve neuronal regeneration in CNS. In the current study, AuNCs functionalized with dihydrolipoic acid (DHLA-AuNCs), an antioxidant with demonstrated neuroprotective roles, were prepared, and their effects on polarization of a microglial cell line (BV2) were examined. DHLA-AuNCs effectively suppressed proinflammatory processes in BV2 cells by inducing polarization toward the M2-like phenotype. This was associated with a decrease in reactive oxygen species and reduced NF-kB signaling and an improvement in cell survival coupled with enhanced autophagy and inhibited apoptosis. Conditioned medium from DHLA-AuNC-treated BV2 cells was able to enhance neurogenesis in both the neuronal cell line N2a and in an ex vivo brain slice stroke model. The direct treatment of brain slices with DHLA-AuNCs also ameliorated stroke-related tissue injury and reduced astrocyte activation (astrogliosis). This study suggests that by regulating neuroinflammation to improve neuronal regeneration, DHLA-AuNCs could be a potential therapeutic agent in CNS disorders.


Asunto(s)
Polaridad Celular/efectos de los fármacos , Oro , Nanopartículas del Metal/química , Microglía/metabolismo , Neurogénesis/efectos de los fármacos , Neuronas/metabolismo , Ácido Tióctico/análogos & derivados , Animales , Línea Celular Tumoral , Oro/química , Oro/farmacología , Ratones , Ácido Tióctico/química , Ácido Tióctico/farmacología
14.
Paediatr Child Health ; 26(6): e258-e264, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34676015

RESUMEN

Objectives: Correction factors have been proposed for traumatic lumbar punctures (LPs) in febrile young infants. However, no studies have assessed their diagnostic utility. We sought to determine the proportion of traumatic LPs safely reclassified as low risk for bacterial meningitis using recently derived white blood cell (WBC) and protein correction factors. Methods: We retrospectively analyzed traumatic LPs among all febrile infants ≤60 days old at two tertiary paediatric hospitals from 2006 through 2018. Traumatic LPs were defined as ≥10,000 RBCs/mm3. Abnormal cerebrospinal fluid (CSF) WBCs and protein were adjusted downward using a newly derived correction factor (877 red blood cells [RBCs]: 1 WBC), three commonly used correction factors (500 WBCs: 1 RBC; 1,000 WBCs: 1 WBC; peripheral RBCs: WBCs), and a newly derived protein correction factor (1,000 RBCs: 0.011 g/L protein). Results: There were 437 traumatic LPs including 357 (82%) with pleocytosis and 4 (0.9%) with bacterial meningitis. Overall, fewer infants were classified as having CSF pleocytosis using 877:1 and 1,000:1 ratios (38% and 43%, respectively), with 100% sensitivity and negative predictive value, and improved specificity (63% for 877:1, 58% for 1,000:1 ratios versus 19% for uncorrected counts). Among infants with pleocytosis, 877:1 and 1,000:1 ratios reclassified 191 (54%) and 171 (48%) as normal with no misclassified bacterial meningitis cases. Ratios of 500:1 and peripheral RBC:WBC misclassified 1 infant that had bacterial meningitis. Corrected CSF protein outperformed uncorrected protein in specificity but did not add diagnostic value following WBC-based correction. Conclusions: Correction ratios of 877:1 and 1,000:1 safely reclassified half of all febrile infants ≤60 days. These corrections should be considered when interpreting CSF results of traumatic LPs.

15.
16.
J Am Chem Soc ; 142(5): 2490-2496, 2020 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-31944687

RESUMEN

The limited efficacy of single-agent immune checkpoint inhibitors in treating tumors has prompted investigations on their combination partners. Here, a tumor-homing indoleamine 2,3-dioxygenase (IDO) nanoinhibitor is reported to selectively inhibit immunosuppressive IDO pathway in the tumor microenvironment. It is self-assembled from a modularly designed peptide-drug conjugate containing a hydrophilic targeting motif (arginyl-glycyl-aspartic acid; RGD), two protonatable histidines, and an ester bond-linked hydrophobic IDO inhibitor, which exhibits pH-responsive disassembly and esterase-catalyzed drug release. Markedly, it achieved potent and persistent inhibition of intratumoral IDO activity with a reduced systemic toxicity, which greatly enhanced the therapeutic efficacy of programmed cell death-ligand 1 blockade in vivo. Overall, this study provides a promising paradigm of combinatorial normalization immunotherapy by exploiting a targeted IDO nanoinhibitor to augment the antitumor immunity of checkpoint inhibitors.


Asunto(s)
Antígeno B7-H1/antagonistas & inhibidores , Diseño de Fármacos , Indolamina-Pirrol 2,3,-Dioxigenasa/antagonistas & inhibidores , Nanopartículas , Profármacos/farmacología , Humanos , Inmunoterapia , Oligopéptidos/química , Profármacos/farmacocinética , Microambiente Tumoral
17.
Clin Gastroenterol Hepatol ; 18(8): 1851-1857, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-31622736

RESUMEN

BACKGROUND & AIMS: Fibrosis stage can decrease following treatment in patients with hemochromatosis caused by mutations in the homeostatic iron regulator gene (HFE), but the effects on cirrhosis are not clear. We assessed regression of severe fibrosis and the ensuing risk of liver cancer after treatment. METHODS: We performed a retrospective analysis of data from 106 patients in France or Australia who were homozygous for the C282Y mutation in HFE with F3 fibrosis (n = 40) or F4 fibrosis (n = 66) at diagnosis and from whom at least 1 liver biopsy was collected during follow up. We collected data from the time of first biopsy and during follow-up period on patient demographics, treatment, smoking habits, alcohol consumption, infection with hepatitis B or C viruses, and other diseases. The median time between first and last liver biopsy was 9.5 years (range, 3.5-15.6 years). We collected results of tests for liver function, markers of iron stores, and platelet levels. Patients were followed for a median 17.6 years (range, 9.8-24.1 years) for development of liver cancer occurrence. RESULTS: At last liver biopsy, 41 patients (38.6%) had fibrosis scores of F2 or less. Liver cancer occurred in 34 patients (52.3%) with F3 or F4 fibrosis at last liver biopsy vs 2 patients (4.8%) with fibrosis scores of F2 or less at last liver biopsy (P < .001). Liver cancer incidences were 32.8 per 1000 person-years (95% CI, 22.7-45.9 per 1000 person-years) in patients with F3 or F4 fibrosis and 2.3 per 1000 person-years (95% CI, 0.2-8.6 per 1000 person-years) in patients with fibrosis scores of F2 or less (P < .001). In multivariate analysis, male sex (hazard ratio [HR], 6.09; 95% CI, 1.21-30.4), age at diagnosis (HR, 1.16; 95% CI, 1.09-1.25), presence of diabetes (HR, 3.07; 95% CI, 1.35-6.97), excess alcohol consumption (HR, 3.1; 95% CI, 1.47-6.35), serum level of ferritin at diagnosis (P < .01), and regression to fibrosis scores of F2 or less (HR, 0.08; 95% CI, 0.01-0.62) were significantly associated with risk of liver cancer. CONCLUSIONS: In a retrospective analysis of patients with hemochromatosis caused by the C282Y mutation in HFE, we found that severe liver fibrosis can regress with treatment. In patients with fibrosis regression to a stage F2 or less, the long-term risk for liver cancer is significantly reduced.


Asunto(s)
Hemocromatosis , Neoplasias Hepáticas , Genes Reguladores , Hemocromatosis/complicaciones , Hemocromatosis/epidemiología , Hemocromatosis/genética , Proteína de la Hemocromatosis/genética , Antígenos de Histocompatibilidad Clase I/genética , Humanos , Hígado/patología , Cirrosis Hepática/patología , Neoplasias Hepáticas/patología , Masculino , Proteínas de la Membrana/genética , Mutación , Estudios Retrospectivos
18.
J Acoust Soc Am ; 147(4): 3000, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32359268

RESUMEN

This paper is an acoustic phonetic study of vowels in Sora, a Munda language of the Austroasiatic language family. Descriptions here illustrate that the Sora vowel system has six vowels and provide evidence that Sora disyllables have prominence on the second syllable. While the acoustic categorization of vowels is based on formant frequencies, the presence of prominence on the second syllable is shown through temporal features of vowels, including duration, intensity, and fundamental frequency. Additionally, this paper demonstrates that acoustic categorization of vowels in Sora is better in the prominent syllable than in the non-prominent syllable, providing evidence that syllable prominence and vowel quality are correlated in Sora. These acoustic properties of Sora vowels are discussed in relation to the existing debates on vowels and patterns of syllable prominence in Munda languages of India. In this regard, it is noteworthy that Munda languages, in general, lack instrumental studies, and therefore this paper presents significant findings that are undocumented in other Munda languages. These acoustic studies are supported by exploratory statistical modeling and statistical classification methods.


Asunto(s)
Fonética , Acústica del Lenguaje , Acústica , India , Lenguaje
19.
Cogn Behav Ther ; 49(1): 55-73, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-30794073

RESUMEN

Public Safety Personnel (PSP; e.g. correctional workers, dispatchers, firefighters, paramedics, police) are frequently exposed to potentially traumatic events (PTEs). Several mental health training program categories (e.g. critical incident stress management (CISM), debriefing, peer support, psychoeducation, mental health first aid, Road to Mental Readiness [R2MR]) exist as efforts to minimize the impact of exposures, often using cognitive behavioral therapy model content, but with limited effectiveness research. The current study assessed PSP perceptions of access to professional (i.e. physicians, psychologists, psychiatrists, employee assistance programs, chaplains) and non-professional (i.e. spouse, friends, colleagues, leadership) support, and associations between training and mental health. Participants included 4,020 currently serving PSP participants. Data were analyzed using cross-tabulations and logistic regressions. Most PSP reported access to professional and non-professional support; nevertheless, most would first access a spouse (74%) and many would never, or only as a last resort, access professional support (43-60%) or PSP leaders (67%). Participation in any mental health training category was associated with lower (p < .01) rates for some, but not all, mental disorders, with no robust differences across categories. Revisions to training programs may improve willingness to access professional support; in the interim, training and support for PSP spouses and leaders may also be beneficial.


Asunto(s)
Trastornos Mentales , Salud Mental/educación , Aceptación de la Atención de Salud/psicología , Policia/psicología , Psicoterapia , Apoyo Social , Adulto , Femenino , Humanos , Masculino , Trastornos Mentales/diagnóstico , Trastornos Mentales/psicología , Trastornos Mentales/terapia , Servicios de Salud Mental , Esposos
20.
J Nutr ; 149(12): 2247-2254, 2019 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-31373375

RESUMEN

BACKGROUND: Brain iron deposition is a feature of Alzheimer disease and may contribute to its development. However, the relative contribution of dietary iron remains unclear. OBJECTIVES: We investigated the impact of high dietary iron on brain pathological changes and cognitive function in adult wild-type (WT) mice and amyloid precursor protein/presenilin 1 (APP/PS1) double transgenic mice. METHODS: Male WT mice and APP/PS1 mice aged 10 wk were fed either a control diet (66 mg Fe/kg) (WT-Ctrl and APP/PS1-Ctrl) or a high iron diet (14 g Fe/kg) (WT-High Fe and APP/PS1-High Fe) for 20 wk. Iron concentrations in brain regions were measured by atomic absorption spectrophotometry. Brain iron staining and amyloid-ß (Aß) immunostaining were performed. Protein expressions in the hippocampus were determined by immunoblotting. Superoxide dismutase (SOD) activity and malondialdehyde concentration were examined. Cognitive functions were tested with the Morris water maze system. RESULTS: In the hippocampus, APP/PS1-High Fe mice had significantly higher iron concentration (2.5-fold) and ferritin (2.0-fold) than APP/PS1-Ctrl mice (P < 0.001), and WT-High Fe mice had significantly higher ferritin (2.0-fold) than WT-Ctrl mice (P < 0.001). Interestingly, APP/PS1 mice had significantly higher iron concentration (2-3-fold) and ferritin (2-2.5-fold) than WT mice fed either diet (P < 0.001). Histological analysis indicated that iron accumulated in the hippocampal dentate gyrus region in APP/PS1 mice, consistent with the pattern of Aß deposition. For both mouse strains, iron treatment induced Aß and phospho-τ expression (1.5-3-fold) in the hippocampus, but had little impact on oxidative stress and cognitive function. Furthermore, APP/PS1 mice had significantly lower SOD activity and higher malondialdehyde concentration than WT mice in the hippocampus (P < 0.0001), paralleled by apparent cognitive dysfunction. CONCLUSIONS: Dietary iron overload induces iron disorder and Aß and phospho-τ expression in the hippocampus of adult WT and APP/PS1 transgenic mice.


Asunto(s)
Péptidos beta-Amiloides/metabolismo , Hipocampo/metabolismo , Homeostasis , Hierro/administración & dosificación , Hierro/metabolismo , Presenilina-1/metabolismo , Proteínas tau/metabolismo , Enfermedad de Alzheimer/metabolismo , Péptidos beta-Amiloides/genética , Animales , Dieta , Crecimiento , Masculino , Ratones , Ratones Transgénicos , Estrés Oxidativo , Fosforilación , Proteínas tau/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA