Myung-Chul Lee

The in vitro effects of dehydroepiandrosterone on human osteoarthritic chondrocytes

OBJECTIVEnTo investigate the in vitro effects of dehydroepiandrosterone (DHEA) on human osteoarthritic chondrocytes.nnnDESIGNnChondrocytes isolated from human osteoarthritic knee cartilage were three-dimensionally cultured in alginate beads, except for cell proliferation experiment. Cells were treated with DHEA in the presence or absence of IL-1beta. The effects on chondrocytes were analyzed using a 3-(4,5-dimethylthiazol-2yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt (MTS) assay (for chondrocyte proliferation), a dimethylmethylene blue (DMB) assay (for glycosaminoglycan (GAG) synthesis), and an indole assay (for DNA amount). Gene expressions of type I and II collagen, metalloproteinase-1 and -3 (MMP-1 and -3), and tissue inhibitor of metalloproteinase-1 (TIMP-1) as well as the IL-1beta-induced gene expressions of MMP-1 and -3 were analyzed by reverse transcription-polymerase chain reaction (RT-PCR). The protein synthesis of MMP-1 and -3 and TIMP-1 was determined by Western blotting.nnnRESULTSnThe treatment of chondrocytes with DHEA did not affect chondrocyte proliferation or GAG synthesis up to 100 micro M of concentration. The gene expression of type II collagen increased in a dose-dependent manner, while that of type I decreased. DHEA suppressed the expression of MMP-1 significantly at concentrations exceeding 50 micro M. The gene expression of MMP-3 was also suppressed, but this was without statistical significance. The expression of TIMP-1 was significantly increased by DHEA at concentrations exceeding 10 micro M. The effects of DHEA on the gene expressions of MMP-1 and -3 were more prominent in the presence of IL-1beta, in which DHEA suppressed not only MMP-1, but also MMP-3 at the lower concentrations, 10 and 50 micro M, respectively. Western blotting results were in agreement with RT-PCR, which indicates that DHEA acts at the gene transcription level.nnnCONCLUSIONSnOur study demonstrates that DHEA has no toxic effect on chondrocytes up to 100 micro M of concentration and has an ability to modulate the imbalance between MMPs and TIMP-1 during OA at the transcription level, which suggest that it has a protective role against articular cartilage loss.

Factors Related to Regional Recurrence in Early Stage Squamous Cell Carcinoma of the Oral Tongue

Objectives This study analyzed various clinical and histopathologic factors for patients with early stage squamous cell carcinoma (SCC) of the oral tongue to define a high risk group for regional recurrence and finally to find out the indication of elective neck dissection (END). Methods Retrospective chart review was performed for 63 patients with T1-T2N0 SCC of the oral tongue who underwent partial glossectomy with/without END. Clinical and histopathologic factors assessed were age, gender, clinical T stage, tumor cell differentiation, depth of invasion, pathologic nodal status, and intrinsic muscle involvement, perineural invasion, lymphovascular emboli and resection margin involvement. Results Five year overall survival rate was 97.1% in stage I and 76.2% in stage II, and 5-yr disease free survival rate was 76.7% in stage I and 43.5% in stage II. Rates of occult nodal metastasis in stage I and II were 15.4% and 42.9%, respectively. Overall regional recurrence rate was 15.9%, which consisted of 10.2% in stage I and 35.7% in stage II. The success rate of salvage treatment was 100% in stage I and 40% in stage II. Higher T stage, higher histologic grade, depth of invasion ≥3 mm, presence of intrinsic muscle involvement were significantly related to regional recurrence (P=0.035, P=0.011, P=0.016, P=0.009, respectively). In stage I, the non-END group (n=36) showed 13.9% of regional recurrence rate, while END group (n=13) did not have any regional recurrence (P=0.198). Five year disease free survival rate of END group was significantly higher than non-END group (100% and 68.7%, respectively, P=0.045). Conclusion We recommend to perform END in early stage SCC of the oral tongue if the primary tumor has T2 stage, and T1 stage with higher histologic grade, depth of invasion more than 3 mm, or presence of intrinsic muscle involvement.

The slippage-proof knot: a new, nonstacking, arthroscopic, sliding locking knot with a lag bight.

The slippage-proof knot is a new, nonstacking, arthroscopic, sliding knot with a lag bight. The knot is easy to tie and ensures smooth sliding and avoidance of premature locking.

Prevalence and prognostic value of human papillomavirus genotypes in tonsillar squamous cell carcinoma: A Korean multicenter study

This study was aimed at investigating the change in the prevalence of human papillomavirus (HPV) genotypes in tonsillar squamous cell carcinoma (TSCC) and the association of the HPV genotype with the prognosis.

Ceramic Femoral Prosthesis in TKA — Present and Future

Total knee arthroplasty is a reliable procedure for the treatment of severely damaged knee joints in patients with osteoarthritis or rheumatoid arthritis. Despite good long-term results, the ultimate failure mode of TKA is osteolysis caused by wear debris from polyethylene. The osteolysis tends to cause aseptic loosening and instability of components, which leads to pain and revision [8,17]. Certainly, in case of elderly patients with lower activity levels, even total knee prostheses with conventional design and materials have achieved excellent long-term results. Over the past 10 years, however, greater demands are recently placed on total knee arthroplasties for younger, more active patients [24]. Therefore, in an attempt to minimize such PE wear, several modifications of the traditional approach to TKR have been introduced. Implant design and surgical instruments are continuously developing, including the use of more conforming articular surfaces [7]. Improvements in manufacturing quality, elimination of sterilization by gamma irradiation in air and cross-linking have reduced the PE wear [16,64]. However, wear and mechanical failures of gamma inert sterilized and highly cross-linked polyethylene have been observed [11,12].

New endoscopic thyroidectomy via a unilateral axillo‐breast approach with gas insufflation: Preliminary report

Invasiveness of endoscopic thyroidectomy has been in debate. The purpose of this study was to introduce new endoscopic thyroidectomy via a unilateral axillo‐breast approach (UABA) with gas insufflation to lessen invasiveness.

A randomized study to compare the efficacy and safety of extended-release and immediate-release tramadol HCl/acetaminophen in patients with acute pain following total knee replacement

Abstract Objective: To evaluate the relative efficacy and safety of extended-release tramadol HCl 75u2009mg/acetaminophen 650u2009mg (TA-ER) and immediate-release tramadol HCl 37.5u2009mg/acetaminophen 325u2009mg (TA-IR) for the treatment of moderate to severe acute pain following total knee replacement. Methods: This phase III, double-blind, placebo-controlled, parallel-group study randomized 320 patients with moderate to severe pain (≥4 intensity on an 11 point numeric rating scale) following total knee replacement arthroplasty to receive oral TA-ER (every 12 hours) or TA-IR (every 6 hours) over a period of 48 hours. In the primary analysis, TA-ER was evaluated for efficacy non-inferior to that of TA-IR based on the sum of pain intensity difference (SPID) at 48 hours after the first dose of study drug (SPID48). Secondary endpoints included SPID at additional time points, total pain relief at all on-therapy time points (TOTPAR), sum of SPID and TOTPAR at all on-therapy time points (SPIDu2009+u2009TOTPAR), use of rescue medication, subjective pain assessment (PGIC, Patient Global Impression of Change), and adverse events (AEs). Results: Analysis of the primary efficacy endpoint (SPID48) could not establish the non-inferiority of TA-ER to TA-IR. However, a post hoc analysis with a re-defined non-inferiority margin did demonstrate the non-inferiority of TA-ER to TA-IR. No statistically significant difference in SPID at 6, 12, or 24 hours was observed between the TA-ER and TA-IR groups. Similarly, analysis of TOTPAR showed that there were no significant differences between groups at any on-therapy time point, and SPIDu2009+u2009TOTPAR at 6 and 48 hours were similar among groups. There was no difference in the mean frequency or dosage of rescue medication required by both groups, and the majority of patients in both the TA-ER and TA-IR groups rated their pain improvement as ‘much’ or ‘somewhat better’. The overall incidence of ≥1 AEs was similar among the TA-ER (88.8%) and TA-IR (89.5%) groups. The most commonly reported AEs by patients treated with TA-ER and TA-IR included nausea (49.7% vs 44.4%), vomiting (28.0% vs 24.2%), and decreased hemoglobin (23.6% vs 26.1%). This study is limited by the lack of placebo control, and the invalidity of the initial non-inferiority margin. Conclusion: This study demonstrated that the analgesic effect of TA-ER is non-inferior to TA-IR, and supports TA-ER as an effective and safe treatment for moderate to severe acute pain post total knee replacement. Clinical trial registration: Clinicaltrials.gov, NCT01814878.

Comparative study of a gasless transaxillary approach versus a bilateral axillo‐breast approach for endoscopic thyroidectomy in a single institute

Gasless transaxillary approach (TA) and the bilateral axillo‐breast approach (BABA) are 2 distinctive approaches for endoscopic thyroidectomy. The purpose of this study was to evaluate and compare these 2 procedures.

A Multicenter, Double-Blind, Phase III Clinical Trial to Evaluate the Efficacy and Safety of a Cell and Gene Therapy in Knee Osteoarthritis Patients

OBJECTIVEnTo test the clinical efficacy of TissueGene-C (TG-C), a cell and gene therapeutic for osteoarthritis consisting of non-transformed and transduced chondrocytes (3:1), retrovirally transduced to overexpress TGF-β1.nnnDESIGNnWe randomly assigned 163 with knee osteoarthritis to receive intra-articular TG-C or placebo in Kellgren-Lawrence grade 3 patients for clinical trial. Primary efficacy measures included criteria for subjective assessment by International Knee Documentation Committee (IKDC) and pain severity by Visual Analog Scale (VAS) for 52 weeks. Secondary efficacy measures included IKDC and VAS at 26 and 39 weeks; pain, stiffness, and physical functions by the Western Ontario and McMaster Universities Arthritis Index (WOMAC); and pain, symptoms, daily activities, functions in sports and recreation, and quality of life by the Knee Injury and Osteoarthritis Outcome Score (KOOS), X ray, MRI, and soluble urine and blood biomarkers.nnnRESULTSnTG-C was associated with statistically significant improvement over placebo in the total IKDC score and individual categories, and in the VAS score at 26, 39, and 52 weeks. WOMAC and KOOS scores also improved with TG-C over placebo. Patients treated with TG-C showed trends directed towards thicker cartilage and slower growing rates of subchondral bone surface area in the medial tibia, lateral tibia, lateral patella, and lateral patella femoral regions, although not statistically significant (P > 0.05). Serum CTX-I and urine CTX II levels showed lower over 1 year in TG-C than placebo treated patients with CTX-I level reaching statistical significance. These tendencies supported TG-C as holding a great potential for disease-modifying osteoarthritis drug. The most frequent adverse events in the TG-C group were peripheral edema (9%), arthralgia (8%), joint swelling (6%), and injection-site pain (5%).nnnCONCLUSIONSnTG-C was associated with statistically significant improvements in functions and pain in patients with knee osteoarthritis. The unexpected adverse events were not observed.nnnTRIAL REGISTRATIONnclinicaltrials.gov NCT02072070 and CRiS: KCT0001112.

Factors associated with discrepancies between preoperatively planned and postoperative alignments in patients undergoing closed-wedge high tibial osteotomy

BACKGROUNDnTo evaluate the difference between preoperative plan and postoperative alignment after closed-wedge HTO and determine factors associated with difference.nnnMETHODSnThis retrospective cohort study included 165 cases with closed-wedge HTO. The following radiographic parameters were measured: mechanical tibiofemoral angle (mTFA), mechanical medial proximal tibial angle (MPTA), joint line convergence angle, mediolateral joint width discrepancy, Kellgren-Lawrence (K-L) grade, and discrepancy between the correction angle in tibia and correction angle in mTFA. The linear regression analysis was used for the preoperative factors that affect the discrepancy between correction angle in tibia and correction angle in mTFA.nnnRESULTSnPreoperative and postoperative mTFA was varus 8.3°±3.7 and valgus 3.1°±2.6. The MPTA was varus 6.2°±3.1 preoperatively, valgus 3.7°±3.0 postoperatively. The mediolateral joint width discrepancy was 3.1mm±1.8 preoperatively and 1.8mm±1.4 postoperatively. The discrepancy between correction angle in tibia and correction angle in mTFA was 1.5°±2.3 valgus. By regression analysis, one degree of valgus overcorrection was found to be related with every 2.5° of joint convergence angle (r2=0.396), 2.4mm of mediolateral joint width discrepancy (r2=0.310) and increased one grade of K-L classification (r2=0.107) as preoperative measurement.nnnCONCLUSIONSnThe 1.5° valgus overcorrection of postoperative mTFA was found compared with planned correction angle in tibia. By the equation, every 2.5° of joint convergence angle and 2.4mm of mediolateral joint width discrepancy preoperatively could predict one degree of valgus overcorrection.