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31.
SMEDI and hog cholera viruses were shown to have marked effects upon the survival of the embryo (from conception to 30 days of gestation), the fetus (from 30 days of gestation until birth), and the neonatal pig (from birth until five days after birth). Embryonic infection was characterized by death and absorption of the embryo and in some instances the return to estrus after an irregular estrous cycle. Embryonic infection also may have been responsible for the development of some abnormal pigs. Fetal infection caused death with mummification of one or more fetuses and occasionally all fetuses in the uterus. Infection established in early gestation produced effects on the fetus which apparently persisted until after birth and varied from a persistent viremia (as in hog cholera infection) to an undefined lack of resistance in the newborn (as in SMEDI virus infection). Hog cholera vaccinal virus was the more virulent of the two virus types and reacted somewhat like rubella virus, in that infection apparently could be established in the fetus even in middle trimester of pregnancy, and possibly later. SMEDI viruses, in contrast, were less virulent and were most pathogenic when the dam was infected during the first 30 days of pregnancy. Immunity against either virus could be established in the nonpregnant gilt and was most effective in preventing intrauterine infections with that virus. However, with as many as 10 enteroviruses (five are known to cause intrauterine infection) it was believed that maintaining a closed breeding herd and introducing new stock into contact with the breeding herd at least 30 days before breeding time might be a safer means of control.  相似文献   
32.
Expression of a tumor-associated antigen, RCAS1, in canine mammary tumors   总被引:2,自引:0,他引:2  
Receptor-binding cancer antigen expressed on SiSo cells (RCAS1), one of novel cancer cell-surface antigens, is strongly expressed in invasive cancers. RCAS1 inhibits the in vitro growth of lymphocytes such as T cells and natural killer (NK) cells, and induces apoptotic cell death. We investigated the expression of RCAS1 in canine mammary tumor cell lines and tumor cells by immunohistochemistry, and also in situ deoxyribonucleic acid (DNA) fragmentation in tumor-infiltrating lymphocytes (TILs) by the terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labeling (TUNEL) method. All canine mammary tumor cell lines expressed RCAS1 at both the messenger ribonucleic acid (mRNA) and protein level. Immunohistochemically, RCAS1 was negative in 100% of normal mammary glands, but was expressed in 100% of malignant tumors examined. In most malignant mammary tumors, RCAS1 was localized in the cytoplasm with no polarity of expression. In benign mammary tumors, it was detected on the luminal surface of the tumor cell. RCAS1 expression or localization was significantly correlated with malignancy. In situ DNA fragmentation of CD3-positive TILs was observed in RCAS1-expressing tumors. RCAS1-expressing tumors, indicating a possible induction of apoptotic cell death in TILs through RCAS1 expression. These observations suggest that RCAS1 probably plays an important role in tumor progression and escape from immune surveillance in canine mammary tumors.  相似文献   
33.
Cell-free protein synthesizing system from yeast mitochondria   总被引:3,自引:0,他引:3  
An active, cell-free protein synthesizing system has been obtained from yeast mitochondria. The system is stimulated by both polyuridylate and R17 RNA and is sensitive to inhibitors of bacterial protein synthesizing systems. A comparison is made between this system and that found in the cytoplasm of yeast.  相似文献   
34.
The protein components of eukaryotic cells face acute and chronic challenges to their integrity. Eukaryotic protein homeostasis, or proteostasis, enables healthy cell and organismal development and aging and protects against disease. Here, we describe the proteostasis network, a set of interacting activities that maintain the health of proteome and the organism. Deficiencies in proteostasis lead to many metabolic, oncological, neurodegenerative, and cardiovascular disorders. Small-molecule or biological proteostasis regulators that manipulate the concentration, conformation, quaternary structure, and/or the location of protein(s) have the potential to ameliorate some of the most challenging diseases of our era.  相似文献   
35.
The product resulting from the reaction between E-2-hexenal and l-cysteine was shown to be a diastereoisomeric mixture of 2-(2-S-l-cysteinylpentyl)-1,3-thiazolidine-4-carboxylic acid 1. Treatment of the conjugate with two sources of cysteine-S-conjugate beta-lyase (tryptophanase from E. coli and a crude enzyme extract prepared from Eubacterium limosum) resulted in the formation of 3-mercaptohexanal. The reaction proceeded with a slight preference for the (S)-configured product, however, with low conversion rate. The role of 3-S-l-cysteinylhexanal 2 as substrate for beta-lyases was demonstrated by in situ generation of 2 from 3-S-(N-acetyl-l-cysteinyl)hexanal using acylase. Opposite enantioselectivity was observed for the liberation of 3-mercaptohexanol from 3-S-l-cysteinylhexanol 5 by the enzyme preparations from Eubacterium limosum and tryptophanase. Various yeasts produced 3-mercaptohexanol starting from 1 as well as from 5. The reactions proceeded without preferential formation of one of the enantiomers.  相似文献   
36.
Feeding trials were carried out to examine substances that could be used as supplements in low‐protein/high‐lipid diets to improve protein digestion of yellowtails (Seriola quinqueradiata) during winter. Dietary supplementation with synthetic or natural (krill and squid extracts) feeding stimulants (FS) improved feed intake and growth performance of yellowtails. Moreover, the apparent protein digestibility (APD) and pepsin, trypsin and chymotrypsin secretions in fish fed diets supplemented with the different FS were superior to those in fish fed the control diet. These findings suggest that the dietary inclusion of either synthetic or natural FS is a potential tool for improving protein digestion at low water temperatures, and may provide a promising solution for the winter growth retardation experienced in yellowtail culture.  相似文献   
37.
Insect antifeedant flavonoids from Gnaphalium affine D. Don   总被引:3,自引:0,他引:3  
The antifeedant flavonoids, 5-hydroxy-3,6,7,8,4'-pentamethoxyflavone (1), 5-hydroxy-3,6,7,8-tetramethoxyflavone (2), 5,6-dihydroxy-3, 7-dimethoxyflavone (3), and 4,4',6'-trihydroxy-2'-methoxychalcone (4), have been isolated from cudweed Gnaphalium affine D. Don (Compositae). Four natural flavonoids showed insect antifeedant activity against the common cutworm (Spodoptera litura F.). These flavonoids were detected in small amounts in the plant by HPLC analysis, but these natural compounds had strong antifeedant activity against the common cutworm. On the other hand, 4 was detected in a large amount in the plant, but this compound had only a slight activity. Therefore, these natural compounds were regarded as one of the plant's defensive systems against phytophagous insects along with the woolly plant surface. As for the structure-activity relationship, it is an advantage for antifeedant activity to have no oxy-substituents on the B-ring of the flavonoid but have an ether linkage such as a pyran in the chemical structure.  相似文献   
38.
This study aims to understand Th2 immune responses and alternative macrophage activation against nematode parasites in aged mice. Eighteen-month (18 M) and three-month (3 M) old C3H/HeN mice were inoculated with Heligmosomoides polygyrus (Hp) larvae. Real-time PCR analysis indicated that interleukin (IL)-4 and IL-13 gene expression was elevated in both groups after infection, but the expression level was significantly low in 18 M mice. Macrophage phenotype was monitored by measuring arginase-1 gene expression and immunofluorescence staining in small intestine, showing a decrease in the number of alternatively activated macrophages (AAMacs) around worm cysts in 18 M mice. These results suggest that the Th2 immune response in aged mice against a nematode parasite was not sufficiently induced to promote AAMacs.  相似文献   
39.
The accident at the Fukushima Daiichi Nuclear Power Plant (FNPP) released a large amount of radioactive substances into the environment. Furthermore, beef contaminated with radioactive cesium above the 500 Bq/kg safety standard was circulated in the food chain in 2011. Japanese consumers remain concerned about the safety of radioactively contaminated food. In our previous study, we detected a linear correlation between radioactive cesium (137Cs) activity in blood and muscle around 500 to 2500 Bq/kg in cattle. However, it was unclear whether the correlation was maintained at a lower radioactivity close to the current safety standard of 100 Bq/kg. In this study, we evaluated 17 cattle in the FNPP evacuation zone that had a 137Cs blood level less than 10 Bq/kg. The results showed a linear correlation between blood 137Cs and muscle 137Cs (Y = 28.0X, R2 = 0.590) at low radioactivity concentration, indicating that cesium radioactivity in the muscle can be estimated from blood radioactivity. This technique would be useful in detecting high‐risk cattle before they enter the market, and will contribute to food safety.  相似文献   
40.
Glutathione which is an abundant reduced sulfur compound in plants is considered to play important roles in the transmission of the sulfur nutrient status between organs within the plant body and in the long-distance transport of reduced sulfur. We determined the concentrations of glutathione, γ-glutamylcysteine (γ-EC), sulfate in the rice phloem sap collected by the insect laser technique. Phloem sap was collected from the plants cultured in sulfur-deficient and control solutions. The concentration of glutathione in the rice phloem sap was higher than that of sulfate in both control and sulfur-deficient plants. Under sulfur-deficient condition, the concentration of glutathione in the phloem sap did not decrease, whereas the sulfate concentration decreased significantly. The pattern of changes in γ-EC concentration was similar to that of glutathione. These data indicate the presence of mechanisms for the maintenance of a constant glutathione concentration in the phloem sap in rice plants under sulfur deficiency, whereas the sulfate concentration was found to be relatively unstable.  相似文献   
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