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1.
Nat Commun ; 15(1): 1263, 2024 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-38341471

RESUMEN

Metallic 2M or 1T'-phase transition metal dichalcogenides (TMDs) attract increasing interests owing to their fascinating physicochemical properties, such as superconductivity, optical nonlinearity, and enhanced electrochemical activity. However, these TMDs are metastable and tend to transform to the thermodynamically stable 2H phase. In this study, through systematic investigation and theoretical simulation of phase change of 2M WS2, we demonstrate that ultrathin 2M WS2 has significantly higher intrinsic thermal stabilities than the bulk counterparts. The 2M-to-2H phase transition temperature increases from 120 °C to 210 °C in the air as thickness of WS2 is reduced from bulk to bilayer. Monolayered 1T' WS2 can withstand temperatures up to 350 °C in the air before being oxidized, and up to 450 °C in argon atmosphere before transforming to 1H phase. The higher stability of thinner 2M WS2 is attributed to stiffened intralayer bonds, enhanced thermal conductivity and higher average barrier per layer during the layer(s)-by-layer(s) phase transition process. The observed high intrinsic phase stability can expand the practical applications of ultrathin 2M TMDs.

2.
Bioresour Technol ; 395: 130409, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38295959

RESUMEN

Traditionally, the time of maximum biomass concentration in stage I is the widely adopted stage conversion time in two-stage microalgae culture. This study challenges this conventional approach, demonstrating that the optimal stage conversion time in stage I is 72 h rather than 120 h for achieving maximum biomass concentration. A comparison of cell characteristics revealed that algal cells at 72 h exhibited better growth potential, leading to a higher biomass concentration after transfer to stage II and, consequently, increased lipid productivity. Moreover, the use of phosphorus repletion (5-fold) in stage II directed carbon flux toward biomass growth and lipid accumulation, thereby enhancing lipid productivity. By optimizing the stage conversion time and implementing phosphorus repletion, the mean lipid productivity of Auxenochlorella pyrenoidosa cultured under autotrophy-nitrogen starvation and autotrophy-high light conditions increased by 31 % and 60 %, respectively. This study underscores the importance of reevaluating the currently widely used stage conversion time.


Asunto(s)
Chlorophyta , Microalgas , Chlorophyta/metabolismo , Biomasa , Nitrógeno/metabolismo , Microalgas/metabolismo , Fósforo/metabolismo , Lípidos , Metabolismo de los Lípidos
5.
Chest ; 161(5): e273-e278, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35526896

RESUMEN

CASE PRESENTATION: An 11-month-old boy was admitted to our hospital because of "recurrent cough with intermittent dyspnea for more than 8 months, aggravated for 1 month." The baby began experiencing a recurrent milk-choking problem within 1.5 months after birth. He had been hospitalized four times, but the symptoms recurred. One month previously, the symptoms were aggravated and a chest CT scan performed at outside hospital showed interstitial changes. Pediatric bronchoscopy revealed bronchial inflammatory features, with hemosiderin-laden macrophages being found in BAL fluid (BALF). Also, periodic acid-Schiff (PAS) staining showed positive results, which indicated the possibility of pulmonary alveolar proteinosis (PAP) or idiopathic pulmonary hemosiderosis (IPH).


Asunto(s)
Hemosiderosis , Enfermedades Pulmonares Intersticiales , Enfermedades Pulmonares , Proteinosis Alveolar Pulmonar , Broncoscopía , Niño , Hemosiderosis/diagnóstico , Humanos , Lactante , Enfermedades Pulmonares/diagnóstico , Enfermedades Pulmonares Intersticiales/complicaciones , Enfermedades Pulmonares Intersticiales/diagnóstico , Masculino , Proteinosis Alveolar Pulmonar/diagnóstico , Proteinosis Alveolar Pulmonar/diagnóstico por imagen , Tomografía Computarizada por Rayos X
6.
Transl Pediatr ; 11(3): 368-374, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35378965

RESUMEN

Background: Neuroblastoma with opsoclonus-myoclonus syndrome (OMS-NB) is a rare disease in children. Few studies of long-term outcome of children with OMS-NB were conducted. This study aimed to review the rate of recovery of neurological symptoms and the long-term neurological outcomes of children with OMS-NB. Methods: This study retrospectively assessed 14 children with OMS-NB diagnosed at Peking University First Hospital from May 2011 to November 2019. Demographic data, neurological symptoms, oncological status and treatments were retrospectively reviewed from the records. Neurological sequelae were recorded by clinical and remote follow-up. Results: During the acute stage, myoclonus and ataxia were observed in all children while opsoclonus was observed in 10/14 children. The median durations of neurological symptoms were 15 months (range, 5-48 months). Approximately 93% (13/14) children revealed neurological sequelae. Significant correlations were as follows: motor retardation with female gender (P<0.001) and residual tumors (P<0.05); language impairment with non-adrenal-gland-located tumors (P<0.05). There were no obvious factors that had a statistical relationship with cognitive disorder or behavioral changes. Conclusions: Children with OMS-NB have favorable outcomes in terms of neurological symptoms. Neurological sequelae occurred in almost all children. Children with different features tend to reveal different sequalae. Features of female gender and residual tumors tend to reveal motor retardation while that of non-adrenal-gland-located tumors tend to reveal language impairment.

7.
Front Med (Lausanne) ; 8: 689568, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34222293

RESUMEN

Objective: Early identification of coronavirus disease 2019 (COVID-19) patients with worse outcomes may benefit clinical management of patients. We aimed to quantify pneumonia findings on CT at admission to predict progression to critical illness in COVID-19 patients. Methods: This retrospective study included laboratory-confirmed adult patients with COVID-19. All patients underwent a thin-section chest computed tomography (CT) scans showing evidence of pneumonia. CT images with severe moving artifacts were excluded from analysis. Patients' clinical and laboratory data were collected from medical records. Three quantitative CT features of pneumonia lesions were automatically calculated using a care.ai Intelligent Multi-disciplinary Imaging Diagnosis Platform Intelligent Evaluation System of Chest CT for COVID-19, denoting the percentage of pneumonia volume (PPV), ground-glass opacity volume (PGV), and consolidation volume (PCV). According to Chinese COVID-19 guidelines (trial version 7), patients were divided into noncritical and critical groups. Critical illness was defined as a composite of admission to the intensive care unit, respiratory failure requiring mechanical ventilation, shock, or death. The performance of PPV, PGV, and PCV in discrimination of critical illness was assessed. The correlations between PPV and laboratory variables were assessed by Pearson correlation analysis. Results: A total of 140 patients were included, with mean age of 58.6 years, and 85 (60.7%) were male. Thirty-two (22.9%) patients were critical. Using a cutoff value of 22.6%, the PPV had the highest performance in predicting critical illness, with an area under the curve of 0.868, sensitivity of 81.3%, and specificity of 80.6%. The PPV had moderately positive correlation with neutrophil (%) (r = 0.535, p < 0.001), erythrocyte sedimentation rate (r = 0.567, p < 0.001), d-Dimer (r = 0.444, p < 0.001), high-sensitivity C-reactive protein (r = 0.495, p < 0.001), aspartate aminotransferase (r = 0.410, p < 0.001), lactate dehydrogenase (r = 0.644, p < 0.001), and urea nitrogen (r = 0.439, p < 0.001), whereas the PPV had moderately negative correlation with lymphocyte (%) (r = -0.535, p < 0.001). Conclusions: Pneumonia volume quantified on initial CT can non-invasively predict the progression to critical illness in advance, which serve as a prognostic marker of COVID-19.

9.
Front Mol Biosci ; 8: 653461, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33987203

RESUMEN

Background: Eosinophilic granulomatosis with polyangiitis (EGPA) prognosis is generally favorable and is treated with combined corticosteroids/immunosuppressor(s) therapy. However, disease flares increase the number of clinical visits. Therefore, discovering new serum biomarkers for early identification of active EGPA is crucial. Objective: To identify reliable serum biomarkers to measure EGPA activity. Methods: The expression of 160 proteins was compared in sera from 15 inactive and 13 active EGPA patients by antibody-based microarray. Network-based analysis identified patterns in the different groups. Differentially expressed proteins (DEPs) in active disease were identified, and the correlation between their serum levels and clinical parameters was assessed. DEPs were further analyzed for GO enrichment and KEGG pathways. Finally, DEP marker candidates were validated by ELISA and Bio-plex as well as against a second cohort of 22 inactive and 18 active EGPA patients. Results: The active group presented higher peripheral and sputum eosinophil counts, FeNO, and FEV1 (% predicted) (P < 0.05). Network-based analysis showed scattered expression patterns in active subjects, but no significant bias in inactive subjects. Significant differences were observed in serum levels of 19 candidate markers, all of which were higher in active EGPA (P < 0.05). KEGG analysis indicated that DEPs were mainly involved in the MAPK, PI3K-Akt, RAS and Rap1 related pathways. Nine out of 19 candidate markers were positively correlated with peripheral eosinophil counts including FGF-7, SCF, GDNF, ß-NGF, IGFBP-4, Axl, PIGF, Insulin, NT-4, ErbB3, OPN and BMP-4 (r = 0.693, r = 0.692, r = 0.687, r = 0.683, r = 0.671, r = 0.606, r = 0.571, r = 0.570, r = 0.516, respectively; P < 0.05), while two, CD14 and MCP-3, were negatively correlated (r = -0.644 and r = -0.515; P < 0.05). The higher expression of Axl, OPN, HCC-4, GDNF, and MCP-3 in active EGPA subjects was confirmed by ELISA and Custom Multiplex Bio-plex analyses. Conclusion: The serum protein profiles were significantly different between active and inactive EGPA. The expression of the candidate proteins correlated with peripheral blood eosinophil count. Serum Axl, OPN, HCC-4, GDNF, and MCP-3 levels were consistently higher in active EGPA, independent of the assessment methods. Finally, Axl had the largest AUC, indicating that this cytokine may serve as novel biomarker for the diagnosis of active EGPA.

10.
AAPS PharmSciTech ; 22(4): 142, 2021 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-33893566

RESUMEN

Apremilast (APST) is an effective inhibitor of phosphodieasterase 4 (PDE4) which is the first oral drug for the treatment of adult patients with active psoriatic arthritis. However, Apremilast's low solubility restricts its dissolution and bioavailability. In this study, APST solid dispersion with D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) and Poly(1-vinylpyrrolidone-co-vinyl acetate) (PVPVA) was developed to improve the dissolution and bioavailability of APST by spray drying. A series of TPGS were synthesized to elucidate the effect of the ratio of monoester to diester on solubilizing capacity. X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), and Fourier transform infrared spectrophotometry (FT-IR) were used to characterize the solid dispersion, and the results showed that APST was amorphous in solid dispersion. In vitro dissolution study showed that the dissolution rate of solid dispersion in phosphate buffered saline (pH 6.8) was remarkably increased, reaching a release of 90% within 10 min. Moreover, in vivo pharmacokinetics study revealed that the bioavailability of solid dispersion in rats had significant improvement. In particular, its Cmax and AUClast were nearly 22- and 12.9-fold greater as compared to APST form B, respectively. In conclusion, APST solid dispersion with TPGS and PVPVA is an alternative drug delivery system to improve the solubility and oral bioavailability of APST.


Asunto(s)
Formas de Dosificación , Inhibidores de Fosfodiesterasa 4/química , Povidona/análogos & derivados , Talidomida/análogos & derivados , Vitamina E/química , Animales , Disponibilidad Biológica , Rastreo Diferencial de Calorimetría , Inhibidores de Fosfodiesterasa 4/farmacocinética , Povidona/química , Difracción de Polvo , Ratas , Solubilidad , Espectroscopía Infrarroja por Transformada de Fourier , Talidomida/química , Talidomida/farmacocinética
11.
Polymers (Basel) ; 12(1)2020 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-31952358

RESUMEN

Uniform alignment of rigid-rod liquid crystal (LC) molecules under applied voltage is critical for achievement of high-quality display for thin-film transistor-driven liquid crystal display devices (TFT-LCDs). The polymeric components that can induce the alignment of randomly aligned LC molecules are called alignment layers (ALs). In the current work, a series of organo-soluble polyimide (SPI) ALs were designed and prepared from an alicyclic dianhydride, hydrogenated 3,3',4,4'-biphenyltetracarboxylic dianhydride (HBPDA), and various aromatic diamines, including 4,4'-methylenedianiline (MDA) for SPI-1, 4,4'-aminodianiline (NDA) for SPI-2, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane (TMMDA) for SPI-3, and 3,3'-diethyl-5,5'-dimethyl-4,4'-diaminodiphenylmethane (DMDEDA) for SPI-4. The derived SPI resins were all soluble in N-methyl-2-pyrrolidone (NMP). Four SPI alignment agents with the solid content of 6 wt.% were prepared by dissolving the SPI resins in the mixed solvent of NMP and butyl cellulose (BC) (NMP/BC = 80:20, weight ratio). Liquid crystal minicells were successfully fabricated using the developed SPI varnishes as the LC molecule alignment components. The SPI ALs showed good alignment ability for the LC molecules with the pretilt angles in the range of 1.58°-1.97°. The LC minicells exhibited good optoelectronic characteristics with voltage holding ratio (VHR) values higher than 96%. The good alignment ability of the SPI ALs is mainly attributed to the good comprehensive properties of the SPI layers, including high volume resistivity, high degree of imidization at the processing temperature (230 °C), good rubbing resistance, good thermal stability with glass transition temperatures (Tgs) higher than 260 °C, and excellent optical transparency with the transmittance higher than 97% at the wavelength of 550 nm.

12.
Hematology ; 24(1): 583-587, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31390973

RESUMEN

Objectives: Hereditary spherocytosis (HS) represents a group of congenital diseases characterized by sphere-shaped erythrocytes on peripheral blood smears. The typical clinical manifestations of HS include haemolysis, jaundice, splenomegaly, and gallstones. Ankyrin1, encoded by the ANK1 gene, is the predominant protein in red blood cells. Defects in ankyrin1 lead to a decrease in erythrocyte surface area, a spherical shape of erythrocytes and, in particular, loss of membrane elasticity and mechanical stability. The purpose of this study was to investigate a Chinese family with HS to determine the causative gene mutation and explore the genotype-phenotype correlation. Methods: A 4-year-old boy was diagnosed with HS based on typical clinical features. In addition, his father had a high possibility of HS. Targeted next-generation sequencing (NGS) followed by Sanger sequencing was performed in the proband and his parents. Results: One mutation in the ANK1 gene was recognized. c1801-1G > C in exon 17, which leads to splicing defects, was detected. To confirm the c1801-1G > C variant, samples from the proband and his parents were analysed by Sanger sequencing, and Sanger verification showed that this mutation was inherited from the father. Conclusion: The present study confirmed that a novel mutation in ANK1 may be causative of HS, which plays an important role in expanding the mutational spectrum of ANK1 mutations. This may contribute to accurate genetic counselling. And it is helpful for understanding the correlation of the genotype and phenotype.


Asunto(s)
Ancirinas/genética , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Esferocitosis Hereditaria/genética , Pueblo Asiatico , Preescolar , Humanos , Masculino , Mutación
13.
Int Immunopharmacol ; 74: 105646, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31200337

RESUMEN

BACKGROUND: Maintaining an airway clear of bacteria, foreign particles and apoptotic cells by alveolar macrophages is very essential for lung homeostasis. In asthma, the phagocytic capacity of alveolar macrophages is significantly reduced, which is thought to be associated with increased oxidative stress. Hydrogen (H2) has been shown to exert potent antioxidant and anti-inflammatory effects, yet its effects on phagocytosis of alveolar macrophages are unknown. This study is aimed to evaluate the beneficial effects of hydrogen gas inhalation on alveolar macrophage phagocytosis in an ovalbumin (OVA)-induced murine asthma model. METHODS: Female C57BL/6 mice were intraperitoneally sensitized with OVA before they were subject to airway challenge with aerosolized OVA. Hydrogen gas was delivered to the mice through inhalation twice a day (2 h once) for 7 consecutive days. Phagocytic function of alveolar macrophages isolated from bronchoalveolar lavage fluid was assessed by fluorescence-labeled Escherichia coli as well as flow cytometry. RESULTS: Alveolar macrophages isolated from OVA-induced asthmatic mice showed decreased phagocytic capacity to Escherichia coli when compared with those of control mice. Defective phagocytosis in asthmatic mice was reversed by hydrogen gas inhalation. Hydrogen gas inhalation significantly alleviated OVA-induced airway hyperresponsiveness, inflammation and goblet cell hyperplasia, diminished TH2 response and decreased IL-4 as well as IgE levels, reduced malondialdehyde (MDA) production and increased superoxide dismutase (SOD) activity. Concomitantly, hydrogen gas inhalation inhibited NF-κB activation and markedly activated Nrf2 pathway in OVA-induced asthmatic mice. CONCLUSIONS: Our findings demonstrated that hydrogen gas inhalation enhanced alveolar macrophage phagocytosis in OVA-induced asthmatic mice, which may be associated with the antioxidant effects of hydrogen gas and the activation of the Nrf2 pathway.


Asunto(s)
Asma/tratamiento farmacológico , Hidrógeno/farmacología , Hidrógeno/uso terapéutico , Macrófagos Alveolares/efectos de los fármacos , Administración por Inhalación , Animales , Asma/inmunología , Asma/patología , Asma/fisiopatología , Líquido del Lavado Bronquioalveolar/citología , Líquido del Lavado Bronquioalveolar/inmunología , Recuento de Células , Citocinas/inmunología , Escherichia coli , Femenino , Hemo-Oxigenasa 1/metabolismo , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Pulmón/patología , Pulmón/fisiopatología , Macrófagos Alveolares/inmunología , Proteínas de la Membrana/metabolismo , Ratones Endogámicos C57BL , Factor 2 Relacionado con NF-E2/metabolismo , FN-kappa B/metabolismo , Ovalbúmina , Fagocitosis/efectos de los fármacos
14.
Zhongguo Dang Dai Er Ke Za Zhi ; 19(12): 1263-1266, 2017 Dec.
Artículo en Chino | MEDLINE | ID: mdl-29237527

RESUMEN

Li-Fraumeni syndrome (LFS) is a hereditary cancer predisposition syndrome, with the characteristics of early onset of cancer and high cancer incidence. TP53 is widely accepted as a pathogenic gene of LFS. A 2 years and 6 months old boy is reported in this article, who was diagnosed with embryonal rhabdomyosarcoma (RMS) in the left submandibular region. His brother died of RMS, and his grandmother was diagnosed with breast cancer. TP53 gene mutation detection was performed in this patient and some family members, indicating a missense mutation in exon 8 of the patient: c.844C>T (p.Arg282Trp, heterozygous). TP53 mutation was also found in his mother and sister. The boy met the diagnostic criteria for LFS. Among pediatric patients, the most common LFS diseases include osteosarcoma, adrenocortical cancer, central nervous system tumor, and soft tissue tumor. Additionally, leukemia and lymphoma are also involved. LFS patients have a high risk to suffer secondary or even multiple cancers. Therefore, it is necessary to perform genetic detection for pediatric cancer patients, especially those with hereditary predisposition cancers. TP53 mutation often indicates poor prognosis, so it is important to take active treatment and systematic monitoring for LFS family.


Asunto(s)
Síndrome de Li-Fraumeni/genética , Rabdomiosarcoma/genética , Preescolar , Genes p53 , Humanos , Masculino , Mutación
15.
Zhongguo Dang Dai Er Ke Za Zhi ; 19(7): 781-785, 2017 Jul.
Artículo en Chino | MEDLINE | ID: mdl-28697831

RESUMEN

OBJECTIVE: To investigate the adverse effects of high-dose methotrexate (HDMTX) therapy, and to provide a theoretical basis for optimizing clinical treatment. METHODS: A retrospective analysis was performed for the clinical data of 120 children with acute lymphoblastic leukemia or non-Hodgkin lymphoma who underwent 601 times of HDMTX therapy. The adverse effects of various systems were analyzed according to the WHO criteria for the classification of adverse effects of anticancer drugs. RESULTS: Almost all the children experienced bone marrow suppression, and 93.3% had granulocytopenia. The most common adverse effects in the digestive system and urinary system were elevated glutamic-pyruvic transaminase (60.4%) and proteinuria (9.2%) respectively. For skin symptoms, skin erythema had the highest incidence rate (7.2%). The adverse effects in the nervous system (hyperpathia, numbness of extremities, or headache) were only observed in 7 cases. Serious adverse effects were only seen in the blood system and digestive system. Compared with the 3 g/m2 methotrexate (MTX) group, the 5 g/m2 HDMTX group had a significantly higher 24-hour plasma MTX concentration, significant reductions in hemoglobin and platelet count, and significantly higher incidence rates of oral mucositis, proteinuria, and skin symptoms (P<0.05). CONCLUSIONS: Serious adverse effects of HDMTX therapy mainly involve the blood system and digestive system, and the adverse effects such as bone marrow suppression, oral mucositis, proteinuria, and skin symptoms occur in a dose-dependent manner.


Asunto(s)
Antimetabolitos Antineoplásicos/efectos adversos , Linfoma no Hodgkin/tratamiento farmacológico , Metotrexato/efectos adversos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Niño , Preescolar , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Estudios Retrospectivos
16.
Pharmacotherapy ; 37(7): e71-e75, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28543284

RESUMEN

Oxcarbazepine is a second-generation antiepileptic drug that is used to treat partial seizures. Although it has been increasingly used in pregnant women, its fetal safety has not been fully validated. We describe a 12-hour-old neonate who developed neonatal abstinence syndrome (NAS) after intrauterine exposure to oxcarbazepine. The neonate was born via cesarean section to a mother who took oxcarbazepine 300 mg/day for treatment of seizures throughout her pregnancy. Approximately 12 hours after birth, the infant developed paroxysmal jitter, which mainly presented as increased excitability, irritability, limb shaking, and increased muscle tone. These symptoms resolved by day 9 of life. Although NAS occurs most often after in utero exposure to opioids, exposure to other drugs during pregnancy may contribute to a small proportion of NAS cases. To our knowledge, this is the second case report of oxcarbazepine-induced NAS. Pregnant women with epilepsy should weigh the pros and cons of continuing oxcarbazepine during their pregnancy when they are prescribed this drug. For infants with in utero oxcarbazepine exposure, comprehensive assessments and examinations are necessary for screening oxcarbazepine-induced NAS.


Asunto(s)
Anticonvulsivantes/efectos adversos , Carbamazepina/análogos & derivados , Síndrome de Abstinencia Neonatal/diagnóstico , Efectos Tardíos de la Exposición Prenatal/inducido químicamente , Efectos Tardíos de la Exposición Prenatal/diagnóstico , Adulto , Anticonvulsivantes/sangre , Carbamazepina/efectos adversos , Carbamazepina/sangre , Femenino , Humanos , Recién Nacido , Masculino , Síndrome de Abstinencia Neonatal/sangre , Oxcarbazepina , Embarazo , Efectos Tardíos de la Exposición Prenatal/sangre
17.
Int J Biol Macromol ; 66: 245-53, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24582936

RESUMEN

Tissue engineering is aiming to build an artificial environment or biological scaffold material that imitates the living environment of cells in the body. In this work, carboxymethyl cellulose sulfates were prepared by reacting carboxymethyl cellulose with N(SO3Na)3 which was synthesized by sodium bisulfite and sodium nitrite in aqueous solution. The reaction conditions affected the degree of substitution (DS) were measured by the barium sulfate nephelometry method. And the anticoagulant activity of carboxymethyl cellulose sulfates with different DS, concentration and molecular weights were investigated by the activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT). In addition, the effect of carboxymethyl cellulose sulfates on wound healing had been evaluated by the rate of wound healing and the histological examinations. The results indicated that the introduction of sulfate groups into the carboxymethyl cellulose sulfates improved its anticoagulant activity, and the wound dressings treated with carboxymethyl cellulose sulfates obviously promoted wound healing.


Asunto(s)
Anticoagulantes/química , Anticoagulantes/farmacología , Carboximetilcelulosa de Sodio/química , Carboximetilcelulosa de Sodio/farmacología , Sulfatos/química , Sulfatos/farmacología , Heridas y Lesiones/tratamiento farmacológico , Animales , Ratones , Peso Molecular , Tiempo de Tromboplastina Parcial/métodos , Tiempo de Protrombina/métodos , Nitrito de Sodio/química , Nitrito de Sodio/farmacología , Sulfitos/química , Sulfitos/farmacología , Tiempo de Trombina/métodos , Cicatrización de Heridas/efectos de los fármacos
18.
Int J Biol Macromol ; 50(1): 31-7, 2012 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-21996571

RESUMEN

Quaternary ammonium chitosan sulfates with diverse degrees of substitution (DS) ascribed to sulfate groups between 0.52 and 1.55 were synthesized by reacting quaternary ammonium chitosan with an uncommon sulfating agent (N(SO(3)Na)(3)) that was prepared from sodium bisulfite (NaHSO(3)) through reaction with sodium nitrite (NaNO(2)) in the aqueous system homogeneous. The structures of the derivatives were characterized by FTIR, (1)H NMR and (13)C NMR. The factors affecting DS of quaternary ammonium chitosan sulfates which included the molar ratio of NaNO(2) to quaternary ammonium chitosan, sulfated temperature, sulfated time and pH of sulfated reaction solution were investigated in detail. Its anticoagulation activity in vitro was determined by an activated partial thromboplastin time (APTT) assay, a thrombin time (TT) assay and a prothrombin time (PT) assay. Results of anticoagulation assays showed quaternary ammonium chitosan sulfates significantly prolonged APTT and TT, but not PT, and demonstrated that the introduction of sulfate groups into the quaternary ammonium chitosan structure improved its anticoagulant activity obviously. The study showed its anticoagulant properties strongly depended on its DS, concentration and molecular weight.


Asunto(s)
Anticoagulantes/química , Quitosano/química , Compuestos de Amonio Cuaternario/química , Escherichia coli/metabolismo , Concentración de Iones de Hidrógeno , Sustancias Macromoleculares/química , Espectroscopía de Resonancia Magnética/métodos , Modelos Químicos , Peso Molecular , Tiempo de Tromboplastina Parcial , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Sulfitos/química , Temperatura , Tiempo de Trombina , Factores de Tiempo
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