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1.
J Prosthet Dent ; 126(4): 560-568, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33004226

RESUMEN

STATEMENT OF PROBLEM: Accessory canals of the canalis sinuosus, a bony canal carrying the anterior superior alveolar nerve and vessels, can often be present but overlooked in the anterior maxilla. Dental implant placement in this area may damage neurovascular branches if this anatomic variation is not carefully identified, resulting in unexpected complications. PURPOSE: The purpose of this retrospective study was to identify accessory canals of the canalis sinuosus and analyze their relationship to the terminal canalis sinuosus and anterior maxilla in Chinese patients to provide a warning for surgeons operating in the anterior maxilla. MATERIAL AND METHODS: Cone beam computed tomography (CBCT) scans of 1007 Chinese patients were examined to identify the prevalence and size of accessory canals with at least 1.0-mm diameter. Axial position of this canal was classified referring to the nasal cavity and adjacent teeth. Its sagittal position was determined by the distance from the bifurcation site of canalis sinuosus to the buccal alveolar crest and the distance from the canal opening to the palatal alveolar crest. Diameter of the terminal canalis sinuosus, distance from the terminal canalis sinuosus to the buccal alveolar crest, and anterior maxillary volume were measured on all scans. Binary logistic regression and the Spearman rank correlation coefficient were used for prevalence and diameter analysis. RESULTS: The prevalence of the accessory canal was 36.9%, positively correlated the anterior maxillary volume (OR 1.408) and negatively correlated with the distance from the terminal canalis sinuosus to the buccal alveolar crest (OR 0.921). Average diameter of such canal was 1.1 ±0.1 mm, significantly higher in men, positively correlated with the diameter of terminal canalis sinuosus (rs=0.163) and the distance from the canal opening to the palatal alveolar crest (rs=0.192). All accessory canals started below the buccal cortical bone, 19.3 ±2.7 mm away from the buccal alveolar crest. There were 61.9% accessory canals opened between the central and the lateral incisors. Openings here and in the central incisor region were closer to the alveolar crest than that between the lateral incisor and the canine (P<.05). CONCLUSIONS: Accessory canals of the canalis sinuosus have high prevalence in the anterior maxilla in a Chinese population. Large anterior maxillary volume has been demonstrated as a risk factor associated with the presence of such canals. The region between the central and the lateral incisors was a predominant location. Openings in this region were closer to the alveolar crest than those between the lateral incisor and the canine.


Asunto(s)
Variación Anatómica , Maxilar , Proceso Alveolar , Tomografía Computarizada de Haz Cónico , Humanos , Masculino , Maxilar/diagnóstico por imagen , Estudios Retrospectivos
2.
Odontology ; 108(3): 376-385, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31912370

RESUMEN

For purpose of enhancing the antibacterial activity of a universal adhesive, the antimicrobial peptide nisin was incorporated into Single Bond Universal and its antibacterial effect on Streptococcus mutans monospecific biofilms and saliva-derived multispecies biofilms was studied. Nisin was incorporated into Single Bond Universal and the antibacterial activity was examined by confocal laser scanning microscopy (CLSM), reverse transcription-quantitative polymerase chain reaction (qRT-PCR), phenol-sulfuric acid method and lactate dehydrogenase enzymatic method. The bonding properties were tested by microtensile bond strength (µTBS) and degree of conversion (DC). Data were analyzed by one-way analysis of variance (ANOVA) and least significant difference multiple comparison tests (P < 0.05). The Single Bond Universal incorporated with 3% (w/v) nisin could significantly inhibit the growth of the S. mutans monospecific biofilms (P< 0.01) and decrease the expression of genes related to extracellular polysaccharide (EPS) synthesis (gtfB, gtfC, gtfD and spaP) and acidogenicity (ldh) (P < 0.05). 3% (w/v) nisin-incorporated Single Bond Universal could also inhibit the growth of saliva-derived multispecies biofilms and decrease the excretion of EPS and lactic acid ( P< 0.05). µTBS and DC of 3% (w/v) nisin-incorporated Single Bond Universal did not deteriorate obviously (P > 0.05). In conclusion, 3% (w/v) nisin-incorporated Single Bond Universal substantially inhibited the growth of both S. mutans monospecific and saliva-derived multispecies biofilms without compromising the bonding properties.


Asunto(s)
Nisina , Streptococcus mutans , Antibacterianos , Biopelículas , Cementos Dentales , Saliva
3.
J Youth Adolesc ; 49(8): 1631-1644, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32451784

RESUMEN

Stress from daily school problems may accumulate and eventually lead to mental health issues in both youth and their parents. With a strong cultural emphasis on school performance, Chinese American families may be particularly vulnerable to such stress. In the current research, Chinese American adolescents (N = 95; Mean age = 13.7 years; 51% girls) and their parents completed daily diary reports of school problems and emotional well-being for 14 continuous days. Adolescents also provided four saliva samples per day for 4 consecutive days. Multilevel modeling analyses showed that youth's daily school problems predicted their lower happiness, higher distress, and higher total cortisol output above and beyond their emotional well-being and cortisol output the prior day. Moreover, there was a spillover effect such that youth's school problems also negatively predicted their parents' emotional well-being. Notably, the negative influence from school problems was moderated by children's cultural orientation, such that youth who were more oriented toward Chinese (vs. American) culture were more vulnerable to the school problems. Taken together, our results highlight the costs on biopsychological adjustment accompanying the academic focus in Chinese American youth and their parents.


Asunto(s)
Asiático , Padres , Adolescente , Niño , Femenino , Humanos , Hidrocortisona , Estudios Longitudinales , Saliva
4.
J Biol Chem ; 290(4): 1898-914, 2015 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-25477521

RESUMEN

Natural rubber (cis-1,4-polyisoprene) is an indispensable biopolymer used to manufacture diverse consumer products. Although a major source of natural rubber is the rubber tree (Hevea brasiliensis), lettuce (Lactuca sativa) is also known to synthesize natural rubber. Here, we report that an unusual cis-prenyltransferase-like 2 (CPTL2) that lacks the conserved motifs of conventional cis-prenyltransferase is required for natural rubber biosynthesis in lettuce. CPTL2, identified from the lettuce rubber particle proteome, displays homology to a human NogoB receptor and is predominantly expressed in latex. Multiple transgenic lettuces expressing CPTL2-RNAi constructs showed that a decrease of CPTL2 transcripts (3-15% CPTL2 expression relative to controls) coincided with the reduction of natural rubber as low as 5%. We also identified a conventional cis-prenyltransferase 3 (CPT3), exclusively expressed in latex. In subcellular localization studies using fluorescent proteins, cytosolic CPT3 was relocalized to endoplasmic reticulum by co-occurrence of CPTL2 in tobacco and yeast at the log phase. Furthermore, yeast two-hybrid data showed that CPTL2 and CPT3 interact. Yeast microsomes containing CPTL2/CPT3 showed enhanced synthesis of short cis-polyisoprenes, but natural rubber could not be synthesized in vitro. Intriguingly, a homologous pair CPTL1/CPT1, which displays ubiquitous expressions in lettuce, showed a potent dolichol biosynthetic activity in vitro. Taken together, our data suggest that CPTL2 is a scaffolding protein that tethers CPT3 on endoplasmic reticulum and is necessary for natural rubber biosynthesis in planta, but yeast-expressed CPTL2 and CPT3 alone could not synthesize high molecular weight natural rubber in vitro.


Asunto(s)
Lactuca/metabolismo , Proteínas de Plantas/metabolismo , Receptores de Superficie Celular/metabolismo , Goma/metabolismo , Transferasas/metabolismo , Agrobacterium/metabolismo , Secuencia de Aminoácidos , Cromatografía en Capa Delgada , ADN/química , Retículo Endoplásmico/metabolismo , Proteínas Fluorescentes Verdes/metabolismo , Hevea , Látex/química , Microscopía Confocal , Microsomas/metabolismo , Datos de Secuencia Molecular , Peso Molecular , Fenotipo , Plantas Modificadas Genéticamente/metabolismo , Unión Proteica , Proteómica , Interferencia de ARN , Homología de Secuencia de Aminoácido , Nicotiana/metabolismo , Técnicas del Sistema de Dos Híbridos , Levaduras/metabolismo
5.
J Mater Sci Mater Med ; 26(1): 5342, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25578696

RESUMEN

In this study, a new Mg-Zn-Ca-Y alloy was evaluated for blood compatibility and in vivo biocompatibility in rabbits after implantation in the sacral crest muscle. Blood test and HE staining was performed to examine the host response, and scanning electron microscope was used to observe the fibrous membrane and corrosion of the magnesium alloy. The results showed that hemolysis rate decreased with the Mg(2+) concentration, in particularly, the hemolysis rate was 47.24 % for the magnesium alloy 100 % mixture solution, while was 0.1372 % for the 1 % extract solution. After implantation, the rabbits showed generally good condition, without swelling and wound secretions. One week after implantation, in the experimental group, a few lymphocytes and macrophages could be observed around the local muscle tissue, and fiber membrane structure had not yet formed; after 2 weeks, loose fiber membranes formed, while the number of inflammatory cells decreased; the fiber membrane became thinner at 4 and 12 weeks,. The fiber membrane thickness at 24 weeks were measured by scanning electron microscopy, at about 15-25 µm, which accord with the U.S. ASTM-F4 implant requirements (<30 µm). Acceptable degradation and corrosion were observed after implantation into rabbits. Through the in vivo study, the new magnesium alloy exhibited good biocompatibility and non-toxic in the experimental animals. Addition of Zn, Ca and Y can slow the degradation rate, and have acceptable side effects in vivo, resulting in improved corrosion properties and desirable biocompatibility at the same time.


Asunto(s)
Aleaciones , Animales , Calcio/química , Femenino , Magnesio/química , Masculino , Conejos , Itrio/química , Zinc/química
6.
J Control Release ; 365: 583-601, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38048963

RESUMEN

The complex etiologies and mechanisms of Alzheimer's disease (AD) underscore the importance for devising multitarget drugs to achieve effective therapy. MicroRNAs (miRNAs) are capable of concurrently regulating the expression of multiple proteins by selectively targeting disease- associated genes in a sequence-specific fashion. Nonetheless, as RNA-based drugs, their stability in the circulation and capacity of traversing the blood-brain barrier (BBB) is largely compromised, thereby limiting their potential clinical applications. In this study, we formulated the nanoliposomes encapsulating polyethyleneimine (PEI)/miR-195 complex (DPMT@PEI/miR-195) that was engineered through dual modifications to contain P-aminophenyl-alpha-d-mannopyranoside (MAN) and cationic cell-penetrating peptide (TAT). DPMT@PEI/miR-195 exhibited the enhanced BBB- and cell membrane penetrating capability. As expected, we observed that DPMT@PEI/miR-195 administered through intravenous tail injection of produced greater effectiveness than donepezil and the same range of effect as aducanumab in alleviating the cognitive decline in 7-month-old APP/PS1 mice. Moreover, the combination treatment with DPMT@PEI/miR-195 and donepezil effectively ameliorated the deterioration of cognition in 16-month-old APP/PS1 mice, with enhanced effects than either DPMT@PEI/miR-195 or donepezil alone. Furthermore, DPMT@PEI/miR-195 effectively attenuated the positive signals of Aß, AT8, and CD68 in APP/PS1 mice without notable side effects. Our findings indicate DPMT@PEI/miR-195 as a promising potentially new agent or approach for the prophylaxis and treatment of early and advanced stages of Alzheimer's disease.


Asunto(s)
Enfermedad de Alzheimer , MicroARNs , Humanos , Ratones , Animales , Lactante , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Liposomas/uso terapéutico , Precursor de Proteína beta-Amiloide/metabolismo , Donepezilo/uso terapéutico , Ratones Transgénicos , MicroARNs/genética , MicroARNs/uso terapéutico , MicroARNs/metabolismo , Modelos Animales de Enfermedad , Péptidos beta-Amiloides/metabolismo
7.
J Dent ; 133: 104522, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37080531

RESUMEN

OBJECTIVES: The study aimed to develop and validate machine learning models for case difficulty prediction in endodontic microsurgery, assisting clinicians in preoperative analysis. METHODS: The cone-beam computed tomographic images were collected from 261 patients with 341 teeth and used for radiographic examination and measurement. Through linear regression (LR), support vector regression (SVR), and extreme gradient boosting (XGBoost) algorithms, four models were established according to different loss functions, including the L1-loss LR model, L2-loss LR model, SVR model and XGBoost model. Five-fold cross-validation was applied in model training and validation. Explained variance score (EVS), coefficient of determination (R2), mean absolute error (MAE), mean squared error (MSE) and median absolute error (MedAE) were calculated to evaluate the prediction performance. RESULTS: The MAE, MSE and MedAE values ​​of the XGBoost model were the lowest, which were 0.1010, 0.0391 and 0.0235, respectively. The EVS and R2 values ​​of the XGBoost model were the highest, which were 0.7885 and 0.7967, respectively. The factors used to predict the case difficulty in endodontic microsurgery were ordered according to their relative importance, including lesion size, the distance between apex and adjacent important anatomical structures, root filling density, root apex diameter, root resorption, tooth type, tooth length, root filling length, root canal curvature and the number of root canals. CONCLUSIONS: The XGBoost model outperformed the LR and SVR models on all evaluation metrics, which can assist clinicians in preoperative analysis. The relative feature importance provides a reference to develop the scoring system for case difficulty assessment in endodontic microsurgery. CLINICAL SIGNIFICANCE: Preoperative case assessment is a crucial step to identify potential risks and make referral decisions. Machine learning models for case difficulty prediction in endodontic microsurgery can assist clinicians in preoperative analysis efficiently and accurately.


Asunto(s)
Microcirugia , Tratamiento del Conducto Radicular , Humanos , Microcirugia/métodos , Tratamiento del Conducto Radicular/métodos , Tomografía Computarizada de Haz Cónico , Algoritmos
8.
Pharm Res ; 29(12): 3312-24, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22798260

RESUMEN

PURPOSE: Tumor vascular normalization by antiangiogenic agents may increase tumor perfusion but reestablish vascular barrier properties in CNS tumors. Vascular priming via nanoparticulate carriers represents a mechanistically distinct alternative. This study investigated mechanisms by which sterically-stabilized liposomal doxorubicin (SSL-DXR) modulates tumor vascular properties. METHODS: Functional vascular responses to SSL-DXR were investigated in orthotopic rat brain tumors using deposition of fluorescent permeability probes and dynamic contrast-enhanced magnetic resonance imaging. Microvessel density and tumor burden were quantified by immunohistochemistry (CD-31) and quantitative RT-PCR (VE-cadherin). RESULTS: Administration of SSL-DXR (5.7 mg/kg iv) initially (3-4 days post-treatment) decreased tumor vascular permeability, k(trans) (vascular exchange constant), vascular endothelial cell content, microvessel density, and deposition of nanoparticulates. Tumor vasculature became less chaotic. Permeability and perfusion returned to control values 6-7 days post-treatment, but intratumor SSL-DXR depot continued to effect tumor vascular endothelial compartment 7-10 days post-treatment, mediating enhanced permeability. CONCLUSIONS: SSL-DXR ultimately increased tumor vascular permeability, but initially normalized tumor vasculature and decreased tumor perfusion, permeability, and nanoparticulate deposition. These temporal changes in vascular integrity resulting from a single SSL-DXR dose have important implications for the design of combination therapies incorporating nanoparticle-based agents for tumor vascular priming.


Asunto(s)
Antibióticos Antineoplásicos/administración & dosificación , Antibióticos Antineoplásicos/farmacología , Neoplasias Encefálicas/irrigación sanguínea , Encéfalo/irrigación sanguínea , Permeabilidad Capilar/efectos de los fármacos , Doxorrubicina/administración & dosificación , Doxorrubicina/farmacología , Animales , Antibióticos Antineoplásicos/uso terapéutico , Encéfalo/efectos de los fármacos , Encéfalo/patología , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/patología , Doxorrubicina/uso terapéutico , Liposomas , Masculino , Neovascularización Patológica/tratamiento farmacológico , Neovascularización Patológica/patología , Ratas , Ratas Endogámicas F344 , Ratas Sprague-Dawley
9.
Comput Intell Neurosci ; 2022: 3475679, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35720942

RESUMEN

Iron tailings sand is a kind of mineral waste, and open-air storage is a common treatment method for iron tailings, which not only has a huge impact on the ecological environment but also occupies a lot of land resources. Therefore, the preparation of high-ductility fiber reinforced iron tailings concrete and its application in practical engineering structures have good application prospects. This paper is based on the deep learning research on the mechanical and carbonization properties of hybrid fiber iron tailings concrete. Therefore, tailings sands with different substitution rates, single-mixed steel fiber, and mixed steel-PVA fiber concrete were prepared in this paper. Its compressive strength, split tensile strength, axial compressive strength, elastic modulus, strain, and carbonization depth were tested. Through the existing concrete compressive stress-strain curve equations, the nonlinear calculation of each group of concrete compressive stress-strain curve equations in this paper is carried out, some parameters are determined, and the carbonation depth equation is established. The results show that, with the increase of tailings content, the properties of concrete increase first and then decrease and the addition of fibers can effectively improve the strength, elastic modulus, peak strain, and carbonization depth of concrete. However, with the increase of PVA fiber content, its performance enhancement effect decreased.


Asunto(s)
Aprendizaje Profundo , Hierro , Ingeniería , Ambiente , Acero
10.
J Dent ; 118: 103947, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35021070

RESUMEN

OBJECTIVES: This study aimed to establish and validate machine learning models for prognosis prediction in endodontic microsurgery, avoiding treatment failure and supporting clinical decision-making. METHODS: A total of 234 teeth from 178 patients were included in this study. We developed gradient boosting machine (GBM) and random forest (RF) models. For each model, 80% of the data were randomly selected for the training set and the remaining 20% were used as the test set. A stratified 5-fold cross-validation approach was used in model training and testing. Correlation analysis and importance ranking were conducted for feature selection. The predictive accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), F1 score, and the area under the curve (AUC) of receiver operating characteristic (ROC) curves were calculated to evaluate the predictive performance. RESULTS: There were eight important predictors, including tooth type, lesion size, type of bone defect, root filling density, root filling length, apical extension of post, age, and sex. For the GBM model, the predictive accuracy was 0.80, with a sensitivity of 0.92, specificity of 0.71, PPV of 0.71, NPV of 0.92, F1 of 0.80, and AUC of 0.88. For the RF model, the accuracy was 0.80, with a sensitivity of 0.85, specificity of 0.76, PPV of 0.73, NPV of 0.87, F1 of 0.79, and AUC of 0.83. CONCLUSIONS: The trained models were developed by eight common variables, showing the potential ability to predict the prognosis of endodontic microsurgery. The GBM model outperformed the RF model slightly on our dataset. CLINICAL SIGNIFICANCE: Clinicians can use machine learning models for preoperative analysis in endodontic microsurgery. The models are expected to improve the efficiency of clinical decision-making and assist in clinician-patient communication.


Asunto(s)
Aprendizaje Automático , Microcirugia , Toma de Decisiones Clínicas , Humanos , Valor Predictivo de las Pruebas , Pronóstico
11.
Nanoscale ; 14(3): 976-983, 2022 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-34989736

RESUMEN

Azobenzenes are great photochromic molecules for switching the physical properties of various materials via trans-cis isomerization. However, the UV light resulted cis-azobenzene is metastable and thermodynamically gets back to trans-azobenzene after ceasing UV irradiation, which causes an unwanted property change of azobenzene-containing materials. Additionally, thermal and mechanical conditions would accelerate this process dramatically. In this present work, a new type of azobenzene-containing surfactant is designed for the fabrication of photoresponsive phase change biomaterials. With a "locked" cis-azobenzene conformation, the resulting biomaterials could maintain their disordered state after ceasing UV light, which exhibit great resistance to thermal and piezo conditions. Interestingly, the "locked" cis-azobenzene could be unlocked by Vis light in high efficiency, which opens a new way for the design of phase change materials only responding to light. By showing stable cis-azobenzene maintained physical state, the newly fabricated biomaterials provide new potential for the construction of advanced materials, like self-healing materials, with less use of long time UV irradiation for maintaining their disordered states.


Asunto(s)
Materiales Biocompatibles , Rayos Ultravioleta , Tensoactivos , Termodinámica
12.
Acta Biomater ; 128: 143-149, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-33930576

RESUMEN

Development of photoliquefiable solid-state biomaterials at room temperature would address scientific challenges in life science. However, external stimuli-induced phase transitions are difficult for some biomacromolecules based materials, due to the high rigidity of these biomolecules. In this present work, by delicate molecule design on azobenzene-type ammonium surfactants, two new types of DNA-surfactant materials are fabricated. At room temperature, these DNA materials show photoliquefaction of ionic crystals to isotropic liquids under UV light, and fast self-assembly from isotropic liquids back to crystals after ceasing UV light, under the assistance of azobenzene isomerization. To achieve this objective, the designed solid-state DNA materials should have melting points near room temperature and an immediate liquid crystal to isotropic liquid transition process just above the melting points, which highly depends on the stoichiometric charge ratio between DNA and surfactants. As proved by the successful self-healing tests, these DNA ionic crystals are good biomaterials with potential applications in biomedicine and life science. This work would provide a new strategy for designing anhydrous functional biomaterials at room temperature by using rigid biomacromolecules. STATEMENT OF SIGNIFICANCE: At room temperature, solid-state biomaterials with photoregulated crystal⇄isotropic liquid phase transition property are attractive functional materials in life science, considering the body temperature and living environment temperature of human beings. Although several kinds of anhydrous materials achieved isothermal photoresponsive phase transitions, the photoregulated phase transition of anhydrous biomacromolecules based materials has not been achieved at room temperature, due to the high rigidity of these biomolecules. In this work, by delicate molecule design on ammonium surfactants, we synthesized two kinds of anhydrous DNA-surfactants ionic crystals. These DNA materials show fast photoliquefaction under UV light and self-assembly after ceasing light, which affords excellent self-healing biomaterials. This work would provide a new strategy for designing anhydrous photoresponsive biomaterials by using rigid biomacromolecules.


Asunto(s)
Cristales Líquidos , Tensoactivos , Materiales Biocompatibles , ADN , Humanos , Temperatura
13.
Colloids Surf B Biointerfaces ; 201: 111642, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33667867

RESUMEN

Etoposide (ETO) is a semi-synthetic derivative of podophyllotoxin with a definite antitumour effect, but its use is hampered by poor solubility and numerous side-effects. In this work, we developed a hyaluronic acid and ethylenediamine dual-modified albumin-polymer nanocomplex for tumour targeted delivery of ETO. The ETO loaded dual-modified albumin-polymer nanocomplexes (E-HEAP NCs) was composed of a hyaluronic acid decorated cationic albumin shell and a stable poly (butyl cyanoacrylate) core. E-HEAP NCs exhibited a high encapsulation efficiency, great stability in vivo. Furthermore, blank HEAP NCs carrier showed excellent biocompatibility in vitro cell cytotoxicity assay. While, E-HEAP NCs represented superior inhibitory effect on HepG2 cells than free ETO. Additionally, E-HEAP NCs exhibited an excellent tumour-targeting effect, due to the enhanced targeting efficacy of hyaluronic acid and albumin-mediated transcytosis. Moreover, E-HEAP NCs displayed an enhanced antitumour effect and extended the survival period in tumour bearing mice. In summary, the developed novel protein-polymer nanocomplex can potentially serve as a drug delivery system for improved cancer therapy.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Nanopartículas , Albúminas , Animales , Carcinoma Hepatocelular/tratamiento farmacológico , Línea Celular Tumoral , Etopósido , Neoplasias Hepáticas/tratamiento farmacológico , Ratones , Polímeros
14.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(4): 464-469, 2020 Aug 01.
Artículo en Zh | MEDLINE | ID: mdl-32865370

RESUMEN

Decompression and curettage can result are effective as treatments for large jaw cysts, which are common diseases in the clinic. Based on a treatment used in a previous study, this paper proposes a "three-step method" to treat large jaw cyst and repair the bone defect by decompression, curettage, and autologous dental bone powder implantation. This paper introduces the processes and key points of the operation involved in the abovementioned method.


Asunto(s)
Quistes Óseos/cirugía , Quistes Maxilomandibulares , Cementos para Huesos , Trasplante Óseo , Legrado , Humanos
15.
Biomed Res Int ; 2018: 8639648, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29581988

RESUMEN

To ensure the biomechanical properties of Ti-24Nb-4Zr-8Sn, stress-shielding effects were compared between Ti-24Nb-4Zr-8Sn and Ti-6Al-4V fixation by using a porcine model. Twelve thoracolumbar spines (T12-L5) of 12-month-old male pigs were randomly divided into two groups: Ti-24Nb-4Zr-8Sn (EG, n = 6) and Ti-6Al-4V (RG, n = 6) fixation. Pedicle screw was fixed at the outer edge of L4-5 vertebral holes. Fourteen measuring points were selected on the front of transverse process and middle and posterior of L4-5 vertebra. Electronic universal testing machine was used to measure the strain resistance of measuring points after forward and backward flexion loading of 150 N. Meanwhile, stress resistance was compared between both groups. The strain and stress resistance of measurement points 1, 2, 5, 6, 9, and 10-14 in Ti-24Nb-4Zr-8Sn fixation was lower than that of Ti-6Al-4V fixation after forward and backward flexion loading (P < 0.05). The strain and stress resistance of measurement points 3, 4, 7, and 8 was higher in Ti-24Nb-4Zr-8Sn fixation than that of Ti-6Al-4V fixation (P < 0.05). Stress-shielding effects of Ti-24Nb-4Zr-8Sn internal fixation were less than that of Ti-6Al-4V internal fixation. These results suggest that Ti-24Nb-4Zr-8Sn elastic fixation has more biomechanical goals than conventional Ti-6Al-4V internal fixation by reducing stress-shielding effects.


Asunto(s)
Aleaciones , Tornillos Óseos , Vértebras Lumbares/cirugía , Fusión Vertebral/métodos , Animales , Vértebras Lumbares/patología , Masculino , Estrés Mecánico , Porcinos
16.
Phytochemistry ; 113: 121-9, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25553584

RESUMEN

Natural rubber, cis-1,4-polyisoprene, is an important raw material in chemical industries, but its biosynthetic mechanism remains elusive. Natural rubber is known to be synthesized in rubber particles suspended in laticifer cells in the Brazilian rubber tree (Hevea brasiliensis). In the rubber tree, rubber elongation factor (REF) and its homolog, small rubber particle protein (SRPP), were found to be the most abundant proteins in rubber particles, and they have been implicated in natural rubber biosynthesis. As lettuce (Lactuca sativa) can synthesize natural rubber, we utilized this annual, transformable plant to examine in planta roles of the lettuce REF/SRPP homologs by RNA interference. Among eight lettuce REF/SRPP homologs identified, transcripts of two genes (LsSRPP4 and LsSRPP8) accounted for more than 90% of total transcripts of REF/SRPP homologs in lettuce latex. LsSRPP4 displays a typical primary protein sequence as other REF/SRPP, while LsSRPP8 is twice as long as LsSRPP4. These two major LsSRPP transcripts were individually and simultaneously silenced by RNA interference, and relative abundance, polymer molecular weight, and polydispersity of natural rubber were analyzed from the LsSRPP4- and LsSRPP8-silenced transgenic lettuce. Despite previous data suggesting the implications of REF/SRPP in natural rubber biosynthesis, qualitative and quantitative alterations of natural rubber could not be observed in transgenic lettuce lines. It is concluded that lettuce REF/SRPP homologs are not critically important proteins in natural rubber biosynthesis in lettuce.


Asunto(s)
Lactuca/química , Goma/metabolismo , Secuencia de Aminoácidos , Brasil , Hemiterpenos/química , Hemiterpenos/metabolismo , Hevea/metabolismo , Látex/química , Látex/metabolismo , Lactuca/genética , Lactuca/metabolismo , Datos de Secuencia Molecular , Proteínas de Plantas/metabolismo , Interferencia de ARN , Goma/química , Homología de Secuencia de Aminoácido
17.
Nanoscale ; 7(21): 9655-63, 2015 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-25959728

RESUMEN

Magnetothermally responsive drug-loaded micelles were designed and prepared for cancer therapy. These specially designed micelles are composed of the thermo-responsive star-block copolymer poly(ε-caprolactone)-block-poly(2-(2-methoxyethoxy)ethyl methacrylate-co-oligo(ethylene glycol)methacrylate) and Mn, Zn doped ferrite magnetic nanoparticles (MZF-MNPs). The thermo-responses of 6sPCL-b-P(MEO2MA-co-OEGMA) copolymers were shown to be dependent on the MEO2MA to OEGMA ratio. The lower critical solution temperature (LCST) of the star-block copolymers was controlled at 43 °C by adjusting the feed molar ratios of MEO2MA/OEGMA at 92 : 8. With the anti-tumor drug doxorubicin (DOX) self-assembling into the carrier system, the thermo-responsive micelles exhibited excellent temperature-triggered drug release behavior. In vitro cytotoxicity results showed high biocompatibility of the polymer micelles. Efficient cellular proliferation inhibition by the drug-loaded micelles was found on the HepG2 cells under different treatments. The thermo-responsive polymer micelles are promising for controlled drug delivery in tumor therapy under an alternating magnetic field.


Asunto(s)
Portadores de Fármacos/química , Micelas , Polímeros/química , Antineoplásicos/química , Antineoplásicos/toxicidad , Supervivencia Celular/efectos de los fármacos , Doxorrubicina/química , Doxorrubicina/toxicidad , Células Hep G2 , Humanos , Poliésteres/química , Temperatura
18.
Nanoscale ; 6(21): 12408-13, 2014 Nov 07.
Artículo en Inglés | MEDLINE | ID: mdl-25232926

RESUMEN

A magnetothermally-responsive nanocarrier was developed for efficient thermo-chemotherapy by combining efficient magnetic hyperthermia (MH) and magnetothermally-facilitated drug release. The effective magnetothermal-response contributed to high enhancement of tumor cell killing by an operating mechanism involving MH-facilitated cellular uptake and Heat Shock Protein over-expression.


Asunto(s)
Antineoplásicos/química , Materiales Biocompatibles/química , Sistemas de Liberación de Medicamentos , Sinergismo Farmacológico , Magnetismo , Neoplasias/tratamiento farmacológico , Línea Celular Tumoral , Proteínas HSP70 de Choque Térmico/metabolismo , Proteínas de Choque Térmico/metabolismo , Células Hep G2 , Humanos , Hipertermia Inducida , Fenómenos Magnéticos , Microscopía Confocal , Microscopía Electrónica de Transmisión , Neoplasias/patología , Polímeros/química , Temperatura , Termogravimetría , Regulación hacia Arriba
19.
Drug Deliv ; 19(5): 264-9, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22823893

RESUMEN

The present study was designed to investigate the in vivo drug release and antibacterial properties of a novel mesoporous hydroxyapatite/chitosan (mesoHA-CS) composite loaded with vancomycin (VCM). VCM-mesoHA/CS composite was prepared via a freeze-drying method. The successful loading of VCM in the composite scaffold was verified by FT IR analyses. SEM observation revealed the mesoporous structure of the VCM-mesoHA/CS composite with the pore size of 50-100 µm. Medicated composites were then implanted into the muscular pockets of extremity in rabbits. The results demonstrated that local VCM concentration in muscle tissue could maintain higher than the minimum inhibitory concentration at the site of implantation for long time (i.e. 4 weeks). As a result, the number of viable methicillin-resistant Staphylococcus aureus (MRSA) on mesoHA/CS could be significantly suppressed after the VCM-mesoHA/CS implantation. These results indicated that the mesoHA/CS composite may be promising scaffold as drug storage and release vehicle applied for local antibacterial drug release and bone repair.


Asunto(s)
Antibacterianos/administración & dosificación , Quitosano/administración & dosificación , Durapatita/administración & dosificación , Vancomicina/administración & dosificación , Animales , Antibacterianos/farmacocinética , Materiales Biocompatibles/administración & dosificación , Almacenaje de Medicamentos , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Ratones , Pruebas de Sensibilidad Microbiana/métodos , Músculos/efectos de los fármacos , Osteoblastos/efectos de los fármacos , Conejos , Vancomicina/farmacocinética
20.
J Biomed Mater Res A ; 94(3): 700-5, 2010 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-20205239

RESUMEN

Anti-inflammatory properties of bioactive titanium metals prepared by anodic oxidation (AO-Ti) and alkali-heat (AH-Ti) treatments were studied by bacterial adhesion test and myeloperoxidase (MPO) activity assay methods. The bioactivities of the metals were also evaluated by apatite formation ability and osteoblasts culture experiments. Both metals could induce apatite formation and support osteoblasts proliferation. At the condition with normal incandescent light shine, both bioactive titanium metals had antibacterial adhesion properties compared with the titanium metal without treatment. The MPO activity assay proved that they both showed anti-inflammatory properties in vivo. The bioactive AO-Ti had better anti-inflammatory properties than the AH-Ti. It indicated that it is possible to optimize the anti-inflammatory properties of the bioactive titanium metals by different preparation methods.


Asunto(s)
Antiinflamatorios/metabolismo , Materiales Biocompatibles/metabolismo , Metales/metabolismo , Titanio/metabolismo , Animales , Apatitas/metabolismo , Bacterias/metabolismo , Línea Celular , Células Cultivadas , Ensayo de Materiales , Osteoblastos/citología , Osteoblastos/metabolismo , Oxidación-Reducción , Peroxidasa/metabolismo , Ratas , Propiedades de Superficie
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