Effects of size and shape of the side holes of a double J stent on the ureter fluid flow after stenosis.

The effect of side holes morphology changes in double J stent (DJS) on encrustation was analyzed using computational fluid dynamics (CFD). We analyzed DJS side holes with inner diameter of 1 mm and outer diameters of 1 (type A), 1.2 (type B) and 1.4 (type C) mm, respectively. Concentric stenosis with three intraureteral degree (0%, 12%, and 88%) was analyzed. The flow rate, shear stress and wall shear stress (WSS) distribution were investigated. Urine flow through SH1 before the ureteropelvic junction (UPJ) differed based on the ureteral stenosis degree. The sum of flow rates through the SHs increased with diameter. In the stented ureter with 12% stenosis, the flow rate through SH1 approximately doubled than that without ureteral stenosis, and the flow rate through SH1 was maximal for the type 'C' stent in both 12% and 88% ureteral stenosis. The mean shear stress in the SHs increased with the degree of stenosis. The WSS around the SHs was higher for type 'C' than types A and B. From the flow rates and shear stresses in and around the SHs, the larger SH diameter of the DJS from the UPJ to mid-ureter is expected to induce encrustation reduction, especially in patients with urinary lithiasis.

Korean vs. Western Exercise Capacity Nomograms for Korean Patients With Cardiovascular Disease.

BACKGROUND: Exercise capacity is known to be an independent predictor of cardiovascular events and mortality. However, most previous studies were based on Western populations. Further study is warranted for Asian patients according to ethnic or national standards. We aimed to compare prognostic values of Korean and Western nomograms for exercise capacity in Korean patients with cardiovascular disease (CVD). METHODS: In this retrospective cohort study, we enrolled 1,178 patients (62 ± 11 years; 78% male) between June 2015 and May 2020, who were referred for cardiopulmonary exercise testing in our cardiac rehabilitation program. The median follow-up period was 1.6 years. Exercise capacity was measured in metabolic equivalents by direct gas exchange method during the treadmill test. The nomogram for exercise capacity from healthy Korean individuals and a previous landmark Western study was used to determine the percentage of predicted exercise capacity. The primary endpoint was the composite of major adverse cardiovascular events (MACE; all-cause death, myocardial infarction, repeat revascularization, stroke and hospitalization for heart failure). RESULTS: A multivariate analysis showed that the risk of primary endpoint was more than double (hazard ratio [HR], 2.20; 95% confidence interval [CI], 1.10-4.40) in the patients with lower exercise capacity (< 85% of predicted) by Korean nomogram. The lower exercise capacity was one of the strong independent predictors along with left ventricular ejection fraction, age, and level of hemoglobin. However, the lower exercise capacity by Western nomogram could not predict the primary endpoint (HR, 1.33; 95% CI, 0.85-2.10). CONCLUSION: Korean patients with CVD with lower exercise capacity have higher risk of MACE. Considering inter-ethnic differences in cardiorespiratory fitness, the Korean nomogram provides more suitable reference values than the Western nomogram to determine lower exercise capacity and predict cardiovascular events in Korean patients with CVD.

Effect of different ratios of phytogenic feed additives on growth performance, nutrient digestibility, intestinal barrier integrity, and immune response in weaned pigs challenged with a pathogenic Escherichia coli.

This study was conducted to investigate the effects of supplementing different ratios of phytogenic feed additives (PFA) to weaned pigs challenged with pathogenic Escherichia coli on growth performance, nutrient digestibility, intestinal barrier integrity, and immune response, and to determine the optimal mixing ratio for post-weaning diarrhea (PWD) prevention. A total of 48 4-wk-old weaned pigs with initial body weight of 8.01 ± 0.39 kg were placed in individual metabolic cages, and then randomly assigned to eight treatment groups. The eight treatments were as follows: a basal diet without E. coli challenge (negative control, NC), a basal diet with E. coli challenge (positive control, PC), PC with supplementing 0.1% mixture of 20% bitter citrus extract (BCE), 10% microencapsulated blend of thymol and carvacrol (MEO), and 70% excipient (T1), PC with supplementing 0.1% mixture of 10% MEO, 20% premixture of grape seed and grape marc extract, green tea, and hops (PGE), and 60% excipient (T2), PC with supplementing 0.1% mixture of 10% BCE, 10% MEO, 10% PGE, and 70% excipient (T3), PC with supplementing 0.1% mixture of 20% BCE, 20% MEO, and 60% excipient (T4), PC with supplementing 0.1% mixture of 20% MEO, 20% PGE, and 60% excipient (T5), and PC with supplementing 0.1% mixture of 10% BCE, 20% MEO, 10% PGE, and 60% excipient (T6). The experiments progressed in 16 days, including 5 days before and 11 days after the first E. coli challenge (day 0). In the E. coli challenge treatments, all pigs were orally inoculated by dividing a total of 10 mL of E. coli F 18 for three consecutive days from day 0 postinoculation (PI). Compared with the PC group, the PFA2 and PFA6 groups significantly increased (P < 0.05) feed efficiency and decreased (P < 0.05) diarrhea during the entire period. At day 11 PI, the PFA6 group significantly improved (P < 0.05) gross energy digestibility compared to the PFA1 group. The PFA6 group significantly decreased (P < 0.05) tumor necrosis factor α (TNF-α) and interleukin-6 in serum and increased (P < 0.05) the villus height to crypt depth ratio (VH:CD). The PFA2 significantly decreased (P < 0.05) the relative protein expression of calprotectin in the ileum. In conclusion, improvements in growth performance, diarrhea reduction, and immunity enhancement are demonstrated when 10% BCE, 20% MEO, 10% PGE, and 60% excipient are mixed.

Phytogenic feed additives (PFA) include various herbs and spices, such as essential oils and polyphenols. Flavonoids and polyphenols contained in PFA are generally known to have antioxidant and antibacterial actions and based on this, PFA is considered an alternative to antibiotics in the swine industry. Pathogenic Escherichia coli infection is one of the most important causes of post-weaning diarrhea (PWD) in pigs. PWD causes intestinal damage, which leads to severe diarrhea, reduced growth performance, and mortality in weaned pigs, resulting in significant financial loss to the swine industry. Therefore, this study was conducted to investigate the effects of supplementing different ratios of PFA to weaned pigs challenged with E. coli and determine the optimal mixing ratio for PWD prevention. Our study results showed that growth performance was improved when supplementing a mixture of 10% bitter citrus extract (BCE), 20% microencapsulated blend of thymol and carvacrol (MEO), 10% premixture of grape seed and grape marc extract, green tea, and hops (PGE), and 60% excipient. Also, the effect of improving the immune response and intestinal morphology was shown. In conclusion, a mixture of 10% BCE, 20% MEO, 10% PGE, and 60% excipients is considered the optimal mixing ratio.

Evaluation of encrustation of double J stents with artificial urine.

PURPOSE: To evaluate the formation of encrustation on double J stents (DJSs) using artificial urine. MATERIALS AND METHODS: In this study, a static urinary system containing artificial urine was created, and a total of 45 DJSs were used to evaluate the formation of encrustation. Three groups of 15 DJSs were tested for 4, 8, or 14 weeks. The formation of encrustation on the DJSs over the weeks was analyzed using methods including X-ray powder diffraction (XRD), inductively coupled plasma spectrophotometer (ICP), and scanning electron microscope (SEM). Statistical analysis and the uncertainty test were used for data analysis using R language. RESULTS: The ICP analyzed the weight of the calcium and magnesium, which are the major components of urinary stones and encrustation, and showed that it was the heaviest at 14 weeks. Measurement of the area of encrustation on the outer surface of the DJSs revealed that the encrustation area at the bottom of the stent was greater than that at the top of the stent, regardless of the experimental period (proximal part: ≤ 41,099 µm2, distal part: ≤ 183,259 µm2). Encrustation occurred around the side holes of DJSs and became bigger over time to fill up the side holes. CONCLUSION: Encrustation spots included the bottom zone of the DJS and around the side holes. These results indicate that the performance of DJSs would be improved by modifying the shape of DJSs located near the bladder and side holes.

Degree of conversion of light-polymerized composite resin in implant prosthesis screw access opening.

PURPOSE: The mechanical and physical properties of implant screw access opening deteriorate if composite resin is not polymerized properly. Therefore, this study aimed to analyze the effect of using composite resin in implant access opening on the degree of conversion (DC). MATERIALS AND METHODS: Two prosthetic materials (Co-Cr and zirconia), two types of composite resin (low and high viscosity), two light-cured resin depths (2 and 3 mm), and two polymerization methods (max-mode 10 s and mid-mode 20 s: 16 and 22 J/cm2 , respectively) were considered (n = 192). The DC of the polymerized composite resin was measured through Fourier-transform infrared spectroscopy. The top and bottom surfaces of the polymerized composite resin body were observed through scanning electron microscopy. Multiple linear regression analysis and analysis of variance were used to identify significant differences in DC (α = 0.05). RESULTS: The DC was lower when the low-viscosity composite resin (ß = -0.431), light-polymerized resin depth of 2 mm (ß = -0.430), zirconia prosthesis (ß = -0.191), and mid-mode polymerization method (ß = -0.164) were used. The resin type, depth of resin to be light-cured, prosthesis material, and polymerization method had an effect on the DC. CONCLUSIONS: Low-viscosity composite resin should be polymerized at a low irradiance and long polymerization time (such that the light-cured resin depth does not exceed 2 mm) to ensure proper composite resin polymerization in implant screw access opening.

Association between Dental Caries and Handgrip Strength: In a Population-Based Study in Korea (KNHANES 2016-2018).

This study aimed to verify the relationship between handgrip strength and oral health using data from the Korea National Health and Nutrition Examination Survey, representing Korean adults. Data from the seventh survey (2016−2018) conducted by the Korea Centers for Disease Control and Prevention were utilized, and 10,607 final study participants were recruited according to the selection and exclusion criteria. A complex sample logistic regression analysis was performed to confirm the relationship between handgrip strength and dental caries according to the sex of the study participants. On analyzing the correlation in men, "C1 (DMFT: 11−32)," when compared to "C4 (DMFT: 0−3)," in Model 1 without adjustment for potential confounders, was 2.92 (95% confidence interval [CI]: 2.15−3.97) times more likely to be associated with lower handgrip strength, and a statistically significant result was detected (p < 0.001). Additionally, significant odds ratios (ORs) were confirmed for all adjusted models. In women, the ORs in Model 1 without adjustment for potential confounders were 1.41 times (95% CI: 1.14−1.75) and demonstrated a significant result; however, the results were not significant in all adjusted models 2−4. Resultantly, a significant association was detected between dental caries and handgrip strength in Korean adults.

CFD study on vesicoureteral reflux in the urinary tract with double J stent.

OBJECTIVE: This study investigates the effects of vesicoureteral reflux (VUR) in the upper and lower urinary tracts with and without ureteral stenosis and with a double J stent (DJS). METHODS: The entire length of the urinary tract with an implanted DJS was modeled. To assess the possibility of VUR, the measured values were used as boundary conditions for the baseline, the maximum cystometric bladder capacity (MCBC) during the filling phase, and maximum vesical pressure during the voiding phase were computed. The flow rates, flow patterns, wall shear stress (WSS) distribution, impact force induced by reflux urination, and helicity of the bladder were investigated for the urinary system. RESULTS: The flow from the bladder to the renal pelvis was detected at maximum vesical pressure (75 cmH2O) during the voiding phase, and a small amount (1.09 mL/s) of VUR was noted at the MCBC during the filling phase. The WSS increased when the reflux was large. Helicity within the bladder varied with the stenosis as well as opening and closing of the urethra. The reflux within the stent was reduced by 40% by inserting a ball into the stent. CONCLUSION: The main VUR factor was the opening and closing of the vesicoureteric junction by the detrusor muscle. The largest urine reflux (11.7 mL/s) to the kidney occurred when the detrusor muscle was relaxed. SIGNIFICANCE: Ureteral stenosis affected the VUR and reduced urine reflux. Ball insertion in the stent reduced urine reflux through the stent lumen.

A Smartphone App (AnSim) With Various Types and Forms of Messages Using the Transtheoretical Model for Cardiac Rehabilitation in Patients With Coronary Artery Disease: Development and Usability Study.

BACKGROUND: Despite strong evidence of clinical benefit, cardiac rehabilitation (CR) programs are currently underutilized and smartphone-based CR strategies are thought to address this unmet need. However, data regarding the detailed process of development are scarce. OBJECTIVE: This study focused on the development of a smartphone-based, patient-specific, messaging app for patients who have undergone percutaneous coronary intervention (PCI). METHODS: The AnSim app was developed in collaboration with a multidisciplinary team that included cardiologists, psychiatrists, nurses, pharmacists, nutritionists, and rehabilitation doctors and therapists. First, a focus group interview was conducted, and the narratives of the patients were analyzed to identify their needs and preferences. Based on the results, health care experts and clinicians drafted messages into 5 categories: (1) general information regarding cardiovascular health and medications, (2) nutrition, (3) physical activity, (4) destressing, and (5) smoking cessation. In each category, 90 messages were developed according to 3 simplified steps of the transtheoretical model of behavioral change: (1) precontemplation, (2) contemplation and preparation, and (3) action and maintenance. After an internal review and feedback from potential users, a bank of 450 messages was developed. RESULTS: The focus interview was conducted with 8 patients with PCI within 1 year, and 450 messages, including various forms of multimedia, were developed based on the transtheoretical model of behavioral change in each category. Positive feedback was obtained from the potential users (n=458). The mean Likert scale score was 3.95 (SD 0.39) and 3.91 (SD 0.39) for readability and usefulness, respectively, and several messages were refined based on the feedback. Finally, the patient-specific message delivery system was developed according to the baseline characteristics and stages of behavioral change in each participant. CONCLUSIONS: We developed an app (AnSim), which includes a bank of 450 patient-specific messages, that provides various medical information and CR programs regarding coronary heart disease. The detailed process of multidisciplinary collaboration over the course of the study provides a scientific basis for various medical professionals planning smartphone-based clinical research.

Validation of FRIEND and ACSM Equations for Cardiorespiratory Fitness: Comparison to Direct Measurement in CAD Patients.

The regression equation of the American College of Sports Medicine (ACSM) was a preferred method for estimating maximal oxygen consumption (VO2max). Recently, a more precise equation from the fitness registry and the importance of exercise national database (FRIEND) for healthy people was developed. This study compared VO2max estimated by the ACSM and FRIEND equations to VO2max directly measured in coronary artery disease (CAD) patients. Overall, 293 CAD patients who participated in cardiac rehabilitation between June 2015 and December 2018 were analyzed. Directly measured VO2max values were compared to the ACSM and FRIEND equations. The directly measured VO2max was significantly different from the estimated VO2max by ACSM equation (24.16 vs. 28.7 mL/kg/min, p < 0.001), which was overestimated by 20% in men and 16% in women. However, there was no statistically significant difference between the directly measured VO2max and the estimated VO2max by the FRIEND equation. (24.16 vs. 24.15 mL/kg/min, p = 0.986). In CAD patients, the estimated VO2max from the ACSM equation was significantly higher than the directly measured VO2max. In addition, estimated cardiorespiratory fitness (CRF) by the FRIEND equation showed similar results with directly measured CRF. As a result, the FRIEND equation can predict CRF more accurately than the ACSM.

Handgrip Strength as a Predictor of Exercise Capacity in Coronary Heart Disease.

PURPOSE: A recent study has shown that quadriceps strength can be used to predict the level of exercise capacity in patients with coronary heart disease. We investigated whether the relationship between muscular strength and exercise capacity is also observed with handgrip strength (HGS). METHODS: We studied 443 participants (61.8 ± 11.2 yr; 78% male) who underwent coronary intervention and participated in cardiac rehabilitation between 2015 and 2018. Logistic regression was used to assess the relationship between various clinical measures (HGS, age, sex, etc) with the distance walked on a 6-minute walk test (6MWT) and maximal oxygen uptake ((Equation is included in full-text article.)O2max). RESULTS: Handgrip strength was related to distance walked on the 6MWT (r = 0.435, P < .001). It was the only predictor of all exercise capacity categories, and one of the strongest predictors of each exercise capacity category. An HGS of 26% of body weight predicted an achievement of a 200-m walk on the 6MWT (positive predictive value = 0.95). However, HGS <36% of body weight predicted that 500 m could not be done in 6 min (negative predictive value = 0.97). This trend was also observed in the subgroups in which (Equation is included in full-text article.)O2max was measured. CONCLUSION: This study demonstrates that HGS is associated with exercise capacity in coronary heart disease and can be used to predict the level of exercise capacity. These findings may contribute to setting the recommended level of daily activity as well as the level of cardiac rehabilitation in coronary heart disease.

Relationship Between Isokinetic Muscle Strength and Functional Tests in Chronic Ankle Instability.

Isokinetic muscle strength measurements and functional tests are usually performed to evaluate ankle condition in chronic ankle instability (CAI), yet there is no clear demonstration of the relationship between isokinetic muscle strength and functional tests. The objective of this study was to evaluate the relationship between isokinetic muscle strength and functional tests in CAI. Between April 2014 and August 2016, 103 patients with unilateral CAI were studied. Single-leg balance, single-heel raise, and single-leg squat tests were performed for static balancing assessment. Single-leg hop, double-leg jump, and sidestep tests were performed for dynamic balancing assessment. The isokinetic muscle strength of both ankles was measured using a dynamometer. The involved ankle showed lower muscle strength in inversion than the uninvolved ankle, while eversion, dorsiflexion, and plantarflexion muscle strength had no significant differences between ankles. There were significant correlations between the isokinetic muscle strength of inversion and the single-leg balance test, single-heel raise test, and sidestep test (Pearson's r; 0.246, 0.514, and 0.229 at 30°/second; 0.288, 0.473, and 0.239 at 180°/second, respectively). The single leg balance, single heel raise, and sidestep tests are useful to assess not only ankle functional performance but also isokinetic muscle strength. Among these tests, the single heel raise test was the most reliable test to reflect muscle strength deficiency in CAI.

Clinical comparison of the two-stranded single and four-stranded double Krackow techniques for acute Achilles tendon ruptures.

PURPOSE: Several different Krackow stitch configurations have been used for acute Achilles tendon rupture repair. Although several biomechanical studies compared different Krackow stitch configurations, to our knowledge, no previous studies compared the clinical outcome of these different suture methods. Therefore, in this study, we aimed to compare the clinical outcomes and complications of the two-stranded single and four-stranded double Krackow techniques. METHODS: Sixty-eight consecutive patients who underwent open repair by using the four-stranded double Krackow (33 patients, group A) or the two-stranded single Krackow (35 patients, group B) techniques between September 2011 and August 2014 were reviewed retrospectively. The isokinetic strength of plantar flexion and dorsiflexion of both ankles was assessed on a Cybex dynamometer 3 and 6 months after surgery. Clinical outcomes were evaluated 3, 6, and 12 months post-operatively. RESULTS: No significant differences were found between the groups regarding patient demographics or activity levels prior to treatment. Significant differences in the Achilles tendon Total Rupture Score, the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot score, or the four-point Boyden scale were not found at any time during follow-up. Rerupture occurred only in one patient from group A. No significant differences were observed between the groups regarding the isokinetic plantar flexion and dorsiflexion strength at any time or any test speed. CONCLUSION: Equally favourable clinical outcomes and isokinetic muscle strength and a low complication rate were achieved with the two-stranded single Krackow technique as compared with the four-stranded double Krackow technique for acute Achilles tendon rupture repair. LEVEL OF EVIDENCE: III.

Pelvic lymph node status assessed by 18F-fluorodeoxyglucose positron emission tomography predicts low-risk group for distant recurrence in locally advanced cervical cancer: a prospective study.

PURPOSE: To develop a prediction model to identify a low-risk group for distant recurrence in patients with locally advanced cervical cancer treated by concurrent chemoradiation. METHODS AND MATERIALS: Prospectively, 62 patients with locally advanced cervical cancer were recruited as a training cohort. Clinical variables and parameters obtained from positron emission tomography (PET) and magnetic resonance imaging were analyzed by logistic regression. For the test set, 54 patients were recruited independently. To identify the low-risk group, negative likelihood ratio (LR) less than 0.2 was set to be a cutoff. RESULTS: Among the training cohort, multivariate logistic analysis revealed that advanced International Federation of Gynecology and Obstetrics (FIGO) stage and a high serum squamous cancer cell (SCC) antigen level were significant risk factors (p=0.015 and 0.025, respectively). Using the two parameters, criteria to determine a low-risk subset for distant recurrence were postulated: (1) FIGO Stage IIB or less and (2) pretreatment SCC<2.4 (Model A). Positive pelvic node on PET completely predicted all cases with distant recurrence and thus was considered as another prediction model (Model B). In the test cohort, although Model A did not showed diagnostic performance, Model B completely predicted all cases with distant recurrence and showed a sensitivity of 100% with negative LR of 0. Across the training and test cohort (n=116), the false negative rate was 0 (95% confidence interval 0%-7.6%). CONCLUSIONS: Positive pelvic node on PET is a useful marker in prediction of distant recurrence in patients with locally advanced cervical cancer who are treated with concurrent chemoradiation.

Preoperative prediction model of lymph node metastasis in endometrial cancer.

BACKGROUND: We aimed to develop a preoperative prediction model identifying the low-risk group for lymph node metastasis in endometrial cancer. METHODS: In 110 patients who underwent preoperative magnetic resonance imaging and serum CA-125 test, logistic analysis was performed to identify predictors. The coefficients obtained from logistic regression were used to construct a scoring system, and a receiver operator characteristic curve was created. RESULTS: Lymph node metastases were found in 14 (12.7%) of 110 patients. After multivariate logistic regression analysis, histologic grade, preoperative CA-125 levels, disease extent, and myometrial invasion assessed by magnetic resonance imaging were selected as viable predictors. The scoring system was internally validated using bootstrapping (P < 0.001), and receiver operator characteristic curve yielded the area under the curve of 0.902. The patients with the score of 0 or 1 (57.3%) were identified as a low-risk group, and no nodal metastasis was observed among them (negative predictive value, 100%: 95% confidence interval, 94.3%-100%). CONCLUSION: The current study suggests that preoperative prediction system to identify the risk of lymph node metastasis is feasible. This model may be useful in preoperative counseling about cost and benefit of systemic lymph node dissection.