• Membrane Journal
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• v.15 no.3
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• pp.224-232
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• 2005

The use of the lung assist device (LAD) would be well suited for acute respiratory failure (ARF) patients, combining the simplicity of mechanical ventilation with the ability of extracoporeal membrane oxygenators (ECMO) to provide temporary relief for the natural lungs. This study's specific attention was focused on the effect of membrane vibration in the LAD. Quantitative experimental measurements were performed to evaluate the performance of the device, and to identify membrane vibration dependence on blood hemolysis. We tried to decide upon excited frequency band of limit hemolysis when blood hemolysis came to through a membrane vibration action. The excited frequency of the module type 5, consisted of 675 hollow fiber membranes, showed the maximum gas transfer rate. We concluded that the maximum oxygen transfer rate seemed to be caused by the occurrence of maximum amplitude and the transfer of vibration to hollow fiber membranes. It was excited up to $25{\pm}5$ Hz at each blood flow rate of module type 5. We found that this frequency became the 2nd mode resonance riequency of the flexible in blood flow. Blood hemolysis was low at the excited frequency of $25{\pm}5$ Hz. Therefore, we decided that limit hemolysis frequency of this LAD was $25{\pm}5$ Hz.

• Progress in Medical Physics
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• v.14 no.2
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• pp.141-148
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• 2003

The purpose of this study is to evaluate the distribution of clusters and blood flow rate in ADHD SPECT brain blood flow images of children using statistical parametric mapping (SPM99). We studied 64 ADHD children (4-15 y, $8.03{\pm}2.57$ y. male/female:52/12) and compared them with a control group of 12 children (6-l7 y, $9.42{\pm}3.37$ y, male/female:8/4). We injected blood flow tracer $^{99m}Tc$-ethylcysteinate dimer (ECD) as a rCBF agent and took blood flow images after 30 min. by SPECT camera. In the case of hyperperfusion of rCBF in the ADHD group, we found 3 clusters clearly separated at the cingulate gyrus, Rt.cerebral occipital lobe and Lt.cerebellar post. lobe, on probability level 0.05 (P<0.05). Thirty-six ADHD patients with average hyperfusion rates between 18.72-19.30% in each cluster had more increase in blood flow than the average perfusion rate at the Rt. cerebral occipital lobe. These levels were influenced by P-value. In the case of hypoperfusion in the ADHD children, 4 decreased clusters on Lt. and Rt. cerebral frontal lobe, Lt. cerebral claustrum and Rt. cerebral, sup. temporal gyrus at P<0.01 can be seen. The average hypoperfusion rates for the ADHD children were 18.41-18.69% in each cluster, which showed more hypopefusion than the average perfusion rate at the Lt. Cerebrum inf. Frontal gyrus. The perfusion rates and the number of patients were not affected by P-value. The result of this study shows significant hyperpefusion clusters at the probability level of P:0.05 and hypoperfusion clusters at P:0.01. The number of ADHD patients in each clusters and the perfusion rate were not affected by P-value.

• Journal of Korean Neurosurgical Society
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• v.52 no.6
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• pp.534-540
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• 2012

Objective : Brainstem arteriovenous malformation (AVM) is rare and radiosurgical management is complicated by the sensitivity of the adjacent neurological structures. Complete obliteration of the nidus is not always possible. We describe over 20 years of radiosurgical procedures for brainstem AVMs, focusing on clinical outcomes and radiosurgical techniques. Methods : Between 1992 and 2011, the authors performed gamma knife radiosurgery (GKRS) in 464 cerebral AVMs. Twenty-nine of the 464 patients (6.3%) reviewed had brainstem AVMs. This series included sixteen males and thirteen females with a mean age of 30.7 years (range : 5-71 years). The symptoms that led to diagnoses were as follows : an altered mentality (5 patients, 17.3%), motor weakness (10 patients, 34.5%), cranial nerve symptoms (3 patients, 10.3%), headache (6 patients, 20.7%), dizziness (3 patients, 10.3%), and seizures (2 patients, 6.9%). Two patients had undergone a previous nidus resection, and three patients had undergone a previous embolization. Twenty-four patients underwent only GKRS. With respect to the nidus type and blood flow, the ratio of compact type to diffuse type and high flow to low flow were 17 : 12 and 16 : 13, respectively. In this series, 24 patients (82.8%) had a prior hemorrhage. The mean target volume was 1.7 $cm^3$ (range 0.1-11.3 $cm^3$). The mean maximal and marginal radiation doses were 38.5 Gy (range 28.6-43.6 Gy) and 23.4 Gy (range 18-27 Gy), and the mean isodose profile was 61.3% (range 50-70%). Results : Twenty-four patients had brainstem AVMs and were followed for more than 3 years. Obliteration of the AVMs was eventually documented in 17 patients (70.8%) over a mean follow-up period of 77.5 months (range 36-216 months). With respect to nidus type and blood flow, the obliteration rate of compact types (75%) was higher than that of diffuse types (66.7%), and the obliteration rate of low flow AVMs (76.9%) was higher than that of high flow AVMs (63.6%) (p<0.05). Two patients (6.9%) with three hemorrhagic events suffered a hemorrhage during the follow-up period. The annual bleeding rate of AVM after GKRS was 1.95% per year. No adverse radiation effects or delayed cystic formations were found. Conclusion : GKRS has an important clinical role in treatment of brainstem AVMs, which carry excessive surgical risks. Angiographic features and radiosurgical techniques using a lower maximal dose with higher isodose profiles are important for lesion obliteration and the avoidance of complications.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.2
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• pp.91-97
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• 1989

The present experiment was carried out to investigate the effects of heat exposure on water metabolism and the passage of indigestible particles in sheep. Water intake, respiratory rate, rectal temperature and pH of ruminal fluid and urine were significantly higher (P<0.05) in the hot environment ($32\;^{\circ}C$) than in the control environment ($20\;^{\circ}C$). Urine osmolality and blood volume were increased, while glomerular filtration rate was decreased, in the hot environment. The liquid flow rate from reticulo-rumen and the excretion of indigestible particles of specific gravity 0.99 (but not 1.27 or 1.38) were increased in the hot environment. From these findings, it is suggested that an increased water intake evoked by heat exposure might affect the flow rate of digesta in sheep.

• Restorative Dentistry and Endodontics
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• v.41 no.3
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• pp.202-209
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• 2016

Objectives: The purpose of this study was to investigate the involvement of TRPA1 in the cinnamaldehyde-induced pulpal blood flow (PBF) change in the feline dental pulp. Materials and Methods: Mandibles of eight cats were immobilized and PBF was monitored with a laser Doppler flowmetry at the mandibular canine tooth. To evaluate the effect of cinnamaldehyde on PBF, cinnamaldehyde was injected into the pulp through the lingual artery at a constant rate for 60 seconds. As a control, a mixture of 70% ethanol and 30% dimethyl sulfoxide (DMSO, vehicle) was used. To evaluate the involvement of transient receptor potential ankyrin 1 (TRPA1) in PBF change, AP18, a specific TRPA1 antagonist, was applied into the pulp through the Class V dentinal cavity followed by cinnamaldehyde-administration 3 minutes later. The paired variables of experimental data were statistically analyzed using paired t-test. A p value of less than 0.05 was considered as statistically significant. Results: Administration of cinnamaldehyde (0.5 mg/kg, intra-arterial [i.a.]) induced significant increases in PBF (p < 0.05). While administration of a TRPA1 antagonist, AP18 (2.5 - 3.0 mM, into the dentinal cavity [i.c.]) caused insignificant change of PBF (p > 0.05), administration of cinnamaldehyde (0.5 mg/kg, i.a.) following the application of AP18 (2.5 - 3.0 mM, i.c.) resulted in an attenuation of PBF increase from the control level (p < 0.05). As a result, a TRPA1 antagonist, AP18 effectively inhibited the vasodilative effect of cinnamaldehyde (p < 0.05). Conclusions: The result of the present study provided a functional evidence that TRPA1 is involved in the mechanism of cinnamaldehyde-induced vasodilation in the feline dental pulp.

• Archives of Plastic Surgery
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• v.36 no.3
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• pp.254-261
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• 2009

Purpose: The objective of this study was to evaluate the heparin effect for a viability of random - pattern dorsal flap in hairless mouse. Methods: A caudally - based random dorsal flap, measuring $1.5{\times}5cm$, was designed and heparin was applied topically after microneeding. Twenty five male hairless mice were randomly divided into control (Group1, n=5); received only microneedling (Group 2, n=5), only heparin(Group3, n=5), microneedling with saline(Group 4, n=5), and microneedling with heparin group(group5,n=5) to the flap during 7 days. The number of the capillaries were compared between the experimental groups and control group with respect to neovascularization after heparin application using imaging analysis program under hematoxylin - eosin stain. The capillary blood flow was measured by laser Doppler flowmetry. After seven days each animal was evaluated for the percentage area of the flap survival. Mann - Whitnety U test and Kruskal - Wallis statistical analysis of survival relationships was performed. Results: It can be observed increased number of the blood vessels in the experimental groups however it was not statistically significant. Blood flow of the haparin with microneedling group maintained higher than other experimental groups. Treated microneeding and heparin mice were significantly better flap viability than in controls (flap survival 67% and $54.4mm^2$ respectively; p<.01). Positive correlation was shown between flap survival rate and laser Doppler flux value only at first day after surgery. Conclusion: Heparin has a beneficial effect on capillary flow and improve peripheral circulatory disturbances in random pattern flaps.

• Journal of the Korean Chemical Society
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• v.45 no.3
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• pp.223-229
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• 2001

A method for the determination of glucose in human whole blood by chemiluminescence method using a stopped flow injection system has been studied. The method is based on the differences in the chemiluminescence intensities of luminol due to the different amounts of hydrogen peroxide produced from the glucose oxidase catalyzed reaction. The enzyme reactor was prepared by immobilization of glucose oxidase on aminopropyl glass beads and the chemiluminescence from a flow cell was measured by means of an optical fiber bundle. In order to obtain the optimum experimental conditions, effects of pH for the chemiluminogenic solution and enzyme reactor, flow rate and temperature on the chemiluminescence intensity were investigated. The calibration curve obtained under optimum experimental conditions was linear over the range from $1.0{\times}10^{-1}$ mM to 7.0 mM and the detection limit was $6.0{\times}10^{-2}$ mM. The proposed method was applied to the determination of glucose in whole human blood sample and the results were compared with those obtained by an official method. The present method was also evaluated by the results of recovery experiments.

• The Journal of Korean Medicine
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• v.26 no.1 s.61
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• pp.115-122
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• 2005

Background and objective: Gastrodiae Rhizoma (GR), the rhizoma of Gastrodia elata BL., is one of the popular drugs to treat headache, dizziness, blackout, numbness of limbs, hemiplegia, facial paralysis, dysphrasia, and infantile convulsions. It has been reported that it provides an antihypertensive effect and lowers cerebrovascular resistance in animal experiments. However, there has been no data about these effects with human subjects. In this study, the author examined the effect of Gastrodiae water extracts on blood pressure and cerebrovascular reactivity in human subjects. Methods: We selected 16 normal volunteers, who were divided into 2 groups: Gastrodiae extract administration group and placebo (creamy powder) group. Using transcranial Doppler ultrasound, we monitored changes of mean flow velocity and breath-holding induced CO2 reactivity of middle cerebral artery in both groups. Mean blood pressure, heart rate and PETCO2 were measured using Compact Anesthesia Monitor. In both groups, all evaluation was performed during basal condition, and repeated at 30, 60, and 90 min after administration. Results: Gastrodiae extract decreased CO2 reactivity after administration, reaching the lowest level at 90 minutes $(-29.1\%\;vs.\;basal\;level)$, which showed significant difference compared with the placebo group (p = 0.004). In the placebo group, the pulse rates tended to decrease over time (at 90 minute, $-5.2\%$ vs. basal level) while in the Gastrodiae group the values showed nearly no change, which showed significant difference between both groups (p = 0.036). However, the changes of mean blood pressure and mean flow velocity did not show significant difference between both groups. Conclusion : This study demonstrated that Gastrodiae extract significantly decreased breath-holding induced CO2 reactivity. This result suggests that the clinical effect of Gastrodiae extract might be caused by increasing cerebral blood flow via dilation of cerebral resistant vessels instead of antihypertensive effect.

• Archives of Reconstructive Microsurgery
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• v.5 no.1
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• pp.46-55
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• 1996

The purpose of this study is to investigate if there is a higher rate of free flap failure in cases of vein grafts compared to non-vein graft, and to analyze the clinical usefulness and necessity in elective free flap surgery. We have used 24 vein grafts in 208 free flaps from May, 1986 until August, 1995. Vein grafts were from 2cm to 50cm in length between the recipient and donor vessels. Reconstructed sites were 10 lower extremities, 8 head and neck, 4 hand, and 2 trunk. Vein grafts were used 14 for arterial, 6 venous, 4 in both arterial and venous anastomoses. We intentionally used long vein grafts longer than 5cm for improved blood flow in cases of peripheral vascular disease, radionecrotic wounds, lower leg trauma. Short vein grafts of about 3cm in length were used to overcome the shortage of vascular length in cases of unexpected vessel anomaly, short donor vessel, and difficult access to recipient vessels after radical neck dissection. All veins were carefully handled with ligation of very small branches and were transferred to the recipient site without irrigation. 8 flaps were failed out of a total of 208 free flaps, however there was no failure among the 24 cases that needed vein grafts between the donor and recipient vessels. Success rates between non-vein grafts free flaps and vein graft free flaps were 95.6%(8/184) and 100%(0/24). Even though the vein grafts increase the operation time and the number of anastomoses, they do not result in any increased failure rate of free flap surgery(4.4% versus 0%). In addition to the reducing tension between recipient and donor vessels, the surgeon can select better recipient vessels with excellent blood flow so that vein grfats in microsurgery can provide a high success rate of free flaps.

• Journal of Biomedical Engineering Research
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• v.14 no.4
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• pp.307-314
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• 1993

Plasma protein adsorption is the first event in the blood-material interaction and influenc- es subsequent platelet adhesion towards thlㅈombus formation. Thiㅈomboembolic events are strongly influenced by surface characteristics of materials and fluid dynamics inside the blood pump. In vitro flow visualizaion and an amimal experiment with the moving actuator type TAH were Performed in order to investigate fluid dynamic effects on the protein adsorption. The diffel'encl level, j of shear rate inside the ventricle Lvere determined by consid- ering the direction of the major opening of four healt valves in the implanted TAH and the visualized flow patterns as well. Each ventricle of the explanted TAH was sectionalized into 12 segments according to the shear rate level. The adsorbed protein on each segment was quantified using the ELISA method after soaking in 2% (wye)SDS/PBS for two days. Adsorbed protein layer thicknesses Itvere measured by the Immunogotd method under TEM. The SEM observation show that right ventricle (RV) , immobilized with albumin, displayed different degrees of platelet adhesion on each segment, whereas the left ventricle (LV), grafted by PEO-sulronate, indicated nearly , iame platelet adhesion behavior, regardless of shear rates. The surface concentrations of adsorbed proteins in the low shear rate region are hlghel'than those in the high region, which was confirmed statistically. A modified adsorption model of plasma protein onto polyurethane surface was suggested by considering the effect of the fluid dynamic characteristics.