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Fang H Howroyd PC Fletcher AM Diters RW Woicke J Sasseville VG Bregman CL Freebern WJ Durham SK Mense MG 《Veterinary pathology》2007,44(3):407-410
Subendothelial heart valve angiectasis has been reported in cows, dogs, pigs, rats, mice, and in human fetuses and newborns. We observed a high incidence (62 in 208 animals examined) of spontaneous angiectasis on the atrioventricular (AV) valves in 10- to 40-week-old Sprague-Dawley rats. The angiectasis was observed predominately on the septal cusp of the right AV valve and located near the AV ostium in 57 of 62 animals. Of the remaining 5 valvular angiectases, 2 were present on the parietal cusp of the right AV valve and 3 were on the left AV valve. The angiectases were single or multiple, ranging from 40 to 300 microm in diameter and were characterized by light microscopy as blood-filled dilatations lined by endothelium. Spontaneously occurring abnormalities in normal laboratory animals, such as the spontaneous valvular angiectasis reported here, need to be differentiated from drug-related lesions. 相似文献
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Southern peas [Vigna unguiculata, (L.) Walp.] cultured with 100% NH+ 4 produced no viable flowers, while treatments in which NO‐ 3 composed 50% or more of the N form were not significantly different in the number of flowers formed. Flower abortion was least with 100% NO‐ 3 at the lower N concentration and with 75% and 100% NO‐ 3 at the higher N concentration. Further increments of NH+ 4 resulted in greater flower abortion. The trends in flower survival were reflected in the number of pods and number of seed/plant. At the lower N concentration, the addition of NH+ 4 slowed pod maturity, while at the higher N concentration pod maturity was hastened with the addition of up to 50% NH+ 4. The dry weight and N content of tissues were generally greater with the higher N concentration and with N combinations containing predominantly NO‐ 3, but trends varied with the plant part being analyzed. Ammonium appears to adversely influence reproductive development and/or NO‐ 3 is essential to complete the reproductive development of southern peas. The observed differences in the response of southern peas to N form may account for previously reported discrepancies concerning the effectiveness of N fertilization on growth and yield parameters. Also, vegetative growth and vegetative N content appear to be poor indicators of final seed yields of southern peas if NH+ 4 supplies a significant portion of the N form utilized by the plant. 相似文献
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VRP Barros AYP Cavalcante TJS Macedo RS Barberino TLB Lins BB Gouveia VG Menezes MAA Queiroz VR Araújo RC Palheta Jr MCP Leite MHT Matos 《Reproduction in domestic animals》2013,48(6):1025-1033
The expression of melatonin type 1 (MT1) and FSH (FSHR) receptors in caprine ovaries and the effects of these hormones on the in vitro development of isolated pre‐antral follicles were evaluated. Follicles (≤200 μm) were cultured for 12 days in α‐MEM (control) or melatonin (100 or 1000 pg/ml) or sequential melatonin medium (100 pg/ml: from day 0 to day 6; 1000 pg/ml: from day 6 to day 12; experiment 1) and in control or sequential FSH (100 ng/ml from day 0 to day 6; 500 ng/ml from day 6 to day 12) or sequential melatonin or this latter plus sequential FSH (experiment 2). MT1 and FSHR expressions were observed in granulosa cells from secondary and antral follicles. The oocytes from primordial and primary follicles also express FSHR. Sequential melatonin increased the percentage of normal follicles and oocyte recovery compared with the control or melatonin (1000 pg/ml) at day 12. In experiment 2, all the treatments increased the normal follicles and growth compared with the control. In conclusion, this study demonstrated the presence of MT1 and FSHR in caprine ovaries. The addition of increased concentrations of melatonin (sequential medium) or FSH can be used to promote the in vitro development of caprine pre‐antral follicles. 相似文献
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Lasing action in organic vertical-cavity surface-emitting laser (OVCSEL) structures is demonstrated. Optically pumped OVCSELs with an active layer composed of a thin-film organic semiconductor tris-(8-hydroxyquinoline) aluminum (Alq3) doped with DCM laser dye produced very narrow linewidth (0.2 +/- 0.1 angstrom), high-power (3 watts) emission that could be varied in different devices from orange to red. The efficient energy transfer from Alq3 to DCM results in a threshold input energy of 300 microjoules per square centimeter. An operational lifetime >10(6) laser pulses was achieved for a device operated well above threshold in atmosphere. The linewidths above threshold are Fourier transform-limited and could potentially be narrowed further. 相似文献
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During the 1984 to 1986 spring hunting seasons in Connecticut, viscera from 300 hunter-killed wild turkeys and blood samples from live-trapped wild turkeys were examined in order to establish a health profile on the State's wild turkey population. Seven species of endoparasites were recovered from 224 (75%) of 300 birds: Metroliasthes lucida, Ascaridia dissimilis, Heterakis gallinarum, Syngamus trachea, Capillaria species, Trichomonas gallinarum, and Eimeria species. The most prevalent parasites were A. dissimilis (52%) and M. lucida (37%). Although some turkeys harbored high intensities of these two helminths, there were no associated gross or microscopic lesions nor body weight changes. The prevalence of S. trachea, H. gallinarum, Capillaria and Eimeria species, which are potential pathogenic parasites in domestic and wild turkeys, was very low (less than 3%). Blood samples from 19 live-trapped wild turkeys were negative for hemoprotozoa and antibodies to 15 common bacterial and viral agents. Serum samples from 82 birds were negative for Mycoplasma gallisepticum and Mycoplasma synoviae. The survey indicates that the wild turkey population of Connecticut presently has little evidence of common infectious diseases and minimal prevalence of potentially pathogenic parasites. 相似文献
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Alain Doucet Martin Williams Mylene C Gagnon Maxime Sasseville Marc Beauregard 《Journal of agricultural and food chemistry》2002,50(1):92-98
Protein design is currently used for the creation of new proteins with desirable traits. In this laboratory the focus has been on the synthesis of proteins with high essential amino acid content having potential applications in animal nutrition. One of the limitations faced in this endeavor is achieving stable proteins despite a highly biased amino acid content. Reported here are the synthesis and characterization of two disulfide-bridged mutants derived from the MB-1 designer protein. Both mutants outperformed their parent protein MB-1 with their bridge formed, as shown by circular dichroism, size exclusion chromatography, thermal denaturation, and proteolytic degradation experiments. When the disulfide bridges were cleaved, the mutants' behavior changed: the mutants significantly unfolded, suggesting that the introduction of Cys residues was deleterious to MB-1-folding. In an attempt to compensate for the mutations used, a Tyr62-Trp mutation was performed, leading to an increase in bulk and hydrophobicity in the core. The Trp-containing disulfide-bridged mutants did not behave as well as the original MB-1Trp, suggesting that position 62 might not be adequate for a compensatory mutation. 相似文献
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JMS Santos VG Menezes RS Barberino TJS Macedo TLB Lins BB Gouveia VRP Barros LP Santos RJS Gonçalves MHT Matos 《Reproduction in domestic animals》2014,49(3):522-528
Studies with sheep are important to improve our knowledge about the factors that control folliculogenesis in mammals and to explore possible physiological differences among species. The aims of this study were to characterize FGF‐2 protein expression in ovine ovaries and to verify the effect of FGF‐2 on the morphology, apoptosis and growth of ovine pre‐antral follicles cultured in vitro. After collection, one fragment of ovarian tissue was fixed for histological analysis and TUNEL analysis (fresh control). The remaining fragments were cultured for 7 days in control medium (α‐MEM+) alone or supplemented with FGF‐2 at different concentrations (1, 10, 50, 100 or 200 ng/ml). After culturing, ovarian tissue was destined to histology and TUNEL analysis, and oocyte and follicle diameters were measured. The immunostaining for FGF‐2 was observed in oocytes from primordial, primary and secondary follicles, as well as in granulosa cells of secondary and antral follicles. The percentage of normal follicles was similar among control medium, 1 and 10 ng/ml FGF‐2, and significantly higher than those observed in 50, 100 or 200 ng/ml FGF‐2. A significant increase in follicle diameter was observed when tissues were cultured in 10, 50, 100 or 200 ng/ml FGF‐2 compared with the fresh control and the other treatments. Similar results were observed for oocyte diameter in tissues cultured with 50, 100 or 200 ng/ml FGF‐2 (p < 0.05). However, the percentage of apoptotic cells only decreased (p < 0.05) in ovarian tissues cultured in 1 or 10 ng/ml FGF‐2 compared with the control medium and other FGF‐2 treatments. In conclusion, this study demonstrated the presence of FGF‐2 in ovine ovaries. Furthermore, 10 ng/ml FGF‐2 inhibits apoptosis and promotes ovine follicle growth. As the sheep ovary is more similar to that of humans, the culture system demonstrated in this work seems to be an appropriate tool for studies towards human folliculogenesis. 相似文献
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