1.Experimental Investigations on the Effects of Ocular Tissues upon the Ultrasonic Waves.
Seung Hwan CHO ; Won Shik YOUN
Journal of the Korean Ophthalmological Society 1971;12(2):51-62
The purpose of this report is to investigate experimentally how the corea, sclera, crystalline lens and focusing lens influence the ultrasound intensity and beam width and to find characteristic differences due to the transducer parameters; frequency and size. A time-amplitude ultrasonic diagnostic apparatus, Aloka Model SSD-2D was used with transcucers of 10 MHz and 5 MHz, 10 mm and 5 mm diameters. The metal ball, 1 mm in diameter, was served as the echo-reflecting target which was immersed in water and moved horizontally under the transducer with a micrometer screw. The distances between the transducer and the metal ball varied from 10 mm to 50 mm in 10 mm step. The amplitudes curves of the echoes so obtained were represented by relative values. In water control experiment, the nearer the metal ball from the transducer, the more irregular the curves, with multiple amplitudes maxima and minima. These irregular curves became homogeneous as the transducer moved away from the target. The multiple peak curves were more marked when measured with transducers of higher frequency and larger diameter. At the end of the near field only a single peak was found in the axial portion of the sound field. In the far field, the beam width reduced slightly due to the divergence of the beam accompanied by slight attenuation of the echo amplitudes. When the sound beam passed through the cornea and sclera, the form of the curves remained almost unchanged, but the amplitudes decreased slightly due to the absorption of the sound energy. Scleral tissue absorbed the energy more strongly then the corneal tissue. When the crystalline lens was placed under the transducer, divergence of the beam and themoderate absorption took place. This effect was more pronounced with the use of transducers of higher frequency and smaller diameter. When a focusing lens, 25 mm focal length, was attached to the transducer surface, sound beam converged to a narrow zone, followed by later scattering. These results suggest that the transducer should be selected as to the frequency and diameter according to the site of the lesion suspected and the nature of the pathology.
Absorption
;
Cornea
;
Lens, Crystalline
;
Pathology
;
Sclera
;
Transducers
;
Ultrasonics*
;
Ultrasonography
;
Water
2.Treatment of traumatic gap in long bones
The Journal of the Korean Orthopaedic Association 1973;8(4):417-422
Recently there has been a noted increase in the incidence of traumatic bony gap in long bones due to accidents in industry, high speed traffic accidents and common gunshot accidents. There are several methods to treat traumatic bony gap such as bone graft (autogenous, homogenous and heterogenous), bone transplantation, periosteal osteogenesis and reinplantation of the extruded bone etc. The authors studied 26 patients of traumatic bony gap in the long bones which had been treated by autogenous bone grafting. The results of the clinical observation were as following; 1 The causes were shotgun accidents, vehicle accidennts and explosive accidents. 2 There was bony gap involved in 10 upper extremities and 16. lower extremities. The radius was the most common site in the upper extremity and the femur in the lower extremity. 3. The largest bony gaps were 10.5cm. in the tibia and next were 10.6cm. in ulna and 9.0cm. im humerus. 4. The period of the bony union in these cases was prolonged 1.5~3 times the usual healing period of simple fractures. 5. It was very important to prevent and control infection of the open fractures and to decide the correct time for bone grafting operation after healing of the infected wounds. We did the bone grafting sugery 2 or 3 months later after the infected wounds had been healed. 6 The authors could avoid some complications such as delayed union, shortening of the affected limbs and stiffness of the joints of the affected limbs etc.
Accidents, Traffic
;
Bone Transplantation
;
Extremities
;
Femur
;
Fractures, Open
;
Humans
;
Humerus
;
Incidence
;
Joints
;
Lower Extremity
;
Osteogenesis
;
Radius
;
Tibia
;
Transplants
;
Ulna
;
Upper Extremity
;
Wounds and Injuries
3.Neurobiology of Alzheimer's Disease.
Young Cho CHUNG ; Seung Woo SEO ; Seung Hwan LEE
Journal of the Korean Society of Biological Psychiatry 2001;8(1):62-70
Alzheimer's disease(AD) is associated with a characteristic neuropathology. The major hallmarks of AD are senile plaques(SPs) and neurofibrillary tangles(NFTs). beta-amyloid protein(Abeta) is derived from the proteolysis of amyloid precursor protein(APP) and then converted to SPs. Mature SPs produce cytotoxicity through direct toxic effects and activation of microglia and complement. NFTs are composed of paired helical filaments(PHFs) including abnormally phosphorylated form of the microtubule-associated protein(MAP) tau and increased tau level in cerebrospinal fluid may be observed in most AD. The aggregation of Abeta and tau formation are thought to be a final common pathway of AD. Acetycholine, dopamine, serotonin, GABA and their receptors are associated with AD. Especially, decreased nicotinic acetylcholine receptors(nAChRs) in AD are reported. Genetic lesions associated with AD are mutations in the structural genes for the APP located on chromosome 21, presenilin(PSN)1 located on chromosome 14 and PSN2 located on chromosome 1. Also, trisomy 21, Apo-E gene located on chromosome 19, PMF locus, low density lipoprotein receptor-related protein and alpha-macroglobulin increase risk of AD. In this article, we will review about the neurobioloby of AD and some newly developed research areas.
Acetylcholine
;
Alzheimer Disease*
;
Amyloid
;
Amyloid beta-Peptides
;
Apolipoproteins E
;
Cerebrospinal Fluid
;
Chromosomes, Human, Pair 1
;
Chromosomes, Human, Pair 14
;
Chromosomes, Human, Pair 19
;
Chromosomes, Human, Pair 21
;
Complement System Proteins
;
Dopamine
;
Down Syndrome
;
gamma-Aminobutyric Acid
;
Genetics
;
Lipoproteins
;
Microglia
;
Neurobiology*
;
Proteolysis
;
Serotonin
4.Renal transplantation using ileal conduit.
Seung Ryeol RHEE ; Baik Hwan CHO ; Young Gon KIM
The Journal of the Korean Society for Transplantation 1992;6(1):101-104
No abstract available.
Kidney Transplantation*
;
Urinary Diversion*
5.Three Cases of Mirtazapine Induced Akathisia.
Seung Hwan LEE ; Min NAM ; Young Cho CHUNG
Journal of the Korean Society of Biological Psychiatry 2001;8(1):162-166
The mirtazapine is a relatively new antidepressant that has noradrenergic and specific serotonin antagonist action(NaSSAs). This has been known as one of the most safest drugs because of its few side effects. Until now, there have been only one case report that mirtazapine causes a EPS side effect(restless leg syndrome). But the peculiar mechanism of this drug makes it impossible to explain the exact reasons why the mirtazapine could induce EPS symptoms. Authors obseved three cases of mirtazapine indeced akathisia. We could not explain the phenomenon the other way except akathisia. So here we presents the three case of mirtazapine induced akathisia and a few possible hypothesis of this phenomenon.
Leg
;
Psychomotor Agitation*
;
Serotonin
6.Epidermal Grafting after Removal of Recipient Epidermis by CO2 Laser Ablation in Vitiligo.
Han Kyoung CHO ; Seung Kyung HANN ; Jung Bin KIM ; Sung Hwan CHO ; Yoon Kee PARK
Korean Journal of Dermatology 1995;33(5):867-872
BACKGROUND: Epidermal grafting using cryotherapy for recipient sites is in widespread use. However the peripheral hypopigmented haloes that occur around the recipient sites require prolon gation of the treatment period. OBJECTIVE: We used a CO2 laser to remove the epidermis of the recipient sites for betteri results. METHODS: We treated lie localized vitiligo patients with CO2 laser to remove t.he epidermis and grafted suction blister rooves. We observed repigmentation and complications 1 month later. RESULTS & CONCLUSIONS : The superiority of this method is demonstrated by the fact 1) all prodedures can be completed on the day of operation 2) the incidence of hypertrophic scar and peripheral hypopigmented halos can be observed.The problems of this method are 1) uneven repigmentation of recipient. sites 2) hyperpigrnentation of recipient sites
Blister
;
Cicatrix, Hypertrophic
;
Cryotherapy
;
Epidermis*
;
Humans
;
Incidence
;
Lasers, Gas*
;
Suction
;
Transplants*
;
Vitiligo*
7.A Case of Inflammatory Metastatic Carcinoma of the Breast.
Chang Geun CHO ; Sang Wook SON ; Seung Hyun HONG ; Gil Ju YI ; Ill Hwan KIM ; Chil Hwan OH
Annals of Dermatology 1998;10(1):28-31
A 51-year-old Korean woman presented with a non-tender, well-demarcated, reddish, edematous patch on the right anterior chest where a previous mastectomy and radiation therapy had been performed. She had been diagnosed as having infiltrating ductal carcinoma of the right breast about 1 year ago. Histopathological findings of the skin lesions were consistent with inflammatory metastatic carcinoma of the breast. Inflammatory carcinoma or carcinoma erysipeloides is a well-established entity most frequently associated with carcinoma of the breast. It is characterized by dermal lymphatic invasion by malignancy and clinically should be distinguished from erysipelas or cellulitis. We describe a case of inflammatory metastatic carcinoma derived from an infiltrating ductal carcinoma of the breast which can be clinically confused with radiation dermatitis.
Breast*
;
Carcinoma, Ductal
;
Cellulitis
;
Dermatitis
;
Erysipelas
;
Erysipeloid
;
Female
;
Humans
;
Mastectomy
;
Middle Aged
;
Skin
;
Thorax
9.The Effect of Small Doses of Oral Corticosteroids in Vitiligo Patients.
Tae Kee MOON ; Sung Bin IM ; Seung Kyung HANN ; Sung Hwan CHO ; Yoon Kee PARK
Korean Journal of Dermatology 1995;33(5):880-885
BACKGROUND: One of the most, probable pathogenesis of vitiliga is autoimmune. Systemic cor tico st,eroids suppress immunity and may arrest the progression of vitiligo and lead to repigmentation. OBJECTIVE: We have assessed the clinical effect of a oral small oral dose of corticosteroid to minimize side effects in vitiligo patients. METHODS: Thirty four patients(9;male, 25;female) with vitiligo were evaluated in this study. The patients took 7.5mg-20mg prednisolone initially for 2 months and then the dosage was tapered to half of the initial dosiat the 3rd month and half of dose of 3rd month for the last 4th month. We compared the effcct of treatment of vitiligo before and aft.er the study by photographs. and side efferts were issessed at. 1, 2, 3 and 4 month. RESULTS: The arrest of the progression of vitiligo was noticed in 79% of patients and repigmentation was noticed in 59% of patients which is statistically significant. The effect, of treatment according to extent, duiation, type, and site of vitiligo were not statistically significant. The side effects of treatment were minimal and did not affect the course of treatment. CONCLUSION: Small doses of iral corticosteroids are effective without any significant side effects in preventing progression and loiiduce repigmentation of active spreading vitiligo and generalized type of vitiligo that is difficult to treat with topical corticosteroids.
Adrenal Cortex Hormones*
;
Humans
;
Prednisolone
;
Vitiligo*
10.The Selective T3 Sympathicotomy in Patients with Essential Palmar Hyperhidrosis.
Seung Hwan YOUN ; Joon CHO ; Chang Taek MOON ; Sang Keun CHANG
Journal of Korean Neurosurgical Society 2000;29(11):1499-1504
No abstract available.
Humans
;
Hyperhidrosis*