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141.
Fernández V Tapia G Varela P Gaete L Vera G Mora C Vial MT Videla LA 《Free radical biology & medicine》2008,44(9):1724-1731
Hepatic ischemia-reperfusion (IR) injury, a major clinical drawback during surgery, is abolished by L-3,3',5-triiodothyronine (T(3)) administration. Considering that the triggering mechanisms are unknown, the aim of this study is to assess the role of oxidative stress in T(3) preconditioning using N-acetylcysteine (NAC) before T(3) administration. Male Sprague-Dawley rats given a single dose of 0.1 mg of T(3)/kg were subjected to 1 h ischemia followed by 20 h reperfusion, in groups of animals pretreated with 0.5 g of NAC/kg 0.5 h before T(3) or with the respective control vehicles. At the end of the reperfusion period, blood and liver samples were taken for analysis of serum aspartate aminotransferase (AST) and hepatic histology, glutathione (GSH) and protein carbonyl contents, and nuclear factor-kappaB (NF-kappaB) and activating protein 1 (AP-1) DNA binding. The IR protocol used led to a 4.5-fold increase in serum AST levels and drastic changes in liver histology, with significant GSH depletion and enhancement of protein carbonyl levels and of the protein carbonyl/GSH content ratio, whereas NF-kappaB and AP-1 DNA binding was decreased and enhanced, respectively. In a time window of 48 h, T(3) exerted protection against hepatic IR injury, with 88% reduction in the protein carbonyl/GSH ratio and normalization of NF-kappaB and AP-1 DNA binding, changes that were suppressed by NAC administration before T(3). Data presented suggest that a transient increase in the oxidative stress status of the liver is an important trigger for T(3) preconditioning, evidenced in a warm IR injury model through antioxidant intervention. 相似文献
142.
Suárez-Varela MM García-Marcos Alvarez L Kogan MD González AL Gimeno AM Aguinaga Ontoso I Díaz CG Pena AA Aurrecoechea BD Monge RM Quiros AB Garrido JB Canflanca IM Varela AL 《International journal of biometeorology》2008,52(8):833-840
Atopic eczema (AE) is a chronic skin disease. Recent reports indicate that the worldwide prevalence of AE is increasing and
that various environmental factors are implicated in its aetiology. Climatic conditions have been related with AE prevalence,
and Spain has varying climatic conditions. The aim of this study is to document the possible climatic influence on the prevalence
of AE in schoolchildren aged 6–7 years in three different climatic regions in Spain. We conducted a cross-sectional population-based
survey of 28,394 schoolchildren aged 6–7 years from 10 Spanish centres in three different climatic regions. The mean participation
rate was 76.5%. AE prevalence was assessed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire
and the Spanish Academy of Dermatology criteria used in Spain to diagnose AE. The data, including annual temperature, precipitation,
relative humidity and the annual number of sunny hours per climatic region, were obtained from the Spanish National Institute
of Meteorology. Different AE prevalences were found in all three climatic regions studied: Atlantic, 32.9; Mediterranean 28.3;
and Continental 31.2 per 100 children studied (p < 0.005). AE was positively associated with precipitation and humidity, and was negatively associated with temperature and
the number of sunny hours. The results show that AE is significantly dependent on meteorological conditions. 相似文献
143.
Nélia Varela Louise Couton César Gemeno Jesús Avilla Jean-Pierre Rospars Sylvia Anton 《Cell and tissue research》2009,337(3):513-526
The oriental fruit moth Cydia molesta is an important pest and the behavioural role of olfactory signals such as pheromones and plant volatiles have been studied
extensively in both sexes. To understand odour processing further, however, detailed knowledge of the anatomy of the olfactory
system is crucial. In the present study, an atlas of the antennal lobe (AL) is presented based on the three-dimensional reconstructions
of both ALs of three male and three female brains by means of neuroanatomical and computational approaches. We identified
48–49 "ordinary" glomeruli and one large glomerulus situated at the entrance of the antennal nerve in males, and 49–52 "ordinary"
glomeruli and one large glomerulus in the ventro-medial part of the AL in females. Anomalous supernumerary, anomalous missing
and sexually dimorphic glomeruli were found in the studied individuals in greater numbers than in other lepidopteran species.
Male and female maps were compared with respect to glomerular size and position with 45 glomeruli being matched, indicating
a conserved glomerular pattern between the sexes. Three additional glomeruli were sexually dimorphic in size and five male-specific
and six female-specific glomeruli were also found. Palp backfills resulted in the staining of a unique glomerulus in both
sexes identified as the sexually dimorphic glomerulus 45. This glomerulus was never stained from antennal backfills, which
stained the other glomeruli of the AL. The three-dimensional atlas can now be used to elucidate the functional role of individual
glomeruli in both sexes of C. molesta.
Nélia Varela and Louise Couton contributed equally to this work.
This study was supported by research grants from INRA (Projet Jeune Equipe and Projet S.P.E.) to S.A. and J.P.R. and by the
Spanish Ministry of Science and Technology (research grant AGL2004-05812/AGR to J.A. and C.G., Spanish Science and Education
Department, MEC). N.V. was financed by fellowship no. BES-2005-7605 (MEC, Spain). 相似文献
144.
A putative multidrug efflux pump, EmrD-3, belonging to the major facilitator superfamily (MFS) of transporters and sharing
homology with the Bcr/CflA subfamily, was identified in Vibrio cholerae O395. We cloned the emrD-3 gene and evaluated its role in antimicrobial efflux in a hypersensitive Escherichia coli strain. The efflux activity of this membrane protein resulted in lowering the intracellular concentration of ethidium. The
recombinant plasmid carrying emrD-3 conferred enhanced resistance to several antimicrobials. Among the antimicrobials tested, the highest relative increase in
minimum inhibitory concentration (MIC) of 102-fold was observed for linezolid (MIC = 256 μg/ml), followed by an 80.1-fold
increase for tetraphenylphosphonium chloride (TPCL) (156.2 μg/ml), 62.5-fold for rifampin (MIC = 50 μg/ml), >30-fold for erythromycin
(MIC = 50 μg/ml) and minocycline (MIC = 2 μg/ml), 20-fold for trimethoprim (MIC = 0.12 μg/ml), and 18.7-fold for chloramphenicol
(MIC = 18.7 μg/ml). Among the fluorescent DNA-binding dyes, the highest relative increase in MIC of 41.7-fold was observed
for ethidium bromide (125 μg/ml) followed by a 17.2-fold increase for rhodamine 6G (100 μg/ml). Thus, we demonstrate that
EmrD-3 is a multidrug efflux pump of V. cholerae, the homologues of which are present in several Vibrio spp., some members of Enterobacteriaceae family, and Gram-positive Bacillus spp. 相似文献
145.
A.S. Varela Junior C.D. Corcini R.R. Ulguim M.V.F. Alvarenga I. Bianchi M.N. Corrêa T. Lucia Jr. J.C. Deschamps 《Animal reproduction science》2009,115(1-4):323-327
Egg yolk is included in extenders for semen cryopreservation due to its protective effect against cold shock, which is attributed to the presence of low density lipoprotein (LDL). This study evaluates how semen quality is affected by using LDL as a replacement for egg yolk in extenders for cooled and frozen dog semen. In Experiment 1, semen was extended in TRIS–glucose at 5 °C, in four treatments: 20% egg yolk (T1); 6% (T2); 8% (T3); and 10% LDL (T4). Sperm motility and membrane integrity after 24, 48, 72 and 96 h and the 50% conservation rate of motile spermatozoa (50 M) were evaluated. The 50 M was less for T1 than for the other treatments (P < 0.01), but T2–T4 did not differ (P > 0.05). In Experiment 2, glycerol at 10% was included in the freezing extender, in treatments similar to those from Experiment 1. Sperm motility and membrane integrity did not differ for T2, T3 and T4 at any period in Experiment 1 and after thawing in Experiment 2 (P > 0.05), but were greater for all LDL treatments than for T1 (P < 0.01), in both experiments. Thus, LDL can replace egg yolk in the composition of the TRIS–glucose extender for cooled or frozen dog semen. 相似文献
146.
Sara Russo Arnaldo Batista Filipa Esgalhado Catarina R. Palma dos Reis Ftima Serrano Valentina Vassilenko Manuel Ortigueira 《Biophysical reviews》2021,13(4):563
Alvarez waves are local rhythmic contractions of the myometrium with high frequency and low intensity. They can be detected using internal or external tocography and electrohysterography. Some researchers correlate these small contractions with the initiation of labor, since they have been described as a pattern representing the uterine response to prostaglandin production. Other authors either do not validate a causality relation between Alvarez waves and labor or suggest that they have low predictive value for preterm labor. Alvarez waves’ research has become a multidisciplinary subject with inputs ranging from medical science, biomedical engineering, and related areas. A comprehensive review is herein conducted to summarize the state of the art regarding Alvarez waves and their role in the initiation of labor, namely in preterm birth. The results show that a large number of studies have analyzed and characterized Alvarez waves without necessarily digging into their relationship with labor. Publications were categorized in three groups: (A) reports about morphology and characterization of Alvarez waves; (B) publications reporting a positive causality relation between Alvarez waves and labor; and (C) publications reporting an absence of causality regarding the previous hypothesis. Studies in group B outnumbered those in group C. A critical analysis is presented. 相似文献
147.
Synthesis of pentopyranosyl-containing thiodisaccharides. Inhibitory activity against β-glycosidases
Alejandro J. Cagnoni María Laura Uhrig Oscar Varela 《Bioorganic & medicinal chemistry》2009,17(17):6203-6212
β-(1→4)-Thiodisaccharides formed by a pentopyranose unit as reducing or non reducing end have been synthesized using a sugar enone derived from a hexose or pentose as Michael acceptor of a 1-thiopentopyranose or 1-thiohexopyranose derivatives. Thus, 2-propyl per-O-acetyl-3-deoxy-4-S-(β-d-Xylp)-4-thiohexopyranosid-2-ulose (3) and benzyl per-O-acetyl-3-deoxy-4-S-(β-d-Galp)-4-thiopentopyranosid-2-ulose (11) were obtained in almost quantitative yields. The carbonyl function of these uloses was reduced with NaBH4 or K-Selectride, and the stereochemical course of the reduction was highly dependent on the reaction temperature, reducing agent and solvent. Unexpectedly, reduction of 3 with NaBH4–THF at 0 °C gave a 3-deoxy-4-S-(β-d-Xylp)-4-thio-α-d-ribo-hexopyranoside derivative (6) as major product (74% yield), with isomerization of the sulfur-substituted C-4 stereocenter of the pyranone. Reduction of 11 gave always as major product the benzyl 3-deoxy-4-S-(Galp)-4-thio-β-d-threo-pentopyranoside derivative 14, which was the only product isolated (80% yield) in the reduction with K-Selectride in THF at −78 °C. Deprotection of 14 and its epimer at C-2 (13) afforded, respectively the free thiodisaccharides 19 and 18. They displayed strong inhibitory activity against the β-galactosidase from Escherichia coli. Thus, compound 18 proved to be a non-competitive inhibitor of the enzyme (Ki = 0.80 mM), whereas 19 was a mixed-type inhibitor (Ki = 32 μM). 相似文献
148.
Evangelina Repetto Carla Marino M. Laura Uhrig Oscar Varela 《Bioorganic & medicinal chemistry》2009,17(7):2703-2711
Thiodisaccharides having β-d-Galf or α-l-Araf units as non-reducing end have been synthesized by the SnCl4- or MoO2Cl2-promoted thioglycosylation of per-O-benzoyl-d-galactofuranose (1), its 1-O-acetyl analogue 4, or per-O-acetyl-α-l-arabinofuranose (16) with 6-thioglucose or 6-thiogalactose derivatives. After convenient removal of the protecting groups, the free thiodisaccharides having the basic structure β-d-Galf(1→6)-6-thio-α-d-Glcp-OMe (5) or β-d-Galf(1→6)-6-thio-α-d-Galp-OMe (15) were obtained. The respective α-l-Araf analogues 18 and 20 were prepared similarly from 16. Alternatively, β-d-Galf(1→4)-4-thio-3-deoxy-α-l-Xylp-OiPr was synthesized by Michael addition to a sugar enone of 1-thio-β-d-Galf derivative, generated in situ from the glycosyl isothiourea derivative of 1. The free S-linked disaccharides were evaluated as inhibitors of the β-galactofuranosidase from Penicillium fellutanum, being 15 and 20 the more active inhibitors against this enzyme. 相似文献
149.
150.
Jennifer S. Powers Rebecca A. Montgomery E. Carol Adair Francis Q. Brearley Saara J. DeWalt Camila T. Castanho Jerome Chave Erika Deinert Jörg U. Ganzhorn Matthew E. Gilbert José Antonio González-Iturbe Sarayudh Bunyavejchewin H. Ricardo Grau Kyle E. Harms Ankila Hiremath Silvia Iriarte-Vivar † Eric Manzane Alexandre A. de Oliveira Lourens Poorter Jean-Baptiste Ramanamanjato Carl Salk Amanda Varela George D. Weiblen Manuel T. Lerdau 《Journal of Ecology》2009,97(4):801-811