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排序方式: 共有98条查询结果,搜索用时 15 毫秒
1.
Damasceno DC Volpato GT de Mattos Paranhos Calderon I Cunha Rudge MV 《Animal reproduction science》2002,72(3-4):235-244
A considerable amount of clinical and experimental evidence now exists suggesting the involvement of free radical-mediated oxidative processes in the pathogenesis of diabetic complications. If the diabetic state is associated with a generalized increase in oxidative stress, it might well be reflected in the alterations in embryonic and fetal development during pregnancy. In the present study, incidence of the malformed fetuses, biochemical parameters and antioxidant system activity of streptozotocin (STZ)-induced diabetic pregnant rats was investigated and the results obtained were compared with those of the control group (non-diabetic). Virgin female Wistar rats were injected with 40 mg/kg streptozotocin (STZ) before mating. All the females were killed on Day 21 of pregnancy and the fetuses were analyzed. A maternal blood sample was collected by venous puncture and the maternal liver was removed for biochemical measurement. The diabetic dams presented hyperglycemia, hyperlipemia, hypertriglyceridemia, hypercholesterolemia, hyperuricemia, decreased reduced glutathione (GSH), hepatic glycogen and superoxide dismutase (SOD) determinations. There was an increased incidence of skeletal and visceral malformation in fetuses from diabetic rats. Our findings suggest that oxidative stress occurs in the diabetic pregnant state, which might promote maternal homeostasis alterations. These diabetic complications might be a contributory factor to conceptus damage causing embryonic death (abortion/miscarriage) or the appearance of malformations in the fetuses of diabetic dams. Antioxidant treatment of women with diabetes may be important in future attempts to prevent congenital malformations. 相似文献
2.
Cordova CA Siqueira IR Netto CA Yunes RA Volpato AM Cechinel Filho V Curi-Pedrosa R Creczynski-Pasa TB 《Redox report : communications in free radical research》2002,7(2):95-102
Calendula officinalis (marigold) has many pharmacological properties. It is used for the treatment of skin disorders, pain and also as a bactericide, antiseptic and anti-inflammatory. Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are known to participate in the pathogenesis of various human diseases and may be involved in the conditions which C. officinalis is used to treat. The aim of this study was to investigate the relationship between the beneficial properties of this plant and its antioxidant action. The butanolic fraction (BF) was studied because it is non-cytotoxic and is rich in a variety of bioactive metabolites including flavonoids and terpenoids. Superoxide radicals (O(2)(*-)) and hydroxyl radicals (HO(*)) are observed in decreasing concentrations in the presence of increasing concentrations of BF with IC(50) values of 1.0 +/- 0.09 mg/ml and 0.5 +/- 0.02 mg/ml, respectively, suggesting a possible free radical scavenging effect. Lipid peroxidation in liver microsomes induced by Fe(2+)/ascorbate was 100% inhibited by 0.5 mg/ml of BF (IC(50) = 0.15 mg/ml). Its total reactive antioxidant potential (TRAP) (in microM Trolox equivalents) was 368.14 +/- 23.03 and its total antioxidant reactivity (TAR) was calculated to be 249.19 +/- 14.5 microM. The results obtained suggest that the butanolic fraction of C. officinalis possesses a significant free radical scavenging and antioxidant activity and that the proposed therapeutic efficacy of this plant could be due, in part, to these properties. 相似文献
3.
Laurent Puymerail Virginie Volpato André Debénath Arnaud Mazurier Jean-François Tournepiche Roberto Macchiarelli 《Comptes Rendus Palevol》2012,11(8):581-593
We describe a human partial femoral shaft discovered during speleological exploration of the “grotte de la Tour”, near the prehistoric site of La Chaise-de-Vouthon (Charente, France). The context of discovery is compatible with a hyena den deposit; the associated mammal assemblage suggests a preliminary chronological attribution to MIS 3. Combined information from its outer morphology, cross-sectional geometric properties, and from the high-resolution 3D imaging and quantitative analysis of its inner structural organization shows that this specimen (CDV-Tour 1) is from an adult Neanderthal individual, more likely a male. 相似文献
4.
5.
Gabriele Volpato Pavlína Kourková Václav Zelený 《Journal of ethnobiology and ethnomedicine》2012,8(1):49
Background
Over the past decade, there has been growing interest within ethnobiology in the knowledge and practices of migrating people. Within this, scholars have given relatively less attention to displaced people and refugees: to the loss, maintenance, and adaptation of refugees’ ethnobiological knowledge, and to its significance for refugees’ wellbeing. This study focuses on cosmetics and remedies used to heal skin afflictions that are traditionally used by Sahrawi refugees displaced in South Western Algerian refugee camps.Methods
The research methods included a structured survey carried out with 37 refugee households, semi-structured interviews with 77 refugees, 24 retrospective interviews with refugees and other knowledgeable informants, and a voucher specimen collection of the plants and products cited.Results
We recorded the use of 55 plant species, nine animal species, and six mineral products used within the three main use categories discussed in this paper: 1) Remedies for health issues that are typical of the desert environment where the Sahrawi once lived as nomads and now live as refugees (e.g. eye afflictions); 2) Remedies for wounds that are influenced by the Sahrawi’s recent history of guerrilla warfare; and 3) Cosmetics and products used for body care, decoration and perfuming (e.g. hair care, teeth cleansing, henna use) and for aromatizing the air inside of tents and which are widely used in everyday life and social practices.Conclusions
We discuss the changes that have occurred in the patterns of use and procurement of these products with exile and sedentarization in refugee camps, and conclude that refugees are not simply passive recipients of national and international aid, but rather struggle to maintain and recover their traditional ethnobiological practices in exile. Finally, we suggest further research into the ethnobiological practices and knowledge of displaced populations.Resumen
Sanando las heridas de guerra y perfumando el exilio: el uso de productos vegetales, animales y minerales con fines de perfumería, cosmética y curativos de la piel entre los refugiados saharauis del Sáhara Occidental.Antecedentes
Durante la última década ha habido un creciente interés en los estudios etnobiológicos de los conocimientos y prácticas de las personas que migran. Dentro de esta tendencia, los estudiosos han prestado relativamente menor atención a las personas desplazadas y a los refugiados: a la pérdida, el mantenimiento y la adaptación de sus conocimientos etnobiológicos, y su importancia para el bienestar de los refugiados. Este estudio se centra en los cosméticos y remedios para curar problemas de la piel tradicionalmente utilizados por los refugiados saharauis en los campamentos de desplazados al sudoeste de Argelia.Métodos
Los métodos de investigación que se utilizaron son: una encuesta estructurada con 37 familias de refugiados, entrevistas semi-estructuradas con 77 refugiados, 24 entrevistas retrospectivas con refugiados e informantes conocedores, y una colección de muestra de las plantas y productos citados.Resultados
Se registró el uso de 55 especies vegetales, nueve especies animales, y seis productos minerales utilizados en tres principales categorías de usos: 1) Recursos contra los problemas de salud característicos del entorno desértico donde una vez vivieron los saharauis como nómadas y donde ahora viven como refugiados (por ejemplo problemas en los ojos); 2) Remedios para heridas que reflejan la historia reciente de guerra de guerrilla de los nómadas saharauis; y 3) Cosméticos y productos utilizados para el cuidado del cuerpo, decoración y perfumes (por ejemplo, atención al cabello, limpieza de dientes, uso del henna) y como aromatizantes del aire al interior de las tiendas, que son ampliamente utilizados en la vida y las prácticas sociales cotidianas de los refugiados.Conclusiones
En la discusión, se analizan los cambios que se han producido en los patrones de uso y en la adquisición de estos productos durante el exilio. Llegamos a la conclusión de que los refugiados no son recipientes pasivos de la ayuda nacional e internacional, sino más bien luchan para mantener y recuperar sus prácticas tradicionales etnobiológicas en el exilio. Finalmente, sugerimos nuevas direcciones para la investigación de las prácticas y los conocimientos etnobiológicos de las poblaciones desplazadas.6.
Acridines were compared regarding their ability to be taken up by submitochondrial particles under energized conditions. pH dependence of uptake was explored, and it was found that acridines fell into three classes independently of their pKa value: acridines which are not taken up, acridines taken up at all pH values, and acridines taken up only at alkaline pH. Partition measurements between H2O and chloroform phase showed a similar pattern, and affinity for the organic phase seemed to parallel uptake. Acridines which are taken up by submitochondrial particles at acidic pH under energized conditions despite a high pKa value could also be extracted into chloroform at acidic pH, thus implying that the dye's uncharged form has a high affinity for the organic phase. By supplementing the aqueous medium with lipophilic anions, the dye may also be extracted in its charged form. The data support a mechanism for acridine uptake in which diffusion of the uncharged form across the membranes is an obligatory step. Some previously reported inhibitory anion effects on uptake may be explained by ion pair formation, which allows release of the accumulated charged form. 相似文献
7.
Ventilation rates indicate stress-coping styles in Nile tilapia 总被引:2,自引:0,他引:2
Behavioural responses to stress can form distinct profiles in a wide range of animals: proactive and reactive profiles or
coping styles. Stress responsiveness can also differentiate between the behavioural profiles. The tendency to regain feed
intake following transfer to a novel social-isolation tank (the speed of acclimation) can discriminate between proactive or
reactive profiles. Consequently, differential stress responsiveness can be linked to this feeding behaviour trait. This study
shows that ventilation rates of Nile tilapia, Oreochromis niloticus (L.), correlate with the rate of feeding resumption, following transfer to a novel social-isolation aquarium. Therefore,
ventilation rate (VR) indicates coping styles; consequently, VR is a proxy for the way fish will deal with environmental challenges. 相似文献
8.
9.
Brahm J. Yachnin Damien Y. Colin Jordan P. Volpato Maximilian Ebert Joelle N. Pelletier Albert M. Berghuis 《Acta Crystallographica. Section F, Structural Biology Communications》2011,67(11):1316-1322
Trimethoprim is an antibiotic that targets bacterial dihydrofolate reductase (DHFR). A plasmid‐encoded DHFR known as R67 DHFR provides resistance to trimethoprim in bacteria. To better understand the mechanism of this homotetrameric enzyme, a tandem dimer construct was created that linked two monomeric R67 DHFR subunits together and mutated the sequence of residues 66–69 of the first subunit from VQIY to INSF. Using a modified crystallization protocol for this enzyme that included in situ proteolysis using chymotrypsin, the tandem dimer was crystallized and the structure was solved at 1.4 Å resolution. Surprisingly, only wild‐type protomers were incorporated into the crystal. Further experiments demonstrated that the variant protomer was selectively degraded by chymotrypsin, although no canonical chymotrypsin cleavage site had been introduced by these mutations. 相似文献
10.
M.S. Carneiro M.N. Crispim C.M. Wilhelm F.C.Z. Volpato A.L. Barth 《Letters in applied microbiology》2022,75(1):17-23
This study aimed to evaluate the filter paper as a means to transport inactivated Gram-negative non-fermentative (GNNF) bacteria and Haemophilus spp. for analysis using MALDI-TOF MS. A total of 133 isolates were evaluated and the analysis of each isolate was performed directly from original bacterial colony and in filter paper after the processing. To evaluate the agreement between the identification performed directly from the colony and after impregnation in filter paper, we assign the scores: >2·3 as excellent (E); 2·0 to 2·3 as very good (VG); 1·7–1·99 as good (G); <1·7 as unidentified (U). The divergences were classified as: Minor Divergence, Intermediate Divergence and Major Divergence. A total of 80 isolates transported in the filter paper disks presented full category concordance; 39 isolates presented Minor Divergence; 4 isolates present Intermediate Divergence; 4 isolates present Major Divergence and 6 isolates present better results after impregnation in filter paper. The proposed methodology of bacteria transportation presented a sensitivity of 96·9% and a specificity of 100%. The filter paper as a means to transport and storage of inactivated GNNF and Haemophilus spp. may be considered a potential tool for faster, more accurate, biosafe and less-expensive identification. 相似文献