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31.
Haemocytes of the giant freshwater prawn, Macrobrachium rosenbergii, were investigated for the induction of apoptosis after phagocytosis of pathogenic yeasts, bacteria and non-pathogenic latex beads in vitro. Isolated haemocytes of M. rosenbergii were cultured at a ratio of 1:50 haemocytes to pathogen with the yeast Debaryomyces hansenii, the bacteria Aeromonas hydrophila or Enterococcus faecium, or with latex beads at 25 degrees C for 2 h, followed by washing to remove free particles. At least 200 haemocytes were counted to determine the phagocytosis rate, and the results showed that haemocytes engulfed latex beads at a higher rate than the aquatic pathogens. By transmission electron microscopy, the yeast- or bacterium-engulfing haemocytes displayed morphological changes characteristic of apoptosis, including formation of cytoplasmic vacuoles, chromatin condensation and fragmentation of nuclei. This pathogen-induced apoptosis was further confirmed by DNA laddering and TUNEL (terminal deoxynucleotidyl transferase-mediated deoxy-UTP nick-end-labelling) assays. Neither haemocytes treated with latex beads nor uninfected haemocytes (control group) showed signs of apoptosis after 48 h in culture.  相似文献   
32.
Ischaemia and reperfusion are suspected to alter chondrocyte metabolism. Here, we studied the effects of three oxygen (O2) tensions on the viability of equine articular chondrocytes isolated from the cartilage of the distal interphalangeal joint of horses. Chondrocytes were cultured in alginate beads under 1%, 5% or 21% gas phase O2 concentration for 14 days, cellular growth kinetics were measured (n=6), and the cells were observed by light microscopy after staining for necrotic and apoptotic cell detection. For information about the metabolic status, the intracellular adenosine triphosphate (ATP) content was measured. The number of chondrocytes remained stable for the first eight days, then decreased especially at 1% and 21% O2. At 21% O2, normal cells decreased and necrotic cells increased at the end of the 14 day-period. No significant variations were found at 5% O2 except for a decrease in necrotic cells at day 14. Most apoptotic cells were found at 1% O2 from days 5 to 11, and normal cells decreased during the same period. But an unexpected increase in normal cells and decrease in apoptotic cells were observed at day 14. The intracellular ATP content remained stable. It was concluded that, in a three-dimensional culture model of equine articular chondrocytes, O2 tension affected the viability of the cells after an 11-day period, with the most important effects observed at 21% and 1% O2 conditions.  相似文献   
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Background: Activation of the KIT receptor tyrosine kinase is associated with the development of canine mast cell tumors (MCT). Hypothesis/Objective: To evaluate the efficacy of masitinib, a potent and selective inhibitor of KIT, in the treatment of canine MCT. Animals: Two hundred and two client‐owned dogs with nonmetastatic recurrent or nonresectable grade II or III MCT. Methods: Double‐blind, randomized, placebo‐controlled phase III clinical trial. Dogs were administered masitinib (12.5 mg/kg/d PO) or a placebo. Time‐to‐tumor progression (TTP), overall survival, objective response at 6 months, and toxicity were assessed. Resulsts: Masitinib increased overall TTP compared with placebo from 75 to 118 days (P= .038). This effect was more pronounced when masitinib was used as first‐line therapy, with an increase in the median TTP from 75 to 253 days (P= .001) and regardless of whether the tumors expressed mutant (83 versus not reached [P= .009]) or wild‐type KIT (66 versus 253 [P= .008]). Masitinib was generally well tolerated, with mild (grade I) or moderate (grade II) diarrhea or vomiting as the most common adverse events. Conclusions and Clinical Importance: Masitinib is safe and effective at delaying tumor progression in dogs presenting with recurrent or nonresectable grade II or III nonmetastatic MCT.  相似文献   
35.
The grape berry microclimate is known to influence berry quality. The effects of the light exposure of grape berry clusters on the composition of berry tissues were studied on the "Merlot" variety grown in a vineyard in Bordeaux, France. The light exposure of the fruiting zone was modified using different intensities of leaf removal, cluster position relative to azimuth, and berry position in the cluster. Light exposures were identified and classified by in situ measurements of berry temperatures. Berries were sampled at maturity (>19 Brix) for determination of skin and/or pulp chemical and metabolic profiles based on (1) chemical and physicochemical measurement of minerals (N, P, K, Ca, Mg), (2) untargeted 1H NMR metabolic fingerprints, and HPLC targeted analyses of (3) amino acids and (4) phenolics. Each profile defined by partial least-square discriminant analysis allowed us to discriminate berries from different light exposure. Discriminant compounds between shaded and light-exposed berries were quercetin-3-glucoside, kaempferol-3-glucoside, myricetin-3-glucoside, and isorhamnetin-3-glucoside for the phenolics, histidine, valine, GABA, alanine, and arginine for the amino acids, and malate for the organic acids. Capacities of the different profiling techniques to discriminate berries were compared. Although the proportion of explained variance from the 1H NMR fingerprint was lower compared to that of chemical measurements, NMR spectroscopy allowed us to identify lit and shaded berries. Light exposure of berries increased the skin and pulp flavonols, histidine and valine contents, and reduced the organic acids, GABA, and alanine contents. All the targeted and nontargeted analytical data sets used made it possible to discriminate sun-exposed and shaded berries. The skin phenolics pattern was the most discriminating and allowed us to sort sun from shade berries. These metabolite classes can be used to qualify berries collected in an undetermined environment. The physiological significance of light and temperature effects on berry composition is discussed.  相似文献   
36.
The pH values and temperatures at 45 min, and 3, 9, 15, and 24 h postmortem in the LM and semimembranosus muscle (SM) and glycolytic potential in LM were measured in 1,030 F(2) animals from a White Duroc x Erhualian resource population. A whole genome scan was performed with 183 microsatellites covering 19 porcine chromosomes to detect QTL for traits measured. A total of 73 QTL have been identified, including 1% genome-wise significant QTL for 24-h pH in LM and SM on SSC 15, and for glycolytic potential, total glycogen, and residual glycogen on SSC3, 6, and 7. Six 5% genome-wise significant QTL were detected for 9-h pH in SM on SSC3, pH decline from 3/9 h to 24 h in SM on SSC7, glycolytic potential on SSC1, and total glycogen on SSC1 and 6. This study confirmed QTL previously identified for pH except those on SSC1, 11, 12, and X, and found 11 new 5% genome-wise significant QTL for glycogen-related traits. This is the first time to report QTL for pH development during post-slaughter and for glycolytic potential at 5% genome-wise significance level. In addition, the observed different QTL for pH and pH decline at different times show that causal genes for pH postmortem play distinct roles at specific stages, in specific muscles, or both. These results provide a starting point for fine mapping of QTL for the traits measured and improve the understanding of the genetic basis of pH metabolism after slaughter.  相似文献   
37.
The aim of this work was to estimate whether genetic dissection of QTL on chromosomes 1, 2, 4, and 7, detected in an F2 Meishan x Large White population, can be achieved with a recombinant back-cross progeny test approach. For this purpose, a first generation of backcross (BC1) was produced by using frozen semen of F1 Large White x Meishan boars with Large White females. Four BC1 boars were selected because of their heterozygosity for at least 1 of the 4 regions. The BC1 boars were crossed with Large White sows, and the resulting BC2 offspring were measured for several growth and body composition traits. Contrary to the F2 animals, BC2 animals were also measured for meat quality traits in adductor, gluteus superficialis (GS), longissimus dorsi, and biceps femoris (BF) muscles. Each BC1 boar was tested for a total of 39 traits and for the 4 regions with statistical interval mapping analyses. The QTL effects obtained in BC1 families showed some differences compared with those described in F1 families. However, we confirmed QTL effects for growth in the SW1301-SW2512 markers interval on chromosome 1 and also for body composition in the SW1828-SW2512 markers interval on chromosome 1, in the SW2443-SWR783 markers interval on chromosome 2, and in the SW1369-SW632 markers interval on chromosome 7. In addition, we detected new QTL for growth traits on chromosome 2 and for meat quality traits on chromosomes 1 and 2. Growth of animals from weaning to the end of the test was influenced by the IGF2 gene region on chromosome 2. Concerning meat quality, ultimate pH of adductor, longissimus dorsi, and BF were affected by the interval delimited by UMNP3000 and SW2512 markers on chromosome 1, and a* of GS, L* of BF, and water-holding capacity of GS were affected by QTL located between marker loci SW2443 and SWR783 on chromosome 2. Recombinant progeny testing appeared to be a suitable strategy for the genetic dissection of the QTL investigated.  相似文献   
38.
The Mars Express Observatoire pour la Minéralogie, l'Eau, les Glaces, et l'Activité (OMEGA) hyperspectral image data covering eastern Terra Meridiani indicate the ubiquitous presence of molecular water in etched terrain materials that disconformably overlie heavily cratered terrains and underlie the hematite-bearing plains explored by the Opportunity rover. Identification of crystalline water in kieserite (MgSO4.H2O) is linked to materials exposed in a valley and plateau to the north of hematite-bearing plains. The mineralogical similarities between the etched terrain deposits examined with OMEGA data and the layered rocks examined by Opportunity imply that the ancient aqueous environments inferred from analyses of the rover data extend over regional scales.  相似文献   
39.
L'étude quantitative du potentiel semencier d'un sol cultivé pose le problème du nombre de prélèvements à réaliser pour avoir une estimation satisfaisante du nombre de semences par hectare. Les prélèvements sont traités séparément et analysés espèce par espèce. On a constaté une relation linéaire entre la moyenne et la variance de la population (après transformation logarithmique), ce qui permet de déterminer la taille de l'échantillon en fonction d'une part, du nombre moyen de semences par prélèvement, d'autre part, du degré de précision souhaité. En pratique, une centaine de prélèvements est nécessaire pour obtenir une précision de 20 à 70 p. 100 (au seuil de 5 p. 100) lorsque le nombre moyen de semences par prélèvement varie de 5 à 0, 1. Study of the size of the sampling for the study of the buried weed seed bank The quantitative study of the weed seed bank of a cultivated soil involves the problem of the number of cores which need to be taken to give a satisfactory estimation of the number of seeds per hectare. The soil cores were treated separately and analysed species by species. There is a linear regression between the mean and the variance of the seed population (after logarithmic transformation) that allows the determination of the number of cores as well as the mean number of seeds per core with the required precision. In practice, one hundred cores was necessary to obtain a precision from 20 to 70% (at 5% level) when the mean number of seeds by core vary from 5 to 0, 1. Studie über die Entnahme von Bodenproben zur Bestimmung des Samenvorrats eines Ackerbodens Eine quantitative Bestimmung des Samenvorrats eines Bodens stellt uns vor das Problem wieviele Bodenmuster zu entnehmen sind, um eine zuverlässige Schätzung der Samenmenge pro Hektar zu erhalten. Die Bodenmuster werden einzeln ausgewartet und auf die vorhandenen Samenarten analysiert. Es wurde eine lineare Beziehung zwischen dem Mittel und der Varianz der Samen-population (nach logarithmischer Transformation) festgestellt, was die Bestimmung des Umfangs der Proben ermöglicht; einerseits in Funktion der mittleren Samenzahl pro Probe, andrerseits in Funktion der gewünschten Genauigkeit. In der Praxis sind ca. 100 Probenentnahmen notwendig um eine Zuverlässigkeit von 20–70% (auf dem Niveau von 5%) zu erreichen, wenn die mittlere Samenzahl pro Muster zwischen 5 und 0,1 liegt.  相似文献   
40.
Salmonella Pathogenicity Island 1 (SPI-1) genes are indispensable for virulence of Salmonella Typhimurium in mice after oral challenge. These genes mediate invasion in intestinal epithelial cells and induce cell death in murine macrophages. The role of SPI-1 in the pathogenesis of Salmonella Typhimurium infections in food producing animals is not known. It was the aim of the present study to characterize the interactions of a porcine Salmonella Typhimurium field strain and its isogenic mutants in the SPI-1 genes hilA, sipA and sipB with porcine macrophages. SPI-1 was found to be important in the invasion of porcine pulmonary alveolar macrophages (PAM) and the induction of the formation of spacious phagosomes. Both early and delayed cytotoxicity were seen in PAM, but only the early cytotoxicity was SPI-1 dependent. Exposure of PAM to Salmonella Typhimurium induced the production of reactive oxygen species (ROS) and interleukin-8, but no differences were noticed between the induction mediated by the wild type strain and its SPI-1 mutant strains. In conclusion, invasion of porcine macrophages and the induction of early, but not delayed, cytotoxicity by Salmonella Typhimurium is SPI-1 dependent. SPI-1 dependent invasion, however, is not a prerequisite to induce a pro-inflammatory response.  相似文献   
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