• Journal of Korean Neurosurgical Society
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• v.29 no.10
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• pp.1289-1295
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• 2000

Purpose : Recent evidence suggests a possible role for leukocytes in brain injury following ischemia and reperfusion. This study examined the temporal profile of ischemic tissue damage and leukocyte response after transient middle cerebral artery occlusion(MCAO) with reperfusion in the mouse. Methods : Focal cerebral ischemia was made by temporary occluding of the stem of the proximal MCA. Two groups of the mouse were investigated : (1) sham operation(n＝10), and (2)those having the arterial occlusion released after 90 minute(n＝20). By 4 hours(n＝10) and 24 hours(n＝10) after the onset of ischemia-reperfusion, fluorescein videoimages were under-taken in the pial venules of the mouse using a closed cranial window technique. Rhodamine 6G was administered as a $80-100{\mu}l/min$ i.v. loading dose and a $30-40{\mu}l/min$ i.v. maintenance dose in saline to selectively label circulating leukocytes. Neuropathologic evaluation for brain injury was accomplished using the histochemical stain 2,3,5-triphen-yltetrazolium chloride(TTC) and hematoxylin and eosin(H & E) stain. Results : The mean number of adherent leukocytes to cerebral venules in the 90 minutes MCAO and 24 hours reperfusion group were $306{\pm}24$ compared with $72{\pm}8$ in the sham operation group. In the TTC staining method, the cortical infarct affecting 34.8% of hemispheric volume were created in all of animals (n＝10) undergoing 90 minute MCAO with 24 hours reperfusion, but the infarcted area were not found in the other(sham operation and 90 minute MCAO with 4 hours reperfusion)groups. In the H & E stain, the brain tissue following 90 minute MCAO with 4 hours reperfusion revealed only a pyknosis of the nuclei with shrunken cytoplasm, but infiltrated leukocytes were not observed. After 24 hours of reperfusion, a many leukocytes were infiltrated within parenchyma and blood vessles. Conclusions : These findings demonstrate the feasiblity of continous in vivo monitoring of leukocyte adherence in cerebral venules and suggest that reperfusion induced leukocyte adherence to venular endothelium may contribute to tissue injury following focal cerebral ischemia.

• Journal of radiological science and technology
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• v.35 no.2
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• pp.165-172
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• 2012

We investigated the vascular characteristics of tumors and normal tissue using perfusion CT in the rabbit brain tumor model. The VX2 carcinoma concentration of $1{\times}10^7$ cells/ml(0.1ml) was implanted in the brain of nine New Zealand white rabbits (weight: 2.4kg-3.0kg, mean: 2.6kg). The perfusion CT was scanned when the tumors were grown up to 5mm. The tumor volume and perfusion value were quantitatively analyzed by using commercial workstation (advantage windows workstation, AW, version 4.2, GE, USA). The mean volume of implanted tumors was $316{\pm}181mm^3$, and the biggest and smallest volumes of tumor were 497 $mm^3$ and 195 $mm^3$, respectively. All the implanted tumors in rabbits are single-nodular tumors, and intracranial metastasis was not observed. In the perfusion CT, cerebral blood volume (CBV) were $74.40{\pm}9.63$, $16.08{\pm}0.64$, $15.24{\pm}3.23$ ml/100g in the tumor core, ipsilateral normal brain, and contralateral normal brain, respectively ($p{\leqq}0.05$). In the cerebral blood flow (CBF), there were significant differences between the tumor core and both normal brains ($p{\leqq}0.05$), but no significant differences between ipsilateral and contralateral normal brains ($962.91{\pm}75.96$ vs. $357.82{\pm}12.82$ vs. $323.19{\pm}83.24$ ml/100g/min). In the mean transit time (MTT), there were significant differences between the tumor core and both normal brains ($p{\leqq}0.05$), but no significant differences between ipsilateral and contralateral normal brains ($4.37{\pm}0.19$ vs. $3.02{\pm}0.41$ vs. $2.86{\pm}0.22$ sec). In the permeability surface (PS), there were significant differences among the tumor core, ipsilateral and contralateral normal brains ($47.23{\pm}25.45$ vs. $14.54{\pm}1.60$ vs. $6.81{\pm}4.20$ ml/100g/min)($p{\leqq}0.05$). In the time to peak (TTP) were no significant differences among the tumor core, ipsilateral and contralateral normal brains. In the positive enhancement integral (PEI), there were significant differences among the tumor core, ipsilateral and contralateral brains ($61.56{\pm}16.07$ vs. $12.58{\pm}2.61$ vs. $8.26{\pm}5.55$ ml/100g). ($p{\leqq}0.05$). In the maximum slope of increase (MSI), there were significant differences between the tumor core and both normal brain($p{\leqq}0.05$), but no significant differences between ipsilateral and contralateral normal brains ($13.18{\pm}2.81$ vs. $6.99{\pm}1.73$ vs. $6.41{\pm}1.39$ HU/sec). Additionally, in the maximum slope of decrease (MSD), there were significant differences between the tumor core and contralateral normal brain($p{\leqq}0.05$), but no significant differences between the tumor core and ipsilateral normal brain($4.02{\pm}1.37$ vs. $4.66{\pm}0.83$ vs. $6.47{\pm}1.53$ HU/sec). In conclusion, the VX2 tumors were implanted in the rabbit brain successfully, and stereotactic inoculation method make single-nodular type of tumor that was no metastasis in intracranial, suitable for comparative study between tumors and normal tissues. Therefore, perfusion CT would be a useful diagnostic tool capable of reflecting the vascularity of the tumors.

• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.237-243
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• 1999

We conducted this study to find the optimal correction factor(${\alpha}$) of Lassen's linearization algorithm which has been applied for correction of flow-limited uptake at a high flow range in $^{99m}Tc$ d,l-hexamethylpropy leneamine oxime(HMPAO) and $^{99m}Tc$ ethyl cysteinate dimer(ECD). Ten patients with chronic cerebral infarction were involved in this study. We obtained the corrected $^{99m}Tc$ HMPAO and $^{99m}Tc$-ECD brain SPECT(single photon emission computed tomography) using the algorithm with ${\alpha}$ values that varied from 0.1 to 10 and compared the results with regional cerebral blood flow determined by positron emission tomography (PET-rCBF). The multi-modal volume registration by maximization of mutual information was used for matching between PET-rCBF and SPECT images. The highest correlation coefficient between $^{99m}Tc$-HMPAO and $^{99m}Tc$-ECD brain uptake and PET-rCBF was revealed at ${\alpha}$ 1.4 and 2.1, respectively. We concluded that the ${\alpha}$ values of Lassen's linearization algorithm for $^{99m}Tc$-HMPAO and $^{99m}Tc$-ECD brain SPECT images were 1.4 and 2.1, respectively to indicate cerebral blood flow with comparison of PET-rCBF.

• Nutrition Research and Practice
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• v.4 no.3
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• pp.196-202
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• 2010

To investigate the neuroprotective effects of bovine colostrums (BC), we evaluate the ability of consuming BC after focal brain ischemia/reperfusion injury rat model to reduce serum cytokine levels and infarct volume, and improve neurological outcome. Sprague-Dawley rats were randomly divided into 4 groups; one sham operation and three experimental groups. In the experimental groups, MCA occlusion (2 h) and subsequent reperfusion (O/R) were induced with regional cerebral blood flow monitoring. One hour after MCAO/R and once daily during the experiment, the experimental group received BC while the other groups received 0.9% saline or low fat milk (LFM) orally. Seven days later, serum pro-inflammatory cytokine (IL-$1{\beta}$, IL-6, and TNF-${\alpha}$) and anti-inflammatory cytokine (IL-10) levels were assessed. Also, the infarct volume was assessed by using a computerized image analysis system. Behavioral function was also assessed using a modified neurologic severity score and corner turn test during the experiment. Rats receiving BC after focal brain I/R showed a significant reduction (-26%/-22%) in infarct volume compared to LFM/saline rats, respectively (P < 0.05). Serum IL-$1{\beta}$, IL-6, and TNF-${\alpha}$ levels were decreased significantly in rats receiving BC compared to LFM/saline rats (P < 0.05). In behavioral tests, daily BC intake showed consistent and significant improvement of neurological deficits for 7 days after MCAO/R. BC ingestion after focal brain ischemia/reperfusion injury may prevent brain injury by reducing serum pro-inflammatory cytokine levels and brain infarct volume in a rat model.

• Journal of Gastric Cancer
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• v.10 no.4
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• pp.241-246
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• 2010

Purpose: Laparoscopy-assisted gastrectomy (LAG) has become a technically feasible and safe procedure for early gastric cancer treatment. LAG is being increasingly performed in many centers; however, there have been few reports regarding LAG at low-volume centers. The aim of this study was to report our early experience with LAG in patients with gastric cancer at a low-volume center. Materials and Methods: The clinicopathologic data and surgical outcomes of 39 patients who underwent LAG for gastric cancer between April 2007 and March 2010 were retrospectively reviewed. Results: The mean age was 68.3 years. Thirty-one patients had medical co-morbidities. The mean patient ASA score was 2.0. Among the 39 patients, 4 patients underwent total gastrectomy and 35 patients underwent distal gastrectomy. The mean blood loss was 145.4 ml and the mean operative time was 259.4 minutes. The mean time-to-first flatus, first oral intake, and the postoperative hospital stay was 2.8, 3.1, and 9.3 days, respectively. The 30-day mortality rate was 0%. Postoperative complications developed in 9 patients, as follows: anastomotic leakage, 1; wound infection, 1; gastric stasis, 2; postoperative ileus, 1; pneumonia, 1; cerebral infarction, 1; chronic renal failure, 1; and postoperative psychosis, 1. Conclusions: LAG is technically feasible and can be performed safely at a low-volume center, but an experienced surgical team and careful patient selection are necessary. Furthermore, for early mastery of the learning curve for LAG, surgeons need education and training in addition to an accumulation of cases.

• Progress in Medical Physics
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• v.21 no.2
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• pp.153-164
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• 2010

To determine the clinical target volumes considering vascularity and cellularity of tumors, the software was developed for mapping of the analyzed biological clinical target volumes on anatomical images using regional cerebral blood volume (rCBV) maps and apparent diffusion coefficient (ADC) maps. The program provides the functions for integrated registrations using mutual information, affine transform and non-rigid registration. The registration accuracy is evaluated by the calculation of the overlapped ratio of segmented bone regions and average distance difference of contours between reference and registered images. The performance of the developed software was tested using multimodal images of a patient who has the residual tumor of high grade gliomas. Registration accuracy of about 74% and average 2.3 mm distance difference were calculated by the evaluation method of bone segmentation and contour extraction. The registration accuracy can be improved as higher as 4% by the manual adjustment functions. Advanced MR images are analyzed using color maps for rCBV maps and quantitative calculation based on region of interest (ROI) for ADC maps. Then, multi-parameters on the same voxels are plotted on plane and constitute the multi-functional parametric maps of which x and y axis representing rCBV and ADC values. According to the distributions of functional parameters, tumor regions showing the higher vascularity and cellularity are categorized according to the criteria corresponding malignant gliomas. Determined volumes reflecting pathological and physiological characteristics of tumors are marked on anatomical images. By applying the multi-functional images, errors arising from using one type of image would be reduced and local regions representing higher probability as tumor cells would be determined for radiation treatment plan. Biological tumor characteristics can be expressed using image registration and multi-functional parametric maps in the developed software. The software can be considered to delineate clinical target volumes using advanced MR images with anatomical images.

• Progress in Medical Physics
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• v.18 no.3
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• pp.149-160
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• 2007

Recent advent of 64-multidetctor (MD) CT enables more coverage of Z-axis in the perfusion imaging. The purpose of this study was to evaluate the clinical usefulness of perfusion CT by using 64-MD CT in detecting the lesion in patients with acute stroke. The perfusion CT was performed by using 64-MD CT in 62 consecutive patients who were initially suspected to have subacute ischemic stroke symptoms during the period of recent 9 months. These patients had subacute stroke (n=62). CT scanning was conducted with Jog Mode which provided 16 imaging slices with 5 mm of slice thickness, and 8 cm of coverage in Z-axis. Scan interval was 1 seconds for each imaging slice and total 15 scans were repeated. After CT scanning, perfusion maps (CBV, CBF, MTT and TTP) were created at Extended Brilliance Workstation. The CBV and CBF maps showed that lesions were smaller images. While on the MTT and TTP map lesions were seen to be larger fifty-one were large than they appeared on these images. Two slices of perfusion maps obtained at the level of the basal ganglia were chosen to simulate conventional older perfusion CT with 8 cm of coverage in Z-axis. TTP and MTT maps may be clinically useful for evaluation of the penumbral zone in cases of aubacute cerebral ischemic stroke. The perfusion CT is useful in the assessment of acute stroke as an initial imaging modality.

• The Korea Journal of Herbology
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• v.32 no.1
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• pp.25-31
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• 2017

Objectives : Mori Radicis Cortex (MRC), the root epidermis of Morus alba L., has been traditionally used to treat lung-related diseases in Korean Medicine. The common of MRC is Mulberry bark Morus bark, and it's pharmaceutical properties and taste are known as sweet and cold, and it promotes urination and reduce edema by reducing heat from the lungs and soothe asthma. In the present study, anti-apoptotic mechanism of MRC in middle cerebral artery occlusion (MCAO) model in mice. Methods : Two-hundred grams of MRC was extracted with methanol at room temperature for 5 days, and this was repeated one time. After filtration, the methanol was removed using vacuum evaporator, then stored at $-20^{\circ}C$ until use. C57BL/6 male mice were housed in an environment with controlled humidity, temperature, and light cycle. In order to determine beneficial effects of MRC on ischemia induced brain damage, infarct volume, neurological deficit scores, activities of several apoptosis-related proteins such as caspase-8, -9, Bcl-xL in MCAO-induced brains of mice were analyzed. Mice in MRC-treated groups were orally administered 30, 100, or 300 mg/kg of body weight for three consecutive days before commencing the MCAO procedure. Results : Pre-treatment of MRC significantly reduced infarct volume in MCAO subjected mice applied with 300 mg/kg of MRC methanol extract, and MRC effectively inhibited Bcl-xL reduction and caspase-9 activation caused by MCAO-induced brain damage. Conclusions : MRC showed neuro-protective effects by regulating apoptosis-related protein signals, and it can be a potential candidate for the therapy of ischemia-induced brain damage.

• Korean Journal of Radiology
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• v.23 no.4
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• pp.446-454
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• 2022

Objective: To evaluate whether hyperoxia-induced ΔR₁ (hyperO₂ΔR₁) can accurately identify histological infarction in an acute cerebral stroke model. Materials and Methods: In 18 rats, MRI parameters, including hyperO₂ΔR₁, apparent diffusion coefficient (ADC), cerebral blood flow and volume, and ¹⁸F-fluorodeoxyglucose uptake on PET were measured 2.5, 4.5, and 6.5 hours after a 60-minutes occlusion of the right middle cerebral artery. Histological examination of the brain was performed immediately following the imaging studies. MRI and PET images were co-registered with digitized histological images. The ipsilateral hemisphere was divided into histological infarct (histological cell death), non-infarct ischemic (no cell death but ADC decrease), and nonischemic (no cell death or ADC decrease) areas for comparisons of imaging parameters. The levels of hyperO₂ΔR₁ and ADC were measured voxel-wise from the infarct core to the non-ischemic region. The correlation between areas of hyperO₂ΔR₁-derived infarction and histological cell death was evaluated. Results: HyperO₂ΔR₁ increased only in the infarct area (p ≤ 0.046) compared to the other areas. ADC decreased stepwise from non-ischemic to infarct areas (p = 0.002 at all time points). The other parameters did not show consistent differences among the three areas across the three time points. HyperO₂ΔR₁ sharply declined from the core to the border of the infarct areas, whereas there was no change within the non-infarct areas. A hyperO₂ΔR₁ value of 0.04 s^-1 was considered the criterion to identify histological infarction. ADC increased gradually from the infarct core to the periphery, without a pronounced difference at the border between the infarct and non-infarct areas. Areas of hyperO₂ΔR₁ higher than 0.04 s^-1 on MRI were strongly positively correlated with histological cell death (r = 0.862; p < 0.001). Conclusion: HyperO₂ΔR₁ may be used as an accurate and early (2.5 hours after onset) indicator of histological infarction in acute stroke.

• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.2
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• pp.179-186
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• 2007

The decrease of masticatory function caused by tooth loss leads to a decrease of cerebral blood flow volume resulting in impairment of cognitive function and learning memory disorder. However, the reduced mastication-mediated morphological alteration in the central nervous system (CNS) responsible for senile deficit of cognition, learning and memory has not been well documented. In this study, the effect of the loss of the molar teeth (molarless condition) on the hippocampal expression of glial fibrillary acidic protein (GFAP) protein was studied by immunohistochemical techniques. The results were as follows : 1. The molarless mice showed a lower density of pyramidal cells in the cornu ammonis 1 (CA1) and dentate gyrus (DG) region of the hippocampus than control mice. 2. Immunohistochemical analysis showed that the molarless condition enhanced the time-dependent increase in the cell density and hypertrophy of GFAP immunoreactivity in the CA1 region of the hippocampus. The molarless condition enhanced an time-dependent decrease in the number of neurons in the hippocampal formation and the time-dependent increase in the number and hypertrophy of GFAP-labeled cells in the same region. The data suggest a possible link between reduced mastication and histological changes in hippocampal formation that may be one risk factor for senile impairment of cognitive function and spatial learning memory.