骨－纤维管内腱鞘囊肿致周围神经嵌压症

目的：探讨骨－纤维管内腱鞘囊肿致周围神经嵌压症的治疗原则。方法：通过３２例临床病历资料总结，根据神经功能恢复情况来判断疗效。结果：随访３个月～４年，治疗效果优良率８７．５％。结论：对此症宜尽早手术治疗，并应根据具体情况采用神经内松解或神经外松解术。     

Long-term depression of a sympathetic ganglionic response to opioids by prolonged synaptic activity and by phorbol esters

We studied the effect of the adenylate cyclase activator forskolin, of protein kinase C-activating phorbol esters and of prolonged preganglionic input activation on the inhibitory response of the perfused superior cervical ganglion of the cat to exogenous met-enkephalin (Met-ENK). Met-ENK inhibited, in a concentration-dependent manner, the postganglionic compound action potential evoked by cervical sympathetic trunk stimulation. The inhibition was reversible, was blocked by naloxone as well as by pertussis toxin and showed no homologous desensitization in the concentration range 0.01–10 μM. Pretreatment of the ganglion with 4β-phorbol 12,13-dibutyrate or 4β-phorbol 12,13-diacetate depressed the Met-ENK response for several hours, while pretreatment with forskolin had no effect. This action of phorbol esters was prevented by the protein kinase inhibitor H-7 but not by the calmodulin antagonist W-7 or the protein kinase A inhibitor HA 1004 and was calcium-dependent. Recovery of the response from the depression produced by phorbol esters was not affected by a protein synthesis inhibitor. A 40 Hz 20 min stimulus train to the cervical sympathetic trunk mimicked the effect of phorbol esters, depressing for several hours the inhibition produced by Met-ENK. Stimulus trains of duration shorter than 5 min or frequency lower than 5 Hz were ineffective. This effect of prolonged preganglionic stimulation occurred even when the stimulus train was delivered during complete block of nicotinic and muscarinic ganglionic transmission but was lost when the stimulus train was delivered during perfusion with calcium-free Krebs. The protein kinase inhibitor H-7 prevented the depression of the Met-ENK response by the train, while W-7 and HA 1004 had no effect. These findings suggest that, in the superior cervical ganglion of the cat, a kinase, activated by phorbol esters and inhibited by H-7, exerts a long-term control of the ganglion cell responsiveness to opiate receptor activation. A similar mechanism can be synaptically activated by a non-cholinergic transmitter, released by the preganglionic axons during prolonged, high frequency, activity.     

压力对大鼠纯化视网膜神经节细胞中bcl-2、bax及p53mRNA表达的影响

目的通过检测不同压力下纯化培养的大鼠视网膜神经节细胞(Retinal ganglioncells,RGCs)中bcl-2,bax,p53mRNA表达情况,了解压力对视网膜神经节细胞凋亡的影响.方法用SD系大鼠脑源性星型胶质细胞同化培养液双界面法[1]培养羊抗鼠Thy1.1单克隆抗体纯化的SD系大鼠RGCs;在纯化培养的RGCs上分别施加0,20mmHg,40mmHg,60mmHg和80mmHg气压,培养24h及48h后TUNEL法检测各组细胞的凋亡,原位杂交检测细胞中bcl-2,bax及p53mRNA的表达.结果纯化的RGCs培养12h及24h用羊抗鼠FITC-Thy-1.1单克隆抗体进行鉴定阳性,纯度为97%.传三代后星型胶质细胞用胶质纤维酸性蛋白(GFAP)单克隆抗体标记和鉴定阳性.培养24h组TUNEL法检测对照组极少数细胞凋亡,20mmHg组见较多细胞凋亡,随着压力的增高细胞凋亡数增多,凋亡指数增高;与对照组相比差异均有显著性.培养48h组压力≥20mmHg各组较相同压力培养24h组凋亡指数增高,差异有显著性(P＜0.05).压力≥40mmHg时bcl-2 mRNA表达逐渐减少,压力≥20mmHg时bax及p53 mRNA表达则逐渐增加;与对照组相比均有显著性差异(P＜0.05).结论高于20mmHg压力时间超过24h可激活体外培养的视网膜神经节细胞的相关凋亡基因导致细胞的凋亡.     

Non-linear spatial summation in cat retinal ganglion cells at different background levels

Summary Cat retinal ganglion cells were identified as X-cells (linear) or Y-cells (non-linear) on the basis of the spatial summation properties of their receptive fields. For each cell, the degree of non-linearity in spatial summation was assessed at a number of different mean luminance levels in order to determine how spatial linearity depended on mean luminance. The stimuli were counterphase sinusoidal gratings whose contrast was sinusoidally modulated in time. A grating with one bar centered on the receptive field was used to measure the contrast sensitivity of the mechanisms which produced responses at the stimulus frequency. A grating with a zero crossing centered on the receptive field was used to measure the contrast sensitivity of mechanisms responsible for the non-linear frequency doubled responses of Y-cells. As the mean luminance was reduced from low photopic to scotopic, the contrast sensitivity decreased for both the linear and non-linear responses. The ratio of non-linear to linear sensitivity in Y-cells changed less with background than did either contrast sensitivity. In some Y-cells this ratio decreased slightly at low luminance levels, but in others it did not. X-cells appeared to sum signals linearly at all levels of illumination. X-cells and Y-cells could still be distinguished on the basis of their spatial summation properties in the scotopic range.     

Immunocytochemical localization of polyamines in the tiger salamander retina

The polyamines spermine and spermidine are present in neural tissue, but their functions there are not well understood. Recent work suggests that the NMDA subtype of glutamate receptors, other glutamate receptor subtypes, and certain K⁺-channels, are neural targets for polyamines. To better understand the neuron-specific roles of polyamines, we have developed antibodies that interact with spermine and spermidine in aldehyde-fixed tissue and used these antibodies in immunocytochemical studies to determine the cellular localization of these polyamines in the tiger salamander retina. The affinity-purified, polyclonal antibodies were highly specific for spermine and spermidine, exhibiting < 1 % cross reactivity with putrescine, and virtually no cross-reactivity with GABA, arginine, lysine, or glutaraldehyde. Polyamine labeling was most abundant in cells in the inner half of the inner nuclear layer and in the ganglion cell layer. Some cells in the outer half of the inner nuclear layer are labeled, and there was some labeling in both synaptic layers. Double-labeling experiments indicated (1) all GABAergic amacrine cells were polyamine-positive; and (2) all ganglion cells (identified by back-filling after microinjections of rhodamine in the optic nerve) were polyamine-positive. These results are consistent with a role for polyamines as modulators of NMDA receptor function and channel function in the inner retina.     

Differential effects of bFGF on development of the rat retina

A variety of growth factors can influence the expression of differentiated properties by cell types of the developing retina. One unresolved question has been whether these factors can direct the differentiation pathway of uncommitted precursors or whether they act to help the expression of properties by already committed cells. To address this question we have studied the effects of basic fibroblast growth factor (bFGF) on the differentiation of ganglion cells and rod photoreceptors in explant cultures of embryonic rat retinas. Incubation of retinas in the presence of bFGF accelerated the appearance of differentiated ganglion cells and incubation in the presence of anti-bFGF antibodies delayed the appearance. bFGF had no effect on the appearance of differentiated rod photoreceptors as judged by expression of opsin, although all-trans-retinoic acid did increase the number of cells expressing opsin. bFGF inhibited the formation of rod photoreceptor rosettes suggesting that it does influence some properties of rods or the adjacent Müller glial cells. The results suggest that bFGF can alter the timing of differentiation of retinal ganglion cells but not direct their production from retinal precursors.     

Comparison of pupil responses to luminance and colour in severe optic neuritis.

OBJECTIVE: The pupil response to light flux increments is abnormal in severe optic neuritis, but little is known about the effects of this condition on the pupil colour response. The aim of this study was to examine how optic neuritis affects pupil responses to light flux and colour modulation and the extent to which such pupil responses mirror the loss and recovery of vision. METHODS: A new pupil examination technique that makes use of sinusoidal modulation of either luminance contrast or chromatic saturation was employed. This technique enables the automatic extraction of both pupil response amplitude and latency and achieves a high signal to noise ratio with fewer averages. RESULTS: The study reveals a greater loss of pupil response amplitude and significantly longer latencies to chromatic modulation (i.e. approximately 80 ms). Stimulation of the unaffected eye in the optic neuritis group results in smaller response amplitudes when compared to the normal group for both light flux and colour modulation. CONCLUSIONS: Pupil response components can be affected differently in optic neuritis. These findings suggest that the pupil colour response, in particular, may provide a useful, objective estimator to judge the extent of damage and recovery in diseases of the optic nerve.     

Ultrasonographic evaluation of wrist ganglia

This study was performed to assess the effectiveness of ultrasonography in the diagnosis of wrist ganglia and in their differentiation from other lesions. Sonographic examination of 73 patients with palpable masses was performed; their healthy hands and those of 25 healthy volunteers constituted the reference standard. Ganglia appeared sonographically as anechoic oval, round, or lobulated cystic structures. Ultrasound proved an accurate tool in their diagnosis, with the general advantages of easy, quick, and inexpensive application.