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91.
The comparative effects of iron-supplemented levels on growth, tissue distribution, haematology and immunology of gilthead sea bream, Sparus aurata (2 g) were investigated, using four organic (50, 100, 200, 300 mg ORG/kg diet) and one inorganic iron source (200 INOR mg/kg diet). Fish were treated for 12 weeks with the experimental diets and maintained at a water temperature of 19–22°C. Growth (final weight and specific growth rate), tissue distribution (spleen, liver and muscle), haematological parameters (red blood cells, haematocrit, haemoglobin and mean corpuscular haemoglobin concentration) and non-specific immune indexes (respiratory burst activity and antibacterial activity of serum) were analysed. No significant differences were found in growth and iron tissue distribution among the tested groups. Red blood cell counting was statistically higher in fish given 50 ORG, 100 ORG, 200 ORG and 200 INOR feeds. However, haematocrit, haemoglobin and mean corpuscular haemoglobin concentration were not significantly affected by increasing dietary iron. Fish receiving the 100 ORG diet had the best performance with respect to the respiratory burst activity and significantly higher values for antibacterial activity of serum were obtained in fish fed with the 300 ORG diet. The present findings provided no clear evidence of the optimum iron concentration. However, there was adequate indication that iron supplementation enhanced the performance of gilthead sea bream, mainly from a haematological and immunological point of view.  相似文献   
92.
93.
Apolipoprotein (apo) C-III is a low molecular mass protein mainly distributed in the high-density lipoprotein (HDL) fraction. In cows with postparturient diseases such as ketosis, concentrations of cholesterol, phospholipids and apoA-I and the activity of lecithin:cholesterol acyltransferase, which are mainly distributed in or functionally associated with HDL, are reduced. The purpose of the present study was to examine whether the serum concentration of apoC-III was similarly decreased in the postparturient diseases. Compared with healthy controls, the apoC-III concentration was significantly (P<0.01) decreased in cows with fatty liver, ketosis, left displacement of the abomasum, milk fever and retained placenta. Concentrations of apoC-III in the HDL fractions from diseased cows were also lower than in controls. Of the diseased cows, the decreased apoC-III concentration was particularly distinct in cows with milk fever. Increased nonesterified fatty acid and reduced free cholesterol, cholesteryl ester and phospholipid concentrations were observed in cows with milk fever, as in the other diseased cows. The decrease in the apoC-III concentration is suggested to be closely associated with the postparturient disorders, in particular with milk fever.  相似文献   
94.
To engineer resistance against potato virus X (PVX), the viral coat protein (CP) gene has been introduced into two potato cultivars. Stable expression of the gene in transgenic clones throughout the growing season has been obtained and resulted in considerably increased virus resistance. With varying frequencies depending on the original cultivar used, true-to-type PVX resistant transgenic clones have been obtained. Since deviant light sprout characteristics were invariably associated with aberrations in plant phenotype, they can be used in procedures to early screen for deviations. Furthermore, it has been possible to unequivocally discriminate between the original untransformed and independent transgenic cultivars. Although no relation has been found between the presence, if any, of the CP of potato virus Y (PVY) or potato leafroll virus (PLRV) in CP gene transgenic potato, appreciable levels of resistance to these viruses has been obtained. This suggests that the mechanism by which a viral CP gene in the potato genome evokes resistance, differs amongst various viruses.  相似文献   
95.
Follicular epithelium of the thyroid gland of the one-humped camel was examined by light and electron microscopy. It consisted of a single type of epithelial cell which varied from flattened to columnar in shape. Follicular epithelial cells were characterized by the presence of markedly dilated cisternae of rough-surfaced endoplasmic reticulum, well developed Golgi apparatus, abundant small vesicles (150 nm to 200 nm in diameter) in the apical cytoplasm, and electron-dense colloid droplets measuring from 250 nm to 1600 nm. Follicular epithelial cells frequently showed apocrine secretion into colloidal lumens. Apocrine protrusions with smooth surface were dome-like or balloon-like structures and contained a fine granular matrix. These findings indicate that the morphological features of the follicular epithelial cells of the thyroid gland of the camel are essentially similar to those of mammals except for the presence of apocrine secretion, which is unique to the camel.  相似文献   
96.
In order to establish a rapid diagnostic method for contagious equine metritis (CEM), we developed and evaluated a polymerase chain reaction (PCR) test. Species-specific PCR primer sets were derived from the DNA sequence of a cloned DNA fragment of Taylorella equigenitalis that did not hybridize with the genome of a taxomonically related species, Oligella urethralis. Single step PCR with primer set P1-N2 and two-step semi-nested PCR with primer sets P1-N2 and P2-N2 detected as low as 100 and 10 CFU of the bacteria, respectively. Single-step PCR detected T. equigenitalis from genital swabs of experimentally infected mares with sensitivity comparable to that of bacterial isolation. Furthermore, two-step PCR was more sensitive than the culture method. Upon examination of field samples, 12 out of 3,123 samples were positive by single-step PCR while only 2 were positive by bacterial culture. The 12 PCR-positive samples originated from 5 mares, of which 3 animals were considered to be carriers based on previous bacteriologic and serologic diagnoses for CEM. The PCR test described in this study would provide a specific and highly sensitive tool for the rapid diagnosis of CEM.  相似文献   
97.
Experiments on the effect of various compounds with plant growth regulating activity led to the hypothesis that conditions inhibitory to indoleacetic acid (IAA) action or leading to a decrease in the IAA level in cucumber seedlings would be unfavourable for the development of cucumber scab, caused byCladosporium cucumerinum. Susceptibility decreased as the result of treatment with growth retardants, which cause an increase in IAA-oxidase activity in the plants, whereas application of indoleacetic acid or compounds expected to decrease the rate of oxidative breakdown of IAA in the seedlings resulted in an increase of susceptibility. Growing the plants under various periods of illumination also influenced both the susceptibility of the plants and the IAA-oxidase activity in the hypocotyl tissue.To obtain further information about the relation between the increase in resistance and the increase in the rate of IAA oxidation, the effect of one compound, viz. L-threo-β-phenylserine (abbr. phenylserine) was studied in more detail. The rate of oxidative breakdown of IAA was increased in extracts of hypocotyls and cotyledons of plants treated with phenylserine as compared with extracts of tissue of untreated plants. Extracts of phenylserine-treated plants were found to contain a higher cofactor and/or a lower inhibitor content than those of control plants. The substances involved were not identified, but this result may indicate a shift in the concentrations of various phenols in the tissue.The question must remain open whether a shift in the concentration of phenols some-how effected by phenylserine treatment determines both degree of susceptibility and rate of IAA oxidation independently, or whether the rate of IAA breakdown and the resulting change in IAA content in the plants is directly related to the degree of susceptibility.  相似文献   
98.
99.
ABSTRACT Alternaria citri, a postharvest pathogen, produces endopolygalacturonase (endoPG) and causes black rot on citrus fruit. We previously described that an endoPG-disrupted mutant of Alternaria citri was significantly reduced in its ability to macerate plant tissue and cause black rot symptoms on citrus. In order to investigate colonization of citrus fruit tissues by Alternaria citri, pTEFEGFP carrying a green fluorescent protein (GFP) gene was introduced into wild-type Alternaria citri and its endoPG-disrupted mutant (M60). Green fluorescence was observed in spores, germ tubes, appressoria, and infection hyphae of transformants G1 (derived from wild type) and GM4 (derived from M60). Hyphae of G1 but not GM4 vertically penetrated the peel, but the hyphae of both G1 and GM4 spread equally in the juice sac area of citrus fruit. Green fluorescence of Alternaria citri transformant EPG7 carrying a GFP gene under control of the endoPG gene promoter of Alternaria citri was induced by pectin in the peel during the infection stage, but repressed completely in the juice sac area, likely by carbon catabolite repression by sugars in the juice.  相似文献   
100.
 A potyvirus, for which the name Japanese hornwort mosaic virus (JHMV) is proposed, was isolated from Japanese hornwort plants (Cryptotaenia japonica) with mosaic disease symptoms. The virus was used to inoculate mechanically 34 plants belonging to 33 species of 10 families. Of these species seven from two families were infected. Faint chlorotic spots appeared on the inoculated leaves of Chenopodium quinoa and C. amaranticolor, but no systemic infection occurred in these plants. JHMV systemically infected only Umbelliferae plants; they did not infect 26 other species in eight families. JHMV was transmitted in a nonpersistent manner by aphids (Myzus persicae). The virus was a flexuous rod-shaped particle about 750 nm in length. Sequencing the nucleotides in the 3′ terminal region of JHMV revealed that the coat protein contains 280 amino acids with a molecular mass of 32.2 kDa. The nucleotide sequence of the coat protein of JHMV had the highest similarity with that of Zantedeschia mosaic virus (83.3%) compared to those of other potyviruses (57.0%–64.9%). An antiserum against JHMV reacted strongly with JHMV and weakly with Potato virus Y. These results indicate that JHMV is a new potyvirus. Received: September 9, 2002 / Accepted: November 7, 2002 RID="*" ID="*" The nucleotide sequence determined in this work appears in the DDBJ/EMBL/GenBank nucleotide sequence databases with the accession number AB081518  相似文献   
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