New bacteriophage-derived lysins, LysJ and LysF, with the potential to control Bacillus anthracis.

Bacillus anthracis is an etiological agent of anthrax, a severe zoonotic disease that can be transmitted to people and cause high mortalities. Bacteriophages and their lytic enzymes, endolysins, have potential therapeutic value in treating infections caused by this bacterium as alternatives or complements to antibiotic therapy. They can also be used to identify and detect B. anthracis. Endolysins of two B. anthracis Wbetavirus phages, J5a and F16Ba which were described by us recently, differ significantly from the best-known B. anthracis phage endolysin PlyG from Wbetavirus genus bacteriophage Gamma and a few other Wbetavirus genus phages. They are larger than PlyG (351 vs. 233 amino acid residues), contain a signal peptide at their N-termini, and, by prediction, have a different fold of cell binding domain suggesting different structural basis of cell epitope recognition. We purified in a soluble form the modified versions of these endolysins, designated by us LysJ and LysF, respectively, and depleted of signal peptides. Both modified endolysins could lyse the B. anthracis cell wall in zymogram assays. Their activity against the living cells of B. anthracis and other species of Bacillus genus was tested by spotting on the layers of bacteria in soft agar and by assessing the reduction of optical density of bacterial suspensions. Both methods proved the effectiveness of LysJ and LysF in killing the anthrax bacilli, although the results obtained by each method differed. Additionally, the lytic efficiency of both proteins was different, which apparently correlates with differences in their amino acid sequence. KEY POINTS: • LysJ and LysF are B. anthracis-targeting lysins differing from lysins studied so far • LysJ and LysF could be overproduced in E. coli in soluble and active forms • LysJ and LysF are active in killing cells of B. anthracis virulent strains.

Development and validation of presumptive spot test for the identification of z-drugs used in drug-facilitated crimes.

The significance and desire for preliminary testing approaches that are straightforward, quick, selective, affordable, and practical for use in the field are highlighted by the increasing enormous amounts of potentially illegal samples being seized worldwide. The "z-drugs," which include zolpidem, zopiclone, and eszopiclone, are non-benzodiazepine medications used to treat insomnia. z-drugs are short-term solutions for sleeplessness and anxiety but have a long history of abuse and misuse. The extensive list is primarily utilized for drug-facilitated crimes and drug dependence. The presumptive color spot test for z-drugs, such as zolpidem, zopiclone, and eszopiclone, has been created and validated in this study. In the preliminary identification of zolpidem, zopiclone, and eszopiclone, no color spot test has been documented as per the literature. The color spot test is the most essential and routinely used technique for identifying any unknown sample substance. The color test method was proven to provide high-quality, dependable presumptive test findings and satisfy standards for preliminary screening usage. Validation experiments demonstrate that, at room temperature, the color change is specific to the zolpidem, zopiclone, and eszopiclone classes and unaffected by the common cutting agent's presence. It was discovered that 5, 10, and 6 ppm were the operational limit of detection of the sample present against the reagents 0.1% diphenyl carbazone, aqueous potassium iodoplatinate, and modified cobalt thiocyanate reagent, respectively. The color test is immediate and validated with other substances of a similar category and 10 ppm was the operational limit of detection.

Exposure to boron trioxide nanoparticles and ions cause oxidative stress, DNA damage, and phenotypic alterations in Drosophila melanogaster as an in vivo model.

Boron trioxide nanoparticles (B2 O3 NPs) have recently been widely used in a range of applications including electronic device technologies, acousto-optic apparatus fields, and as nanopowder for the production of special glasses. We propose Drosophila melanogaster as a useful in vivo model system to study the genotoxic risks associated with NP exposure. In this study, we have conducted a genotoxic evaluation of B2 O3 NPs (size average 55.52 ± 1.41 nm) and its ionic form in D. melanogaster. B2 O3 NPs were supplied to third instar larvae at concentrations ranging from 0.1-10 mM. Toxicity, intracellular oxidative stress (reactive oxygen species, ROS), phenotypic alterations, genotoxic effect (via the wing somatic mutation and recombination test, SMART), and DNA damage (via Comet assay) were the end-points evaluated. B2 O3 NPs did not cause any mutagenic/recombinogenic effects in all tested non-toxic concentrations in Drosophila SMART. Negative data were also obtained with the ionic form. Exposure to B2 O3 NPs and its ionic form (at two highest concentrations, 2.5 and 5 mM) was found to induce DNA damage in Comet assay. Additionally, ROS induction in hemocytes and phenotypic alterations were determined in the mouths and legs of Drosophila. This study is the first study reporting genotoxicity data in the somatic cells of Drosophila larvae, emphasizing the importance of D. melanogaster as a model organism in investigating the different biological effects in a concentration-dependent manner caused by B2 O3 NPs and its ionic form. The obtained in vivo results contribute to improvement the genotoxicity database on the B2 O3 NPs.

Nickel and cobalt release from beauty tools: A field study in the German cosmetics trade.

BACKGROUND: Relevant nickel and cobalt release from hairdressing tools has recently been evidenced. Comparable data are not available for tools used in beauty salons. OBJECTIVES: Screening of beauty tools for nickel and cobalt release. METHODS/MATERIALS: Three hundred eight beauty tools were tested in seven beauty salons located in two North-German states. A nickel spot test and a cobalt spot test were used to test the tools for nickel release and cobalt release, respectively. RESULTS: One hundred forty-three of 308 beauty tools overall (46.4%; 95% confidence interval [CI]: 40.8%-52.2%) released nickel and 18 of 308 beauty tools overall (5.8%; 95%CI: 3.5%-9.1%) released cobalt. Nickel release was found in 22 of 99 metal tools (22.2%; 95%CI: 14.5%-31.7%) and 121 of 209 tools with metallic parts (57.9%; 95%CI: 50.9%-64.7%); cobalt release was detected in 3 of 99 metal tools (3.0%; 95%CI: 0.63%-8.6%) and 15 of 209 tools with metallic parts (7.2%; 95%CI: 4.1%-11.6%). CONCLUSIONS: Nickel and cobalt are emitted at allergologically relevant levels by a wide range of beauty tools (i.e., metal tools and tools with metallic parts) utilized in the German cosmetics trade. Beauty tools should thus be considered occupational sources of nickel and cobalt exposure.

Nickel release from metal items in contact with skin: a comparison of methods and practical implications for regulation in Europe.

Contact allergy to Nickel is the most prevalent contact allergy in western societies. This has led to regulation for metallic items that come into prolonged and direct contact with the skin, such as buttons on clothing, belt buckles, jewelry and watches. In Europe, the legal provision is based on a test in which there is a limit to the amount of nickel that may be released from the item to an artificial sweat solution (EN 1811). This test is costly and has reproducibility issues. The resulting undertesting of items placed on the market, leads to many nickel releasing non-compliant articles being available in spite of the regulations that are in place. In this study, the performance of the standard release test is compared to the performance of a rapid nickel spot test based on dimethylglyoxime (DMG-test). The data suggest that using the rapid DMG-test for compliance testing is sufficiently equivalent to the current gold standard of EN 1811. Previously published comparisons between the DMG-test and EN 1811 did not consider the effect of accelerated wear and corrosion testing according to EN 12472. This study shows that by applying EN 12472, the number of deviating results between the DMG-test and EN 1811 decreases significantly. Regarding consumer protection, it is necessary for wear and corrosion resistance to be considered.

Designing, fabrication and evaluation of a rapid, point-of-care and noninvasive system for the detection of lead (Pb2+).

Non-invasive collection of biological sample such as sweat, urine, saliva, hairs and, stool and onsite detection of anlaytes in those samples is an interesting and viable approach for rapid screening of various toxicants in body. Environmental exposure/presence of lead (82Pb) and its rapid detection provide one such opportunity. A chemical spot based colorimetric method and a transdermal patch device based on this spot test, is developed for rapid and qualitative assessment of inorganic lead (Pb2+) in non-coloured biological or environmental liquid samples. The transdermal patch system contains two important parts, a chemical spot prepared on a thin glass sheet and, an absorbent paper (11 µm pore size). A one step colour development reaction is able to identify the presence or absence of Pb2+. In-vitro evaluation for sensitivity and cut-off value determination, within run and between run precision testing, specificity testing were done. In-vivo evaluation of the developed patch system was performed in occupationally lead-exposed subjects and in control volunteers. In-vivo field testing results were further validated with gold standard test for lead detection. Blood lead levels and patch lead levels were found to be positively correlated (r = 0.57, P < 0.0001). In addition, the sensitivity and specificity of device in identification of Pb2+ was found to be 75.93% (95% CI = 62.36%-86.51%) and 95.24% (95% CI = 76.18%-99.88%). The developed system appears as a reliable, non-invasive rapid test with minimum step involve for identification of Pb2+ in a given system.

Phytochemical prospecting, isolation, and protective effect of the ethanolic extract of the leaves of Jatropha mollissima (Pohl) Baill.

Jatropha mollissima is used in folk medicine as antimicrobial, antiparasitic, and larvicidal. However, few toxicogenetic studies have been carried out. Therefore, the aim of this study was to determine the phytochemical profile of ethanolic leaf extract of J. mollissima (EEJM) as well as potential cytotoxic, mutagenic, and antimutagenic properties. The EEJM was subjected to successive fractionation for the isolation of secondary metabolites, and five concentrations (0.01; 0.1; 1; 10 and 100 mg/ml) of extract were investigated using Allium cepa assay and the Somatic Mutation and Recombination (SMART) test. The mitotic index and % damage reduction were analyzed for A. cepa and the frequency of mutant hair for SMART. The presence of coumarins, alkaloids, flavonoids, saponins, and tannins was detected, while spinasterol and n-triacontane were the isolates identified for the first time for this species. EEJM did not exhibit cytotoxicity and was not mutagenic at 1 or 10 mg/ml using A. cepa and all concentrations of EEJM were not mutagenic in the SMART test. A cytoprotective effect was found at all concentrations. At 1 or 10 mg/ml EEJM exhibited antimutagenicity in A. cepa. In SMART, the protective effect was observed at 0.1 to 100 mg/ml EEJM. Our results demonstrate the important chemopreventive activity of EEJM, a desired quality in the search for natural anticarcinogenic compounds.

Chromium and cobalt release from metallic earrings from the Danish market.

BACKGROUND: Chromium and cobalt are important skin sensitizers. It has, however, been difficult to identify causative exposures. Studies on nickel allergy have demonstrated piercing as critical for both sensitization and elicitation. It may be speculated that the same applies for chromium and cobalt. OBJECTIVE: To examine the content and release of chromium and cobalt from earrings randomly purchased in Denmark. METHODS: Three hundred four earrings were examined with x-ray fluorescence (XRF) spectrometry. Earrings with measured content of chromium or cobalt were spot tested with diphenylcarbazide spot test (n = 166) or Nitroso-R spot-test (n = 99), respectively. Chromium and cobalt release were quantified in a selected subsample (n = 100) with the artificial sweat test (EN 1811). RESULTS: Chromium was present in 54.6% (166/304) of earrings and cobalt was present in 72.0% (219/304),- measured by XRF. All chromium spot tests for chromium VI were negative. The cobalt spot test was positive for one component. Chromium release was found from 59/100 (median concentration = -0.06 µg/cm2 /week) and cobalt release from 29/100 (median concentration = -0.06 µg/cm2 /week) of earrings in tested subsample. CONCLUSION: Earrings for piercing release chromium and cobalt and may on a case basis be a source of chromium and cobalt allergy.

Nickel release from metallic earrings: A survey of the Danish market and validation of the nickel spot test.

BACKGROUND: Exposure to nickel-releasing ear-piercing jewellery may explain the persistently high prevalence of nickel allergy in Europe. While nickel release from earrings is regulated, field studies show that the regulation is not always respected. More knowledge is needed regarding the risk of piercing exposure including suitable screening methods. OBJECTIVE: To examine the proportion of earrings on the Danish market that release more nickel than allowed, and to validate the use of the dimethylglyoxime (DMG) test as a screening tool. METHODS: A total of 304 earrings were purchased and tested with the DMG test and X-ray fluorescence spectrometry. The level of nickel release was quantified in a selected subsample of 100 earrings by the European reference test EN 1811. The DMG spot test was validated against EN 1811 at different thresholds. RESULTS: Excessive nickel release according to the European regulation was found in 45 (14.8%) tested earrings. The sensitivity of the DMG test decreased with reduced levels of nickel release (sensitivity of 45.2% at ≥0.2 µg/cm2 /week vs 61.1% at >0.5 µg/cm2 /week). CONCLUSION: Excessive nickel release is common in earrings on the Danish market. Because of low sensitivity, the DMG test has limited use in screening of earrings for research but may still be used clinically.

Human Hazard Assessment Using Drosophila Wing Spot Test as an Alternative In Vivo Model for Genotoxicity Testing-A Review.

Genomic instability, one of cancer's hallmarks, is induced by genotoxins from endogenous and exogenous sources, including reactive oxygen species (ROS), diet, and environmental pollutants. A sensitive in vivo genotoxicity test is required for the identification of human hazards to reduce the potential health risk. The somatic mutation and recombination test (SMART) or wing spot test is a genotoxicity assay involving Drosophila melanogaster (fruit fly) as a classical, alternative human model. This review describes the principle of the SMART assay in conjunction with its advantages and disadvantages and discusses applications of the assay covering all segments of health-related industries, including food, dietary supplements, drug industries, pesticides, and herbicides, as well as nanoparticles. Chemopreventive strategies are outlined as a global health trend for the anti-genotoxicity of interesting herbal extract compounds determined by SMART assay. The successful application of Drosophila for high-throughput screening of mutagens is also discussed as a future perspective.

The practical examination types (spot test and slide test) of gross anatomy course in faculty of medicine: a simultaneous evaluation of the aspect of student success.

PURPOSE: This study aimed to compare the students' scores of the spot (spotter/classical/traditional/tag/ring/bell-ringer) test (3D environment) performed in the laboratory with the slide test (gross anatomy images) (2D environment) in the class. The observation of our department regarding both types for practical examination was reported, in terms of exam marks of the students. Both are preferred as the practical examination types for gross anatomy course our in medical faculty. METHODS: The 29 blocks' scores in 5 years (2013/2014-2017/2018) belonging to first- and second-year medical students' spot tests and slide tests are evaluated retrospectively and statistically compared. Correlations of the spot tests and the slide tests, besides the correlations between theoretical examinations and the practical examination types, are calculated. RESULTS: Spot test scores were significantly higher (p < 0.05) in nine blocks, while slide test scores were higher significantly (p < 0.05) in fourteen. There was no statistically significant difference between the practical examination types (spot/slide) in six blocks. There were correlations between the spot test and the slide test in all blocks (p < 0.001). CONCLUSION: It is considered that the spot test reflects the success/ability in a 3D environment, while the slide test reflects it in the 2D environment. In conclusion, neither of these two types of examinations stands out absolutely. Both types of examinations have their own features in areas, such as assessment power, applicability, and effect on success.

Introducing free response short answer questions in anatomy spot tests: experiment study.

PURPOSE: A spot test is commonly used to assess practical knowledge through a series of specific questions related to the marked anatomical structures on cadavers. However, the continuous reviewing and developing of the medical curricula demands the need to improve the assessment method of the practical examination of anatomical knowledge. Therefore, the aim of the study was to examine the effectiveness of a free response short-answer questions (FRSAQs) test and traditional questions on medical students' performance. METHODS: This is an experimental study using a Randomized Posttest-Only Control Group Design to compare the mean of students' performance in addition to their perceptions about the two versions of the spot tests. Two hundred and ninety preclinical-year medical students were invited to participate in this study. RESULTS: Only 109 (38%) students participated in this study. The data analysis showed a significant improvement in students' performance in the FRSAQs test (5.3 ± 2.7) than the traditional spot test (4.7 ± 2.6), (P = 0.04). The majority of the students (70%) preferred the FRSAQs spot test, citing that it is good test to assess practical knowledge. The psychometric analysis revealed that the FRSAQs produced more ideal stations (60%) when compared to the traditional spot test (10%). CONCLUSION: The current study found that the FRSAQs spot test had a significant impact on students' performance, and it was considered an ideal, flexible, and stress-free assessment method when compared to the traditional spot test. Implementation of the strategy in teaching and in assessment is recommended.

[Clinical Status and Research Progress of Tuberculous Peritonitis].

Tuberculous peritonitis(TBP)is currently one of the common manifestations of extrapulmonary tuberculosis.Due to the atypical clinical features,diverse types of diseases to be distinguished,and limited detection methods,TBP is difficult to be diagnosed and the fatality caused by delayed diagnosis increases significantly.We studied the current research status of TBP and found that T cells spot test,abdominal CT,and laparoscopic biopsy were of high diagnostic value for TBP.However,the application of ascites Xpert-MTB/RIF-ultra assay,ascites ADA,and whole-body positron emission tomography/computed tomography remained to be studied.Serum CA125 helps to judge the efficacy of anti-tuberculosis treatment.

Clinical effect of T-SPOT.TB test for the diagnosis of tuberculosis.

BACKGROUND: The goal of this study was to further investigate the clinical effectiveness of the T-SPOT.TB test in diagnosing tuberculosis (TB), including the effects of T-SPOT.TB test on evaluating diverse TB types and locations. METHODS: We collected 20,332 specimens from patients suspected to have TB. Afterwards, we performed an integrative analysis of T-SPOT.TB results and clinical diagnoses, and evaluated the composition ratio and positive detection rate of the T-SPOT.TB test in various age groups, sample types, and hospital departments. In addition, we compared the spot number and composition rate between latent TB infection (LTBI), active TB infection, and old TB infection groups. The active TB group was then further divided into pulmonary TB (PTB), pulmonary and extrapulmonary TB (PETB), and extrapulmonary TB (EPTB) subgroups, and we evaluated whether there were statistical differences in spot number and composition rate between subgroups. RESULTS: Positive results from the T-SPOT.TB test were found across different age groups, specimen types, and hospital departments. Elderly patient groups, pleural effusion samples, and thoracic surgery departments showed the highest rates of positivity. There were no statistically significant differences in spot number of CFP-10 and ESAT-6 wells between disease groups or active TB subgroups. The composition rate, however, was significantly different when ESAT-6 and CFP-10 wells were double-positive. The spot number and composition rate were statistically different between the three disease groups, but showed no significant differences between the three subgroups of active TB. CONCLUSIONS: The results of T-SPOT. TB test showed differences in LTBI, active TB and old TB. Additionally, a higher spot number level was observed in the active TB group.

Undeclared formaldehyde levels in patient consumer products: formaldehyde test kit utility.

PURPOSE: Formaldehyde allergic contact dermatitis (ACD) may be due to products with free formaldehyde or formaldehyde-releasing agents; however, assessment of formaldehyde levels in such products is infrequently conducted. The present study quantifies total releasable formaldehyde from "in-use" products associated with formaldehyde ACD and tests the utility of commercially available formaldehyde spot test kits. MATERIALS AND METHODS: Personal care products from 2 patients with ACD to formaldehyde were initially screened at the clinic for formaldehyde using a formaldehyde spot test kit. Formaldehyde positive products were sent to the laboratory for confirmation by gas chromatography-mass spectrometry. In addition, 4 formaldehyde spot test kits were evaluated for potential utility in a clinical setting. RESULTS: Nine of the 10 formaldehyde spot test kit positive products obtained from formaldehyde allergic patients had formaldehyde with total releasable formaldehyde levels ranging from 5.4 to 269.4 µg/g. Of these, only two shampoos tested listed a formaldehyde-releasing agent in the ingredients or product literature. Subsequently, commercially available formaldehyde spot test kits were evaluated in the laboratory for ability to identify formaldehyde in personal care products. CONCLUSIONS: Chemical based formaldehyde spot test were more reliable than the enzymatic based test in identifying product releasable formaldehyde content. It is concluded that product labeled ingredient lists and available information are often inadequate to confirm the potential for formaldehyde exposure and chemical based spot test kits may have utility for identification of potential formaldehyde exposure from personal care products.

Searching for antigenotoxic properties of marine macroalgae dietary supplementation against endogenous and exogenous challenges.

The functional characterization of marine macroalgae toward their potential to strength genome protection is still scarce. Hence, the aim of this study was to assess the antigenotoxic potential of Ulva rigida, Fucus vesiculosus, and Gracilaria species in Drosophila melanogaster following dietary exposure and adopting the somatic mutation and recombination test (SMART). All macroalgae displayed a genoprotection activity, namely against an exogenous challenge (streptonigrin). The action against subtler endogenous pressures was also noted indicating that supplementation level is a critical factor. Gracilaria species provided ambivalent indications, since 10% of G. vermiculophylla inhibited the egg laying and/or larvae development, while 10% of G. gracilis promoted spontaneous genotoxicity. The effects of U. rigida were modulated (in intensity) by the growing conditions, demonstrating higher genoprotection against streptonigrin-induced damage when grown in an aquaculture-controlled system, while the effectiveness against spontaneous genotoxicity was more apparent in specimens grown under wild conditions. In contrast, F. vesiculosus did not produce significant differences in its potential under varying growing conditions. Overall, these findings shed some light on the macroalgae ability toward genome protection, contributing to the development of algaculture industry, and reinforcing the concept of functional food and its benefits.

Contamination of skin and surfaces by cobalt in the hard metal industry.

BACKGROUND: It is well known that hard metal workers have historically been affected by contact allergy to cobalt. Knowledge is sparse about occupational skin exposure to cobalt, in terms of skin doses and sources of exposure, which could be used to improve protection of workers. OBJECTIVES: To improve knowledge about skin doses and sources of skin exposure to cobalt within hard metal production, thereby facilitating better protection of workers. METHODS: Forty workers were sampled on the index finger by acid wipe sampling after 2 hours of work. The samples were analysed with inductively coupled plasma mass spectrometry. Cobalt spot testing was performed in the work environment. RESULTS: The highest skin doses were found among raw material workers. Skin doses among other production workers were also significant. Most office workers had low, but measurable, levels of cobalt on the skin. Glove use varied between workers. Cobalt was found on production equipment, on items in the canteen area, and on handles and buttons throughout the company. CONCLUSIONS: Cobalt skin doses were prominent, and originated from contact with raw materials, sintered materials, and contaminated surfaces. Cobalt was present on surfaces outside production areas. Companies need to identify and reduce skin exposure for protection of workers.

False-positive result when a diphenylcarbazide spot test is used on trivalent chromium-passivated zinc surfaces.

BACKGROUND: A colorimetric 1,5-diphenylcarbazide (DPC)-based spot test can be used to identify hexavalent chromium on various metallic and leather surfaces. DPC testing on trivalent chromium-passivated zinc surfaces has unexpectedly given positive results in some cases, apparently indicating the presence of hexavalent chromium; however, the presence of hexavalent chromium has never been confirmed with more sensitive and accurate test methods. OBJECTIVES: To examine the presence of hexavalent chromium on trivalent chromium-passivated zinc surfaces with a DPC-based spot test. METHODS: A colorimetric DPC spot test was used for the initial detection of hexavalent chromium on new and 1-year-aged trivalent chromium-passivated zinc surfaces. Then, X-ray photoelectron spectroscopy (XPS) was performed for all samples. RESULTS: The DPC spot test indicated the presence of hexavalent chromium in aged, but not new, trivalent chromium passivation on zinc; however, subsequent analysis by XPS could not confirm the presence of chromium in a hexavalent state. CONCLUSIONS: Unintended oxidation of DPC induced by atmospheric corrosion is suggested as a possible reason for the false-positive reaction of the DPC test on a trivalent chromium-passivated zinc surface. Further validation of the use of the DPC test for chromium-containing metallic surfaces is required.

Assessing genotoxicity of diuron on Drosophila melanogaster by the wing-spot test and the wing imaginal disk comet assay.

The aim of this study was to evaluate the genotoxicity of the herbicide diuron in the wing-spot test and a novel wing imaginal disk comet assay in Drosophila melanogaster. The wing-spot test was performed with standard (ST) and high-bioactivation (HB) crosses after providing chronic 48 h treatment to third instar larvae. A positive dose-response effect was observed in both crosses, but statistically reduced spot frequencies were registered for the HB cross compared with the ST. This latter finding suggests that metabolism differences play an important role in the genotoxic effect of diuron. To verify diuron's ability to produce DNA damage, a wing imaginal disk comet assay was performed after providing 24 h diuron treatment to ST and HB third instar larvae. DNA damage induced by the herbicide had a significantly positive dose-response effect even at very low concentrations in both strains. However, as noted for the wing-spot test, a significant difference between strains was not observed that could be related to the duration of exposure between both assays. A positive correlation between the comet assay and the wing-spot test was found with regard to diuron genotoxicity.