Amyloid beta-peptide worsens cognitive impairment following cerebral ischemia-reperfusion injury

Amyloid 13-peptide, a major component of senile plaques in Alzheimer＇s disease, has been implicated in neuronal cell death and cognitive impairment. Recently, studies have shown that the pathogenesis of cerebral ischemia is closely linked with Alzheimer＇s disease. In this study, a rat model of global cerebral ischemia-reperfusion injury was established via occlusion of four arteries; meanwhile, fibrillar amyloid [3-peptide was injected into the rat lateral ventricle. The Morris water maze test and histological staining revealed that administration of amyloid 13-peptide could further aggravate impairments to learning and memory and neuronal cell death in the hippocampus of rats subjected to cerebral ischemia-reperfusion injury. Western blot showed that phosphorylation of tau protein and the activity of glycogen synthase kinase 313 were significantly stronger in cerebral ischemia-reperfusion injury rats subjected to amyloid [3-peptide administration than those undergo- ing cerebral ischemia-repetfusion or amyloid 13-peptide administration alone. Conversely, the activ- ity of protein phosphatase 2A was remarkably reduced in rats with cerebral ischemia-reperfusion injury following amyloid 13-peptide administration. These findings suggest that amyloid 13-peptide can potentiate tau phosphorylation induced by cerebral ischemia-reperfusion and thereby aggravate cognitive impairment.

Phosphorylation of tau protein over time in rats subjected to transient brain ischemia

Transient brain ischemia has been shown to induce hyperphosphorylation of the micro- tubule-associated protein tau. To further determine the mechanisms underlying these processes, we investigated the interaction between tau, glycogen synthase kinase （GSK）-313 and protein phos- phatase 2A. The results confirmed that tau protein was dephosphorylated during brain ischemia; in addition, the activity of GSK-3β was increased and the activity of protein phosphatase 2A was de- creased. After reperfusion, tau protein was hyperphosphorylated, the activity of GSK-3β was de- creased and the activity of protein phosphatase 2A remained low. Importantly, the interaction of tau with GSK-3β and protein phosphatase 2A was altered during ischemia and reperfusion. Lithium chloride could affect tau phosphorylation by regulating the interaction of tau with GSK-3β and pro- tein phosphatase 2A, and improve learning and memory ability of rats after transient brain ischemia. The present study demonstrated that it was the interaction of tau with GSK-3β and protein phos- phatase 2A, rather than their individual activities, that dominates the phosphorylation of tau in tran- sient brain ischemia. Hyperphosphorylated tau protein may play an important role in the evolution of brain injury in ischemic stroke. The neuroprotective effects of lithium chloride partly depend on the inhibition of tau phosphorylation during transient brain ischemia.

Application of multimodal image fusion technology in brain tumor surgical procedure

Objective: To construct brain tumors and their surrounding anatomical structures through the method of registration, fusion and, three-dimensional(3D) reconstruction based on multimodal image data and to provide the visual information of tumor, skull,brain, and vessels for preoperative evaluation, surgical planning, and function protection.Methods: The image data of computed tomography(CT) and magnetic resonance imaging(MRI) were collected from fifteen patients with confirmed brain tumors.We reconstructed brain tumors and their surrounding anatomical structures using Neuro Tech software. Results: The whole 3D structures including tumor, brain surface, skull, and vessels were successfully reconstructed based on the CT and MRI images. Reconstruction image clearly shows the tumor size, location, shape, and the anatomical relationship of tumor and surrounding structures. We can hide any reconstructed images such as skull,brain tissue, blood vessles, or tumors. We also can adjust the color of reconstructed images and rotate images to observe the structures from any direction. Reconstruction of brain and skull can be semi transparent to display the deep structure; reconstruction of the structures can be axial, coronal, and sagittal cutting to show relationship among tumor and surrounding structures. The reconstructed 3D structures clearly depicted the tumor features, such as size, location, and shape, and provided visual information of the spatial relationship among its surrounding structures. Conclusions: The method of registration, fusion, and 3D reconstruction based on multimodal images to provide the visual information is feasible and practical. The reconstructed 3D structures are useful for preoperative assessment, incision design,the choice of surgical approach, tumor resection, and functional protection.

Repairing skull defects in children with nano-hap/collagen composites: A clinical report of thirteen cases

Objective:To evaluate the clinical results of repairing skull defects with biomimetic bone(nano-hap/collagen composites,NHACs)in children.Methods:Thirteen children with skull defects were treated with NHACs in our hospital.The NHACs molded with the help of a 3D printer were used in the operations.Results:All 13 operations were successful,and patients recovered without infection.Only one patient suffered from subcutaneous hydrops post-operation.The implanted NHACs remained fixed well after 1 year,and their CT HU values raised gradually.Skull shapes of children developed normally.Recovery of neurological and cognitive function was significant.Conclusions:NHAC,chosen to repair skull defects in children,can coexist with normal skull and reduce the negative effects on growth and development.NHAC could be a good choice for children with skull defects.

Comparison of different microsurgery methods for trigeminal neuralgia

Objective: To study the influence of different microsurgical methods on surgical outcomes and complications, and to improve the surgical outcomes for trigeminal neuralgia. Methods: The clinical data of 109 patients with trigeminal neuralgia, who were treated with microsurgery, were analyzed retrospectively. All patients were divided into 3 groups according to surgical modality: the trigeminal neuralgia decompression group(TND group, 19 patients), the TND and rhizotomy group(rhizotomy group,55 patients), and the TND and selective lesioning group(lesioning group, 35 patients).The mid-term and short-term effects of microsurgery, and the occurrences of complications, were compared between the 3 groups. Results: There were no statistical differences in the frequency of complications between the 3 groups(P > 0.05). Eighty-four patients were followed up for 6 to 33 months. The rate of pain disappearance was found to be 94.4% in the TND group, and 100% in both the rhizotomy and lesioning groups; thus, no significant differences were found between these 3 groups(P > 0.05). Additionally, 50% of the patients in the rhizotomy group and 3.6% of the patients in the lesioning group had facial numbness while no patients were affected with facial numbness in the TND group, and the differences between these 3 groups were significant(P < 0.05). Conclusions: Microsurgery is effective and safe for trigeminal neuralgia. The use of TND, in combination with selective lesioning, ensures therapeutic efficacy and improves the quality of life in postoperative patients.

Controlled release of nerve growth factor and basic fibroblast growth factor combined with small-gap anastomosis enhances sciatic nerve regeneration

Objectives: Nerve regeneration after peripheral nerve injury is a slow process with a limited degree of functional recovery, resulting ina high disability rate. Thus, accelerating the rate of nerve regeneration and improving the degree of nerve repair is a clinical challenge. This study aimed to investigate the role of growth factor gel combined with small‐gap nerve anastomosis in the regeneration of sciatic nerve injury in rats. This was achieved by injecting nerve growth factor(NGF) and basic fibroblast growth factor(bF GF) gel into a silicon chamber that bridged the transection of the nerve. Methods: In 27 randomly chosen Sprague Dawley rats, a sharp blade was used to transect the right hind leg sciatic nerve. The rats were divided into 3 groups: in groups A and B, silicon tubes containing NGF and bF GF gel or saline, respectively, were used to bridge the nerve proximal and distal ends(3‐mm gap), and in group C, the nerve proximal and distal ends were directly sutured. Eight weeks after surgery, the sciatic nerve function index, neural electrophysiology, and muscle wet weight as well as histological, ultrastructural, and immunohistochemical parameters were evaluated.Results: The sciatic nerve function index, nerve conduction velocity, muscle wet weight,density of regenerated nerve fibers, and myelination in group A were better than those in group Bor C, but the sciatic nerve function index, muscle wet weight, and thickness of myelination in the 3 groups were not significantly different3(P > 0.05). There were no significant differences innerve conduction velocitybetween groups A and B(P > 0.05),but it was higher in both groups than that of group C(P < 0.05). The regenerated nerve fiber densityin the 3 groups showed significant differences(P < 0.05). Conclusions: Small‐gap nerve anastomosis can provide a good regenerative microenvironment for rat sciatic nerve regeneration, and the combined strategy of growth factor gel with small‐gap nerve anastomosis appears to havea superior effect on nerve repair.

Effects of aging on working memory performance and prefrontal cortex activity: A time-resolved spectroscopy study

Objective:This study aimed to employ time‐resolved spectroscopy(TRS)to explore age‐related differences in prefrontal cortex(PFC)activity while subjects performed a working memory task.Methods:We employed TRS to measure PFC activity in ten healthy younger and ten healthy older subjects while they performed a working memory(WM)task.All subjects performed the Sternberg test(ST)in which the memory‐set size varied between one and six digits.Using TRS,we recorded changes in cerebral blood oxygenation as a measure of changes in PFC activity during the task.In order to identify left/right asymmetry of PFC activity during the working memory task,we calculated the laterality score,i.e.,Δoxy‐Hb(rightΔoxy‐Hb—leftΔoxy‐Hb);positive values indicate greater activity in the right PFC,while negative values indicate greater activity in the left PFC.Results:During the ST,statistical analyses showed no significant differences between the younger and older groups in accuracy for low memory‐load and high memory‐load.In high memory‐load tasks,however,older subjects were slower than younger subjects(P<0.05).We found that the younger group showed right lateral responses with a stronger right than left activation in the frontal pole,whereas the older group showed bilateral responses(P<0.05).Conclusions:The present results are consistent with the hemispheric asymmetry reduction in older adults(HAROLD)model;working memory tasks cause asymmetrical PFC activation in younger adults,while older adults tend to show reduced hemispheric lateralization.

Cerebral glioblastoma mimicking a cavernous malformation: A case report and literature review

Glioblastomas are highly malignant and invasive brain tumors. Cerebral cavernous malformations(CCMs) are vascular diseases of congenital and occult vascular dysplasia, which may arise sporadically or may be inherited due to autosomal dominant condition. To the best of our knowledge, cases of glioblastoma in the cerebral hemisphere mimicking cavernous malformation have not been reported in the literature. We reported a case of glioblastoma mimicking CCM. The patient was admitted at our hospital in July 2015 due to a 9-day history of intermittent dizziness. The present study reports a case of a glioblastoma on the right temporal lobe mimicking CCM, which was confirmed by postoperative pathology. The diagnosis of glioblastoma was not determined even during surgery, and the lesion was totally resected with no complications. During the surgical procedure, the lesion was very similar to a CCM. In conclusion, it is difficult to distinguish between glioblastoma and CCM. Therefore, when a lesion is present with hemorrhage and the imaging features are very similar to a vascular disease, a tumor must be considered in the differential diagnosis.

Ride the wind,cleave the waves,and set sail to cross the sea——A newfound journal,a new platform,and a new hope

Taking the first step is as good as being half finished.Warm congratulations and wishes for the success of this newly founded magazine.Heartfelt thanks to Ihe Chinese and international editorial board,reviewers,editorial staff,friends of the publisher (Tsinghua University Press),and colleagues and friends

The century of neuroscience

A new journal entitled Translational Neuroscience and Clinics first appeared in September 2015.Its main purpose is to publish articles focusing on information derived from human experimentation so as to optimize the communication between basic and clinical neurosciences.In the field of medical science,it has been advocated since 1990s that the 21st