Inhibitory Effect of Radiation on the Transdifferentiation of Lens Epithelial Cells into Fibroblasts

PURPOSE: We estimated the effectiveness of radiation on transdifferentiation of the lens epithelial cells into fibroblast. METHODS: The morphologic changes and number of fibroblasts were determined using a phase contrast microscope. The proliferation of lens epithelial cells was analyzed by PCNA and BrdU assay in the control group and in the experimental groups exposed to 500, 1000 or 2000 rad of X-ray on the 7th day of culture. Expression of type IV collagen was estimated by Western blot and apoptosis was investigated using TUNEL assay. RESULTS: The number of fibroblast transdifferentiated from lens epithelial cell was 300+/-1.58 in control group, and 240+/-1.58, 231.75+/-4.1E, and 213.50+/-0.22 in the group exposed to 500 (experimental group I), 1000 (experimental group II), and 2000 rad (experimental group III), respectively, on the 7th day of culture (radiation was decreased in a dose-dependent manner). The index of PCNA and count of BrdU labeling cells were 56+/-1.58% and 27.6+/-4.6 in control group; 26+/-1.56% and 18.4+/-8.5 in experimental group I; 24+/-1.60% and 17.2+/-4.2 in experimental group II; 16+/-1.58% and 8.6+/-2.4 in experimental group III, respectively. These results indicated that proliferation of lens epithelial cells was inhibited by radiation in a dose-dependant manner. The Western blot showed that the expression of collagen decreased in experimental groups I and II and markedly decreased in experimental group III, compared with control group. TUNEL showed no differences between the control and experimental groups I and II but showed increased apoptosis in experimental group III. CONCLUSIONS: Radiation may inhibit the transdifferentiation of lens epithelial cells into fibroblasts. It would be practicable that radiation suppresses proliferation of lens epithelial cells in posterior capsular opacity.

A Case of Adenoma of Nonpigmented Ciliary Epithelium

Acquired tumors of the nonpigmented ciliary epithelium are rare diseases. They are difficult to diagnose and present as pseudoadenomatous hyperplasia, adenoma or adenocarcinoma. They exhibit slowly progressive enlargement leading to a subluxated lens, cataract, and secondary glaucoma. And some of the more malignant tumors may extend extrasclerally. We report a case of adenoma of nonpigmented ciliary epithelium which produced a cataract.

Electron Microscopic Examination of the Cat Oculomotor Nucleus Innervating the Medial Rectus Muscle

Oculoinotor nerve is a very important nerve in the ophthalornology, innervating the medial rectus, inferior rectus, inferior oblique, superior rectus, levator palpebrae superioris, and the presynaptic parasyrnpathetic outflow to the internal muscles of eye (the ciliary muscle and the sphincter muscle of the iris) . To examine the fine structure of neurons and synapses in the oculomotor nucleus projecting the rnedial rectus Hiuscle, 50% horseradish peroxidase (HRP) solution was injected into the rnedial rectus rnuscle of the cat, and serial sections of midbrain were studied with electron microscopes. Large motor neuron, small motor neuron and spindleshape motor neuron were examined. Cell body contained rich organells that. were nucleus, rough endoplasmic reticulum, HRP containing lysosorne, mitochondria and ribosome etc. Three kinds of synapses that are axosomatic synapse, axo-dendritic synapse and axo-axonic synapse were examed. Moreover, the nerve terminals had spherical-shaped synaptic vesicles. These results suggest that the function of inotorneurons related to the medial rectus muscle is not. defined by the shape and distribution of nerve terrninals but. depends on the shape of synaptic vesicles.

Clinical Evaluation of the Eye Patients Visiting Emergency Medical Center in Sungnam

To examine the clinical characteristics of ocular emergency in Sungnam, we analyzed 3784 of the eye patients who visited emergency medical center of Inha university hospital during 3 years from January 1, 1995 to December 31, 1997 The ambulation rate of eye patients was 3.97% of total patients visiting emergency medical center and the admission rate was 8.30%. Male was more common than female about 2-fold and the patients in the age of 3rd decade(30.8%) and 4th decade(23.7%) were common Regarding the eye in trouble, there was no significant difference between right eye and left eye. September and autumn were most common month and season and visit rate of Sunday(27.7%) was highest in a week. According to the arrival time at emergency medical center, largest group was between 9 PM and 12 AM and within 1 hour from the onset of disease most patients visit emergency medical center. Most frequent cause of visit was beating by fist and common ocular diseases were conjunctivitis(20.4%), orbital contusion(17.9%) and eyelid laceration(13.9%).

A Case of Superior Oblique Myokymia

Superior oblique myokymia is an unusual disorder of ocular motility characterized by rapid, small ampulitude and rotary oscillations limited to one eye. Symptoms of monocular oscillopsia and torsional diplopia are experienced by the patient, and the cause remains obscure. We experienced a case of superior oblique myokymia that developed in a 53-year-old male. We report this unusual case with literature review.