Antimicrobial hydrogels based on PVA and diphlorethohydroxycarmalol (DPHC) derived from brown alga Ishige okamurae: An in vitro and in vivo study for wound dressing application.

In this study, we fabricated polyvinyl alcohol hydrogels containing diphlorethohydroxycarmalol (DPHC) from Ishige okamurae for its anti-bacterial effect in wound-dressing applications. First, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of DPHC against Staphylococcus aureus and Pseudomonas aeruginosa were investigated, and these were found to be about 128 µg/mL and 512 µg/mL, respectively. Polyvinyl alcohol hydrogels loaded with different concentrations of DPHC were then produced for the dressing of wounds to assist in the healing process and to provide an antibacterial effect. To investigate the characteristics of the proposed PVA/DPHC hydrogels, we conducted SEM analysis, rheological analysis, thermogravimetric analysis, water swelling analysis, drug release testing, and gel fraction assessment. The antibacterial activity of the PVA/DPHC hydrogels was also tested against the gram-positive bacterium S. aureus and the gram-negative bacterium P. aeruginosa using ASTM E2149 tests. The biocompatibility of the PVA/DPHC hydrogels was assessed using in vitro indirect and direct contact tests and in vivo tests on ICR mice. The PVA/DPHC hydrogels exhibited the ability to reduce the viability of S. aureus and P. aeruginosa by about 99% in ASTM E2149 testing, while not producing any toxic effect on NHDF-Neo or HaCaT cells as shown in MTT assays and in vitro FDA fluorescence analysis. In addition, the PVA/DPHC hydrogels had a strong wound healing effect when compared to non-treated groups of ICR mice in vivo. Based on the characterization of the PVA/DPHC hydrogels in vitro and in vivo, this study suggests that the proposed hydrogel has significant potential for use in wound dressing.

Risk of Water and Food-Borne Communicable Diseases in Travelers Entering Korea.

OBJECTIVES: It was supposed to analyze status and affecting factors in water and food-borne communicable disease by screening entrants with diarrhea symptom at the point of entry in Korea. METHODS: Symptomatic travelers with water and food-borne communicable diseases who entered Korea were diagnosed by a health declaration and detection of causative agents in water and food using laboratory tests. Among those entered in 2017, the affecting factors in the incidence of communicable diseases among those who had diarrhea at the entry into Korea, were analyzed, with frequency and chi-square test. RESULTS: The number of travel entrants with gastrointestinal communicable diseases increased by 40.19% from 2013 to 2017. The percentage of causative agents of water and food-borne communicable diseases was the highest at 69.2% from July to September. The rate of detection of causative agents of communicable disease pathogens in travelers from Southeast Asia entering Korea was 70.2%, which was higher than people arriving from East Asia and Central Asia (57.5%; p < 0.001). CONCLUSION: The positive ratio of causative agents of water and food-borne communicable diseases was high among travelers that had entered Korea from July to September, with a high number among entrants from Southeast Asia. Based on the positive detection of causative agents, the entry period and countries visited were statistically significant affecting factors (p < 0.001).

Characterization and biological activity of PVA hydrogel containing chitooligosaccharides conjugated with gallic acid.

Propionibacterium acnes plays a key role in the onset of inflammation leading to acne and in downregulation of the defense system against oxidative stress. Therefore, antibiotics such as macrolides, tetracyclines, azelaic acid, and erythromycin are used to reduce microbial proliferation and resulting inflammation. Nonetheless, antibiotic treatment has side effects including cytotoxicity, allergy, and diarrhea. Therefore, recent studies were focused on the development of alternative antimicrobial materials. We conjugated chitooligosaccharide (COS) with gallic acid (GA) by the hydrogen peroxide-mediated method and evaluated antioxidant and antimicrobial activities. Then, we fabricated a polyvinyl alcohol (PVA) hydrogel containing COS conjugated with GA (GA-COS) for acne treatment. GA-COS at 5-10 kDa showed an excellent antioxidant activity and a better antimicrobial activity against P. acnes as compared with COS. In addition, the PVA hydrogel with GA-COS inhibited intracellular formation of reactive oxygen species and exerted antimicrobial action better than controls did.

Evaluation of computer-aided detection and dual energy software in detection of peripheral pulmonary embolism on dual-energy pulmonary CT angiography.

PURPOSE: To evaluate the sensitivity of computer-aided detection(CAD) and dual-energy software('Lung PBV', 'Lung Vessels') for detecting peripheral pulmonary embolism(PE). MATERIALS AND METHODS: Between Jan-2007 and Jan-2008, 309 patients underwent dual-energy CT angiography(DECTA) for the evaluation of suspected PE. Among them, 37 patients were retrospectively selected; 21 with PE at segmental-or-below levels and 16 without PE according to clinical reports. A standard computer assisted detection (CAD) package and two new types of software('Lung PBV', 'Lung Vessels') were applied on a dedicated workstation. This resulted in four alternative tests for detecting PE: DECTA alone and DECTA with CAD, 'Lung Vessels' and 'Lung PBV'. Two radiologists independently read all cases at different reading sessions. Two thoracic radiologists set the reference standard by combining all information from DECTA and software. The sensitivity of detection for all, segmental and subsegmental-or-below PE were assessed. RESULTS: The reference standard contained 136 PE(segmental 65, subsegmental-or-below 71). With DECTA alone, the sensitivity of detection for all, segmental and subsegmental-or-below pulmonary arteries was 54.5%/73.7%/34.4%; DECTA with CAD, 57.8%/76.8%/37.9%; DECTA with 'Lung PBV', 61.1%/79.9%/41.4%; DECTA with 'Lung Vessels', 64.0%/78.3%/48.5% respectively. CONCLUSION: The use of CAD, Lung Vessels and Lung PBV shows improved capability to detect peripheral PE.

Dual-energy CT for assessment of the severity of acute pulmonary embolism: pulmonary perfusion defect score compared with CT angiographic obstruction score and right ventricular/left ventricular diameter ratio.

OBJECTIVE: The purpose of this study was to prospectively evaluate the usefulness of scoring perfusion defects on perfusion images at dual-energy CT for assessment of the severity of pulmonary embolism. SUBJECTS AND METHODS: Thirty patients (13 men, 17 women; mean age, 55 +/- 15 [SD] years; range, 26-81 years) with pulmonary thromboembolism underwent dual-source CT at two voltages (140 and 80 kV). The weighted average image of two acquisitions was used for CT angiograms, and a color-coded iodine image was used for perfusion images. Two thoracic radiologists with 15 and 6 years of clinical experience independently assigned perfusion defect scores to perfusion images and both a CT angiographic (CTA) obstruction score and right ventricular-to-left ventricular (RV/LV) diameter ratio to CT angiograms. The CTA obstruction score was based on the Qanadli method. The perfusion defect score was defined as Sigma (n . d) / 40 x 100, where n is the number of segments and d is the degree of perfusion from 0 to 2. Correlations between perfusion defect score, CTA obstruction score, and RV/LV diameter ratio were evaluated. Agreement between perfusion defect score and CTA score was assessed per patient and per segment. Interobserver agreement regarding perfusion defect and CTA obstruction scores was analyzed. RESULTS: Perfusion defect and CTA obstruction scores had good correlation with RV/LV diameter ratio (r = 0.69, r = 0.66; all p < 0.001). Per patient, correlation between perfusion defect score and CTA obstruction score also was good (reader 1, r = 0.87; reader 2, r = 0.85; all p < 0.001). Per segment, moderate agreement was found between perfusion defect score and CTA obstruction score (reader 1, kappa = 0.56; reader 2, kappa = 0.51; all p < 0.05). Both readers were in strong agreement on perfusion defect score and CTA obstruction score. CONCLUSION: The proposed perfusion defect score had good correlation with RV/LV diameter ratio and CTA obstruction score. Therefore, acquisition of perfusion images at dual-energy CT may be helpful for assessing the severity of acute pulmonary embolism.

Isoflavones prevent endoplasmic reticulum stress-mediated neuronal degeneration by inhibiting tau hyperphosphorylation in SH-SY5Y cells.

Several studies have demonstrated a protective effect of estrogen against the risk of developing neurodegenerative diseases; however, the molecular mechanisms involved have not been fully addressed. Isoflavones have been proposed as potential alternatives to estrogen replacement therapy. Therefore, in the present study, we investigated effects of isoflavones on cell death and tau phosphorylation in SH-SY5Y human neuroblastoma cells. Cells were treated with tunicamycin (TM) to induce endoplasmic reticulum (ER) stress-mediated toxicity, which is involved in development of neurodegenerative diseases. Treatment of cells with either 17beta-estradiol or isoflavones (either genistein or daidzein) significantly protected cells against cell death. The protective effect against cell death was blocked by a specific estrogen receptor blocker, ICI 182,780, suggesting that isoflavones protect against cell death via estrogen receptor-dependent pathways. Isoflavones also suppressed ER stress as determined by decreased expressions of the immunoglobulin binding protein (BiP) mRNA, spliced X-box binding protein-1 (Xbp-1) mRNAs, and C/EBP homologous protein (CHOP). TM activated glycogen synthase kinase 3beta (GSK3beta), a kinase involved in tau phosphorylation; in contrast, isoflavones inactivated GSK3beta and decreased tau hyperphosphorylation. In conclusion, our results clearly demonstrate that isoflavones prevent ER stress-mediated neurotoxicity by inhibiting tau hyperphosphorylation in SH-SY5Y cells.

Clinical utility of dual-energy CT in the evaluation of solitary pulmonary nodules: initial experience.

PURPOSE: To determine the clinical utility of dual-energy computed tomography (CT) in evaluating solitary pulmonary nodules (SPNs). MATERIALS AND METHODS: This study was approved by the institutional review board, and informed consent was obtained. CT scans were obtained before and 3 minutes after contrast material injection in 49 patients (26 men, 23 women; mean age, 60.39 years +/- 12.24 [standard deviation]) by using a scanner with a dual-energy technique. Image sets that included nonenhanced weighted average, enhanced weighted average, virtual nonenhanced, and iodine-enhanced images were reconstructed. CT numbers of SPNs on virtual nonenhanced and nonenhanced weighted average images were compared, and CT numbers on iodine-enhanced image and the degree of enhancement were compared. Diagnostic accuracy for malignancy by using CT number on iodine-enhanced image and the degree of enhancement were compared. On the virtual nonenhanced image, the number and size of calcifications were compared with those on the nonenhanced weighted average image. Radiation dose was compared with that of single-energy CT. RESULTS: CT numbers on virtual nonenhanced and nonenhanced weighted average images and CT numbers on the iodine-enhanced image and the degree of enhancement showed good agreements (intraclass correlation coefficients: 0.83 and 0.91, respectively). Diagnostic accuracy for malignancy by using CT numbers on iodine-enhanced image was comparable to that by using the degree of enhancement (sensitivity, 92% and 72%; specificity, 70% and 70%; accuracy, 82.2% and 71.1%, respectively). On virtual nonenhanced image, 85.0% (17 of 20) of calcifications in the SPN and 97.8% (44 of 45) of calcifications in the lymph nodes were detected, and the apparent sizes were smaller than those on the nonenhanced weighted average image. Radiation dose (average dose-length product, 240.77 mGy cm) was not significantly different from that of single-energy CT (P = .67). CONCLUSION: Dual-energy CT allows measurement of the degree of enhancement and detection of calcifications without additional radiation dose.

Insulin resistance is associated with gallstones even in non-obese, non-diabetic Korean men.

It remains unclear as to whether insulin resistance alone or in the presence of wellknown risk factors, such as diabetes or obesity, is associated with gallstones in men. The aim of this study was to determine whether insulin resistance is associated independently with gallstone disease in non-diabetic men, regardless of obesity. Study subjects were 19,503 Korean men, aged 30-69 yr, with fasting blood glucose level <126 mg/dL and without a documented history of diabetes. Gallbladder status was assessed via abdominal ultrasonography after overnight fast. Body mass index and waist circumference were measured. Insulin resistance was estimated by the Homeostasis Model Assessment of insulin resistance (HOMA-IR). The prevalence of obesity, abdominal obesity, and metabolic syndrome in the subjects with gallstones were higher than in those without. The prevalence of elevated HOMA (>75 percentile) in subjects with gallstones was significantly higher than in those without, and this association remained even after the obesity stratification was applied. In multiple logistic regression analyses, only age and HOMA proved to be independent predictors of gallstones. Insulin resistance was positively associated with gallstones in non-diabetic Korean men, and this occurred regardless of obesity. Gallstones appear to be a marker for insulin resistance, even in non-diabetic, nonobese men.

Radiologic and clinical findings of Behçet disease: comprehensive review of multisystemic involvement.

Behçet disease is a chronic, relapsing, systemic disorder of unknown etiology, characterized by recurrent oral and genital ulcers, uveitis, and other clinical manifestations in multiple organ systems. Although the diagnosis is made on the basis of the combination of typical clinical symptoms, radiologic findings of Behçet disease show characteristic features of its involvement in the gastrointestinal, neurologic, cardiovascular, and thoracic organ systems. In the gastrointestinal tract, Behçet disease may produce various types of ulcers in the esophagus, stomach, and small and large intestines, as well as deeply penetrating ulcerations in the ileocecal region, with frequently accompanying enteric fistulas. Neurologic involvement includes typical and atypical parenchymal neurobehcet disease, dural sinus thrombosis, cerebral arterial aneurysm, occlusion, dissection, and meningitis. Vascular involvement is divided into three subsets including venous occlusion, arterial occlusion, and arterial aneurysm. Cardiac manifestations include intracardiac thrombus, endomyocardial fibrosis, periaortic pseudoaneurysm, and rupture of the sinus of Valsalva. Manifestations of Behçet disease in the thorax include pulmonary arterial aneurysm, pulmonary arterial thromboembolism, thrombosis in the superior vena cava, pulmonary infarction, hemorrhage, and vasculitis of the pleura and pericardium. These various manifestations of Behçet disease respond to steroid treatment; however, one of the characteristics of Behçet disease is the high rate of complications and recurrence after surgery. Familiarity with its various radiologic and clinical characteristics is essential in making an accurate early diagnosis and for prompt treatment of patients with Behçet disease.

Coronary artery anomalies: classification and electrocardiogram-gated multidetector computed tomographic findings.

Congenital coronary artery anomaly is an uncommon condition. Most of these anomalies are clinically silent without associated myocardial ischemia, but some of those may cause significant myocardial ischemia or infarction. Multidetector computed tomography with electrocardiogram (ECG)-gating has a faster volume coverage and higher spatial and temporal resolution and is a noninvasive and accurate technique that can be used to show these kinds of anomalies. Understanding the computed tomographic findings of various coronary artery anomalies is important for obtaining an accurate diagnosis and for formulating an optimal patient treatment plan.

Quantitatively assessed dynamic contrast-enhanced magnetic resonance imaging in patients with chronic obstructive pulmonary disease: correlation of perfusion parameters with pulmonary function test and quantitative computed tomography.

OBJECTIVES: The purpose of this study is to evaluate the correlation of the perfusion parameters of 3-dimensional, contrast-enhanced magnetic resonance (MR) imaging (3D CEMRI) with pulmonary function test (PFT) and quantitative computed tomography (CT) parameters in patients with chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS: In 14 patients with COPD, 3D CEMRI was performed. From the signal intensity-time curves, pulmonary blood flow (PBF), pulmonary blood volume (PBV), and mean transit time of each pixel was calculated. From the volumetric CT data, the quantitative parameters including the volume fraction of the lung below -950 Housefield Units (V(-950)) and mean lung density were assessed. The correlation between the MR perfusion parameters and the parameters from quantitative CT and PFT was assessed using Spearman correlation analysis. The correspondence of the regional impairment of perfusion on MR perfusion maps to the areas of emphysema on quantitative CT maps in each patient was assessed qualitatively using a 4-class visual scoring method by 2 readers. RESULTS: All 3D CEMRI examinations were successfully completed and MR perfusion parameters were obtained in all patients. The Spearman correlation test showed that PBF positively correlated with forced expiratory volume in 1 second (FEV(1))/forced vital capacity (FVC) (R = 0.49, P = 0.044), PBV positively correlated with FEV(1)/FVC (R = 0.69, P = 0.006) and negatively correlated with V-950 (R = -0.61, P = 0.020), and mean transit time positively correlated with FEV(1) (R = 0.63, P = 0.017) and FEV(1)/FVC (R = 0.76, P = 0.002). The areas of perfusion impairment on PBF and PBV maps were relatively well correlated with the areas of emphysema on CT maps [very good or good: PBF 71.5% (reader 1) and 64.3% (reader 2) of the patients, kappa = 0.47 (P < 0.001); PBV 78.6% (reader 1) and 78.6% (reader 2) of the patients, kappa = 0.89 (P < 0.001)]. CONCLUSIONS: This study shows that the deterioration of perfusion parameters measured on MR in patients with COPD, correlates with worsening of airflow limitation on PFT and emphysema index on CT. Regional heterogeneity of emphysema on CT matches with the decreased perfusion on MR.

Involvement of Endoplasmic Reticulum Stress in Palmitate-induced Apoptosis in HepG2 Cells.

The results of recent studies indicate that high levels of free fatty acids (FFAs) and adipokines may be the main causes of non-alcoholic liver disease; however, the molecular mechanism that links FFAs to lipotoxicity remains unclear. In the present study, we treated HepG2 cells with FFA (either palmitate or oleate) to investigate the mechanisms involved in lipotoxicity in the liver cells. We also treated cells with palmitate in the presence of a chemical chaperone, 4-phenylbutyric acid (PBA), to confirm the involvement of ER stress in lipotoxicity. Palmitate significantly induced cytotoxicity in dose- and time-dependent manners. Apoptosis was also significantly induced by palmitate as measured by caspase-3 activity and DAPI staining. Palmitate led to increased expressions of the spliced form of X-box-protein (Xbp)-1 mRNA and C/EBP homologous transcription factor (CHOP) protein, suggesting activation of the unfolded-protein response. PBA co-incubation significantly attenuated apoptosis induced by palmitate. The above data demonstrate that high levels of palmitate induce apoptosis via the mediation of ER stress in the liver cells and that chemical chaperones act to modulate ER stress and accompanying apoptosis.

Acute and chronic complications of aortic intramural hematoma on follow-up computed tomography: incidence and predictor analysis.

OBJECTIVE: To ascertain the incidence of acute and chronic complications of aortic intramural hematoma (IMH) and to analyze the predictors of the development of each complication. MATERIALS AND METHODS: This retrospective study includes 107 consecutive patients diagnosed with aortic IMH by means of computed tomography (CT) during the period from January 1998 to December 2003 and followed up with serial CT examinations (median follow-up period, 320 days). There were 36 patients with type A and 71 with type B IMH. Initial and follow-up CT scans were reviewed, with special attention given to the development of complications, such as increase in the thickness of IMH, clinical and hemodynamic evolution requiring urgent surgery, and development of aortic dissection and/or aneurysm. If each complication developed within 30 days after the initial episode, we classified it as an acute complication; the others were classified as chronic complications. The time interval between the initial and the subsequent CT examination showing each complication was recorded. To identify the predictors of each complication, we analyzed the demographic and CT findings with regard to the following factors: age, sex, maximum thickness of the hematoma, maximum aortic diameter on initial CT examination, ulcerlike projection (ULP) on initial and follow-up CT examinations, and the degree of atherosclerosis. The Cox proportional hazards regression model with stepwise multivariate analyses was used to determine the significant predictors of each complication. RESULTS: Sixteen patients had acute complications consisting of aortic dissection (n = 7), aortic aneurysm (n = 6), and acute clinical and hemodynamic evolution requiring operation (n = 3). Three additional patients with aortic dissection (n = 1) and aneurysm (n = 2) underwent emergency surgery. Twenty-three patients with chronic complications had aortic dissection (n = 3), and aortic aneurysm (n = 20). Cox proportional hazards regression model revealed that the maximal diameter of involved aorta is the only significant predictor of the development of acute complications (P = 0.006), whereas the age (P = 0.040), type A IMH (P = 0.015), presence of ULP (P = 0.015), and newly developed ULP as revealed on follow-up CT examination (P = 0.032) were significant predictors of the development of chronic complications. With regard to the aortic dissection in 10 patients (9.3%; type A/B ratio, 5:5; median time interval, 34 days), Cox proportional hazards regression model revealed that the maximal thickness of the hematoma is the only significant predictor (P = 0.018). Twenty-one saccular and 5 fusiform aneurysms (24.3%) developed, as revealed on follow-up CT examinations (median time interval, 180 days). The presence of ULP (P = 0.030), type A (P = 0.038) and the maximal thickness of the hematoma (P = 0.017) were significant predictors for the development of an aneurysm. CONCLUSIONS: The maximum thickness of a hematoma on the initial CT is the significant factor predicting the development of aortic dissection and aortic aneurysm. Patients with type A IMH and ULP, as revealed by initial and short-term follow-up CT examinations, should be carefully followed up with subsequent CT examination to monitor the development of an aortic aneurysm, which is a relatively common chronic complication of IMH.

Apoptotic effect of IP(6) was not enhanced by co-treatment with myo-inositol in prostate carcinoma PC3 cells.

Inositol hexaphosphate (IP(6)) is a major constituent of most cereals, legumes, nuts, oil seeds and soybean. Previous studies reported the anticancer effect of IP(6) and suggested that co-treatment of IP(6) with inositol may enhance anticancer effect of IP(6). Although the anticancer effect of IP(6) has been intensively studied, the combinational effect of IP(6) and inositol and involved mechanisms are not well understood so far. In the present study, we investigated the effect of IP(6) and myo-inositol (MI) on cell cycle regulation and apoptosis using PC3 prostate cancer cell lines. When cells were co-treated with IP(6) and MI, the extent of cell growth inhibition was significantly increased than that by IP(6) alone. To identify the effect of IP(6) and MI on apoptosis, the activity of caspase-3 was measured. The caspase-3 activity was significantly increased when cells were treated with either IP(6) alone or both IP(6) and MI, with no significant enhancement by co-treatment. To investigate the effect of IP(6) and MI of cell cycle arrest, we measured p21 mRNA expression in PC3 cells and observed significant increase in p21 mRNA by IP(6). But synergistic regulation by co-treatment with IP(6) and MI was not observed. In addition, there was no significant effect by co-treatment compared to IP(6) treatment on the regulation of cell cycle progression although IP(6) significantly changed cell cycle distribution in the presence of MI or not. Therefore, these findings support that IP(6) has anticancer function by induction of apoptosis and regulation of cell cycle. However, synergistic effect by MI on cell cycle regulation and apoptosis was not observed in PC3 prostate cancer cells.

The fate of high-density lesions on the non-contrast CT obtained immediately after intra-arterial thrombolysis in ischemic stroke patients.

OBJECTIVE: Hyperdense lesions can frequently be observed on the CT obtained immediately after intra-arterial (IA) thrombolysis, and it is sometimes difficult to differentiate contrast extravasation from the hemorrhagic lesions. The purposes of this study are to classify the hyperdense lesions according to their morphologic features and to track the outcome of those lesions. MATERIALS AND METHODS: Among the 94 patients who suffered with anterior circulation ischemic stroke and who were treated with IA thrombolysis, 31 patients revealed hyperdense lesions on the CT obtained immediately after the procedure. The lesions were categorized into four types according to their volume, shape, location and density: cortical high density (HD), soft HD, metallic HD and diffuse HD. The follow-up images were obtained 3-5 days later in order to visualize the morphologic changes and hemorrhagic transformation of the lesions. RESULTS: Among the 31 patients with HD lesions, 18 (58%) showed hemorrhagic transformation of their lesion, and six of them were significant. All the cortical HD lesions (n = 4) revealed spontaneous resolution. Seven of the soft HD lesions (n = 13) showed spontaneous resolution, while the rest of the group showed hemorrhagic transformation. Among them the hemorrhage was significant in only two patients (2/6) who did not achieve successful recanalization. All the metallic HD lesions (n = 10) resulted in hemorrhagic transformation; among them, three cases (30%) with a maximum CT value more than 150 HU (Hounsfield unit) subsequently showed significant hemorrhagic transformation on the follow-up CT. There were four diffuse HD lesions, and two of them showed hemorrhagic transformation. CONCLUSION: The parenchymal hyperdense lesions observed on the CT obtained immediately after IA thrombolysis in ischemic stroke patients exhibited varying features and they were not always hemorrhagic. Most of the soft HD lesions were benign, and although all of the metallic HD lesions were hemorrhagic, some of them were ultimately found to be benign.