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1.
PLoS One ; 19(3): e0301193, 2024.
Article in English | MEDLINE | ID: mdl-38547090

ABSTRACT

This study aimed to investigate the efficacy and safety of using optimized parameters obtained by computer simulation for ultrasound-guided high-intensity focused ultrasound (HIFU) treatment of uterine adenomyosis in comparison with conventional parameters. We retrospectively assessed a single-institution, prospective study that was registered at Clinical Research Information Service (CRiS) of Republic of Korea (KCT0003586). Sixty-six female participants (median age: 44 years) with focal uterine adenomyosis were prospectively enrolled. All participants were treated with a HIFU system by using treatment parameters either for treating uterine fibroids (Group A, first 20 participants) or obtained via computer simulation (Group B, later 46 participants). To assess the treatment efficacy of HIFU, qualitative indices, including the clinically effective dysmenorrhea improvement index (DII), were evaluated up to 3 years after treatment, whereas quantitative indices, such as the nonperfused volume ratio and adenomyosis volume shrinkage ratio (AVSR), on MRI were evaluated up to 3 months after treatment. Quantitative/qualitative indices were compared between Groups A and B by using generalized linear mixed effect model. A safety assessment was also performed. Results showed that clinically effective DII was more frequently observed in Group B than in Group A (odds ratio, 3.69; P = 0.025), and AVSR were higher in Group B than in Group A (least-squares means, 21.61; P = 0.001). However, two participants in Group B developed skin burns at the buttock and sciatic nerve pain and required treatment. In conclusion, parameters obtained by computer simulation were more effective than the conventional parameters for treating uterine adenomyosis by using HIFU in terms of clinically effective DII and AVSR. However, care should be taken because of the risk of adverse events.


Subject(s)
Adenomyosis , High-Intensity Focused Ultrasound Ablation , Female , Humans , Adult , Adenomyosis/diagnostic imaging , Adenomyosis/therapy , Retrospective Studies , Prospective Studies , Computer Simulation , High-Intensity Focused Ultrasound Ablation/adverse effects , High-Intensity Focused Ultrasound Ablation/methods , Treatment Outcome , Dysmenorrhea/therapy
2.
Heliyon ; 9(9): e19341, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37809955

ABSTRACT

SARS-CoV-2 is a novel coronavirus that emerged as an epidemic, causing a respiratory disease with multiple severe symptoms and deadly consequences. ACE-2 and TMPRSS2 play crucial and synergistic roles in the membrane fusion and viral entry of SARS-CoV-2 (COVID-19). The spike (S) protein of SARS-CoV-2 binds to the ACE-2 receptor for viral entry, while TMPRSS2 proteolytically cleaves the S protein into S1 and S2 subunits, promoting membrane fusion. Therefore, ACE-2 and TMPRSS2 are potential drug targets for treating COVID-19, and their inhibition is a promising strategy for treatment and prevention. This study proposes that ginsenoside compound K (G-CK), a triterpenoid saponin abundant in Panax Ginseng, a dietary and medicinal herb highly consumed in Korea and China, effectively binds to and inhibits ACE-2 and TMPRSS2 expression. We initially conducted an in-silico evaluation where G-CK showed a high affinity for the binding sites of the two target proteins of SARS-CoV-2. Additionally, we evaluated the stability of G-CK using molecular dynamics (MD) simulations for 100 ns, followed by MM-PBSA calculations. The MD simulations and free energy calculations revealed that G-CK has stable and favorable energies, leading to strong binding with the targets. Furthermore, G-CK suppressed ACE2 and TMPRSS2 mRNA expression in A549, Caco-2, and MCF7 cells at a concentration of 12.5 µg/mL and in LPS-induced RAW 264.7 cells at a concentration of 6.5 µg/mL, without significant cytotoxicity.ACE2 and TMPRSS2 expression were significantly lower in A549 and RAW 264.7 cells following G-CK treatment. These findings suggest that G-CK may evolve as a promising therapeutic against COVID-19.

3.
Materials (Basel) ; 16(1)2023 Jan 03.
Article in English | MEDLINE | ID: mdl-36614802

ABSTRACT

Welding defects are common during the production of large welded structures. However, few studies have explored methods of compensating for clear welding defects without resorting to re-welding. Here, an ultrasonic peening method to compensate for the deteriorated mechanical properties of overlap weld defects without repair welding was studied. We experimentally investigated changes in the mechanical properties of defective welds before and after ultrasonic peening. The weld specimen with an overlap defect contained a large cavity-type defect inside the weld bead, which significantly reduced the fatigue life. When the surface of the defective test piece was peened, the fatigue life of the weld plate was restored, resulting in an equivalent or higher number of cycles to failure, compared to a specimen with a normal weld. The recovery of mechanical properties was attributed to the effect of surface work hardening by ultrasonic peening and the change in stress distribution. Thus, ultrasonic peening could compensate for the deterioration of mechanical properties such as tensile strength, fatigue life, and elongation due to overlap defects, without resorting to repair welding.

4.
Front Pharmacol ; 13: 999192, 2022.
Article in English | MEDLINE | ID: mdl-36532751

ABSTRACT

Ginseng and ginsenosides have been reported to have various pharmacological effects, but their efficacies depend on intestinal absorption. Compound K (CK) is gaining prominence for its biological and pharmaceutical properties. In this study, CK-enriched fermented red ginseng extract (DDK-401) was prepared by enzymatic reactions. To examine its pharmacokinetics, a randomized, single-dose, two-sequence, crossover study was performed with eleven healthy Korean male and female volunteers. The volunteers were assigned to take a single oral dose of one of two extracts, DDK-401 or common red ginseng extract (DDK-204), during the initial period. After a 7-day washout, they received the other extract. The pharmacokinetics of DDK-401 showed that its maximum plasma concentration (Cmax) occurred at 184.8 ± 39.64 ng/mL, Tmax was at 2.4 h, and AUC0-12h was 920.3 ± 194.70 ng h/mL, which were all better than those of DDK-204. The maximum CK absorption in the female volunteers was higher than that in the male volunteers. The differentially expressed genes from the male and female groups were subjected to a KEGG pathway analysis, which showed results in the cell death pathway, such as apoptosis and necroptosis. In cytotoxicity tests, DDK-401 and DDK-204 were not particularly toxic to normal (HaCaT) cells, but at a concentration of 250 µg/mL, DDK-401 had a much higher toxicity to human lung cancer (A549) cells than DDK-204. DDK-401 also showed a stronger antioxidant capacity than DDK-204 in both the DPPH and potassium ferricyanide reducing power assays. DDK-401 reduced the reactive oxygen species production in HaCaT cells with induced oxidative stress and led to apoptosis in the A549 cells. In the mRNA sequence analysis, a signaling pathway with selected marker genes was assessed by RT-PCR. In the HaCaT cells, DDK-401 and DDK-204 did not regulate FOXO3, TLR4, MMP-9, or p38 expression; however, in the A549 cells, DDK-401 downregulated the expressions of MMP9 and TLR4 as well as upregulated the expressions of the p38 and caspase-8 genes compared to DDK-204. These results suggest that DDK-401 could act as a molecular switch for these two cellular processes in response to cell damage signaling and that it could be a potential candidate for further evaluations in health promotion studies.

5.
Nanomaterials (Basel) ; 12(19)2022 Sep 30.
Article in English | MEDLINE | ID: mdl-36234555

ABSTRACT

For over 2000 years, ginseng (roots of Panax ginseng C.A. Meyer) has been used as a traditional herbal medicine. Ginsenosides are bioactive compounds present in ginseng responsible for the pharmacological effects and curing various acute diseases as well as chronic diseases including cardiovascular disease, cancer and diabetes. Structurally, ginsenosides consist of a hydrophobic aglycone moiety fused with one to four hydrophilic glycoside moieties. Based on the position of sugar units and their abundance, ginsenosides are classified into major and minor ginsenosides. Despite the great potential of ginsenosides, major ginsenosides are poorly absorbed in the blood circulation, resulting in poor bioavailability. Interestingly, owing to their small molecular weight, minor ginsenosides exhibit good permeability across cell membranes and bioavailability. However, extremely small quantities of minor ginsenosides extracted from ginseng plants cannot fulfill the requirement of scientific and clinical studies. Therefore, the production of minor ginsenosides in mass production is a topic of interest. In addition, their poor solubility and lack of targetability to tumor tissues limits their application in cancer therapy. In this review, various methods used for the transformation of major ginsenosides to minor ginsenoside compound K (CK) are summarized. For the production of CK, various transformation methods apply to major ginsenosides. The challenges present in these transformations and future research directions for producing bulk quantities of minor ginsenosides are discussed. Furthermore, attention is also paid to the utilization of nanoformulation technology to improve the bioavailability of minor ginsenoside CK.

6.
Pain Ther ; 11(2): 591-600, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35284992

ABSTRACT

INTRODUCTION: The time criteria used in many studies of postherpetic neuralgia (PHN) are arbitrary and do not have supporting evidence. Therefore, this study sought to determine the definite time criterion for PHN by analyzing the skin temperature to estimate the time point when zoster-induced skin inflammatory reaction ends. METHODS: Infrared thermography was used to measure the difference in skin temperature between the affected and unaffected areas (ΔTemp) in the craniocervical and thoracic regions of patients with herpes zoster (HZ). Because the ΔTemp changes from a positive value to zero when the skin is no longer inflamed, a ΔTemp ≤ 0 was defined as the end of skin inflammation, and this time point was considered the starting point for PHN. This cutoff time point was estimated using receiver operating characteristic (ROC) curve analysis. RESULTS: A total of 503 patients were included in this study. The ROC curve analysis showed that the time point when the ΔTemp was ≤ 0 occurred at 12 weeks after HZ onset (95% confidence interval 11-15 weeks, area under the ROC curve 0.901). Using this time point as the time criterion of PHN, the sensitivity, specificity, and classification accuracy were 0.807, 0.905, and 0.871, respectively. CONCLUSIONS: The transition of skin temperature from warm to cold occurs 12 weeks after HZ onset, which implies the end of local inflammation. Therefore, PHN associated with pathophysiologic change may be defined as 12 weeks after the skin rash. This finding provides a theoretical basis for the timing definition of PHN.

7.
Anesthesiology ; 136(2): 314-325, 2022 02 01.
Article in English | MEDLINE | ID: mdl-34890455

ABSTRACT

BACKGROUND: The present study was designed to test the hypothesis that botulinum toxin would prolong the duration of a lumbar sympathetic block measured through a sustained increase in skin temperature. The authors performed a randomized, double-blind, controlled trial to investigate the clinical outcome of botulinum toxin type A for lumbar sympathetic ganglion block in patients with complex regional pain syndrome. METHODS: Lumbar sympathetic ganglion block was conducted in patients with lower-extremity complex regional pain syndrome using 75 IU of botulinum toxin type A (botulinum toxin group) and local anesthetic (control group). The primary outcome was the change in the relative temperature difference on the blocked sole compared with the contralateral sole at 1 postoperative month. The secondary outcomes were the 3-month changes in relative temperature differences, as well as the pain intensity changes. RESULTS: A total of 48 participants (N = 24/group) were randomly assigned. The change in relative temperature increase was higher in the botulinum toxin group than in the control group (1.0°C ± 1.3 vs. 0.1°C ± 0.8, respectively; difference: 0.9°C [95% CI, 0.3 to 1.5]; P = 0.006), which was maintained at 3 months (1.1°C ± 0.8 vs. -0.2°C ± 1.2, respectively; P = 0.009). Moreover, pain intensity was greatly reduced in the botulinum toxin group compared with the control group at 1 month (-2.2 ± 1.0 vs. -1.0 ± 1.6, respectively; P = 0.003) and 3 months (-2.0 ± 1.0 vs. -0.6 ± 1.6, respectively; P = 0.003). There were no severe adverse events pertinent to botulinum toxin injection. CONCLUSIONS: In patients with complex regional pain syndrome, lumbar sympathetic ganglion block using botulinum toxin type A increased the temperature of the affected foot for 3 months and also reduced the pain.


Subject(s)
Autonomic Nerve Block/methods , Botulinum Toxins, Type A/administration & dosage , Complex Regional Pain Syndromes/therapy , Ganglia, Sympathetic/drug effects , Lumbar Vertebrae , Neuromuscular Agents/administration & dosage , Adult , Complex Regional Pain Syndromes/diagnosis , Double-Blind Method , Female , Follow-Up Studies , Ganglia, Sympathetic/physiology , Humans , Lumbar Vertebrae/innervation , Male , Middle Aged
8.
Anesthesiology ; 134(6): 925-936, 2021 06 01.
Article in English | MEDLINE | ID: mdl-33857291

ABSTRACT

BACKGROUND: Deep spinal infection is a devastating complication after epidural injection. This study aimed to investigate the incidence of deep spinal infection primarily after outpatient single-shot epidural injection for pain. Secondarily, this study assessed the national trends of the procedure and risk factors for said infection. METHODS: Using South Korea's National Health Insurance Service sample cohort database, the 10-yr national trend of single-shot epidural injections for pain and the incidence rate of deep spinal infection after the procedure with its risk factors were determined. New-onset deep spinal infections were defined as those occurring within 90 days of the most recent outpatient single-shot epidural injection for pain, needing hospitalization for at least 1 night, and receiving at least a 4-week course of antibiotics. RESULTS: The number of outpatient single-shot epidural injections per 1,000 persons in pain practice doubled from 40.8 in 2006 to 84.4 in 2015 in South Korea. Among the 501,509 injections performed between 2007 and 2015, 52 cases of deep spinal infections were detected within 90 days postprocedurally (0.01% per injection). In multivariable analysis, age of 65 yr or more (odds ratio, 2.91; 95% CI, 1.62 to 5.5; P = 0.001), living in a rural area (odds ratio, 2.85; 95% CI, 1.57 to 5.0; P < 0.001), complicated diabetes (odds ratio, 3.18; 95% CI, 1.30 to 6.7; P = 0.005), multiple epidural injections (three times or more) within the previous 90 days (odds ratio, 2.34; 95% CI, 1.22 to 4.2; P = 0.007), and recent use of immunosuppressants (odds ratio, 2.90; 95% CI, 1.00 to 6.7; P = 0.025) were significant risk factors of the infection postprocedurally. CONCLUSIONS: The incidence of deep spinal infection after outpatient single-shot epidural injections for pain is very rare within 90 days of the procedure (0.01%). The data identify high-risk patients and procedure characteristics that may inform healthcare provider decision-making.


Subject(s)
Infections/epidemiology , Outpatients/statistics & numerical data , Spinal Diseases/epidemiology , Age Factors , Aged , Cohort Studies , Databases, Factual , Female , Humans , Immunosuppressive Agents/therapeutic use , Incidence , Injections, Epidural/adverse effects , Male , Middle Aged , National Health Programs , Republic of Korea/epidemiology , Retrospective Studies , Risk Factors , Rural Population/statistics & numerical data , Sex Factors , Spinal Diseases/microbiology , Spine/microbiology
9.
Mayo Clin Proc ; 96(4): 943-951, 2021 04.
Article in English | MEDLINE | ID: mdl-33722397

ABSTRACT

OBJECTIVES: To determine the prevalence and breakdown of pain symptoms among patients with coronavirus disease 2019 (COVID-19) infection admitted for nonpain symptoms and the association between the presence of pain and intensive care unit (ICU) admission and death. PATIENTS AND METHODS: In this multicenter prospective study, data on the intensity and type of pain were collected on 169 patients with active severe acute respiratory syndrome coronavirus 2 infection at 2 teaching hospitals in the United States and Korea and on 8 patients with acute pain at another large teaching hospital between February 1, 2020, and June 15, 2020. RESULTS: Sixty-five of 169 patients (38.5%) reported an active pain condition. Among the 73 patients with pain, the most common pain symptoms were headache (n=22; 30.1%), chest pain (n=17; 23.3%), spinal pain (n=18; 24.7%), myalgia (n=13; 17.8%), abdominal or pelvic pain (n=13; 17.8%), arthralgia (n=11; 15.1%), and generalized pain (n=9; 12.3%). Those reporting headache as their main symptom were less likely to require ICU admission (P=.003). Acetaminophen or nonsteroidal anti-inflammatory drugs were prescribed to 80.8% (n=59), opioids to 17.8% (n=13), adjuvants to 8.2% (n=6), and ketamine to 5.5% (n=4) of patients with pain. When age 65 years and older and sex were controlled for in multivariable analysis, the absence of pain was associated with ICU admission (odds ratio, 2.92; 95% CI, 1.42 to 6.28; P=.004) and death (odds ratio, 3.49; 95% CI, 1.40 to 9.76; P=.01). CONCLUSION: Acute pain is common during active COVID-19 infection with the most common manifestations being headache, chest pain and spine pain. Individuals without pain were more likely to require intensive care and expire than those with pain. Reasons why pain may be associated with reduced mortality include that an intense systemic stimulus (eg, respiratory distress) might distract pain perception or that the catecholamine surge associated with severe respiratory distress might attenuate nociceptive signaling.


Subject(s)
Acute Pain , COVID-19 , Pain Management/methods , Pain Measurement/methods , Pain Perception/physiology , Acute Pain/diagnosis , Acute Pain/etiology , Acute Pain/physiopathology , Age Factors , COVID-19/epidemiology , COVID-19/physiopathology , COVID-19/therapy , Female , Hospitalization/statistics & numerical data , Humans , Intensive Care Units/statistics & numerical data , Male , Middle Aged , Outcome and Process Assessment, Health Care , Republic of Korea/epidemiology , Sex Factors , United States/epidemiology
10.
Materials (Basel) ; 13(24)2020 Dec 10.
Article in English | MEDLINE | ID: mdl-33321944

ABSTRACT

Glass with strong durability and transparency has been in the spotlight in various fields, including displays. Elastic and shear moduli and Poisson's ratio are important properties of glasses. The purpose of this study is to evaluate the change in mechanical properties, such as the dynamic elastic modulus and Poisson's ratio, with respect to the chemical strengthening time of glass for display applications, as measured by static and dynamic methods. The basic measurement principle of the dynamic method is to measure acoustic speed or resonant frequency using an ultrasonic generator. The mechanical properties of both non-strengthened and chemically strengthened glasses were investigated. It was found that the strength of the chemically strengthened glass decreased when chemical strengthening time increased. Chemical strengthening increased the bending strength and decreased the elastic modulus due to the introduction of compressive residual stress at the surface.

11.
Medicine (Baltimore) ; 99(51): e23725, 2020 Dec 18.
Article in English | MEDLINE | ID: mdl-33371123

ABSTRACT

BACKGROUND: There is no sufficient evidence on the effectiveness of acupuncture for neuropathic pain. This protocol describes a study that aims to evaluate the effectiveness and safety of electroacupuncture combined with conventional medicine for patients with intractable neuropathic pain, when compared with conventional medicine alone. METHODS/DESIGN: This study is a prospective, open-labeled, randomized, cross-over clinical trial. A total of 40 patients with neuropathic pain who had a numeric rating scale (NRS) score of over 4 despite receiving conventional treatment for more than 3 months will be enrolled. Participants will receive conventional treatment for neuropathic pain (treatment C) or treatment C combined with 12 additional sessions of electroacupuncture treatment (treatment A) for 6 weeks. Participants will be randomly assigned to 1 of the 2 sequence groups (AC and CA group) with a 1:1 allocation. The differences of responder in the composite efficacy outcomes, which consist of the NRS, Brief Pain Inventory-Short Form (BPI-SF) pain subscale, and global assessment at 6 weeks after randomization will be examined as the primary outcome. Secondary outcomes include differences in the NRS, the Short-Form McGill Pain Questionnaire, BPI-SF, Fatigue Severity Scale, Hospital Anxiety and Depression Scale, Medical Outcomes Study Sleep Scale, global assessment, EQ-5D, and incremental cost-effective ratio at 6 and 15 weeks after randomization. Adverse events, vital signs, and physical examinations will be recorded to evaluate safety. DISCUSSION: The study protocol for this trial will provide up-to-date evidence on the effectiveness and safety of electroacupuncture for patients with intractable neuropathic pain. The results will be disseminated through a peer-reviewed journal and conference presentations. TRIAL REGISTRATION: Clinical Research Information Service, ID: KCT0003615. Registered on March 12, 2019. https://cris.nih.go.kr/cris/search/search_result_st01_kren.jsp?seq=13410& ltype=&rtype=.


Subject(s)
Electroacupuncture/methods , Neuralgia/therapy , Chronic Disease , Cost-Benefit Analysis , Cross-Over Studies , Electroacupuncture/adverse effects , Electroacupuncture/economics , Fatigue/epidemiology , Female , Humans , Male , Mental Health , Pain Measurement , Prospective Studies , Quality of Life , Research Design , Severity of Illness Index , Single-Blind Method
12.
J Pain Res ; 13: 3395-3403, 2020.
Article in English | MEDLINE | ID: mdl-33363406

ABSTRACT

PURPOSE: Ultrasound-guided thoracic paravertebral block (US-TPVB) is considered a treatment option for the management of acute pain in various pain-related conditions. We conducted a prospective pilot study to evaluate the possibility of US-TPVB as a sympathetic blockade in patients with neuropathic pain disorders in the upper extremities. PATIENTS AND METHODS: A total of 12 patients underwent US-TPVB between the T2 and T3 paravertebral space with 10 mL of 1% mepivacaine. The temperature change (°C) before and after the procedure was compared between the ipsilateral and contralateral hands. We counted the proportion of patients showing a temperature increase ≥1.5°C and compared a change in the pain intensity before and after the procedure. RESULTS: The median increase in the temperature change between the ipsilateral and contralateral hands was 1.54°C (interquartile range, 1.28-2.20). There were seven patients (58.3%) who showed a temperature difference ≥1.5°C between both hands after the US-TPVB. Eleven patients (91.7%) reported a reduction in pain according to the score on the 11-point numerical rating scale. No serious complications relevant to the procedure were reported. CONCLUSION: US-TPVB could be a useful technique for sympathetic blockade in patients with upper extremity pain.

13.
J Altern Complement Med ; 26(12): 1136-1143, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33074703

ABSTRACT

Objective: To test the effectiveness of electroacupuncture (EA) for managing intractable neuropathic pain (NeP) and assess the protocol for a larger confirmatory trial. Design: A prospective, multicenter, single-armed, add-on, pilot study. Settings/location: At two tertiary university-based hospitals in Seoul, Republic of Korea. Subjects: Patients with chronic peripheral NeP, who have received conventional oral medications but complained of moderate to severe pain. Interventions: Two Korean medicine doctors conducted 12 sessions of EA (2 sessions per week for 4 weeks, followed by 1 session per week for the second month) in addition to conventional treatment. Outcome measures: During the 8-week treatment period, pain intensity, pain natures such as burning, electric shock-like, temperature or mechanical hyperalgesia, and numbness, Short Form of the McGill Pain Questionnaire (SF-MPQ) and the Brief Pain Inventory (BPI-SF), the EuroQol five dimensions questionnaire, patients' satisfaction, and adverse events were evaluated. The primary endpoint was a change in pain intensity (%) at 4 weeks from the baseline. Results: Among 22 patients, 19 finished the protocol. The eight EA sessions over a month reduced pain intensity from 6.0 ± 1.6 at baseline to 3.2 ± 0.9 at 4 weeks, which was a 46.7% reduction (p < 0.001). The incidences of severe burning, electric shock-like pain, and mechanical hyperalgesia reduced at 8 weeks [36%-16% (p = 0.04), 53%-21% (p = 0.009), and 53%-26% (p = 0.03), respectively]. The affective dimensions in the SF-MPQ (p = 0.007) and the pain interference parameters, including mood (p = 0.02), relations with other people (p = 0.03), and enjoyment of life (p = 0.002) in the BPI-SF, were improved at 4 and 8 weeks. The majority of patients (68%) responded that their pain was "much or somewhat improved." Overall, 84.2% expressed "satisfaction" with their multidisciplinary management. Conclusions: EA might decrease the intensity of NeP, in particular, such as burning, electric shock-like pain, and mechanical hyperalgesia, which was accompanied by psychosocial and functional improvement. A larger study is warranted to prove the effectiveness of EA for managing refractory NeP. Trial registration: ClinicalTrials.gov: NCT03315598. Retrospectively registered on October 20, 2017.


Subject(s)
Electroacupuncture , Neuralgia/therapy , Pain Management/methods , Aged , Chronic Pain/therapy , Female , Humans , Male , Middle Aged , Pilot Projects , Prospective Studies , Republic of Korea
14.
Materials (Basel) ; 13(14)2020 Jul 16.
Article in English | MEDLINE | ID: mdl-32708583

ABSTRACT

The current research reports the improvement in surface integrity and tribological characteristics of steel prepared using a powder metallurgy (PM) by ultrasonic nanocrystal surface modification (UNSM) at 25 and 300 °C. The surface integrity and tribological properties of three samples, namely, as-PM, UNSM-25 and UNSM-300 were investigated. The average surface roughness (Ra) of the as-PM, UNSM-25 and UNSM-300 samples was measured using a non-contact 3D scanner, where it was found to be 3.21, 1.14 and 0.74 µm, respectively. The top surface hardness was also measured in order to investigate the influence of UNSM treatment temperature on the hardness. The results revealed that the as-PM sample with a hardness of 109 HV was increased up to 165 and 237 HV, corresponding to a 32.1% and 57.2% after both the UNSM treatment at 25 and 300 °C, respectively. XRD analysis was also performed to confirm if any changes in chemistry and crystal size were took place after the UNSM treatment at 25 and 300 °C. In addition, dry tribological properties of the samples were investigated. The friction coefficient of the as-PM sample was 0.284, which was reduced up to 0.225 and 0.068 after UNSM treatment at 25 and 300 °C, respectively. The wear resistance was also enhanced by 33.2 and 52.9% after UNSM treatment at both 25 and 300 °C. Improvements in surface roughness, hardness and tribological properties was attributed to the elimination of big and deep porosities after UNSM treatment. Wear track of the samples and wear scar of the counter surface balls were investigated by SEM to reach a comprehensive discussion on wear mechanisms. Overall, it was confirmed that UNSM treatment at 25 and 300 °C had a beneficial effect on the surface integrity and tribological characteristics of sintered steel by the PM that is used in a shock absorber for a car engine.

15.
Pain Med ; 21(10): 2288-2297, 2020 10 01.
Article in English | MEDLINE | ID: mdl-32443142

ABSTRACT

OBJECTIVE: To compare the nonadaptive manual system with the position-adaptive system in subjects with permanent spinal cord stimulator (SCS) implantation over a two-year follow-up period. DESIGN: Retrospective study. SETTING: Tertiary university-based national hospital. SUBJECTS: Patients who underwent permanent SCS implantation procedures. METHODS: Patients were divided into an adaptive group and a nonadaptive group according to the type of implanted SCS device. The primary outcome was the change (%) in pain intensity from baseline between the adaptive and nonadaptive groups at 24 months after SCS implantation. The secondary outcomes were comparisons of detailed clinical variables such as the scores of patient pain and satisfaction during the two-year follow-up after SCS therapy. Further, the number of subjects with SCS removal or revision within two years after SCS implantation was investigated. RESULTS: Of 187 patients with permanent SCS implantation, 85 in the nonadaptive group and 64 in the position-adaptive group were finally analyzed. The reduction in pain intensity at 24 months was higher in the adaptive group (-38.6%) than in the nonadaptive group (-30.8%, P = 0.05). Similarly, patient satisfaction with the SCS treatment at 24 months was superior in the adaptive group than in the nonadaptive group (85.7% vs 67.5% were satisfied in each group, respectively, P = 0.024). During the two years, 5.3% of patients (N = 10) underwent SCS removal and 7.0% (N = 13) underwent revision procedures. CONCLUSIONS: There was a trend of a sustained reduction in pain intensity as well as improvement in patient satisfaction at two-year follow-up in the position-adaptive system, suggesting long-term benefit over the nonadaptive manual system during SCS treatment.


Subject(s)
Chronic Pain , Spinal Cord Stimulation , Chronic Pain/therapy , Follow-Up Studies , Humans , Pain , Pain Management , Retrospective Studies , Spinal Cord , Treatment Outcome
16.
Korean J Pain ; 32(4): 292-300, 2019 Oct 01.
Article in English | MEDLINE | ID: mdl-31569922

ABSTRACT

BACKGROUND: The aim of this study was to investigate the clinical characteristics of complex regional pain syndrome (CRPS) in young male patients in South Korea, especially focusing on the association with military service. METHODS: From January 2007 to May 2017, we investigated the electronic medical records of 430 consecutive patients, aged 18 to 30 years, who visited Seoul National University Hospital Pain Center, with a suspected diagnosis of CRPS at the initial visit. The following patient details were available for analysis: demographic and disease-related variables, relevance to military service, medications, and the treatment modalities received. RESULTS: Out of 430 patients, 245 (57.0%) were diagnosed with CRPS, of which, 200 were male patients and 45 were female patients. Of the male patients, 95 (47.5%) developed CRPS during military service. CRPS during military service was more likely to result from sprain/strain, and the incidence of CRPS was significantly higher in the lower extremities in patients from the military service group than in those from the non-military service group. During the follow-up period, 37.9% of male CRPS patients (n = 61/161) were treated successfully. Patients with moderate to severe initial pain intensity, and diagnosed during their military service, showed better outcomes. CONCLUSIONS: Our results demonstrated that manifestation of CRPS in the young Korean population was more common in male and among those male CRPS patients, about half the cases developed during the military service period.

17.
J Clin Med ; 8(9)2019 Aug 27.
Article in English | MEDLINE | ID: mdl-31461935

ABSTRACT

BACKGROUND: Because it affords greater accuracy than landmark-based techniques, ultrasound guidance may reduce the volume of local anesthetic required for sympathetic blockade of the upper extremity. We hypothesized that 4 mL would provide a similar clinical effect when compared to larger volumes. METHODS: One hundred and two patients with chronic neuropathic pain of the upper extremity or face were randomly assigned to receive an ultrasound-guided (USG) stellate ganglion block (SGB) with either 4 mL (group A), 6 mL (group B) or 8 mL (group C) mL of 1.0% lidocaine. Skin temperatures of the face, hand, and axillary fold were measured bilaterally at baseline, 10, 20, and 30 min after the block. Our primary outcome was the relative increase in hand temperature on the blocked side at 30 min and our non-inferiority margin was -0.6 °C. Secondary outcomes included success rate (as defined by a relative temperature increase of ≥1.5 °C), pain relief, degree of ptosis and side-effects. RESULTS: The 95% confidence intervals for the difference of the means exceeded our non-inferiority margin (A versus B: -0.76 to 0.24; A versus C: -0.89 to 0.11) for temperature changes in the hand; however, success rates were similar (44, 45 and 55% for A, B and C respectively, p = 0.651). No intergroup differences were found in temperature-related outcomes for the other measurement sites (face, axilla). The incidence of minor side-effects was significantly higher in group C and no block-related complications were noted. CONCLUSIONS: We were unable to establish the non-inferiority of a 4 mL volume for sympathetic blockade of the hand. The clinical significance of these findings is unclear as success rates were similar between the different groups. In contrast, the 6- and 8 mL volumes were not associated with greater temperature changes in the face and axilla.

18.
Anesth Analg ; 129(3): 864-873, 2019 09.
Article in English | MEDLINE | ID: mdl-31425231

ABSTRACT

BACKGROUND: As national opioid consumption in South Korea has soared, well-validated screening tools for opioid use disorder (OUD) have become indispensable. The aims of our study were to evaluate OUD using the Korean version of the CAGE-Adapted to Include Drugs (CAGE-AID) and the CAGE-Opioid (an alternative version of the CAGE-AID), and to investigate clinical predictors that might be useful to screen for OUD in conjunction with the CAGE-AID/Opioid questionnaires. METHODS: A single-center, prospective, observational study was performed. After linguistic validation of the Korean version of the CAGE-AID/Opioid questionnaires, we assessed OUD in patients with chronic opioid treatment. Multivariable logistic models of the CAGE-AID/Opioid questionnaires combined with relevant clinical predictors were established. Then, the receiver operating characteristic curve analysis of the multivariable CAGE-AID/Opioid models was conducted to assess diagnostic accuracy to screen for OUD. Next, we calculated predicted probability with >85% sensitivity and >50% specificity in each CAGE-AID and CAGE-Opioid model. Using the optimal value of the predicted probability, a cutoff score of the CAGE-AID/Opioid questionnaires combined with the relevant clinical factors was suggested to screen for OUD. RESULTS: Among 201 participants, 51 patients showed ≥1 OUDs. In the multivariable regression model, male sex, comorbid neuropsychiatric disorder, and current heavy drinking significantly remained as clinical variables to predict OUD combined with the scores of the Korean CAGE-AID/Opioid questionnaire. The area under the curve was 0.77 (95% confidence interval, 0.71-0.83) for the CAGE-AID model and 0.78 (95% confidence interval, 0.71-0.83) for the CAGE-Opioid model. The optimal predicted probability values to screen for OUD in the CAGE-AID/Opioid models were >0.135 (sensitivity, 0.86; specificity, 0.52) and >0.142 (sensitivity, 0.86; specificity, 0.53), respectively. When we used these predictive probabilities, the cutoff score of the CAGE-AID/Opioid questionnaires ranged from 0 to 3, which was dependent on the presence of the relevant clinical variables in each model. CONCLUSIONS: In this study, one fourth of the total participants with chronic opioid treatment showed OUD in the Korean population. The multivariable models of the CAGE-AID/Opioid with sex, comorbid neuropsychiatric disorder, and current heavy drinking are valid parameters to screen for OUD, with the cutoff scores of the CAGE-AID/Opioid questionnaires ranging from 0 to 3 depending on the presence of the clinical variables.


Subject(s)
Analgesics, Opioid/adverse effects , Opioid-Related Disorders/diagnosis , Opioid-Related Disorders/epidemiology , Surveys and Questionnaires/standards , Translating , Adult , Aged , Female , Humans , Male , Middle Aged , Pain Management/adverse effects , Pain Management/standards , Predictive Value of Tests , Prospective Studies , Republic of Korea/epidemiology
19.
Int J Hyperthermia ; 35(1): 617-625, 2018.
Article in English | MEDLINE | ID: mdl-30303419

ABSTRACT

BACKGROUND: High-intensity focused ultrasound (HIFU) is a noninvasive thermodestructive procedure targeting internal organs with concentrated sonification energy that may cause pain. We aimed to compare the effectiveness of epidural analgesia (EA) and monitored anesthesia care (MAC) in HIFU treatment of uterine adenomyosis. MATERIALS AND METHODS: Sixty-eight patients were included in this case-control study. Thirty-seven patients underwent MAC; 31 patients underwent fluoroscope-guided epidural analgesia. The primary outcome was a frequency of patients reporting severe or very severe intraoperative pain. Secondary outcomes were differences in dosages of analgesics, ablation ratio, and other clinical factors. RESULTS: The EA group reported a significantly lower frequency of severe or very severe intraoperative pain than did the MAC group (41.9% vs. 75.7%; p = .006). Consumption of remifentanil during treatment was significantly lower in the EA group (173 ± 189 µg vs. 426 ± 380 µg; p = .001), as was the use of fentanyl in the recovery room (52 ± 38 µg vs. 75 ± 44 µg; p = .030). Multivariable analysis revealed EA to be the largest contributing factor to increased nonperfused volume ratio (B = 0.41; 95% confidence interval = 0.29 to 0.53; p < .001). The frequency of thermal injury after HIFU was significantly lower in the EA group (22.6% vs. 54.1%; p = .008). CONCLUSIONS: EA during HIFU treatment of uterine adenomyosis improved quality of pain control and ablation ratio over MAC without increasing risk of treatment-related complications. EA also reduced consumption of opioid analgesics during and after HIFU treatment.


Subject(s)
Adenomyosis/diagnostic imaging , Analgesia, Epidural/methods , Anesthesia/methods , High-Intensity Focused Ultrasound Ablation/methods , Adult , Case-Control Studies , Female , Humans , Retrospective Studies , Young Adult
20.
J Clin Med ; 7(10)2018 Oct 14.
Article in English | MEDLINE | ID: mdl-30322212

ABSTRACT

Opioid consumption has increased worldwide, which carries the risk of opioid use disorder (OUD). However, the literature on OUD and opioid-related chemical coping (OrCC) in chronic noncancer pain (CNCP) is heterogeneous, with most studies conducted in the United States. We performed a multicenter, observational, cross-sectional study to address OrCC in long-term opioid therapy (LtOT) for CNCP in South Korea. The objectives were to determine the frequency and predictors of OrCC. We included 258 patients. Among them, fifty-five (21%) patients showed OrCC. The sample had high pain catastrophizing (≥30 points; 66%), moderate-severe insomnia (≥15 points; 63%), low resilience (68 points), and high suicidal ideation (67%). OrCC patients had greater pain interference (85.18% vs. 58.28%, p = 0.017) and lower satisfaction with the LtOT (56.4% vs. 78.3%, p = 0.002). In multivariable analysis, alcohol abuse (OR = 6.84, p = 0.001), prescription drugs abuse (OR = 19.32, p = 0.016), functional pain (OR = 12.96, p < 0.001), head and neck pain (OR = 2.48, p = 0.039), MEDD (morphine equivalent daily dose) ≥ 200 mg/day (OR = 3.48, p = 0.006), and ongoing litigation (OR = 2.33, p = 0.047) were significant predictors of OrCC. In conclusion, the break-out of OrCC in CNCP in South Korea was comparable to those in countries with high opioid consumption, such as the United States, regardless of the country's opioid consumption rate.

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