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41.
Tumor necrosis factor (TNF) receptor-associated factors (TRAFs) were identified as signal transducers for the tumor necrosis factor receptor (TNFR) superfamily. In this study, we cloned and characterized two genes that encode chicken TNFR-II and TRAF5. The initial cDNA fragments were obtained by suppressive subtractive hybridization (SSH) of chicken spleen cells with or without lipopolysaccharide stimulation (Salmonella typhimurium SL1181 (RE-mutant)). The results showed that chicken TNFR-II is 1518 bp in length with an open reading frame (ORF) of 1386 bp having 31% homology with human TNFR-II. Expression analysis of chicken TNFR-II revealed that it is highly expressed in the spleen and bursa of Fabricius. The chicken cell lines IN24, MSB1 and 1104B express TNFR-II abundantly. The time course analysis of expression in spleen, bursa of Fabricius and IN24 cell line showed that TNFR-II is maximally expressed at 6 h after stimulation in bursa of Fabricius and after 8 h stimulation in the IN24 cell line. With regard to TRAF5, the complete sequence was 1936 bp in length with an ORF of 1671 bp that showed 71.3% homology with human TRAF5. Expression analysis showed that, among the tissues examined, TRAF5 was strongly expressed in spleen and bursa of Fabricius, while among the cell lines examined, it was maximally expressed in IN24. Thus, both genes were expressed in the same tissues and cell line among examined materials. These results suggest that chicken TNFR-II may interact with TRAF5 adaptor protein to complete its signal transduction pathway.  相似文献   
42.
To study whether or not passive immunity of neonatal calves against Shiga toxin-producing Escherichia coli (STEC) O26, O111, and O157 was obtained by colostrum administration, serum antibodies in calves after the feeding were determined by enzyme-linked immunosorbent assay (ELISA) in comparison with antibodies in colostrum and sera from donor dams. The highest antibody titers to STEC in colostrum from dams were detected soon after parturition. The antibody titers were found to be elevated in sera of neonatal calves (4-9 hr after birth) orally administered with colostrum with high antibody titers, suggesting that passive immunity of neonatal calves to STEC infection may be obtained by feeding colostrum. These results suggest that colostrum administration to neonatal calves may play an important role in elevating serum antibodies against STEC in neonatal calves.  相似文献   
43.
The existence of CD3(+)CD4(-)CD8(-) T cells in thymus and spleen has already been known. However, because of the presence of large amounts of thrombocytes in peripheral blood (PB), the proportion of CD3(+)CD4(-)CD8(-) T cells in PB has yet to be investigated. Therefore, the proportion of peripheral T cell-subsets was investigated in 6-week-old chickens. The percentage of CD3(+) cells, CD4(+) cells, CD8 alpha(+) cells, CD8 beta(+), and CD3(+)CD4(-)CD8(-) cells was 76%, 41%, 14%, 5%, and 15%, respectively. The proportion of CD3(+)CD4(-)CD8(-) cells in PB increased during egg-laying periods and in chickens treated with an analog of estrogen, while it decreased with age and in response to restraint stress. All of the CD3(+)CD4(-)CD8(-) cells expressed TCR1, and did not have NK activity. CD3(+)CD4(-)CD8(-) cells represent about 60% of peripheral TCR1(+) cells. These findings indicate that the proportion of CD3(+)CD4(-)CD8(-) cells is regulated by the endocrine and nerve systems.  相似文献   
44.
More than 99% of follicles in mammalian ovaries undergo atresia, but the mechanisms regulating the strict selection process are still unclear. Granulosa cell apoptosis is considered the trigger of follicular atresia, which occurs in advance of the death of an oocyte. Cellular FLICE-like inhibitory protein (cFLIP), a homologue of procaspase-8 (also called FLICE), is an intracellular anti-apoptotic protein. It is expressed in granulosa cells of porcine ovaries, where its levels decreases during follicular atresia. We hypothesized that cFLIP regulates granulosa cell apoptosis by acting as a pro-survival factor. In the present study, to further reveal the function of cFLIP in granulosa cells, we examined the anti-apoptotic mechanism of cFLIP using KGN, a human granulosa tumor cell line. Fas-mediated apoptosis was induced by co-treatment with anti-Fas antibody (CH-11), which acts as an agonist of Fas-ligand, and cycloheximide (CHX). When cFLIP was stably expressed in KGN cells following transfection of an expression vector, the Fas-mediated apoptosis was inhibited. Suppression of cFLIP by small interfering RNA (siRNA) spontaneously induced cell death. Silencing of cFLIP promoted cleavage of procaspase-8, and the cell death caused by cFLIP siRNA was completely blocked by a caspase-8 inhibitor (Z-IETD-FMK), indicating that cFLIP regulates apoptosis in KGN cells by inhibiting cleavage of procaspase-8. In conclusion, cFLIP is an essential pro-survival factor for granulosa cells, and it prevents granulosa cell apoptosis by inhibiting procaspase-8 activation.  相似文献   
45.
46.
Gain-of-function mutations in the proto-oncogene c-kit have been considered the molecular mechanism of neoplastic proliferation of mast cells. However, the importance of c-kit gene mutations is not well evaluated in canine mast cell tumors (MCTs). In the present study, we established and characterized a mast cell line, HRMC, derived from a dog with MCT. We also examined c-kit mutations in HRMC cells and assessed an inhibitory effect of a tyrosine kinase inhibitor, STI571, on HRMC cells. HRMC cells had cytoplasmic metachromatic granules, chymase and tryptase, and expressed both KIT and FcepsilonRI on the cell surface. HRMC cells contained histamine and released beta-hexosaminidase through FcepsilonRI cross-linking and calcium ionophore stimulation. Nucleotide sequence analysis demonstrated no mutations in an open reading frame of c-kit cDNA and genomic DNA of the juxtamembrane domain of c-kit in HRMC cells. STI571 did not show any inhibitory effects on the proliferation of HRMC cells. These findings clearly demonstrated the existence of c-kit mutations-independent neoplastic canine mast cell proliferation. The growth factor-independent mast cell line established in this study might be valuable to explore novel mechanisms of c-kit mutations-independent neoplastic proliferation of mast cells in dogs.  相似文献   
47.
Histopathologic features of hepatic peribiliary cysts were described in a young slaughtered pig. The animal was an apparently healthy 6-month-old pig of mixed breed. Macroscopically, all lobes of the liver contained numerous cysts of varying size containing serous fluid in all lobes. Histopathologically, the cysts were located mainly around the large bile duct and in the connective tissue of the portal tracts. Within serial sections, these cysts were assumed to be solitary or multilocular, but they were separated from the bile duct. The cysts were lined by a single layer of columnar, cuboidal, and flattened epithelial cells. Occasionally, goblet cells were observed. The epithelial cells were stained with periodic acid-Schiff/alcian blue and high-iron diamine/alcian blue, indicating the presence of neutral mucin, sialomucin, and sulfomucin. Grimalius' method revealed the presence of endocrine cells in the lining epithelium. There was no bile pigment in the cysts by the Hall method.  相似文献   
48.
Occlusion of the internal carotid artery by insertion of intravascular platinum microcoils for guttural pouch mycosis was experimentally evaluated in 9 healthy adult Thoroughbred horses. The internal carotid artery was ligated to its origin, and an arteriotomy was made distal to the ligature, which was then occluded by insertion of the microcoil approximately 13 cm distal to its origin. Cessation of blood flow was determined visually and by angiography at the arteriotomy site. Six horses were evaluated for complication clinically and by endoscopy after surgery. One horse was necropsied after 30 days of surgery for histological evaluation of artery thrombus formation. In the other 3 horses, the blood flow of the right internal carotid artery was monitored, before and after microcoil occlusion of the left internal carotid artery. One or 2 microcoils stopped blood flow within a few minutes. No other abnormal findings were observed clinically. Thrombus was observed in the occluded segment of 1 horse 30 days after insertion; but no abnormalities were detected. The blood flow in the right internal carotid artery increased by approximately 28-58% after occlusion of the left internal carotid artery. This microcoil vascular occlusion technique causes an effective thrombosis, and based on experimental studies and clinical application in 2 horses with epistaxis due to guttural pouch mycosis, this technique would appear to be safe and efficacious.  相似文献   
49.
In this study, we determined the color vision and spectral sensitivity of pointhead flounder, slime flounder, and red halibut by recording electrophysiological S-potentials from isolated retinas; this basic data was collected to aid the selection of appropriate colors and effective wavelengths for selective fishing gear for sustainable fisheries. Four kinds of L-response and one C-response were recorded in the pointhead flounder and red halibut. Two kinds of L-response were recorded in the slime flounder. The occurrence of a C-response indicates the possession of color vision. The C-responses show that the pointhead flounder has superior distinction from blue to yellow, and red halibut has superior distinction from blue and green to red. The most frequently recorded L-responses indicate high spectral sensitivity at 544 nm in pointhead flounder and 518 nm in slime flounder and red halibut. All recorded L- and C-responses indicate sensitivity to ultraviolet wavelengths.  相似文献   
50.
The lengths of conidiophores in fungal colonies of the melon powdery mildew pathogen Podosphaera xanthii Pollacci KMP-6 N cultured under greenhouse (natural) conditions differed markedly from those cultured in a growth chamber. We hypothesized that light wavelength was responsible for the differences in conidiophore length. In this study, we examined the effects of light-emitting diode (LED) irradiation (purple, blue, green, orange, and red light) and white light on colony development and conidiophore formation in KMP-6 N using a stereomicroscope and a high-fidelity digital microscope. Colonies on leaves were flat under greenhouse conditions and under red LED light irradiation but were stacked under growth chamber conditions and under purple, blue, green, and orange LED light irradiation. In addition, KMP-6 N formed catenated conidia comprising six conidia per conidiophore under greenhouse conditions and red light but more than seven conidia per conidiophore under growth chamber conditions and purple, blue, green, and orange light. Furthermore, almost none of the conidia on top of the conidiophores grown under blue light were fully constricted. Therefore, these fungi could not scatter their conidia and spread infection. This is the first report of the effects of LED lights on conidiophore formation in the melon powdery mildew fungus P. xanthii. The results provide insight into the mechanisms underlying the responses of conidiophores to light of specific wavelengths and conidial scatter from conidiophores of melon powdery mildew fungi.  相似文献   
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