Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Bioresour Technol ; 211: 574-83, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27038266

RESUMO

This work aims at revealing the adhesion characteristics and microbial community of the biofilm in an integrated moving bed biofilm reactor-membrane bioreactor, and further evaluating their variations over time. With multiple methods, the adhesion characteristics and microbial community of the biofilm on the carriers were comprehensively illuminated, which showed their dynamic variation along with the operational time. Results indicated that: (1) the roughness of biofilm on the carriers increased very quickly to a maximum value at the start-up stage, then, decreased to become a flat curve, which indicated a layer of smooth biofilm formed on the surface; (2) the tightly-bound protein and polysaccharide was the most important factor influencing the stability of biofilm; (3) the development of biofilm could be divided into three stages, and Gammaproteobacteria were the most dominant microbial species in class level at the last stage, which occupied the largest ratio (51.48%) among all microbes.


Assuntos
Reatores Biológicos/microbiologia , Membranas Artificiais , Consórcios Microbianos , Biofilmes/crescimento & desenvolvimento , Desenho de Equipamento
2.
J Physiol Sci ; 64(3): 177-83, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24619404

RESUMO

Hyperthermia is a promising anti-cancer treatment in which the tissue temperature is increased to 42-45 °C, and which is often used in combination with chemotherapy or radiation therapy. Our aim in the present work was to examine the feasibility of combination therapy for oral cancer with cisplatin and hyperthermia generated with ferucarbotran (Resovist(®); superparamagnetic iron oxide) in an alternating magnetic field (AMF). First, we established that administration of ferucarbotran at the approved dosage for magnetic resonance imaging provides an iron concentration sufficient to increase the temperature to 42.5 °C upon exposure to AMF. Then, we examined the effect of cisplatin combined with ferucarbotran/AMF-induced hyperthermia on cultured human oral cancer cells (HSC-3 and OSC-19). Cisplatin alone induced apoptosis of cancer cells in a dose-dependent manner, as is well known. However, the combination of cisplatin with ferucarbotran/AMF was significantly more effective than cisplatin alone. This result suggests that it might be possible to reduce the clinically effective dosage of cisplatin by administering it in combination with ferucarbotran/AMF-induced hyperthermia, thereby potentially reducing the incidence of serious cisplatin-related side effects. Further work seems justified to evaluate simultaneous thermo-chemotherapy as a new approach to anticancer therapy.


Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma de Células Escamosas/patologia , Cisplatino/farmacologia , Dextranos , Neoplasias de Cabeça e Pescoço/patologia , Hipertermia Induzida/métodos , Campos Magnéticos , Nanopartículas de Magnetita , Neoplasias Bucais/patologia , Linhagem Celular Tumoral , Quimioterapia Adjuvante , Relação Dose-Resposta a Droga , Estudos de Viabilidade , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Humanos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Fatores de Tempo
3.
PLoS One ; 9(2): e89292, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24586666

RESUMO

Store-operated Ca(2+) entry (SOCE) is a major mechanism of Ca(2) (+) import from extracellular to intracellular space, involving detection of Ca(2+) store depletion in endoplasmic reticulum (ER) by stromal interaction molecule (STIM) proteins, which then translocate to plasma membrane and activate Orai Ca(2+) channels there. We found that STIM1 and Orai1 isoforms were abundantly expressed in human melanoma tissues and multiple melanoma/melanocyte cell lines. We confirmed that these cell lines exhibited SOCE, which was inhibited by knockdown of STIM1 or Orai1, or by a pharmacological SOCE inhibitor. Inhibition of SOCE suppressed melanoma cell proliferation and migration/metastasis. Induction of SOCE was associated with activation of extracellular-signal-regulated kinase (ERK), and was inhibited by inhibitors of calmodulin kinase II (CaMKII) or Raf-1, suggesting that SOCE-mediated cellular functions are controlled via the CaMKII/Raf-1/ERK signaling pathway. Our findings indicate that SOCE contributes to melanoma progression, and therefore may be a new potential target for treatment of melanoma, irrespective of whether or not Braf mutation is present.


Assuntos
Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Melanócitos/metabolismo , Melanoma/metabolismo , Neoplasias Cutâneas/metabolismo , Animais , Canais de Cálcio/metabolismo , Linhagem Celular Tumoral , Retículo Endoplasmático/metabolismo , Humanos , Melanoma/patologia , Camundongos , Neoplasias Cutâneas/patologia
4.
J Physiol Sci ; 62(3): 251-7, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22392350

RESUMO

Cellular reactive oxygen species (ROS) production is increased by both temperature and anticancer drugs. Antioxidants are known to suppress ROS production while cancer patients may take them as dietary supplement during chemotherapy and hyperthermic therapy. We examined changes in ROS production in prostate cancer cells in the presence of various anticancer drugs and antioxidants at different temperatures. ROS production was increased with temperature in cancer cells, but not in normal cells; this increase was potently inhibited by ascorbic acid. ROS production was also increased in the presence of some anticancer drugs, such as vinblastine, but not by others. Dietary antioxidant supplements, such as ß-carotene, showed variable effects. Ascorbic acid potently inhibited ROS production, even in the presence of anticancer drugs, while ß-carotene showed no inhibition. Accordingly, our results suggest that cancer patients should carefully choose antioxidants during their cancer chemotherapy and/or hyperthermic therapy.


Assuntos
Antineoplásicos/uso terapêutico , Antioxidantes/farmacologia , Ácido Ascórbico/farmacologia , Hipertermia Induzida , Neoplasias da Próstata/tratamento farmacológico , Espécies Reativas de Oxigênio/metabolismo , Animais , Dextranos/farmacologia , Nanopartículas de Magnetita , Masculino , Ratos , Células Tumorais Cultivadas
5.
J Environ Manage ; 92(6): 1651-62, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21339040

RESUMO

Affected by natural and anthropogenic disturbances such as forest fires, insect-induced mortality and harvesting, forest stand age plays an important role in determining the distribution of carbon pools and fluxes in a variety of forest ecosystems. An improved understanding of the relationship between net primary productivity (NPP) and stand age (i.e., age-related increase and decline in forest productivity) is essential for the simulation and prediction of the global carbon cycle at annual, decadal, centurial, or even longer temporal scales. In this paper, we developed functions describing the relationship between national mean NPP and stand age using stand age information derived from forest inventory data and NPP simulated by the BEPS (Boreal Ecosystem Productivity Simulator) model in 2001. Due to differences in ecobiophysical characteristics of different forest types, NPP-age equations were developed for five typical forest ecosystems in China (deciduous needleleaf forest (DNF), evergreen needleleaf forest in tropic and subtropical zones (ENF-S), deciduous broadleaf forest (DBF), evergreen broadleaf forest (EBF), and mixed broadleaf forest (MBF)). For DNF, ENF-S, EBF, and MBF, changes in NPP with age were well fitted with a common non-linear function, with R(2) values equal to 0.90, 0.75, 0.66, and 0.67, respectively. In contrast, a second order polynomial was best suitable for simulating the change of NPP for DBF, with an R(2) value of 0.79. The timing and magnitude of the maximum NPP varied with forest types. DNF, EBF, and MBF reached the peak NPP at the age of 54, 40, and 32 years, respectively, while the NPP of ENF-S maximizes at the age of 13 years. The highest NPP of DBF appeared at 122 years. NPP was generally lower in older stands with the exception of DBF, and this particular finding runs counter to the paradigm of age-related decline in forest growth. Evaluation based on measurements of NPP and stand age at the plot-level demonstrates the reliability and applicability of the fitted NPP-age relationships. These relationships were used to replace the normalized NPP-age relationship used in the original InTEC (Integrated Terrestrial Ecosystem Carbon) model, to improve the accuracy of estimated carbon balance for China's forest ecosystems. With the revised NPP-age relationship, the InTEC model simulated a larger carbon source from 1950-1980 and a larger carbon sink from 1985-2001 for China's forests than the original InTEC model did because of the modification to the age-related carbon dynamics in forests. This finding confirms the importance of considering the dynamics of NPP related to forest age in estimating regional and global terrestrial carbon budgets.


Assuntos
Carbono/análise , Ecossistema , Agricultura Florestal/métodos , Modelos Biológicos , Árvores/crescimento & desenvolvimento , Fatores Etários , Biomassa , China , Árvores/química , Incerteza
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...