Chitosan/polyurethane blended fiber sheets containing silver sulfadiazine for use as an antimicrobial wound dressing.

Electrospun chitosan (CTS) nanofibers have been well known for use as a wound dressing in the biomedical field. Nevertheless, fatal bacterial infections are still a serious problem when CTS nanofibers are used for wound treatment. In this study, we designed a novel wound dressing based on blending the chitosan with polyurethane (CTS/PU) containing silver sulfadiazine (AgSD) in order to enhance both antibacterial activity and mechanical strength. This fiber sheet was produced using the electrospinning (ELSP) technique. The CTS/PU containing AgSD fiber sheet was characterized by energy-dispersive X-ray spectroscopy (EDX). The physicochemical properties of the CTS/PU/AgSD fiber sheets were also characterized by thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The electrospun fibers were morphologically characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). For an in vitro evaluation, the CTS/PU/AgSD fiber sheets were tested for their antibacterial activity against gram-negative Pseudomonas aeruginosa (P. aeruginosa), gram-positive Staphylococcus aureus (S. aureus) and Methicillin-resistant Staphylococcus aureus (MRSA). The results indicate that CTS/PU/AgSD fiber sheets have strong antimicrobial activity as displayed by inhibition of bacterial growth and prevention of infection during the healing process. These results indicate that this material would be good for use as a wound dressing material.

Analysis of morphological and histologic changes in intraoral fasciocutaneous free flaps used for oropharyngeal reconstruction.

The fasciocutaneous flap transplanted into the oral cavity often acquires a gross appearance resembling that of intraoral mucosa. The purpose of this study was to analyze the histologic and morphological changes of the fasciocutaneous free flap in oropharyngeal reconstruction and attempt to determine the related causes. A study was done from January 2006 to February 2010. Study subjects included 67 of 239 patients who had undergone reconstructive surgery after oropharyngeal tumor resection. Histologic evaluation of biopsy specimens was also performed in 20 patients. The correlation of the morphological changes with various factors was analyzed. The histologic examination revealed that numerous histologic changes occurred although the overall structure of the skin was maintained. Analysis of the associated factors showed that the primary defect site was highly correlated with this morphological change in the intraoral flaps.Analysis of the associated factors showed that the primary defect site was highly correlated with this morphological change in the intraoral flaps. Histologic analysis reveals that fasciocutaneous free flaps maintain their feature as cutaneous skin yet undergo changes because of the characteristic oral cavity environment, which resulted in an intermediate-stage morphology.

Ultrasonographically detected non-alcoholic fatty liver disease is an independent predictor for identifying patients with insulin resistance in non-obese, non-diabetic middle-aged Asian adults.

OBJECTIVES: We assessed the association among ultrasonographically detected non-alcoholic fatty liver disease (US-NAFLD), metabolic syndrome (MetS), and insulin resistance (IR) in non-obese, non-diabetic middle-aged adults, to find out whether US-NAFLD is independently associated with IR in this population. METHODS: A total of 5,878 non-obese (body mass index, ≥ 18.5 and < 25), non-diabetic individuals were analyzed. IR was estimated with the homeostasis model assessment index (HOMA2-IR) and defined when HOMA2-IR ≥ 1.5. MetS was defined by the Adult Treatment Panel III (ATP III) criteria. RESULTS: MetS was present in 381 (6.5%) participants, IR was present in 801 (13.6%) participants, and US-NAFLD was present in 1,611 (27.4%) participants. The increase in the prevalence of US-NAFLD closely followed the increase in the number of metabolic components diagnosed according to the ATP III criteria (15.2%, 28.5%, 48.0%, 65.7%, 71.4%, and 100% for 0, 1, 2, 3, 4, and 5 metabolic components, respectively, P < 0.001). US-NAFLD showed a significantly higher odds ratio (OR) for IR, regardless of the number of metabolic components (OR (95% confidence interval) of 3.48 (2.45-4.94), 3.63 (2.74-4.82), 3.19 (2.29-4.44), and 2.43 (1.43-3.81) for 0, 1, 2, and ≥ 3 metabolic components, respectively, P < 0.001 for all values). MetS showed a low sensitivity (0.22) for the identification of individuals with IR, and either US-NAFLD alone (0.60) or US-NAFLD with MetS (0.66) improved sensitivity with acceptable trade-off in specificity. CONCLUSIONS: US-NAFLD was an independent predictor for IR, irrespective of the number of metabolic components of MetS in the non-obese, non-diabetic middle-aged Asian adults. US-NAFLD could identify individuals with IR that cannot be identified by MetS in this population.

Upper normal threshold of serum alanine aminotransferase in identifying individuals at risk for chronic liver disease.

BACKGROUND/AIMS: Serum alanine aminotransferase (ALT) is an easily available, low-cost screening tool for detecting silent chronic liver disease. Recent studies have suggested that the currently accepted healthy ALT thresholds be lowered. METHODS: In this retrospective cross-sectional study, we determined upper thresholds for ALT values in a nationally representative healthy cohort (n = 3337) from the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV). Sensitivity and specificity of the currently used ALT threshold (40 IU/L, regardless of gender) was compared against study-derived, gender-specific ALT thresholds for detecting individuals at risk for chronic liver disease in 27 913 health check-up participants. RESULTS: The 95th percentile levels for ALT in healthy weight, metabolically normal, liver disease-free KNHANES participants were 34 IU/L for men and 25 IU/L for women. The prevalence of ALT elevation among health check-up participants was 11.0% in currently used thresholds, and increased to 22.6% with study-derived, gender-specific thresholds. Of the population who were additionally defined to have elevated ALT levels under new ALT threshold, 65.7% were at risk for chronic liver disease. Sensitivity for detecting individuals at risk for chronic liver disease improved from 18 to 33% with new thresholds whereas a trade-off in specificity (from 96 to 88%) was observed. CONCLUSIONS: It is recommendable to lower the current ALT thresholds to better identify individuals at risk for chronic liver disease.

Optimization of a Cryopreservation Method for the Endangered Korean Species Pogostemon yatabeanus Using a Systematic Approach: The Key Role of Ammonium and Growth Regulators.

Cryopreservation provides a secure long-term conservation option for rare and endangered plant species with non-orthodox or limitedly available seeds. Wide application of cryopreservation to biobank wild flora is hampered by the need to re-optimize nearly all protocol steps for every new species. We applied a systematic approach to simplify optimization of a multi-stage droplet-vitrification method for the endangered wetland Korean species, Pogostemon yatabeanus. This approach consisted of a standard procedure pre-selected based on material type and size, which was complemented with 11 additional treatments to reveal the most impactful conditions. Effect of ammonium nitrate at various protocol steps was also tested. The highest shoot tip survival (92%) and plant regeneration (90%) after cryopreservation were achieved using preculture with 10% sucrose followed by 40 min osmoprotection and 60 min treatment with vitrification solution A3-80% (33.3% glycerol + 13.3% dimethyl sulfoxide + 13.3% ethylene glycol + 20.1% sucrose) on ice. A three-step regrowth procedure starting with ammonium-free medium with 1 mg/L GA3 and 1 mg/L BA followed by ammonium-containing medium with and without growth regulators was essential for the development of healthy plants from cryopreserved shoot tips. This approach enables fast optimization of the cryopreservation procedure for new osmotic stress-sensitive plant species.

[Nonrotation of the prearterial segment of midgut presenting as duodenal obstruction in a 60-year-old man].

Intestinal malrotation is a developmental anomaly resulting from embryologic failure of fixation and rotation of the gut and predisposed to midgut vovulus and small bowel obstruction. Although various forms of malrotation anomalies in the gut can occur, nonrotation of prearterial segment with the initial symptomatic presentation at advanced age has been rarely reported. Here, we report a case of nonrotation of the prearterial segment of the midgut presenting with duodenal obstruction in a 60-year-old man. To our best knowledge, this is the first case reported about nonrotation of prearterial segment of the midgut in Korea.

Correlation of the grade of hepatic steatosis between controlled attenuation parameter and ultrasound in patients with fatty liver: a multi-center retrospective cohort study.

BACKGROUND/AIMS: The controlled attenuation parameter (CAP), based on transient elastography, is widely used for noninvasive assessment of the degree of hepatic steatosis (HS). We investigated the correlation of the degree HS between CAP and ultrasound (US) in patients with HS. METHODS: In total, 986 patients with US-based HS who underwent transient elastography within 1 month were evaluated. The US-based grade of HS was categorized as mild (grade 1), moderate (grade 2), or severe (grade 3). RESULTS: The CAP was significantly correlated with the US-based grade of HS (r = 0.458, p < 0.001). The median CAP value of each US-based HS grade showed a positive correlation with grade (271.1, 303.7, and 326.7 dB/m for grades 1, 2, and 3). In a multivariate analysis, the US-based HS grade, body mass index, serum albumin, alanine aminotransferase, and total cholesterol, and liver stiffness were all significantly correlated with the CAP value (all p < 0.05). The areas under the receiver operating characteristic curves for grade 2 to 3 and grade 3 HS were 0.749 (95% confidence interval [CI], 0.714 to 0.784) and 0.738 (95% CI, 0.704 to 0.772). The optimal cut-off CAP values to maximize the sum of the sensitivity and specificity for grade 2 to 3 and grade 3 HS were 284.5 dB/m (sensitivity 78.6%, specificity 61.7%) and 298.5 dB/m (sensitivity 84.6%, specificity 55.6%). CONCLUSION: The correlation of the degree of HS between CAP and US was significantly high in patients with HS, and the optimal cut-off CAP values for grade 2 to 3 and grade 3 HS were 284.5 and 298.5 dB/m.

[A case of intramural duodenal hematoma accompanied by acute pancreatitis following endoscopic hemostasis for duodenal ulcer bleeding].

Intramural duodenal hematoma is an uncommon condition, which usually develops after blunt abdominal trauma. It is also reported as a complication of anticoagulant therapy, blood dyscrasia, pancreatic disease, and diagnostic and therapeutic endoscopy. The typical clinical pictures of intramural duodenal hematoma consist of upper abdominal pain, vomiting, fever, and hematochezia, and it is rarely accompanied by intestinal obstruction, peritonitis, and pancreatitis as its complication. We report a case of intramural duodenal hematoma extended to peritoneal cavity, and accompanied by acute pancreatitis following therapeutic endoscopy for duodenal ulcer bleeding in a 32-year-old man who was on maintenance of anti-coagulation therapy after valvular heart surgery.

Optimization of exposure parameters and relationship between subjective and technical image quality in cone-beam computed tomography.

PURPOSE: This study was performed to investigate the effect of exposure parameters on image quality obtained using a cone-beam computed tomography (CBCT) scanner and the relationship between physical factors and clinical image quality depending on the diagnostic task. MATERIALS AND METHODS: CBCT images of a SedentexCT IQ phantom and a real skull phantom were obtained under different combinations of tube voltage and tube current (Alphard 3030 CBCT scanner, 78-90 kVp and 2-8 mA). The images obtained using a SedentexCT IQ phantom were analyzed technically, and the physical factors of image noise, contrast resolution, spatial resolution, and metal artifacts were measured. The images obtained using a real skull phantom were evaluated for each diagnostic task by 6 oral and maxillofacial radiologists, and each setting was classified as acceptable or unacceptable based on those evaluations. A statistical analysis of the relationships of exposure parameters and physical factors with observer scores was conducted. RESULTS: For periapical diagnosis and implant planning, the tube current of the acceptable images was significantly higher than that of the unacceptable images. Image noise, the contrast-to-noise ratio (CNR), the line pair chart on the Z axis, and modulation transfer function (MTF) values showed statistically significant differences between the acceptable and unacceptable image groups. The cut-off values obtained using receiver operating characteristic curves for CNR and MTF 10 were useful for determining acceptability. CONCLUSION: Tube current had a major influence on clinical image quality. CNR and MTF 10 were useful physical factors that showed significantly associations with clinical image quality.

Internal derangement as a predictor of provoked pain on mouth opening: A magnetic resonance imaging study.

PURPOSE: This study investigated the relationship between pain and internal derangement in temporomandibular disorder (TMD) patients using magnetic resonance imaging (MRI). MATERIALS AND METHODS: This study analyzed 356 TMD patients (712 temporomandibular joints [TMJs]). The inclusion criteria were the presence of spontaneous or provoked pain on one or both TMJs and having undergone MRI. The patients with provoked pain were divided into 3 groups: pain on palpation, pain on mouth opening, and pain on mastication. MRI was performed using a 1.5-T scanner. T1- and T2-weighted parasagittal and paracoronal images were obtained. According to the findings on the T1-weighted images, another 3 groups were created based on internal derangement: normal, disc displacement with reduction, and disc displacement without reduction. The MRI findings were independently interpreted by 2 experienced oral and maxillofacial radiologists at 2 different times. Statistical analysis was performed by the chi-square test using SPSS (version 12.0; SPSS Inc., Chicago, IL, USA). RESULTS: Provoked pain on mouth opening was found to be correlated with internal derangement in TMD patients (P<.05). However, spontaneous pain and provoked pain on palpation or mastication were not associated with internal derangement (P>.05). CONCLUSION: These results suggest that internal derangement was a significant predictor of provoked pain on mouth opening.

Gardner syndrome associated with multiple osteomas, intestinal polyposis, and epidermoid cysts.

Gardner syndrome is known as a variant of familial adenomatous polyposis. This syndrome is characterized by multiple intestinal polyposes, osteomas, and epidermoid cysts. In addition, dental abnormalities include an increased frequency of multiple odontomas, as well as supernumerary and impacted teeth. The authors report the case of a 7-year-old male patient with Gardner syndrome. Radiographic findings revealed multiple osteomas in both sides of the maxilla, multiple diffuse enostoses in both jaws, and a complex odontoma in the left mandibular body. Two years later, multiple epidermoid cysts on the scalp were found. Since this patient was suspected to have Gardner syndrome, the authors recommended gastrointestinal endoscopy to check for intestinal polyposis. Gastrointestinal endoscopic examination revealed multiple polyposes in the upper gastrointestinal tract and fundus of the stomach. As a result, the final diagnosis was Gardner syndrome.

[A Case of Severe Peripheral Polyneuropathy Occurring after Entecavir Treatment in a Hepatitis B Patient].

Entecavir (Baraclude®) is an oral antiviral drug used for the treatment of HBV. Entecavir is a reverse transcriptase inhibitor which prevents the HBV from multiplying. Most common adverse reactions caused by entecavir are headache, fatigue, dizziness, and nausea. Until now, there has been no report of peripheral neuropathy as a side effect associated with entecavir treatment. Herein, we report a case of peripheral neuropathy which probably occurred after treatment with entecavir in a hepatitis B patient. The possibility of the occurrence of this side effect should be carefully taken into consideration when a patient takes a high dose of entecavir for a long period of time or has risk factors for neuropathy at the time of initiating entecavir therapy.

Desmoplastic variant of ameloblastoma of the maxilla: A case report.

The desmoplastic variant of ameloblastoma is a rare form of ameloblastoma characterized by unique radiographic and histologic features. A 46-year-old female was referred to our hospital, complaining of swelling in the left upper lip area. Radiographic findings revealed an ill-defined multilocular lesion with a large cystic lesion and thick sclerotic trabeculae on the left anterior maxilla. After the patient underwent partial osteotomy, histologic analysis revealed a desmoplastic ameloblastoma with no evidence of a hybrid lesion or cyst formation. The radiographic findings in the present case were different from those described in previous case reports. These findings are of special importance due to the unfamiliar radiographic and histologic features of this lesion.

Preoperative predictive factors for gastrointestinal stromal tumors: analysis of 375 surgically resected gastric subepithelial tumors.

BACKGROUND: Gastrointestinal stromal tumors (GISTs) and non-GIST subepithelial tumors (SETs) account for about 75 and 25% of gastric hypoechoic SETs ≥2 cm, respectively. Therefore, identifying preoperative predictive factors for GISTs are required to refine surgical indications. METHODS: We performed a retrospective review of 375 surgically resected gastric hypoechoic SETs ≥2 cm. Demographic data and tumor characteristics based on upper endoscopy and CT findings were compared between GIST and non-GIST SETs originating from muscularis propria layer (leiomyomas, Schwannomas, glomus tumors, and ectopic pancreas). RESULTS: In cardia, leiomyomas were found twice more frequently than GISTs (63.6 versus 31.8%). Perilesional lymph node enlargement (PLNE) was found only in patients with GIST or Schwannomas. Patients with GIST showed a significantly lower rate of PLNE than those with Schwannomas (3.5 versus 29.0%). In multivariate analysis, tumor site outside cardia (odds ratio, 9.157), absence of PLNE (odds ratio, 11.519), old age, large tumor size, exophytic growth pattern, and ulceration or dimpling were identified as independent preoperative predictive factors for GISTs versus non-GIST SETs. CONCLUSIONS: The effort for preoperative pathologic diagnosis such as endosonography-guided tissue sampling might be positively considered for SETs at cardia and SETs with PLNE where the possibility of GIST is low.

Relationship between pain and effusion on magnetic resonance imaging in temporomandibular disorder patients.

PURPOSE: This study was performed to find the relationship between pain and joint effusion using magnetic resonance imaging (MRI) in temporomandibular disorder (TMD) patients. MATERIALS AND METHODS: The study subjects included 232 TMD patients. The inclusion criteria in this study were the presence of spontaneous pain or provoked pain on one or both temporomandibular joints (TMJs). The provoked pain was divided into three groups: pain on palpation (G1), pain on mouth opening (G2), and pain on mastication (G3). MRI examinations were performed using a 1.5-T MRI scanner. T1- and T2-weighted images with para-sagittal and para-coronal images were obtained. According to the T2-weighted image findings, the cases of effusions were divided into four groups: normal, mild (E1), moderate (E2), and marked effusion (E3). A statistical analysis was carried out using the χ(2) test with SPSS (version 12.0, SPSS Inc., Chicago, IL, USA). RESULTS: Spontaneous pain, provoked pain, and both spontaneous and provoked pain were significantly related to joint effusion in TMD patients (p<0.05). However, among the various types of provoked pain, pain on palpation of the masticatory muscles and TMJ (G1) was not related to joint effusion in TMD patients (p>0.05). CONCLUSION: Spontaneous pain was related to the MRI findings of joint effusion; however, among the various types of provoked pain, pain on palpation of the masticatory muscles and TMJ was not related to the MRI findings of joint effusion. These results suggest that joint effusion has a significant influence on the prediction of TMJ pain.

Relationship between anterior disc displacement with/without reduction and effusion in temporomandibular disorder patients using magnetic resonance imaging.

PURPOSE: This study was performed to evaluate the relationship between anterior disc displacement and effusion in temporomandibular disorder (TMD) patients using magnetic resonance imaging (MRI). MATERIALS AND METHODS: The study subjects included 253 TMD patients. MRI examinations were performed using a 1.5 T MRI scanner. T1- and T2-weighted images with para-sagittal and para-coronal images were obtained. According to the MRI findings, temporomandibular joint (TMJ) disc positions were divided into 3 subgroups: normal, anterior disc displacement with reduction (DWR), and anterior disc displacement without reduction (DWOR). The cases of effusion were divided into 4 groups: normal, mild (E1), moderate (E2), and marked effusion (E3). Statistical analysis was made by the Fisher's exact test using SPSS (version 12.0, SPSS Inc., Chicago, IL, USA). RESULTS: The subjects consisted of 62 males and 191 females with a mean age of 28.5 years. Of the 253 patients, T1- and T2-weighted images revealed 34 (13.4%) normal, DWR in 103 (40.7%), and DWOR in 116 (45.9%) on the right side and 37 (14.6%) normal, DWR in 94 (37.2%), and DWOR in 122 (48.2%) joints on the left side. Also, T2-images revealed 82 (32.4%) normal, 78 (30.8%) E1, 51 (20.2%) E2, and 42 (16.6%) E3 joints on the right side and 79 (31.2%) normal, 85 (33.6%) E1, 57 (22.5%) E2, and 32 (12.7%) E3 on the left side. There was no difference between the right and left side. CONCLUSION: Anterior disc displacement was not related to the MRI findings of effusion in TMD patients (P>0.05).

Poly(L-lactic acid)/hydroxyapatite nanocylinders as nanofibrous structure for bone tissue engineering scaffolds.

Poly (L-lactic acid) (PLLA), a biodegradable and biocompatible polyester, has been used as material of for tissue engineered scaffold and regenerative medicine. In this study, hydroxyapatite (HAp) and PLLA composite was electrospun. PLLA fibers were treated with an amino groups containing base in order to fabricate amino groups modified polymeric microcylinders. Simvastatin was loaded into the PLLA/HAp microcylinders. Our study focuses on the incorporation HAp and Simvastatin into the fibrous and cylindrical structure, its effects on the loading and release of simvastatin, and biological responses to osteoblast cells. The aspect ratio of microcylinders was tunable by varying the aminolysis treatment time and density of the base. The effects of the PLLA/HAp composites on osteoblast cell proliferation were evaluated. The PLLA/HAp may interact with osteoblast and obtain desired effects that were stimulating osteoblast function and restraining the osteoclast function for bone tissue regeneration. The potential of the developed composite microcylinders could be a promising way to fabricate the microfibrous structural scaffold that accelerates cell proliferation and functions for bone tissue engineering.

Fluorescent peptide indicator displacement assay for monitoring interactions between RNA and RNA binding proteins.

This paper describes a sensitive, non-destructive displacement assay, using a fluorescent peptide indicator, for real-time monitoring of the interactions between RNA and RNA binding proteins (RBPs). The developed fluorescent peptide indicators, each containing a mid-sequence fluorophore unit, allowed sensing of target RNA and RNA-RBP interactions through changes in fluorescence intensity. We anticipate that this assay will open up new possibilities for meaningful studies of RNA-RBP interactions.

Prediction of age-related osteoporosis using fractal analysis on panoramic radiographs.

PURPOSE: This study was performed to evaluate the trabecular pattern on panoramic radiographs to predict age-related osteoporosis in postmenopausal women. MATERIALS AND METHODS: Thirty-one postmenopausal osteoporotic women and 25 postmenopausal healthy women between the ages of 50 and 88 were enrolled in this study. The bone mineral density (BMD) of the lumbar vertebrae and femur were calculated using dual-energy X-ray absorptiometry (DXA), and panoramic radiographs were obtained. Fractal dimension (FD) was measured using the box counting method from 560 regions of interest (51×51 pixels) in 6 sites on the panoramic radiographs. The relationships between age and BMD and between FD and BMD were assessed, and the intraobserver agreement was determined. RESULTS: There was a significant difference in the FD values between the osteoporotic and normal groups (p<0.05). There was a significant difference in the FD values at three sites in the jaws (p<0.05). Age was significantly correlated with the BMD measurements, with an odds ratio of 1.25. However, the FD values were not significantly correlated with the BMD measurements, with an odds ratio of 0.000. The intraobserver agreement showed relatively higher correlation coefficients at the upper premolar, lower premolar, and lower anterior regions than the other sites. CONCLUSION: Age was an important risk factor for predicting the presence of osteoporosis in postmenopausal women. The lower premolar region was the most appropriate site for evaluating the FD value on panoramic radiographs. However, further investigation might be needed to predict osteoporosis using an FD value on panoramic radiographs.

Malignant melanoma of unknown primary origin presenting as cardiac metastasis.

Malignant melanoma has a very high propensity to metastasize to the heart. However, melanoma may sometimes present as a metastatic lesion in the absence of a primary lesion, which are called melanomas of unknown primary origin. We report a case in which a patient presented with a metastatic maligant melanoma in the right atrium with pericardial effusion and without a primary origin.