1.Comprehensive examination of visual electrophysiology of visual function assessment after cataract operation
Linnong WANG ; Lixun CHEN ; Taihong ZHAO ; Lei XIAO
Recent Advances in Ophthalmology 2000;20(5):353-355
Objective To study the value of comprehensive examination of visual electrophysiology in prognosis of visual function after cataract operation.Methods 315 patients with cataract(408 eyes) underwent preoperative routine examination with pattern reversal visual evoked potential(PVEP), red and blue flicker electroretinogram(ERG) and oscillatory potential (OPs). Normal control group included 162 cases (266 eyes). All of the ocular fundi were examined postoperatively and corrected visual acuities were obtained 3 months after operation. Results Postoperative corrected visions ≥0.5(Ⅰ) and <0.5(Ⅱ) in case group compared with that in control group, amplitudes of PVEP P100-wave decreased significantly and PVEP P100-wave latency times prolonged significantly in group Ⅰ and Ⅱ. There was much more prominent changes in P100-wave of group Ⅱ due to other factors influencing visual function. There wasn't significant difference of the amplitudes and the latency times of a-wave and b-wave of Red-Blue ERG in group Ⅰ and the control group preoperatively. The amplitudes of a-wave and b-wave of Red ERG decreased, the latency times of a-wave and b-wave of Red ERG prolonged, the amplitudes of a-wave and b-wave of Blue ERG decreased but latency times didn' t prolong in group Ⅱ. The value of OPs decreased in groupⅡ compared with that of the control group, which was related to the retinopathy due to blood circulation obstruction.Conclusion Combined examination of visual electrophysiology can estimate visual function thoroughly. The prognosis will be good if various examinations are normal before operation, but will not be good if PVEP P100 latency time prolong, the amplitudes of a-wave and b-wave of Red ERG decrease and the latency time prolong, the amplitudes of a-wave and b-wave of Blue ERG decrease and the value of OPs decrease.
2.Establishment and application of a high-throughput screening assay for premature activation of HIV-1 precursors.
Quan ZHANG ; Xiaoyu LI ; Zhenlong LIU ; Pingping JIA ; Xiaolu WEI ; Lixun ZHAO ; Jiandong JIANG ; Shan CEN
Acta Pharmaceutica Sinica 2010;45(2):247-52
Strict regulation of HIV-1 PR function is critical for efficient production of mature viral particles. During viral protein expression and viral assembly, HIV-1 PR located within Gag-Pol precursor must be inactive to prevent premature cytoplasmic processing of the viral Gag and Gag-Pol precursors. Premature activation of HIV-1 precursors leads to major defects in viral assembly and production of viral particles. A cell-level premature activation of HIV-1 precursors assay using bioluminescence resonance energy transfer (BRET) was established. Three thousand compounds were screened to evaluate this assay. The results showed that the assay is sensitive, specific and stable (Z' factor is 0.905).
3.High performance liquid chromatographic separation of thirteen drugs collected in Chinese Pharmacopoeia 2010(Ch.P2010) on cellulose ramification chiral stationary phase
Ying ZHOU ; Chao MA ; Yan WANG ; Qiming ZHANG ; Yiying ZHANG ; Jie FU ; Hong GAO ; Lixun ZHAO
Journal of Pharmaceutical Analysis 2012;02(1):48-55
The enantiomers separation of thirteen drugs collected in Ch.P2010 was performed on chiral stationary phase of cellulose ramification (chiralpak OD and chiralpak OJ) by high performance liquid chromatographic (HPLC) methods,which included ibuprofen (Cl),ketoprofen (C2),nitrendipine (C3),nimodipine (C4),felodipine (C5),omeprazole (C6),praziquantel (C7),propranolol hydrochloride (C8),atenolol (C9),sulpiride (C10),clenbuterol hydrochloride (C11),verapamil hydrochloride (C12),and chlorphenamine maleate (C13).The mobile phase consisted of isopropanol and n-hexane.The detection wavelength was set at 254 nm and the flow rate was 0.7 mL/min.The enantiomers separation of these thirteen racemates on chiralpak OD column and chiralpak OJ column was studied,while the effects of proportion of organic additives,alcohol displacer and temperature on the separation were studied.And the mechanism of some of racemates was discussed.The results indicated that thirteen chiral drugs could be separated on chiral stationary phase of cellulose ramification in normal phase chromatographic system.The chromatographic retention and resolution of enantiomers could be adjusted by factors including column temperature and the concentration of alcohol displacer and organic alkaline modifier in mobile phase.It was shown that the resolution was improved with reducing concentration of alcohol displacer.When concentration of organic alkaline modifier was 0.2% (v/v),the resolution and the peak shape were fairly good.Most racemates mentioned above had better resolution at column temperature of 25 ℃.When racemates were separated,the temperature should be kept so as to obtain stable separation results.
4.Establishment and drug susceptibility test of isoniazid resistant Mycobacterium smegmatis.
Pingping JIA ; Lili ZHAO ; Xiaoyu LI ; Quan ZHANG ; Zhenlong LIU ; Xin WANG ; Liyan YU ; Lixun ZHAO ; Shan CEN
Acta Pharmaceutica Sinica 2011;46(4):377-82
With the emergence of drug resistant tuberculosis, it is very urgent to find novel anti-tuberculosis drugs, especially novel anti-drug-resistant tuberculosis drugs. Because of the slow growth and the need to work in a biosafty environment of Mycobacterium tuberculosis, the development of evaluation of drug effect is severely impeded. In order to solve these issues, non-pathogenic fast-growing Mycobacterium smegmatis is introduced as test organism. The inhA is one of a target of isoniazid (INH) overexpression or mutation of this gene in Mycobacterium tuberculosis conferring resistant to INH. A recombinant plasmid bearing inhA was constructed and electroporated into Mycobacterium smegmatis, using shuttle expression vector pMV261. Transformants were induced to express a protein of inhA, identified by SDS-PAGE. Results show that Mycobacterium smegmatis containing inhA plasmids exhibited 100-fold or greater increased resistance to INH, but it conferred no increased resistance to others first-line anti-tuberculosis drugs. Resazurin microtiter assay plate testing of Mycobacterium smegmatis susceptibility to drugs is a rapid, simple, and inexpensive method and could decrease color background of drugs by detecting fluorescence. It will be benefit for high-throughout screening of drugs of anti-isoniazid-resistant Mycobacteria.
5.Prevention of bone cement implantation syndrome by inferior vena cava filter
Xiaoqin SHI ; Wangang GUO ; Na PENG ; Zheng GUO ; Baojun HAN ; Xiong ZHAO ; Zhonghua LUO ; Ming YU ; Lixun LIU ; Chen WANG
Chinese Journal of Orthopaedic Trauma 2009;11(3):255-258
Objective To observe the effect of inferior vena cava filter (IVCF) on prevention of bone cement implantation syndrome (BCIS). Methods Ten sheep were divided into 2 even groups, BCIS and LVCF intervention ones. First IVCF was implanted into the inferior vena cava through cervical vena-right atrium pathway under fluoroscopic monitoring to observe the influence of IVCF on BCIS. Then BCIS was es-tablished in the same sheep by compressing 10 mL of bone cement into a sheep medullary canal after mutilation of the left femur. Arterial blood pressure, heart rate, central venous pressure (CVP) and blood gas were monitored, while an ultrasonic device was utilized to monitor fat embolisms in the right atriums of the sheep. Oil red staining was performed to detect fat embolisms in pulmonary arteries after the sheep were executed. Results In BCIS group, dotted uneven resonances were found in the right atrium and right ventricle when the medullary canal pressure was increased to 120 mm Hg, indicating embolisms in the right chambers. The dotted resonances were increased to ponderous, snowflake-like ones as the medullary canal pressure climbed up. At the same time, blood pressure and Pa02 dropped significantly, the systolic blood pressure dropped to (80±11) mm Hg and PaO<.2> to the minimum 25 minutes after cone cement implantation. The heart rate and CVP increased continuously. The blood gas assay indicated respiratory and metabolic acidosis. The oil red staining showed bulk fat embolus in pulmonary arteries. But in IVCF group, the similar resonances were not observed throughout the surgery and the medullary canal pressure climbed to 400 mm Hg, reaching the maximum of our pressure gage range. The blood pressure, PaO2, heart rate and CVP did not change much compared to those before implantation. The blood gas and pulmonary oil red staining showed few changes either. Conclusion IVCF implantation can prevent the genesis of BCIS.
6.Diffusion tensor imaging map of anterior cruciate ligament contrasted with MRI in healthy adults.
Lixun CHEN ; Heng ZHAO ; Jingsong LI ; Xiaobing QUAN ; Weipeng QING ; Wenwen LIU ; Jincai LIU
Journal of Central South University(Medical Sciences) 2013;38(6):610-616
OBJECTIVE:
To measure anterior cruciate ligament (ACL) by diffusion tensor imaging (DTI), combined with ACL half quantitative measurement magnetic resonance imaging (MRI) method as the contrast, and to preliminarily investigate the feasibility of DTI for ACL.
METHODS:
The ACLs of 31 healthy volunteers were scanned with ordinary MRI and DTI. At ordinary MRI map, sagittal ACL-tibial angle, coronal ACL-tibial angle, Blumensaat line-ACL angle, angle of inclination of the intercondylar roof, and ACL-tibial insertion site were measured. As for DTI analysis of ACL, ACL was divide to 5 portions, namely 1(st), 2(nd), 3(rd), 4(th), 5(th), and all fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of every portion were recorded and repeated.
RESULTS:
The sagittal ACL-tibial angle, coronal ACL-tibial angle, Blumensaat line-ACL angle, angle of inclination of the intercondylar roof, and ACL-tibial insertion site were 53.00°±2.46°, 52.42°±5.15°, 12.67°±5.71°, 39.41°±2.64°, (24.90±2.84)%, respectively. FA values of different portions were 0.611±0.042, 0. 618±0.051, 0.596±0.045, 0.566±0.059, and 0.497±0.072. ADC values of 1(st)-5(th) portion were (1.068±0.216), (1.128±0.268), (1.189±0.197), (1.455±0.423), and (1.779±0.384)× 10(-3) mm(2)/s. The correlation coefficient of sagittal ACL-tibial angle and the FA value of 2(nd) and 3(rd) portion was -0.568 and -0.429. The correlation coefficient of Blumensaat line-ACL angle and the FA value of 1(st) and 4(th) portion was -0.507 and -0.633. The correlation coefficient of ACL-tibial insertion site and the FA value of 4(th) portion was -0.593, all with statistical significance. FA and ADC values of all portions in both team's ACL didn't have significant difference (P>0.05), but had obvious correlation.
CONCLUSION
DTI can be used to effectively evaluate the orientation and connection of ACL, having good contrast virtue with ACL half quantitative MRI measurement. It may provide more profound ACL information for clinicians, and it is of great significance for the further research and large sample data base of ACL pathology.
Adolescent
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Adult
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Anterior Cruciate Ligament
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anatomy & histology
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Diffusion Tensor Imaging
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Female
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Healthy Volunteers
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Humans
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Magnetic Resonance Imaging
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Male
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Reference Values
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Young Adult
7.Research progress on cellular senescence and senescence-associated secretory phenotype in pathogenesis and treatment of age-related macular degeneration
Yuchen LI ; Yidan XU ; Feng ZHAO ; Lixun CHEN
Chinese Journal of Ocular Fundus Diseases 2024;40(3):233-238
Age-related macular degeneration (AMD) is one of the leading irreversible causes of blindness in China. The pathogenesis of AMD is not fully understood at present. Under various stress conditions, cellular senescence is activated, characterized by telomere shortening, mitochondrial dysfunction, DNA damage, and the release of various senescence-related secretory phenotype factors. Senescence is implicated in the pathogenesis of AMD through multiple pathways, contributing to chronic inflammation and the onset and progression of AMD. Mechanisms such as oxidative stress, lipofuscin, β amyloid protein and the membrane attack complex have become hotspots of study in the pathogenesis of AMD. The cyclic guanosine phosphate - adenosine synthase - interferon stimulating factor synthase-stimulator of interferon gene pathway has emerged as a critical signaling pathway in the early development of AMD, providing direction for further research on AMD. Currently, senolytics, selective agents targeting the induction of senescent cell apoptosis, show significant potential in the treatment of AMD. The integration of new technologies with cellular senescence may offer a novel approach to AMD treatment, and intervening in the AMD treatment through anti-cellular senescence pathways holds promising prospects.
8.Identification, expression and DNA variation analysis of high affinity nitrate transporter NRT2/3 gene family in Sorghum bicolor.
Shanshan ZHAO ; Zhiqiang GUO ; Lixun ZHU ; Jiali FAN ; Bohui YANG ; Wenting CHAI ; Huiqiong SUN ; Fan FENG ; Yuexiu LIANG ; Chunlei ZOU ; Xiaodong JIANG ; Weijun ZHAO ; Jinhui LÜ ; Chunlai ZHANG
Chinese Journal of Biotechnology 2023;39(7):2743-2761
Nitrate is the main form of inorganic nitrogen that crop absorbs, and nitrate transporter 2 (NRT2) is a high affinity transporter using nitrate as a specific substrate. When the available nitrate is limited, the high affinity transport systems are activated and play an important role in the process of nitrate absorption and transport. Most NRT2 cannot transport nitrates alone and require the assistance of a helper protein belonging to nitrate assimilation related family (NAR2) to complete the absorption or transport of nitrates. Crop nitrogen utilization efficiency is affected by environmental conditions, and there are differences between varieties, so it is of great significance to develop varieties with high nitrogen utilization efficiency. Sorghum bicolor has high stress tolerance and is more efficient in soil nitrogen uptake and utilization. The S. bicolor genome database was scanned to systematically analyze the gene structure, chromosomal localization, physicochemical properties, secondary structure and transmembrane domain, signal peptide and subcellular localization, promoter region cis-acting elements, phylogenetic evolution, single nucleotide polymorphism (SNP) recognition and annotation, and selection pressure of the gene family members. Through bioinformatics analysis, 5 NRT2 gene members (designated as SbNRT2-1a, SbNRT2-1b, SbNRT2-2, SbNRT2-3, and SbNRT2-4) and 2 NAR2 gene members (designated as SbNRT3-1 and SbNRT3-2) were identified, the number of which was less than that of foxtail millet. SbNRT2/3 were distributed on 3 chromosomes, and could be divided into four subfamilies. The genetic structure of the same subfamilies was highly similar. The average value of SbNRT2/3 hydrophilicity was positive, indicating that they were all hydrophobic proteins, whereas α-helix and random coil accounted for more than 70% of the total secondary structure. Subcellular localization occurred on plasma membrane, where SbNRT2 proteins did not contain signal peptides, but SbNRT3 proteins contained signal peptides. Further analysis revealed that the number of transmembrane domains of the SbNRT2s family members was greater than 10, while that of the SbNRT3s were 2. There was a close collinearity between NRT2/3s of S. bicolor and Zea mays. Protein domains analysis showed the presence of MFS_1 and NAR2 protein domains, which supported executing high affinity nitrate transport. Phylogenetic tree analysis showed that SbNRT2/3 were more closely related to those of Z. mays and Setaria italic. Analysis of gene promoter cis-acting elements indicated that the promoter region of SbNRT2/3 had several plant hormones and stress response elements, which might respond to growth and environmental cues. Gene expression heat map showed that SbNRT2-3 and SbNRT3-1 were induced by nitrate in the root and stem, respectively, and SbNRT2-4 and SbNRT2-3 were induced by low nitrogen in the root and stem. Non-synonymous SNP variants were found in SbNRT2-4 and SbNRT2-1a. Selection pressure analysis showed that the SbNRT2/3 were subject to purification and selection during evolution. The expression of SbNRT2/3 gene and the effect of aphid infection were consistent with the expression analysis results of genes in different tissues, and SbNRT2-1b and SbNRT3-1 were significantly expressed in the roots of aphid lines 5-27sug, and the expression levels of SbNRT2-3, SbNRT2-4 and SbNRT3-2 were significantly reduced in sorghum aphid infested leaves. Overall, genome-wide identification, expression and DNA variation analysis of NRT2/3 gene family of Sorghum bicolor provided a basis for elucidating the high efficiency of sorghum in nitrogen utilization.
Nitrate Transporters
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Nitrates/metabolism*
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Sorghum/metabolism*
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Anion Transport Proteins/metabolism*
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Phylogeny
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Protein Sorting Signals/genetics*
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Nitrogen/metabolism*
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DNA
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Gene Expression Regulation, Plant
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Plant Proteins/metabolism*