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排序方式: 共有1918条查询结果,搜索用时 453 毫秒
961.
962.
Ana Patrícia C. Silva Auricélio A. Macêdo Luciana F. Costa Cláudia E. Rocha Luize N. N. Garcia Jade R. D. Farias Priscilla P. R. Gomes Gustavo C. Teixeira Kessler W. J. Fonseca Andréa R. F. Maia Gabriela G. Neves Everton L. Rom?o Teane M. A. Silva Juliana P. S. Mol Renata M. Oliveira Márcio S. S. Araújo Ernane F. Nascimento Olindo A. Martins-Filho Humberto M. Brand?o Tatiane A. Paix?o Renato L. Santos 《PloS one》2015,10(8)
This study aimed to evaluate protection induced by the vaccine candidate B. ovis ΔabcBA against experimental challenge with wild type B. ovis in rams. Rams were subcutaneously immunized with B. ovis ΔabcBA encapsulated with sterile alginate or with the non encapsulated vaccine strain. Serum, urine, and semen samples were collected during two months after immunization. The rams were then challenged with wild type B. ovis (ATCC25840), and the results were compared to non immunized and experimentally challenged rams. Immunization, particularly with encapsulated B. ovis ΔabcBA, prevented infection, secretion of wild type B. ovis in the semen and urine, shedding of neutrophils in the semen, and the development of clinical changes, gross and microscopic lesions induced by the wild type B. ovis reference strain. Collectively, our data indicates that the B. ovis ΔabcBA strain is an exceptionally good vaccine strain for preventing brucellosis caused by B. ovis infection in rams. 相似文献
963.
Apoptosis as a mechanism for removal of mutated cells of Saccharomyces cerevisiae: the role of Grx2 under cadmium exposure 总被引:1,自引:0,他引:1
Gomes DS Pereira MD Panek AD Andrade LR Eleutherio EC 《Biochimica et biophysica acta》2008,1780(2):160-166
Cadmium is a strong mutagen that acts by inhibiting DNA mismatch repair, while its toxic effect seems to be related to an indirect oxidative stress that involves glutathione (GSH) mobilization. Among the roles of GSH is the protection of proteins against oxidative damage, by forming reversible mixed disulfides with cysteine residues, a process known as protein glutathionylation and catalyzed by glutaredoxins (Grx). In this current study, Saccharomyces cerevisiae cells deficient in GRX2, growing in 80 muM CdSO(4), showed high mitochondrial mutagenic rate, determined by frequency of mutants that had lost mitochondrial function (petite mutants), high tolerance and lower apoptosis induction. The mutant strain also showed decreased levels of glutathionylated-protein after cadmium exposure, which might difficult the signaling to apoptosis, leading to increased mutagenic rates. Taken together, these results suggest that Grx2 is involved with the apoptotic death induced by cadmium, a form of cellular suicide that might lead of removal of mutated cells. 相似文献
964.
Candotti CT Loss JF Melo Mde O La Torre M Pasini M Dutra LA de Oliveira JL de Oliveira LP 《Canadian journal of physiology and pharmacology》2008,86(5):272-278
The purpose of this study was to determine the validity of using the electromyography (EMG) signal as a noninvasive method of estimating the lactate threshold (LT) power output in recreational cyclists. Using an electromagnetic bicycle ergometer and constant pedaling cadence of 80 rpm, 24 recreational cyclists performed an incremental exercise protocol that consisted of stepwise increases in power output of 25 W every 3 min until exhaustion. The EMG signal was recorded from the right vastus lateralis (VL) and right rectus femoris (RF) throughout the test. Blood samples were taken from the fingertip every 3 min. The LT was determined by examining the relation between the lactate concentration and the power output using a log-log transformation model. The root mean square (RMS) value from the EMG signal was calculated for every 1-second non-superimposing window. Sets of pairs of straight regression lines were plotted and the corresponding determination coefficients (R(2)) were calculated. The intersection point of the pair of lines with the highest R(2) product was chosen to represent the EMG threshold (EMGT). The results showed that the correlation coefficients (r) between EMGT and LT were significant (p < 0.01) and high for the VL (r = 0.826) and RF (r = 0.872). The RF and VL muscles showed similar behavior during the maximal incremental test and the EMGT and LT power output were equivalent for both muscles. The validity of using EMG to estimate the LT power output in recreational cyclists was confirmed. 相似文献
965.
Carvalho WA Bechara GH Moré DD Ferreira BR da Silva JS de Miranda Santos IK 《Experimental parasitology》2008,118(4):587-591
Tick bites may trigger acute phase responses. Positive and negative acute phase proteins were measured in infested cattle genetically resistant and susceptible to ticks. During heavier infestations levels of haptoglobin increased significantly in susceptible bovines; levels of serum amyloid A increased in resistant bovines; levels of alpha-1-acid glycoprotein decreased significantly in resistant bovines; levels of transferrin decreased significantly in susceptible bovines. In conclusion, tick infestations trigger acute phase responses and enhancement of specific acute phase proteins differs according to the genetic composition of hosts. Acute phase proteins may constitute useful biological signatures for monitoring the stress induced by tick infestations. 相似文献
966.
Carvalho LO Calabrese Kda S da Costa SC Mendes VG da Silva AP Barros AC Melo Sde A Abreu-Silva AL 《Experimental parasitology》2008,120(1):123-125
We infected Swiss and C57BL/6 female mice in the left hind footpad with 104Leishmania (L.) amazonensis promastigotes in stationary phase. The macroscopic examination showed a nodular non-ulcerated lesion at the site of inoculation and hepatic and spleenic enlargement. Histopathologically, the primary lesion showed an extensive liquefactive necrosis and inflammatory infiltrate, mainly consisting of macrophages filled with amastigotes, and rare lymphocytes. The inflammatory reaction in liver, spleen and kidney showed amyloid deposits. Additionally, C57BL/6 had accentuated amyloidosis in both ovarian cortical and medullar region and inflammatory infiltrates in the pancreas and adrenal gland. 相似文献
967.
AdipoR1 mediates the anorexigenic and insulin/leptin-like actions of adiponectin in the hypothalamus
Coope A Milanski M Araújo EP Tambascia M Saad MJ Geloneze B Velloso LA 《FEBS letters》2008,582(10):1471-1476
Adiponectin exerts an insulin-sensitizing effect, improving insulin action in peripheral tissues and restraining insulin resistance. Here, we explore the hypothesis that adiponectin can reproduce some of the actions of insulin/leptin in the hypothalamus. The presence of AdipoR1 and AdipoR2 was mapped to the arcuate and lateral hypothalamic nuclei. Icv adiponectin reduced food intake, which was accompanied by activation/engagement of IRS1/2, ERK, Akt, FOXO1, JAK2 and STAT3. All these actions were dependent on AdipoR1, since inhibition of this receptor, and not of AdipoR2, completely reversed the effects described above. Thus, adiponectin acts in the hypothalamus, activating elements of the canonical insulin and leptin signaling pathways and promoting reduction of food intake. 相似文献
968.
Elba V M Maciel Vanduir S Araújo-Filho Mineo Nakazawa Yara M Gomes Luana C B B Coelho Maria T S Correia 《Biologicals》2004,32(1):57-60
The mitogenic effect of Cratylia mollis seed lectin preparations containing two (Cramoll 1,4) or one molecular form (Cramoll 1) showed activity similar to the well known T-cell mitogen, concanavalin A (Con A). The effect on human lymphocytes was analyzed through a colorimetric assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT). Inhibition of lymphocyte proliferation with methyl-alpha-d-mannoside (both preparations) indicated that the mitogenic effect involved carbohydrate lectin binding sites. 相似文献
969.
Braga FR Araújo JV Araujo JM Carvalho RO Silva AR Campos AK Tavela AO 《Journal of helminthology》2008,82(3):241-243
The ovicidal activity of Paecilomyces lilacinus was evaluated on Moniezia sp. eggs. Eggs of Moniezia sp. were incubated on plates with 2% agar-water inoculated with grown fungal isolates and a control treatment without fungus. After 5, 10 and 15 days post-inoculation, the eggs were removed and classified according to the following parameters: effect type 1, lytic effect without morphological damage to eggshells; effect type 2, lytic effect with morphological change in embryos and eggshells; and effect type 3, lytic effect with morphological change in embryos and eggshells, with hyphal penetration and internal colonization of eggs. Paecilomyces lilacinus showed percentages for ovicidal activity (P < 0.01), mainly type 3 effect, of 19, 20 and 23% on eggs of Moniezia sp., after 5, 10 and 15 days post-inoculation, respectively. Therefore P. lilacinus can be considered as a potential biological control agent for this cestode. 相似文献
970.
Interaction between the nematophagous fungus Duddingtonia flagrans and infective larvae of Haemonchus contortus (Nematoda: Trichostrongyloidea) 总被引:1,自引:0,他引:1
The interaction between Duddingtonia flagrans and infective larvae of Haemonchus contortus was studied in vitro under optical and scanning electron microscopy. Trap formation by the fungus started 9 hours after inoculation and first larvae were found 11 hours after larval inoculation on colonies grown on the surface of dialysis membranes. Scanning electron micrographs were taken 12, 24, 36 and 48 h after larval predation. Details of predation structures and fungus-larvae interaction are described. A mucilaginous substance occurred at the points of adherence of traps to nematode cuticle. Bacteria were also found at some points of interaction between fungus and larval cuticle. Cuticle penetration by fungus hyphae occurred only 48 h after predation. 相似文献