No abstract available.
Rabbits*

No abstract available.
Rabbits*

No abstract available.
Rabbits*

No abstract available.
Rabbits*

No abstract available.
Rabbits*

PURPOSE: The aim of this study was to evaluate the effectiveness and indication of radiofrequency ablation(RFA) using renal VX2 tumors by implantation of VX2 tumor cells under the renal capsule in rabbits. MATERIALS AND METHODS: Ten rabbits were injected with 30-40microliter VX2 tumor cells(1.2x10(7) viable cells/ml) under the renal capsule of the right kidney by right subcostal incision. On the 14th day after the tumor cells were implanted, we checked for the development of renal tumors, and the sizes and shapes(exophytic or central) of the tumors by the use of computed tomography. We performed RFA in the renal VX2 tumors with a 17G StarBurst electrode through kidney exposure. After the first and third day following RFA, renal function was checked. On the third day, we performed CT and harvested the kidneys for gross and microscopic evaluation. RESULTS: We confirmed the development of renal VX2 tumors in nine cases. Tumor shapes were exophytic in seven cases and central in two cases; the mean size of the tumors was 2.1 cm(range, 1.1-3.8cm). In all tumors, RFA was performed. From the use of enhanced CT after RFA on the third day, all of the lesions treated with RFA showed no enhancement. From the pathological findings, coagulative necroses were seen on all of the lesions treated with RFA. The necrotized tumor size after RFA was not different statistically as measured by CT and a pathological examination (p=0.833) CONCLUSIONS:: In centrally located renal tumors, we experienced thermal injury in pelvocalyceal systems. RFA is an effective method for nephron sparing surgery as the tumor cells completely disappear and there is preserved renal function and the procedure is easy to apply. We suggest that the RFA method for exophytic renal tumors is more effective than other procedures.
Rabbits ; Animals

Experiments were carried out on adult rabbit without disease in anterior half-part of both eyes, weight 1.5 - 2 kg. Sulfuric acid 30% with dose 100 mcL can penetrate quickly to anterior chamber, reduce significantly the aqueous humor pH level within 90 minutes after burning and damage seriously to iris and anterior surface of lens. However, the aqueous humor pH level was normalized gradually by the body.
burns ; Rabbits

The authors studied the early morphologic changes of peripheral nerve, which is known as relatively radioresistant tissue to the X-ray irradiation, but recently clamied by several clinician through development of neuropathies after radiotherapy of the malignacy. Rabbits were received 1,000 or 2,000 cGy of X-ray on the knee joint areas. Sciatic nerves were extracted out 30 minutes, 1, 2, 4, 24 hours, and 3 and 7 days after irradiation. The morphologic changes were observed by light and electron microscopes. The results were summarized as follows: Light microscopically, only mild edema is noted. Electron microscopically, irregular separation and folding of myelin sheath with spherical body formation are noted. Above features were more prominent at later stages and aggregated nests of fragmented myelin were scattered 16 hours after irradiation. Schwann cell necrosis is noted after 24 hours. But above degenerative changes were scarcely present 7 days after irradiation. There is no remarkable axonal changes. The interstitial tissue revealed swelling and irregularity of surface of endothelial cells, and edema. On the basis of the results, it may be concluded that the peripheral nerve is injured by irradiation in early stages, and the main target of irradiation injury is thought to be myelin sheath and Schwann cells, which would be reversible and could be recovered promptly.
Rabbits ; Animals

Apraclonidine is a potent alpha-adrenergic agonist that, like clonidine, is relatively selective for alpha-2 receptors. Apraclonidine has been shown to lower intraocular pressure by diminishing aqueous humor formation. The purpose of this study is to know the morphological changes in the ciliary epithelium by apraclonidine against aqueous formation. In group I, two drops of 1% apraclonidine hydrochloride were instilled on the right eye of the pigmented rabbits and the eyes were enucleated on 1,2.6 and 24 hours after instillation to find out the duration of action of the drug and the tissue response. In group II, one drop was instilled twice daily for seven days on the right eye and the eyes were enucleated on 1, 2 and 5 days after cessation of the instillation observing the cumulative effect of the drug and the tissue response. These eyes were studied with electron mIcroscopIc examiation. As a result, widening of cell membranes(basal infoldings) of the non-pigmented epithelium(NPE) were observed. This change was recovered with time, and seems to be the principal morphological changes of apraclonidine against aqueous formation in the ciliary body. In group II, the cellular changes were minimal except for well developed rough endoplasmic reticulum representing resumed secretary function of the cell.
Rabbits ; Animals

Under the postulation that double Ruiz procedure could increase the effect of radial keratotomy(RK), RK combined with horizontal and vertical Ruiz procedure was performed in three groups of 22 rabbit eyes. In the group A of six eyes, RK with vertical Ruiz procedure was performed, and eight weeks later the horizontal Ruiz procedure was added. In the group B of eight eyes, RK with horizontal Ruiz procedure was performed, and four weeks later the vertical Ruiz procedure was added. In the group C of eight eyes, RK with horizontal and vertical Ruiz procedure were performed simultaneously. As a control, in the group D of eight eyes, RK without Ruiz procedure was performed. Changes in keratometry for four weeks and eight weeks postoperatively were analyzed. The results were as follows: 1. At eight weeks postoperatively, mean changes in keratometry were 6.434D, 3.663D, 4.030D and 1.585D in groups A,B,C and D, respectively. 2. Mean changes in keratometry of groups A,B and C were significantly higher than that of group D. 3. Mean change in keratometry of 6.434D in group A was significantly the highest of the three groups in which the double Ruiz procedure was performed. From the above results, it was concluded that the double Ruiz procedure increased the effect of RK and that the procedure was more effective when secondary Ruiz procedure was added eight weeks later.
Rabbits ; Animals