Nerve conduction and microanatomy in the rabbit sciatic nerve after gradual limb lengthening-distraction neurogenesis.

To clarify how the peripheral nerve adapts to elongation during gradual limb lengthening, electrophysiological and histomorphometric examinations were performed on the sciatic nerves in 18 rabbits. External fixators were used to lengthen the right femora by 30 mm (30%), at a daily rate of 0.5 mm (Group 1) or 2.0 mm (Group 2). Examinations were performed immediately after the limb lengthening procedure. Electrophysiologically, mild conduction slowing was observed in Group 1; a conduction block was evident in Group 2. Histologically, the mean diameter of myelinated fibers was unchanged in Group 1, but a significantly decreased diameter was observed in Group 2. Electron microscopy revealed that mild degenerative change of unmyelinated axons occurred sporadically in two cases in Group 2, but neither group showed evidence of thinning of myelin sheath of myelinated fibers. The mean internodal length (between nodes of Ranvier) of teased fibers was 1216+/-295 microm in the control contralateral side, 1484+/-347 microm in Group 1, and 1467+/-322 microm in Group 2. Thus the internodes were lengthened by 22.1% (Group 1) and 20.7% (Group 2) in comparison with those of the controls. Straightening of the geometry of paranodal myelin sheath was significantly correlated with the rate of distraction. These results indicate that myelinated nerve fibers adapt to gradual elongation by lengthening each Schwann cell body, not by proliferation of Schwann cells.     

Hypofluorescent spots in indocyanine green angiography of peau d‘orange and fundus

Purpose. Hypofluorescent spots were seen inindocyanine green (ICG) angiography of peau dorangefundus in eyes with angioid streaks. Origin of the hypofluorescentspots were examined with attention to their correlationwith a peau dorange appearance of the central fundususing a computer-assisted image comparison system. Methods. ICG angiography was performed in 5 patientshaving peau dorange appearance of fundus using ascanning laser ophthalmoscope (SLO) and a digitalvideo-fundus camera. The same central fundus areas corresponding to hypofluorescent spots in an ICGangiogram were then digitally identified in afluorescein angiogram and in a red-free picture in all10 eyes of the 5 patients. Monochromatic lightobservation was also performed with a dark fieldobservation using a SLO to see subretinal orintrachoroidal pigment clumping. Results. In no patient, the areas identified withhypofluorescent spots did show relevant changes ina fluorescein angiogram or a red-free picture. SLOexamination revealed not perfusion defect at the sameareas. The dark field observation showed no pigmentclumping at the peripapillary and papillomacularbundle regions where hypofluorescent spots were seen.Conclusions: Hypofluorescent spots seen in ICGangiograms did not show exact consistency with peau dorange changes in their location and shape. Perfusion defects or blocking by pigments were not acause of hypofluorescent spots. The scatteredhypofluorescent spots were considered to be relevantwith irregular affinity of the fundus to ICG dye.     

Implication of core beliefs about negative-self in neuroticism

Abstract

Objective: Core beliefs about negative-self are beliefs about self-deficiencies in basic aspects of human adaptation. Meanwhile, neuroticism is a personality trait characterised by negative emotionality, i.e., a tendency to react to stress with negative emotions. The present study tested the hypothesis that core beliefs about negative-self are implicated in neuroticism.

Methods: The subjects were 309 Japanese healthy volunteers. Core beliefs about negative-self were evaluated by the Brief Core Schema Scales, and neuroticism was evaluated by the NEO Personality Inventory-Revised.

Results: In both multiple regression analysis and structural equation modelling, higher neuroticism was strongly predicted by higher levels of core beliefs about negative-self.

Limitations: The present study cannot determine the causal relationship between core beliefs about negative-self and neuroticism, because of its cross sectional design.

Conclusions: The present study suggests that core beliefs about negative-self are deeply implicated in neuroticism.

• Key Points

• Implication of core beliefs about negative-self in neuroticism was examined.

• Neuroticism was predicted by higher levels of these core beliefs.

• These core beliefs may be involved in negative emotionality of neuroticism.

     

Transient hypoglycorrhachia with paroxysmal abnormal eye movement in early infancy

Paroxysmal abnormal eye movement in early infancy is one of the initial symptoms of glucose transporter 1 deficiency syndrome (GLUT1DS). We describe four early infants with transient hypoglycorrhachia presenting with abnormal eye movements. Their symptoms disappeared after the introduction of a ketogenic diet (KD), and their development was normal. Since no variants in SLC2A1 were detected, the CSF-to-blood glucose ratios (C/B) were re-examined, and within normal range. None of the four patients displayed recurrent symptoms after withdrawal from the KD. Because long-term KD has potential adverse effects and could affect the quality of life of patients and their families, re-examination of CSF glucose during late infancy should be considered in the case of absence of the SLC2A1 pathogenic variant.     

Characterization of early onset neurofibromatosis type 2

Neurofibromatosis type 2 (NF2) is an autosomal dominant multiple neoplasia syndrome of the central nervous system. The aim of the present study was to characterize the clinical course of early onset NF2. The specific Japanese disease registry for NF2 in 2010 was analyzed retrospectively. The male:female ratio for the 312 patients identified in the database was 1:1.29. The median age at onset was 25 years (range 2–76 years), with 31.3% of patients exhibiting symptoms at <20 years of age. Patients with an age at onset of <20 years were found to have more frequent spinal cord and extravestibular cranial nerve involvement, cutaneous signs, and convulsions than patients with a later age at onset. Of patients younger than 18 years of age, half did not exhibit hearing problems; in contrast, they frequently had other cranial nerve schwannomas, cranial meningioma, spinal cord tumors, and subcutaneous schwannoma. There were weak but significant positive correlations between symptomatic periods and disability scores in patients with an age of onset of ?20 years (R = 0.225; P < 0.01) and those with an earlier age of onset (R = 0.306; P < 0.01). Although there were no significant differences in disability scores between genders or patients with an age at onset of <20 versus ?20 years, patients with an earlier age at onset had significantly higher disability scores for spinal symptoms than patients with an age at onset of ?20 years. Atypical extravestibular presentation is common in early onset NF2, with more prominent spinal symptoms.     

s‐Afadin binds more preferentially to the cell adhesion molecules nectins than l‐afadin

l‐Afadin was originally purified from rat brain as an actin filament (F‐actin)‐binding protein that was homologous to the AF‐6 gene product. Concomitantly, s‐afadin that did not show an F‐actin‐binding capability was copurified with l‐afadin. Structurally, s‐afadin lacks the C‐terminal F‐actin‐binding domain but has two short sequences that were not present in l‐afadin. The properties and roles of l‐afadin have intensively been investigated, but those of s‐afadin have poorly been understood. We show here an additional difference in their biochemical properties other than binding to F‐actin between l‐afadin and s‐afadin. Both l‐afadin and s‐afadin bound to nectins, immunoglobulin‐like cell adhesion molecules, whereas s‐afadin more preferentially bound to nectins than l‐afadin. The PDZ domain of l‐afadin and s‐afadin was essential for their binding to nectin‐3. The dilute domain of l‐afadin negatively regulated its binding to nectin‐3, but the deletion of the C‐terminal F‐actin‐binding domain of l‐afadin did not increase the binding of l‐afadin to nectin‐3. These results indicate that the s‐afadin‐specific C‐terminal inserts may be involved in its preference of binding to nectin‐3 and raise the possibility that there are proteins other than nectins that more preferentially bind s‐afadin than l‐afadin.