1.Effects of n-Hexane and Benzene on Tibial Nerve for Rats.
Young Soo LEE ; Jae Hoon ROH ; Young Hahn MOON
Korean Journal of Preventive Medicine 1987;20(2):236-246
n-Hexane and benezene are organic compounds which have been widely used as industrial solvents. However, they are also increasingly recognized as important pollutants in working environment. The purpose of this study is to analyze neurotoxicity of benzene and n-Hexane. In this study, tibial nerve of Sprague-Dawley rats were observed after exposing them to two different concentrations of these compounds (6000 ppm of n-Hexane and 2000 ppm of benezene) which were known to be the levels to cause subacute toxicity for the three different periods; two weeks, four weeks, and sex weeks. The following results were obtained from the analysis of variance, Duncan's multiple comparison test, and regression analysis: 1) Myelin sheath thickness of nerve fiber for two n-Hexane exposed groups (four weeks and six weeks) were both reduced compared with the control group and the benezene exposed group. 2) There were positive relationships between nerve fiber diameter and myelin sheath thickness for both exposed and control groups. 3) There were significant difference in myelin sheath thickness from equal diameter nerve fibers between benzene exposed group and control group, but the greater number of thin myelin sheath were observed for n-Hexane exposed group compared with control group. Thus, it is concluded that n-Hexane tends to reduce the rate of growth of nerve fiber more than the benzene and control group. While these results shed light on understanding the effects of benzene and n-Hexane, the duration of exposure was not long enough to apply these results to real working environments. In addition, to further understand the mechanism of nerve degeneration caused by organic solvents, both epidemiological and biochemical studies should accompanied by this kind of study.
Animals
;
Benzene*
;
Myelin Sheath
;
Nerve Degeneration
;
Nerve Fibers
;
Rats*
;
Rats, Sprague-Dawley
;
Solvents
;
Tibial Nerve*
2.Comparative Study on the Epithelial Regeneration of the Corneal Ulceration after Cryocautery and Iodine Cautery.
Young Soo HAHN ; Haeng Ja MOON ; Jong Park KIM
Journal of the Korean Ophthalmological Society 1969;10(3):5-8
Recently cryogenic therapy is widely used for the treatment of herpes simplex keratitis. We had experimental studies on the effect of iodine cautery and cryocautery upon the regeneration of corneal ulceration. On 10 adult albino rabbits, one eye was treated by iodine, and the other by cryocautery in area of 0.6cm X 0.6cm. The epithelium in this area was completly removed by cotton applicator. There after, the rate of epithelial regeneration was observed every 12 hours. The results were as follows: (1) The average period of complete epithelial regeneration was 48 hours in animal treated with cryocautery and 78 hours in animals treated with iodine cautery. This difference is statistically highly significant. (2) Corneal opacity was not demonstrated in eyes treated with cryocautery. Six eyes treated with iodine, however, showed various degree of corneal opacities. These results support the view that the healing time in human herpes simplex keratitis is shortened in patients with cryocautery as compared with iodine.
Adult
;
Animals
;
Cautery*
;
Corneal Opacity
;
Corneal Ulcer*
;
Epithelium
;
Humans
;
Iodine*
;
Keratitis, Herpetic
;
Rabbits
;
Regeneration*
3.Hearing Disturbance in Primary Glaucoma Patients.
Dong Ho YOUN ; Bong Leen CHANG ; Young Soo HAHN
Journal of the Korean Ophthalmological Society 1971;12(2):63-66
There were many instances in which glaucoma, esp. primary, combined with hearing disturbance. The etiology of these cases has not been known until now. We had 15 primary glaucoma patients for whom pure tone audiometry wa~ performed, and could find the hearing defect in high tone in 5 cases (1/3 among those patients). The audiometric curve was similar to that in the presbycusis, but severer in degree than that occured within the normal physiological aging process. The average age was 62.4 year in the group with the hearing defect, and 45.6 year in the group without the hearing defect. There were no relationship between the hearing defect and intraocular tension, visual field change, glaucomatous cupping, and duration of glaucoma. These results may support the opinion of the authors that the hearing disturbance in glaucomatous patients is related to the arterioscIerotic changes which aggrevate the presbycusis, and not related to glaucoma itself. On the otherhand, however, it is stilI impossible for us to rule out that the pleiotropic and multifactorial genetic factors may play as a common important role in the hearing disturbances and glaucoma. And further studies would be necessary for these problems.
Aging
;
Audiometry
;
Glaucoma*
;
Hearing*
;
Humans
;
Presbycusis
;
Visual Fields
4.Amputation of Four Limbs and Prosthetics A Clinical Comparison Between Myoelectric Prosthesis and Conventional Prostheisis
Soo Bong HAHN ; Byeong Mun PARK ; Jin Young LEE
The Journal of the Korean Orthopaedic Association 1985;20(6):1157-1163
Amputation is an unpleasant affair, generating a very negative aura that must be consciously combated. For optimal care of amputation, the surgeon needs not only to be comprehensive trained in reconstructive surgery but also to be knowledgeable about prosthetics. The evolution of an artificial arm can be traced first from the cosmetic prosthesis, then to that with passive movements, and lastly to an artificial limb with active movement which made it possible to restore to some degree the lost function of the amputation limb. But the gap between basic requirement of function and cosmesis is still present in conventional prosthesis. Myoelectric prosthesis was introduced for upper extremity amputees since 1960 by Korbinski and his co-workers and was most exciting improvement in the field of prosthetics. Two patients of bilateral above-elbow and bilateral below-knee amputees with myoelectric prostheses and conventional prostheses were compared in their function, cosmesis and acceptability of patient. Myoelectric prosthesis shows not only favorable cosmesis but also excellent function in range of motion and coordination of mechanical joints. And myoelectric prosthesis provides superior pinch force and requires less energy expenditure than a body-powered conventional prosthesis. So, in spite of the high cost of the appliance and of continued maintenance and repair, improvement in comfort, cosmesis and function have had to good level of acceptance of patients. Further research will undoubtedly improve the appearance, function and durability of the present electrically powered myoelectric prosthesis, making them even more acceptable and useful to lower limb and upper limb amputees.
Amputation
;
Amputees
;
Artificial Limbs
;
Energy Metabolism
;
Epilepsy
;
Extremities
;
Humans
;
Joints
;
Lower Extremity
;
Prostheses and Implants
;
Range of Motion, Articular
;
Upper Extremity
5.An Experimental Evaluation of Microvascular Grafts
Soo Bong HAHN ; Dae Young HAN ; Jun Seop JAHNG
The Journal of the Korean Orthopaedic Association 1986;21(2):295-302
Vascular grafts are often required in clinical stiuations to bridge arterial or venous grafts. Numerous studies exist in the literature concerning the results of such arterial and venous graft of relatively large vessels. There are only a few reports dealing with experimental microvascular grafts. Histopathological features of the grafted vessels were studied after autogenous venous grafts,autogenous arterial grafts and venous allografts using microsurgical techniques. The results were summerized as follow. 1. The patency rate of grafted vessels by microsurgical techniques was 86.8%. 2. In autogenous venous grafts histopathological changes occur later, and to a less pronounced degree, than that in autogenous arterial grafts. 3. Venous allografts showed severe acute inflammatory reaction throughout the layer at 3~7 days postoperatively, but histopathological features of grafted vessels of autografts and venous allografts' did not differ each other in later results. 4. Autogenous venous grafts, autogenous arterial gtafts and venous allografts persist as living sucture but undergo certain histological changes consisting of fibrous reinforcement. 5. It may be said that histological examination of the specimen led general conclusion that the most useful microvascular graft to reestablish circulation of damaged vessels is the autogenous venous graft, but autogenous arterial graft and venous allograft are also applicable when autogenous venous tissue is not available.
Allografts
;
Autografts
;
Transplants
6.Comparison of Antimicrobial Efficacy of Topical Antibiotics in Rabbit Keratitis Model with Ciprofl oxacin, Methicillin-Resistant Staphylococcus Aureus.
Ik Soo KIM ; Yeun Mi SHIN ; Soo Jin KIM ; Hung Won TCHAH ; Young Ho HAHN ; Tae Won HAHN
Journal of the Korean Ophthalmological Society 2000;41(4):807-814
To compare the antimicrobial efficacy of several antibiotics in the treatment of ciprofloxacin and methicillin-resistant staphylococcus aureus(MCRSA)keratitis, we established a rabbit keratitis model by using MCRSA isolated from keratitis patient. A strain of MCRSA, approroximately 100 colony forming units in 10 microliterof phosphate buffered saline was injected intrastromally into the each cornea of New Zealand white rabbits. 30 rabbtits(30 eyes)were randomly divided into 5 groups and treated with either 0.3%ciprofloxacin, 0.3%trovafloxacin, 5%vancomycin, 5%cefazolin, or sterile deionized water.Topical antibiotics were administered every 15 min for 6 hours(750microliter). Rabbits were sacrified 1hour after the last eyedrop, and excised corneas were homogenized, diluted, and plated on BAP medium.Bacterial colonyforming units per cornea were quantified after 48-hour incubation. Aqueous humor were collected from each eye and drug concentration was counted with HPLC. The log1 0 value of colony forming units(CFUs)of vancomycin treated group was 4.85+/-0.64;ciprofloxacin, 6.16+/-0.46;trovafloxacin, 6.58+/-0.29;cefazolin, 6.25+/-0.25;and sterile deionized water, 6.57+/-0.33.In view of mean CFU, vancomycin showed greater antimicrobial activity and it was statistically significant(p<0.05). However, all of these treatment did not completely sterilize any corneas with 6-hour treatment. From these results, only topical vancomycin(5%)represented effective antimicrobial activity with short-term treatment in rabbit keratitis with MCRSA.
Anti-Bacterial Agents*
;
Aqueous Humor
;
Chromatography, High Pressure Liquid
;
Ciprofloxacin
;
Cornea
;
Humans
;
Keratitis*
;
Methicillin Resistance*
;
Methicillin-Resistant Staphylococcus aureus*
;
Rabbits
;
Staphylococcus
;
Stem Cells
;
Vancomycin
;
Water
7.Efficacy of Fluconazole in The Treatment of Candida albicans Keratitis in Rabbits.
Kyung Soo BYUN ; Young Ho HAHN
Journal of the Korean Ophthalmological Society 1995;36(7):1162-1170
In order to evaluate the effect of fluconazole on Candida albicans induced keratitis, an experimental study was conducted on 30 rabbits. After 4 days of inoculation with Candida albicans on rabbit cornea, animals were divided into three treatment groups: daily treatment with a single oral dose of 50mg fluconazole(group 1); topical therapy with 0.3% fluconazole solution 6 times a day(group 2); control animals without any medical treatment(group 3). The rabbits were treated for 28 days following completion of Candida albicans inoculation, and the severity of keratitis was examined with a slit lamp biomicroscope every two days throughout the treatment period. After the treatment, animals were sacrified and histopathological study of the corneas were per formed. Animals in group 1 and 2 showed significant improvements in keratitis compared to that of control animals beginning 10 days of treatment(p<0.05). No statistically significant difference between the group 1 and group 2 were noted in response to treatment(p>0.05). Thus, we suggest that fluconazole is effective in treatment of keratitis induced by Candida albicans.
Animals
;
Candida albicans*
;
Candida*
;
Cornea
;
Fluconazole*
;
Keratitis*
;
Rabbits*
8.Concentration in the Cornea After Topical Administration of 1% Clotrimazole in Rabbits.
Soo Hwan CHOI ; Young Ho HAHN ; Kwan Hyuk KIM
Journal of the Korean Ophthalmological Society 1993;34(10):972-977
The concentration of clotrimazole in the cornea considering the lapse of time after topical administration of 1% clotrimazole, in a single drop or 13 drops at an interval of 5 minutes, was evaluated by agar diffusion bioassay, The rabbits were divided into 3 groups: normal cornea, deepithelized cornea and Aspergillus keratitis, In the case of a single dose, the drug concentration in the normal cornea was lower than the value which can be measured, and the concentration in deeptithelized cornea was significantly higher than in keratitis(p<0.05). In the case of multiple doses, the drug concentration in keratitis was higher than in the deepitheHzed cornea and both of these were higher than in the norma cornea. EspeciaUy the group of keratitis had a significantly higher level(p<0.05) and an abrupt decrease of the drug concentration than the group of deepithelized cornea. This result means that the cornea during inflammation has increased permeability and great metabolic activity. In general the drug concentration in all groups except a single dose in the normal cornea was higher than minimal inhibitory concentration of clotrimazole against A. fumigatus, and this result suggests that the topical administration of 196 dotrimazole is likely to be efficacious in the treatment of Aspergillus keratitis.
Administration, Topical*
;
Agar
;
Aspergillus
;
Biological Assay
;
Clotrimazole*
;
Cornea*
;
Diffusion
;
Inflammation
;
Keratitis
;
Permeability
;
Rabbits*
9.A Case of Penicillium Keratitis.
Young Ho HAHN ; Kyung Soo BYUN ; Myung Woong CHANG
Journal of the Korean Ophthalmological Society 1995;36(3):373-377
Although the incidence of the Penicillium keratitis increases, there is no available reports from the literature. Dense, gray-whitish infiltration combined with ulceration was observed at the central cornea of 62-y-o-man. Hypopyon was observed also. Colonies on Sabouraud's agar showed light violet pigmentation. On the light microscopic examination of the recipicent cornea after penetrating keratoplasty, proliferation of the fungal hyphae in the deep corneal stroma was observed, but collagen fibers of the superficial stroma were re-formed over the necrotic stromal tissue. Electron microscopy showed a hiypha with triple cell wall.
Agar
;
Cell Wall
;
Collagen
;
Cornea
;
Corneal Stroma
;
Hyphae
;
Incidence
;
Keratitis*
;
Keratoplasty, Penetrating
;
Microscopy, Electron
;
Penicillium*
;
Pigmentation
;
Ulcer
;
Viola
10.Experimental Studies on the Vitreous Substitutes.
Young Soo HAHN ; Won Shik YOUN
Journal of the Korean Ophthalmological Society 1973;14(4):309-314
Experimental replacements of rabbit vitreous by air, normal saline, dextran and Haemaccel were tried in albino rabbits. After aspiration of 0.7ml of liquid vitreous from the central portion of vitreous, 0.5ml of substitutes were injected. Clinically, these substitutes were well tolerated with slight uveal inflammation which subsided within one week. Intraocular pussure returned to normal value after 5 days. Hexosamine content of the whole vitreous samples showed moderate increase after Haemaccel injection which decreased slowly thereafter, whereas no significant changes were observed with other substitutes. Hydroxyproline content of the whole vitreous also showed marked increase after injection of Haemaccel, owing to the high hydroxyproline content of HaemacceJ. After 6 weeks 22.9% of the injected hydroxyproline remained in the vitreous. With other substitutes no change was observed.
Dextrans
;
Hydroxyproline
;
Inflammation
;
Polygeline
;
Rabbits
;
Reference Values