Objective To evaluate the cytotoxicity of microdosis peracetic acid (PAA) so as to provide the evidence for making residual l imit of PAA steril ization. Methods Mouse fibroblasts (L929 cell l ine) cultured in vitro were observed to evaluate the influence of microdosis PAA including 1 × 10-6, 2 × 10-6, 3 × 10-6, 4 × 10-6, 5 × 10-6, and 10 × 10-6 (V/V). Theproliferation of cells was determined by MTT assay at 2, 4, and 7 days of culture. The growth curve and the relative growth rate (RGR) were obtained. The cytotoxicity of PAA at different concentrations was evaluated according to RGR. Results At 2, 4, and 7 days after culture, fibroblasts of 1 × 10-6 group grew with normal morphology analogous to control group, while the cell growth of other groups were poor. With the increase of PAA concentration, the absorbance (A) values decreased, which suggested that there was a significant negative correlation between cell prol iferation and PAA concentration. And the correlation coefficient was — 1.000 at 2 and 4 days, — 0.964 at 7 days. There was no significant difference in A value between 1 × 10-6 group and the control group (P gt; 0.05), while there were significant differences in A value between the control group and other concentration groups (P lt; 0.05). The growth curve of 1 × 10-6 group was similar to that of the control group, both had obvious phase of exponential growth. The growth curves of other groups had no obvious phase of exponential growth. The cytotoxicity of 1 × 10-6 group was classified as level 1, 2 × 10-6 group as level 2, 3 × 10-6 group as level 3, 4 × 10-6 group as level 3-4, 5 × 10-6 group and 10 × 10-6 group as level 4. Conclusion PAA of 1 × 10-6 had no obvious cytotoxicity. The residual l imit of PAA less than 1 × 10-6 was recommended.
Objective To inverstingate the effect of perfluorohexyloctane(F6H8)to the retina of rabbit eyes. Methods Fifteen vitrectomized New Zealand white rabbits were injectedF6H8(experiment group,12 rabbits ) and BSS(control group,3 rabbits) into vitreous cavity.Slit-lamp biomicroscopy and indirect ophthalmoscopy were performed pre- and postoperatively in all the eyes.Histopathological examination was done after the rabbits were sacrificed at the end of the study. Results A large clear balb was formed after intravitreal injection of theF6H8 in the vitreous was injected and no retinal detachment and cataract were found.The OPL was edematous and then thinned out in 4th week in experimental group.Degenerating cells was found in inner and outer nuclear layers.Cellular vaculoar degeneration was present in TEM. ConclusionF6H8 in vitreous cavity may cause significant side effects on retina,we could not recommend it to be used as an intraocular temponade.
Purpose To investigate retinoic acid (RA) induced apoptosis in retinal pigment epithelial (RPE) cells. Methods 10-5、10-6、10-7 mol/L were added to cultured PRE cells.Aridine orange fluorescence and TdT-mediated dUTP nick end labelling(TUNEL) techniques were used to observe apoptotic changes. Resultss 10-5、10-6、10-7 mol/L RA induced apoptosis in RPE cells.Cell shringkage,chromatin condensation and nuclear DNA fragmentation of RPE cells were observed by TUNEL technique.When 10-7、10-6、10-5mol/L RA treated RPE cells for 5 days,apoptotic index(AI)was 36.9%、4409% and 61.4% respectively,and 48.0%、59.9%、74.2% for 6 days.At the same concentration of RA,AI increased when time prolonged．At the same day,AI increased when the concentration of RA rose.There was significant difference in the results(Plt;0.05). Conclusion Our results showed that RA-induced apoptosis in RPE cells was detected with a good dose and time response. (Chin J Ocul Fundus Dis,1998,14:153-155)
Hydroxychloroquine is widely used in the treatment of autoimmune diseases and skin diseases, mainly for the treatment of diseases such as systemic lupus erythematosus, rheumatoid arthritis and other diseases. Hydroxychloroquine has many benefits to patients, but long-term use of the drug may lead to retinal chronic toxicity changes, seriously affect the patient’s vision and quality of their lives. However, there are few studies on retinal toxicity of hydroxychloroquine in the world, easy to miss diagnosis and misdiagnosis clinically. ophthalmologists should increase the knowledge with the etiology and pathology of hydroxychloroquine retinal toxicity, through relevant auxiliary check early detection of the drug to the retina and timely suggest patients to stop. This can effectively reduce the risk of vision loss caused by retinal toxicity, and reduce the adverse effects of hydroxychloroquine on the retina while patients get a good treatment effect.
An experimental model of retinal acute photic injury was developed in Wister rats. Aninmls were exposed to white light in intensity of 20 000 lux under general anesthesia for 1 hr. Two rats were sacrificed at 24, 48hr, day 7, 14,21,28,35 after liht exposure respectively. The histopathologic study showed that the retinal acute photic injury initiated in the outer seSment characterized by disorganization and loss of the outer segment at the early stage, and then the inner segment and RPE were involved. The decrease of the thickness of the outer nuclear layer was seen in a few of our cases. Some of our samples showed recovery of the outer and inner segment from the light damage of certian degrees 2 or 3 weeks after light exposure, but others did not. One sample from 5 weeks after light exposure demonstrated that the outer nuclear layer, the outer and inner segment completely lost. Thc inflammatory responses were not observed in all of our samples inplicating that the retinal acute photic damage is a degeneration process. （Chin J Ocul Fundus Dis,1994,10:84-85）
OBJECTIVE:To evaluate the toxicity of retinoic acid in silicone oil to the retinal tissue. METHOD:Twelve New Zealand white rabbits(24 eyes)were divided into three grorps at random. Three days after gas-compression vitrectomy,24 eyes were unedrgone gas/silicone oil exchange. The silicone oil 0.5 ml was injected intravitreally in 4 eyes as controls ,and 5mu;g/ml retinoic acid silicone oil 0.5ml in 10 eyes and 10 mu;g/ml retinoic acid silicone oil 0.5 ml in 10 eyes respectively as 2 study groups. After intravitrea[ injections, all the eyes were examined by ophthalmoscopy on the 1st, 3rd, 7th, 14th, 21st and 28th day. The retinas of the enucleated eyes on the 28th day were then examined by light microscopy and transmission electrone microscopy. RESULT: No evidence of toxicity was found in retinas after intravitreal injections of silicone oil with 5 mu;g/ml or 10 mu;g/ml retinoic acid. CONCLUSION :There was no toxic effect on the retinas by using 5 mu;g/ml or 10 mu;g/ml retinoic acid in intravitreal silicone oil tamponade operation. （Chin J Ocul Fundus Dis,1997,13: 81-82）
ObjectiveTo evaluate the security of intravitreal injection with ciproflaxacin to retina.MethodsTweenty-four rabbits were randomly divided into 4 groups with 6 rabbits in each group. 0.1 ml ciproflaxacin in doses of 2 500,5 000,and 10 000 μg was intravitreally injected into the rabbits eyes, retrospectively. And 0.1 ml saline solution was injected into the vitreous body of the rats in the control group. Indirect microscope, light microscope and electroretinogram (ERG) were used to observe the changes of ocular fundus.ResultsNormal results of light microscopy and ultrastructure were found in 250 μg and 500 μg groups; irregularly arranged outer and inner nuclear layers, dropsical or even lost ganglion cells, and ultrastructural changes were in 1 000 μg group. There was no apparent difference of ERG′s a and b amplitudes before and after intravitreal injection with ciproflaxacin in each group.ConclusionIntravitreal injection with ciproflaxacin is safe, and 500 μg or less is the secure dosage in rabbits' eyes. (Chin J Ocul Fundus Dis, 2005,21:180-182)
Objective To investigate the ingestion, metabolism and subcellular localization of indocyanine green (ICG) in human retinal epithelial (R PE) cells.Methods RPE cells were incubated with 0.25 mg/ml ICG under the condition of 37oC in the camera. The ICG granule and ultrastructure of RPE cells were observed under the electron microscopy after 1, 4, and 24hour incubation, and the ICG autofluorescence was detected by fluorescence microscopy after the incubation for 1, 2, 4, 8, 12, 24, and 48 hours, respectively. The ab sorbency (A value) of ICG solution was measured at 805 nm with ultraviol et/v isible specrtrometer. The standard curve of concentration of ICG was drawn and the related equation of concentration of ICG and the A value was calculated. After being incubated for 1, 2, 4, 8, 12, 24, 48, and 72 hours, respectively, the A value of supernatant fluid was calculated according to the equation. Aft er incubated with ICG for 24 hours, one sample was observed under electron microscope and fluorescence microscope per week to evaluate the metabolizable period of ICG .Results ICG granules were distributed evenly after entering the RPE cells. After incubated with 0.25 mg/ml ICG for 24 hours, no significant change of the ultrastructure of the RPE cells was found. ICG granules accu mulated in the cells as the time goes by and reached the peak after 24 hours, and then they decreased because of the slowdown of the metabolism. Few ICG was still remained in the cells 1 week later Conclusions RPE cells may take in ICG actively. ICG metabolizable period in RPE cells is long, which may be one of the mechanisms of the toxicity of ICG to the retina in the vitreous operation.(Chin J Ocul Fundus Dis，2004，20：179-181)
Objective To evaluate the toxic effects of staphylococcus aureus exotoxins and neutrophils on retinal pigment epithelium (RPE) cells (RPEC). Methods An in-vitro model of bacteroidal endophthalmitis was established by co-culturing of human RPE cell line D407 and human peripheral blood neutrophils in the present of staphylococcus aureus exotoxins ATCC29213. The level of lactate dehydrogenase hydroxide（LDH）in the cuture supernant was measured, and the viability of RPE was evlauated by flow cytometry and Hoechst 33342/Propidium Iodide（PI）staining. Results When RPE cells were cultured with the exotoxin ATCC29213, the LDH level and necrotic RPE cells were positive proportional to the dosage of exotoxin, but only 250mu;l or 500mu;l of ATCC29213 had a statistical significant effect. When RPE cells were co-cultured with neutrophils in the present of ATCC29213 for 6 hours, 100mu;l of ATCC29213 already had a statistical significant effect on LDH level and necrotic RPEC, and the effect was proportional to the amount of neutrophils in the culture. Conclusion Both staphylococcus aureus exotoxins and neutrophils can damage the RPEC by inducing necrosis, and their function had synergetic effect.
This paper is to evaluate the biocompatibility and cytotoxicity of a new Ni-free Zr-based bulk metallic glass (BMG), Zr60.14Cu22.31Fe4.85Al9.7Ag3, by comparing it with conventional Ti6Al4V alloy. According to ISO 10993-5:1999 and GB/T 16886.5-1997 standards, Zr60.14Cu22.31Fe4.85Al9.7Ag3, pure Zr and Ti6Al4V materials were extracted with surface area of sample/volume of medium ratio being 1 cm2/mL and 0.5 cm2/mL, respectively. The viabilities of MG-63 cells (Human osteosarcoma cell line) cultured in the BMG medium extracts for 1, 3 and 5 days were determined by CCK-8 assay. The cellular morphology of MG-63 cells cultured on the surface of samples for 3 days was tested through laser scanning confocal microscopy (LSCM) and scanning electron microscopy (SEM). The relative growth rate (RGR) of MG-63 cells cultured in Zr60.14Cu22.31 Fe4.85 Al9.7Ag3 and pure Zr were both more than 85%, indicating that the cytotoxicity of BMG was relatively low and met the national biomedical material eligibility standard. There was insignificant difference in the morphology of MG-63 cells cultured in the BMG medium extracts and the control group through LSCM and SEM, which showed the BMG had excellent biological compatibility. The Zr-based bulk metallic glass Zr60.14Cu22.31Fe4.85Al9.7Ag3 and the conventional Ti6Al4V alloy both had no obvious cytotoxicity to MG-63 cells. These results provided evidence that the new Zr-based bulk metallic glass could be potential replacement material for the orthopedic surgical implant.