Straatsma syndrome / Síndrome de Straatsma

Abstract The presence of retinal myelinated nerve fibers is not a rare finding during routine examinations, and it is usually a benign and isolated finding. However, in some rare cases, it can be associated with other ophthalmological conditions. We describe a case of a patient with the triad myelin nerve fibers, myopia and ambliopia, which configures the Straatsma Syndrome.

Resumo A presença de fibras de mielina é um achado comum durante exames oftalmológicos de rotina. Na maior parte das vezes, tem caráter beningno e é um achado isolado. No entanto, em alguns raros casos, a presença de mielinização pode estar associada a outras condições oftalmológicas. Descrevemos um caso de paciente com a tríade presença de fibras nervosas retinianas mielinizadas, miopia, e ambliopia, configurando a síndrome de Straatsma.

Changes of white matter in LDLR knockout hypercholesterolemic rats / 国际脑血管病杂志

Objective To investigate the difference between histopathological changes of brain white matter in low-density lipoprotein receptor (LDLR) homozygous mutation rats with hypercholesterolemia and wild-type rats.Methods Thirty LDLR-/-rats and 28 wild-type rats were selected.Plasma cholesterol levels were measured by enzyme-linked immunosorbent assay at 15,18 and 26 weeks old respectively.The axonal structure of the corpus callosum area was observed by transmission electron microscopy.The myelin basic protein (MBP) of the corpus callosum area was quantitatively analyzed by Western blotting.In addition,at 26 weeks old,the myelin sheaths were stained by fast blue staining.The expression level of MBP in white matter was further detected by immunofluorescence staining,and the morphological changes of glial cells were observed.Results Compared with the wild-type rats,the plasma cholesterol concentration in LDLR-/-rats increased significantly,and it could be as high as 3.3 times at 26 weeks.The results of electron microscopy showed that the LDLR-/-rats had axonal injury at 15 weeks and aggravated gradually over time.At 26 weeks,Western blot analysis of the LDLR-/-rats showed that the MBP expression level of the corpus callosum area decreased significantly.Fast blue staining showed loosening of nerve fibers,diffuse vacuole formation,and myelinated nerve fiber loss in the corpus callosum area.In addition,it was also found that the number of oligodendrocytes in LDLR-/-rats was significantly reduced,and large numbers of astrocytes and microglia were activated.Conclusions LDLR-/-rats will have spontaneous hypercholesterolemia.Axonal injury,demyelination,decreased oligodendrocytes,as well as the abnormal activation of astrocytes and microglia are present in the early adult brain white matter area.

Straatsma syndrome: two case reports / Síndrome de Straatsma: dois relatos de caso

Abstract This article reports two cases of Straatsma Syndrome, a rare disease, emphasizing its clinical features that inclued myopia, strabismus and amblyopia associated with persistent myelinated fibers in the retina. Ophthalmic examination, color retinography and optical coherence tomography were performed.

Resumo Este artigo relata dois casos de síndrome de Straatsma, uma doença rara, enfatizando suas características clínicas que incluem miopia, estrabismo e ambliopia associada a persistência de fibras de mielina na retina. Foram realizados exame oftalmológico, retinografia e tomografia de coerência óptica.

Synthetic biodegradable nerve conduits for repair of injured peripheral nerve:good biocompatibility / 中国组织工程研究

BACKGROUND:In the treatment of peripheral nerve injury, we can use autologous nerve or the nerve conduit of different materials. OBJECTIVE:To explore the effects of biodegradable nerve conduit in repairing peripheral nerve injury. METHODS:A total of 48 New Zealand white rabbits were randomly divided into autologous nerve graft group, silicone catheter group and biodegradable nerve conduit group. 10-mm sciatic nerve was obtained from each group to construct animal models of sciatic nerve defect, which was repaired with autologous nerve, silicone catheter and biodegradable nerve conduit. RESULTS AND CONCLUSION:At 3 weeks after transplantation, motor nerve conduction and recovery rate of triceps muscle wet weight were poorer in the silicone catheter group than in the autologous nerve graft group. Motor nerve conduction and recovery rate of triceps muscle wet weight were similar between the biodegradable nerve conduit group and autologous nerve graft group. At 12 weeks, a large number of uniform myelinated nerve fiber was visible in the autologous nerve graft group. A large number of uneven myelinated nerve fiber was found in the biodegradable nerve conduit group. A smal number of uneven myelinated nerve fiber was seen in the silicone catheter group. These data suggest that the synthetic biodegradable materials of nerve conduit can obtain good effect, which is close to the autologous nerve graft.

The brain functional magnetic resonance imaging characteristics induced by contact heat stimulations in normal adults / 中华神经科杂志

Objective Aδ and C fiber nociceptors can be excited when people received contact heat stimulation(CHS) and this excitation may be reflected by functional magnetic resonance imaging(fMRI).The aim of this study was to observe the different fMRI characteristics in CHS with distinct temperatures in healthy people and to explore the pain related functional network.Depending on the fMRI results,we can evaluate the values of CHS-fMRI during the research of brain functional connectivity.Methods Twenty-two healthy volunteers were recruited to this study.During the acquisition of fMRI,the right dorsal forearm received two different CHS in 41 and 51 degree respectively(41 ℃ CHS-fMRI group and 51 ℃ CHS-fMRI group),and two series of fMRI data were obtained for each subject.The brain activation was obtained by using one sample t test for the 41 ℃CHS-fMRI group and 51 ℃CHS-fMRI group separately.The difference between 41 ℃ CHS-fMRI group and 51 ℃ CHS-fMRI group was analyzed by paired-sample t-test.Result These activated brain areas in 41 ℃ CHS-fMRI group included bilateral superior temporal gyrus (STG),contralateral transverse temporal gyrus,contralateral amygdala,bilateral insula,bilateral inferior frontal gyrus (IFG),contralateral hippocampus,bilateral putamen,contralateral supramarginal,ipsilateral postcentral,ipsilateral inferior parietal lobule,ipsilateral middle temporal gyrus (MTG),bilateral cerebelum,bilateral middle cingulate cortex and bilateral posterior cingulate cortex.These activated brain areas in 51 ℃ CHS-fMRI group included bilateral STG,bilateral amygdala,contralateral hippocampus,bilateral thalamus,contralateral putamen,bilateral insula,bilateral IFG,bilateral cerebellum,contralateral postcentral,contralateral superior parietal lobule,bilateral MTG,bilateral precuneus,and contralateral cuneus.Compared with 41 ℃ CHS-fMRI group,the 51 ℃ CHS-fMRI group showed higher brain activation in bilateral cerebellum (right:4.455,left:3.891),ipsilateral precuneus (4.150),contralateral insula (3.530),contralateral IFG (3.530),and contralateral postcentral (3.530; t =2.83,P ＜ 0.01).Conclusions There are common brain activated areas and specific areas for each group,which suggested that existence of two central pathways activated by Aδ and C fiber which have different effects in perception of pain and have their brain network responsively.It may become one of the ideal pain stimulation methods with CHS-fMRI,which warrant worth further research.

The analysis of the clinical and pathologic features in patients with peripheral neuropathy as main manifestation of microscopic polyangiitis / 中华神经科杂志

Objective To investigate the clinical and pathologic features in patients of microscopic polyangiitis (MPA) with peripheral nerve abnormality.Methods We collected clinical data of 6 patients with MPA that was confirmed by immunological,pathological and clinical findings.Electroneurophysiologic examinations and sural nerve biopsies were performed in these patients.Two normal controls were included in these studies.Results All of 6 patients developed asymmetric polyneuropathies.Electrodiagnostic studies showed reduced amplitudes of the sensory nerve action potential and compound motor action potential with mild impaired conductive velocities.The patients presented vasculitis changes with cell infiltration by monocytes and lymphocytes.Sural nerve biopsies found loss of myelinated fibers in all of the patients indicating axonal degeneration.Some of them associated with regeneration clusters of myelinated fibers.Conclusions Asymmetric neuropathy with sensory nerve injuries is the mainfeature in the MPA associated polyneuropathy.Electrodiagnostic examination indicated axonal lesions in mononeuritis multiplex.Sural nerve biopsies confirmed the active axonal lesions and vasculitis.

An Experimental Study on the Pattern and Significance of Perineurium Regeneration during Peripheral Nerve Repair / 第三军医大学学报

The repair process of the iibial fascicle of the rabbit sciatic nerve which had been transected and sutured or simply crushed was studied by means of light and . electron microscopy.It was found that the perineurium was able to heal after the nerve had been transected and sutured through the formation of a new epineurium-perineurium tube which contained many minute fascicles of regenerated nerve fibers. The newlyformed epineurium-perineurium tubs rejoined ths two stumps of the transected epineurium theath perineurium tube. The healing process of the nerve fascicle after crushing was similar to that after transection and suturing.From the transection and suturing of the nerve to the formation of the new epineurium-perineurium tubs the sequence of pathological events occurring in the epineurium and perineurium could be divided into 3 stages, the first stage of trau-matic inflammation, degeneration and necrosis of the perineurium, the second stage of perineurial cell proliferation, and the regeneration nerve fiber growth into the pre-perineurium mass and the third stage of the formation of new small nerve fascicles.The formation of the new epineurium-perineurium tube is of vital importance to nerve regeneration, it can prevent the nerve fibers from growing astray and guide them to the distal perineurium tube. The pro-perineurial cells might originate from the proliferation of the perineurial cells, themselves.The normal histological and ultrastructural morphology of the rab bit sciatic nerve was described. The nuclei of the perineurial cells have the tendency to form palisades. It seems that this may explain the palisading of the nuclei of neurofibr-oma cells.