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The strong immunoreactivity and the release of b-FGF in cultured fibroblasts of recurrent pterygia suggest that fibroblasts may play an important role in the recurrence of pterygium.

TNP-470 appears to have a marked inhibitory effect on PF proliferation, and it may be of considerable value in the prevention of pterygium growth and recurrence.

The expression pattern of VEGF, p53 and ICAM-1 was studied in conjunctiva of diabetic patients with and without retinopathy. All patients underwent a complete ophthalmic examination, including retinal fluorescein angiography. Indirect immunoperoxidase method was performed on 20 eyes of 20 patients with type II diabetes without DR and on 5 eyes of 5 patients with PDR. A control study was performed on 6 normal conjunctiva undertaken during cataract surgery. Immunoreactivity of VEGF, p53 and ICAM-1 was found in epithelial, fibroblast and vascular endothelial cells. For the same duration of diabetes, a strong to moderate or weak immunoreactivity was observed in the conjunctiva of patients without retinopathy. In patients with PDR, the expression was strong for all these proteins. The immunoreactivity was correlated between VEGF, p53 and ICAM-1. In the normal conjunctiva, a weak to negative immunostaining was observed. The presence of these proteins in the conjunctiva of diabetic patients without retinopathy may add new data in the pathogenesis of diabetic retinopathy. Further studies are needed to confirm this hypothesis.

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Manganese superoxide dismutase (Mn-SOD) is a naturally-occurring scavenger of superoxide, one of several reactive oxygen intermediates. To determine if Mn-SOD expression is enhanced as a defensive mechanism against oxidative challenges, such as intense light exposure, rats were exposed to cyclic light (80 lux) for 2 weeks, intense light (1,800 lux) for 24 h, and then again to cyclic light. Experimental and control (exposed to cyclic light only) eyes were enucleated 3 h, 1, 3, 7, and 14 days after light challenge. Protein expression was examined immunohistochemically using rabbit antisera against rat Mn-SOD. There was no significant difference between the light-exposed and the control groups in the thickness of the outer nuclear layers. Both retinal pigment epithelial cells and photoreceptor inner segments in the normal retina were labeled for Mn-SOD. Mn-SOD labeling was lost 3 h and day 1 after light challenge. It was re-expressed in the retinal pigment epithelial cells 3, 7, and 14 days after the light challenge, and in the photoreceptor inner segments after day 14. These results suggest that the retina might have a protective potential against light damage, in which Mn-SOD may play an important role.

Laser confocal microscopy is a powerful tool for histochemical and cytochemical studies. It enables us to detect the fluorescencelabeled molecules in the specimens by optical. Simultaneous staining of nuclei with appropriate fluorescent dyes as counterstaining greatly facilitates the identification of the localization of the label. Recently, a variety of nucleic acid binding fluorescent dyes have been developed. We screened 20 nucleic acid-specific dyes for use in nuclear staining in laser confocal microscopy with Kr/Ar laser. Results were evaluated in 1) fluorescent intensity, 2)DNA specificity, and 3)bleaching characteristics. Among green fluorochromes excited at 488 nm, YO-PRO-1, SYTOX Green, and SYBR Green l were suitable for nuclear DNA staining. Among red fluorochromes excited at 568 nm, propidium iodide stained nuclear DNA with simultaneous staining of cytoplasmic and nucleolar RNAs. Among far-red fluorochromes excited at 647 nm,TO-PRO-3 was specific for DNA, whereas TOTO-3 strongly co-stained cytoplasmic and nucleolar RNAs. Bleaching by laser illumination was retarded by mounting with media containing and-bleaching reagents such as DABCO and PPDA. Nuclear staining fluorescent dyes should be selected by comparing these characteristics. We evaluated both the number of chromosome 17 and nuclear DNA content on an identical nucleus by means of computer-controlled auto-scanning cytofluorometry in order to demonstrate the significance of the nuclei with 17-aneusomy among whole population of tumor cells in cases of human colorectal tumor. MATERIALS and METHODS We investigated a total of 14 lesions from surgically resected colorectal tumors. We prepared isolated cell smears from paraffin-embedded archival blocks, and memorized the position of the cells using a computer-controlled auto-scanning stage. Then, we evaluated nuclear DNA content and the number of chromosome 17 sequentially in the order of cell position data. We compared statistics of DNA profile between the nuclei with 17-disomy and those with 17-aneusomy. RESULTS and DISCUSSIONSWe detected an alteration of DNA profile in 3 diploid adenomas and 3 aneuploid carcinomas. In the 3 diploid adenomas, we found a minor population of cells having DNA aneuploid in the 17-aneusomy cells, and the existence of this population resulted in the significant difference between the nuclei with 17-disomy and 17-aneusomy. In the 3 aneuploid carcinomas, there was a remarkable alteration in the height of each peak of the DNA profile. We considered that an alteration in the constituent ratio of karyotypically different subpopulations among cytofluorometrically distinct subpopulations yielded the significant difference of DNA profile.

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