Weihua Liao

Therapeutic Evaluation of Epstein-Barr Virus-encoded Latent Membrane Protein-1 Targeted DNAzyme for Treating of Nasopharyngeal Carcinomas

The ability of the 10–23 DNAzyme to specifically cleave RNA with high efficiency has fuelled expectation that this agent may have useful applications for targeted therapy. Here, we, for the first time, investigated the antitumor and radiosensitizing effects of a DNAzyme (DZ1) targeted to the Epstein-Barr virus (EBV)-LMP1 mRNA of nasopharyngeal carcinoma (NPC) in patients. Preclinical studies indicated that the DNAzyme was safe and well tolerated. A randomized and double-blind clinical study was conducted in 40 NPC patients who received DZ1 or saline intratumorally, in conjunction with radiation therapy. Tumor regression, patient survival, EBV DNA copy number and tumor microvascular permeability were assessed in a 3-month follow-up. The mean tumor regression rate at week 12 was significantly higher in DZ1 treated group than in the saline control group. Molecular imaging analysis showed that DZ1 impacted on tumor microvascular permeability as evidenced by a faster decline of the Ktrans in DZ1-treated patients. The percentage of the samples with undetectable level of EBV DNA copy in the DZ1 group was significantly higher than that in the control group. No adverse events that could be attributed to the DZ1 injection were observed in patients.

Antiangiogenic and antitumoral effects mediated by a vascular endothelial growth factor receptor 1 (VEGFR-1)-targeted DNAzyme.

Antiangiogenesis is a promising antitumor strategy that inhibits tumor vascular formation to suppress tumor growth. DNAzymes are synthetic single-strand deoxyribonucleic acid (DNA) molecules that can cleave ribonucleic acids (RNAs). Here, we conducted a comprehensive in vitroselection of active DNAzymes for their activity to cleave the vascular endothelial growth factor receptor (VEGFR-1) mRNA and screened for their biological activity in a matrigel tube-formation assay. Among the selected DNAzymes, DT18 was defined as a lead molecule that was further investigated in several model systems. In a rat corneal vascularization model, DT18 demonstrated significant and specific antiangiogenic activity, as evidenced by the reduced area and vessel number in VEGF-induced corneal angiogenesis. In a mouse melanoma model, DT18 was shown to inhibit B16 tumor growth, whereas it did not affect B16 cell proliferation. We further assessed the DT18 effect in mice with established human nasopharyngeal carcinoma (NPC). A significant inhibition of tumor growth was observed, which accompanied downregulation of VEGFR-1 expression in NPC tumor tissues. To evaluate DT18 effect on vasculature, we performed dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) on the human NPC xenograft mice treated with DT18 and showed a reduction of the parameter of Ktrans (volume constant for transfer of contrast agent), which reflects the condition of tumor microvascular permeability. When examining the safety and tolerability of DT18, intravenous administration of Dz18 to healthy mice caused no substantial toxicities, as shown by parameters such as body weight, liver/kidney function, and histological and biochemical analyses. Taken together, our data suggest that the anti-VEGFR-1DNAzyme may be used as a therapeutic agent for the treatment of cancer, such as NPC.

Application of diffusion tensor imaging in multiple system atrophy: the involvement of pontine transverse and longitudinal fibers.

Purpose: Many studies have demonstrated the degeneration of pontine transverse and longitudinal tracts in multiple system atrophy (MSA). One purpose of this study was to assess whether diffusion tensor imaging (DTI) can show microstructural abnormalities in these tracts in patients with MSA cerebellar type (MSA-C). Another purpose was to determine the correlation between cross sign progress and pontine fiber degeneration in these patients. Materials and Methods: Thirty patients with MSA-C and 30 healthy volunteers underwent conventional magnetic resonance imaging (MRI) and DTI. Regions of interest were placed in both cerebral peduncles, the posterior limbs of the internal capsule and the pontine crossing tract of each subject. Quantitative indexes such as fractional anisotropy (FA) and mean diffusivity (MD) were compared between groups by analysis of variance. Cross sign was divided into three grades as follows: 0, no cross sign; 1, vertical line only; 2, clear cross sign. Spearman rank correlation analysis was used between FA, MD, and the cross grade in patients with MSA-C. Results: FA and MD in the MSA-C group, and each cross grade, showed statistically significant differences compared to control groups. There was a close correlation between all measures. FA decreased and MD increased, and cross grade formed gradually in the patients. Conclusion: DTI can identify microstructural abnormalities in pontine transverse and longitudinal fibers even in patients without abnormalities on conventional MRI. Along with pontine transverse tract degeneration, the cross sign develops accompanied by the start of longitudinal tract degeneration, ultimately resulting in the complete formation of a cross sign.

Magnetic resonance T2 relaxation time at 7 Tesla associated with amyloid β pathology and age in a double-transgenic mouse model of Alzheimer's disease.

The aim of this study was to better understand the effect of amyloid-β plaques on magnetic resonance T2 relaxation time. We investigated these changes associated with age in an APP/PS1 mouse model of AD at 7 Tesla, combined with histology. Ten double-transgenic AD and ten wild type (WT) female mice (aged 12-20 months) were used in a cross-sectional study. Mean T2 values and standard deviations were calculated for each Regions of interest (ROIs) on T2 map. Immunohistochemistry for amyloid plaques and fluorescence staining with thioflavine S were performed of brain sections after imaging. The results showed that mean T2 values of the hippocampus, cortex, corpus callosum, and thalamus of older mice were significantly lower than of the younger. Compared to WT mice, the T2 values of the hippocampus, corpus callosum, and thalamus in younger AD mice were significantly greater, while the T2 values of the hippocampus and cortex in older AD mice were significantly less. Aβ-40 immunohistochemistry and thioflavine S stainging were positive in the matched region both for younger and older AD mice, while neither Aβ-40 nor thioflavine S were observed in WT mice. These findings suggest that regional T2 values of AD mice may decrease with age, and changes in T2 values in AD mice may be influenced by many factors besides amyloid-β plaque accumulation. Furthermore, they support that the standard deviation of the mean T2 value should be considered as well as the mean.

Resting state fMRI studies in SPG4-linked hereditary spastic paraplegia

OBJECTIVE The study aimed to investigate the functional alterations of spontaneous brain activity in patients with spastic paraplegia type 4 (SPG4), and the relationship with the severity of spasticity. METHODS Twelve patients with SPG4 and ten healthy controls underwent resting-state functional magnetic resonance imaging (rs-fMRI). Amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) were used to characterize regional neural function, and functional connectivity (FC) was used to evaluate the functional integration of the brain network. RESULTS Compared to healthy controls, patients with SPG4 exhibited significantly decreased ReHo values in the medial superior frontal gyrus. ALFF values were lower in left insula and higher in right precentral and superior frontal gyrus of the patient group. Increased ALFF values in the right precentral gyrus negatively correlated with Spastic Paraplegia Rating Scale (SPRS) scores in the patients. The connectivity study showed that the SPG4 patients had one increased FC between the left middle frontal gyrus to the left middle orbitofrontal gyrus, and pairs of decreased FC. CONCLUSIONS Our findings confirm that the baseline regional neural activity and interregional connectivity are altered in many brain regions in patients with SPG4, and certain changes are correlated with disease severity, providing potential diagnostic markers for SPG4.

Cortical Surface Area Rather Than Cortical Thickness Potentially Differentiates Radiation Encephalopathy at Early Stage in Patients With Nasopharyngeal Carcinoma

Radiation encephalopathy (RE) is one of the most severe complications in nasopharyngeal carcinoma (NPC) patients after radiotherapy (RT). However, the morphological alteration of early RE is insufficiently investigated. We aimed to investigate the cortical thickness and surface area alterations in NPC patients with or without RE in the follow-up. A total of 168 NPC patients each underwent a single scan and analysis at various times either Pre-RT (n = 56) or Post-RT (n = 112). We further divided the Post-RT NPC patients into three groups based on the time of the analysis following RT (Post-RTwithin 6 months and Post-RT7-12 months) or whether RE signs were detected in the analysis (Post-RTRE proved in follow-up). We confined the vertex-wise analyses of the cortical thickness and surface area to the bilateral temporal lobes. Interestingly, we revealed a gradual increase in the cortical surface area of the temporal lobe with increasing time after RT within the Post-RTRE proved in follow-up group, consistent with the between-group findings, which showed a significant increase in cortical surface area in the Post-RTRE proved in follow-up group relative to the Pre-RT group and the Post-RTwithin 6 months group. By contrast, such a trend was not observed in the cortical thickness findings. We concluded that the cortical surface area, rather than cortical thickness, may serve as a potential biomarker for early diagnosis of RE.

Gliosarcoma: a clinical and radiological analysis of 48 cases

ObjectivesTo retrospectively review the radiological and clinicopathological features of gliosarcoma (GSM) and differentiate it from glioblastoma multiforme (GBM).MethodsThe clinicopathological data and imaging findings (including VASARI analysis) of 48 surgically and pathologically confirmed GSM patients (group 1) were reviewed in detail, and were compared with that of other glioblastoma (GBM) cases in our hospital (group 2).ResultsThere were 28 men and 20 women GSM patients with a median age of 52.5 years (range, 24-80 years) in this study. Haemorrhage (n = 21), a salt-and-pepper sign on T2-weighted images (n = 36), unevenly thickened wall (n = 36) even appearing as a paliform pattern (n = 32), an intra-tumoural large feeding artery (n = 32) and an eccentric cystic portion (ECP) (n = 19) were more commonly observed in the GSM group than in GBM patients. Based on our experience, GSM can be divided into four subtypes according to magnetic resonance imaging (MRI) features. When compared to GBM (group 2), there were more patients designated with type III lesions (having very unevenly thickened walls) and IV (solid) lesions among the GSM cases (group 1). On univariate prognostic analysis, adjuvant therapy (radiotherapy, chemotherapy, and radiochemotherapy) and existence of an eccentric cyst region were prognostic factors. However, Coxs regression model showed only adjuvant therapy as a prognostic factor for GSM.ConclusionsWhen compared to GBM, certain imaging features are more likely to occur in GSM, which may help raise the possibility of this disease. All GSM patients are recommended to receive adjuvant therapy to achieve a better prognosis with radiotherapy, chemotherapy or radiochemotherapy all as options.Key Points• Diagnosis of gliosarcoma can be suggested preoperatively by imaging.• Gliosarcoma can be divided into four subtypes based on MRI.• Paliform pattern and ECP tend to present in gliosarcoma more than GBM.• The cystic subtype of gliosarcoma may predict a more dismal prognosis.• All gliosarcoma patients should receive adjuvant therapy to achieve better prognosis.

Resting-state fMRI in primary Sjögren syndrome:

Background The involvement of the central nervous system in primary Sjögren syndrome (pSS) remains controversial. Functional magnetic resonance imaging (fMRI) is a relatively new method that can be applied to investigate the heterogeneity of central nervous system (CNS) involvement in pSS patients through regional homogeneity (ReHo) analysis. Purpose To collect data from pSS patients and healthy controls, and use ReHo analysis to elucidate the neurobiological mechanism of CNS involvement in pSS. Material and Methods Fourteen clinically diagnosed pSS patients and 14 age- and gender-matched healthy controls underwent resting-state fMRI. The data were processed by ReHo analysis. The double sample t-test was used to compare ReHo data between groups. Results Compared to controls, pSS patients had significantly increased ReHo values in the right cerebrum, left limbic lobe, right middle temporal gyrus, and the inferior parietal lobe. However, ReHo values significantly decreased in the right lingual gyrus, left cuneiform lobe, left superior occipital gyrus, bilateral middle occipital gyrus, and the fronto-parietal junction area (P < 0.01, clusters ≥ 50 voxels). Conclusion This study demonstrates the abnormal brain activity in the visual cortex and fronto-parietal junction area in pSS patients, suggesting pathological neuronal dysfunction in these regions.

Altered States of Consciousness In Epilepsy: A DTI Study of the Brain

Background: A disturbance in the level of consciousness is a classical clinical sign of several seizure types. Recent studies have shown that altered states of consciousness in seizures are associated with structural and functional changes of several brain regions. Prominent among these are the thalamus, the brain stem and the default mode network, which is part of the consciousness system. Our study used diffusion tensor imaging (DTI) to evaluate these brain regions in patients with three different types of epilepsies that are associated with altered consciousness: complex partial seizures (CPS), primary generalized tonic–clonic seizures (PGTCS) or secondary generalized tonic–clonic seizures (SGTCS). Additionally, this study further explores the probable mechanisms underlying impairment of consciousness in seizures. Materials and methods: Conventional MRI and DTI scanning were performed in 51 patients with epilepsy and 51 healthy volunteers. The epilepsy group was in turn subdivided into three subgroups: CPS, PGTCS or SGTCS. Each subgroup comprised 17 patients. Each subject involved in the study underwent a DTI evaluation of the brain to measure the apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values of nine regions of interest: the postero-superior portion of midbrain, the bilateral dorsal thalamus, the bilateral precuneus/posterior cingulate, the bilateral medial pre-frontal gyri and the bilateral supramarginalgyri. The statistical significance of the measured ADC and FA values between the experimental and control groups was analysed using the paired t-test, and one-way analysis of variance was performed for a comparative analysis between the three subgroups. Results: Statistically significantly higher ADC values ( p < 0.01) were observed in the bilateral dorsal thalamus and postero-superior aspect of the midbrain in the three patient subgroups than in the control group. There were no significant changes in the ADC values ( p > 0.05) in the bilateral precuneus/posterior cingulate, bilateral medial pre-frontal gyri or bilateral supramarginalgyri in the experimental group. Among the three patient subgroups and the ADC values of corresponding brain regions, there were no statistically significant changes. Statistically significantly lower FA values ( p < 0.05) were observed in the bilateral dorsal thalamus of the patients in the three subgroups than in the control group. Significantly lowered FA values from the postero-superior aspect of the mid brain ( p < 0.01) were observed in patients with PGTCS compared with the control group. There were no significant changes in the FA values ( p > 0.05) from the bilateral precuneus/posterior cingulate, bilateral medial frontal gyri or bilateral supramarginalgyri in the experimental group. Among the three patient subgroups and the FA values of the corresponding brain regions, there were no statistically significant changes. Conclusion: In epileptic patients with CPS, PGTCS or SGTCS, there seems to be a long-lasting neuronal dysfunction of the bilateral dorsal thalamus and postero-superior aspect of the midbrain. The thalamus and upper brain stem are likely to play a key role in epileptic patients with impaired consciousness.

Microstructural Alterations in Asymptomatic and Symptomatic Patients with Spinocerebellar Ataxia Type 3: A Tract-Based Spatial Statistics Study

Objective Spinocerebellar ataxia type 3 (SCA3) is the most commonly occurring type of autosomal dominant spinocerebellar ataxia. The present study aims to investigate progressive changes in white matter (WM) fiber in asymptomatic and symptomatic patients with SCA3. Methods A total of 62 participants were included in this study. Among them, 16 were asymptomatic mutation carriers (pre-SCA3), 22 were SCA3 patients with clinical symptoms, and 24 were normal controls (NC). Group comparison of tract-based spatial statistics was performed to identify microstructural abnormalities at different SCA3 disease stages. Results Decreased fractional anisotropy (FA) and increased mean diffusivity (MD) were found in the left inferior cerebellar peduncle and superior cerebellar peduncle (SCP) in the pre-SCA3 group compared with NC. The symptomatic SCA3 group showed brain-wide WM tracts impairment in both supratentorial and infratentorial networks, and the mean FA value of the WM skeleton showed a significantly negative correlation with the International Cooperative Ataxia Rating Scale (ICARS) scores. Specifically, FA of the bilateral posterior limb of the internal capsule negatively correlated with SCA3 disease duration. We also found that FA values in the right medial lemniscus and SCP negatively correlated with ICARS scores, whereas FA in the right posterior thalamic radiation positively correlated with Montreal Cognitive Assessment scores. In addition, MD in the middle cerebellar peduncle, left anterior limb of internal capsule, external capsule, and superior corona radiate positively correlated with ICARS scores in SCA3 patients. Conclusion WM microstructural changes are present even in the asymptomatic stages of SCA3. In individuals in which the disease has progressed to the symptomatic stage, the integrity of WM fibers across the whole brain is affected. Furthermore, abnormalities in WM tracts are closely related to SCA3 disease severity, including movement disorder and cognitive dysfunction. These findings can deepen our understanding of the neural basis of SCA3 dysfunction.