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Background Chondroitin sulphate proteoglycans (CSPGs) can cause the termination of ocular dominance plasticity in the visual cortex.Recently,protein tyrosine phosphatase σ (PTPσ) has been identified as a receptor that inhibits CSPGs.However,whether PTPσ and its downstream molecules participate in the reactivation of ocular dominance plasticity in adult visual cortex has not been studied.Objective The present study was to investigate the changes in the expression of the PTPσ,probabilistic neural networks (PNNs),and molecules downstream of PNN,such as N-cadherin/β-catenin,after the reactivation of adult visual cortical plasticity.Methods Fifty-four SPF Long Evans rats were grouped according to different postnatal week (PW) as the PW1 (6 rats),PW3 (6 rats),PW5 (6 rats),PW7 (24 rats),and PW9 (12 rats) groups,and the upper and lower eyelids were sutured in the 12 rats from the PW7 group for 14 days to establish the binocular plasticity reactivation models.Expression of PTPσ and PNNs in the rat visual cortex was detected using immunochemistry,and changes of PTPσ mRNA,N-cadherin mRNA and β-catenin mRNA expression in the rat visual cortex with plasticity reactivation were assessed by real-time fluorescence quantitative PCR (RT Q-PCR).The use of animals followed the Regulations for the Administration of Affairs Concerning Experimental Animals by State Science and Technology Commission.Results The expression level of PTPσ mRNA was significantly higher in the PW9 group than that of the binocular plasticity reactivation models and the PW7 group (t =1.965,3.526,P＜0.01).The staining of the rat visual cortex for PTPσwas localized to the cellular membrane,cytoplasm and axon.Cell densities of the PW9 group in the Ⅱ-Ⅲ layer,Ⅳ layer and Ⅴ-Ⅵ layer of the visual cortex were elevated in the PW9 rats compared with the PW7 rats (t =24.593,23.444,13.556,P＜0.01) and rats from the binocular plasticity reactivation model (t =44.111,43.000,16.556,P＜0.01).Cell densities for PNNs in the Ⅳ and Ⅴ-Ⅵ layers were significantly increased in the PW9 rats in comparison with the PW7 rats (t=1.926,P＜0.01 ;t=1.370,P＜0.05),but the cell density in the Ⅱ-Ⅱ layer has no statistical significance (t=0.889,P＞0.05).However,cell densities for PNNs in the Ⅱ-Ⅲ and Ⅳ layers in the binocular plasticity reactivation models were lower than those of the PW9 rats (t =2.556,4.585,P＜0.01).Compared with PW1 rats,the expression levels of the N-cadherin mRNA in the PW3,PW5,PW7,PW9 rats were lower (t =28.932,28.988,27.083,28.908,P＜0.01),but those in the PW7 rats were enhanced in comparison with the PW3 rats,PW5 rats and PW9 rats (t =1.848,1.904,1.825,P＜0.01).No significant difference was seen in the expression of the N-cadherin mRNA between the PW9 rats and rats from the binocular plasticity reactivation model (t =0.072,P＞0.05).A statistically significant increase was found in the β-catenin mRNA expression in the PW1 rats compared with the PW3,PW5,PW7 and PW9 rats (t =3.918,3.534,2.645,4.652,P＜ 0.0 1),as well as between rats from the binocular plasticity reactivation model and the PW9 rats (t =0.570,P＜0.01).Conclusions PTPr,PNNs and β-catenin are involved in the reactivation of ocular dominance plasticity in the adult visual cortex.
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Background Oscillatory potentials (OPs) of scotopic electroretinogram (ERG) plays an important role in the evaluation of visual function in multiple retinal diseases.However,the origin of OPs is uncompletely clear.It is essential to analyze the time domain and frequency domain components for the further study of OPs.Objective The present study was to investigate the change characteristics of frequency spectrum of scotopic OPs with age and stimulating intensity.Methods RCS-rdy+-p+rats with the ages of 21,25,32,35,37,46,60,90 days were selected iu this study and 3 rats for each.Scotopic flash ERG were recorded from all the rats with RETI-scan system.Gold-foil ring cornea recording electrode was used as the recording electrode and the steel needle electrode was used as the reference and earth electrode during the record.The intensity of stimulating light was set at-20,-10,-5,0 and 5 dB respectively.Data were output into the computer and processed by the software Matlab7.0.Results The principle frequency corresponding to maximum amplitude component was 80-120 Hz in the various ages of rats under the different stimulating conditions above.With the increase of the intensity of stimulating light,high frequency component (200-250 Hz) began to appear and the amplitudes showed a gradually raise upon the intensity of light.The major component was subdivided into two peaks at 0 dB stimulation.Further,the age affected the major frequency peak with the maximum value at 60-day-old rats and the minimum value at 25-day-old rats.Also,the pass-band width of main amplitude appeared to be maximal at 60-day-old rats and minimal at 25-day-old rats.Conclusions OPs in Rcsrdy+-p+ rats are influenced by stimulating intensity and agc.Stimulating intensity affects the amplitude and age lead to the change of distribution of primary frequency of OPs.It is possible to know the influences of the degeneration of rods and be helpful to diagnosis this kind of disease.
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Background Channelrhodopsin-2 (ChR2)is a cation channel isolated from the eyespot of Chlamydomonas algae and has been used to control neuron activity.The light stimulation is a more precise fashion whether space or time than that of electrical,magnetic and ultrasound stimulation. Objective This study was to construct a replication deficient recombinant adenovirus cxpression vector of ChR2 and to determine its function.Methods Human embryo kidney 293 (HEK293) cell line was cultured and passaged in DF12 medium containing 10％ fetal bovine serum(FBS).The ChR2 gene was cloned at the downstream of cytomegalovirus(CMV)promoter of the adenoviral shuttle plasmid pSB291 in sense direction,and the resultant recombinant plasmid pSB291-hChR2- GFP was transfected into HEK293 cell together with plasmid pBHG lox ( deltaE1,3 ) containing adenoviral genome,then small amounts replication deficient recombinant adenovirus expression vector of ChR2 (Ad-ChR2) was obtained.Through amplification gradient centrifugation and dialysis,pure Ad-ChR2 was obtained.Visual cortex cells derived from 4 1-day-old clean Long Evans rats were primary cultured with serum-free culture media and infected by AdChR2.When expressing green fluorescencc,those cells received the stimulated of blue light with 460 nm.Patch clamp technique was applied to record an action potential. Results After purification and concentration,the titer of AdhCHR2 reached 7.9×1010 PFU/ml.Twenty-four hours after transfect of Ad-ChR2,HEK293 cell membrane showed the green fluorescence for the recombinant plasmid with green fluorescence protein under the inversed fluorescence microscope.The HEK293 cells change their shape from flat to round 13 days after transfected.The primary cultured visual cortex cells exhibited the green fluorescence 3-5 days after infected by Ad-ChR2.The action potentials evoked by blue light stimulation were recorded with patch clamp on those cells expressing green fluorescence. Conclusions Ad-ChR2 expressing vector is constructed successfully in this study.It is verified that Ad-ChR2 expressing vector can infect visual cortex cells with visual function.This result is very important for visual plasticity study.
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BackgroundRetinitis pigmentosa (RP)is a group of progressive monogenic inheritance disease.Seldom epidemiology is performed to summarize the varied clinical phenotypes,especially some sporadic cases with untypical genetic history.ObjectiveThe aim of this survey was to investigate the clinical epidemiological characteristics and phenotype of sporadic RP.MethodsA prospective cohort study was designed.A survey of a series of clinically diagnosed sporadic primary RP patients was conducted at the Southwest Eye Hospital from July 2010 to November 2011.A total of 130 patients that matched the inclusion criteria were enrolled in this survey.Clinical ocular examinations and questionnaire surveys were given,including ophthalmoscopic examination,best corrective visual acuity( BCVA ),perimetry and Ganzfield electroretinogram (ERG)and color fundus photo.RP with different phenotypes were classified. ResultsA total of 130 sporadic RP patients were collected in this survey.Of them,66 were male and 64 were female with a mean age of (36.9±14.4) years.The average onset age of these subjects was (21.2±18.4) years.Seven (5.38％) patients had consanguineous marriage history,and 13 ( 10.00％ )patients had systemic disease.Forty-four (33.85％) patients had outdoor jobs,and 86 (66.15％ ) worked indoor.Eighty-nine patients had typical RP ( 68.5％ ),and the number of patients that developed central RP and sine pigmento RP were 16 ( 12.3％ ) and 16( 12.3％ ),respectively.An absence of a- and b-waves in full-field ERG wasdetected in 99 (76.15％ ) cases.The longest duration of night blindness was identified in typical RP patients and the lowest BCVA in central RP patients.ConclusionsThe age at first onset is early in sporadic RP.There are wide variations in different types of RP,but the ERG outcome is specific for all RP types.
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Background There are no noticeable symptoms in early stages of diabetic retinopathy(DR)and the detection of presymptomatic DR remains challenging. Therefore, data on the prevalence and progress of DR will help in prevention and treatment programs in China. Objective This study was to survey the prevalence and risk factors of diabetic retinopathy( DR ) in a population aged 40 years or older in the Shunyi district of Beijing city.Methods A cross-sectional study was designed. Cluster sampling was used to randomly select 4167 (91.6%)individuals aged ≥40 years in 24 clusters in the Shunyi district of Beijing city in China. The Questionnaire data,including general information, living habits, present history, past history, family history, education level etc., were obtained from each subjects. The height, body weight and blood pressure were examined, and slit-lamp examination, direct ophthalmoscopy,indirect ophthalmoscopy and nonmydriatic fundus photography were performed during the study duration. Diabetic mellitus (DM)was diagnosed and graded according to the criteria of Early Treatment Diabetic Retinopathy Study Research Group(ETDRS). The associated factors with DR were analyzed byx2 test,trend x2 test,and multivariate Logistic regression analysis. This protocol was approved by the Ethic Committee of Peking University. Informed consent was obtained from each individual prior to the survey. Results A total of 4167 ( 91.6% )individuals were examined from the 4549 samples with a response rate of 86. 4%. This study showed a prevalence of 29. 2% for DR, 5.4% for sight-threatening diabetic retinopathy ( STDR), and 1.3% for prolifrative retinopathy (PDR) in type 2 DM subjects. Of the type 2 DM subjects,0. 4% (4/445)had social blindness( VA＜0. 1 ) ,and 6. 3% (28/445) presented with visual impairment (VA ＜ 0. 3 )in bilateral eyes. Univariate Logistic regression analysis indicated that insulin therapy ( P = 0.011 ) and lower body mass index ( BMI, kg/m2 ) ( P = 0. 022 ) appeared to be significantly associated with DR, and the multivariate Logistic regression analysis demonstrated that longer duration of diabetes( P＜ 0. 01 ) , increased fasting glucose ( P ＜ 0.01 ) and lower education level ( P = 0. 031 ) were significant independent predictors of DR. Conclusion The prevalence of DR is lower among diabetic Chinese aged ≥ 40 years than those of matched population in Western countries. Lower BMI and insulin therapy were the significantly associated factors of DR, and a longer duration of disease and higher fasting glucose level are independent risk factors of DR. Education attainment is important for the DM patients as a protective factor of DR.
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Background The visual evoked potential (VEP) is an important functional index to assess visual cortex plasticity.Monocular form deprivation(MD) of rat is a classic model to study visual cortex plasticity change.Utilizing VEP technique record the shift of ocular dominance in adult rats model is of an important significance for explore the treating opportunities of amblyopia.Objective The present study was to observe the pattern VEP changes in different ages of Long-Evens rats and the adult rats after binocular form deprivation.Methods Thirty-six healthy SPF Long-Evens rats were divided into PW3,PW4,PW5,PW6 groups according to the postnatal weeks,and PW7 rats included 36 SPF Long-Evens rats.The left eye lids of the rats were sutured in PW3,PW6 and PW7 rats for 3,5,7 days respectively,and PVEP in both left and right eye were recorded to assess the rat age that visual cortex plasticity ended.Bilateral PVEP were recorded in PW7 rats,and the bilateral eyelids were sutured to establish the bilateral form deprivation models.The right eyes were opened in 7,10,14 days,and the left eyes were opened in the next 3,5,7 days respectively and the PVEPs were recorded again to find the shift of ocular dominance and whether binocular form deprivation induce the visual cortex plasticity in adult rats.Results The P100amplitudes of the left eyes were gradually declined and those of the right eyes were raised from 3 to 7 days after MD of the left eyes in rats of PW3 group in comparison with before MD ( P＜0.01 ).In PW6 groups,no significant changes in P100amplitudes of both the right and left eyes were found in the third day after MD,but significant raise in the right eyes and lowing in the left eyes were seen in the 5 and 7 days after MD in comparison with before MD(P＜0.01 ).No any P100changes in both eyes were found in 3-7 days after MD compared with before MD in PW7 rats (P＞0.05).The C/I ratio (contralateral VEP amplitude to ipsilateral VEP amplitude in occluded eyes) in the rats of PW3,PW4 and PW5 groups were 1.07±0.15,1.16±0.16 and 1.14±0.15 respectively in 3 days after MD,showing the significant lowing in comparison with before MD (2.69±0.45,2.58±0.4,2.62±0.32) (P＜0.01),but those of PW6 and PW7 were unchanged (2.80±0.48 vs 2.90±0.46,2.59 ±0.36 vs 2.90±0.46,P＞0.05 ),indicating the absence of ocular dominance plasticity in the adult rats.In rats of PW7 with binocular form deprivation for 14 days,a significant decrease was observed in the C/I ratio in rats with next MD for 3 days,demonstrating that the visual cortex plasticity was reactivated after 14 days of binocular form deprivation in PW7 rats( 1.33±0.18 vs 2.70±0.45,P＜0.01 ).Conclusions PVEP can be recorded in Long-Evens rats.It is a major index for identifying the shift of ocular dominance in the Long-Evens rats.Binocular form deprivation can reflect the visual cortex plasticity in the adult rats.
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Background Visual impairment influent the life quality of patient and bring about the economical burden to their families and society.Epidemiology survey of the prevalence and main causes of visual impairment is the basis of the prevention of blindness.Objective The goal of this survey was to investigate the visual impairment in the subjects aged 40 years or older living in Shunyi district and assist in the design of intervention programs.Methods A cross-sectional survey was performed in this study.Cluster sampling was used to randomly select 4549 individuals aged ≥40 years in Shunyi district,and visual impairment was evaluated based on WHO criteria and analyzed based on the 10-year interval groups.The questionnaire,best corrected visual acuity (BCVA)and comprehensive eye examination were provided for eligible residents.To evaluate the independentassociation of significant sociodemographic variables with visual impairment,a regression model was constructed including age,sex and education level.This study was approved by the Ethic Committee of Peking University Medical Department.Written informed consent was signed by each subject before any medial survey.Results A total of 4167 subjects participated in this survey with the response rate of 91.6％.The age of the subjects ranged from 40-94 years(mean:56.61±11.10 years).The numbers of visual impairment was 161 with the prevalence 3.9％.Trend x2 test showed that the number and percentage of visual impairment were elevated as the increase of age,showing a significantly difference among different age groups(x2 =159.487,P＜0.01).The prevalence rate of visual impairment in 70 and older group was 15 times more than that of 60-69-year-old group(OR =0.114,95％ CI:0.056-0.234).No significant difference was found between gender and prevalence of visual impairment(OR =0.901,95％ CI:0.627 -1.295).The prevalence rate of visual impairment in illiterate group was 5.5 fold more than that of educated group (OR =2.743,95％ CI:1.830-4.111).Conclusions Ageing and low education degree are the important factors of visual impairment.Education attainment is an independent protective factor of visual impairment.
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Background RCS-rdy--P+ rat occur retinitis pigmentosa (PR) with the aging and development.To find OUt the retinal functional change using electrophysiological technique is useful for the further study of RCS-rdy--P+ rat. Ohjectlve The goal of this experiment was to investigate the dark-adapted electroretinogram (ERG) of RCS rats with aging. Methods The series of seotopic ERG were recorded in postnatal 21-,32-,37-,45-,60-day-old RCS-rdy--P+ rats respectively,and the age-matched RCS-rdy+-P+ rats were simultaneously recorded as control group.The ERG record was performed by a series of flash with RETI-scan system,gold-foil ring form cornea recording electrode and home-made stainless steel needle electrode.The use of animals complied with the Regulations of the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission. Results Increase dark adaptation duration led to an ascended amplitude in ERG b-wave within 12 hours under the same light intensity,frequency and body temperature.Compared with the RCS-rdy+-P+ rats,the amplitudes of scotopic ERG a-wave and b-wave in RCS-rdy--P+ rats with postnatal 21 days age were apparently declined,showing significant difference between them(P<0.01).The implicit time of both RCS-rdy+-P+ rats and RCS-rdy--P+ rats were delayed, especially for the a-wave. The amplitudes of a-wave and b-wave were declined drastically with the growth of RCS-rdy--P+ rats and progression of their retinal degeneration, and the ERG responses were undetectable at the postnatal 60 days. Both the b-wave and a-wave amplitudes were lowered at P21-day RCS-rdy+-P+ rats and after that,significant increase amplitudes were noted till the P32-day rats. Thereafter, the b-wave amplitude and a-wave amplitude were stable from P32 d to P45 d,and much more ascending of b-wave and a-wave amplitudes was at P60 d RCS-rdy+-P+ rats. Conclusion RCS-rdy--P+ rats occur the retrogression of retinal function along with the ages growth. The scotopic ERG changes of RCS-rdy--P+ rats with aging is evidently different and is in accordance to the characteristics of the RP.
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<p><b>OBJECTIVE</b>To objectively assess the effect of Qiming Granule in the treatment of diabetic retinopathy (DR) by fluorescence fundus angiography (FFA).</p><p><b>METHODS</b>In a multi-center, randomized, parallel controlled clinical trial, patients with DR were randomly assigned to the control group (calcium dobesilate capsule) and the test group (Qiming Granule). Changes in the retinal blood circulation time were recorded by FFA after 3 months of medication.</p><p><b>RESULTS</b>Significant reduction was observed in the retinal arterio-venous circulation time (AVCT) in both groups (P<0.01), the value was 7.635+/-3.149 s before treatment and 5.165 +/-3.382 s after treatment in the treated group, and 7.737+/-3.413 s and 5.313+/-3.472 s in the control group respectively. Qiming Granule also reduced the arm-to-retinal circulation time (ARCT, P<0.05). The value was 17.867+/-3.872 s before treatment and 15.643+/-4.648 s after treatment in the treated group, and 17.217+/-3.833 s and 16.312+/-3.613 s in the control group (P>0.05) respectively. The ARCT in the tested group was reduced, with a statistically significant difference post-medication (P<0.01).</p><p><b>CONCLUSION</b>As a Chinese medicine complex prescription, Qiming Granule may alleviate retinal hypoxia and ischemia by increasing retinal blood flow and improving the blood circulation.</p>
Subject(s)
Aged , Female , Humans , Male , Middle Aged , Diabetes Mellitus, Type 2 , Diabetic Retinopathy , Drug Therapy , Drugs, Chinese Herbal , Pharmacology , Therapeutic Uses , Fluorescein Angiography , Retinal VesselsABSTRACT
<p><b>OBJECTIVE</b>To evaluate the prevalence of rhodopsin (RHO) mutations and the genotype-phenotype relationships in Chinese patients with autosomal dominant retinitis pigmentosa (ADRP) by conformation sensitive gel electrophoresis (CSGE) and direct DNA sequencing.</p><p><b>METHODS</b>We have screened the five coding exons and splice sites of RHO gene in 27 probands who had no relativity from Chinese ADRP families and 100 normal controls to identify disease-associated mutations, using CSGE and direct DNA sequencing. Family members of some probands with disease-associated mutations were also genotyped to determine whether the RHO mutations segregated with retinitis pigmentosa (RP) in their families.</p><p><b>RESULTS</b>Two RHO mutations, Pro347Leu and Pro327 (1-bp del), were identified separately in two families, thus the frequency of RHO mutations among this set of Chinese ADRP families is about 7.4% (2/27). Pro347Leu mutation was found in one ADRP proband as well as three her children who also had RP. She had relatively early onset at about 17 years. The only one child without this mutation had no symptom or sign of RP at age of 34. Pro327 (1-bp del) was identified in a late-onset ADRP patient, who appeared night blindness around 30 years old and in her fifties electroretinogram (ERG) has been flat in both scotopic and photopic phases. Family analysis showed that this mutation also existed in her younger daughter and her elder sister, both of them also had RP. Three other family members were genotypically and phenotypically normal. Neither of the two mutations was detected in 100 normal controls.</p><p><b>CONCLUSIONS</b>The frequency of RHO mutations in Chinese patients was lower than that in Europe and North America. The phenotype of the patients with Pro347Leu corresponded to type 1 ADRP, with severe rod degeneration and some cone preservation later, while the phenotype of the patients carrying Pro327 (1-bp del) corresponded to type 2 ADRP, with a concomitant loss of rod and cone visual function. CSGE was found to be a sensitive, simple, and practical method for the screening of a large number of samples under highly reproducible conditions, and could be utilized in routine molecular diagnostic laboratories.</p>