• The Korean Journal of Pain
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• v.21 no.2
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• pp.106-111
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• 2008

Background: Chronic pain after thoracotomy has been recently reproduced in a rat model that allows investigating the effect of potentially beneficial drugs that might reduce the incidence of allodynia or alleviate pain. Local anesthetics produce antinociception in normal animals and alleviate mechanical allodynia in animals with nerve injury although their mechanisms of action may differ in these situations. Our purpose of this study was to test whether the preoperative intercostal nerve block of bupivacaine could prevent the development of allodynia in a rat model of chronic postthoracotomy pain. Methods: All male Sprague-Dawley rats were anesthetized and the right 4th and 5th ribs were exposed surgically. The pleura were opened between the ribs to which a retractor was placed and was opened 10 mm in width. Retraction was maintained for one hour. Total 1 mg of 0.5% bupivacaine was injected at the intercostal nerves before (n = 17) or after (n = 16) surgery. A control group (n = 25) that underwent rib retraction did not receive any drug. Rats were tested for mechanical allodynia using calibrated von Frey filaments applied around the incision site during the three weeks following surgery. Results: The incidence of development of mechanical allodynia in the group that received intercostal injection with bupivacaine before surgery was significantly lower than that in the control group (P < 0.05). Conclusions: Preoperative intercostal nerves block around the surgical incision before thoracotomy may decrease the incidence of postthoracotomy pain syndrome.

• Journal of Korean Neurosurgical Society
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• v.56 no.3
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• pp.237-242
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• 2014

Objective : The purpose of this study was to investigate the clinical features and outcomes of pediatric cavernous malformation (CM) in the central nervous system. Methods : Twenty-nine pediatric patients with supratentorial CM underwent microsurgical excision. In selected cases, transparent tubular retractor system (TTRS) was used to reduce retraction injury and intraoperative neuromonitoring (IONM) was held to preserve functioning cortex. Patients' demographics and symptoms were reviewed and surgical outcomes were discussed. Results : The main initial clinical manifestations included the following : seizures (n=13, 45%), headache (n=7, 24%), focal neurological deficits (n=3, 10%), and an incidental finding (n=6, 21%). Overt hemorrhage was detected in 7 patients (24%). There were 19 children (66%) with a single CM and 10 (34%) children with multiple CMs. In 7 cases with deep-seated CM, we used a TTRS to minimize retraction. In 9 cases which location of CM was at eloquent area, IONM was taken during surgery. There was no major morbidity or mortality after surgery. In the 29 operated children, the overall long-term results were satisfactory : 25 (86%) patients had no signs or symptoms associated with CMs, 3 had controllable seizures, and 1 had mild weakness. Conclusion : With the assistance of neuronavigation systems, intraoperative neuromonitoring, and TTRS, CMs could be targeted more accurately and excised more safely. Based on the satisfactory seizure outcome achieved, complete microsurgical excision in children is recommended for CMs presenting with seizures but removal of hemosiderin-stained areas seems to be unnecessary.

• Journal of the Korean Arthroscopy Society
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• v.13 no.2
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• pp.119-125
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• 2009

The primary purposes of revision repair for a failed rotator cuff repair are a relief of pain and functional improvement. Therefore, revision repair is most proper in patients with the functional deficit accompanied with the shoulder weakness as well as the persistent pain. The important factor that is considered in revision repair is a quality of torn cuff. Especially, Care must be taken to ensure that the revision repair is possible, considering the size of tendon defect, atrophy of the muscle, fatty infiltration and extent of the retraction of tendon. Revision repair of a failed rotator cuff repair is more difficult, and the functional results are less satisfactory than those of primary repair, because excessive bursal scarring and tendon retraction may be exhibited, a large or massive tear is often detected, tear has usually been present for a long time, and a quality of muscle-tendon may be poor. So, we discuss our experiences related to revision repair after a failed cuff repair that has been recently introduced through the articles.

• Journal of Periodontal and Implant Science
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• v.50 no.6
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• pp.358-367
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• 2020

Purpose: The aim of this study was to investigate the efficacy and validity of subgingival bacterial sampling using a retraction cord, and to evaluate how well this sampling method reflected changes in periodontal conditions after periodontal therapy. Methods: Based on clinical examinations, 87 subjects were divided into a healthy group (n=40) and a periodontitis group (n=47). Clinical measurements were obtained from all subjects including periodontal probing depth (PD), bleeding on probing (BOP), clinical attachment loss (CAL), and the plaque index. Saliva and gingival crevicular fluid (GCF) as a subgingival bacterial sample were sampled before and 3 months after periodontal therapy. The salivary and subgingival bacterial samples were analyzed by reverse-transcription polymerase chain reaction to quantify the following 11 periodontal pathogens: Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Tannerella forsythus (Tf), Treponema denticola (Td), Prevotella intermedia (Pi), Fusobacterium nucleatum (Fn), Pavimonas micra (Pm), Campylobacter rectus (Cr), Prevotella nigrescens (Pn), Eikenella corrodens (Ec), and Eubacterium nodatum (En). Results: Non-surgical periodontal therapy resulted in significant decreases in PD (P<0.01), CAL (P<0.01), and BOP (P<0.05) after 3 months. Four species (Pg, Tf, Pi, and Pm) were significantly more abundant in both types of samples in the periodontitis group than in the healthy group. After periodontal therapy, Cr was the only bacterium that showed a statistically significant decrease in saliva, whereas statistically significant decreases in Cr, Pg, and Pn were found in GCF. Conclusions: Salivary and subgingival bacterial sampling with a gingival retraction cord were found to be equivalent in terms of their accuracy for differentiating periodontitis, but GCF reflected changes in bacterial abundance after periodontal therapy more sensitively than saliva.

• Archives of Plastic Surgery
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• v.46 no.2
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• pp.129-134
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• 2019

Background Nipple-areolar complex (NAC) reconstruction is the final stage of breast reconstruction. Ideal reconstruction of the NAC requires symmetry in position, size, shape, texture, pigmentation, and permanent projection, and although many technical descriptions of NAC reconstruction exist in the medical literature, there is no gold standard technique. The technique devised by the authors is very versatile, with excellent results, and it enables 1-step reconstruction with optimal results in terms of shape and nipple projection. Methods Our technique consists of a combination of modified local flaps and a full-thickness skin graft. Patients were observed for 18 months to estimate the amount of retraction. This procedure was performed in 40 patients, four of them bilaterally. The duration of the follow-up was 30 months. Complications occurred in 10% of patients, and included infections (5%), ischemia (2.5%), and hematoma (2.5%). Results No cases of total nipple necrosis were reported. The NAC shape remained optimal in all cases, with a very small reduction of the vertical and horizontal diameters of the areola, which maintained its designed round shape well, and negligible retraction in the diameter and projection of the nipple. Conclusions The oval technique represents a major step forward, involving a combination of existing techniques, such as the C-V flap and the cutaneous graft, to achieve excellent results regarding areola shape and nipple projection, significantly reducing the cases of nipple ischemia. These results were substantially obtained through subcutaneous equatorial sutures, skin grafting, and flattening of the apexes of the flap.

• Journal of Ginseng Research
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• v.45 no.4
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• pp.490-497
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• 2021

Background and objective: Synthetic ginsenoside compounds G-Rp (1,3, and 4) and natural ginsenosides in Panax ginseng 20(S)-Rg3, Rg6, F4 and Ro have inhibitory actions on human platelets. However, the inhibitory mechanism of ginsenoside Rk1 (G-Rk1) is still unclear thus, we initiated investigation of the anti-platelet mechanism by G-Rk1 from Panax ginseng. Methodology: Our study focused to investigate the action of G-Rk1 on agonist-stimulated human platelet aggregation, inhibition of platelet signaling molecules such as fibrinogen binding with integrin α_IIbβ₃ using flow cytometry, intracellular calcium mobilization, fibronectin adhesion, dense granule secretion, and thromboxane B2 secretion. Thrombin-induced clot retraction was also observed in human platelets. Key Results: Collagen, thrombin, and U46619-stimulated human platelet aggregation were dose-dependently inhibited by G-Rk1, while it demonstrated a more effective suppression on collagen-stimulated platelet aggregation using human platelets. Moreover, G-Rk1 suppressed collagen-induced elevation of Ca²⁺ release from endoplasmic reticulum, granule release, and α_IIbβ₃ activity without any cytotoxicity. Conclusions and implications: These results indicate that G-Rk1 possess strong anti-platelet effect, proposing a new drug candidate for treatment and prevention of platelet-mediated thrombosis in cardiovascular disease.

• Journal of the Korean Society of Visualization
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• v.19 no.3
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• pp.15-21
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• 2021

In this study, we investigated the dynamics of a droplet impacting rough hydrophobic surfaces through high-speed imaging. Micrometer-sized structures with grooves and pillars were fabricated on smooth Polydimethylsiloxane (PDMS) surfaces by laser ablation. We used Newtonian and non-Newtonian liquid droplets to study the drop impact dynamics. De-ionized water and aqueous glycerin solutions were used for the Newtonian liquid droplet. The solutions of xanthan gum in water were prepared to provide elastic property to the Newtonian droplet. We found that the orientation of the surface structures affected the maximal spreading diameter of the droplet due to the degree of slippage. During the droplet retraction, the dynamic receding contact angles were measured to be around 90° or less. It resulted in the formation of the micro-capillary bridges between the receding droplet and the surface structures. Then, the rupture of the capillary bridge led to the formation of micrometer-sized droplets on top of the surface structures. The size of the microdroplets was found to increase with increasing the impacting velocity and viscosity of the Newtonian liquid droplets. However, the size of the isolated microdroplets decreased with enhancing the elasticity of the droplets, and the size of the non-Newtonian microdroplets was not affected by the impacting velocity.

• The korean journal of orthodontics
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• v.52 no.3
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• pp.220-235
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• 2022

Objective: To evaluate the available evidence regarding the clinical effectiveness of different types of anchorage devices. Methods: A comprehensive literature search of different electronic databases was conducted for systematic reviews investigating different anchorage methods published up to April 15, 2021. Any ongoing systematic reviews were searched using PROSPERO, and a grey literature search was undertaken using Google Scholar and OpenGrey. No language restriction was applied. Screening, quality assessment, and data extraction were performed independently by two authors. Information was categorized and narratively synthesized for the key findings from moderate- and high-quality reviews. Results: Fourteen systematic reviews were included (11 were of moderate/high quality). Skeletal anchorage with miniscrews was associated with less anchorage loss (and sometimes with anchorage gain). Similarly, skeletal anchorage was more effective in retracting anterior teeth and intruding incisors and molars, resulting in minor vertical skeletal changes and improvements in the soft tissue profile. However, insufficient evidence was obtained for the preference of any anchorage method in terms of the duration of treatment, number of appointments, quality of treatment, patient perception, or adverse effects. The effectiveness of skeletal anchorage can be enhanced when: directly loaded, used in the mandible rather than the maxilla, used buccally rather than palatally, using dual rather than single miniscrews, used for en-masse retraction, and in adults. Conclusions: The level of evidence regarding anchorage effectiveness is moderate. Nevertheless, compared to conventional anchorage, skeletal anchorage can be used with more anchorage preservation. Further high-quality randomized clinical trials are required to confirm these findings.

• Clinics in Shoulder and Elbow
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• v.25 no.4
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• pp.257-264
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• 2022

Background: Chronic subscapularis tendon tear (SBT) is a degenerative disease and a common pathologic cause of shoulder pain. Several potential risk factors for chronic SBT have been reported. Although metabolic abnormalities are common risk factors for degenerative disease, their potential etiological roles in chronic SBT remains unclear. The purpose of this study was to investigate potential risk factors for chronic SBT, with particular attention to metabolic factors. Methods: This study evaluated single shoulders of 939 rural residents. Each subject undertook a questionnaire, physical examinations, blood tests, and simple radiographs and magnetic resonance imaging (MRI) evaluations of bilateral shoulders. Subscapularis tendon integrity was determined by MRI findings based on the thickness of the involved tendons. The association strengths of demographic, physical, social, and radiologic factors, comorbidities, severity of rotator cuff tear (RCT), and serologic parameters for SBT were evaluated using logistic regression analyses. The significance of those analyses was set at p<0.05. Results: The prevalence of SBT was 32.2% (302/939). The prevalence of partial- and full-thickness tears was 23.5% (221/939) and 8.6% (81/939), respectively. The prevalence of isolated SBT was 20.2% (190/939), SBT combined with supraspinatus or infraspinatus tendon tear was 11.9% (112/939). In multivariable logistic regression analysis, dominant side involvement (p<0.001), manual labor (p=0.002), diabetes (p<0.001), metabolic syndrome (p<0.001), retraction degree of Patte tendon (p<0.001), posterosuperior RCT (p=0.010), and biceps tendon injury (p<0.001) were significantly associated with SBT. Conclusions: Metabolic syndrome is a potential risk factor for SBT, as are these factors: overuse activity, diabetes, posterosuperior RCT, increased retraction of posterosuperior rotator cuff tendon, and biceps tendon injury.

• The korean journal of orthodontics
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• v.53 no.5
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• pp.307-316
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• 2023

Objective: To evaluate the effects of an electric toothbrush with vibrational frequencies of 125 Hz and 150 Hz on the orthodontic tooth movement (OTM) rate and the production of prostaglandin E2 (PGE2). Methods: Out of thirty patients (aged 18-25 years; 16 females and 14 males), ten patients each formed Group A and B, who used electric toothbrushes with 125 Hz and 150 Hz vibrations, respectively. The remaining ten patients (Group C) served as the control group and did not use electric toothbrushes. The rate of OTM and levels of PGE2 using microcapillary pipettes were calculated before the start of retraction (T0), on the 30th day (T1), on the 60th day (T2), and on the 90th day (T3) from the start of retraction in all the groups. Results: There was a statistically significant difference in the mean OTM values and PGE2 levels in all three groups at different time intervals, with the maximum difference seen in Group B compared to Group A and least in Group C at T1, T2 and T3. Conclusions: The rate of OTM and levels of PGE2 were highest in patients who used an electric toothbrush with 150 Hz mechanical vibration compared to those who used an electric toothbrush with 125 Hz mechanical vibration and least in patients who did not use an electric toothbrush. Mechanical vibration led to an increase in the PGE2 levels and accelerated the OTM.