Distribution of Aquaporin-4 channels in hippocampus and prefrontal cortex in mk-801-treated balb/c mice.

Functional disorders of the glymphatic system and Aquaporin-4 (AQP-4) channels take part in the pathophysiology of neurodegenerative disease. The aim of this study was to describe the distribution of AQP-4 channels in the prefrontal cortex and hippocampus in a mouse model of NMDA receptor blocking agent-induced schizophrenia-like behavior model. NMDA receptor antagonist MK-801 was used to produce the experimental schizophrenia model. MK-801 injections were administered for eleven days to Balb/c mice intraperitoneally. Beginning from the sixth day of injection, the spatial learning and memory of the mice were tested by the Morris water maze (MWM) task. A group of mice was injected with MK-801 for ten days without the MWM task. Hippocampus and prefrontal specimens were collected from this group. Tissue samples were stained immunohistochemically and AQP-4 channels were examined by electron microscope. Time to find the platform was significantly longer at MK-801 injected group than the control group at the MWM task. Also, time spent at the target quadrant by the MK-801 group was shorter compared to the control group. AQP-4 expression increased significantly at MK-801 group glial cells, neuronal perikaryon, perineuronal and pericapillary spaces. In the MK-801 group, there was remarkable damage in neurons and glial cells. Increased AQP-4 channel expression and neurodegeneration at the MK-801 group induced with schizophrenia-like behavior model. MK-801 induced NMDA receptor blockade causes a decline in cognitive and memory functions. Increased AQP-4 expression at the prefrontal cortex and hippocampus to elicit and transport products of synaptic neurotransmitters and end metabolites is suggested.

Cervical Myelopathy Caused by Invaginated Laminae of the Axis into the Spinal Canal in a Pediatric Patient.

Cervical myelopathy caused by invaginated laminae of the axis is an extremely rare entity. Advanced imaging techniques are useful to define this rare pathology and site of the spinal canal compression. Surgical removal of the floating laminae is commonly an adequate treatment method. Fusion procedures should be added in the presence of instability. There are few cases of invaginated anomalous laminae of the axis in the literature. In this report, to the best of our knowledge having reviewed the literature, the youngest and first female patient is presented.

Impact of Adjuvant Radiotherapy on Recurrence of Surgically Treated Atypical Meningiomas and Retrospective Analysis of Prognostic Factors.

AIM: The role of adjuvant radiotherapy after surgery for atypical meningiomas remains controversial. The present study was designed to investigate the recurrence rate of atypical meningiomas after surgery (with or without adjuvant radiotherapy) and determine which factors were related with recurrence. MATERIAL AND METHODS: Data obtained from 83 patients who underwent surgery and histopathologically diagnosed with atypical meningioma at a single institution between January 2009 and June 2019 were retrospectively reviewed. Then, the patients were divided into two groups: the surgery-only (n = 43) and surgery + adjuvant radiotherapy (n = 40) groups. RESULTS: The mean age of the patients was 53.5 ± 14.6 years. Among them, 51 (61.4%) were female and 32 (38.6%) were male. The recurrence rates were 30.2% (n = 13) in the surgery-only group and 17.5% (n = 7) in the surgery + adjuvant radiotherapy group. A statistically significant decrease in the recurrence rate was observed after adjuvant radiotherapy application (p = 0.046). Moreover, adjuvant radiotherapy significantly increased progression-free survival (p = 0.042). Peritumoral edema, sinus invasion, brain invasion, subtotal tumor resection, and complications were significant predictors of tumor recurrence, and the main risk factors for the recurrence of atypical meningiomas were brain invasion (p = 0.019) and subtotal tumor resection (p = 0.006). Progression-free survival and overall survival of the study group were 45.50 ± 27.56 and 56.69 ± 28.17 months, respectively. The parameters examined in the study, except for tumor recurrence, did not show a statistically significant influence on overall survival. CONCLUSION: This study revealed that the important prognostic factors for tumor recurrence are subtotal tumor resection and brain invasion. Moreover, adjuvant radiotherapy in addition to surgical resection reduces the recurrence rate of atypical meningiomas and improves progression-free survival of the patients. However, adjuvant radiotherapy did not show a significant influence on overall survival.