• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.1
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• pp.60-68
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• 2010

In case of sensorineural hearing loss, auditory perception can be activated by electrical stimulation of the nervous system via electrode implanted into the cochlea or auditory nerve. Since the tonotopic map of the human auditory nerve has not been definitively identified, the recording of auditory nerve signal with microelectrode is desirable for determining the tonotopic map. This paper proposes the multi-channel analog front-end for auditory nerve signal detection. A channel of the proposed analog front-end consists of an AC coupling circuit, a low-power 4th-order Gm-C LPF, and a single-slope ADC. The AC coupling circuit transfers only AC signal while it blocks DC signal level. Considering the bandwidth of the auditory signal, the Gm-C LPF is designed with OTAs adopting floating-gate technique. For the channel-parallel ADC structure, the single-slope ADC is used because it occupies the small silicon area. Experimental results shows that the AC coupling circuit and LPF have the bandwidth of 100 Hz - 6.95 kHz and the ADC has the effective resolution of 7.7 bits. The power consumption per a channel is $12\;{\mu}W$, the power supply is 3.0 V, and the core area is $2.6\;mm\;{\times}\;3.7\;mm$. The proposed analog front-end was fabricated in a 1-poly 4-metal $0.35-{\mu}m$ CMOS process.

• Pediatric Infection and Vaccine
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• v.24 no.1
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• pp.65-70
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• 2017

Cytomegalovirus (CMV) infection is one of the most common congenital infections. The first case of discordant congenital CMV infection in twins occurred in Korea. A 31-year-old woman became pregnant with twins (dichorionic-diamniotic). An elective caesarean section was performed at 37 weeks. The first baby was male, weighing 2,410 g with an Apgar score of 8/9. The second baby was female, weighing 1,380 g with an Apgar score of 5/8. She had experienced intrauterine growth retardation, and presented with microcephaly, micrognathia, and joint stiffness. During the work-up for discordant twins, the second baby's serum test was positive for CMV immunoglobulin M. Her urine, blood, and cerebrospinal fluid (CSF) were CMV polymerase chain reaction positive. The first baby's CMV tests were negative. Ophthalmologic exam and audiometry performed on the second baby showed CMV retinitis and bilateral sensorineural hearing loss. She was treated with intravenous ganciclovir. Currently, she is bed-ridden and has significant developmental delay. Although the causes of discordant congenital CMV infection in twins are unclear, this case shows that discordant congenital CMV infection should be considered in twins with significant differences in intrauterine growth or clinical symptoms after birth.

• Journal of Applied Biological Chemistry
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• v.59 no.2
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• pp.113-124
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• 2016

Red ginseng is known to have many beneficial effects. Cisplatin, an effective antineoplastic drug, can cause many side effects like irreversible sensorineural hearing loss and serious tinnitus in humans. This study is aimed to reduce a cisplatin's side effect, nephrotoxicity by fermentated korean red ginseng. Korea ginseng was produced by steaming and dring and fermentation. And mice were divided into 4 groups- (A) normal mice, (B) Vehicle treated cisplatin mice, (C) RG0F0-treated cisplatin mice, (D) RG8F3-treated cisplatin mice. C and D groups were feed each material 200 mg/kg/day during 4 days. And cisplatin 20 mg/kg injected to B, C, and D groups as abdominal injection. After 24 h, blood sample was collected. The kidneys were harvested for histological, immuno histochemical and western blot analysis. 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity was depended on steaming hours. RG0F0 and RG8F3 (ginseng-8 h steamed and fermented by Saccharomyces cerevisiae) were showed antioxidants effect in DPPH and ABTS radical scavenging activity. Component amounts according to steaming hours. 8 h steamed red ginseng had the most ingredients of ginsenoside. Treatments with RG8F3 reduced cisplatin-induced nephrotoxicity in the mice resulting in increase of GSH and decrease of ROS, BUN, creatinine, and inflammatory mediators. This result seems to be involved with the restriction of the inflammation in the kidney. Therefore, fermented red ginseng might have therapeutic efficacy in reduce kidney injury induced by cisplatin treatment.

• Journal of Genetic Medicine
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• v.7 no.2
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• pp.145-150
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• 2010

Acrodysostosis is an extremely rare disorder characterized by short fingers and toes with peripheral dysostosis, nasal hypoplasia, and mental retardation. We report a 16-year-old Korean boy with acrodysostosis who had characteristic clinical features and cervical spine stenosis manifested by neurologic symptoms. On presentation, he complained of difficulty in raising his arms, and suffered from intermittent pain and weakness in both upper extremities. He had short stature and dysmorphic facial features, including a broad, depressed nasal bridge, small, upturned nose, bilateral epicanthal folds, and mild hypertelorism. Moderate mental retardation and sensorineural hearing loss in both ears were also present. Radiological findings included broad, short metacarpals and phalanges with cone-shaped epiphyses, bilateral Madelung deformities, hypertrophied first metatarsals, and thickening of the calvarium. Magnetic resonance imaging findings included stenosis of the cervical spine, platybasia with compression into the cervicomedullary junction, and downward displacement of the cerebellar tonsils. Here, we report a case of acrodysostosis with symptoms and signs of cervical spinal stenosis first in Korea. If it is diagnosed in the early stages, possible life-threatening complications, including spinal canal stenosis, can be managed properly and permanent neurologic sequelae might be avoided. Therefore, it is important to consider acrodysostosis in the differential diagnosis of peripheral dysostosis.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.14 no.2
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• pp.134-145
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• 2001

Introduction: Noises in the ear, whether real or imagined, are called tinnitus. Subjective causes of tinnitus(which is heard only by the patient) are extremely common and the majority of them are treated conservatively. For certain individuals their tinnitus is a major handicap; for others a trivial concern. The most common from of subjective tinnitus is a rushing, hissing or buzzing noise; it is frequently associated with sensorineural heanng loss. The patient may be unaware of the hearing loss, especially if it is a high frequency deficit of moderate severity. The character of the tinnitus may give a clue to the etiology. But the patient often has difficulty in explaining his/her tinnitus in absolute terms, as they have no other tinnitus with which to compare it but their own Tinnitus, like pain, is a subjective state and trying to objectively assess the severity is problematic. Audiological techniques to match subjective loudness to machine-produced noise may offer some help, in that sound intensity matches can bear little correspondence to subjective complaint. In spite of many studies, most patients presently seen complaining of tinnitus are told by their doctors that there is no treatment and that they will have to learn to live with this symptom. Objectives: To perform a clinical analysis of tinnitus and estimate the efficacy of Oriental Medical treatment according to the Byeonjeung(辨證). Subject: We studied 34 patients with complaints of tinnitus who had visited Pundang Cha Oriental Medicine Hospital Department of Otorhinolaryngology from March 1998 to February 2000. All of them had been treated 2 or 3 times a week with acupuncture treatment and had taken herbs according to the Byeonjeung(辨證) method. It was therefore possible for me to know whether their symptoms improved or not. Parameters Observed and Method: We treated them with acupuncture & herb-medication. Sometimes we gave them moxibustion or negative therapy with bloodletting at the acupuncture points(耳門, 聽宮, 聽會). Parameters Observed 1) Distribution of age & sex 2) Chief complaints 3) The sites of tinnitus 4) The quality of tinnitu 5) The duration of disease 6) The problem induced tinnitus 7) Factors increasing disease severity 8) The classification of the Byeonjeung(辨證) 9) The efficacy of treatments Results: 1. Age and sex distribution: The most common occurrence was found in males in their twenties: 6 males($17.7\%$), and in females in their thirties and over sixty: 8 females($23.5\%$). Total patient numbers for men and women were 20 men($58.8\%$), 14 women ($41.2\%$). 2. The most frequent major complaints were hearing disturbances related to tinnitus; and dizziness with tinnitus; each comprising 10 cases($29.4\%$). There were also 7 patients($20.6\%$) with only tinnitus. 3. Tinnitus sites: 13($38.2\%$) said that they felt tinnitus in both ears, equally. In the right ear, 9($26.5\%$), in the left, 6($17.7\%$). 4. The most frequent descriptive symptoms of tinnitus were: humming, hissing, buzzing etc. 5. The duration of disease. 14cases($41.2\%$) had a duration of less than 1 year. 6. 15cases($44.1\%$) complained that it was hard to watch TV or make a phone call because of tinnitus. 10 cases($29.4\%$) complained about depression. 7. Factors increasing severity of tinnitus: ⅰ) fatigue: 18cases($52.9\%$) ⅱ) stress/ tension: 10 cases($29.4\%$) ⅲ) alcohol and tobacco: 5cases($l4.7\%$) 8. Classification through Byeonjeung : ⅰ) 19 cases($55.9\%$) were classified as showing Deficiency syndrome. ⅱ) 15 cases($44.l\%$) were classified as showing Excess syndrome. The deficiency of Qi was 7($20.6\%$), deficiency of Xue, 8($23.5\%$) and insufficiency of the Kidney Yin & Yang, 4($11.8\%$). The flare of Liver fire was 8($23.5\%$) and phlegm-fire, 7($20.6\%$), 9. The efficacy of treatments showed: an improvement in 17cases($50.0\%$); no real improvement or changes in 13 cases($38.2\%$); and some worsening in 4 cases($11.8\%$). In the group with deficiency in Qi, 4($57.1\%$) improved, 1($14.3\%$) showed no change and 2($28.6\%$) were aggravated. In the cases of deficiency in Xue, 6($75.0\%$) improved, 2($25.0\%$) showed no change. In the cases of insufficiency of Kidney Yin & Yang, 3($75.0\%$) showed no change and 1($25.0\%$) were aggravated. In the group of flare of Liver fire, 4($50.0\%$) improved, 3($37.5\%$) no change and 1($12.5\%$) were aggravated. In the cases of phlegm-fire, 3($42.9\%$) improved, 4($57.1\%$) showed no change. Conclusion: We would recommend that any further studies of tinnitus utilize trial treatments of longer than 2 months duration, as any positive effects observed in our study showed that improvement occurred fairly slowly. And we suggest that this study could be utilized as a reference for clinical Oriental Medical treatment of tinnitus. If we try to apply music or sound therapy treatment properly combined with ours, we expect it to provide psycological stability in addition to inducing masking effects, even though it may not directly decrease or completely remove tinnitus.

• Childhood Kidney Diseases
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• v.4 no.1
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• pp.48-56
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• 2000

Purpose: Alport SD., the most common herectitary rephriris, is a renal disease with rapid progression. Deafness, ocular abnormalities and a specific EM finding may be associated in addition to a family history. We have aralyged retrospectively. Methods: We observed 12 children with Alport syndrome who were diagnosed at Dept. of pediatrics in Kyunghee Univ., College of Medicine, from Apr. 1991 until Jun. 1999. We used four criteria for diagnosis: renal disease, family history, deafness or eye abnormalities, and a specific finding in electron microscopy Results: 2 of 12 patients had all features of the four diagnostic criteria. We could not trace an exact family history in 3 patients, and 6 patients did not exhibit deafness or eye abnormality. One could not have renal biopsy because offer chronic renal failure. Other three criteria were observed in her. The ratio of male to female observed was 1:2 respectively and the mean age of initial renal symptom was 5.6 years. 9 of 12 patients had a family history of renal disease. In the audiogram and ocular examination for 11 of 12 cases, sensorineural hearing loss was observed in 6 and ocular abnormality in 2 cases. In electron microscopic finding, irregular thickness of the capillary basement membranes with lamination of lamina densa and foot process obliteration was noted in 9 of 11 and thin basement membrane with splitting and foot process obliteration was noted in the other 2. The mean period of follow-up was 3 6/12 years. And one patient developed the chronic renal failure until now and had kidney transplantation. Conclusion: For the diagnosis of Alport syndrome, the following four diagnostic criteria are very important : renal disease, family history, deafness or eye abnormalities, and a specific finding on electron microscopy. We expect that more patients can be detected through the analysis of these characteristics.

• Childhood Kidney Diseases
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• v.5 no.2
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• pp.164-175
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• 2001

Purpose : Alport syndrome is a hereditary nephrotic disease characterized by progressive nephrotic symptom, sensorineural hearing loss, ophthalmic abnormality, typical microscopic findings, and familial occurrence. In this study, we tried to find the risk factors related with its prognosis by taking a close observation on clinical symptoms of children with Alport syndrome reviewing retrospectively. Materials & methods : We chose children diagnosed as Alport syndrome in renal biopsy during 20 years(from 1980, Jan. until 1999, Dec.) who could receive follow up studies in tile department of pediatrics. They were divided into two groups by comparing renal function at the time of diagnosis and at current status. We compared several clinical aspects in them, and applied nonparametric test for statistical analysis. Results : The sex ratio(male:female) of 24 children was 3:1. The most common clinical symptom presented at their first visit was gross hematuria. Among those 24 children, 11 cases($46\%$) of progressing into chronic renal failure(Group II) were observed. Hypertension, proteinuria and edema were seen much frequently in group II. The level of serum protein, albumin, and creatinine clearance were decreased while BUN, creatinine were relatively increased. All the results were statistically significant. Conclusion Clinically significant risk factors related to prognosis in Alport syndrome were the presence of hypertension, edema, and proteinuria at the time of diagnosis. Also, the level of serum protein, albumin, BUN, creatinine, and glomerular filtration rate were proved to be important factors in predicting prognosis. We believe that studies on these possible risk factors would be of great help in treating and predicting prognosis of children suffering with Alport syndrome. (J Korean Soc Pediatr Nephrol 2001;5 : 164-75)

• Clinical and Experimental Pediatrics
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• v.48 no.2
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• pp.186-190
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• 2005

Purpose : The purpose of this study was to evaluate the responses and toxicities of risk-adapted chemotherapy in pediatric intracranial germ cell tumors(IC-GCT). Methods : Fourteen patients who were diagnosed as IC-GCT from October 2002 to December 2003 received chemotherapy as an initial treatment modality. The low risk(LR) group was defined as follows : Pure germinoma and normal AFP level. Beta-hCG level 50 mIU/mL or less. The others belonged to the high risk(HR) group. Chemotherapy was composed of cisplatin, cyclophosphamide, etoposide and vincristine. Double doses of cisplatin and cyclophosphamide was used in HR patients. Results : Pathologic confirmation was done in all but one. Median age at diagnosis was 11.6 yr (1.2-18.7 yr), and nine patients belonged to the HR group. Tumor markers were normalized after chemotherapy in all patients whose tumor markers had been elevated. Four LR patients(80 percent) and seven HR patients(77.8 percent) showed complete response(CR) at the end of chemotherapy. An additional two of the three patients with partial response(PR) achieved CR after radiation therapy (RT), and the remaining one relapsed before RT. Four LR and all HR patients experienced infectious episodes that required hospitalization. Four of the nine HR patients(44.4 percent) suffered from tinnitus, three of whom developed sensorineural hearing loss. All but one are surviving, event-free, with a median follow-up of 13.9 mo(8.1-22.3 mo). Conclusion : Risk-adapted cisplatin-based chemotherapy was effective even in HR patients, but regimen modification seems to be necessary to avoid an unacceptably high toxicity rate.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.23 no.1
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• pp.25-30
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• 2023

Leigh syndrome is a rare progressive neurodegenerative mitochondrial disorder with clinical and genetic heterogeneity. Recently, balletic IARS2 variants have been identified in a number of patients presenting broad clinical phenotypes from Leigh and West syndrome to a rare syndrome CAGSSS characterized by cataracts, growth hormone deficiency, sensory neuropathy, sensorineural hearing loss, and skeletal dysplasia syndrome (OMIM#616007). We describe a child with Korean Leigh syndrome with urologic manifestations resulting from a compound heterozygote mutation in IARS2. A 5-year-old girl visited the emergency room with a complaint of abdominal pain accompanied by abdominal distension. Abdominal-pelvic CT showed a markedly distended urinary bladder without definite obstructive lesions. She was diagnosed with neurogenic bladder dysfunction based on a urodynamic study. She had global delayed development due to neurologic regression after 6 months of age and a history of bilateral cataract surgery at the age of 2 years. Her brain magnetic resonance imaging showed symmetrically increased signal intensities in the bilateral putamen and caudate nuclei with diffuse cerebral atrophy. No gene variants were identified through whole-mitochondrial genome analysis. Whole exome sequencing was performed for diagnosis, and compound heterozygous pathogenic variants were identified in IARS2: c.2446C>T (p. Arg816Ter) and c.2450G>A (p. Arg817His). To the best of our knowledge, this is the first case report of bladder dysfunction manifestation in a patient with IARS2-related Leigh syndrome. Thus, it broadens the clinical and genetic spectrum of IARS2-associated diseases.