Publications by authors named "Hoon Park"

160 Publications

Point Prevalence and Associated Factors of Hip Displacement in Pediatric Patients With Mitochondrial Disease.

Front Pediatr 2021 4;9:637240. Epub 2021 Nov 4.

Department of Orthopaedic Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea.

Mitochondrial disease is a multisystem disorder resulting from mitochondrial dysfunction. Although musculoskeletal system is vulnerable to mitochondrial dysfunction, little information is available on orthopedic issues such as hip displacement and scoliosis in patients with mitochondrial disease. We aimed to examine the point prevalence of hip displacement and investigate the associated factors in patients with mitochondrial disease. We retrospectively reviewed the medical records and plain radiographs of patients diagnosed with mitochondrial disease between January 2006 and January 2019 at a single institution. Data, including patient age, sex, follow-up duration, syndromic diagnosis, and gross motor function were collected. Migration percentage was measured on the radiographs. The clinical and radiologic variables were compared between patients classified according to the presence of hip displacement and motor function level. We included 225 patients (135 men, 90 women). The mean age at the latest follow-up was 11.1 years, and the mean follow-up duration was 7.0 years. Hip displacement was noted in 70 (31.1%) patients. The proportion of patients with Leigh disease ( = 0.007) and the ratio of non-ambulators ( < 0.001) were higher among patients with hip displacement. The proportion of patients with Leigh disease was higher in the non-ambulators than the ambulators. One-third of patients with mitochondrial disease developed hip displacement. Hip displacement was more common in non-ambulators or patients with hypertonia. Careful and serial monitoring for hip problems is required for non-ambulatory patients with mitochondrial disease who have increased muscle tone.
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http://dx.doi.org/10.3389/fped.2021.637240DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8599976PMC
November 2021

Relationships between monocyte count to high-density lipoprotein cholesterol ratio and cardiovascular outcomes in patients commencing dialysis.

J Int Med Res 2021 Nov;49(11):3000605211058861

Division of Nephrology, Department of Internal Medicine, Incheon St. Mary's Hospital, The Catholic University of Korea.

Objective: High monocyte to high-density lipoprotein cholesterol ratio (MHR) is known to be a risk factor for cardiovascular (CV) complications. We aimed to evaluate the relationship between MHR and CV outcomes in patients commencing dialysis.

Methods: The medical records of patients who started maintenance dialysis between January 2006 and July 2017 were reviewed. The primary outcomes were all-cause mortality and overall CV mortality and the secondary outcomes were CV event-free survival and the incidence of CV complications.

Results: Five hundred ninety-seven patients were enrolled and allocated to low- or high-MHR groups. All-cause mortality did not differ between the groups during a mean follow-up period of 3.9 years. In addition, overall CV mortality did not differ between the groups. However, CV event-free survival was significantly lower in the high-MHR group than in the low-MHR group (47.5% . 59.0%). Multivariate Cox regression analysis showed that high MHR was an independent predictor of CV events (HR 1.886, 95% CI 1.015-3.505).

Conclusion: High MHR at the time of initiation of dialysis may represent a useful predictor of CV complications.
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http://dx.doi.org/10.1177/03000605211058861DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8607493PMC
November 2021

Prevalence and Treatment Outcome of Displaced High-Long Oblique Supracondylar Humeral Fractures in Children.

Front Pediatr 2021 27;9:739909. Epub 2021 Oct 27.

Division of Pediatric Orthopedic Surgery, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, South Korea.

The treatment protocol for supracondylar humeral fracture has mainly been based only on the severity of displacement and percutaneous pinning has been recommend as a first treatment. However, a long oblique fracture line is difficult to fix by the traditional cross pinning. The purpose of this study is to assess the prevalence of high-long oblique supracondylar humeral (HLO) fracture and evaluate the surgical outcome of percutaneous pin fixation. We reviewed 690 children who had undergone an operation for the displaced supracondylar humeral fracture. HLO fracture was defined as having a fracture line starting from either cortex above the metaphyseal-diaphyseal junction and finishing at the opposite cortex around or below the olecranon fossa. Clinical and radiographic parameter outcomes were assessed. There were 14 patients diagnosed with the HLO fracture (14/690) and all the patients were treated by pin fixation. The median age was 5 years 1 month (range, 2-11 years). The common mode of injury was direct contact injury to the elbow. There were 6 patients with lateral HLO fracture, and 8 patients had medial HLO type. In medial HLO type, medial pinning only was done in 3 patients due to the difficulty in lateral pin insertion. In addition, the lateral pin was not a bicortical fixation through capitellum entry in 2 patients who had it fixed by cross pinning. The final Baumann angle and lateral humero-capitellar angle were 20.5 (5-67.6) degrees and 49.3 (23.3-71.9) degrees, respectively, without statistical significance compared to the normal side. Flynn's cosmetic grade showed satisfactory results in all patients. The prevalence of HLO fractures was 2% in the displaced supracondylar humeral fracture. The mechanism of injury of HLO fractures may be direct contact injury. In medial HLO fractures, medial pinning is important for stability, and sometimes lateral pinning was impossible. Contrarily, lateral HLO fracture could easily be fixed by lateral-only pinning, but the correct lateral pinning is necessary because medial pinning is difficult. The HLO fracture is a difficult pattern to treat by traditional percutaneous pinning and another surgical option should be considered.
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http://dx.doi.org/10.3389/fped.2021.739909DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8578841PMC
October 2021

Anti-adipogenic Effects of the Probiotic Lactiplantibacillus plantarum KU15117 on 3T3-L1 Adipocytes.

Probiotics Antimicrob Proteins 2021 Jul 15. Epub 2021 Jul 15.

Department of Food Science and Biotechnology of Animal Resource, Konkuk University, Seoul, 05029, Republic of Korea.

In this study, we investigated the probiotic properties and anti-obesity effects of bacterial strains isolated from homemade kimchi. Lactiplantibacillus plantarum KU15117 was isolated using lactobacilli selective medium. L. plantarum KU15117 did not produce β-glucuronidase and showed high tolerance to artificial gastric juice and bile salt, acceptable resistance to antibiotics, and high adhesion ability to HT-29 cells. The anti-adipogenic activity of L. plantarum KU15117 at 10 CFU/well was confirmed by the reduction of oil red O staining and intracellular triglyceride level. Additionally, the expression levels of fatty acid synthase, CCAAT/enhance-binding protein-α, and peroxisome proliferator-activated receptor-γ, which are associated with the early stage of adipocyte differentiation, were significantly lower in the probiotic-treated group than in the control group. These results suggest that L. plantarum KU15117 has probiotic properties and anti-obesity effects and could be used as a prophylactic probiotics.
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http://dx.doi.org/10.1007/s12602-021-09818-zDOI Listing
July 2021

Enfortumab vedotin after PD-1 or PD-L1 inhibitors in cisplatin-ineligible patients with advanced urothelial carcinoma (EV‑201): a multicentre, single-arm, phase 2 trial.

Lancet Oncol 2021 06 12;22(6):872-882. Epub 2021 May 12.

Perlmutter Cancer Center at NYU Langone Health, New York, NY, USA.

Background: Locally advanced or metastatic urothelial carcinoma is generally incurable and has scarce treatment options, especially for cisplatin-ineligible patients previously treated with PD-1 or PD-L1 therapy. Enfortumab vedotin is an antibody-drug conjugate directed at Nectin-4, a protein highly expressed in urothelial carcinoma. We aimed to evaluate the efficacy and safety of enfortumab vedotin in the post-immunotherapy setting in cisplatin-ineligible patients.

Methods: EV-201 is a multicentre, single-arm, phase 2 study of enfortumab vedotin in patients with locally advanced or metastatic urothelial carcinoma previously treated with PD-1 or PD-L1 inhibitors. Cohort 2 included adults (aged ≥18 years) with an Eastern Cooperative Oncology Group performance status score of 2 or less who were considered ineligible for cisplatin at enrolment and who had not received platinum-containing chemotherapy in the locally advanced or metastatic setting. Enfortumab vedotin was given intravenously at a dose of 1·25 mg/kg on days 1, 8, and 15 of every 28-day cycle. The primary endpoint was confirmed objective response rate per Response Evaluation Criteria in Solid Tumours version 1.1 assessed by blinded independent central review. Efficacy and safety were analysed in all patients who received at least one dose of enfortumab vedotin. EV-201 is an ongoing study and the primary analysis is complete. This study is registered with Clinicaltrials.gov, NCT03219333.

Findings: Between Oct 8, 2017, and Feb 11, 2020, 91 patients were enrolled at 40 sites globally, of whom 89 received treatment. Median follow-up was 13·4 months (IQR 11·3-18·9). At data cutoff (Sept 8, 2020), the confirmed objective response rate was 52% (46 of 89 patients; 95% CI 41-62), with 18 (20%) of 89 patients achieving a complete response and 28 (31%) achieving a partial response. 49 (55%) of 89 patients had grade 3 or worse treatment-related adverse events. The most common grade 3 or 4 treatment-related adverse events were neutropenia (eight [9%] patients), maculopapular rash (seven [8%] patients), and fatigue (six [7%] patients). Treatment-related serious adverse events occurred in 15 (17%) patients. Three (3%) patients died due to acute kidney injury, metabolic acidosis, and multiple organ dysfunction syndrome (one [1%] each) within 30 days of first dose and these deaths were considered by the investigator to be related to treatment; a fourth death from pneumonitis occurred more than 30 days after the last dose and was also considered to be related to treatment.

Interpretation: Treatment with enfortumab vedotin was tolerable and confirmed responses were seen in 52% of cisplatin-ineligible patients with locally advanced or metastatic urothelial carcinoma who were previously treated with PD-1 or PD-L1 inhibitors. These patients have few treatment options, and enfortumab vedotin could be a promising new therapy for a patient population with a high unmet need.

Funding: Astellas Pharma Global Development and Seagen.
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http://dx.doi.org/10.1016/S1470-2045(21)00094-2DOI Listing
June 2021

The effect of levodopa on bilateral coordination and gait asymmetry in Parkinson's disease using inertial sensor.

NPJ Parkinsons Dis 2021 May 14;7(1):42. Epub 2021 May 14.

Department of Orthopaedic Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, South Korea.

This study aimed to evaluate the effect of levodopa on the phase coordination index (PCI) and gait asymmetry (GA) of patients with Parkinson's disease (PD) and to investigate correlations between the severity of motor symptoms and gait parameters measured using an inertial sensor. Twenty-six patients with mild-to-moderate-stage PD who were taking levodopa participated in this study. The Unified Parkinson's Disease Rating Scale part III (UPDRS III) was used to assess the severity of motor impairment. The Postural Instability and Gait Difficulty (PIGD) subscore was calculated from UPDRS III. Patients were assessed while walking a 20-m corridor in both "OFF" and "ON" levodopa medication states, and gait analysis was performed using inertial sensors. We investigated the changes in gait parameters after taking levodopa and the correlations between UPDRS III, PIGD, and gait parameters. There was a significant improvement in PCI after taking levodopa. No significant effect of levodopa on GA was found. In "OFF" state, PCI and GA were not correlated with UPDRS III and PIGD. However, in "ON" state, PCI was the only gait parameter correlating with UPDRS III, and it was also highly correlated with PIGD compared to other gait parameters. Significant improvement in bilateral-phase coordination was identified in patients with PD after taking levodopa, without significant change in gait symmetricity. Considering the high correlation with UDPRS III and PIGD in "ON" states, PCI may be a useful and quantitative parameter to measure the severity of motor symptoms in PD patients who are on medication.
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http://dx.doi.org/10.1038/s41531-021-00186-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8121791PMC
May 2021

Hypertension-Mediated Organ Damage and Long-term Cardiovascular Outcomes in Asian Hypertensive Patients without Prior Cardiovascular Disease.

J Korean Med Sci 2020 Dec 14;35(48):e400. Epub 2020 Dec 14.

Division of Cardiology, Department of Internal Medicine, Veterans Health Service Medical Center, Seoul, Korea.

Background: Hypertension-mediated organ damage (HMOD), comprising structural and functional changes in arteries or end organs, is a marker of cardiovascular (CV) disease. However, there are limited data on evaluation of risk of CV disease regarding HMOD, especially in Asians. We sought to investigate the association between CV events and HMOD, and we tried to determine the most important diagnostic marker among the component of HMOD for prevention of mortality and CV events in treated Korean hypertensive patients.

Methods: From January 2008 to December 2010, a total of 35,000 hypertensive Vietnamese War veterans who consecutively visited our hospital for medical check-up were reviewed, and 6,158 patients without established CV disease were enrolled. The patients were divided into two groups as follows: HMOD group (n = 766) and non-HMOD group (n = 5,392). The primary outcome was all-cause death.

Results: Median age was 63.3 years (interquartile range [IQR], 61.4-65.4), and median follow-up was 6.6 years (IQR, 5.9-7.2). Patients with old age, diabetes, and chronic kidney disease were more prevalent in the HMOD group than in the non-HMOD group (all < 0.05). The lipid profiles were not significantly different between the two groups. Nephropathy was the most prevalent (54.7%) organ damage in the HMOD group. The 6-year incidence of all-cause death was higher in the HMOD group than in the non-HMOD group (22.5% vs. 9.0%; adjusted hazard ratio [HR], 1.42; 95% confidence interval [CI], 1.01-2.00; = 0.04). The incidence of cardiac death, ischemic heart disease, and ischemic and hemorrhagic stroke were also significantly higher in the HMOD group than in the non-HMOD group ( < 0.05, respectively). In multivariate analysis, proteinuria (adjusted HR, 2.21; 95% CI, 1.52-3.20; < 0.001) was the most powerful independent risk factor to predict all-cause death among components of HMOD. As the degree of proteinuria increased, the rate of all-cause death also increased (long-rank < 0.001).

Conclusion: HMOD was associated with increased risk of mortality and CV events. Proteinuria was the most powerful independent risk factor for all-cause death, and the degree of proteinuria and mortality rate were proportional. Our data suggest that monitoring of the proteinuria is important to predict long-term CV events in hypertensive patients.
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http://dx.doi.org/10.3346/jkms.2020.35.e400DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7735919PMC
December 2020

Mechanisms of collision recovery in flying beetles and flapping-wing robots.

Science 2020 12;370(6521):1214-1219

Department of Smart Vehicle Engineering, Konkuk University, Seoul 05029, South Korea.

At rest, beetles fold and tuck their hindwings under the elytra. For flight, the hindwings are deployed through a series of unfolding configurations that are passively driven by flapping forces. The folds lock into place as the wing fully unfolds and thereafter operates as a flat membrane to generate the aerodynamic forces. We show that in the rhinoceros beetle (), these origami-like folds serve a crucial shock-absorbing function during in-flight wing collisions. When the wing collides with an object, it collapses along the folds and springs back in place within a single stroke. Collisions are thus dampened, helping the beetle to promptly recover the flight. We implemented this mechanism on a beetle-inspired wing on a flapping-wing robot, thereby enabling it to fly safely after collisions.
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http://dx.doi.org/10.1126/science.abd3285DOI Listing
December 2020

One-Stage Extension Shortening Osteotomy for Syndromic Camptodactyly.

J Clin Med 2020 Nov 20;9(11). Epub 2020 Nov 20.

Division of Pediatric Orthopaedic Surgery, Severance Children's Hospital, Yonsei University College of Medicine, Seoul 03722, Korea.

Syndromic camptodactyly often affects multiple fingers, and severe deformities are common compared to idiopathic camptodactyly. This study aimed to evaluate the use of a one-stage extension shortening osteotomy of the proximal phalanx for patients with syndromic camptodactyly without tendon surgery. Forty-nine cases of syndromic camptodactyly were included. Forty fingers (81.6%) were associated with arthrogryposis multiplex congenita, and nine (18.4%) with other syndromes. Six fingers presented with a moderate form (30° to 60°) of camptodactyly, whereas 43 fingers manifested the severe form (>60°). The mean age at the time of surgery was 8.5 years, and the patients were followed for a mean of 3.9 years. The mean length of the shortening of the proximal phalanx was 4.9 mm, which averaged 17.8% of the proximal phalanx's original preoperative length. The mean operative time was 25.8 min, and the PIP joint was fixed using Kirschner wires with an average flexion position of 7.6°. The mean flexion contracture improved from 76° preoperatively to 41° postoperatively. The mean preoperative active arc of motion was 23°, which improved to 49° postoperatively. A one-stage extension shortening osteotomy is a straightforward and effective technique for the improvement of finger function through the indirect lengthening of volar structures without the flexor tendon lengthening. The osteotomy could simultaneously correct bony abnormalities. This simple procedure is especially suitable for surgery on multiple fingers in patients with syndromic camptodactyly.
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http://dx.doi.org/10.3390/jcm9113731DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7699896PMC
November 2020

Role of Renal Replacement Therapy During the Peri-Transplant Period of Heart Transplantation.

Ann Transplant 2020 Nov 24;25:e925648. Epub 2020 Nov 24.

Division of Nephrology, Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, South Korea.

BACKGROUND Heart transplantation (HT) is the most useful treatment modality for heart failure. Although several studies have reported the impact of acute kidney injury (AKI) on clinical outcomes after transplantation, little is known about the impact of peri-transplant renal replacement therapy (RRT) on clinical outcomes. We compared the clinical outcomes according to RRT use status among patients with AKI during the peri-transplant period. MATERIAL AND METHODS The medical records of 21 patients who underwent HT from January 2006 to May 2019 were reviewed. We assessed the heart failure cause, comorbidities, immunosuppressant type, requirement for extracorporeal membrane oxygenation, AKI incidence, and cardiac and renal functions over time. The patients were divided into 3 groups: those without AKI (non-AKI group, n=6), those who underwent perioperative RRT (RRT group, n=10), and those who did not undergo RRT (non-RRT group, n=5). RESULTS The most common cause of HT was dilated cardiomyopathy (52.4%). Fifteen patients (71.4%) experienced AKI during the peri-transplant period. Among them, 9 (90%) in the RRT group underwent continuous RRT and only 1 (10%) underwent intermittent hemodialysis. Until 6 months after HT, the renal function of the RRT group was worse than that of the non-RRT group (estimated glomerular filtration rate 44.2 vs. 69.2 mL/min/1.73 m2, P=0.015), but the differences dissipated by 9 months. Finally, all patients, even in the RRT group, withdrew from dialysis. CONCLUSIONS RRT during the peri-transplant period in HT may be a good bridge therapy for renal function recovery in patients with cardiorenal AKI.
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http://dx.doi.org/10.12659/AOT.925648DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7697654PMC
November 2020

Tailored Graphene Micropatterns by Wafer-Scale Direct Transfer for Flexible Chemical Sensor Platform.

Adv Mater 2021 Jan 20;33(2):e2004827. Epub 2020 Nov 20.

Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, Republic of Korea.

2D materials, such as graphene, exhibit great potential as functional materials for numerous novel applications due to their excellent properties. The grafting of conventional micropatterning techniques on new types of electronic devices is required to fully utilize the unique nature of graphene. However, the conventional lithography and polymer-supported transfer methods often induce the contamination and damage of the graphene surface due to polymer residues and harsh wet-transfer conditions. Herein, a novel strategy to obtain micropatterned graphene on polymer substrates using a direct curing process is demonstrated. Employing this method, entirely flexible, transparent, well-defined self-activated graphene sensor arrays, capable of gas discrimination without external heating, are fabricated on 4 in. wafer-scale substrates. Finite element method simulations show the potential of this patterning technique to maximize the performance of the sensor devices when the active channels of the 2D material are suspended and nanoscaled. This study contributes considerably to the development of flexible functional electronic devices based on 2D materials.
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http://dx.doi.org/10.1002/adma.202004827DOI Listing
January 2021

Is Computed Tomography Necessary for Diagnostic Workup in Displaced Pediatric Medial Epicondyle Fractures?

Diagnostics (Basel) 2020 Nov 17;10(11). Epub 2020 Nov 17.

Department of Orthopaedic Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul 06273, Korea.

This study aimed to compare the treatment outcomes and complications between operatively and nonoperatively treated medial epicondyle fractures with displacement of >5 mm as accurately measured on three-dimensional computed tomography (3D CT). We retrospectively reviewed 77 patients who had isolated medial epicondylar fractures with displacement of >5 mm. The mean age at injury was 11.4 years. Patients were assigned to one of two groups: 21 patients treated nonoperatively and 56 patients treated surgically. Additionally, patients treated operatively were divided into two subgroups according to fixation method; 31 patients underwent internal fixation with K-wires and 25 patients underwent internal fixation with a screw. Radiological and functional outcomes were compared among the three groups. Although the bony union rate was significantly higher in patients treated operatively compared to patients treated non-operatively (96.4% vs. 23.8%, < 0.001), there were no significant differences in functional outcomes between the two groups. In the nonoperative group, three patients underwent osteosynthesis for symptomatic nonunion. There were no significant differences in radiological and functional outcomes between the two subgroups divided by fixation method. In a pediatric medial epicondylar fracture with a displacement of >5 mm as accurately measured on 3D CT, despite the difference in union rate, there was no difference in functional outcomes between operative and nonoperative treatment. Performing CT only to measure the fracture displacement in obviously displaced medial epicondylar fracture is not considered as a part of the "necessary" diagnostic workups.
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http://dx.doi.org/10.3390/diagnostics10110957DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7696012PMC
November 2020

Development of New Hemodialysis Catheter Using Numerical Analysis and Experiments.

ASAIO J 2021 07;67(7):817-824

From the School of Mechanical Engineering, Sungkyunkwan University, Suwon, Republic of Korea.

A hemodialysis (HD) catheter, especially one with a symmetric tip design, plays an important role in the long-term treatment of patients with renal failure. It is well known that the design of the HD catheter has a considerable effect on blood recirculation and thrombus formation around it, which may cause inefficiencies or malfunctions during HD. However, hemodynamic analyses through parametric studies of its designs have been rarely performed; moreover, only comparisons between the existing models have been reported. In this study, we numerically analyzed the design of the HD catheter's side hole and distal tip for evaluating their effects on hemodynamic factors such as recirculation rate (RR), shear stress, and blood damage index (BDI). The results indicated that a larger side hole and a nozzle-shaped distal tip can significantly reduce the RR and shear stress around the HD catheter. Furthermore, based on these hemodynamic insights, we proposed three new HD catheter designs and compared their performances with existing catheters using numerical and in vitro methods. These new designs exhibited lower RRs and BDI values, thus providing better performance than the existing models. These results can help toward commercialization of more efficient HD catheters.
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http://dx.doi.org/10.1097/MAT.0000000000001315DOI Listing
July 2021

Development of donepezil-induced hypokalemia following treatment of cognitive impairment.

Yeungnam Univ J Med 2021 Jan 1;38(1):65-69. Epub 2020 Jun 1.

Division of Nephrology, Department of Internal Medicine, Eunpyeong St. Mary's Hospital, The Catholic University of Korea, Seoul, Korea.

Donepezil is a cholinesterase inhibitor used extensively to treat Alzheimer disease. The increased cholinergic activity is associated with adverse effects, therefore gastrointestinal symptoms, including nausea, vomiting, and diarrhea, are common. Hypokalemia is a rare adverse event that occurs in less than 1% of donepezil-treated patients. Although hypokalemia of mild and moderate grade does not present serious signs and symptoms, severe hypokalemia often results in prolonged hospitalization and mortality. Herein, we report a case of hypokalemia developed after the initiation of donepezil therapy for cognitive impairment.
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http://dx.doi.org/10.12701/yujm.2020.00269DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7787899PMC
January 2021

Mimicking nature's flyers: a review of insect-inspired flying robots.

Curr Opin Insect Sci 2020 12 30;42:70-75. Epub 2020 Sep 30.

Department of Smart Vehicle Engineering, Konkuk University, Artificial Muscle Research Center, 120 Neungdong-ro, Gwangjin-gu, Seoul, South Korea. Electronic address:

Insects have attracted much interest from scientists and engineers as they offer an endless source of inspiration for creating innovative engineering designs. By mimicking flying insects, it may be possible to create highly efficient biomimetic drones. In this paper, we provide an overview on how the principles of insect flight, including large stroke amplitudes and wing rotations, the clap-and-fling effect and flight control have been implemented to successfully demonstrate untethered, controlled free-flight in the insect-inspired flying robots. Despite the lack of insect-like muscles, various electro-mechanical systems have been invented to actuate insect robots. Achieving controlled free-flight is a cornerstone of next-generation insect-inspired robots which in addition to flight will be equipped with multiple modes of transportation, similar to real flying insects.
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http://dx.doi.org/10.1016/j.cois.2020.09.008DOI Listing
December 2020

Longitudinal Observation of Changes in the Ankle Alignment and Tibiofibular Relationships in Hereditary Multiple Exostoses.

Diagnostics (Basel) 2020 Sep 25;10(10). Epub 2020 Sep 25.

Division of Pediatric Orthopaedic Surgery, Severance Children's Hospital, Yonsei University College of Medicine, Seoul 03722, Korea.

The longitudinal changes in the tibiofibular relationship as the ankle valgus deformity progresses in patients with hereditary multiple exostoses (HME) are not well-known. We investigated the longitudinal changes and associating factors in the tibiofibular relationship during the growing period. A total of 33 patients (63 legs) with HME underwent two or more standing full-length anteroposterior radiographs. Based on the change in ankle alignments, thirty-five patients with an increase in tibiotalar angle were grouped into group V, and 28 patients with a decreased angle into group N. In terms of the change in radiographic parameters, significant differences were noted in the tibial length, the fibular/tibial ratio, and the proximal and distal epiphyseal gap. However, age, sex, initial ankle alignment, location of osteochondroma, and presence of tibiofibular synostosis did not affect the tibiofibular alignment. The tibial growth was relatively greater than the fibular growth and was accompanied by significant relative fibular shortening in the proximal and distal portions. In pediatric patients with HME, age, sex, initial ankle alignment, location of the osteochondroma, and synostosis did not predict the progression of the ankle valgus deformity. However, when valgus angulation progressed, relative fibular shortening was observed as the tibia grew significantly in comparison to the fibula.
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http://dx.doi.org/10.3390/diagnostics10100752DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7600422PMC
September 2020

Quantified Vascular Calcification at the Dialysis Access Site: Correlations with the Coronary Artery Calcium Score and Survival Analysis of Access and Cardiovascular Outcomes.

J Clin Med 2020 May 21;9(5). Epub 2020 May 21.

Department of Internal Medicine, Chuncheon Sacred Heart Hospital, Chuncheon 24253, Korea.

Vascular calcification is a major contributor to mortality in end-stage renal disease (ESRD) patients. In this study, we investigated whether there was a correlation between the coronary artery calcium score (CACS) and the vascular calcification score (VCS), and whether higher VCS increased the incidence of interventions and major adverse cardiac and cerebrovascular events (MACCE). ECG-gated CT, including vascular access and the coronary vessel, was taken. CACS and VCS were calculated by the Agatston method. A comparison of CACS and survival analysis according to VCS groups was performed. Using a cutoff of VCS = 500, 77 patients were divided into two groups. The vintage was significantly older in the higher VCS group. The median CACS was higher in the higher VCS group (21 [0, 171] vs. 552 [93, 2430], < 0.001). The hazard ratio (HR) for interventions and MACCEs in the higher VCS group increased by 3.2 and 2.3, respectively. Additionally, a longer duration of hemodialysis and higher magnesium levels (>2.5 mg/dL) showed lower HRs for interventions (<1). We quantified VCS and found that it was associated with the CACS. Additionally, higher VCS increased the risk of access interventions and MACCE. VCS of the access site may be suggested as a biomarker to predict ESRD patients.
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http://dx.doi.org/10.3390/jcm9051558DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7290563PMC
May 2020

Longitudinal mode model-based controller design for tailless flapping wing robot with loop shaping compensator.

Bioinspir Biomim 2020 07 7;15(5):056004. Epub 2020 Jul 7.

Department of Aerospace Information Engineering, Konkuk University, Seoul 05029, Republic of Korea.

In this study, the stable proportional-derivative (PD) controller gains for pitch control (longitudinal control) are obtained using the linearized and non-coupled longitudinal-mode flight dynamics model of the tailless, hover-capable, flapping wing robot named KUBeetle. To acquire a more realistic longitudinal model of KUBeetle, we incorporated the dynamics of the sensors, filters, and servo. Then, the range of PD controller gains that yield stable and sufficient stability robustness are determined using the Routh-Hurwitz, root locus, and H norm stability analyses. We observed that the stability of the closed loop controller is affected significantly by the dynamics that are incorporated. The PD controller gain with good robustness is selected based on the stability analysis. However, the low frequency gain of the PD controller was too small to attain the setpoint, although the stability margin was sufficiently high. A loop shaping compensator is designed and added to the control loop to improve the low frequency gain while sustaining the stability margin. The frequency and time domain analyses reveal that the proposed control loop can be used for stabilizing KUBeetle. To test the performance experimentally, we implemented the control loop in an onboard control system, which includes a microprocessor and MEMS sensors. The experimental results closely matched the simulation results, demonstrating that the proposed controller could maintain stability in a real system with high flapping noises.
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July 2020

Comparison of vascular access patency and patient survival between native arteriovenous fistula and synthetic arteriovenous graft according to age group.

Hemodial Int 2020 07 5;24(3):309-316. Epub 2020 May 5.

Division of Nephrology, Department of Internal Medicine, The Catholic University of Korea School of Medicine, Seoul, Republic of Korea.

Introduction: Arteriovenous fistula (AVF) is historically known to be the ideal option for vascular access (VA) for hemodialysis compared with arteriovenous graft (AVG). However, this approach has been recently questioned in the aging population because of their poor vessel quality and multiple comorbidities.

Methods: Data from a total of 2200 patients from the VA category of The Catholic Medical Center nephrology registry from March 2009 to February 2017 were analyzed. We compared VA patency and patient survival between two groups, AVF and AVG, according to age.

Findings: Compared with the AVG group, survival benefit in the AVF group continued even in patients ≥80 years. In the whole population, all the primary patency (PP), primary-assisted patency (PAP), and secondary patency (SP) measures were superior in the AVF group. With regard to subgroups, PP was comparable between the two groups in patients ≥65 years, whereas PAP and SP were superior in the AVF group even in septuagenarian patients who are from 70 to 79 years old. In patients ≥80 years, all the patency measures were comparable between the two groups. When the separate comparison of lower-arm AVF (or upper-arm AVF) and AVG, lower-arm AVF failed to demonstrate its superiority in any kind of patency in septuagenarian patients compared with AVG, whereas upper-arm AVF demonstrated its superiority in PAP and SP in septuagenarian patients. However, even upper-arm AVF failed to demonstrate its superiority in any kind of patency in patients ≥80 years.

Discussion: Arteriovenous fistula if using upper-arm vessel showed the superior VA patency up to septuagenarian patients, whereas, in HD patients ≥80 years, AVF and AVG were comparable in VA patency.
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http://dx.doi.org/10.1111/hdi.12836DOI Listing
July 2020

Corrigendum to "Central venous disease in hemodialysis patients" [Volume 38, Issue 3, September 2019, Pages 309-317].

Kidney Res Clin Pract 2020 Mar;39(1):112-113

Department of Radiology, St. Vincent's Hospital, School of Medicine, The Catholic University of Korea, Suwon, Republic of Korea.

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http://dx.doi.org/10.23876/j.krcp.20.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7105623PMC
March 2020

Outcome of Femoral Varus Derotational Osteotomy for the Spastic Hip Displacement: Implication for the Indication of Concomitant Pelvic Osteotomy.

J Clin Med 2020 Jan 17;9(1). Epub 2020 Jan 17.

Division of Pediatric Orthopaedic Surgery, Severance Children's Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.

No previous studies have suggested a reliable criterion for determining the addition of a concomitant pelvic osteotomy by using a large patient cohort with quadriplegic cerebral palsy and a homogenous treatment entity of femoral varus derotational osteotomies (VDRO). In this retrospective study, we examined our results of hip reconstructions conducted without a concomitant pericapsular acetabuloplasty in patients with varying degrees of hip displacement. We wished to investigate potential predictors for re-subluxation or re-dislocation after the index operation, and to suggest the indications for a simultaneous pelvic osteotomy. We reviewed the results of 144 VDROs, with or without open reduction, in 72 patients, at a mean follow-up of 7.0 (2.0 to 16.0) years. Various radiographic parameters were measured, and surgical outcomes were assessed based on the final migration percentage (MP) and the Melbourne Cerebral Palsy Hip Classification Scale (MCPHCS) grades. The effects of potential predictive factors on the surgical outcome was assessed by multivariate regression analysis. A receiver operating characteristic (ROC) curve analysis was also performed to determine whether a threshold of each risk factor existed above which the rate of unsatisfactory outcomes was significantly increased. In total, 113 hips (78.5%) showed satisfactory results, classified as MCPHCS grades I, II, and III. Thirty-one hips (21.5%) showed unsatisfactory results, including six hip dislocations. Age at surgery and preoperative acetabular index had no effects on the results. Lower pre- and postoperative MP were found to be the influential predictors of successful outcomes. The inflection point of the ROC curve for unsatisfactory outcomes corresponded to the preoperative MP of 61.8% and the postoperative MP of 5.1%, respectively; these thresholds of the pre- and postoperative MP may serve as a guideline in the indication for a concomitant pelvic osteotomy. Our results also indicate that the severely subluxated or dislocated hip, as well as the hip in which the femoral head is successfully reduced by VDRO but is still contained within the dysplastic acetabulum, may benefit from concomitant pelvic osteotomy.
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http://dx.doi.org/10.3390/jcm9010256DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7020049PMC
January 2020

Architecture of the Triceps Surae Muscles Complex in Patients with Spastic Hemiplegia: Implication for the Limited Utility of the Silfverskiöld Test.

J Clin Med 2019 Dec 1;8(12). Epub 2019 Dec 1.

Division of Pediatric Orthopaedic Surgery, Severance Children's Hospital, Yonsei University College of Medicine, Seoul 03722, Korea.

The Silfverskiöld test has long been used as an important tool for determining the affected muscles of the triceps surae in patients with equinus deformity. However, the test may not reflect the altered interactions between the muscles of the triceps which are affected by spasticity. The purpose of this study was to compare the architectural properties of the triceps surae muscles complex using ultrasonography, between hemiplegic patients and typically-developing children. Specifically, we wished to examine any differences in the architecture of the three muscles with various angle configurations of the knee and ankle joints. Ultrasound images of the medial gastrocnemius, lateral gastrocnemius, and soleus were acquired from paretic (group I) and non-paretic (group II) legs of ten patients and the legs (group III) of 10 age-matched normal children. A mixed model was used to evaluate the differences in the measurements of muscle architecture among the groups and the effects of various joint configurations on the measurements within the muscles. Compared to the results of measurements in groups II and III, the fascicle length was not different in the medial gastrocnemius of a paretic leg but it was longer in the lateral gastrocnemius and shorter in the soleus; the pennation angle was smaller in both medial and lateral gastrocnemii and was not different in the soleus; and the muscle thickness was found to be reduced in the three muscles of the paretic leg. Contrary to the observations in both the medial and lateral gastrocnemii, the fascicle length was increased and the pennation angle was decreased in the soleus with an increase of knee flexion. Through the current simulation study of the Silfverskiöld test using ultrasonography, we found that the changes detected in the architectural properties of the three muscles induced by systematic variations of the position at the ankle and the knee joints were variable. We believe that the limited utility of the Silfverskiöld test should be considered in determining an appropriate operative procedure to correct the equinus deformity in patients with altered architecture of the muscles in conditions such as cerebral palsy, as the differing muscle architectures of the triceps surae complex may affect the behavior of the muscles during the Silfverskiöld test.
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http://dx.doi.org/10.3390/jcm8122096DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6947161PMC
December 2019

Quantitative analysis of the bilateral coordination and gait asymmetry using inertial measurement unit-based gait analysis.

PLoS One 2019 1;14(10):e0222913. Epub 2019 Oct 1.

Department of Orthopaedic Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.

Inertial measurement unit (IMU)-based gait analysis can be used to quantitatively analyze the bilateral coordination and gait asymmetry (GA). The purpose of this study was to investigate changes in bilateral coordination and GA due to gait speed using an IMU based gait analysis and identify spatiotemporal factors affecting bilateral coordination and GA. Eighty healthy adults (40 men and 40 women) participated in the study. The mean age was 26.2 years, and the mean body mass index was 22.8 kg/m2. Three different walking speeds (80%, 100%, and 120% of preferred walking speed) on a treadmill were applied for 1 min of continuous level walking using a shoe-type IMU-based gait analysis system. The phase coordination index (PCI) and GA were calculated on three different walking speeds. Several variables (gait speed, height, body mass index, cadence, and step length) were analyzed as possible factors affecting the PCI and GA. Bilateral coordination and GA improved during fast walking (p = 0.005 and p = 0.019, respectively) and deteriorated during slow walking (p<0.001 and p = 0.008, respectively), compared with the participants' preferred walking speeds. The correlation analysis revealed that PCI was negatively correlated with step length at each walking condition and lower gait speed was negatively correlated with PCI and GA during slow walking. Both bilateral coordination and GA had a negative linear relationship with gait speed, showing an improvement in the fast walking condition and deterioration in the slow walking condition. Step length was the factor associated with the change in the bilateral coordination.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0222913PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6771998PMC
March 2020

Overgrowth of the Femur After Internal Fixation in Children With Femoral Shaft Fracture-A Multicenter Study.

J Orthop Trauma 2020 Mar;34(3):e90-e95

Division of Orthopaedic Surgery, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea.

Objectives: To evaluate overgrowth after internal fixation for pediatric femur fracture and to identify any factors related with overgrowth in terms of fracture type and fixation method.

Design: Retrospective comparative study.

Setting: Multicenter, children's hospital and general hospital.

Patients/participants: Eighty-seven children between 4 and 10 years of age were included. Length-stable fracture was noted in 49 children, and length-unstable fracture was found in 38 children.

Intervention: Thirty-six children were treated by minimal invasive plate osteosynthesis (MIPO), and elastic stable intramedullary nail fixation (ESIN) was used in 51 children.

Main Outcome Measurements: The degree of overgrowth after internal fixation compared to fracture type, fracture site, and surgical method. Multivariable logistic regression analysis was conducted to identify factors related with overgrowth.

Results: The average overgrowth of the femur was 10.5 ± 7.3 mm. There was no patient who required correction for final leg length discrepancy (>2 cm). There was no significant difference in overgrowth between ESIN (9.9 ± 7.2 mm) and MIPO (11.2 ± 7.6 mm) (P = 0.417). Overgrowth was similar among length-unstable fractures (12.3 ± 7.4 mm) and length-stable fractures (9.2 ± 7.0 mm), although it was statistically greater in length-unstable fractures (P = 0.048). In the MIPO group, length-unstable fractures were associated with an increased log odds of 6.873 for overgrowth of the femur (P = 0.042).

Conclusions: Femur overgrowth after internal fixation seems to not be a clinically significant problem, regardless of whether that be for length-stable or length-unstable fractures and whether they were treated by MIPO or ESIN. Length-unstable fracture may be a risk factor for overgrowth in children. However, the difference is very small, and the postoperative overgrowth would likely not be a significant factor in deciding the surgical plan.

Level Of Evidence: Therapeutic Level III. See Instructions for authors for a complete description of levels of evidence.
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http://dx.doi.org/10.1097/BOT.0000000000001652DOI Listing
March 2020

Distal Femoral Shortening Osteotomy for Severe Knee Flexion Contracture and Crouch Gait in Cerebral Palsy.

J Clin Med 2019 Sep 1;8(9). Epub 2019 Sep 1.

Division of Pediatric Orthopaedic Surgery, Severance Children's Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.

Although there have been advancements of surgical techniques to correct gait abnormalities seen in patients with cerebral palsy, the crouch gait remains one of the most difficult problems to treat. The purpose of this retrospective study was to examine our results of distal femoral shortening osteotomy (DFSO) and patellar tendon advancement (PTA), performed in patients with crouch gait associated with severe knee flexion contracture. A total of 33 patients with a mean fixed knee contracture of 38° were included in the study. The mean age at the time of surgery was 12.2 years and the mean follow-up was 26.9 months. The measurements of clinical, radiological, and gait parameters were performed before and after surgery. The mean degrees of knee flexion contracture, Koshino index of patella height, and Gait Deviation Index were found to be significantly improved at the time of final follow-up. The maximum knee extension during the stance phase improved by an average of 25°, and the range of knee motion during gait increased postoperatively. On the other hand, the mean anterior pelvic tilt increased by 9.9°. Also, the maximum knee flexion during the swing phase decreased and the timing of peak knee flexion was observed to be delayed. We conclude that combined procedure of DFSO and PTA is an effective and safe surgical method for treating severe knee flexion contracture and crouch gait. However, the surgeons should be aware of the development of increased anterior pelvic tilt and stiff knee gait after the index operation.
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http://dx.doi.org/10.3390/jcm8091354DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6780050PMC
September 2019

Extremely large sweep amplitude enables high wing loading in giant hovering insects.

Bioinspir Biomim 2019 09 13;14(6):066006. Epub 2019 Sep 13.

Artificial Muscle Research Center, Konkuk University, Seoul, Republic of Korea. Department of Smart Vehicle Engineering, Konkuk University, Seoul, Republic of Korea.

Beetle Allomyrina dichotoma is one of the largest insects that performs many remarkable modes of locomotion, particularly hovering flight capability. In order to stay airborne, its flexible hindwings are flapped so as to work as a thrust generator. However, the wing loading of the beetle is relatively large (38.94  ±  3.73 N m) compared to those of other insects and hummingbirds, indicating that it is challenging for it to achieve flight. Here, we measured the hindwing morphology and kinematics of the beetle in order to discover its flight performance. Unlike many other insects, the beetle flaps its hindwings with an extremely large sweep amplitude of about 191.33  ±  6.12 deg at high flapping frequencies ranging from 36 to 41 Hz (mean wing tip speed  ≈  13.45  ±  0.58 m s). These capabilities enable the beetle to produce enough lift force to stay airborne with its bulky body (4-10 g). In order to investigate how the sweep amplitude affects the beetle's flight efficiency, we utilized the unsteady blade element model to estimate the power requirements of the same vertical force production for various sweep amplitudes. The results indicate that the sweep amplitude as high as 190 deg is more beneficial for power requirements than the smaller amplitudes, which require higher frequencies resulting in higher inertial powers to produce the same vertical force. Thus, for this large beetle, high sweep amplitude may be a biological strategy for staying airborne. In addition, we thoroughly discussed the effects of input constraints on the outcome by investigating power loadings for variable sweep amplitudes at a constant vertical force, mean wing tip speed, and flapping frequency. Effect of wing surface area was also investigated and discussed to provide useful information for the development of an insect-inspired flapping-wing robot.
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http://dx.doi.org/10.1088/1748-3190/ab3d55DOI Listing
September 2019

Central venous disease in hemodialysis patients.

Kidney Res Clin Pract 2019 09;38(3):309-317

Department of Radiology, St. Vincent's Hospital, School of Medicine, The Catholic University of Korea, Suwon, Korea.

Central venous disease (CVD) is difficult to treat and often resistant to treatment. In CVD, hemodialysis vascular access should sometimes be abandoned, or in serious cases, the patient's life may be threatened. Therefore, prevention is ideal. However, as the prevalence of chronic kidney disease (CKD) has increased steadily with population aging, CKD patients with a peripherally inserted central catheter (PICC) are encountered frequently. PICCs can cause CVD, and the basilic vein, which is regarded as the important last option for native arteriovenous fistula (AVF) creation in end-stage renal disease (ESRD) patients, is destroyed frequently after its use as the entry site of PICC. The most well-established risk factors for CVD are a history of central venous catheter (CVC) insertion and its duration of use. Therefore, to reduce the incidence of CVD, catheterization in the central vein (CV) should be minimized, along with its duration of use. In this review, we will first explain the basic territories of the CV and introduce its pathophysiology, clinical features, and advanced treatment options. Finally, we will emphasize prevention of CVD.
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http://dx.doi.org/10.23876/j.krcp.19.025DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6727898PMC
September 2019

The effect of vascular access type on intra-access flow volume during hemodialysis.

J Vasc Access 2019 Nov 31;20(6):746-751. Epub 2019 May 31.

Division of Nephrology, Department of Internal Medicine, School of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.

Introduction: Previous studies have revealed that vascular access resistance is constant during hemodialysis, but differs according to vascular access type. It is possible that intra-access flow volume (Qac) variation during hemodialysis may also differ according to vascular access type. We conducted this study to investigate whether there are differences in Qac according to vascular access type during hemodialysis.

Methods: A total of 58 lower-arm arteriovenous fistula, 14 lower-arm arteriovenous graft, 27 upper-arm arteriovenous fistula, and 45 upper-arm arteriovenous graft cases were studied. Three consecutive Qac values (at 30, 120, and 240 min after the start of hemodialysis) were measured in each patient by the ultrasound dilution technique. Variations in Qac over time were analyzed using repeated measures analysis of variance and multivariate regression analyses, to assess the impact of different factors on Qac variation.

Results: The repeated measures analysis of variance revealed that a significant interaction exists between time and vascular access type (p < 0.001). This suggests that vascular access type affects Qac change (%) variation over time during hemodialysis. In a multivariate analysis, mean arterial pressure change during hemodialysis (p = 0.009), access type (p < 0.001), and access location (p < 0.001) were independent variables causing Qac change variation.

Conclusion: This study showed that there is a significant difference in Qac variation according to vascular access type during hemodialysis and that arteriovenous graft (vs arteriovenous fistula) and the lower-arm location (vs upper arm) were associated with a decrease in Qac during hemodialysis. This suggests that consideration of vascular access type is required to minimize Qac variation during hemodialysis.
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http://dx.doi.org/10.1177/1129729819850942DOI Listing
November 2019

Radiographic Assessment of Foot Alignment in Juvenile Hallux Valgus and Its Relationship to Flatfoot.

Foot Ankle Int 2019 Sep 27;40(9):1079-1086. Epub 2019 May 27.

2 Department of Orthopaedic Surgery, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.

Background: The relationship between juvenile hallux valgus (JHV) and flatfoot has not been clearly established. The aim of this study was to assess radiographic measurements in feet with JHV compared with matched controls and to investigate whether the foot alignment of JHV is related to flatfoot.

Methods: We retrospectively reviewed 163 patients with JHV as defined as hallux valgus angle greater than 20 degrees and intermetatarsal greater than angle than 10 degrees. Patients with open physes of the feet and who had weight-bearing radiographs of the feet were included. Another 55 normal participants served as controls. Patients with JHV were divided into 2 subgroups: Group 1 included patients with asymptomatic JHV and group 2 consisted of those treated with correctional surgery for painful JHV. Twelve radiographic indices were analyzed, including calcaneal pitch angle, tibiocalcaneal angle, talocalcaneal angle, naviculocuboid overlap, talonavicular coverage angle, lateral talo-first metatarsal angle, anteroposterior talo-first metatarsal angle, metatarsus adductus angle, hallux valgus angle, intermetatarsal angle, distal metatarsal articular angle, and first metatarsal cuneiform angle. The groups were compared by age, gender, and the above radiographic parameters.

Results: There was no significant difference in hindfoot alignment of patients with JHV and controls. Naviculocuboid overlap ( <.001), lateral talo-first metatarsal angle ( = .002), and metatarsus adductus angle ( = .004) were significantly greater in patients with JHV than in controls, whereas the anteroposterior talo-first metatarsal angle ( = .026) was significantly less. Symptomatic and asymptomatic JHV patient subsets showed no significant radiologic differences.

Conclusion: Radiographic profiles in patients with JHV were inconsistent with regard to features of flatfoot, and foot alignment was unrelated to the presence of symptoms or degree of deformity in JHV.

Level Of Evidence: Level III, retrospective comparative series.
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http://dx.doi.org/10.1177/1071100719850148DOI Listing
September 2019

Clinical and Gait Parameters Related to Pelvic Retraction in Patients with Spastic Hemiplegia.

J Clin Med 2019 May 14;8(5). Epub 2019 May 14.

Division of Pediatric Orthopaedic Surgery, Severance Children's Hospital, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea.

Pelvic retraction during walking is a common finding seen in patients with spastic hemiplegia. However, potential factors related to this condition have not been comprehensively examined in a systemic manner in previous studies. The purpose of this study was to elucidate any clinical and gait parameters related to pelvic retraction in patients with hemiplegic cerebral palsy. A total of 212 independent ambulatory patients were enrolled in the study. Group I consisted of 113 patients who had persistent pelvic retraction, and Group II of 99 with a normal range of pelvic rotation throughout the gait cycle as evidenced by kinematic analysis. A multivariate logistic regression analysis using a clustering technique was performed, with use of eight gait factors and five clinical factors. Decreased ankle dorsiflexion, increased hip internal rotation, increased anterior pelvic tilt, the Winters classification type II, and were found to be related to pelvic retraction. This is the only study including a broader array of assessment domains of both clinical and gait parameters with a considerably large and homogenous population with hemiplegia. Further studies will be needed to see whether the rectification of those parameters may improve abnormal gait and pelvic retraction in hemiplegia.
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http://dx.doi.org/10.3390/jcm8050679DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6571873PMC
May 2019
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