Biomedical subjects

D Z Wu

Publications and source records attributed to D Z Wu.

At least 19 recordsLinked to original sources

PubMed2001

The electroretinogram in patients with retinal vascular occlusion.

PURPOSE: To measure and analyze the electroretinogram (ERG) in patients with retinal vascular occlusion. METHOD: Fifty-eight cases (59 eyes) of retinal vascular occlusion and the fellow eyes of 47 cases were tested with Ganzfeld ERG. The scotopic and photopic ERG, and oscillatory potentials were tested according to the ERG standard of ISCEV. RESULTS: The abnormal rates of OPs and b wave were higher in retinal vascular occlusion. The abnormal ERG appeared mostly in CRVO among four types of retinal vascular occlusion. The comparisons of some amplitudes and latencies between the fellow eyes and the affected eyes showed statistically significant difference. CONCLUSION: The oscillatory potentials and b waves have important roles in evaluating the retinal function of patients with retinal vascular occlusions. There are some clinical significance for comparing ERG between the affected eye and the fellow eye.

Adolescent↗

PubMed2001

Motion perception of short-wavelength sensitive cones in glaucoma using random dots moving.

PURPOSE: To determine whether motion perception of short-wavelength sensitive(SWS) cones is capable of predicting primary open angle glaucoma(POAG) optic neuropathy. METHODS: Motion perceptions of SWS cones were isolated by Blue random dot stimulus displayed on the Yellow background, then the detecting displacement threshold of motion perception from SWS cone in POAG was measured, and compared with the age-matched normal group. RESULTS: The detecting displacement thresholds of motion perception from SWS cones in 8 sites of 15 degrees were all elevated in POAG compared with the normal group. CONCLUSION: These findings suggest that motion perception of SWS cones may reveal preclinical visual nerve damage in early POAG.

Adolescent↗

PubMed2001

[Effect of satragaloside IV on the increase of microvascular permeability induced by histamine in pial microvessels of rat].

OBJECTIVE: To study the effect of satragaloside IV on the microvascular permeability induced by histamine in pial microvessels. METHOD: The microvascular permeability was expressed by changes in the transendothelial electrical resistance which was measured with technique using microelectrode impaled into the vascular lumen and based on cable analysis of vessels in rat. RESULT: The transendothelial electrical resistance of microvessels superfused with artificial cerebrospinal fluid was about 2500 omega.cm2, indicating a tight barrier with extremely low ion permeability, and application of 10(-4) mol.L-1 histamine in superfusate caused a rapid and reversible decrease in transendothelial electrical resistance. In paired experiment, the decrease of transendothelial electrical resistance induced by 10(-4) mol.L-1 histamine was inhibited by adding 0.8 x 10(-4) mol.L-1 satragaloside IV in superfusate. CONCLUSION: The results indicated that increases in the microvascular permeability induced by histamine, and satragaloside IV can inhibit the increases in the microvascular permeability induced by histamine. It is necessary that the cellular mechanism of permeability response induced by satragaloside IV be further elucidated.

Animals↗

PubMed2000

[Effects of components isolated from Astragalus membranaceus Bunge on cardiac function injured by myocardial ischemia reperfusion in rats].

OBJECTIVE: To investigate the effects of components isolated from Astragalus membranaceus on myocardial ischemia reperfusion injury. METHODS: The myocardial ischemia reperfusion injury model was created by the left anterior descending coronary artery occlusion from the oracotouated rats, and the total saponins, total flavonids and astragaloside i.v. isolated from A. membranaceus on hemodynamics during acute myocardial ischemia, Na(+)-K(+)-ATPase activity, cAMP and malondialdehyede (MDA) contents in the ischemic myocardium were observed. RESULTS: The total saponins, total flavonids and astragaloside i.v. attenuated the declines of the amplitudes of LVSP and +/- LVdp/dtmax in rat heart injured by ischemia reperfusion in vivo, and decreased Na(+)-K(+)-ATPase activity in the ischemic myocardium. Otherwise, the total saponins increased the cAMP content and the total flavonids decreased the level of MDA production in the ischemic myocardium. CONCLUSION: The effects of different components isolated from A. membranaceus on protecting the cardiac function in the process of ischemia reperfusion may be related to the mechanism of improving energy metabolism, scavenging the oxygen free radicals and inhibiting the production of free radicals in the ischemic myocardium.

Animals↗

PubMed2000

A comparative evaluation of Humphrey perimetry and the multi-channel pattern visual evoked potentials.

PURPOSES: To compare the multi-channel pattern visual evoked potentials to Humphrey perimetry in the assessment of central visual function in primary open angle glaucoma. METHODS: The multi-channel checkerboard reversal PVEPs waves to full-field and half-field stimulus of 25 normal persons and 74 patients with primary open angle glaucoma were recorded and analyzed, All patients were examined using Humphrey Field Analyzer. The area of visual field corresponding to the area of retina stimulated during multi-channel PVEPs testing were analysed, straight-line correlation and regression analyses of the various multi-channel PVEPs parameters and the total dB losses were performed. RESULTS: The multi-channel PVEPs demonstrated a low detection rate compared with Humphrey perimetry in the early glaucoma, absolute latency and field loss were correlated in the late stage of glaucoma, and absolute amplitude and field loss were not correlated. CONCLUSIONS: In relation to signalling "early" loss the multi-channel PVEPs was inferior to Humphrey perimetry, in late loss of primary open angle glaucoma, multi-channel PVEPs can provide a valuable, objective complement to Humphrey perimetry.

Adolescent↗

PubMed2000

Detection of glutamate and gamma-aminobutyric acid in vitreous of patients with proliferative diabetic retinopathy.

PURPOSE: To study the levels of glutamate and gamma-aminobutyric acid (GABA) in vitreous of patients with proliferative diabetic retinopathy (PDR) and to investigate their roles in retinal ischemia. METHOD: Vitreous samples were collected from 25 patients (27 eyes) with PDR and 14 patients (14 eyes) with idiopathic macular hole. Glutamate and GABA detection were performed by high-performance liquid chromatography (HPLC). RESULTS: Patients with PDR had significantly higher concentrations of glutamate and GABA than the control group. The glutamate level has a significantly positive correlation with GABA level. CONCLUSION: Detection of glutamate and GABA in vitreous provides biochemical support for the mechanism and treatment of ischemic retinal damage in patients with PDR.

Diabetic Retinopathy↗

PubMed2000

[The clinical application of different brightness and different saturation D-15 tests].

PURPOSE: To compare the clinical application of different brightness and different saturation D-15 tests. METHODS: Eighteen normal subjects (30 eyes), 19 cases (38 eyes) of congenital color vision defects and 36 cases (59 eyes) of eye diseases were tested with Panel D-15 test, Hann's double D-15 test, middle and low saturation CAS-PI (Psychological Institute, Chinese Academy of Sciences) D-15 tests. RESULTS: A few of the normal eyes made minor errors in the low saturation D-15 tests. All of the protanopes and deuteranopes could be detected correctly. Protanomalias and deuteranomalias showed normal arrange or some type of abnormal arranges in all of the 5 sets of D-15 tests. In sick eyes, the abnormal rates were the highest in the low saturation D-15 tests and the lowest in Panel D-15 test. CONCLUSION: The five sets of different brightness and different saturation D-15 tests had similar efficiencies of detecting congenital color vision defects. The abnormal rates of CAS-PI(4/5)D-15 tests and the CAS-PI(2/5)D-15 tests were similar to those of Panel D-15 test and Hann's Double D-15 test. Both tests can be used in the clinical setting.

Adolescent↗

PubMed1999

Gene therapy for human hepatocellular carcinoma with cytosine deaminase gene and prodrug flucytosine.

AIM: To investigate the antitumor effects of cytosine deaminase (CD) gene in combination with prodrug flucytosine (Flu, 5-fluorocytosine) on human hepatocellular carcinoma. METHODS: CD gene was transduced into human hepatocellular carcinoma cell line SMMC7721 with retroviral method and the cytotoxicity of Flu on the tumor cells was assayed in vitro with clonogenic techniques. The xenograft tumor model in nude mice was used to study in vivo therapeutic effects of CD gene/Flu system against human hepatocellular carcinoma. RESULTS: CD gene/Flu system had significant antitumor activities on human hepatocellular carcinoma cells in vitro and in nude mice. The antitumor activities of Flu 500 mg.kg-1 on hepatocellular carcinoma xenografts in nude mice were more potent than those of 5-fluouracil 10 mg.kg-1. CD gene/Flu system possessed bystander killing effects on hepatocellular carcinoma xenografts in nude mice. CONCLUSION: The experiment demonstrates the potential value of the CD gene/Flu system in the treatment of human hepatocellular carcinoma.

Animals↗

PubMed1999

Elevated vascular endothelial growth factor levels in the vitreous of patients with proliferative diabetic retinopathy.

OBJECTIVE: To detect the levels of vascular endothelial growth factor (VEGF) in the vitreous of patients with proliferative diabetic retinopathy (PDR) and to investigate the possible role of VEGF in the development of neovascularization in PDR. METHODS: Undiluted vitreous samples and fasting venous blood samples were obtained from 27 patients with PDR and 14 subjects with idiopathic macular hole who underwent pars plana vitrectomy. The concentration of VEGF was determined by quantitative enzyme-linked immunosorbent assay (ELISA). RESULTS: The level of vitreous VEGF in patients with PDR (median 0.41 ng/ml, range 0.09-11.56 ng/ml) was significantly elevated when compared with that in control subjects (median 0.017 ng/ml, range 0.008-0.04 ng/ml) (P < 0.001). The median of PDR patients' serum VEGF concentration was 0.19 ng/ml (0.090.46 ng/ml) which was far lower than vitreous VEGF concentration (P < 0.05). Vitreous VEGF concentration was higher in PDR patients with retinal detachment than that in patient without retinal detachment (P < 0.05). CONCLUSIONS: Vitreous levels of VEGF were remarkably elevated in eyes with PDR, and they were not influenced by its serum concentrations. VEGF played an important role in neovascularization of PDR.

Adult↗

PubMed1999

Characteristics of indocyanine green angiography in exudative age-related macular degeneration.

OBJECTIVE: To observe the characteristics of indocyanine green angiography (ICGA) in exudative age-related macular degeneration (AMD). METHODS: Thirty-one cases (39 eyes) were diagnosed as exudative AMD by ocular examination, fundus color photography, fundus fluorescein angiography (FFA) and ICGA. Their ages ranged from 50 to 82 years and visual acuities from FC/30 cm to 0.7. We analyzed and compared the characteristics of ICGA and FFA in these patients. RESULTS: Of 26 eyes with occult choroidal neovascularization (CNV) by FFA, 15 (57.7%) had classic CNV by ICGA. Of 4 eyes with serous retinal pigment epithelial detachment (PED) without CNV by FFA, 1 had serous PED with classic CNV by ICGA. The hyperfluorescence of the scar staining was detecfed by ICGA. CONCLUSION: ICGA adds clinically useful information and is an important adjunct in the evaluation, classification, and laser treatment of patients with occult CNV in AMD.

Aged↗

PubMed1998

Analysis of oscillatory potentials of flash electroretinogram in frequency domain and time domain in retinal vein occlusion.

PURPOSE: To analyse the parameters of frequency domain and time domain of the OPs in branch retinal vein occlusion (BRVO) and central retinal vein occlusion (CRVO). METHODS: OPs from 9 eyes of BRVO, 9 eyes of CRVO and 40 normal control eyes were tested. The frequency spectra of the OPs were derived through Fast Fourier Transform (FFT). The mean frequency spectra, the total power, the maximum magnitude, the maximum power and the dominant frequency in frequency domain of the OPs from the eyes of BRVO, CRVO and the normal control group were compared with each other. The OPs waveforms were reconstructed with the OPs frequency spectra data by counter-FFT. In time domain, the latencies, the amplitudes and the sum of the amplitudes of the four wavelets of OPs were measured and compared in the above subjects. RESULTS: There were no statistically significant differences in the magnitudes of frequency spectra, the total power, the maximum magnitude and the maximum power in the frequency range from 110 to 250 Hz between BRVO and normal subjects. However, in BRVO, the dominant frequency decreased significantly, the latencies of the first to the third OPs wavelet prolonged significantly, the amplitudes of the first and the second OPs wavelet and the summed amplitude of the four OPs wavelets attenuated significantly. Comparing the results of CRVO with those of normal subjects, there were statistically significant decrease in the magnitudes of frequency spectra from 150 to 180 Hz, there were statistically significant decrease in the total power, the maximum magnitude, the maximum power and the dominant frequency in the frequency range from 110 to 250 Hz, the latencies of the first to the fourth OPs wavelet prolonged significantly, the amplitudes of the first to the third OPs wavelet and the summed amplitude of the four OPs wavelets attenuated significantly. CONCLUSION: Some parameters of OPs in frequency domain and time domain are abnormal in branch retinal vein occlusion and in central retinal vein occlusion, which is more marked in the latter.

Aged↗

PubMed1998

The multi-channel VEP topographies in patients with late-stage glaucoma.

PURPOSE: To study the clinical application of multi-channel VEP topographies in patients with late-stage glaucoma. METHODS: The multi-channel checkerboard reversal VEP waves of 25 normal persons and 15 patients with late-stage glaucoma were recorded and analyzed, All patients were examined using Humphrey Field Analyzer. The VEP topographies of multi-channel VEP waves were shown by computer processing system. RESULTS: In normal subjects, the topographies showed symmetric distribution to full-field pattern stimulation. In all patients with late-stage glaucoma, even whose visual field was severely damaged, multi-channel VEP could be recorded, All channels showed simple 'NPN' wave form, N1, N2 waves were not conspicuous, even both were lost, all channels showed the reduced amplitudes of P1 waves, and longer latency. The multi-channel VEP topographies showed irregular distribution, Some showed amplitude asymmetry, other limited or widespread, lateralized. CONCLUSIONS: Despite the severely damaged visual field, the patients with late-stage glaucoma showed special multi-channel VEPs topographies, Multi-channel VEP topographies should be useful in following up patients suffering from late-stage glaucoma and studying visual processing in human brain.

Adolescent↗

PubMed1998

The study of local electrophysiology in macular diseases.

PURPOSES: To observe the features and clinical utility values of local electroretinogram (LERG) and local visual evoked potentials (LVEP) in macular diseases. METHODS: The spot stimuli were obtained by changing the shutters with different sizes of hole at the posterior of Ganzfeld ball. The recording electrode for LERG was made with the filament of platinum as blepharophthalmostat like. The LERG and LVEP were simultaneously recorded in macular diseases. RESULTS: The exudative AMD, Stargardt's disease, central serous chorioretinopathy and idiopathic macular hole had seriously decreased amplitudes of LERG and higher abnormal rates, comparing with atrophic AMD and idiopathic preretinal membranes in the region of 2.5 degrees and 5 degrees at macula. The abnormal rates in these diseases were higher for LERG than for LVEP. CONCLUSION: The LERG can objectively measure the variation of macular function in maculopathies. The sensitivities of LVEP are lower than those of LERG for macular diseases.

Adult↗

PubMed1997

[Objective assessment of visual acuity with visual evoked potential].

PURPOSE: To study the technique for objectively assessment of visual acuity with Pattern Visual Evoked Potential (PVEP) and Discrete Fourier Transform (DFT). METHOD: Thirty-three normal eyes were tested in this study. Reversal square-wave gratings of eight different sizes (30, 20, 18, 12, 10, 6, 4, 2 min. of arc) were used as stimuli. The reversal rate of the stimuli was 10 times/sec. The harmonic amplitudes of VEP at 10 Hz were calculated with Discrete Fourier Transform. A relation curve between the harmonic amplitude and the size of grating was plotted from the data of each tested eye. Regression line was fitted to the data points in the approximately linear section of the curve which is near the threshold of zero amplitude. The threshold of the grating size was obtained by extrapolating of the regression line to zero amplitude, and the visual acuity was assessed with the threshold. RESULT: In seventy percent of tested eyes, the visual acuities assessed with VEPs were consistent with those measured with the International Standard Test Chart. CONCLUSION: The VEP technique for visual acuity assessment is reliable.

Adolescent↗

PubMed1997

[Indocyanine green choroidal angiography in macular hemorrhage of uncertain origin].

PURPOSE: To search for the underlying pathology of macular hemorrhage of uncertain origin with Fundus Fluorescein Angiography (FFA). METHODS: 18 Patients (20 eyes) were tested and analyzed using Indocyanine Green Choroidal Angiography (ICGCA). RESULTS: ICGCA clearly demonstrated the underlying pathology of macular hemorrhage as the choroidal neovascularization secondary to age-related macular degeneration (14 eyes), abnormality of retinal vascular (3 eyes) and accidental macular hemorrhage (3 eyes). CONCLUSIONS: The results showed that ICGCA is very usefull for detecting the underlying pathology of macular hemorrhage of uncertain origin.

Adolescent↗

PubMed1997

[Effect of levodopa on visual evoked potential in amblyopia].

PURPOSE: To evaluate the efficacy of levodpa treatment for amblyopia. METHODS: The patients with amblyopin were given a single dose of levodopa, and the normal control group was established with the other normal eye in unilateral amblyopia. Their pattern visual evoked potential(PVEP) were tested before and after taking levodopa. RESULTS: After taking a single dose of levodopa, the PVEP in the normal eyes showed that the N1P1 amplitudes evoked by middle spatial frequency stimuli and the P1N2 amplitudes evoked by high spatial frequency stimuli increased, however, in the amblyopic eyes showed that the N1 latency evoked by low spatial frequency stimuli and P1 latency evoked by middle spatial frequency decreased. CONCLUSION: A single dose of levodopa administration can induce improvement of PVEP in the amblyopic eyes, and levodopa may be efficacious in the amblyopic therapy.

Adolescent↗

PubMed1997

[The objective evaluation of the interaction between color vision and motion perception].

PURPOSE: To measure equiluminance values of green/red grating luminosity ratios with different moving velocity in normal subjects and to explore the interaction between color vision and motion perception. METHODS: Optokinetic nystagmus (OKN) of eye movement elicited by moving color grating stimulus could be recorded with electrooculograph (EOG). The equiluminance points were determined when OKN changed in direction in various moving velocities. Sixteen cases (32 eyes) normal subjects were tested, 6 cases male and 10 cases female, Age ranged from 20 to 51 years old. RESULTS: The mean equiluminance points were 0.525, 0.425, 0.397, 0.391, 0.367 under 595, 400, 301, 239 and 200 mm/s groups of grating moving velocity respectively. There were statistically significant differences of mean equiluminance points among 595 mm/s group and other groups (P < 0.01), there were no statistically significant differences of mean equiluminance points among other 4 groups (P > 0.05). CONCLUSION: There are some influences to color vision under the high moving condition.

Adult↗

PubMed1996

Macrophages in human epiretinal and vitreal membranes in patients with proliferative intraocular disorders.

PURPOSE: Macrophages are versatile cells and have been known as a cellular component of epiretinal membranes of proliferative intraocular disorders (PID). However, the origin and functions of these cells in the membranes are not yet clear. In the present study we investigated the characterization of macrophages/monocytes in various types of human epiretinal membranes from patients with proliferative vitreortinopathy (PVR), proliferative diabetic retinopathy (PDR) and ocular perforating injury by means of immunohistochemical techniques. METHODS: A total of 49 epiretinal membranes of PID in which 24 were PDR specimens, 17 were PVR and 8 were proliferations after perforating eye injury were studied. Monoclonal antibodies against human macrophages, monocytes, HLA-DR antigen and interleukin-1 (IL-1) were used. The alkaline phosphatase anti-alkaline phosphatase (APAAP) technique was performed. RESULTS: The results showed that 19 out of 24 PDR specimens (79%), 15 out of 17 PVR specimens (88%) and 7 out of 8 traumatic specimens (87%) contained macrophages, HLA-DR antigen was detected in 20 out of the 24 PDR membranes (83%), 14 out of 17 PVR membranes (82%) and 5 out of 8 traumatic membranes (63%); monocytes were only detected in 10 out of the 24 PDR specimens (41%). In addition, in a group of PDR specimens, interleukin-1 (IL-1) was detected in 8 out of 13 tested specimens (62%). CONCLUSION: The results revealed that the macrophages in the membranes were in an active stage and may play a significant role in the development of proliferative intraocular disorders through either inducing inflammatory reactions or immune responses, or the effects of their cytokines.

Diabetic Retinopathy↗