BACKGROUND: Handgrip and cold pressor test may increase the afterload of the heart. And in left ventricular hypertrophy, it is known that mitral flow pattern is affected by decreased left ventricular compliance. We investigated the effects of handgrip and cold pressor test on mitral flow pattern in patients with left ventricular hypertrophy. METHODS: Handgrip and cold pressor test were performed in 12 subjects with left ventricular hypertrophy and in 14 healthy normal subjects. In supine position, blood pressure, heart rate and Doppler echocardiographic parameters(early peak flow velocity : E, atrial peak flow velocity : A) were obtained at rest, 1 and 3 minutes after the onset of tests respectively. RESULTS: In both groups, handgrip and cold pressor test increased blood pressure slightly without a statistical significance. In left ventricular hypertrophy group, there were significant increments in heart rates at 1 minute of handgrip (78+/-12min-1, p<0.001) and cold pressor test(77+/-7min-1, p<0.05) as compared to that at rest (73+/-12min-1). Mitral flow velocities did not show significant change after the tests in control group. A waves after 1 minute of handgrip(85.2+/-18.4cm/sec, p<0.05) and cold pressor test (87.3+/-17.8cm/sec, p<0.001) showed significant increases as compared to that at rest (79.1+/-14.9cm/sec) in left ventricular hypertrophy group whereas E waves did not. CONCLUSION: Although handgrip and cold pressor tests did not affect the mitral flow significantly in control group, each test raised A waves in left ventricular hypertrophy group. These results suggest that increased A waves may be due to a rise in afterload and decreased left ventricular compliance caused by handgrip and cold pressor test in left ventricular hypertrophy group.
Blood Pressure ; Compliance ; Echocardiography ; Heart ; Heart Rate ; Humans ; Hypertrophy, Left Ventricular* ; Supine Position

BACKGROUND: Confirm the stability of intervertebral disc sustaining each fused lumbar spine cases, comparing vertical compression, A-P shear force and rotational moment on intervertebral disc of instrumented lumbar spine with simple vertical compression load and follower load using finite element analysis. MATERIALS AND METHODS: We analyze the stability of intervertebral disc L4-5 supporting fused lumbar spine segments. After performing finite element modelling about L1-L5 lumbar vertebral column and L1-L4 each fusion level pedicle screw system for fused lumbar spine fine element model. Intervertebral discs with complex structure and mechanical properties was modeled using spring element that compensate stiffness and tube-to-tube contact element was employed to give follower load. Performing geometrical non-linear analysis. RESULTS: The differences of intervertebral disc L4-5 behavior under the follower compression load in comparision with vertical compression load are as follows. CONCLUSION: As a result of finite element interpretation of instrumented lumbar spine, the stability of L4-5 sustaining fused lumbar segment, the long level fused lumbar spine observed hing stability under follower load. This research method can be the basis tool of effects prediction for instrumentation, a invention of a more precious finite element interpretation model which consider the role of muscle around the spine is loaded.
Finite Element Analysis ; Intervertebral Disc* ; Inventions ; Spine*

BACKGROUND: Confirm the stability of intervertebral disc sustaining each fused lumbar spine cases, comparing vertical compression, A-P shear force and rotational moment on intervertebral disc of instrumented lumbar spine with simple vertical compression load and follower load using finite element analysis. MATERIALS AND METHODS: We analyze the stability of intervertebral disc L4-5 supporting fused lumbar spine segments. After performing finite element modelling about L1-L5 lumbar vertebral column and L1-L4 each fusion level pedicle screw system for fused lumbar spine fine element model. Intervertebral discs with complex structure and mechanical properties was modeled using spring element that compensate stiffness and tube-to-tube contact element was employed to give follower load. Performing geometrical non-linear analysis. RESULTS: The differences of intervertebral disc L4-5 behavior under the follower compression load in comparision with vertical compression load are as follows. CONCLUSION: As a result of finite element interpretation of instrumented lumbar spine, the stability of L4-5 sustaining fused lumbar segment, the long level fused lumbar spine observed hing stability under follower load. This research method can be the basis tool of effects prediction for instrumentation, a invention of a more precious finite element interpretation model which consider the role of muscle around the spine is loaded.
Finite Element Analysis ; Intervertebral Disc* ; Inventions ; Spine*

Purpose: This study compared clinical outcomes depending on the fixation modality in patients who underwent arthrodesis surgery for Eaton-Littler stage III trapeziometacarpal (TM) joint arthritis between 2009 and 2022. Methods: In total, 39 patients with 44 hands (five patients had surgery on both hands) were selected. Depending on the operative fixation instruments, patients were divided into two groups: group 1, surgery with 25-gauge interosseous wiring and Kirschner wire or headless screw fixation; group 2, surgery with only multiple headless screws for fixation. Bone union was achieved at 62 days after surgery in group 1 and 75 days in group 2 (p=0.165). Results: The preoperative mean visual analogue scores improved during the postoperative outpatient follow-up period in both groups (group 1, from 4.0 preoperatively to 1.0 at the final follow-up; group 2, from 5.0 preoperatively to 2.0 at the final follow-up). Mean grip strength and pinch strength increased after surgery. One patient (4.8%) experienced nonunion in group 1, whereas nonunion occurred in four patients (17.4%) in group 2. This difference was not statistically significant. Four patients in group 1 and no patients in group 2 underwent fixation instrument removal after sound union. Conclusion Adequate stability can be achieved during arthrodesis by combining interosseous wiring and other implants or multiple headless compression screws, resulting in successful outcomes for patients with Eaton-Littler stage III degenerative TM arthritis.

OBJECTIVE: To determine whether the use of contrast enhancement (especially its extent) predicts malignant brain edema after intra-arterial thrombectomy (IAT) in patients with acute ischemic stroke. METHODS: We reviewed the records of patients with acute ischemic stroke who underwent IAT for occlusion of the internal carotid artery or the middle cerebral artery between January 2012 and March 2015. To estimate the extent of contrast enhancement (CE), we used the contrast enhancement area ratio (CEAR)-i.e., the ratio of the CE to the area of the hemisphere, as noted on immediate non-enhanced brain computed tomography (NECT) post-IAT. Patients were categorized into two groups based on the CEAR values being either greater than or less than 0.2. RESULTS: A total of 39 patients were included. Contrast enhancement was found in 26 patients (66.7%). In this subgroup, the CEAR was greater than 0.2 in 7 patients (18%) and less than 0.2 in the other 19 patients (48.7%). On univariate analysis, both CEAR > or =0.2 and the presence of subarachnoid hemorrhage were significantly associated with progression to malignant brain edema (p<0.001 and p=0.004), but on multivariate analysis, only CEAR > or =0.2 showed a statistically significant association (p=0.019). In the group with CEAR > or =0.2, the time to malignant brain edema was shorter (p=0.039) than in the group with CEAR <0.2. Clinical functional outcomes, based on the modified Rankin scale, were also significantly worse in patients with CEAR > or =0.2 (p=0.003) CONCLUSION: The extent of contrast enhancement as noted on NECT scans obtained immediately after IAT could be predictive of malignant brain edema and a poor clinical outcome.
Brain Edema* ; Brain* ; Carotid Artery, Internal ; Humans ; Infarction* ; Middle Cerebral Artery ; Multivariate Analysis ; Stroke ; Subarachnoid Hemorrhage ; Thrombectomy*

PURPOSE: The aim of this study was to investigate the clinical characteristics of primary spontaneous pneumothorax (PSP) in adolescents and identify risk factors for the recurrence of PSP. METHODS: A total of 292 patients diagnosed with PSP from January 1998 to December 2011 were retrospectively studied. Clinical data on demographics, diagnostic imaging, therapies, and risk factors of recurrence were collected and analyzed. RESULTS: The sex ratio of 292 patients was 19.8:1 (male:female), and the average age of the patients was 17.0 years. The average body mass index of the patients was 18.8 kg/m2. The most common presenting symptom was chest pain. There was no seasonal variation in the incidence of PSP. Thirty patients (10.2%) had a history of smoking. The most common location of PSP was the left side. Out of 249 patients, 169 (67.9%) had cysts (blebs/bullae). Fifty-four patients (18.5%) received oxygen therapy, 3 patients (1%) needle aspiration, 119 patients (40.8%) closed tube drainage, and 116 patients (39.7%) surgery. The recurrence rate was 38.6%. Smoking was associated with the size of pneumothorax (P=0.002). Also, the size of pneumothorax and surgery was associated with recurrence (P=0.040 and P=0.004). However, previously reported risk factors for recurrence were not identified in our patients. CONCLUSION: Pediatric PSP occurred mainly in males in late adolescence with normal body mass index. No significant risk factors were related to recurrence of PSP in our study.
Adolescent* ; Body Mass Index ; Chest Pain ; Demography ; Diagnostic Imaging ; Drainage ; Humans ; Incidence ; Male ; Needles ; Oxygen ; Pneumothorax* ; Recurrence* ; Retrospective Studies ; Risk Factors ; Seasons ; Sex Ratio ; Smoke ; Smoking

PURPOSE: Both under-nutrition and obesity may be associated with severity of viral infection. We investigated the association of obesity with clinical factors and the severity of acute bronchiolitis in infants. METHODS: We reviewed 740 infants younger than 1 year of age who were admitted with the first episode of acute bronchiolitis between 2010 and 2013. Subjects were classified into 3 groups according to the weight-for-length Z-score. RESULTS: Younger age (3.6+/-2.6 months) was more frequent in the obesity group (P<0.001). Infants aged < or =6 months (90%) dominantly included in the obesity group. Logistic regression showed that age (younger than 3 months) was independently associated with the overweight and obesity groups with acute bronchiolitis in infants (odds ratio [OR], 1.77; P=0.001 for overweight; OR, 4.67; P<0.001 for obesity). Moreover, the obesity group was associated with an increased risk of chest retraction, hypoxia, respiratory syncytial virus detection, length of stay (more than 5 days), and need for oxygen supplement. These factors tended to increase from the overweight group toward the obesity group. CONCLUSION: Younger than 3 months of age was a risk factor for developing worse clinical course in overweight and obesity groups with acute bronchiolitis in infants. Careful attention should be paid to the clinical course of younger obese infants with acute bronchiolitis.
Anoxia ; Bronchiolitis* ; Humans ; Infant* ; Length of Stay ; Logistic Models ; Obesity* ; Overweight ; Oxygen ; Respiratory Syncytial Viruses ; Risk Factors ; Thorax

PURPOSE: The anatomic relationships of the lower lid and soft tissue between younger and older groups were compared using CT scans for confirming the negative vector relationship in the Korean population. METHODS: The study sample was composed of 100 patients with no history of previous surgery and no ocular disease. Two groups of 100 patients, younger (less than 30 years of age) versus older (above 50 years of age), were studied using CT scans. The distances from the anterior cornea to the lower lid fat, inferior orbital rim and anterior cheek mass were measured at the midpupillary plane. RESULTS: The mean age of the younger group was 22.0 years (ages 14 through 29), compared with 60.6 years (ages 53 thru 73) for the older group. Comparison of mean linear measurements revealed an anterior movement of the lower lid fat between younger and older groups (-5.09 mm vs. -3.50 mm, respectively, P < 0.01). A regression of the inferior orbital rim (-6.93 mm vs. -8.98 mm, P < 0.01) and anterior cheek mass (3.07 mm vs. 0.43 mm, P < 0.01) was observed with age in the sagittal cross section view. CONCLUSIONS: The present study demonstrates the orbital remodeling according to age in the Korean population. Because the negative vector is more common in the elderly and portends a greater risk for lower lid complications after surgery, surgeons need to consider the orbital remodeling according to age before surgery.
Aged ; Cheek ; Cornea ; Humans ; Orbit

PURPOSE: To clarify the behavior of the lumbar spine under vertical compressive load and follower compressive load and to confirm the effect of the follower load on the stability of the spinal column using finite element method. MATERIALS AND METHODS: Describing follower compression test to overcome underestimation of load carrying capacity, the problem in existing ex-vivo lumbar spine compression test, with finite element analysis, comparing with the result of simple vertical compressive load, we analyze the property of kinetic behavior. After performing finite element modelling about L1-L5 lumbar vertebral column, analyze it about vertical compressive load and follower compressive load. Intervertebral discs with complex structure and mechanical properties was modeled using spring element that compensate stiffness and tube-to-tube contact element was employed to give follower load. With compressive load, change of lumbar spinal curve is so much, that geometrical analysis should be done. RESULTS: Under the follower compressive load, the vertebral column was so stiff that vertical displacement of the upper end plate of L1 was markedly reduced, comparing with that under the simple vertical compressive load. Sagittal rotation of that upper end plate was also decreased in the opposite direction. Compressive load on the intervertebral disc was evenly distributed along the entire column. The bending moment at each disc was reduced in the opposite direction. A lesser A-P shear force occurred at the intervertebral disc. CONCLUSION: As a result of finite element interpretation of lumbar spine, the stability and load carrying capacity was increased largely, and the compressive load was transmitted through the column in a more pattern, when follower compressive load applied. This can provide the basis for explaining the difference of early buckling occurrence reported in ex-vivo testing, and load carrying capacity of the lumbar spine in-vivo, but, for more precise replication of behavior of lumbar spine in-vivo to variable loading. A invention of a more precious finite element interpretation model which consider the role of muscle around the spine is loaded.
Natural Resources ; Finite Element Analysis ; Intervertebral Disc ; Inventions ; Spine*

PURPOSE: We investigated the clinical difference between single infection and coinfection with respiratory virus in hospitalized children with acute respiratory tract infections. METHODS: We reviewed 727 patients who were admitted with the diagnosis of acute respiratory infection at the Department of Pediatrics, Bundang Jesaeng Hospital between January and December of 2014. Diagnoses were made using the multiplex reverse transcriptase polymerase chain reaction (RT-PCR) assay targeting 16 viruses in nasopharyngeal swabs. Subjects were classified as the single virus infection and coinfection groups. RESULTS: A total of 439 patients were enrolled; 359 (77.2%) under 24 months. Single virus was detected in 279 (63.6%). Coinfection with multiple virus was detected in 160 (36.4%): 126 (28.7%) with 2 viruses, 30 (6.8%), and 4 (0.9%) with 3 to 4 viruses. Viral coinfection was detected in 28 samples (17.5%), with respiratory syncytial virus (RSV) A and rhinovirus being the most dominating combination. There were no clinical differences between the single infection and coinfection groups, except sputum and the frequency of high RSV load. Sputum was significantly more frequent in the coinfection group (P=0.043), and the frequency of high RSV load was significantly higher in the single infection group (P=0.029). Disease severity (high fever, the duration of fever [≥5 days], and the length of hospital stay [≥5 days], O₂ therapy) did not differ significantly between both groups. RSV was a frequent virus of single infection during winter. Coinfection was most common in winter. CONCLUSION: There were no clinical differences between single infection and coinfection, except sputum and the frequency of high RSV load.
Child ; Child, Hospitalized ; Coinfection* ; Diagnosis ; Fever ; Humans ; Length of Stay ; Multiplex Polymerase Chain Reaction ; Pediatrics ; Respiratory Syncytial Viruses ; Respiratory Tract Infections ; Reverse Transcriptase Polymerase Chain Reaction ; Rhinovirus ; Sputum