Efficacy and Safety of Guselkumab for Moderate to Severe Psoriasis in Korea:A Retrospective Study / 대한피부과학회지

Background@#Guselkumab is a monoclonal antibody that selectively targets interleukin-23 in the treatment of moderate to severe psoriasis. Several multinational clinical studies have reported on its efficacy. However, data on its efficacy and safety in Korean patients are currently very limited. @*Objective@#This study evaluated the real-world efficacy and safety of guselkumab for treating patients with moderate to severe psoriasis in Korea. @*Methods@#This single-center retrospective study included 40 patients treated with guselkumab for at least 12 weeks.Electronic medical records were reviewed for demographics, clinical characteristics, psoriasis area and severity index (PASI) score, body surface area, and adverse events. @*Results@#The average PASI score at baseline (12.0±8.3) was significantly reduced to 3.3±3.8 at week 12, 2.2±2.2 at week 36, and 1.6±1.5 at week 52. At week 60, 93%, 60%, and 33% of patients achieved a PASI of 75, 90, and 100, respectively. Obesity, psoriatic arthritis, and previous biologics treatment experience were not significant indicators of guselkumab treatment efficacy. Seven patients reported adverse events; however, none discontinued guselkumab treatment. @*Conclusion@#Guselkumab is an effective and safe treatment option for moderate to severe psoriasis in Korea.

Opening Wedge High Tibia Osteotomy / 대한정형외과학회잡지

Proximal tibial osteotomy is the preferred method for treating medial compartment knee arthritis with varus deformity. The purpose of this treatment is to reduce the weight burden of the lesion by correcting the mechanical axis of the patient with degenerative arthritis of medial tibiofemoral joint and abnormal alignment. In general, the proximal tibial osteotomy provides satisfactory clinical results when suitable patient are selected by considering the extent of cartilaginous injury and the age of the patient and the correct technique is performed. In tibial osteotomy, medial open wedge osteotomy is used widely because of its short operation time and relatively simple technique. This review describes the current knowledge of patient selection, preoperative evaluation and planning, treatment principles, surgical techniques, rehabilitation procedures and complications in open wedge high tibial osteotomy.

Ginkgo biloba extract (EGb761) did not express estrogenic activity in an immature rat uterotrophic assay

Ginkgo biloba is a dioecious tree that has been used in traditional Chinese medicine for about 5,000 years. In previous studies on Ginkgo biloba extract (EGb761) using in vitro systems, we confirmed that EGb761 has biphasic effects on estrogenicity. In this study, we evaluated the agonistic and antagonistic activities of EGb761 using a uterotrophic assay in immature female rats. To evaluate agonistic and antagonistic effects of EGb761 on uterus, 21-day-old immature Sprague-Dawley (SD) female rats were treated with EGb761 (100, 200, or 400 mg/kg) by oral gavage, 10 μg/kg of estradiol (E2) or 1 mg/kg tamoxifen (TM) by subcutaneous injection, or with EGb761 plus E2 or TM for 3 consecutive days. At the end of the treatment period, animals were sacrificed and their body weights and organ weights (liver, lung, spleen and kidney) were measured. In addition, estrogen-related gene expressions (IGFBP-1 in liver and CaBP-9 in uterus) were determined. During the experiment, no animal showed clinical signs, a change in body weight or died. EGb761 treatment alone had no effect on absolute/relative uterine weight, luminal epithelial cell height (LECH, μm), or luminal circumference (LC, μm). In addition, uterine weights, LECHs, and LC induced by E2 or TM were not significantly changed by EGb761 at any dose. These results collectively suggested EGb761 has no agonistic/antagonistic effects in utero.

Ginkgo biloba extract (EGb761) did not express estrogenic activity in an immature rat uterotrophic assay

Ginkgo biloba is a dioecious tree that has been used in traditional Chinese medicine for about 5,000 years. In previous studies on Ginkgo biloba extract (EGb761) using in vitro systems, we confirmed that EGb761 has biphasic effects on estrogenicity. In this study, we evaluated the agonistic and antagonistic activities of EGb761 using a uterotrophic assay in immature female rats. To evaluate agonistic and antagonistic effects of EGb761 on uterus, 21-day-old immature Sprague-Dawley (SD) female rats were treated with EGb761 (100, 200, or 400 mg/kg) by oral gavage, 10 μg/kg of estradiol (E2) or 1 mg/kg tamoxifen (TM) by subcutaneous injection, or with EGb761 plus E2 or TM for 3 consecutive days. At the end of the treatment period, animals were sacrificed and their body weights and organ weights (liver, lung, spleen and kidney) were measured. In addition, estrogen-related gene expressions (IGFBP-1 in liver and CaBP-9 in uterus) were determined. During the experiment, no animal showed clinical signs, a change in body weight or died. EGb761 treatment alone had no effect on absolute/relative uterine weight, luminal epithelial cell height (LECH, μm), or luminal circumference (LC, μm). In addition, uterine weights, LECHs, and LC induced by E2 or TM were not significantly changed by EGb761 at any dose. These results collectively suggested EGb761 has no agonistic/antagonistic effects in utero.

Comparison of Hematologic Variability between Clozapine Monotherapy and Augmentation Therapy with Atypical Antipsychotics for Schizophrenia: Results from a 6-Month Retrospective Follow-Up Study / 대한정신분열병학회지

OBJECTIVES: Clozapine is an antipsychotic agent commonly prescribed in patients with treatment-resistant schizophrenia. A drawback of using clozapine is risk of hematologic side effects ranging from mild neutropenia to fatal agranulocytosis. In clinical settings, other atypical antipsychotic agents are frequently combined with clozapine because some treatment-resistant patients would not respond to clozapine alone. Unfortunately, other atypical antipsychotics may also cause hematologic side effects, and the combination therapy might aggravate the possible neutropenic side effects. The purpose of this study was to investigate the difference in the incidence of hematologic side effects between clozapine monotherapy and augmentation therapy. METHODS: We retrospectively reviewed the medical records of 114 patients who were diagnosed with schizophrenia and being prescribed with clozapine in a single university hospital. White blood cell count (WBC) and absolute neutrophil count (ANC) were identified every 1 month in clozapine monotherapy group and clozapine-atypical antipsychotics augmentation therapy group. RESULTS: Compared with clozapine monotherapy group, augmentation therapy group showed no significant differences in WBC and ANC for the first 6 months of combination. Amisulpride augmentation showed temporary increases in WBC and ANC, especially compared with paliperidone augmentation. CONCLUSION: Augmentation of amisulpride to clozapine might be associated with temporary increases in WBC and ANC during the first 3 months of combination. Further investigations should be carried out to clarify the clinical significance of our findings.

Comparison of Hematologic Variability between Clozapine Monotherapy and Augmentation Therapy with Atypical Antipsychotics for Schizophrenia: Results from a 6-Month Retrospective Follow-Up Study / 대한정신분열병학회지

OBJECTIVES: Clozapine is an antipsychotic agent commonly prescribed in patients with treatment-resistant schizophrenia. A drawback of using clozapine is risk of hematologic side effects ranging from mild neutropenia to fatal agranulocytosis. In clinical settings, other atypical antipsychotic agents are frequently combined with clozapine because some treatment-resistant patients would not respond to clozapine alone. Unfortunately, other atypical antipsychotics may also cause hematologic side effects, and the combination therapy might aggravate the possible neutropenic side effects. The purpose of this study was to investigate the difference in the incidence of hematologic side effects between clozapine monotherapy and augmentation therapy. METHODS: We retrospectively reviewed the medical records of 114 patients who were diagnosed with schizophrenia and being prescribed with clozapine in a single university hospital. White blood cell count (WBC) and absolute neutrophil count (ANC) were identified every 1 month in clozapine monotherapy group and clozapine-atypical antipsychotics augmentation therapy group. RESULTS: Compared with clozapine monotherapy group, augmentation therapy group showed no significant differences in WBC and ANC for the first 6 months of combination. Amisulpride augmentation showed temporary increases in WBC and ANC, especially compared with paliperidone augmentation. CONCLUSION: Augmentation of amisulpride to clozapine might be associated with temporary increases in WBC and ANC during the first 3 months of combination. Further investigations should be carried out to clarify the clinical significance of our findings.

Morphological transformation induced by silver nanoparticles in a Balb/c 3T3 A31-1-1 mouse cell model to evaluate in vitro carcinogenic potential

Carcinogenesis is a complex process involved in genotoxic and non-genotoxic pathways. The carcinogenic potential of silver nanoparticles (AgNPs) has been predicted by examining their genotoxic effects using several in vitro and in vivo models. However, there is no little information regarding the non-genotoxic effects of AgNPs related to carcinogenesis. The in vitro cell transformation assay (CTA) provides specific and sensitive evidence for predicting the tumorigenic potential of a chemical, which cannot be obtained by genotoxicity testing. Therefore, we carried out CTA in Balb/c 3T3 A31-1-1 cells to evaluate the carcinogenic potential of AgNPs. Colony-forming efficiency and crystal violet assays were carried out to determine the cytotoxicity of AgNPs. A cytokinesis-block micronucleus (CBMN) assay and CTA were performed using Balb/c 3T3 A31-1-1 cells to predict the in vitro carcinogenic potential of AgNPs. In the CBMN assay, AgNPs (10.6 μg/mL) induced a significant increase in micronucleus formation indicating a genotoxic effect. Thus, AgNPs could be an initiator of carcinogenesis. In the CTA, used to assess the carcinogenic potential of AgNPs, cells exposed to AgNPs for 72 hours showed significantly induced morphological neoplastic transformation at all tested doses (0.17, 0.66, 2.65, 5.30, and 10.60 μg/mL), and the transformation frequency was significantly increased in a dose-dependent manner. These results indicate that short-term exposure (72 hours) to AgNPs had in vitro carcinogenetic potency in Balb/c 3T3 A31-1-1 cells.

The effects of the standardized extracts of Ginkgo biloba on steroidogenesis pathways and aromatase activity in H295R human adrenocortical carcinoma cells

OBJECTIVES: Aromatase inhibitors that block estrogen synthesis are a proven first-line hormonal therapy for postmenopausal breast cancer. Although it is known that standardized extract of Ginkgo biloba (EGb761) induces anti-carcinogenic effects like the aromatase inhibitors, the effects of EGb761 on steroidogenesis have not been studied yet. Therefore, the effects of EGb761 on steroidogenesis and aromatase activity was studied using a H295R cell model, which was a good in vitro model to predict effects on human adrenal steroidogenesis. METHODS: Cortisol, aldosterone, testosterone, and 17β-estradiol were evaluated in the H295R cells by competitive enzyme-linked immunospecific assay after exposure to EGb761. Real-time polymerase chain reaction were performed to evaluate effects on critical genes in steroid hormone production, specifically cytochrome P450 (CYP11/17/19/21) and the hydroxysteroid dehydrogenases (3β-HSD2 and 17β-HSD1/4). Finally, aromatase activities were measured with a tritiated water-release assay and by western blotting analysis. RESULTS: H295R cells exposed to EGb761 (10 and 100 μg/mL) showed a significant decrease in 17β-estradiol and testosterone, but no change in aldosterone or cortisol. Genes (CYP19 and 17β-HSD1) related to the estrogen steroidogenesis were significantly decreased by EGb761. EGb761 treatment of H295R cells resulted in a significant decrease of aromatase activity as measured by the direct and indirect assays. The coding sequence/ Exon PII of CYP19 gene transcript and protein level of CYP19 were significantly decreased by EGb761. CONCLUSIONS: These results suggest that EGb761 could regulate steroidogenesis-related genes such as CYP19 and 17β-HSD1, and lead to a decrease in 17β-estradiol and testosterone. The present study provides good information on potential therapeutic effects of EGb761 on estrogen dependent breast cancer.

Surgical Results of the Cephalomedullary Nail for the Femoral Intertrochanteric Fracture: Comparison between Non-experienced Surgeons and Experienced Surgeon / 대한고관절학회지

PURPOSE: Cephalomedullary nail (CM nail) in the treatment of femoral intertrochanteric fractures is in the lime light in recent years. The purpose of this study is to compare surgical outcomes between experienced surgeon and non-experienced surgeons in respect of CM nail for femoral intertrochanteric fractures. MATERIALS AND METHODS: The 129 patients underwent CM nail for femoral intertrochanteric fracture more than six months of follow-up from April 2011 to March 2014 in Seoul Medical Center (Seoul, Korea) were participated in this study. For this study, group A consisted of experienced surgeons who performed more than 500 times of CM nail, and group B consisted of non-experienced surgeons who performed less than 50 times of CM nail. Clinical and radiologic outcomes, complications and the need for reoperation between both groups were compared in the study. RESULTS: According to clinical result, both the mean operation time and transfusion volume were significantly longer and greater in group B (P<0.05). In the radiologic outcomes, adequacy of reduction, tip-apex distance and numbers of case placed in the Cleveland zones 5, 6 and 8; there was no statistical difference between both groups. Moreover, rate of complication and reoperation had same results as radiologic outcomes. CONCLUSION: There was no significant difference with statistical data in complications from CM nail for femoral intertrochanteric fractures between experienced surgeon and non-experienced surgeon. Although the operation time and transfusion volume were significantly longer and greater in the case of operation by non-experienced surgeon, satisfactory performance was seen in the complications and the need for reoperation.

Relationship between Metabolic Syndrome and Rheumatoid Arthritis / 가정의학회지

BACKGROUND: Rheumatoid arthritis (RA) and metabolic syndrome (Mets) are considered to be diseases with common traits that can increase the risk of cardiovascular disease incidence; studies in other countries examined the relationship between these diseases. However, existing studies did not show consistent results. In the present study, the relationship between RA and Mets in Koreans was examined using the data of the 4th and 5th Korea National Health and Nutrition Examination Survey (KNHANES). METHODS: The present study used the data of the 4th and 5th KNHANES, conducted between 2007 and 2012. Among 25,812 adults aged over 40, 19,893 were selected as study subjects, excluding 5,919 who did not have variable information needed for the analysis. T-test and chi-square test were used for the analysis of related variables. To determine the relationship between diagnostic status of RA and Mets, multivariate logistic regression analysis was performed by controlling confounding variables, which were selected through literature review and statistical analysis. RESULTS: Multivariate logistic regression analysis was conducted to examine the relationship between diagnostic status of RA and Mets. When age, education level, average monthly household income, smoking, alcohol consumption, and level of physical activity were adjusted, the prevalence of Mets was lower in RA patients (adjusted odds ratio [aOR], 0.79; 95% confidence interval [CI], 0.65 to 0.96). Multivariate logistic regression analysis was performed to examine the relationship between treatment status of RA and Mets. When age, education level, average monthly household income, smoking, alcohol consumption, and level of physical activity were adjusted, there was a significant negative correlation in women (aOR, 0.65; 95% CI, 0.44 to 0.96). CONCLUSION: The relationship between RA and Mets showed a significantly negative correlation in Korean women. The group that received RA treatment showed significantly lower prevalence of the Mets as compared to the untreated group in Korean RA women.

Relationship between Changes in Fatigue and Exercise by Follow-Up Period / 가정의학회지

BACKGROUND: Fatigue is one of the most common presenting symptoms in primary care in Korea. In this study, we aimed to determine the effect of exercise intervention on the severity of fatigue of unknown medical cause during a period of follow-up. METHODS: We used the data collected from an outpatient fatigue clinic in Seoul National University Bundang Hospital. The study was conducted from March 3, 2010 to May 31, 2014. We measured the body mass index of each patient and evaluated variables including lifestyle factors (smoking, alcohol consumption, and regular exercise), quality of sleep, anxiety, depression, stress severity, and fatigue severity using questionnaires. A total of 152 participants who completed questionnaires to determine changes in fatigue severity and the effect of exercise for each period were evaluated. We used univariate analysis to verify possible factors related to fatigue and then conducted multivariate analysis using these factors and the literature. RESULTS: Of 130 patients with the complaint of chronic fatigue for over 6 months, over 90 percent reported moderate or severe fatigue on the Fatigue Severity Scale and Brief Fatigue Inventory questionnaires. The fatigue severity scores decreased and fatigue improved over time. The amount of exercise was increased in the first month, but decreased afterwards. CONCLUSION: There was no significant relationship between changes in the amount of exercise and fatigue severity in each follow-up period. Randomized controlled trials and a cohort study with a more detailed exercise protocol in an outpatient setting are needed in the future.

Screening of toxic potential of graphene family nanomaterials using in vitro and alternative in vivo toxicity testing systems

OBJECTIVES: The widely promising applications of graphene nanomaterials raise considerable concerns regarding their environmental and human health risk assessment. The aim of the current study was to evaluate the toxicity profiling of graphene family nananomaterials (GFNs) in alternative in vitro and in vivo toxicity testing models. METHODS: The GFNs used in this study are graphene nanoplatelets ([GNPs]-pristine, carboxylate [COOH] and amide [NH2]) and graphene oxides (single layer [SLGO] and few layers [FLGO]). The human bronchial epithelial cells (Beas2B cells) as in vitro system and the nematode Caenorhabditis elegans as in vivo system were used to profile the toxicity response of GFNs. Cytotoxicity assays, colony formation assay for cellular toxicity and reproduction potentiality in C. elegans were used as end points to evaluate the GFNs' toxicity. RESULTS: In general, GNPs exhibited higher toxicity than GOs in Beas2B cells, and among the GNPs the order of toxicity was pristine>NH2>COOH. Although the order of toxicity of the GNPs was maintained in C. elegans reproductive toxicity, but GOs were found to be more toxic in the worms than GNPs. In both systems, SLGO exhibited profoundly greater dose dependency than FLGO. The possible reason of their differential toxicity lay in their distinctive physicochemical characteristics and agglomeration behavior in the exposure media. CONCLUSIONS: The present study revealed that the toxicity of GFNs is dependent on the graphene nanomaterial's physical forms, surface functionalizations, number of layers, dose, time of exposure and obviously, on the alternative model systems used for toxicity assessment.

Screening of toxic potential of graphene family nanomaterials using in vitro and alternative in vivo toxicity testing systems

OBJECTIVES: The widely promising applications of graphene nanomaterials raise considerable concerns regarding their environmental and human health risk assessment. The aim of the current study was to evaluate the toxicity profiling of graphene family nananomaterials (GFNs) in alternative in vitro and in vivo toxicity testing models. METHODS: The GFNs used in this study are graphene nanoplatelets ([GNPs]-pristine, carboxylate [COOH] and amide [NH2]) and graphene oxides (single layer [SLGO] and few layers [FLGO]). The human bronchial epithelial cells (Beas2B cells) as in vitro system and the nematode Caenorhabditis elegans as in vivo system were used to profile the toxicity response of GFNs. Cytotoxicity assays, colony formation assay for cellular toxicity and reproduction potentiality in C. elegans were used as end points to evaluate the GFNs' toxicity. RESULTS: In general, GNPs exhibited higher toxicity than GOs in Beas2B cells, and among the GNPs the order of toxicity was pristine>NH2>COOH. Although the order of toxicity of the GNPs was maintained in C. elegans reproductive toxicity, but GOs were found to be more toxic in the worms than GNPs. In both systems, SLGO exhibited profoundly greater dose dependency than FLGO. The possible reason of their differential toxicity lay in their distinctive physicochemical characteristics and agglomeration behavior in the exposure media. CONCLUSIONS: The present study revealed that the toxicity of GFNs is dependent on the graphene nanomaterial's physical forms, surface functionalizations, number of layers, dose, time of exposure and obviously, on the alternative model systems used for toxicity assessment.

Physical Activity Level of Korean Adults with Chronic Diseases: The Korean National Health and Nutritional Examination Survey, 2010-2012 / 가정의학회지

BACKGROUND: Proper physical activities are known to be helpful in the prevention and management of chronic diseases. However, the physical activity level of patients with chronic diseases is low. Therefore, this study aimed to investigate the physical activity compliance of patients with hypertension, diabetes, and dyslipidemia in Korea. METHODS: This study analyzed the 2010-2012 Fifth Korean National Health and Nutrition Examination Survey data. We included 13,873 individuals in the analysis. The level of physical activity compliance was measured by performing multivariate logistic regression analyses. RESULTS: In the univariate analysis, the subjects with hypertension or diabetes tended to comply with the physical activity guidelines less faithfully than their healthy counterparts. The proportion of subjects with hypertension who were insufficiently physically active was 65.4% among the men and 75.8% among the women. For diabetes, the proportions were 66.7% and 76.8%, respectively. No significant difference was found between the subjects with dyslipidemia and their healthy counterparts. In the multivariate logistic regression analysis, no significant difference in physical activity compliance was observed between the subjects with hypertension, diabetes, or dyslipidemia and their healthy counterparts for both sexes. CONCLUSION: The patients with hypertension or diabetes tended to have lower physical activity prevlaence than their healthy counterparts. However, for dyslipidemia, no significant difference was found between the two groups. Given the significance of physical activities in the management of chronic diseases, the physical activities of these patients need to be improved.

Barrier Factors to the Completion of Diabetes Education in Korean Diabetic Adult Patients: Korea National Health and Nutrition Examination Surveys 2007-2012 / 가정의학회지

BACKGROUND: Diabetes is a disease with high social burdens and is expected to increase gradually. A long-term management is essential for the treatment of diabetes, requiring patient self-cares. Diabetes education is important for such self-cares, but it does not sufficiently take place. In addition, little studies have been conducted on the barriers to the completion of diabetes education. This study, thus, aimed to analyze the factors related to the completion of diabetes education and investigate its barriers. METHODS: Of 50,405 respondents to the fourth and fifth Korea National Health and Nutrition Examination Survey, a total of 3,820 were selected for the analysis, excluding those aged 29 or younger and those with missing values. The completion of diabetes education was set as a dependent variable and an analysis was made on the factors that affect the dependent variable. A multivariable logistic regression was employed for the analysis. RESULTS: Lower educational level was associated with less diabetes education, and the degree of diabetes education was lower in the group with male, the group that didn't have a family history or was not aware of a family history, the group that was not currently aware of diabetes and the group without a spouse. There was no difference in the completion of diabetes education by underlying diseases, family income level, age, residing area, economic activity status, insurance coverage, smoking, and drinking. CONCLUSION: Diabetes education is of importance for the treatment and management of diabetes. Currently, however, diabetes education is not sufficiently carried out in Korea. The completion rate of diabetes education was low in male, patients without or not knowing a family history, patients who were not currently aware of their diabetes, patients without a spouse, and patients with low educational level. Therefore, encouraging these patients to take the education will be a more effective approach to increase the completion rate of diabetes education.

Different Responses of Aripiprazole Combination Treatment in Antipsychotics-Induced Hyperprolactinemia: 2 Cases / 대한정신약물학회지

Hyperprolactinemia is a well-known neuroendocrine side effect to antipsychotic agent. Combined treatment of aripiprazole is recognized as an effective solution against hyperprolactinemia caused by antipsychotic agent. We report 2 progressive clinical cases where both are treated with combined use of aripiprazole which has a unique mechanism of action to resolve olanzapine and amisulpride-induced hyperprolactinemia.

Ethanolic extract of dandelion (Taraxacum mongolicum) induces estrogenic activity in MCF-7 cells and immature rats / 中国天然药物

Plants of the genus Taraxacum, commonly known as dandelions, are used to treat breast cancer in traditional folk medicine. However, their use has mainly been based on empirical findings without sufficient scientific evidence. Therefore, we hypothesized that dandelions would behave as a Selective estrogen receptor modulator (SERM) and be effective as hormone replacement therapy (HRT) in the postmenopausal women. In the present study, in vitro assay systems, including cell proliferation assay, reporter gene assay, and RT-PCR to evaluate the mRNA expression of estrogen-related genes (pS2 and progesterone receptor, PR), were performed in human breast cancer cells. Dandelion ethanol extract (DEE) significantly increased cell proliferation and estrogen response element (ERE)-driven luciferase activity. DEE significantly induced the expression of estrogen related genes such as pS2 and PR, which was inhibited by tamoxifen at 1 μmol·L(-1). These results indicated that DEE could induce estrogenic activities mediated by a classical estrogen receptor pathway. In addition, immature rat uterotrophic assay was carried out to identify estrogenic activity of DEE in vivo. The lowest concentration of DEE slightly increased the uterine wet weight, but there was no significant effect with the highest concentration of DEE. The results demonstrate the potential estrogenic activities of DEE, providing scientific evidence supporting their use in traditional medicine.

Intranasal Oxytocin Lessens the Attentional Bias to Adult Negative Faces: A Double Blind within-Subject Experiment

OBJECTIVE: Oxytocin is a neuropeptide that is involved in social emotional processing. A leading hypothesis is that oxytocin facilitates positive prosocial behaviors; the peptide may also play a more general role in inhibiting withdrawal-related social behaviors. The present study examined these possibilities. METHODS: A double-blind, placebo controlled crossover design was used with 31 healthy women. Forty-five minutes following the administration of 40 IU of intranasal oxytocin or a placebo, the participants were presented with two dot probe tests with pairs of face stimuli depicting emotional and neutral faces in adults. RESULTS: Oxytocin specifically reduced the attention bias toward the location of the faces of adults showing negative emotions, particularly in the case of disgust. Oxytocin did not enhance the attentional bias toward adult happy faces. The effect of oxytocin toward adult negative emotion was correlated with the sensitivity of the drive in the behavioral motivational system. CONCLUSION: Oxytocin reduces attention to negative social emotions in adults, which supports oxytocin serves to inhibit withdrawal-related social behaviour.

Skin corrosion and irritation test of sunscreen nanoparticles using reconstructed 3D human skin model

OBJECTIVES: Effects of nanoparticles including zinc oxide nanoparticles, titanium oxide nanoparticles, and their mixtures on skin corrosion and irritation were investigated by using in vitro 3D human skin models (KeraSkin(TM)) and the results were compared to those of an in vivo animal test. METHODS: Skin models were incubated with nanoparticles for a definite time period and cell viability was measured by the 3-(4, 5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide method. Skin corrosion and irritation were identified by the decreased viability based on the pre-determined threshold. RESULTS: Cell viability after exposure to nanomaterial was not decreased to the pre-determined threshold level, which was 15% after 60 minutes exposure in corrosion test and 50% after 45 minutes exposure in the irritation test. IL-1alpha release and histopathological findings support the results of cell viability test. In vivo test using rabbits also showed non-corrosive and non-irritant results. CONCLUSIONS: The findings provide the evidence that zinc oxide nanoparticles, titanium oxide nanoparticles and their mixture are 'non corrosive' and 'non-irritant' to the human skin by a globally harmonized classification system. In vivo test using animals can be replaced by an alternative in vitro test.

Appropriate In Vitro Methods for Genotoxicity Testing of Silver Nanoparticles

OBJECTIVES: We investigated the genotoxic effects of 40-59 nm silver nanoparticles (Ag-NPs) by bacterial reverse mutation assay (Ames test), in vitro comet assay and micronucleus (MN) assay. In particular, we directly compared the effect of cytochalasin B (cytoB) and rat liver homogenate (S9 mix) in the formation of MN by Ag-NPs. METHODS: Before testing, we confirmed that Ag-NPs were completely dispersed in the experimental medium by sonication (three times in 1 minute) and filtration (0.2 microm pore size filter), and then we measured their size in a zeta potential analyzer. After that the genotoxicity were measured and especially, S9 mix and with and without cytoB were compared one another in MN assay. RESULTS: Ames test using Salmonella typhimurium TA98, TA100, TA1535 and TA1537 strains revealed that Ag-NPs with or without S9 mix did not display a mutagenic effect. The genotoxicity of Ag-NPs was also evaluated in a mammalian cell system using Chinese hamster ovary cells. The results revealed that Ag-NPs stimulated DNA breakage and MN formation with or without S9 mix in a dose-dependent manner (from 0.01 microg/mL to 10 microg/mL). In particular, MN induction was affected by cytoB. CONCLUSIONS: All of our findings, with the exception of the Ames test results, indicate that Ag-NPs show genotoxic effects in mammalian cell system. In addition, present study suggests the potential error due to use of cytoB in genotoxic test of nanoparticles.