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1.
Int J Mol Sci ; 25(5)2024 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-38474179

RESUMEN

Ischemic stroke is associated with a high mortality rate, and effective treatment strategies are currently lacking. In this study, we aimed to develop a novel nano delivery system to treat ischemic stroke via intranasal administration. A three-factor Box-Behnken experimental design was used to optimize the formulation of liposomes co-loaded with Panax notoginseng saponins (PNSs) and Ginsenoside Rg3 (Rg3) (Lip-Rg3/PNS). Macrophage membranes were coated onto the surface of the optimized liposomes to target the ischemic site of the brain. The double-loaded liposomes disguised by macrophage membranes (MM-Lip-Rg3/PNS) were spherical, in a "shell-core" structure, with encapsulation rates of 81.41% (PNS) and 93.81% (Rg3), and showed good stability. In vitro, MM-Lip-Rg3/PNS was taken up by brain endothelial cells via the clathrin-dependent endocytosis and micropinocytosis pathways. Network pharmacology experiments predicted that MM-Lip-Rg3/PNS could regulate multiple signaling pathways and treat ischemic stroke by reducing apoptosis and inflammatory responses. After 14 days of treatment with MM-Lip-Rg3/PNS, the survival rate, weight, and neurological score of middle cerebral artery occlusion (MCAO) rats significantly improved. The hematoxylin and eosin (H&E) and TUNEL staining results showed that MM-Lip-Rg3/PNS can reduce neuronal apoptosis and inflammatory cell infiltration and protect the ischemic brain. In vivo biological experiments have shown that free Rg3, PNS, and MM-Lip-Rg3/PNS can alleviate inflammation and apoptosis, especially MM-Lip-Rg3/PNS, indicating that biomimetic liposomes can improve the therapeutic effects of drugs. Overall, MM-Lip-Rg3/PNS is a potential biomimetic nano targeted formulation for ischemic stroke therapy.


Asunto(s)
Accidente Cerebrovascular Isquémico , Saponinas , Ratas , Animales , Liposomas/química , Células Endoteliales , Administración Intranasal , Saponinas/farmacología , Macrófagos
2.
J Am Chem Soc ; 145(14): 8150-8162, 2023 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-37014064

RESUMEN

Difunctionalization of olefins offers an attractive approach to access complex chiral structures. Reported herein is the design of N-protected O-allylhydroxyamines as bifunctional olefins that undergo catalytic asymmetric 1,2-carboamidation with three classes of (hetero)arenes to afford chiral amino alcohols via C-H activation. The C═C bond in O-allylhydroxyamine is activated by the intramolecular electrophilic amidating moiety as well as a migrating directing group. The asymmetric carboamidation reaction pattern depends on the nature of the (hetero)arene reagent. Simple achiral (hetero)arenes reacted to give centrally chiral ß-amino alcohols in excellent enantioselectivity. The employment of axially prochiral or axially racemic heteroarenes afforded amino alcohols with both axial and central chirality in excellent enantio- and diastereoselectivity. In the case of axially racemic heteroarenes, the coupling follows a kinetic resolution pattern with an s-factor of up to >600. A nitrene-based reaction mechanism has been suggested based on experimental studies, and a unique mode of induction of enantio- and diastereoselectivity has been proposed. Applications of the amino alcohol products have been demonstrated.

3.
J Liposome Res ; 29(2): 121-132, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30821573

RESUMEN

Schisandra chinensis fructus (SCF) is widely used traditional Chinese medicine, which possesses hepato-protective potential. Schisandrin (SD), schisantherin (ST), and γ-schizandrin (SZ) are the major bioactive lignans. The main problem associated with the major bioactive lignans oral administration is low oral bioavailability due to the lignans' poor aqueous solubility and taste. The aim of the present research work was to develop liposome (SCL) encapsulated ß-cyclodextrin (ß-CD) inclusion complex loaded with SCF extract (SCF-E). The SD, ST, and SZ were selected as effective candidates to perform comparisons of liver targeting among the solution (SES), ß-cyclodextrin inclusion compound (SCF-E-ß-CD), liposome (SEL), and SCL of SCF-E to characterize the pharmacokinetic behaviors and liver targeting in rats. The ß-CD inclusion complex (SCF-E-ß-CD) was used to improve the solubility. The concentrations were determined using high-performance liquid chromatography (HPLC) and analyzed by DAS3.0. The pharmacokinetic results indicate that the plasma concentration-time courses were fitted well to the one-compartment model with the first weighing factor. The half-life period (t1/2) and area under the concentration-time curve (AUC) of the three components in SCL were the largest. The SCL exhibit a relatively high liver targeting effect. The results would be helpful for guiding the clinical application of this herbal medicine.


Asunto(s)
Ciclooctanos/farmacocinética , Lignanos/farmacocinética , Hígado/metabolismo , Extractos Vegetales/farmacocinética , Compuestos Policíclicos/farmacocinética , Schisandra/química , beta-Ciclodextrinas/química , Administración Oral , Animales , Disponibilidad Biológica , Cromatografía Líquida de Alta Presión , Ciclooctanos/administración & dosificación , Ciclooctanos/efectos adversos , Composición de Medicamentos , Lignanos/administración & dosificación , Lignanos/efectos adversos , Liposomas , Tamaño de la Partícula , Extractos Vegetales/administración & dosificación , Extractos Vegetales/efectos adversos , Compuestos Policíclicos/administración & dosificación , Compuestos Policíclicos/efectos adversos , Ratas Wistar
4.
Org Lett ; 26(25): 5295-5299, 2024 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-38874590

RESUMEN

Rh(III)-catalyzed direct oxidative C-H/C-H cross-coupling between N-pyrimidylindoles and ß-ketoesters is presented. Easily available ß-ketoesters are used as an alkylating agent for the facile construction of all-carbon quaternary centers under mild conditions. The ester group in the product can undergo decarboxylation or decarboxylative amination.

5.
Anal Sci ; 40(7): 1349-1356, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38683477

RESUMEN

Based on the automatic light wave ashing instrument, palladium nitrate was used as an ashing aid for the first time to collect selenium in the process of food ashing pre-treatment, and a method for the determination of selenium in food by ashing method was established with inductively coupled plasma mass spectrometry. At the same time, the effects of magnesium nitrate, rhodium nitrate, and nickel nitrate as ashing aids on selenium collection were investigated using certified plant standard materials. The capture of selenium by magnesium nitrate, rhodium nitrate, and nickel nitrate as ashing aids did not exceed 50%. Using palladium nitrate as an ashing aid, six food standard materials were measured, with selenium recovery rates ranging from 97 to 106%. A complete analysis cycle can be completed within an hour. The method detection limit of selenium was 0.021 µg g-1, and the relative standard deviation of five measurements was less than 7%. The experimental results show that palladium nitrate is an excellent ashing aid for capturing selenium, and it is far superior to the other three aids. In addition, the mechanism of palladium nitrate as an ashing aid for capturing selenium was discussed.


Asunto(s)
Análisis de los Alimentos , Espectrometría de Masas , Paladio , Selenio , Selenio/análisis , Selenio/química , Paladio/química , Paladio/análisis , Análisis de los Alimentos/métodos , Nitratos/análisis , Nitratos/química , Automatización , Rayos Infrarrojos
6.
Int J Nanomedicine ; 19: 6177-6199, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38911498

RESUMEN

Purpose: Ginsenoside Rg3 (Rg3) and Panax notoginseng saponins (PNS) can be used for ischemic stroke treatment, however, the lack of targeting to the ischemic region limits the therapeutic effect. To address this, we leveraged the affinity of macrophage membrane proteins for inflamed brain microvascular endothelial cells to develop a macrophage membrane-cloaked liposome loaded with Rg3 and PNS (MM-Lip-Rg3/PNS), which can precisely target brain lesion region through intranasal administration. Methods: MM-Lip-Rg3/PNS was prepared by co-extrusion method and was performed by characterization, stability, surface protein, and morphology. The cellular uptake, immune escape ability, and blood-brain barrier crossing ability of MM-Lip-Rg3/PNS were studied in vitro. The in vivo brain targeting, biodistribution and anti-ischemic efficacy of MM-Lip-Rg3/PNS were evaluated in MACO rats, and we determined the diversity of the nasal brain pathway through the olfactory nerve blockade model in rats. Finally, the pharmacokinetics and brain targeting index of MM-Lip-Rg3/PNS were investigated. Results: Our results indicated that MM-Lip-Rg3/PNS was spherical with a shell-core structure. MM-Lip-Rg3/PNS can avoid mononuclear phagocytosis, actively bind to inflammatory endothelial cells, and have the ability to cross the blood-brain barrier. Moreover, MM-Lip-Rg3/PNS could specifically target ischemic sites, even microglia, increase the cumulative number of drugs in the brain, improve the inflammatory environment of the brain, and reduce the infarct size. By comparing olfactory nerve-blocking rats with normal rats, it was found that there are direct and indirect pathways for nasal entry into the brain. Pharmacokinetics demonstrated that MM-Lip-Rg3/PNS exhibited stronger brain targeting and prolonged drug half-life. Conclusion: MM-Lip-Rg3/PNS might contribute to the accumulation of Rg3 and PNS in the ischemic brain area to improve treatment efficacy. This biomimetic nano-drug delivery system provides a new and promising strategy for the treatment of ischemic stroke.


Asunto(s)
Administración Intranasal , Barrera Hematoencefálica , Ginsenósidos , Accidente Cerebrovascular Isquémico , Liposomas , Macrófagos , Animales , Liposomas/química , Accidente Cerebrovascular Isquémico/tratamiento farmacológico , Ratas , Masculino , Ginsenósidos/farmacocinética , Ginsenósidos/química , Ginsenósidos/administración & dosificación , Ginsenósidos/farmacología , Barrera Hematoencefálica/efectos de los fármacos , Macrófagos/efectos de los fármacos , Sistemas de Liberación de Medicamentos/métodos , Ratas Sprague-Dawley , Distribución Tisular , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Materiales Biomiméticos/química , Materiales Biomiméticos/farmacocinética , Materiales Biomiméticos/administración & dosificación , Saponinas/farmacocinética , Saponinas/química , Saponinas/administración & dosificación , Saponinas/farmacología , Ratones
7.
Materials (Basel) ; 17(5)2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38473551

RESUMEN

This study elucidates the thermodynamic reaction mechanism of the GeCl4 hydrogen reduction process for Ge preparation. Five independent reactions in the Ge-Cl-H ternary system were identified, utilizing the phase law, mass conservation principles, and thermodynamic data, with H2 as the reducing agent. Additionally, the effects of the temperature, feed ratio, and pressure on the germanium deposition rate during the GeCl4 hydrogen reduction process were investigated, guided by these five reactions. The results indicate that, with fixed temperature and pressure, a higher feed ratio (nH2/nGeCl4) leads to an increased germanium deposition rate. Conversely, with a constant feed ratio, increased pressure results in a lower deposition rate at low temperatures. The optimal operating conditions for germanium preparation via the hydrogen reduction of GeCl4 were determined: the temperature was 450 °C, the feed ratio was 20, the pressure was 0.1 MPa, and the deposition rate of the germanium was 36.12% under this condition.

8.
Chem Commun (Camb) ; 59(8): 1030-1033, 2023 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-36601999

RESUMEN

The viscosity of the cell microenvironment is a parameter that affects cell physiological processes. A fluorescent probe X-V was designed to detect the viscosity changes of a hepatic ischemia-reperfusion injury (HIRI) cell model with high selectivity and sensitivity. The fluorescence emission wavelength is 615 nm and the Stokes shift can be up to 125 nm, which can be used not only for intracellular viscosity changes stimulated by different drugs but also for the detection of cell viscosity changes in the HIRI cell model. Probe X-V provides a useful tool to study the relationship between mitochondrial viscosity and related diseases.


Asunto(s)
Colorantes Fluorescentes , Daño por Reperfusión , Humanos , Viscosidad , Mitocondrias , Microscopía Fluorescente/métodos , Imagen Óptica/métodos , Células HeLa
9.
World J Clin Cases ; 11(27): 6483-6490, 2023 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-37900239

RESUMEN

BACKGROUND: The pathological complete response (ypCR) rate following neoadjuvant chemotherapy for advanced gastric cancer remains low and lacks a universally accepted treatment protocol. Immunotherapy has achieved breakthrough progress. CASE SUMMARY: We report two female patients with gastric cancer defined as clinical stage cT4N1-2M0. Detection of mismatch repair protein showed mismatch repair function defect, and perioperative treatment with programmed death protein 1 inhibitor combined with S-1+oxaliplatin achieved ypCR. Surprisingly, the patients underwent clinical observation after surgery but developed different degrees of metastasis at ~6 mo after surgery. CONCLUSION: PD-1 inhibitor combined with chemotherapy provides a more strategic choice for comprehensive perioperative treatment of gastric cancer.

10.
Sci Rep ; 12(1): 11208, 2022 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-35778432

RESUMEN

Interleukin 7 (IL-7) has been demonstrated regulating lymphangiogenesis, apoptosis, and proliferation. Whether IL-7 induce or inhibit autophagy in non-small cell lung cancer (NSCLC) are unknown. In this study, Western blot was used to detect cytoplasmic and nuclear protein of p53, total protein of AMP-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR) and Light chain 3 (LC3). Quantitative Real-Time PCR (qRT-PCR) was used to detect p53 mRNA level after treated with IL-7. Then using transmission electron microscopy to observe the morphological change of autophagosome. 123 cases of NSCLC were collected for survival analysis, immunohistochemistry staining and cox regression multivariate analysis. We find that IL-7 induce the p53 translocation from nucleus to cytoplasm, then IL-7 down-regulate phosphorylation of AMPK and up-regulate phosphorylation of mTOR. The expression of AMPK and p53 were associated with IL-7/IL-7R and mTOR expression. Clinically, AMPK and p53 were well correlated with stage and survival of lung cancer patients. IL-7R, mTOR and tumor stage were the strongest predictors of survival. In conclusion, IL-7 inhibit autophagy in NSCLC via P53 regulated AMPK/mTOR signaling pathway. AMPK and p53 are correlated with patients' survival. IL-7R, mTOR and tumor stage are the strongest predictor of survival.


Asunto(s)
Proteínas Quinasas Activadas por AMP , Carcinoma de Pulmón de Células no Pequeñas , Interleucina-7 , Neoplasias Pulmonares , Serina-Treonina Quinasas TOR , Proteína p53 Supresora de Tumor , Proteínas Quinasas Activadas por AMP/metabolismo , Autofagia/efectos de los fármacos , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Humanos , Interleucina-7/metabolismo , Interleucina-7/farmacología , Neoplasias Pulmonares/metabolismo , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo , Proteína p53 Supresora de Tumor/metabolismo
11.
Int J Nanomedicine ; 17: 3443-3456, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35959279

RESUMEN

Purpose: While developing huperzine A (HupA) to explore new approaches to treating Alzheimer's disease (AD), intranasal administration was proposed as an alternative route to deliver drugs into the brain. This study aimed to prepare nanoemulsions (NEs) of HupA to investigate their potential "nose-to-brain" pathways and to evaluate their pharmacokinetic and brain-targeting parameters. Methods: HupA-NE and Lf-HupA-NE that underwent surface modification with lactoferrin (Lf) were characterized to determine various physicochemical properties, such as their size, PDI, zeta potential, pH, and loading efficiency; in addition, transmission electron microscopy and stability assessments were performed. We utilized an aggregation-caused quenching (ACQ) probe to monitor intact NEs in the brains of olfactory nerve transection model and normal rats. Immunohistochemistry, pharmacokinetic and targeting index analyses were performed to investigate the in vivo effects of HupA-NE and Lf-HupA-NE. Results: Based on the live imaging results, HupA-NE and Lf-HupA-NE could be transported into the brain via nerve and blood circulation pathways. Immunohistochemical staining tests demonstrated that the efflux proteins P-gp, MRP1, and BCRP were expressed in brain tissue. NEs can inhibit efflux pumps to improve drug concentrations in the brain. The findings of this study showed that NEs (especially Lf-HupA-NE) had better pharmacokinetic profiles and a better nose-to-brain drug transport efficiency than free HupA. Conclusion: The newly designed formulations might contribute to the transport and accumulation of HupA to achieve therapeutic results. The delivery system may be a promising strategy for the brain-targeted delivery of HupA.


Asunto(s)
Encéfalo , Proteínas de Neoplasias , Transportador de Casetes de Unión a ATP, Subfamilia G, Miembro 2 , Administración Intranasal , Alcaloides , Animales , Sistemas de Liberación de Medicamentos/métodos , Mucosa Nasal/metabolismo , Proteínas de Neoplasias/metabolismo , Ratas , Sesquiterpenos
12.
Carcinogenesis ; 32(2): 154-67, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21081474

RESUMEN

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) exhibits potent antitumor activity via membrane receptors on cancer cells without deleterious side effects for normal tissue. Unfortunately, breast cancer cells, as many other cancer types, develop resistance to TRAIL; therefore, TRAIL sensitizing agents are currently being explored. 2-Tellurium-bridged ß-cyclodextrin (2-TeCD) is a synthetic organotellurium compound, with both glutathione peroxidase-like catalytic ability and thioredoxin reductase inhibitor activity. In the present study, we reported that 2-TeCD sensitized TRAIL-resistant human breast cancer cells and xenograft tumors to undergo apoptosis. In vitro, 2-TeCD efficiently sensitized MDA-MB-468 and T47D cells, but not untransformed human mammary epithelial cells, to TRAIL-mediated apoptosis, as evidenced by enhanced caspase activity and poly (adenosine diphosphate-ribose) polymerase cleavage. From a mechanistic standpoint, we showed that 2-TeCD treatment of breast cancer cells significantly upregulated the messenger RNA and protein levels of TRAIL receptor, death receptor (DR) 5, in a transcription factor Sp1-dependent manner. 2-TeCD treatment also suppressed TRAIL-induced nuclear factor-κB (NF-κB) prosurvival pathways by preventing cytosolic IκBα degradation, as well as p65 nuclear translocation. Consequently, the combined administration suppressed anti-apoptotic molecules that are transcriptionally regulated by NF-κB. In vivo, 2-TeCD and TRAIL were well tolerated in mice and their combination significantly inhibited growth of MDA-MB-468 xenografts and promoted apoptosis. Upregulation of DR5 and downregulation of NF-κB by the dual treatment were also observed in tumor tissues. Overall, 2-TeCD sensitizes resistant breast cancer cells to TRAIL-based apoptosis in vitro and in vivo. These findings provide strong evidence for the therapeutic potential of this combination against breast cancers.


Asunto(s)
Apoptosis/efectos de los fármacos , Neoplasias de la Mama/tratamiento farmacológico , Ciclodextrinas/farmacología , Inhibidores Enzimáticos/farmacología , FN-kappa B/antagonistas & inhibidores , Compuestos Organometálicos/farmacología , Receptores del Ligando Inductor de Apoptosis Relacionado con TNF/fisiología , Ligando Inductor de Apoptosis Relacionado con TNF/farmacología , Reductasa de Tiorredoxina-Disulfuro/antagonistas & inhibidores , Animales , Neoplasias de la Mama/patología , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Factor de Transcripción Sp1/fisiología
13.
Iran J Public Health ; 50(12): 2536-2545, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36317034

RESUMEN

Background: To evaluate the inhibitory effect of adalimumab on diabetic nephropathy (DN) through animal models. Methods: We carried out the study in Weifang People's Hospital, Weifang 261041, China in December 2020. Streptozotocin was used to induce DN in model animal Sprague-Dawley (SD) rats. The DN animal model was given treatment with adalimumab, and the inhibitory effect of adalimumab on the development process of DN was evaluated by detecting changes in blood glucose and urinary albumin levels. Meanwhile, the content of UN, Cr and CysC of the blood in different experimental groups was tested by weighing the ratio of kidney and performing ELISA to evaluate the protective effect of adalimumab on kidney of DN animal model. In addition, the changes in the transcription and translation levels of tumor necrosis factor alpha (TNF-α) and its downstream regulatory factors MCP-1 and NF-kB in kidney of different experimental groups were detected by fluorescence quantitative PCR and Western blot tests to further reveal the molecular mechanism of adalimumab inhibiting the diabetic nephropathy. Results: adalimumab could significantly downregulate blood glucose and urinary albumin levels (P <0.05). The renal body weight ratio and the contents of UN, Cr and Cysc in blood in the adalimumab group were significantly lower than those in the placebo group (P <0.05). Meanwhile, adalimumab could significantly downregulate the expression of these molecules (P <0.05). Conclusion: adalimumab could exert its therapeutic effect on diabetic nephropathy through its specific targeting TNF-α signaling pathways.

14.
Front Microbiol ; 12: 782621, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35003012

RESUMEN

The bacterial communities of the root-zone soil are capable of regulating vital biogeochemical cycles and the succession of plant growth. Stipa as grassland constructive species is restricted by the difference features of east-west humidity and north-south heat, which shows the population substituting distribution. The distribution, turnover, and potential driving factors and ecological significance of the root-zone bacterial community along broad spatial gradients of Stipa taxa transition remain unclear. This paper investigated seven Stipa species root-zone soils based on high-throughput sequencing combined with the measurements of multiple environmental parameters in arid and semi-arid steppe. The communities of soil bacteria in root zone had considerable turnover, and some regular variations in structure along the Stipa taxa transition are largely determined by climatic factors, vegetation coverage, and pH at a regional scale. Bacterial communities had a clear Stipa population specificity, but they were more strongly affected by the main annual precipitation, which resulted in a biogeographical distribution pattern along precipitation gradient, among which Actinobacteria, Acidobacteria, Proteobacteria, and Chloroflexi were the phyla that were most abundant. During the transformation of Stipa taxa from east to west, the trend of diversity shown by bacterial community in the root zone decreased first, and then increased sharply at S. breviflora, which was followed by continuous decreasing toward northwest afterwards. However, the richness and evenness showed an opposite trend, and α diversity had close association with altitude and pH. There would be specific and different bacterial taxa interactions in different Stipa species, in which S. krylovii had the simplest and most stable interaction network with the strongest resistance to the environment and S. breviflora had most complex and erratic. Moreover, the bacterial community was mainly affected by dispersal limitation at a certain period. These results are conducive to the prediction of sustainable ecosystem services and protection of microbial resources in a semi-arid grassland ecosystem.

15.
ACS Omega ; 6(1): 656-665, 2021 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-33458518

RESUMEN

Bletilla striata is widely used for stanching bleeding. In this study, polysaccharides from B. striata (BSP) were extracted by hot water. Four polysaccharides named BSP-1-BSP-4 were fractionated using DEAE-52 cellulose. BSP fractions contained sulfate, and the degrees of substitution of BSP-3 and BSP-4 were 1.59 and 1.70, respectively. Analysis of monosaccharide composition showed that four polysaccharides were mainly composed of mannan and glucose. The in vitro results showed that BSP-1-BSP-4 elicited pro-coagulant capacities by shortening the activating partial thromboplastin time, prothrombin time, and thrombin time and elevating the fibrinogen content. Immunomodulatory activity was evaluated by MTT assay, the pinocytic capacity and NO production. Although BSP fractions did not affect RAW 264.7 cell viability, they, especially BSP-2, enhanced the immunomodulatory activity by increasing the pinocytic capacity and NO production. Overall, BSP may be developed as a potential coagulant with immunomodulatory effects.

16.
J AOAC Int ; 93(1): 323-6, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20334194

RESUMEN

A practical and nontarnishing method for the determination of trace nickel (Ni) in hydrogenated cottonseed oil by inductively coupled plasma/mass spectrometry (ICP/MS) was developed. In order to avoid tarnishing in the pretreatment of samples, the technology of pressurized PTFE vessel acid digestion was applied. The temperature and acid content in the digestion were optimized. The results showed that hydrogenated cottonseed oil could be digested completely by the proposed method. Compared with the U.S. Pharmacopeia 28 and British Pharmacopoeia 2003 methods, the developed method avoided the risk of using platinum and the tarnish from silica crucibles. In addition, the analytical cycle of the test solution was shortened by the use of ICP/MS instead of graphite furnace atomic absorption spectrophotometry.


Asunto(s)
Aceite de Semillas de Algodón/química , Contaminación de Alimentos/análisis , Espectrometría de Masas/métodos , Níquel/análisis , Espectrofotometría Atómica/métodos , Ácidos , Calor , Humanos , Hidrogenación , Politetrafluoroetileno , Presión
17.
Ultrasound Med Biol ; 46(8): 1941-1948, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32451195

RESUMEN

The purpose of this study was to determine whether incorporation of the ultrasound (US) features of the primary tumor and axillary lymph node (ALN) could improve the prediction of high axillary nodal burden (HNB) and, thus, avoid unnecessary sentinel lymph node biopsy (SLNB). A total of 347 patients with Breast Imaging Reporting and Data System US category 4 or 5 breast cancer lesions were included. Their pre-operative US features and post-operative pathologic results were collected. The patients were then divided into the following groups based on surgical histology: limited nodal burden (LNB: 0-2 LNs involved) and heavy nodal burden (HNB: ≥3 metastatic LNs). Univariate and multivariate logistic regression analyses were conducted to determine the most valuable variables for HNB prediction. Receiver operating characteristic curves were obtained to assess their values. We found that a non-circumscribed margin, cortical thickness (≥3 mm) and number (≥3) of suspicious ALNs are indicators for HNB prediction. The false-negative rate (FNR) in model 1 (cortical thickness + number of suspicious ALNs) was 15.5% versus 3.4% in model 2 (non-circumscribed margin + cortical thickness + number of suspicious ALNs). Our results indicate that combining the US features of the primary tumor and ALNs can reduce the FNR during HNB prediction.


Asunto(s)
Neoplasias de la Mama/diagnóstico por imagen , Ganglios Linfáticos/diagnóstico por imagen , Metástasis Linfática/diagnóstico por imagen , Ultrasonografía , Adulto , Anciano , Anciano de 80 o más Años , Axila , Neoplasias de la Mama/diagnóstico , Neoplasias de la Mama/patología , Reacciones Falso Negativas , Femenino , Humanos , Ganglios Linfáticos/patología , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Retrospectivos , Ultrasonografía/métodos
18.
Int J Nanomedicine ; 14: 9217-9234, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31819426

RESUMEN

BACKGROUND: Huperzine A (HupA) is a selective acetylcholinesterase inhibitor used to treat Alzheimer's disease. The existing dosage of HupA lacks brain selectivity and can cause serious side effects in the gastrointestinal and peripheral cholinergic systems. PURPOSE: The aim of this study was to develop and characterize a HupA nanoemulsion (NE) and a targeted HupA-NE modified with lactoferrin (Lf) for intranasal administration. METHODS: The NE was formulated using pseudo-ternary phase diagrams and optimized with response surface methodology. Particle size distribution and zeta potential were evaluated, and transmission electron microscopy was performed. We investigated the transport mechanisms of HupA-NEs into hCMEC/D3 cells, an in vitro model of the blood-brain barrier. HupA-NE, Lf-HupA-NE, and HupA solution were intranasally administered to rats to investigate the brain-targeting effects of these formulations. A drug targeting index (DTI) was calculated to determine brain-targeting efficiency. RESULTS: Optimized HupA-NE had a particle size of 15.24±0.67 nm, polydispersity index (PDI) of 0.128±0.025, and zeta potential of -4.48±0.97 mV. The composition of the optimized HupA-NE was 3.00% isopropyl myristate (IPM), 3.81% Capryol 90, and 40% Cremophor EL + Labrasol. NEs, particularly Lf-HupA-NE, were taken up into hCMEC/D3 cells to a greater extent than pure drug alone. Western blot analysis showed that hCMEC/D3 cells contained P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and multidrug resistance associated protein 1 (MRP1) transporters. The likely mechanisms resulting in higher NE transport to the brain were uptake by specific transporters and transcytosis. In vivo, intranasal Lf-HupA-NE significantly enhanced drug delivery to the brain compared to HupA-NE, which was confirmed by differences in pharmacokinetic parameters. The DTI of Lf-HupA-NE (3.2±0.75) demonstrated brain targeting, and the area under the curve for Lf-HupA-NE was significantly higher than that for HupA-NE. CONCLUSION: Lf-HupA-NE is a promising nasal drug delivery carrier for facilitating delivery of HupA to the central nervous system.


Asunto(s)
Emulsiones/química , Lactoferrina/química , Nanopartículas/química , Administración Intranasal , Alcaloides/farmacocinética , Enfermedad de Alzheimer/metabolismo , Animales , Transporte Biológico , Barrera Hematoencefálica/metabolismo , Encéfalo/efectos de los fármacos , Línea Celular , Liberación de Fármacos , Humanos , Lactoferrina/administración & dosificación , Masculino , Nanopartículas/administración & dosificación , Mucosa Nasal/metabolismo , Tamaño de la Partícula , Transición de Fase , Ratas Wistar , Sesquiterpenos/farmacocinética , Solubilidad , Electricidad Estática , Distribución Tisular
19.
Front Chem ; 7: 339, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31139622

RESUMEN

Tin-based anode materials with high capacity attract wide attention of researchers and become a strong competitor for the next generation of lithium-ion battery anode materials. However, the poor electrical conductivity and severe volume expansion retard the commercialization of tin-based anode materials. Here, SnO2-SnS2@C nanoparticles with heterostructure embedded in a carbon matrix of nitrogen-doped graphene (SnO2-SnS2@C/NG) is ingeniously designed in this work. The composite was synthesized by a two-step method. Firstly, the SnO2@C/rGO with a nano-layer structure was synthesized by hydrothermal method as the precursor, and then the SnO2-SnS2@C/NG composite was obtained by further vulcanizing the above precursor. It should be noted that a carbon matrix with nitrogen-doped graphene can inhibit the volume expansion of SnO2-SnS2 nanoparticles and promote the transport of lithium ions during continuous cycling. Benefiting from the synergistic effect between nanoparticles and carbon matrix with nitrogen-doped graphene, the heterostructured SnO2-SnS2@C/NG further fundamentally confer improved structural stability and reaction kinetics for lithium storage. As expected, the SnO2-SnS2@C/NG composite exhibited high reversible capacity (1201.2 mA h g-1 at the current rate of 0.1 A g-1), superior rate capability and exceptional long-life stability (944.3 mAh g-1 after 950 cycles at the current rate of 1.0 A g-1). The results demonstrate that the SnO2-SnS2@C/NG composite is a highly competitive anode material for LIBs.

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