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1.
Cell ; 183(4): 1024-1042.e21, 2020 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-32991844

RESUMEN

Analysis of the specificity and kinetics of neutralizing antibodies (nAbs) elicited by SARS-CoV-2 infection is crucial for understanding immune protection and identifying targets for vaccine design. In a cohort of 647 SARS-CoV-2-infected subjects, we found that both the magnitude of Ab responses to SARS-CoV-2 spike (S) and nucleoprotein and nAb titers correlate with clinical scores. The receptor-binding domain (RBD) is immunodominant and the target of 90% of the neutralizing activity present in SARS-CoV-2 immune sera. Whereas overall RBD-specific serum IgG titers waned with a half-life of 49 days, nAb titers and avidity increased over time for some individuals, consistent with affinity maturation. We structurally defined an RBD antigenic map and serologically quantified serum Abs specific for distinct RBD epitopes leading to the identification of two major receptor-binding motif antigenic sites. Our results explain the immunodominance of the receptor-binding motif and will guide the design of COVID-19 vaccines and therapeutics.


Asunto(s)
Anticuerpos Neutralizantes/inmunología , Mapeo Epitopo/métodos , Glicoproteína de la Espiga del Coronavirus/inmunología , Enzima Convertidora de Angiotensina 2 , Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/genética , Anticuerpos Monoclonales/inmunología , Anticuerpos Neutralizantes/sangre , Anticuerpos Neutralizantes/química , Anticuerpos Antivirales/sangre , Anticuerpos Antivirales/química , Anticuerpos Antivirales/inmunología , Reacciones Antígeno-Anticuerpo , Betacoronavirus/inmunología , Betacoronavirus/aislamiento & purificación , Betacoronavirus/metabolismo , Sitios de Unión , COVID-19 , Infecciones por Coronavirus/patología , Infecciones por Coronavirus/virología , Epítopos/química , Epítopos/inmunología , Humanos , Inmunoglobulina A/sangre , Inmunoglobulina A/inmunología , Inmunoglobulina G/sangre , Inmunoglobulina G/inmunología , Inmunoglobulina M/sangre , Inmunoglobulina M/inmunología , Cinética , Simulación de Dinámica Molecular , Pandemias , Peptidil-Dipeptidasa A/química , Peptidil-Dipeptidasa A/metabolismo , Neumonía Viral/patología , Neumonía Viral/virología , Unión Proteica , Dominios Proteicos/inmunología , Estructura Cuaternaria de Proteína , SARS-CoV-2 , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/genética , Glicoproteína de la Espiga del Coronavirus/metabolismo
2.
J Med Internet Res ; 24(1): e29969, 2022 01 03.
Artículo en Inglés | MEDLINE | ID: mdl-34982034

RESUMEN

BACKGROUND: Leveraging artificial intelligence (AI)-driven apps for health education and promotion can help in the accomplishment of several United Nations sustainable development goals. SnehAI, developed by the Population Foundation of India, is the first Hinglish (Hindi + English) AI chatbot, deliberately designed for social and behavioral changes in India. It provides a private, nonjudgmental, and safe space to spur conversations about taboo topics (such as safe sex and family planning) and offers accurate, relatable, and trustworthy information and resources. OBJECTIVE: This study aims to use the Gibson theory of affordances to examine SnehAI and offer scholarly guidance on how AI chatbots can be used to educate adolescents and young adults, promote sexual and reproductive health, and advocate for the health entitlements of women and girls in India. METHODS: We adopted an instrumental case study approach that allowed us to explore SnehAI from the perspectives of technology design, program implementation, and user engagement. We also used a mix of qualitative insights and quantitative analytics data to triangulate our findings. RESULTS: SnehAI demonstrated strong evidence across fifteen functional affordances: accessibility, multimodality, nonlinearity, compellability, queriosity, editability, visibility, interactivity, customizability, trackability, scalability, glocalizability, inclusivity, connectivity, and actionability. SnehAI also effectively engaged its users, especially young men, with 8.2 million messages exchanged across a 5-month period. Almost half of the incoming user messages were texts of deeply personal questions and concerns about sexual and reproductive health, as well as allied topics. Overall, SnehAI successfully presented itself as a trusted friend and mentor; the curated content was both entertaining and educational, and the natural language processing system worked effectively to personalize the chatbot response and optimize user experience. CONCLUSIONS: SnehAI represents an innovative, engaging, and educational intervention that enables vulnerable and hard-to-reach population groups to talk and learn about sensitive and important issues. SnehAI is a powerful testimonial of the vital potential that lies in AI technologies for social good.


Asunto(s)
Salud Sexual , Envío de Mensajes de Texto , Adolescente , Inteligencia Artificial , Femenino , Humanos , India , Masculino , Salud Reproductiva , Adulto Joven
3.
J Exp Bot ; 72(20): 7229-7246, 2021 10 26.
Artículo en Inglés | MEDLINE | ID: mdl-34279634

RESUMEN

Soil salinity has a serious impact on plant growth and agricultural yield. Inoculation of crop plants with fungal endophytes is a cost-effective way to improve salt tolerance. We used metabolomics to study how Trichoderma harzianum T-22 alleviates NaCl-induced stress in two barley (Hordeum vulgare L.) cultivars, Gairdner and Vlamingh, with contrasting salinity tolerance. GC-MS was used to analyse polar metabolites and LC-MS to analyse lipids in roots during the early stages of interaction with Trichoderma. Inoculation reversed the severe effects of salt on root length in sensitive cv. Gairdner and, to a lesser extent, improved root growth in more tolerance cv. Vlamingh. Biochemical changes showed a similar pattern in inoculated roots after salt treatment. Sugars increased in both cultivars, with ribulose, ribose, and rhamnose specifically increased by inoculation. Salt stress caused large changes in lipids in roots but inoculation with fungus greatly reduced the extent of these changes. Many of the metabolic changes in inoculated cv. Gairdner after salt treatment mirror the response of uninoculated cv. Vlamingh, but there are some metabolites that changed in both cultivars only after fungal inoculation. Further study is required to determine how these metabolic changes are induced by fungal inoculation.


Asunto(s)
Hordeum , Trichoderma , Hypocreales , Lípidos , Raíces de Plantas , Salinidad , Tolerancia a la Sal , Estrés Fisiológico
4.
Biomacromolecules ; 22(8): 3237-3250, 2021 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-34252271

RESUMEN

The periosteum is an indispensable part of the bone that nourishes the cortical bone and acts as a repertoire of osteoprogenitor cells. Periosteal damage as a result of traumatic injuries, infections, or surgical assistance in bone surgeries is often associated with a high incidence of delayed bone healing (union or nonunion) compounded with severe pain and a risk of a secondary fracture. Developing bioengineered functional periosteal substitutes is an indispensable approach to augment bone healing. In this study, we have developed a biomimetic periosteum membrane consisting of electrospun oxygen-releasing antioxidant polyurethane on collagen membrane (polyurethane-ascorbic acid-calcium peroxide containing fibers on collagen (PUAOCC)). Further, to assist bone formation, we have developed a bioactive inorganic-organic composite cryogel (bioglass-collagen-gelatin-nanohydroxyapatite (BCGH)) as a bone substitute. In an in vitro simulated oxidative stress model, PUAOCC supported the primary periosteal cell survival. Moreover, in an in vivo, critical-sized (5.9 mm × 3.2 mm × 1.50 mm) unicortical rat tibial bone defect, implantation of PUAOCC along with the functionalized BCGH led to significant improvement in bone formation along with periosteal regeneration. The periosteal regeneration was confirmed by expression of periosteum-specific periostin and neuronal regulation-related protein markers. Our study demonstrates the development of a periosteum-mimicking membrane with promising applications to facilitate periosteal regeneration, thus assisting bone formation when used in combination with bone composites and mimicking the natural bone repair process.


Asunto(s)
Sustitutos de Huesos , Periostio , Animales , Regeneración Ósea , Osteogénesis , Ratas , Ingeniería de Tejidos
5.
PLoS Med ; 16(4): e1002773, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30939136

RESUMEN

BACKGROUND: The sites of mycobacterial infection in the lungs of tuberculosis (TB) patients have complex structures and poor vascularization, which obstructs drug distribution to these hard-to-reach and hard-to-treat disease sites, further leading to suboptimal drug concentrations, resulting in compromised TB treatment response and resistance development. Quantifying lesion-specific drug uptake and pharmacokinetics (PKs) in TB patients is necessary to optimize treatment regimens at all infection sites, to identify patients at risk, to improve existing regimens, and to advance development of novel regimens. Using drug-level data in plasma and from 9 distinct pulmonary lesion types (vascular, avascular, and mixed) obtained from 15 hard-to-treat TB patients who failed TB treatments and therefore underwent lung resection surgery, we quantified the distribution and the penetration of 7 major TB drugs at these sites, and we provide novel tools for treatment optimization. METHODS AND FINDINGS: A total of 329 plasma- and 1,362 tissue-specific drug concentrations from 9 distinct lung lesion types were obtained according to optimal PK sampling schema from 15 patients (10 men, 5 women, aged 23 to 58) undergoing lung resection surgery (clinical study NCT00816426 performed in South Korea between 9 June 2010 and 24 June 2014). Seven major TB drugs (rifampin [RIF], isoniazid [INH], linezolid [LZD], moxifloxacin [MFX], clofazimine [CFZ], pyrazinamide [PZA], and kanamycin [KAN]) were quantified. We developed and evaluated a site-of-action mechanistic PK model using nonlinear mixed effects methodology. We quantified population- and patient-specific lesion/plasma ratios (RPLs), dynamics, and variability of drug uptake into each lesion for each drug. CFZ and MFX had higher drug exposures in lesions compared to plasma (median RPL 2.37, range across lesions 1.26-22.03); RIF, PZA, and LZD showed moderate yet suboptimal lesion penetration (median RPL 0.61, range 0.21-2.4), while INH and KAN showed poor tissue penetration (median RPL 0.4, range 0.03-0.73). Stochastic PK/pharmacodynamic (PD) simulations were carried out to evaluate current regimen combinations and dosing guidelines in distinct patient strata. Patients receiving standard doses of RIF and INH, who are of the lower range of exposure distribution, spent substantial periods (>12 h/d) below effective concentrations in hard-to-treat lesions, such as caseous lesions and cavities. Standard doses of INH (300 mg) and KAN (1,000 mg) did not reach therapeutic thresholds in most lesions for a majority of the population. Drugs and doses that did reach target exposure in most subjects include 400 mg MFX and 100 mg CFZ. Patients with cavitary lesions, irrespective of drug choice, have an increased likelihood of subtherapeutic concentrations, leading to a higher risk of resistance acquisition while on treatment. A limitation of this study was the small sample size of 15 patients, performed in a unique study population of TB patients who failed treatment and underwent lung resection surgery. These results still need further exploration and validation in larger and more diverse cohorts. CONCLUSIONS: Our results suggest that the ability to reach and maintain therapeutic concentrations is both lesion and drug specific, indicating that stratifying patients based on disease extent, lesion types, and individual drug-susceptibility profiles may eventually be useful for guiding the selection of patient-tailored drug regimens and may lead to improved TB treatment outcomes. We provide a web-based tool to further explore this model and results at http://saviclab.org/tb-lesion/.


Asunto(s)
Antituberculosos/administración & dosificación , Antituberculosos/farmacocinética , Pulmón/metabolismo , Tuberculosis Resistente a Múltiples Medicamentos/etiología , Tuberculosis Pulmonar/tratamiento farmacológico , Adulto , Técnicas de Apoyo para la Decisión , Progresión de la Enfermedad , Esquema de Medicación , Cálculo de Dosificación de Drogas , Farmacorresistencia Bacteriana Múltiple , Quimioterapia Combinada , Femenino , Humanos , Isoniazida/administración & dosificación , Isoniazida/farmacocinética , Kanamicina/administración & dosificación , Kanamicina/farmacocinética , Linezolid/administración & dosificación , Linezolid/farmacocinética , Pulmón/efectos de los fármacos , Pulmón/patología , Masculino , Persona de Mediana Edad , Pirazinamida/administración & dosificación , Pirazinamida/farmacocinética , Estudios Retrospectivos , Rifampin/administración & dosificación , Rifampin/farmacocinética , Distribución Tisular , Insuficiencia del Tratamiento , Tuberculosis Resistente a Múltiples Medicamentos/metabolismo , Tuberculosis Resistente a Múltiples Medicamentos/patología , Tuberculosis Pulmonar/metabolismo , Tuberculosis Pulmonar/patología , Adulto Joven
6.
J Craniofac Surg ; 30(4): e308-e311, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31166275

RESUMEN

This study was planned to evaluate the improvement in mandibular function, facial esthetics and quality of life after reconstruction of complex mandibular defects using patient-specific three-dimensional (3D) titanium implant. A total of 7 patients, who visited our outpatient clinic for reconstruction of mandibular defects after removal of their primary mandibular lesion and refused treatment with autologous bone grafts were treated with patient-specific implant for reconstruction of mandible. Three-dimensional virtual treatment planning was carried out using their 3D computed-tomographic data. The unaffected contralateral side of mandible was superimposed on the defect side and a customized implant was designed in the desired size and shape on the virtual model using computer aided designing and milled in titanium using selective laser melting, for precise anatomic mandibular reconstruction. There was significant improvement in their esthetics, function, and quality of life. The symmetry of the face and occlusion was restored with adequate mouth opening, closing, and lateral movements of the mandible with no deviation of jaw during movements. The patient specific implants appear to be very useful for precise reconstruction of mandible with greater accuracy. The concept of using customized implant with the help of 3D virtual treatment planning, stereolithographic models and computer aided designing greatly improves mandibular restoration and helps to achieve good facial profile, aesthetics and dental rehabilitation preventing severe complications related to autologous grafts.


Asunto(s)
Trasplante Óseo/métodos , Enfermedades Mandibulares/cirugía , Reconstrucción Mandibular/métodos , Prótesis e Implantes , Adulto , Diseño Asistido por Computadora , Estética Dental , Femenino , Humanos , Imagenología Tridimensional/métodos , Masculino , Mandíbula/cirugía , Diseño de Prótesis , Calidad de Vida , Estudios Retrospectivos , Titanio/uso terapéutico , Tomografía Computarizada por Rayos X
9.
Eukaryot Cell ; 13(8): 1104-12, 2014 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24972934

RESUMEN

NDR (nuclear Dbf-2-related) kinases constitute key regulatory nodes in signaling networks that control multiple biological processes such as growth, proliferation, mitotic exit, morphogenesis, and apoptosis. Two NDR pathways called the septation initiation network (SIN) and the morphogenesis Orb6 network (MOR) exist in the fission yeast Schizosaccharomyces pombe. The SIN promotes cytokinesis, and the MOR drives cell separation at the end of cytokinesis and polarized growth during interphase. We showed previously that cross talk exists between these two pathways, with the SIN inhibiting the MOR during cytokinesis through phosphorylation of the MOR component Nak1 by the SIN Sid2 kinase. The reason for this inhibition remained uncertain. We show here that failure to inhibit MOR signaling during cytokinesis results in cell lysis at the site of septum formation. Time-lapse analysis revealed that MOR signaling during cytokinesis causes cells to prematurely initiate septum degradation/cell separation. The cell lysis phenotype is due to premature initiation of cell separation because it can be rescued by mutations in genes required for cell separation/septum degradation. We also shed further light on how the SIN inhibits the MOR. Sid2 phosphorylation of the MOR proteins Sog2 and Nak1 is required to prevent cell lysis during cytokinesis. Together, these results show that SIN inhibition of the MOR enforces proper temporal ordering of cytokinetic events.


Asunto(s)
Citocinesis , Schizosaccharomyces/citología , Transducción de Señal , Proteínas Portadoras/fisiología , Fosforilación , Proteínas Quinasas/fisiología , Procesamiento Proteico-Postraduccional , Proteínas Serina-Treonina Quinasas , Schizosaccharomyces/enzimología , Proteínas de Schizosaccharomyces pombe/fisiología
10.
Blood ; 120(6): 1262-73, 2012 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-22740450

RESUMEN

Cyclin dependent kinase (CDK) inhibitors, such as flavopiridol, demonstrate significant single-agent activity in chronic lymphocytic leukemia (CLL), but the mechanism of action in these nonproliferating cells is unclear. Here we demonstrate that CLL cells undergo autophagy after treatment with therapeutic agents, including fludarabine, CAL-101, and flavopiridol as well as the endoplasmic reticulum (ER) stress-inducing agent thapsigargin. The addition of chloroquine or siRNA against autophagy components enhanced the cytotoxic effects of flavopiridol and thapsigargin, but not the other agents. Similar to thapsigargin, flavopiridol robustly induces a distinct pattern of ER stress in CLL cells that contributes to cell death through IRE1-mediated activation of ASK1 and possibly downstream caspases. Both autophagy and ER stress were documented in tumor cells from CLL patients receiving flavopiridol. Thus, CLL cells undergo autophagy after multiple stimuli, including therapeutic agents, but only with ER stress mediators and CDK inhibitors is autophagy a mechanism of resistance to cell death. These findings collectively demonstrate, for the first time, a novel mechanism of action (ER stress) and drug resistance (autophagy) for CDK inhibitors, such as flavopiridol in CLL, and provide avenues for new therapeutic combination approaches in this disease.


Asunto(s)
Autofagia/fisiología , Resistencia a Antineoplásicos , Estrés del Retículo Endoplásmico/fisiología , Flavonoides/farmacología , Piperidinas/farmacología , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Autofagia/efectos de los fármacos , Autofagia/genética , Técnicas de Cultivo de Célula , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Resistencia a Antineoplásicos/genética , Resistencia a Antineoplásicos/fisiología , Estrés del Retículo Endoplásmico/efectos de los fármacos , Estrés del Retículo Endoplásmico/genética , Flavonoides/uso terapéutico , Regulación Leucémica de la Expresión Génica/efectos de los fármacos , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/patología , Piperidinas/uso terapéutico , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Transducción de Señal/fisiología , Inanición/patología , Células Tumorales Cultivadas , Vidarabina/análogos & derivados , Vidarabina/farmacología
11.
Blood ; 120(23): 4621-34, 2012 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-23034282

RESUMEN

The nuclear export protein XPO1 is overexpressed in cancer, leading to the cytoplasmic mislocalization of multiple tumor suppressor proteins. Existing XPO1-targeting agents lack selectivity and have been associated with significant toxicity. Small molecule selective inhibitors of nuclear export (SINEs) were designed that specifically inhibit XPO1. Genetic experiments and X-ray structures demonstrate that SINE covalently bind to a cysteine residue in the cargo-binding groove of XPO1, thereby inhibiting nuclear export of cargo proteins. The clinical relevance of SINEs was explored in chronic lymphocytic leukemia (CLL), a disease associated with recurrent XPO1 mutations. Evidence is presented that SINEs can restore normal regulation to the majority of the dysregulated pathways in CLL both in vitro and in vivo and induce apoptosis of CLL cells with a favorable therapeutic index, with enhanced killing of genomically high-risk CLL cells that are typically unresponsive to traditional therapies. More importantly, SINE slows disease progression, and improves overall survival in the Eµ-TCL1-SCID mouse model of CLL with minimal weight loss or other toxicities. Together, these findings demonstrate that XPO1 is a valid target in CLL with minimal effects on normal cells and provide a basis for the development of SINEs in CLL and related hematologic malignancies.


Asunto(s)
Acrilatos/farmacología , Carioferinas/metabolismo , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Receptores Citoplasmáticos y Nucleares/metabolismo , Triazoles/farmacología , Acrilatos/química , Acrilatos/metabolismo , Transporte Activo de Núcleo Celular/efectos de los fármacos , Animales , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Cristalografía por Rayos X , Humanos , Immunoblotting , Interleucina-10/metabolismo , Interleucina-6/metabolismo , Carioferinas/química , Carioferinas/genética , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/metabolismo , Ratones , Ratones SCID , Ratones Transgénicos , Microscopía Confocal , Modelos Moleculares , Estructura Molecular , Unión Proteica , Estructura Terciaria de Proteína , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , Interferencia de ARN , Receptores Citoplasmáticos y Nucleares/química , Receptores Citoplasmáticos y Nucleares/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Linfocitos T/efectos de los fármacos , Linfocitos T/metabolismo , Triazoles/química , Triazoles/metabolismo , Proteína Exportina 1
12.
ACS Appl Mater Interfaces ; 16(6): 7670-7685, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38310585

RESUMEN

The phase separation of ceramics in a biopolymer matrix makes it challenging to achieve satisfactory mechanical properties required for orthopedic applications. It has been found that silane coupling agents can modify the surface of the bioceramic phase by forming a molecular bridge between the polymer and the ceramic, resulting in improved interfacial strength and adhesion. Therefore, in the present study, silane-modified diopside (DI) ceramic and ε-polycaprolactone (PCL) biopolymer composites were fabricated by injection molding method. The silane modification of DI resulted in their uniform dispersion in the PCL matrix, whereas agglomeration was found in composites containing unmodified DI. The thermal stability of the silane-modified DI-containing composites also increased. The Young's modulus of the composite containing 50% w/w DI modified by 3% w/w silane increased by 103% compared to composites containing 50% w/w unmodified DI. The biodegradation of the unmodified composites was significantly high, indicating their weak interfacial strength with the PCL matrix (p ≤ 0.001). The osteoconductive behavior of the composites was also validated by in vitro cell-material studies. Overall, our findings supported that the silane-modified composites have improved surface roughness, mechanical, and osteoconductive properties compared to the unmodified composite and have the potential for orthopedic applications.


Asunto(s)
Polímeros , Silanos , Ácido Silícico , Biopolímeros
13.
ChemistryOpen ; : e202400147, 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39246226

RESUMEN

2,4-Thiazolidinedione derivatives represent nitrogen-containing heterocyclic compounds utilized in type 2 diabetes mellitus management. Recent advances in medicinal chemistry have unveiled diverse therapeutic potentials and structural modifications of these derivatives. This review delves into novel TZD derivatives, encompassing their synthesis, structure-activity relationships, and pharmacokinetic profiles. Various therapeutic potentials of TZDs are explored, including anticancer, antimicrobial, anti-inflammatory, antioxidant, anticonvulsant, antihyperlipidemic, anticorrosive, and antitubercular activities. Additionally, it addresses mitigating side effects associated with marketed TZD derivatives such as weight gain, oedema, fractures, and congestive heart failure in type 2 diabetes mellitus management. The review elaborates on in vivo, in vitro, and ex vivo studies supporting different biological activities, alongside predicting ADME and drug-likeness properties of TZDs. Computational studies are also integrated to elucidate binding modes and affinities of novel TZD derivatives. Furthermore, a plethora of novel TZD derivatives with varied and enhanced therapeutic potentials are presented, warranting further evaluation of their biological activities.

14.
Colloids Surf B Biointerfaces ; 237: 113859, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38547794

RESUMEN

The main goal of bone tissue engineering research is to replace the allogenic and autologous bone graft substitutes that can promote bone repair. Owing to excellent biocompatibility and osteoconductivity, hydroxyapatite is in extensive research and high demand for both medical and non-medical applications. Although various methods have been developed for the synthesis of hydroxyapatite, in the present study we have shown the use of nanosecond laser energy in the wet precipitation method of nano-hydroxyapatite (nHAP) synthesis without using ammonium solution or any other chemicals for pH maintenance. Here, the present study aimed to fabricate the nanohydroxyapatite using a nanosecond laser. The X-ray diffraction and Fourier transform infrared spectroscopy have confirmed the hydroxyapatite formation under laser irradiation in less time without aging. A transmission electron microscopy confirmed the nano size of synthesized nHAP, which is comparable to conventional nHAP. The length and width of the laser-assisted nHAP were found to be in the range of 50-200 nm and 15-20 nm, respectively, at various laser parameters. The crystallite size obtained by Debye Scherrer formulae was found to be in the range of ∼ 16-36 nm. In addition, laser-assisted nHAP based composite cryogel (nanohydroxyapatite/gelatin/collagen I) was synthesized and impregnated with bioactive molecules (bone morphogenic protein and zoledronic acid) that demonstrated significant osteogenic potential both in vitro in cell experiment and in vivo rat muscle pouch model (abdomen and tibia muscles). Dual-energy X-ray analysis, micro-CT, and histological analysis confirmed ectopic bone regeneration. Micro-CT based histomorphometry showed a higher amount (more than 10-fold) of mineralization for animal groups implanted with composite cryogels loaded with bioactive molecules compared to only composite cryogels groups. Our findings thus demonstrate a controlled and rapid synthetic method for the synthesis of nHAP with various physical, chemical, and biological properties exhibited as comparable to conventionally synthesized nHAP.


Asunto(s)
Criogeles , Durapatita , Pirenos , Ratas , Animales , Durapatita/farmacología , Durapatita/química , Regeneración Ósea/fisiología , Huesos , Andamios del Tejido/química
15.
Int J Biol Macromol ; 278(Pt 1): 134402, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39094885

RESUMEN

3D printed scaffolds have revolutionized the field of regenerative medicine by overcoming the lacunas such as precision, customization, and reproducibility observed through traditional methods of scaffold preparation such as freeze-drying, electrospinning, etc. Combining the advantages of 3D printed scaffolds along with bioactive cues such as signaling molecules can be an effective treatment approach. In the present study, cellulose nanocrystals (CNCs) along with gelatin, in different ratios, were used for scaffold preparation through the direct ink writing technique and thoroughly characterized. The scaffolds showed porous microstructure, high swelling ratio (∼390 to 590), degradability and porosity (∼65 %). In vitro biocompatibility assays showed high biocompatibility and no toxicity through live-dead, proliferation and hemolysis assay. Further, the optimum formulation was functionalized with nitric oxide (NO)-releasing modified gelatin to enhance the scaffold's biomedical applicability. Functionality assays with this formulation, scratch, and neurite outgrowth showed positive effects of NO on cell migration and neurite length. The study presents the fabrication, modification, and biomedical applicability of the aforementioned inks, which paves new pathways in the field of 3D printing of scaffolds with significant potential for biomedical applications, soft tissue engineering, and wound dressing, for example.


Asunto(s)
Materiales Biocompatibles , Celulosa , Gelatina , Nanopartículas , Impresión Tridimensional , Medicina Regenerativa , Andamios del Tejido , Gelatina/química , Celulosa/química , Andamios del Tejido/química , Nanopartículas/química , Medicina Regenerativa/métodos , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Animales , Ingeniería de Tejidos/métodos , Proliferación Celular/efectos de los fármacos , Porosidad , Humanos , Hemólisis/efectos de los fármacos , Movimiento Celular/efectos de los fármacos , Óxido Nítrico/química , Ensayo de Materiales
16.
J Biol Chem ; 287(7): 4503-17, 2012 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-22158627

RESUMEN

Runt-related transcription factors (RUNX1, RUNX2, and RUNX3) are key lineage-specific regulators of progenitor cell growth and differentiation but also function pathologically as cancer genes that contribute to tumorigenesis. RUNX2 attenuates growth and stimulates maturation of osteoblasts during bone formation but is also robustly expressed in a subset of osteosarcomas, as well as in metastatic breast and prostate tumors. To assess the biological function of RUNX2 in osteosarcoma cells, we examined human genomic promoter interactions for RUNX2 using chromatin immunoprecipitation (ChIP)-microarray analysis in SAOS-2 cells. Promoter binding of both RUNX2 and RNA polymerase II was compared with gene expression profiles of cells in which RUNX2 was depleted by RNA interference. Many RUNX2-bound loci (1550 of 2339 total) exhibit promoter occupancy by RNA polymerase II and contain the RUNX consensus motif 5'-((T/A/C)G(T/A/C)GG(T/G). Gene ontology analysis indicates that RUNX2 controls components of multiple signaling pathways (e.g. WNT, TGFß, TNFα, and interleukins), as well as genes linked to cell motility and adhesion (e.g. the focal adhesion-related genes FAK/PTK2 and TLN1). Our results reveal that siRNA depletion of RUNX2, PTK2, or TLN1 diminishes motility of U2OS osteosarcoma cells. Thus, RUNX2 binding to diverse gene loci may support the biological properties of osteosarcoma cells.


Asunto(s)
Neoplasias Óseas/metabolismo , Movimiento Celular , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Genoma Humano , Proteínas de Neoplasias/metabolismo , Osteosarcoma/metabolismo , Elementos de Respuesta , Neoplasias Óseas/genética , Adhesión Celular/genética , Línea Celular Tumoral , Inmunoprecipitación de Cromatina , Subunidad alfa 1 del Factor de Unión al Sitio Principal/genética , Sitios Genéticos , Humanos , Proteínas de Neoplasias/genética , Análisis de Secuencia por Matrices de Oligonucleótidos , Osteosarcoma/genética , ARN Polimerasa II/genética , ARN Polimerasa II/metabolismo
17.
Phytother Res ; 27(11): 1735-8, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23280566

RESUMEN

The potentiating action of the flavonolignan, (-)-hydnocarpin, in combination with vincristine was evaluated in the 697 acute lymphoblastic leukemia cell line and a P-gp-expressing variant, 697-R. Vincristine at 3 nM caused nearly complete growth inhibition in 697 cells versus a 17% growth inhibition in 697-R cells. When combined with (-)-hydnocarpin at concentrations of 10 and 5 µM, vincristine-mediated growth inhibition in the 697-R cells increased significantly over the sum of the individual agents to 72% (p ≤ 0.0001) and 41% (p = 0.0256), respectively. Vincristine at 1.5 nM (66% growth inhibition) and 0.75 nM (39% growth inhibition) combined with (-)-hydnocarpin at 10 µM (42% growth inhibition) in the 697 cells caused a significant increase in growth inhibition to 83% (p = 0.03) and to 61% (p < 0.0001), respectively, when compared to vincristine treatment as a single agent. To investigate the mechanism for the vincristine re-sensitization caused by (-)-hydnocarpin, the P-gp inhibitory effect of (-)-hydnocarpin was evaluated.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Resistencia a Antineoplásicos/efectos de los fármacos , Flavonolignanos/farmacología , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Vincristina/farmacología , Línea Celular Tumoral , Humanos , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología
18.
J Funct Biomater ; 14(11)2023 Nov 02.
Artículo en Inglés | MEDLINE | ID: mdl-37998109

RESUMEN

Extracellular vesicles (EVs) are nano-sized vehicles secreted by all live cells to establish communication with adjacent cells. In recent years, mammalian EVs (MEVs) have been widely investigated for their therapeutic implications in human disease conditions. As the understanding of MEV composition and nature is advancing, scientists are constantly exploring alternatives for EV production with similar therapeutic potential. Plant-derived exosome-like nanovesicles (PDEVs) may be a better substitute for MEVs because of their widespread sources, cost-effectiveness, and ease of access. Cissus quadrangularis (CQ), known as "bone setter or Hadjod", is a perennial plant utilized for its osteogenic potential. Its crude powder extract formulations are widely used as tablets and syrups. The present work elucidates the isolation of exosome-like nanovesicles (henceforth exosomes) from the culture supernatants of an in vitro cultured callus tissue derived from CQ. The physical and biological properties of the exosomes were successfully investigated using different characterization techniques. The therapeutic potential of the CQ exosomes was found to ameliorate the wound scratch injury and oxidative stress conditions in human-derived mesenchymal stem cells (hMSCs) and the pre-osteoblast (MC3T3) cell line. These exosomes also induced the proliferation and differentiation of hMSCs, as observed by alkaline phosphatase activity. These findings may serve as a proof of concept for further investigating the CQ exosomes as a nanocarrier for drug molecules in various therapeutic bone applications.

19.
Contracept Reprod Med ; 8(1): 25, 2023 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-36978137

RESUMEN

BACKGROUND: Postpartum intrauterine contraceptives device (PPIUCD) offers an effective means of providing contraceptive services to women in countries with high rates of unmet needs for family planning services. However, scientific literature estimating the long-term retention rates is scarce. We estimate the factors affecting acceptance and retention of PPIUCD and explore the risk factors against PPIUCD Discontinuation at six months". MATERIAL AND METHOD: This prospective observational study was conducted between 2018 and 20 at a tertiary care institute in North India. PPIUCD was inserted following a detailed counseling session and consent. The women were followed up for six months. Bivariate analysis was done to depict the association between socio-demographic characteristics and acceptance. Logistic regression, cox regression, and Kaplan Meier analysis were applied to explore factors affecting acceptance and retention of PPIUCD. RESULTS: Of the 300 women counseled for PPIUCD, 60% accepted them. The majority of these women were between 25 and 30 years (40.6%), primigravida (61.7%), educated (86.1%), and from urban areas (61.7%). Retention rates at six months were about 65.6%, while 13.9% and 5.6% were either removed or expelled. Women declined PPIUCD due to refusal by spouses, partial knowledge, inclination towards other methods, non-willingness, religious beliefs, and fear of pain and heavy bleeding. Adjusted logistic regression depicted that higher education, housewife status, lower-middle and richest SES, Hinduism, and counseling in early pregnancy promoted acceptance of PPIUCD. The most common reasons for removal were AUB, infection, and family pressure (23.1%). Adjusted hazard ratio depicted religion other than Hinduism, counseling in late stages of pregnancy, and normal vaginal delivery were significant predictors for early removal or expulsion. While education, higher socio-economic status favoured retention. CONCLUSION: PPIUCD is a safe, highly effective, low-cost, long-acting, and feasible method of contraception. Skill enhancement of healthcare personnel for insertion techniques, adequate antenatal counseling, and advocacy of PPIUCD can help increase the acceptance of PPIUCD.

20.
Br J Ophthalmol ; 107(5): 635-643, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-34916211

RESUMEN

AIMS: To develop a comprehensive three-dimensional analyses of segmental tomography (placido and optical coherence tomography) using artificial intelligence (AI). METHODS: Preoperative imaging data (MS-39, CSO, Italy) of refractive surgery patients with stable outcomes and diagnosed with asymmetric or bilateral keratoconus (KC) were used. The curvature, wavefront aberrations and thickness distributions were analysed with Zernike polynomials (ZP) and a random forest (RF) AI model. For training and cross-validation, there were groups of healthy (n=527), very asymmetric ectasia (VAE; n=144) and KC (n=454). The VAE eyes were the fellow eyes of KC patients but no further manual segregation of these eyes into subclinical or forme-fruste was performed. RESULTS: The AI achieved an excellent area under the curve (0.994), accuracy (95.6%), recall (98.5%) and precision (92.7%) for the healthy eyes. For the KC eyes, the same were 0.997, 99.1%, 98.7% and 99.1%, respectively. For the VAE eyes, the same were 0.976, 95.5%, 71.5% and 91.2%, respectively. Interestingly, the AI reclassified 36 (subclinical) of the VAE eyes as healthy though these eyes were distinct from healthy eyes. Most of the remaining VAE (n=104; forme fruste) eyes retained their classification, and were distinct from both KC and healthy eyes. Further, the posterior surface features were not among the highest ranked variables by the AI model. CONCLUSIONS: A universal architecture of combining segmental tomography with ZP and AI was developed. It achieved an excellent classification of healthy and KC eyes. The AI efficiently classified the VAE eyes as 'subclinical' and 'forme-fruste'.


Asunto(s)
Queratocono , Humanos , Queratocono/diagnóstico , Inteligencia Artificial , Topografía de la Córnea/métodos , Córnea , Paquimetría Corneal , Tomografía de Coherencia Óptica , Curva ROC
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