Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Neuroscience ; 429: 203-212, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31962145

RESUMO

Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) have been implicated in the trafficking of postsynaptic glutamate receptors, including N-methyl-d-aspartate (NMDA)-subtype glutamate receptors (NMDARs) that are critical for nociceptive plasticity and behavioral sensitization. However, the components of SNAREs complex involved in spinal nociceptive processing remain largely unknown. Here we found that SNAP25, syntaxin4, VAMP2 and Munc18-1 were localized at postsynaptic sites and formed the complex in the superficial lamina of spinal cord dorsal horn of rats. The complex formation between these SNAREs components were accelerated after intraplantar injection of complete Freund's adjuvant (CFA), pharmacological removal of GABAergic inhibition or activation of NMDAR in intact rats. The increased SNAP25/syntaxin4/VAMP2/Munc18-1 interaction facilitated the surface delivery and synaptic accumulation of NMDAR during inflammatory pain. Disruption of the molecular interaction between SNAP25 with its SNARE partners by using a blocking peptide derived from the C-terminus of SNAP25 effectively repressed the surface and synaptic accumulation of GluN2B-containing NMDARs in CFA-injected rats. This peptide also alleviated inflammatory mechanical allodynia and thermal hypersensitivity. These data suggested that SNAREs complex assembly in spinal cord dorsal horn was involved in the inflammatory pain hypersensitivity through promoting NMDAR synaptic trafficking.

2.
Medicine (Baltimore) ; 98(51): e18386, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31861001

RESUMO

RATIONALE: Pulmonary embolisms (PEs) are caused by emboli, which mostly originate from deep venous thrombi that travel to and suddenly block the pulmonary arteries. The emboli are usually thrombi, and right atrial myxoma emboli are rare. PATIENT CONCERNS: A 55-year-old man presented with shortness of breath and syncope. We proceeded with computed tomography pulmonary angiography (CTPA) and transthoracic echocardiogram (TTE), the results of which suggested that the diagnosis was a right atrial mass. DIAGNOSIS: A definitive diagnosis compatible with a right atrial myxoma (RAM) with tumoral pulmonary emboli after surgical excision was made. INTERVENTION: Right atrial and pulmonary artery embolectomy. OUTCOMES: The patient followed an uneventful course during the 6 years of follow-up after surgery. According to a review of the literature, RAMs are often not diagnosed in a timely manner or even go completely undiagnosed. TTE, transesophageal echocardiography (TEE), CT, magnetic resonance imaging (MRI), and positron emission tomography/computed tomography may be helpful in the preoperative diagnosis. Surgical removal of the masses from the atrium and pulmonary arteries was relatively uneventful. LESSONS: RAMs should be considered unlikely reasons for fatal pulmonary embolisms.


Assuntos
Átrios do Coração/diagnóstico por imagem , Neoplasias Cardíacas/diagnóstico por imagem , Mixoma/diagnóstico por imagem , Embolia Pulmonar/etiologia , Angiografia por Tomografia Computadorizada , Ecocardiografia , Átrios do Coração/cirurgia , Neoplasias Cardíacas/patologia , Neoplasias Cardíacas/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Mixoma/patologia , Mixoma/cirurgia , Embolia Pulmonar/cirurgia
3.
Plants (Basel) ; 8(12)2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31766615

RESUMO

The allocation of net primary production (NPP) between above- and belowground components is a key step of ecosystem material cycling and energy flows, which determines many critical parameters, e.g., the fraction of below ground NPP (BNPP) to NPP (fBNPP) and root turnover rates (RTR), in vegetation models. However, direct NPP estimation and partition are scarcely based on field measurements of biomass dynamics in the alpine grasslands on the Northern Tibetan Plateau (NTP). Consequently, these parameters are unverifiable and controversial. Here, we measured above- and belowground biomass dynamics (monthly from May to September each year from 2013 to 2015) to estimate NPP dynamics and allocations in four typical alpine grassland ecosystems, i.e., an alpine meadow, alpine meadow steppe, alpine steppe and alpine desert steppe. We found that NPP and its components, above and below ground NPP (ANPP and BNPP), increased significantly from west to east on the NTP, and ANPP was mainly affected by temperature while BNPP and NPP were mainly affected by precipitation. The bulk of BNPP was generally concentrated in the top 10 cm soil layers in all four alpine grasslands (76.1% ± 9.1%, mean ± SD). Our results showed that fBNPP was significantly different among these four alpine grasslands, with its means in alpine meadow (0.93), alpine desert steppe (0.92) being larger than that in the alpine meadow steppe (0.76) and alpine steppe (0.77). Both temperature and precipitation had significant and positive effects on the fBNPP, while their interaction effects were significantly opposite. RTR decreased with increasing precipitation, but increased with increasing temperature across this ecoregion. Our study illustrated that alpine grasslands on the NTP, especially in the alpine meadow and alpine desert steppe, partitioned an unexpected and greater NPP to below ground than most historical reports across global grasslands, indicating a more critical role of the root carbon pool in carbon cycling in alpine grasslands on the NTP.

5.
PLoS Biol ; 17(8): e3000371, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31433808

RESUMO

Inhibitory glycinergic transmission in adult spinal cord is primarily mediated by glycine receptors (GlyRs) containing the α1 subunit. Here, we found that α1ins, a longer α1 variant with 8 amino acids inserted into the intracellular large loop (IL) between transmembrane (TM)3 and TM4 domains, was expressed in the dorsal horn of the spinal cord, distributed at inhibitory synapses, and engaged in negative control over nociceptive signal transduction. Activation of metabotropic glutamate receptor 5 (mGluR5) specifically suppressed α1ins-mediated glycinergic transmission and evoked pain sensitization. Extracellular signal-regulated kinase (ERK) was critical for mGluR5 to inhibit α1ins. By binding to a D-docking site created by the 8-amino-acid insert within the TM3-TM4 loop of α1ins, the active ERK catalyzed α1ins phosphorylation at Ser380, which favored α1ins ubiquitination at Lys379 and led to α1ins endocytosis. Disruption of ERK interaction with α1ins blocked Ser380 phosphorylation, potentiated glycinergic synaptic currents, and alleviated inflammatory and neuropathic pain. These data thus unraveled a novel, to our knowledge, mechanism for the activity-dependent regulation of glycinergic neurotransmission.

6.
Eur J Med Chem ; 182: 111636, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31466017

RESUMO

Developing novel antimicrobial agents is a top priority in fighting against bacterial resistance. Thus, a series of new monomer and dimer peptides were designed and synthesized by conjugating fatty acids at the N-terminus of partial d-amino acid substitution analogues of anoplin and dimerization. The new peptides exhibited more efficient killing of gram-negative and gram-positive bacteria, including methicillin-resistant Staphylococcus aureus compared with the parent peptide anoplin, and the dimer peptides were superior to the monomer peptides. It was important that the new peptides displayed low impact on bacterial resistance development. In addition, the antimicrobial activities were not significantly influenced by a physiological salt environment. They also presented high stability in the presence of protease or serum. Almost all of the new peptides had better selectivity towards anionic bacterial membranes over zwitterionic mammalian cell membranes. Moreover, the new peptides displayed synergistic or additive effects when used together with the antibiotics rifampicin and polymyxin B. These results showed that the new peptides could also prevent the formation of bacterial biofilms. Furthermore, outer/inner membrane permeabilization and cytoplasmic membrane depolarization experiments revealed that the new peptides had strong membrane permeabilization and depolarization. Confocal laser scanning microscopy, flow cytometry analysis and scanning electron microscopy further demonstrated that the new peptides could damage the integrity of the bacterial membrane. Finally, a DNA-binding affinity assay showed that the new peptides could bind to bacterial DNA. In summary, the conjugation of fatty acids at the N-terminus of peptides and dimerization are promising strategies for obtaining potent antimicrobial agents.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Desenho de Drogas , Ácidos Graxos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Animais , Antibacterianos/síntese química , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/síntese química , Peptídeos Catiônicos Antimicrobianos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Ácidos Graxos/síntese química , Ácidos Graxos/química , Camundongos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Células RAW 264.7 , Relação Estrutura-Atividade
7.
Eur J Pharmacol ; 854: 62-69, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-30951721

RESUMO

Src Homology 2 domain-containing protein tyrosine phosphatase 1 (SHP1) interacts specifically with GluN2A subunit of N-methyl-D-aspartate (NMDA) subtype of glutamate receptors in spinal cord dorsal horn. This molecular interaction is involved in the development of GluN2A-dependent spinal sensitization of nociceptive behaviors. Intrathecal application of a GluN2A-derived polypeptide (short for pep-GluN2A) has been shown to disturb spinal GluN2A/SHP1 interaction and inhibit inflammatory pain. Here we found that SHP1 was also located at dorsal root ganglion (DRG) neurons and formed complexes with GluN2A subunit. Peripheral inflammation activated SHP1 in DRG neurons, which promoted GluN2A tyrosine phosphorylation. The SHP1 binding to GluN2A facilitated the glutamate release from primary afferent fibers and exaggerated nociceptive synaptic transmission onto postsynaptic spinal cord neurons. Our data showed that intradermal application of pep-GluN2A disrupted GluN2A/SHP1 interaction in DRG neurons, attenuated the ability of GluN2A subunit-containing NMDA receptors to regulate the presynaptic glutamate release and more importantly, alleviated the pain hypersensitivity caused by carrageenan, complete Freund's adjuvant and formalin. The neuropathic pain induced by spared nerve injury was also ameliorated by intradermal pep-GluN2A application. These data suggested that disruption of GluN2A/SHP1 interaction in DRG neurons generated an effective analgesic action against pathological pain.


Assuntos
Gânglios Espinais/efeitos dos fármacos , Neuralgia/tratamento farmacológico , Peptídeos/farmacologia , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Sequência de Aminoácidos , Animais , Comportamento Animal/efeitos dos fármacos , Gânglios Espinais/patologia , Masculino , Neuralgia/metabolismo , Neuralgia/patologia , Neuralgia/fisiopatologia , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/patologia , Nociceptividade/efeitos dos fármacos , Peptídeos/química , Peptídeos/uso terapêutico , Ligação Proteica/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
8.
Neuropharmacology ; 148: 358-365, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30721695

RESUMO

Glycine receptors (GlyRs) are pentameric proteins that consist of α (α1-α4) subunits and/or ß subunit. In the spinal cord of adult animals, the majority of inhibitory glycinergic neurotransmission is mediated by α1 subunit-containing GlyRs. The reduced glycinergic inhibition (disinhibition) is proposed to increase the excitabilities and spontaneous activities of spinal nociceptive neurons during pathological pain. However, the molecular mechanisms by which peripheral lesions impair GlyRs-α1-mediated synaptic inhibition remain largely unknown. Here we found that activity-dependent ubiquitination of GlyRs-α1 subunit might contribute to glycinergic disinhibition after peripheral inflammation. Our data showed that HUWE1 (HECT, UBA, WWE domain containing 1), an E3 ubiquitin ligase, located at spinal synapses and specifically interacted with GlyRs-α1 subunit. By ubiquitinating GlyRs-α1, HUWE1 reduced the surface expression of GlyRs-α1 through endocytic pathway. In the dorsal horn of Complete Freund's Adjuvant-injected mice, shRNA-mediated knockdown of HUWE1 blunted GlyRs-α1 ubiquitination, potentiated glycinergic synaptic transmission and attenuated inflammatory pain. These data implicated that ubiquitin modification of GlyRs-α1 represented an important way for peripheral inflammation to reduce spinal glycinergic inhibition and that interference with HUWE1 activity generated analgesic action by resuming GlyRs-α1-mediated synaptic transmission.


Assuntos
Inibição Neural/fisiologia , Receptores da Glicina/fisiologia , Corno Dorsal da Medula Espinal/fisiopatologia , Proteínas Supressoras de Tumor/fisiologia , Ubiquitina-Proteína Ligases/fisiologia , Ubiquitinação/efeitos dos fármacos , Animais , Células Cultivadas , Humanos , Masculino , Camundongos , Inibição Neural/efeitos dos fármacos , Dor/prevenção & controle , RNA Interferente Pequeno/farmacologia , Receptores da Glicina/efeitos dos fármacos , Receptores da Glicina/metabolismo , Transmissão Sináptica/efeitos dos fármacos , Proteínas Supressoras de Tumor/antagonistas & inibidores , Proteínas Supressoras de Tumor/farmacologia , Ubiquitina-Proteína Ligases/antagonistas & inibidores , Ubiquitina-Proteína Ligases/farmacologia
9.
Neuroscience ; 388: 1-10, 2018 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-30049666

RESUMO

Neuroligin 1 (NLGN1), a cell adhesion molecule present at excitatory glutamatergic synapses, has been shown to be critical for synaptic specialization and N-methyl-d-aspartate (NMDA)-subtype glutamate receptor-dependent synaptic plasticity. Whether and how NLGN1 is engaged in nociceptive behavioral sensitization remains largely unknown. In this study, we found an activity-dependent regulation of NLGN1 synaptic expression in pain-related spinal cord dorsal horns of mice. The enhancement of neuronal activity by pharmacological activation of NMDA receptor (NMDAR) or removal of GABAergic inhibition in intact mice significantly increased NLGN1 concentration at synaptosomal membrane fraction. Intraplantar injection of complete Freund's adjuvant (CFA) also increased the NLGN1 expression at synapses. NMDAR might act through Ca2+/calmodulin-dependent protein kinase II (CaMKII) and Src-family protein tyrosine kinase member Fyn to induce the synaptic redistribution of NLGN1. We also found that one of the important roles of NLGN1 was to facilitate the clustering of NMDAR at synapses. The NLGN1-targeting siRNA suppressed the synaptic expression of GluN2B-containing NMDAR in CFA-injected mice and meanwhile, attenuated the inflammatory mechanical allodynia and thermal hypersensitivity. These data suggested that tissue injury-induced synaptic redistribution of NLGN1 was involved in the development of pain hypersensitivity through facilitating the synaptic incorporation of NMDARs.


Assuntos
Moléculas de Adesão Celular Neuronais/metabolismo , Hiperalgesia/metabolismo , Inflamação/metabolismo , Corno Dorsal da Medula Espinal/metabolismo , Sinapses/metabolismo , Transmissão Sináptica/fisiologia , Animais , Moléculas de Adesão Celular Neuronais/genética , Modelos Animais de Doenças , Adjuvante de Freund , Regulação da Expressão Gênica/fisiologia , Temperatura Alta , Masculino , Camundongos Endogâmicos C57BL , RNA Interferente Pequeno , Ratos Sprague-Dawley , Receptores de N-Metil-D-Aspartato/metabolismo , Técnicas de Cultura de Tecidos , Tato
10.
Neuroscience ; 371: 155-165, 2018 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-29229558

RESUMO

The δ subunit-containing γ-Aminobutyric acid type A receptors (δ-GABAARs) are located at extrasynaptic sites and persistently active in the control of neuronal excitability. Here we recorded primary afferent C fiber-evoked field potentials in the superficial dorsal horn of rat spinal cords in vivo and investigated the possible influence of δ-GABAARs activities on nociceptive synaptic transmission. We found that δ-GABAARs-preferring agonist 4,5,6,7-tetrahydroisoxazolol [4,5-c] pyridine-3-ol (THIP), when topically applied onto spinal cord dorsum, inhibited the basal synaptic responses in a dose-dependent manner. Low-frequency stimulation (LFS) of sciatic nerves elicited long-term potentiation (LTP) of C fiber transmission, a synaptic correlate of central sensitization. Pretreatment with THIP before LFS delivery blocked the induction of LTP. When applied at 30 min and 180 min post-LFS, THIP reduced the magnitudes of established LTP. Intraplantar injection of formalin naturally evoked LTP in anesthetized rats. Spinal administration of THIP not only reversed formalin-induced LTP, but alleviated the spontaneous painful behaviors and mechanical hyperalgesia. Biochemical analysis demonstrated that δ-GABAARs activation by THIP decreased the synaptic expression and phosphorylation of AMPA receptor GluA1 subunit in formalin-injected rats, and meanwhile, increased synaptic GluA2 content, allowing the switch of GluA2-lacking AMPA receptors to GluA2-containing ones at synapses. THIP also suppressed the synaptic accumulation and phosphorylation of NMDA receptor GluN1 subunit in formalin-injected rats. Our data suggested that enhanced δ-GABAARs activities blunted the initiation and maintenance of spinal LTP, which correlated with the amelioration of central sensitization of nociceptive behaviors.


Assuntos
Potenciação de Longa Duração/fisiologia , Dor/metabolismo , Receptores de GABA-A/metabolismo , Medula Espinal/metabolismo , Animais , Relação Dose-Resposta a Droga , Formaldeído , Agonistas de Receptores de GABA-A/farmacologia , Isoxazóis/farmacologia , Potenciação de Longa Duração/efeitos dos fármacos , Masculino , Fibras Nervosas Amielínicas/efeitos dos fármacos , Fibras Nervosas Amielínicas/metabolismo , Dor/tratamento farmacológico , Ratos Sprague-Dawley , Receptores de AMPA/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Nervo Isquiático/metabolismo , Nervo Isquiático/fisiologia , Medula Espinal/efeitos dos fármacos , Sinapses/efeitos dos fármacos , Sinapses/metabolismo
11.
PLoS One ; 10(12): e0144752, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26660306

RESUMO

Understanding the influences of climatic changes on water use efficiency (WUE) of Tibetan alpine meadows is important for predicting their long-term net primary productivity (NPP) because they are considered very sensitive to climate change. Here, we collected wool materials produced from 1962 to 2010 and investigated the long-term WUE of an alpine meadow in Tibet on basis of the carbon isotope values of vegetation (δ13Cveg). The values of δ13Cveg decreased by 1.34‰ during 1962-2010, similar to changes in δ13C values of atmospheric CO2. Carbon isotope discrimination was highly variable and no trend was apparent in the past half century. Intrinsic water use efficiency (Wi) increased by 18 µmol·mol-1 (approximately 23.5%) during 1962-2010 because the increase in the intercellular CO2 concentration (46 µmol·mol-1) was less than that in the atmospheric CO2 concentration (Ca, 73 µmol·mol-1). In addition, Wi increased significantly with increasing growing season temperature and Ca. However, effective water use efficiency (We) remained relatively stable, because of increasing vapor pressure deficit. Ca, precipitation, and growing season temperature collectively explained 45% of the variation of We. Our findings indicate that the We of alpine meadows in the Tibetan Plateau remained relatively stable by physiological adjustment to elevated Ca and growing season temperature. These findings improve our understanding and the capacity to predict NPP of these ecosystems under global change scenarios.


Assuntos
Carbono/química , Solo/química , Água/química , Lã/química , Animais , Dióxido de Carbono/química , Isótopos de Carbono , Pradaria , Poaceae/química , Poaceae/fisiologia , Estações do Ano , Carneiro Doméstico , Temperatura Ambiente , Tibet
12.
PLoS One ; 10(4): e0122486, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25849325

RESUMO

Estimate of net ecosystem carbon exchange (NEE) between the atmosphere and terrestrial ecosystems, the balance of gross primary productivity (GPP) and ecosystem respiration (Reco) has significant importance for studying the regional and global carbon cycles. Using models driven by satellite data and climatic data is a promising approach to estimate NEE at regional scales. For this purpose, we proposed a semi-empirical model to estimate NEE in this study. In our model, the component GPP was estimated with a light response curve of a rectangular hyperbola. The component Reco was estimated with an exponential function of soil temperature. To test the feasibility of applying our model at regional scales, the temporal variations in the model parameters derived from NEE observations in an alpine grassland ecosystem on Tibetan Plateau were investigated. The results indicated that all the inverted parameters exhibit apparent seasonality, which is in accordance with air temperature and canopy phenology. In addition, all the parameters have significant correlations with the remote sensed vegetation indexes or environment temperature. With parameters estimated with these correlations, the model illustrated fair accuracy both in the validation years and at another alpine grassland ecosystem on Tibetan Plateau. Our results also indicated that the model prediction was less accurate in drought years, implying that soil moisture is an important factor affecting the model performance. Incorporating soil water content into the model would be a critical step for the improvement of the model.


Assuntos
Carbono/metabolismo , Ecossistema , Pradaria , Modelos Teóricos , Ciclo do Carbono , Imagens de Satélites , Estações do Ano
13.
World J Gastroenterol ; 20(29): 10193-201, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-25110448

RESUMO

Gastric adenosquamous carcinoma (ASC) is a rare type of gastric cancer. It is a mixed neoplasm, consisting of glandular cells and squamous cells. It is often diagnosed at an advanced stage, thus carrying a poor prognosis. We describe a case of a 73-year-old male, who presented with refractory fever and an intra-abdominal mass on imaging. He underwent a laparoscopic exploration followed by a successful totally laparoscopic total gastrectomy with D2 lymphadenectomy for gastric cancer. Postoperative pathology revealed primary gastric ASC (T4aN0M0). The patient received adjuvant radiotherapy and chemotherapy with S1 and is alive 20 mo after surgery without recurrence. This is the first case of advanced gastric ASC with fever as the initial presentation treated with totally laparoscopic total gastrectomy reported in the English literature.


Assuntos
Carcinoma Adenoescamoso/complicações , Febre/etiologia , Neoplasias Gástricas/complicações , Idoso , Biópsia , Carcinoma Adenoescamoso/patologia , Carcinoma Adenoescamoso/terapia , Quimiorradioterapia Adjuvante , Gastrectomia/métodos , Gastroscopia , Humanos , Laparoscopia , Excisão de Linfonodo , Masculino , Estadiamento de Neoplasias , Neoplasias Gástricas/patologia , Neoplasias Gástricas/terapia , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento
14.
Ying Yong Sheng Tai Xue Bao ; 25(12): 3458-68, 2014 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-25876395

RESUMO

Abstract: Fertilization is an effective management measure for recovery of degraded grasslands. To better understand the effects of fertilization on community structure and productivity of lightly and severely degraded alpine meadows, we conducted a fertilization experiment in northern Tibet since 2008. The treatments were addition of nitrogen (N) alone (50 kg N x hm(-2) x a(-1), LN; 100 kg N x hm(-2) x a(-1), HN) or addition of both phosphorus (P) and N (50 kg N x hm(-2) x a(-1) +50 kg P x hm(-2) x a(-1), LN+P; 100 kg N x hm(-2) x a(-1) +50 kg P x hm(-2) x a(-1), HN+P) in each of the two types of degraded alpine meadows. N addition alone significantly affected plant community coverage or productivity in neither the slightly nor the severely degraded alpine meadow, while addition of both N and P significantly increased plant community coverage, aboveground and below- ground biomass of the alpine meadows. This suggested that productivity of this alpine meadow is co-limited by N and P. HN and HN+P significantly decreased species richness and evenness in the lightly degraded grassland, indicating that HN was not beneficial for the lightly degraded grassland to maintain species diversity and community stability. N addition significantly reduced the root to shoot ratio in the severely degraded meadow. In the lightly degraded meadow, N addition alone, especially with a high amount (HN) , enhanced the importance values (IV) and biomass of grasses, while fertilization with both N and P increased those of sedges. In the severely degraded meadow, fertilization had little effect on IV of grasses or sedges, but improved biomass of forbs. The results suggested that LN+P could be employed in recovery of lightly degraded alpine meadows, but other management measures such as fencing and reseeding may be needed for recovery of severely degraded alpine meadows.


Assuntos
Pradaria , Nitrogênio/química , Fósforo/química , Solo/química , Biomassa , Fertilizantes , Raízes de Plantas , Plantas , Poaceae/crescimento & desenvolvimento , Tibet
15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(10): 2810-4, 2012 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-23285892

RESUMO

The present study focused on variation of vegetation types and canopy spectra along the altitudinal gradients in south-facing slope of Dangxiong valley in Tibet. Spectral extraction methods including red edge analysis and vegetation indices were used for vegetation spectral characteristics analysis. Through the hierarchical clustering analysis based on the vegetation spectral features, the feasibility of remote sensing classification of vegetation types along the elevation gradients in the experimental area was evaluated. The experimental results showed that: there were significant differences in spectral features including water index (WI), red edge POSITION (REP), and normalized difference vegetation index (NDVI) in different plots along elevation gradients in the study area, and there were strong correlations between WI and leaf water content, REP and dry biomass, NDVI and vegetation coverage. The hierarchical clustering analysis result of 12 vegetation samples along the altitudinal gradients is consistent with the ground survey, which shows that the selected vegetation spectral features can characterize the vertical distribution of vegetation types in the experimental area. The vegetation spectral analysis in this study can provide the priori knowledge support of spectral characteristics for the vegetation vertical distribution information extraction in the Tibet Plateau.


Assuntos
Poaceae/química , Tecnologia de Sensoriamento Remoto , Análise Espectral/métodos , Árvores/química , Altitude , Análise por Conglomerados , Ecossistema , Monitoramento Ambiental/métodos , Poaceae/crescimento & desenvolvimento , Análise Espectral/instrumentação , Tibet , Árvores/crescimento & desenvolvimento
16.
Sci China Life Sci ; 53(9): 1142-51, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21104375

RESUMO

Plant traits and individual plant biomass allocation of 57 perennial herbaceous species, belonging to three common functional groups (forbs, grasses and sedges) at subalpine (3700 m ASL), alpine (4300 m ASL) and subnival (≥5000 m ASL) sites were examined to test the hypothesis that at high altitudes, plants reduce the proportion of aboveground parts and allocate more biomass to belowground parts, especially storage organs, as altitude increases, so as to geminate and resist environmental stress. However, results indicate that some divergence in biomass allocation exists among organs. With increasing altitude, the mean fractions of total biomass allocated to aboveground parts decreased. The mean fractions of total biomass allocation to storage organs at the subalpine site (7% ± 2% S.E.) were distinct from those at the alpine (23% ± 6%) and subnival (21% ± 6%) sites, while the proportions of green leaves at all altitudes remained almost constant. At 4300 m and 5000 m, the mean fractions of flower stems decreased by 45% and 41%, respectively, while fine roots increased by 86% and 102%, respectively. Specific leaf areas and leaf areas of forbs and grasses deceased with rising elevation, while sedges showed opposite trends. For all three functional groups, leaf area ratio and leaf area root mass ratio decreased, while fine root biomass increased at higher altitudes. Biomass allocation patterns of alpine plants were characterized by a reduction in aboveground reproductive organs and enlargement of fine roots, while the proportion of leaves remained stable. It was beneficial for high altitude plants to compensate carbon gain and nutrient uptake under low temperature and limited nutrients by stabilizing biomass investment to photosynthetic structures and increasing the absorption surface area of fine roots. In contrast to forbs and grasses that had high mycorrhizal infection, sedges had higher single leaf area and more root fraction, especially fine roots.


Assuntos
Altitude , Biomassa , Fenômenos Fisiológicos Vegetais , Plantas/anatomia & histologia , Plantas/metabolismo , Adaptação Biológica , China , Ecossistema , Tibet
17.
Am J Forensic Med Pathol ; 31(1): 77-9, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19918157

RESUMO

BACKGROUND: Moyamoya disease (MMD) is a chronic occlusive cerebrovascular disorder. Patients diagnosed asymptomatic MMD should have no prior ischemic or hemorrhagic episode and no history of neurologic diseases. The incidence of asymptomatic MMD has turned out to be higher than previously thought due to better diagnosis with the increasing availability of magnetic resonance imaging or magnetic resonance angiography technology. However, the clinical symptoms of asymptomatic MMDs are still obscure. CLINICAL CASE: This report presents an asymptomatic MMD patient, who was a previously healthy 42-year-old-woman. The patient suffered from burst coma and started vomiting 3 hours before hospitalization. The patient died of the rupture of hemorrhage located on the right temporal lobe near the cortex. Autopsy revealed that the vascular networks were increased at the right postcentral gyrus and on the surface of the occipital lobe. CONCLUSIONS: As a small number of asymptomatic MMD patients have clinical symptoms, we must be aware of the possibility of MMD. The clinical symptoms of transient ischemic attack, ischemic stroke, or/and intracranial bleeding maybe the manifestation of this disease. Early recognition, accurate diagnosis and prompt treatment are vital to the survival of the patients with asymptomatic MMD.


Assuntos
Encéfalo/patologia , Doença de Moyamoya/patologia , Adulto , Coma/etiologia , Encefalocele/patologia , Feminino , Patologia Legal , Humanos , Hemorragias Intracranianas/patologia , Vômito/etiologia
18.
J Neuropathol Exp Neurol ; 65(9): 905-13, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16957584

RESUMO

Caspases and inhibitor of apoptosis proteins (IAPs) are antagonizing key apoptosis regulators. Limited studies of a few IAPs indicated their roles in astrocytomas. However, the overall expression status and significance of apoptosis regulators in astrocytomas is not clear. We examined the expression profile of the caspases (CASP3, 6, 7, 8, 9, 10, and 14), APAF1, SMAC, BCL2, the IAPs (BIRC5/survivin, CIAP1, CIAP2, XIAP, and LIVIN), and the proliferation markers Ki67 and PHH3 in 78 diffusely infiltrating astrocytomas and 24 normal brain samples by immunohistochemistry. Western blotting for major caspases and IAPs and reverse transcription-polymerase chain reaction analyses for IAPs were performed on a subset of 27 fresh samples. Our data showed BIRC5 nuclear labeling index (BIRC5-N) was the apoptosis marker most significantly different in World Health Organization grade II to IV astrocytomas and most strongly associated with proliferative activity. Expression level of other apoptosis-related proteins was modest or low in astrocytomas and did not correlate significantly with tumor grade or proliferation. Apoptosis regulators and proliferation markers were not detected in astrocytes of normal brain by immunostaining. This expression profile suggested involvement of apoptosis regulators in astrocytoma tumorigenesis, but tumor progression was more closely associated with proliferative advantages of which BIRC5 nuclear expression appeared to be a manifestation.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Apoptose , Astrocitoma/metabolismo , Neoplasias Encefálicas/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , Adulto , Idoso , Astrocitoma/patologia , Western Blotting/métodos , Neoplasias Encefálicas/patologia , Feminino , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Imuno-Histoquímica/métodos , Proteínas Inibidoras de Apoptose , Masculino , Proteínas Associadas aos Microtúbulos/genética , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Estatísticas não Paramétricas , Survivina
19.
Mod Pathol ; 19(11): 1487-97, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16892011

RESUMO

The caspase family proteases are key proapoptotic proteins while the inhibitor of apoptosis proteins (IAP) prevent apoptosis by antagonizing the caspases or other key proapoptotic proteins. Limited studies of IAPs suggested their deregulation contributed to urothelial neoplasia. However, the expression status and biologic or prognostic significance of the caspase and IAP family proteins in urothelial neoplasms is not clear. In the present study, we first systematically evaluated the expression profile of the major apoptosis regulators, including caspases (CASP3, 6, 7, 8, 9, 10, and 14), IAPs (survivin/BIRC5, CIAP1, CIAP2, XIAP, and LIVIN), APAF1, SMAC, and BCL2, as well as proliferation markers Ki67 and PHH3, in Ta/T1 human urinary bladder urothelial carcinomas and normal urothelium samples by immunohistochemistry. The analysis showed that survivin/BIRC5 nuclear labeling index (BIRC5-N), but not cytoplasmic staining, was the only apoptotic marker which correlated significantly with tumor grade, stage, and patient outcome. We further analyzed the prognostic value of BIRC5-N in 101 Ta/T1 urinary bladder urothelial carcinomas by univariate analysis, which showed that BIRC5-N as well as the more classical prognosticators (stage, grade, and Ki67 index) were of prognostic significance. However, multivariate analysis by Cox proportional hazard regression demonstrated BIRC5-N was a stronger prognosticator than tumor grade, stage, and Ki67 labeling index. BIRC5-N index of 8% or more predicted unfavorable disease-specific survival (relative risk (RR)=6.6, 95% confidence interval=1.6-26.7, P=0.0080) as well as progression-free survival (RR=4.4, 95% confidence interval=1.3-14.6, P=0.0151). We conclude that BIRC5-N is a superior biologic and prognostic marker for Ta/T1 urothelial carcinomas of urinary bladder.


Assuntos
Biomarcadores Tumorais/análise , Núcleo Celular/química , Proteínas Associadas aos Microtúbulos/análise , Proteínas de Neoplasias/análise , Neoplasias da Bexiga Urinária/química , Urotélio/química , Idoso , Apoptose , Western Blotting , Proliferação de Células , Estudos de Coortes , Citoplasma/química , Estudos de Avaliação como Assunto , Feminino , Seguimentos , Humanos , Imuno-Histoquímica , Proteínas Inibidoras de Apoptose , Estimativa de Kaplan-Meier , Masculino , Análise Multivariada , Invasividade Neoplásica , Estadiamento de Neoplasias , Razão de Chances , Prognóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Survivina , Fatores de Tempo , Resultado do Tratamento , Neoplasias da Bexiga Urinária/mortalidade , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/terapia , Urotélio/patologia
20.
Pathol Int ; 55(9): 590-5, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16143036

RESUMO

Adenosquamous carcinomas of the small intestine are extremely rare, with only three documented jejunal and three ileal cases being reported in the English-language medical literature. Presented herein is a case of primary jejunal adenosquamous carcinoma in an 80-year-old woman. The jejunal carcinoma consisted predominantly of a squamous component throughout the tumor but peritoneal nodules carrying metastases from the adenocarcinoma element were noted, making it the first case of jejunal adenosquamous carcinoma with metastases from the adenocarcinoma component. The finding that metastases could arise from the minor component of a jejunal adenosquamous carcinoma indicates that an accurate diagnosis must be based upon thorough examination of both the primary and the metastases, not just mesenteric nodule biopsy alone. Histological foci of closely intermingled squamous and glandular components with apparent morphological transition were noted, indicating the pathogenetic possibility that the squamous component might arise by transformation from the glandular element. The squamous component was strongly positive with immunostaining for p63 (nuclear staining) and for cytokeratin 10/13 (cytoplasmic staining), while the adenocarcinoma element was negative. The immunohistochemical results suggest that p63 and cytokeratin 10/13 might be useful in identifying squamous differentiation in jejunal carcinoma.


Assuntos
Carcinoma Adenoescamoso/secundário , Neoplasias do Jejuno/patologia , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/análise , Carcinoma Adenoescamoso/química , Carcinoma Adenoescamoso/cirurgia , Núcleo Celular/química , Núcleo Celular/patologia , Citoplasma/química , Citoplasma/patologia , Proteínas de Ligação a DNA , Evolução Fatal , Feminino , Genes Supressores de Tumor , Humanos , Técnicas Imunoenzimáticas , Neoplasias do Jejuno/química , Neoplasias do Jejuno/cirurgia , Queratinas/análise , Fosfoproteínas/análise , Transativadores/análise , Fatores de Transcrição , Proteínas Supressoras de Tumor
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA