Palmatine, a protoberberine alkaloid, inhibits both Ca(2+)- and cAMP-activated Cl(-) secretion in isolated rat distal colon

BACKGROUND AND PURPOSE

The protoberberine alkaloid berberine has been reported to inhibit colonic Cl(-) secretion. However, it is not known if other protoberberine alkaloids share these effects. We have therefore selected another protoberberine alkaloid, palmatine, to assess its effects on active ion transport across rat colonic epithelium.

EXPERIMENTAL APPROACH

Rat colonic mucosa was mounted in Ussing chambers and short circuit current (I (SC)), apical Cl(-) current and basolateral K(+) current were recorded. Intracellular cAMP content was determined by an enzyme immunoassay. Intracellular Ca(2+) concentration was measured with Fura-2 AM.

KEY RESULTS

Palmatine inhibited carbachol-induced Ca(2+)-activated Cl(-) secretion and the carbachol-induced increase of intracellular Ca(2+) concentration. Palmatine also inhibited cAMP-activated Cl(-) secretion induced by prostaglandin E(2) (PGE(2)) or forskolin. Palmatine prevented the elevation of intracellular cAMP by forskolin. Determination of apical Cl(-) currents showed that palmatine suppressed the forskolin-stimulated, apical cAMP-activated Cl(-) current but not the carbachol-stimulated apical Ca(2+)-activated Cl(-) current. Following permeabilization of apical membranes with nystatin, we found that palmatine inhibited a carbachol-stimulated basolateral K(+) current that was sensitive to charybdotoxin and resistant to chromanol 293B. However, the forskolin-stimulated basolateral K(+) current inhibited by palmatine was specifically blocked by chromanol 293B and not by charybdotoxin.

CONCLUSIONS AND IMPLICATIONS

Palmatine attenuated Ca(2+)-activated Cl(-) secretion through inhibiting basolateral charybdotoxin-sensitive, SK4 K(+) channels, whereas it inhibited cAMP-activated Cl(-) secretion by inhibiting apical CFTR Cl(-) channels and basolateral chromanol 293B-sensitive, KvLQT1 K(+) channels.

[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.

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.

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.

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.

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.

[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.

[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.

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.

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.

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.

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.

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.

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.

[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.

[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.

[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.

[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.

[The study of local electroretinogram in age-related macular degeneration]

PURPOSE

Observing the features of electro-activities at macular region in age-related macular degeneration (AMD), and evaluating the sensitivities of local electroretinogram (LERG).

METHODS

The LERG of 2.5, 5, 7.5 degrees at macula had been recorded in 99 eyes (68 dry form, 31 wet form) of 80 AMD patients. The contrast study had also been carried out with visual acuities and lesion areas at the corresponding region.

RESULTS

The results showed that there were no significant differences between the decreased amplitudes of a and b waves of LERG in dry form AMD with normal controls (P > 0. 05). While significant differences existed in wet form AMD (P < 0.01). The changes of LERG at 2.5 degrees were greater than those of the other two regions. The correlation study on b wave amplitude and visual acuity of AMD patients showed that there was a positive correlation existed between them only in wet form AMD at 2.5 degrees region (r = 0.516, P < 0.05). The negative correlations were observed between amplitudes of b wave and lesion areas in wet form AMD at the three macular regions. Drusen of dry form AMD had no effects on the amplitudes of LERG.

CONCLUSIONS

The impairments on macular function from two types of AMD are different. This study reveals that the LERG is a sensitive method of visual electrophysiology for measuring macular function. The smaller the testing area, the higher the sensitivity.

[Study of pathogenesis of age-related macular degeneration]

OBJECTIVES

To explore the pathogenesis of age-related macular degenerastion (AMD) for its early prevention and treatment.

METHODS

The enzymes of red blood cells, levels of serum mineral elements and antiretinal antibodies were determined in AMD and controls. Electronic microscopy, immunohistochemical survey of the AMD patient subretinal neovascular membrane were performed. The light exposure of animal experiment was also made.

RESULTS

The levels of superoxide dismutase and catalase as well as serum zinc were decreased in AMD patients, the ratio of copper and zinc was increase. The retinal antibody reaction was higher than that of controls, and the subretinal neovascular membrane showed inflammatory granulomatous appearance.

CONCLUSIONS

In addition to age, AMD may be related to light damage, change in human defense system and chronic inflammatory process.

A study of motion perception in primary open angle glaucoma

PURPOSE

To study the features of the motion perception (MP) and explore the worth of the clinical application of MP test in primary open angle glaucoma (POAG).

METHODS

MPs were recorded from 41 patients (67 eyes) with POAG ang 56 normal subjects (112 eyes) by the MP software in PC compatible computer. Meanwhile, the MP ways and MP sites were analyzed and MP abnormal rate was compared to the clinical parameters and the visual function indices related to glaucoma.

RESULTS

The results showed that the total abnormal rate of MP was 89.5% in POAG, and the abnormal rate was 81.6% in early stage of POAG, and MP abnormal degree had positive correlation with C/D, ocular tension and corrected loss variance (CLV), and negative correlation with visual acuity and mean sensitivity (MS), and no correlation with age and short-term fluctuation (SF) in the patients with POAG.

CONCLUSION

These results suggest that the MP test provides a newly effective examination method in diagnosing the early POAG.

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.

Local electroretinogram and pattern visual evoked potential in maculopathies

PURPOSES

To observe the characteristics of local electroretinogram (LERG) in normal subjects and patients with maculopathies, and to evaluate the applied worth of LERG and pattern visual evoked potential (PVEP) in maculopathies.

METHODS

LERGs at 5 degrees and 15 degrees macular regions were recorded from 27 normal subjects (54 eyes). The factors of age, different eyes and stimulate areas for LERG influence were observed. Meanwhile, the LERG and PVEP were recorded from 25 patients (35 eyes) with maculopathies for making contrast study.

RESULTS

In normal subjects, there was no significant influence of age to LERG. As the stimulated areas increased, the a- and b-wave amplitudes of LERG increased. In the patients with maculopathies, the a- and b-wave amplitudes of LERG at 5 degrees, 10 degrees and 15 degrees macular regions were significantly lowered and the mean values of P1 latency were prolonged and N1-P1 amplitudes of VEP were lowered, comparing with the control group. In the nearing stimulated area (5 degrees LERG and 14.9 x 19 degrees PVEP), there were no significant differences of the abnormal rates of both LERG and PVEP.

CONCLUSION

There are close sensitivities of testing the function of macular region with LERG and PVEP in maculopathies. However, LERG is not influenced by the visual path diseases and visual acuity, it is a more effective and direct way than PVEP in measuring macular function.

Visual rehabilitation in low vision patients with aging macular degeneration

Using optical visual aids, visual rehabilitation was performed in 14 cases (25 eyes) for low-vision patients with aging macular degeneration (AMD). With distance aids, visual acuity improvements were recorded for 24 eyes (95 percent) out of 25 eyes. Twelve eyes (48 percent) achieved vision equal to or better than 0.4. Utilizing near visual aids, the near visual acuity for all eyes (100 percent) were improved. Thirteen eyes (52 percent) received near vision equal to or better than 0.5. Ten patients were able to read No. 5 equal to or better than 0.5. Ten patients were able to read No. 5 Chinese print (corresponding visual angle is 0.67 at 30 cm of reading distance). The reading success rate was 71.4 percent. The results suggest that the application of visual aids is an effective method to improve the distance and near visual acuity of low vision patients with AMD.

A study of spectral electroretinogram of color vision defects due to macular diseases

Studies of spectral electroretinograms in central serous retinopathy (CSR) and hereditary macular degeneration (HMD) showed that the b-wave amplitudes of most wavelengths of CSR were significantly decreased as compared with normal controls, and those of HMD were obviously lower than the normal values. Patients of HMD with type-A color vision defects (CVD) had primarily a reduction of b-wave amplitudes in the full spectrum of 480-620 nm, and patients with type-I CVD a reduction of b-wave amplitudes wave-lengths of 480-560 nm. These differences might reflect differences in damages to the medium-and long-wave length.

PVEP in patients with different types of congenital cataract

The preoperative and postoperative PVEP in 79 eyes of 45 patients with three types of congenital namely lamellar cataract, nuclear cataract and total cataract was studied. The results showed that visual acuity of patients who could be cooperatively examined was improved significantly after operation. The examination of PVEP revealed that more abnormal waveforms were found in total cataract group before operation. P1 latencies of low and medium spatial frequencies (140', 70', and 35') became much longer in total cataract group than those in lamellar and nuclear cataract groups. The abnormal changes of P1 latency of high spatial frequency (17.5') showed similar in three groups. It is suggested that time for surgery should be based on visual function in the different types of congenital cataract. The total congenital cataract and unilateral cataract should be extracted as early as possible.

[Development of visual function in infants and children]

The development of P1 component of VEP was studied in 150 normal infants and children between the age of 2 weeks and 9 years. The results indicates that the VEP consists of simple positive waves within 8 weeks following birth, the latencies of P1 components shorten dramatically from 2 to 4 months, the development of the latencies of low, medium and high spatial frequencies of P1 components reaches adult levels in infants and children of 4 months, 4 years and 9 years, respectively and the VEP amplitudes of infants and children are significantly higher than those of adults. Based on the results of our research, the development of visual function can be divided into 3 phases: the first, within 4 months following birth; the second, 5 months to 4 years and the third, 5 to 9 years.

Inhibitory effects of sho-seiryu-to on acetylcholine-induced responses in nasal gland acinar cells

Sho-seiryu-to, a traditional Japanese herbal medicine, has been used extensively in the treatment of allergic rhinitis. The effects of Sho-seiryu-to on electrical responses induced by acetylcholine in dissociated nasal gland acinar cells were investigated using patch-clamp and microfluorimetric imaging techniques. The application of Sho-seiryu-to inhibited both K+ and Cl- currents augmented by acetylcholine. The elevation of intracellular Ca2+ and Na+ concentrations induced by acetylcholine was also inhibited by Sho-seriyu-to. These findings suggest that Sho-seiryu-to attenuated the secretion of water and electrolytes from the nasal glands through an anti-cholinergic effect.

[Laser treatment for the membranous cataract: the significance of pre-laser interferometric acuity]

Laser interferometer was used for the detection of interferometric acuity before and after membranous cataract disruption by Q--switched Nd: YAG laser in 23 patients (23 eyes). There was no significant difference between the interferometric acuity before and after laser surgery (p < 0.05). The postoperative corrected acuity was related positively to the preoperative one (p < 0.05). 65.2% of the eyes had a postoperative corrected acuity better than the postoperative interferometric acuity. These results show that laser interferometric acuity is a valuable method in the evaluation of postoperative visual acuity, but false negative and false positive ones should be considered under some circumstances. The interferometric acuity can be affected by aphakia (high refractive error).

The normal color vision evaluated with FM 100-hue test

One hundred and twenty normal subjects (240 eyes) aged from 10 to 69 were tested with FM 100-hue test. They were divided into 6 groups according to their age. It was shown that there were no statistically significant difference in the total error score (TES) between the males and females or between the right and left eyes, but there existed some relationships between the TES and age. The total error score (TES) was the lowest in the 20-29 age group and increased gradually with aging. The analysis of the partial error score (PES) in each age group showed that the PES was the lowest in 20-29 age group and that the larger PES appeared around the axis of titan with age increasing.

[Pattern visual evoked potential and electroretinogram in idiopathic senile macular hole]

Of 12 patients (15 eyes) with idiopathic senile full-thickness macular hole, 3 were bilateral and 9 monocular. Flash ERG and pattern VEP were performed in all eyes of the patients. The abnormal rate of pattern VEP was 93%, manifested by prolonged latency, reduced amplitude and wave deformity of P100; and the abnormal rate of flash ERG was 53%, characterized by reduced amplitude of the b-waves. The difference between the 2 rates was statistically significant. The halo diameter of the macular hole was positively correlated with the latency of P100, which was not related with the hole diameter. In the 9 fellow eyes without macular holes, 3 showed abnormal pattern VEP, of which 1 eye manifested a macular cyst. The results indicated that the pattern VEP provided more information of macular function than did the flash ERG, and follow-up of the fellow eye with this test was useful.

An immunologic study on age-related macular degeneration

Forty-one patients with age-related macular degeneration (AMD) were detected for serum autoantibodies against normal human retinal protein by means of Western immunoblot analysis. Twenty-seven out of the 41 patients showed positive response, with a rate of 66 per cent. The positive rate of anti-retinal antibody in the AMD patients was significantly higher than that in normal controls (18%) and in patients with other retinal diseases (24%) (p < 0.0005). These antiretinal antibodies from the AMD patients partly reacted with the retinal protein of molecular weight between 28 and 32 Kd, partly with Mr of 38 to 42 Kd, 48 to 52 Kd, 62 to 65 Kd or 110 to 130 Kd. Of them, the antiretinal antibody against the protein with Mr of 28 to 32 Kd in the AMD patients was higher than in normal controls (p < 0.05). Two or more antibodies were found in the serum from AMD patients, showing a significant difference between the patients and the controls (p < 0.005). The results indicated that in the occurrence of AMD and/or during its developing process there were inflammation and immunological response, involving antibodies against retinal proteins of various molecular weight.

[The clinical use of steady-state flash visual evoked potentials]

The authors applied 30Hz flash stimuli to record steady-state flash visual evoked potentials (FVEP) and extracted the amplitudes and phases of the first and second harmonics as the characteristic value by discrete Fourier transform (DFT). 46 normal controls (89 eyes) and 78 patients (109 eyes) were detected and analysed by this method. The result showed that the characteristic values of the normal controls are significantly different in three age groups and showed the positive in 35 eyes with the optic never diseases (82.9%), 25 eyes with age-related macular degeneration (92%), and 9 eyes with retinal detachment involved macular (100%). It indicates the method is a sensitive index to evaluate the macular visual function. After preliminary observation, the visual acuities of postoperation were found above 0.4 in cataracts (28 eyes) or opacities (12 eyes) if preoperative FVEP were normal and non-complicated, or less than 0.4 if preoperative FVEP were abnormal. This suggests the method is one of the effective index to detect the postoperative vision of the media opacities. The advantages, disadvantages and the clinical applications were discussed.

The natural history of dry type of age-related macular degeneration

To study the natural history of dry type of age-related macular degeneration (AMD) and search for a sensitive method for detecting the development of the disease, the fundus fluorescein angiography, visual acuity, electroretinogram and FM 100-hue test were used to examine 75 eyes, 147 eyes, 73 eyes, and 94 eyes respectively. These examinations were taken at least twice during the follow-up periods. The average age was 63.2 years (50-80 years). The average follow-up was 29.8 months with a range of 3-74 months. It was shown tht there were not any statistically significant difference in the macular lesions and electroretinogram between the initial examinations and after follow-up (P > 0.05). 91.14% of the eyes maintained good visual acuity during the follow-up. Subretinal neovascularization developed only in one of the eyes. The total error score of FM 100-hue test had a statistically significant difference between the initial test and the test taken two years afterwards (P < 0.01). It was suggested that most of the dry type of AMD had a favorable prognosis and that color visual test was a sensitive method for monitoring the development of dry type of AMD.

Development of PVEP in infants and children

The development of components of VEP was studied in 150 infants and children between 2 weeks and 9 years of age participated as subjects. Ten adult subjects, 25 to 35 years of age were also studied. The results indicated that the VEP had a simple wave form, consisting of only a slowly rising positive wave to 140', 70' and 35' checks from infants of 2 to 8 weeks following birth. P1 wave appeared in response to 17.5' check stimulus at 10 weeks following birth. The latencies of P1 components shortened dramatically from infants of 2 to 4 months and the latencies of low spatial frequencies (140' and 70' checks) from infants at 4 months of age reached adult level but P1 latency of medium spatial frequency (35' check) did not reach adult level until age of 4 years. The latency of P1 component of high spatial frequency was matured by the end of 9 years of age. The development of P1 waves from both eyes was parallel in normal infants and children. The amplitudes N1P1 and P1N2 from infants and children with 2 months to 9 years were not affected by the age and significantly higher than those of adults group by 2 to 3 factors. Based on the results of our research, three phases were found in the development of the visual function in infants and children. The first phase was up to 4 months after birth, and characterized by the maturation of the low spatial frequencies.(ABSTRACT TRUNCATED AT 250 WORDS)

[A software design for standard grayscale printout of China-made automatic static quantitative TBC visual field analyser]

A method of "TBC GRAPH" software design for standard grayscale printout of TBC static quantitative perimetry is introduced. The software is operated in IBM PC/XT or PC/AT compatible computer, using Chinese Character Disk Operating System (CCDOS) which has widespread users in China. Symbols were established by using CCDOS word--make function, and sectoral as well as symbolic matrix were made, which realized the standard grayscale printout. The software is recommended for use in ophthalmic clinic and education.

Visual functions and trace element metabolism in tobacco-toxic optic neuropathy

Visual functions and nutrition metabolic characteristics were studied in 8 subjects (16 eyes) with tobacco-toxic optic neuropathy (TTON). Their visual functions tested by psychophysical and electrophysiologic methods showed that 1: 1. central vision diminished in 16 eyes, 2. dyschromatopsias were found in 14 tested eyes, 3. bilateral symmetrical central or cecocentral scotomas were the visual field characteristics in all cases, 4. PVEP were severe abnormal in 3 spatial frequencies in all cases and 56.3% of 15' checkboard PVEP showed flat responses, which indicated the impairment of optic nerve dominated by the central field. However, the preserved visual responses could be obtained by FVEP test in 14 tested eyes even though their visual acuity were between the range of 0.02-0.2 and flat PVEP responses. The II and III wave latencies of primary stage were more prolonged than those of control group (P < 0.01), which further indicated the preferential demyelination corresponding to the papillomacular bundles, 5. ERG showed slightly attenuated amplitudes in 5 of 8 tested eyes, which indicated the secondary and mild retinal lesion. On the other hand, TTON occurred on a background of long-term, heavy smoking, drinking, emaciation and malnutrition bodies with low serum zinc level.

The spectral VEP in normal subjects and dichromats

The spectral VEP in 13 normal subjects (25 eyes), four cases (8 eyes) of protanopes and 8 cases (15 eyes) of deuteranopes were tested. In normal subjects, the shortest latencies of N1, P1, N2 were in 560 nm and the greatest amplitudes of N1-P1 and P1-N2 were 560-570 nm, around which the latencies were delayed and the amplitudes were decreased as the wavelengths of stimulative light increased or decreased gradually. The spectral VEP pattern of deuteranopes was similar to the normal subjects. In the protanopes, the shorter latencies of N1,P1,N2 and greater amplitudes of N1-P1, P1-N2 appeared in 520-530 nm and 570 nm, forming the two-thoughs and two-peaks shapes, with the shortest latencies and the greatest amplitudes in 520-530 nm. There were statistically significant differences of amplitudes and/or latencies in some wavelengths between the protanopes and normals and between the deuteranopes and normals.

Quantitative evaluation of flicker ERG waveforms in low vision patients

Flicker electroretinograms (FERGs) of 30Hz were recorded for 46 eyes (23 cases) of low vision, including 38 eyes with retinal diseases and 8 eyes with optic neuropathy, and for 39 normal eyes (33 cases). The recorded wave forms were analysed by two methods: (1) to measure the peak to peak amplitude and pseudophase directly, and (2) to measure the amplitude and phase of fundamental response component (30Hz) by discrete Fourier transform (DFT). The abnormality ratios between these two methods were compared in low vision patients. All the eyes with optic neuropathy showed normal flicker ERG, the abnormality ratios of directly measured amplitude and the amplitude by DFT were 60.9% in 28 eyes and 71.7% in 33 eyes with retinal diseases respectively, the difference being no statistically significant (P > 0.05), while the abnormality ratios of directly measured pseudo-phase and the phase by DFT were 60.9% in 28 eyes and 82.6% in 38 eyes with retinal diseases respectively, the difference being statistically significant (P < 0.05). These results suggest that FERGs are an objective way to test the retinal function, and DFT for flicker ERGs are more useful in quantitative evaluation of the retinal function.

The contrast sensitivity function in low vision

The contrast sensitivity of 51 low vision patients (95 eyes) showed a substantial decrease in all spatial frequencies. The peak contrast sensitivity was shifted to 1 C/D from the normal 3-4 C/D. The high-frequency cut off is correlated to the visual acuity positively. Of the 33 patients, the preferred eye was the eye with better peak sensitivity in 28 patients (84%), while the preferred eye was the eye with better visual acuity in 22 patients (66%). It seems that the peak sensitivity is more important than visual acuity in determining eye preference. It provides a useful information for the clinician to determine which eye to train with low vision aids. Forty patients among 46 patients (87%) with RFN (Recognized Frequency Number) > or = 3 are able to read No.5 reading card, while 5 patients among 5 patients with RFN < 3 are not able to read No.5 reading card. The contributions of CSF to the low vision are evaluated.

The electrophysiology in idiopathic senile macular hole

Of 12 patients with idiopathic senile full-thickness macular hole, 3 had bilateral involvement, 9 had monocular macular hole. Flash ERG and pattern VEP were performed in the bilateral eyes of all patients. The abnormal rate of the pattern VEP was 93.3% when we used 15' checkboard stimulus, the changes of the VEP appeared as delayed latencies, reduced amplitudes or malformation of P100. The abnormal rate of the flash ERG was 53.3%, showing primary characteristics of reduced amplitudes of cone response b-wave. There was statistically significant difference between the abnormal rates of the VEP and the ERG (P < 0.05). The halo diameters of the macular hole were significantly related to the latencies of P100 (P < 0.01), but there was no correlation between the hole diameter and the latencies of P100. In 9 fellow eyes which did not form macular hole, 3 eyes had the abnormal pattern VEP, including one eye having formed macular cyst. The results show that, in idiopathic senile macular hole, the pattern VEP provides more functional information than does the ERG, and prompts the importance of close follow-up of fellow eye.

Detection of gene alteration for color vision defects by polymerase chain reaction

According to the fact that the abnormalities of visual pigment genes were always involved in the changing of the exon 5, two oligonucleotide primers were designed to amplify the exon 5 of red pigment gene and green pigment gene. After electrophoresis of the PCR products digested with Rsal or Sau3A, the DNA fragments from the exon 5 of red pigment gene (RPG) and green pigment gene (GPG) were separated since there are different restriction endonuclease sites. On the other hand, we analyzed the exon 5 related fragment by Southern blot hybridization with probe out of the 3' end of the fourth intron of green pigment gene. The results of PCR are consistent with nucleic acid hybridization. PCR technique will be of value in prenatal evaluation and genetic counselling.

[Clinical observation and analysis in age-related macular degeneration with one eye of wet form and the other of dry form]

Twenty two cases (44 eyes) of age-related macular degeneration with one eye of wet form and the other of dry form were included in this study. The range of the lesion was determined on magnified negative film of fluorescein angiography. In the dry group 72.7% eyes had normal FAZ and in the wet group 59.1% eyes revealed the lesion involving whole FAZ. The area of the lesion was measured by polar coordinates computational method, the mean area was 5.048mm2 in the wet form and 1.034mm2 in the dry form, there was statistically significant difference between the mean areas of the two groups (P < 0.01). The mean amplitude of photopic ERG b-wave was 101.74 mu v in the wet form and 126.35 mu v in the dry form. The morphological characteristics, the abnormalities of the visual function and possible changes in the two groups of this disease were discussed.

Abnormalities of ERG in congenital aniridia

Congenital aniridia is generally associated with nystagmus, corneal pannus, cataract, ectopia lentis, glaucoma, macular hypoplasia, optic nerve hypoplasia and compromised visual function. Many theories have been proposed, including a failure in the development of the neural ectoderm and/or an aberrant development of mesoderm. We observed the ERG from 19 patients with congenital aniridia. Fourteen patients had abnormal ERG, including the reduced a wave trough under dark adapted red stimuli with dark adaptation; abnormal a or/and b waves in dark or/and light adapted ERG or abnormal oscillatory potentials. The ERG abnormalities reflected the disturbances either in the outer retina such as photoreceptors or in the structures of inner retina. The preserved visual function and several ocular abnormalities show that the aniridia may be a consequence of several pathogenetic mechanisms. This fact supported the opinion that congenital aniridia would be a concurrent failure of both ectoderm and mesoderm in embryonate development.

Visual rehabilitation in low vision patients with age-related macular degeneration

Using optical visual aids, visual rehabilitation was performed in 14 low vision patients (25 eyes) with age-related macular degeneration. With distance aids, visual acuity improvement appeared in 24 eyes (95%) out of the 25 eyes. Twelve eyes (48%) obtained a visual acuity equal to or better than 0.4. With near visual aids, near acuity of all eyes (100%) was improved. Thirteen eyes (52%) got the near vision equal to or better than 0.5. Ten patients could read No. 5 Chinese Reading Card. The reading success rate was 71.4%. The results suggest that application of visual aids is an effective method to improve the distant and near visual acuity of low vision patients with AMD.

Spectral characteristics of electroretinogram in X-linked dichromats--a preliminary study

Spectral characteristics of X-linked Dichromats (13 protanopes, 20 deuteranopes) were studied with spectral ERG. The results are as follows: The maximal spectral response of the b-wave in protanopes tended to shift toward the short wavelength side and the sensitivity to long wavelengths decreased obviously. The ratio value of the amplitude in 500 nm and in 620 nm (500/620) was greater in the protanope than that in the normal subject. Like the normals, the maximal response of the b-wave in deuteranopes appeared at 550-570 nm. Though the differences between the normals and deuteranopes in the ratio values (600/620 and b/a at 520 nm) were found by means of analysing a, b wave responses at each wavelength, most of the ratio values (600/620 or b/a at 520 nm) overlapped between the normals and deuteranopes. We established the discriminant function or score made up by the combination of two ratios basing on Fisher's rule, which can raise the diagnostic rate for deuteranopes.

[Quantitative evaluation of flicker ERG wave forms in low vision patients]

Flicker ERGs of 30 Hz were recorded for 46 eyes (23 cases) of low vision, including 38 eyes with retinal diseases and 8 eyes with optic neuropathy, and also for 39 normal eyes. The abnormality ratios were compared with regard to (1) the directly measured peak to peak amplitude and pseudo-phase, and (2) the amplitude and phase of fundamental response component (30 Hz) by discrete Fourier transform (DFT). All eyes with optic neuropathy showed normal flicker ERG, while the abnormality ratios of the directly measured pseudophase and the phase by DFT were 60.9% in 28 eyes and 82.6% in 38 eyes with retinal diseases respectively, the difference being statistically significant (P less than 0.05). These findings suggest that DFT for flicker ERG is more useful in quantitative evaluation of the retinal function.

[The color vision in patients with optic neuritis and chronic open-angle glaucoma]

Twenty eight cases (50 eyes) of chronic open-angle glaucoma and 21 cases (27 eyes) of optic neuritis were investigated with FM 100-hue test and panel D-15 test. In patients with optic neuritis, 70.37% and 85.19% of the affected eyes appeared abnormal in Panel D-15 test and FM 100-hue test respectively. The main defects were tritan-like in both of the tests. In patients with chronic open-angle glaucoma, 20% and 32% of the affected eyes had abnormal results in Panel D-15 test and FM 100-hue test respectively. The main defects were also tritan-like color vision defect. The total error scores of FM 100-hue test in patients with chronic open-angle glaucoma had no relation with the cup disc ratio and the area of peripheral visual field but had relation with the area of central visual field.