• The Korean Journal of Pharmacology
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• v.31 no.1 s.57
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• pp.27-37
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• 1995

In anesthetized rats, we examined the possibility that endothelium-derived relaxing factor (EDRF) or nitric oxide (NO) released in response to cholinergic mechanism may contribute to the reflex autoregulation of cerebral blood flow. Suffusion with mock cerebrospinal fluid (CSF), containing acetylcholine (ACh, $10^{-9}{\sim}10^{-6}M$) evoked concentration-dependent vasodilatation of the resting pial artery (mean, $19.3{\pm}1.7{\mu}m$, n=36), which was significantly inhibited not only by $N{\omega}$-nitro-L-arginine (L-NNA, $10^{-5}M$) but also by methylene blue ($10^{-6}M$) and oxyhemoglobin ($10^{-6}M$). The muscarinic receptors in the endothelium of pial artery implicated in the release of EDRF were considered to be $M_1\;and\;M_3$ subtypes. When suffused with mock CSF containing L-arginine it caused a transient vasodilatation, which was strongly inhibited by LY 83583 ($10^{-5}M$), but not by L-NNA ($10^{-5}M$). Additionally, both ACh- and L-arginine-induced vasodilation were significantly inhibited by glibenclamide, a specific ATP-sensitive $K^+$ channel blocker. On the other hand, changes in pial arterial diameter were plotted as a function of changes in systemic arterial blood pressure. The slopes of regression lines for vasodilation and vasoconstriction were not affected by pretreatment with $10^{-5}M$ L-NNA, but significantly reduced by $3{\times}10^{-6}M$ glibenclamide. Thus it is suggested that the reflex vasodilation of rat pial arteries in response to a transient hypotension is not mediated by EDRF (NO).

• Journal of Biomedical Engineering Research
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• v.22 no.5
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• pp.403-412
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• 2001

The Present study analyzed the pressure-flow characteristics of a Korean shunt valve. Changes in the characteristic currie depending on the design parameters were also investigated. The Korean shunt valve used in the present study was constant pressure type and our analyses were validated through experiments. We applied fluid-structure interaction to solve the flow dynamic Problem because the small diaphragm in the valve was made from flexible silicone elastomers. Considering the material nonlinearity of the hyper-elastic material. the Mooney-Rivlin approximation was employed. The results of the numerical analyses were close to the experimental results The major Pressure drop was observed to happen in the small diaphragm. The slope of the pressure-flow characteristic curve was computed to be 0.37mm$H_2O$.hr/cc, which was similar to the average value of commercial shunt valves. 0.40mm$H_2O$.hr/cc. Therefore. our valves analyzed in the Present study showed a Proper Pressure control characteristics of the constant pressure type shunt valves. The opening pressure could be controlled by adjusting the amount of predeflection of the valve diaphragm. In order to obtain opening pressures of 25mm$H_2O$ and 80mm$H_2O$, respectively, and the required predeflection was found to be 10.2$\mu$m and 35.3$\mu$m. The flow orifice size was found to be within 10$\mu$m during valve operation Therefore, Precision design and manufacturing techniques are necessary for successful operations of the shunt valve. The study indicated the amount of predeflection as well as the magnitude of corner rounding of the diaphragm edge are important design parameters to influence the slope of the pressure-flow characteristic curve.

• Applied Microscopy
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• v.32 no.4
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• pp.377-383
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• 2002

We have detected the murine zinc transporter, ZnT3, and zinc ions in the mouse choroid plexus by immunocytochemistry (ICC) and zinc selenium autometallography ($ZnSe^{AMG}$), respectively. BALB/c mice served as experimental animals. Routine floating ABC immunocytochemical procedures were used for the ZnT3 immunocytochemistry, and the mice were injected intraperitoneally (i.p.) with sodium selenide (10 mg/kg) for the zinc selenium autometallography. The choroid plexus showed weak immunoreactivity (Ir) for ZnT3. At high magnification, ZnT3-Ir was seen to be located in the choroid epithelium and the connective tissue of the capillaries. At the EM level, a high electron density of ZnT3-immunoreactivity was restricted to vesicle membranes as well as microvilli in the apical membrane. In contrast, immunostaining of ZnT3 was completely absent in the basolateral plasma membrane and other cell organelles. After silver enhancement, fine $ZnSe^{AMG}$ grains were observed in both the epithelial and endothelial cells of the choroid plexus. Few $ZnSe^{AMG}$ grains present in the cell bodies of the choroid epithelial cells were located in multivesicular bodies. It is striking that very many $ZnSe^{AMG}$ grains were observed in the endothelial cells of the capillaries. These findings establish the choroid plexus as a non-neuronal pool of zinc ions in the brain, although the functional significance of this pool is not clear. The choroid epithelium, however, may play an important role in the transportation of zinc between the CSF and brain tissue.

• Parasites, Hosts and Diseases
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• v.30 no.3
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• pp.209-218
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• 1992

When cystic fluid of Taenia solium metacestodes (CF) was filtrated through Sephacryl S-300 Superfine, major proteins were in fractions III add IV Major protein in fraction III was Band C protein of 150 kDa and that in fraction IV was Band N protein (Choi et of., 1990). When CF was electrophoresed in 0.9% agarose gel and reacted with anti-CF rabbit serum (RACF), two main bands, a long outer and a short inner band, were precipitated, together with 8 minor bands. RACF reacted with fraction III forming the long outer band whereas RACF formed the short infer band with fraction IV in immunoelectrophoresis (IEP) The long outer precipitin band of CF fraction III was similar to antigen B in hydatid fluid (HF) of Oriol et at. (1971), while the short inner band of CF fraction IV was similar to HF antigen 5 of Caption et at. (1967) . When HF was reacted with RACF, the short inner band was immunoprecipitated without forming the long outer band. Common antigenicity between CF and HF seemed to exist in fraction IV rather than in fraction III of CF. Patient sera of neurocysticercosis reacted more frequently with fraction III than with fraction IV.

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.340-343
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• 2006

A 10-year-old, intact female Beagle dog was presented for examination of acute onset of right-sided head tilt and moderate ataxia. Clinical signs were acutely presented 12 days ago and had been progressively alleviated until the admission day. The dog was bright, alert, and responsive. On neurological examinations, mild head tilt to the right and mild ataxia were noted, thus vestibular disorders were suspected. Central vestibular disease was ruled out based on the clinical signs, magnetic resonance imaging(MRI), and cerebrospinal fluid(CSF) analysis. Otoscopic examination showed that the tympanic membranes were intact and normal in appearance. On radiographic and MR examinations, abnormalities were not found in the tympanic bulla and the petrous portion of the temporal bone. Hypothyroidism was ruled out by thyroid-stimulation hormone(TSH) stimulation test. Clinical signs were completely disappeared at 2 weeks after discharge without any therapy. Thus, the dog was definitively diagnosed as idiopathic vestibular disease based on the clinical signs, excluding other causes of vestibular dysfunction, and the alleviation of clinical signs with time.

• Journal of Chest Surgery
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• v.37 no.9
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• pp.774-780
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• 2004

Although traumatic thoracic aortic rupture is potentially a fatal condition requiring surgical attention, the presence of concomitant injury involving other parts of the body may greatly increase the risk of cardio-pulmonary bypass. We report our experience of treating associated injuries prior to the thoracic aortic rupture in these patients. Material and Method: From 1997 to 2003, the medical records of 24 traumatic aortic rupture patients were retrospectively reviewed and checked for the presence of associated injury, surgical method, postoperative course, and complications. Surgical technique comprised thoracotomy with proximal anastomosis under deep hypothermic circulatory arrest followed by side arm perfusion to reestablish cerebral circulation. CSF drainage was performed to prevent lower extremity paraplegia. Result： Major concomitant injuries (n=83) were noted in all of the reviewed patients, Of these, there were 49 thoracic injuries, 18 musculoskeletal injuries, and 13 abdominal injuries, Operations for associated injuries (n=16) were performed in 12 patients on mean 7.6$\pm$12.6 days following the injury. The diagnosis of aortic rupture at the time of injury was detected in only 18 patients. Delayed surgery of the thoracic aorta was performed on average 695$\pm$1350 days after injury and there were no deaths or progression of rupture in any of these patients during the observation period. There were no operative deaths and no major postoperative complications. Conclusion: Treating concomitant major injuries prior to the aortic injury in traumatic aortic rupture may reduce surgical mortality and morbidity.

• Radiation Oncology Journal
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• v.8 no.2
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• pp.169-176
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• 1990

Radiotherapy result was analyzed in 23 children with retinoblastoma treated in Seoul National University Hospital from 1980 to 1987. Three ($17\%$) had bilateral tumor at diagnosis. Among 20 children with unilateral retinoblastoma 13 children got radiotherapy after enucleation, 2 were treated with radiotherapy alone, and 5 were delivered with radiotherapy after relapse. Of 15 non-recurrent unilateral tumors, there were 5 stage II children, 8 stage III, and 2 stage IV by staging system proposed by St. Jude Children's Research Hospital. Chemotherapy was combined when resection margin of the optic nerve was positive or when malignant cell was found in CSF. Of 12 children who completed radiotherapy, local or distant failure was not found but 2 cases of relapse at the contralateral retina were observed. Their 5 year survival rate was $82.2\%$. Another case of contralateral relapse was detected in children who was treated with radiotherapy alone. Thus overall frequency of the bilateral disease was $33\%$. Prognosis of recurrent tumors were so poor that no cases of CR was obtained and that 3 year survival rate was $20\%$. Two of 3 bilateral cases at diagnosis were in NED status. Complication were sunken orbit only. Result of radiotherapy was so good in early stage or small bulk tumor that treatment delay after diagnosis must not be allowed.

• Radiation Oncology Journal
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• v.6 no.2
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• pp.177-182
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• 1988

A retrospective analysis was peformed on 23 patients with pineal region tumors treated with radiation from 1979 through 1985 at the Department of Therapeutic Radiology, Seoul National University Hospital. Histologic confirmation was done in only one case by surgical removal, and in the remaining 22 patients, the diagnosis was based on clinical and radiological findings. The radiation volume was the primary tumor site in 1 case, whole brain in 14 cases, and the whole craniospinal axis En 8 cases. The overall 5 year survival was $71.5\%$. The 5 year survival was $69.3\%$ for whole brain treated group and $73.3\%$ for craniospinal axis treated group. The survival for the two groups did not differ significantly. In two cases sites of recurrence were detected, one in supratentorial area, and the other in the lung. The results from this retrospective analysis and the review of other reports indicate that routine use of prophylactic spinal irradiation is not warranted in pineal region tumor, and the craniospinal irradiation is recommended in cases with high risk for subarachnoid seeding such as positive CSF cytology, surgical removal or biopsy.

• Parasites, Hosts and Diseases
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• v.26 no.1
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• pp.33-38
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• 1988

A coiled nematode, which was removed surgically from a Thai woman, was consulted to the authors in July, 1987. She was known to surfer from meningoencephalitis since she was in Thailand. Numerous eosinophils were detected from her CSF. The worm was 12.3mm long and 0.9mm wide. It had a head bulb beset with eight rows of spines, a cervical constriction, esophagus, cervical sacs, dark intestine and testis, Cuticle of anterior half of the worm was covered with numerous spines. The spines at anterior part was stout and had 3∼4 tips, but they became slender, shorter, single tipped and sparser and finally they disappeared posteriorly. Cuticular spines reappeared at tail which had 4 pairs of pedunculated papillae. By above morphological characteristics, the worm was identified as an adult male of Gnathostcma spinigerum. The Present case is the first authentic case of imported intracranial gnathostomiasis in Korea, although clinical informations of the case were obtained limitedly.

• Investigative Magnetic Resonance Imaging
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• v.5 no.2
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• pp.116-122
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• 2001

Purpose : To find sensitivity of MRI imaging methods to slow flow phantom study was performed with conventional Spin-Echo, gradient echo based Phase Contrast, fast GRASS, and heavily T2-weighted Fast Spin Echo pulse sequences. Materials and Methods : A siphon driven flow phantom was constructed with a ventriculo-peritoneal shunt catheter and a GE phantom to achieve continuous variable flow. Four different pulse sequences including Spin-Echo, Phase Contrast, GRASS and Heavily T2-weighted Fast Spin Echo were evaluated to depict slow flow in the range from 0.08 ml/min to 1.7 ml/min and to compare signal intensities between static fluid and flowing fluid. Results : In the slow flow above 0.17 ml/min conventional Spin-Echo showed superior apparent contrast between static and flowing fluid while GRASS was more sensitive to the very slow flow below 0.17 ml/mim. It was not accurate to calculate flow and velocity below 0.1 ml/min with a modified PC imaging. Conclusion : Four different MR pulse sequences demonstrated different sensitivity to the range of slow flow from 0.08 ml/min to 1.7 ml/min. This finding may be clinically useful to measure CSF shunt flow or detecting CSF collection and thrombosis.