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Intramammary infusion of Bifidobacterium breve (B. breve)-induced somatic cell (SC) counts, chemiluminescent response (CL), lactoferrin (LF) concentrations and mastitis-causing pathogens from quarters with subclinical mastitis were measured to evaluate innate immune response of mammary glands in dairy cows at 3 to 4 weeks before drying off. SC counts in 7 quarters of 7 control cows and 5 quarters of 6 cows with mastitis increased markedly on day 1 and SC values in control cows were significantly (P<0.05) increased and returned to pre-infusion levels on day 5 after B. breve-infusion. CL values in both groups increased markedly on day 1 and then decreased after B. breve-infusion; however, CL values in cows with mastitis did not return to normal levels on day 5 and at postpartum. The CL values were highly correlated with their SC counts in milk from both groups. LF concentrations increased toward day 3 after B. breve-infusion and were higher in cows with mastitis. B. breve-infusion eliminated 16.6% (1/6) of pathogens from 6 quarters with chronic subclinical mastitis. B. breve-induced SC responses in quarters from 3 cows with mastitis showed characteristic patterns of recovery, persistent and new infections. B. breve-induced SC counts in quarters from the cows in the pre-drying off were lower (25.7–70.6%) than those of the cows in mid-lactation. The intrinsic innate immune response in cows on pre-drying off may be decreased and appears to be insufficient to eliminate pathogens from mammary gland in the pre-drying off.  相似文献   
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Research on sex-determining region Y-box 2 (SOX2)-positive pituitary stem/progenitor cells, as a source of hormone-producing cells, is progressing rapidly in rodents. However, the stem/progenitor cells supplying hormone-producing cells that are essential for growth, reproduction, and lactation in bovines have not yet been identified. In this study, we characterized SOX2-positive cells in the pituitary gland of dairy cattle (Holstein heifers) after sexual maturity. Immunofluorescence analysis revealed that the localization pattern of SOX2-positive cells in the dairy cattle pituitary gland was similar to that observed in the rodent pituitary gland; the marginal cell layer (MCL), dense cell clusters, and single cells scattered in the parenchyma of the anterior lobe. Furthermore, most of the SOX2-positive cells were positive for the pituitary stem/progenitor cell niche markers E-cadherin and cytokeratin 8+18, which have been reported in rodents. In addition, in the MCL of the anterior lobe, there was a subpopulation of SOX2-positive cells positive for paired-related homeobox 1 and 2, whereas negative for S100β. Moreover, in the parenchyma of the anterior lobe, co-localization of SOX2 and pituitary hormones was infrequent. In summary, this study reveals the localization of putative pituitary stem/progenitor cells positive for SOX2 in dairy cattle. These results provide valuable information to support further investigation of cell supply in the dairy cattle pituitary gland.  相似文献   
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In order to investigate the energy expended in chewing during eating and rumination in sheep fed timothy or sudangrass hay at the same intake level, the energy expenditure of the head was measured using the arterial-venous difference technique and that of the whole body was measured using an open-circuit, indirect respiration calorimeter. There was no difference in the per-chew energy expenditure between timothy hay and sudangrass hay during eating and rumination, but for both types of hay there was a difference in energy expenditure between eating (0.25 J per chew per kilogram body weight) and rumination (0.18 J per chew per kilogram body weight). There was no effect of time period after feeding on the energy expended in one chew during eating and rumination. On average, for a given type of hay, the energy expended in chewing during eating + rumination accounted for 4.9% of the daily energy expenditure of the whole body.  相似文献   
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The activation of α2 adrenergic receptors contributes to analgesia not only in the central nervous system but also in the peripheral nervous system. We reported that noradrenaline inhibits the activity of transient receptor potential vanilloid 1 (TRPV1) evoked by capsaicin through α2 receptors in cultured rat dorsal root ganglion (DRG) neurons. However, it is unclear whether activation of TRPV1 expressed in peripheral nerve terminals is inhibited by α2 receptors and whether this phenomenon contributes to analgesia. Therefore, we examined effects of clonidine, an α2 receptor agonist, on several types of nociceptive behaviors, which may be caused by TRPV1 activity, and subtypes of α2 receptors expressed with TRPV1 in primary sensory neurons in rats. Capsaicin injected into hind paws evoked nociceptive behaviors and clonidine preinjected into the same site inhibited capsaicin-evoked responses. This inhibition was not observed when clonidine was injected into the contralateral hind paws. Preinjection of clonidine into the plantar surface of ipsilateral, but not contralateral, hind paws reduced the sensitivity to heat stimuli. Clonidine partially reduced formalin-evoked responses when it was preinjected into ipsilateral hind paws. The expression level of α2C receptor mRNA quantified by real-time PCR was highest followed by those of α2A and α2B receptors in DRGs. α2A and α2C receptor-like immunoreactivities were detected with TRPV1-like immunoreactivities in the same neurons. These results suggest that TRPV1 and α2 receptors are coexpressed in peripheral nerve terminals and that the functional association between these two molecules causes analgesia.  相似文献   
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Causes of low seed set in white clover (Trifolium repens L.)   总被引:1,自引:0,他引:1  
A field experiment was conducted to clarify the factors responsible for poor seed set in four white clover ( Trifolium repens L.) cultivars. Although the mean number of ovules per floret was 5·18–5·29, the average number of seeds per floret was found to be only 1·23-1·82. A stainclearing technique was used to examine the cytoplasmic state of the embryo sac in intact, unfertilized, mature ovules and it was found that 28–33% of ovules per carpel were sterile. The abortion rate of fertilized ovules and immature seeds (7 days after pollination) ranged between 32 and 34%. Beyond this period, it was observed that only a very small proportion of the total seeds were lost. The observation of high pollen fertility and a high pollen load strongly suggests that poor pollination does not account for the reduced number of seeds per floret. A 'nutrient competition' hypothesis was proposed for high ovule sterility and post-fertilization abortion of developing seeds.  相似文献   
9.
自发性急性犬瘟热的原发性脱髓性脑病   总被引:3,自引:1,他引:3  
为了进一步观察犬瘟热病毒引起的原发性脑损伤和包涵体形成的特点,调查脑组织的损伤与神经症状的关系,对10只急性犬瘟热病犬的脑组织进行了详细的病理学研究。为了仔细地观察病变,本试验按照解剖学关系将脑组织分成3个大部分和11个切面,即大脑(4个切面),脑干(5个切面)和小脑(2个切面)。组织切片经HE、LFB和免疫组织化学染色后进行检查,结果表明:在大脑,脱髓呈弥漫性发生,程度较轻;脑干的周围或靠近第三脑室的白质脱髓较重;小脑在轻度或中度脱髓的基础上常出现严重的多发性脱髓灶。脱髓部呈空泡或海绵状,有少量胶质细胞存在,但无炎性反应。脱髓性病损是非时称性发生,对神经束没有特殊的亲和力。在脑室的室管膜细胞内发现有较多的嗜酸性胞浆或核内包涵体。用抗犬瘟热病毒抗体染色,带有包涵体的室管膜细胞呈现强阳性反应。部分锥体细胞,神经核细胞和漓氏细胞变性、溶解或胞浆深染。胞核浓缩。这种变化以小锥体神经细胞表现得最为明显。根据此研究结果,作者认为由犬瘟热病毒引起的原发性脑组织损伤是一种脱髓性脑病,而不是脑炎变化;位于室管膜细胞内的包涵体对于脑组织犬瘟热的确诊具有重要的作用;由于犬瘟热病毒引起神经细胞的损伤是非特异性的,对脑组织的侵害是非对称性的。对神经束的作用无特殊的亲和力,所以患犬瘟热的犬在临床上可出现不同的神经症状。  相似文献   
10.
The pituitary is an important endocrine tissue of the vertebrate that produces and secretes many hormones. Accumulating data suggest that several types of cells compose the pituitary, and there is growing interest in elucidating the origin of these cell types and their roles in pituitary organogenesis. Therein, the histogenous cell line is an extremely valuable experimental tool for investigating the function of derived tissue. In this study, we compared gene expression profiles by microarray analysis and real-time PCR for murine pituitary tumor-derived non-hormone-producing cell lines TtT/GF, Tpit/F1 and Tpit/E. Several genes are characteristically expressed in each cell line: Abcg2, Nestin, Prrx1, Prrx2, CD34, Eng, Cspg4 (Ng2), S100β and nNos in TtT/GF; Cxcl12, Raldh1, Msx1 and Twist1 in Tpit/F1; and Cxadr, Sox9, Cdh1, EpCAM and Krt8 in Tpit/E. Ultimately, we came to the following conclusions: TtT/GF cells show the most differentiated state, and may have some properties of the pituitary vascular endothelial cell and/or pericyte. Tpit/F1 cells show the epithelial and mesenchymal phenotypes with stemness still in a transiting state. Tpit/E cells have a phenotype of epithelial cells and are the most immature cells in the progression of differentiation or in the initial endothelial-mesenchymal transition (EMT). Thus, these three cell lines must be useful model cell lines for investigating pituitary stem/progenitor cells as well as organogenesis.  相似文献   
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