Nanoparticles: Weighing the Pros and Cons from an Eco-genotoxicological Perspective

The exponential growth of nanotechnology and the industrial production have raised concerns over its impact on human and environmental health and safety (EHS). Although there has been substantial progress in the assessment of pristine nanoparticle toxicities, their EHS impacts require greater clarification. In this review, we discuss studies that have assessed nanoparticle eco-genotoxicity in different test systems and their fate in the environment as well as the considerable confounding factors that may complicate the results. We highlight key mechanisms of nanoparticle-mediated genotoxicity. Then we discuss the reliability of endpoint assays, such as the comet assay, the most favored assessment technique because of its versatility to measure low levels of DNA strand breakage, and the micronucleus assay, which is complementary to the former because of its greater ability to detect chromosomal DNA fragmentation. We also address the current recommendations on experimental design, including environmentally relevant concentrations and suitable exposure duration to avoid false-positive or -negative results. The genotoxicity of nanoparticles depends on their physicochemical features and the presence of co-pollutants. Thus, the effect of environmental processes (e.g., aggregation and agglomeration, adsorption, and transformation of nanoparticles) would account for when determining the actual genotoxicity relevant to environmental systems, and assay procedures must be standardized. Indeed, the engineered nanoparticles offer potential applications in different fields including biomedicine, environment, agriculture, and industry. Toxicological pathways and the potential risk factors related to genotoxic responses in biological organisms and environments need to be clarified before appropriate and sustainable applications of nanoparticles can be established.

Nanoparticles: Weighing the Pros and Cons from an Eco-genotoxicological Perspective

The exponential growth of nanotechnology and the industrial production have raised concerns over its impact on human and environmental health and safety (EHS). Although there has been substantial progress in the assessment of pristine nanoparticle toxicities, their EHS impacts require greater clarification. In this review, we discuss studies that have assessed nanoparticle eco-genotoxicity in different test systems and their fate in the environment as well as the considerable confounding factors that may complicate the results. We highlight key mechanisms of nanoparticle-mediated genotoxicity. Then we discuss the reliability of endpoint assays, such as the comet assay, the most favored assessment technique because of its versatility to measure low levels of DNA strand breakage, and the micronucleus assay, which is complementary to the former because of its greater ability to detect chromosomal DNA fragmentation. We also address the current recommendations on experimental design, including environmentally relevant concentrations and suitable exposure duration to avoid false-positive or -negative results. The genotoxicity of nanoparticles depends on their physicochemical features and the presence of co-pollutants. Thus, the effect of environmental processes (e.g., aggregation and agglomeration, adsorption, and transformation of nanoparticles) would account for when determining the actual genotoxicity relevant to environmental systems, and assay procedures must be standardized. Indeed, the engineered nanoparticles offer potential applications in different fields including biomedicine, environment, agriculture, and industry. Toxicological pathways and the potential risk factors related to genotoxic responses in biological organisms and environments need to be clarified before appropriate and sustainable applications of nanoparticles can be established.

Huge Ancient Hematoma in the Calf

No abstract available.

Differentiation of Human Dental Pulp Stem Cells into Dopaminergic Neuron-like Cells in Vitro

We investigated the potential of human dental pulp stem cells (hDPSCs) to differentiate into dopaminergic neurons in vitro as an autologous stem cell source for Parkinson's disease treatment. The hDPSCs were expanded in knockout-embryonic stem cell (KO-ES) medium containing leukemia inhibitory factor (LIF) on gelatin-coated plates for 3-4 days. Then, the medium was replaced with KO-ES medium without LIF to allow the formation of the neurosphere for 4 days. The neurosphere was transferred into ITS medium, containing ITS (human insulin-transferrin-sodium) and fibronectin, to select for Nestin-positive cells for 6-8 days. The cells were then cultured in N-2 medium containing basic fibroblast growth factor (FGF), FGF-8b, sonic hedgehog-N, and ascorbic acid on poly-l-ornithine/fibronectin-coated plates to expand the Nestin-positive cells for up to 2 weeks. Finally, the cells were transferred into N-2/ascorbic acid medium to allow for their differentiation into dopaminergic neurons for 10-15 days. The differentiation stages were confirmed by morphological, immunocytochemical, flow cytometric, real-time PCR, and ELISA analyses. The expressions of mesenchymal stem cell markers were observed at the early stages. The expressions of early neuronal markers were maintained throughout the differentiation stages. The mature neural markers showed increased expression from stage 3 onwards. The percentage of cells positive for tyrosine hydroxylase was 14.49%, and the amount was 0.526 ± 0.033 ng/mL at the last stage. hDPSCs can differentiate into dopaminergic neural cells under experimental cell differentiation conditions, showing potential as an autologous cell source for the treatment of Parkinson's disease.

Differentiation of Human Dental Pulp Stem Cells into Dopaminergic Neuron-like Cells in Vitro

We investigated the potential of human dental pulp stem cells (hDPSCs) to differentiate into dopaminergic neurons in vitro as an autologous stem cell source for Parkinson's disease treatment. The hDPSCs were expanded in knockout-embryonic stem cell (KO-ES) medium containing leukemia inhibitory factor (LIF) on gelatin-coated plates for 3-4 days. Then, the medium was replaced with KO-ES medium without LIF to allow the formation of the neurosphere for 4 days. The neurosphere was transferred into ITS medium, containing ITS (human insulin-transferrin-sodium) and fibronectin, to select for Nestin-positive cells for 6-8 days. The cells were then cultured in N-2 medium containing basic fibroblast growth factor (FGF), FGF-8b, sonic hedgehog-N, and ascorbic acid on poly-l-ornithine/fibronectin-coated plates to expand the Nestin-positive cells for up to 2 weeks. Finally, the cells were transferred into N-2/ascorbic acid medium to allow for their differentiation into dopaminergic neurons for 10-15 days. The differentiation stages were confirmed by morphological, immunocytochemical, flow cytometric, real-time PCR, and ELISA analyses. The expressions of mesenchymal stem cell markers were observed at the early stages. The expressions of early neuronal markers were maintained throughout the differentiation stages. The mature neural markers showed increased expression from stage 3 onwards. The percentage of cells positive for tyrosine hydroxylase was 14.49%, and the amount was 0.526 ± 0.033 ng/mL at the last stage. hDPSCs can differentiate into dopaminergic neural cells under experimental cell differentiation conditions, showing potential as an autologous cell source for the treatment of Parkinson's disease.

Application of Short Screening Tools for Post-Traumatic Stress Disorder in the Korean Elderly Population

OBJECTIVE: Post-traumatic stress disorder (PTSD) is often missed or incorrectly diagnosed in primary care settings. Although brief screening instruments may be useful in detecting PTSD, an adequate validation study has not been conducted with older adults. This study aimed to evaluate the reliability and validity of the Korean version of the primary care PTSD screen (PC-PTSD) and single-item PTSD screener (SIPS) in elderly veterans. METHODS: The PC-PTSD and SIPS assessments were translated into Korean, with a back-translation to the original language to verify accuracy. Vietnamese war veterans [separated into a PTSD group (n=41) and a non-PTSD group (n=99)] participated in several psychometric assessments, including the Korean versions of the PC-PTSD (PC-PTSD-K), SIPS (SIPS-K), a structured clinical interview from the Diagnostic and Statistical Manual of Mental Disorders-IV(SCID), and PTSD checklist(PCL). RESULTS: The PC-PTSD-K showed high internal consistency (Cronbach α=0.76), and the test-retest reliability of the PC-PTSD-K and SIPS-K were also high (r=0.97 and r=0.91, respectively). A total score of 3 from the PC-PTSD-K yielded the highest diagnostic efficiency, with sensitivity and specificity values of 0.90 and 0.86, respectively. The 'bothered a lot' response level from the SIPS-K showed the highest diagnostic efficiency, with sensitivity and specificity values of 0.85 and 0.89, respectively. CONCLUSION: Our findings suggest that both PC-PTSD-K and SIPS-K have good psychometric properties with high validity and reliability for detecting PTSD symptoms in elderly Korean veterans. However, further research will be necessary to increase our understanding of PTSD characteristics in diverse groups with different types of trauma.

Application of Mobile App and Paper Survey of PTSD Checklist in the Elderly Korean Veterans of the Vietnam War / 신경정신의학

OBJECTIVES: The posttraumatic stress disorder (PTSD) checklist (PCL) is currently the most popular self-report scale employed in screening PTSD. This study was conducted 1) to test the reliability and validity of PCL in veterans of the Vietnam War and 2) to compare the results when using a conventional paper survey and mobile app survey. METHODS: Participants included 186 Korean veterans of the Vietnam War. Mini Mental Status Examination, PTSD module of Structured Clinical Interview for DSM-IV (SCID), and Life Event Checklist were administered. PCL was administered in either written format or mobile app. Diagnostic validity of the PCL was compared using the PTSD module of SCID. Other psychometric properties of PCL were also calculated. RESULTS: PCL results using different methods, paper and mobile app, showed no significant difference in each item and total score. Cronbach's coefficient of PCL was 0.95, optimal cut-off 49.5, sensitivity 91.7%, and specificity 93.5%. CONCLUSION: PCL showed excellent internal reliability, sensitivity, specificity, and validity. There was no statistically significant difference between survey methods. These results suggest that PCL is a reliable self-report scale in veterans. In addition, PCL with mobile app can be helpful in screening PTSD.

Extraglandular Manifestations in Korean Patients with Primary Sjogren's Syndrome

OBJECTIVES: To investigate the clinical findings upon initial diagnosis and extraglandular manifestations in Korean patients with primary Sjogren's syndrome (pSS). METHODS: We collected clinical and laboratory data from 238 pSS patients enrolled at Seoul National University Hospital, Seoul National University Bundang Hospital and Seoul Medical Center from March 2011 to December 2014. All patients met the American-European Consensus Group criteria for pSS. RESULTS: Upon initial diagnosis, sicca symptoms (xerophthalmia or xerostomia) as the chief complaint were only observed in 129 (54.2%) pSS patients, while extraglandular manifestation was more common as the chief complaint in male patients or those with younger age (<40 years) than female or older patients (both p<0.05). Extraglandular manifestations were found in 178 (74.8%) patients, with musculoskeletal manifestations being most common (53.8%). Peripheral neuropathy in pSS patients was associated with Raynaud phenomenon and elevated serum total immunoglobulin G (IgG) levels (both p<0.05). Serum beta2-microglobulin (beta2-M) levels were significantly correlated with European League against Rheumatism (EULAR) Sjogren's syndrome disease activity index, erythrocyte sedimentation rate and serum total IgG (all p<0.001), and were higher in patients with extraglandular manifestations than those without (p<0.05). Serum C3 levels were decreased in patients with extraglandular manifestation, compared to those without (p<0.05). Malignant lymphoma was found in Korean pSS patients (1.7%) and associated with elevated serum beta2-M levels (p<0.0001). CONCLUSION: Extraglandular manifestations were common in pSS patients and may be a diagnostic tool for male or younger pSS patients. Serum beta2-M levels can be useful markers for monitoring pSS patients.

Human Urine-derived Stem Cells Seeded Surface Modified Composite Scaffold Grafts for Bladder Reconstruction in a Rat Model

We conducted this study to investigate the synergistic effect of human urine-derived stem cells (USCs) and surface modified composite scaffold for bladder reconstruction in a rat model. The composite scaffold (Polycaprolactone/Pluronic F127/3 wt% bladder submucosa matrix) was fabricated using an immersion precipitation method, and heparin was immobilized on the surface via covalent conjugation. Basic fibroblast growth factor (bFGF) was loaded onto the heparin-immobilized scaffold by a simple dipping method. In maximal bladder capacity and compliance analysis at 8 weeks post operation, the USCs-scaffold(heparin-bFGF) group showed significant functional improvement (2.34 ± 0.25 mL and 55.09 ± 11.81 microL/cm H2O) compared to the other groups (2.60 ± 0.23 mL and 56.14 ± 9.00 microL/cm H2O for the control group, 1.46 ± 0.18 mL and 34.27 ± 4.42 microL/cm H2O for the partial cystectomy group, 1.76 ± 0.22 mL and 35.62 ± 6.69 microL/cm H2O for the scaffold group, and 1.92 ± 0.29 mL and 40.74 ± 7.88 microL/cm H2O for the scaffold(heparin-bFGF) group, respectively). In histological and immunohistochemical analysis, the USC-scaffold(heparin-bFGF) group showed pronounced, well-differentiated, and organized smooth muscle bundle formation, a multi-layered and pan-cytokeratin-positive urothelium, and high condensation of submucosal area. The USCs seeded scaffold(heparin-bFGF) exhibits significantly increased bladder capacity, compliance, regeneration of smooth muscle tissue, multi-layered urothelium, and condensed submucosa layers at the in vivo study.

Simplified V-Shape Incision Technique for Saving Hair Follicles

BACKGROUND: The scalp is the second most visible part of the anatomy next to the face. Thus, aesthetic considerations such as scars and alopecia are important when planning excision of a mass from the scalp. Aesthetic results have not been satisfactory due to scar widening and hair follicle injury. Many methods have been tried to improve these results, however, they require multiple procedures and longer operation time. METHODS: We evaluated a easy and time-saving V-shape incision for excising a scalp mass. This technique of simplified V-shape incision was performed in 32 patients with benign scalp masses treated from September 2011 to March 2013. The incisions were performed with a blade to make a V-shape margin and preserve deep hair follicles at the flap margins. The defect was closed by approximation of two edges. RESULTS: All tumors were benign and superficial. The size of the scalp masses was 0.4-2.0 cm in width and 1.0-5.0 cm in length. Many hairs from the deep hair follicles grew into the scar, making the scar line almost unnoticeable in all 32 patients. Although some scar widening was evident, the number of hairs per unit was high enough to camouflage the scars. CONCLUSIONS: The simplified V-shape incision was beneficial as a simple, mini-surgical, time-saving procedure. Although the scars were slightly wider, they were covered with penetrating hairs and became unnoticeable.

Immediate Debridement and Reconstruction with a Pectoralis Major Muscle Flap for Poststernotomy Mediastinitis

BACKGROUND: Poststernotomy mediastinitis is a rare, but life-threatening complication, thus early diagnosis and proper management is essential for poststernotomy mediastinitis. The main treatment for mediastinitis is aggressive debridement. Several options exist for reconstruction of defects after debridement. The efficacy of immediate debridement and reconstruction with a pectoralis major muscle flap designed for the defect immediately after the diagnosis of poststernotomy mediastinitis is demonstrated. METHODS: Between September 2009 and June 2011, 6 patients were referred to the Department of Plastic and Reconstructive Surgery and the Department of Thoracic and Cardiovascular Surgery of Ajou University Hospital for poststernotomy mediastinitis. All of the patients underwent extensive debridement and reconstruction with pectoralis major muscle flaps, advanced based on the pedicle of the thoracoacromial artery as soon as possible following diagnosis. A retrospective review of the 6 cases was performed to evaluate infection control, postoperative morbidity, and mortality. RESULTS: All patients had complete wound closures and reduced severity of infections based on the erythrocyte sedimentation rate and C-reactive protein levels and a reduction in poststernal fluid collection on computed tomography an average of 6 days postoperatively. A lack of growth of organisms in the wound culture was demonstrated after 3 weeks. There were no major wound morbidities, such as hematomas, but one minor complication required a skin graft caused by skin flap necrosis. No patient expired after definitive surgery. CONCLUSIONS: Immediate debridement and reconstruction using a pectoralis major muscle flap is a safe technique for managing infections associated with poststernotomy mediastinitis, and is associated with minimal morbidity and mortality.