• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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• pp.323-326
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• 1997

In this study, we investigated the circardian rhythm of complexity of cardiac dynamics in humans. Dynamic 24-hour electrocardiographic recordings were obtained from 30 healthy ambulant subjects aged 41 to 50 years. or each recordings, normalized low frequency (0.04-0.1 hertz) and high frequency (>0.15 hertz) component are calculated. our different indexes obtained from separate algorithms of nonlinear dynamics - approximate entropy, correlation dimension, Lyapunov exponent and fractal dimension - were calculated. During early morning, low frequency component rose rapidly with concomitant withdrawl of high frequency component. All the our indexes of nonlinear dynamics showed remarkably same circardian rhythm: an early morning dip preceded by a steep decline during late night, a gradual recovery during evening and a peak around midnight. These data indicate that the simultansous losses of all of the our different mechanisms of nonlinear control of heart rate during early morning, concomitent with the surge of symapathetic activity and reduction of vagal activity, may contribute to the increased incidence of cardiovascular events during morning hours.

• Journal of Trauma and Injury
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• 제26권3호
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• pp.226-228
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• 2013

Elderly patients with acute subdural hematomas have higher mortality and lower functional recovery rates compared with those of other head-injured patients. Early and widely surgical decompression and active intensive care represent the best way to assist these patients. However, abrupt decompression of the hematoma can lead to brain disruption and secondary ischemia in the brain surrounding the craniectomy site. Acute brain swelling and brain extrusion, which take place shortly after decompression, can lead to a catastrophic situation during the operation due to the impossibility of appropriate closure of the dura and scalp. To avoid the deleterious consequences of disruption of brain tissue, we have adopted multiple fenestrations of the dura in a mesh-like fashion and gradual release of subdural clots through the small dural openings that are left open. This is especially important in cases in which there are massive amount of subdural hematomas with small parenchymal lesion and severe midline shifts in elderly patients. Further clinical experiences should be conducted in a more selected series patients to estimate the impact of this technique on morbidity and mortality rates.

• 대한수의학회지
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• 제45권1호
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• pp.7-15
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• 2005

To elucidate the roles of phospho-IkB expression in the development and progression of EAE, we investigated the expression of phospho-IkB in the central nervous system (CNS) of rats during experimental autoimmune encephalomyelitis (EAE) using immunohistochemistry and Western blot analysis. In Western blot analysis, the increased expression of phospho-IkB went parallel to severity of EAE. The expression of phospho-IkB increased significantly at the peak stage of EAE followed by gradual decrease. Immunohistochemical studies showed that the phospho-IkB immunoreactivity was mainly expressed in inflammatory cells (macrophages, T cells) and glial cells (astrocytes, microglial cells) at the peak stage of EAE and disappeared at the recovery stage. These findings suggest that the phosphorylation of IkB is closely associated with autoimmune inflammation in the CNS and plays an important role in the initiation and progression of EAE.

• 한국동물학회지
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• 제10권1호
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• pp.17-20
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• 1967

The present experiment was perform to investigate the frequencies of chromosome aberration with special regard to the chromosome groups and the various time intervals after X-irradiation (60 r) in ormal human foetus cells grown in culture. The cytological preparations were prepared at every 5 through 30 hours after X-irradiation by the air-drying method. 1. The frequencies of chormosome aberration are on the whole decreased as tie elapses after irradiation and this is thought to be due to gradual recovery with time . However, a slight increase in frequencies is observed at 25 and 30 hours after irradiation respectively. This shows that the cells at the these periods are more sensitivity to X-irradation , and those cells are thought to be at G$_2$ and late S stage at the time of irradiation respectively, so t is evident that G$_2$ and late S stages a the time of irradiation respectively , so it is evident that G$_2$ and late S stages are more sensitive to X-irradiation than any other stages. 2. The frequencies of chormosome aberration are decreased in descending order of chormosome group number. The differences among these frequencies are highly significant statistically . Therefore it can be concluded that there is a highly significant difference in radiosensitivity among chromosome groups. that is, the chromosomes of the group A are the most radiosensitive , followed by B, C, D ,E and G in descending order.

• 항공우주의학회지
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• 제31권1호
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• pp.21-23
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• 2021

Purpose: Human papillomavirus (HPV) vaccination schedule is recommended by Strategic Advisory Group of Experts on Immunization of World Health Organization to achieve high efficacy and immunogenicity. However, the patients often cannot keep up their schedule for several reasons. Methods: Monthly numbers of visitors for HPV vaccination between 2019 and 2021 were analyzed to measure the impact of coronavirus disease-19 (COVID-19) outbreak which was the main cause of this delay. Results: In February 2020, the number of foreign patients vaccinated with HPV was dropped suddenly due to COVID-19. Prior to this impact, the average patients per month for HPV vaccination was 160 (95% confidence interval [CI]: 143-176). It was then 30 (95% CI: 20-40). However recent trends show a gradual recovery. Conclusion: If a woman is pregnant after starting the HPV vaccine series, the reminder doses should be delayed until she is no longer pregnant. If this series is interrupted for any length of time, it can be resumed without restarting the series. HPV vaccine series need to be administered with a minimum interval of 14 days before or after administration of COVID-19 vaccines.

• 대한의생명과학회지
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• 제28권4호
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• pp.211-222
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• 2022

After more than two years of efforts to end the corona pandemic, a gradual recovery is starting in countries with high vaccination rates. Easing public health policies for a full-fledged post-corona era, such as lifting the mandatory use of outdoor mask and quarantine measures in entry have been considered in Korea. However, the continuous emergence of new variants of SARS-CoV-2 and limitations in vaccine efficacy still remain challenging. Fortunately, T cells and memory T cells, which are key components of adaptive immunity appear to contribute substantially in COVID-19 control. SARS-CoV-2 specific CD4⁺/CD8⁺ T cells are induced by natural infection or vaccination, and rapid induction and activation of T cells is mainly associated with viral clearance and attenuated clinical severity. In addition, T cell responses induced by recognition of a wide range of epitopes were minimally affected and conserved against the highly infectious subsets of omicron variants. Polyfunctional SARS-CoV-2 specific T cell memory including stem cell-like memory T cells were also developed in COVID-19 convalescent patients, suggesting long lasting protective T cell immunity. Thus, a robust T-cell immune response appears to serve as a reliable and long-term component of host protection in the context of reduced efficacy of humoral immunity and persistent mutations and/or immune escape.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권3호
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• pp.276-280
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• 2011

BSSRO (bilateral sagittal split ramus osteotomy) is an effective surgical method for maxillofacial deformities. Rigid fixation using a plate and screws can stabilize bony segments and induce early mouth opening. Though this procedure has a low complication rate, normal function and esthetic recovery is achieved through proper and early management of the complications. Complications consisting of temporomandibular disorders, sensory disturbances due to inferior alveolar nerve damage, open bite, malunion or nonunion, and facial nerve palsy occur, but these rarely develop. Facial nerve palsy causes the muscles involved in facial expression to depress, which results in ocular dryness or retinal damage. When facial nerve palsy develops, early management involving steroid medication and physical therapy is effective. In the case of severe damage, surgical intervention should be considered. A 20-year-male patient came to the oral and maxillofacial surgery department for orthognathic surgery. The mandible was set back by BSSRO under general anesthesia. Facial nerve palsy was observed on the left side of the face: steroid and vitamins were administered early and physical therapy was performed daily. These forms of management can aid in function and allow for gradual esthetic recovery. Presumed causes were excessive soft tissue retraction or soft tissue injury by the osteotome at the horizontal osteotomy of the ramus. Careful dissection, retraction and a precise osteotomy are needed for protection of the facial nerve. If nerve damage is observed, early management can help in the recovery of facial nerve function and esthetics.

• 치과방사선
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• 제20권2호
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• pp.171-182
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• 1990

The purpose of this study was to investigate the effects of irradiation on the striated duct cells of the rat submandibular gland ductal tissues which control the characteristics of saliva. For this study, the experimental group was composed of 36 irradiated Sprague Dawley strain rats divided into 8 subgroups 1 hour, 2 hours, 3 hours, 6 hours, 12 hours, 24 hours, 48 hours, 72 hours after irradiation. 4 non-irradiated rats were used as the control group. The experimental animals were singly irradiated with a dose of 18Gy gamma ray to their head and neck region by the Co-6- teletherapy unit and sacrificed after each experimental duration. The specimens were examined with a light microscope with an H-E stain and with a trans- mission electron microscope. The results of this study were as follows. In the light micrograph, a severe atrophic change occurred in the striated duct cells at 2hours after irradiation and gradual recovery occurred from 6 hours after irradiation. 2. The nuclear chromosomes of the striated duct cells were changed granular at 2 hours after irradiation. Recovery was observed at 6 hours after irradiation. Nuclear bodies were also observed from 3 hours after irradiation. 3. The mitochondria of the striated duct cells had indistinct cristae at 2 hours after irradiation, and were degenerated or swollen at 3 hours after irradiation. They recovered, however, from 6 hours, with an increasing number at 48 hours and a regular arrangement was observed at 72 hours after irradiation. 4. The microvilli showed atrophic changes at 2 hours after irradiation and were almost lost at 3 hours after irradiation. They were observed again from 48 hours after irradiation. 5. The rough endoplasmic reticulum and golgi body were not apparent at 1 hour after irradiation and were dilated with degeneration 2 hours after, but intact rough endoplasmic reticulum were observed from 3 hours after irradiation and developed well at 24 hours after irradiation. By the result of this study, showing a mild change in the functional morphology of the salivary striated duct cells immediately following irradiation, it is considered that the many complications which occur after radiation therapy, will disappear in time with the histological and the functional recovery of the glandular tissues.

• 대한치과교정학회지
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• 제20권1호
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• pp.23-45
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• 1990

It is the aim of this study to determine the effects of facial denervation on physiological properties of facial muscles and facial bones in growing rabbits. Experimental animals of fifty two Oryctolagus cuniculus rabbits were employed. Unilateral dissection of facial nerve was carried out on twelve rabbits, bilateral dissection of facial nerve was made on another twelve rabbits and the other twenty rabbits were on unilateral dissection of facial nerve for the histochemical analyses. Six rabbits on the bilateral surgical sham operations and six rabbits of non-intervention served the control groups. EMG records of the orbicularis oris, buccinator and masseter muscles as well as lateral and dorsoventral cephalometric films were taken and analyzed at 0, 1, 2, 5 and 8 weeks respectively. The orbicularis oris, buccinator and masseter muscles of both sides were removed from the animals of the histochemistry group and muscle fibers were classified on the basis of histochemical staining for $\alpha$-GPD, NADH-D and myosin ATPase. EMG activities of orbicularis oris and buccinator muscles were vanished immediately after denervation. Recovery of activities were detected one week after denervation in buccinator and five weeks in orbicularis oris muscles. Histochemical properties of masseter muscles remained as fast glycolytic through the experimental period. Orbicularis oris muscle fibers showed the gradual diminution of size and ratio of the slow oxidative fibers accompanied with atrophy, phagocytosis and vacuolation as well as the augmentation of fast oxidative glycolytic fibers. The buccinator muscle manifested the augmentation of fast oxidative glycolytic fibers at five weeks of experiment. Visual changes in morphology of craniofacial area were not evident, however it variety of subtle changes were apparent from statistical analysis of cephalometric measurements. It is concluded facial nerve regulates the physiological properties of facial muscles and interrelation between the function of the facial muscles and changes of facial bones would be in some degrees.

• 대한골관절종양학회지
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• 제5권1호
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• pp.56-62
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• 1999

Purpose : This study was conducted to analyze the clinical materials and treatment results of 13 cases of subungual exostosis. Materials and Methods : Thirteen subungual exostoses of the foot treated from January 1991 to December 1997 were studied. We analyzed the clinical data and results of treatment to identify the clinical characteristics of this disease. We investigated the location, shape and relation of exostosis to phalanx with simple x-ray of the foot to identify the radiological characteristics. All the cases were sent to pathologic examination after resection to determine the pathological characteristics. Results : The results of physical examination on presentation were various. Most cases were located at the dorsomedial side of the distal phalanx and were involved in the toe nail. Eleven cases were located at great toes and one each at the 2nd and 3rd toe. Causes of exostosis were not clear, but 2 cases were related to trauma. For the type of exostosis, 7 cases were sessile and 6 were stalk type. On histologic examination, 9 cases showed a cartilaginous portion with overlying proliferating fibrous tissue and underlying bone formation. There was a gradual maturation of spindle cell proliferation from cartilage to cancellous bone. The cartilage was moderately cellular with some pleomorphism, but true anaplasia was not present. Conclusion : The clinical presentation and findings of simple x-rays were most helpful in diagnosing subungual exostosis. Complete excision of the mass achieved complete relief of symptoms and recovery without recurrence in all cases.