• Korean Journal of Radiology
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• v.21 no.12
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• pp.1285-1293
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• 2020

Objective: To evaluate the effects of vasodilators on contrast enhancement and transluminal attenuation gradient (TAG) of coronary arteries at coronary computed tomography angiography (CCTA). Materials and Methods: We retrospectively reviewed CCTA scans of patients who underwent double-acquisition CCTA; CCTA without a vasodilator, and CCTA during a intravenous (IV) infusion of nitrate. Among them, we enrolled 19 patients who had no significant atherosclerotic lesions or coronary spasms. In the control group, 28 patients were enrolled who showed normal coronary arteries on CCTA, which was acquired by a conventional method (sublingual vasodilator). We measured the TAG and Hounsfield units for each of the three major epicardial coronary arteries (reported as 'ProxHU') and then compared the results between the nitrate administration methods (CT without vasodilator [CT_pre], CT with IV vasodilator [CT_iv], and CT with sublingual vasodilator [CT_sub]). Results: The mean TAG showed a significant difference between the coronary arteries (right coronary artery [RCA] > left anterior descending artery [LAD] > left circumflex artery [LCX], p < 0.05), while there was no difference in ProxHU of each coronary artery in all three types of nitrate administration methods (p > 0.05). The TAG of CT_pre group showed steeper slope than those of vasodilator groups (CT_iv and CT_sub) on LAD and LCX ([LAD: CT_pre = -22.1 ± 6.66, CT_iv = -16.76 ± 5.78, and CT_sub = -16.47 ± 5.78, p = 0.005], [LCX: CT_pre = -31.26 ± 17.43, CT_iv = -23.74 ± 14.06, and CT_sub = -20.94 ± 12.15, p = 0.051]), while that of RCA showed no significant differences (p = 0.600). When comparing proxHU, CT_iv showed higher proxHU than that of CT_pre or CT_sub, especially on LCX (CT_pre = 426.7 ± 68.3, CT_iv = 467.9 ± 84.9, and CT_sub = 404.9 ± 63.3, p = 0.013). ProxHU showed a negative correlation with TAG on all three of methods (r = -0.280, p < 0.001). Conclusion: TAG in CCTA was significantly affected by vasodilator administration. Both TAG and ProxHU of coronary arteries tend to increase with vasodilator administration on CCTA.

• Clinical and Experimental Pediatrics
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• v.50 no.11
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• pp.1041-1048
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• 2007

Not a few patients in children and adolescents are suffering from right ventricular (RV) dysfunction resulting from various conditions such as chronic lung disease, left ventricular dysfunction, pulmonary hypertension, or congenital heart defect. The RV is different from the left ventricle in terms of ventricular morphology, myocardial contractile pattern and special vulnerability to the pressure overload. Right ventricular failure (RVF) can be evaluated in terms of decreased RV contractility, RV volume overload, and/or RV pressure overload. The management for RVF starts from clear understanding of the pathophysiology of RVF. In addition to correction of the underlying disease, management of RVF per se is very important. Meticulous control of volume status, inotropic agents, vasopressors, and pulmonary selective vasodilators are the main tools in the management of RVF. The relative importance of each tool depends on the individual clinical status. Medical assist device and surgery can be considered selectively in case of refractory RVF to optimal medical treatment.

• Archives of Plastic Surgery
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• v.42 no.6
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• pp.695-703
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• 2015

Background It is still difficult to prevent partial or full-thickness flap necrosis. In this study, the effects of a cream containing menthol and methyl salicylate on the viability of random-pattern skin flaps were studied. Methods Forty female Sprague-Dawley rats were divided into two equal groups. Caudally based dorsal random-pattern skin flaps were elevated, including the panniculus carnosus. In the study group, 1.5 mL of a cream containing menthol and methyl salicylate was applied to the skin of the flap, and saline solution (0.9%) was used in the control group. Upon completion of the experiment, flap necrosis was analyzed with imaging software and radionuclide scintigraphy. Histopathological measurements were made of the percentage of viable flaps, the number of vessels, and the width of the panniculus carnosus muscle. Results According to the photographic analysis, the mean viable flap surface area in the study group was larger than that in the control group (P=0.004). According to the scintigrams, no change in radioactivity uptake was seen in the study group (P>0.05). However, a significant decrease was observed in the control group (P=0.006). No statistically significant differences were observed between the groups in terms of the percentage of viable flaps, the number of vessels, or the width of the panniculus carnosus muscle (P>0.05). Conclusions Based on these results, it is certain that the cream did not reduce the viability of the flaps. Due to its vasodilatory effect, it can be used as a component of the dressing in reconstructive operations where skin perfusion is compromised.

• Journal of Chest Surgery
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• v.28 no.8
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• pp.742-746
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• 1995

The present study was aimed at investigating possible transmitter mechanisms in the endothelial cell layer in regulating the tone of the vascular smooth muscle. The thoracic aorta was isolated from the anesthetized male white rabbits and its helical strips were prepared. Electrical field stimulation was delivered to platinum wire electrodes positioned parallel to the vessel segment preconstricted with phenylephrine [3.5x10-6 mol/L at a distance of 1.5-2.0 mm. The electrical stimulation [70 V, 5 msec, 0.5-200 Hz caused either relaxation only [34% or a biphasic response [prolonged relaxation following a weak and transient contraction, 66% . The relaxation response was frequency- dependent, and at 200 Hz a complete relaxation was noted. Mechanical rubbing of the endothelial layer abolished or greatly attenuated the relaxation. The relaxation was also markedly attenuated in the presence of NG-nitro- L-arginine methyl ester [10-3mol/L or procaine hydrochloride [3.5x10-4mol/L . Tetrodotoxin,guanethidine, atropine or indomethacin failed to block or enhance the relaxation response to electrical field stimulation. It is concluded that the vascular endothelium in the aorta contains diffusible substances that regulates the function of the smooth muscle layer, in which relaxation is more prominent than contraction. Their release by the electrical stimualtion in vitro may not involve classic neuronal transmitter release mechanisms or metabolism of arachidonic acids by cyclooxygenase. The release of the relaxing agents may require an increase in cytosolic calcium level. The chemical nature of the relaxant may be, to a large extent, nitric oxide.

• Journal of Chest Surgery
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• v.31 no.2
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• pp.102-107
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• 1998

It has not been clear whether L-arginine plays solely a role contributing to vascular nitric oxide (NO) synthesis. To investigate the mechanisms by which L-arginine induces vasorelaxation, effects of L-arginine on the isometric tension, and tissue NOx and cyclic guanosine monophosphate(cGMP) contents were examined in the isolated rat thoracic aorta. L-Arginine induced a dose-dependent relaxation of aortic rings only with intact endothelium only. The vasorelaxation response to low concentrations of L-arginine was abolished by the pretreatment with NG-nitro-L-arginine methyl ester(L-NAME, 10-4 mol/L), whereas the relaxation caused by higher concentrations L-arginine(10-5-10-3 mol/L) was maintained and even more pronounced in the presence of L-NAME. L-Arginine did not affect the vascular tension precontracted with KCl. The vascular tissue contents of NOx/cGMP were not significantly affected by L-arginine, while they were decreased by L-NAME. L-Arginine could not completely recover the NOx/cGMP decreased by L-NAME. Methylene blue only partially antagonized the relaxation response to L-arginine. Indomethacin did not affect the L-arginine-induced vasorelaxation, whereas ouabain markedly attenuated the relaxation. It is suggested that L-arginine induces vasorelaxation not only through its contribution to NO synthesis, but also through enhancing another endothelium-dependent mechanism which is NO/cGMP-independent and cyclooxygenase- independent.

• Journal of Yeungnam Medical Science
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• v.2 no.1
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• pp.95-102
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• 1985

This report offers descriptive data about the drugs utilized in out patient department (OPD) of Yeungnam University Hospital (YUH) in the period of march to august in 1985. The data in this report were produced by the computerized totalization of the number of mentions of individual drugs included in the prescriptions. The 100 drug entries that were most frequently recorded are listed in rank order. The listing is arbiturarily restricted to the drugs that were prescribed as single preparations, the drugs of basis of compound preparations and the drugs of adjuvent or corrective of compound preparations that have significant therapeutic effects either by generic names. And in addition, the listing also involves the compound preparations used in relatively large frequency, and the individual components of which have the unique pharmacological actions each other by proprietary names. And all routes of administrations were allowed. The 10 drugs most frequently named are diazepam, aluminum compounds, acetaminophen, isoniazid, metoclopramide, $polaramine^{(R)}$, carboxymethylcystem, ephedrine, codeine and caroverine in order. The 521,855 drug mentions listed as above are described by the chief therapeutic usage that each is intended to apply generally. The drugs which account the largest proportion of total mentions were those acting on the central nervous system (20.57%), including tranquilhzers and sedative hypnotics (11.71%), analgesic antipyretics (5.55%), antidepressants (2.15%) etc. Gastrointestinal drugs and smooth muscle preparations (18.64%) included antacids and anti-ulcer drugs (9.24%), antiemetics (3.57%), spasmolytics (3.14%) and others. Respiratory drugs (16.11%) included expectorants and cough preparations (10.99%) and bronchodilators (5.12%). Chemotherapeutic agents (15.12%) included the antiTbc drugs (7.09%) most frequently, and the penicillins (3.33%) accounted the largest proportion among the antibiotics. Cardiovascular drugs (5.64%) included cardiac drugs and coronary vasodilator (4.12%) and antihypertensives and vasodilators (1.06%). And anti-inflammatory drugs (4.33%), vitamins of single preparations (3.76%), hormones and their antagonists (3.29%), common cold preparations (3.12%), diuretics (2.81%), drugs supporting liver function (2.02%), drugs affecting autonomic nervous system(1.89%) including anti-glaucomas, atropine and cerebral vasodilators, antihistamine drugs (1.02%) and disinfectants (0.74%) were following in order. The data in this report were compared to those reported by H. Koch, et al. in United States (US), 1981 as "Drugs Most Frequently Used in Office Practice:National Ambulatory Medical Case Survey, 1981." Cardiovascular drugs prescribed in YUH were much less in proportion than in US (10.56%), but gastrointestinal drugs accounted the larger proportion than in US (3.72%). Expectorants and cough preparations in YUH also accounted the larger proportion than in US (2.74%). In conclusion, in the period of march to august, 1985, OPD of YUH prescribed the CNS drugs including diazepam most frequently, and gastrointestinal, repiratory and chemotherapeutic drugs in next orders. It is supposed that the eating habits of Koreans and a unique atmospheric condition in Taegu as a basin were some important factors that affected the proportions of drugs acting on gastrointestinal and respiratory tracts.