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1.
Environ Res ; 245: 118012, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38154564

RESUMO

The interactive effect of soil cooling and nitrogen (N) addition can accurately simulate climatic and anthropogenic effects on terrestrial and other land-based ecosystems, but direct empirical measurements on the effects of cooling and N addition on soil carbon (C) and N are lacking. Hence, transplanting soils into colder regions was used to evaluate the effects of cooling and N addition on soil C and N. We used PVCs of 30 cm in height and 8 cm in diameter to extract soil samples. Soil C and N were significantly (P < 0.05) increased by transplanting soils into colder regions. In contrast, cooling has insignificantly (P > 0.05) increased the soil dissolved organic C (DOC) and dissolved organic (DON), but the effect was negatively significant on soil pH compared to the C/N ratio. Similarly, N addition significantly increased the measured soil N stock. However, the effect was negatively significant on soil pH (P < 0.05) compared to the C/N ratio (P > 0.05). Nevertheless, the interaction of cooling and N addition did not affect the soil C and N storage. A similar effect was observed on the soil DOC and DON. The results presented here illustrate that transplanting soils into colder regions and N deposition has perfectly simulated the effects of climate-forcing factors on soil C and N storage in terrestrial and other land-based ecosystems. Accordingly, this study suggests that low temperatures have stimulated the accumulation of the measured soil organic and dissolved properties, but the effect is less consequential when low temperature interacts with N addition in high-elevation areas where ecosystem structures and functions are limited by temperature and may serve as a baseline for future research on land feedbacks to the climate system.


Assuntos
Ecossistema , Solo , Solo/química , Carbono , Florestas , Nitrogênio/análise
2.
PLoS One ; 11(4): e0151502, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27064569

RESUMO

Hedyotis Diffusa Willd, used in Traditional Chinese Medicine, is a treatment for various diseases including cancer, owing to its mild effectiveness and low toxicity. The aim of this study was to identify the main anticancer components in Hedyotis Diffusa Willd, and explore mechanisms underlying their activity. Hedyotis Diffusa Willd was extracted and fractionated using ethyl acetate to obtain the H-Ethyl acetate fraction, which showed higher anticancer activity than the other fractions obtained against HepG2 cells with sulforhodamine B assays. The active component of the H-Ethyl acetate fraction was identified to be 1,3-dihydroxy-2-methylanthraquinone (DMQ) with much high inhibitory rate up to 48.9 ± 3.3% and selectivity rate up to 9.4 ± 4.5 folds (p<0.01) at 125 µmol/L. HepG2 cells treated with the fraction and DMQ visualized morphologically using light and fluorescence microscopy. Annexin V--fluorescein isothiocyanate / propidium iodide staining flow cytometry, DNA ladder and cell cycle distribution assays. Mechanistic studies showed up-regulation of caspase-3, -8, and -9 proteases activities (p<0.001), indicating involvement of mitochondrial apoptotic and death receptor pathways. Further studies revealed that reactive oxygen species in DMQ and the fraction treated HepG2 cells increased (p<0.01) while mitochondrial membrane potential reduced significantly (p<0.001) compared to the control by flow cytometry assays. Western blot analysis showed that Bax, p53, Fas, FasL, p21 and cytoplasmic cytochrome C were up-regulated (p<0.01), while Bcl-2, mitochondrial cytochrome C, cyclin E and CDK 2 were down-regulated dose-dependently (p<0.01). The reverse transcriptase-polymerase chain reaction showed that mRNA expressions of p53 and Bax increased (p<0.001) while that of Bcl-2 decreased (p<0.001). Pre-treatment with caspase-8 inhibitor Z-IETD-FMK, or caspase-9 inhibitor Z-LEHD-FMK, attenuated the growth-inhibitory and apoptosis-inducing effects of DMQ and the fraction on HepG2 cells. These results suggested that DMQ and the H-Ethyl acetate fraction of Hedyotis Diffusa Willd showed potential anticancer effects. Furthermore, the mechanisms of action may involve mitochondrial apoptotic and death receptor pathways.


Assuntos
Acetatos/química , Antraquinonas/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/patologia , Hedyotis/química , Extratos Vegetais/farmacologia , Western Blotting , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas
3.
Acta Ophthalmol ; 87(2): 211-5, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18811638

RESUMO

PURPOSE: This study aimed to investigate dynamic changes in the anterior segment in patients with acute anterior uveitis (AAU) using ultrasound biomicroscopy (UBM). METHODS: Acute anterior uveitis was diagnosed in 18 patients according to history and ocular examinations. Ultrasound biomicroscopy was performed and the results at three time-points (within 2 weeks of the uveitis attack, and at 2-4 weeks and 6 weeks after it) were analysed. The relationships between clinical manifestations and UBM findings were also evaluated. RESULTS: All investigated AAU patients showed severe ciliary injection, numerous dust keratic precipitates (KPs), aqueous flare and inflammatory cells, and were treated predominantly with corticosteroid and cycloplegic eyedrops. Ultrasound biomicroscopy showed a large number of cells in the anterior and posterior chamber, marked oedema and exudates in and around the iris and ciliary body within 2 weeks of AAU onset. These abnormalities were dramatically improved at 2-4 weeks and almost resolved at 6 weeks and thereafter. CONCLUSIONS: Ultrasound biomicroscopy reveals severe inflammatory changes in and around the ciliary body in patients with AAU. These signs rapidly resolve upon treatment.


Assuntos
Segmento Anterior do Olho/diagnóstico por imagem , Microscopia Acústica , Uveíte Anterior/diagnóstico por imagem , Doença Aguda , Corticosteroides/administração & dosagem , Adulto , Idoso , Feminino , Humanos , Inflamação/diagnóstico por imagem , Inflamação/tratamento farmacológico , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Midriáticos/administração & dosagem , Soluções Oftálmicas , Resultado do Tratamento , Uveíte Anterior/tratamento farmacológico , Adulto Jovem
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