Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 135
Filter
1.
Phys Rev E ; 109(4-1): 044152, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38755945

ABSTRACT

This work is devoted to the emergence of a connected network of slots (cracks) on a square grid. Accordingly, extensive Monte Carlo simulations and finite-size scaling analysis have been conducted to study the site percolation of straight slots with length l measured in the number of elementary cells of the grid with the edge size L. A special focus was made on the dependence of the percolation threshold p_{C}(l,L) on the slot length l varying in the range 1≤l≤L-2 for the square grids with edge size in the range 50≤L≤1000. In this way, we found that p_{C}(l,L) strongly decreases with increase of l, whereas the variations of p_{C}(l=const,L) with the variation of ratio l/L are very small. Consequently, we acquire the functional dependencies of the critical filling factor and percolation strength on the slot length. Furthermore, we established that the slot percolation model interpolates between the site percolation on square lattice (l=1) and the continuous percolation of widthless sticks (l→∞) aligned in two orthogonal directions. In this regard, we note that the critical number of widthless sticks per unit area is larger than in the case of randomly oriented sticks. Our estimates for the critical exponents indicate that the slot percolation belongs to the same universality class as standard Bernoulli percolation.

2.
Rev. esp. med. nucl. imagen mol. (Ed. impr.) ; 43(2): 79-83, Mar-Abr. 2024. ilus, tab
Article in Spanish | IBECS | ID: ibc-231816

ABSTRACT

Introducción: La SPECT portátil puede ser una técnica de imagen útil para la planificación preoperatoria de la biopsia selectiva del ganglio centinela (BSGC) ya que permite la localización del ganglio centinela (GC) mediante imágenes tomográficas en 3D y en tiempo real y determina su profundidad, después de unos minutos de exploración. El objetivo del estudio fue evaluar la correlación entre el número de GC detectados entre las imágenes de la SPECT portátil y la linfogammagrafía (LG). Materiales y métodos: Cien pacientes con diagnóstico de cáncer de mama infiltrante y sin evidencia clínica de afectación ganglionar, se sometieron prospectivamente a una BSGC. El estudio preoperatorio incluyó imágenes de SPECT portátil a los 15 min tras la inyección y de LG a los 25 y 60-90 min (precoz y tardía). Se analizó el acuerdo observado y se realizó un estudio de concordancia entre el número de GC detectados con SPECT portátil y LG. Resultados: El acuerdo observado en la detección de GC entre SPECT portátil y LG precoz fue del 72%; entre SPECT portátil y LG tardía del 85%, y entre la LG precoz y la tardía de un 87%. En el estudio de concordancia se registró una concordancia moderada entre la SPECT portátil y la LG precoz (coeficiente kappa: 0,42); una concordancia moderada-alta entre la SPECT portátil y la LG tardía (coeficiente kappa: 0,60), y una concordancia de moderada-alta entre la LG precoz y la tardía (coeficiente kappa: 0,70), sin diferencias significativas entre ellos (valor p=0,16). Conclusión: La SPECT portátil presentó una concordancia moderada-alta con los estudios de imagen convencional y podría ser una alternativa válida para el estudio prequirúrgico de la BSGC en el cáncer de mama.(AU)


Introduction: Freehand SPECT can be a useful imaging technique for preoperative planning of sentinel lymph node biopsy (SLNB) as it allows localization of the sentinel node by 3D and real-time tomographic imaging and determines its depth after a few minutes of scanning. The aim of the study was to evaluate the correlation between the number of detected SNs between freehand SPECT images and lymphoscintigraphy (LS). Materials and methods: One hundred patients with a diagnosis of invasive breast cancer and no clinical evidence of lymph node involvement prospectively underwent SLNB. The preoperative study included freehand SPECT imaging at 15min after injection and LS imaging at 25 and 60–90min after injection (early and late). The observed agreement was analyzed and a concordance study was performed between the number of SNs detected with freehand SPECT and LS. Results: The observed agreement in the detection of SNs between freehand SPECT and early LS was 72%; between freehand SPECT and late LS was 85%; and between early and late LS was 87%. In the concordance study, there was moderate concordance between freehand SPECT and early LS (kappa coefficient: 0.42); moderate-high concordance between freehand SPECT and late LS (kappa coefficient: 0.60); and moderate-high concordance between early and late LS (kappa coefficient: 0.70), with no significant differences between them (p-value=0.16). Conclusion: Freehand SPECT showed a moderate-high concordance with conventional imaging studies and could be a valid alternative for the presurgical study of SLNB in breast cancer.(AU)


Subject(s)
Humans , Female , Breast Neoplasms/diagnostic imaging , Radionuclide Imaging , Sentinel Lymph Node/diagnostic imaging , Sentinel Lymph Node Biopsy , Lymphoscintigraphy , Nuclear Medicine , Molecular Imaging
3.
Article in English | MEDLINE | ID: mdl-38387784

ABSTRACT

INTRODUCTION: Freehand SPECT can be a useful imaging technique for preoperative planning of sentinel lymph node biopsy (SLNB) as it allows localization of the sentinel node by 3D and real-time tomographic imaging and determines its depth after a few minutes of scanning. The aim of the study was to evaluate the correlation between the number of detected SNs between freehand SPECT images and lymphoscintigraphy (LS). MATERIALS AND METHODS: 100 patients with a diagnosis of invasive breast cancer and no clinical evidence of lymph node involvement prospectively underwent SLNB. The preoperative study included freehand SPECT imaging at 15min after injection and LS imaging at 25 and 60-90min after injection (early and late). The observed agreement was analyzed and a concordance study was performed between the number of SNs detected with freehand SPECT and LS. RESULTS: The observed agreement in the detection of SNs between freehand SPECT and early LS was 72%; between freehand SPECT and late LS was 85%; and between early and late LS was 87%. In the concordance study, there was moderate concordance between freehand SPECT and early LS (kappa coefficient: 0.42); moderate-high concordance between freehand SPECT and late LS (kappa coefficient: 0.60); and moderate-high concordance between early and late LS (kappa coefficient: 0.70), with no significant differences between them (p-value=0.16). CONCLUSION: Freehand SPECT showed a moderate-high concordance with conventional imaging studies and could be a valid alternative for the presurgical study of SLNB in breast cancer.


Subject(s)
Breast Neoplasms , Sentinel Lymph Node , Humans , Female , Sentinel Lymph Node/diagnostic imaging , Sentinel Lymph Node/pathology , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/surgery , Breast Neoplasms/pathology , Sentinel Lymph Node Biopsy/methods , Tomography, Emission-Computed, Single-Photon/methods , Lymph Nodes/pathology
4.
Rev. esp. med. nucl. imagen mol. (Ed. impr.) ; 42(2): 83-92, mar.-abr. 2023. tab, ilus
Article in Spanish | IBECS | ID: ibc-217324

ABSTRACT

Objetivo Sintetizar la evidencia actual sobre la utilidad de la radiómica en el análisis de la imagen PET/TC en cáncer de mama local o localmente avanzado y evaluar la calidad metodológica de los estudios radiómicos publicados al respecto. Material y métodos Revisión sistemática de artículos en distintas bases de datos hasta 2021 utilizando los términos «PET», «radiomics», «texture», «breast». Se seleccionaron solo artículos con datos humanos y que incluyeran una imagen de PET en su análisis. Se excluyeron estudios con datos de pruebas y menos de 20 pacientes. De cada artículo se extrajo el tamaño muestral, el radiotrazador utilizado, la técnica de imagen y las características de imagen extraídas. Se determinó la calidad metodológica de los estudios mediante el instrumento QUADAS-2. Resultados Se seleccionaron 18 artículos. El diseño retrospectivo fue el más utilizado. La característica radiómica más estudiada fue el SUVmax. Diversos parámetros radiómicos se correlacionaron con la caracterización tumoral, y la heterogeneidad tumoral demostró utilidad para predecir el curso de la enfermedad y la respuesta al tratamiento. La mayoría de los artículos mostraron un alto riesgo de sesgo, derivado principalmente de la selección de pacientes. Conclusiones Se observó una alta probabilidad de sesgo en los artículos publicados. La radiómica es un campo aún en desarrollo y son necesarios más estudios para demostrar su utilidad en la práctica clínica habitual. La herramienta QUADAS-2 permite la valoración crítica de la calidad metodológica de la evidencia disponible. Pese a las limitaciones, la radiómica se muestra como una herramienta que puede ayudar a conseguir un manejo oncológico personalizado en el cáncer de mama (AU)


Aim To synthesize the current evidence of the usefulness of radiomics in PET/CT image analysis in local and locally advanced breast cancer. Also, to evaluate the methodological quality of the radiomic studies published. Methods Systematic review of articles in different databases until 2021 using the terms «PET», «radiomics», «texture», «breast». Only articles with human data and that included a PET image were included. Studies with simulated data and with less than 20 patients were excluded. The sample size, radiotracer used, imaging technique, and radiomics characteristics were extracted from each article. The methodological quality of the studies was determined using the QUADAS-2 tool. Results Eighteen articles were selected. The retrospective design was the most used. The most studied radiomic characteristic was SUVmax. Several radiomic parameters were correlated with tumor characterization, and tumor heterogeneity proved useful for predicting disease course and response to treatment. Most articles showed a high risk of bias, mainly from the patient selection. Conclusions A high probability of bias was observed in most of the published articles. Radiomics is a developing field and more studies are needed to demonstrate its usefulness in routine clinical practice. The QUADAS-2 tool allows critical assessment of the methodological quality of the available evidence. Despite its limitations, radiomics is shown to be an instrument that can help to achieve personalized oncologic management of breast cancer (AU)


Subject(s)
Humans , Female , Positron Emission Tomography Computed Tomography/methods , Breast Neoplasms/diagnostic imaging , Image Processing, Computer-Assisted , Reproducibility of Results , Fluorodeoxyglucose F18
5.
J Biomater Appl ; 37(9): 1632-1644, 2023 04.
Article in English | MEDLINE | ID: mdl-36916869

ABSTRACT

This study aimed to develop bone regenerative therapeutic strategies, based on the addition of bone marrow stromal cells (BMSC) on bioglass/collagen (BG/COL) scaffolds. For this purpose, an in vivo study was conducted using tissue response of the BG/COL scaffolds combined with BMSC in a critical-size defects. Wistar rats were submitted to the surgical procedure to perform the cranial critical size bone defects and distributed in four groups (20 animals per group): Control Group (CG) (rats submitted to the cranial bone defect surgery without treatment), Bioglass Group (BG) (rats treated with BG), BG/COL Group (rats treated with BG/COL) and Bioglass/Collagen and BMSC Group (BG/COL/BMSC) (rats treated with BG/COL scaffolds enriched with BMSCs). Animals were euthanized 15 and 30 days after surgery. Scanning electron microscopy, histopathological and immunohistochemistry analysis were used. SEM analysis demonstrated that porous scaffolds were obtained, and Col fibers were successfully impregnated to BG matrices. The implantation of the BMSC on BG/COL based scaffolds was effective in stimulating newly bone formation and produced an increased immunoexpression of markers related to the bone repair. These results highlight the potential of BG/COL scaffolds and BMSCs to be used as a therapeutic approach for bone regeneration.


Subject(s)
Mesenchymal Stem Cells , Tissue Scaffolds , Rats , Animals , Rats, Wistar , Collagen/pharmacology , Osteogenesis , Bone Regeneration , Models, Theoretical , Bone Marrow Cells , Tissue Engineering/methods
6.
Article in English | MEDLINE | ID: mdl-36375751

ABSTRACT

AIM: To synthesize the current evidence of the usefulness of radiomics in PET/CT image analysis in local and locally advanced breast cancer. Also, to evaluate the methodological quality of the radiomic studies published. METHODS: Systematic review of articles in different databases until 2021 using the terms "PET", "radiomics", "texture", "breast". Only articles with human data and that included a PET image were included. Studies with simulated data and with less than 20 patients were excluded. Were extracted sample size, radiotracer used, imaging technique, and radiomics characteristics from each article. The methodological quality of the studies was determined using the QUADAS-2 tool. RESULTS: 18 articles were selected. The retrospective design was the most used. The most studied radiomic characteristic was SUVmax. Several radiomic parameters were correlated with tumor characterization, and tumor heterogeneity proved useful for predicting disease course and response to treatment. Most articles showed a high risk of bias, mainly from the patient selection. CONCLUSIONS: A high probability of bias was observed in most of the published articles. Radiomics is a developing field and more studies are needed to demonstrate its usefulness in routine clinical practice. The QUADAS-2 tool allows critical assessment of the methodological quality of the available evidence. Despite its limitations, radiomics is shown to be an instrument that can help to achieve personalized oncologic management of breast cancer.


Subject(s)
Breast Neoplasms , Positron Emission Tomography Computed Tomography , Humans , Female , Positron Emission Tomography Computed Tomography/methods , Fluorodeoxyglucose F18 , Retrospective Studies , Image Processing, Computer-Assisted/methods
7.
Acta Ortop Mex ; 37(5): 276-282, 2023.
Article in English | MEDLINE | ID: mdl-38382452

ABSTRACT

Superior pubic rami fractures are commonly associated with a posterior pelvic ring disruption. It has been shown that fixing both the anterior pelvic arch and the posterior ring increases stability and enhances clinical results. Several techniques for fixing the superior pubic rami exist, and multiple studies showed that minimally invasive methods decrease wound-related complications, with the advantage of preserving soft tissues. We describe a surgical procedure to treat simple pubic rami fractures associated with posterior pelvic ring disruptions by placing an intramedullary elastic titanium nail (TEN). We propose this technique as an alternative fixation method for superior pubic rami fractures.


Las fracturas de la rama superior del pubis se asocian con frecuencia a una alteración del anillo pélvico posterior. Se ha demostrado que la fijación tanto del arco pélvico anterior como del anillo posterior aumenta la estabilidad y mejora los resultados clínicos. Existen varias técnicas para fijar la rama superior del pubis, y múltiples estudios han demostrado que los métodos mínimamente invasivos disminuyen las complicaciones relacionadas con la herida, con la ventaja de preservar los tejidos blandos. Describimos un procedimiento quirúrgico para tratar fracturas simples de la rama púbica asociadas a disrupciones del anillo pélvico posterior mediante la colocación de un clavo intramedular elástico de titanio (TEN). Proponemos esta técnica como método de fijación alternativo para las fracturas superiores de la rama púbica.


Subject(s)
Fractures, Bone , Pelvic Bones , Humans , Titanium , Pelvic Bones/surgery , Nails , Fractures, Bone/surgery , Fracture Fixation, Internal/methods , Retrospective Studies
8.
Eur Rev Med Pharmacol Sci ; 26(12): 4420-4430, 2022 06.
Article in English | MEDLINE | ID: mdl-35776043

ABSTRACT

OBJECTIVE: Nausea and vomiting of pregnancy is a common disease that affects many women suffering from mild to severe symptoms. Amongst the different treatments, a fixed dose combination of doxylamine and pyridoxine has been proven safe and effective although the mechanism of action is not well established. There are different pharmaceutical dosage forms in the European market. The objective of this study was to compare the characteristics of a capsule formulation, Cariban® and a tablet formulation, Xonvea® to evaluate the potential impact of their release profiles on their onset of action. MATERIALS AND METHODS: 10 mg/10 mg of doxylamine succinate/pyridoxine hydrochloride capsules (Cariban®) and tablets (Xonvea®) were used as reference materials. Appearance, mass, composition, and in vitro dissolution profiles were compared. Bibliographic data from 4 pharmacokinetic studies of Xonvea® and 1 pharmacokinetic study of Cariban® was reviewed. RESULTS: In vitro dissolution studies showed significant differences in dissolution profiles of tablets and capsules. The later exhibiting some release of both drug substances in acid conditions followed by a non-complete release after a total of 3 hours while the tablets demonstrated gastro-resistant properties and rapid API release in about 20-30 minutes after the acid stage. Comparison of PK data showed greater Cmax for pyridoxine. CONCLUSIONS: At pH 6.8, complete and faster release of the fixed dose combination for Xonvea® gastro-resistant tablets compared to Cariban® capsules could possibly explain the greater Cmax observed in vivo for the tablet's formulation. This could translate into faster onset of action and relief of nausea for pregnant women taking the tablets vs. the capsules.


Subject(s)
Antiemetics , Doxylamine , Female , Gastrointestinal Agents , Humans , Nausea , Pregnancy , Pyridoxine , Solubility , Tablets
9.
J Bone Miner Metab ; 38(5): 639-647, 2020 Sep.
Article in English | MEDLINE | ID: mdl-32303916

ABSTRACT

INTRODUCTION: Collagen from marine esponges has been used as a promising material for tissue engineering proposals. Similarly, photobiomodulation (PBM) is able of modulating inflammatory processes after an injury, accelerating soft and hard tissue healing and stimulating neoangiogenesis. However, the effects of the associated treatments on bone tissue healing have not been studied yet. In this context, the present study aimed to evaluate the biological temporal modifications (using two experimental periods) of marine sponge collagen or sponging (SPG) based scaffold and PBM on newly formed bone using a calvaria bone defect model. MATERIAL AND METHODS: Wistar rats were distributed into two groups: SPG or SPG/PBM and euthanized into two different experimental periods (15 and 45 days post-surgery). A cranial critical bone defect was used to evaluate the effects of the treatments. Histology, histomorfometry and immunohistological analysis were performed. RESULTS: Histological findings demonstrated that SPG/PBM-treated animals, 45 days post-surgery, demonstrated a higher amount of connective and newly formed bone tissue at the region of the defect compared to CG. Notwithstanding, no difference among groups were observed in the histomorphometry. Interestingly, for both anti-transforming growth factor-beta (TGF-ß) and anti-vascular endothelial growth factor (VEGF) immunostaining, higher values for SPG/PBM, at 45 days post-surgery could be observed. CONCLUSION: It can be concluded that the associated treatment can be considered as a promising therapeutical intervention.


Subject(s)
Aquatic Organisms/chemistry , Collagen/pharmacology , Low-Level Light Therapy , Skull/pathology , Tissue Scaffolds/chemistry , Wound Healing/drug effects , Animals , Disease Models, Animal , Male , Rats, Wistar , Skull/drug effects , Transforming Growth Factor beta/metabolism , Vascular Endothelial Growth Factor A/metabolism
10.
Dalton Trans ; 49(14): 4549-4558, 2020 Apr 07.
Article in English | MEDLINE | ID: mdl-32196043

ABSTRACT

Cation doping is one of the most dynamic strategies to enhance the electrochemical properties of cathode materials for lithium-ion batteries. Nevertheless, the maximum partial substitution capacity depends on the solubility of each metal ion, and so the formation of impurities is a very common consequence. Thus, the correlation between electrochemical performance and the doping effect is frequently unknown. In this study, the effect of the partial substitution of copper by manganese, iron or nickel in Li2CuO2 is evaluated, as well as the effect on the electrochemical performance of the modified Li2CuO2 samples as lithium ion battery cathode materials. XRD characterization confirmed single phase formation for all samples, and the incorporation of the transition metal in the Li2CuO2 structure was evaluated by XRD profile fitting, EPR and 7Li-NMR. The results showed modifications in intra- and inter-chain interactions, associated with the variations in the Cu-O-Cu bond angle and changes in magnetic order, due to the presence of the doping transition metal. Among all samples, only manganese partial substitution reveals a drastic improvement in the electrochemical stability during the charge/discharge processes even at potentials higher than 3.9 V. It was corroborated that the higher stability is attributed to (i) the increase in the superexchange interactions between the copper sites and manganese, directly modifying lithium diffusivity and electronic conductivity, both inferred from dynamic thermogravimetric analysis for CO2 sorption and conductivity tests, respectively and (ii) the lower propensity to enable O2 evolution during several charge cycles. These results are totally attributed to manganese cation partial substitution, which has a huge impact on the utilization of copper-based materials in real applications.

11.
Acta Ortop Mex ; 34(4): 222-227, 2020.
Article in Spanish | MEDLINE | ID: mdl-33535279

ABSTRACT

Arthroscopic surgery of the hip has evolved significantly over the last years, offering an opportunity of treatment in several intra-articular pathologies. Recent methods and instrumental advances have allowed more frequent use of this procedure, with various indications such as: hip pain, acetabular labrum lesions, extraction of foreign bodies, debridement in septic arthritis, pincer impingement, and some extra-articular injuries. Another intra-articular hip pathology that benefits from arthroscopic assistance could be found in the management of simple acetabular fractures. Therefore, this report presents the case of a patient with a posterior column fracture treated with an arthroscopic approach. Arthroscopic techniques for the fixation of intra-articular fractures offer the advantage of a direct visualization of the articular surface, which results in an anatomical reduction. In addition, arthroscopic techniques also present a benefit for intra-articular injuries such as the posterior labral lesion in this case. In simple fractures of the posterior acetabular column with minimum displacement, where percutaneous screw fixation is useful as a definitive fixation method, hip arthroscopy is useful for the reduction process and verifies the extra-articular screw trajectory.


La cirugía artroscópica de la cadera ha evolucionado considerablemente en los últimos años, ofreciendo oportunidad de tratamiento a muchas patologías intraarticulares no reconocidas previamente. Con avances recientes en métodos e instrumentos quirúrgicos, se realiza cada vez más frecuentemente, con indicaciones que incluyen: diagnóstico de pacientes con dolor de cadera, lesiones del labrum acetabular, extracción de cuerpos extraños, desbridamiento en artritis séptica, pinzamiento femoroacetabular y algunos daños extraarticulares. Otra patología intraarticular de la cadera que se beneficia de la asistencia por artroscopía se podría encontrar en el manejo de fracturas acetabulares simples. Reportamos el caso de un paciente con fractura de columna posterior acetabular, tratado vía artroscópica, y los resultados obtenidos. Las técnicas artroscópicas para la fijación de fracturas intraarticulares ofrecen la ventaja de una visualización y reducción superiores de la superficie articular, ya que se hacen mediante observación del foco de fractura, permitiendo una reducción anatómica. Además, las técnicas de reducción artroscópica ofrecen otro beneficio para las lesiones intraarticulares, como en este caso la lesión de labrum posterior. En los trazos simples con poco desplazamiento de las fracturas de columna posterior acetabular, donde la fijación percutánea con tornillos es útil como método de fijación definitiva, la artroscopía de cadera es de utilidad con el fin de asistir durante el proceso de reducción y verificar que el trayecto del tornillo no se encuentre intraarticular.


Subject(s)
Arthroscopy , Hip Fractures , Acetabulum/diagnostic imaging , Acetabulum/surgery , Bone Screws , Hip Joint , Humans
12.
Braz. j. biol ; 79(3): 404-409, July-Sept. 2019. tab
Article in English | LILACS | ID: biblio-1001466

ABSTRACT

Abstract Passion fruits species presents a larger economic importance for in natura consumption and industry. The main way to propagate these species is by seeds; however, the aril presence and environmental conditions may inhibit the seeds germination. In this sense, the objective of this study was to evaluate the effect of aril removal methods and light conditions on P. edulis var. flavicarpa seeds quality and germination. There were used five methods to remove the seeds aril: (1) friction on steel mesh sieve for 5 minutes; (2) friction with coarse sand on steel mesh sieve for 5 minutes; (3) immersion in lime solution at 10% (w/v), for 30 minutes; (4) fermentation in sugar solution at 10% (w/v), during 48 hours; and (5) natural pulp fermentation, during five days. The seeds were submitted to germination test at darkness and lightness, as well as, to length seedlings and emergence test. Regardless the aril removal method, the germination percentage was lower at lightness than darkness highlighting the natural pulp fermentation treatment, which presented 86% of seeds germinated. On the other hand, the aril removal methods did not affect the seedlings emergence, with emergence percentages ranged from 88 to 94%.


Resumo As espécies de maracujá apresentam grande importância econômica, tanto para o consumo in natura, quanto para a indústria. A principal maneira de propagar essas espécies é por sementes; contudo, a presença de arilo e condições ambientais pode inibir a germinação. Nesse sentido, objetivou-se estudar o efeito de métodos de remoção do arilo e luminosidade na qualidade e germinação das sementes de Passiflora edulis var. flavicarpa. Cinco métodos foram empregados para a remoção do arilo: (1) fricção em peneira de malha de aço por cinco minutos; (2) fricção com areia grossa em peneira de malha de aço por cinco minutos; (3) imersão em solução de cal a 10% (m/v), por 30 minutos; (4) fermentação da polpa em solução de açúcar a 10% (m/v), por 48 horas; e (5) fermentação natural da polpa, por cinco dias. As sementes foram submetidas ao teste de germinação no escuro e no claro, teste de comprimento de plântulas e teste de emergência. Independente do método de remoção do arilo, a porcentagem de germinação no claro apresentou-se menor em comparação ao escuro, com destaque para o tratamento de fermentação natural da polpa, o qual apresentou 86% de sementes germinadas. Por outro lado, os métodos de remoção do arilo não afetaram a emergência das plântulas, com porcentagem de emergência variando entre 88 a 94%.


Subject(s)
Seeds/physiology , Germination/physiology , Passiflora/physiology , Flowers/physiology , Seeds/growth & development , Seeds/radiation effects , Passiflora/growth & development , Passiflora/radiation effects , Seedlings/physiology , Light
13.
Colloids Surf B Biointerfaces ; 181: 856-863, 2019 Sep 01.
Article in English | MEDLINE | ID: mdl-31382333

ABSTRACT

Flavonoid-metal complexes are widely studied because of their interesting luminescent behavior and biological activity. Despite the extensive exploration of flavonoid-metal coordination processes in solution, the formation of complexes using the flavonoid molecule inserted in a lipid membrane has been little investigated. This effect could provide important insight into the biological activity of flavonoids at lipid membranes and could represent an attractive strategy to design supramolecular structures. Here, we studied the complexation between Sr2+ and morin inserted in an octadecylphosphonic acid (OPA) Langmuir monolayer. This is a relevant system due to the synergism imposed by the association of the Sr2+ ability to control bone formation/resorption with the morin antioxidative effect. Morin incorporation into the OPA monolayers and further Sr2+ complexation were monitored by surface pressure isotherms. Electronic absorption spectroscopy and fluorescence techniques showed Sr-morin complexation both in solution and at the air-liquid interface. Although morin complexation has been described to occur only at basic pH, the specific thermodynamic properties at the air-liquid interface drove metal complexation. LB films were deposited on Ti surfaces, and the resulting OPA/Sr-morin coatings exhibited high surface free energy and increase on its polar component. This optimized surface feature supported further serum protein adsorption and osteoblast growth and differentiation, indicating that these lipid-based coatings are promising for bioactive coating design. This study paves the way for the use of this lipid-based coating in the design of implants for faster osteointegration. Moreover, flavonoid-metal complexation at membranes could also help to shed light on the biological role played by flavonoids.


Subject(s)
Coordination Complexes/pharmacology , Drug Design , Flavonoids/pharmacology , Strontium/pharmacology , Adsorption , Cell Differentiation/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Coordination Complexes/chemical synthesis , Coordination Complexes/chemistry , Flavonoids/chemistry , Humans , Molecular Structure , Optical Imaging , Osteoblasts/drug effects , Particle Size , Strontium/chemistry , Surface Properties , Thermodynamics , Wettability
14.
Plant Dis ; 103(6): 1156-1165, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30995151

ABSTRACT

Persian lime (Citrus latifolia Tan.) is an important and widely cultivated fruit crop in several regions of Mexico. In recent years, severe symptoms of gummosis, stem cankers, and dieback were detected in the Persian lime-producing region in the states of Veracruz and Puebla, Mexico. The aims of this study were to identify the species of Lasiodiplodia associated with these symptoms, determine the distribution of these species, and test their pathogenicity and virulence on Persian lime plants. In 2015, symptomatic samples were collected from 12 commercial Persian lime orchards, and 60 Lasiodiplodia isolates were obtained. Fungal identification of 32 representative isolates was performed using a phylogenetic analysis based on DNA sequence data of the internal transcribed spacer region and part of the translation elongation factor 1-α and ß-tubulin genes. Sequence analyses were carried out using the Maximum Likelihood and Bayesian Inference methods. Six Lasiodiplodia species were identified as Lasiodiplodia pseudotheobromae, Lasiodiplodia theobromae, Lasiodiplodia brasiliense, Lasiodiplodia subglobosa, Lasiodiplodia citricola, and Lasiodiplodia iraniensis. All Lasiodiplodia species of this study are reported for the first time in association with Persian lime in Mexico and worldwide. L. pseudotheobromae (46.9% of isolates) was the most frequently isolated species followed by L. theobromae (28.1%) and L. brasiliense (12.5%). Pathogenicity on Persian lime young plants using a mycelial plug inoculation method showed that all identified Lasiodiplodia species were able to cause necrotic lesions and gummosis, but L. subglobosa, L. iraniensis, and L. pseudotheobromae were the most virulent.


Subject(s)
Ascomycota , Citrus , Phylogeny , Plant Diseases , Ascomycota/classification , Ascomycota/genetics , Bayes Theorem , Citrus/microbiology , DNA, Fungal , Mexico , Plant Diseases/microbiology , Sequence Analysis, DNA
15.
J Pharm Biomed Anal ; 169: 70-74, 2019 May 30.
Article in English | MEDLINE | ID: mdl-30831452

ABSTRACT

A new method for the quantification of metabolites in the absence of a chemically synthetized authentic standard is described herein. Metabolites to be used as reference standards were obtained biologically from microsomes incubation. The method is a stepwise process in which, only the radiolabeled (14C) and non-radiolabeled parent compound are required. Briefly, the separation and principles of equimolar detection of LC-radioactivity were applied and, a calibration curve of the 14C-parent compound was used to quantify the formation of its 14C-metabolite. In turn, serial dilutions of this 14C-metabolite were the base for the calibration curve that allowed the quantification of the non-radiolabeled metabolite. This method was applied in plasma samples obtained from a dog pharmacokinetic study in which, a PharmaMar compound (lurbinectedin) and its N-desmethylated metabolite were quantified and, the results compared to those obtained by the classical approach (with the chemically synthetized N-desmethylated metabolite). Plasma concentrations obtained with the two methods were very similar, with standard relative errors between -11% to -4%. Similar, main pharmacokinetic parameters were calculated with the concentrations obtained either thru this method or by using a chemically synthetized authentic standard.


Subject(s)
Blood Chemical Analysis/methods , Animals , Calibration , Carbon Radioisotopes/chemistry , Chromatography, Liquid , Dogs , Microsomes/chemistry , Microsomes/metabolism , Plasma/chemistry , Reference Standards , Swine , Swine, Miniature
16.
Mater Sci Eng C Mater Biol Appl ; 99: 762-769, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30889751

ABSTRACT

SrCO3 is frequently used as Sr2+ source in ceramic cements, but its application as bioactive coating for metallic implants has not been explored yet. Aiming at rapid osteointegration and because of the well-known Sr2+ effects on bone metabolism, researchers have sought to design Sr2+-containing biomaterials. In this context, developing simple techniques to prepare Sr2+-based coatings is a must nowadays. Here, we describe the use of a bioinspired lipid-mediated approach to grow SrCO3 hybrid films on Ti surfaces at room temperature. To obtain these coatings, we applied the Langmuir-Blodgett technique to deposit phospholipid films with high degree of organization on Ti. In this way, we expected that controlled SrCO3 crystal growth could be templated by the array of nucleation points arising from electrostatic interaction between Sr2+ and the phospholipid polar heads. To control surface composition and the amount of Sr2+ released from the coatings, we also promoted CaCO3 co-precipitation in the hybrid films. We characterized the hybrid coatings in terms of morphology, chemical structure, wettability, and ability to release Sr2+ upon immersion in biological medium. In vitro osteoblast culture on mixed SrCO3/CaCO3 films revealed that the osteogenic response depended on surface composition, as indicated by alkaline phosphatase activity overexpression, which is an early indicator of osteoblast differentiation. Results showed that the mixed SrCO3/CaCO3 hybrid film created a synergic environment for osteoblasts, and that proper Sr2+ release associated with a Ca2+-rich environment might have optimized the Sr2+ anabolic effect. In conclusion, we have proposed a bioinspired and versatile technique to grow hybrid films that can control surface composition and Sr2+ release. Our results open an opportunity to explore the use of SrCO3-based coatings for rapid metallic implant osteointegration.


Subject(s)
Calcium Carbonate/chemistry , Carbonates/chemistry , Coated Materials, Biocompatible/pharmacology , Lipids/pharmacology , Osteogenesis/drug effects , Strontium/chemistry , Titanium/pharmacology , Animals , Cell Line , Mice , Spectroscopy, Fourier Transform Infrared , Surface Properties , X-Ray Diffraction
17.
Mar Biotechnol (NY) ; 21(1): 65-75, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30443837

ABSTRACT

Bone fractures characterize an important event in the medical healthcare, being related to traumas, aging, and diseases. In critical conditions, such as extensive bone loss and osteoporosis, the tissue restoration may be compromised and culminate in a non-union consolidation. In this context, the osteogenic properties of biomaterials with a natural origin have gained prominence. Particularly, marine sponges are promising organisms that can be exploited as biomaterials for bone grafts. Thus, the objectives of this study were to study the physicochemical and morphological properties of biosilica (BS) from sponges by using scanning electron microscopy, Fourier-transform infrared, X-ray diffraction (SEM, FTIR and XRD respectively), mineralization, and pH. In addition, tests on an osteoblast precursor cell line (MC3T3-E1) were performed to investigate its cytotoxicity and proliferation in presence of BS. Bioglass (BG) was used as gold standard material for comparison purposes. Sponge BS was obtained, and this fact was proven by SEM, FTIR, and XRD analysis. Calcium assay showed a progressive release of this ion from day 7 and a more balanced pH for BS was maintained compared to BG. Cytotoxicity assay indicated that BS had a positive influence on MC3T3-E1 cells viability and qRT-PCR showed that this material stimulated Runx2 and BMP4 gene expressions. Taken together, the results indicate a potential use of sponge biosilica for tissue engineering applications.


Subject(s)
Biocompatible Materials/pharmacology , Bone Substitutes/pharmacology , Osteoblasts/drug effects , Porifera/chemistry , Silicon Dioxide/pharmacology , Animals , Biocompatible Materials/isolation & purification , Biomarkers/metabolism , Bone Morphogenetic Protein 4/genetics , Bone Morphogenetic Protein 4/metabolism , Bone Substitutes/isolation & purification , Bone and Bones/cytology , Bone and Bones/drug effects , Bone and Bones/metabolism , Cell Line , Cell Proliferation/drug effects , Cell Survival/drug effects , Core Binding Factor Alpha 1 Subunit/genetics , Core Binding Factor Alpha 1 Subunit/metabolism , Fractures, Bone/therapy , Gene Expression , Humans , Mice , Osteoblasts/cytology , Osteoblasts/metabolism , Silicon Dioxide/isolation & purification , Tissue Engineering/methods
18.
Hand Surg Rehabil ; 38(1): 14-19, 2019 02.
Article in English | MEDLINE | ID: mdl-30472073

ABSTRACT

Due to increased gun availability/prevalence in current times, low-velocity firearm injuries have risen dramatically. This study describes the epidemiology of gunshot wounds (GSW) to the hand. We identified all patients (January 2005 - August 2015) who presented to our Level 1 trauma center with GSW's to the hand. Analysis of each record was performed to collect epidemiological variables. Cross-sectional analyses were performed to quantify the results. Following inclusion/exclusion criteria, 97 patients were selected. Individuals who sustained GSW's to the hand were typically male (93.8%) between the ages of 18 and 30 (48.5%). Injuries were mostly self-inflicted (81.4%), and isolated (89.7%) to the digits (55.7%) or metacarpals (35.1%) of the left hand (74.2%). Most were fired from BB/pellet guns (45.4%) or handguns (33.0%), while cleaning/loading them (65.1%). Over one-half of patients (58.8%) were uninsured. Surgery was required in 35.1% of patients. Patients shot with something other than a BB/Pellet gun (e.g., handgun, shotgun) required surgery significantly more than those shot with a BB/Pellet gun (P < 0.0001). An odds ratio further describing this relationship was 0.13 (P = 0.0002), reflecting an 87% reduction in the odds of surgery for individuals shot by a BB/pellet vs. a different type of gun. The typical GSW to the hand involves a middle-aged male receiving an isolated injury to the digits or metacarpals of the left hand, from a BB/Pellet gun or handgun while they are cleaning/loading the firearm. Patients sustaining injury by a BB/pellet gun are least likely to require surgery.


Subject(s)
Hand Injuries/epidemiology , Wounds, Gunshot/epidemiology , Academic Medical Centers , Accidents/statistics & numerical data , Adolescent , Adult , Age Distribution , Employment/statistics & numerical data , Female , Humans , Male , Medically Uninsured/statistics & numerical data , Orthopedic Procedures/statistics & numerical data , Patient Admission/statistics & numerical data , Peripheral Nerve Injuries/epidemiology , Retrospective Studies , Sex Distribution , Substance-Related Disorders/epidemiology , Texas/epidemiology , Trauma Centers , Young Adult
19.
Braz J Biol ; 79(3): 404-409, 2019.
Article in English | MEDLINE | ID: mdl-30304250

ABSTRACT

Passion fruits species presents a larger economic importance for in natura consumption and industry. The main way to propagate these species is by seeds; however, the aril presence and environmental conditions may inhibit the seeds germination. In this sense, the objective of this study was to evaluate the effect of aril removal methods and light conditions on P. edulis var. flavicarpa seeds quality and germination. There were used five methods to remove the seeds aril: (1) friction on steel mesh sieve for 5 minutes; (2) friction with coarse sand on steel mesh sieve for 5 minutes; (3) immersion in lime solution at 10% (w/v), for 30 minutes; (4) fermentation in sugar solution at 10% (w/v), during 48 hours; and (5) natural pulp fermentation, during five days. The seeds were submitted to germination test at darkness and lightness, as well as, to length seedlings and emergence test. Regardless the aril removal method, the germination percentage was lower at lightness than darkness highlighting the natural pulp fermentation treatment, which presented 86% of seeds germinated. On the other hand, the aril removal methods did not affect the seedlings emergence, with emergence percentages ranged from 88 to 94%.


Subject(s)
Flowers/physiology , Germination/physiology , Passiflora/physiology , Seeds/physiology , Light , Passiflora/growth & development , Passiflora/radiation effects , Seedlings/physiology , Seeds/growth & development , Seeds/radiation effects
20.
J Thromb Haemost ; 15(5): 1032-1039, 2017 05.
Article in English | MEDLINE | ID: mdl-28294518

ABSTRACT

Essentials Endothelial secretion of von Willebrand factor (VWF) promotes inflammation and thrombosis. We studied the role of protein phosphatase 2B (PP2B) and Munc18c protein complex in VWF secretion. Disruption of PP2B-Munc18c complex in endothelial cells reduced agonist-induced VWF secretion. PP2B-Munc18c complex represents a potential target for thrombotic and inflammatory conditions. SUMMARY: Background Aberrant secretion of von Willebrand factor (VWF) from endothelial cells contributes to inflammation and vascular thrombosis. Agonist-induced VWF secretion is facilitated by protein kinase and phosphatase-mediated signaling. Although the catalytic subunit of protein phosphatase 2B (PP2B-Aα) is targeted to the secretory machinery via an interaction with the vesicle trafficking protein Munc18c in endothelial cells, the functional relevance of this phosphatase complex is unclear. Objective To assess the contribution of the PP2B-Aα-Munc18c complex to endothelial VWF secretion. Results Here, we show that amino acids 120-130 of PP2B-Aα are important to support an interaction with Munc18c. A synthetic myristylated cell-permeable peptide, which is derived from amino acids 121-130 of PP2B-Aα, disrupted endogenous PP2B-Aα-Munc18c complexes in human umbilical vein endothelial cells, and decreased low-dose histamine-stimulated and thrombin-stimulated VWF secretion. Conclusion These studies indicate that PP2B-Aα-Munc18c complex supports agonist-induced VWF secretion, and suggest the potential of targeting this phosphatase complex in thrombotic and inflammatory conditions.


Subject(s)
Calcineurin/metabolism , Human Umbilical Vein Endothelial Cells/enzymology , Munc18 Proteins/metabolism , von Willebrand Factor/metabolism , Calcineurin/genetics , Cells, Cultured , Down-Regulation , Histamine/pharmacology , Human Umbilical Vein Endothelial Cells/drug effects , Human Umbilical Vein Endothelial Cells/metabolism , Humans , Mutation , Peptide Fragments/pharmacology , Protein Binding , Protein Interaction Domains and Motifs , Thrombin/pharmacology , Transfection
SELECTION OF CITATIONS
SEARCH DETAIL
...