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1.
BMC Plant Biol ; 20(1): 76, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32059642

RESUMO

BACKGROUND: Rice ratooning has traditionally been an important component of the rice cropping system in China. However, compared with the rice of the first harvest, few studies on factors effecting ratoon rice yield have been conducted. Because ratoon rice is a one-season rice cultivated using axillary buds that germinate on rice stakes and generate panicles after the first crop's harvest, its production is mainly affected by the growth of axillary buds. The objectives of this study were to evaluate the sprouting mechanism of axillary buds to improve the ratoon rice yield. RESULTS: First, we observed the differentiation and growth dynamics of axillary buds at different nodes of Shanyou 63, and found that they differentiated from bottom to top before the heading of the mother stem, and that they developed very slowly. After heading they differentiated from top to bottom, and the ones on the top, especially the top 2nd node, developed much faster than those at the other nodes. The average length and dry weight of the axillary buds were significantly greater than those at other nodes by the yellow ripe stage, and they differentiated into pistils and stamens by 6 d after the yellow ripe stage. The morphology of vegetative organs from regenerated tillers of Shanyou 63 also suggested the superior growth of the upper buds, which was regulated by hormones, in ratoon rice. Furthermore, a comprehensive proteome map of the rice axillary buds at the top 2nd node before and after the yellow ripe stage was established, and some proteins involved in steroid biosynthesis were significantly increased. Of these, four took part in brassinosteroid (BR) biosynthesis. Thus, BR signaling may play a role in the germination of axillary buds of ratoon rice. CONCLUSIONS: The data provide insights into the molecular mechanisms underlying BR signaling, and may allow researchers to explore further the biological functions of endogenous BRs in the germination of axillary buds of ratoon rice.

2.
Phys Chem Chem Phys ; 21(3): 1315-1323, 2019 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-30574640

RESUMO

Composition regulation of semiconductors can engineer the band structures and hence optimize their properties for better applications. Herein, we report a BixSb2-xTe3 (BST) single QL with high ZT values (∼1.2 to ∼1.5) at 300 K across a wide range of compositions 0 < x≤ 1. The improved description of band structures by the unfold method reveals the multi-valley bands near the Fermi energy. The high power factor of a p-type BST single QL originates from the robust multi-valley character of valence bands. The wide composition range is ensured by the valence band maximum dominated by the antibonding states of Sb-Te2 bonds, which would be affected little by the disorder. The optimal composition for the BST single QL is attributed to the different contributions from Sb and Bi to the valence band edge. This work paves the way for the further combination of a large power factor and low thermal conductivity across a wide range of compositions.

3.
Medicine (Baltimore) ; 97(41): e12775, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30313094

RESUMO

The aim of this study is to evaluate the safety and effectiveness in the treatment of thoracic aggressive vertebral hemangiomas (AVHs) with neurologic deficit by multiple surgical treatments.The clinical and radiographic data of 5 patients suffering from thoracic AVHs with neurologic deficit and treated by multiple surgical treatments, including percutaneous curved vertebroplasty (PCVP) combined with pedicle screw fixation and decompressive laminectomy, were reviewed and analyzed retrospectively.Five patients (3 women and 2 man, with a mean age of 57.40 ±â€Š11.93) were diagnosed with AVHs from July 2010 to April 2016. All of them had objective neurologic deficit, myelopathy, and back pain. They underwent multiple surgical treatments and were followed-up for 12 to 23 months. At final follow-up, Frankel Grade D was achieved in all 5 patients. Patients were free from pain and neurologic symptoms, and the functional status was improved. No major complication was found.The treatment of AVHs with neurologic deficit is a challenge for surgeons. PCVP combined with pedicle screw fixation and decompressive laminectomy is safe and effective, and can be used for AVHs with neurologic deficit. Further studies with more samples are required to validate the effectiveness and safety of PCVP combined with pedicle screw fixation and decompressive laminectomy.


Assuntos
Dor nas Costas/cirurgia , Hemangioma/cirurgia , Doenças do Sistema Nervoso Periférico/cirurgia , Doenças da Medula Espinal/cirurgia , Neoplasias da Coluna Vertebral/cirurgia , Adulto , Idoso , Dor nas Costas/etiologia , Descompressão Cirúrgica/métodos , Feminino , Hemangioma/complicações , Hemangioma/diagnóstico por imagem , Humanos , Laminectomia/métodos , Masculino , Pessoa de Meia-Idade , Parafusos Pediculares , Doenças do Sistema Nervoso Periférico/diagnóstico por imagem , Doenças do Sistema Nervoso Periférico/etiologia , Estudos Retrospectivos , Doenças da Medula Espinal/etiologia , Neoplasias da Coluna Vertebral/complicações , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Vértebras Torácicas/diagnóstico por imagem , Vértebras Torácicas/cirurgia , Resultado do Tratamento , Vertebroplastia/métodos
4.
Nature ; 556(7699): E5-E7, 2018 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-29620726
5.
ACS Appl Mater Interfaces ; 8(39): 26126-26134, 2016 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-27612285

RESUMO

Sb2Te3 exhibits outstanding performance among the candidate materials for phase-change memory; nevertheless, its low electrical resistivity and thermal stability hinder its practical application. Hence, numerous studies have been carried out to search suitable dopants to improve the performance; however, the explored dopants always cause phase separation and thus drastically reduce the reliability of phase-change memory. In this work, on the basis of ab initio calculations, we have identified yttrium (Y) as an optimal dopant for Sb2Te3, which overcomes the phase separation problem and significantly increases the resistivity of crystalline state by at least double that of Sb2Te3. The good phase stability of crystalline Y-doped Sb2Te3 (YST) is attributed to the same crystal structure between Y2Te3 and Sb2Te3 as well as their tiny lattice mismatch of only ∼1.1%. The significant increase in resistivity of c-YST is understood by our findings that Y can dramatically increase the carrier's effective mass by regulating the band structure and can also reduce the intrinsic carrier density by suppressing the formation of SbTe antisite defects. Y doping can also improve the thermal stability of amorphous YST based on our ab initio molecular dynamics simulations, which is attributed to the stronger interactions between Y and Te than that of Sb and Te.

6.
Sci Rep ; 6: 29941, 2016 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-27511822

RESUMO

The γ/γ' interface dislocation network is reported to improve the high temperature creep resistance of single crystal superalloys and is usually found to deposit in {001} interface. In this work, a new type of dislocation network was found in {111} γ/γ' interface at a single crystal model superalloy crept at 1100 °C/100 MPa. The dislocations in the network are screw with Burgers vectors of 1/2 a<110> and most interestingly, they exhibit a pair-coupling structure. Further investigation indicates that the formation of {111} interface dislocation network occurs when the γ' raft structure begins to degrade by the dislocations cutting into the rafted γ' through the interface. In this condition, the pair-coupling structure is established by the dislocations gliding in a single {111} plane of γ', in order to remove the anti-phase boundary in γ'; these dislocations also act as diffusion channels for dissolving of the γ' particle that is unstable under the interfacial stress from lattice misfit, which leads to the formation of {111}-type zigzag interface. The formation of this network arises as a consequence of more negative misfit, low-alloying γ' particle and proper test conditions of temperature and stress.

7.
Differentiation ; 92(5): 318-325, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-26965419

RESUMO

p205, an interferon-inducible protein, is induced in the course of osteogenesis in mouse bone marrow stromal cells (BMSCs). Knocking down p205 markedly impairs whereas overexpressing p205 enhances the osteoblast differentiation of BMSCs, as revealed by the altered expression of osteogenic genes, the change of ALP activity and the ARS-stained mineral nodules. The positive role of p205 in BMSC osteogenesis is probably due, at least in part, to the association of it with Id proteins. Further investigation indicated that p205 may disturb the formation of Runx2/Ids complex and free more Runx2 to induce the differentiation process. Taken together, our findings demonstrated for the first time that p205 functions as an activator in osteoblast differentiation.


Assuntos
Diferenciação Celular/genética , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Células-Tronco Mesenquimais/citologia , Neuropeptídeos/genética , Osteogênese/genética , Animais , Interferons/administração & dosagem , Células-Tronco Mesenquimais/efeitos dos fármacos , Camundongos , Osteoblastos/citologia , Osteoblastos/efeitos dos fármacos , Receptores de Quinase C Ativada
8.
Science ; 351(6269): 141-4, 2016 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-26612831

RESUMO

Thermoelectric technology, harvesting electric power directly from heat, is a promising environmentally friendly means of energy savings and power generation. The thermoelectric efficiency is determined by the device dimensionless figure of merit ZT(dev), and optimizing this efficiency requires maximizing ZT values over a broad temperature range. Here, we report a record high ZT(dev) ∼1.34, with ZT ranging from 0.7 to 2.0 at 300 to 773 kelvin, realized in hole-doped tin selenide (SnSe) crystals. The exceptional performance arises from the ultrahigh power factor, which comes from a high electrical conductivity and a strongly enhanced Seebeck coefficient enabled by the contribution of multiple electronic valence bands present in SnSe. SnSe is a robust thermoelectric candidate for energy conversion applications in the low and moderate temperature range.

9.
Mitochondrial DNA A DNA Mapp Seq Anal ; 27(5): 3192-3, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-25707414

RESUMO

Kashgarian loach, Triplophysayarkandensis (Day, 1877), a native species in the Tarim River of Northwest China, has been dramatically declined in population size in recent years. In this article, the mitochondrial genome of Kashgarian loach was first determined. The whole mtDNA sequence was 16,574 bp in length, which is similar to other bony fishes in gene order, including 2rRNA genes, 22tRNA, 13 protein-coding and 1 putative control region.


Assuntos
Cipriniformes/genética , Genoma Mitocondrial , Animais , Espécies em Perigo de Extinção , Proteínas de Peixes/genética , Ordem dos Genes , RNA Ribossômico/genética , RNA de Transferência/genética
10.
Sci Rep ; 5: 14688, 2015 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-26434766

RESUMO

Titanium and its alloys have become the most attractive implant materials due to their high corrosion resistance, excellent biocompatibility and relatively low elastic modulus. However, the current Ti materials used for implant applications exhibit much higher Young's modulus (50 ~ 120 GPa) than human bone (~30 GPa). This large mismatch in the elastic modulus between implant and human bone can lead to so-called "stress shielding effect" and eventual implant failure. Therefore, the development of ß-type Ti alloys with modulus comparable to that of human bone has become an ever more pressing subject in the area of advanced biomedical materials. In this study, an attempt was made to produce a bone-compatible metastable ß-type Ti alloy. By alloying and thermo-mechanical treatment, a metastable ß-type Ti-33Nb-4Sn (wt. %) alloy with ultralow Young's modulus (36 GPa, versus ~30 GPa for human bone) and high ultimate strength (853 MPa) was fabricated. We believe that this method can be applied to developing advanced metastable ß-type titanium alloys for implant applications. Also, this approach can shed light on design and development of novel ß-type titanium alloys with large elastic limit due to their high strength and low elastic modulus.

11.
Plant Mol Biol ; 89(4-5): 475-92, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26438231

RESUMO

Damaged proteins containing abnormal isoaspartyl (isoAsp) accumulate as seeds age and the abnormality is thought to undermine seed vigor. Protein-L-isoaspartyl methyltransferase (PIMT) is involved in isoAsp-containing protein repair. Two PIMT genes from rice (Oryza sativa L.), designated as OsPIMT1 and OsPIMT2, were isolated and investigated for their roles. The results indicated that OsPIMT2 was mainly present in green tissues, but OsPIMT1 largely accumulated in embryos. Confocal visualization of the transient expression of OsPIMTs showed that OsPIMT2 was localized in the chloroplast and nucleus, whereas OsPIMT1 was predominately found in the cytosol. Artificial aging results highlighted the sensitivity of the seeds of OsPIMT1 mutant line when subjected to accelerated aging. Overexpression of OsPIMT1 in transgenic seeds reduced the accumulation of isoAsp-containing protein in embryos, and increased embryo viability. The germination percentage of transgenic seeds overexpressing OsPIMT1 increased 9-15% compared to the WT seeds after 21-day of artificial aging, whereas seeds from the OsPIMT1 RNAi lines overaccumulated isoAsp in embryos and experienced rapid loss of seed germinability. Taken together, these data strongly indicated that OsPIMT1-related seed longevity improvement is probably due to the repair of detrimental isoAsp-containing proteins that over accumulate in embryos when subjected to accelerated aging.


Assuntos
Oryza/enzimologia , Proteínas de Plantas/metabolismo , Proteína D-Aspartato-L-Isoaspartato Metiltransferase/metabolismo , Ácido Abscísico/biossíntese , Sequência de Aminoácidos , Genes de Plantas , Dados de Sequência Molecular , Oryza/embriologia , Oryza/genética , Filogenia , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Proteína D-Aspartato-L-Isoaspartato Metiltransferase/genética , Interferência de RNA , Elementos Reguladores de Transcrição , Sementes/enzimologia , Sementes/genética , Homologia de Sequência de Aminoácidos , Estresse Fisiológico , Frações Subcelulares/metabolismo
12.
Sci Rep ; 5: 8357, 2015 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-25665501

RESUMO

The design principles for naturally occurring biological materials have inspired us to develop next-generation engineering materials with remarkable performance. Nacre, commonly referred to as nature's armor, is renowned for its unusual combination of strength and toughness. Nature's wisdom in nacre resides in its elaborate structural design and the judicious placement of a unique organic biopolymer with intelligent deformation features. However, up to now, it is still a challenge to transcribe the biopolymer's deformation attributes into a stronger substitute in the design of new materials. In this study, we propose a new design strategy that employs shape memory alloy to transcribe the "J-curve" mechanical response and uniform molecular/atomic level deformation of the organic biopolymer in the design of high-performance hybrid materials. This design strategy is verified in a TiNi-Ti3Sn model material system. The model material demonstrates an exceptional combination of mechanical properties that are superior to other high-performance metal-based lamellar composites known to date. Our design strategy creates new opportunities for the development of high-performance bio-inspired materials.


Assuntos
Biopolímeros/química , Níquel/química , Estanho/química , Titânio/química
13.
Plant Biotechnol J ; 13(4): 526-39, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25545811

RESUMO

Lipid peroxidation plays a major role in seed longevity and viability. In rice grains, lipid peroxidation is catalyzed by the enzyme lipoxygenase 3 (LOX3). Previous reports showed that grain from the rice variety DawDam in which the LOX3 gene was deleted had less stale flavour after grain storage than normal rice. The molecular mechanism by which LOX3 expression is regulated during endosperm development remains unclear. In this study, we expressed a LOX3 antisense construct in transgenic rice (Oryza sativa L.) plants to down-regulate LOX3 expression in rice endosperm. The transgenic plants exhibited a marked decrease in LOX mRNA levels, normal phenotypes and a normal life cycle. We showed that LOX3 activity and its ability to produce 9-hydroperoxyoctadecadienoic acid (9-HPOD) from linoleic acid were significantly lower in transgenic seeds than in wild-type seeds by measuring the ultraviolet absorption of 9-HPOD at 234 nm and by high-performance liquid chromatography. The suppression of LOX3 expression in rice endosperm increased grain storability. The germination rate of TS-91 (antisense LOX3 transgenic line) was much higher than the WT (29% higher after artificial ageing for 21 days, and 40% higher after natural ageing for 12 months). To our knowledge, this is the first report to demonstrate that decreased LOX3 expression can preserve rice grain quality during storage with no impact on grain yield, suggesting potential applications in agricultural production.


Assuntos
Elementos Antissenso (Genética) , Endosperma/enzimologia , Genes de Plantas , Lipoxigenase/genética , Oryza/enzimologia , Regulação para Baixo , Temperatura Alta , Oryza/genética , Proteínas de Plantas/metabolismo , Transgenes
14.
Nat Commun ; 3: 873, 2012 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-22643900

RESUMO

The magnetostructural coupling between the structural and the magnetic transition has a crucial role in magnetoresponsive effects in a martensitic-transition system. A combination of various magnetoresponsive effects based on this coupling may facilitate the multifunctional applications of a host material. Here we demonstrate the feasibility of obtaining a stable magnetostructural coupling over a broad temperature window from 350 to 70 K, in combination with tunable magnetoresponsive effects, in MnNiGe:Fe alloys. The alloy exhibits a magnetic-field-induced martensitic transition from paramagnetic austenite to ferromagnetic martensite. The results indicate that stable magnetostructural coupling is accessible in hexagonal phase-transition systems to attain the magnetoresponsive effects with broad tunability.

15.
J Phys Condens Matter ; 23(22): 225504, 2011 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-21576767

RESUMO

We have investigated site occupancy and interfacial energetics of a TiAl-Ti(3)Al binary-phase system with O using a first-principles method. Oxygen is shown to energetically occupy the Ti-rich octahedral interstitial site, because O prefers to bond with Ti rather than Al. The occupancy tendency of O in TiAl alloy from high to low is α(2)-Ti(3)Al to the γ-α(2) interface and γ-TiAl. We demonstrate that O can largely affect the mechanical properties of the TiAl-Ti(3)Al system. Oxygen at the TiAl-Ti(3)Al interface reduces both the cleavage energy and the interface energy, and thus weakens the interface strength but strongly stabilizes the TiAl/Ti(3)Al interface with the O(2) molecule as a reference. Consequently, the mechanical property variation of TiAl alloy due to the presence of O not only depends on the number of TiAl/Ti(3)Al interfaces but also is related to the O concentration in the alloy.

16.
Artigo em Inglês | MEDLINE | ID: mdl-20831352

RESUMO

Viscosity of blood substitutes is among the important determinants to restore microcirculation. Sodium alginate (SA) is always mentioned as "viscosity modifier" in creating blood substitutes. In the present study, the whole blood was diluted using SA solutions to final hematocrits of 10%, 20%, and 35%, respectively. The whole blood viscosity (WBV) at different shear rates, plasma viscosity (PV), and rheological behavior of red blood cells (RBCs) was studied in vitro. The results show that SA may induce RBCs aggregation in a dose-dependent manner. Furthermore, the effect of SA on RBCs aggregation maybe involve the regulation of microcirculation.


Assuntos
Alginatos/farmacologia , Viscosidade Sanguínea/efeitos dos fármacos , Agregação Eritrocítica/efeitos dos fármacos , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Adulto , Deformação Eritrocítica/efeitos dos fármacos , Ácido Glucurônico/farmacologia , Hematócrito , Ácidos Hexurônicos/farmacologia , Humanos , Suspensões
17.
Nan Fang Yi Ke Da Xue Xue Bao ; 30(6): 1298-300, 2010 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-20584661

RESUMO

OBJECTIVE: To investigate the constituent expression of PH domain leucine-rich repeat protein phosphatase 1 (PHLPP1) in human umbilical vein endothelial cells (HUVECs) and the effect of PHLPP1 gene transfer on the proliferation of the cells in vitro. METHODS: Cultured HUVECs were transfected with pcDNA3-GFP or pcDNA3HA-PHLPP1 via lipofectamine 2000. The cell proliferation ability was determined by cell counting and MTT colorimetric assay, and Western blotting was used to detect the protein expression of PHLPP1 in the cells. RESULTS: No PHLPP1 protein was detected in the non-transfected cells or pcDNA3-GFP-transfected cells. pcDNA3HA-PHLPP1 gene transfection significantly increased PHLPP1 expression in the HUVECs (P<0.01), but the cell proliferation status remained unchanged (P>0.05). The absorbance of the cells measured by MTT assay was 0.134-/+0.0152, 0133-/+0.014 and 0.137-/+0.016, with cell counts of (8.293-/+0.962)x10(5), (7.937-/+0.101)x10(5) and (8.127-/+0.112)x10(5), respectively, showing no significant differences between the 3 groups (P>0.05). CONCLUSIONS: Phosphatase PHLPP1 may not be the most important signal protein in the regulation of HUVEC proliferation.


Assuntos
Proliferação de Células , Células Endoteliais da Veia Umbilical Humana/citologia , Proteínas Nucleares/genética , Fosfoproteínas Fosfatases/genética , Transfecção , Técnicas de Transferência de Genes , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos
18.
Biochemistry ; 48(51): 12159-68, 2009 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-19916559

RESUMO

While the transcription-dependent mechanism of p53 has been extensively studied, recently the transcription-independent apoptotic activity of p53 has also been described. Bcl-2 and Bcl-X(L) interact with p53 and induce apoptosis. Initially, the p53 DNA-binding domain (p53DBD) was found to bind to Bcl-2 and Bcl-X(L). Later, the p53 N-terminal domain (p53NTD) was reported to be sufficient for inducing the transcription-independent apoptotic activity of p53 and also shown to interact with Bcl-X(L). Here, we further document that the transactivation domain of p53 (p53TAD) in p53NTD alone binds to Bcl-X(L). We demonstrated that the MDM2-binding region (residues S15 to N29, herein referred to as SN15) in p53TAD is the binding site for Bcl-X(L). The binding interface on Bcl-X(L) was identified at the hydrophobic pocket formed by the BH1, BH2, and BH3 domains, which also binds to the Bak/Bad BH3 peptides, suggesting Bcl-X(L) and MDM2 share a common binding motif in p53TAD. Our NMR structural studies have shown that the SN15 peptide undergoes a conformational change upon binding to Bcl-X(L). A Bcl-X(L)/SN15 complex structural model suggests that the SN15 peptide adopts an extended alpha-helical structure to bind to the hydrophobic pocket on the Bcl-X(L), which is similar to the mode of binding between BH3 peptides and Bcl-X(L).


Assuntos
Proteína Supressora de Tumor p53/química , Proteína bcl-X/química , Motivos de Aminoácidos , Sítios de Ligação , Humanos , Conformação Molecular , Dados de Sequência Molecular , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-mdm2/química , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Proteína bcl-X/genética , Proteína bcl-X/metabolismo
19.
J Phys Condens Matter ; 21(4): 045506, 2009 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-21715812

RESUMO

The electronic structures and formation energies of the Ni(9)Mn(4)Ga(3-x)Al(x) and Ni(9)Mn(4)Ga(3-x)In(x) alloys have been investigated using the first-principles pseudopotential plane-wave method based on density functional theory. The results show that both the austenite and martensite phases of Ni(9)Mn(4)Ga(3) alloy are stabilized by Al alloying, while they become unstable with In alloying. According to the partial density of states and structural energy analysis, different effects of Al and In alloying on the phase stability are mainly attributed to their chemical effects. The formation energy difference between the austenite and martensite phases decreases with Al or In alloying, correlating with the experimentally reported changes in martensitic transformation temperature. The shape factor plays an important role in the decrease of the formation energy difference.

20.
Am J Emerg Med ; 26(1): 54-8, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18082781

RESUMO

OBJECTIVES: The aim of the study was to investigate the changes of the activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) in plasma and organ damage during the acute severe hemorrhagic shock (ASHS), as well as to analyze their relationship. METHODS: Twenty male Wistar rats (230-270 g) were randomly divided into sham hemorrhage shock (SHS) group and ASHS group. Acute severe hemorrhagic shock rats were induced by drawing blood through a femoral arterial catheter for 15 minutes with the final mean arterial blood pressure decreased to 35 to 40 mm Hg. The animals were killed after the mean arterial blood pressure was maintained at this level for 1 hour. The activity of SOD and the level of MDA in plasma were measured, and pathologic changes of the major organs (heart, liver, spleen, lung, kidney, and brain) were observed by microscopy. RESULTS: The SOD activities and MDA levels in the ASHS group both increased continuously during the whole experiment. The SOD activities and MDA levels in plasma were not significantly different between the prehemorrhagic stage of ASHS and that of SHS (P > .05). The SOD activities and MDA levels were significantly higher in the ASHS initial stage than in the prehemorrhagic stage (P < .01). Compared with the ASHS initial stage, there was a significant (P < .01) increase in SOD activities and MDA levels in the ASHS end stage. Severe microscopic injuries appeared in the major organs (heart, liver, spleen, lung, kidney, and brain) of ASHS rats. CONCLUSION: The changes of the activity of SOD and the level of MDA in ASHS may have a positive correlation.


Assuntos
Malondialdeído/sangue , Choque Hemorrágico/sangue , Choque Hemorrágico/patologia , Superóxido Dismutase/metabolismo , Animais , Encéfalo/patologia , Rim/patologia , Fígado/patologia , Pulmão/patologia , Masculino , Miocárdio/patologia , Estresse Oxidativo/fisiologia , Ratos , Ratos Wistar , Baço/patologia
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