Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 196
Filtrar
1.
Nat Immunol ; 25(2): 268-281, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38195702

RESUMO

Melanoma cells, deriving from neuroectodermal melanocytes, may exploit the nervous system's immune privilege for growth. Here we show that nerve growth factor (NGF) has both melanoma cell intrinsic and extrinsic immunosuppressive functions. Autocrine NGF engages tropomyosin receptor kinase A (TrkA) on melanoma cells to desensitize interferon γ signaling, leading to T and natural killer cell exclusion. In effector T cells that upregulate surface TrkA expression upon T cell receptor activation, paracrine NGF dampens T cell receptor signaling and effector function. Inhibiting NGF, either through genetic modification or with the tropomyosin receptor kinase inhibitor larotrectinib, renders melanomas susceptible to immune checkpoint blockade therapy and fosters long-term immunity by activating memory T cells with low affinity. These results identify the NGF-TrkA axis as an important suppressor of anti-tumor immunity and suggest larotrectinib might be repurposed for immune sensitization. Moreover, by enlisting low-affinity T cells, anti-NGF reduces acquired resistance to immune checkpoint blockade and prevents melanoma recurrence.


Assuntos
Melanoma , Receptor de Fator de Crescimento Neural , Humanos , Receptor de Fator de Crescimento Neural/genética , Receptor de Fator de Crescimento Neural/metabolismo , Fator de Crescimento Neural/genética , Fator de Crescimento Neural/metabolismo , Tropomiosina , Melanoma/terapia , Receptor trkA/genética , Receptor trkA/metabolismo , Citoproteção , Inibidores de Checkpoint Imunológico , Células T de Memória , Terapia de Imunossupressão , Imunoterapia , Receptores de Antígenos de Linfócitos T
2.
Eur Spine J ; 33(3): 892-899, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37046075

RESUMO

PURPOSE: Lumbar spinal stenosis (LSS) is the most common reason for spinal surgery in patients over the age of 65, and there are few effective non-surgical treatments. Therefore, the development of novel treatment or preventative modalities to decrease overall cost and morbidity associated with LSS is an urgent matter. The cause of LSS is multifactorial; however, a significant contributor is ligamentum flavum hypertrophy (LFH) which causes mechanical compression of the cauda equina or nerve roots. We assessed the role of a novel target, microRNA-29a (miR-29a), in LFH and investigated the potential for using miR-29a as a therapeutic means to combat LSS. METHODS: Ligamentum flavum (LF) tissue was collected from patients undergoing decompressive surgery for LSS and assessed for levels of miR-29a and pro-fibrotic protein expression. LF cell cultures were then transfected with either miR-29a over-expressor (agonist) or inhibitor (antagonist). The effects of over-expression and under-expression of miR-29a on expression of pro-fibrotic proteins was assessed. RESULTS: We demonstrated that LF at stenotic levels had a loss of miR-29a expression. This was associated with greater LF tissue thickness and higher mRNA levels of collagen I and III. We also demonstrated that miR29-a plays a direct role in the regulation of collagen gene expression in ligamentum flavum. Specifically, agents that increase miR-29a may attenuate LFH, while those that decrease miR-29a promote fibrosis and LFH. CONCLUSION: This study demonstrates that miR-29a may potentially be used to treat LFH and provides groundwork to initiate the development of a therapeutic product for LSS.


Assuntos
Cauda Equina , MicroRNAs , Estenose Espinal , Humanos , Colágeno Tipo I , Hipertrofia , MicroRNAs/genética , Procedimentos Neurocirúrgicos , Estenose Espinal/terapia
3.
Glob Chang Biol ; 29(14): 3883-3894, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36872638

RESUMO

The spatial extent of marine and terrestrial protected areas (PAs) was among the most intensely debated issues prior to the decision about the post-2020 Global Biodiversity Framework (GBF) of the Convention on Biological Diversity. Positive impacts of PAs on habitats, species diversity and abundance are well documented. Yet, biodiversity loss continues unabated despite efforts to protect 17% of land and 10% of the oceans by 2020. This casts doubt on whether extending PAs to 30%, the agreed target in the Kunming-Montreal GBF, will indeed achieve meaningful biodiversity benefits. Critically, the focus on area coverage obscures the importance of PA effectiveness and overlooks concerns about the impact of PAs on other sustainability objectives. We propose a simple means of assessing and visualising the complex relationships between PA area coverage and effectiveness and their effects on biodiversity conservation, nature-based climate mitigation and food production. Our analysis illustrates how achieving a 30% PA global target could be beneficial for biodiversity and climate. It also highlights important caveats: (i) achieving lofty area coverage objectives alone will be of little benefit without concomitant improvements in effectiveness, (ii) trade-offs with food production particularly for high levels of coverage and effectiveness are likely and (iii) important differences in terrestrial and marine systems need to be recognized when setting and implementing PA targets. The CBD's call for a significant increase in PA will need to be accompanied by clear PA effectiveness goals to reduce and revert dangerous anthropogenic impacts on socio-ecological systems and biodiversity.


Assuntos
Biodiversidade , Ecossistema , Clima , Oceanos e Mares , Carbidopa , Conservação dos Recursos Naturais
4.
BMC Nephrol ; 24(1): 346, 2023 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-37993798

RESUMO

BACKGROUND: Kidney transplantation is the optimal treatment option for most patients with end-stage kidney disease given the significantly lower morbidity and mortality rates compared to remaining on dialysis. Rejection and graft failure remain common in transplant recipients with limited improvement in long-term transplant outcomes despite therapeutic advances. There is an unmet need in the development of non-invasive biomarkers that specifically monitor graft function and predict transplant pathologies that affect outcomes. Despite the potential of proteomic investigatory approaches, up to now, no candidate biomarkers of sufficient sensitivity or specificity have translated into clinical use. The aim of this review was to collate and summarise protein findings and protein pathways implicated in the literature to date, and potentially flag putative biomarkers worth validating in independent patient cohorts. METHODS: This review followed the Joanna Briggs' Institute Methodology for a scoping review. MedlineALL, Embase, Web of Science Core Collection, Scopus and Google Scholar databases were searched from inception until December 2022. Abstract and full text review were undertaken independently by two reviewers. Data was collated using a pre-designed data extraction tool. RESULTS: One hundred one articles met the inclusion criteria. The majority were single-centre retrospective studies of small sample size. Mass spectrometry was the most used technique to evaluate differentially expressed proteins between diagnostic groups and studies identified various candidate biomarkers such as immune or structural proteins. DISCUSSION: Putative immune or structural protein candidate biomarkers have been identified using proteomic techniques in multiple sample types including urine, serum and fluid used to perfuse donor kidneys. The most consistent findings implicated proteins associated with tubular dysfunction and immunological regulatory pathways such as leukocyte trafficking. However, clinical translation and adoption of candidate biomarkers is limited, and these will require comprehensive evaluation in larger prospective, multicentre trials.


Assuntos
Transplante de Rim , Humanos , Proteômica , Estudos Retrospectivos , Estudos Prospectivos , Diálise Renal , Biomarcadores
5.
Artigo em Alemão | MEDLINE | ID: mdl-37964045

RESUMO

In October 2019, an integrated dentistry program (iMED DENT) was implemented at the University of Hamburg and was the first of its kind in Germany. This model curriculum builds on didactic concepts that have been applied successfully for many years in curricula for human medicine, including interdisciplinary teaching, early clinical experience, and scientific education. The first year focuses on the healthy situation ("normal function") and aims to integrate the natural sciences (biology, chemistry, physics) and the basic medical subjects (anatomy, biochemistry, physiology, medical terminology) in the context of dental health. Further, basic practical and clinical tasks are assigned to the students during the first year.From the experience of the first four cohorts, initial conclusions can be drawn about this stage of study. Generally, its modular structure results in a condensation of learning content, which students judge as demanding. However, its interdisciplinary approach is well accepted. For instance, presenting the basics of the natural sciences in the context of their dental relevance is much better evaluated in the new compared to the previous curriculum, in which this content was taught without specific references to dental health. Teaching the basics of medicine within clinical context and the inclusion of early clinical practice are similarly appreciated. Presently, the interdisciplinary approach is limited by the focus on practical competencies of the dentistry curriculum, as some practical courses offer only few opportunities for other disciplines to interconnect their teaching. The continuous evaluation of the curriculum and exchange of experiences between the disciplines will further improve the integrative concept of the curriculum.


Assuntos
Currículo , Disciplinas das Ciências Naturais , Humanos , Alemanha , Aprendizagem , Odontologia
6.
BMC Med Educ ; 22(1): 515, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35778720

RESUMO

BACKGROUND: E-learning based laboratory classes can replace or enhance in-classroom laboratories. They typically offer temporal flexibility, self-determined learning speed, repeatability and do not require supervision or face-to-face contact. The aim of this feasibility study was to investigate whether the established in-classroom laboratory class on the baroreceptor reflex (BRR) can be transformed into a new e-learning based asynchronous laboratory class for untrained, non-supervised students without medical equipment. The BRR is a fundamental cardiovascular process which is regularly visualized in physiology during in-classroom laboratories by a student-performed Active Standing Test (AST). During this voluntary provocation of orthostatic stress, the BRR reliably causes a solid rise in heart rate (HR) and a stabilization or even increase in blood pressure (BP). METHODS: The conventional AST was modified by omission of BP measurements which would require medical devices and was embedded into a framework of interactive digital material allowing independent student performance. With specific adaptions, this instrument was implemented to 1st and 2nd year curricula of human medicine, dental medicine, midwifery and pharmacy. An audience response system was used to collect the students' data on HR, epidemiology, technical problems, satisfaction and orthostatic symptoms. As primary outcome, we investigated the students' correct performance of the modified AST regarding textbook conformity of the HR data. Secondary outcomes included technical feasibility, the students' satisfaction and consistency of HR data within predefined subgroups (e.g., gender, curricula). Descriptive statistics are reported. RESULTS: The class was completed by 217 students (mean age: 23 ± 8 [SD], 81% female, 19% male). Mean reported rise of HR during standing was ~ 20 bpm (~ 30%) which is highly concordant to textbooks. Reported feasibility (~ 80% negated any technical issues) and students' satisfaction (4.4 on 5-point Likert-scale) were high. The HR data were consistent within the subgroups. CONCLUSION: This study demonstrates that the highly relevant BRR can be successfully addressed in an e-learning based asynchronous laboratory class implementing a non-supervised AST restricted to HR measurements embedded in digital material. The robust HR response and the adjustable complexity allow an application to different healthcare-related curricula. This class, therefore, provides a broad audience access to a fundamental concept of cardiovascular physiology.


Assuntos
Barorreflexo , Instrução por Computador , Adolescente , Adulto , Currículo , Feminino , Humanos , Aprendizagem , Masculino , Estudantes , Adulto Jovem
7.
BMC Dev Biol ; 21(1): 10, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-34225660

RESUMO

BACKGROUND: Mice with a loss of function mutation in Wdpcp were described previously to display severe birth defects in the developing heart, neural tube, and limb buds. Further characterization of the skeletal phenotype of Wdpcp null mice was limited by perinatal lethality. RESULTS: We utilized Prx1-Cre mice to generate limb bud mesenchyme specific deletion of Wdpcp. These mice recapitulated the appendicular skeletal phenotype of the Wdpcp null mice including polydactyl and limb bud signaling defects. Examination of late stages of limb development demonstrated decreased size of cartilage anlagen, delayed calcification, and abnormal growth plates. Utilizing in vitro assays, we demonstrated that loss of Wdpcp in skeletal progenitors lead to loss of hedgehog signaling responsiveness and associated proliferative response. In vitro chondrogenesis assays showed this loss of hedgehog and proliferative response was associated with decreased expression of early chondrogenic marker N-Cadherin. E14.5 forelimbs demonstrated delayed ossification and expression of osteoblast markers Runx2 and Sp7. P0 growth plates demonstrated loss of hedgehog signaling markers and expansion of the hypertrophic zones of the growth plate. In vitro osteogenesis assays demonstrated decreased osteogenic differentiation of Wdpcp null mesenchymal progenitors in response to hedgehog stimulation. CONCLUSIONS: These findings demonstrate how Wdpcp and associated regulation of the hedgehog signaling pathway plays an important role at multiple stages of skeletal development. Wdpcp is necessary for positive regulation of hedgehog signaling and associated proliferation is key to the initiation of chondrogenesis. At later stages, Wdpcp facilitates the robust hedgehog response necessary for chondrocyte hypertrophy and osteogenic differentiation.


Assuntos
Proteínas do Citoesqueleto/genética , Proteínas Hedgehog , Botões de Extremidades/crescimento & desenvolvimento , Osteogênese , Animais , Diferenciação Celular , Proliferação de Células , Condrócitos , Condrogênese , Proteínas Hedgehog/genética , Camundongos , Transdução de Sinais
8.
Br J Cancer ; 124(4): 786-796, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33223535

RESUMO

BACKGROUND: The Glasgow Microenvironment Score (GMS) combines peritumoural inflammation and tumour stroma percentage to assess interactions between tumour and microenvironment. This was previously demonstrated to associate with colorectal cancer (CRC) prognosis, and now requires validation and assessment of interactions with adjuvant therapy. METHODS: Two cohorts were utilised; 862 TNM I-III CRC validation cohort, and 2912 TNM II-III CRC adjuvant chemotherapy cohort (TransSCOT). Primary endpoints were disease-free survival (DFS) and relapse-free survival (RFS). Exploratory endpoint was adjuvant chemotherapy interaction. RESULTS: GMS independently associated with DFS (p = 0.001) and RFS (p < 0.001). GMS significantly stratified RFS for both low risk (GMS 0 v GMS 2: HR 3.24 95% CI 1.85-5.68, p < 0.001) and high-risk disease (GMS 0 v GMS 2: HR 2.18 95% CI 1.39-3.41, p = 0.001). In TransSCOT, chemotherapy type (pinteraction = 0.013), but not duration (p = 0.64) was dependent on GMS. Furthermore, GMS 0 significantly associated with improved DFS in patients receiving FOLFOX compared with CAPOX (HR 2.23 95% CI 1.19-4.16, p = 0.012). CONCLUSIONS: This study validates the GMS as a prognostic tool for patients with stage I-III colorectal cancer, independent of TNM, with the ability to stratify both low- and high-risk disease. Furthermore, GMS 0 could be employed to identify a subset of patients that benefit from FOLFOX over CAPOX.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/patologia , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Capecitabina/administração & dosagem , Quimioterapia Adjuvante , Estudos de Coortes , Intervalo Livre de Doença , Feminino , Fluoruracila/administração & dosagem , Humanos , Estimativa de Kaplan-Meier , Leucovorina/administração & dosagem , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Compostos Organoplatínicos/administração & dosagem , Oxaliplatina/administração & dosagem , Prognóstico , Reprodutibilidade dos Testes , Microambiente Tumoral
9.
BMC Microbiol ; 21(1): 105, 2021 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-33832427

RESUMO

BACKGROUND: The rise of microbial antibiotic resistance is a leading threat to the health of the human population. As such, finding new approaches to tackle these microbes, including development of novel antibiotics is vital. RESULTS: In this study, we mined a rumen eukaryotic metatranscriptomic library for novel Antimicrobial peptides (AMPs) using computational approaches and thereafter characterised the therapeutic potential of the AMPs. We identified a total of 208 potentially novel AMPs from the ruminal eukaryotome, and characterised one of those, namely Lubelisin. Lubelisin (GIVAWFWRLAR) is an α-helical peptide, 11 amino acid long with theoretical molecular weight of 1373.76 D. In the presence of Lubelisin, strains of methicillin-resistant Staphylococcus aureus (MRSA) USA300 and EMRSA-15 were killed within 30 min of exposure with ≥103 and 104 CFU/mL reduction in viable cells respectively. Cytotoxicity of Lubelisin against both human and sheep erythrocytes was low resulting in a therapeutic index of 0.43. Membrane permeabilisation assays using propidium iodide alongside transmission electron microscopy revealed that cytoplasmic membrane damage may contribute to the antimicrobial activities of Lubelisin. CONCLUSIONS: We demonstrate that the rumen eukaryotome is a viable source for the discovery of antimicrobial molecules for the treatment of bacterial infections and further development of these may provide part of the potential solution to the ongoing problem of antimicrobial resistance. The role of these AMPs in the ecological warfare within the rumen is also currently unknown.


Assuntos
Eucariotos , Staphylococcus aureus Resistente à Meticilina , Proteínas Citotóxicas Formadoras de Poros , Rúmen/parasitologia , Animais , Membrana Celular/efeitos dos fármacos , Membrana Celular/ultraestrutura , Descoberta de Drogas , Eritrócitos/efeitos dos fármacos , Eucariotos/metabolismo , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Proteínas Citotóxicas Formadoras de Poros/química , Proteínas Citotóxicas Formadoras de Poros/isolamento & purificação , Proteínas Citotóxicas Formadoras de Poros/farmacologia , Transcriptoma
10.
Glob Chang Biol ; 27(16): 3718-3731, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33887083

RESUMO

Human activity and land use change impact every landscape on Earth, driving declines in many animal species while benefiting others. Species ecological and life history traits may predict success in human-dominated landscapes such that only species with "winning" combinations of traits will persist in disturbed environments. However, this link between species traits and successful coexistence with humans remains obscured by the complexity of anthropogenic disturbances and variability among study systems. We compiled detection data for 24 mammal species from 61 populations across North America to quantify the effects of (1) the direct presence of people and (2) the human footprint (landscape modification) on mammal occurrence and activity levels. Thirty-three percent of mammal species exhibited a net negative response (i.e., reduced occurrence or activity) to increasing human presence and/or footprint across populations, whereas 58% of species were positively associated with increasing disturbance. However, apparent benefits of human presence and footprint tended to decrease or disappear at higher disturbance levels, indicative of thresholds in mammal species' capacity to tolerate disturbance or exploit human-dominated landscapes. Species ecological and life history traits were strong predictors of their responses to human footprint, with increasing footprint favoring smaller, less carnivorous, faster-reproducing species. The positive and negative effects of human presence were distributed more randomly with respect to species trait values, with apparent winners and losers across a range of body sizes and dietary guilds. Differential responses by some species to human presence and human footprint highlight the importance of considering these two forms of human disturbance separately when estimating anthropogenic impacts on wildlife. Our approach provides insights into the complex mechanisms through which human activities shape mammal communities globally, revealing the drivers of the loss of larger predators in human-modified landscapes.


Assuntos
Animais Selvagens , Características de História de Vida , Animais , Ecossistema , Atividades Humanas , Humanos , Mamíferos , América do Norte
11.
Int J Med Sci ; 18(5): 1277-1284, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33526989

RESUMO

Rationale: To assess the longitudinal changes and relationships of clinical measures and extent of CT lung abnormalities in COVID-19. Methods: 81 patients with COVID-19 were prospectively enrolled and followed until discharge. CT scores were quantified on a basis of a CT scoring system where each lung was divided into 3 zones: upper (above the carina), middle, and lower (below the inferior pulmonary vein) zones; each zone was evaluated for percentage of lung involvement on a scale of 0-4 (0, 0%; 1, 0-24%; 2, 25% - 49%; 3, 50% -74%; 4, >74%).Temporal trends of CT scores and the laboratory parameters characteristic of COVID-19 were analyzed. Correlations between the two were determined at three milestones (initial presentation, worst CT manifestation, and recovery finding before discharge). Their correlations with duration to worst CT manifestation and discharge from symptom onset were evaluated. Results: CT scores peaked during illness days 6-11 (median: 5), and stayed steady. C-reactive protein and lactate dehydrogenase increased, peaked on illness days 6-8 and 8-11 (mean: 23.5 mg/L, 259.9 U/L), and gradually declined. Continual decrease and increase were observed in hemoglobin and lymphocyte count, respectively. Albumin reduced and remained at low levels with a nadir on illness days 12-15 (36.6 g/L). Both initial (r = 0.58, 0.64, p < 0.05) and worst CT scores (r = 0.47, 0.65, p < 0.05) were correlated with C-reactive protein and lactate dehydrogenase; and CT scores before discharge, only with albumin (r = -0.41, p < 0.05). Duration to worst CT manifestation was associated with initial and worst CT scores (r = 0.33, 0.29, p < 0.05). No parameters were related to timespan to discharge. Conclusion: Our results illustrated the temporal changes of characteristic clinical measures and extent of CT lung abnormalities in COVID-19. CT scores correlated with some important laboratory parameters, and might serve as prognostic factors.


Assuntos
COVID-19/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Adulto , Proteína C-Reativa/metabolismo , COVID-19/sangue , Feminino , Humanos , L-Lactato Desidrogenase/sangue , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Radiografia Torácica , Tomografia Computadorizada por Raios X
12.
Handb Exp Pharmacol ; 265: 235-268, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33471201

RESUMO

Musculoskeletal injuries and associated conditions are the leading cause of physical disability worldwide. The concept of tissue engineering has opened up novel approaches to repair musculoskeletal defects in a fast and/or efficient manner. Biomaterials, cells, and signaling molecules constitute the tissue engineering triad. In the past 40 years, significant progress has been made in developing and optimizing all three components, but only a very limited number of technologies have been successfully translated into clinical applications. A major limiting factor of this barrier to translation is the insufficiency of two-dimensional cell cultures and traditional animal models in informing the safety and efficacy of in-human applications. In recent years, microphysiological systems, often referred to as organ or tissue chips, generated according to tissue engineering principles, have been proposed as the next-generation drug testing models. This chapter aims to first review the current tissue engineering-based approaches that are being applied to fabricate and develop the individual critical elements involved in musculoskeletal organ/tissue chips. We next highlight the general strategy of generating musculoskeletal tissue chips and their potential in future regenerative medicine research. Exemplary microphysiological systems mimicking musculoskeletal tissues are described. With sufficient physiological accuracy and relevance, the human cell-derived, three-dimensional, multi-tissue systems have been used to model a number of orthopedic disorders and to test new treatments. We anticipate that the novel emerging tissue chip technology will continually reshape and improve our understanding of human musculoskeletal pathophysiology, ultimately accelerating the development of advanced pharmaceutics and regenerative therapies.


Assuntos
Medicina Regenerativa , Engenharia Tecidual , Animais , Humanos , Regeneração
13.
EMBO Rep ; 19(6)2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29777051

RESUMO

Cellular senescence is a unique cell fate characterized by stable proliferative arrest and the extensive production and secretion of various inflammatory proteins, a phenomenon known as the senescence-associated secretory phenotype (SASP). The molecular mechanisms responsible for generating a SASP in response to senescent stimuli remain largely obscure. Here, using unbiased gene expression profiling, we discover that the scavenger receptor CD36 is rapidly upregulated in multiple cell types in response to replicative, oncogenic, and chemical senescent stimuli. Moreover, ectopic CD36 expression in dividing mammalian cells is sufficient to initiate the production of a large subset of the known SASP components via activation of canonical Src-p38-NF-κB signaling, resulting in the onset of a full senescent state. The secretome is further shown to be ligand-dependent, as amyloid-beta (Aß) is sufficient to drive CD36-dependent NF-κB and SASP activation. Finally, loss-of-function experiments revealed a strict requirement for CD36 in secretory molecule production during conventional senescence reprogramming. Taken together, these results uncover the Aß-CD36-NF-κB signaling axis as an important regulator of the senescent cell fate via induction of the SASP.


Assuntos
Precursor de Proteína beta-Amiloide/metabolismo , Antígenos CD36/fisiologia , Senescência Celular/fisiologia , NF-kappa B/metabolismo , Antígenos CD36/genética , Células Cultivadas , Senescência Celular/genética , Fibroblastos/metabolismo , Humanos , Mutação com Perda de Função , Transdução de Sinais
15.
Magn Reson Med ; 81(4): 2728-2735, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30394578

RESUMO

PURPOSE: Duchenne muscular dystrophy (DMD) is a genetic condition caused by mutations in the DMD gene leading to muscle degeneration, fatty replacement of muscle cells and fibrosis. A major obstacle to advancing therapeutic research into muscular dystrophies is development of sensitive, noninvasive outcome measures. To date, no validated method to noninvasively quantify fibrosis within skeletal muscle exists. EP3533 is a gadolinium-based MRI contrast agent with an affinity to collagen-1. The purpose of this study was to determine whether EP3533-enhanced MRI could quantify fibrosis in a murine model of DMD (mdx) in muscle. METHODS: Mdx (n = 8) and control mice (BL10; n = 5) underwent contrast-enhanced MRI acquisitions with EP3533. T1 mapping pre- and postcontrast was performed in skeletal and cardiac muscle. Post-MRI the tibialis anterior (TA) and gastrocnemius (GCN) muscles and the heart were removed for fibrosis quantification by means of Masson's trichrome staining and the hydroxyproline assay. RESULTS: Significant differences in postcontrast R1 were demonstrated between mdx and BL10 mice using EP3533 (cardiac P = 0.02, GCN P = 0.04, TA P = 0.04). Change in R1 from baseline following EP3533 administration correlated strongly to hydroxyproline levels (GCN: r = 0.83, P = 0.001; TA: r = 0.73, P = 0.01). CONCLUSIONS: This study provides evidence for the suitability of EP3533 in the quantification of muscular fibrosis in mdx mice and demonstrated that EP3533-derived measurements correlated strongly to ex vivo fibrosis measurement.


Assuntos
Colágeno/química , Meios de Contraste/química , Gadolínio DTPA/química , Coração/diagnóstico por imagem , Imageamento por Ressonância Magnética , Músculo Esquelético/diagnóstico por imagem , Distrofia Muscular de Duchenne/diagnóstico por imagem , Miocárdio/patologia , Peptídeos/química , Animais , Fibrose/diagnóstico por imagem , Gadolínio , Camundongos , Camundongos Endogâmicos mdx , Músculo Esquelético/patologia , Distrofia Muscular de Duchenne/patologia , Mutação
16.
Ann Surg Oncol ; 26(13): 4397-4404, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31605345

RESUMO

BACKGROUND: Tumor budding is an independent prognostic factor in colorectal cancer (CRC) and has recently been well-defined by the International Tumour Budding Consensus Conference (ITBCC). OBJECTIVE: The aim of the present study was to use the ITBCC budding evaluation method to examine the relationship between tumor budding, tumor factors, tumor microenvironment, and survival in patients with primary operable CRC. METHODS: Hematoxylin and eosin-stained slides of 952 CRC patients diagnosed between 1997 and 2007 were evaluated for tumor budding according to the ITBCC criteria. The tumor microenvironment was evaluated using tumor stroma percentage (TSP) and Klintrup-Makinen (KM) grade to assess the tumor inflammatory cell infiltrate. RESULTS: High budding (n = 268, 28%) was significantly associated with TNM stage (p < 0.001), competent mismatch repair (MMR; p < 0.05), venous invasion (p < 0.001), weak KM grade (p < 0.001), high TSP (p < 0.001), and reduced cancer-specific survival (CSS) (hazard ratio 8.68, 95% confidence interval 6.30-11.97; p < 0.001). Tumor budding effectively stratifies CSS stage T1 through to T4 (all p < 0.05) independent of associated factors. CONCLUSIONS: Tumor budding effectively stratifies patients' survival in primary operable CRC independent of other phenotypic features. In particular, the combination of T stage and budding should form the basis of a new staging system for primary operable CRC.


Assuntos
Neoplasias Colorretais/patologia , Microambiente Tumoral , Idoso , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/cirurgia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida
17.
BMC Nephrol ; 20(1): 478, 2019 12 26.
Artigo em Inglês | MEDLINE | ID: mdl-31878889

RESUMO

BACKGROUND: Administering anti-vascular endothelial growth factor (anti-VEGF) by intraocular injection has been shown to have a safe systemic profile. Nevertheless, incidents of acute kidney injury following anti-VEGF injection have been reported. We assessed the long-term effect of multiple intravitreal anti-VEGF injections on measures of renal function in patients with diabetes including rate of change of estimated glomerular filtration rate (eGFR) and urine albumin-to-creatinine ratio (ACR). METHODS: A retrospective review of patients receiving diabetic macular oedema (DMO) treatment was undertaken. Serum creatinine, ACR, number of intravitreal anti-VEGF injections and clinical characteristics were collected from electronic healthcare records (EHR). A co-efficient of eGFR and ACR change with time was calculated over a mean duration of 2.6 years. Regression modelling was used to assess variation in the number of anti-VEGF injections and change in eGFR and ACR. RESULTS: The EHR of 85 patients with DMO (59% male, 78% type 2 diabetes mellitus [T2DM]) were reviewed. On average, 26.8 intravitreal anti-VEGF injections were given per patient over a mean duration of 31 months. No association between increasing number of anti-VEGF injections and rate of eGFR decline (beta = 0.04, 95% confidence intervals [CI]: - 0.02, 0.09; p = 0.22) or ACR change over time (beta = 0.02, CI: - 0.19, 0.23; p = 0.86) was detected, following adjustment for hypertension, cerebrovascular disease, T2DM, and medications taken. CONCLUSION: Our data suggests regular long-term intravitreal VEGF inhibition does not significantly alter the rate of change in eGFR and/or ACR with increasing number of treatment injections.


Assuntos
Diabetes Mellitus Tipo 2/sangue , Injeções Intravítreas/métodos , Edema Macular/sangue , Ranibizumab/sangue , Receptores de Fatores de Crescimento do Endotélio Vascular/sangue , Proteínas Recombinantes de Fusão/sangue , Fator A de Crescimento do Endotélio Vascular/sangue , Idoso , Inibidores da Angiogênese/administração & dosagem , Estudos de Coortes , Diabetes Mellitus Tipo 2/tratamento farmacológico , Nefropatias Diabéticas/sangue , Nefropatias Diabéticas/tratamento farmacológico , Feminino , Barreira de Filtração Glomerular , Humanos , Injeções Intravítreas/efeitos adversos , Edema Macular/tratamento farmacológico , Masculino , Ranibizumab/administração & dosagem , Receptores de Fatores de Crescimento do Endotélio Vascular/administração & dosagem , Proteínas Recombinantes de Fusão/administração & dosagem , Estudos Retrospectivos , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores
18.
BMC Musculoskelet Disord ; 20(1): 325, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31299945

RESUMO

BACKGROUND: The purpose of the study was to evaluate whether tranexamic acid (TXA) administration could reduce blood loss and transfusion risk after simultaneous bilateral total knee arthroplasty (SBTKA). METHODS: As a multicenter retrospective study, a total of 575 patients were assigned into three groups on the basis of TXA usage, including intravenous (IV) group (1 g IV TXA 5-10 min prior to the incision), combined group (1 g IV TXA combined with intra-articular injection of 1 g TXA prior to the closure every knee) and control group (no TXA use). The primary outcomes were total blood loss (TBL). The secondary outcomes were maximum hemoglobin (Hb) and hematocrit (Hct) drop, transfusion rate, drain volume, length of stay, hospitalization expenses and the incidence of complications. RESULTS: The mean TBL in control group (1685.0 ± 571.4 mL) were higher than that in IV group (1061.1 ± 689.6 mL, p = 0.006 and combined group (988.3 ± 559.3 mL, p = 0.003). The maximum Hb and Hct drop in combined group (28.5 ± 13.4 g/L, p = 0.016; 0.074 ± 0.053, p < 0.001) and IV group (28.8 ± 14.5 g/L, p = 0.025; 0.082 ± 0.056, p = 0.001) were lower than those in control group (33.4 ± 14.0; 0.131 ± 0.049). But the difference between IV and combined groups was not significant. The similar trend was detected on drain volume, length of stay and hospitalization expenses. The incidence of complications did not differ significantly among the three groups (p > 0.05). CONCLUSIONS: The study indicates that TXA could reduce blood loss with no apparent increase in the incidence of complications during SBTKA.


Assuntos
Antifibrinolíticos/administração & dosagem , Artroplastia do Joelho/efeitos adversos , Osteoartrite do Joelho/cirurgia , Complicações Pós-Operatórias/epidemiologia , Ácido Tranexâmico/administração & dosagem , Administração Intravenosa , Idoso , Antifibrinolíticos/efeitos adversos , Artroplastia do Joelho/métodos , Perda Sanguínea Cirúrgica/prevenção & controle , Perda Sanguínea Cirúrgica/estatística & dados numéricos , Transfusão de Sangue/estatística & dados numéricos , Feminino , Hematócrito , Hemoglobinas/análise , Humanos , Incidência , Injeções Intra-Articulares , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/sangue , Complicações Pós-Operatórias/etiologia , Estudos Retrospectivos , Ácido Tranexâmico/efeitos adversos , Resultado do Tratamento
19.
J Biol Chem ; 292(2): 748-759, 2017 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-27903634

RESUMO

Targeted inhibitors of the human epidermal growth factor receptor 2 (HER2), such as trastuzumab and lapatinib, are among the first examples of molecularly targeted cancer therapy and have proven largely effective for the treatment of HER2-positive breast cancers. However, approximately half of those patients either do not respond to these therapies or develop secondary resistance. Although a few signaling pathways have been implicated, a comprehensive understanding of mechanisms underlying HER2 inhibitor drug resistance is still lacking. To address this critical question, we undertook a concerted approach using patient expression data sets, HER2-positive cell lines, and tumor samples biopsied both before and after trastuzumab treatment. Together, these methods revealed that high expression and activation of a specific subset of receptor tyrosine kinases (RTKs) was strongly associated with poor clinical prognosis and the development of resistance. Mechanistically, these RTKs are capable of maintaining downstream signal transduction to promote tumor growth via the suppression of cellular senescence. Consequently, these findings provide the rationale for the design of therapeutic strategies for overcoming drug resistance in breast cancer via combinational inhibition of the limited number of targets from this specific subset of RTKs.


Assuntos
Neoplasias da Mama , Resistencia a Medicamentos Antineoplásicos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Quinazolinas/farmacologia , Transdução de Sinais , Trastuzumab/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Humanos , Lapatinib , Receptor ErbB-2 , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética
20.
EMBO J ; 33(8): 862-77, 2014 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-24534091

RESUMO

The MRE11-RAD50-NBS1 (MRN) complex is essential for the detection of DNA double-strand breaks (DSBs) and initiation of DNA damage signaling. Here, we show that Rad17, a replication checkpoint protein, is required for the early recruitment of the MRN complex to the DSB site that is independent of MDC1 and contributes to ATM activation. Mechanistically, Rad17 is phosphorylated by ATM at a novel Thr622 site resulting in a direct interaction of Rad17 with NBS1, facilitating recruitment of the MRN complex and ATM to the DSB, thereby enhancing ATM signaling. Repetition of these events creates a positive feedback for Rad17-dependent activation of MRN/ATM signaling which appears to be a requisite for the activation of MDC1-dependent MRN complex recruitment. A point mutation of the Thr622 residue of Rad17 leads to a significant reduction in MRN/ATM signaling and homologous recombination repair, suggesting that Thr622 phosphorylation is important for regulation of the MRN/ATM signaling by Rad17. These findings suggest that Rad17 plays a critical role in the cellular response to DNA damage via regulation of the MRN/ATM pathway.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Quebras de DNA de Cadeia Dupla , Enzimas Reparadoras do DNA/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Nucleares/metabolismo , Multimerização Proteica , Transdução de Sinais , Hidrolases Anidrido Ácido , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Linhagem Celular , Humanos , Proteína Homóloga a MRE11 , Fosforilação , Ligação Proteica , Processamento de Proteína Pós-Traducional
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA