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1.
Eur Cell Mater ; 41: 108-120, 2021 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-33501637

RESUMO

Human dental pulp stem cell (DPSC) differentiation toward the osteoblastic phenotype is enhanced when culture media are supplemented with differentiating factors, i.e. ascorbic acid, ß-glycerophosphate and dexamethasone. Liposomes, spherical vesicles formed by a phospholipid bilayer, are frequently used as carriers for drugs, growth factors and hydrophobic molecules. The aim of this work was to speed up DPSC commitment to the osteogenic lineage by embedding differentiating factors within liposomes. Firstly, liposomes were prepared by rehydrating a phospholipidic thin film and characterised in terms of dimensions. Secondly, liposome-exposed DPSCs were characterised by their immunophenotypic profile. Levels of CD90 were significantly decreased in the presence of liposomes filled with ascorbic acid, ß-glycerophosphate and dexamethasone (Lipo-Mix) with respect to normal differentiation medium (DM), while CD73 and CD29 expression were enhanced, suggesting osteogenic commitment. Additionally, an appreciable extracellular matrix deposition is detected. Thirdly, the Lipo-Mix formulation better increases alkaline phosphatase activity and levels of Collagen I secretion with respect to DM. In parallel, the new liposome formulation is capable of decreasing the release of H2O2 and of triggering a precocious antioxidant cell response, redressing the redox balance required upon mesenchymal stem cell commitment to osteogenesis. It can be therefore hypothesised that Lipo-Mix could represent a suitable tool for clinical regenerative purposes in the field of tissue engineering by speeding up DPSC osteogenic commitment, mineralised matrix deposition and remodelling.


Assuntos
Células-Tronco Mesenquimais , Osteogênese , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Polpa Dentária , Humanos , Peróxido de Hidrogênio , Lipossomos
2.
Br J Cancer ; 123(7): 1101-1113, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32684628

RESUMO

BACKGROUND: Epithelioid inflammatory myofibroblastic sarcoma (eIMS) is characterised by perinuclear ALK localisation, CD30 expression and early relapse despite crizotinib treatment. We aimed to identify therapies to prevent and/or treat ALK inhibitor resistance. METHODS: Malignant ascites, from an eIMS patient at diagnosis and following multiple relapses, were used to generate matched diagnosis and relapse xenografts. RESULTS: Xenografts were validated by confirmation of RANBP2-ALK rearrangement, perinuclear ALK localisation and CD30 expression. Although brentuximab-vedotin (BV) demonstrated single-agent activity, tumours regrew during BV therapy. BV resistance was associated with reduced CD30 expression and induction of ABCB1. BV resistance was reversed in vitro by tariquidar, but combination BV and tariquidar treatment only briefly slowed xenograft growth compared with BV alone. Combining BV with either crizotinib or ceritinib resulted in marked tumour shrinkage in both xenograft models, and resulted in prolonged tumour-free survival in the diagnosis compared with the relapse xenograft. CONCLUSIONS: CD30 is a therapeutic target in eIMS. BV efficacy is limited by the rapid emergence of resistance. Prolonged survival with combination ALK and CD30-targeted-therapy in the diagnosis model provides the rationale to trial this combination in eIMS patients at diagnosis. This combination could also be considered for other CD30-positive, ALK-rearranged malignancies.


Assuntos
Quinase do Linfoma Anaplásico/antagonistas & inibidores , Quinase do Linfoma Anaplásico/genética , Rearranjo Gênico , Antígeno Ki-1/antagonistas & inibidores , Chaperonas Moleculares/genética , Miofibroblastos/patologia , Complexo de Proteínas Formadoras de Poros Nucleares/genética , Sarcoma/tratamento farmacológico , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Idoso de 80 Anos ou mais , Animais , Brentuximab Vedotin/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Humanos , Inflamação , Masculino , Camundongos , Sarcoma/genética , Ensaios Antitumorais Modelo de Xenoenxerto
3.
Phys Chem Chem Phys ; 22(17): 9448-9459, 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32314758

RESUMO

The UV absorption cross-sections of the Criegee intermediate CH2OO, and kinetics of the CH2OO self-reaction and the reaction of CH2OO with I are reported as a function of pressure at 298 K. Measurements were made using pulsed laser flash photolysis of CH2I2/O2/N2 gas mixtures coupled with time-resolved broadband UV absorption spectroscopy at pressures between 6 and 300 Torr. Results give a peak absorption cross-section of (1.37 ± 0.29) × 10-17 cm2 at ∼340 nm and a rate coefficient for the CH2OO self-reaction of (8.0 ± 1.1) × 10-11 cm3 s-1, with no significant pressure dependence of the absorption cross-sections or the self-reaction kinetics over the range investigated. The rate coefficient for the reaction between CH2OO and I demonstrates pressure dependence over the range investigated, with a Lindemann fit giving k0 = (4.4 ± 1.0) × 10-29 cm6 s-1 and k∞ = (6.7 ± 0.6) × 10-11 cm3 s-1. The origins of IO in the system have been investigated, the implications of which are discussed.

4.
J Phys Chem A ; 124(37): 7416-7426, 2020 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-32816480

RESUMO

Furans are promising second generation biofuels with comparable energy densities to conventional fossil fuels. Combustion of furans is initiated and controlled to a large part by reactions with OH radicals, the kinetics of which are critical to understand the processes occurring under conditions relevant to low-temperature combustion. The reactions of OH radicals with furan (OH + F, R1), 2-methyl furan (OH + 2-MF, R2), and 2,5-dimethyl furan (OH + 2,5-DMF, R3) have been studied in this work over the temperature range 294-668 K at pressures between 5 mbar and 10 bar using laser flash photolysis coupled with laser-induced fluorescence (LIF) spectroscopy to generate and monitor OH radicals under pseudo-first-order conditions. Measurements at p ≤ 200 mbar were made in N2, using H2O2 or (CH3)3COOH radical precursors, while those at p ≥ 2 bar were made in He, using HNO3 as the radical precursor. The kinetics of reactions R1-R3 were observed to display a negative dependence on temperature over the range investigated, indicating the dominance of addition reactions under such conditions, with no significant dependence on pressure observed. Master equation calculations are in good agreement with the observed kinetics, and a combined parametrization of addition channels and abstraction channels for R1-R3 is provided on the basis of this work and previous shock tube measurements at higher temperatures. This work significantly extends the temperature range previously investigated for R1 and represents the first temperature-dependent measurements of R2 and R3 at temperatures relevant for atmospheric chemistry and low-temperature combustion.

5.
J Neurosci ; 38(41): 8831-8844, 2018 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-30120206

RESUMO

Transforming a brief sensory event into a persistent neural response represents a mechanism for linking temporally disparate stimuli together to support learning. The cerebellum requires this type of persistent input during trace conditioning to engage associative plasticity and acquire adaptively timed conditioned responses (CRs). An initial step toward identifying the sites and mechanisms generating and transmitting persistent signals to the cerebellum is to identify the input pathway. The medial auditory thalamic nuclei (MATN) are the necessary and sufficient source of auditory input to the cerebellum for delay conditioning in rodents and a possible input to forebrain sites generating persistent signals. Using pharmacological and computational approaches, we test (1) whether the necessity of MATN during auditory eyelid conditioning is conserved across species, (2) whether the MATN are necessary for the expression of trace eyelid CRs, and if so, (3)whether this relates to the generation of persistent signals. We find that contralateral inactivation of MATN with muscimol largely abolished trace and delay CRs in male rabbits. Residual CRs were decreased in amplitude, but CR timing was unaffected. Results from large-scale cerebellar simulations are consistent with previous experimental demonstrations that silencing only CS-duration inputs does not abolish trace CRs, and instead affects their timing. Together, these results suggest that the MATN are a necessary component of both the direct auditory stimulus pathway to the cerebellum and the pathway generating task-essential persistent signals.SIGNIFICANCE STATEMENT Persistent activity is required for working memory-dependent tasks, such as trace conditioning, and represents a mechanism by which sensory information can be used over time for learning and cognition. This neuronal response entails the transformation of a discrete sensory-evoked response into a signal that extends beyond the stimulus event. Understanding the generation and transmission of this stimulus transformation requires identifying the input sources necessary for task-essential persistent signals. We report that the medial auditory thalamic nuclei are required for the expression of auditory trace conditioning and suggest that these nuclei are a component of the pathway-generating persistent signals. Our study provides a foundation for testing circuit-level mechanisms underlying persistent activity in a cerebellar learning model with identified inputs and well defined behavioral outputs.


Assuntos
Cerebelo/fisiologia , Condicionamento Palpebral/fisiologia , Núcleo Mediodorsal do Tálamo/fisiologia , Memória de Curto Prazo/fisiologia , Estimulação Acústica , Animais , Vias Auditivas/fisiologia , Masculino , Modelos Neurológicos , Redes Neurais de Computação , Coelhos
6.
Int Endod J ; 48(9): 839-49, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25231818

RESUMO

AIM: To evaluate the effect of TEGDMA on human gingival fibroblasts (HGFs) in vitro co-cultured with Streptococcus mitis, focusing on the signalling pathways underlying cell tissue remodelling and inflammatory response processes. METHODOLOGY: ß1 integrin expression was evaluated by means of imaging flow cytometry. The Western blot technique was used to investigate the expression of protein kinase C (PKC), extracellular signal-regulated kinase (ERK), matrix metalloproteinase 9 (MMP9) and 3 (MMP3). RT-PCR was performed to quantify nuclear factor-kb subunits (Nf-kb1, ReLa), IkB kinase ß (IkBkB), cyclooxygenase II (COX-2) and tumour necrosis factor-α (TNF-α) mRNA levels. Statistical analysis was performed using the analysis of variance (anova). RESULTS: When HGFs are co-cultured with S. mitis, ß1 integrin intensity, phosphorylated PKC (p-PKC), activated ERK (p-ERK), IkBkB mRNA level and MMP9 expression increased (for all molecules P < 0.05 HGFs versus HGFs co-cultured with S. mitis). A higher level of MMP3 in HGFs treated with TEGDMA was recorded (P < 0.05 HGFs versus HGFs exposed to TEGDMA). COX-2 inflammatory factor mRNA level appeared higher in HGFs exposed to 1 mmol L(-1) TEGDMA (P < 0.01 HGFs versus HGFs exposed to TEGDMA), whereas TNF-α gene expression was higher in HGFs co-cultured with S. mitis (P < 0.05 HGFs versus HGFs co-cultured with S. mitis). CONCLUSIONS: ß1 integrin triggered the signalling pathway, transduced by p-PKCα and involving ERK 1 and 2 and MMPs. This pathway resulted in an unbalanced equilibrium in tissue remodelling process, along with inflammatory response when HGFs are exposed to bacteria or biomaterial alone. On the contrary, the TEGDMA/S. mitis combination restored the balance between extracellular matrix deposition and degradation and prevented an inflammatory response.


Assuntos
Fibroblastos/efeitos dos fármacos , Gengiva/efeitos dos fármacos , Polietilenoglicóis/farmacologia , Ácidos Polimetacrílicos/farmacologia , Streptococcus mitis/efeitos dos fármacos , Técnicas de Cocultura , Fibroblastos/citologia , Fibroblastos/enzimologia , Gengiva/citologia , Gengiva/enzimologia , Humanos , Inflamação/metabolismo , Integrina beta1/metabolismo , Proteína Quinase C-alfa/metabolismo , Transdução de Sinais , Streptococcus mitis/fisiologia , Fator de Necrose Tumoral alfa/metabolismo
7.
Biomater Adv ; 160: 213849, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38599041

RESUMO

Spheroids derived from human mesenchymal stem cells (hMSCs) are of limited use for cartilage regeneration, as the viability of the cells progressively decreases during the period required for chondrogenic differentiation (21 days). In this work, spheroids based on hMSCs and a lactose-modified chitosan (CTL) were formed by seeding cells onto an air-dried coating of CTL. The polymer coating can inhibit cell adhesion and it is simultaneously incorporated into spheroid structure. CTL-spheroids were characterized from a morphological and biological perspective, and their properties were compared with those of spheroids obtained by seeding the cells onto a non-adherent surface (agar gel). Compared to the latter, smaller and more viable spheroids form in the presence of CTL as early as 4 days of culture. At this time point, analysis of stem cells differentiation in spheroids showed a remarkable increase in collagen type-2 (COL2A1) gene expression (~700-fold compared to day 0), whereas only a 2-fold increase was observed in the control spheroids at day 21. These results were confirmed by histological and transmission electron microscopy (TEM) analyses, which showed that in CTL-spheroids an early deposition of collagen with a banding structure already occurred at day 7. Overall, these results support the use of CTL-spheroids as a novel system for cartilage regeneration, characterized by increased cell viability and differentiation capacity within a short time-frame. This will pave the way for approaches aimed at increasing the success rate of procedures and reducing the time required for tissue regeneration.


Assuntos
Diferenciação Celular , Quitosana , Condrogênese , Lactose , Células-Tronco Mesenquimais , Esferoides Celulares , Quitosana/farmacologia , Quitosana/química , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/citologia , Humanos , Diferenciação Celular/efeitos dos fármacos , Condrogênese/efeitos dos fármacos , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/citologia , Lactose/farmacologia , Lactose/química , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Colágeno Tipo II/metabolismo , Colágeno Tipo II/genética
8.
Phys Med ; 123: 103394, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38852364

RESUMO

PURPOSE: To present the results of the first multi-centre real-world validation of autoplanning for whole breast irradiation after breast-sparing surgery, encompassing high complexity cases (e.g. with a boost or regional lymph nodes) and a wide range of clinical practices. METHODS: The 24 participating centers each included 10 IMRT/VMAT/Tomotherapy patients, previously treated with a manually generated plan ('manplan'). There were no restrictions regarding case complexity, planning aims, plan evaluation parameters and criteria, fractionation, treatment planning system or treatment machine/technique. In addition to dosimetric comparisons of autoplans with manplans, blinded plan scoring/ranking was conducted by a clinician from the treating center. Autoplanning was performed using a single configuration for all patients in all centres. Deliverability was verified through measurements at delivery units. RESULTS: Target dosimetry showed comparability, while reductions in OAR dose parameters were 21.4 % for heart Dmean, 16.7 % for ipsilateral lung Dmean, and 101.9 %, 45.5 %, and 35.7 % for contralateral breast D0.03cc, D5% and Dmean, respectively (all p < 0.001). Among the 240 patients included, the clinicians preferred the autoplan for 119 patients, with manplans preferred for 96 cases (p = 0.01). Per centre there were on average 5.0 ± 2.9 (1SD) patients with a preferred autoplan (range [0-10]), compared to 4.0 ± 2.7 with a preferred manplan ([0,9]). No differences were observed regarding deliverability. CONCLUSION: The automation significantly reduced the hands-on planning workload compared to manual planning, while also achieving an overall superiority. However, fine-tuning of the autoplanning configuration prior to clinical implementation may be necessary in some centres to enhance clinicians' satisfaction with the generated autoplans.


Assuntos
Automação , Neoplasias da Mama , Planejamento da Radioterapia Assistida por Computador , Radioterapia de Intensidade Modulada , Planejamento da Radioterapia Assistida por Computador/métodos , Humanos , Neoplasias da Mama/radioterapia , Radioterapia de Intensidade Modulada/métodos , Órgãos em Risco/efeitos da radiação , Dosagem Radioterapêutica , Feminino , Radiometria
9.
J Org Chem ; 78(22): 11172-83, 2013 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-24050840

RESUMO

Peptoids are an increasingly important class of peptidomimetic foldamers comprised of N-alkylglycine units that have been successfully developed as antimicrobial agents, lung surfactant replacements, enzyme inhibitors, and catalysts, among many other applications. Since peptoid secondary structures can be crucial to their desired functions, significant efforts have been devoted to developing means of modularly controlling peptoid backbone amide cis-trans isomerism using side chains. Strategic engineering of interactions between side chain aromatic rings and backbone cis-amides (n→π*(Ar) interactions) is an attractive strategy for stabilizing helical structures in N-a-chiral aromatic peptoids, which are among the most utilized classes of structured peptoids. Herein, we report the first detailed computational and experimental study of n→π*(Ar) interactions in models of peptoids containing backbone thioamides, which we term "thiopeptoids". Our work has revealed that these interactions significantly affect amide rotamerism in both peptoid and thiopeptoid models via a newly characterized "bridged" mode of interaction mediated by the N-α-C-H σ orbitals. Overall, this work elucidates new strategies for controlling both peptoid and thiopeptoid folding and suggests that thiopeptoids will be highly structured and therefore potentially useful as therapeutics, biological probes, and nanostructural engineering elements.


Assuntos
Peptoides/química , Tioamidas/química , Modelos Moleculares , Estrutura Molecular , Teoria Quântica , Estereoisomerismo
10.
Adv Exp Med Biol ; 756: 223-8, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22836639

RESUMO

During development and aging, vascular remodeling represents a critical adaptive response to modifications in oxygen supply to tissues. Hypoxia inducible factor (HIF) has a crucial role and is modulated by oxygen levels, with an age-dependent response in neonates, adult, and aged people. ROS are generated under hypoxic conditions and the accumulation of free radicals during life reduces the ability of tissues to their removal. In this immunohistochemical study we investigated the presence and localization of VEGF and iNOS in human carotid bodies (CB) sampled at autopsy from three children (mean age - 2 years), four adult young subjects (mean age - 44.3 years), and four old subjects (mean age - 67.3 years). VEGF immunoreactivity was significantly enhanced in CB tissues from the children (7.2 ± 1.2%) and aged subjects (4.7 ± 1.7%) compared with the young adults (1.4 ± 0.7%). On the other hand, iNOS immunoreactivity was enhanced in CB tissues from the children (0.4 ± 0.04%) and young adult subjects (0.3 ± 0.02%) compared with the old subjects (0.2 ± 0.02%). Prevention of oxygen desaturation, reducing all causes of hypoxemia from neonatal life to aging would decrease the incidence of diseases in the elderly population with lifespan extension.


Assuntos
Envelhecimento/fisiologia , Corpo Carotídeo/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Oxigênio/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Adulto , Idoso , Corpo Carotídeo/enzimologia , Diferenciação Celular , Pré-Escolar , Humanos , Hipóxia/metabolismo , Adulto Jovem
11.
Adv Exp Med Biol ; 788: 59-64, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23835959

RESUMO

The aim of the present study was to evaluate the presence of Neuroglobin (Ngb) and Cytoglobin (Cygb) in the solitary tract nucleus (STN) and in the carotid body of human subjects. Transverse serial sections of formalin-fixed, paraffin-embedded brainstems, taken from six subjects, were investigated. Ngb and Cygb are expressed in both the structures. Differences in expression of Ngb and Cygb among dorsal and ventral area of the STN may be related to their different functions and different metabolic demands. Because the STN plays an important role in the processing of cardiovascular and respiratory reflex inputs, Ngb and Cygb may play an integrative central modulatory action for the two systems.


Assuntos
Tronco Encefálico/metabolismo , Corpo Carotídeo/metabolismo , Regulação da Expressão Gênica , Globinas/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Núcleo Solitário/metabolismo , Citoglobina , Densitometria , Humanos , Processamento de Imagem Assistida por Computador , Imuno-Histoquímica , Neuroglobina , Neurotransmissores/metabolismo , Distribuição Tecidual
12.
Int Endod J ; 46(5): 466-76, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23137186

RESUMO

AIM: To investigate the inflammatory response in human gingival fibroblasts (HGFs) treated with a relatively low 2-hydroxyethyl methacrylate (HEMA) concentration by studying reactive oxygen species (ROS) production, cyclooxygenase-2 (COX-2) and tumour necrosis factor-alpha (TNF-α) gene expression, and prostaglandin E2 (PGE2) release. METHODOLOGY: Cultured HGFs were exposed to 3 mmol L⁻¹ HEMA for 0, 24 or 96 h. ROS production was investigated by flow cytometry; TNF-α and COX-2 gene expression was determined by RT-PCR, and prostaglandin E2 production was detected by an enzyme immunoassay. RESULTS: After 24- or 96-h HEMA incubation, ROS levels were approximately eightfold and elevenfold higher than controls, whilst COX-2 gene expression was approximately twofold or fourfold higher than controls, respectively. Twenty-four-hour exposure enhanced TNF-α mRNA levels by approximately 66%, whilst after 96-h incubation, TNF-α gene expression was fivefold higher than controls. Ninety-six-hour HEMA treatment increased PGE2 concentration in the culture medium by around 17% compared with controls. CONCLUSIONS: 2-Hydroxyethyl methacrylate treatment (3 mmol L⁻¹) induced an inflammatory response in HGFs modulated by ROS production, as well as by the increase in TNF-α and COX-2 gene expression and by PGE2 release.


Assuntos
Materiais Dentários/farmacologia , Fibroblastos/efeitos dos fármacos , Gengiva/efeitos dos fármacos , Metacrilatos/farmacologia , Acetilcisteína/farmacologia , Técnicas de Cultura de Células , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ciclo-Oxigenase 2/efeitos dos fármacos , Dinoprostona/análise , Sequestradores de Radicais Livres/farmacologia , Gengiva/citologia , Humanos , Mediadores da Inflamação/farmacologia , Espécies Reativas de Oxigênio/análise , Fatores de Tempo , Fator de Necrose Tumoral alfa/efeitos dos fármacos
13.
Int Endod J ; 46(12): 1164-72, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23611114

RESUMO

AIM: To investigate in coculture of human gingival fibroblasts (HGFs) and Streptococcus mitis, the molecular mechanisms driving the response to 2-hydroxyethyl methacrylate (HEMA) in terms of eukaryotic/prokaryotic cell adhesion, signal transduction and apoptosis. METHODOLOGY: The clinical strain S. mitis DS12, cultured in Trypticase soy broth was added to HGFs, obtained from fragments of healthy marginal gingival tissue and cultured in DMEM, treated with 3 mmol L(-1) 2-hydroxyethyl methacrylate (HEMA) for 48 h and processed for microscopic, western blotting and flow cytometric analyses. RESULTS: 2-hydroxyethyl methacrylate (HEMA) treatment increased the adhesion between S. mitis and HGFs, which seemed to be mediated by the PKC α/integrin ß 1 signalling system, improved by the presence of saliva. It also reduced the viability and the adhesion of HGFs to polypropylene substrate in terms of procollagen I and MMP3 expression. The presence of saliva and S. mitis reduced the number of necrotic HGFs and upregulated the expression of both procollagen I and MMP3. CONCLUSIONS: These results shed more light on the biological and molecular events occurring in vitro in a coculture model that mimics the environment of the oral cavity with HEMA treatment. The key role played by oral bacteria and saliva in preventing inflammatory and toxic processes that occur in vivo in human gingival fibroblasts upon the release of dental material monomers is confirmed.


Assuntos
Aderência Bacteriana/efeitos dos fármacos , Gengiva/enzimologia , Integrina beta1/metabolismo , Metacrilatos/farmacologia , Proteína Quinase C-alfa/metabolismo , Streptococcus mitis/fisiologia , Técnicas de Cocultura , Gengiva/citologia , Gengiva/metabolismo , Gengiva/microbiologia , Humanos
14.
Phys Med ; 113: 102657, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37567068

RESUMO

PURPOSE: Different methods are available to identify haematopoietically active bone marrow (ActBM). However, their use can be challenging for radiotherapy routine treatments, since they require specific equipment and dedicated time. A machine learning (ML) approach, based on radiomic features as inputs to three different classifiers, was applied to computed tomography (CT) images to identify haematopoietically active bone marrow in anal cancer patients. METHODS: A total of 40 patients was assigned to the construction set (training set + test set). Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography (18FDG-PET) images were used to detect the active part of the pelvic bone marrow (ActPBM) and stored as ground-truth for three subregions: iliac, lower pelvis and lumbosacral bone marrow (ActIBM, ActLPBM, ActLSBM). Three parameters were used for the correspondence analyses between 18FDG-PET and ML classifiers: DICE index, Precision and Recall. RESULTS: For the 40-patient cohort, median values [min; max] of the Dice index were 0.69 [0.20; 0.84], 0.76 [0.25; 0.89], and 0.36 [0.15; 0.67] for ActIBM, ActLSBM, and ActLPBM, respectively. The Precision/Recall (P/R) ratio median value for the ActLPBM structure was 0.59 [0.20; 1.84] (over segmentation), while for the other two subregions the P/R ratio median has values of 1.249 [0.43; 4.15] for ActIBM and 1.093 [0.24; 1.91] for ActLSBM (under segmentation). CONCLUSION: A satisfactory degree of overlap compared to 18FDG-PET was found for 2 out of the 3 subregions within pelvic bones. Further optimization and generalization of the process is required before clinical implementation.


Assuntos
Neoplasias do Ânus , Medula Óssea , Humanos , Medula Óssea/diagnóstico por imagem , Fluordesoxiglucose F18 , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada por Raios X , Neoplasias do Ânus/diagnóstico por imagem , Neoplasias do Ânus/terapia , Aprendizado de Máquina , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Compostos Radiofarmacêuticos , Estudos Retrospectivos
15.
Adv Exp Med Biol ; 758: 265-71, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23080171

RESUMO

Hypoxia inducible factor 1(HIF-1α) is the regulator of oxygen homeostasis in tissue correlated with neuroglobin (NGB) a member of the family of globins in vertebrates. The present study investigates, the expression and the location of NGB, HIF-1α in human carotid bodies, sampled at autopsy from children (mean age: 2 year ±), young (mean age: 27.5) and 4 old subjects (mean age: 73.5). The percentage of NGB positive area was higher in the old subjects (4.4 ±2.8%), as compared with the young ones (2.4 ±1.8%) and children (1.0 ±1.8%). Positive HIF-1α nuclei were detected in young and old subjects (1.0 ±0.14% vs 3.0 ±0.28%, respectively), whereas CB tissues from children did not show any HIF-1α reaction. The increase of NGB and HIF-1α expression suggests a possible role of the two oxygen sensors in the aging processes. Even though the physiological role of NGB is not well understood, it could be suggested that is act as a respiratory protein connected with HIF.


Assuntos
Envelhecimento/fisiologia , Corpo Carotídeo/fisiologia , Globinas/fisiologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Adulto , Idoso , Pré-Escolar , Globinas/análise , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/análise , Imuno-Histoquímica , Proteínas do Tecido Nervoso/análise , Neuroglobina
16.
Int Endod J ; 44(12): 1145-54, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21902700

RESUMO

AIM: To evaluate and observe the cellular reactions that occur during the interaction/integration between 2-hydroxyethyl methacrylate/host tissue/microbial environment, in a co-culture of human gingival fibroblasts (HGF) and Streptococcus mitis strains. METHODOLOGY: Streptococcus mitis were cultured with strains in the presence of 3 mmol L(-1) HEMA for 48 h and 72 h. Cytotoxicity was evaluated by the trypan blue dye exclusion test. Apoptosis was evaluated by TUNEL analysis. Adhesion was evaluated by immunofluorescence and western blot analyses. Quantitative analyses of the results were acquired by Qwin Plus 3.5 and QuantityOne I-D analysis software, respectively. The statistical significance of the results was evaluated using t-tests and linear regression tests. RESULTS: The trypan blue dye test revealed 47.3% and 46.5% of dead fibroblasts after 48 and 72 h HEMA treatment, respectively, while bacterial viability was not influenced by the presence of HEMA and fibroblasts. The expression of pro-collagen I, involved in fibroblast adhesion, in untreated samples ranged from 12.49% to 6.91% of the positive area after 48 and 72 h, respectively, dropping to below 2% of the positive area in the other experimental conditions. Unlike the trypan blue test, co-cultured samples treated with HEMA showed 20% and 25% versus 17% and 21% (after 48 and 72 h, respectively) of apoptotic cells. CONCLUSIONS: The evidence for HEMA toxicity and anti-adhesive effects against eukaryotic cells was reduced in the presence of bacteria, suggesting that dental resins should be well polymerized to avoid the spread of toxic monomers within the mouth.


Assuntos
Apoptose/efeitos dos fármacos , Materiais Dentários/farmacologia , Fibroblastos/efeitos dos fármacos , Gengiva/efeitos dos fármacos , Metacrilatos/farmacologia , Streptococcus mitis/efeitos dos fármacos , Aderência Bacteriana/efeitos dos fármacos , Western Blotting , Adesão Celular/efeitos dos fármacos , Técnicas de Cultura de Células , Morte Celular/efeitos dos fármacos , Forma Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Cocultura , Colágeno Tipo I/análise , Colágeno Tipo I/efeitos dos fármacos , Corantes , Materiais Dentários/toxicidade , Imunofluorescência , Gengiva/citologia , Humanos , Processamento de Imagem Assistida por Computador , Marcação In Situ das Extremidades Cortadas , Metacrilatos/toxicidade , Viabilidade Microbiana/efeitos dos fármacos , Fatores de Tempo , Azul Tripano
17.
BMJ Open ; 11(9): e049858, 2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34588252

RESUMO

INTRODUCTION: There is currently only one approved medication effective at improving walking distance in people with intermittent claudication. Preclinical data suggest that the ß3-adrenergic receptor agonist (mirabegron) could be repurposed to treat intermittent claudication associated with peripheral artery disease. The aim of the Stimulating ß3-Adrenergic Receptors for Peripheral Artery Disease (STAR-PAD) trial is to test whether mirabegron improves walking distance in people with intermittent claudication. METHODS AND ANALYSIS: The STAR-PAD trial is a Phase II, multicentre, double-blind, randomised, placebo-controlled trial of mirabegron versus placebo on walking distance in patients with PAD. A total of 120 patients aged ≥40 years with stable PAD and intermittent claudication will be randomly assigned (1:1 ratio) to receive either mirabegron (50 mg orally once a day) or matched placebo, for 12 weeks. The primary endpoint is change in peak walking distance as assessed by a graded treadmill test. Secondary endpoints will include: (i) initial claudication distance; (ii) average daily step count and total step count and (iii) functional status and quality of life assessment. Mechanistic substudies will examine potential effects of mirabegron on vascular function, including brachial artery flow-mediate dilatation; MRI assessment of lower limb blood flow, tissue perfusion and arterial stiffness and numbers and angiogenesis potential of endothelial progenitor cells. Given that mirabegron is safe and clinically available for alternative purposes, a positive study is positioned to immediately impact patient care. ETHICS AND DISSEMINATION: The STAR-PAD trial is approved by the Northern Sydney Local Health District Human Research Ethics Committee (HREC/18/HAWKE/50). The study results will be published in peer-reviewed medical or scientific journals and presented at scientific meetings, regardless of the study outcomes. TRIAL REGISTRATION NUMBER: ACTRN12619000423112; Results.


Assuntos
Doença Arterial Periférica , Receptores Adrenérgicos beta 3 , Acetanilidas , Ensaios Clínicos Fase II como Assunto , Método Duplo-Cego , Humanos , Estudos Multicêntricos como Assunto , Doença Arterial Periférica/tratamento farmacológico , Desempenho Físico Funcional , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Tiazóis , Caminhada
18.
Int J Immunopathol Pharmacol ; 23(2): 589-99, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20646354

RESUMO

Both oxidative stress and inflammation are elevated in brains of Alzheimer's disease patients, but their pathogenic significance still remains unclear. Current evidence support the hypothesis that non-steroidal anti-inflammatory drugs (NSAIDs) and antioxidant therapy might protect against the development of Alzheimer's disease, and ibuprofen has the strongest epidemiological support. In the present work our attention was focused on (R)-alpha-lipoic acid considered as a potential neuroprotective agent in Alzheimer's disease therapy. In particular, we investigated a new co-drug (1) obtained by joining (R)-alpha-lipoic acid and ibuprofen via a diamide bond, for evaluating its potential to antagonize the deleterious structural and cognitive effects of beta-amyloid (1-40) in an infused Alzheimer's disease rat model. Our results indicated that infusion of beta-amyloid (1-40) impairs memory performance through a progressive cognitive deterioration; however, ibuprofen and co-drug 1 seemed to protect against behavioural detriment induced by simultaneous administration of beta-amyloid (1-40) protein. The obtained data were supported by the histochemical findings of the present study: beta-amyloid protein was less expressed in 1-treated than in ibuprofen and (R)-alpha-lipoic acid alone-treated cerebral cortex. Taken together, the present findings suggest that co-drug 1 treatment may protect against the cognitive dysfunction induced by intracerebroventricular infusion of beta-amyloid (1-40) in rats. Thus, co-drug 1 could prove useful as a tool for controlling Alzheimer's disease-induced cerebral amyloid deposits and behavioural deterioration.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Peptídeos beta-Amiloides/toxicidade , Ibuprofeno/administração & dosagem , Fármacos Neuroprotetores/farmacologia , Fragmentos de Peptídeos/toxicidade , Ácido Tióctico/administração & dosagem , Animais , Modelos Animais de Doenças , Ibuprofeno/farmacocinética , Imuno-Histoquímica , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Atividade Motora/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Ratos , Ratos Wistar , Distribuição Tecidual
19.
Gerontology ; 56(6): 544-52, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20299780

RESUMO

BACKGROUND: Hypoxia and aging determine on mammalian cells a stress response which implies modified production of oxidants, reactive oxygen species or reactive nitrogen species at the mitochondrial level, interfering with cell-signaling proteins and inducing mitochondrial damage, apoptosis occurrence and functional consequences. OBJECTIVE: Here we report the effects of hypoxia on the in vivo morphological and biochemical response of young and aged Wistar rat hearts. METHODS: Left ventricles were excised from each experimental point and processed. Investigations of vascular endothelial growth factor (VEGF) expression and apoptotic events, mitochondrial damage, were performed by light and electron microscopy, respectively; endothelial, inducible and neuronal NOS, PKCα, pPKCα, caspase-3 expression and Apaf-1/cytochrome c complex formation were assessed by Western blotting and co-immunoprecipitation analyses, respectively. RESULTS: Besides morphological modifications, which confirm mitochondrial suffering upon hypoxia exposure in both young and aged hearts, the role played by PKCα in controlling nitric oxide synthase (NOS) protein level was investigated. Downstream PKCα activation, a dramatic iNOS expression increase, concomitant to enhanced apoptotic cell percentage and Apaf-1/cytochrome c co-immunoprecipitation, is evident in the hypoxic young, suggesting iNOS-mediated activation of the mitochondrial apoptotic pathway. CONCLUSIONS: Moreover, overexpression of iNOS and VEGF in the hypoxic young rat hearts suggests that an increased VEGF level may allow coordinated development of the lymphatic and blood vasculature, necessary for fluid homeostasis and to counteract oxidative stress. Thus the inhibition of such growth factor proposes new therapeutic possibilities for diseases associated to vascular function and for solid tumors which show pathological angiogenesis and lymphoangiogenesis.


Assuntos
Apoptose , Ventrículos do Coração/metabolismo , Mitocôndrias Cardíacas/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Envelhecimento/metabolismo , Animais , Apoptossomas/metabolismo , Fator Apoptótico 1 Ativador de Proteases/metabolismo , Caspase 3/metabolismo , Hipóxia Celular , Senescência Celular , Citocromos c/metabolismo , Ventrículos do Coração/patologia , Redes e Vias Metabólicas , Neovascularização Patológica/metabolismo , Proteína Quinase C-alfa/metabolismo , Ratos , Ratos Wistar , Estresse Fisiológico , Fator A de Crescimento do Endotélio Vascular
20.
Int J Immunopathol Pharmacol ; 22(4): 1105-16, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-20074475

RESUMO

Bone regeneration procedures allow oral rehabilitation with dental implants also in edentulous ridges with severe bone atrophy. The integration of grafted materials with the host tissue can initiate regenerative, inflammatory and apoptotic response. Since molecular mechanisms exist at the basis of such response, the aim of this work is to investigate, by immunohistochemical analyses, the expression of proteins involved in the graft integration process, in parallel to clinical and histological modifications, occurring on sites treated with extraoral autologous bone graft deriving from the parietal region of the calvaria (eAB), intraoral autologous bone graft deriving from mandibular ramus (iAB) and heterologous bone graft from swine (hB) in human patients. In our study, the immunohistochemical expression of BSP, VEGF, eNOS in eAB samples was significantly higher (p < 0.05) compared to values recorded in iAB and hB samples. The inflammatory response, investigated by iNOS expression, was found lower in all autologous samples (eAB and iAB) compared to hB, at statistically significant values. Moreover, the expression of the pro-apoptotic molecule, Bax, resulted significantly lower (p < 0.05) in eAB than in iAB and hB samples. These values, together with the low number of apoptotic cells detected in autologous samples, suggest a good regenerative response when extraoral autologous bone graft is used in comparison to the response from the other grafts, and also suggest the use of calvaria graft as a predictable therapeutic procedure for repairing severe bone defects in oral and maxillofacial surgery, not only by clinical and biomechanical criteria, but also from a biomolecular aspect.


Assuntos
Perda do Osso Alveolar/cirurgia , Transplante Ósseo/métodos , Mandíbula/transplante , Maxila/cirurgia , Doenças Maxilares/cirurgia , Óxido Nítrico Sintase Tipo III/metabolismo , Osseointegração , Osso Parietal/transplante , Fator A de Crescimento do Endotélio Vascular/metabolismo , Idoso , Perda do Osso Alveolar/enzimologia , Perda do Osso Alveolar/patologia , Animais , Colágeno Tipo I/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Mediadores da Inflamação/metabolismo , Sialoproteína de Ligação à Integrina , Masculino , Maxila/enzimologia , Maxila/patologia , Doenças Maxilares/enzimologia , Doenças Maxilares/patologia , Pessoa de Meia-Idade , NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Osteotomia , Pró-Colágeno/metabolismo , Sialoglicoproteínas/metabolismo , Suínos , Transplante Autólogo , Transplante Heterólogo , Resultado do Tratamento , Proteína X Associada a bcl-2/metabolismo
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