PLATELET-ACTIVATING FACTOR AND PLATELET- ACTIVATING FACTOR ACETYLHYDROLASE ACTIVITY IN RAT UTERUS AND PLACENTA DURING PREGNANCY Katsuhiko Yasuda, Mayumi Sanezumi, Hidetaka Okada, Tatsuya Nakajima, Takashi Matsubara, and Hideharu Kanzaki, Department of Obstetrics and Gynecology, Kansai Medical University, Osaka, JAPAN

We evaluated the roles of PAF and PAF acetylhydrolase(PAF-AH) activity in late pregnancy. Uterine and placental concentration of PAF were determined by the washed rabbit platelet aggregation bioassay. The PAF concentration of the uterus increased 4-fold between the 15 and 21 day of pregnancy. However, the concentration of placental PAF was decreased by 75% during the same time period. Plasma and uterine PAF-AH activities decreased significantly, however, the placental PAF-AH activity significantly increased. These findings suggested that the PAF concentration in tissues may be regulated by the PAF-AH activities. The increased PAF activity in the pregnant rat uterus may be related to the initiation of the labor due its known effect on myometrial contraction. The decreased PAF levels in the placenta may contribute to the fetoplacental circulation due to its known hypotensive activity and the increase in vascular permeability.

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Temporary Amniotic Membrane Graft for Persistent Epithelial Defects with Ulceration.((J.C. Kim’, K.S. Kim, H.M. Kim, S.H. Choi, and W.R. We.))‘Department of Ophthalmology’, Yongsan Hosp. Chung-Ang Univ. 65-207, Seoul, Korea, 140-757, Korea.

w: We determined whether temporary amniotic membrane graft(TAMG) can be used as a combined approach to treat vision-threatening persistent epithelial defect(PED) with ulceration difficult to be treated. M&Q& Human amniotic membrane was prepared and preserved using our previously described method with minor modification. TAMG was performed in total 47 PED with ulceration patients, which had numerous causes, such as chemical bum(n=6), thermal bum(n=2), post-infectious(n=S), neurotrophic condition(n=9), bullous keratopathy(n=5), post- photorefractive keratotomy(n=4), and etc. m: Mean duration time of TAMG lasted for 7.1 days. Mean numbers of TAMG application were 1.5 times. Cornea1 epithelial defect was healed within mean 15.1 days compared with before the TAMG(P<O.Ol). Postoperatively, visual acuity and ocular surface were much improved in most cases. TAMG failed in two cases of preexisting cornea1 perforation and two cases of long-standing PED with marked stromal thinning. Conclusions: This new procedure of TAMG has proved to be very useful treatment for recalcitrant PED with ulcerations that are refractory to conventional treatment. Before treatment by conjunctival flap, tarsorrhaphy and keratoplasty should be considered. Supported by grant of Good Health RND project(HMP-97-M-5-0055), Ministry of Health and Welfare. R.O.K.

AMNIOTIC MEMBRANE TRANSPLANTATION FOR CICATRICIAL KERATOCOJUNCTIVITIS. J.Shimazaki, Department of Ophthalmology, Tokyo Dental College

End-stage cicatricial keratoconjunctivitis forms complex disorders including comeal epithelial stem cell dysfunction , fibrosis, and desciccation. Transplantation of human preserved amniotic membrane (AM) is a recently introduced method which serves substrates for ocular surface epithelia. Clinically, AM transplantation causes decrese in inflammation, prompt epithelialization , and suppression of fibrosis. Histopathologically, transplanted AM stroma remains on the sclera for a few months. Immunohistochemistry and ELISA test show that AM is rich in growth factors such as bFGF, HGF, TGF-P 1 and - fl 2 especially in the epithelial lesion. With cryopreservation with DMSO , AM epithelium remains for about a week after surgery. Addition of homogenized AM suppresses conjunctival epithelial growth. These results indicate that growth factors in AM may play a role for modulating differentiation and proliferation of cx~lar surface epihelial and fibroblasts.

CORNEAL SURFACES RECONSTRUCTION BY AMNIOTIC MEMBRANE WITH CULTIVATED AUTOLOGOUS LIMBO-CORNEAL EPITHELIUM. Ray J&Fang Tsai, Chang Gung Memorial Hospital, Chang Gung University, Taipei, Taiwan.

Background Limbal transplantation is indicated for reconstruction the comeal surface with limbal stem cell deficiency. In autografts, a large limbaI graft will have to be taken from the contralateral healthy eye. We investigated the possibility of using amniotic membrane precoured with autologous comeal epithelial sheets generated by a small limbal explants. Methods Cells were cultivated on the amniotic membrane from a lmm* biopsy sample taken from the limbus of the healthy eye of three patients suffering from alkali burn on the fellow eye. These epithelial sheets with the amniotic membrane were grafted onto the damaged eyes and followed up for more than 4 months. Results It took 2 to 3 weeks for the explant to growth into l.5xl.5cm2 diameter size of sheet on the amniotic mebrane. Histology showed an organized stratified epithelium, negative to PAS but positive to AE-5 staining. When the amniotic membrane and the autologously cultivated limbo-comeal epithelia was transplanted on the comeal surface, following superficial keratectomy, reepithelization was completed in one week. One month later, the ocular surfaces became quite and stable comeal epithelium and showed improved clarity. Discussion Cultivation of limbo-cornea1 epithelium on the amniotic membrane might be an alternate to limbal autograft for comeal surface reconstruction in patients with unilateral or bilateral with asymmetrical involvement of limbal deficiency.