Perspectives on trace chemical safety and chemophobia: risk communication and risk management.

Safety issues regarding consumer products contaminated with trace amounts of chemicals are of great concern to consumers, with the degree of concern occasionally escalating to the psychological syndrome, chemophobia (i.e., the fear of chemicals). Hazardous substances frequently implicated in safety concerns include heavy metals (arsenic, mercury, cadmium, and lead), volatile organic compounds (VOC) such as benzene and o-toluidine, pesticides, carcinogens, radioactive substances, and endocrine disrupting chemicals (EDC) such as bisphenol A and phthalates. To improve communication of risk to society, members of academia, government, consumer organizations, and industry participated in this workshop to discuss and exchange perspectives on trace chemical safety. From the perspective of academia, integrated risk assessments need to be implemented to encompass various exposure sources and routes. The identification and investigation of new exposure-related biomarkers are also recommended to verify direct causal relationships between specific chemical exposure and effects on human health. As for regulation, governments need to establish and maintain acceptable limits for trace chemicals in products. In addition, harmonized efforts need to be undertaken among government agencies to share regulatory limits and effectively control trace chemicals in consumer products. Manufacturers need to faithfully abide by Good Manufacturing Practice (GMP) guidelines, monitor sources of contamination, and minimize these for consumer safety. To effectively resolve safety issues arising from trace chemicals exposure, collaborative efforts are needed involving academia, government, consumer organizations, and industry. Further, scientific evidence-based risk assessment is a critical approach to effectively manage trace chemical safety issues.

Perspectives on trace chemical safety and chemophobia: risk communication and risk management.

Safety issues regarding consumer products contaminated with trace amounts of chemicals are of great concern to consumers, with the degree of concern occasionally escalating to the psychological syndrome, chemophobia, i.e., the fear of chemicals. Hazardous substances frequently implicated in safety concerns include heavy metals (arsenic, mercury, cadmium, and lead), volatile organic compounds (VOC) such as benzene and o-toluidine, pesticides, carcinogens, radioactive substances, and endocrine disrupting chemicals (EDC) such as bisphenol A and phthalates. To improve communication of risk to society, members of academia, government, consumer organizations, and industry participated in this workshop to discuss and exchange perspectives on trace chemical safety. From the perspective of academia, integrated risk assessments need to be implemented to encompass various exposure sources and routes. The identification and investigation of new exposure-related biomarkers are also recommended to verify direct causal relationships between specific chemical exposure and effects on human health. As for regulation, governments need to establish and maintain acceptable limits for trace chemicals in products. In addition, harmonized efforts need to be undertaken among government agencies to share regulatory limits and effectively control trace chemicals in consumer products. Manufacturers need to faithfully abide by Good Manufacturing Practice (GMP) guidelines, monitor sources of contamination, and minimize these for consumer safety. To effectively resolve safety issues arising from trace chemicals exposure, collaborative efforts are needed involving academia, government, consumer organizations, and industry. Further, scientific evidence-based risk assessment is a critical approach to effectively manage trace chemical safety issues.

Risk assessment of volatile organic compounds (VOCs) detected in sanitary pads.

Disposable sanitary pads are a necessity for women's health, but safety concerns regarding the use of these products have created anxiety. The aim of this study was to conduct a risk assessment of 74 volatile organic compounds (VOCs), which were expected to be contained within sanitary pads. Of the 74 VOCs, 50 were found in sanitary pads retailed in Korea at concentrations ranging from 0.025 to 3548.09 µg/pad. In order to undertake a risk assessment of the VOCs, the toxicological database of these compounds in the United States Environmental Protection Agency (USEPA), Agency for Toxic Substances and Disease Registry (ATSDR), National Toxicology Program (NTP) and World Health Organization (WHO) was searched. Ethanol was found to exhibit the highest reference dose (RfD) while 1,2-dibromo-3-chloro-propane displayed the lowest RfD. Consequently, a worst-case exposure scenario was applied in this study. It was assumed that there was the use of 7.5 sanitary napkins/day for 7 days/month. In the case of panty liners or overnight sanitary napkins, the utilization of 90 panty liners/month or 21 overnight sanitary napkins/month was assumed, respectively. In addition, 43 kg, the body weight of 12 to 13-year-old young women, and 100% VOCs skin absorption were employed for risk assessment. The systemic exposure dose (SED) values were calculated ranging from 1.74 (1,1,2-trichloroethane) ng/kg/day to 144.4 (ethanol, absolute) µg/kg/day. Uncertainty factors (UFs) were applied ranging from 10 to 100,000 in accordance with the robustness of animal or human experiments. The margin of exposure (MOE) of 34 VOCs was more than 1 (acceptable MOE > 1). Applicable carcinogenic references reported that the cancer risk of five VOCs was below 10-6. Based on our findings, evidence indicates that the non-cancer and cancer risks associated with VOCs detected in sanitary pads currently used in South Korea do not pose an adverse health risk in women.

Miniplate with a bendable C-tube head allows the clinician to alter biomechanical advantage without physically moving the skeletal anchorage device.

BACKGROUNDS: This article introduces a binary function of a miniplate with a bendable C-tube head used in corticotomy-assisted segment intrusion. The advantage of the device is that the point of force application can be altered without having to move the miniplate or place an additional anchorage device. METHODS: Cases for this study were selected from patients who received perisegmental corticotomy with compression osteogenesis (Speedy Surgical Orthodontics) for segmental intrusion. For the skeletal anchorage on patients who received Speedy Surgical Orthodontics for posterior segment intrusion to improve on severe open bite correction, the C-tube was placed on the buccal wall of the maxilla for traction of orthopedic force as a temporary skeletal anchorage. The C-tube head portion is made with titanium grade II, which makes bending easy with a Weingart plier. This adjustment regains distance and range needed to continue intrusion of posterior segment. RESULTS: As an alternative to orthognathic surgery to correct a severe open bite, perisegmental corticotomy combined with orthopedic force application from a temporary skeletal anchorage device can be used. The corticotomy-assisted segment intrusion is a 2-stage procedure: first, the corticotomy is performed in the palate and 2 weeks later in the buccal alveolus. A C-plate was placed in the midpalatal area, and a C-tube was placed apical to the buccal corticotomy site. Elastics were used with orthopedic forces to induce compression osteogenesis. As the intrusion took place, the elastic stretched, and resultant force and range in the buccal segment decreased. The C-tube head was adjusted by bending to gain more distance, reviving the elastic force on the posterior segment until desired intrusion was accomplished. CONCLUSIONS: The miniplate with a bendable C-tube head serves for temporary skeletal anchorage of orthopedic traction force to achieve segmental intrusion and has the advantage that the bendable head can be adjusted to improve the force application for intrusion without having to move or place another temporary skeletal anchorage device.

Neuroprotective and immunomodulatory effects of superoxide dismutase on SH-SY5Y neuroblastoma cells and RAW264.7 macrophages.

Superoxide dismutase (SOD) is an antioxidant enzyme that protects the body from free radicals. It has both antioxidant and immunomodulatory properties, inducing macrophage polarization from M1 to M2. Macrophages, key mediators of the innate immune response, are divided into the M1 (pro-inflammatory) and M2 (anti-inflammatory) subtypes. In this study, we aimed to assess the antioxidant and neuroprotective effects of SOD on nerve cells and its immunomodulatory effects on macrophages. We observed that SOD inhibited the accumulation of reactive oxygen species and enhanced the viability of H2O2-treated nerve cells. Furthermore, SOD reduced the degree of necrosis in nerve cells treated with the conditioned medium from macrophages, which induced inflammation. In addition, SOD promoted the M1 to M2 transition of macrophages. Our findings suggest that SOD protects nerve cells and regulates immune responses.

Chin plate with a detachable C-tube head serves for both osteotomy fixation and orthodontic anchorage.

BACKGROUNDS: This article reports the dual function of a double-Y miniplate with a detachable C-tube head (C-chin plate; Jin Biomed Co., Bucheon, Korea) used to fixate an anterior segmental osteotomy and provide skeletal anchorage during orthodontic tooth movement. METHODS: Cases were selected for this study from patients who underwent anterior segmental osteotomy under local anesthesia. A detachable C-tube head portion was combined with a double-Y chin plate. The double-Y chin plates were fixated between the osteotomy segments and the mandibular base with screws in a conventional way. The C-tube head portion exited the tissue near the mucogingival junction. RESULTS: Biocreative Chin Plates were placed on the anterior segmental osteotomy sites. The device allowed 3 points of fixation: 1, minor postosteotomy vertical adjustment of the segment during healing; 2, minor shift of the midline during healing; and 3, to serve as temporary skeletal anchorage device during the post-anterior segmental osteotomy orthodontic treatment. When tooth movement goals are accomplished, the C-tube head of the chin plate can be easily detached from the fixation miniplate by twisting the head using a Weingart plier under local anesthesia. This dual-purpose device spares the patient from the need for 2 separate installations for stabilization of osteotomy segments. CONCLUSIONS: The dual-purpose double-Y miniplate combined with a C-tube head (Biocreative Chin Plate) provided versatile application of 3 points of post-osteotomy fixation and of temporary skeletal anchorage for orthodontic tooth movement.

Amelioration of DSS-induced colitis in mice by TNF-α-stimulated mesenchymal stem cells derived from feline adipose tissue via COX-2/PGE2 activation.

BACKGROUND: Mesenchymal stem cells (MSCs) have been investigated as therapeutic agents for inflammatory bowel disease (IBD). Stimulation of MSCs with pro-inflammatory cytokines is an approach to enhance their immunomodulatory effects. However, further investigation is required to support their application in immune-mediated disorders and companion animals. OBJECTIVES: This study aimed to assess the therapeutic effect of tumor necrosis factor (TNF)-α-stimulated feline adipose tissue-derived MSCs (fAT-MSCs) in a dextran sulfate sodium (DSS)-induced colitis mouse model. METHODS: Colitis mice was made by drinking water with 3% DSS and fAT-MSCs were injected intraperitoneally. Colons were collected on day 10. The severity of the disease was evaluated and compared. Raw 264.7 cells were cultured with the conditioned medium to determine the mechanism, using quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. RESULTS: TNF-α-stimulated fAT-MSCs more improved severity of DSS-induced colitis in disease activity, colon length, histologic score, and inflammatory cytokine. In sectionized colon tissues, the group comprising TNF-α-stimulated fAT-MSCs had higher proportion of CD11b+CD206+ macrophages than in the other groups. In vitro, TNF-α-stimulation increased cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) secretion from fAT-MSCs. The conditioned medium from TNF-α-stimulated fAT-MSCs enhanced the expression of interleukin-10 and arginase-1 in LPS-activated Raw 264.7 cells. CONCLUSIONS: These results represent that TNF-α-stimulated fat-mscs ameliorate the inflamed colon more effectively. Furthermore, we demonstrated that the effectiveness was interlinked with the COX-2/PGE2 pathway.

A case of metastatic leptomeningeal carcinomatosis from early gastric carcinoma.

Metastatic leptomeningeal carcinomatosis is estimated to occur in 3% to 8% of solid carcinomas. The most common causes of leptomeningeal carcinomatosis are breast cancer, lung cancer and malignant melanoma. Leptomeningeal carcinomatosis associated with gastric cancer, especially in its early stages, is exceedingly rare. Its presenting symptoms include headache, nausea and seizures. In this report, we describe a case of leptomeningeal metastasis that presented with early-stage gastric cancer. A 67-year-old woman with a history of early-stage gastric cancer in remission was admitted to our hospital with 3 days of headache and nausea. Her gastric cancer had been treated 29 months prior to presentation by a radical subtotal gastrectomy with a Billroth I anastomosis. She had an uneventful recovery until she was diagnosed with metastases to the left axilla and neck 26 months after surgery. Her presenting symptoms of headache and nausea prompted cytologic examination of the cerebrospinal fluid and measurement of tumor markers, which revealed metastatic leptomeningeal carcinomatosis from her gastric cancer. This report aims to raise awareness of the possibility that even early-stage gastric cancer can lead to leptomeningeal carcinomatosis.

FHL tendon transfer in diabetics for treatment of non-healing plantar heel ulcers.

BACKGROUND: In diabetics, although heel ulcers occurring after Achilles tendon lengthening for managing forefoot ulcers are rare, they are a very troublesome complication. The purpose of this study was to evaluate the results of FHL tendon transfer for management of a plantar heel ulcer as a sequelae of insufficiency of the Achilles tendon in diabetic patients. MATERIALS AND METHODS: Nine diabetic patients who underwent FHL tendon transfer for treatment of non-healing plantar heel ulcers due to insufficiency of the Achilles tendon for management of forefoot ulcers were treated between October 2005 and April 2007. All of the patients had undergone Achilles tendon lengthening with Hoke's triple hemisection method. The mean age was 55.9 +/- 9.7 years old. The average duration of a plantar heel ulcer was 11.9 +/- 3.8 months. The mean period of followup was 23.9 +/- 8.0 months. Between the occurrence of a heel ulcer and the FHL transfer, five of the patients underwent more than one attempt at direct Achilles tendon repair. The mean size of the wound was 1.2 +/- 0.6 cm2. We assessed the healing time of the heel plantar ulcers and recurrence rates during followup periods. The complication rate and walking ability was also evaluated. RESULTS: All of the plantar heel ulcers healed within 8 weeks after the operation and had not recurred as of the last followup. Two patients had recurrences of previous forefoot ulcers. One patient had a local infection in the FHL tendon transfer area. All of patients could walk without a brace or walking aid device after surgery. CONCLUSION: We believe that Achilles tendon reconstruction using an FHL transfer for non-healing plantar heel ulcers resulting from a triple Hoke lengthening of the Achilles tendon is a good treatment option for diabetic patients.

Molecular epidemiology of community-associated antimicrobial-resistant Staphylococcus aureus in Seoul, Korea (2003): pervasiveness of multidrug-resistant SCCmec type II methicillin-resistant S. aureus.

There is an extremely high incidence of antimicrobial resistance of the clinical isolates of Staphylococcus aureus in Korea. This study carried out a molecular investigation to determine the prevalence of the community-associated antimicrobial-resistant S. aureus and methicillin-resistant S. aureus (MRSA). The percentage resistance from the nasal swabs of healthy volunteers in 2003 in Seoul is as follows: penicillin (91%), erythromycin (EM, 14%), gentamicin (GM, 9.3%), tetracycline (TE, 8.2%), cephalothin (4%), oxacillin (OX, MRSA; 3.8%), clindamycin (CC, 2.6%), ciprofloxacin (CIP, 0.8%), and sulfamethoxazole/trimethoprim (0.6%). The community-associated MRSA (C-MRSA) strains were examined by pulsed-field gel electrophoresis (PFGE) analysis of the SmaI macro-fragments, multilocus sequence typing (MLST), and staphylococcal cassette chromosome mec (SCCmec) typing using the PCR analysis. The Korean C-MRSA isolates were clustered into three distinct groups. One PFGE group containing the C-MRSA strains showed resistance to CC, EM, and GM, a high level (32-96 microg/ml) of resistance to methicillin, sequence type 5 (ST5), and SCCmec type II, which is the most common hospital associated-MRSA (H-MRSA) isolated in Korea. These results highlight the heterogeneous genetic background of the C-MRSA as well as the pervasiveness of the H-MRSA isolates in this community.

Displacement pattern of the anterior segment using antero-posterior lingual retractor combined with a palatal plate.

OBJECTIVE: To evaluate and compare the effects of two appliances on the en masse retraction of the anterior teeth anchored by temporary skeletal anchorage devices (TSADs). METHODS: The sample comprised 46 nongrowing hyperdivergent adult patients who planned to undergo upper first premolar extraction using lingual retractors. They were divided into three groups, based on the lingual appliance used: the C-lingual retractor (CLR) group (group 1, n = 16) and two antero-posterior lingual retractor (APLR) groups (n = 30, groups 2 and 3). The APLR group was divided by the posterior tube angulation; posterior tube parallel to the occlusal plane (group 2, n = 15) and distally tipped tube (group 3, n = 15). A retrospective clinical investigation of the skeletal, dental, and soft tissue relationships was performed using lateral cephalometric radiographs obtained pretreatment and post en masse retraction of the anterior teeth. RESULTS: All groups achieved significant incisor and canine retraction. The upper posterior teeth did not drift significantly during the retraction period. The APLR group had less angulation change in the anterior dentition, compared to the CLR group. By changing the tube angulation in the APLR, the intrusive force significantly increased in the distally tipped tube of group 3 patients and remarkably reduced the occlusal plane angle. CONCLUSIONS: Compared to the CLR, the APLR provides better anterior torque control and canine tipping while achieving bodily translation. Furthermore, changing the tube angulation will affect the amount of incisor intrusion, even in patients with similar palatal vault depth, without the need for additional TSADs.

Nanoscale bonding between human bone and titanium surfaces: osseohybridization.

Until now, the chemical bonding between titanium and bone has been examined only through a few mechanical detachment tests. Therefore, in this study, a sandblasted and acid-etched titanium mini-implant was removed from a human patient after 2 months of placement in order to identify the chemical integration mechanism for nanoscale osseointegration of titanium implants. To prepare a transmission electron microscopy (TEM) specimen, the natural state was preserved as much as possible by cryofixation and scanning electron microscope/focused ion beam (SEM-FIB) milling without any chemical treatment. High-resolution TEM (HRTEM), energy dispersive X-ray spectroscopy (EDS), and scanning TEM (STEM)/electron energy loss spectroscopic analysis (EELS) were used to investigate the chemical composition and structure at the interface between the titanium and bone tissue. HRTEM and EDS data showed evidence of crystalline hydroxyapatite and intermixing of bone with the oxide layer of the implant. The STEM/EELS experiment provided particularly interesting results: carbon existed in polysaccharides, calcium and phosphorus existed as tricalcium phosphate (TCP), and titanium existed as oxidized titanium. In addition, the oxygen energy loss near edge structures (ELNESs) showed a possibility of the presence of CaTiO3. These STEM/EELS results can be explained by structures either with or without a chemical reaction layer. The possible existence of the osseohybridization area and the form of the carbon suggest that reconsideration of the standard definition of osseointegration is necessary.

En-masse retraction with a preformed nickel-titanium and stainless steel archwire assembly and temporary skeletal anchorage devices without posterior bonding.

OBJECTIVE: To evaluate the therapeutic effects of a preformed assembly of nickel-titanium (NiTi) and stainless steel (SS) archwires (preformed C-wire) combined with temporary skeletal anchorage devices (TSADs) as the sole source of anchorage and to compare these effects with those of a SS version of C-wire (conventional C-wire) for en-masse retraction. METHODS: Thirty-one adult female patients with skeletal Class I or II dentoalveolar protrusion, mild-to-moderate anterior crowding (3.0-6.0 mm), and stable Class I posterior occlusion were divided into conventional (n = 15) and preformed (n = 16) C-wire groups. All subjects underwent first premolar extractions and en-masse retraction with pre-adjusted edgewise anterior brackets, the assigned C-wire, and maxillary C-tubes or C-implants; bonded mesh-tube appliances were used in the mandibular dentition. Differences in pretreatment and post-retraction measurements of skeletal, dental, and soft-tissue cephalometric variables were statistically analyzed. RESULTS: Both groups showed full retraction of the maxillary anterior teeth by controlled tipping and space closure without altered posterior occlusion. However, the preformed C-wire group had a shorter retraction period (by 3.2 months). Furthermore, the maxillary molars in this group showed no significant mesialization, mesial tipping, or extrusion; some mesialization and mesial tipping occurred in the conventional C-wire group. CONCLUSIONS: Preformed C-wires combined with maxillary TSADs enable simultaneous leveling and space closure from the beginning of the treatment without maxillary posterior bonding. This allows for faster treatment of dentoalveolar protrusion without unwanted side effects, when compared with conventional C-wire, evidencing its clinical expediency.

Lateral and cross-lateral focusing of spherical particles in a square microchannel.

The inertial migration of particles in micro-scale flows has received much attention due to its promising applications, such as the membrane-free passive separation of particles or cells. The particles suspended in rectangular channels are known to be focused near the center of each channel face as the channel Reynolds number (R(C)) increases due to the lift force balance and the hydrodynamic interactions of the particles with the wall. In this study, the three-dimensional positions of neutrally buoyant spherical particles inside a square microchannel are measured using the digital holographic microscopy technique, and a transition from the lateral tubular pinch to the cross-lateral focusing with increasing R(C) is reported. The particles are found to migrate first in the lateral direction and then cross-laterally toward the four equilibrium positions. A general criterion that can be used to secure the fully developed state of particle focusing in Lab-on-a-Chip applications is also derived. This criterion could be helpful for the accurate estimation of the design parameters of inertial microfluidic devices, such as R(C), channel length and width, and particle diameter.

Carbon and nitrogen storage in an age-sequence of Pinus densiflora stands in Korea.

The carbon (C) and nitrogen (N) storage capabilities of Pinus densiflora in six different stand ages (10, 27, 30, 32, 44, and 71 years old) were investigated in Korea. Thirty sample trees were destructively harvested and 12 were excavated. Samples from the above and belowground tree components, coarse woody debris (CWD), forest floor, and mineral soil (0-30 cm) were collected. Tree biomass was highest in the 71-year-old stand (202.8 t ha(-1)) and lowest in the 10-year-old stand (18.4 t ha(-1)). C and N storage in the mineral soil was higher in the 71-year-old stand than in the other stands, mainly due to higher soil C and N concentrations. Consequently, the total ecosystem C and N storage (tree+forest floor+CWD+soil) was positively correlated with stand age: increasing from a minimum in the 10 year old stand (18.8 t C ha(-1) and 1.3 t N ha(-1)) to a maximum in the 71-year-old stand (201.4 t C ha(-1) and 8.5 t N ha(-1)). The total ecosystem C storage showed a similar sigmoidal pattern to that of tree C storage as a function of the age-sequence, while N storage in the CWD, forest floor and mineral soil showed no significant temporal trends. Our results provide important insights that will increase our understanding of C and N storage in P. densiflora stands and our ability to predict changes according to stand age in the region.

Saucernetin-8 isolated from Saururus chinensis induced the differentiation of human acute promyelocytic leukemia HL-60 cells.

The present work was performed to investigate the effects of saucernetin-8 on proliferation and differentiation of human leukemia HL-60 cells as well as the underlying mechanisms for these effects. Saucernetin-8 exhibited a potent antiproliferative activity against HL-60 cells. This compound was also found to be a potent inducer of differentiation in human leukemia derived HL-60 cells through the examination of differentiation markers, as assessed by nitroblue tetrazolium reduction test, esterase activity assay, phagocytic activity assay, morphology change, and expression of CD14 and CD66b surface antigens. These results suggest that saucernetin-8 induces the differentiation of human leukemia cells to granulocytes and monocytes/macrophages lineage. Moreover, DNA flow-cytometry indicated that saucernetin-8 induced a G1 phase arrest of HL-60 cells. The protein and mRNA expression levels of p21 were up-regulated during saucernetin-8-dependent HL-60 cell differentiation, whereas the level of c-myc was down-regulated. Taken together, our results suggest that saucernetin-8 may have potential as a therapeutic agent in human leukemia.