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:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   20篇
  免费   1篇
水产渔业   1篇
畜牧兽医   19篇
植物保护   1篇
  2022年   2篇
  2021年   1篇
  2017年   1篇
  2015年   1篇
  2013年   2篇
  2010年   1篇
  2009年   4篇
  2006年   2篇
  2005年   3篇
  2003年   1篇
  1999年   3篇
排序方式: 共有21条查询结果,搜索用时 421 毫秒
1.
2.
3.
OBJECTIVE: To analyze the morphology, cytoarchitecture, and lumbosacral spinal cord projections of the red nucleus (RN) in cattle. ANIMALS: 8 healthy Friesian male calves. PROCEDURES: Anesthetized calves underwent a dorsal laminectomy at L5. Eight bilateral injections (lateral to the midline) of the neuronal retrograde fluorescent tracer fast blue (FB) were administered into the exposed lumbosacral portion of the spinal cord. A postsurgical calf survival time of 38 to 55 days was used. Following euthanasia, the midbrain and the L5-S2 spinal cord segments were removed. Nissl's method of staining was applied on paraffin-embedded and frozen sections of the midbrain. RESULTS: The mean length of the RN from the caudal to cranial end ranged from 6,680 to 8,640 microm. The magnocellular and parvicellular components of the RN were intermixed throughout the nucleus, but the former predominate at the caudal portion of the nucleus and the latter at the cranial portion with a gradual transitional zone. The FB-labeled neurons were found along the entire craniocaudal extension of the nucleus, mainly in its ventrolateral part. The number of FB-labeled neurons was determined in 4 calves, ranging from 191 to 1,469 (mean, 465). The mean cross-sectional area of the FB-labeled neurons was approximately 1,680 microm2. CONCLUSIONS AND CLINICAL RELEVANCE: In cattle, small, medium, and large RN neurons, located along the entire craniocaudal extension of the RN, contribute to the rubrospinal tract reaching the L6-S1 spinal cord segments. Thus, in cattle, as has been shown in cats, the RN parvicellular population also projects to the spinal cord.  相似文献   
4.
Helicobacter-like organisms are frequently observed in the stomach of dogs but the relationship between these microorganisms and gastric pathology has not been clearly established. Different species of helicobacters are known to be present in the canine stomach but their specific prevalence in naturally infected dogs is unknown. The aims of this study were to isolate and characterize helicobacters in canine gastric biopsies, to compare the commonly used tests for the identification of Helicobacter spp. and to determine the occurrence of these species in dogs. Twenty-three out of 25 dogs (92%) were positive for Helicobacter-like organisms in cytological screening. Culture was successful from biopsies of 5/25 dogs. The isolates were analyzed by electron microscopy, biochemical and physiological tests, whole protein analysis and 16S rDNA sequencing. Helicobacter felis was identified in four samples and Helicobacter bizzozeronii in one sample. Only the whole protein analysis in combination with electron microscopy was able to clearly discriminate the two species. Compared to the high prevalence of Helicobacter-like organisms, the occurrence of H. felis and H. bizzozeronii, was low (17 and 4%, respectively). No Flexispira rappini-like organisms or H. salomonis were detected. Electron microscopy revealed that H. bizzozeronii-like microorganisms were present in three additional biopsies where we were unable to culture any Helicobacter-like organisms. These observations indicate that in the stomach of dogs not all helicobacters are culturable. The unculturable bacteria appeared to be the prevalent ones and may represent different spiral organisms. The presence of distinct helicobacters with different characteristics can reflect different roles in the pathogenesis of canine gastric disease.  相似文献   
5.
In vertebrates, chemosensitivity of nutrients occurs through the activation of taste receptors coupled with G-protein subunits, including α-transducin (Gαtran) and α-gustducin (Gαgust). This study was aimed at characterising the cells expressing Gαtran immunoreactivity throughout the mucosa of the sea bass gastrointestinal tract. Gαtran immunoreactive cells were mainly found in the stomach, and a lower number of immunopositive cells were detected in the intestine. Some Gαtran immunoreactive cells in the stomach contained Gαgust immunoreactivity. Gastric Gαtran immunoreactive cells co-expressed ghrelin, obestatin and 5-hydroxytryptamine immunoreactivity. In contrast, Gαtran immunopositive cells did not contain somatostatin, gastrin/cholecystokinin, glucagon-like peptide-1, substance P or calcitonin gene-related peptide immunoreactivity in any investigated segments of the sea bass gastrointestinal tract. Specificity of Gαtran and Gαgust antisera was determined by Western blot analysis, which identified two bands at the theoretical molecular weight of ~45 and ~40 kDa, respectively, in sea bass gut tissue as well as in positive tissue, and by immunoblocking with the respective peptide, which prevented immunostaining. The results of the present study provide a molecular and morphological basis for a role of taste-related molecules in chemosensing in the sea bass gastrointestinal tract.  相似文献   
6.
7.
Reason for performing study: In horses, morpho‐functional studies related to the enteric nervous system (ENS) controlling the sphincters are lacking. Objectives: To investigate immunohistochemically the morphology, distribution, density, phenotypes and projections of neurons controlling the ileocaecal junction (ICJ). Methods: Two young horses were anaesthetised and underwent midline laparotomy. The neuronal retrograde fluorescent tracer Fast Blue (FB) was injected into the wall of the ICJ. A post surgical survival time of 30 days was used. Following euthanasia, the ileum and a small portion of caecum were removed. Cryosections were used to investigate the immunoreactivity (IR) of the neurons innervating the ICJ for choline acetyltransferase (ChAT), neuronal nitric oxide synthase (nNOS), substance P (SP), calcitonin gene‐related peptide (CGRP) and neurofilament NF200kDa (NF). Results: Ileal FB‐labelled neurons innervating the ICJ were located in the myenteric plexus (MP) and submucosal plexus (SMP) up to 48 cm and 28 cm, respectively, from the point of the FB injections. Descending MP and SMP neurons were nitrergic (54 ± 11% and 68 ± 4%, respectively), cholinergic (60 ± 19% and 82 ± 11%, respectively), NF‐IR (54 ± 9% and 78 ± 21%, respectively), and SP‐IR (about 20% in both the plexuses). CGRP‐IR was expressed only by SMP descending neurons (45 ± 21%). In both the plexuses descending neurons coexpressing nNOS‐and ChAT‐IR were also observed (25 ± 11% and 61 ± 27%, respectively). Conclusions: The presence of ileal long projecting neurons innervating the ICJ suggests that they are critical for its modulation. Consequently, in bowel diseases in which the resection of the terminal jejunum and proximal ileum are required, it is preferable, whenever possible, to conserve the major portion of the ileum. Potential relevance: The knowledge of the phenotype of ENS neurons of the ileum might be helpful for developing pharmaceutical treatment of the ICJ motility disorders.  相似文献   
8.
OBJECTIVE: To determine the location, morphology, and neurochemical code of spinal cord and dorsal root ganglion neurons that innervate the gastrocnemius muscle (GM) and superficial digital flexor muscle (FDSM) in cattle. ANIMALS: 5 healthy Friesian male calves. Procedure: 2 different types of neuronalretrograde fluorescent tracers (fast blue and diamidino yellow) were injected into the GM and FDSM, respectively. The neurochemical code (substance P, calcitonin gene-related peptide, galanin, and neuronal nuclear protein) of labeled neurons was investigated by immunohistochemistry. RESULTS: Neurons innervating the GM and FDSM were located along the L6-S2 spinal cord segments and ganglionic levels. A cranial-to-caudal topographic distribution for each muscle was found, indicating that the motor nuclei of the 2 muscles are organized by a somatotopic pattern. The GM and FDSM motoneurons were immunoreactive only for calcitonin gene-related peptide, whereas the afferent neurons were immunoreactive for all of the neurochemical markers considered. CONCLUSION AND CLINICAL RELEVANCE: In our study, location and the extent of neurons that supply the GM and FDSM of cattle were characterized completely. Because the GM and FDSM are involved in spastic paresis of calves and it is thought that spastic paresis results from an excessive activity of the neuromuscular spindle reflex arc, findings in our study may be useful for further electrophysiologic and clinical studies. Knowledge of the neurochemical code of neurons that supply the GM and FDSM in healthy calves could be used to compare chemical alterations in the same neuronal population of affected calves.  相似文献   
9.
10.
This study described the morphological features of the Persian leopard (Panthera pardus saxicolor) tongue using light and scanning electron microscopy techniques. The keratinized filiform papillae were distributed all over the entire dorsal surface of the tongue and contained small processes. They were changed into a cylindrical shape in the body and conical shape in the root. The fungiform papillae were found on the apex and margin of the tongue. Few taste pores were observed on the dorsal surface of each papilla. The foliate papillae on the margins of the tongue were composed of several laminae and epithelial fissures. Taste buds were not seen within the non‐keratinized epithelium. The vallate papillae were six in total and arranged in a “V” shape just rostral to the root. Each papilla was surrounded by a groove and pad. Taste buds were seen within their lateral walls. Lyssa was visible on the ventral surface of the tongue tip and was found as cartilaginous tissue surrounded by thin connective tissue fibres. The core of the tongue was composed of lingual glands, skeletal muscle and connective tissue. These glands were confined to the posterior portion of the tongue and were composed of many serous cells and a few mucous cells. The results of this study contributed to the knowledge of the morphological characteristics of the tongue of wild mammals and provided data for the comparison with other mammals.  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