Fabrication of a label-free electrochemical cell-based biosensor for toxicity assessment of thiram.

Thiram has been widely used in agriculture and may invades the food chain, posing a threat to human health. In this research, a label-free electrochemical cell-based biosensor was presented for in vitro toxicity assessment of thiram. HepG2 cells were cultured on poly-l-lysine@gold nano-flowers functionalized indium tin oxide coated glass electrode (PLL@AuNFs/ITO) to serve as biorecognition elements. AuNFs were electrodeposited on ITO to provide an enlarged specific surface area and benefited the output signal amplification. PLL was selected as an effective biocompatible coating material to facilitate cell adhesion and proliferation, thereby realizing one-step recording of electrochemical signals from thiram-treated cells. With the aid of the differential pulse voltammetry method, the fabricated biosensor was applied to assess the cytotoxicity of thiram. Results showed that the cytotoxicity measured by the fabricated biosensor exhibited a linear relationship related to thiram concentration ranging from 5 to 50 µM with a detection limit of 2.23 µM. The IC50 of thiram obtained by the biosensor was 29.5 µM, which was close to that of conventional MTT assay (30.8 µM). The effects of thiram on HepG2 cells were also investigated via SEM and flow cytometry. Meanwhile, the proposed biosensor was used to evaluate the toxicity of thiram in fruit samples. Results indicated that the toxicity of thiram cannot be ignored even at a low residual concentration in food (≤5 mg/kg). In conclusion, the developed sensor showed excellent sensitivity, stability, and reliability, which provided a great capacity for the convenient toxicity evaluation of thiram residue in food.

Microdroplet-captured tapes for rapid sampling and SERS detection of food contaminants.

Simple, effective, and rapid detection of chemically relevant hazards is a highly desirable research goal, which can provide early-warning information to improve the patient-care outcomes for public health. Here, we introduce a microdroplet-captured tape toward rapid SERS screening of food contaminants. The dominant sensing unit lies on functionalized microwell in conductive carbon tapes, which is simply prepared by physical punching, magnetron sputtering and electrochemical deposition of Au nanodendrites. The tape-based sensors not only possess highly branched Au nanodendrites in microwell for promoting SERS activity, but also enable anchoring the microdroplets via direct dip-pulling from pristine analytes solutions upon sticky incorporated on a glove. Early-warning SERS detection of food contaminants including Sudan-1, thiram, and thiabendazole from the real samples can be achieved by such simple sampling method. These tape-based sensors with a facile operation module and accessible signal read-out represent an innovative point-of-care testing (POCT) device for forensic, military, consumer protection, environmental monitoring, and food safety applications.

Allergic contact dermatitis caused by synthetic rubber gloves in healthcare workers: Sensitization to 1,3-diphenylguanidine is common.

BACKGROUND: The frequency of allergic contact dermatitis has significantly increased in healthcare workers since the transition from latex to synthetic rubber gloves, with 1,3-diphenylguanidine being identified as the most frequently implicated allergen. OBJECTIVES: To highlight the role of 1,3-diphenylguanidine as the culprit allergen in contact allergies to synthetic rubber gloves, to propose recommendations for patch testing, and to discuss alternatives for sensitized subjects. MATERIALS AND METHODS: Patch test data from healthcare workers who developed hand dermatitis after wearing rubber gloves and who reacted positively to glove samples and rubber additives were collected from September 2010 to December 2017 in a Belgian hospital. RESULTS: A total of 44 caregivers were included in this study. Patch tests showed that: (a) 84% of the study population reacted positively to carba mix; (b) 86% reacted positively to 1,3-diphenylguanidine; and (c) 13 (30%) reacted positively to thiuram mix. Half of the subjects reacted positively to gloves containing 1,3-diphenylguanidine, whereas none reacted to accelerator-free gloves. CONCLUSION: The most commonly identified allergen was 1,3-diphenylguanidine, far ahead of thiurams, which were previously described as the most sensitizing accelerators. The use of 1,3-diphenylguanidine-free gloves is recommended. No subject reacted to gloves without accelerators, thus confirming their efficiency among accelerator-sensitized patients. We recommend that 1,3-diphenylguanidine be added to the European baseline series.

Rubber Accelerators in Medical Examination and Surgical Gloves.

BACKGROUND: Rubber accelerators play a significant role in glove-related occupational contact dermatitis, especially among health care workers. Currently, there is limited information readily available outlining the accelerators used in specific medical examination and surgical gloves. OBJECTIVE: The aim of this study was to ascertain the accelerators used in medical examination and surgical gloves for major glove manufacturers within the United States. METHODS: An initial Internet-based search was performed to establish relevant manufacturers and product lines, with subsequent inquiry with each corresponding company regarding accelerators used in each medical and surgical glove line. RESULTS: Eleven glove manufacturers were identified and contacted. Responses were obtained from all manufacturers, but because of legal limitations, changes in product lines, or inability to supply necessary data, only 8 companies were able to be included in the final analysis, totaling data for 190 gloves. Carbamates were the most common accelerator, used in 90.5% (172/190) of gloves, whereas thiurams were used in only 11 gloves (5.8%). Eight companies surveyed are now advertising and offering touted accelerator-free gloves. CONCLUSIONS: Accelerators are used in most examination and surgical gloves; however, manufacturers are now expanding their product offerings to include accelerator-free options.

Accelerator-free gloves as alternatives in cases of glove allergy in healthcare workers.

BACKGROUND: Accelerators in rubber gloves constitute an important group of contact allergens, particularly in healthcare workers. OBJECTIVES: To assess the efficacy of accelerator-free medical gloves in the secondary prevention of allergic contact dermatitis caused by rubber accelerators in healthcare workers. METHODS: Nine healthcare workers with hand eczema were advised to use accelerator-free rubber gloves after a diagnosis of allergic contact dermatitis caused by rubber accelerators. RESULTS: Switching from conventional medical single-use gloves containing accelerators to accelerator-free medical gloves led to improvement in all cases, and more than two-thirds of the patients were completely free of symptoms. CONCLUSION: The use of accelerator-free medical gloves can be an effective alternative in healthcare workers who are allergic to rubber accelerators.

Occupational skin disease among Australian healthcare workers: a retrospective analysis from an occupational dermatology clinic, 1993-2014.

BACKGROUND: Healthcare workers (HCWs) are at risk of developing occupational skin disease (OSD). OBJECTIVES: To ascertain the causes of OSD in Australian HCWs in a tertiary referral clinic. METHODS: A retrospective review was performed of patients assessed at the Occupational Dermatology Clinic in Melbourne from 1993 to 2014. RESULTS: Of 685 HCWs assessed in the clinic over a period of 22 years, 555 (81.0%) were diagnosed with OSD. The most common diagnosis was irritant contact dermatitis (ICD) (79.1%), followed by allergic contact dermatitis (ACD) (49.7%). Natural rubber latex allergy was also relatively frequent (13.0%). The major substances causing ACD were rubber glove chemicals (thiuram mix and tetraethylthiuram disulfide), preservatives (formaldehyde, formaldehyde releasers, and isothiazolinones), excipients in hand cleansers, which are hard-to-avoid weak allergens, and antiseptics. ACD caused by commercial hand cleansers occurred more frequently than ACD caused by alcohol-based hand rubs (ABHRs). Occupational ICD was mostly caused by water/wet work and hand cleansers, and environmental irritants such as heat and sweating. CONCLUSIONS: Understanding the causes of OSD in HCWs is important in order to develop strategies for prevention. We suggest that skin care advice should be incorporated into hand hygiene education. The use of ABHRs should be encouraged, weak allergens in skin cleansers should be substituted, and accelerator-free gloves should be recommended for HCWs with OSD.

Occupational Contact Dermatitis: Workers' Compensation Patch Test Results of Portland, Oregon, 2005-2014.

BACKGROUND: Workers are exposed to potential irritants and allergens with constant introduction of new industrial chemicals in the workplace. OBJECTIVE: Characterize the final diagnoses, demographics, occupations, exposures, clinical presentations, patch test results, dermatologic histories, and risk factors of workers evaluated for suspected work-related allergic contact dermatitis (ACD). METHODS: A retrospective chart review of 310 workers' compensation independent medical examinations evaluated for suspected work-related ACD was performed. Workers were seen in a community dermatology clinic in Portland, Oregon, from 2005 to 2014. Evaluation included history, physical examination, patch testing, and further diagnostic workup when indicated. RESULTS: Hand dermatitis was the most common presentation (n = 148, 47.7%). Prevalent occupations included health care workers (n = 51, 16.5%), custodial staff (n = 41, 13.2%), and machinists (n = 36, 11.6%). Allergic contact dermatitis (47.5%) was more common than irritant contact dermatitis (ICD) (38.9%) in those diagnosed as having occupational skin disease (n = 185). The highest-frequency work-related allergens were thiuram mix (21 of 88, 23.9%), carba mix (20 of 88, 22.7%), potassium dichromate (9 of 88, 10.2%), and epoxy resin (9 of 88, 10.2%). CONCLUSIONS: Allergic contact dermatitis and ICD are common occupational skin disorders. In this population of workers' compensation referrals, ACD was more common, with 73.3% of those cases work related, compared with 86.7% of ICD. Blue collar work and wet work were risk factors for the development of ACD and ICD.

Assessment of mutagenic potential of thiram.

Thiram is a widely used dithiocarbamate fungicide. In this study, the mutagenicity of thiram was investigated using the micronucleus and dominant lethal tests in Swiss albino mice. A single ip injection of 100 mg thiram/kg body weight, which is the maximum tolerated dose (MTD), significantly induced micronucleus formation in bone marrow cells after 30 and 48 hr of exposure; 50% and 25% of the MTD also induced micronucleus formation after the above time periods. A significant number of dead implants were induced when thiram was given to male mice in the diet at 10% of the oral LD50 during the whole spermatogenesis cycle (8 wk); this post-implantation loss indicates a dominant lethal mutation.