Protective Effects of Red Ginseng Against Tacrine-Induced Hepatotoxicity: An Integrated Approach with Network Pharmacology and Experimental Validation

Introduction

Tacrine, an FDA-approved acetylcholinesterase inhibitor, has shown efficacy in treating Alzheimer's disease, but its clinical use is limited by hepatotoxicity. This study investigates the protective effects of red ginseng against tacrine-induced hepatotoxicity, focusing on oxidative stress.

Methods

A network depicting the interaction between compounds and targets was constructed for RG. Effect of RG was determined by MTT and FACS analysis with cells stained by rhodamine 123. Proteins were extracted and subjected to immunoblotting for apoptosis-related proteins.

Results

The outcomes of the network analysis revealed a significant association, with 20 out of 82 identified primary RG targets aligning with those involved in oxidative liver damage including notable interactions within the AMPK pathway. in vitro experiments showed that RG, particularly at 1000μg/mL, mitigated tacrine-induced apoptosis and mitochondrial damage, while activating the LKB1-mediated AMPK pathway and Hippo-Yap signaling. In mice, RG also protected the liver injury induced by tacrine, as similar protective effects to silymarin, a well-known drug for liver toxicity protection.

Discussion

Our study reveals the potential of RG in mitigating tacrine-induced hepatotoxicity, suggesting the administration of natural products like RG to reduce toxicity in Alzheimer's disease treatment.

Antioxidant Efficacy of Hwangryunhaedok-tang through Nrf2 and AMPK Signaling Pathway against Neurological Disorders In Vivo and In Vitro

Alzheimer's disease (AD) is a representative cause of dementia and is caused by neuronal loss, leading to the accumulation of aberrant neuritic plaques and the formation of neurofibrillary tangles. Oxidative stress is involved in the impaired clearance of amyloid beta (Aβ), and Aβ-induced oxidative stress causes AD by inducing the formation of neurofibrillary tangles. Hwangryunhaedok-tang (HHT, Kracie K-09®), a traditional herbal medicine prescription, has shown therapeutic effects on various diseases. However, the studies of HHT as a potential treatment for AD are insufficient. Therefore, our study identified the neurological effects and mechanisms of HHT and its key bioactive compounds against Alzheimer's disease in vivo and in vitro. In a 5xFAD mouse model, our study confirmed that HHT attenuated cognitive impairments in the Morris water maze (MWM) test and passive avoidance (PA) test. In addition, the prevention of neuron impairment, reduction in the protein levels of Aβ, and inhibition of cell apoptosis were confirmed with brain tissue staining. In HT-22 cells, HHT attenuates tBHP-induced cytotoxicity, ROS generation, and mitochondrial dysfunction. It was verified that HHT exerts a neuroprotective effect by activating signaling pathways interacting with Nrf2, such as MAPK/ERK, PI3K/Akt, and LKB1/AMPK. Among the components, baicalein, a bioavailable compound of HHT, exhibited neuroprotective properties and activated the Akt, AMPK, and Nrf2/HO-1 pathways. Our findings indicate a mechanism for HHT and its major bioavailable compounds to treat and prevent AD and suggest its potential.

Forsythiaside A Activates AMP-Activated Protein Kinase and Regulates Oxidative Stress via Nrf2 Signaling

Forsythiaside A (FA) is an active constituent isolated from Forsythia suspensa, a beneficial herb used in traditional medicine known for its antioxidant and anti-inflammatory properties. Although various studies have suggested that FA has the protective effects, its impacts on arachidonic acid (AA) plus iron in vitro models and carbon tetrachloride (CCl₄)-induced mouse liver damage in vivo have not been explored. In this study, HepG2 cells were subjected to AA + iron treatment to induce apoptosis and mitochondrial impairment and determine the molecular mechanisms. FA exhibited protective effects by inhibiting cell damage and reactive oxygen species (ROS) production induced by AA + iron, as assessed via immunoblot and flow cytometry analyses. Further molecular investigations revealed that FA resulted in the activation of extracellular-signal-related protein kinase (ERK), which subsequently triggered the activation of AMP-activated protein kinase (AMPK), a critical regulator of cellular oxidative stress. Additionally, FA modulated the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway, which is a significant antioxidant transcription factor regulated by the AMPK pathway. For in vivo studies, mice were orally administered FA and then subjected to induction of CCl₄-based hepatotoxicity. The protective effect of FA was confirmed via blood biochemistry and immunohistochemical analyses. In conclusion, our findings demonstrated the protective effects of FA against oxidative stress both in vitro and in vivo, thus indicating that FA is a potential candidate for liver protection. Our study sheds light on the mechanistic pathways involved in the antioxidant effects of FA, highlighting the hepatoprotective potential of naturally occurring compounds in traditional herbs, such as FA.

Kaempferol stimulation of autophagy regulates the ferroptosis under the oxidative stress as mediated with AMP-activated protein kinase

Recent studies have highlighted the positive effects of Kaempferol (KP), including its anti-inflammatory and antioxidant properties. However, its impact on oxidative damage induced by heavy metals and pro-inflammatory mediators, such as arachidonic acid (AA), has not yet been identified. Our objective was to specifically evaluate liver damage due to AA + iron-induced oxidative stress, both in vitro and in vivo. In HepG2 cells, KP activated the AMP-activated protein kinase (AMPK), suggesting a hepatoprotective effect through AMPK inhibition, as assessed by immunoblot and FACS analysis (EC50 = 10 μM). KP also stimulated autophagy, a degradation process that eliminates aged, damaged, and unnecessary components, via mTOR inhibition and ULK1 phosphorylation. This activation was further validated by the upregulation of autophagy-related genes (ATG5) and Beclin-1, along with the conversion of LC3BI to LC3BII. Ferroptosis, a non-apoptotic type of cell death characterized by oxidative stress from the production of reactive oxygen species (ROS) and excessive iron accumulation, was linked to the activation of autophagy, as confirmed through the protein expression of deferoxamine (DFO) and ferrostatin-1 (Fer-1), the representative ferroptosis inhibitors (positive controls). In mice, oral administration of KP demonstrated protective effects against CCl4-induced hepatotoxicity. In conclusion, KP provides hepatoprotective effects against oxidative stress induced by AA + iron treatment in vitro and CCl4 treatment in vivo.

Unraveling the Antioxidant Capacity of Spatholobi caulis in Nonalcoholic Fatty Liver Disease: A Multiscale Network Approach Integrated with Experimental Validation

Nonalcoholic fatty liver disease (NAFLD) is a global health problem that is closely associated with obesity and metabolic syndrome. Spatholobi caulis (SC) is a herbal medicine with potential hepatoprotective effects; however, its active compounds and underlying mechanisms have not been fully explored. In this study, we combined a multiscale network-level approach with experimental validation to investigate SC's antioxidant properties and their impact on NAFLD. Data collection and network construction were performed, and active compounds and key mechanisms were identified through multi-scale network analysis. Validation was conducted using in vitro steatotic hepatocyte models and in vivo high-fat diet-induced NAFLD models. Our findings revealed that SC treatment improved NAFLD by modulating multiple proteins and signaling pathways, including AMPK signaling pathways. Subsequent experiments showed that SC treatment reduced lipid accumulation and oxidative stress. We also validated SC's effects on AMPK and its crosstalk pathways, emphasizing their role in hepatoprotection. We predicted procyanidin B2 to be an active compound of SC and validated it using a lipogenesis in vitro model. Histological and biochemical analyses confirmed that SC ameliorated liver steatosis and inflammation in mice. This study presents SC's potential use in NAFLD treatment and introduces a novel approach for identifying and validating active compounds in herbal medicine.

Integrative approach to uncover antioxidant properties of Bupleuri Radix and its active compounds: Multiscale interactome-level analysis with experimental validation

Acute and chronic liver disease are global problems with high morbidity and mortality. Bupleuri Radix (BR) is an herbal medicine that has been prescribed empirically in traditional Asian medicine to modulate liver metabolism. However, its active compounds and therapeutic mechanisms remain unclear. Here, we integrated a network-based approach and experimental validation to elucidate BR's therapeutic potential in treating oxidative liver injury. Our approach incorporated data collection and network construction utilizing bioinformatics tools, and identified active compounds and key mechanisms based on the multiscale interactome. The proposed mechanisms were validated using an in vitro oxidative stress model and an in vivo carbon tetrachloride-induced model. We found that BR ameliorated the oxidative hepatic damage by acting on multiple proteins (STAT3, TNF, and BCL2) and signaling pathways (AMPK and Hippo signaling pathways). Subsequent in vitro experiments confirmed that BR significantly inhibited oxidative stress and mitochondrial damage. We further validated the effect of BR on the AMPK and Hippo-YAP pathways; a key mechanism for the antioxidant properties of BR. We prioritized the active compounds in BR based on a multiscale interactome-based approach, and further experiments revealed that saikosaponin A was a key active compound involved in hepatocyte protection (EC₅₀ = 50 μM), similar to the result using metformin and 5-aminoimidazole-4-carboxamide ribonucleotide. Histochemistry and blood biochemistry established that BR significantly inhibited carbon tetrachloride-induced oxidative tissue damage in mice. Thus, BR can be used to develop novel therapeutics for oxidative liver injury. Moreover, we suggest a novel strategy to prioritize and validate the active compounds and key mechanisms of herbal medicine based on the multiscale interactome.

Coordination of AMPK and YAP by Spatholobi Caulis and Procyanidin B2 Provides Antioxidant Effects In Vitro and In Vivo

The liver is vulnerable to oxidative attacks from heavy metals, such as iron, as well as some drugs, including acetaminophen. It has been shown that enhanced oxidative stress in the liver leads to excessive ROS production and mitochondrial dysfunction, resulting in organ injury. The beneficial effects of Spatholobi Caulis (SC), a natural herbal medicine, include treating ischemic stroke, inhibiting tumor cell invasion, pro-angiogenic activities, and anti-inflammatory properties. Scientific studies on its effects against hepatotoxic reagents (e.g., iron and acetaminophen), as well as their underlying mechanisms, are insufficient. This study examined the antioxidant effects and mechanisms of SC in vitro and in vivo. In cells, the proinflammatory mediator, arachidonic acid (AA), plus iron, significantly induced an increase in ROS generation, the damage in mitochondrial membrane potential, and the resulting apoptosis, which were markedly blocked by SC. More importantly, SC affected the activation of AMP-activated protein kinase (AMPK)-related proteins, which were vital to regulating oxidative stress in cells. In addition, SC mediated the expression of Yes-associated protein (YAP)-related proteins. Among the active compounds in SC, the procyanidin B2, but not liquiritigenin, daidzein, and genistein, significantly inhibited the cytotoxicity induced by AA + iron, and activated the LKB1-AMPK pathway. In mice, the oral administration of SC alleviated the elevations of ALT and histological changes by the acetaminophen-induced liver injury. These results reveal the potential of SC and a key bioactive component, procyanidin B2, as antioxidant candidates for hepatoprotection.

Angelica gigas NAKAI and Its Active Compound, Decursin, Inhibit Cellular Injury as an Antioxidant by the Regulation of AMP-Activated Protein Kinase and YAP Signaling

Natural products and medicinal herbs have been used to treat various human diseases by regulating cellular functions and metabolic pathways. Angelica gigas NAKAI (AG) helps regulate pathological processes in some medical fields, including gastroenterology, gynecology, and neuropsychiatry. Although some papers have reported its diverse indications, the effects of AG against arachidonic acid (AA)+ iron and carbon tetrachloride (CCl₄) have not been reported. In HepG2 cells, AA+ iron induced cellular apoptosis and mitochondrial damage, as assessed by mitochondrial membrane permeability (MMP) and the expression of apoptosis-related proteins. On the other hand, AG markedly inhibited these detrimental phenomena and reactive oxygen species (ROS) production induced by AA+ iron. AG activated the liver kinase B1 (LKB1)-dependent AMP-activated protein kinase (AMPK), which affected oxidative stress in the cells. Moreover, AG also regulated the expression of yes-associated protein (YAP) signaling as mediated by the AMPK pathways. In mice, an oral treatment of AG protected against liver toxicity induced by CCl₄, as indicated by the plasma and histochemical parameters. Among the compounds in AG, decursin had antioxidant activity and affected the AMPK pathway. In conclusion, AG has antioxidant effects in vivo and in vitro, indicating that natural products such as AG could be potential candidate for the nutraceuticals to treat various disorders by regulating mitochondrial dysfunction and cellular metabolic pathways.

Visit-to-visit changes in fasting blood sugar and the risk for cardiovascular disease and mortality in the Korean population: a nationwide population-based cohort study

OBJECTIVE

The importance of continuous monitoring of fasting blood sugar (FBS) levels of diabetic patients has been established.

MATERIALS AND METHODS

An observational prospective study was conducted. Our analysis included 1,700,796 individuals from the nationwide South Korean National Health Insurance System cohort. FBS variability was measured by standard deviation (SD).

RESULTS

Kaplan-Meier curves demonstrated elevated disease probability in the higher FBS fluctuation group compared with the lower FBS fluctuation group. After adjusting for confounding variables, Cox proportional hazards analysis showed that the hazard ratios of 411 individuals in the highest quartile of SD variation of FBS were 1.77 (95% confidence interval 1.37-2.28, p<0.001) compared with the lowest quartile of SD variation of FBS. The impact of FBS fluctuation on the risk of cardiovascular diseases (CVDs), cerebrovascular diseases, CVD mortality and all-cause mortality in the highest quartiles of diabetic and non-diabetic individuals was statistically significant.

CONCLUSIONS

Visit-to-visit FBS variability has prognostic value for predicting micro- and macrovascular disease, cardiovascular mortality, and all-cause mortality.

Improved STR analysis of degraded DNA from human skeletal remains through in-house MPS-STR panel

DNA analysis of degraded samples and low-copy number DNA derived from skeletal remains, one of the most challenging forensic tasks, is common in disaster victim identification and genetic analysis of historical materials. Massively parallel sequencing (MPS) is a useful technique for STR analysis that enables the sequencing of smaller amplicons compared with conventional capillary electrophoresis (CE), which is valuable for the analysis of degraded DNA. In this study, 92 samples of human skeletal remains (70+ years postmortem) were tested using an in-house MPS-STR system designed for the analysis of degraded DNA. Multiple intrinsic factors of DNA from skeletal remains that affect STR typing were assessed. The recovery of STR alleles was influenced more by DNA input amount for amplification rather than DNA degradation, which may be attributed from the high quantity and quality of libraries prepared for MPS run. In addition, the higher success rate of STR typing was achieved using the MPS-STR system compared with a commercial CE-STR system by providing smaller sized fragments for amplification. The results can provide constructive information for the analysis of degraded sample, and this MPS-STR system will contribute in forensic application with regard to skeletal remain sample investigation.

Genomic profiling of the residual disease of advanced high-grade serous ovarian cancer after neoadjuvant chemotherapy

The goal of our study was to demonstrate the spectrum of genomic alterations present in the residual disease of patients with advanced high-grade serous ovarian cancer (HGSOC) after neoadjuvant chemotherapy (NAC), including matched pretreatment biopsies. During the study period between 2006 and 2017, we collected pre-NAC and post-NAC tumor tissue samples from patients with advanced HGSOC. We performed combined next-generation sequencing and immunohistochemistry to identify actionable targets and pathway activation in post-NAC residual tumors. We also examined whether post-NAC profiling of residual HGSOC identified targetable molecular lesions in the chemotherapy-resistant component of tumors. Among 102 post-NAC samples, 41 (40%) of patients had mutations in homologous recombination repair (HRR) genes (HRR deficiency). Patients with HRR mutations had higher tumor mutation burdens (p < 0.001) and higher alterations in the PI3K-AKT-mTOR pathway (p = 0.004) than patients without these HRR mutations. Nevertheless, we found no significant differences in progression-free survival (p = 0.662) and overall survival (OS; p = 0.828) between the two groups. Most patients (91%) had alterations in at least one of the targetable pathways, and those patients with cell cycle (p = 0.004) and PI3K-AKT-mTOR signaling (p = 0.005) pathway alterations had poorer OS (Bonferroni-corrected threshold = 0.0083, 0.05/6). We showed the genomic landscape of tumor cells remaining in advanced HGSOC after NAC. Once validated, these data can help inform biomarker-driven adjuvant studies in targeting residual tumors to improve the outcomes of patients with advanced HGSOC after NAC.

Abstract P3-03-02: Redo sentinel lymph node biopsy for ipsilateral breast tumor recurrence after breast conserving surgery with negative sentinel nodes: A pooled analysis from a systematic review and two institutes

Background:Cases of redo sentinel lymph node biopsy (SLNB) are growing according to the increase of ipsilateral breast tumor recurrence (IBTR) after breast-conservative surgery (BCS). To evaluate a feasibility of redo SLNB in patients with IBTR after negative SLN, we conveyed a pooled analysis using data from a systematic review and two institutes.

Materials and methods:A systematic search of PubMed was conducted to identify data of patient level from publications evaluating redo SLNB for cases with IBTR. Eligible patients who underwent BCS and were confirmed as negative axilla after SLNB were identified. An identification rate (IR) and a false-negative rate (FNR) were calculated. To identify FNR, we only included cases with back-up axillary node dissection (ALND) from retrieved data.

Results:In a systematic review, a total of 197 peer-reviewed publications were retrieved, of which 19 papers included patients who met eligibility criteria. Data from 464 patients were collected. In two-institutes, 38 cases with same criteria were identified. A total of 502 patient's data were pooled. The IR of redo-SLNB was 71.7% (360/502) in pooled data. For the FNR, data from 147 patients with back-up ALND after SLNB was analyzed. The FNR and accuracy of redo-SLNB were 9.8% (5/51) and 97% (142/147).

Conclusions:We found that the IR and the FNR of redo SLNB were 71.7% and 9.8%, respectively. Redo SLNB is reliable procedure for axillary staging in patients with IBTR after negative SLNB.

Citation Format: Yoon C-i, Bae SJ, Choi JE, Cha CH, Park SE, Ahn SG, Jeong J. Redo sentinel lymph node biopsy for ipsilateral breast tumor recurrence after breast conserving surgery with negative sentinel nodes: A pooled analysis from a systematic review and two institutes [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-03-02.

Abstract P4-02-11: Accuracy of breast magnetic resonance imaging has limited value to reduce the margin-positive rate: A study in relation to the molecular subtypes

Background: Newly released guideline standardizing a negative margin after breast-conservative surgery (BCS) as “no ink on tumor” by SSO-ASTRO stressed the importance of estimation tumor extent with comprehensive breast imaging studies. To evaluate clinical value of breast magnetic resonance imaging (MRI) in patients with BCS, we compared the degree of correlation between MRI-pathology and ultrasonography (US)-pathology according to subtypes. In addition, we investigated the margin-positive rates and secondary operation rates for margin clearance.

Methods: We identified patients with invasive breast cancer who had preoperative breast MRI and ultrasound between 2011 and 2016. We excluded patients having large tumor more than 5cm or multiple tumors or undergoing mastectomy. Patients were classified into 4 subtypes based on the immunohistochemistry; luminal A, luminal B/HER2, HER2, triple-negative breast cancer (TNBC). Lin's concordance correlation coefficient was used to measure the agreement between the MRI or US and tumor extent. Tumor extent was defined as pathologic tumor size including in situ carcinoma. Margin-positivity was assessed based on intraoperative frozen examination.

Results: A total 516 patients with single tumor undergoing BCS were included. Means of tumor size were 1.99 ± 0.91 cm by pathologic examination, 1.91 ± 1.01 cm by MRI, and 1.76 ± 0.92 cm by US, respectively. The correlation coefficient of MRI-pathology was significantly higher than that of US-pathology (r=0.6975 vs. 0.6211, P=0.001). A superiority of MRI than US in measuring pathologic extent was only observed in TNBC (r=0.8089 vs. 0.6014, P&lt;0.001), whereas the agreement between the MRI or US and tumor extents was low in the HER2 (MRI: 0.3509, US: 0.3165). Also, the margin-positive rate was higher in HER2 (luminal A, 11.6%; luminal B/HER2, 17.5%; HER2, 29.6%; TNBC, 17.8%; P=0.0382). In the post-hoc test, the HER2 was more likely to have positive margin compared to Luminal A (P=0.0039). There is no significant difference in secondary operation as margin clearance according to the subtypes (P&gt;0.999).

Margin positive and re-excision rates according to the subtypes Luminal A (n=302)Luminal B (n=80)HER2 (n=27)TNBC (n=107)P valuePositive margin35 (11.6)14 (17.5)8 (29.6)19 (17.8)0.0382Re-excision14 (4.6)4 (5.0)1 (3.7)5 (4.7)&gt;0.9999

Conclusions: Given a superiority of MRI to US in preoperative assessment, MRI-guided BCS did not reduce the margin-positive rate in TNBC. In the HER2, size correlation of MRI-pathology was very low, and the margin-positive rate was high. Collectively, our findings suggest that accuracy of MRI has limited value to reduce the margin-positive rate.

Citation Format: Bae SJ, Ahn SG, Yoon C, Cha YJ, Jeong J. Accuracy of breast magnetic resonance imaging has limited value to reduce the margin-positive rate: A study in relation to the molecular subtypes [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-02-11.

NADPH oxidase 4 is required for the generation of macrophage migration inhibitory factor and host defense against Toxoplasma gondii infection

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidases (Nox) are an important family of catalytic enzymes that generate reactive oxygen species (ROS), which mediate the regulation of diverse cellular functions. Although phagocyte Nox2/gp91phox is closely associated with the activation of host innate immune responses, the roles of Nox family protein during Toxoplasma gondii (T. gondii) infection have not been fully investigated. Here, we found that T. gondii-mediated ROS production was required for the upregulation of macrophage migration inhibitory factor (MIF) mRNA and protein levels via activation of mitogen-activated protein kinase and nuclear factor-κB signaling in macrophages. Interestingly, MIF knockdown led to a significant increase in the survival of intracellular T. gondii in bone marrow-derived macrophages (BMDMs). Moreover, Nox4 deficiency, but not Nox2/gp91phox and the cytosolic subunit p47phox, resulted in enhanced survival of the intracellular T. gondii RH strain and impaired expression of T. gondii-mediated MIF in BMDMs. Additionally, Nox4-deficient mice showed increased susceptibility to virulent RH strain infection and increased cyst burden in brain tissues and low levels of MIF expression following infection with the avirulent ME49 strain. Collectively, our findings indicate that Nox4-mediated ROS generation plays a central role in MIF production and resistance to T. gondii infection.

Pilot study on the correlation between skin auto-fluorescence and serum antioxidant enzyme: skin auto-fluorescence is negatively associated with levels of malondialdehyde

BACKGROUND/PURPOSE

Various methods have been used to objectively record skin changes. However, estimating the intrinsic and extrinsic aging of skin remains a challenge. Our objective was to study intrinsic skin aging with respect to patient age and extrinsic photo-aging of human dorsal (photo-exposed) and volar (photo-protected) forearm in vivo through skin auto-fluorescence (AF). We also examined the correlations between serum antioxidant enzyme, malondialdehyde(MDA), and skin AF.

METHODS

37 healthy volunteers were enrolled. We measured skin AF and its heterogeneity on the dorsal and volar forearms. We also examined serum concentration of catalase, superoxide dismutase, vitamin E, and MDA levels in every participant.

RESULTS

In photo-protected areas, skin AF intensity in the 40 years or older group was significantly higher compared to the group less than 40 years-old. On the other hand, heterogeneity value was significantly higher in the less than 40 years-old group in photo-protected area. With respect to serum antioxidant enzyme and MDA level, only MDA level showed a negative correlation with skin AF intensity in photo-exposed area.

CONCLUSION

We determined that skin AF intensity of the photo-protected area reflects intrinsic skin aging. In addition, degree of photo-aging could be indirectly inferred by skin AF of photo-exposed area and serum MDA level.

The circulating sphingosine-1-phosphate level predicts incident fracture in postmenopausal women: a 3.5-year follow-up observation study

A high level of circulating sphingosine-1-phosphate (S1P) is associated with a high incidence of osteoporotic fracture and a high rate of an insufficient response to bisphosphonate therapy.

INTRODUCTION

Sphingosine-1-phosphate (S1P) is a significant regulator of bone metabolism. Recently, we found that a high plasma S1P level is associated with low bone mineral density (BMD), high levels of bone resorption markers (BRMs), and a high risk of prevalent vertebral fracture in postmenopausal women. We investigated the possibility that S1P is a predictor of incident fracture.

METHODS

A total of 248 postmenopausal women participated in this longitudinal study and were followed up for a mean duration of 3.5 years (untreated [n = 76] or treated with bisphosphonate or hormone replacement therapy [n = 172]). The baseline plasma S1P level and prevalent and incident fracture occurrence were assessed.

RESULTS

A high S1P level was significantly associated with a higher rate of prevalent fracture after adjusting for femoral neck (FN) BMD, BRM, and potential confounders (odds ratio = 2.05; 95 % confidence interval [CI] = 1.03-4.00). Incident fractures occurred more frequently in the highest S1P tertile (T3) than in the lower two tertiles (T1-2) after adjusting for confounders, including baseline FN BMD, prevalent fracture, antiosteoporotic medication, annualized changes in FN BMD, BRM, and potential confounders (hazard ratio = 5.52; 95 % CI = 1.04-56.54). Insufficient response to bisphosphonate therapy occurred more frequently in T3 than T1-2 (odds ratio = 4.43; 95 % CI = 1.02-21.25).

CONCLUSIONS

The plasma S1P level may be a potential predictor of fracture occurrence and an insufficient response to bisphosphonate therapy in postmenopausal women.

Effects of MBL2 polymorphisms in patients with diisocyanate-induced occupational asthma

Diisocyanate (DI) is the most common cause of occupational asthma (OA) in Korea. Mannose-binding lectin (MBL) initiates the lectin complement activation pathway following oxidative stress and plays an important role in the regulation of inflammatory processes. To determine whether there is a genetic association between MBL2 polymorphisms and DI-OA, 99 patients with DI-OA, 99 asymptomatic exposed controls (AECs) and 144 unexposed normal controls were enrolled in this study. Three polymorphisms (-554 G>C, -431A>C and -225 G>C) in the MBL2 promoter were genotyped, and serum MBL levels were determined by enzyme-linked immunosorbent assay. Functional variabilities in the promoter polymorphisms were analyzed by a luciferase reporter assay and electrophoretic mobility shift assay (EMSA). A significantly higher frequency of haplotype (ht) 2 [CAG] was noted in the DI-OA group compared with the AEC group (P=0.044). The patients with DI-OA carrying ht2 [CAG] had significantly lower PC20 methacholine levels (P<0.001) than the non-carriers. The serum MBL levels were significantly higher in the DI-exposed subjects (both the DI-OA patients and AECs) carrying ht1 [GAG] (P=0.028). Luciferase activity was significantly enhanced in ht1 [GAG] compared with ht2 [CAG] in human hepatocarcinoma cells (Hep3B) (P=0.002). The EMSA showed that a -554G probe produced a specific shifted band compared with the -554C probe. These findings suggest that decreased serum MBL levels due to polymorphisms of the MBL2 gene may increase susceptibility to the development of DI-OA in DI-exposed individuals.

Effect of material properties on stability of silver nanoparticles in water

Increased production and use of silver nanoparticles (AgNPs) could potentially lead to their release into the environment. Estimating the exposure to engineered nanomaterials in the environment is essential for assessing their risk. This study examined the aggregation and sedimentation kinetics behaviors of citrate- (Cit-AgNPs) and polyvinylpyrrolidone-coated silver nanoparticles (PVP-AgNPs) with three different average sizes in calcium chloride (CaCl2) solutions, emphasizing the effects of particle size and type of coating material on both behaviors. As the ionic strength increased, Cit-AgNPs (stabilized by charge repulsion) aggregated rapidly and settled down, while PVP-AgNPs (stabilized by steric repulsion) did not aggregate, even at an ionic strength of 10 mM CaCl2, due to likely steric hiderance effects of PVP coating. Interestingly, however, PVP-AgNPs sedimented without aggregating within 7 days and this tendency seems to having relevance to the particle size. These results suggest that the particle size and type of coating material play important roles in determining nanoparticle fate and transport.

Higher serum uric acid as a protective factor against incident osteoporotic fractures in Korean men: a longitudinal study using the National Claim Registry

In this large longitudinal study of 16,078 Korean men aged 50 years or older, we observed that baseline elevation of serum uric acid level significantly associated with a lower risk of incident fractures at osteoporosis-related sites during an average follow-up period of 3 years.

INTRODUCTION

Male osteoporosis and related fractures are becoming recognized as important public health concerns. Oxidative stress has detrimental effects on bone metabolism, and serum uric acid (UA) is known to be a strong endogenous antioxidant. In the present study, we performed a large longitudinal study with an average follow-up period of 3 years to clarify the role of UA on the risk of incident osteoporotic fractures (OFs).

METHODS

A total of 16,078 Korean men aged 50 years or older who had undergone comprehensive routine health examinations were enrolled. Incident fractures at osteoporosis-related sites (e.g., hip, spine, distal radius, and proximal humerus) that occurred after the baseline examinations were identified from the nationwide claims database of the Health Insurance Review and Assessment Service of Korea by using selected International Classification of Diseases, 10th revision codes.

RESULTS

In total, 158 (1.0 %) men developed incident OFs. The event rate was 33.1 per 10,000 person-years. Subjects without incident OFs had 6.0 % higher serum UA levels than subjects with OFs (P = 0.001). Multivariable-adjusted Cox proportional hazard analyses adjusted for age, body mass index, glomerular filtration rate, lifestyle factors, medical and drug histories, and the presence of baseline radiological vertebral fractures revealed that the hazard ratio per standard deviation increase of baseline UA levels for the development of incident OFs was 0.829 (95 % CI = 0.695-0.989, P = 0.038).

CONCLUSIONS

These data provide the epidemiological evidence that serum UA may act as a protective factor against the development of incident OFs in Korean men.

Higher serum uric acid is associated with higher bone mass, lower bone turnover, and lower prevalence of vertebral fracture in healthy postmenopausal women

Higher serum uric acid (UA) was associated with higher bone mass, lower bone turnover, and lower prevalence of vertebral fracture in postmenopausal women. Furthermore, UA suppressed osteoclastogenesis and decreased production of reactive oxygen species in osteoclast precursors, indicating UA may have beneficial effects on bone metabolism as an antioxidant.

INTRODUCTION

UA is known to play a physiological role as an antioxidant, and oxidative stress has detrimental effects on bone metabolism. In the present study, we investigated the association of serum UA level with the osteoporosis-related phenotypes and its direct effect on bone-resorbing osteoclasts using in vitro systems.

METHODS

This is a large cross-sectional study, including 7,502 healthy postmenopausal women. Bone mineral density (BMD) and serum UA concentrations were obtained from all subjects. Data on bone turnover markers and lateral thoracolumbar radiographs were available for 1,023 and 6,918 subjects, respectively. An in vitro study investigated osteoclastogenesis and reactive oxygen species (ROS) levels according to UA treatment.

RESULTS

After adjusting for multiple confounders, serum UA levels were positively associated with BMD at all sites (all p < 0.001). Compared with the participants in the highest UA quartile, the odds for osteoporosis were 40 % higher in those in the lowest quartile. The serum UA levels were inversely related to both serum C-terminal telopeptide of type I collagen and osteocalcin levels (p < 0.001 and p = 0.004, respectively). Consistently, subjects with vertebral fracture had lower serum UA levels, compared with those without it (p = 0.009). An in vitro study showed that UA decreased osteoclastogenesis in a dose-dependent manner and reduced the production of ROS in osteoclast precursors.

CONCLUSION

These results provide epidemiological and experimental evidence that serum UA may have a beneficial effect on bone metabolism as an antioxidant in postmenopausal women.

Relative contributions of insulin resistance and β-cell dysfunction to the development of Type 2 diabetes in Koreans

AIMS

Controversies still exist regarding the relative contributions of insulin resistance and β-cell dysfunction to the pathogenesis of Type 2 diabetes in different populations. We examined the associations of baseline insulin resistance and β-cell function indices with the development of Type 2 diabetes in Koreans.

METHODS

We analysed the clinical and laboratory data of 17 878 Korean adults (age 20-79 years) who underwent routine medical examinations with a median interval of 3.5 years (range 2.5-4.7 years). Using the homeostasis model assessment, insulin resistance (HOMA-IR) and β-cell function (HOMA-%B) indices at baseline were assessed.

RESULTS

Those who developed diabetes (n = 732, 4.1%) had significantly higher fasting serum insulin level (53.4 ± 31.2 vs. 41.4 ± 23.4 pmol/l) and HOMA-IR (2.38 ± 1.45 vs. 1.65 ± 1.02) and lower HOMA-%B (74 ± 47 vs. 85 ± 48) at baseline (P < 0.001 for all). Both high HOMA-IR and low HOMA-%B were independently associated with an increased odds ratio of incident Type 2 diabetes. Among the participants who developed diabetes, 29% demonstrated predominant β-cell dysfunction (HOMA-%B < 25th percentile) and 51% had predominant insulin resistance (HOMA-IR > 75th percentile). When we divided the participants according to the median BMI of the whole population (23.7 kg/m²), 49% of participants in the low BMI group demonstrated predominant β-cell dysfunction and 26% had predominant insulin resistance, whilst 21% in the high BMI group demonstrated mainly β-cell dysfunction and 60% had mainly insulin resistance.

CONCLUSIONS

In individuals with low BMI, β-cell dysfunction is the predominant defect, whereas insulin resistance is the predominant pathogenetic factor in individuals with high BMI in the development of Type 2 diabetes in Koreans.

Preparation and characterization of carbon-titania nanocomposite-supported Pd3Co alloy nanoparticles for oxygen reduction

A TiO2-modified carbon (C-TiO2) has been employed as a catalyst support of Pd3Co alloy for electroduction of oxygen. Due to the strong interaction between highly dispersed TiO2 and Pd3Co alloy, the C-TiO2 support was shown to be effective for a fine dispersion of Pd3Co alloys. The degree of sintering of Pd3Co on C-TiO2 could largely decrease during heat-treatment for reduction compared to that on unmodified carbon support (C). In oxygen reduction reaction (ORR), the reduced catalysts (Pd3Co/C-X and Pd3Co/C-TiO2-X; X represents reduction temperature) showed higher catalytic performance than their as-prepared catalysts. The catalytic activities of Pd3Co/C-TiO2-X were largely enhanced compared to those of Pd3Co/C-X. The ORR activity was measured to be the highest on Pd3Co/C-TiO2-300, which was 9 times enhanced activity (at 0.85 V) relative to the best-performed catalyst supported on carbon (Pd3Co/C-400). A positive role of TiO2 for the metal dispersion, the retardation of metal growth during heat-treatment, and the modification of electronic structure of Pd3Co was responsible for the enhanced ORR performance on Pd3Co/C-TiO2-X.

Association between metabolic syndrome and bone loss at various skeletal sites in postmenopausal women: a 3-year retrospective longitudinal study

Although the presence of metabolic syndrome (MetS) and increasing numbers of MetS components were associated with attenuated bone loss at various skeletal sites in postmenopausal women, this beneficial effect of MetS on bone mass can be mainly explained by higher mechanical loading in the affected subjects.

INTRODUCTION

Previous cross-sectional epidemiological studies reported the inconsistent results regarding the combined effects of MetS on bone mass. In our present report, we performed a large, longitudinal study to evaluate MetS in relation to annualized bone mineral density (BMD) changes in postmenopausal Korean women.

METHODS

The study cohort consisted of 1,218 postmenopausal women who had undergone comprehensive routine health examinations with an average follow-up interval of 3 years. The BMD at the lumbar spine and proximal femur sites was measured with dual-energy X-ray absorptiometry using the same equipment at baseline and at follow-up.

RESULTS

Following adjustment for age, baseline BMD, and lifestyle factors, the women with MetS had 21.7, 17.0, 26.7, and 31.1 % less bone loss at the total femur, femur neck, trochanter, and lumbar spine, respectively, compared with MetS-free women (P = 0.004 to 0.041). Consistently, the rates of bone loss at all skeletal sites were linearly attenuated with increasing numbers of MetS components (P = 0.004 to <0.001). Importantly, when weight and height were added as confounding factors, the differences and trends of annualized BMD changes according to the MetS status disappeared.

CONCLUSION

Our current results indicate that the beneficial effects of MetS on bone mass can be mainly explained by higher mechanical loading in the affected subjects. Consequently, MetS per se may not be a meaningful concept for predicting future bone loss and for explaining associations between osteoporosis and cardiovascular diseases.

The effect of lipopolysaccharide on enhanced inflammatory process with age: Modulation of NF-κB

Oxidative stress is thought to be a causative factor for age-related damage in a wide variety of cellular constituents that can lead to dysfunction and various pathological conditions, including the inflammatory process. At the molecular level, the redox-sensitive transcription factor, NF-κB plays a key role in the regulation of the inflammatory process, along with cytokines, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS). We studied the mechanism underlying the modulation of the inflammatory reaction with age by investigating NF-κB activation and the expression of COX-2, iNOS, and cytokines genes in hepatic tissues isolated from young and old rats. We expanded our investigation of these factors in rats injected with the inflammatory activator, lipopolysaccharide (LPS). Data showed that NF-κB activity was up-regulated with age and was further enhanced by LPS injection, indicating an increased susceptibility and sensitivity to the inflammatory stimulus with age. To explore further the molecular events leading to NF-κB activation, we investigated the inhibitory component of NF-κB complex, IκB. Cytosolic IκBα, but not IκBβ, was significantly decreased in both old and LPS-treated rats, signifying the enhanced migration of cytosolic NF-κB complex into the nucleus following dissociation from the inhibitor. The appearance of the polypeptide, p65, as determined in the nucleus, corresponded with the change in IκBα, providing further supporting evidence for the molecular process involved in NF-κB activation. Our additional investigation of two proinflammatory-related enzymes, COX-2 and iNOS, and three cytokines, interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α, clearly showed aged-related increases, in corroboration with the NF-κB activation. Our results demonstrated that LPS injection caused the enhanced gene expression of inducible proinflammatory proteins, COX-2 and iNOS through NF-κB activation.

Long-term viability of transplanted hybrid cellular spheroids within chondrocyte sheets

Encapsulation of transplanted cells within an immunoisolating membrane may provide a new strategy for protecting these cells from recipient immune responses without the use of immunosuppressive drugs. We have previously reported a novel concept of immunoisolation and immunodelusion using recipient cells instead of traditional artificial materials. We developed a chondrocyte sheeting immunodelusive immunoisolated bioartificial pancreas (CSI-BAP) that would enable transplantation of cells across allogeneic and xenogeneic barriers without the cells being recognized as donor cells and without the need for immunosuppression. Recently, we have constructed hybrid cellular spheroids (HCSs) containing cells from two different cell lines (RIN-5F, an insulin-secreting cell line, and Hep-G2, a hepatocellular carcinoma cell line) to enhance the function and biocompatibility of the HCSs. These HCSs were then encapsulated with multiple layers of chondrocyte sheets obtained from the auricular cartilage of Sprague-Dawley (SD) rats. The in vitro ability of the CSI-BAP to secrete insulin was tested before transplantation. Histological evaluation of CSI-BAP chondrocyte microencapsulated immunoisolated islet morphology and viability of allogeneic or xenogeneic cell lines was performed 100 days after the CSI-BAP was transplanted into SD rats. Morphological evaluations revealed good viability of the islets and progression of islet encapsulation. In vitro insulin secretion from the CSI-BAP was well maintained. Additionally, insulin and albumin secretion from the CSI-BAP was confirmed by in vivo immunohistochemical examination. Moreover, the cell lines transplanted into the subcutaneous space in the form of HCSs within the chondrocyte sheets showed good viability of more than 100 days and sustained insulin and albumin secreting ability.

Microencapsulation of pancreatic islets with canine ear cartilage for immunoisolation

Improving human islet transplantation is often limited by the shortage of donors and the side effects of immunosuppressive agents. If immunoisolation is properly used, it can overcome these obstacles. Because artificial materials are adopted in this technique, however, there are still multiple issues with biocompatibility and foreign body reactions. We developed a chondrocyte microencapsulated immunoisolated islet (CMI-islet) that allows living cells to act as the immunoisolating material. To manufacture CMI-islets for xenotransplantation, isolated rat pancreatic islets were placed on low cell-binding culture dishes. Subsequently, expanded canine auricular cartiage primary cells were seeded on these dishes at a high density and maintained in a suspended state via a shaking culture system. Morphological evaluations showed good islet viability and a clear progression of the islet- encapsulation events. When the cells were challenged with glucose, they were able to secrete sufficient insulin according to glucose concentrations. The CMI-islets responded better to the glucose challenge than did nude pancreatic islets and created better glucose-insulin feedback regulation. Moreover, insulin secretion into the culture medium was confirmed over a period of 100 days, showing the survival and secretory capacity of the CMI-islet cells. By microencapsulating pancreatic islets with recipient ear cartilage cells, long-term insulin secretion can be maintained and the response to glucose challenges improved. This new immunodelusion technology differs from other immunoisolation techniques in that the donor tissue is enclosed with the recipient's tissue, thus allowing the transplanted cells to be recognized as recipient cells. This microencapsulation method may lead to developing viable xenotransplantation techniques that do not use immunosuppressive drugs.

Diagnostic patterns in the evaluation of patients presenting with syncope at the emergency or outpatient department

PURPOSE

Patterns of syncope evaluation vary widely among physicians and hospitals. The aim of this study was to assess current diagnostic patterns and medical costs in the evaluation of patients presenting with syncope at the emergency department (ED) or the outpatient department (OPD) of a referral hospital.

MATERIALS AND METHODS

This study included 171 consecutive patients with syncope, who visited the ED or OPD between January 2009 and July 2009.

RESULTS

The ED group had fewer episodes of syncope [2 (1-2) vs. 2 (1-5), p=0.014] and fewer prodromal symptoms (81.5% vs. 93.3%, p=0.018) than the OPD group. Diagnostic tests were more frequently performed in the ED group than in the OPD group (6.2±1.7 vs. 5.3±2.0; p=0.012). In addition, tests with low diagnostic yields were more frequently used in the ED group than in the OPD group. The total cost of syncope evaluation per patient was higher in the ED group than in the OPD group [823,000 (440,000-1,408,000) won vs. 420,000 (186,000-766,000) won, p<0.001].

CONCLUSION

There were some differences in the clinical characteristics of patients and diagnostic patterns in the evaluation of syncope between the ED and the OPD groups. Therefore, a selective diagnostic approach according to the presentation site is needed to improve diagnostic yields and to reduce the time and costs of evaluation of syncope.

The association between serum osteocalcin levels and metabolic syndrome in Koreans

The association between serum osteocalcin levels and metabolic syndrome (MS) in Korean individuals was investigated. Serum osteocalcin levels are significantly lower in subjects with MS than in those without the disease, regardless of glucose metabolism.

INTRODUCTION

Osteocalcin was recently shown to affect energy metabolism. In the present study, we investigated the possible association between serum osteocalcin concentrations and MS.

METHODS

A cross-sectional community-based survey was conducted. Serum osteocalcin, type 1 collagen C-telopeptide (CTX) and total alkaline phosphatase (ALP) concentrations were determined in 567 subjects. MS was defined according to NCEP-ATP III criteria.

RESULTS

Serum osteocalcin concentrations were significantly lower in subjects with MS than those without MS in postmenopausal women (18.923 ± 7.685 vs 22.513 ± 7.344 ng/ml, P<0.001) and marginally lower in subjects with MS than those without MS in men (14.550 ± 5.090 vs 16.125 ± 4.749 ng/ml, P=0.086) after adjustment for age and BMI. Further controlling with CTX or ALP did not affect this association in postmenopausal women; however, controlling with osteocalcin abolished the association between CTX and MS. Significant differences in serum osteocalcin levels by MS status were noted in subjects with normal glucose tolerance as well as those with abnormal glucose tolerance (P=0.032 and P<0.001, respectively). Compared with subjects with the highest quartile of osteocalcin, those in the lower quartile groups (Q1-Q3) had significantly increased risks of MS (ORs=5.18, CIs=1.15-23.42) in men. In postmenopausal women, the ORs for MS were significantly higher in the lowest quartile than in the highest quartile (ORs=5.25, CIs=2.42-11.36).

CONCLUSIONS

These findings suggest that osteocalcin is associated with MS, independently of glucose metabolism.

Association of restrictive ventilatory dysfunction with insulin resistance and type 2 diabetes in koreans

AIMS

To investigate associations of obstructive and restrictive patterns of ventilatory dysfunction with insulin resistance and type 2 diabetes mellitus (DM) in Koreans.

METHODS

We cross-sectionally examined clinical, laboratory, and pulmonary function data on 35,456 Korean adults (age 18-93 years, 40% women) recorded during regular health check-ups. Insulin resistance (IR) was determined from fasting serum insulin concentration and homeostasis model assessment (HOMA).

RESULTS

Individuals with type 2 DM and those with pre-diabetes (impaired fasting glucose levels) showed a higher prevalence of both restrictive (18% and 11%, respectively, VS. 8%; P<0.01) and obstructive (4.3% and 3.2%, respectively, VS. 2.3%; P<0.01) ventilatory dysfunction than did individuals with normal fasting glucose levels. Compared to subjects with normal ventilatory function, those with restrictive or obstructive ventilatory dysfunction were older, had higher systolic and diastolic blood pressure, and had elevated glucose and HbA1c levels. However, serum triglyceride, fasting insulin, and HOMA-IR were higher only in subjects with restrictive ventilatory dysfunction, and not in those with obstructive ventilatory dysfunction. On logistic regression analysis, the age and gender-adjusted odds ratio (OR) of restrictive ventilatory dysfunction for type 2 DM was 1.59 (95% confidence interval, 1.43-1.78). The increased OR remained significant after controlling for exercise, drinking, and smoking habits, presence of hypertension, body mass index, and waist circumference (OR=1.38 [1.23-1.55]). However, further adjustment for HOMA-IR attenuated the OR (1.11 [0.97-1.26]), making the OR statistically insignificant. In contrast, obstructive ventilatory dysfunction was not independently related to type 2 DM status.

CONCLUSION

Restrictive ventilatory dysfunction is independently associated with type 2 DM, probably VIA insulin resistance.

Involvement of gaseous low molecular monoxides in the cutaneous reverse passive Arthus reaction: cytoprotective action of carbon monoxide

The deposition of immune complexes (IC) induces an acute inflammatory response with tissue injury, for which the involvement of nitric oxide (NO) and carbon monoxide (CO) has been suggested. NO is induced by NO synthase (NOS) and CO is generated by haeme oxygenase (HO). Among HO isoenzymes, HO-1 is an induced type. To assess the role of NO and CO in the pathogenic process, the cutaneous reverse passive Arthus reaction was examined using NOS inhibitor, HO-1 stimulator and HO-1 inhibitor. To evaluate the reaction we considered oedema, tumour necrosis factor-alpha, interleukin-6, and neutrophil number. The values of these four parameters were significantly reduced in mice treated with HO-1 stimulator as compared with the positive control mice. Quite the reverse was observed in mice treated with HO-1 inhibitor. These results suggest that the HO-1/CO signalling pathway is a therapeutic target for human IC-mediated disease.

Decreased cerebral blood flow of thalamus in PTSD patients as a strategy to reduce re-experience symptoms

OBJECTIVE

To investigate alterations of regional cerebral blood flow (rCBF) in subjects with post-traumatic stress disorder (PTSD).

METHOD

Using [99Tcm]-hexamethyl propylenamino oxime single photon emission computed tomography, the rCBF under resting condition was compared between 19 survivors of the Taegu subway fire with PTSD and 19 comparison subjects.

RESULTS

PTSD patients showed a decreased rCBF in the right thalamus and an increased rCBF in the right superior parietal lobe relative to comparison subjects (corrected P < 0.05). The rCBF in the right thalamus positively correlated with the severity of current re-experience symptoms in PTSD subjects.

CONCLUSION

Our finding of the thalamic rCBF decrease in PTSD patients may be a strategy to reduce re-experience symptom, by evading the process of external and internal information which can evoke traumatic memory. In addition, the parietal rCBF increase in our PTSD patients might be related to altered information processing in PTSD.

Usefulness of reversed display of soft-copy abdominal radiographs for urinary calculi detection

PURPOSE

To determine the usefulness of reversed display of soft-copy abdominal radiographs for urinary calculi detection.

MATERIAL AND METHODS

Sixty radiographs with a single urinary calculus less than 5 mm in the long diameter (15 in the kidney; 15 in the proximal ureter; 15 in the mid-ureter, 15 in the distal ureter) and 15 radiographs without calculi were evaluated. Four readers blinded to the presence or absence of urinary calculi on each radiograph reviewed the radiographs in the conventional display, reversed display, and combination of conventional and reversed displays at 1-week intervals. All images were evaluated in random order and the presence or absence of urinary calculi was interpreted using the confidence score from 1 to 5.

RESULTS

Multireader analysis for calculi in all locations showed a greater area under the receiver operating curve for combination of the two displays (0.764) than for the conventional display alone (0.655) (P=0.031). In the single-reader analysis for calculi in all locations, the third reader showed a greater area under the receiver operating curve for the reversed display (0.784) than for the conventional display (0.622) (P=0.027). Multireader analysis of the calculi in the kidney showed a greater area under the receiver operating curve for combination of the two displays (0.824) than for the conventional display alone (0.703) (P=0.043).

CONCLUSION

The reversed display of soft-copy abdominal radiographs may be useful for urinary calculi detection.

Stress response, tachykinin, and cutaneous inflammation

In the last decade, several new aspects of glucocorticoid (GC)-actions on immune cells have been recognized. This recognition has been largely obtained through clinical observations of stress-induced exacerbations of certain dermatologic diseases. To clarify whether GC modulates cutaneous inflammatory reactions besides its known anti-inflammatory effect, first we examined the effect of long-term application of topical GC on several kinds of inflammatory responses induced in the murine model and demonstrated that these regimens significantly augmented the classical contact sensitivity reaction, the croton oil-induced irritant reaction, and the IgE-mediated biphasic cutaneous reaction. In addition, large dose topical steroid and its withdrawal enhanced scratching behavior in hapten-challenged mice. This augmented scratching behavior correlated with the induction of preprotachykinin mRNA expression in the challenged skin. In an in vitro experiment, a low-dose, stress-induced level of glucocorticoid significantly upregulated hapten-induced proinflammatory cytokine (IL1alpha) production by murine keratinocyte cell line Pam 212 and induced substance P peptide production from cultured human keratinocytes. Our results suggest that unsuitable use of GC in addition to stress-induced GC may modulate immune function in the skin through aberrant production of tachykinin, such as substance P or other epidermal cell derived cytokines.

Wernicke's encephalopathy: atypical manifestation at MR imaging

SUMMARY

We report a case of atypical manifestation of hyperintense lesions in a 64-year-old female patient with Wernicke's encephalopathy. Fluid-attenuated inversion recovery and T2-weighted images demonstrated symmetrical distribution of hyperintense lesions in cerebellar dentate nuclei, tegmentum of the lower pons, red nuclei, and tectum of the midbrain, and T1-weighted sagittal images showed atrophy of the mamillary bodies. The hyperintense lesions were completely resolved on follow-up MR images.

Synthesis of a chiral aziridine derivative as a versatile intermediate for HIV protease inhibitors

[reaction: see text] Chiral aziridine derivative 1 was prepared from D-tartaric acid. This compound could be utilized as a common intermediate for the synthesis of hydroxyethylamine class HIV protease inhibitors such as saquinavir, amprenavir, or nelfinavir.

Useful CT findings for predicting the progression of aortic intramural hematoma to overt aortic dissection

PURPOSE

The purpose of this work was to assess useful CT findings for predicting the progression of aortic intramural hematoma to aortic dissection.

METHOD

We analyzed the CT findings of 29 patients with aortic intramural hematoma with regard to the following: involved site, maximum thickness of hematoma, presence or absence of compression of true lumen, and pericardial and pleural effusion. CT findings were compared with those of the patients who progressed to aortic dissection (Group I) and those who did not (Group II). Each CT finding was evaluated with independent t test and Mann-Whitney U test (p < 0.05).

RESULTS

Seven of 8 cases of Type A aortic intramural hematoma and 3 of 21 cases of Type B aortic intramural hematoma progressed to aortic dissection. The type of aortic intramural hematoma, maximum thickness of hematoma, compression of true lumen, and pericardial or pleural effusion were significantly different in Groups I and II.

CONCLUSION

Type A aortic intramural hematoma, maximum thickness of hematoma, compression of true lumen, and pericardial or pleural effusion are the useful CT findings for predicting the progression of aortic intramural hematoma to aortic dissection.

Molecular characteristics of the inhibition of human neutrophil elastase by nonsteroidal antiinflammatory drugs

Nonsteroidal antiinflammatory drugs(NSAIDs) are known as clinically effective agents for treatment of inflammatory diseases. Inhibition of cyclooxygenase has been thought to be a major facet of the pharmacological mechanism of NSAIDs. However, it is difficult to ascribe the antiinflammatory effects of NSAIDs solely to the inhibition of prostaglandin synthesis. Human neutrophil elastase (HNElastase; HNE, EC 3.4.21.37) has been known as a causative factor in inflammatory diseases. To investigate the specific relationship between HNElastase inhibition and specificity of molecular structure of several NSAIDs, HNElastase was purified by Ultrogel AcA54 gel filtration, CM-Sephadex ion exchange, and HPLC (with TSK 250 column) chromatography. HNElastase was inhibited by aspirin and salicylate in a competitive manner and by naproxen, ketoprofen, phenylbutazone, and oxyphenbutazone in a partial competative manner, but not by ibuprofen and tolmetin. HNElastase-phenylbutazone-complex showed strong Raman shifts at 200, 440, 1124, 1194, 1384, 1506, and 1768 cm(-1). The Raman bands 1194, 1384, and 1768 cm(-1) may represent evidences of the conformational change at -N=N-phi radical, pyrazol ring, and -C=O radical of the elastase-drug complex, respectively. Phenylbutazone might be bound to HNElastase by ionic and hydrophobic interaction, and masked the active site. Inhibition of HNElastase could be another mechanism of action of NSAIDs besides cyclooxygenase inhibition in the treatment of inflammatory diseases. Different inhibition characteristics of HNE-lastase by NSAIDs such as aspirin, phenylbutazone-like drugs and ineffective drugs could be important points for drawing the criteria for appropriate drugs in clinical application.

Clustering of breast microcalcifications: revisited

AIM

To verify the diagnostic value of the traditional definition of 'clustering' of microcalcifications (more than five in the area of 1 cm(2)or 1 cm(3)) on mammography in the differential diagnosis of benign and malignant breast disease.

METHODS AND MATERIALS

Three radiologists without knowledge of the final pathology retrospectively counted the number of microcalcifications per 0.25 cm(2) (0.5 x 0.5 cm) unit area on mammography in 57 pathologically proven non-palpable lesions including 26 cancers and 31 benign diseases. Pleomorphism of the microcalcifications, associated architectural distortion or mass or increased density and distribution of microcalcifications were also evaluated.

RESULTS

The mean numbers of microcalcifications per 0.25 cm(2) were 16.4 in malignant and 16.7 in benign diseases (no statistically significant difference between the two groups). Pleomorphism of the microcalcifications, associated architectural distortion or mass or increased density were, however, important determining parameters. Clustering was more frequently observed in benign diseases.

CONCLUSION

In this study, the mean number of microcalcifications per unit area is much larger than the traditional definition of 'clustering' and clustering itself is not effective in the differential diagnosis of benign and malignant breast lesions. Imaging features other than numbers of calcification per unit area are more important in assessing the significance of mammographic clustered microcalcifications.

Interleukin-5 involvement in ovalbumin-induced eosinophil infiltration in mouse food-allergy model

A number of studies demonstrating the important role of interleukin-5 (IL-5) in eosinophil infiltration were reported. Antigen-induced eosinophil infiltrations to the trachea and skin were inhibited by pretreatment with monoclonal anti-IL-5 antibody. In this study, the role of IL-5 in eosinophil infiltration to the gut by oral challenge in mice is investigated. A marked eosinophil infiltration to the lamina propria was induced by oral challenge with ovalubumin (OVA) in Balb/c mice intraperitoneally sensitized with OVA, and peaked at 6 h after the oral challenge. Intraperitoneal preadministration of monoclonal anti-IL-5 antibody significantly decreased the eosinophil infiltration to the lamina propria. Furthermore, analysis by reverse transcription polymerase chain reaction (RT-PCR) demonstrated that IL-5 mRNA expression was induced in the lamina propria in an antigen-specific manner and the expression peaked at 6 h and declined thereafter. In-situ hybridization (ISH) revealed the presence of IL-5 mRNA positive cells at lesion site. As in bronchial mucosa and skin, IL-5 may play an important role in eosinophil recruitment to the lesion site in IgE mediated gut late phase reaction.

The inhibitory effect of anti-adhesion molecule antibodies on eosinophil infiltration in cutaneous late phase response in Balb/c mice sensitized with ovalbumin (OVA)

In this study, we investigated the involvement of the adhesion molecules intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), very late activation antigen-4 (VLA-4), lymphocyte function-associated antigen 1 (LFA-1) and macrophage antigen-1 (Mac-1) on eosinophil infiltration in the cutaneous late phase response (LPR) in OVA-sensitized Balb/c mice by two approaches, immunostaining and inhibition assays with each monoclonal antibody. The eosinophil infiltration into the skin reached a peak at 12 hr after an intradermal challenge with OVA. Infiltrated eosinophils and mononuclear cells in the skin expressed Mac-1 (eosinophils: 38.9 +/- 1.55%, mononuclear cells: 51.2 +/- 2.15%), LFA-1 (eosinophils: 33.3 +/- 0.95%, mononuclear cells: 23.1 +/- 1.07%) and VLA-4 (eosinophils: 14.3 +/- 1.6%, mononuclear cells: 17.2 +/- 1.38%) at 12 h. Intraperitoneal administration of anti-mouse ICAM-1, VCAM-1, and VLA-4 monoclonal antibodies (mAb) before the challenge decreased the eosinophil infiltration by 66.2%, 61.0%, and 54.0%, respectively. On the other hand, pretreatment with anti-mouse LFA-1 mAb or Mac-1 mAb did not significantly decrease the infiltration. These results suggest that VCAM-1/VLA-4 interaction and ICAM-1 play important roles in eosinophil infiltration in cutaneous LPR.

[The inhibitory effect of LTB4 antagonist on eosinophil infiltration in cutaneous and gut late phase response in BALB/C mice sensitized with ovalubumin (OVA)]

In this study we investigated the effect of LTB4 antagonist on eosinophil infiltration in skin and gut late phase response (LPR) in OVA-sensitized BALB/c mice. The eosinophil infiltrations to skin and gut induced by skin and oral challenge reached a peak at 12 h and 6 h after the challenge, respectively. Intraperitoneal administration of LTB4 antagonist (ONO-4057) before the challenge significantly inhibited eosinophil infiltrations to the skin and gut by 53.3% and 73.7%, respectively (p < 0.05). Next, we investigated the effect to that by PAF antagonist (ONO-6240) and anti-IL-5 mAb in the skin system. OVA-induced eosinophil infiltration at 12 h after intracutaneous challenge was significantly inhibited by peritoneal administration of anti-IL-5 mAb before the challenge by 89.6% (p < 0.05), but not by that of PAF antagonist. Our results demonstrated the inhibitory effect of LTB4 antagonist on eosinophil infiltration in skin and gut LPR, suggesting the potency of LTB4 antagonist for treatment of skin lesion and food allergy in atopic dermatitis considered to be associated with LPR.

Thermodynamics of the thermal unfolding of eglin c in the presence and absence of guanidinium chloride

The thermal unfolding of eglin c, a small proteinase inhibitor of molecular weight 8.1 kDa, is studied by means of high sensitivity scanning calorimetry over a wide pH range in dilute buffer solutions, and in the presence of varying concentrations of guanidinium chloride at pH 7.00 and 10.55. The temperature of half-completion of the unfolding transition, t1/2, in dilute buffer varies from 41 degrees C at pH 1.1 to 86 degrees C at pH 7.0 to 10.55, with corresponding enthalpy changes of approximately 40 kcal mol-1 and 71 kcal mol-1. This latter enthalpy change, amounting to 8.7 cal g-1, is unusually large for a protein, especially for one of unusually small molecular weight. Addition of 3.3 M guanidinium chloride at pH 10.55 lowered t1/2 from 86 degrees C to 40 degrees C and decreased the enthalpy change from approximately 71 kcal mol-1 to 25 kcal mol-1.

The effects of the p-nitrophenyl esters of the even-numbered fatty acids from caproic (C6) to stearic (C18) on the main phase transition of dimyristoylphosphatidylcholine

Differential scanning calorimetry (DSC) is employed in a study of the effects of the p-nitrophenyl esters of the even numbered fatty acids from C6 (caproic acid) to C18 (stearic acid) on the main phase transition of multilamellar suspensions of dimyristoylphosphatidylcholine (DMPC). Mole fractions in the range of 0.02-0.12 were used. Within this concentration range the observed transitions could be well fit on the basis of a model assuming ideal behavior of the esters in both the gel and liquid crystal phases of the lipid, and independently additive van't Hoff and impurity broadening. As expected on the basis of this model, the transition temperatures decreased linearly with increasing ester concentration and the transition enthalpies were independent of ester concentration. Significant differences between the effects of the various esters were observed, but these did not change with changing ester chain length in any regular fashion.

The effects of calcium channel blocking drugs on the thermotropic behavior of dimyristoylphosphatidylcholine

The effects of four calcium channel blocking drugs, diltiazem, verapamil, nimodipine and nisoldipine, on the main phase transition of dimyristoylphosphatidylcholine have been studied by high resolution differential scanning calorimetry. In all cases, the phase transition temperature is lowered, though much more effectively by nimodipine and nisoldipine than by the other two drugs. Nimodipine and nisoldipine markedly reduce the enthalpy of transition while diltiazem and verapamil have no significant effect on the enthalpy within the drug concentration range studied. Analysis of the data in terms of ideal solution theory is presented. X-ray and neutron scattering studies indicate that nimodipine and verapamil differ significantly with respect to their location within a lipid bilayer, and this difference suggests a partial rationalization of the experimental results presented here.

Tryptophan repressor of Escherichia coli shows unusual thermal stability

Differential scanning calorimetry demonstrates that the tryptophan repressor of Escherichia coli is unusually resistant to thermal denaturation. The dimeric protein undergoes reversible dissociative unfolding at pH 7.5 centered at about 90 degrees C. The thermal stability may be due in part to the unusual structure of the protein, which is composed of two identical intertwined polypeptide chains.