Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
1.
Inorg Chem ; 63(20): 9184-9194, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38722234

RESUMO

We report a new nickel hydroxyfluoride diaspore Ni(OH)F prepared using hydrothermal synthesis from NiCl2·6H2O and NaF. Magnetic characterization reveals that, contrary to other reported transition-metal hydroxyfluoride diaspores, Ni(OH)F displays weak ferromagnetism below the magnetic ordering temperature. To understand this difference, neutron diffraction is used to determine the long-range magnetic structure. The magnetic structure is found to be distinct from those reported for other hydroxyfluoride diaspores and shows an antiferromagnetic spin ordering in which ferromagnetic canting is allowed by symmetry. Furthermore, neutron powder diffraction on a deuterated sample, Ni(OD)F, reveals partial anion ordering that is distinctive to what has previously been reported for Co(OH)F and Fe(OH)F. Density functional theory calculations show that OH/F ordering can have a directing influence on the lowest energy magnetic ground state. Our results point toward a subtle interplay between the sign of magnetic exchange interactions, the electronic configuration, and anion disordering.

2.
PLoS Negl Trop Dis ; 18(3): e0012013, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38484018

RESUMO

BACKGROUND: Chikungunya virus (CHIKV) has spread across Brazil with varying incidence rates depending on the affected areas. Due to cocirculation of arboviruses and overlapping disease symptoms, CHIKV infection may be underdiagnosed. To understand the lack of CHIKV epidemics in São José do Rio Preto (SJdRP), São Paulo (SP), Brazil, we evaluated viral circulation by investigating anti-CHIKV IgG seroconversion in a prospective study of asymptomatic individuals and detecting anti-CHIKV IgM in individuals suspected of dengue infection, as well as CHIKV presence in Aedes mosquitoes. The opportunity to assess two different groups (symptomatic and asymptomatic) exposed at the same geographic region aimed to broaden the possibility of identifying the viral circulation, which had been previously considered absent. METHODOLOGY/PRINCIPAL FINDINGS: Based on a prospective population study model and demographic characteristics (sex and age), we analyzed the anti-CHIKV IgG seroconversion rate in 341 subjects by ELISA over four years. The seroprevalence increased from 0.35% in the first year to 2.3% after 3 years of follow-up. Additionally, we investigated 497 samples from a blood panel collected from dengue-suspected individuals during the 2019 dengue outbreak in SJdRP. In total, 4.4% were positive for anti-CHIKV IgM, and 8.6% were positive for IgG. To exclude alphavirus cross-reactivity, we evaluated the presence of anti-Mayaro virus (MAYV) IgG by ELISA, and the positivity rate was 0.3% in the population study and 0.8% in the blood panel samples. In CHIKV and MAYV plaque reduction neutralization tests (PRNTs), the positivity rate for CHIKV-neutralizing antibodies in these ELISA-positive samples was 46.7%, while no MAYV-neutralizing antibodies were detected. Genomic sequencing and phylogenetic analysis revealed CHIKV genotype ECSA in São José do Rio Preto, SP. Finally, mosquitoes collected to complement human surveillance revealed CHIKV positivity of 2.76% of A. aegypti and 9.09% of A. albopictus (although it was far less abundant than A. aegypti) by RT-qPCR. CONCLUSIONS/SIGNIFICANCE: Our data suggest cryptic CHIKV circulation in SJdRP detected by continual active surveillance. These low levels, but increasing, of viral circulation highlight the possibility of CHIKV outbreaks, as there is a large naïve population. Improved knowledge of the epidemiological situation might aid in outbreaks prevention.


Assuntos
Aedes , Febre de Chikungunya , Vírus Chikungunya , Dengue , Animais , Humanos , Vírus Chikungunya/genética , Estudos Prospectivos , Brasil/epidemiologia , Filogenia , Estudos Soroepidemiológicos , Febre de Chikungunya/epidemiologia , Anticorpos Antivirais , Dengue/diagnóstico , Dengue/epidemiologia , Anticorpos Neutralizantes/genética , Imunoglobulina G , Imunoglobulina M
3.
J Mater Sci ; 58(35): 14207-14219, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37745186

RESUMO

The development of a 3D printed sensor for direct incorporation within stoma pouches is described. Laser induced graphene scribed on either side of polyimide film served as the basis of a 2 electrode configuration that could be integrated within a disposable pouch sensor for the periodic monitoring of ileostomy fluid pH. The graphene sensors were characterised using electron microscopy, Raman spectroscopy, DekTak profilometry with the electrochemical properties investigated using both cyclic and square wave voltammetry. Adsorbed riboflavin was employed as a biocompatible redox probe for the voltammetric measurement of pH. The variation in peak position with pH was found to be linear over pH 3-8 with a sub Nernstian response (43 mV/pH). The adsorbed probe was found to be reversible and exhibited minimal leaching through repeated scanning. The performance of the system was assessed in a heterogeneous bacterial fermentation mixture simulating ileostomy fluid with the pH recorded before and after 96 h incubation. The peak profile in the bacterial medium provided an unambiguous signal free from interference with the calculated pH before and after incubation (pH 5.3 to 3.66) in good agreement with that obtained with commercial pH probes. Supplementary Information: The online version contains supplementary material available at 10.1007/s10853-023-08881-x.

4.
Phys Biol ; 20(6)2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37769681

RESUMO

It is now established that endo-lysosomes, also referred to as late endosomes, serve as intracellular calcium store, in addition to the endoplasmic reticulum. While abundant calcium-binding proteins provide the latter compartment with its calcium storage capacity, essentially nothing is known about the mechanism responsible for calcium storage in endo-lysosomes. In this paper, we propose that the structural organization of endo-lysosomal membranes drives the calcium storage capacity of the compartment. Indeed, endo-lysosomes exhibit a characteristic multivesicular ultrastructure, with intralumenal membranes providing a large amount of additional bilayer surface. We used a theoretical approach to investigate the calcium storage capacity of endosomes, using known calcium binding affinities for bilayers and morphological data on endo-lysosome membrane organization. Finally, we tested our predictions experimentally after Sorting Nexin 3 depletion to decrease the intralumenal membrane content. We conclude that the major negatively-charge lipids and proteins of endo-lysosomes serve as calcium-binding molecules in the acidic calcium stores of mammalian cells, while the large surface area of intralumenal membranes provide the necessary storage capacity.

5.
Nurs Educ Perspect ; 44(6): E25-E32, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37053551

RESUMO

AIM: The study aim was to identify and explore relationships among cognitive and noncognitive factors that may contribute to prelicensure baccalaureate nursing students' academic success across their program of study. BACKGROUND: Nurse educators are challenged to improve students' academic success. With limited evidence, cognitive and noncognitive factors have been identified in the literature as potential factors that influence academic success and may support students' readiness for practice as new graduate nurses. METHOD: Data sets from 1,937 BSN students at multiple campuses were analyzed using an exploratory design and structural equation modeling. CONCLUSION: Six factors were conceptualized as contributing equally to the initial cognitive model. The final noncognitive model, with deletion of two factors, yielded the best fit for the four-factor model. Cognitive and noncognitive factors were not significantly correlated. This study provides a beginning understanding of cognitive and noncognitive factors associated with academic success that may support readiness for practice.

6.
Micromachines (Basel) ; 13(7)2022 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-35888949

RESUMO

The combination of paraffin wax and O,O'-bis(2-aminopropyl) polypropylene glycol-block-polyethylene glycol-block-polypropylene glycol was used as a phase-change material (PCM) for the controlled delivery of curcumin. The PCM was combined with a graphene-based heater derived from the laser scribing of polyimide film. This assembly provides a new approach to a smart patch through which release can be electronically controlled, allowing repetitive dosing. Rather than relying on passive diffusion, delivery is induced and terminated through the controlled heating of the PCM with transfer only occurring when the PCM transitions from solid to liquid. The material properties of the device and release characteristics of the strategy under repetitive dosing are critically assessed. The delivery yield of curcumin was found to be 3.5 µg (4.5 µg/cm2) per 3 min thermal cycle.

7.
Chron Respir Dis ; 18: 14799731211017895, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34142582

RESUMO

What is the impact of including an allied health assistant (AHA) role on physiotherapy service delivery in an acute respiratory service? A pragmatic pre-post design study examined physiotherapy services across two 3-month periods: current service delivery [P1] and current service delivery plus AHA [P2]. Clinical and non-clinical activity quantified as number, type and duration (per day) of all staff activity categorised for skill level (AHA, junior, senior). Physiotherapy service delivery increased in P2 compared to P1 (n = 4730 vs n = 3048). Physiotherapists undertook fewer respiratory (p < 0.001) and exercise treatments (p < 0.001) but increased reviews for inpatients (p < 0.001) and at multidisciplinary clinics in P2 (56% vs 76%, p < 0.01). The AHA accounted for 20% of all service provision. AHA activity comprised mainly non-direct clinical care including oversight of respiratory equipment use (e.g. supply, set-up, cleaning, loan audits) and other patient-related administrative tasks associated with delegation handovers, supervision and clinical documentation (72%), delegated supervision of established respiratory (5%) and exercise treatments (10%) and delegated exercise tests (3%). The AHA completed most of the exercise tests (n = 25). AHA non-direct clinical tasks included departmental management activities (11%). No adverse events were reported. AHA inclusion in an acute respiratory care service changed physiotherapy service provision. The AHA completed delegated routine clinical and non-clinical tasks. Physiotherapists increased clinic activity and annual reviews. Including an AHA role offers sustainable options for enhancing physiotherapy service provision in acute respiratory care.


Assuntos
Fibrose Cística , Fisioterapeutas , Adulto , Humanos , Modalidades de Fisioterapia , Terapia Respiratória
8.
Joint Bone Spine ; 88(1): 105065, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32896669

RESUMO

OBJECTIVES: Erosion development is of crucial significance as it impacts prognosis and therapy decisions in patients with inflammatory joint diseases. Our study aimed to determine the sensitivity of high-resolution peripheral quantitative computed tomography (HR-pQCT) to detect change of bone surface over time and to identify erosion development in early inflammatory arthritis (EIA) patients. Moreover, the contribution of prognostic factors on periarticular bone damage in the first year of diagnosis assessed by HR-pQCT was explored. METHODS: 46 patients with arthritic symptoms for less than one year, and a clinical diagnosis of inflammatory arthritis were prospectively imaged at baseline and 12-months. HR-pQCT scans of the 2nd and 3rd MCP joints and CR of the hands and feet were performed. Joint space width (JSW), total bone mineral density (Tt.BMD), erosion presence and volume were assessed with HR-pQCT. Scan-rescan precision was assessed to define an individual-level least significant change (LSC) criterion. Regression analyses explored prognostic factors for bone damage progression. RESULTS: We observed no significant group-level changes in JSW, Tt.BMD or erosion volume. 20% or fewer joints demonstrated individual-level changes greater than the LSC criterion for mean JSW, Tt.BMD and erosion volume. HR-pQCT detected more erosions than CR in the 2nd and 3rd MCP. Increased symptom duration at diagnosis was weakly associated (P<0.10) with lower JSW minimum and higher JSW standard deviation. CONCLUSIONS: Gradual degradation of JSW, proportional to symptom duration, was detected by HR-pQCT. EIA patients need to be closely monitored for exacerbation of arthritis and progression of periarticular bone damage.


Assuntos
Artrite Reumatoide , Articulação Metacarpofalângica , Artrite Reumatoide/diagnóstico por imagem , Densidade Óssea , Osso e Ossos , Estudos de Coortes , Humanos , Tomografia Computadorizada por Raios X
9.
BMC Pulm Med ; 20(1): 16, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31952502

RESUMO

BACKGROUND: The 2013 update of the Infection Prevention and Control (IP&C) Guideline outlined recommendations to prevent the spread of CF respiratory pathogens. We aimed to investigate the current infection control practices used in Australian and New Zealand (NZ) CF centers. METHODS: Two online surveys were distributed to Australian and NZ CF centers regarding the uptake of selected IP&C recommendations. One survey was distributed to all the Medical Directors and Lead CF Nurses and the second survey was distributed to all the Lead CF Physiotherapists. RESULTS: The response rate was 60% (60/100) for medical/nursing and 58% (14/24) for physiotherapy. Over 90% (55/60) of CF centers followed CF-specific infection control guidelines and consistent infection control practices were seen in most CF centers; 76% (41/54) had implemented segregation strategies for ambulatory care and no CF centers housed people with CF in shared inpatient accommodation. However, the application of contact precautions (wearing gloves and apron/gown) by healthcare professionals when reviewing a CF person was variable between CF center respondents but was most often used when seeing CF persons with MRSA infection in both ambulatory care and hospital admission (20/50, 40% and 42/45, 93% of CF centers, respectively). Mask wearing by people with CF was implemented into 61% (36/59) of centers. Hospital rooms were cleaned daily in 79% (37/47) of CF centers and the ambulatory care consult rooms were always cleaned between consults (49/49, 100%) and at the end of the clinic session (51/51, 100%); however the staff member tasked with cleaning changed with 37% (18/49) of CF centers responding that CF multidisciplinary team (MDT) members cleaned between patients whereas at the end of the clinic session, only 12% (6/51) of the CF MDT cleaned the consult room. CONCLUSIONS: Overall, Australian and NZ CF centers have adopted many recommendations from the IP&C. Although, the application of contact precautions was inconsistent and had overall a low level of adoption in CF centers. In ~ 25% of centers, mixed waiting areas occurred in the ambulatory care. Given the variability of responses, additional work is required to achieve greater consistency between centers.


Assuntos
Assistência Ambulatorial , Fibrose Cística/terapia , Desinfecção , Hospitalização , Controle de Infecções/métodos , Equipamento de Proteção Individual , Austrália , Fidelidade a Diretrizes , Humanos , Controle de Infecções/normas , Máscaras , Staphylococcus aureus Resistente à Meticilina , Nova Zelândia , Enfermeiros Administradores , Política Organizacional , Isolamento de Pacientes , Quartos de Pacientes , Fisioterapeutas , Diretores Médicos , Consultórios Médicos , Dispositivos de Proteção Respiratória , Infecções Estafilocócicas/prevenção & controle , Inquéritos e Questionários
10.
Nat Commun ; 10(1): 5291, 2019 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-31757939

RESUMO

Histone deacetylase 3 (Hdac3) regulates the expression of lipid metabolism genes in multiple tissues, however its role in regulating lipid metabolism in the intestinal epithelium is unknown. Here we demonstrate that intestine-specific deletion of Hdac3 (Hdac3IKO) protects mice from diet induced obesity. Intestinal epithelial cells (IECs) from Hdac3IKO mice display co-ordinate induction of genes and proteins involved in mitochondrial and peroxisomal ß-oxidation, have an increased rate of fatty acid oxidation, and undergo marked remodelling of their lipidome, particularly a reduction in long chain triglycerides. Many HDAC3-regulated fatty oxidation genes are transcriptional targets of the PPAR family of nuclear receptors, Hdac3 deletion enhances their induction by PPAR-agonists, and pharmacological HDAC3 inhibition induces their expression in enterocytes. These findings establish a central role for HDAC3 in co-ordinating PPAR-regulated lipid oxidation in the intestinal epithelium, and identify intestinal HDAC3 as a potential therapeutic target for preventing obesity and related diseases.


Assuntos
Enterócitos/metabolismo , Histona Desacetilases/genética , Metabolismo dos Lipídeos/genética , Obesidade/genética , Animais , Calorimetria , Dieta Hiperlipídica , Ácidos Graxos/metabolismo , Deleção de Genes , Regulação da Expressão Gênica , Mucosa Intestinal/metabolismo , Peroxidação de Lipídeos/genética , Lipidômica , Camundongos , Mitocôndrias/metabolismo , Receptores Ativados por Proliferador de Peroxissomo/agonistas , Receptores Ativados por Proliferador de Peroxissomo/genética , Triglicerídeos/metabolismo
11.
Front Plant Sci ; 10: 1120, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31681341

RESUMO

Plant pathogens infecting marijuana (Cannabis sativa L.) plants reduce growth of the crop by affecting the roots, crown, and foliage. In addition, fungi (molds) that colonize the inflorescences (buds) during development or after harvest, and which colonize internal tissues as endophytes, can reduce product quality. The pathogens and molds that affect C. sativa grown hydroponically indoors (in environmentally controlled growth rooms and greenhouses) and field-grown plants were studied over multiple years of sampling. A PCR-based assay using primers for the internal transcribed spacer region (ITS) of ribosomal DNA confirmed identity of the cultures. Root-infecting pathogens included Fusarium oxysporum, Fusarium solani, Fusarium brachygibbosum, Pythium dissotocum, Pythium myriotylum, and Pythium aphanidermatum, which caused root browning, discoloration of the crown and pith tissues, stunting and yellowing of plants, and in some instances, plant death. On the foliage, powdery mildew, caused by Golovinomyces cichoracearum, was the major pathogen observed. On inflorescences, Penicillium bud rot (caused by Penicillium olsonii and Penicillium copticola), Botrytis bud rot (Botrytis cinerea), and Fusarium bud rot (F. solani, F. oxysporum) were present to varying extents. Endophytic fungi present in crown, stem, and petiole tissues included soil-colonizing and cellulolytic fungi, such as species of Chaetomium, Trametes, Trichoderma, Penicillium, and Fusarium. Analysis of air samples in indoor growing environments revealed that species of Penicillium, Cladosporium, Aspergillus, Fusarium, Beauveria, and Trichoderma were present. The latter two species were the result of the application of biocontrol products for control of insects and diseases, respectively. Fungal communities present in unpasteurized coconut (coco) fiber growing medium are potential sources of mold contamination on cannabis plants. Swabs taken from greenhouse-grown and indoor buds pre- and post-harvest revealed the presence of Cladosporium and up to five species of Penicillium, as well as low levels of Alternaria species. Mechanical trimming of buds caused an increase in the frequency of Penicillium species, presumably by providing entry points through wounds or spreading endophytes from pith tissues. Aerial distribution of pathogen inoculum and mold spores and dissemination through vegetative propagation are important methods of spread, and entry through wound sites on roots, stems, and bud tissues facilitates pathogen establishment on cannabis plants.

12.
iScience ; 21: 624-637, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31731200

RESUMO

Biliary tract cancers (BTCs) currently have no approved targeted therapies. Although genomic profiling of primary BTCs has identified multiple potential drug targets, accurate models are needed for their evaluation. Genomic profiling of 22 BTC cell lines revealed they harbor similar mutational signatures, recurrently mutated genes, and genomic alterations to primary tumors. Transcriptomic profiling identified two major subtypes, enriched for epithelial and mesenchymal genes, which were also evident in patient-derived organoids and primary tumors. Interrogating these models revealed multiple mechanisms of MAPK signaling activation in BTC, including co-occurrence of low-activity BRAF and MEK mutations with receptor tyrosine kinase overexpression. Finally, BTC cell lines with altered ERBB2 or FGFRs were exquisitely sensitive to specific targeted agents, whereas surprisingly, IDH1-mutant lines did not respond to IDH1 inhibitors in vitro. These findings establish BTC cell lines as robust models of primary disease, reveal specific molecular disease subsets, and highlight specific molecular vulnerabilities in these cancers.

13.
EMBO Rep ; 20(7): e47055, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31267706

RESUMO

Most cells acquire cholesterol by endocytosis of circulating low-density lipoproteins (LDLs). After cholesteryl ester de-esterification in endosomes, free cholesterol is redistributed to intracellular membranes via unclear mechanisms. Our previous work suggested that the unconventional phospholipid lysobisphosphatidic acid (LBPA) may play a role in modulating the cholesterol flux through endosomes. In this study, we used the Prestwick library of FDA-approved compounds in a high-content, image-based screen of the endosomal lipids, lysobisphosphatidic acid and LDL-derived cholesterol. We report that thioperamide maleate, an inverse agonist of the histamine H3 receptor HRH3, increases highly selectively the levels of lysobisphosphatidic acid, without affecting any endosomal protein or function that we tested. Our data also show that thioperamide significantly reduces the endosome cholesterol overload in fibroblasts from patients with the cholesterol storage disorder Niemann-Pick type C (NPC), as well as in liver of Npc1-/- mice. We conclude that LBPA controls endosomal cholesterol mobilization and export to cellular destinations, perhaps by fluidifying or buffering cholesterol in endosomal membranes, and that thioperamide has repurposing potential for the treatment of NPC.


Assuntos
Colesterol/metabolismo , Endossomos/efeitos dos fármacos , Lisofosfolipídeos/metabolismo , Monoglicerídeos/metabolismo , Doença de Niemann-Pick Tipo C/metabolismo , Piperidinas/farmacologia , Animais , Células Cultivadas , Endossomos/metabolismo , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Células HeLa , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C
14.
J Lipid Res ; 60(4): 832-843, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30709900

RESUMO

In specialized cell types, lysosome-related organelles support regulated secretory pathways, whereas in nonspecialized cells, lysosomes can undergo fusion with the plasma membrane in response to a transient rise in cytosolic calcium. Recent evidence also indicates that lysosome secretion can be controlled transcriptionally and promote clearance in lysosome storage diseases. In addition, evidence is also accumulating that low concentrations of cyclodextrins reduce the cholesterol-storage phenotype in cells and animals with the cholesterol storage disease Niemann-Pick type C, via an unknown mechanism. Here, we report that cyclodextrin triggers the secretion of the endo/lysosomal content in nonspecialized cells and that this mechanism is responsible for the decreased cholesterol overload in Niemann-Pick type C cells. We also find that the secretion of the endo/lysosome content occurs via a mechanism dependent on the endosomal calcium channel mucolipin-1, as well as FYCO1, the AP1 adaptor, and its partner Gadkin. We conclude that endo-lysosomes in nonspecialized cells can acquire secretory functions elicited by cyclodextrin and that this pathway is responsible for the decrease in cholesterol storage in Niemann-Pick C cells.


Assuntos
Ciclodextrinas/farmacologia , Endossomos/efeitos dos fármacos , Doença de Niemann-Pick Tipo C/tratamento farmacológico , Canais de Potencial de Receptor Transitório/antagonistas & inibidores , Colesterol/análise , Endossomos/metabolismo , Células HeLa , Humanos , Microscopia de Fluorescência , Doença de Niemann-Pick Tipo C/metabolismo , Doença de Niemann-Pick Tipo C/patologia , Canais de Potencial de Receptor Transitório/metabolismo , Células Tumorais Cultivadas
15.
J Cell Biochem ; 120(8): 12450-12460, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30805994

RESUMO

Osteoclasts (OCs) are large, multinucleated bone resorbing cells originating from the bone marrow myeloid lineage, and share a common progenitor with macrophages and dendritic cells. Bone marrow cells (BMCs) are a common source for in vitro osteoclastogenesis assays but are a highly heterogeneous mixture of cells. Protocols for in vitro osteoclastogenesis vary considerably thus hindering interpretation and comparison of results between studies. Macrophage colony-stimulating factor (M-CSF) pretreatment is commonly used to expand OC progenitors (OCPs) in BMC cultures before in vitro differentiation. However, the failure of osteoclastogenesis of M-CSF primed bone marrow myeloid blasts has been reported. In this study, we used a simple method of differential adherence to plastic to enrich OCP from mouse BMCs. We found that M-CSF pretreatment of plastic-adherent BMCs (adBMCs) increased the number of CD11b-F4/80+ macrophages and decreased the number of CD11b+ monocytes resulting in decreased OC formation. M-CSF pretreatment of purified c-Kit+ progenitors weakly inhibited OC formation, whereas M-CSF pretreatment of purified c-Kit-CD11b+ progenitors promoted the formation of large OC. M-CSF pretreatment increased the proliferation of both purified c-Kit+ and c-Kit-CD11b+ cells and increased the percentage of CD11b-F4/80+ cells from c-Kit+ progenitors. In addition, M-CSF pretreatment increased the percentage of CD11b+ F4/80- cells from purified c-Kit-CD11b+ cells. M-CSF pretreatment increased the percentage of CD14 + CD16 + intermediate monocytes and subsequent OC formation from human 2adBMCs, and increased OC formation of purified CD14 + cells. Together, these results indicate that in vitro OCP expansion in the presence of M-CSF and bone marrow stromal cells is dependent upon the developmental stage of myeloid cells, in which M-CSF favors macrophage differentiation of multipotent progenitors, promotes monocyte maturation and supports differentiation of late-stage OCP cells.


Assuntos
Células da Medula Óssea/citologia , Diferenciação Celular , Fator Estimulador de Colônias de Macrófagos/farmacologia , Células Mieloides/citologia , Osteoclastos/citologia , Osteogênese , Células-Tronco/citologia , Animais , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Células Cultivadas , Feminino , Hematopoese , Fator Estimulador de Colônias de Macrófagos/administração & dosagem , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células Mieloides/efeitos dos fármacos , Células Mieloides/metabolismo , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo
16.
Exp Mol Pathol ; 105(3): 404-410, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30423315

RESUMO

Breast cancers arising in women carrying a germline mutation in BRCA1 are typically high-grade, early-onset and have distinct morphological features (BRCA1-like). However, the majority of early-onset breast cancers of this morphological type are not associated with germline BRCA1 mutations or constitutional BRCA1 promoter methylation. We aimed to assess DNA methylation across the genome for associations with the "BRCA1-like" morphology. Genome-wide methylation in blood-derived DNA was measured using the Infinium HumanMethylation450K BeadChip assay for women under the age of 40 years participating in the Australian Breast Cancer Family Study (ABCFS) diagnosed with: i) BRCA1-like breast cancer (n = 30); and ii) breast cancer without BRCA1-like morphological features (non BRCA1-like; n = 30), and age-matched unaffected women (controls; n = 30). Corresponding tumour-derived DNA from 43 of the affected women was also assessed. Methylation of blood-derived DNA was found to be elevated across 17 consecutive marks in the BRCA1 promoter region and decreased at several other genomic regions (including TWIST2 and CTBP1) for 7 women (23%) diagnosed with BRCA1-like breast cancer compared with women in the other groups. Corresponding tumour-derived DNA available from 5 of these 7 women had elevated methylation within the BRCA1 and SPHK2 promoter region and decreased methylation within the ADAP1, IGF2BP3 and SPATA13 promoter region when compared with the other breast tumours. These methylation marks could be biomarkers of risk for BRCA1-like breast cancer, and could be responsible in part for their distinctive morphological features and biology. As such, they may assist with prevention and targeted therapies for this cancer subtype.


Assuntos
Proteína BRCA1/genética , Neoplasias da Mama/genética , Metilação de DNA/genética , Adulto , Austrália , Feminino , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Humanos , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Sistema de Registros
17.
Elife ; 72018 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-30256193

RESUMO

How trafficking pathways and organelle abundance adapt in response to metabolic and physiological changes is still mysterious, although a few transcriptional regulators of organellar biogenesis have been identified in recent years. We previously found that the Wnt signaling directly controls lipid droplet formation, linking the cell storage capacity to the established functions of Wnt in development and differentiation. In the present paper, we report that Wnt-induced lipid droplet biogenesis does not depend on the canonical TCF/LEF transcription factors. Instead, we find that TFAP2 family members mediate the pro-lipid droplet signal induced by Wnt3a, leading to the notion that the TFAP2 transcription factor may function as a 'master' regulator of lipid droplet biogenesis.


Assuntos
Gotículas Lipídicas/metabolismo , Fator de Transcrição AP-2/genética , Proteína Wnt3A/genética , Animais , Regulação da Expressão Gênica/genética , Humanos , Camundongos , Regiões Promotoras Genéticas , Transdução de Sinais/genética , Ativação Transcricional/genética , Via de Sinalização Wnt/genética
18.
J Vis Exp ; (126)2017 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-28872124

RESUMO

Many early endosome functions, particularly cargo protein sorting and membrane deformation, depend on patches of short F-actin filaments nucleated onto the endosomal membrane. We have established a microscopy-based in vitro assay that reconstitutes the nucleation and polymerization of F-actin on early endosomal membranes in test tubes, thus rendering this complex series of reactions amenable to genetic and biochemical manipulations. Endosomal fractions are prepared by floatation in sucrose gradients from cells expressing the early endosomal protein GFP-RAB5. Cytosolic fractions are prepared from separate batches of cells. Both endosomal and cytosolic fractions can be stored frozen in liquid nitrogen, if needed. In the assay, the endosomal and cytosolic fractions are mixed, and the mixture is incubated at 37 °C under appropriate conditions (e.g., ionic strength, reducing environment). At the desired time, the reaction mixture is fixed, and the F-actin is revealed with phalloidin. Actin nucleation and polymerization are then analyzed by fluorescence microscopy. Here, we report that this assay can be used to investigate the role of factors that are involved either in actin nucleation on the membrane, or in the subsequent elongation, branching, or crosslinking of F-actin filaments.


Assuntos
Actinas/metabolismo , Endossomos/metabolismo , Animais , Polimerização
19.
Mol Biol Cell ; 28(20): 2637-2649, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-28768829

RESUMO

Changes in cellular sterol species and concentrations can have profound effects on the transcriptional profile. In yeast, mutants defective in sterol biosynthesis show a wide range of changes in transcription, including a coinduction of anaerobic genes and ergosterol biosynthesis genes, biosynthesis of basic amino acids, and several stress genes. However the mechanisms underlying these changes are unknown. We identified mutations in the SAGA complex, a coactivator of transcription, which abrogate the ability to carry out most of these sterol-dependent transcriptional changes. In the erg3 mutant, the SAGA complex increases its occupancy time on many of the induced ergosterol and anaerobic gene promoters, increases its association with several relevant transcription factors and the SWI/SNF chromatin remodeling complex, and surprisingly, associates with an endocytic protein, Rvs167p, suggesting a moonlighting function for this protein in the sterol-regulated induction of the heat shock protein, HSP42 and HSP102, mRNAs.


Assuntos
Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Transativadores/genética , Transativadores/metabolismo , Montagem e Desmontagem da Cromatina , Ergosterol/genética , Ergosterol/metabolismo , Regulação Fúngica da Expressão Gênica , Regiões Promotoras Genéticas , Esteróis/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica
20.
Trends Plant Sci ; 22(6): 472-490, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28389147

RESUMO

With world population growing quickly, agriculture needs to produce more with fewer inputs while being environmentally friendly. In a context of changing environments, crop models are useful tools to simulate crop yields. Wheat (Triticum spp.) crop models have been evolving since the 1960s to translate processes related to crop growth and development into mathematical equations. These have been used over decades for agronomic purposes, and have more recently incorporated advances in the modeling of environmental footprints, biotic constraints, trait and gene effects, climate change impact, and the upscaling of global change impacts. This review outlines the potential and limitations of modern wheat crop models in assisting agronomists, breeders, and policymakers to address the current and future challenges facing agriculture.


Assuntos
Produtos Agrícolas/metabolismo , Produtos Agrícolas/fisiologia , Triticum/metabolismo , Triticum/fisiologia , Adaptação Fisiológica/genética , Adaptação Fisiológica/fisiologia , Produtos Agrícolas/genética , Modelos Teóricos , Triticum/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...