PURPOSE: Wallerian degeneration (WD) is an antegrade degenerative process distal to peripheral nerve injury. Numerous genes are differentially regulated in response to the process. However, the underlying mechanism is unclear, especially the early response. We aimed at investigating the effects of sciatic nerve injury on WD via CLDN 14/15 interactions in vivo and in vitro. METHODS: Using the methods of molecular biology and bioinformatics analysis, we investigated the molecular mechanism by which claudin 14/15 participate in WD. Our previous study showed that claudins 14 and 15 trigger the early signal flow and pathway in damaged sciatic nerves. Here, we report the effects of the interaction between claudin 14 and claudin 15 on nerve degeneration and regeneration during early WD. RESULTS: It was found that claudin 14/15 were upregulated in the sciatic nerve in WD. Claudin 14/15 promoted Schwann cell proliferation, migration and anti-apoptosis in vitro. PKCα, NT3, NF2, and bFGF were significantly upregulated in transfected Schwann cells. Moreover, the expression levels of the β-catenin, p-AKT/AKT, p-c-jun/c-jun, and p-ERK/ERK signaling pathways were also significantly altered. CONCLUSION Claudin 14/15 affect Schwann cell proliferation, migration, and anti-apoptosis via the β-catenin, p-AKT/AKT, p-c-jun/c-jun, and p-ERK/ERK pathways in vitro and in vivo. The results of this study may help elucidate the molecular mechanisms of the tight junction signaling pathway underlying peripheral nerve degeneration.
Animals ; Claudins ; Nerve Regeneration ; Peripheral Nerve Injuries ; Rats ; Schwann Cells/pathology* ; Sciatic Nerve ; Wallerian Degeneration/pathology*

No abstract available.
Nitrous Oxide* ; Subacute Combined Degeneration*

The human nervus terminalis (terminal nerve) and the nerves to the vomeronasal organ (VNON) are both associated with the olfactory nerves and are of major interest to embryologists. However, there is still limited knowledge on their topographical anatomy in the nasal septum and on the number and distribution of ganglion cells along and near the cribriform plate of the ethmoid bone. We observed serial or semiserial sections of 30 fetuses at 7–18 weeks (crown rump length [CRL], 25–160 mm). Calretinin and S100 protein staining demonstrated not only the terminal nerve along the anterior edge of the perpendicular lamina of the ethmoid, but also the VNON along the posterior edge of the lamina. The terminal nerve was composed of 1–2 nerve bundles that passed through the anterior end of the cribriform plate, whereas the VNON consisted of 2–3 bundles behind the olfactory nerves. The terminal nerve ran along and crossed the posterior side of the nasal branch of the anterior ethmoidal nerve. Multiple clusters of small ganglion cells were found on the lateral surfaces of the ethmoid's crista galli, which are likely the origin of both the terminal nerve and VNON. The ganglions along the crista galli were ball-like and 15–20 µm in diameter and, ranged from 40–153 in unilateral number according to our counting at 21-µm-interval except for one specimen (480 neurons; CRL, 137 mm). An effect of nerve degeneration with increasing age seemed to be masked by a remarkable individual difference.
Calbindin 2 ; Ethmoid Bone ; Fetus ; Ganglion Cysts ; Humans ; Individuality ; Masks ; Nasal Septum ; Nerve Degeneration ; Neurons ; Olfactory Nerve ; Vomeronasal Organ

We report two cases of subacute combined degeneration (SCD) caused by nitrous oxide (N₂O) gas intoxication, which is rarely reported in Korea. Two patients recreationally inhaled N₂O gas daily for several months. They presented with paresthesia of limbs, voiding difficulty, and gait disturbance. The initial vitamin B₁₂ levels were normal or decreased, but homocysteine levels of the two patients were increased. Magnetic resonance imaging of the cervical spine showed T2-weighted hyperintensity in the bilateral dorsal columns of the cervical spinal cord. Electromyography and somatosensory evoked potential tests for both patients suggested posterior column lesion of the spinal cord combined with sensorimotor polyneuropathy. According to these findings, we concluded that the two patients had SCD. The patient’s symptoms partially improved after cessation of N₂O gas inhalation and the receiving of vitamin B₁₂ supplementation therapy. As the incidence of recreational N₂O gas inhalation is increasing in Korea, physicians must be alert to the N₂O induced SCD in patients presenting with progressive myelopathy.
Cervical Cord ; Electromyography ; Evoked Potentials, Somatosensory ; Extremities ; Gait ; Homocysteine ; Humans ; Incidence ; Inhalation ; Korea ; Magnetic Resonance Imaging ; Nitrous Oxide ; Paresthesia ; Polyneuropathies ; Recreation ; Spinal Cord ; Spinal Cord Diseases ; Spine ; Subacute Combined Degeneration ; Vitamin B 12 ; Vitamins

OBJECTIVE: To detect mutation of NDP gene in a pedigree affected with Norrie disease. METHODS: Sanger sequencing was used to analyze the NDP gene at Xp11.3. Prenatal diagnosis was performed on amniotic fluid sample after the causative gene was detected. RESULTS: Sanger sequencing has revealed a c.2T>C (p.M1T) missense mutation of the NDP gene in the proband and the fetus. The same variation was not found in ClinVar and HGMD database. CONCLUSION The c.2T>C mutation of the NDP gene probably underlies the Norrie disease in this pedigree.
Blindness ; congenital ; Eye Proteins ; Female ; Genetic Diseases, X-Linked ; Humans ; Nerve Tissue Proteins ; Nervous System Diseases ; Pedigree ; Pregnancy ; Prenatal Diagnosis ; Retinal Degeneration ; Spasms, Infantile

BackgroundWallerian degeneration (WD) of bilateral middle cerebellar peduncles (MCPs) can occur following pontine infarction, but its characteristics have not yet been clarified because of the low incidence. Thus, the present study discussed the clinical and radiological features to improve the awareness of this disease.

MethodsClinical and radiological information from consecutive individuals diagnosed with WD of bilateral MCPs following pontine infarction in three hospitals over the past 4 years between October 2012 and October 2016 were retrospectively investigated and compared with a control group (patients with pontine infarction had no secondary WD).

Results:This study involved 30 patients with WD of MCPs, with a detection rate of only 4.9%. The primary infarctions (χ =24.791, P = 0.001, vs. control group) were located in the paramedian pons in 21 cases (70.0%), and ventrolateral pons in nine cases (30.0%). WD of the MCPs was detected 8-24 weeks after pons infarction using conventional magnetic resonance imaging (MRI); all secondary WDs were asymptomatic and detected incidentally. All WD lesions exhibited bilateral, symmetrical, and boundary blurring on MRI. The signal features were hypointense on T1-weighted imaging, hyperintense on T2-weighted imaging and fluid-attenuated inversion recovery, and slightly hyperintense or isointense on diffusion-weighted imaging and apparent diffusion coefficient maps. Secondary brainstem atrophy was found in six (20.0%) cases. A Modified Rankin Scale score 0-2 was found in 10 (33.3%) cases and score >2 in 20 (66.7%) cases at 90 days after discharge, and the short-term prognosis was worse than that in control group (χ =12.814, P = 0.001).

ConclusionsDespite the rarity of bilateral and symmetrical lesions of MCPs, secondary WD should be highly suspected if these lesions occur within 6 months after pontine infarction, particularly paramedian pons. Conventional MRI appears to be a relatively sensitive method for detecting WD of MCPs, which might affect the short-term prognosis.

Adult ; Aged ; Diffusion Magnetic Resonance Imaging ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Models, Biological ; Prognosis ; Retrospective Studies ; Wallerian Degeneration ; diagnostic imaging

OBJECTIVES: Glaucoma is an incurable eye disease and the second leading cause of blindness in the world. Until 2020, the number of patients of this disease is estimated to increase. This paper proposes a glaucoma detection method using statistical features and the k-nearest neighbor algorithm as the classifier. METHODS: We propose three statistical features, namely, the mean, smoothness and 3rd moment, which are extracted from images of the optic nerve head. These three features are obtained through feature extraction followed by feature selection using the correlation feature selection method. To classify those features, we apply the k-nearest neighbor algorithm as a classifier to perform glaucoma detection on fundus images. RESULTS: To evaluate the performance of the proposed method, 84 fundus images were used as experimental data consisting of 41 glaucoma image and 43 normal images. The performance of our proposed method was measured in terms of accuracy, and the overall result achieved in this work was 95.24%, respectively. CONCLUSIONS: This research showed that the proposed method using three statistics features achieves good performance for glaucoma detection.
Blindness ; Classification ; Eye Diseases ; Glaucoma ; Humans ; Methods ; Optic Disk ; Optic Nerve Diseases ; Retinal Degeneration

OBJECTIVES: The retinal nerve fiber layer (RNFL) is a site of glaucomatous optic neuropathy whose early changes need to be detected because glaucoma is one of the most common causes of blindness. This paper proposes an automated RNFL detection method based on the texture feature by forming a co-occurrence matrix and a backpropagation neural network as the classifier. METHODS: We propose two texture features, namely, correlation and autocorrelation based on a co-occurrence matrix. Those features are selected by using a correlation feature selection method. Then the backpropagation neural network is applied as the classifier to implement RNFL detection in a retinal fundus image. RESULTS: We used 40 retinal fundus images as testing data and 160 sub-images (80 showing a normal RNFL and 80 showing RNFL loss) as training data to evaluate the performance of our proposed method. Overall, this work achieved an accuracy of 94.52%. CONCLUSIONS: Our results demonstrated that the proposed method achieved a high accuracy, which indicates good performance.
Blindness ; Glaucoma* ; Methods ; Nerve Fibers* ; Optic Nerve Diseases ; Retinal Degeneration ; Retinaldehyde*

No abstract available.
Inhalation ; Nitrous Oxide ; Pulmonary Embolism ; Subacute Combined Degeneration

No abstract available.
Humans ; Subacute Combined Degeneration ; Vitamin B 12