• Title/Summary/Keyword: blood flow distribution

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Drug interaction of Cimetidine and Rifampicin in normal Human subjects (시메티딘과 리팜피신의 상호작용)

  • Moon, Hong-Seob;Choi, In;Cho, Joon-Shik;Shin, Yong-Jun
    • Korean Journal of Clinical Pharmacy
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    • v.3 no.1
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    • pp.1-13
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    • 1993
  • The intraction between cimetidine and rifampicin was studied pharmacokinetically in normal human subjects. The serum level and the area under the serum concentration curve(AUC) of rifampicin administrated orally were elevated significantly by cimetidine. Volume of distribution, total clearance and elimination rate constant of rifampicin were reduced significanyly by cimetidine. Biological half-life of rifampicin was prolonged significantly by cimetidine. The mechanism of this results is probably related to the inhibition of rifampicin metabolism(deacetyl form) or reduction of blood flow in the liver. It is desirable that dosage regimen of rifampicin shoud be adjusted when combined with cimetidine in clinical pharmacy practice.

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Changes in Total Cerebral Blood Flow with Aging, Parenchymal Volume Changes, and Vascular Abnormalities: a Two-dimensional Phase-Contrast MRI Study (나이와 뇌실질부피 변화 및 혈관이상에 따른 총뇌혈류량 변화: 이차원 위상대조 자기공명영상을 이용한 연구)

  • Liu Haiying;Shin Tae-Beom;Youn Seong-Kuk;Oh Jong-Yong;Lee Young-Il;Choi Sun-Seob
    • Investigative Magnetic Resonance Imaging
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    • v.8 no.1
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    • pp.17-23
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    • 2004
  • Purpose : To evaluate changes in total cerebral blood flow (tCBF) with aging, parenchymal volume changes and vascular abnormalities, using 2 dimensional (D) phase-contrast magnetic resonance imaging (PC MRI). Materials and Methods : Routine brain MRI including T2 weighted image, time-of-flight (TOF) MR Angiography (MRA) and 2D PC MRI were performed in 73 individuals, including 12 volunteers. Normal subjects (12 volunteers, and 21 individuals with normal MRI and normal MRA) were classified into groups according to age (18-29, 30-49 and 50-66 years). For the group with abnormalities in brain MRIs, cerebral parenchymal volume changes were scored according to the T2 weighted images, and atherosclerotic changes were scored according to the MRA findings. Abnormal groups were classified into 4 groups: (i) mild reduction in volume, (ii) marked reduction in volume by parenchymal volume and atherosclerotic changes, and (iii) increased volume and (iv) Moya-moya disease. Volumetric flow was measured at the internal carotid artery (ICA) and vertebral artery bilaterally using the velocity-flow diagrams from PC MRI, and combined 4 vessel flows and tCBF were compared among all the groups. Results : The age-specific distribution of tCBFs in normal subjects were as follows: $12.0{\pm}2.1ml/sec$ in 18-29 years group, $11.8{\pm}1.9ml/sec$ in 30-49 years group, $10.9{\pm}2.2ml/sec$ in 50-66 years group. The distribution of tCBFs in the different subsets of the abnormal population were as follows: $9.5{\pm}2.5ml/sec$ in the group with mild reduction in volume, $7.6{\pm}2.0ml/sec$ in the group with marked reduction in volume, and $7.3{\pm}1.2ml/sec$ and $7.0{\pm}1.1ml/sec$ in the increased parenchymal volume and Moya-moya disease groups respectively. Conclusion : Total cerebral blood flow decreases with increasing age with a concomitant reduction in parenchymal volumes and increasing atherosclerotic changes. It is also reduced in the presence of increased parenchymal volume and Moya-moya disease.2D PC MRI can be used as a tool to evaluate tCBF with aging and in the presence of various conditions that can affect parenchymal volume and cerebral vasculature.

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The Clinical Analysis on 32 Cases of Dementia (치매환자(患者) 32례(例)에 대(對)한 임상적(臨床的) 고찰(考察))

  • Lee, Y.W.;Kang, H.J.;Cho, M.R.;Jin, C.S.;Hong, S.;Kim, J.S.
    • The Journal of Internal Korean Medicine
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    • v.19 no.1
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    • pp.301-317
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    • 1998
  • A clinical analysis was carried out for 32 patients who were treated in Dept. of Dong-shin Oriental Medicine Hospital from 10st January to 16st May in 1998 and ruled out as dememtia. The results were summarized as follows. 1. In the distribution of sex, female was more than male. And the age of seventies(17 cases, 53.125%) was highest in the frequency of age. 2. In the distribution of having history of drinking and smoking were each 4 cases(12.5%) and 7 cases(21.875%). 3. In the distribution of seasons, the ratio of spring and winter were each 16 cases(50.0%), 15 cases(46.875%), that of summer and fall were comparatively low. 4. In the period from onset to admission, the period within a week had 20 cases(62.5%) as top, and the most period of treatment was 2 and 3 weeks(28.125%). 5. The number of cases that had preceding disease was 35 cases(71.875%), a major portion of preceding diseases were hypertension, diabetes mellitus, stroke. 6. The most common symptom was disorientation(78.125%), and the next common symptom was motor desability(71.875%), and memory disturbance, verbal disturbance was each 59.375 and 47.1%. 7. In the distribution of the CT scan films, 15 cases(46.875%) showed cerebral infarction and that of another 5cases (15.625%) showed cerebral hemorrhage, that of another 2 cases(6.25%) showed brain atrophy. 8. In the lipid density of blood, T-Cholesterol, TG, HDL-Cholesterol, LDL- Cholesterol was within normal limit. 9. In the MMSE-K, the most score was from 16 point to 20 point, and second only was from 11 point to 15 point, and the next was from 6 point to 10 point. 10. In the Ischemic score, 20 cases(62.5%) was diagnosed as brain vascular type dementia, and mixed type dementia was 9 cases(28.125%), Alzheimer type dementia was 3 cases(9.375%). 11. The most used recipes were a sort of recipes to activate of flow the vital energy and the blood, to remove the phlegm(41 cases 33.9%), especially DODAMHOALHEL TANG (12 cases, 9.9%), ANSINCHUNGNOITANG (8 case, 6.6%) was the most used recipe. 12. In the judgement of efficacy, 17 cases(53.125%) showed excellent efficacy, 10 cases(31.25%) showed good efficacy, 5 cases(15.625%) showed no change and that according to MMSE-K, 4 case(18.18%) showed excellent efficacy, 15 cases(68.18%) showed good efficacy, 15 cases(68.18%) showed no change.

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Differential Distribution of miR-20a and miR-20b may Underly Metastatic Heterogeneity of Breast Cancers

  • Li, Jian-Yi;Zhang, Yang;Zhang, Wen-Hai;Jia, Shi;Kang, Ye;Zhu, Xiao-Yu
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.1901-1906
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    • 2012
  • Background: The discovery that microRNA (miRNA) regulates metastasis provide a principal molecular basis for tumor heterogeneity. A characteristic of solid tumors is their heterogenous distribution of blood vessels, with significant hypoxia occurring in regions (centers of tumor) of low blood flow. It is necessary to discover the mechanism of breast cancer metastasis in relation to the fact that there is a differential distribution of crucial microRNA in tumors from centers to edges. Methods: Breast tissues from 48 patients (32 patients with breast cancer) were classified into the high invasive and metastatic group (HIMG), low invasive and metastatic group (LIMG), and normal group. Samples were collected from both the centers and edges of all tumors. The first six specimens were detected by microRNA array, and the second ten specimens were detected by real-time qRT-PCR and Western blot analyses. Correlation analysis was performed between the miRNAs and target proteins. Results: The relative content of miR-20a and miR-20b was lower in the center of the tumor than at the edge in the LIMG, lower at the edge of the tumor than in the center in the HIMG, and lower in breast cancer tissues than in normal tissues. VEGF-A and HIF-1alpha mRNA levels were higher in the HIMG than in the LIMG, and levels were higher in both groups than in the normal group; there was no difference in mRNA levels between the edge and center of the tumor. VEGF-A and HIF-1alpha protein levels were higher in the HIMG than in the LIMG, and protein levels in both groups were higher than in the normal group; there was a significant difference in protein expression between the edge and center of the tumor. Correlation analysis showed that the key miRNAs (miR-20a and miR-20b) negatively correlated with the target proteins (VEGF-A and HIF-1alpha). Conclusions: Our data suggest that miR-20a and miR-20b are differentially distributed in breast cancer, while VEGF-A and HIF-1alpha mRNA had coincident distributions, and VEGF-A and HIF-1alpha proteins had uneven and opposing distributions to the miRNAs. It appears that one of the most important facets underlying metastatic heterogeneity is the differential distribution of miR-20a and miR-20b and their regulation of target proteins.

Computational Hemodynamics in the Intracranial Aneurysm Model (뇌동맥류 모델에 대한 혈류역학 해석)

  • Seo, Taewon;Byun, Jun Soo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.10
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    • pp.927-932
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    • 2013
  • The intracranial aneurysm model is extracted based on the Computed Tomography (CT) scan images. Computational fluid dynamics simulations were conducted under both steady and realistic flow conditions in ANSYS-FLUENT. The minimum wall shear stress in the intracranial aneurysm tended to occur in the aneurysmal region. The magnitude of wall shear stress along inner wall of the curvature in the right M1 segment of middle cerebral artery is approximately 20 times higher than that along both the proximal and distal walls. However, the magnitudes of the wall shear stress at the aneurysm region were considerably low. The blood flow has the complex distribution in the aneurysmal region during the systolic period. Complex helical flow patterns are observed inside the aneurysm. Through an analysis of the hemodynamic characteristics, one may predict the rupture of the cerebral aneurysms.

Changes in the Oral Microflora in Patients with Acute Myeloid Leukemia during the Period of Induction Therapy (항암 화학요법중인 급성 골수성 백혈병 환자의 구강내 세균변화에 관한 연구)

  • Byul-Hee Lee;Chong-Youl Kim
    • Journal of Oral Medicine and Pain
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    • v.18 no.1
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    • pp.73-82
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    • 1993
  • To investigate the changes in aerobic and facultative anaerobic oral microflora during remission-induction chemotherapy in patients with acute myeloid leukemia, 10 consecutive patients were studied during a period of 28 days. One day before, during and after the induction therapy, patients were given 10% Betadine solution for mouthrinses after breakfast and kept from eating and drinking. After 3 hours, paraffin-stimulated whole saliva was obtained for 2 minutes and transported to the laboratory. The samples were dispersed and homogenized by use of vortex mixer for 20 seconds. From these samples 10-fold serial dilutions (from 10-1 through 10-3) were prepared. Each dilution of 0.1 ml was plated on duplicate set of one nonselective medium (Blood agar) and four selective media (Sabourauds dextrose agar, Mannitol salt agar, Mac-Conkey agar, SF medium ) using applicator woods. All agar plate were incubated at 37$^{\circ}C$ for 48 hours. The total number of microorganisms was calculated and the percentage distribution of the various microorganisms from each specimen was drawn. 1. The salivary flow rate decreased by 66%, going from 5.38 ml/2min to 1.81 ml/2min over two days during the chemotherapy. 2. The total number of microorganisms in saliva increased by 22%, going from 4.88$\times$105/ml to 6.00$\times$105/ml over two days during the chemotherapy. 3. The salivary flow rate and the total number of microorganisms in saliva were recovered within 28 days after the chemotherapy. 4. The quantitative alteration in oral Enterobacteria, Enterococci, Staphylococci, Cndida during the chemotherapy had no statistical significance. 5. In saliva of the patients with acute myeloid leukemia who ahd intraoral ulcer, Enterobacteria was quantitatively predominent. Our study suggests that chemotherapy-induced transient xerostomia may induce acute oral infection. Consequently, the use of saliva substitute, the removal of intraoral infection source and the consistent oral hygiene care seem to be required to avoid the transmission of potential pathogenes in this group of patients.

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A Simple Design of an Imaging System for Accurate Spatial Mapping of Blood Oxygen Saturation Using a Single Element of Multi-wavelength LED (혈중 산소 포화도의 정확한 공간 매핑을 위한 다중 파장 LED 단일소자를 활용한 이미징 시스템 설계)

  • Jun Hwan Kim;Gi Yeon Yu;Ye Eun Song;Chan Yeong Yu;Yun Chae Jang;Riaz Muhammad;Kay Thwe Htun;Ahmed Ali;Seung Ho Choi
    • Journal of Biomedical Engineering Research
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    • v.44 no.6
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    • pp.450-464
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    • 2023
  • Pulse oximetry, a non-invasive technique for evaluating blood oxygen saturation, conventionally depends on isolated measurements, rendering it vulnerable to factors like illumination profile, spatial blood flow fluctuations, and skin pigmentation. Previous efforts to address these issues through imaging systems often employed red and near-infrared illuminations with distinct profiles, leading to inconsistent ratios of transmitted light and the potential for errors in calculating spatial oxygen saturation distributions. While an integrating sphere was recently utilized as an illumination source to achieve uniform red and near-infrared illumination profiles on the sample surface, its bulkiness presented practical challenges. In this work, we have enhanced the pulse oximetry imaging system by transitioning illumination from an integrating sphere to a multi-wavelength LED configuration. This adjustment ensures simultaneous emission of red and near-infrared light from the same position, creating a homogeneous illumination profile on the sample surface. This approach guarantees consistent patterns of red and near-infrared illuminations that are spatially uniform. The sustained ratio between transmitted red and near-infrared light across space enables precise calculation of the spatial distribution of oxygen saturation, making our pulse oximetry imaging system more compact and portable without compromising accuracy. Our work significantly contributes to obtaining spatial information on blood oxygen saturation, providing valuable insights into tissue oxygenation in peripheral regions.

A Case of Atypical Distribution of Pulmonary Tuberculosis in Bedridden Patient with Quadriplegia (사지마비로 장기 침상안정 환자에서 폐결핵 발생부위 변화 1예)

  • Hwang, Hun-Gyu;Jung, Eun-Jung;Lim, Gune-Il;Yang, Seung-Boo;Im, Han-Hyeok
    • Tuberculosis and Respiratory Diseases
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    • v.69 no.1
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    • pp.52-55
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    • 2010
  • Pulmonary tuberculosis has intermediate prevalence in Korea. It is known that tuberculosis infection predominantly involves the upper lobes, based on the fact that multiplication of Mycobacterium tuberculosis is favored in areas with decreased pulmonary blood flow, impaired lymphatic drainage, and high oxygen tension. We report this case of a 40-year-old man who was brought to our hospital with hemoptysis and dyspnea. Prior to admission, the patient had been in a bedridden state for 15 years due to an injury of the cervical spine 4~5. A 3-Dimensional computed tomography showed predominantly longitudinal distribution of centrilobular nodules along the anterior chest wall, in the left lung. MTB-PCR and AFB culture of bronchial washing fluid revealed pulmonary tuberculosis. This case shows that long-standing supine posture and decreased motion of the anterior chest wall may change the distribution of preferential infection site of Mycobacterium tuberculosis in the lung, resulting in a ventral predominance of tuberculosis infection in the quadriplegic patient.

Transport of Some Solutes in Blood Plasma Through Poly(2-Hydroxyethyl Methacrylate) Hydrogel Membrane (혈장내 염의 Poly(2-Hydroxyethyl Methacrylate) 격막 투과현상)

  • Jee Jong Gi;Jhon Mu Shik;Ree Tai Kyue
    • Journal of the Korean Chemical Society
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    • v.22 no.5
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    • pp.304-310
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    • 1978
  • The relative permeabilities, distribution coefficients and diffusion coefficient of some salts which are important components in blood plasma through a poly(HEMA) membrane were measured. The crosslinker which was used for preparing the membrane was tetraethylene glycol dimethacrylate(TEGDMA), the weight percentage of the latter was about 2.8. We found that the diffusion coefficients ($D_m$) of the solutes decrease exponentially with increasing molecular weight, and also that $D_m$'s decrease linearly (except urea) with cylindrical radius (a). These facts were explained by a sieve pore flow model. The relative permeability and diffusion coefficient of urea at various temperature were larger than those of other solutes such as glycine, ${\beta}$-alanine, D-glucose, saccharose and maleic acid. The result indicates that the poly(HEMA) membrane might be suitable for hemodialysis application.

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Association Between Vertebrobasilar Insufficiency and Cervicogenic Headache: Hypothetical Approach Towards Etiopathogenesis of Headache

  • Kaur, Aninditya;Rakesh, N.;Reddy, Sujatha S.;Thomas, Nithin;Nagi, Ravleen;Patil, Deepa Jatti
    • Journal of Oral Medicine and Pain
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    • v.45 no.4
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    • pp.97-109
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    • 2020
  • Purpose: Cervicogenic headache (CGH) is pain referred to the head/ face from the structures in vicinity of upper cervical spinal nerves via trigeminocervical pathway. Ponticulus Posticus (PP) and Elongated Styloid Process (ESP) are anatomical structures that cause compression of vasculature present around upper cervical nerve plexus. Recently, computational fluid dynamics (CFD) has shown to play an essential role in identification of these high-pressure zones in the brain. The aim of this research is to study the association of ESP and PP in patients with CGH and to develop a hypothesis by CFD to analyse vertebrobasilar insufficiency as a contributing factor in occurrence of CGH. Methods: Retrospective analysis of 4500 full skull CBCT scans was done for the presence of partial or complete PP and length of Styloid Process (SP). Research was divided into two phases; In first Preliminary Phase, 150 scans that showed the presence of PP and ESP were analysed, and only 134 patients gave consent to fill the questionnaire containing 96 question items pertaining to symptoms associated with CGH. In the second phase, simulation of Vertebral and Carotid Artery was done using Fluent 14.5 Software and by CFD, pressure distribution on arteries was obtained that helped to identify high pressure regions. Results: Both PP and ESP showed a statistically significant association with CGH (p<0.001). By CFD analysis, both steady and transient phases of simulation showed drop in pressure due to constriction of internal carotid and vertebral artery by ESP and PP respectively and were found to decrease the volume of blood reaching the brain, 0.12 /0.13 mL and 0.06 mL respectively. Conclusions: Our analysis proves ESP and PP as contributing factors towards CGH. Hence for proper diagnosis and management of headache disorders, clinicians should have adequate knowledge about these anatomical structures and their resulting clinical symptoms.