Dong-Wook Kim

Protective Effects of Hyperoside against Carbon Tetrachloride-Induced Liver Damage in Mice

In this study, the hepatoprotective effects of hyperoside (1), a flavonoid glycoside isolated from Artemisia capillaris, have been examined against carbon tetrachloride (CCl4)-induced liver injury. Mice were treated intraperitoneally with vehicle or 1 (50, 100, and 200 mg·kg(-1)) 30 min before and 2 h after CCl4 (20 μL·kg(-1)) injection. Levels of serum aminotransferases were increased 24 h after CCl4 injection, and these increases were attenuated by 1. Histological analysis showed that 1 prevented portal inflammation, centrizonal necrosis, and Kupffer cell hyperplasia. Lipid peroxidation was increased and hepatic glutathione content was decreased significantly after CCl4 treatment, and these changes were reduced by administration of 1. Protein and mRNA expression of tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and heme oxygenase-1 (HO-1) and nuclear protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2) significantly increased after CCl4 injection. Compound 1 suppressed TNF-α, iNOS, and COX-2 protein and mRNA expression and augmented HO-1 protein and mRNA expression and Nrf2 nuclear protein expression. These results suggest that 1 has protective effects against CCl4-induced acute liver injury, and this protection is likely due to enhancement of the antioxidative defense system and suppression of the inflammatory response.

Intra-articular Ganglion Cysts of the Knee

A ganglion is a cystic mass with myxoid matrix that occasionally occurs within muscles, tendons, and menisci. A ganglion cyst within the knee is very rare, with few reports to be found. We are reporting eight cases of a ganglion within the knee joint. Our cases include two ganglia in the infrapatellar fat pad which have not been previously reported. Ganglion cysts do not have specific symptoms. We hypothesize that symptoms of a ganglion cyst may correlate with the size and the location within the knee joint. The diagnosis of ganglia within the knee was established by magnetic resonance imaging study and confirmed by pathological testing. All the patients were treated successfully using the arthroscopic technique.

Intraarticular anatomic variants associated with discoid meniscus in Koreans.

From July 1990 through June 1994, 106 knees (102 patients) were treated for discoid meniscus. Fifteen knees (15 patients) were associated with other intraarticular anatomic variants. There were eight knees (8 patients) with anomalous insertion of the anterior horn of the medial meniscus into the anterior cruciate ligament, and seven knees (7 patients) with anterior expansion of the anterior portion of the anterior cruciate ligament below the anterior tibial margin. Among the latter, one patient also had anterior transposition of the anterior insertion of the medial meniscus, while obliteration of the popliteal hiatus was seen in another patient. The discoid menisci were reshaped in 13 knees (13 patients), totally resected in one knee, and in one patient the discoid meniscus was treated with repair of a peripheral tear and reshaping. Followup ranged from 24 to 54 months (average, 37 months) after surgery. The results were excellent in eight knees, good in five knees, and fair in two knees as graded using the Ikeuchi scale. These anatomic variants, other than the discoid meniscus, did not seem to be related to the patients symptoms.

Protective effects of Mg-CUD against D-galactosamine-induced hepatotoxicity in rats.

This study examined the protective effects of magnesium chenoursodeoxycholic acid (Mg-CUD), a magnesium trihydrate salt of chenodeoxycholic acid (CDCA) and ursodeoxycholic acid (UDCA), against D-galactosamine (D-GalN)-induced liver injury. Hepatotoxicity was induced by intraperitoneal injection of D-GalN (700mg/kg) and Mg-CUD (15.625, 31.25 and 62.5mg/kg) was administered orally once a day for 2weeks and 6h after D-GalN injection. Significant increases in the level of serum alanine aminotransferase activity and lipid peroxidation were attenuated by Mg-CUD 24h after D-GalN treatment. Hepatic glutathione/oxidized glutathione ratio was decreased, and this decrease was attenuated by Mg-CUD. Mg-CUD attenuated the increase in the levels of serum tumor necrosis factor (TNF)-α and interleukin (IL)-6, while it augmented the increase in serum IL-10 level and heme oxygenase (HO)-1 protein expression. Mg-CUD attenuated increased levels of TNF-α, IL-6, and IL-1β mRNA expression. Increased levels of IL-10 and HO-1 mRNA expression were augmented by Mg-CUD. The increased nuclear level of nuclear factor-κB (NF-κB) and decreased cytosolic level of Inhibitory κB-α protein were attenuated by Mg-CUD. Nuclear phosphorylated c-Jun (p-c-Jun) level showed a significant increase and this increase was attenuated by Mg-CUD. Our results suggest that Mg-CUD ameliorates D-GalN-induced acute hepatitis and that this protection is likely due to its anti-oxidative and anti-inflammatory activities, and inhibition of NF-κB nuclear translocation and nuclear p-c-Jun expression.

Scoparone attenuates d-galactosamine/lipopolysaccharide-induced fulminant hepatic failure through inhibition of toll-like receptor 4 signaling in mice

The purpose of this study was to investigate the protective effects and molecular mechanisms of scoparone on d-galactosamine (D-GalN)/lipopolysaccharide (LPS)-induced fulminant hepatic failure (FHF) in mice. FHF was induced in mice by intraperitoneal injection of D-GalN (800 mg/kg)/LPS (40 μg/kg). Mice were treated intraperitoneally with scoparone 1h before D-GalN/LPS treatment. Treatment with d-GalN/LPS markedly increased mortality, serum aminotransferase activity, and tolllike receptor 4 (TLR4) protein expression, and these increases were attenuated by scoparone. Treatment with d-GalN/LPS markedly increased myeloid differentiation primary response gene 88 protein expression, phosphorylation of p38, extracellular signal-regulated kinase and c-Jun N-terminal kinase, nuclear protein expression of nuclear factor κB and phosphorylated c-Jun, and levels of serum tumor necrosis factor-α and interleukin-6 and these increases were attenuated by scoparone. In addition, increased levels of toll-receptor-associated activator of interferon protein expression, phosphorylation of interferon (IFN) regulatory factor 3, and serum IFN-β level in D-GalN/LPS-treated mice were attenuated by scoparone. Our results suggest that scoparone attenuates d-GalN/LPSinduced liver damage by inhibition of the TLR-mediated inflammatory pathway.

Cementless total hip arthroplasty using Biolox®delta ceramic-on-ceramic bearing in patients with osteonecrosis of the femoral head

Purpose The purpose of this study was to evaluate the results of cementless total hip arthroplasty (THA) using a 32 mm or larger Biolox®delta ceramic-on-ceramic (CoC) bearing in patients with osteonecrosis of the femoral head after a minimum of 5 years of follow-up. Materials and methods We retrospectively analysed 44 patients (53 hips) who underwent cementless THA using Biolox®delta CoC bearing. There were 33 men (40 hips) and 11 women (13 hips) with the mean age of 49 years. A 36 mm head was used in 42 (79%) of 53 hips and a 32 mm head was used in 11 hips with smaller acetabular shells. The mean duration of follow-up was 5.3 years (range 5-6 years). Results The mean Harris Hip Score improved from 50 points preoperatively to 97 points at final follow-up (p<0.001). All acetabular and femoral components showed radiographic evidence of osseointegration. No osteolysis was observed. No patients sustained ceramic fracture. An audible hip noise was identified in 2 (4%) of the 53 hips (1 squeaking and 1 clicking). Survivorship with revision for any reason at a minimum of 5 years was 100% in the best-case scenario and 95 % in the worst-case scenario. Conclusions The minimum 5-year results of cementless THA using a 32 mm or larger Biolox®delta CoC bearing in patients with osteonecrosis of the femoral head were encouraging with excellent survivorship. However, it was also found that the risk of noise development remains even for the new alumina matrix composite ceramic.

Primary Ceramic-on-ceramic Total Hip Arthroplasty Using a 32-mm Ceramic Head With a Titanium-alloy Sleeve

BackgroundModern ceramic-on-ceramic bearings have become attractive alternatives to conventional polyethylene in total hip arthroplasty (THA) as a result of their low wear and minimal particle production. However, 28-mm heads in ceramic-on-ceramic bearing couples have been associated with ceramic fracture. To address these issues, 32-mm and larger ceramic heads with a titanium-alloy sleeve have been introduced, although limited data are available on their durability and clinical outcomes.Questions/purposesWe determined (1) the survivorship of the primary ceramic-on-ceramic THA using a 32-mm ceramic head with a titanium-alloy sleeve at a minimum followup of 5 years; (2) Harris hip scores; (3) the incidence of ceramic fracture and noisy hip; and (4) the proportion of hips showing radiographic evidence of osteolysis.MethodsFrom November 2005 to August 2009, we performed 301 ceramic-on-ceramic THAs using a 32-mm ceramic head with a titanium-alloy sleeve in 270 patients. Of these, 12 patients (12 hips [4%]) died from problems unrelated to surgery and 13 patients (15 hips [5%]) were lost during followup before a minimum of 5 years had been reached, leaving 245 patients who had 274 THAs with a minimum followup of 5 years (mean, 6.5 years; range, 5–9 years) in this retrospective analysis. During the study period, 30% (301 of 997 hips) were performed with this articulation based on the operating surgeon’s discretion. The mean patient age at the time of surgery was 55 years (range, 16–82 years). All operations were performed at a single center. All of the ceramic implants were hot isostatic-pressed, laser-marked, proof-tested third-generation alumina. We determined the implant survival, Harris hip scores, incidence of ceramic fracture or noisy hips (based on a questionnaire), and presence of osteolysis.ResultsThe survival rate of ceramic-on-ceramic bearings in primary THA using a 32-mm ceramic head with a titanium-alloy sleeve was 98% (95% confidence interval, 96%–100%) at 9 years. The Harris hip score improved from a mean of 47 points preoperatively to 93 points at last followup. One ceramic head fractured at 6 years postoperatively. No ceramic liners fractured. Audible hip clicking and squeaking were identified in four hips and one hip, respectively. Osteolysis was detected in three hips, but none had symptoms.ConclusionsPrimary ceramic-on-ceramic THA using a 32-mm ceramic head with a titanium-alloy sleeve has a survivorship of 98% at 9-year followup. Nevertheless, surgeons should be aware of the potential risks of ceramic fracture, noise, and osteolysis associated with the use of a ceramic head with a titanium-alloy sleeve.Level of EvidenceLevel IV, therapeutic study.

Hearing impairment simulation for the performance evaluation of hearing aid system

With the advent of high speed digital signal processing chips, many digital techniques have been introduced to hearing aids. As new techniques are developed a subject-based test is needed to verify the performance of each new technique, which requires much time and cost. Here, the authors propose an indirect way to evaluate and predict the performance of a hearing aid system without the help of such a subject-based test. The system is developed based on a model constructed from the auditory test results of sensorineural hearing impaired persons. To verify the proposed system, a processed signal was heard by normal persons and their responses were compared with those of a real impaired person. The results showed only a slight difference between them. In addition, 3 kinds of currently available digital hearing aid algorithm were applied to the system and evaluated.

Effect of oral factor Xa inhibitor and low-molecular-weight heparin on surgical complications following total hip arthroplasty

This prospective study was conducted to report the effect of oral factor Xa inhibitor and low-molecular-weight heparin (LMWH) on surgical complications following total hip arthroplasty (THA). The patients with an age < 60 years were randomly assigned to three groups (rivaroxaban, enoxaparin, and placebo) and the patients with an age ≥ 60 years were assigned to two groups (rivaroxaban and enoxaparin). All drug regimens started at 12 hours postoperatively and continued for two weeks after surgery. Primary measure outcome was major surgical wound complications defined as haematoma requiring any intervention, superficial wound infection, deep periprosthetic infection, and increased wound bleeding. Secondary measured outcome included minor surgical complications (swelling, drainage, erythema, and oozing), organ bleeding, and venous thromboembolic (VTE) events. A total of 184 patients aged < 60 years and 167 patients aged ≥ 60 years were included as the analysis population per group. Up to 14 days after surgery, the overall incidence of major surgical complications associated with thromboprophylaxis was 6.5 % (58/886). There were no significant differences in the rate of major surgical complications among all the three groups of the patients aged < 60 years and between two groups of the patients aged ≥ 60 years. For the patients aged < 60 years, wound oozing continued significantly longer in the pharmacological group than in the placebo group, but wound infection did not occur in any case. The VTE events were similar in all the groups.