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1.
Int J Mol Sci ; 24(24)2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-38139290

RESUMO

The intricate mechanisms governing brain health and function have long been subjects of extensive investigation. Recent research has shed light on two pivotal systems, the glymphatic system and the endocannabinoid system, and their profound role within the central nervous system. The glymphatic system is a recently discovered waste clearance system within the brain that facilitates the efficient removal of toxic waste products and metabolites from the central nervous system. It relies on the unique properties of the brain's extracellular space and is primarily driven by cerebrospinal fluid and glial cells. Conversely, the endocannabinoid system, a multifaceted signaling network, is intricately involved in diverse physiological processes and has been associated with modulating synaptic plasticity, nociception, affective states, appetite regulation, and immune responses. This scientific review delves into the intricate interconnections between these two systems, exploring their combined influence on brain health and disease. By elucidating the synergistic effects of glymphatic function and endocannabinoid signaling, this review aims to deepen our understanding of their implications for neurological disorders, immune responses, and cognitive well-being.


Assuntos
Sistema Glinfático , Doenças do Sistema Nervoso , Humanos , Sistema Glinfático/metabolismo , Endocanabinoides/metabolismo , Encéfalo/metabolismo , Sistema Nervoso Central , Doenças do Sistema Nervoso/metabolismo
2.
EMBO J ; 37(13)2018 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-29807932

RESUMO

Preclinical evidence depicts the capacity of redaporfin (Redp) to act as potent photosensitizer, causing direct antineoplastic effects as well as indirect immune-dependent destruction of malignant lesions. Here, we investigated the mechanisms through which photodynamic therapy (PDT) with redaporfin kills cancer cells. Subcellular localization and fractionation studies based on the physicochemical properties of redaporfin revealed its selective tropism for the endoplasmic reticulum (ER) and the Golgi apparatus (GA). When activated, redaporfin caused rapid reactive oxygen species-dependent perturbation of ER/GA compartments, coupled to ER stress and an inhibition of the GA-dependent secretory pathway. This led to a general inhibition of protein secretion by PDT-treated cancer cells. The ER/GA play a role upstream of mitochondria in the lethal signaling pathway triggered by redaporfin-based PDT Pharmacological perturbation of GA function or homeostasis reduces mitochondrial permeabilization. In contrast, removal of the pro-apoptotic multidomain proteins BAX and BAK or pretreatment with protease inhibitors reduced cell killing, yet left the GA perturbation unaffected. Altogether, these results point to the capacity of redaporfin to kill tumor cells via destroying ER/GA function.


Assuntos
Retículo Endoplasmático/efeitos dos fármacos , Complexo de Golgi/efeitos dos fármacos , Fotoquimioterapia , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/farmacologia , Sulfonamidas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Retículo Endoplasmático/fisiologia , Feminino , Complexo de Golgi/fisiologia , Humanos , Luz , Camundongos Endogâmicos C57BL , Fármacos Fotossensibilizantes/efeitos da radiação , Fármacos Fotossensibilizantes/uso terapêutico , Porfirinas/efeitos da radiação , Porfirinas/uso terapêutico , Sulfonamidas/efeitos da radiação , Sulfonamidas/uso terapêutico
3.
Bioconjug Chem ; 33(8): 1505-1514, 2022 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-35852911

RESUMO

Sodium citrate-stabilized gold nanoparticles (AuNPs) are destabilized when dispersed in cell culture media (CCMs). This may promote their aggregation and subsequent sedimentation, or under the proper conditions, their interaction with dispersed proteins can lead to the formation of a NP-stabilizing protein corona. CCMs are ionic solutions that contain growth substances which are typically supplemented, in addition to serum, with different substances such as dyes, antioxidants, and antibiotics. In this study, the impact of phenol red, penicillin-streptomycin, l-glutamine, and ß-mercaptoethanol on the formation of the NP-protein corona in CCMs was investigated. Similar protein coronas were obtained except in the presence of antibiotics. Under these conditions, the protein corona took more time to be formed, and its density and composition were altered, as indicated by UV-vis spectroscopy, Z potential, dynamic light scattering, and liquid chromatography-mass spectrometry analyses. As a consequence of these modifications, a significantly different AuNP cellular uptake was measured, showing that NP uptake increased as did the NP aggregate formation. AuNP uptake studies performed in the presence of clathrin- and caveolin-mediated endocytosis inhibitors showed that neither clathrin receptors nor lipid rafts were significantly involved in the internalization mechanism. These results suggest that in these conditions, NP aggregation is the main mechanism responsible for their cellular uptake.


Assuntos
Nanopartículas Metálicas , Coroa de Proteína , Antibacterianos , Técnicas de Cultura de Células , Citratos/química , Ácido Cítrico , Clatrina , Ouro/química , Nanopartículas Metálicas/química , Coroa de Proteína/metabolismo
4.
Blood ; 122(14): 2402-11, 2013 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-23966420

RESUMO

Caloric restriction (CR) is proposed to decrease tumorigenesis through a variety of mechanisms including effects on glycolysis. However, the understanding of how CR affects the response to cancer therapy is still rudimentary. Here, using the Eµ-Myc transgenic mouse model of B-cell lymphoma, we report that by reducing protein translation, CR can reduce expression of the prosurvival Bcl-2 family member Mcl-1 and sensitize lymphomas to ABT-737-induced death in vivo. By using Eµ-Myc lymphoma cells lacking p53, we showed that CR mimetics such as 2-deoxyglucose led to a decrease in Mcl-1 expression and sensitized lymphoma cells to ABT-737-induced death independently of p53. In keeping with this, Eµ-Myc lymphoma cells lacking the BH3-only proapoptotic members Noxa, Puma, or Bim were also sensitized by CR mimetics to ABT-737-induced death. Remarkably, neither the loss of both Puma and Noxa, the loss of both Puma and Bim, nor the loss of all three BH3-only proteins prevented sensitization to ABT-737 induced by CR mimetics. Thus, CR can influence Mcl-1 expression and sensitize cells to BH3 mimetic-induced apoptosis, independently of the main BH3-only proteins and of p53. Exploiting this may improve the efficiency of, or prevent resistance to, cancer therapy.


Assuntos
Restrição Calórica , Resistencia a Medicamentos Antineoplásicos/fisiologia , Linfoma de Células B/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo , Compostos de Bifenilo/farmacologia , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Proteína de Sequência 1 de Leucemia de Células Mieloides , Nitrofenóis/farmacologia , Piperazinas/farmacologia , Sulfonamidas/farmacologia
5.
Chemistry ; 21(44): 15506-10, 2015 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-26493876

RESUMO

Excessive apoptotic cell death is at the origin of several pathologies, such as degenerative disorders, stroke or ischemia-reperfusion damage. In this context, strategies to improve inhibition of apoptosis and other types of cell death are of interest and may represent a pharmacological opportunity for the treatment of cell-death-related disorders. In this scenario new peptide-containing delivery systems (solids S1 -P1 and S1 -P2 ) are described based on mesoporous silica nanoparticles (MSNs) loaded with a dye and capped with the KKGDEVDKKARDEVDK (P1 ) peptide that contains two repeats of the DEVD target sequence that are selectively hydrolyzed by caspase 3 (C3). This enzyme plays a central role in the execution-phase of apoptosis. HeLa cells electroporated with S1 -P1 are able to deliver the cargo in the presence of staurosporin (STS), which induces apoptosis with the consequent activation of the cytoplasmic C3 enzyme. Moreover, the nanoparticles S1 -P2 , containing both a cell-penetrating TAT peptide and P1 also entered in HeLa cells and delivered the cargo preferentially in cells treated with the apoptosis inducer cisplatin.


Assuntos
Caspase 3/química , Caspase 3/metabolismo , Cisplatino/química , Portadores de Fármacos/química , Nanopartículas/química , Dióxido de Silício/química , Apoptose , Portadores de Fármacos/metabolismo , Células HeLa , Humanos , Porosidade , Dióxido de Silício/metabolismo
6.
Chemistry ; 20(47): 15309-14, 2014 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-25303093

RESUMO

New capped silica mesoporous nanoparticles for intracellular controlled cargo release within cathepsin B expressing cells are described. Nanometric mesoporous MCM-41 supports loaded with safranin O (S1-P) or doxorubicin (S2-P) containing a molecular gate based on a cathepsin B target peptidic sequence were synthesized. Solids were designed to show "zero delivery" and to display cargo release in the presence of cathepsin B enzyme, which selectively hydrolyzed in vitro the capping peptide sequence. Controlled delivery in HeLa, MEFs WT, and MEFs lacking cathepsin B cell lines were also tested. Release of safranin O and doxorubicin in these cells took place when cathepsin B was active or present. Cells treated with S2-P showed a fall in cell viability due to nanoparticles internalization, cathepsin B hydrolysis of the capping peptide, and cytotoxic agent delivery, proving the possible use of these nanodevices as new therapeutic tools for cancer treatment.


Assuntos
Catepsina B/metabolismo , Nanopartículas/química , Peptídeos/química , Dióxido de Silício/química , Antineoplásicos/química , Antineoplásicos/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Doxorrubicina/química , Doxorrubicina/farmacologia , Portadores de Fármacos/química , Células HeLa , Humanos , Peptídeos/síntese química , Peptídeos/metabolismo , Porosidade
7.
Chemistry ; 20(18): 5271-81, 2014 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-24700694

RESUMO

The synthesis and characterization of two new capped silica mesoporous nanoparticles for controlled delivery purposes are described. Capped hybrid systems consist of MCM-41 nanoparticles functionalized on the outer surface with polymer ε-poly-L-lysine by two different anchoring strategies. In both cases, nanoparticles were loaded with model dye molecule [Ru(bipy)3](2+). An anchoring strategy involved the random formation of urea bonds by the treatment of propyl isocyanate-functionalized MCM-41 nanoparticles with the lysine amino groups located on the ε-poly-L-lysine backbone (solid Ru-rLys-S1). The second strategy involved a specific attachment through the carboxyl terminus of the polypeptide with azidopropyl-functionalized MCM-41 nanoparticles (solid Ru-tLys-S1). Once synthesized, both nanoparticles showed a nearly zero cargo release in water due to the coverage of the nanoparticle surface by polymer ε-poly-L-lysine. In contrast, a remarkable payload delivery was observed in the presence of proteases due to the hydrolysis of the polymer's amide bonds. Once chemically characterized, studies of the viability and the lysosomal enzyme-controlled release of the dye in intracellular media were carried out. Finally, the possibility of using these materials as drug-delivery systems was tested by preparing the corresponding ε-poly-L-lysine capped mesoporous silica nanoparticles loaded with cytotoxic drug camptothecin (CPT), CPT-rLys-S1 and CPT-tLys-S1. Cellular uptake and cell-death induction were studied. The efficiency of both nanoparticles as new potential platforms for cancer treatment was demonstrated.


Assuntos
Preparações de Ação Retardada/química , Nanopartículas/química , Polilisina/química , Dióxido de Silício/química , Linhagem Celular Tumoral , Corantes/administração & dosagem , Preparações de Ação Retardada/metabolismo , Células HeLa , Humanos , Lisossomos/enzimologia , Nanopartículas/metabolismo , Nanopartículas/ultraestrutura , Polilisina/metabolismo , Porosidade , Rutênio/administração & dosagem , Dióxido de Silício/metabolismo
8.
Cell Death Discov ; 10(1): 292, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38897995

RESUMO

Cancer metabolic reprogramming has been recognized as one of the cancer hallmarks that promote cell proliferation, survival, as well as therapeutic resistance. Up-to-date regulation of metabolism in T-cell lymphoma is poorly understood. In particular, for human angioimmunoblastic T-cell lymphoma (AITL) the metabolic profile is not known. Metabolic intervention could help identify new treatment options for this cancer with very poor outcomes and no effective medication. Transcriptomic analysis of AITL tumor cells, identified that these cells use preferentially mitochondrial metabolism. By using our preclinical AITL mouse model, mimicking closely human AITL features, we confirmed that T follicular helper (Tfh) tumor cells exhibit a strong enrichment of mitochondrial metabolic signatures. Consistent with these results, disruption of mitochondrial metabolism using metformin or a mitochondrial complex I inhibitor such as IACS improved the survival of AITL lymphoma-bearing mice. Additionally, we confirmed a selective elimination of the malignant human AITL T cells in patient biopsies upon mitochondrial respiration inhibition. Moreover, we confirmed that diabetic patients suffering from T-cell lymphoma, treated with metformin survived longer as compared to patients receiving alternative treatments. Taking together, our findings suggest that targeting the mitochondrial metabolic pathway could be a clinically efficient approach to inhibit aggressive cancers such as peripheral T-cell lymphoma.

9.
Chemistry ; 19(4): 1346-56, 2013 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-23225567

RESUMO

The preparation of a new capped silica mesoporous material, Rh-Azo-S, for on-command delivery applications in the presence of target enzymes is described. The material consists of nanometric mesoporous MCM-41-like supports loaded with Rhodamine B and capped with an azopyridine derivative. The material was designed to show "zero delivery" and to display a cargo release in the presence of reductases and esterases, which are usually present in the colon, mainly due to intestinal microflora. The opening and cargo release of Rh-Azo-S in vitro studies were assessed and seen to occur in the presence of these enzymes, whereas no delivery was noted in the presence of pepsine. Moreover, Rh-Azo-S nanoparticles were used to study controlled Rhodamine B dye delivery in intracellular media. HeLa cells were employed for testing the "non"-toxicity of nanoparticles. Moreover, delivery of the dye in these cells, through internalization and enzyme-mediated gate opening, was confirmed by confocal microscopy. Furthermore, the nanoparticles capped with the Azo group and loaded with a cytotoxic camptothecin (CPT) were also prepared (solid CPT-Azo-S) and used as delivery nanodevices in HeLa cells. When this solid was employed, the cell viability decreased significantly due to internalization of the nanoparticles and delivery of the cytotoxic agent.


Assuntos
Compostos Azo/química , Oxirredutases/metabolismo , Piridinas/química , Compostos de Piridínio/química , Dióxido de Silício/química , Compostos Azo/síntese química , Compostos Azo/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Células HeLa , Humanos , Células MCF-7 , Nanopartículas/química , Oxirredutases/química , Porosidade , Compostos de Piridínio/síntese química , Compostos de Piridínio/toxicidade , Rodaminas/química
10.
Chemistry ; 19(34): 11167-71, 2013 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-23839913

RESUMO

Bug busters: A novel nanodevice consisting of mesoporous nanoparticles loaded with vancomycin and capped with ε-poly-L-lysine (ε-PL) was prepared and its interaction with different Gram-negative bacteria studied. A remarkable improvement in the efficacy of the antimicrobial drug ε-PL and a broadening of the antimicrobial spectrum of vancomycin is demonstrated.


Assuntos
Antibacterianos/química , Nanopartículas/química , Vancomicina/química , Antibacterianos/farmacologia , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Polilisina/química , Porosidade , Dióxido de Silício/química
11.
Ther Adv Hematol ; 14: 20406207231173485, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37273421

RESUMO

Non-Hodgkin's lymphomas (NHLs) comprise a diverse group of diseases, either of mature B-cell or of T-cell derivation, characterized by heterogeneous molecular features and clinical manifestations. While most of the patients are responsive to standard chemotherapy, immunotherapy, radiation and/or stem cell transplantation, relapsed and/or refractory cases still have a dismal outcome. Deep sequencing analysis have pointed out that epigenetic dysregulations, including mutations in epigenetic enzymes, such as chromatin modifiers and DNA methyltransferases (DNMTs), are prevalent in both B- cell and T-cell lymphomas. Accordingly, over the past decade, a large number of epigenetic-modifying agents have been developed and introduced into the clinical management of these entities, and a few specific inhibitors have already been approved for clinical use. Here we summarize the main epigenetic alterations described in B- and T-NHL, that further supported the clinical development of a selected set of epidrugs in determined diseases, including inhibitors of DNMTs, histone deacetylases (HDACs), and extra-terminal domain proteins (bromodomain and extra-terminal motif; BETs). Finally, we highlight the most promising future directions of research in this area, explaining how bioinformatics approaches can help to identify new epigenetic targets in B- and T-cell lymphoid neoplasms.

12.
Nanomaterials (Basel) ; 13(15)2023 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-37570527

RESUMO

Cerium oxide nanoparticles (CeO2NPs) have exceptional catalytic properties, rendering them highly effective in removing excessive reactive oxygen species (ROS) from biological environments, which is crucial in safeguarding these environments against radiation-induced damage. Additionally, the Ce atom's high Z number makes it an ideal candidate for utilisation as an X-ray imaging contrast agent. We herein show how the injection of albumin-stabilised 5 nm CeO2NPs into mice revealed substantial enhancement in X-ray contrast, reaching up to a tenfold increase at significantly lower concentrations than commercial or other proposed contrast agents. Remarkably, these NPs exhibited prolonged residence time within the target organs. Thus, upon injection into the tail vein, they exhibited efficient uptake by the liver and spleen, with 85% of the injected dose (%ID) recovered after 7 days. In the case of intratumoral administration, 99% ID of CeO2NPs remained within the tumour throughout the 7-day observation period, allowing for observation of disease dynamics. Mass spectrometry (ICP-MS) elemental analysis confirmed X-ray CT imaging observations.

13.
Antioxidants (Basel) ; 12(3)2023 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-36979013

RESUMO

Nanoparticle (NP) pharmacokinetics significantly differ from traditional small molecule principles. From this emerges the need to create new tools and concepts to harness their full potential and avoid unnecessary risks. Nanoparticle pharmacokinetics strongly depend on size, shape, surface functionalisation, and aggregation state, influencing their biodistribution, accumulation, transformations, and excretion profile, and hence their efficacy and safety. Today, while NP biodistribution and nanoceria biodistribution have been studied often at short times, their long-term accumulation and excretion have rarely been studied. In this work, 3 nm nanoceria at 5.7 mg/kg of body weight was intravenously administrated in a single dose to healthy mice. Biodistribution was measured in the liver, spleen, kidney, lung, brain, lymph nodes, ovary, bone marrow, urine, and faeces at different time points (1, 9, 30, and 100 days). Biodistribution and urinary and faecal excretion were also studied in rats placed in metabolic cages at shorter times. The similarity of results of different NPs in different models is shown as the heterogeneous nanoceria distribution in organs. After the expectable accumulation in the liver and spleen, the concentration of cerium decays exponentially, accounting for about a 50% excretion of cerium from the body in 100 days. Cerium ions, coming from NP dissolution, are most likely excreted via the urinary tract, and ceria nanoparticles accumulated in the liver are most likely excreted via the hepatobiliary route. In addition, nanoceria looks safe and does not damage the target organs. No weight loss or apathy was observed during the course of the experiments.

14.
Chemistry ; 18(41): 13068-78, 2012 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-22927363

RESUMO

The synthesis and characterisation of new capped silica mesoporous nanoparticles for on-command delivery applications is reported. Functional capped hybrid systems consist of MCM-41 nanoparticles functionalised on the external surface with polyesters bearing azobenzene derivatives and rhodamine B inside the mesopores. Two solid materials, Rh-PAzo8-S and Rh-PAzo6-S, containing two closely related polymers, PAzo8 and PAzo6, in the pore outlets have been prepared. Materials Rh-PAzo8-S and Rh-PAzo6-S showed an almost zero release in water due to steric hindrance imposed by the presence of anchored bulky polyesters, whereas a large delivery of the cargo was observed in the presence of an esterase enzyme due to the progressive hydrolysis of polyester chains. Moreover, nanoparticles Rh-PAzo8-S and Rh-PAzo6-S were used to study the controlled release of the dye in intracellular media. Nanoparticles were not toxic for HeLa cells and endocytosis-mediated cell internalisation was confirmed by confocal microscopy. Furthermore, the possible use of capped materials as a drug-delivery system was demonstrated by the preparation of a new mesoporous silica nanoparticle functionalised with PAzo6 and loaded with the cytotoxic drug camptothecin (CPT-PAzo6-S). Following cell internalisation and lysosome resident enzyme-dependent gate opening, CPT-PAzo6-S induced CPT-dependent cell death in HeLa cells.


Assuntos
Compostos Azo/química , Camptotecina/química , Camptotecina/toxicidade , Nanopartículas/química , Poliésteres/química , Dióxido de Silício/química , Sistemas de Liberação de Medicamentos , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Porosidade
15.
Langmuir ; 28(41): 14766-76, 2012 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-22998170

RESUMO

An ethylene glycol-capped hybrid material for the controlled release of molecules in the presence of esterase enzyme has been prepared. The final organic-inorganic hybrid solid S1 was synthesized by a two-step procedure. In the first step, the pores of an inorganic MCM-41 support (in the form of nanoparticles) were loaded with [Ru(bipy)(3)]Cl(2) complex, and then, in the second step, the pore outlets were functionalized with ester glycol moieties that acted as molecular caps. In the absence of an enzyme, release of the complex from aqueous suspensions of S1 at pH 8.0 is inhibited due to the steric hindrance imposed by the bulky ester glycol moieties. Upon addition of esterase enzyme, delivery of the ruthenium complex was observed due to enzymatic hydrolysis of the ester bond in the anchored ester glycol derivative, inducing the release of oligo(ethylene glycol) fragments. Hydrolysis of the ester bond results in size reduction of the appended group, therefore allowing delivery of the entrapped cargo. The S1 nanoparticles were not toxic for cells, as demonstrated by cell viability assays with HeLa and MCF-7 cell lines, and were found to be associated with lysosomes, as shown by confocal microscopy. However, when S1 nanoparticles were filled with the cytotoxic drug camptothecin (S1-CPT), S1-CPT-treated cells undergo cell death as a result of S1-CPT cell internalization and subsequent cellular enzyme-mediated hydrolysis and aperture of the molecular gate that induced the release of the camptothecin cargo. These findings point to a possible therapeutic application of these nanoparticles.


Assuntos
Esterases/metabolismo , Ésteres/metabolismo , Glicóis/metabolismo , Dióxido de Silício/metabolismo , Camptotecina/química , Camptotecina/farmacologia , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Esterases/química , Ésteres/química , Glicóis/química , Células HeLa , Humanos , Hidrólise , Células MCF-7 , Porosidade , Dióxido de Silício/síntese química , Dióxido de Silício/química , Propriedades de Superfície , Células Tumorais Cultivadas
16.
Angew Chem Int Ed Engl ; 51(42): 10556-60, 2012 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-22996839

RESUMO

Learning to let go with age: Intracellular controlled release of molecules within senescent cells was achieved using mesoporous silica nanoparticles (MSNs) capped with a galacto-oligosaccharide (GOS) to contain the cargo molecules (magenta spheres; see scheme). The GOS is a substrate of the senescent biomarker, senescence-associated ß-galactosidase (SA-ß-gal), and releases the cargo upon entry into SA-ß-gal expressing cells.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Dióxido de Silício/química , Linhagem Celular Tumoral , Senescência Celular , Sistemas de Liberação de Medicamentos/instrumentação , Corantes Fluorescentes/administração & dosagem , Corantes Fluorescentes/química , Humanos , Porosidade , Rodaminas/administração & dosagem , Rodaminas/química , beta-Galactosidase/química , beta-Galactosidase/metabolismo
17.
Artigo em Inglês | MEDLINE | ID: mdl-35682339

RESUMO

The purpose of this study was to determine the mean propulsive velocity (MVP) at various percentages of one repetition maximum (1RM) in the full squat and chest press exercises. A total of 96 young women and 256 young men (recreational athletes) performed an incremental test (50−60−70−80% 1RM) comprising the bench press and full squat exercises in two different sessions. The individual load and velocity ratios were established through the MPV. Data were analyzed using SPSS software version 25.0, with the significance level set at 5%. The following findings were revealed: highly linear load-velocity relationships in the group of women (r = 0.806 in the squat, and r = 0.872 in the bench press) and in the group of men (r = 0.832 and r = 0.880, respectively); significant differences (p < 0.001) in the MPV at 50−70−80% 1RM between the bench press and the full squat in men and at 70−80% 1RM in women; and a high variability in the MPV (11.49% to 22.63) in the bench press and full squat (11.58% to 25.15%) was observed in women and men (11.31% to 21.06%, and 9.26% to 24.2%) at the different percentages of 1RM evaluated. These results suggest that the load-velocity ratio in non-strength-trained subjects should be determined individually to more precisely establish the relative load to be used in a full squat and bench press training program.


Assuntos
Força Muscular , Treinamento Resistido , Atletas , Terapia por Exercício , Feminino , Humanos , Masculino , Músculo Esquelético , Treinamento Resistido/métodos , Levantamento de Peso
18.
J Funct Morphol Kinesiol ; 7(4)2022 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-36278740

RESUMO

The purpose of this study was to examine the type of relationship between measures of maximal force (dynamic and isometric), maximal power, and mean propulsive velocity. In total, 355 recreational athletes, 96 women (age 20.5 ± 2.5 years; height 158.2 ± 17.3 cm; weight 61.8 ± 48.4 kg) and 259 men (age 21.0 ± 2.6 years; height 170.5 ± 12.6 cm; weight 65.9 ± 9.2 kg) were evaluated in three sessions separated by 72 h each in isometric midthigh pull exercise (ISOS) (kg), bench press maximum strength (1RM MSBP) (kg), jump height (CMJ) (m), and maximum pedaling power (WT) the maximum squat strength (1RM MSS) (kg), the mean propulsive velocity in the bench press (MPVBP) (m·s-1), and the peak power (PPBP) (w), mean propulsive squat velocity (MPVS) (m·s-1), peak power (PP) (w), maximum handgrip force (ISOHG) (kg), and 30 m movement speed (V30) (s). Significant correlations (p ≤ 0.01) were identified between 95% of the various manifestations of force, and only 5% presented a significance of p ≤ 0.05; however, when the magnitude of these correlations is observed, there is great heterogeneity. In this sense, the dynamic strength tests present the best correlations with the other strength and power tests used in the present study, followed by PPBP and PP. The results of this study complement what is reported in the literature regarding the correlation between different types of force manifestations being heterogeneous and contradictory.

19.
Med Res Rev ; 31(4): 649-75, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20099266

RESUMO

Programmed cell death, apoptosis, is a highly regulated cellular pathway, responsible for the elimination of cells in the organism that are no longer needed or extensively damaged. Defects in the regulation of apoptosis could be at the molecular basis of different diseases, either when it is insufficient or excessive. The formation of the macromolecular complex, apoptosome, is a key event in this pathway, which has also been defined as the intrinsic apoptosis pathway. The apoptosome is a holoenzyme multiprotein complex formed by cytochrome c-activated apoptotic protease-activating factor (Apaf-1), dATP, and procaspase-9. Recent studies have produced a wealth of information about the regulation and functions of Apaf-1, but additional studies aimed at elucidating its role as a signaling device at the crosstalk between different signaling pathways are needed to take advantage for the development of modulators of apoptosis pathways and possible therapeutic applications.


Assuntos
Fator Apoptótico 1 Ativador de Proteases/metabolismo , Apoptossomas/metabolismo , Humanos , Modelos Biológicos
20.
Bone ; 143: 115782, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33278654

RESUMO

INTRODUCTION: Severe burns can alter bone metabolism through different mechanisms. Despite prior published studies describing the association between burns and a decrease in bone mineral density (BMD), no clinical guidelines currently exist recommending the systematic evaluation of bone health in patients after severe burns. This study aims to describe the BMD of individuals with severe burn injuries and healthy controls and determine the frequency of low-to-normal bone mass (LNBM) and BMD below the expected range for age (BEA). MATERIALS AND METHODS: We conducted a retrospective cohort of patients with either severe thermal or electrical burns and healthy controls paired by gender and age. We performed a dual-energy X-ray absorptiometry at least 90 days after the burn and collected data from each patient's clinical evaluation and clinical file. RESULTS: A total of 77 patients (64 men and 13 women) and their paired controls were included in the study (age [mean ± standard deviation, SD]: 30.37 ± 8.66 years). Patients participated in the study an average of 315 ± 438 days after their burn. The BMD (grs/cm2) in total hip burned vs controls was: 0.998 ± 0.135 vs 1.059 ± 0.12 (p = 0.004); femoral neck 0.876 ± 0.121 vs 0.915 ± 0.097 (p = 0.031), spine 0.977 ± 0.127 vs 1.003 ± 0.076 (p = 0.132).The Z-scores for total hip were - 0.06 ± 1.05 vs 0.41 ± 0.80 (p = 0.002); for neck -0.39 ± 0.89 vs -0.01 ± 0.77 (p = 0.005); and for spine -0.75 ± 1.11 vs -0.32 ± 0.73 (p = 0.005). The proportion of subjects with BMD BEA in burns vs controls was 5.2 vs 1.2% (p = 0.05) in total hip, 3.9 vs 0% (p = 0.045) in the neck, and 18.2 vs 1.2% (p = 0.001) in the spine. The logistic regression model found-in burn patients vs controls-an OR of 9.83 for BMD BEA (CI 95%: 2.17-44.45, p = 003), OR = 4.05 for electrical burns (CI 95%: 1.72-20.89, p = 004) and OR = 15.16 for thermal burns (CI 95%: 2.91-79.00, p = 001). The model also found an OR = 2.48 for LNBM (CI 95%: 1.25-4.93, p = 0.009). The burn variables associated with BMD BEA at any site in the patients were BMI >25 Kg/m2 with an OR = 0.180 (CI 95%: 0.046-0.710, p = 0.014); and the lower limb amputation with an OR = 7.33 (CI 95%; 1.12-48.33, p = 0.038). Five burn patients had a fragility fracture. CONCLUSION: BMD was significantly lower in severely burned patients than in controls, and the proportion BMD BEA cases was significantly higher in the burn patient sample. Severe burns are a strong independent predictor of bone loss, and this risk is maintained for an extended period after the burn.


Assuntos
Densidade Óssea , Queimaduras , Absorciometria de Fóton , Adulto , Estudos de Coortes , Feminino , Humanos , Masculino , Estudos Retrospectivos , Adulto Jovem
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