Sexual dimorphism of the kidney in the NMRI mouse as shown by Dolichos biflorus agglutinin labelling     

Johanna  Plendl  Barbara  Schoenlejber  W. Schmahl    A. Beatrice  Murray F. Sinowatz 《Anatomia, histologia, embryologia》1992,21(2):118-126

The histological affinity pattern of Dolichos biflorus agglutinin (DBA) in kidneys from mice (NMRI, Balb/c, CBA) and rats (Wistar) fixed by perfusion with formalin, Bouin, or HgCl2 was investigated with a horseradish peroxidase conjugate. The animals were examined from fetal stage to adulthood. Adult female NMRI mice exhibited constant DBA labelling, with DBA binding to cells of the proximal and collecting tubules. Moreover the vascular endothelium of the renal papilla was found to be DBA-positive in 50% of adult female animals. In contrast, there was only very little DBA binding in the kidneys of male adult NMRI mice. There was no sexual dimorphism in lectin labelling in kidneys from other strains of mice or from rats.  相似文献   

Serological diagnosis of human hypodermosis: A preliminary report     

Chantal Boulard  J. Petithory 《Veterinary parasitology》1977,3(3):259-263

In France, farm workers are occasionally infested with the larvae of Hypoderma lineatum and H. bovis, which are primirily parasites of cattle. A specific serological test for diagnosing human cases is described here.The immunological responses in cattle are directed mainly against the proteolytic secretion of the first instar larvae. This secretion was used as an antigen for the diagnostic immuno-electrophoretic test in man. The antigen was highly specific and produced negative results to human sera from 108 patients with other forms of parasitoses and 23 non- parasitized controls.We report here on 13 cases of Hypoderma infestation in man. Ten of these were positive and three negative to the test. In the negative cases, the serum was collected 1–2 months after the emergence of the larvae. The immunological response disappeared rapidly after larval emergence; in one case within 9 days.  相似文献   

Factors associated with fusarium crown and root rot of asparagus outbreaks in quebec     

Hamel C  Vujanovic V  Nakano-Hylander A  Jeannotte R  St-Arnaud M 《Phytopathology》2005,95(8):867-873

ABSTRACT The Fusarium spp. causing Fusarium crown and root rot (FCRR) are ubiquitous and abundant in soils, but in contrast, disease expression is localized and sporadic. Previous studies have related FCRR infection to phenolic acids released by asparagus, to the repression of Mn-reducers in soil, and to various soil physicochemical conditions. Fifty commercial asparagus plantations were surveyed using an exploratory approach in order to pinpoint the ecological conditions associated with FCRR development. Twenty-eight variables were used to describe the soil environments of the asparagus crops as well as the influence of crop management practices used locally. The data set was analyzed both as a whole and parsed by main cultivars (Jersey Giant and Guelph Millenium). Both field conditions and percentage of field area affected by FCRR varied widely between asparagus plantations. Planting depth was positively correlated with percentage of field area affected by FCRR and, hence, deep planting may favor FCRR infection. Plantation age was positively correlated with percentage of field area affected by FCRR, while soil available Mn was inversely correlated. Most importantly, soil Mn availability decreased with increasing plantation age, supporting the hypothesis of an asparagusmediated negative impact on Mn-reducing bacteria and of the involvement of reduced Mn availability in FCRR development. Improving the availability of Mn could provide a solution to the problem of FCRR in asparagus plantations.  相似文献   

Genetic Variability and Structure of Canadian Populations of the Sapstain Fungus Ceratocystis resinifera     

Morin C  Breuil C  Bernier L 《Phytopathology》2004,94(12):1323-1330

ABSTRACT Genomic DNA was extracted from 129 isolates of Ceratocystis resinifera, a species belonging to the C. coerulescens complex, and 19 polymorphic random amplified polymorphic DNA markers were used to study the population genetic structure of this fungus. The analysis suggested a moderate value for genetic diversity (H(S) = 0.209). However, when monomorphic markers and rare alleles, representing 89 markers, also were included in the calculation, the genetic diversity of Canadian populations of C. resinifera appeared to be much lower (H(S) = 0.045). This could be explained by two hypotheses: (i) recent introduction of this species into North America and (ii) clonal reproduction (by selfing). No specialization by C. resinifera for coniferous tree species was observed based on genetic differentiation index between isolates sampled from Pinus and Picea spp. and on phylogenetic analysis using Dice coefficient of association. In spite of a low genetic diversity, a very high genetic differentiation was observed among the nine geographical populations studied (F(ST) = 20.8%). The genetic differences were especially striking when populations from Eastern Canada were compared with populations from Western Canada (phiST = 0.27%; P < 0.001), suggesting that a geographic reproductive barrier occurs in Central Canada. This barrier may be the consequence of a weak migration of insect vectors of C. resinifera due to reduced presence of hosts in the Canadian Great Plains, where extensive agriculture occurs. However, results from pairwise F(ST) matrix and phylogeny of haplotypes suggest that the barrier is not totally impenetrable because some gene flow occurred from the west and from the east in the Big River (Saskatchewan) population located in the middle of the Great Plains.  相似文献   

Immune response and antigen recognition in non-pregnant ewes experimentally infected with Neospora caninum tachyzoites     

Rettigner C  Lasri S  De Meerschman F  Focant C  Beckers JF  Losson B 《Veterinary parasitology》2004,122(4):261-271

The cellular and humoral responses as well as the antigen recognition during the acute stage of a Neospora caninum (NC) infection were investigated in non-pregnant ewes. The experimentally infected ewes developed specific lymphoproliferative and humoral responses within 2 weeks post-infection (PI). The magnitude of the cellular response showed large variations between animals. A significant decrease in the proliferative response to Con A mitogen and N. caninum, Toxoplasma gondii (TG) antigens was recorded on day 21 post-infection (PI). The humoral response and the pattern of antigen recognition were similar among infected ewes. Proteins of 44, 42, 40, 39 and 28 kDa were intensively recognized by the infected animals during the experiment. The 42 and 28 kDa antigens should be considered as useful for the diagnostic of N. caninum infection, as the intensity of recognition infection of the other antigens had decreased markedly 8 weeks post-infection. For some antigens a sequential recognition was recorded. The 59, 54 and 38-37 kDa proteins were frequently recognized by infected sera during the first weeks of the infection, but recognition of these antigens was absent or rare at the end of the experiment. These antigens could be related to the acute stage of the infection.  相似文献   

Structural requirements for the antimicrobial activity of carvacrol     

Veldhuizen EJ  Tjeerdsma-van Bokhoven JL  Zweijtzer C  Burt SA  Haagsman HP 《Journal of agricultural and food chemistry》2006,54(5):1874-1879

Carvacrol is a component of several essential oils and has been shown to exert antimicrobial activity. The structural requirements for the activity of carvacrol were determined by comparison to structurally related (nonessential oil) compounds. Removal of the aliphatic ring substituents of carvacrol slightly decreased the antimicrobial activity. The effect of the hydroxyl group of carvacrol on activity could not be determined by simply comparing it to p-cymene, because this compound is immiscible with water; therefore, 2-amino-p-cymene, the amino analogue of carvacrol, which has a similar hydrophobicity and structural characteristics, was used. 2-Amino-p-cymene had similar membrane disruption and bacterial killing characteristics as carvacrol showing that, contrary to previous reports, the hydroxyl group of carvacrol itself is not essential for the antimicrobial activity. However, the observed 3-fold lower activity for 2-amino-p-cymene as compared to carvacrol indicates special features in the antimicrobial mode of action of carvacrol due to the hydroxyl group.  相似文献   

Effect of protein structure on laccase-catalyzed protein oligomerization     

Mattinen ML  Hellman M  Permi P  Autio K  Kalkkinen N  Buchert J 《Journal of agricultural and food chemistry》2006,54(23):8883-8890

Laccase-catalyzed oligomerization of proteins was studied using Trametes hirsuta laccase (ThL) and coactosin as a model system. The reaction mechanism was elucidated using free amino acids and the tripeptide Gly-Leu-Tyr as substrates. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and high-performance liquid chromatography (HPLC) as well as oxygen consumption measurements and SDS-PAGE were used to study the reactions. Of the 15 selected amino acids, ThL was found to oxidize tryptophan (Trp), tyrosine (Tyr), and cysteine (Cys), of which the reactions with Tyr and Cys have been described earlier. ThL was able to link four full-length coactosins, whereas coactosin that was truncated from its C-terminus remained unpolymerized. Of the four tyrosine residues present in coactosin, only the tyrosine in the C-terminus was found to be reactive. Polymerization between tyrosine side-chains was unambiguously shown using different oligomers of Gly-Leu-Tyr as parent ions in MALDI-TOF/TOF MS fragment ion analyses.  相似文献   

The flavonol quercetin-3-glucoside inhibits cyanidin-3-glucoside absorption in vitro   总被引：1，自引：0，他引：1  

Walton MC  McGhie TK  Reynolds GW  Hendriks WH 《Journal of agricultural and food chemistry》2006,54(13):4913-4920

At present, little is known about the mechanisms responsible for intestinal absorption of anthocyanins (ACNs). For example, it has not yet been established if ACNs are absorbed through an active transport mechanism, such as the sodium-dependent glucose transporter (SGLT1), or by passive diffusion. Previously, we found that the absorption of ACNs differs between regions of the digestive tract and is maximal in the jejunum, suggesting that an active transport mechanism is involved. In the present study, we examined the effect of d-glucose (main substrate of SGLT1), phloridzin (inhibitor of SGLT1), and quercetin-3-glucose (Q3G, a flavonol) on the absorption of cyanidin-3-glucoside (C3G; approximately 5 micromol/L) by mouse jejunum mounted in Ussing chambers. We found that the presence of either D-glucose (10, 20, and 40 mmol/L) or phloridzin (50, 100, and 200 micromol/L) resulted in a small but insignificant inhibition of C3G disappearance from the mucosal solution (decrease of disappearance with glucose, 33%; with phloridzin, 18%; NS). However, when the flavonol Q3G (50 micromol/L) was added to the mucosal solution together with the C3G, the disappearance of C3G was significantly decreased (74%; p < 0.001), and Q3G disappeared instead. In addition, we found phloretin and quercetin, the aglycones of phloridzin and Q3G, respectively, present in the mucosal solution and tissue extracts, indicating hydrolysis of these compounds by the enterocytes of the jejunum. In contrast, the aglycone cyanidin was not detected at all. Our results show that in the mouse small intestine, ACN absorption is not solely dependent on the activity of the SGLT1 transporter, as d-glucose and phloridzin had only a slight effect on uptake. Q3G, however, clearly inhibited C3G disappearance. These results suggest that there might be a competitive inhibition between C3G and Q3G absorption. It is possible that an absorption mechanism other than the SGLT1 is involved, which has a structural preference toward flavonols.  相似文献   

Biodiversity research still grounded     

Hendriks IE  Duarte CM  Heip CH 《Science (New York, N.Y.)》2006,312(5781):1715

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Analysis of factors to predict piglet body weight at the end of the nursery phase     

Paredes SP  Jansman AJ  Verstegen MW  Awati A  Buist W  Den Hartog LA  Van Hees HM  Quiniou N  Hendriks WH  Gerrits WJ 《Journal of animal science》2012,90(9):3243-3251

In pig (Sus Scrofa) production, within-batch variation in bw gain of piglets during the nursery period (up to 10 wk of age) can be high and is of high economic importance. Homogeneity of BW within batches of animals is important as it influences the efficiency of use of the grower and finisher facilities, and provides an extra value for the fattening farms. In the current study, factors for a light BW at the end of the nursery period of pigs were determined by analyzing datasets from 3 different swine research centers in the Netherlands and France. The entire dataset contained information on 77,868 individual piglets born between 2005 and 2010. Body weight was determined at different time points over the pre- and post-weaning phase, and sex, season of birth, litter information (litter size at day of birth and after cross-fostering, number of piglets born alive per litter, number of total born littermates, sow parity number), cross-fostered animals (yes or no), and pen group size over the post-weaning period were recorded. A risk factor analysis approach was used to analyze the datasets to determine factors that predict piglet bw at the end of the nursery period. Body weight at the end of the nursery period corrected for age was mainly determined by season (P < 0.001), birth weight (BiW, P < 0.001), weaning weight (WW, P < 0.001), and BW at 6 wk of age (P < 0.001). These variables were consistent among datasets and explained approximately 70% of the overall variation in BW at the end of the nursery period. Litter information did not significantly (P > 0.05) contribute to explaining the BW at the end of the nursery period. To discard the possibility of intrauterine growth retarded piglets (IUGR) being the reason for the influence of BiW as an explanatory factor in the regression model, a further analysis was performed on the effect of this category of piglets on the results of the regression analysis. Overall, it was concluded that the bw of piglets at the end of the nursery phase is mainly determined by season, sex, birth, WW, and BW at 6 wk of age. Piglets with a BiW greater than the mean biw minus 2.5 times the sd have the potential to compensate during the subsequent phases of growth.  相似文献