Neurodegeneración retiniana en pacientes diabéticos tipo 2 sin retinopatía diabética

In diabetes mellitus (DM) patients retinal complications were typically considered part of a vascular process. Recent research suggests that retinal degeneration in DM might also be caused by a neuropathy that could precede microvascular alterations. The present work reviews the currently available bibliography about neurodegeneration in patients with type 2 DM (DM2) without diabetic retinopathy (DR).In patients with non-severe, early DM2 without DR and good metabolic control visual function parameters show early abnormalities that precede clinical DR (in which we diagnose with a conventional ophthalmological examination). Using optical coherence tomography (OCT) technology, a reduction in macular and peripapillary thickness has been observed in different studies. Recent researches suggest that systemic complications (especially ischaemia) and a possible microvascular alteration eventually contributes to retinal neurodegeneration, which opens the door to new studies that include new techniques for evaluating the microvascularization of the retinal layers.     

小脑发育不良性神经节细胞瘤的影像诊断（附4例报告及文献复习）

目的探讨小脑发育不良性神经节细胞瘤的影像表现及诊断。材料与方法回顾性分析4例经病理证实的小脑发育不良性神经节细胞瘤的影像资料。结果CT显示病变为不均匀低密度影;MRI显示病灶为长T1长T2信号影,其内可见条纹状等T1等T2信号影,增强扫描病灶无明显强化。结论小脑发育不良性神经节细胞瘤的影像学表现有一定的特征性,有利于术前诊断。     

肝癌分期诊断与治疗策略

目的研究先天性肛门直肠畸形直肠盲端及瘘管神经节细胞发育及分布情况。方法肛门成形术时试验组切取瘘管及部分直肠盲端组织34例，取直肠盲端组织21例。标本常规送病理HE染色检查，并与术后半年内患儿便秘情况对比。结果闭锁位置越高，其神经节细胞发育越差、分布越稀少，术后半年内便秘发生率越高。但半年后便秘情况大部分好转或消失。结论术中取活检是必要的，可作为判断其预后的指标之一。     

Chromatic properties of the retinal afferents in the thalamus and the tectum of the frog (Rana temporaria)

In order to clarify physiological mechanisms underlying colour-specific visually guided behaviour, we measured spectral sensitivities of On-fibres projecting to the thalamus and class 2 and 3 fibres passing to tectum opticum. In addition we recorded responses of these fibres to moving coloured papers with known spectral reflectancies. The latter method, here called paper colourimetry, allowed us to change the relative stimulations of the blue-, green- and red-sensitive photoreceptors in any direction desired. Under the photopic conditions used the tectal fibres were driven exclusively by red-sensitive receptors, while the thalamic fibres received strong On-inputs from both red- and blue-sensitive receptors. Due to a partly antagonistic interaction between these inputs the On-fibres acted in a dichromatic way, responding with specific extended low-frequency discharges to all relative increases in blue receptor stimulation, e.g. to a great reduction in red stimulation combined with unchanged blue stimulation. Thus they have functional characteristics which could serve a visual system showing colour constancy.     

颈中交感神经节阻滞治疗偏头痛及与血清C反应蛋白的关系

目的 :C -反应蛋白 (CRP)作为监测炎症反应的一种新的免疫指标 ,该文观察了颈中交感神经节阻滞治疗偏头痛的临床效果 ,并探讨其与血清C反应蛋白的关系。方法 :颈中交感神经节阻滞采用气管旁颈 6横突法 ,每日 1次 ,两侧交替阻滞 ,共 7次。采用散射比浊法测定 4 8例偏头痛患者治疗前后和 2 8例正常人血清CRP水平。结果 :偏头痛患者经颈中交感神经节阻滞后头痛次数减少、头痛时间明显缩短、程度减轻 ,与治疗前比较有显著性差异 (P <0 .0 1)。偏头痛患者血清CRP显著增高 (P <0 .0 1) ,颈中交感神经节阻滞后血清CRP恢复正常。结论 :偏头痛患者神经内分泌免疫调节网络可能存在一些障碍 ,颈中交感神经节阻滞可调节偏头痛患者的神经、内分泌及免疫功能。     

The ganglion cell and cone distributions in the monkey''s retina: Implications for central magnification factors

The distribution of cones and ganglion cells was determined in whole-mounted monkey retinae. Ganglion cell density along the horizontal meridian was asymmetric, being up to three times greater in nasal retina. A similar but smaller asymmetry occurred with cones. The total number of ganglion cells varied from 1.4 to 1.8 X 10(6), agreeing well with counts of optic nerve axons. The variation of ganglion cell density with eccentricity indicates the magnification factor (MF) of the retina. This was compared with MF at the dorsal lateral geniculate nucleus and at striate cortex, revealing that the relative representation of the fovea increases substantially in both thalamus and cortex.     

Different reinnervation patterns in the celiac/mesenteric and superior cervical ganglia following guanethidine sympathectomy in adult rats

We sought to determine whether chronic guanethidine (Gu) treatment in adult rats produces depletion of sympathetic neurons and hyperinnervation by sensory neuropeptides in the celiac/superior mesenteric (C/SMG) ganglion. Rats received Gu 40 mg/kg per day i.p or saline for 5 weeks. Upon completion of treatment, the C/SMG and the superior cervical ganglion (SCG) were examined for neuropeptide Y (NPY), substance P (SP), calcitonin gene-related peptide (CGRP) and vasoactive intestinal polypeptide (VIP), both by immunocytochemistry (ICC) and radioimmunoassay (RIA). Gu produced marked depletion of NPY-containing neurons and NPY content in the C/SMG, similar to that in the SCG (−89 ± 2vs.−92 ± 4%, respectively). SP and CGRP immunoreactivities were significantly higher iontrol C/SMG as compared with SCG; after Gu treatment, there was no significant increase in either SP or CGRP in the C/SMG, however, both increased in the SCG. In contrast, VIP levels were similar in the SCG and C/SMG in controls and increased in the C/SMG but not in the SCG after Gu treatment. Thus, in adult rats, the C/SMG is as susceptible as the SCG to Gu treatment; the different pattern of hyperinnervation by SP, CGRP and VIP of the C/SMG as compared with the SCG may reflect the different sources for these neuropeptides in prevertebral as compared with paravertebral ganglia.     

Intravitreal kainic acid severely reduces the size of the developing optic tectum in newly hatched chickens

Following a single intravitreal injection of 200 nmol of kainic acid (KA) to newly hatched chickens, there are acute and long-term effects on retinal ganglion cells in the chicken retina. Thirty min after injection, most ganglion cells showed cytoplasmic vacuolization. However, 14 days later, most ganglion cell soma appeared normal. Almost 60% of the cells in the ganglion cell layer (GCL) were lost, suggesting that displaced amacrine cells and not more than 40% of the ganglion cells had been eliminated. Following intravitreal injection of wheat germ agglutinin conjugated to horseradish peroxidase 14 days after the KA lesion, the amount of HRP reaction product was reduced in all retinorecipient layers, especially layers IIc and IId, of the tectum contralateral to the KA-treated eye. Fourteen days after the injection of kainic acid, during which the control tecta grow appreciably, all the superficial layers of the tectum contralateral to the kainic acid-lesioned eye, especially layers IIc and IId, were smaller than in controls, and did not differ in size from those seen in tecta contralateral to cut optic nerves. It is not clear whether this is a result of a developmental failure, or a shrinkage, or a combination of these factors. These results suggest that subtypes of ganglion cells may have a disproportionate influence in the maintenance of the cytoarchitectural integrity in the optic tectum. Alternatively the removal of the OFF-bipolar cells and amacrine cells presynaptic to ganglion cells may decrease their metabolism, and restrict the supply of trophic influences to the developing tectal cells.     

Electrical stimulation activates two different sites within the guinea pig cochlea

This study investigates whether auditory brainstem responses (ABRs) can be used to assess the functioning of electrically stimulated cochleas. Electrically evoked auditory brainstem responses (EABRs) were recorded in guinea pigs with normal hearing and guinea pigs deafened by amikacin, a powerful ototoxic antibiotic, combined with diuretic aminooxyacetic acid (AOAA). Two different types of EABRs were observed in normal animals, depending on the electrical pulse intensity applied to the round window: long-latency brainstem responses were evoked by low stimulation intensities, short-latency brainstem responses by high intensities. The absence of effect of strychnine applied intracochlearly ruled out the possibility of medial efferents being involved in these responses. Conversely, an intracochlear application of tetrodotoxin (TTX), an Na⁺-channel blocker, resulted in the disappearance of both types of responses, attesting that the sites activated by the electrical stimulation were located within the cochlea. In AOAA/ amikacin poisoned cochleas, in which most of the hair cells were missing with apparently normal ganglion neurons, the long-latency brainstem responses evoked by low intensities were completely lacking. These findings suggest that low currents applied to the round window of the guinea pig cochlea primarily activate the hair cells, the neurons being directly excited at higher intensities.     

Anaplastic ganglioglioma of the brain stem demonstrating active neurosecretory features of neoplastic neuronal cells

Summary An autopsy case of anaplastic ganglioglioma in the brain stem of a 12-year-old girl is reported. The ill-defined tumor involved the right cerebellar peduncle, medulla oblongata and upper cervical spinal cord, and showed mixed proliferation of many ganglioid cells and atypical pilocytic astrocytes with necrotic areas. Immunohistochemical studies revealed the presence of chromogranin A in most ganglioid cells and of metenkephalin in some large ganglioid cells. Glial cells were positive for glial fibrillary acidic protein and vimentin. Ultrastructurally, numerous dense-core granules of 90–220 nm in diameter were demonstrated in ganglioid cells and abundant glial filaments in glial cells. High neurosecretory activity in neuronal cells, suggested by chromogranin-immunoreactivity and dense-core granules, seems to be the most characteristic property of ganglion cell tumors.