首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:从到   被引次数:从到   他引次数:从到 提示：输入*表示无穷大
全文获取类型
  收费全文   29篇
  免费   0篇
专业分类
综合类   1篇
水产渔业   3篇
畜牧兽医   25篇
出版年
  2016年   2篇
  2015年   2篇
  2014年   6篇
  2013年   4篇
  2012年   2篇
  2011年   1篇
  2009年   4篇
  2008年   1篇
  2007年   1篇
  2006年   1篇
  2004年   1篇
  2003年   1篇
  2002年   1篇
  1957年   1篇
  1953年   1篇
排序方式： 共有29条查询结果，搜索用时 31 毫秒
1.
We investigated the concentration of the bacterial endotoxin lipopolysaccharide (LPS) in the blood, ovarian follicular fluid and uterine fluid of a clinical case of bovine metritis. A 2-year-old lactating Holstein cow exhibited continuous fever >39.5°C for more than 2 weeks after normal calving. The cow produced a fetid, watery, red-brown uterine discharge from the vagina and was diagnosed with metritis. The LPS concentrations in plasma and uterine fluid were 0.94 and 6.34 endotoxin units (EU)/ml, respectively. One of seven follicles showed an extremely high level of LPS (12.40 EU/ml) compared to the other follicles (0.62–0.97 EU/ml). These results might suggest the presence of high concentration of LPS in follicles in cows with postpartum metritis.  相似文献   
2.
  相似文献   
3.
Injury initiates a repair process characterized by influx of fibroblasts and the rapid formation of fibrous scar tissue and subsequent tissue contraction. The response to injury and behavior of the different tendon fibroblast populations, however, has been poorly characterized. We hypothesized that the fibroblasts recovered from tendon with acute injury would exhibit different cell properties relating to adhesion, migration and tensegrity. To test this hypothesis we evaluated the ability of fibroblasts recovered from normal and injured equine superficial digital flexor tendons (SDFTs). The injured tendon-derived cells showed greater contraction of the collagen gel but poorer adhesion to pepsin-digested collagen, and migration over extracellular matrix proteins compared to normal SDFT-derived fibroblasts. Thus, the cells present within the tendon after injury display different behavior related to wound healing.  相似文献   
4.
The purification and characterization of a bacteriocin produced by Leuconostoc mesenteroides strain 406 that was isolated from traditional Mongolian fermented mare's milk, airag, were carried out. Leuconostoc mesenteroides strain 406 was identified on the basis of its morphological and biochemical characteristics and carbohydrate fermentation profile and by API 50 CH kit and 16S ribosomal DNA analyses. The neutral‐pH cell‐free supernatant of this bacterium inhibited the growth of several lactic acid bacteria and food spoilage and pathogenic organisms, including Listeria monocytogenes and Clostridium botulinum. The bacteriocin was heat‐stable and not sensitive to acid and alkaline conditions, but was sensitive to several proteolytic enzymes such as pepsin, pronase E, proteinase K, trypsin, and α‐chymotrypsin, but not catalase. Optimum bacteriocin production (4000 activity units/mL) was achieved when the strain was cultured at 25°C for 24–36 h in Man Rogosa Sharpe medium. The bacteriocin was partially purified by ammonium sulfate precipitation (80% saturation), dialysis (cut‐off MW: 1000), and gel filtration chromatography. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis revealed that the bacteriocin had a molecular weight of approximately 3.3 kDa. To our knowledge, this is the first report of the isolation of a bacteriocin‐producing Leuconostoc strain from airag. An application to fermented milks would be desired.  相似文献   
5.
This study aimed to investigate the role of epithelial cells in regulating innate immunity in bovine oviduct epithelial cell (BOEC) culture. We studied the effect of Escherichia coli lipopolysaccharide (LPS) and its interaction with ovarian steroids, estradiol (E2) and progesterone (P4), and luteinizing hormone (LH) at concentrations observed during the preovulatory period on immune responses in BOEC culture. Immunohistochemistry of oviduct tissue showed intensive expression of Toll-like receptor-4 (TLR-4) and TLR-2 in epithelial cells. A dose of 10 ng/ml LPS stimulated TLR-4, cyclooxygenase-2 (COX-2), nuclear factor kappa B inhibitor A (NFKBIA), interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) expression, indicating an early pro-inflammatory response. A dose of 100 ng/ml LPS did not induce expression of these genes but stimulated TLR-2, IL-10,IL-4 and microsomal prostaglandin E synthase-1 (mPGES-1) expression and PGE2 secretion, indicating an anti-inflammatory response. Ovarian steroids and LH completely block LPS (10 ng/ml)-induced TLR-4, IL-1β and TNF-α expression as well as LPS (100 ng/ml)-induced TLR-2 expression. Taken together, this study suggests the existence of an early signaling system to respond to infection in the BOEC. In addition, ovarian steroids and LH may play a critical role in inducing homeostasis and in controlling hyperactive pro-inflammatory responses detrimental to epithelial cells, sperm and the embryo.  相似文献   
6.
The purpose of this study was to evaluate the survival and colonization of Lactobacillus plantarum 301102 in porcine gastrointestinal tract and its influence on the intestinal microflora. This strain was isolated from traditional cheese from Inner Mongolia, China. Fermented milk prepared with strain 301102 was administered to pigs and fecal microflora was examined. Intestinal passage of strain 301102 was monitored by a combination of selection with selective medium and the carbohydrate fermentation test, and confirmed by analysis of plasmid DNA patterns. Colonization of this strain was assessed by recovery 7 days after administration. The numbers of Lactobacillus and Bifidobacterium cells in the feces of pigs administered fermented milk prepared with strain 301102 were increased. This strain was recovered from all the pigs during the administration period, and from four of six pigs 7 days after administration. L. plantarum 301102 can pass through the gastrointestinal tract, balance the intestinal microflora, and colonize the intestinal tract, and is therefore an appropriate candidate for a probiotic.  相似文献   
7.
We investigated the effect of bradykinin (BK) on isolated equine basilar arterial rings with and without endothelium. BK induced concentration-dependent contraction of resting arterial rings and no relaxation when the rings were precontracted by prostaglandin F2α. The maximal response and pD2 value were 161.2 ± 28.1% (to 60 m m KCl-induced contraction) and 8.24 ± 0.25 respectively. The cumulative concentration–response curve for BK was not shifted to the right by des-Arg9-[Leu8]-BK (a B1-receptor antagonist), HOE140 (a B2-receptor antagonist) or NPC567 (another B2-receptor antagonist). In four of six basilar arteries, NPC567 induced concentration-dependent contraction. Indomethacin (a cyclooxygenase inhibitor), nordihydroguaiaretic acid (a lipoxygenase inhibitor), quinacrine (a phospholipase A2 inhibitor), tetrodotoxin (a selective blocker of Na+ channels), guanethidine (a nor-adrenergic neuron blocking drug), phentolamine (an α-adrenoceptor antagonist), Nω-nitro- l -arginine ( l -NNA, a nitric oxide (NO) synthase inhibitor) and endothelial denudation did not affect the BK-induced contraction. l -NNA and indomethacin induced contraction and relaxation under resting vascular tone respectively. These results suggest that endothelial cells are not involved in BK-induced contraction and that the contraction is not mediated via activation of known B1 and B2 receptors. Arachidonic acid metabolites and neurotransmitters like norepinephrine and NO might not play a role in BK-induced contraction in equine basilar artery.  相似文献   
8.
In this study, we examined the existence and structure of areolae and the steroidogenesis of areolar trophoblast cells in the Antarctic minke whale placenta morphologically and immunohistochemically. Placentas were collected from the 15th, 16th and 18th Japanese Whale Research Program under Special Permit in the Antarctic (JARPA) and 1st JARPA II organized by the Institute of Cetacean Research in Tokyo, Japan. The opening and cavity of fetal areolae formed by taller columnar trophoblast cells (areolar trophoblast cells) with long microvilli and a bright cytoplasm, as compared with the trophoblast cells of the chorionic villi interdigitating with the endometrial crypts, were recognized in observations of serial sections. The opening of the areolar cavity was hidden by chorionic villi with areolar trophoblast cells. Furthermore, a closed pouch-like structure lined by tall columnar cells similar to areolar trophoblast cells within the stroma of chorionic villi was noticed and continued to the areolar cavity, with the opening seen on serial sections. In a surface investigation of the chorion and endometrium by SEM, maternal (endometrial) areolae irregularly surrounded by endometrial folds were obvious. Moreover, we distinguished areolar trophoblast cells with long microvilli attached with many blebs from trophoblast cells. In our immunohistochemical observations, a steroidogenic enzyme, cytochrome P450 side chain cleavage enzyme (P450scc), was detected with strong immunoreactivity in trophoblast cells. However, areolar trophoblast cells showed weak or no immunoreactivity for P450scc.  相似文献   
9.
In the rat, induction of maternal behavior depends on the parity of the female. For example, nulliparous (NP) females need longer exposure to pups than multiparous (MP) or lactating (L) females to exhibit similar maternal behavior. In this study, we investigated the role of brain oxytocin in the approaching behavior of these female rats. Olfactory preferences for pup odors were examined for 8 consecutive days. Each preference test was followed by direct overnight exposure to pups. On the 8th day, MP and L, but not NP females showed robust pup-odor preferences. After the behavioral test, half of the females were exposed to pups for 2 h, whereas the other half were not. The females were then sacrificed to analyze brain oxytocin (OXT) and vasopressin (AVP) activities by cFos immunohistochemistry and to quantify their receptor mRNA expression using real-time PCR. In the paraventricular nucleus (PVN), the percentage of cFos-positive OXT neurons was significantly larger in MP and L females than in NP females after pup exposure. No significant differences were found in cFos expression in OXT neurons of the supraoptic nucleus (SON) or in AVP neurons of either the PVN or SON. Expression of OXT receptor mRNA in the medial preoptic area and amygdala of the control groups was also higher in MP females than in NP females. Finally, we demonstrated that infusion of OXT into the lateral ventricle of NP females promoted preferences for pup odors. These results indicate that puerperal and parental experiences enhance the responsiveness of OXT neurons in the PVN to pup stimuli and establish olfactory preferences for these odors in a parity-dependent manner.  相似文献   
10.
The present study aimed to assess the effect of polymorphisms in the tumor necrosis factor α (TNF-α) promoter (A/A, A/G and G/G) and exons (T/T, T/C and C/C) on immune function and reproductive performance in dairy cows. The occurrence of the first postpartum ovulation within 3 weeks in the cows with the TNF-α promoter A/G and G/G genotypes was higher than in the A/A group. Among the different TNF-α exon genotypes, the occurrence of early first postpartum ovulation was higher in the T/C and C/C genotype groups than in the T/T group. Single nucleotide polymorphisms (SNPs) in the TNF-α gene did not affect the rate of artificial insemination (AI) or duration from parturition to next conception (days open). The apoptosis rate of polymorphonuclear leukocytes (PMNs) did not differ among the TNF-α promoter genotypes, but the PMN transmigration rate was significantly higher for the A/A and A/G genotypes than for the G/G genotype. Interleukin 8 (IL-8) mRNA expression in PMNs and peripheral blood mononuclear cells (PBMCs) before culture was significantly higher for the A/A genotype compared with the G/G genotype. There were no significant differences between the genotypes in the mRNA expression of TNF-α, IL-6, IL-1β, and toll-like receptor 4 (TLR4) in PMNs and PBMCs before and 4 h after culture. IL-8 and IL-1β production by PBMCs cultured for 4 h was significantly higher for the animals with the A/A genotype than for those with the G/G genotype. On the other hand, no significant difference was observed in IL-8 and IL-1β production by PMNs among different TNF-α genotypes. Taken together, these results suggest that SNP in the TNF-α gene affects immune function and reproductive performance in dairy cows.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号