淡竹叶清热作用探析

分析淡竹叶清热作用,包括清透风热治外感、清心热以除烦、清小肠热以治淋,及其现代药理学基础。     

Gracile bone dysplasia

Gracile bones are a frequent abnormality associated with fetal hypokinesia of any cause. With the exception of thin, undermineralized bones, the chondro-osseous structure is usually normal in these cases. We present a lethal skeletal dysplasia comprising minor anomalies, central nervous system abnormalities, gracile long bones, and abnormal chondro-osseous morphology. In addition to a short, disordered growth plate, the chondrocytes contained dilated loops of rough endoplasmic reticulum, suggesting an abnormality of an extracellular matrix protein. This protein appears to have effects on chondro-osseous and on facial and central nervous system development. We suggest the term “gracile bone dysplasia” to describe this disorder. Am. J. Med. Genet. 75:95–100, 1998. © 1998 Wiley-Liss, Inc.     

Spino‐olivary projections in the rat are anatomically separate from postsynaptic dorsal column projections

The gracile nucleus (GN) and lateral part of rostral dorsal accessory olive (rDAO) are important relays for indirect, postsynaptic dorsal column, and direct ascending pathways, respectively, that terminate as climbing fibers in the “hindlimb‐receiving” parts of the C1 and C3 zones in the cerebellar cortex. While the spinal cells of origin of that project to GN and rDAO are from largely separate territories in the spinal cord, previous studies have indicated that there could be an area of overlap between these two populations in the medial dorsal horn. Given the access of these two ascending tracts to sensory (thalamic) versus sensorimotor (precerebellar) pathways, the present study therefore addresses the important question of whether or not individual neurons have the potential to contribute axons to both ascending pathways. A double‐fluorescent tracer strategy was used in rats (red Retrobeads and Fluoro‐Ruby or green Retrobeads and Fluoro‐Emerald) to map the spatial distribution of cells of origin of the two projections in the lumbar spinal cord. The two pathways were found to receive input from almost entirely separate territories within the lumbar cord (levels L3–L5). GN predominantly receives input from lamina IV, while rDAO receives its input from three cell populations: medial laminae V–VI, lateral lamina V, and medial laminae VII–VIII. Cells that had axons that branched to supply both GN and rDAO represented only about 1% of either single‐labeled cell population. Overall, the findings therefore suggest functional independence of the two ascending pathways. J. Comp. Neurol. 522:2179–2190, 2014. © 2013 Wiley Periodicals, Inc.     

中药淡竹叶的化学成分研究

目的研究淡竹叶 (LophatherumgracileBrongn.)的化学成分。 方法色谱方法分离化学成分 ,波谱技术及理化常数鉴定结构。结果分离鉴定了 4个化合物 ,3,5 二甲氧基 4 羟基苯甲醛(Ⅰ )、反式对羟基桂皮酸 (Ⅱ )、苜蓿素 (Ⅲ )和苜蓿素 7 O β D 葡萄糖苷 (Ⅳ )。 结论均为首次从该属植物中分离得到。     

Contralateral termination of pudendal nerve fibers in the gracile nucleus of the rat

After applying horseradish peroxidase (HRP) unilaterally to central cut end of the pudendal nerve of the rat, transganglionic HRP-labeling of presumed axon terminals was constantly seen in the nucleus gracilis bilaterally with an ipsilateral predominance.     

风轮菜属5种药用植物的形态、解剖及化学成分

本文报道5种常见的风轮菜属药用植物的形态、解剖及化学成分的比较研究。对5种植物分别进行了生药性状描述,叶主脉、叶柄、茎的解剖构造和粉末特征以及花粉粒的光学显微镜及扫描电镜的观察;并用薄层层析法对它们的化学成分作了比较。     

Activation of microglia and p38 mitogen-activated protein kinase in the dorsal column nucleus contributes to tactile allodynia following peripheral nerve injury

The activation of glial cells in the CNS has been suggested to be involved in abnormal pain sensation after peripheral nerve injury. Previous studies demonstrated phosphorylation of p38 mitogen-activated protein kinase (MAPK) in spinal cord glial cells after peripheral nerve injury, and such phosphorylation has been suggested to be involved in the development of neuropathic pain. The aim of this study was to examine the dorsal column nuclei for phosphorylation of p38 MAPK following peripheral nerve injury and to explore a possibility of its contribution to neuropathic pain. Immunohistochemical labeling for phosphorylated p38 (p-p38) MAPK was performed in histological sections of the rat spinal cord and medulla oblongata after the fifth lumbar (L5) spinal nerve ligation (SNL). The number of p-p38 MAPK-immunoreactive (IR) cells was significantly increased in the L5 dorsal horn and the gracile nucleus ipsilateral to the injury at days 3-21 after SNL. Double immunofluorescence labeling with cell-specific markers revealed that p-p38 MAPK-IR cells co-expressed OX-42, suggesting their microglial identity. Increased immunofluorescence labeling for OX-42 indicated that microglial cells were activated by SNL in the L5 dorsal horn and the gracile nucleus ipsilateral to the injury. Continuous infusion of a p38 MAPK inhibitor into the cisterna magna for 14 days beginning on the day of SNL suppressed the development of tactile allodynia, but not thermal hyperalgesia induced by nerve injury. These results demonstrate that SNL activates p38 MAPK pathway in microglia in the gracile nucleus as well as in the spinal cord dorsal horn. Activation of p38 MAPK in medullary microglia may contribute to the pathogenesis of neuropathic pain.     

Connection from the dorsal column nuclei to the superior colliculus in the rat: topographical organization and somatotopic specific plasticity in response to neonatal enucleation

Somatosensory stimuli from the body to deep and intermediate strata of the superior colliculus (SC) are relayed from the dorsal column nuclei (DCN), gracile (GrN) and cuneate (CuN). Electrophysiological studies have shown that the somatosensory representation in SC is arranged into a map-like pattern. However, there is a lack of studies confirming a morphological correlate of such an organization. On the other hand, after neonatal enucleation in rodents, somatosensory inputs ascend from their normal termination territory in intermediate and deep collicular strata to invade the more dorsally located visual strata. However, the origin of these reactive afferents has not been specified. By using anterograde (biotinylated dextran amine 10,000; BDA) and retrograde (Fluoro-Gold; FG) tracers, we studied separately the connection from GrN and CuN to the intact and neonatally deafferented SC. GrN-collicular afferents were found to terminate mainly within the periphery of the caudomedial SC quadrant, whereas CuN-collicular fibers innervated primarily the lateral part of the rostrolateral and caudolateral collicular quadrants, in a way consistent with previously described functional data. Retrograde tracing experiments using FG injected in SC confirmed this topographical arrangement. Injections of BDA in GrN or CuN of neonatally enucleated rats showed that reactive fibers reaching superficial strata are only those CuN-collicular fibers innervating the caudolateral SC quadrant, where the forelimb is represented. The present results provide an anatomical substrate for the known somatotopic organization of tactile representation in SC and further reinforce the previous proposal that the plastic reorganization of DCN-collicular afferents following neonatal enucleation constitutes a functional compensatory response.     

Phosphorylation-dependent epitopes on neurofilament proteins and neurofilament densities differ in axons in the corticospinal and primary sensory dorsal column tracts in the rat spinal cord.

The highest molecular weight neurofilament protein (NF-H) is multiply phosphorylated at epitopes which can be distinguished by specific monoclonal antibodies on Western blots. Eight characterized antibodies were used in immunocytochemistry to examine the tissue distributions of phosphorylated variants of NF-H in axons of the adult rat spinal cord. The most striking difference in staining was found between axons in the cuneate tract and those in the neighboring dorsal corticospinal tract. Axons in the cuneate tract reacted intensely with antibodies to phosphorylated epitopes of NF-H and poorly with antibodies to dephosphorylated epitopes of NF-H, whereas the reverse was the case for the axons of the dorsal corticospinal tract. These differences showed that systematic variations in the phosphorylation of NF-H in long-tract axons in the central nervous system occur as a function of cell type. When the cytoskeletons of these axons were compared by electron microscopy, the neurofilaments of the cuneate fibers were seen to be more abundant and formed a latticework, more compactly organized than the neurofilaments of the dorsal corticospinal axons. By comparison, the dorsal corticospinal axons were relatively richer in microtubules than the cuneate axons. Although the cuneate fiber tract contained many more large (greater than 2.0 microns 2 in cross section) axons than did the dorsal corticospinal tract, these differences in cytoskeletal organization were apparent even when myelinated axons of similar sizes (0.4 micron 2 to 2.0 microns 2) were compared. In addition, the number of neurofilaments in cuneate axons in the 0.4 to 2.0 microns 2 size range was significantly better correlated with axon size than was the case for this size range of dorsal corticospinal axons. Thus, the differences seen in the organization of the neurofilament latticework and the phosphorylation of NF-H between axons found in these two tracts both appeared to be correlated with cell type, and were independent of length or caliber of the axons.     

Serotoninergic innervation of the dorsal column nuclei and its relation to cytoarchitectonic subdivisions: An immunohistochemical study in cats and monkeys (Aotus trivirgatus)

The serotoninergic innervation of the dorsal column nuclei (DCN) was investigated in cats and owl monkeys (Aotus trivirgatus) with immunohistochemical methods. A dense network of serotonin-immunoreactive fibers was present in the reticular regions of DCN in cats, and in the pars triangularis of the cuneate nucleus and the peripheral and caudal regions of the gracile nucleus in owl monkeys. The cat's cluster regions and the monkey's rotund regions were more sparsely innervated. Electron microscopic examination showed that the labeled fibers were thin and unmyelinated. Vesicle-containing, terminal-like structures were small. They were in contact with dendrites, other terminals and cell bodies, but synapses were rare. The results demonstrate that the serotoninergic projection to the DCN in both cats and owl monkeys is heterogeneously distributed in a pattern that is faithfully related to the cytoarchitectonic subdivisions of the DCN. The densely innervated reticular regions in the DCN of cats and the corresponding regions in monkeys are predominantly involved in the processing of sensory information to the cerebellum, either directly, or indirectly through projections to the inferior olive, pontine gray, tectum, pretectum, red nucleus, or zona incerta. Thus, the present findings suggest that the serotoninergic innervation of the DCN is primarily related to the DCN's involvement in motor functions. © 1993 Wiley-Liss, Inc.