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1.
Cell Mol Biol Lett ; 25(1): 47, 2020 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-33292166

RESUMO

BACKGROUND: Circular RNAs (circRNAs) are thought to be involved in the development of various malignancies. The expression and function of hsa_circ_0006916, a newly identified circRNA, in hepatocellular carcinoma remain unclear. METHODS: Quantitative RT-PCR was used to detect hsa_circ_0006916 in hepatocellular carcinoma. In vitro function assays were conducted to explore growth and invasion of hepatocellular carcinoma cells. Next, the mechanism of hsa_circ_0006916 function in hepatocellular carcinoma was determined by luciferase reporter and RIP assays. RESULTS: Hsa_circ_0006916 was substantially overexpressed in hepatocellular carcinoma tissues and cells. High levels of hsa_circ_0006916 in hepatocellular carcinoma patients were associated with advanced clinical characteristics. Down-regulation of hsa_circ_0006916 decreased the growth and invasion of hepatocellular carcinoma cells in vitro. The results suggested that hsa_circ_0006916 acted as a sponge of miR-337-3p and had an important functional use in the regulation of STAT3 levels in hepatocellular carcinoma cells. Moreover, miR-337-3p inhibition or STAT3 overexpression abolished the effect of hsa_circ_0006916 suppression on the progression of hepatocellular carcinoma cells. CONCLUSIONS: Our data suggest a novel hsa_circ_0006916/miR-337-3p/STAT3 axis in hepatocellular carcinoma, and provide a new target for treatment.


Assuntos
Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , MicroRNAs/genética , Fator de Transcrição STAT3/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Progressão da Doença , Regulação para Baixo/genética , Regulação Neoplásica da Expressão Gênica/genética , Células HEK293 , Células Hep G2 , Humanos , RNA Circular/genética , Regulação para Cima/genética
2.
World J Clin Cases ; 9(15): 3655-3661, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-34046466

RESUMO

BACKGROUND: Paradoxical psoriasis induced by tumor necrosis factor alpha antagonists is a rare side effect of those drugs and has similarities with and differences from classical psoriasis in clinical and pathological characteristics. Treating severe paradoxical psoriasis is challenging because the reported cases are rare, with treatment experience being only anecdotal. CASE SUMMARY: We report 2 cases of paradoxical psoriasis caused by infliximab. Both cases manifested with a significant number of pustular lesions and had protracted and complicated clinical courses. In case 1, secukinumab alone could not control the eruptions, but colchicine supplementation markedly decreased disease activity. In case 2 miscellaneous medications were administered, including the systemic drug acitretin, the immunosuppressive drug cyclosporine, and the biologic agent ustekinumab. However, multiple applications of those medications failed to prevent new lesions from occurring. Both cases showed moderate-to-high anti-nuclear antibody titers. CONCLUSION: Based on these cases, moderate-to-high anti-nuclear antibody titer seems to be a risk factor for paradoxical psoriasis. In addition, extensive pustular presentation may be a negative prognostic indicator and may portend a protracted clinical course refractory to therapy.

3.
Huan Jing Ke Xue ; 42(3): 1177-1184, 2021 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-33742914

RESUMO

A pot experiment was conducted to investigate the growth response and Cd accumulation characteristics among different populations of Hylotelephium spectabile in Cd-contaminated cinnamon soil (2.22 mg·kg-1) with the addition of different concentrations of NaCl. Results showed that the biomasses and Cd concentrations of H. spectabile showed significant differences among different populations under Cd alone or Cd-salt combined stress. Moreover, salt stress aggravated the growth inhibition of H. spectabile and the Cd concentrations in different H. spectabile populations showed a declining trend, which may be related to the salt-derived pH increase leading to a decrease in Cd bioavailability. In addition, the growth and Cd absorption responses of H. spectabile under salt stress were significantly different in the different populations. The shoot biomasses of the LN population were significantly higher than in other populations under different treatment, and showed no significant decrease with the addition of 1% NaCl when compared with the control treatment and the tolerance index remained 0.91. At the same time, the shoot Cd concentration of the LN population was significantly higher than in other populations under different treatments. The result may be attributed to the Cd accumulation and detoxification mechanisms in LN are prior than other populations that may also have important physiological mechanisms for tolerance of salt stress. In summary, although Cd uptake in H. spectabile decreased with salt stress, there were significant differences among different populations. LN populations accumulated 84.4 µg·plant-1 Cd in shoots with 2% NaCl addition, which was 48.4%-89.3% higher than in other populations. Therefore, H. spectabile, especially LN populations, is a good candidate for phytoremediation of Cd-contaminated saline soil.


Assuntos
Cádmio , Poluentes do Solo , Biodegradação Ambiental , Cádmio/toxicidade , Raízes de Plantas , Estresse Salino , Poluentes do Solo/toxicidade
4.
Huan Jing Ke Xue ; 41(2): 970-978, 2020 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-32608759

RESUMO

A hydroponic experiment was conducted to explore the differences in growth status and Cd accumulation characteristics of two Brassica napus L. cultivars (QY-1 and SYH) under different concentrations of cadmium (Cd) stress (0, 2, and 5 mg·L-1). The Cd subcellular compartmentalization and antioxidant enzyme activities were determined to elucidate the intrinsic mechanism of the differences in the Cd accumulation capacity between the two cultivars of Brassica napus L. Furthermore, field trials were conducted to further verify the differences in phytoremediation of the two cultivars. Results show that neither of the cultivars exhibited obvious growth inhibition under Cd stress. Under the 2 mg·L-1 Cd condition, there were no significant differences in shoot Cd concentrations between the two cultivars. Under 5 mg·L-1 Cd condition, however, the Cd concentrations in both shoot and root of SYH were significantly higher than that of QY-1, which increased by 32.05% and 99.57%, respectively. In addition, the bioconcentration factor (BCF) of the root in SYH is significantly higher than that of QY-1. The subcellular Cd distribution in leaves of the two cultivars of Brassica napus L. showed that, with an increase of Cd stress, Cd concentrations of heat stable protein (HSP) and metal-rich granule (MRG) fractions in leaves significantly increased by 143.69% and 118.91% for QY-1, and by 63.34% and 118.91% for SYH. Thus, the segregation of Cd in HSP and MRG, which was reported to be biological detoxified metal fractions (BDM), might play an important role in the detoxification of Brassica napus L. at a subcellular level under Cd stress. Moreover, the distribution of Cd in the cellular debris fraction might be another important factor contributing to the differences in Cd accumulation of the two Brassica napus L. cultivars, which was 4.41 times higher in SYH than in QY-1 under Cd stress. The results of the antioxidant enzyme activities of two Brassica napus L. cultivars showed that, under the 5 mg·L-1 Cd condition, the antioxidant enzyme system may represent an important detoxification mechanism for QY-1 to cope with stress induced by high concentrations of Cd, while SYH is more effective in reducing the toxicity of Cd by separation of Cd into BDM fractions. The results of the field trial confirmed that the Cd concentrations in the above- and underground parts of SYH were 2.34 and 1.43 times higher than in QY-1, respectively. Therefore, SYH possess a higher Cd phytoextraction capacity than QY-1, and might be a good candidate for the remediation of moderate and mildly Cd-contaminated farmland.


Assuntos
Brassica napus/metabolismo , Cádmio/metabolismo , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Raízes de Plantas , Brotos de Planta
5.
Huan Jing Ke Xue ; 41(9): 4226-4233, 2020 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-33124304

RESUMO

A field experiment with an orthogonally designed experiment L9(34) was designed to investigate the effect of different N, P, and K levels on plant growth and Cd uptake by Hylotelephium spectabile. The results showed that the biomass of H. spectabile significantly increased with the N application rate. The highest dry weight in the shoot occurred in the treatments with a high level of N (337.5 kg ·hm-2), which was 0.86-2.00 times higher than the value with no fertilizer treatment. The addition of K contributed to promoting the Cd absorption of H. spectabile, while no effect was observed when N and P were added. Consequently, NPK fertilizers contribute to increasing the Cd uptake of H. spectabile, and the N and K fertilizer play important role in plant growth and Cd absorption respectively. Moreover, the effect of fertilizers on Cd uptake of H. spectabile was in the order of N > K > P, which indicated that N fertilizer was the main factor for promoting the Cd phytoextraction efficiency of H. spectabile by increasing the biomass. Therefore, the application of high levels of N combined with moderate levels of P and K will be an effective approach to improve the Cd phytoremediation efficiency of H. spectabile by promoting its growth, and the Cd uptake can be increased by a factor of 0.9-2.2 compared to no fertilizer treatment condition.


Assuntos
Cádmio , Poluentes do Solo , Biodegradação Ambiental , Cádmio/análise , Fertilizantes/análise , Nitrogênio , Nutrientes , Solo , Poluentes do Solo/análise
6.
Huan Jing Ke Xue ; 40(1): 470-479, 2019 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-30628307

RESUMO

A hydroponic experiment was conducted to study the interaction of Cd and Zn affecting the root morphology and accumulation of Cd and Zn in Sedum aizoon. The results show that S. aizoon exhibits a high tolerance to single stress of Cd and Zn and the concentrations of Cd and Zn in the leaf, stem, and root of S. aizoon increase as the stress levels increase. A strong phytoextraction capacity in S. aizoon was also observed for the Cd concentration in the aboveground part reaching 133.0 mg·kg-1. The combined stress of Cd and Zn has a greater effect on the growth of S. aizoon than single stress to which the root is more sensitive. The root length, surface area, root volume, and tips significantly decrease under combined stress of Cd and Zn; the effect on the tips is most significant. The low-level Zn application (10 mg·L-1) has a synergistic effect on the Cd accumulation in the shoot of S. aizoon because of the promotion of Cd translocation from root to shoot. However, the addition of Cd leads to a notable antagonism of the Zn absorption of S. aizoon. The concentration ratio of Zn and Cd also has a significant effect on the Cd uptake of S. aizoon. A high ratio promotes the Cd accumulation in the shoot, while the latter is inhibited by a low Zn/Cd ratio. Therefore, S. aizoon possesses a strong potential of Cd phytoextraction and can be applied for phytoremediation of Cd-contaminated soil, while the adjustment of the ratio of Cd and Zn in the growth medium will help to enhance the phytoremediation efficiency of S. aizoon.


Assuntos
Cádmio/efeitos adversos , Raízes de Plantas/efeitos dos fármacos , Sedum/efeitos dos fármacos , Poluentes do Solo/efeitos adversos , Zinco/efeitos adversos , Biodegradação Ambiental , Sedum/química
7.
J Huazhong Univ Sci Technolog Med Sci ; 37(4): 563-567, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28786071

RESUMO

Erythroderma with complicated etiology is one of the severe skin diseases and has high mortality, of which the incidence was 0.5‰-1.5‰ in skin diseases. Erythrodermic psoriasis (EP) is the commonest type of erythroderma. In addition, there are drug-induced erythroderma, erythroderma secondary to preexisting dermatoses, malignancy-related erythroderma, and idiopathic erythroderma of unknown etiology. Erythroderma of different etiologies has various clinical manifestations, resulting in relevant curative effects and outcomes. In this article, we retrospectively investigated 205 erythroderma patients about clinical symptoms, auxiliary examination and treatments, and evaluated the efficacy and prognosis. There were 84 cases of EP among 205 patients, 10 cases of erythroderma caused by specific drugs, 77 cases of erythroderma secondary to preexisting dermatoses (excluding psoriasis), 7 cases of erythroderma patients suffering from malignancy and 27 cases with unknown causes. We concluded that the etiology of male patients in different age groups had significant difference. The incidence of EP was the highest among all types. The EP was commonly accompanied with hypoproteinemia, and changed into psoriasis vulgaris after treatment. Drug-induced erythroderma was commonly accompanied with fever, and mostly cured by systematic steroid therapy. For erythroderma secondary to preexisting dermatoses, the original dermatoses must be actively treated to achieve a satisfying prognosis. Erythroderma with malignancy or unknown causes had long-term duration, poor response to the treatment, and high potential to relapse. Therefore, clarifying the etiology, providing an appropiate and individual regimen, and regular follow-up are crucial for the successful treatment of erythroderma with unknown causes.


Assuntos
Dermatite Esfoliativa/complicações , Dermatite Esfoliativa/patologia , Psoríase/complicações , Psoríase/patologia , Fatores Etários , Dermatite Esfoliativa/epidemiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Psoríase/epidemiologia , Fatores Sexuais , Resultado do Tratamento
8.
Huan Jing Ke Xue ; 36(8): 2964-71, 2015 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-26592028

RESUMO

For a comprehensive understanding of the pollution characteristics and ecological risk of heavy metals of farmland soil in Du'an Autonomous County of Guangxi Zhuang Autonomous Region, China, this study evaluated the cadmium (Cd), arsenic (As), nickel (Ni), zinc (Zn), chromium (Cr), antimony (Sb), copper (Cu) and lead ( Pb) pollution situation using the single factor index, the Nemerow pollution index and the Hakanson ecological risk index. The results showed that heavy-metal pollution of farmland soil in Du'an County was serious. 74.6% of the soil samples had heavy metals concentrations higher than the Grade II of National Soil Environmental Quality Standard (GB 15618-1995). The over standard rates of Cd, As, Ni, Zn, Cr, Sb, Cu, Pb were 70.6%, 42.9%, 34.9%, 19.8%, 19.6%, 2.94%, 1.59%, 0.79%, respectively. Cd and As were the main contaminants in Du'an County, the pollution was far more serious than those of the national and Guangxi Zhuang Autonomous Region. In terms of the ecological risk, heavy metals of farmland soil in Du'an County showed a "middle" ecological risk, with Cd accounting for 88% of the total ecological risk. The north-west of Jiudu Town and the zone between Bao'an Town and Dongmiao Town were two areas with high ecological risk in Du'an County. The contamination of farmland soils in Du'an County was caused by two main sources, whereas the pollution of As and Sb of farmland soils near Diaojiang River was mainly caused by the upstream mining industry.


Assuntos
Monitoramento Ambiental , Metais Pesados/análise , Poluentes do Solo/análise , Agricultura , Antimônio , Arsênio , Cádmio , China , Cromo , Cobre , Chumbo , Níquel , Medição de Risco , Solo , Zinco
9.
Environ Sci Pollut Res Int ; 21(1): 325-36, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23764987

RESUMO

The frequent co-existence of arsenic (As) and lead (Pb) necessitates the investigation of clean-up technologies for multi-metal(loid)s. Field survey and hydroponic experiments were conducted to elucidate the co-accumulation of As and Pb in Pteris vittata L. The P. vittata population isolated from a Pb-Zn mine in Yunnan province, China is a potential extractor of As and Pb co-contamination. Hydroponic experiment found that the highest frond As and Pb concentrations in mining population of P. vittata reached 12.2 and 0.99 g kg(-1), respectively. The interaction between As and Pb in P. vittata was further more disclosed. Pb (2 mg L(-1)) improved the frond As concentration by 60 to 150% in mining populations of P. vittata. Micro-X-ray absorption spectroscopy indicated that under the combined exposure of As and Pb, the As content in the rhizoid epidermis increased by about 10-fold, and the As(V) percentage increased in each rhizoid tissue, as compared with that under As exposure alone. The co-absorption of As and Pb on the epidermis and the enhanced transportation of As(V) from epidermis into the rhizoid were suggested to contribute to the increased As accumulation.


Assuntos
Arsênio/análise , Chumbo/análise , Pteris/fisiologia , Poluentes do Solo/análise , Arsênio/química , Arsênio/metabolismo , Biodegradação Ambiental , China , Chumbo/química , Chumbo/metabolismo , Mineração , Poluentes do Solo/química , Poluentes do Solo/metabolismo , Espectroscopia por Absorção de Raios X
10.
Huan Jing Ke Xue ; 34(9): 3675-8, 2013 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-24289022

RESUMO

In order to disclose soil pollution caused by lead (Pb) smeltery and its human health risks, this study investigated Pb concentrations in farmland soil, hair and blood of residents surrounding a Pb smeltery in Henan Province, and discussed the rationality of estimation of the health protection zone from the Pb smeltery. It was found that the Pb concentrations in blood of children living in both M and Y villages exceeded the international Pb poisoning diagnostic criteria. The highest Pb concentration in blood was 491 microg x L(-1), with the percentages of mild, medium and severe Pb poisoning reaching 52.5%, 42.5% and 5.0%, respectively. Pb concentrations in hair of children living in Y village were in excess of the related standard, with the highest being 156 mg x kg(-1), and the average value 2.9 times of that in hair of adults. In terms of Pb in soil, Pb concentrations in 66.7% of the topsoils (0-20 cm) around the smeltery exceeded Grade II (350 mg x kg(-1), pH > 7.5) of the National Soil Environmental Quality Standard (GB 15618-1995), with the highest reaching up to 1687 mg x kg(-1). The severe soil pollution may have played a role in children's health issues in the villages surrounding the smeltery. Therefore, more attention should be paid to the scientific estimation of health protection zone from Pb smeltery and the remediation of heavy-metal contaminated soil in the surrounding areas.


Assuntos
Chumbo/análise , Poluentes do Solo/análise , Solo/química , Adulto , Criança , China , Monitoramento Ambiental , Indústrias Extrativas e de Processamento , Cabelo/química , Humanos , Chumbo/sangue , Intoxicação por Chumbo/diagnóstico
11.
Chemosphere ; 82(3): 468-76, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20970158

RESUMO

Mapping the spatial distribution of contaminants in soils is the basis of pollution evaluation and risk control. Interpolation methods are extensively applied in the mapping processes to estimate the heavy metal concentrations at unsampled sites. The performances of interpolation methods (inverse distance weighting, local polynomial, ordinary kriging and radial basis functions) were assessed and compared using the root mean square error for cross validation. The results indicated that all interpolation methods provided a high prediction accuracy of the mean concentration of soil heavy metals. However, the classic method based on percentages of polluted samples, gave a pollution area 23.54-41.92% larger than that estimated by interpolation methods. The difference in contaminated area estimation among the four methods reached 6.14%. According to the interpolation results, the spatial uncertainty of polluted areas was mainly located in three types of region: (a) the local maxima concentration region surrounded by low concentration (clean) sites, (b) the local minima concentration region surrounded with highly polluted samples; and (c) the boundaries of the contaminated areas.


Assuntos
Monitoramento Ambiental/métodos , Metais Pesados/análise , Poluentes do Solo/análise , Poluição Ambiental/estatística & dados numéricos , Estatística como Assunto , Incerteza
12.
Zhongguo Zhen Jiu ; 31(5): 409-12, 2011 May.
Artigo em Chinês | MEDLINE | ID: mdl-21692284

RESUMO

OBJECTIVE: To observe the therapeutic effect and safety of perineal, crissal and progenital pruritus treated with acupuncture according to differentiation. METHODS: Self-control method was applied in these 32 cases. Changqiang (GV 1), Huiyin (CV 1), Qugu (CV 2), Sanyinjiao (SP 6) and Ashi points etc. were punctured as main points, and adjunct points were added according to differentiation: Taichong (LR 3) and Ququan (LR 8) etc. were added for wind and heat excess of liver meridian, Xuehai (SP 10) and Quchi (LI 11) etc. were added for blood deficiency and wind dryness. Itchiness, skin lesions sign scores and therapeutic effects were observed before and after treatment. RESULTS: The total scores of itchiness before and after treatment were 6.06 +/- 1.46 and 2.19 +/- 1.71 respectively, and the total scores of skin lesions sign were 4.38 +/- 2.21 and 1.50 +/- 1.44, indicating that the scores and the total scores of itchiness and skin lesions sign reduced obviously after treatment (P < 0.05, P < 0.01); the cured and markedly effective rate was 73.4% (11/15) for wind and heat excess of liver meridian, and 70.6% (12/17) for blood deficiency and wind dryness, presenting similar therapeutic effect (P > 0.05). Hematoma or ecchymosis appeared in 2 cases, and disappeared spontaneously after 2-3 days, without obvious adverse reaction. CONCLUSION: Simple perineal, crissal and progenital pruritus treated with acupuncture according to differentiation is effective, safe and applicable.


Assuntos
Terapia por Acupuntura , Prurido Anal/terapia , Prurido Vulvar/terapia , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Adulto Jovem
13.
Huan Jing Ke Xue ; 32(10): 3094-8, 2011 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-22279929

RESUMO

This study has taken advantage of the characteristics of concentration of soil organic matter (SOC) and delta13 C(SOC) values to provide proofs for environment quality assessment and to know more about polluted sources, sizes and processes in Beijing steel company area. delta13C values of SOC is good for tracing sources and documenting shifts in community composition and distribution. Two sections (Beijing steel company area and Yongledian, Tongzhou) which belong to two different soil types collected in Beijing, and organic carbon isotopic composition and total soil organic carbon were analyzed. These results shows that SOC of soil samples from Beijing steel company area are quite high, and even 9.7% at the surface sample, however SOC from unpolluted area (Yongledian area) is lower than those of industrial area. delta13 C(SOC) from soils of Beijing steel company area and Yongledian area respectively vary from -24.8 per thousand to -23.1 per thousand and -26.4 per thousand to -20.5 per thousand, the results are quite different. The results reflect that there are different organic carbon sources in different types' soil: Organic carbon from Beijing steel company area has been mainly affected by coal burning, soil organic carbon concentrations are quite high, and pollution can affect on soils 70 cm deep underground; and soils from Yongledian area, have been not polluted, and organic matter is from natural litter (C3 plants). Although there are different soil organic carbon concentrations and isotope compositions, two soil sections have similar variation trends. This study provides proofs for environment quality assessment and know more about polluted and natural sources, sizes in Beijing.


Assuntos
Isótopos de Carbono/análise , Carbono/análise , Compostos Orgânicos/análise , Poluentes do Solo/análise , China , Cidades , Monitoramento Ambiental , Indústrias
14.
Huan Jing Ke Xue ; 29(2): 506-11, 2008 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-18613528

RESUMO

Hydroponic culture was conducted to study the effect of Cd on the growth, metal accumulation and nitrogen metabolism in Brassica chinensis. The enzymatic activities of nitrogen metabolism including nitrate reductase (NR), glutamine synthetase (GS) and GS-transferase as well as the concentrations of chlorophyll, free proline, soluble protein, NO3(-) -N, NH4+ -N and nutrients in Brassica chinensis were determined. Results indicated that the addition of Cd reduced the content of the soluble protein and the accumulation of Cu, Ca, Fe and Mg, but promoted the P uptake. Low level of Cd (1 mg x L(-1)) could significantly increase the biomass and the content of chlorophyll of Brassica chinensis and the activities of NR, GS and GS-transferase when compared to control plants. However, when the Cd levels were above 2.5 mg x L(-1) in the culture medium, the activities of these enzymes were inhibited. Accordingly, the contents of NO3(-) -N, NH4+ -N, free proline and the activity of protease in the leaf of Brassica chinensis increased significantly. These results suggested that Cd addition could interfere with the assimilation of N in Brassica chinensis. The increase of free proline might alleviate the toxicity of ammonium in Brassica chinensis.


Assuntos
Brassica/efeitos dos fármacos , Cádmio/farmacologia , Nitrogênio/metabolismo , Prolina/metabolismo , Brassica/crescimento & desenvolvimento , Brassica/metabolismo , Clorofila/metabolismo , Relação Dose-Resposta a Droga , Glutamato-Amônia Ligase/metabolismo , Nitrato Redutase/metabolismo
15.
Ying Yong Sheng Tai Xue Bao ; 19(6): 1349-54, 2008 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-18808031

RESUMO

The kinetic characteristics of Zn uptake by Potentilla griffithii Hook. f. var. velutina Card. were studied with hydroponic culture under different Zn supply and its exposure time. When the Zn supply was 10 mg x L(-1), the Zn concentration in shoot and root reached the peak on the 8th day, being 2.49 x 10(3) mg x kg(-1) and 2.21 x 10(3) mg x kg(-1), respectively; while when the supply was 100 mg x L(-1), the Zn concentration in shoot reached the maximum (1.23 x 10(3) mg x kg(-1)) on the 16th day, but that in root did not exhibit saturation. The Zn concentration in leaf and leafstalk increased with increasing Zn supply from 0 to 160 mg x L(-1), but had no increase or even decreased when the Zn supply was higher than 160 mg x L(-1). The Zn concentration in root exhibited a positive correlation with Zn supply and its exposure time, and the kinetic curve of Zn uptake fitted linear-quadratic (LQ) model, i. e., fast linear uptake first and slow saturation uptake later, with the dividing point at about 1-2 hours' exposure, which could be related with the Zn adsorption on root cell wall and the Zn transportation across the cell membrane.


Assuntos
Potentilla/metabolismo , Zinco/metabolismo , Transporte Biológico , Cinética , Raízes de Plantas/metabolismo
16.
Huan Jing Ke Xue ; 29(7): 2028-36, 2008 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-18828396

RESUMO

Using the differential centrifugation technique and sequential chemical extraction method, effects of Cd, Pb and different Zn salts on subcellular distribution and chemical form of Zn in Zn hyperaccumulator Potentilla griffithii var. velutina under nutrient solution culture were analyzed. Under all treatments except for the control, 46%-74% and 16%-33% of total Zn in the plants are distributed in cell wall and in soluble fraction, respectively. Further, 74%-95% of total Zn are localized in these two parts under all treatments, which suggest that cell wall and soluble fraction in the plant are major storage sites for Zn. Compared with the control, Zn percentage significantly increases by 9%-38% in the cell wall and decreases by 6%-40% in the soluble fraction with addition of Zn, Cd and Pb treatment (p < 0.05). Although the addition of Cd and Pb has no influence on the pattern of Zn subcellular distribution presenting cell wall > soluble fraction > karyon and chloroplast > mitochondrion, it generally reduces Zn percentage in the chloroplast, karyon and mitochondrion and increases that in the cell wall or soluble fraction, suggesting that Cd and Pb promote the transferring processes of Zn from organelle to either cell wall or vacuole. As to the chemical forms, 61%-87% of total Zn exist as ethanol- and water-extractable forms in plants under control and only leaves under Zn addition treatment; while 62%-73% of total Zn exist as NaCl- and ethanol-extractable forms in leafstalks and roots under Zn addition treatment. NaCl-, ethanol- and water-extractable forms are also the main chemical forms in the plants, occupied almost 70%-89% of total Zn under Zn/Cd and Zn/Pb compound treatments. The addition of Zn, Cd and Pb generally increases the percentage of NaCl-extractable Zn forms, but decreases that of ethanol-extractable Zn, which facilitates Zn chemical form transferring from relatively higher active forms to less active ones. These results mentioned above indicate that cell wall binding, vacuolar compartmentalization and reduction of total percentage in higher active chemical forms are main tolerance mechanisms for Zn in Potentilla griffithii var. velutina in response to Zn, Zn/Cd and Zn/Pb treatments. Additionally, different Zinc salts have no obvious influence on Zn subcellular distribution in the plant, whereas the treatment of Zinc nitrate turns Zn ethanol-extraction to a dominant chemical form.


Assuntos
Cádmio/toxicidade , Poluentes Ambientais/toxicidade , Chumbo/toxicidade , Potentilla/metabolismo , Zinco/metabolismo , Transporte Biológico/efeitos dos fármacos , Parede Celular/metabolismo , Cloroplastos/metabolismo , Mitocôndrias/metabolismo , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo , Zinco/química
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