• The Korean Journal of Nuclear Medicine
• /
• v.17 no.2
• /
• pp.1-17
• /
• 1983

The purpose of this study is to investigate the effects of thyroid hormone on the left ventricular(LV) volume arid function in man with untreated hyperthyroidism and to determine the effects of successful therapy for thyrotoxicosis on the ventricular pathophysiology. In the present study, equilibrium radionuclide cardiac angiography was performed and LV volume index, ejection phase indexes of LV performance, serum thyroid hormone levels and other hemodynamic parameters were measured in 28 normal subjects and 39 patients with hyperthyroidism before treatment and again every 4 weeks for the first 2 months after the initiation of effective therapy. The results obtained were as follows; 1) In the untreated hyperthyroid state heart rate, blood volume, cardiac index and stroke volume index($97{\pm}14$ beats/min, $73.5{\pm}11.8ml/kg,\;6.9{\pm}1.4\;l/min/m^2$ and $77.6{\pm}13.8ml/m^2$, respectively) were increased significantly compared to those in normal control($74{\pm}12beats/min$, $66.6{\pm}14.8ml/kg,\;3.8{\pm}1.2\;l/min/m^2$ and $56.6{\pm}13.2ml/m^2$ respectively). $(Mean{\pm}SD)$ 2) There was a significant increase in LV end-diastolic volume index in patients with hyperthyroidism ($30.5{\pm}7.5$ for hyperthyroid group compared to a normal control of $22.2{\pm}6.5$; p<0.001), whereas end-systolic volume index remained unchanged $9.6{\pm}3.6\;and\;8.8{\pm}3.3$ respectively).3) In patients with hyperthyroidism, LV ejection fraction was $70.0{\pm}5.6%$, fractional shortening $32.9{\pm}5.1%$, mean velocity of circumferential fiber shortening(mean Vcf) $1.34{\pm}0.31$ circ/sec and maximum ejection rate $3.47{\pm}0.80$. All the ejection phase indexes were significantly greater than those in normal control($65.2{\pm}5.7%,\;28.8{\pm}3.2%,\;0.88{\pm}0.37$ circ/see and $2.27{\pm}0.50$, respectively; p<0.001). 4) Effective therapy produced significant decrease in all the values of serum thyroid hormone concentrations(p<0.00l), hemodynamic parameters(p<0.001), end-diastolic volume index(p<0.01) and ejection phase indexes of LV contractility in patients with hyperthyroidism and after one to two months, when the patients were euthyroid, these measurements were in the range of normal. 5) A significant linear correlation between mean Vcf and serum thyroxine level(r=0.63, p<0.001) as well as between mean Vcf and serum triiodothyronine level(r=0.62, p<0.001) was found. The lesser degree of correlation was also noted between other ejection phase indexes and serum thyroid hormone concentrations. The results indicate that the major effects of excess thyroid hormone on the LV in human beings with hyperthyroidism are an enhancement of LV function and an increase in LV enddiastolic volume and that these effects cause predictable reversible cardiac alteration which are changed dramatically and immediately after effective therapy.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.2
• /
• pp.925-928
• /
• 2014

Background: Gestational trophoblastic neoplasia (GTN) is a spectrum of disease with abnormal trophoblastic proliferation. Treatment is based on FIGO stage and WHO risk factor scores. Patients whose score is 12 or more are considered as at extremely high risk with a high likelihood of resistance to first line treatment. Optimal therapy is therefore controversial. Objective: This study was conducted in order to summarize the regimen used for extremely high risk or resistant GTN patients in our institution the in past 10 years. Materials and Methods: All the charts of GTN patients classified as extremely high risk, recurrent or resistant during 1 January 2002 to 31 December 2011 were reviewed. Criteria for diagnosis of GTN were also assessed to confirm the diagnosis. FIGO stage and WHO risk prognostic score were also re-calculated to ensure the accuracy of the information. Patient characteristics were reviewed in the aspects of age, weight, height, BMI, presenting symptoms, metastatic area, lesions, FIGO stage, WHO risk factor score, serum hCG level, treatment regimen, adjuvant treatments, side effects and response to treatment, including disease free survival. Results: Eight patients meeting the criteria of extremely high risk or resistant GTN were included in this review. Mean age was 33.6 years (SD=13.5, range 17-53). Of the total, 3 were stage III (37.5%) and 5 were stage IV (62.5%). Mean duration from previous pregnancies to GTN was 17.6 months (SD 9.9). Mean serum hCG level was 864,589 mIU/ml (SD 98,151). Presenting symptoms of the patients were various such as hemoptysis, abdominal pain, headache, heavy vaginal bleeding and stroke. The most commonly used first line chemotherapeutic regimen in our institution was the VAC regimen which was given to 4 of 8 patients in this study. The most common second line chemotherapy was EMACO. Adjuvant radiation was given to most of the patients who had brain metastasis. Most of the patients have to delay chemotherapy for 1-2 weeks due to grade 2-3 leukopenia and require G-CSF to rescue from neutropenia. Five form 8 patients were still survived. Mean of disease free survival was 20.4 months. Two patients died of the disease, while another one patient died from sepsis of pressure sore wound. None of surviving patients developed recurrence of disease after complete treatment. Conclusions: In extremely high risk GTN patients, main treatment is multi-agent chemotherapy. In our institution, we usually use VAC as a first line treatment of high risk GTN, but since resistance is quite common, this may not suitable for extremely high risk GTN patients. The most commonly used second line multi-agent chemotherapy in our institution is EMA-CO. Adjuvant brain radiation was administered to most of the patients with brain metastasis in our institution. The survival rate is comparable to previous reviews. Our treatment demonstrated differences from other institutions but the survival is comparable. The limitation of this review is the number of cases is small due to rarity of the disease. Further trials or multicenter analyses may be considered.

• Journal of Chest Surgery
• /
• v.45 no.2
• /
• pp.85-90
• /
• 2012

Background: At present, many surgeons prefer axillary artery cannulation because it facilitates antegrade cerebral perfusion and may diminish the risk of cerebral embolization. However, axillary artery cannulation has not been established as a routine procedure because there is controversy about its clinical advantage. Materials and Methods: We examined 111 patients diagnosed with acute type A aortic dissection between January 2000 and December 2009. The right axillary artery was cannulated in 58 patients (group A) and the femoral artery was cannulated in 53 (group F). The postoperative outcomes were retrospectively reviewed and compared between the two groups. Results: There were 46 male and 65 female patients with a mean age of $58.9{\pm}13.1$ years (range, 26 to 84 years). The extent of aortic replacement in both groups did not differ. There were 8 early deaths (7.2%) and 2 late deaths (1.8%). The mean follow-up duration was $46.0{\pm}32.6$ months (range, 1 month to 10 years). Transient neurologic dysfunction was observed in 11 patients (19.0%) in group A and 14 patients (26.4%) in group F. A total of 11 patients (9.9%) suffered from a permanent neurologic dysfunction. Early and delayed stroke were observed in 6 patients (10.3%) and 2 patients (3.4%), respectively, in group A as well as 2 patients (3.8%) and 1 patient (1.9%), respectively, in group F. There were no statistical differences in the cannulation-related complications between both groups (3 in group A vs. 0 in group F). Conclusion: There were no differences in postoperative neurologic outcomes and cannulation-related complications according to the cannulation sites. The cannulation site in an aortic dissection should be carefully chosen on a case-by-case basis. It is important to also pay attention to the possibility of intraoperative malperfusion syndrome occurring and the subsequent need to change the cannulation site.

• Nuclear Medicine and Molecular Imaging
• /
• v.42 no.5
• /
• pp.347-353
• /
• 2008

Purpose: Cortical reorganization has an important role in the recovery of stroke. We analyzed the compensatory cerebral and cerebellar perfusion change in patients with unilateral cerebral infarction using statistical parametric mapping (SPM). Materials and Methods: Fifty seven $^{99m}TC-Ethylene$ Cystein Diethylester (ECD) cerebral perfusion SPECT images of 57 patients (male/female=38/19, mean age=$56{\pm}17\;years$) with unilateral cerebral infarction were evaluated retrospectively. Patients were divided into subgroups according to the location (left, right) and the onset (acute, chronic) of infarction. Each subgroup was compared with normal controls (male/female=11/1, mean age=$36{\pm}10\;years$) in a voxel-by-voxel manner (two sample t-test, p<0.001) using SPM. Results: All 4 subgroups showed hyperperfusion in the ipsilateral cerebral cortex, but not in the contralateral cerebral cortex. Chronic left and right infarction groups revealed hyperperfusion in the ipsilateral primary sensorimotor cortex, meanwhile, acute subgroups did not. Contralateral cerebellar hyperperfusion was also demonstrated in the chronic left infarction group. Conclusion: Using $^{99m}Tc-ECD$ SPECT, we observed ipsilateral cerebral and contralateral cerebeller hyperperfusion in patients with cerebral infarction. However, whether these findings are related to the recovery of cerebral functions should be further evaluated.

• Journal of Chest Surgery
• /
• v.36 no.5
• /
• pp.316-320
• /
• 2003

Background: The detection of circulating microemboli by transcranial Doppler ultrasonography (TCD) has the potential to select the patients with high risk for future symptomatic brain embolism. We prospectively evaluated the positive rate and the frequency of microembolic signals (MES) before and after the heart valve surgery (HVS). Material and Method: Fifty in-patients with heart valve disease were enrolled in this study. Patients with history of previous stroke or heart valve surgery were excluded. Two unilateral TCD monitoring sessions were peformed from middle cerebral artery for 1-hour, before and after HVS. Result: Mechanical Heart valves were implanted in 28 patients, tissue valves were implanted in 10 patients, and remaining 12 patients received mitral valve repair. Positive rate of MES was significantly increased after HVS (50%), compared to that of before HVS (8%, p=0.00). There was no relation between MES after HVS and intensity of anticoagulation, cardiac rhythm, patients' age, and history of hypertension. The positive rate of MES after implantation of mechanical heart valve (71.4%) was significantly higher than those after implantation of tissue valve or mitral valve plasty (p=0.002). Conclusion: Positive rate of MES was increased significantly after the implantation of HVS. The changes of MES in those with mechanical prosthesis may be related to the increased risk or embolism after Hvs.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.34 no.1
• /
• pp.32-41
• /
• 2006

In this study, the thrust generation by simultaneous flapping airfoils in tandem configuration is parametrically studied with respect to flapping frequency, amplitude and relative location. Navier-Stokes solver with overset grid topology is employed to calculate the unsteady flowfields. The computation results indicate that when the two airfoils stroke in-phase - flapping phase lag is zero - the maximum propulsive efficiency and thrust can be obtained for most frequency and amplitude range. At a flapping amplitude of 0.2 chord and a reduced frequency of 0.75, the propulsive efficiency of aft airfoil is enhanced by about 37 % compared with that of forward airfoil. However, if flapping frequency exceeds some critical value, the strength of the leading edge vortex of aft airfoil is fortified by the trailing edge vortex of the forward airfoil, resulting in poor propulsive efficiency. It is also found that out-of-phase flapping has relatively low propulsive efficiency and thrust since vortical wake of the forward airfoil interacts with the leading edge vortex of aft airfoil in the unfavorable fashion. The total thrust and propulsive efficiency are shown to decrease with the horizontal miss distance of the aft airfoil. On the contrary, the vertical miss distance has little effect on the overall aerodynamic performance.

• The KIPS Transactions:PartD
• /
• v.8D no.3
• /
• pp.295-304
• /
• 2001

The standards of a telephone Hangul keyboard should be decided in terms of objective factors : the number of strokes and fingers’moving distance. A number of designers will agree on them, because these factors can be calculated in an objective manner. So, We developed the model which can evaluate the efficiency of inputting Hangul on a telephone keyboard in terms of two factors. As compared with other models, the major features of this model are as follows : in order to evaluate the efficiency of Hangul input on a telephone keyboard, (1) this model calculated not a typing time but the number of strokes ; (2) concurrence frequency that had been counted on KOREA-1 Corpus was used directly ; (3) a total set of 67 consonants and vowels was used ; and (4) this model could evaluate a number of keyboards that use a kind of syllabic function key-the complete key, the null key and the final consonant key and also calculate a lot of keyboards that adopt no syllabic function key. However, there are many other factors to judge the efficiency of inputting Hangul on a telephone keyboard. If we want to make more accurate estimate of a telephone Hangul keyboard, we must consider both logical data and experimental data as well.

• Journal of the Society of Naval Architects of Korea
• /
• v.48 no.6
• /
• pp.528-538
• /
• 2011

As a forming method for curved hull plates more efficient than the flame bending, mechanical bending using multi point press forming and die-less forming is discussed in this paper. the mechanical forming is a flexible manufacturing system for automatically forming of hull parts. It is especially suited to varied curved parts. This paper discusses a multiple point pressing machine composed of a pair of reconfigurable punches in order to achieve the rapid forming of curved hull plates using division forming and presents how forming information is obtained from the given design surface. Although the mechanical forming can be efficient in the metal forming, spring back after pressing is a phenomenon which must be carefully considered when quantifying the process variables. If the spring back is not accurately controlled, the fabricated shell plate cannot meet assembly tolerance. This paper describes the principles to calculate the proper stroke of each punch at the divided areas. the strokes are determined by an iterative process of sequential pressing and spring back compensation from an unfolded flat shape to its given design surface. FEA(finite element analysis) is used to simulate the spring back of the plate and the IDA(iterative displacement adjustment) method adjusts the offset of pressing punches from the deformation results and the design surface. The shape deviations of two surfaces due to spring back are compensated by integrated system using FEA and IDA method. For the practical application, It is aimed to develop an integrated system that can automatically perform the compensation process and calculate strokes of punches of the double sides' reconfigurable multiple-press machine and some experimental results obtained with mechanical bending are presented.

• Journal of Life Science
• /
• v.19 no.7
• /
• pp.905-916
• /
• 2009

Pinelliae rhizoma (Pr, 半夏) is a traditional medicine used in the treatment of incipient stroke. We investigated the effects of Pr on gene expression in a hypoxic model using cultured rat cortical cells. Pr (2.5 $\mu$g/ml) was added to the culture medium on DIV 12. A hypoxic shock (2% 0$_2$/5% CO$_2$, 37$^{\circ}$C, 3 hr) was given two days later (on DIV 14), and total mRNAs were isolated at 24 hr post-shock from both Pr-treated samples and untreated control cultures. Microarray using TwinChip $^{TM}$ Rat-5K (Digital Genomics, Seoul) indicated that Pr upregulated genes for cell growth and differentiation (tubb5, tgfa, ptpn11, n-ras, pdgfa) and antiapoptosis (mcl-1), while downregulating the apoptosis-induced gene (tieg). Therefore, it is interpreted that Pr protects neurons from hypxoic shock by maintaining cell growth and differentiation and by preventing apoptosis.

• Journal of Chest Surgery
• /
• v.45 no.5
• /
• pp.295-300
• /
• 2012

Background: With growing attention to the aortopathy associated with aortic valve diseases, the number of candidates for accompanying ascending aorta and/or root replacement is increasing among the patients who require aortic valve replacement (AVR). However, such procedures have been considered more risky than AVR alone. This study aimed to compare the surgical outcome of isolated AVR and AVR combined with aortic procedures. Materials and Methods: A total of 86 patients who underwent elective AVR between 2004 and June 2010 were divided into two groups: complex AVR (n=50, AVR with ascending aorta replacement in 24 and the Bentall procedure in 26) and simple AVR (n=36). Preoperative characteristics, surgical data, intra- and postoperative allogenic blood transfusion requirement, the postoperative clinical course, and major complications were retrospectively reviewed and compared. Results: The preoperative mean logistic European System for Cardiac Operative Risk Evaluation (%) did not differ between the groups: $11.0{\pm}7.8%$ in the complex AVR group and $12.3{\pm}8.0%$ in the simple AVR group. Although complex AVR required longer cardiopulmonary bypass ($152.4{\pm}52.6$ minutes vs. $109.7{\pm}22.7$ minutes, p=0.001), the quantity of allogenic blood products did not differ ($13.4{\pm}14.7$ units vs. $13.9{\pm}11.2$ units). There was no mortality, mechanical circulatory support, stroke, or renal failure requiring hemodialysis/filtration. No difference was found in the incidence of bleeding (40% vs. 33.3%) which was defined as red blood cell transfusion ${\geq}5$ units, reoperation, or intentional delayed closure. The incidence of mediastinitis (2.0% vs. 0%), ventilator ${\geq}24$ hours (4.0% vs. 2.8%), atrial fibrillation (18.0% vs. 25.0%), mean intensive care unit stay (34.5 hours vs. 38.8 hours), and median hospital stay (8 days vs. 7 days) did not differ, either. Conclusion: AVR combined with additional aortic or root replacement showed an excellent outcome and recovery course equivalent to that after isolated AVR.