1.Effects of naringenin on ocular blood flow and choroidal neovascularization in experimental animals
Jie, JI ; Xin-Rong, XU ; George C Y CHIOU
International Eye Science 2009;9(1):1-4
AIM: To investigate the effects of naringenin on laser-induced experimental choroidal neovascularization (CNV) in rat models,ocular blood flow in rabbit eyes and retinal function recovery after ischemic insults in rat eyes.membrane. Naringenin 10g/L(20mg/kg) was given once-daily through intraperitoneal injection for 4 weeks after laser treatment. The development of CNV was determined by fluorescein angiography(FA) performed on weeks 2 and 4. The colored microsphere technique and electroretinography method were used for the study of ocular blood flow and retinal function recovery,respectively.RESULTS: The choroidal blood flow in elevated intraocular pressure (IOP) rabbit eyes was significantly increased by 10g/L naringenin solution as compared to control group(P<0.05) . The retinal function recovery after ischemic insults in rat eyes indicated significant increase of b-wave recovery in treated group,as compared to control group(P<0.05).The intensity of fluorescein leakage from the photocoagulated lesions decreased significantly in treated group,compared to the control group(75.8%-95.0%,P<0.01). CONCLUSION: Naringenin could prevent the development of CNV on laser-induced experimental rat models,increase the choroidal blood flow in elevated IOP rabbit eyes and be beneficial on retinal function recovery in ischemic rat eyes.
2.The effect of D-Timolol and L-Timolol on rat experimental choroidal neovascularization vivo and endothelial cells in vitro
Xin-Rong, XU ; Yan-Hong, ZOU ; George C. Y. CHIOU
International Eye Science 2005;5(5):831-835
·AIM: Impairment of choroidal perfusion was found in AMD patients. We postulated that vasoactive agents,which can reduce choroidal blood flow resistance, might prevent the development of choroidal neovascularization (CNV). D-Timolol and L-Timolol are hypotensive agents used in cardiovascular and glaucoma therapy. Their effects on laser-induced experimental CNV rat model and human umbilical vein endothelial cells (HUVEC) were thus evaluated.·METHODS: Male Brown Norway rats were anesthetized to receive Nd:YAG laser to break the Bruch's membrane. D-Timolol and L-Timolol were given once daily through intraperitoneal injection after laser treatment for 4wk. Fluorescein angiography was performed on 2wk and 4wk. HUVEC were tested by proliferation assay and adhesion assay with D-Timolol and L-Timolol at different concentrations.· RESULTS: D-Timolol reduced the fluorescein leakage to 83% of the control group in laser-induced rat's CNV model at a dosage of 15mg/(kg·d). L-Timolol had no effect on CNV formation even at a higher dosage of 20mg/(kg·d). D-Timolol inhibited the endothelial cells proliferation significantly by 300mg/L. L-Timolol also significantly inhibited the cell proliferation at 1 000mg/L. But at a lower dose such as 300mg/L, no significant inhibitory effect was found. Both drugs showed no effect on cell adhesion function in cell culture experiments.· CONCLUSION: D-Timolol was found to prevent CNV development in laser-induced model in vivo and inhibit vascular endothelial cells proliferation in vitro. L-Timolol had no effect on cell proliferation at the same dose, and neither on rat CNV model. The results indicate these two isomers have different functions on rat's CNV prevention and on HUVEC cell proliferation.
3.Induce and differentiation of pig Müller cells into photoreceptors in vitro
Ni, XU ; Yongqing, LIU ; Dean C DOUGLAS ; Fangtian, DONG
Chinese Journal of Experimental Ophthalmology 2016;34(1):43-48
Background Recent studies indicated that rat and mouse Müller cells can be induced and differentiated into photoreceptor-like cells in vitro, but it is not known whether this also happens to adult pig Müller cells nowadays.Objective This study was to test whether adult pig Müller cells can be differentiated to the retinal photoreceptors (the primary transmission neurons of the retina) in vitro.Methods Müller cells were isolated from the neural retina of adult pig eyes and cultured and passaged.The 3rd and 4th generation of cells were themonolayerly cultured,and the cells forced to form spheres in suspension in altra-low adherent dishes for 2-3 days first and then reseeded in normal adherent plates,and both of them were cultured in a specifically formulated medium to induce the differentiation of retinal photoreceptor.The cells was verified by immunocytochemistry.Cell morphology and immunofluorescence staining were utilized to measure the efficacy of the differentiation.Results The 2nd,3rd and 4th generation of Müller cells expressed glutamate synthetase (GS) , a specific maker of Müller cells.Inaddition, the 3rd generation of cells also expressed glial fibrillary acidic protein (GFAP) and another specific maker of Müller cells.Three visual fields under fluorescence-microscope were randomly chosen to calculate the average positive ratio of rhodopsin,a specific marker of mature photoreceptors.The photoreceptor differentiation ratios of the 2nd generation of cells for monolayer culture only and with additional sphere suspension culture were (27.99±6.53 (% and (16.54±3.40) % , respectively.With passages, the number of rhodopsin positive cells gradually decreased, and the intensity of rhodopsin expression gradually weakened.The directed rhodopsin positive ratios of the 2nd,3rd and 4th generation of cells from sphere formation were (56.23±7.32)% , (36.26 ±8.55)% and (12.68 ±3.18)% , respectively.Although the rhodopsin expression was weakened over passages,the differentiated cells were more slender and elongated.There was no statistic ally significant difference between different groups (F =2.618, P =0.099).Conclusions Adult pig Müller cells can be differentiated into retinal photoreceptors in vitro.The morphology of the differentiated cells appears moreslender and elongates if the sphere-induced differentiation method is used and/or the directed differentiation time is further extended.
4.A familial XY gonadal dysgenesis causing high incidence of embryonic gonadal tumors- a report of the fourth dysgerminoma in sibling suffering from 46, XY gonadal dysgenesis (author's transl).
Chinese Journal of Oncology 1981;3(2):89-90
Adolescent
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Adult
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Dysgerminoma
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etiology
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genetics
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Female
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Gonadal Dysgenesis
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genetics
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Gonadal Dysgenesis, 46,XY
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genetics
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Humans
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Ovarian Neoplasms
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genetics
5.Progressive Supranuclear Gaze Palsy with Predominant Cerebellar Ataxia: A Case Series with Videos.
Zheyu XU ; Tchoyoson C C LIM ; Wing Lok AU ; Louis C S TAN
Journal of Movement Disorders 2017;10(2):87-91
Progressive supranuclear palsy (PSP) with predominant cerebellar ataxia (PSP-C) is a rare phenotype of PSP. The clinical and radiological features of this disorder remain poorly characterized. Through a retrospective case series, we aim to characterize the clinical and radiological features of PSP-C. Four patients with PSP-C were identified: patients who presented with prominent cerebellar dysfunction that disappeared with the progression of the disease. Supranuclear gaze palsy occurred at a mean of 2.0 ± 2.3 years after the onset of ataxia. Mild cerebellar volume loss and midbrain atrophy were detected on brain imaging, which are supportive of a diagnosis of PSP. Videos are presented illustrating the co-existence of cerebellar signs and supranuclear gaze palsy and the disappearance of cerebellar signs with disease progression. Better recognition and the development of validated diagnostic criteria would aid in the antemortem recognition of this rare condition.
Ataxia
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Atrophy
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Cerebellar Ataxia*
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Cerebellar Diseases
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Diagnosis
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Disease Progression
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Humans
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Mesencephalon
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Neuroimaging
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Paralysis*
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Phenotype
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Retrospective Studies
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Supranuclear Palsy, Progressive
6.Ebola preparedness in the Western Pacific Region, 2014
Zhen Xu ; Boris I Pavlin ; Raynal C Squires ; Thilaka Chinnayah ; Chin-Kei Lee ; Ailan Li
Western Pacific Surveillance and Response 2015;6(1):66-72
West Africa is currently experiencing the largest outbreak of Ebola virus disease (EVD) in history with intense transmission in several affected countries. For non-affected countries, the best protective measures are adequate levels of preparedness including vigilant surveillance to detect cases early and well-prepared health systems to ensure rapid containment of the virus and to avoid further spread. The World Health Organization Regional Office for the Western Pacific recently conducted two activities: a web-based EVD preparedness survey and an EVD simulation exercise to determine the overall level of EVD preparedness in the Region. The survey and exercise together demonstrate there is a good overall level of preparedness for a potential imported case of EVD in the Western Pacific Region. However, a number of areas still require further strengthening before the Region can efficiently and effectively respond to potential EVD events, including laboratory testing arrangements; clinical management and infection prevention and control; and public health intervention measures, particularly at points of entry. Importantly, the survey and exercise also highlight the unique situation in Pacific island countries and emphasize that special considerations are needed to better support these countries in EVD preparedness.
7.Application of denaturing high performance liquid chromatography to mutation detection of the c-kit gene in mastocytosis.
Ling-Yan ZHANG ; Gong-Li XU ; Nicholas C P CROSS
Journal of Experimental Hematology 2006;14(5):981-984
The aim of study was to detect mutation of tyrosine domain of c-kit gene in mastocytosis using denaturing high performance liquid chromatography technique, and to investigate the significance of this gene mutation in diagnosis and therapy of mastocytosis. Genomic DNA was obtained from bone marrow or peripheral blood leukocytes using the phenol/chloroform method from 7 mastocytosis patients. PCR was performed with AmpliTaq Gold DNA polymerase and 100 ng genomic DNA to amplify the entire coding sequence and exon-intron boundaries of c-kit exon 17 approximately exon 19. Denaturing high-performance liquid chromatography (DHPLC) analysis was performed on a WAVE DNA Fragment Analysis System. Each PCR product was mixed with an equal quantity of amplified human placental DNA (served as normal control) and was denatured at 95 degrees C for 5 minutes, followed by slowly cooling down to room temperature by 1.5 degrees C per minute to allow heteroduplexes formation. All the conditions for the DHPLC analysis, including melting temperature and buffer gradients were determined using the Transgenomic software Navigator. Samples with extra peaks or with different peak form on DHPLC were directly sequenced using the BigDye Terminator Cycle Sequencing Reaction kit and ABI 3100 Genetics Analyser. The results showed that DHPLC revealed an aberrant peak in one patient in exon 17 and the D816V mutation was identified by direct sequencing. The other two patients had an extra peak for exon 18/19 and direct sequencing revealed a conservative sequence change (L862L) within exon 18. It is concluded that denaturing high performance liquid chromatography is a high efficiency and reliable technique for mutation detection of c-kit gene and the detection results would be helpful for the selection of therapy in mastocytosis.
Adult
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Aged
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Base Sequence
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Chromatography, High Pressure Liquid
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methods
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Chromosomes, Human, Pair 4
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genetics
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Humans
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Mastocytosis
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genetics
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Middle Aged
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Molecular Sequence Data
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Mutation
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genetics
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Proto-Oncogene Proteins c-kit
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genetics
8.Multivoxel MR spectroscopic imaging--distinguishing intracranial tumours from non-neoplastic disease.
Veena Arpit NAGAR ; Jieru YE ; Maosheng XU ; Wai-Hoe NG ; Tseng-Tsai YEO ; Peck-Leong ONG ; C C Tchoyoson LIM
Annals of the Academy of Medicine, Singapore 2007;36(5):309-313
INTRODUCTIONMulti-voxel MR spectroscopic imaging (MRSI) provides chemical metabolite information that can supplement conventional MR imaging in the study of intracranial neoplasia. Our purpose was to use a robust semi-automated spectroscopic analysis to distinguish intracranial tumours from non-neoplastic disease.
MATERIALS AND METHODSTwenty intracranial tumours and 15 patients with non-neoplastic disease confirmed on histological examination or serial neuroimaging were studied with 2-dimensional MRSI using point-resolved spectroscopic (PRESS) imaging localisation. Using semi-automated post-processing software, spectra were analysed for peak heights of choline (Cho), creatine (Cr), N-acetyl aspartate (NAA), lactate (Lac) and lipid (Lip). Normalised Cho (nCho) ratios, computed by dividing maximum Cho in the lesion by the normal-appearing brain, were compared between intracranial tumours and non-neoplastic disease.
RESULTSMeningiomas displayed homogeneously elevated Cho. Malignant tumours, especially large glioblastoma multiforme, displayed inhomogeneity of metabolites within the tumour. All tumours had elevation of nCho >1 (mean 1.91 +/- 0.65), and non-neoplastic diseases had tumour nCho <1 (mean 0.91 +/- 0.46), which was significantly lower (P <0.05). Two patients with non-neoplastic lesions, one with subacute cerebral infarction and the other with cryptococcoma, had elevated Cho compared to normal tissue (false positive rate 13%).
CONCLUSIONUsing semi-automated MRSI method, a simplified normalised Cho algorithm provides a method to distinguish intracranial tumours from non-neoplastic disease.
Adult ; Aged ; Aged, 80 and over ; Biomarkers, Tumor ; analysis ; Brain Neoplasms ; diagnosis ; metabolism ; Diagnosis, Differential ; Female ; Humans ; Magnetic Resonance Spectroscopy ; methods ; Male ; Middle Aged ; Retrospective Studies
9.Identification of key genes in esophageal adenocarcinoma and its clinical significance
YAN Zhaoyanga ; XU Tongxinb ; WU Zhengc ; GUO Weic ; DONG Zhimingc
Chinese Journal of Cancer Biotherapy 2020;27(12):1393-1398
[Abstract] Objective: To screen the key genes associated with esophageal adenocarcinoma by using TCGA and GEO databases, and to analyze their biological functions, relevant signaling pathways and clinical significance. Methods: The esophageal adenocarcinoma data downloaded from TCGA database and GSE92396 microarray data from GEO database were integrated. The analysis of differentially expressed genes (DEGs) were performed by using DEseq2 and Limma packages of R software to obtain the co-differentially expressed genes, which were then chosen for the GO function enrichment analysis and KEGG pathway analysis with clusterProfiler package of R software. The key node genes that regulate the protein expressions in esophageal adenocarcinoma were screened out by protein-protein interaction (PPI) network analysis using the string website and Cytoscape 3.7.2 software. The correlation between key node genes and the survival of patients was further analyzed by combining with TCGA database. Results: By analyzing the chip data of 90 cases of adenocarcinoma tissues and 18 cases of normal esophageal tissues from databases, a total of 521 co-differentially expressed genes were obtained, including 356 upregulated genes and 165 downregulated genes. These genes were closely related to the metabolic-associated functions mainly involving epidermis development, epidermal cell differentiation and signaling pathways involving cytokine-cytokine receptor interaction, etc. The PPI network analysis revealed 15 key node genes. The survival time for patients with low CXCL8 and CCL20 expression was significantly longer compared with the patients with high expression level (median survival: 32.4 vs 19.7 months, P<0.05; 32.4 vs 13.9 months, P<0.05). Conclusion: These results show that CXCL8 and CCL20 may play an important role in the occurrence, development and prognosis of esophageal adenocarcinoma, and may be used as potential indicators to judge the prognosis of patients.
10.Direct protection of cultured neurons from ischemia-like injury by minocycline.
Wendy C HUANG ; Yanli QIAO ; Lijun XU ; Rachid KACIMI ; Xiaoyun SUN ; Rona G GIFFARD ; Midori A YENARI
Anatomy & Cell Biology 2010;43(4):325-331
Minocycline, a tetracycline antibiotic, is now known to protect cells via an anti-inflammatory mechanism. We further explored this effect using an in vitro model of ischemia-like injury to neurons. Coculturing neurons with microglia, the brain's resident immune cell, modestly increased cell death due to oxygen and glucose deprivation (OGD), compared to neurons alone. Treatment of cocultures with minocycline decreased cell death to a level significantly lower than that of neurons alone. Treatment of cocultures with minocycline or inhibitors of various immune mediators, also led to decreased cell death. Importantly, treatment of neuron cultures without added microglia with these same inhibitors of tissue plasminogen activator, matrix metalloproteinases, TNF-alpha and inducible nitric oxide synthase as well as minocycline also led to decreased cell death. Thus, anti-inflammatory treatments appear to be directly protective of neurons from in vitro ischemia.
Cell Death
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Coculture Techniques
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Glucose
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Ischemia
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Matrix Metalloproteinases
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Microglia
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Minocycline
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Neurons
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Nitric Oxide Synthase Type II
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Oxygen
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Tetracycline
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Tissue Plasminogen Activator
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Tumor Necrosis Factor-alpha