Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 138
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Zhonghua Zhong Liu Za Zhi ; 42(10): 843-848, 2020 Oct 23.
Artículo en Zh | MEDLINE | ID: mdl-33113625

RESUMEN

Objective: To investigate the effects of pre-B lymphocytic leukemia transcription factor (PBX1) expression on the apoptosis, reactive oxygen species (ROS) content and transcriptional activation factor 3 (STAT3) signaling pathway of lung cancer cells. Methods: Real-time quantitative polymerase chain reaction was used to detect the expression level of PBX1 in lung cancer tissues and adjacent tissues. The correlation between PBX1 expression level and clinical pathological parameters of patients were analyzed. Western blot was used to detect the protein expression level of PBX1 in human lung cancer cell lines, including A549, SPC-A1, SK-MES-1 and H1299. A549 cells were transfected with blank control (blank group), negative control (NC group) or PBX1 small interfering RNA (siRNA group), respectively. The cells apoptosis and ROS content were detected by flow cytometry. The protein expression levels of PBX1, STAT3, phosphorylated STAT3 (p-STAT3), B cell lymphoma/leukemia-2 (Bcl-2) and survivin in each group were detected by western blot. Results: The expression level of PBX1 mRNA in lung cancer was (2.36±0.23), significantly higher than (1.02±0.15) in paracancerous tissues (P<0.05). The expression level of PBX1 was correlated with lung cancer differentiation, lymph node metastasis and TNM stage (P<0.05). The expression levels of PBX1 in human lung cancer cells A549, SPC-A1, SK-MES-1 and H1299 were (0.454±0.038), (0.403±0.034), (0.311±0.028) and (0.377±0.035), respectively, significantly higher than (0.041±0.007) of human normal lung cells MRC-5 (P<0.05). The expression level of PBX1 protein in A549 cells transfected with PBX1 siRNA was (0.082±0.010), significantly lower than (0.704±0.065) of the blank group (P<0.05). The apoptosis rate and ROS content of siPBX1 group were (30.78±3.64)% and (51.55±5.03), respectively, significantly higher than (3.92±0.27)% and (22.36±1.31) of blank group (P<0.05). The protein expressions of p-STAT3, Bcl-2 and survivin were (0.051±0.006), (0.202±0.018) and (0.068±0.008), respectively, significantly lower than (0.172±0.010), (0.425±0.041) and (0.196±0.021) of blank group (P<0.05). Conclusion: Inhibition of PBX1 expression can induce the apoptosis of lung cancer cell, the mechanism may be related to ROS production and down-regulation of STAT3 signal.


Asunto(s)
Silenciador del Gen , Neoplasias Pulmonares , Factor de Transcripción 1 de la Leucemia de Células Pre-B/genética , Especies Reactivas de Oxígeno/metabolismo , Apoptosis , Línea Celular Tumoral , Proliferación Celular , Regulación Neoplásica de la Expresión Génica , Humanos , Pulmón/metabolismo , Neoplasias Pulmonares/genética , Factor de Transcripción STAT3/metabolismo , Transducción de Señal
2.
Zhonghua Bing Li Xue Za Zhi ; 48(1): 31-36, 2019 Jan 08.
Artículo en Zh | MEDLINE | ID: mdl-30641643

RESUMEN

Objective: To investigate the clinical manifestations, imaging features, clinicopathologic features, and differential diagnosis of solitary fibrous tumors/anginoblastomas (SFT/HPCs) originating in the central nervous system. Methods: Sixty cases of SFT/HPCs originating in the central nervous system were collected at Nanjing Jinling Hospital, from January 1, 2008 to December 31, 2016. The clinical data, imaging data, histomorphologic changes and immunohistochemical finding were analyzed in the sixty cases. Results: The 60 cases included 26 males and 34 females, aged 14 to 85 (median 49) years. The main clinical manifestations were headache, dizziness with nausea and vomiting. Radiologically, the tumors were large, enhancing, solid and cystic masses attached to the dura. Histopathologically, the neoplasms were composed of spindle cells with oval nuclei, inconspicuous nucleoli and moderate amount of eosinophilic cytoplasm arranged in fascicles with areas of hyalinized stroma, myxoid changes and a staghorn vascular pattern. Immunohistochemically, tumor cells of all cases were positive for vimentin (100.0%, 60/60), STAT6 (98.3%, 59/60), CD34 (61.7%, 37/60), and the tumor cells were typically positive for CD99, bcl-2, EMA and SSTR2 as well.Negative for S-100 protein, SOX10, E-cadherin, GFAP. Ki-67 index ranged from 1% to 50%. Forty cases were followed up for 6 to 82 months with average of 40 months, 30 patients were alive and 10 patients died. Conclusions: Central nervous system SFT/HPCs can be aggressive and relapses may occur several years after diagnosis. STAT6 is highly sensitive and specific for the diagnosis. Complete tumor resection is optional treatment followed by radiotherapy and chemotherapy. There is a correlation between the prognosis and the location of the disease, the histological grade, Ki-67 index, and fusion gene variants.


Asunto(s)
Neoplasias del Sistema Nervioso Central , Hemangiopericitoma , Tumores Fibrosos Solitarios , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor , Neoplasias del Sistema Nervioso Central/química , Neoplasias del Sistema Nervioso Central/complicaciones , Neoplasias del Sistema Nervioso Central/diagnóstico por imagen , Neoplasias del Sistema Nervioso Central/patología , Diagnóstico Diferencial , Femenino , Hemangiopericitoma/química , Hemangiopericitoma/complicaciones , Hemangiopericitoma/diagnóstico por imagen , Hemangiopericitoma/patología , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia , Pronóstico , Tumores Fibrosos Solitarios/química , Tumores Fibrosos Solitarios/complicaciones , Tumores Fibrosos Solitarios/diagnóstico por imagen , Tumores Fibrosos Solitarios/patología , Adulto Joven
3.
Int Endod J ; 49(2): 189-202, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25688929

RESUMEN

AIM: To report a severe and rare case of multiple idiopathic cervical root resorption (MICRR) in an adult female. SUMMARY: A healthy 27-year-old Chinese female, with no significant associated factors, presented with MICRR. Resorption progressed quickly and lesions varied in severity, involving 29 teeth and leading to the loss of 23 teeth over a period of only 3 years. The inner surface of the crown showed extensive areas with worm-eaten lacunar resorption, and the resorptive lesions had abundant lysosomes throughout their cytoplasm. Further, heavy deposits of reaction products were shown in variously sized lysosomes.


Asunto(s)
Resorción Radicular/patología , Resorción Radicular/terapia , Adulto , Tomografía Computarizada de Haz Cónico , Progresión de la Enfermedad , Femenino , Humanos , Microscopía Electrónica de Rastreo , Radiografía Panorámica , Resorción Radicular/diagnóstico por imagen
4.
Epidemiol Infect ; 143(15): 3327-34, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25792346

RESUMEN

Mycoplasma infections are most frequently associated with disease in the urogenital or respiratory tracts and, in most cases, mycoplasmas infect the host persistently. In HIV-infected individuals the prevalence and role of genital mycoplasmas has not been well studied. To investigate the six species of Mycoplasma and the risk factors for infection in Jiangsu province, first-void urine and venous blood samples were collected and epidemiological questionnaires were administered after informed consent. A total of 1541 HIV/AIDS patients were recruited in this study. The overall infection rates of six Mycoplasma species were: Ureaplasma urealyticum (26·7%), Mycoplasma hominis (25·3%), M. fermentans (5·1%), M. genitalium (20·1%), M. penetrans (1·6%) and M. pirum (15·4%). The Mycoplasma infection rate in the unmarried group was lower than that of the married, divorced and widowed groups [adjusted odds ratio (aOR) 1·432, 95% confidence interval (CI) 1·077-1·904, P < 0·05]. The patients who refused highly active antiretroviral therapy (HAART) had a much higher risk of Mucoplasma infection (aOR 1·357, 95% CI 1·097-1·679, P < 0·05). Otherwise, a high CD4+ T cell count was a protective factor against Mycoplasma infection (aOR 0·576, 95% CI 0·460-0·719, P < 0·05). Further research will be required to confirm a causal relationship and to identify risk factors for Mycoplasma infection in HIV/AIDS populations.


Asunto(s)
Terapia Antirretroviral Altamente Activa/estadística & datos numéricos , Infecciones por VIH/epidemiología , Estado Civil/estadística & datos numéricos , Infecciones por Mycoplasma/epidemiología , Infecciones por Ureaplasma/epidemiología , Adolescente , Adulto , Anciano , China/epidemiología , Coinfección/epidemiología , Estudios Transversales , Infecciones por VIH/tratamiento farmacológico , VIH-1 , Humanos , Masculino , Persona de Mediana Edad , Mycoplasma/genética , Mycoplasma/aislamiento & purificación , Infecciones por Mycoplasma/microbiología , Mycoplasma fermentans/genética , Mycoplasma fermentans/aislamiento & purificación , Mycoplasma genitalium/genética , Mycoplasma genitalium/aislamiento & purificación , Mycoplasma hominis/genética , Mycoplasma hominis/aislamiento & purificación , Mycoplasma penetrans/genética , Mycoplasma penetrans/aislamiento & purificación , Reacción en Cadena de la Polimerasa , Prevalencia , Factores de Riesgo , Ureaplasma urealyticum/genética , Ureaplasma urealyticum/aislamiento & purificación , Adulto Joven
5.
J Acoust Soc Am ; 138(1): 223-31, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26233021

RESUMEN

On the basis of the principle of stationary phase, Chuprov [Ocean Acoustics: Current State (Nauka, Moscow, 1982)] proposed a scalar parameter-the waveguide invariant ß, to interpret the dispersive properties of underwater acoustic waveguide. It has been found that ß may be useful in many applications in underwater acoustics. A reasonable prediction of the value of ß is often necessary in such applications. It was known that ß has some "canonical" values for waveguides with simple sound speed profiles (SSP). When a thermocline exists, ß for refractive modes (with a turning point) is no longer constant and can even change its sign. In this paper, by dividing the SSP into the non-refractive part and the refractive part, a clear explanation of how the value of ß is affected by the thermocline is presented. The results show that ß can be positive and increase continually from around 1 to +∞; or negative from -∞ to about -3. An analytic criterion of the sign of ß is developed. This method can also be used to analyze the value of ß for any other kind of SSP.

6.
Bioorg Khim ; 41(5): 627-32, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26762102

RESUMEN

A novel hydrogel was prepared from polysialic acid (PSA) and carboxymethyl chitosan (CMCS) using glutaraldehyde as the cross-linking agent. The resulting PSA-CMCS hydrogel exhibited pH sensitivity, in which the swelling ratio under acidic conditions was higher than those under neutral or alkaline conditions. The swelling ratio of PSA-CMCS hydrogel at equilibrium depended on the medium pH, the cross-linking agent concentration, and the ratio of PSA to CMCS (w/w). Bovine serum albumin (BSA) and 5-fluorouracil (5-FU) were used as model drugs to prepare hydrogel delivery systems. The loading efficiencies of the hydrogel for BSA and 5-FU were 26.25 and 36.74%, respectively. Release behaviors of BSA and 5-FU were influenced by the pH. MTT assays confirmed that PSA-CMCS hydrogel has no cytotoxicity toward the NIH-3T3 cell line; in fact, the 100% aqueous extract of the PSA-CMCS hydrogel enhanced cell growth. These results suggest that PSA-CMCS hydrogel may be a promising pH-sensitive delivery system, especially for hydrophobic chemicals.


Asunto(s)
Quitosano/análogos & derivados , Portadores de Fármacos/síntesis química , Hidrogeles/química , Ácidos Siálicos/química , Animales , Antimetabolitos Antineoplásicos/administración & dosificación , Supervivencia Celular/efectos de los fármacos , Reactivos de Enlaces Cruzados/química , Portadores de Fármacos/química , Portadores de Fármacos/toxicidad , Liberación de Fármacos , Fluorouracilo/administración & dosificación , Glutaral/química , Concentración de Iones de Hidrógeno , Ratones , Microscopía Electrónica de Rastreo , Células 3T3 NIH , Porosidad , Espectrofotometría Infrarroja
7.
Eur J Clin Microbiol Infect Dis ; 33(2): 189-95, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23949791

RESUMEN

Males who have sex with men (MSM) are considered at high risk of blood-borne and sexually transmitted infections (STIs), mainly due to the practice of unsafe sex, often combined with drug use and needle-sharing. A cross-sectional study was designed for the detection of genital mycoplasmas during the period from March 2009 to May 2010 in Jiangsu province. This work was approved by the Research ethics Committee of Jiangsu Centers for Diseases Prevention and Control (CDC), and written consent was obtained from all participants. In total, 243 human immunodeficiency virus-1 (HIV-1)-infected MSM were screened in this study. Over half of them reported a history of sexual activity with females (65.0 %), and 26.3 % reported a history of sexually transmitted diseases (STDs) other than HIV. 44.0 % of patients were in the first 2 years of their HIV infection, and 72.4 % were still in HIV progression. Of the 243 analyzed samples, all were positive for at least one kind of mycoplasma. The infection rates of Mycoplasma genitalium, M. fermentans, M. penetrans, and M. pirum were 25.5, 9.9, 2.5, and 18.5 %, respectively. The M. genitalium infection was associated with a history of sexual activity with females, and those who had sex with females showed higher infection rates. Six M. penetrans-positive patients were still in HIV infection progression and did not receive highly active antiretroviral therapy (HAART). Men who perform this particular behavior are at higher risk of Mycoplasma infections. Further molecular and epidemiological cohort studies with larger populations are needed in order to identify the role of Mycoplasma infections in HIV-1-infected MSM.


Asunto(s)
Bisexualidad , Infecciones por VIH/complicaciones , Homosexualidad Masculina , Infecciones por Mycoplasma/epidemiología , Mycoplasma/aislamiento & purificación , Infecciones del Sistema Genital/epidemiología , Adulto , Anciano , China/epidemiología , Estudios Transversales , Femenino , Infecciones por VIH/virología , VIH-1/aislamiento & purificación , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Infecciones por Mycoplasma/microbiología , Infecciones del Sistema Genital/microbiología , Adulto Joven
8.
Zhonghua Nei Ke Za Zhi ; 58(3): 164-166, 2019 Mar 01.
Artículo en Zh | MEDLINE | ID: mdl-30803171
9.
Prikl Biokhim Mikrobiol ; 50(1): 44-51, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25272751

RESUMEN

Curdlan is produced by Agrobacterium sp. ATCC 31749 under nitrogen-limited conditions not associated with cell growth. A novel curdlan production process was developed based on the different nutrient requirements for microbial cell growth and its efficiency was increased by integrating carbon/nitrogen sources control and sequencing dual fed-batch fermentors operation. By feeding ammonium solution to supply abundant nitrogen source and controlling pH in Fermentor I, cell growth was accelerated. High cell density of 29 g/L was attained. The culture broth in Fermentor I was then inoculated into sequencing Fermentor II which alleviated the high requirement for dissolved oxygen and accumulation of inhibitory metabolic by-products during curdlan production. Fermentor I promoted cell growth. Curdlan production started instantaneously in Fermentor II. By feeding nutrient solution with high carbon/nitrogen ratio and NaOH solution for pH adjustment, a feasible and optimal curdlan production process was formulated. The productivity, conversion efficiency and curdlan yield were achieved of 0.98 g/(L h), 57% (w) and 67 g/L, respectively. Such novel process can be scaled up for significant cost reduction at the industrial level.


Asunto(s)
Agrobacterium/metabolismo , Carbono/metabolismo , Nitrógeno/metabolismo , beta-Glucanos/metabolismo , Agrobacterium/ultraestructura , Amoníaco/metabolismo , Técnicas de Cultivo Celular por Lotes , Reactores Biológicos , Medios de Cultivo , Fermentación , Concentración de Iones de Hidrógeno , Oxígeno/metabolismo , Control de Calidad
10.
Plant Dis ; 97(1): 138, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30722302

RESUMEN

Chinese bean tree, Catalpa fargesii f. duciouxii (Dode) Gilmour, is an ornamental arbor plant. Its roots, leaves, and flowers have long been used for medicinal purposes in China. During July 2010, severe outbreaks of leaf spot disease on this plant occurred in Kunming, Yunnan Province. The disease incidence was greater than 90%. The symptoms on leaves began as dark brown lesions surrounded by chlorotic halos, and later became larger, round or irregular spots with gray to off-white centers surrounded by dark brown margins. Leaf tissues (3 × 3 mm), cut from the margins of lesions, were surface disinfected in 0.1% HgCl2 solution for 3 min, rinsed three times in sterile water, plated on potato dextrose agar (PDA), and incubated at 28°C. The same fungus was consistently isolated from the diseased leaves. Colonies of white-to-dark gray mycelia formed on PDA, and were slightly brown on the underside of the colony. The hyphae were achromatic, branching, septate, and 4.59 (±1.38) µm in diameter on average. Perithecia were brown to black, globose in shape, and 275.9 to 379.3 × 245.3 to 344.8 µm. Asci that formed after 3 to 4 weeks in culture were eight-spored, clavate to cylindrical. The ascospores were fusiform, slightly curved, unicellular and hyaline, and 13.05 to 24.03 × 10.68 to 16.02 µm. PCR amplification was carried out by utilizing universal rDNA-ITS primer pair ITS4/ITS5 (2). Sequencing of the PCR products of DQ1 (GenBank Accession No. JN165746) revealed 99% similarity (100% coverage) with Colletotrichum gloeosporioides isolates (GenBank Accession No. FJ456938.1, No. EU326190.1, No. DQ682572.1, and No. AY423474.1). Phylogenetic analyses (MEGA 4.1) using the neighbor-joining (NJ) algorithm placed the isolate in a well-supported cluster (>90% bootstrap value based on 1,000 replicates) with other C. gloeosporioides isolates. The pathogen was identified as C. gloeosporioides (Penz.) Penz. & Sacc. (teleomorph Glomerella cingulata (Stoneman) Spauld & H. Schrenk) based on the morphological characteristics and rDNA-ITS sequence analysis (1). To confirm pathogenicity, Koch's postulates were performed on detached leaves of C. fargesii f. duciouxii, inoculated with a solution of 1.0 × 106 conidia per ml. Symptoms similar to the original ones started to appear after 10 days, while untreated leaves remained healthy. The inoculation assay used three leaves for untreated and six leaves for treated. The experiments were repeated once. C. gloeosporioides was consistently reisolated from the diseased tissue. C. gloeosporioides is distributed worldwide causing anthracnose on a wide variety of plants (3). To the best of our knowledge, this is the first report of C. gloeosporioides causing leaf spots on C. fargesii f. duciouxii in China. References: (1) B. C. Sutton. Page 1 in: Colletotrichum: Biology, Pathology and Control. CAB International. Wallingford, UK, 1992. (2) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990. (3) J. Yan et al. Plant Dis. 95:880, 2011.

12.
Eur Rev Med Pharmacol Sci ; 27(15): 6985-6995, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37606148

RESUMEN

OBJECTIVE: This study aimed to systematically evaluate the effect of whole-body vibration (WBV) training on the improvement of limb function in patients with Parkinson's disease (PD). MATERIALS AND METHODS: An electronic search was performed on the databases, including PubMed, Web of Science, Scopus, SCI-hub, ScienceDirect, Embase, IEEE, Medline, Wiley, ClinicaIKey, CNKI, Wanfang, VIP database, Chinese Medical Association, and CBM Database from inception to May 2022 to collect randomized controlled studies on whole-body vibration training for patients with Parkinson's disease. Two researchers independently screened the literature, extracted the data, and evaluated the quality of the literature, then used ReviewManager 5.4 software for quantitative statistical analysis, including heterogeneity test, sensitivity analysis, risk of bias assessment, combined outcome index effect size and effect size inspection. RESULTS: A total of 9 studies were included in the meta-analysis, including 346 patients, 174 patients in the control group and 172 patients in the observation group. Meta-analysis results showed that, compared with conventional physical therapy or drug therapy alone, whole-body vibration reduced the Unified Parkinson's Disease Rating Scale (UPDRSIII) score and significantly improved the motor function of patients with Parkinson's disease [MD=-2.39, 95% CI (-4.41, -0.37), Z=2.14 (p=0.23)]. Moreover, whole-body vibration significantly improved the walking stability of Parkinson's patients [MD=-1.96, 95% CI (-2.71-1.21), Z=1.17 (p=0.03)]. However, its improvement in balance ability [MD=-0.06, 95% CI (-0.77, 0.65), Z=1.07 (p=0.19)] and daily living ability [MD=0.03, 95% CI (-1.68, 0.74), Z=0.24 (p=0.87)] of patients, it was not t statistically significant. CONCLUSIONS: Compared with conventional therapy, WBV has certain advantages in improving the balance function and gait performance of PD patients, but the effect on balance ability and daily living ability is not significant. Thus, more high-quality research is required for further verification.


Asunto(s)
Enfermedad de Parkinson , Vibración , Humanos , Marcha , Enfermedad de Parkinson/terapia , Vibración/uso terapéutico
13.
J Acoust Soc Am ; 131(5): 3691-7, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22559346

RESUMEN

The waveguide invariant ß is affected by the shallow-water environment. The effect due to bottom sediment on ß is investigated in this paper. It is found that the effect of sediment bottom can be concentrated on one parameter P-the bottom reflection phase-shift parameter. For a Pekeris waveguide, under Wentzel-Kramers-Brillouin (WKB) approximation, a very simple analytic relation is given: ß ≈ 1 + P/(k(0)H(eff)), where H(eff) is the "effective depth," and H(eff) = H + P/2 k(0). The value of ß related to different high-speed sediments (including layered sediment) ranges from 1.0 to 1.5. Some numerical examples including the layered sediment case are conducted to verify this result. Good agreement between the results calculated by KRAKEN and by WKB with parameter P has been found. Hence, the application of parameter P provides a model-free platform to investigate the bottom effect on the waveguide invariant ß in shallow-water.

14.
J Dent Res ; 101(8): 912-920, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35184584

RESUMEN

Use of high-performance fibers such as poly(p-phenylene-2,6-benzobisoxazole) (PBO) improves the mechanical properties of dental fiber-reinforced composites (FRCs). However, the surfaces of high-performance fibers are relatively inert, and the interface with the resin matrix is poor. This has become a limitation restricting the performance of PBO FRCs in dentistry. Nanomaterials were introduced onto PBO fibers to construct various hierarchical reinforcements to obtain a dental FRC with higher flexural performance and optimized interface bonding. Four hierarchical reinforcements were constructed: PBO-ZnO nanoparticles (NPs), PBO-ZnO nanowires (NWs), PBO-ZnO NPs-cage silsesquioxane (POSS), and PBO-ZnO NWs-POSS. Performance following this optimized method was evaluated at macroscale and microscale levels, including measurement of the interfacial properties and mechanical properties of FRCs. The physicochemical characteristics of PBO fibers before and after modification were measured to determine the interfacial bonding mechanisms and to verify the connection between the microinterface and macromechanical properties. The cytotoxicity of the preferred PBO FRC was evaluated using the CCK8 assay. In comparison to other designs, the interfacial shear strength (IFSS) of PBO-ZnO NWs-POSS was the highest (29.31 ± 2.40 MPa). The corresponding FRC had the highest flexural strength under a static load (925.0 ± 39.2 MPa), the flexural modulus (39.39 ± 1.41 GPa) was equivalent to that of human dentin, and in vitro cytotoxicity was acceptable. The interfacial bonding mechanisms of PBO-ZnO NWs-POSS resulted from mechanical interlocking, chemical bonds, hydrogen bonds, and van der Waals forces. In summary, the PBO-ZnO NWs-POSS hierarchical reinforcement was introduced in dental FRCs and showed remarkable enhancement of the IFSS and flexural properties. We verified that the PBO-ZnO NWs-POSS hierarchical reinforcement was successful. This PBO FRC may be applied in dentistry as a new option for endodontic posts. Our study provides an interface design strategy for developing high-performance FRCs reinforced with high-performance fibers for dental applications.


Asunto(s)
Óxido de Zinc , Resinas Compuestas/química , Materiales Dentales/química , Resistencia Flexional , Humanos , Ensayo de Materiales , Propiedades de Superficie
15.
Int J Immunopathol Pharmacol ; 24(2): 345-56, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21658309

RESUMEN

Eugenol and isoeugenol, two components of clover oil, have been reported to possess several biomedical properties, such as anti-inflammatory, antimicrobial and antioxidant effects. This study aims to examine the anti-inflammatory effects of eugenol, isoeugenol and four of their derivatives on expression of inducible nitric oxide synthase (iNOS) activated by lipopolysaccharide (LPS) in mouse macrophages (RAW 264.7), and to investigate molecular mechanisms underlying these effects. We found that two derivatives, eugenolol and glyceryl-isoeugenol, had potent inhibitory effects on LPS-induced upregulation of nitrite levels, iNOS protein and iNOS mRNA. In addition, they both suppressed the release of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) induced by LPS. Moreover, they both attenuated the DNA binding of NF-kB and AP-1, phosphorylation of inhibitory kB-alpha (IkB-alpha), and nuclear translocation of p65 protein induced by LPS. Finally, we demonstrated that glyceryl-isoeugenol suppressed the phosphorylation of ERK1/2, JNK and p38 MAPK, whereas eugenolol suppressed the phosphorylation of ERK1/2 and p38 MAPK. Taken together, these results suggest that that eugenolol and glyceryl-isoeugenol suppress LPS-induced iNOS expression by down-regulating NF-kB and AP-1 through inhibition of MAPKs and Akt/IkB-alpha signaling pathways. Thus, this study implies that eugenolol and glyceryl-isoeugenol may provide therapeutic benefits for inflammatory diseases.


Asunto(s)
Antiinflamatorios/farmacología , Endotoxinas/farmacología , Eugenol/farmacología , Glicerol/farmacología , Proteínas I-kappa B/metabolismo , Macrófagos/efectos de los fármacos , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Factor de Transcripción AP-1/metabolismo , Animales , Línea Celular , Supervivencia Celular/efectos de los fármacos , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Relación Dosis-Respuesta a Droga , Regulación hacia Abajo , Eugenol/análogos & derivados , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Mediadores de Inflamación/metabolismo , Interleucina-1beta/metabolismo , Macrófagos/enzimología , Macrófagos/inmunología , Ratones , Inhibidor NF-kappaB alfa , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/genética , Fosforilación , ARN Mensajero/metabolismo , Factor de Transcripción ReIA/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo
16.
Prikl Biokhim Mikrobiol ; 47(5): 537-43, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22232894

RESUMEN

The changes in transcription of genes involved in nitrogen metabolism and curdlan biosynthesis, and total protein expression were firstly analyzed to define the responses of Agrobacterium sp. ATCC 31749 to nitrogen source availability during curdlan fermentation. The transcription of all nitrogen metabolism and regulation genes increased significantly under nitrogen limitation. The genes of carbon (exoC) and nitrogen (ntrB, ntrC, and nifR) metabolism showed distinctive transcriptional responses to nitrogen limitation. Their relative expression level was increased by 14, 9, 7 and 7-fold, respectively. Two-dimentional electrophoresis (2-DE) revealed that the expression of 14 proteins were elevated and 6 proteins were down-regulated significantly under nitrogen starvation. Furthermore, 4 proteins (GroEL, ABC transporter, Atu1730 and enoyl-acyl carrier protein reductase) in which the expression level changed significantly were identified. The results showed that Agrobacterium sp. regulates its carbon flux and nitrogen assimilation effectively for better survival.


Asunto(s)
Agrobacterium/metabolismo , Carbono/metabolismo , Nitrógeno/metabolismo , beta-Glucanos/metabolismo , Agrobacterium/genética , Fermentación , Regulación Bacteriana de la Expresión Génica , Genes Bacterianos , Redes y Vías Metabólicas , Transcripción Genética , beta-Glucanos/química
17.
J Cell Biol ; 135(5): 1207-18, 1996 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8947545

RESUMEN

Xenopus egg extracts initiate DNA replication specifically at the dihydrofolate reductase (DHFR) origin locus with intact nuclei from late G1-phase CHO cells as a substrate, but at nonspecific sites when purified DNA is assembled by the extract into an embryonic nuclear structure. Here we show that late G1-phase CHO nuclei can be cycled through an in vitro Xenopus egg mitosis, resulting in the assembly of an embryonic nuclear envelope around G1-phase chromatin. Surprisingly, replication within these chimeric nuclei initiated at a novel specific site in the 5' region of the DHFR structural gene that does not function as an origin in cultured CHO cells. Preferential initiation at this unusual site required topoisomerase II-mediated chromosome condensation during mitosis. Nuclear envelope breakdown and reassembly in the absence of chromosome condensation resulted in nonspecific initiation. Introduction of condensed chromosomes from metaphase-arrested CHO cells directly into Xenopus egg extracts was sufficient to elicit assembly of chimeric nuclei and preferential initiation at this same site. These results demonstrate clearly that chromosome architecture can determine the sites of initiation of replication in Xenopus egg extracts, supporting the hypothesis that patterns of initiation in vertebrate cells are established by higher order features of chromosome structure.


Asunto(s)
Núcleo Celular/metabolismo , Cromosomas/ultraestructura , Replicación del ADN , Origen de Réplica , Animales , Células CHO , Extractos Celulares , Núcleo Celular/ultraestructura , Cromosomas/metabolismo , Cricetinae , Fase G1 , Genes , Metafase , Mitosis , Membrana Nuclear/metabolismo , Óvulo , Tetrahidrofolato Deshidrogenasa/genética , Xenopus
18.
J Cell Biol ; 33(3): 451-67, 1967 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-4226960

RESUMEN

A comparison of the times necessary to incorporate tritium-labeled lysine and arginine into histones and tritium-labeled thymidine into DNA indicates that the periods of DNA and histone synthesis prior to division closely coincide. (The comparison was made by determining the times necessary, after pulse labeling, for cells with marked chromosomes to enter and then leave the division stages.) An additional period of chromosomal protein synthesis, of short duration, occurs late in interphase. Most of the chromosomal proteins appear either to be synthesized in the nucleus or to migrate there shortly after synthesis. Much of this protein is conserved from one division to the next. Studies of the effects of puromycin and fluorodeoxyuridine on the syntheses of DNA and histone suggest that continuation of DNA synthesis is dependent on a concurrent protein synthesis. Histone synthesis, on the other hand, can proceed at a normal rate under conditions in which DNA synthesis is inhibited.


Asunto(s)
ADN/biosíntesis , Histonas/biosíntesis , Plantas/metabolismo , Arginina/metabolismo , Autorradiografía , División Celular/efectos de los fármacos , Nucléolo Celular , Núcleo Celular/metabolismo , Cromosomas , Citoplasma , Floxuridina/farmacología , Lisina/metabolismo , Puromicina/farmacología , Timidina/metabolismo , Tritio
19.
Science ; 271(5253): 1270-2, 1996 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-8638106

RESUMEN

Nuclei isolated from Chinese hamster ovary (CHO) cells at various times during the G1 phase of the cell cycle were stimulated to enter S phase by incubation in Xenopus egg cytosol. Replication of DNA initiated within the dihydrofolate reductase (DHFR) origin locus in nuclei isolated late in G1, but at random sites in nuclei isolated early in G1. A discrete transition point occurred 3 to 4 hours after metaphase. Neither replication licensing nor nuclear assembly was sufficient for origin recognition. Thus, a distinct cell cycle-regulated event in the nucleus restricts the initiation of replication to specific sites downstream of the DHFR gene.


Asunto(s)
Núcleo Celular/metabolismo , Fase G1/fisiología , Origen de Réplica , Tetrahidrofolato Deshidrogenasa/genética , Animales , Células CHO , Cricetinae , Replicación del ADN , Óvulo , Fase S , Factores de Tiempo , Xenopus
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA