Preclinical Evaluation of an Everolimus-Eluting Bioresorbable Vascular Scaffold Via a Long-Term Rabbit Iliac Artery Model

BACKGROUND@#Biodegradable poly (l-lactic acid) (PLLA), a bio safe polymer with a large elastic modulus, is widely used in biodegradable medical devices. However, because of its poor mechanical properties, a PLLA strut must be made twice as thick as a metal strut for adequate blood vessel support. Therefore, the mechanical properties of a drug-eluting metal-based stents (MBS) and a bioresorbable vascular scaffolds (BVS) were evaluated and their safety and efficacy were examined via a long-term rabbit iliac artery model. @*METHODS@#The surface morphologies of the MBSs and BVSs were investigated via optical and scanning electron microscopy. An everolimus-eluting (EE) BVS or an EE-MBS was implanted into rabbit iliac arteries at a 1.1:1 stent-toartery ratio. Twelve months afterward, stented iliac arteries from each group were analyzed via X-ray angiography, optical coherence tomography (OCT), and histopathologic evaluation. @*RESULTS@#Surface morphology analysis of the EE coating on the MBS confirmed that it was uniform and very thin (4.7 lm). Comparison of the mechanical properties of the EE-MBS and EE-BVS showed that the latter outperformed the former in all aspects (radial force (2.75 vs. 0.162 N/mm), foreshortening (0.24% vs. 1.9%), flexibility (0.52 vs. 0.19 N), and recoil (3.2% vs. 6.3%). At all time points, the percent area restenosis was increased in the EE-BVS group compared to the EE-MBS group. The OCT and histopathological analyses indicate no significant changes in strut thickness. @*CONCLUSION@#BVSs with thinner struts and shorter resorption times should be developed. A comparable long-term safety/efficacy evaluation after complete absorption of BVSs should be conducted.

Choice Stepping Reaction Time under Unstable Conditions in Healthy Young and Older Adults: A Reliability and Comparison Study

Purpose@#We aimed to analyze the reliability of the test for choice stepping reaction time (CSRT) under an unstable surface and determine whether there were differences in CSRT between support surface conditions (stable vs. unstable conditions) and between age groups (young adults vs. community-dwelling older adults). @*Methods@#Twenty healthy community-dwelling older adults and twenty young adults performed the stepping task under an unstable condition over two visits. The mean of the two trials measured for each visit was used for the analysis. The test-retest reliability was analyzed using intra-class correlation coefficient (ICC) with a 95% confidence interval, standard error of measurement (SEM), and minimal detectable change (MDC). Differences in CSRT between support surface conditions and age groups were analyzed using the independent t-test with Bonferroni correction. @*Results@#Excellent consistency was observed for ICC > 0.90 in both groups. Moreover, the SEM and MDC values of the CSRT in older and young adults were 0.03 and 0.09 and 0.01 and 0.04, respectively. There was a significant difference in the CSRT between the age groups under stable (p < 0.001) and unstable conditions (p < 0.001). @*Conclusion@#The findings demonstrated that the test for CSRT under an unstable condition had reliable results in both groups. Although older adults demonstrated longer reaction times than younger adults in all surface conditions, increasing the balance control demand by implementing a choice stepping task concomitant with a balance task had no influence on the reaction time in both age groups.

Preclinical Evaluation of a Novel Polymer-free Everolimus-eluting Stent in a Mid-term Porcine Coronary Restenosis Model

Background@#Titanium dioxide films exhibit good biocompatibility and may be effective as drug-binding matrices for drug-eluting stents. We conducted a mid-term evaluation of a novel polymer-free everolimus-eluting stent using nitrogen-doped titanium dioxide film deposition (TIGEREVOLUTION® ) in comparison with a commercial durable polymer everolimus-eluting stent (XIENCE Alpine® ) in a porcine coronary restenosis model. @*Methods@#Twenty-eight coronary arteries from 14 mini-pigs were randomly allocated to TIGEREVOLUTION® stent and XIENCE Alpine® stent groups. The stents were implanted in the coronary artery at a 1.1–1.2:1 stent-to-artery ratio. Eleven stented coronary arteries in each group were finally analyzed using coronary angiography, optical coherence tomography, and histopathologic evaluation 6 months after stenting. @*Results@#Quantitative coronary analysis showed no significant differences in the preprocedural, post-procedural, and 6-month lumen diameters between the groups. In the volumetric analysis of optical coherence tomography at 6 months, no significant differences were observed in stent volume, lumen volume, and percent area stenosis between the groups. There were no significant differences in injury score, inflammation score, or fibrin score between the groups, although the fibrin score was zero in the TIGEREVOLUTION® stent group (0 vs. 0.07 ± 0.11, P = 0.180). @*Conclusion@#Preclinical evaluation, including optical coherence tomographic findings 6 months after stenting, demonstrated that the TIGEREVOLUTION® stent exhibited efficacy and safety comparable with the XIENCE Alpine® stent, supporting the need for further clinical studies on the TIGEREVOLUTION® stent.

Preclinical Evaluation of a Novel Polymer-free Everolimus-eluting Stent in a Mid-term Porcine Coronary Restenosis Model

Background@#Titanium dioxide films exhibit good biocompatibility and may be effective as drug-binding matrices for drug-eluting stents. We conducted a mid-term evaluation of a novel polymer-free everolimus-eluting stent using nitrogen-doped titanium dioxide film deposition (TIGEREVOLUTION® ) in comparison with a commercial durable polymer everolimus-eluting stent (XIENCE Alpine® ) in a porcine coronary restenosis model. @*Methods@#Twenty-eight coronary arteries from 14 mini-pigs were randomly allocated to TIGEREVOLUTION® stent and XIENCE Alpine® stent groups. The stents were implanted in the coronary artery at a 1.1–1.2:1 stent-to-artery ratio. Eleven stented coronary arteries in each group were finally analyzed using coronary angiography, optical coherence tomography, and histopathologic evaluation 6 months after stenting. @*Results@#Quantitative coronary analysis showed no significant differences in the preprocedural, post-procedural, and 6-month lumen diameters between the groups. In the volumetric analysis of optical coherence tomography at 6 months, no significant differences were observed in stent volume, lumen volume, and percent area stenosis between the groups. There were no significant differences in injury score, inflammation score, or fibrin score between the groups, although the fibrin score was zero in the TIGEREVOLUTION® stent group (0 vs. 0.07 ± 0.11, P = 0.180). @*Conclusion@#Preclinical evaluation, including optical coherence tomographic findings 6 months after stenting, demonstrated that the TIGEREVOLUTION® stent exhibited efficacy and safety comparable with the XIENCE Alpine® stent, supporting the need for further clinical studies on the TIGEREVOLUTION® stent.

Influence of Local Myocardial Infarction on Endothelial Function, Neointimal Progression, and Inflammation in Target and Non-Target Vascular Territories in a Porcine Model of Acute Myocardial Infarction

BACKGROUND: Patients with acute myocardial infarction (AMI) have worse clinical outcomes than those with stable coronary artery disease despite revascularization. Non-culprit lesions of AMI also involve more adverse cardiovascular events. This study aimed to investigate the influence of AMI on endothelial function, neointimal progression, and inflammation in target and non-target vessels. METHODS: In castrated male pigs, AMI was induced by balloon occlusion and reperfusion into the left anterior descending artery (LAD). Everolimus-eluting stents (EES) were implanted in the LAD and left circumflex (LCX) artery 2 days after AMI induction. In the control group, EES were implanted in the LAD and LCX in a similar fashion without AMI induction. Endothelial function was assessed using acetylcholine infusion before enrollment, after the AMI or sham operation, and at 1 month follow-up. A histological examination was conducted 1 month after stenting. RESULTS: A total of 10 pigs implanted with 20 EES in the LAD and LCX were included. Significant paradoxical vasoconstriction was assessed after acetylcholine challenge in the AMI group compared with the control group. In the histologic analysis, the AMI group showed a larger neointimal area and larger area of stenosis than the control group after EES implantation. Peri-strut inflammation and fibrin formation were significant in the AMI group without differences in injury score. The non-target vessel of the AMI also showed similar findings to the target vessel compared with the control group. CONCLUSION: In the pig model, AMI events induced endothelial dysfunction, inflammation, and neointimal progression in the target and non-target vessels.

Effect of Stents Coated with Artemisinin or Dihydroartemisinin in a Porcine Coronary Restenosis Model

BACKGROUND AND OBJECTIVES: Artemisinin and dihydroartemisinin are drugs used to treat malaria. These drugs suppress inflammatory reactions. The aim of this study was to examine the anti-intima hyperplasia effect of a novel drug-eluting stent with artemisinin or dihydroartemisinin in a porcine coronary restenosis model. MATERIALS AND METHODS: Pigs were randomized into four groups; in the first, the coronary arteries (20 pigs, a total of 40 coronary arteries, with 10 coronary arteries in each group) was implanted with bare metal stents (BMS, n=10); the second group was given polymer-coated stents (PCS, n=10); the third group was treated with artemisinin-eluting stents (AES, n=10); and the fourth group was given dihydroartemisinin-eluting stents (DAES, n=10). Histopathologic analysis was performed 28 days after stenting. RESULTS: The injury and fibrin scores among the four groups were not significantly different. However, the internal elastic lamina, lumen area, and neointima area were significantly different. Moreover, the percent area of stenosis (46.2±18.66% in BMS vs. 89.4±10.92% in PCS vs. 83.3±17.07% in AES vs. 36.7±11.20% in DAES, p<0.0001) and inflammation score (1.0 [range: 1.0-1.0] vs. 3.0 [range: 2.25-3.0] vs. 3.0 [range: 1.0-3.0] vs. 2.0 [range: 1.75-3.0] in BMS, PCS, AES, and DAES, respectively; p<0.001) were markedly decreased in the DAES group compared to the PCS group. CONCLUSION: DES, which uses a natural substance, dihydroartemisinin, showed a neointima and inflammatory suppressive effect in a porcine coronary restenosis model.

The Control of Drug Release and Vascular Endothelialization after Hyaluronic Acid-Coated Paclitaxel Multi-Layer Coating Stent Implantation in Porcine Coronary Restenosis Model

BACKGROUND AND OBJECTIVES: Hyaluronic acid (HA) is highly biocompatible with cells and the extracellular matrix. In contrast to degradation products of a synthetic polymer, degradation products of HA do not acidify the local environment. The aim of this study was to fabricate an HA-coated paclitaxel (PTX)-eluting stent via simple ionic interactions and to evaluate its effects in vitro and in vivo. MATERIALS AND METHODS: HA and catechol were conjugated by means of an activation agent, and then the stent was immersed in this solution (resulting in a HA-coated stent). After that, PTX was immobilized on the HA-coated stent (resulting in a hyaluronic acid-coated paclitaxel-eluting stent [H-PTX stent]). Study groups were divided into 4 groups: bare metal stent (BMS), HA, H-PTX, and poly (L-lactide)-coated paclitaxel-eluting stent (P-PTX). Stents were randomly implanted in a porcine coronary artery. After 4 weeks, vessels surrounding the stents were isolated and subjected to various analyses. RESULTS: Smoothness of the surface was maintained after expansion of the stent. In contrast to a previous study on a PTX-eluting stent, in this study, the PTX was effectively released up to 14 days (a half amount of PTX in 4 days). The proliferation of smooth muscle cells was successfully inhibited (by 80.5±12.11% at 7 days of culture as compared to the control) by PTX released from the stent. Animal experiments showed that the H-PTX stent does not induce an obvious inflammatory response. Nevertheless, restenosis was clearly decreased in the H-PTX stent group (9.8±3.25%) compared to the bare-metal stent group (29.7±8.11%). CONCLUSION: A stent was stably coated with PTX via simple ionic interactions with HA. Restenosis was decreased in the H-PTX group. These results suggest that HA, a natural polymer, is suitable for fabrication of drug-eluting stents (without inflammation) as an alternative to a synthetic polymer.

Cardioprotective Effect of Fimasartan, a New Angiotensin Receptor Blocker, in a Porcine Model of Acute Myocardial Infarction

Cardioprotective effect of fimasartan, a new angiotensin receptor blocker (ARB), was evaluated in a porcine model of acute myocardial infarction (MI). Fifty swine were randomized to group 1 (sham, n=10), group 2 (no angiotensin-converting enzyme inhibitor [ACEI] or ARB, n=10), group 3 (perindopril 2 mg daily, n=10), group 4 (valsartan 40 mg daily, n=10), or group 5 (fimasartan 30 mg daily, n=10). Acute MI was induced by occlusion of the left anterior descending artery for 50 min. Echocardiography, single photon emission computed tomography (SPECT), and F-18 fluorodeoxyglucose cardiac positron emission tomography (PET) were performed at baseline, 1 week, and 4 weeks. Iodine-123 meta-iodobenzylguanidine (MIBG) scan was done at 6 weeks for visualization of cardiac sympathetic activity. Left ventricular function and volumes at 4 weeks were similar between the 5 groups. No difference was observed in groups 2 to 5 in SPECT perfusion defect, matched and mismatched segments between SPECT and PET at 1 week and 4 weeks. MIBG scan showed similar uptake between the 5 groups. Pathologic analysis showed similar infarct size in groups 2 to 5. Infarct size reduction was not observed with use of fimasartan as well as other ACEI and ARB in a porcine model of acute MI.

Effect of Pretreatment of Ezetimibe/Simvastatin on Arterial Healing and Endothelialization after Drug-Eluting Stent Implantation in a Porcine Coronary Restenosis Model

BACKGROUND AND OBJECTIVES: We sought to evaluate the effect of the early use of ezetimibe/simvastatin (Vytorin(R)) on arterial healing and endothelialization after the implantation of a drug-eluting stent (DES) in a porcine model of coronary restenosis. MATERIALS AND METHODS: A total of 20 pigs (40 coronary arteries) were randomly allocated to a pretreatment or no treatment group. The pretreatment group (n=20) received oral ezetimibe/simvastatin (10/20 mg) daily for 7 days before stenting and the no pretreatment group (n=20) did not. All pigs were treated with ezetimibe/simvastatin (10/20 mg) daily after stenting for 4 weeks. Stenting was performed using a bare-metal stent (BMS, n=10) and three types of DES: biolimus A9-eluting stent (BES, n=10), zotarolimus-eluting stent (ZES, n=10), and everolimus-eluting stents (EES, n=10). Four weeks later, pigs underwent a follow-up coronary angiography and were sacrificed for histopathologic analysis. RESULTS: There were no significant differences between the pretreatment and no pretreatment groups in the internal elastic lamina area, lumen area, neointima area, stenotic area, injury score, fibrin score, and inflammation score. In both groups, the fibrin score was higher in pigs with DES than in BMS, particularly in ZES and EES. The inflammatory score was not different between DES and BMS. CONCLUSION: In a porcine model of coronary restenosis, pretreatment with ezetimibe/simvastatin before DES implantation failed to improve arterial healing and endothelialization compared to treatment after stenting.

Effect of Atorvastatin-Eluting Stents in a Rabbit Iliac Artery Restenosis Model / 전남의대학술지

Statins have pleiotropic effects, which include the inhibition of neointima hyperplasia, the inhibition of vascular inflammation, and platelet inhibition. The aim of this study was to examine the effect of an atorvastatin-eluting stent (AES) in a rabbit iliac artery overstretch restenosis model. Ten rabbits were used in this study (10 rabbits, 10 iliac arteries for each stent). An AES and paclitaxel-eluting stent (PES) were implanted in the left and right iliac arteries in a rabbit (2 stents in each rabbit). The stents were deployed with oversizing (stent/artery ratio 1.3:1), and histopathologic analysis was assessed at 28 days after stenting. There were no significant differences in the injury score, lumen area, or inflammation score. There were significant differences in the neointimal area (0.7+/-0.18 mm2 in the AES group vs. 0.4+/-0.25 mm2 in the PES group, p<0.01), in the percentage stenosis area (14.8+/-5.06% in the AES group vs. 10.5+/-6.80% in the PES group, p<0.05), and in the fibrin score (0.4+/-0.51 in the AES group vs. 2.7+/-0.48 in the PES group, p<0.001). Although the AES did not suppress neointimal hyperplasia compared with the PES, it showed a superior arterial healing effect in a rabbit iliac artery overstretch restenosis model.

Mechanical and Histopathological Comparison between Commercialized and Newly Designed Coronary Bare Metal Stents in a Porcine Coronary Restenosis Model / 전남의대학술지

The aim of this study was to compare the stent designed by Chonnam National University Hospital (designated as CNUH) with commercial cobalt-chromium coronary stent in a porcine coronary overstretch restenosis model. CNUH stent was subjected to mechanical performance tests. Pigs were randomized into two groups in which the coronary arteries (10 pigs, 10 coronaries in each group) had either CNUH stent or control commercial bare metal stent. Histopathologic analysis was assessed at 28 days after stenting. In mechanical performance tests, CNUH stent showed 2.65N, 35.1N, 0.52N, 1.94%, 4.29% in the flat plate radial compression, radial force, 3 point bending, Foreshortening and recoil test, respectively. There was no significant difference in the injury score, internal elastic lamina (IEL), lumen area, neointima area, percent area stenosis, inflammation score and fibrin score between the two groups (1.2+/-0.35, 4.1+/-0.41 mm2, 2.7+/-0.56 mm2, 1.6+/-0.47 mm2, 36.7+/-11.2%, 1.2+/-0.62, 0.2+/-0.34 in CNUH stent group vs. 1.2+/-0.38, 3.7+/-0.64 mm2, 2.5+/-0.49 mm2, 1.5+/-0.61 mm2, 36.3+/-12.17%, 1.1+/-0.12, 0.4+/-0.46 in commercial stent group, respectively). In the mechanical performance test, CNUH stent showed the moderated performance under the guideline of FDA. CNUH stent demonstrated similar histological reactions compared with commercial cobalt-chromium stent in a porcine coronary overstretch restenosis model.

Histopathological Comparison among Biolimus, Zotarolimus and Everolimus-Eluting Stents in Porcine Coronary Restenosis Model

BACKGROUND AND OBJECTIVES: The aim of this study was to examine the histolopathogical effects among the biolimus, zotarolimus, and everolimus eluting stent (EES) in the porcine coronary restenosis model. SUBJECTS AND METHODS: Pigs were randomized into three groups in which the coronary arteries (15 pigs, 10 coronaries in each group) had either a biolimus A9 eluting stent (BES, n=10), zotarolimus eluting stent (ZES, n=10) or an EES (n=10). Histopathologic analysis was performed at 28 days after stenting. RESULTS: There were no significant differences in the injury score among the three groups. There was a significant difference in the internal elastic lamina, lumen area, neointima area, percent area stenosis, and the fibrin and inflammation score among the three groups (4.3+/-0.53 mm2, 2.5+/-0.93 mm2, 1.8+/-1.03 mm2, 40.7+/-20.80%, 1.7+/-0.41, 1.4+/-0.72 in the BES group vs. 5.1+/-0.55 mm2, 2.3+/-1.14 mm2, 2.8+/-1.00 mm2, 55.4+/-21.23%, 2.0+/-0.39, 1.6+/-0.76 in the ZES group vs. 4.4+/-0.53 mm2, 1.7+/-1.22 mm2, 2.8+/-1.23 mm2, 64.0+/-26.00%, 1.8+/-0.76, 2.1+/-0.90 in the EES group, respectively). BES is more effective in inhibiting neointimal hyperplasia compared to ZES and EES (p<0.0001). According to the fibrin and inflammation score, BES and EES are more effective in decreasing the fibrin deposition compared to ZES (p<0.001). Moreover, BES and ZES are more effective in reducing the inflammatory reaction compared to EES (p<0.001). CONCLUSION: The result demonstrates that BES shows better histopathological characteristics than ZES and EES at one month after stenting in the porcine coronary restenosis model.

Effect of Atorvastatin-Eluting Stents in a Rabbit Iliac Artery Restenosis Model / 전남의대학술지

Statins have pleiotropic effects, which include the inhibition of neointima hyperplasia, the inhibition of vascular inflammation, and platelet inhibition. The aim of this study was to examine the effect of an atorvastatin-eluting stent (AES) in a rabbit iliac artery overstretch restenosis model. Ten rabbits were used in this study (10 rabbits, 10 iliac arteries for each stent). An AES and paclitaxel-eluting stent (PES) were implanted in the left and right iliac arteries in a rabbit (2 stents in each rabbit). The stents were deployed with oversizing (stent/artery ratio 1.3:1), and histopathologic analysis was assessed at 28 days after stenting. There were no significant differences in the injury score, lumen area, or inflammation score. There were significant differences in the neointimal area (0.7+/-0.18 mm2 in the AES group vs. 0.4+/-0.25 mm2 in the PES group, p<0.01), in the percentage stenosis area (14.8+/-5.06% in the AES group vs. 10.5+/-6.80% in the PES group, p<0.05), and in the fibrin score (0.4+/-0.51 in the AES group vs. 2.7+/-0.48 in the PES group, p<0.001). Although the AES did not suppress neointimal hyperplasia compared with the PES, it showed a superior arterial healing effect in a rabbit iliac artery overstretch restenosis model.

Mechanical and Histopathological Comparison between Commercialized and Newly Designed Coronary Bare Metal Stents in a Porcine Coronary Restenosis Model / 전남의대학술지

The aim of this study was to compare the stent designed by Chonnam National University Hospital (designated as CNUH) with commercial cobalt-chromium coronary stent in a porcine coronary overstretch restenosis model. CNUH stent was subjected to mechanical performance tests. Pigs were randomized into two groups in which the coronary arteries (10 pigs, 10 coronaries in each group) had either CNUH stent or control commercial bare metal stent. Histopathologic analysis was assessed at 28 days after stenting. In mechanical performance tests, CNUH stent showed 2.65N, 35.1N, 0.52N, 1.94%, 4.29% in the flat plate radial compression, radial force, 3 point bending, Foreshortening and recoil test, respectively. There was no significant difference in the injury score, internal elastic lamina (IEL), lumen area, neointima area, percent area stenosis, inflammation score and fibrin score between the two groups (1.2+/-0.35, 4.1+/-0.41 mm2, 2.7+/-0.56 mm2, 1.6+/-0.47 mm2, 36.7+/-11.2%, 1.2+/-0.62, 0.2+/-0.34 in CNUH stent group vs. 1.2+/-0.38, 3.7+/-0.64 mm2, 2.5+/-0.49 mm2, 1.5+/-0.61 mm2, 36.3+/-12.17%, 1.1+/-0.12, 0.4+/-0.46 in commercial stent group, respectively). In the mechanical performance test, CNUH stent showed the moderated performance under the guideline of FDA. CNUH stent demonstrated similar histological reactions compared with commercial cobalt-chromium stent in a porcine coronary overstretch restenosis model.

Single coronary artery originating from the right aortic sinus without a left anterior descending and circumflex artery in conventional swine / 한국실험동물학회지

Single coronary artery is a rare coronary artery anomaly. Very few previous reports of this anatomical malformation in swine have been found. A 22 kg Yorkshire X Landrace F1 crossbred castrated male swine was presented for enrollment in a coronary stent implantion study. Coronary angiography revealed a single coronary artery arising from the right aortic sinus. The right coronary artery and anomalous left coronary artery were implanted with novel coronary stents without any side effects.

Sequential Analysis of Postural Control Resource Allocation During a Dual Task Test

OBJECTIVE: To investigate the postural control factors influencing the automatic (reflex-controlled) and attentional (high cortical) factors on dual task. METHODS: We used a dual task model to examine the attentional factors affecting the control of posture, subjecting test subjects to vibration stimulation, one-leg standing and verbal or nonverbal task trials. Twenty-three young, healthy participants were asked to stand on force plates and their centers of pressure were measured during dual task trials. We acquired 15 seconds of data for each volunteer during six dual task trials involving varying task combinations. RESULTS: We observed significantly different sway patterns between the early and late phases of dual task trials, which probably reflect the attentional demands. Vibration stimulation perturbed sway more during the early than the late phases; with or without vibration stimulation, the addition of secondary tasks decreased sway in all phases, and greater decreases in sway were observed in the late phases, when subjects were assigned nonverbal tasks. Less sway was observed during the nonverbal task in a sequential study. CONCLUSION: The attentional and automatic factors were analyzed during a sequential study. By controlling the postural control factors, optimal parameters and training methods might be used in clinical applications.

Development of a Motor Driven Rowing Machine with Automatic Functional Electrical Stimulation Controller for Individuals with Paraplegia; a Preliminary Study

OBJECTIVE: To examine the cardiorespiratory responses of patients with spinal cord injury (SCI) paraplegia using a motor driven rowing machine. METHOD: Ten SCI patients with paraplegia [A (n=6), B (n=1), and C (n=3) by the American Spinal Injury Association impairment scale] were selected. Two rowing techniques were used. The first used a fixed seat with rowing achieved using only upper extremity movement (fixed rowing). The second used an automatically moving seat, facilitating active upper extremity movement and passive lower extremity movement via the motorized seat (motor rowing). Each patient performed two randomly assigned rowing exercise stress tests 1-3 days apart. The work rate (WR), time, respiratory exchange ratio (R), oxygen consumption (VO2), heart rate (HR), metabolic equivalents (METs), and rating of perceived exertion (RPE) were recorded. RESULTS: WR, time, VO2, and METs were significantly higher after the motor rowing test than after fixed motor rowing test (p<0.05). HR after motor rowing was significantly lower than fixed rowing (p<0.05). CONCLUSION: Cardiorespiratory responses as VO2, HR and METs can be elicited by the motor rowing for people with paraplegic SCI.

Seated Postural Control in Elderly on Unstable Plate

OBJECTIVE: To investigate differences of the postural control in unstable sitting position between elderly and young adults. METHOD: Twenty five healthy elderly and twenty five healthy young adults were included. The evaluation system for postural control consisted of unstable plate, frame, safety harness, monitor and computer. Subjects sat on an unstable plate with arms crossed. Using two tilt sensor and postural control software in unstable platform measured the center of pressure (COP) of subject. COP sway (COP was maintained on the center circle and the distance from the central location for 30 sec) time and mean absolute deviation (MAD), COP maintaining (COP was maintained on the desired target in anterior, posterior, left or right directions during 30 sec) time and MAD, COP moving time (the time required to move the COP to desired target location away from center), COP sine curve maintaining (COP was maintained on the circle on moving sine curve during 30 sec) time and MAD were recorded in both groups. Each subject performed three trials and the mean value of the trials was used for analysis. RESULTS: In static evaluation, there was no significant difference in COP sway between two groups. In dynamic evaluations, elderly showed significantly decreased maintaining time in all four directions, decreased sine curve trace and increased moving time in all eight directions (p<0.001). CONCLUSION: Elderly revealed significantly impaired dynamic sitting postural control, regardless of directions. It might be related to decreased movement and proprioception of trunk.

The Analysis of Postural Control of Children with Spastic Diplegic Cerebral Palsy in Unstable Sitting

OBJECTIVE: To investigate differences in the dynamic postural control in unstable sitting position between children with spastic diplegic cerebral palsy (CP) and normally developing children. METHOD: Sixteen children with spastic diplegic CP who could sit alone and walk independently and sixteen age- matched normally developing children were included. The evaluation system for postural control consisted of unstable platform, force plate, frame, safety harness, monitor and computer. Force plate on unstable platform measured center of pressure (COP) of the subject. COP sway, COP maintaining time and COP moving time were recorded in both groups. In diplegic CP group, Gross Motor Function Measure (GMFM) was evaluated. RESULTS: In COP sway, the distance away from central location was significantly increased and time maintaining on circle at center decreased significantly in diplegic CP group (p<0.05). The children with diplegic CP showed significant decrease in maintaining time and significant increase in moving time in all directions. COP sway was significantly correlated with GMFM. CONCLUSION: Postural control in children with spastic diplegic CP walking independently was revealed to be significantly worse compared to normal age-matched children. Further studies are necessary to find out whether the training for seated postural control could improve the motor function.

Comparison of Quality in Chest Compressions at Scene, in a Moving Ambulance by Student Nurses, the 119 Member Group, and an Automatic CPR Machine

PURPOSE: In an emergency, the quality of CPR prior to hospital arrival is a very important component for the survival of victims. We want to know differences in chest compression quality performed by groups that have variant experiences of CPR, and automatic CPR machine on the floor, or in an ambulance moving at 40 km/hr, or at 80 km/hr. METHODS: We analysed the chest compression quality of each group, and that performed on the floor, in an ambulance moving as 40 km/hr, and at 80 km/hr. We measured the following factors: mean compression depth; mean compression rate; exact performance percentile; and the compression error through too deep, too weak, wrong compression location, and no full recoil. RESULTS: In the student-nurse group, the quality of chest compression performed on the floor was better than that performed in a moving ambulance. In 119 member group, chest compression performed in an ambulance moving as 40 km/hr was better than that performed in an ambulance moving at 80 km/hr. The use of an automatic CPR machine, there were no differences in chest compression quality in all circumstances. In comparing each group, compression quality of the 119 member group and the automatic CPR machine group was better than that of the student nurses. CONCLUSION: In the group with real CPR experience, there were no differences between chest compression performed on the floor and that performed moving at 40 km/hr. Chest compression performed moving as 40 km/hr is better than that performed moving at 80km/hr. In the group without CPR experience, chest compression performed on the floor is better than that performed in a moving ambulance.