Hiroshi Sakata

Effect of FK 506 administered topically versus intramuscularly on suppression of the corneal immune reaction in rats

The immunosuppressive effect of FK 506 on penetrating keratoplasty in rats was evaluated following intramuscular and topical administration. Implanted corneal grafts were inspected weekly by clinical evaluation for 3 weeks. Cytotoxic T lymphocyte (CTL) activity was measured in the spleen on postoperative day 21, and the grafts were examined histologically. A dose of FK 506, 0.1 mg/kg given intramuscularly, only moderately suppressed CTL activity and the graft failed. In contrast, doses of either 0.024 mg/day topically or 0.3 mg/kg intramuscularly suppressed CTL activity and the grafts remained intact. Results suggest that FK 506 administered topically would be effective in preventing failure of human corneal grafts.

Postoperative posterior retinal holes after pars plana vitrectomy for primary retinal detachment.

BACKGROUND Although retinal breaks occur frequently during vitrectomy, the postoperative occurrence of new retinal holes close to the vascular arcade after vitrectomy for rhegmatogenous retinal detachment rarely has been reported. METHODS Three patients with rhegmatogenous, retinal detachment were treated by vitrectomy. More than 49 days after vitrectomy, posterior retinal holes with no retinal detachment occurred halfway between the vascular arcade and the chorioretinal scar around the extrusion hole or the primary retinal tear. RESULTS These new holes were effectively managed with photocoagulation. CONCLUSION New hole formation could be caused by the technique of the internal drainage, the contraction of the photocoagulation scar, or epiretinal membrane contraction. Another possibility is that new holes occur through two opposite tangential traction contractile forces: one induced by the contraction of the photocoagulation scar, the other caused by the contraction of the premacular cortical vitreous attached to the vascular arcade.

Induction of Cytotoxic T Lymphocytes from Splenocytes after Orthotopic Penetrating Keratoplasty in the Rat

We used a rat model of orthotopic penetrating keratoplasty to study splenic cell cytotoxicity in the host. DA (RT1avl) rats received grafts of Fischer (F344, RT1lv1) rat corneas. Cytotoxic T lymphocyte (CTL) activity was measured by the cell-mediated lymphocytotoxicity assay using 4/4R.M.-4 cells as target cells. CTL activity became detectable in vitro 2 weeks after grafting and peaked at 3 weeks. This simple method of quantifying CTL activity in the orthotopic penetrating keratoplasty model should provide a reliable tool for studying the CTL response in corneal transplantation.

Cellular localization of prostaglandin E in the rabbit iris by indirect immunofluorescence method.

To demonstrate the cellular localization of prostaglandin E (PGE) in the normal and irritated rabbit iris, the indirect immunofluorescence method was employed. The amounts of PGE1 and PGF2α in the aqueous humor were determined with radioimmunoassay. Immunofluorescence of PGE was observed in the cytoplasm of mesenchymal cells of the iris. PGE-positive cells in the normal iris were scattered in the fibrous stroma, and the shape of these cells was oval to spindle-shaped. The numbers of these cells were remarkably increased in the iridectomized and inflamed iris. The amounts of PGE1 in the aqueous humor was 2.0±0.53 ng/ml in the normal eyes and 7.92±2.93 ng/ml in the irritated eyes. The mean level of PGF2α was 0.4±0.27 ng/ml in the normal eyes and 0.8±0.58 ng/ml in the irritated eyes. Um die celluläre Lokalisation von Prostaglandin E in normaler und entzündeter Iris darzustellen, wurde die Methode der indirekten Immunofluoreszenz angewandt. Außerdem stellte sich die Aufgabe, die Menge von PGE1 und PGF2α im Kammerwasser radioimmunologisch zu bestimmen. Die Immunofluoreszenz von PGE ließ sich im Cytoplasma der mesenchymalen Zellen der Iris beobachten. Die PGE-positiven Zellen lagen im Normalfall in die fibrillären Fasern des Sromas verstreut und zeigten eine ovale bis spindelartige Form. In der ausgeschnittenen und entzündeten Iris fand sich die Anzahl dieser Zellen merklich erhöht.-Die Menge der PGE1 im Kammerwasser betrug im normalen Auge 2,0±0,53 ng/ml und im gereizten Auge 7,92±2,93 ng/ml. Im normalen Auge lag der Durchschnittswert von PGF2α bei 0.4±0.27 ng/ml und im gereizten Auge bei 0.8±0.58 ng/ml.

Cytotoxic T Lymphocyte Activity after Intravitreal Inoculation of Herpes simplex Virus Type I in Mice

After inoculating mice with herpes simplex virus (HSV) by a corneal or intravitreal route, cytotoxic T lymphocyte (CTL) activity in the cervical lymph nodes and spleen was assayed. The spleen and cervical lymph nodes were removed at various points till 2 weeks after inoculation, and CTL activity was assayed in a groups: (A) mice intravitreally inoculated with HSV, and (B) mice with topical application of HSV. The reactivity of delayed type sensitivity was determined by the thickness of the mouse ear pinna on the 6th day in both groups. CTL activity in the spleen was at the same level in both groups. Up to 10 days after inoculation CTL activity in the cervical lymph nodes in group (A) was lower than in group (B). The reactivity of delayed type sensitivity in group (A) was lower than in group (B). These results indicate that an anterior chamber associated immune deviation (ACAID)-like phenomenon occurred after HSV inoculation into the vitreous cavity.

Time Course of Cytotoxic T Lymphocyte Activity after Inoculation of Herpes simplex Virus into the Anterior Chamber of Mice

The time course of the activity of cytotoxic T lymphocytes (CTL) was studied after injecting herpes simplex virus (HSV) into the anterior chamber of C3H/He mice and compared with that following corneal inoculation. CTL activity in cervical lymph nodes was suppressed during the 14 days after the inoculation, while that in the spleen increased 2 days earlier compared with the activity after corneal inoculation. The difference between the peaks of CTL activity after inoculation via each route was not significant. Thus, CTLs from the spleen appear to play a role in the immune response defending mice against intraocular infection by HSV.

Immunological studies on herpetic keratitis: effect of IL-2 on HSV-specific CTL.

The effect of interleukin 2 (IL-2) on cytotoxic T lymphocytes (CTL) was examined in mice with corneal infection of herpes simplex virus (HSV). The corneas of the mice were inoculated with HSV after scratching the corneal epithelium. Ten days after the inoculation, CTL were induced in vitro from spleen cells of the mice. IL-2 was added for the initiation of CTL induction. CTL induced without IL-2 served as controls. After the culture, viable cells were counted and cytotoxicity of CTL was measured by 3H-proline releasing assay. IL-2 promoted proliferation of HSV specific CTL without increasing the cytotoxicity of HSV specific CTL.

Immunological studies on experimental herpes simplex virus infection in mice: mitogen responses of spleen cells

The responses of in vitro spleen cells to phytohemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM) and lipopolysaccharide (LPS) were studied in mice with herpes simplex virus (HSV) infection of the cornea. For 1 week after corneal inoculation of HSV, the responses of spleen cells from mice infected with HSV to PWM and LPS were comparable to those from normal mice, but the responses to Con A and PHA were lower. These results suggest that in acute herpetic keratitis in mice, the responses of T 6cells are more markedly suppressed than those of B cells.