脑弥漫性轴索损伤32例影像学诊断分析

目的　通过对脑弥漫性轴索损伤 (DAI)临床、CT及MRI的影像学表现的分析 ,以期提高对DAI的诊断水平。方法　分析有完整临床资料 ,同时进行过CT和MRI检查 ,特别是CT检查相对阴性的 32例DAI患者的影像学诊断结果。结果　 32例DAI患者CT检查相对阴性 ,MRI检查发现在胼胝体、基底节、脑干及灰白质交界处多发小的异常信号灶。结论　临床拟诊DAI的患者在CT检查相对阴性时可进行MRI检查 ,其MRI影像学表现有助于DAI的诊断     

Neuron-specific enolase as an effective immunohistochemical marker for injured axons after fatal brain injury

Recently, it has been reported that a diagnosis of diffuse axonal injury in cases with a short survival period can be made with the use of immunolabelling for β-amyloid precursor protein (APP). We examined whether immunostaining for neuron-specific enolase (NSE) can also be a useful marker for the detection of axonal injury in its early stages. Sections of the corpus callosum from 19 cases of head injury and from 9 cases of no head injury were immunostained for NSE and stained by the standard Holmes’ silver method. For comparison, serial sections from several cases were immunostained for APP. Immunostaining for NSE as well as for APP, labelled injured axons in head injury cases with as early as 1.5 h survival where Holmes’ staining failed to detect any changes of axons. Since NSE and APP labelled only injured axons but not normal axons, the results were readily interpretable. These findings indicate that NSE should be an effective marker for the detection of axonal injury in its early stages. Received: 7 December 1998 / Received in revised form: 11 March 1999     

手术治疗巨大裂孔视网膜脱离的预后分析

目的：探讨不同的手术方法对巨大裂孔视网膜脱离病例的预后影响。方法：回顾１９９５年１月～１９９７年３月间我院住院治疗的巨大裂孔视网膜脱离７２例７３眼。手术方法分为四种。结果：术后随访３月,总视网膜解剖复位率为５７／７３（７８．１％）,其中单纯型为１４／１６（８７．５％）,复杂型为４３／５７（７５．４％）。单纯型与复杂型患眼的术后复位率无统计学差异。环扎加压术后,单纯型患眼的复位率高于复杂型。对于复杂型患眼,玻璃体手术合并环扎加压术与否对其复位率无影响;玻璃体手术中使用Ｃ１０Ｆ１８与否对其复位率无影响。结论：环扎加压术对于治疗单纯型巨大裂孔视网膜脱离,尚属一种有效的方法。Ｃ３Ｆ８气体和全氟碳液是治疗有翻转后瓣的巨大裂孔视网膜脱离的有效手段。部分复杂型巨大裂孔视网膜脱离常用硅油填充。根据患眼的具体情况,选择合适的手术方法至关重要。     

Analysis of orthograde fast axonal transport and nonaxonal transport along the optic pathway of albino rabbits during increased and decreased intraocular pressure

Orthograde fast axonal and nonaxonal transport through the optic disc was studied quantitatively and autoradiographically in albino rabbits during elevated (30 or 50 mmHg), normal (13–15 mmHg) and decreased (0–4 mmHg) intraocular pressure (IOP). In cases of intraocular hypertension up to 50 mmHg, autoradiographic findings of a disturbed orthograde fast axonal transport were seen in the optic disc within 3 hr. The blockage was relatively mild and uniform, and was distributed adjacent to the extension line of sclera. Despite this histological evidence of blockage, a quantitative analysis showed no statistically significant decrease in axonally transferred radioactivity within 3 hr. Decrease in the transferred material was evident at 6 hr, and the extent of decrease was mild (ca. 20% at the most prominent portion). In cases of moderate intraocular hypertension (30 mmHg) for 6 hr, a quantitative analysis showed no decrease in axonal transport. After 3–6 hr of intraocular hypotension (0–4 mmHg), papilledema did not develop and autoradiographically there was no accumulatjon of axonal components. Axonally transferred material remained quantitatively at the same level as in the control animals. Nonaxonal transport along the optic nerve was doubly enhanced in cases of intraocular hypertension up to 50 mmHg, and was reduced to one thrid at level of 0–4 mmHg. Filtration of intraocular fluid through the optic disc appears to be the largest component of the nonoxonal transport.     

Plasticity of the corticospinal tract following midthoracic spinal injury in the postnatal rat

Rats received a midthoracic spinal cord "overhemisection" including right hemicord and left dorsal funiculus at birth (neonatal operates, N = 15) or 21 days of age (weanling operates, N = 14). In a second experiment neonatal (N = 6), 6-day (N = 3), and 12-day (N = 7) rats sustained a right sensorimotor cortex (SmI) ablation to destroy the left corticospinal tract (CST) at the same time as the spinal injury (double lesion operates). Later (3-12 months) injections of 3H-proline and autoradiography were used to label the left or right CST. The results of the first experiment showed that most right CST axons failed to grow around the spinal lesion in neonatal operates (N = 9). There was an increase in the density of label, mainly to CST projection areas, in a 1-mm zone rostral to the lesion. However, left CST axons bypassed the lesion by growing through the intact tissue in neonatal operates (N = 6). These displaced axons were consistently located within the dorsal portion of the lateral funiculus (dLF) and remained within that location caudal to the lesion, an area normally containing only a few CST axons. In spite of this abnormal position, these axons terminated bilaterally throughout the remainder of the cord in normal CST sites. In weanling operates, CST axons severed by the lesion did not regenerate around the lesion site. An increased density of label over the few spared axons within the left dLF and in CST projection zones immediately caudal to the lesion site suggested axonal sprouting by these axons. The results of the second experiment showed that the lack of growth of right CST axons around this injury in neonatal operates was, at least partially, due to an interaction with left CST axons. In neonatal double lesion operates, right CST axons grew around the spinal injury for a varying distance within the left dLF and distributed bilaterally to normal CST sites. The number of right CST axons bypassing the lesion was related to the configuration of the lesion site. A smaller number of right CST axons bypassed the lesion in 6-day double lesion operates and most terminated within 2-3 mm of the lesion site. Right CST axons failed to grow around this injury in 12-day double lesion operates.(ABSTRACT TRUNCATED AT 400 WORDS)     

Adult Retinofugal Axons Regenerating Through Peripheral Nerve Grafts Can Restore the Light-induced Pupilloconstriction Reflex

To investigate the ability of mature regenerating retinal axons to form functional connections within central targets, severed axons were guided into the primary visual centres which subserve the pupillary constriction reflex in response to light. The ocular stump of the transected optic nerve of adult rats was connected by means of an autologous peripheral nerve graft with the pretectal region which contains the relay nucleus of pupillary constriction, the olivary pretectal nucleus. This nucleus is efferently connected with preganglionic neurons in the oculomotor nuclear complex which innervates parasympathetically the muscle constrictors of the iris. Six to sixteen weeks after optic nerve transection and peripheral nerve transplantation, brisk responses were observed in the pupils upon illumination of the transplanted eye. Recovery of the pupil responses indicated that retinal neurons used the peripheral nerve 'bridge' to access the pretectum, in which they established synaptic contacts in sufficient density and with appropriate specificity to reconstitute the function of the traumatically interrupted neuronal circuitry.     

Progesterone Receptor-Containing Neurons in the Guinea-Pig Mediobasal Hypothalamus have Axonal Projections to the Medial Preoptic Area

The location and number of progesterone receptor-containing neurons in the mediobasal hypothalamus that project to the medial preoptic area were determined by combining retrograde fluorescent tract tracing with progesterone receptor immunocytochemistry. Injections of the retrograde tract tracer Fluoro-gold were made in the preoptic area of female guinea-pigs ovariectomized and primed with estradiol. After 5 days survival to allow for retrograde transport, tissue sections were incubated with monoclonal antibodies to the progesterone receptor to detect the presence of progesterone receptor-immunoreactive neurons. Cell bodies were labelled with Fluoro-gold throughout the arcuate nucleus. These neurons were not concentrated in any particular area of the nucleus but were diffusely distributed bilaterally. Retrogradely-labelled neurons were also observed in the ventrolateral and ventromedial nuclei mainly contralateral to the injection site. Progesterone receptor immunofluorescence labelled a subpopulation (7% to 10%) of these retrogradely-labelled cells particularly in the arcuate nucleus, including the median eminence. The double-labelled cells were more numerous in the anterior two-thirds of the arcuate nucleus. Although our estimates of the proportion of hypothalamic progesterone receptor-immunoreactive neurons that sent axons directly to the medial preoptic area were low, (about 0.35%), these neurons may be part of a neural circuit involved in the regulation of reproductive processes.     

Corticotropin-releasing factor binding sites undergo axonal transport in the rat vagus nerve

Corticotropin-releasing factor (CRF) binding sites were found to be present in the rat vagus nerve and underwent axonal transport. Binding sites accumulated on both sides of ligatures placed on the nerve and at similar rates following ligation of right or left cervical vagal trunks of either male or female rats. CRF binding sites also accumulated proximal and distal to ligatures on subdiaphragmatic vagal trunks. Binding was specific, reversible and inhibited by the CRF receptor antagonist α-helical-CRF(9-41). [(125) l]Tyr(0) -ovine-CRF binding to rat vagus nerve was not guanine nucleotide-sensitive. CRF and cholecystokinin binding sites were transported at a similar rate in the cervical vagus, although turnover of CRF binding sites was more rapid. No differences in CRF binding site transport were observed between Zucker rats of lean or obese genotype.     

Specificity in the Development of Vertical Connections in Cat Striate Cortex

The main efferent axons of pyramidal cells in layer 2/3 in the adult cat striate cortex make collateral connections specifically within layer 2/3 and layer 5 and avoid the intervening layer 4. Intracellular dye injections in vitro were used to determine how, during early postnatal development, this precise pattern of laminar connections was achieved. These investigations revealed that the pattern of collateral outgrowth was specific from the very earliest time that axons began sprouting collaterals. During the first postnatal week, sprouts were seen exclusively within layers 2/3 and 5; no evidence for a transient connection to layer 4 was observed. Furthermore, collaterals emerged simultaneously within layers 2/3 and 5, despite the large difference in the postmigratory ages of the two layers. By the end of the second postnatal week, the adult number of collaterals was achieved. Further elaboration of the local arbors occurred by repeated branching of already existing collaterals, rather than by addition of new collaterals to the main axon. These results demonstrate that the formation of local connections between cortical layers is highly specific, in contrast to the development of clustered horizontal connections by these same cells within layers 2/3 and 5, which involves extensive remodelling of local connections.     

Giant aneurysm of the calloso-marginal artery

A giant aneurysm of the right callosomarginal artery is reported in a 3-month-old child. This location is rare: including our case reported here, only three cases have been described. Clinicoradiological findings are presented and the surgical procedure is illustrated.