Biomedical subjects

Y S Cai

Publications and source records attributed to Y S Cai.

10 recordsLinked to original sources

PubMed1994

[Triamcinolone acetonide in the prevention of experimental proliferative vitreoretinopathy].

Macrophages were used to induce an experimental model of proliferative vitreoretinopathy (PVR) for the evaluation of drug efficacy of triamcinolone acetonide in the prevention of PVR. After injection of macrophages into the rabbit vitreous, 1 mg of triamcinolone and 0.1 ml saline, respectively, were also injected into the vitreous of the treated group and the control group. Afterwards, on the 28th day, retinal detachment developed in 77% of the eyes in the control group and in 13% of the eyes in the treated group (n = 30, P < 0.01). The time of triamcinolone being cleared up from the vitreous was 35-63 days (average 45.5 days). Electroretinogram and transmission electron microscopic examinations demonstrated that up to 4 mg of triamcinolone was nontoxic to the retina. The results suggest that during inflammatory stage, the use of triamcinolone effectively and safely prevent the development of PVR.

Animals↗

PubMed1993

Corticosteroids and daunomycin in the prevention of experimental proliferative vitreoretinopathy induced by macrophages.

An experimental model of proliferative vitreoretinopathy (PVR) induced by macrophages simulates a special form of wound healing process in the eye and mimics the development of PVR from its initial stage. We used this model for the evaluation of drug efficacy in the prevention of PVR. One mg triamcinolone acetonide (TA), 10 micrograms daunomycin-liposome (DL), 5 micrograms free daunomycin (FD) and 0.1 ml saline or empty liposomes (as controls) were injected into the vitreous in four groups of animals (30 or 40 rabbit eyes each) after macrophage injection. Retinal detachment developed in 77.5% of the control eyes on day 28, compared to 13.3% of the TA-treated eyes (P < 0.01), to 33.3% of the eyes treated with DL (P < 0.01), and 50% of the FD-treated eyes (P < 0.05). TA cleared up from the vitreous within 35-63 days (average 45.5 days). The half-time of FD clearance was 145.5 min. Although DL declined rapidly during the first 2 days, there was an average of 0.64 microgram/ml daunomycin in the vitreous on day 14. Transmission electron microscopy showed that FD at a dosage of over 5 micrograms or DL over 20 micrograms was toxic to the retina and that up to 4 mg TA was nontoxic. These results suggest that steroids such as TA, given at the inflammatory stage, can effectively and safely prevent the development of PVR, and that encapsulation in liposomes of cytotoxic agents such as daunomycin can enhance drug efficacy and reduce toxicity. The time course of initiation and development of PVR is important in the selection of particular drugs.

Animals↗

PubMed1989

Clinical, pathological and photochemical studies of laser injury of the retina.

Nineteen cases of acute accidental laser injury of the human retina and two groups of laser workers with chronic retinal damage were reviewed. Most acute cases had macular injury and vision impairment; the chronic cases usually suffered from nonspecific eye complaints. Pathological and photochemical studies of laser injury to rabbit retina were also made following exposure to a 0.49-W Ar laser. The retinal pigment epithelial cells and photoreceptors were mildly damaged in the laser spot center, but the Bruch's membrane was still intact. Malondialdehyde (MDA), the main degradation product of lipid peroxidation of the retina, was assessed with fluorescence spectrophotometry. The level of MDA in the injured retina was significantly higher than that in control eyes, suggesting that thermal levels of Ar laser exposure can yield evidence of photochemical light damage mechanisms.

Adult↗

PubMed1989

[Optic nerve decompression by the transorbital sphenoethmoidal approach].

5 cases of intracanalicular optic nerve injury were treated with decompression by the transorbital-sphenoethmoidal approach. The methodology and a typical case were presented. The indications and principles of the operation were discussed. The authors deemed the procedure facile, safe and with few complications, hence worthy of recommendation for early adoption, preferably within 2 weeks after the trauma for good effect.

Adult↗

PubMed1988