Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 154
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nucleic Acids Res ; 51(8): 3540-3555, 2023 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-36919604

RESUMO

Combination cancer chemotherapy is one of the most useful treatment methods to achieve a synergistic effect and reduce the toxicity of dosing with a single drug. Here, we use a combination of two well-established anticancer DNA intercalators, actinomycin D (ActD) and echinomycin (Echi), to screen their binding capabilities with DNA duplexes containing different mismatches embedded within Watson-Crick base-pairs. We have found that combining ActD and Echi preferentially stabilised thymine-related T:T mismatches. The enhanced stability of the DNA duplex-drug complexes is mainly due to the cooperative binding of the two drugs to the mismatch duplex, with many stacking interactions between the two different drug molecules. Since the repair of thymine-related mismatches is less efficient in mismatch repair (MMR)-deficient cancer cells, we have also demonstrated that the combination of ActD and Echi exhibits enhanced synergistic effects against MMR-deficient HCT116 cells and synergy is maintained in a MMR-related MLH1 gene knockdown in SW620 cells. We further accessed the clinical potential of the two-drug combination approach with a xenograft mouse model of a colorectal MMR-deficient cancer, which has resulted in a significant synergistic anti-tumour effect. The current study provides a novel approach for the development of combination chemotherapy for the treatment of cancers related to DNA-mismatches.


Assuntos
Neoplasias Colorretais , Equinomicina , Humanos , Animais , Camundongos , Dactinomicina/química , Equinomicina/química , Timina , Sequência de Bases , Sítios de Ligação , Conformação de Ácido Nucleico , DNA/química
2.
J Microsc ; 290(3): 153-160, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36916012

RESUMO

In this paper, an optical waveguide evanescent field fluorescence microscopy is studied. Based on Maxwell's equation, a seven-layer theoretical analysis model is developed for the evaluation of an optical waveguide excitation fluorescence microscopy. The optical waveguide excitation fluorescence microscopy structure is systematically and comprehensively analysed at the wavelengths of 488, 532 and 646 nm for fluorescent dyes. The analysis results provide some useful suggestions, which will be beneficial to the research of an optical waveguide evanescent field fluorescence microscopy.

3.
Oral Dis ; 2022 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-36546840

RESUMO

OBJECTIVE: To explore the protective effect of human urine-derived stem cell exosomes (hUSC-Exos) on radiation-induced salivary gland (SG) injuries in Sprague Dawley rats. METHODS: Fresh adult urine was collected, and primary hUSCs were isolated and identified. The hUSCs were hypoxia-pretreated with 1% oxygen for 24 h and then transferred to a normoxic culture environment for 24 h. The hUSC-Exos were collected and identified for exosomes. A radiation-induced injury model was established in the rats, and exosomes were introduced by local injection in the SG and tail vein. The submandibular gland was excised for morphological observation 1 week later. Immunohistochemical detection of the glandular tissue was conducted by α-smooth muscle actin (a-SMA), stem cell growth factor receptor (c-Kit) staining, and periodic acid-Schiff staining. Qualitative polymerase chain reaction and western blot analysis were adopted to detect the gene and protein expression of Wnt3a, GSK3ß, and Axin. RESULTS: In both the normoxic and hypoxic hUSC-Exo groups, microvesicular structures with bilayer membranes of approximately 80 nm in diameter were detected, and the expressions of CD9 and CD63 were detected by nanoflow cytometry. Compared with the control group, in the radiation-induced injury model group, the expression of a-SMA was significantly higher, the expression of c-Kit was significantly lower, and the expressions of Wnt3a, GSK3ß, and Axin were significantly upregulated; the differences were statistically significant (p < 0.05). Compared with the model group, in the normoxic and hypoxic hUSC-Exo groups, the expression of a-SMA was significantly decreased, the expression of c-Kit was significantly increased, and the expressions of Wnt3a, GSK3ß, and Axin were significantly upregulated; the differences were statistically significant (p < 0.05). CONCLUSION: Hypoxia-pretreated hUSC-Exos could repair radiation-induced SG injuries by activating the Wnt3a/GSK3ß pathway to suppress the expressions of a-SMA and c-Kit.

4.
J Med Internet Res ; 24(3): e28978, 2022 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-35323120

RESUMO

BACKGROUND: Telemedicine plays an important role in the management of inflammatory bowel disease (IBD), particularly during a pandemic such as COVID-19. However, the effectiveness and efficiency of telemedicine in managing IBD are unclear. OBJECTIVE: This systematic review and meta-analysis aimed to compare the impact of telemedicine with that of standard care on the management of IBD. METHODS: We systematically searched the PubMed, Cochrane Library, EMBASE, Web of Science, and Scopus databases on April 22, 2020. Randomized controlled trials comparing telemedicine with standard care in patients with IBD were included, while conference abstracts, letters, reviews, laboratory studies, and case reports were excluded. The IBD-specific quality of life (QoL), disease activity, and remission rate in patients with IBD were assessed as primary outcomes, and the number of in-person clinic visits per patient, patient satisfaction, psychological outcome, and medication adherence were assessed as secondary outcomes. Review Manage 5.3 and Stata 15.1 were used for data analysis. RESULTS: A total of 17 randomized controlled trials (2571 participants) were included in this meta-analysis. The telemedicine group had higher IBD-specific QoL than the standard care group (standard mean difference 0.18, 95% CI 0.01 to 0.34; P.03). The number of clinic visits per patient in the telemedicine group was significantly lower than that in the standard care group (standard mean difference -0.71, 95% CI -1.07 to -0.36; P<.001). Subgroup analysis showed that adolescents in the telemedicine group had significantly higher IBD-specific QoL than those in the standard care group (standard mean difference 0.42, 95% CI 0.15 to 0.69; I2=0; P.002), but there was no significant difference between adults in the 2 groups. There were no significant differences in disease activity, remission rate, patient satisfaction, depression, self-efficacy, generic QoL, and medication adherence outcomes between the telemedicine and standard care groups. CONCLUSIONS: Telemedicine intervention showed a promising role in improving IBD-specific QoL among adolescents and decreased the number of clinic visits among patients with IBD. Further research is warranted to identify the group of patients with IBD who would most benefit from telemedicine.


Assuntos
COVID-19 , Doenças Inflamatórias Intestinais , Telemedicina , Adolescente , Adulto , Humanos , Doenças Inflamatórias Intestinais/terapia , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto
5.
Sensors (Basel) ; 22(9)2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35591004

RESUMO

Non-invasive foetal electrocardiography (NI-FECG) has become an important prenatal monitoring method in the hospital. However, due to its susceptibility to non-stationary noise sources and lack of robust extraction methods, the capture of high-quality NI-FECG remains a challenge. Recording waveforms of sufficient quality for clinical use typically requires human visual inspection of each recording. A Signal Quality Index (SQI) can help to automate this task but, contrary to adult ECG, work on SQIs for NI-FECG is sparse. In this paper, a multi-channel signal quality classifier for NI-FECG waveforms is presented. The model can be used during the capture of NI-FECG to assist technicians to record high-quality waveforms, which is currently a labour-intensive task. A Convolutional Neural Network (CNN) is trained to distinguish between NI-FECG segments of high and low quality. NI-FECG recordings with one maternal channel and three abdominal channels were collected from 100 subjects during a routine hospital screening (102.6 min of data). The model achieves an average 10-fold cross-validated AUC of 0.95 ± 0.02. The results show that the model can reliably assess the FECG signal quality on our dataset. The proposed model can improve the automated capture and analysis of NI-FECG as well as reduce technician labour time.


Assuntos
Aprendizado Profundo , Processamento de Sinais Assistido por Computador , Algoritmos , Eletrocardiografia/métodos , Feminino , Feto , Humanos , Redes Neurais de Computação , Gravidez
6.
BMC Gastroenterol ; 21(1): 169, 2021 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-33849450

RESUMO

BACKGROUND: Surgical resection remains the best option for long-term survival in colorectal cancer (CRC); however, surgery can lead to tumor cell release into the circulation. Previous studies have also shown that surgery can affect cancer cell growth. The role of perioperative factors influencing long-term survival in patients presenting for CRC surgery remains to be investigated. METHODS: This retrospective single-center cohort study was conducted to collect the clinical data of patients who underwent elective laparoscopic resection for CRC from January 2014 to December 2015, namely clinical manifestations, pathological results, and perioperative characteristics. Survival was estimated using the Kaplan-Meier log-rank test. Univariable and multivariable Cox regression models were used to compare hazard ratios (HR) for death. RESULTS: A total of 234 patients were eligible for analysis. In the multivariable Cox model, tumor-node-metastasis (TNM) stage (stage IV: HR 30.63, 95% confidence interval (CI): 3.85-243.65; P = 0.001), lymphovascular invasion (yes: HR 2.07, 95% CI 1.09-3.92; P = 0.027), inhalational anesthesia with isoflurane (HR 1.96, 95% CI 1.19-3.21; P = 0.008), and Klintrup-Makinen (KM) inflammatory cell infiltration grade (low-grade inflammation: HR 2.03, 95% CI 1.20-3.43; P = 0.008) were independent risk factors affecting 5-year overall survival after laparoscopic resection for CRC. CONCLUSIONS: TNM stage, lymphovascular invasion, isoflurane, and KM grade were independent risk factors affecting CRC prognosis. Sevoflurane and high-grade inflammation may be associated with improved survival in CRC patients undergoing resection.


Assuntos
Neoplasias Colorretais , Estudos de Coortes , Neoplasias Colorretais/patologia , Neoplasias Colorretais/cirurgia , Humanos , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Fatores de Risco
7.
Exp Cell Res ; 382(2): 111486, 2019 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-31255598

RESUMO

Neutrophils activated during acute lung injury (ALI) form neutrophil extracellular traps (NETs) to capture pathogens. However, excessive NETs can cause severe inflammatory reactions. Macrophages are classified as M1 macrophages with proinflammatory effects or M2 macrophages with anti-inflammatory effects. During ALI, alveolar macrophages (AMs) polarize to the M1 phenotype. This study tested the hypothesis that NETs may aggravate ALI or acute respiratory distress syndrome (ARDS) inflammation by promoting alveolar macrophage polarization to the M1 type. Our research was carried out in three aspects: clinical research, animal experiments and in vitro experiments. We determined that NET levels in ARDS patients were positively correlated with M1-like macrophage polarization. NET formation was detected in murine ALI tissue and associated with increased M1 markers and decreased M2 markers in BALF and lung tissue. Treatment with NET inhibitors significantly inhibitor NETs generation, downregulated M1 markers and upregulated M2 markers. Regardless of LPS pre-stimulation, significant secretion of proinflammatory cytokines and upregulated M1 markers were detected from bone marrow-derived macrophages (M0 and M2) cocultured with high concentrations of NETs; conversely, M2 markers were downregulated. In conclusion, NETs promote ARDS inflammation during the acute phase by promoting macrophage polarization to the M1 phenotype. We propose that NETs play an important role in the interaction between neutrophils and macrophages during the early acute phase of ALI.


Assuntos
Lesão Pulmonar Aguda/patologia , Polaridade Celular , Armadilhas Extracelulares/metabolismo , Macrófagos Alveolares/patologia , Síndrome do Desconforto Respiratório/patologia , Animais , Feminino , Lipopolissacarídeos , Camundongos Endogâmicos C57BL
8.
Mol Cell ; 45(2): 171-84, 2012 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-22196886

RESUMO

Proinflammatory cytokine TNFα plays critical roles in promoting malignant cell proliferation, angiogenesis, and tumor metastasis in many cancers. However, the mechanism of TNFα-mediated tumor development remains unclear. Here, we show that IKKα, an important downstream kinase of TNFα, interacts with and phosphorylates FOXA2 at S107/S111, thereby suppressing FOXA2 transactivation activity and leading to decreased NUMB expression, and further activates the downstream NOTCH pathway and promotes cell proliferation and tumorigenesis. Moreover, we found that levels of IKKα, pFOXA2 (S107/111), and activated NOTCH1 were significantly higher in hepatocellular carcinoma tumors than in normal liver tissues and that pFOXA2 (S107/111) expression was positively correlated with IKKα and activated NOTCH1 expression in tumor tissues. Therefore, dysregulation of NUMB-mediated suppression of NOTCH1 by TNFα/IKKα-associated FOXA2 inhibition likely contributes to inflammation-mediated cancer pathogenesis. Here, we report a TNFα/IKKα/FOXA2/NUMB/NOTCH1 pathway that is critical for inflammation-mediated tumorigenesis and may provide a target for clinical intervention in human cancer.


Assuntos
Carcinoma Hepatocelular/metabolismo , Transformação Celular Neoplásica/metabolismo , Fator 3-beta Nuclear de Hepatócito/genética , Quinase I-kappa B/metabolismo , Neoplasias Hepáticas/metabolismo , Receptor Notch1/metabolismo , Animais , Carcinoma Hepatocelular/patologia , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Fator 3-beta Nuclear de Hepatócito/metabolismo , Humanos , Neoplasias Hepáticas Experimentais/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Modelos Biológicos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Fosforilação , Receptor Notch1/genética , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo
9.
Zhongguo Zhong Yao Za Zhi ; 45(22): 5504-5510, 2020 Nov.
Artigo em Zh | MEDLINE | ID: mdl-33350212

RESUMO

To prepare a new dosage form that can improve the drug loading of the film--ginkgolide B nanosuspension lyophilized powder orodispersible film(GB-NS-LP-ODF) and to evaluate its quality. Firstly, ginkgolide B nanosuspension(GB-NS) was prepared by media milling method, and then ginkgolide B nanosuspension lyophilized powder(GB-NS-LP) was prepared with freeze-drying method. The mannitol was used as lyoprotectant and its dosage was also investigated. GB-NS-LP-ODF was prepared by solvent casting method and its formulation was screened by single factor test method and optimized by orthogonal test. The appearance, mechanical properties, content uniformity and in vitro dissolution of the optimized GB-NS-LP-ODF were investigated. The particle size of prepared GB-NS was about 201 nm, and the optimal dosage of mannitol was 8%. According to the optimal formula, the GB-NS-LP-ODF was prepared with GB-NS-LP 35.6%, PVA 0588 49.4%, PEG 400 10.7% and CMS-Na 4.3%, and completely disintegrated in about 30 s, and the particle size of reconstituted GB nanoparticles from ODF was about 210 nm. The film with smooth appearance and good mechanical properties was stable within 30 days and the content uniformity(A+2.2 S<15) conformed to the regulations. Scanning electron microscope(SEM) showed that GB-NS-LP-ODFs were evenly distributed and the particle size was about 200 nm. X-rays diffraction(XRD) showed that its crystallinity was significantly lower than that of GB raw drug and GB-ODF. The results of in vitro release test showed that the drug film was completely dissoluted within 10 minutes. These results indicated that nanosuspension lyophilized powder was prepared by freeze drying of nanosuspensions, and then loaded into the orodispersible film to effectively increase the drug loading of the ODF and have broad application prospects.


Assuntos
Lactonas , Nanopartículas , Ginkgolídeos , Tamanho da Partícula , Pós , Solubilidade , Suspensões
10.
Zhongguo Dang Dai Er Ke Za Zhi ; 22(7): 744-748, 2020 Jul.
Artigo em Zh | MEDLINE | ID: mdl-32669172

RESUMO

OBJECTIVE: To study the clinical features of children with severe adenovirus pneumonia (SAP) and hemophagocytic syndrome (HPS). METHODS: A retrospective analysis was performed from the chart review data of 30 children with SAP and HPS who were admitted from January 2014 to June 2019. According to the prognosis, the children were divided into a good prognosis group (n=18) and a poor prognosis group (n=12). RESULTS: Among the 30 children with SAP and HPS, the ratio of male to female was 2:1. The median age of onset was 1 year and 3 months (range 3 months to 5 years), and the mean course of fever was 19±7 d. Of the 30 children, 28 (93%) experienced disease onset in January to June. High-throughput gene detection of serum pathogens showed that 16 (53%) children were positive for human adenovirus type 7 (HAdV-7), and the other 14 (47%) children were positive for HAdV antigen based on immunofluorescence assay for throat swab, with unknown type. Of all 30 children, 29 (97%) had respiratory complications, 24 (80%) had cardiovascular complications, 16 (53%) had gastrointestinal complications, and 9 (30%) had toxic encephalopathy. Eighteen children (60%) improved or recovered and 12 (40%) did not recover (3 died). Compared with the good prognosis group, the poor prognosis group had a significantly longer course from onset to diagnosis of HPS (P<0.05), significantly higher levels of fibrinogen and tumor necrosis factor-α (P<0.05), and a significantly lower level of interferon-γ (P<0.05). The mean follow-up time was 6±2 months; 11 (41%) children recovered, 1 (4%) experienced recurrence of HPS, and 15 (56%) had the sequela of post-infectious bronchiolitis obliterans (PIBO). CONCLUSIONS: HPS may be observed in children with SAP, and PIBO is the most common sequela of SAP.


Assuntos
Infecções por Adenoviridae , Linfo-Histiocitose Hemofagocítica , Pneumonia Viral , Adenoviridae , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estudos Retrospectivos
11.
Biochem Biophys Res Commun ; 519(1): 8-14, 2019 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-31474337

RESUMO

To explore the effect of double-stranded RNA-dependent kinase (PKR) in acute lung injury (ALI) and resultant acute respiratory distress syndrome (ARDS). A mouse model of lipopolysaccharide (LPS)-induced ALI was used to evaluate the levels of phosphorylated (p)-PKR and NLRP3 in lung tissue, and the protective effects of a PKR inhibitor on lung injury. And in vitro, macrophages were incubated with LPS, with or without PKR inhibitor pre-treatment. It was observed that the levels of p-PKR protein and NLRP3 protein were significantly increased compared with those in control tissues after LPS administration. Meanwhile, treatment with PKR inhibitor decreased inflammation, injury score, wet/dry weight ratio, bronchoalveolar lavage fluid (BALF) protein levels, neutrophil count in BALF, myeloperoxidase activity and expression of high-mobility group box1(HMGB1) and interleukin(IL)-1ß in the lungs of LPS-challenged mice. In vitro, we demonstrated that the levels of p-PKR and NLRP3, and cell mortality rate were increased in macrophages which were incubated with LPS compared with those without LPS administration, and PKR inhibitor significantly suppressed the level of NLRP3, caspase-1, HMGB1 and IL-1ß. These results indicate that PKR plays a key role in ALI through NLRP3-pyrotosis pathway and pharmacological inhibition of PKR may have potential therapeutic effects in the treatment of patients with ALI and ARDS.


Assuntos
Lesão Pulmonar Aguda/metabolismo , Modelos Animais de Doenças , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Piroptose , eIF-2 Quinase/metabolismo , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/patologia , Animais , Lipopolissacarídeos/administração & dosagem , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , eIF-2 Quinase/antagonistas & inibidores
12.
Exp Cell Res ; 364(1): 95-103, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29409862

RESUMO

Acinetobacter baumannii is a Gram-negative coccobacillus found primarily in hospital settings that has recently emerged as a source of hospital-acquired infections, including bacterial pneumonia. The hLF(1-11) peptide comprising the first 11 N-terminal residues of human lactoferrin exerts antimicrobial activity in vivo and was highly effective against multidrug-resistant A. baumannii strains in vitro and in vivo. Pyroptosis is a caspase-1-dependent inflammatory cell death process and is induced by various microbial infections. In the present study, we investigated the molecular mechanisms that regulate pyroptosis induced by A. baumannii in macrophages. Our results revealed that A. baumannii induced pyroptosis through caspase-1 activation and IL-1ß production. We also found that caspase-1 activation and IL-1ß maturation in A. baumannii-triggered pyroptotic cell death were reduced by hLF(1-11) treatment. Moreover, hLF(1-11) inhibited the A. baumannii-induced caspase-1 activation and pyroptosis of pulmonary alveolar macrophages in vivo.


Assuntos
Infecções por Acinetobacter/tratamento farmacológico , Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Lactoferrina/farmacologia , Macrófagos Alveolares/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Piroptose/efeitos dos fármacos , Infecções por Acinetobacter/microbiologia , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Humanos , Inflamassomos/efeitos dos fármacos , Macrófagos Alveolares/microbiologia , Macrófagos Alveolares/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Catelicidinas
13.
Ann Hematol ; 97(4): 697-707, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29349655

RESUMO

Total body irradiation (TBI) is frequently used in hematopoietic stem cell transplantation (HSCT) and is associated with many complications due to radiation injury to the normal cells, including normal stem cells. Nevertheless, the effects of TBI on the mesenchymal stromal stem cell (MSC) are not fully understood. Bone marrow-derived MSCs (BM-MSCs) isolated from normal adults were irradiated with 200 cGy twice daily for consecutive 3 days, a regimen identical to that used in TBI-conditioning HSCT. The characteristics, differentiation potential, cytogenetics, hematopoiesis-supporting function, and carcinogenicity of the irradiated BM-MSCs were then compared to the non-irradiated control. The irradiated and non-irradiated MSCs shared similar morphology, phenotype, and hematopoiesis-supporting function. However, irradiated MSCs showed much lower proliferative and differentiative potential. Irradiation also induced clonal cytogenetic abnormalities of MSCs. Nevertheless, the carcinogenicity of irradiated MSCs is low in vitro and in vivo. In parallel with the ex vivo irradiation experiments, decreased proliferative and differentiative abilities and clonal cytogenetic abnormalities can also be found in MSCs isolated from transplant recipients who had received TBI-based conditioning previously. Thus, TBI used in HSCT drastically injury MSCs and may contribute to the development of some long-term complications associated with clonal cytogenetic abnormality and poor adipogenesis and osteogenesis after TBI.


Assuntos
Apoptose/efeitos da radiação , Células da Medula Óssea/efeitos da radiação , Aberrações Cromossômicas/efeitos da radiação , Células-Tronco Hematopoéticas/efeitos da radiação , Células-Tronco Mesenquimais/efeitos da radiação , Lesões por Radiação/patologia , Irradiação Corporal Total/efeitos adversos , Adulto , Células-Tronco Adultas/efeitos da radiação , Células da Medula Óssea/citologia , Células da Medula Óssea/patologia , Diferenciação Celular/efeitos da radiação , Proliferação de Células/efeitos da radiação , Células Cultivadas , China , Transtornos Cromossômicos/etiologia , Transtornos Cromossômicos/patologia , Feminino , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/patologia , Hospitais Universitários , Humanos , Leucemia/patologia , Leucemia/terapia , Masculino , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/patologia , Necrose , Lesões por Radiação/etiologia , Condicionamento Pré-Transplante/efeitos adversos , Células Tumorais Cultivadas , Adulto Jovem
14.
Appl Opt ; 57(3): 544-550, 2018 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-29400779

RESUMO

As antibiotic residue becomes more and more serious all over the world, a rapid and effective detection method is needed to evaluate the antibiotic residue in feed matrices to ensure food safety for consumers. In this study, three different kinds of fluoroquinolones (norfloxacin, enrofloxacin, and ofloxacin) in feed matrices were analyzed using terahertz (THz) spectroscopy, respectively. Meanwhile, pure fluoroquinolones and pure feed matrices were also measured in the same way. Then, the absorption spectra of all of the samples were extracted in the transmission mode. Pure norfloxacin has two absorption peaks at 0.825 and 1.187 THz, and they could still be observed when mixing norfloxacin with feed matrices. Also, there was an obvious and strong absorption peak for ofloxacin at 1.044 THz. However, no obvious absorption peak for enrofloxacin was observed, and only a weak absorption peak was located at 0.8 THz. Then, the different models were established with different chemometrics to identify the fluoroquinolones in feed matrices and determined the fluoroquinolones content in the feed matrices. The least squares support vector machines, Naive Bayes, Mahalanobis distance, and back propagation neural network (BPNN) were used to build the identification model with a Savitzky-Golay filter and standardized normal variate pretreatments. The results show that the excellent classification model was acquired with the BPNN combined with no pretreatment. The optimal classification accuracy was 80.56% in the testing set. After that, multiple linear regression and stepwise regression were used to establish the quantitative detection model for different kinds of fluoroquinolones in feed matrices. The optimal correlation coefficients for norfloxacin, enrofloxacin, and ofloxacin in the prediction set were obtained with multiple linear regression that combined absorption peaks with wavelengths selected by stepwise regression, which were 0.867, 0.828, and 0.964, respectively. Overall, this research explored the potential of identifying the fluoroquinolones in feed matrices using THz spectroscopy without a complex pretreatment process and then quantitatively detecting the fluoroquinolones content in feed matrices. The results demonstrate that THz spectra could be used to identify fluoroquinolones in feed matrices and also detect their content quantitatively, which has great significance for the food safety industry.

15.
Stem Cells ; 34(8): 2183-93, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27250566

RESUMO

Mesenchymal stem cells (MSCs) are multipotent precursors that can undergo multilineage differentiation, including osteogenesis and adipogenesis, which are two mutually exclusive events. Previously, we demonstrated that enhancer of zeste homolog 2 (EZH2), the catalytic component of the Polycomb-repressive complex 2, mediates epigenetic silencing of histone deacetylase 9c (HDAC9c) in adipocytes but not in osteoblasts and that HDAC9c accelerates osteogenesis while attenuating adipogenesis of MSCs through inactivation of peroxisome proliferator-activated receptor gamma 2 activity. Importantly, disrupting the balance between adipogenesis and osteogenesis can lead to age-associated bone loss (osteoporosis) and obesity. Here, we investigated the relationship between age, and osteogenic and adipogenic differentiation potential of MSCs by comparing EZH2 and HDAC9c expression in osteoblasts and adipocytes of both human and mice origins to determine whether the EZH2-HDAC9c axis regulates age-associated osteoporosis and obesity. Our findings indicated that a decline in HDAC9c expression over time was accompanied by increased EZH2 expression and suggested that a therapeutic intervention for age-associated osteoporosis and obesity may be feasible by targeting the EZH2-HDAC9c axis. Stem Cells 2016;34:2183-2193.


Assuntos
Adipócitos/citologia , Envelhecimento/metabolismo , Diferenciação Celular , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Histona Desacetilases/metabolismo , Células-Tronco Mesenquimais/citologia , Osteoblastos/citologia , Proteínas Repressoras/metabolismo , Adipócitos/metabolismo , Adipogenia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Técnicas de Silenciamento de Genes , Humanos , Células-Tronco Mesenquimais/metabolismo , Camundongos , Pessoa de Meia-Idade , Modelos Biológicos , Osteoblastos/metabolismo , Osteogênese , Adulto Jovem
16.
Mol Cell ; 36(1): 131-40, 2009 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-19818716

RESUMO

IkappaB kinase beta (IKKbeta) is involved in tumor development and progression through activation of the nuclear factor (NF)-kappaB pathway. However, the molecular mechanism that regulates IKKbeta degradation remains largely unknown. Here, we show that a Cullin 3 (CUL3)-based ubiquitin ligase, Kelch-like ECH-associated protein 1 (KEAP1), is responsible for IKKbeta ubiquitination. Depletion of KEAP1 led to the accumulation and stabilization of IKKbeta and to upregulation of NF-kappaB-derived tumor angiogenic factors. A systematic analysis of the CUL3, KEAP1, and RBX1 genomic loci revealed a high percentage of genome loss and missense mutations in human cancers that failed to facilitate IKKbeta degradation. Our results suggest that the dysregulation of KEAP1-mediated IKKbeta ubiquitination may contribute to tumorigenesis.


Assuntos
Quinase I-kappa B/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , NF-kappa B/metabolismo , Transdução de Sinais/fisiologia , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Proteínas Culina/genética , Proteínas Culina/metabolismo , Variações do Número de Cópias de DNA/genética , Feminino , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Humanos , Quinase I-kappa B/genética , Interleucina-8/genética , Estimativa de Kaplan-Meier , Proteína 1 Associada a ECH Semelhante a Kelch , Camundongos , Mutação/fisiologia , Neoplasias/genética , Neoplasias/metabolismo , Neovascularização Fisiológica/genética , Ligação Proteica/fisiologia , Domínios e Motivos de Interação entre Proteínas/fisiologia , RNA Interferente Pequeno/genética , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição RelA/metabolismo , Transfecção , Fator de Necrose Tumoral alfa/farmacologia , Ubiquitinação/fisiologia
18.
BMC Med Educ ; 14: 98, 2014 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-24884854

RESUMO

BACKGROUND: Neurology is complex, abstract, and difficult for students to learn. However, a good learning method for neurology clerkship training is required to help students quickly develop strong clinical thinking as well as problem-solving skills. Both the traditional lecture-based learning (LBL) and the relatively new team-based learning (TBL) methods have inherent strengths and weaknesses when applied to neurology clerkship education. However, the strengths of each method may complement the weaknesses of the other. Combining TBL with LBL may produce better learning outcomes than TBL or LBL alone. We propose a hybrid method (TBL + LBL) and designed an experiment to compare the learning outcomes with those of pure LBL and pure TBL. METHODS: One hundred twenty-seven fourth-year medical students attended a two-week neurology clerkship program organized by the Department of Neurology, Sun Yat-Sen Memorial Hospital. All of the students were from Grade 2007, Department of Clinical Medicine, Zhongshan School of Medicine, Sun Yat-Sen University. These students were assigned to one of three groups randomly: Group A (TBL + LBL, with 41 students), Group B (LBL, with 43 students), and Group C (TBL, with 43 students). The learning outcomes were evaluated by a questionnaire and two tests covering basic knowledge of neurology and clinical practice. RESULTS: The practice test scores of Group A were similar to those of Group B, but significantly higher than those of Group C. The theoretical test scores and the total scores of Group A were significantly higher than those of Groups B and C. In addition, 100% of the students in Group A were satisfied with the combination of TBL + LBL. CONCLUSIONS: Our results support our proposal that the combination of TBL + LBL is acceptable to students and produces better learning outcomes than either method alone in neurology clerkships. In addition, the proposed hybrid method may also be suited for other medical clerkships that require students to absorb a large amount of abstract and complex course materials in a short period, such as pediatrics and internal medicine clerkships.


Assuntos
Estágio Clínico/métodos , Neurologia/educação , China , Estágio Clínico/organização & administração , Currículo , Avaliação Educacional , Humanos , Masculino , Aprendizagem Baseada em Problemas , Avaliação de Programas e Projetos de Saúde , Ensino/métodos , Adulto Jovem
19.
J Physiol Biochem ; 80(2): 249-260, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38158555

RESUMO

N6-methyladenosine (m6A) is one of the most abundant epitranscriptomic modifications on eukaryotic mRNA. Evidence has highlighted that m6A is altered in response to inflammation-related factors and it is closely associated with various inflammation-related diseases. Multiple subpopulations of myeloid cells, such as macrophages, dendritic cells, and granulocytes, are crucial for the regulating of immune process in inflammation-related diseases. Recent studies have revealed that m6A plays an important regulatory role in the functional of multiple myeloid cells. In this review, we comprehensively summarize the function of m6A modification in myeloid cells from the perspective of myeloid cell production, activation, polarization, and migration. Furthermore, we discuss how m6A-mediated myeloid cell function affects the progression of inflammation-related diseases, including autoimmune diseases, chronic metabolic diseases, and malignant tumors. Finally, we discuss the challenges encountered in the study of m6A in myeloid cells, intended to provide a new direction for the study of the pathogenesis of inflammation-related diseases.


Assuntos
Adenosina , Adenosina/análogos & derivados , Inflamação , Células Mieloides , Adenosina/metabolismo , Humanos , Inflamação/metabolismo , Células Mieloides/metabolismo , Animais , Doenças Autoimunes/metabolismo , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Neoplasias/metabolismo , Neoplasias/patologia , Neoplasias/imunologia , Neoplasias/genética , Doenças Metabólicas/metabolismo , Doenças Metabólicas/imunologia , Doenças Metabólicas/patologia
20.
Phys Rev E ; 109(3-2): 035303, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38632759

RESUMO

Real-world water wave fields exhibit significant nonlinear and nonisospectral characteristics, making it challenging to predict their evolution by relying solely on numerical simulation or exact solutions using integrable system theory. Hence, this paper introduces a fast and adaptive method of modal identification and prediction in nonisospectral water wave fields using the reduced-order nonlinear solution (RONS) scheme. Specifically, we discuss the coarse graining and mode extraction of wave field snapshots from the data-driven and physics-driven perspectives and utilize the RONS method for principle modal prediction of nonisospectral water wave fields. This is achieved by investigating the standard and nonisospectral Gardner system describing nonlinear water waves as a demonstration. Through detailed comparison and analysis, the fundamental solitary behaviors and dispersive effects in the Gardner system are discussed. Subsequently, a neighbor approximation is developed that combines the essences of symbolic precomputation and numerical computation in the RONS procedure, which exploits the locality of nonlinear interactions in water wave fields.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA