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21.
Ernesto Chanes Rodríguez-Ramírez José Antonio Vázquez-García Ignacio García-González Othón Alcántara-Ayala Isolda Luna-Vega 《Journal of Plant Ecology》2020,13(3):331
本文旨在探讨气候变化如何影响两种特有墨西哥木兰的导管性状可塑性和其每年的年轮宽度。尽管如此,很少有研究评估干旱对墨西哥东部热带山地云林导管性状的影响。通过生长年轮的数字图像,我们对所研究的墨西哥木兰树种的径向生长率、树龄和导管性状可塑性进行了评估,比较了两种墨西哥木兰树种在干旱年和非干旱年的导管密度、水力直径和传导面积百分比。本研究首次对墨西哥两个热带山地云林中的两个濒危木兰树种(Magnolia vovidesii 和M. schiedeana)的多孔木质部导管性状对长期气候变化的可塑性进行了分析。结果发现,当比较干旱和非干旱年份时,温度和降水量与年轮宽度的差异密切相关。扩散型多孔木质导管解剖结构具有很高的可塑性,这与所研究的两种木兰树种的温度和/或水的有效性有关。我们的结论是,与非干旱年份相比,对干旱年份的解剖学适应导致了导管性状的大量减少;这些可塑的适应性在植物长期环境胁迫下的水分运输以及生存的安全性方面起着重要的作用。 相似文献
22.
Lessa JA Guerra JC de Miranda LF Romeiro CF Da Silva JG Mendes IC Speziali NL Souza-Fagundes EM Beraldo H 《Journal of inorganic biochemistry》2011,105(12):1729-1739
Complexes [Au(H2Ac4DH)Cl]?MeOH (1) [Au(H22Ac4Me)Cl]Cl (2) [Au(H22Ac4Ph)Cl]Cl?2H2O (3) and [Au(H22Bz4Ph)Cl]Cl (4) were obtained with 2-acetylpyridine thiosemicarbazone (H2Ac4DH), its N(4)-methyl (H2Ac4Me) and N(4)-phenyl (H2Ac4Ph) derivatives, as well as with N(4)-phenyl 2-benzoylpyridine thiosemicarbazone (H2Bz4Ph). The compounds were cytotoxic to Jurkat (immortalized line of T lymphocyte), HL-60 (acute myeloid leukemia), MCF-7 (human breast adenocarcinoma) and HCT-116 (colorectal carcinoma) tumor cell lines. Jurkat and HL-60 cells were more sensitive than MCF-7 and HCT-116 cells. Upon coordinating to the gold(I) metal centers in complexes (2) and (4), the cytotoxic activity of the H2Ac4Me and H2Bz4Ph ligands increased against the HL-60 and Jurkat tumor cell lines. 2 was more active than auranofin against both leukemia cells. Most of the studied compounds were less toxic than auranofin to peripheral blood mononuclear cells (PBMC). All compounds induced DNA fragmentation in HL-60 and Jurkat cells indicating their pro-apoptotic potential. Complex (2) strongly inhibited the activity of thioredoxin reductase (TrxR), which suggests inhibition of TrxR to be part of its mechanism of action. 相似文献
23.
Isolda A. Popova Lizelle Lubbe Pavel A. Petukhov Gavriil F. Kalantarov Ilya N. Trakht Elena R. Chernykh Olga Y. Leplina Alex V. Lyubimov Joe G.N. Garcia Steven M. Dudek Edward D. Sturrock Sergei M. Danilov 《Protein science : a publication of the Protein Society》2021,30(8):1577
Angiotensin I‐converting enzyme (ACE, CD143) plays a crucial role in blood pressure regulation, vascular remodeling, and immunity. A wide spectrum of mAbs to different epitopes on the N and C domains of human ACE have been generated and used to study different aspects of ACE biology, including establishing a novel approach–conformational fingerprinting. Here we characterized a novel set of 14 mAbs, developed against human seminal fluid ACE. The epitopes for these novel mAbs were defined using recombinant ACE constructs with truncated N and C domains, species cross‐reactivity, ACE mutagenesis, and competition with the previously mapped anti‐ACE mAbs. Nine mAbs recognized regions on the N domain, and 5 mAbs–on the C domain of ACE. The epitopes for most of these novel mAbs partially overlap with epitopes mapped onto ACE by the previously generated mAbs, whereas mAb 8H1 recognized yet unmapped region on the C domain where three ACE mutations associated with Alzheimer''s disease are localized and is a marker for ACE mutation T877M. mAb 2H4 could be considered as a specific marker for ACE in dendritic cells. This novel set of mAbs can identify even subtle changes in human ACE conformation caused by tissue‐specific glycosylation of ACE or mutations, and can detect human somatic and testicular ACE in biological fluids and tissues. Furthermore, the high reactivity of these novel mAbs provides an opportunity to study changes in the pattern of ACE expression or glycosylation in different tissues, cells, and diseases, such as sarcoidosis and Alzheimer''s disease. 相似文献
24.
Soares MA Lessa JA Mendes IC Da Silva JG Dos Santos RG Salum LB Daghestani H Andricopulo AD Day BW Vogt A Pesquero JL Rocha WR Beraldo H 《Bioorganic & medicinal chemistry》2012,20(11):3396-3409
N(4)-Phenyl 2-acetylpyridine thiosemicarbazone (H2Ac4Ph; N-(phenyl)-2-(1-(pyridin-2-yl)ethylidene)hydrazinecarbothioamide) and its N(4)-ortho-, -meta- and -para-fluorophenyl (H2Ac4oFPh, H2Ac4mFPh, H2Ac4pFPh), N(4)-ortho-, -meta- and -para-chlorophenyl (H2Ac4oClPh, H2Ac4mClPh, H2Ac4pClPh), N(4)-ortho-, -meta- and -para-iodophenyl (H2Ac4oIPh, H2Ac4mIPh, H2Ac4pIPh) and N(4)-ortho-, -meta- and -para-nitrophenyl (H2Ac4oNO(2)Ph, H2Ac4mNO(2)Ph, H2Ac4pNO(2)Ph) derivatives were assayed for their cytotoxicity against human malignant breast (MCF-7) and glioma (T98G and U87) cells. The compounds were highly cytotoxic against the three cell lineages (IC(50): MCF-7, 52-0.16 nM; T98G, 140-1.0 nM; U87, 160-1.4 nM). All tested thiosemicarbazones were more cytotoxic than etoposide and did not present any haemolytic activity at up to 10(-5)M. The compounds were able to induce programmed cell death. H2Ac4pClPh partially inhibited tubulin assembly at high concentrations and induced cellular microtubule disorganization. 相似文献
25.
Alberto González‐Zamora Isolda Luna Vega José Luis Villaseñor Carlos Alberto Ruiz‐Jiménez 《分类学与生物多样性》2013,11(2):135-144
Biogeographical patterns of distribution of 74 species of Asteraceae that inhabit mainly the temperate forests of eastern Mexico were studied usingtrack analysis. Five generalized tracks were identified and conservation areas proposed based on degree of complexity of floristic patterns (Luna et al., 1999) and biotic richness. The northern part of the Sierra Madre Oriental harbours a high concentration of narrowly restricted species. In this area there are four track nodes that coincide with the Mexican priority terrestrial regions (RTPs) proposed by the Comisión Nacional para el Conocimiento y Uso de la Biodiversidad (CONABIO) and with previously identified areas of importance for bird conservation (AICAs). Two more nodes are found in the central and southern part of the Sierra. With the gathered information, we propose particular selected species of Asteraceae to be included in the Mexican areas of endangered species (NOM). 相似文献
26.
Thaíssa de Oliveira Bastos Betânia Maria Soares Patrícia Silva Cisalpino Isolda Castro Mendes Raquel Gouvea dos Santos Heloisa Beraldo 《Microbiological research》2010,165(7):573-577
A family of 2-pyridineformamide-derived thiosemicarbazones and their gallium(III) complexes were tested against several isolates of pathogenic Cryptococcus strains. On complexation the antifungal activity significantly increases, suggesting coordination to gallium(III) to be an interesting strategy of antifungal dose reduction. 相似文献
27.
Isolda Luna Vega Othón Alcántara Ayala David Espinosa Organista Juan J. Morrone 《Journal of Biogeography》1999,26(6):1299-1305
Mexican cloud forests, situated between 600 and 3000 m of elevation, exhibit a remarkable high biotic diversity. They follow a fragmented pattern, similar to that of an archipelago, that makes them suitable to vicariance modelling. A Parsimony Analysis of Endemicity (PAE) was applied to the presence/absence of 1267 species of vascular plants (gymnosperms, angiosperms, and pteridophytes) from twenty-four patches of Mexican cloud forests, in order to postulate a preliminary hypothesis of relationships. The single cladogram obtained grouped the twenty-four cloud forests into five clades. These results indicate that the Sierra Madre Oriental, Sierra Madre del Sur, and Serranías Meridionales floristic provinces do not represent natural units. A preliminary vicariance model is presented to explain the sequence of fragmentation of the Mexican cloud forests. 相似文献