Post-exposure Period Research Articles

Risk of retinal detachment and exposure to fluoroquinolones, common antibiotics, and febrile illness using a self-controlled case series study design: Retrospective analyses of three large healthcare databases in the US.

The risk of retinal detachment (RD) following exposure to fluoroquinolone (FQ) has been assessed in multiple studies, however, results have been mixed. This study was designed to estimate the risk of RD following exposure to FQ, other common antibiotics, and febrile illness not treated with antibiotics (FINTA) using a self-controlled case series (SCCS) study design to reduce risk of confounding from unreported patient characteristics. Retrospective database analysis-SCCS. Primary and Secondary Care. 40,981 patients across 3 US claims databases (IBM® MarketScan® commercial and Medicare databases, Optum Clinformatics). RD. Exposures included FQ as a class of drugs, amoxicillin, azithromycin, trimethoprim with and without sulfamethoxazole, and FINTA. For the primary analysis, all drug formulations were included. For the post hoc sensitivity analyses, only oral tablets were included. Risk windows were defined as exposure period (or FINTA duration) plus 30 days. Patients of all ages with RD and exposures in 3 US claims databases between 2012 to 2017 were included. Diagnostics included p value calibration and pre-exposure outcome analyses. Incidence rate ratios (IRR) and 95% confidence interval (CI) comparing risk window time with other time were calculated. Our primary analysis showed an increased risk for RD in the 30 days prior to exposure to FQ or trimethoprim without sulfamethoxazole. This risk decreased but remained elevated for 30 days following first exposure. Our post-hoc analysis, which excluded ophthalmic drops, showed no increased risk for RD at any time, with FQ and other antibiotics. Our results did not suggest an association between FQ and RD. Oral FQ was not associated with an increased risk for RD during the pre- or post-exposure period. ClinicalTrials.gov identifier: NCT03479736-March 21, 2018.

Evolution of SARS-CoV-2 during the first year of the COVID-19 pandemic in Northwestern Argentina

Studies about the evolution of SARS-CoV-2 lineages in different backgrounds such as naive populations are still scarce, especially from South America. This work aimed to study the introduction and diversification pattern of SARS-CoV-2 during the first year of the COVID-19 pandemic in the Northwestern Argentina (NWA) region and to analyze the evolutionary dynamics of the main lineages found. In this study, we analyzed a total of 260 SARS-CoV-2 whole-genome sequences from Argentina, belonging to the Provinces of Jujuy, Salta, and Tucumán, from March 31st, 2020, to May 22nd, 2021, which covered the full first wave and the early second wave of the COVID-19 pandemic in Argentina. In the first wave, eight lineages were identified: B.1.499 (76.9%), followed by N.5 (10.2%), B.1.1.274 (3.7%), B.1.1.348 (3.7%), B.1 (2.8%), B.1.600 (0.9%), B.1.1.33 (0.9%) and N.3 (0.9%). During the early second wave, the first-wave lineages were displaced by the introduction of variants of concern (VOC) (Alpha, Gamma), or variants of interest (VOI) (Lambda, Zeta, Epsilon) and other lineages with more limited distribution. Phylodynamic analyses of the B.1.499 and N.5, the two most prevalent lineages in the NWA, revealed that the rate of evolution of lineage N.5 (7.9 × 10−4 substitutions per site per year, s/s/y) was a ∼40% faster than that of lineage B.1.499 (5.6 × 10−4 s/s/y), although both are in the same order of magnitude than other non-VOC lineages. No mutations associated with a biological characteristic of importance were observed as signatures markers of the phylogenetic groups established in Northwestern Argentina, however, single sequences in non-VOC lineages did present mutations of biological importance or associated with VOCs as sporadic events, showing that many of these mutations could emerge from circulation in the general population. This study contributed to the knowledge about the evolution of SARS-CoV-2 in a pre-vaccination and without post-exposure immunization period.

Limited behavioural effects of ocean acidification on a Mediterranean anemone goby (Gobius incognitus) chronically exposed to elevated CO2 levels

An in situ reciprocal transplant experiment was carried around a volcanic CO2 vent to evaluate the anti-predator responses of an anemone goby species exposed to ambient (∼380 μatm) and high (∼850 μatm) CO2 sites. Overall, the anemone gobies displayed largely unaffected behaviors under high-CO2 conditions suggesting an adaptive potential of Gobius incognitus to ocean acidification (OA) conditions. This is also supported by its 3-fold higher density recorded in the field under high CO2. However, while fish exposed to ambient conditions showed an expected reduction in the swimming activity in the proximity of the predator between the pre- and post-exposure period, no such changes were detected in any of the other treatments where fish experienced acute and long-term high CO2. This may suggest an OA effect on the goby antipredator strategy. Our findings contribute to the ongoing debate over the need for realistic predictions of the impacts of expected increased CO2 concentration on fish, providing evidence from a natural high CO2 system.

The Acute and Short-Term Inhalation of Carbon Nanofiber in Sprague-Dawley Rats.

The inhalation toxicity of carbon nanofibers (CNFs) is not clearly known due to relatively few related studies reported. An acute inhalation study and short-term inhalation study (5 days) were therefore conducted using Sprague-Dawley rats. In the acute inhalation study, the rats were grouped and exposed to a fresh air control or to low (0.238 ± 0.197), moderate (1.935 ± 0.159), or high (24.696 ± 6.336 mg/m3) CNF concentrations for 6 h and thereafter sacrificed at 14 days. For the short-term inhalation study, the rats were grouped and exposed to a fresh air control or low (0.593 ± 0.019), moderate (2.487 ± 0.213), or high (10.345 ± 0.541 mg/m3) CNF concentrations for 6 h/day for 5 days and sacrificed at 1, 3, and 21 days post-exposure. No mortality was observed in the acute inhalation study. Thus, the CNF LC50 was higher than 25 mg/m3. No significant body or organ weight changes were noted during the 5 days short-term inhalation study or during the post-exposure period. No significant effects of toxicological importance were observed in the hematological, blood biochemical, and coagulation tests. In addition, the bronchoalveolar lavage (BAL) fluid cell differential counts and BAL inflammatory markers showed no CNF-exposure-relevant changes. The histopathological examination also found no CNF-exposure-relevant histopathological lesions. Thus, neither acute nor 5 days inhalation exposure to CNFs induced any noticeable toxicological responses.

Delayed effects of radiation in adipose tissue reflect progenitor damage and not cellular senescence.

The pathogenesis of many age-related diseases is linked to cellular senescence, a state of inflammation-inducing, irreversible cell cycle arrest. The consequences and mechanisms of age-associated cellular senescence are often studied using in vivo models of radiation exposure. However, it is unknown whether radiation induces persistent senescence, like that observed in ageing. We performed analogous studies in mice and monkeys, where young mice and rhesus macaques received sub-lethal doses of ionizing radiation and were observed for ~ 15% of their expected lifespan. Assessments of 8-hydroxy-2' -deoxyguanosine (8-OHdG), senescence-associated beta-galactosidase (SAβ-gal), and p16Ink4a and p21 were performed on mitotic and post-mitotic tissues - liver and adipose tissue - 6months and 3years post-exposure for the mice and monkeys, respectively. No elevations in 8-OHdG, SA-βgal staining, or p16 Ink4a or p21 gene or protein expression were found in mouse and monkey liver or adipose tissue compared to control animals. Despite no evidence of senescence, progenitor cell dysfunction persisted after radiation exposure, as indicated by lower in situ CD34+ adipose cells (p = 0.03), and deficient adipose stromal vascular cell proliferation (p < 0.05) and differentiation (p = 0.04) ex vivo. Our investigation cautions that employing radiation to study senescence-related processes should be limited to the acute post-exposure period and that stem cell damage likely underpins the dysfunction associated with delayed effects of radiation.

Unchanged pulmonary toxicity of ZnO nanoparticles formulated in a liquid matrix for glass coating

The inclusion of nanoparticles can increase the quality of certain products. One application is the inclusion of Zinc oxide (ZnO) nanoparticles in a glass coating matrix to produce a UV-absorbing coating for glass sheets. Yet, the question is whether the inclusion of ZnO in the matrix induces toxicity at low exposure levels. To test this, mice were given single intratracheal instillation of 1) ZnO powder (ZnO), 2) ZnO in a glass matrix coating in its liquid phase (ZnO-Matrix), and 3) the matrix with no ZnO (Matrix). Doses of ZnO were 0.23, 0.67, and 2 µg ZnO/mouse. ZnO Matrix doses had equal amounts of ZnO, while Matrix was adjusted to have an equal volume of matrix as ZnO Matrix. Post-exposure periods were 1, 3, or 28 d. Endpoints were pulmonary inflammation as bronchoalveolar lavage (BAL) fluid cellularity, genotoxicity in lung and liver, measured by comet assay, histopathology of lung and liver, and global gene expression in lung using microarrays. Neutrophil numbers were increased to a similar extent with ZnO and ZnO-Matrix at 1 and 3 d. Only weak genotoxicity without dose-response effects was observed in the lung. Lung histology showed an earlier onset of inflammation in material-exposed groups as compared to controls. Microarray analysis showed a stronger response in terms of the number of differentially regulated genes in ZnO-Matrix exposed mice as compared to Matrix only. Activated canonical pathways included inflammatory and cardiovascular ones. In conclusion, the pulmonary toxicity of ZnO was not changed by formulation in a liquid matrix for glass coating.

Immediate and Sustained Effects of Cobalt and Zinc-Containing Pigments on Macrophages.

Pigments are among the oldest nanoparticulate products known to mankind, and their use in tattoos is also very old. Nowadays, 25% of American people aged 18 to 50 are tattooed, which poses the question of the delayed effects of tattoos. In this article, we investigated three cobalt [Pigment Violet 14 (purple color)] or cobalt alloy pigments [Pigment Blue 28 (blue color), Pigment Green 14 (green color)], and one zinc pigment [Pigment White 4 (white color)] which constitute a wide range of colors found in tattoos. These pigments contain microparticles and a significant proportion of submicroparticles or nanoparticles (in either aggregate or free form). Because of the key role of macrophages in the scavenging of particulate materials, we tested the effects of cobalt- and zinc-based pigments on the J774A.1 macrophage cell line. In order to detect delayed effects, we compared two exposure schemes: acute exposure for 24 hours and an exposure for 24 hours followed by a 3-day post-exposure recovery period. The conjunction of these two schemes allowed for the investigation of the delayed or sustained effects of pigments. All pigments induced functional effects on macrophages, most of which were pigment-dependent. For example, Pigment Green 19, Pigment Blue 28, and Pigment White 4 showed a delayed alteration of the phagocytic capacity of cells. Moreover, all the pigments tested induced a slight but significant increase in tumor necrosis factor secretion. This effect, however, was transitory. Conversely, only Pigment Blue 28 induced both a short and sustained increase in interleukin 6 secretion. Results showed that in response to bacterial stimuli (LPS), the secretion of tumor necrosis factor and interleukin 6 declined after exposure to pigments followed by a recovery period. For chemoattractant cytokines (MCP-1 or MIP-1α), delayed effects were observed with a secretion decreased in presence of Pigment Blue 28 and Pigment violet 14, both with or without LPS stimuli. The pigments also induced persisting changes in some important macrophage membrane markers such as CD11b, an integrin contributing to cell adhesion and immunological tolerance. In conclusion, the pigments induced functional disorders in macrophages, which, in some cases, persist long after exposure, even at non-toxic doses.

Improving knowledge on genotoxicity dynamics in somatic and germ cells of crayfish (Procambarus clarkii).

The harmful effects of pesticides can be extended beyond the exposure time scale. Appraisals combining exposure and long-term post-exposure periods appear as an unavoidable approach in pesticide risk assessment, thus allowing a better understanding of the real impact of agrochemicals in non-target organisms. This study aimed to evaluate the progression of genetic damage in somatic and germ tissues of the crayfish Procambarus clarkii, also seeking for gender-specificities, following exposure (7 days) to penoxsulam (23 μg L-1 ) and a post-exposure (70 days) period. The same approach was applied to the model genotoxicant ethyl methanesulfonate (EMS; 5mg L-1 ) as a complementary mean to improve knowledge on genotoxicity dynamics (induction vs. recovery). Penoxsulam induced DNA damage in all tested tissues, disclosing tissue- and gender-specificities, where females showed to be more vulnerable than males in the gills, while males demonstrated higher susceptibility in what concerns internal organs, that is, hepatopancreas and gonad. Crayfish were unable to recover from the DNA damage induced by EMS in gills and hepatopancreas (both genders) as well as in spermatozoa. The genotoxicity in the hepatopancreas was only perceptible in the post-exposure period. Oxidative DNA lesions were identified in hepatopancreas and spermatozoa of EMS-exposed crayfish. The spermatozoa proved to be the most vulnerable cell type. It became clear that the characterization of the genotoxic hazard of a given agent must integrate a complete set of information, addressing different types of DNA damage, tissue- and gender-specificities, as well as a long-term appraisal of temporal progression of damage.

Are Metarhizium brunneum conidia transferred between male and female Agriotes obscurus adults?

ABSTRACT The success of autodissemination of entomopathogenic fungi depends to some degree on the transmission of infective conidia or spores from contaminated hosts to conspecifics. In the present study, we examined the potential for direct transmission of a lethal dose of Metarhizium brunneum (Petch) conidia between opposite sex pairs of Agriotes obscurus L in the laboratory. Male and female beetles were exposed to M. brunneum conidia prior to pairing with an uncontaminated opposite sex partner (‘indirectly exposed’ to M. brunnneum), 2, 21 and 45 h after M. brunneum exposure. Ninety-six percent of the female beetles that had been exposed to M. brunneum granules died by day 15, as compared to 59% and 53% of the indirectly exposed and control females. From 15 days after the beginning of the experiment, females indirectly exposed to M. brunneum had higher odds of dying at any point in time than unexposed females across all post-exposure time periods. There was no significant difference in the odds of dying between indirectly exposed males and their unexposed counterparts at any point during the experiment. When the female beetle was exposed to M. brunneum forty-five hours prior to pairing, the pairs engaged in fewer courtship interactions relative to the other treatment groups, however less than 50% of all the pairs engaged in courtship interactions. The low incidence of courtship interactions and limited transfer of conidia between A. obscurus beetle pairs suggests that negligible horizontal transmission of M. brunneum conidia may occur between conspecifics.

Rat hematological parameters of subacute multifrequency electromagnetic next-generation cellular communications exposure

The cellular communication electromagnetic fields have become a significant physical environmental factor recently, which cannot but cause reasonable concern due to the possible adverse effects of human health. Experimental laboratory animal studies are an integral part of the development and substantiation maximal permissible levels, in which the blood system is an objective functional indicator of the electromagnetic field biological effects. Thus, the purpose of the research was to study the hematological parameters of the male and female rat blood of subacute multi-frequency electromagnetic exposure from cellular communication systems and possible long-term biological effects. The object of research was male and female Wistar line rats. There were multi-frequency 30-days electromagnetic field exposure with 500 μW/cm2 power density at 3.5, 28 and 37 GHz summary. Hematological parameters of peripheral rat blood of the experimental and control groups were determined at the end of 30 days of exposure and 30 days after exposure. 30 days exposure did not lead to statistically significant changes in the blood cell composition in either male or female rats compared with sham exposure. In post exposure period (30 days after), significant changes in hematological parameters shown female rats only, which consisted in a decrease in the average content (MCH) and the average concentration (MCHC) of hemoglobin (Hb) in erythrocyte (RBC), the level of leukocytes (WBC), lymphocytes (LYM) and an increase in monocytes (MON). There were no statistical changes in all hematological parameters in male rats. The research results suggest the development of aftereffect adaptive reactions in rats upon completion of subacute electromagnetic exposure and their correlation to the effect depending on the sex of the animal.

Moroccan entomopathogenic nematodes as potential biocontrol agents against Dactylopius opuntiae (Hemiptera: Dactylopiidae)

Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae) or prickly pear cochineal, is the most damaging pest on cactus species with heavy economic losses worldwide. The efficacy of two Moroccan EPN isolates; Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae) and Heterorhabditis bacteriophora (Poinar) (Rhabditida: Heterorhabditidae) (applied at 25, 50, and 75 IJs cm−2) against D. opuntiae nymphs and young females were evaluated under both laboratory bioassays and field conditions. Results showed that S. feltiae was more effective, causing higher mortality of nymphs and adult females (98.8% and 97.5%, respectively) after 8 days of exposure, resulting in an LT50 value of 5.9 days (nymph) and 6.0 days (young female). While, H. bacteriophora had lower mortalities (83.8% for nymph and 81.3% for adult females). For the cochineal nymphs and adult females, no significant difference was observed among S. feltiae at 25, 50, and 75 IJs cm−2, and the positive control, d-limonene applied at 0.5 g/L which was used due to its high effectiveness against nymphs and females of D. opuntiae. In the field experiment, d-limonene at 0.5 g/L and S. feltiae applied at 75 IJs cm−2 were effective in reducing nymph and adult female populations by 85.3–93.9% at 12 days of post exposure period. To our knowledge, this work is the first report on the use of EPNs to control D. opuntiae. Thus, in addition to d-limonene, both Moroccan EPN isolates S. feltiae, and H. bacteriophora could be used as part of the integrated pest management strategy against D. opuntiae. Many factors such as temperature can affect the establishment and effectiveness of EPNs under field conditions. Therefore, additional studies under field conditions are needed.

Inhalation toxicity of copper compounds: Results of 14-day range finding study for copper sulphate pentahydrate and dicopper oxide and 28-day subacute inhalation exposure of dicopper oxide in rats

Inhalation exposure to copper may occur during a range of occupational activities and the purpose of this study was to characterise the toxicological response to repeated inhalation of two copper compounds, representative of copper substances in large-scale production/use. Crl:CD(SD) rats were repeatedly exposed to aerosols of dicopper oxide (Cu2O) or copper sulphate pentahydrate (CuSO4.5 H2O) for 14-days as part of a range finding study at normalised copper doses of 0.18, 0.71, 1.78 and 8.9 mg/m3 Cu. Within a 28-days main study (Cu2O only), animals were repeatedly exposed to 0.2, 0.4, 0.8 and 2.0 mg/m3 Cu2O following OECD TG 412. The main study also consisted of satellite groups exposed for 1-, 2- or 3- weeks as well as a 13-week post-exposure recovery period group. Repeated exposure for 14-days to both copper compounds, normalised for copper content, led to an acute influx of polymorphonuclear leukocytes (neutrophils) and macrophages whilst only CuSO4.5 H2O exposure resulted in epithelial hyperplasia. This differential response may reflect the highly dissolvable nature of CuSO4.5 H2O in lung lining fluid leading to a release of copper ions at the epithelial surface whilst Cu2O is relatively indissolvable at neutral pH. In the 28-day study with Cu2O, an increase in cellularity was also evident in both histological and BALF samples and was dose-related with minimal to mild (neutrophilic) inflammation observed > 0.4 mg/m3 in the lung tissue sections and significant increases from 0.2 mg/m3 in BALF. There were no minimal haematological findings, no clinical findings and systemic organs were unaffected by inhalation exposure to dicopper oxide. The lung cellular response was limited to alveolar histiocytosis and neutrophil influx with no evidence of epithelial hyperplasia or fibrosis and all lung biomarkers returned to control levels within the post-exposure recovery period. Interestingly, the satellite groups showed that this acute cellular response followed a biphasic rather than monotonic pattern with a peak in lung biomarkers between weeks 1–3 and reduction thereafter. This reduction in lung biomarkers occurred during continued exposure and may indicate an adaptive response to copper exposure. Overall, these results show that repeated exposure to copper compounds results in an acute cellular response with no associated pathology and which fully resolved after the cessation of exposure. Therefore, the cellular response is evidence of a controlled and adaptive response associated with the removal of Cu2O from the alveolar surface.

Association between proton pump inhibitor use and risk of pneumonia in children: nationwide self-controlled case series study in Sweden

ObjectiveTo evaluate the association between use of proton pump inhibitors (PPIs) and risk of pneumonia in children.DesignNationwide register-based self-controlled case series study.SettingSweden, July 2006 to December 2016.ParticipantsChildren aged <18 years...

Behavioral Variables to Assess the Toxicity of Unionized Ammonia in Aquatic Snails: Integrating Movement and Feeding Parameters

Behavioral endpoints are important parameters to assess the effects of toxicants on aquatic animals. These endpoints are useful in ecotoxicology because several toxicants modify the animal behavior, which may cause adverse effects at higher levels of ecological organization. However, for the development of new bioassays and for including the behavior in ecotoxicological risk assessment, the comparison of sensitivity between different behavioral endpoints is necessary. Additionally, some toxicants remain in aquatic environments for a few hours or days, which may lead to animal recovery after toxicant exposure. Our study aimed to assess the effect of unionized ammonia on the movement and feeding behaviors of the aquatic gastropod Potamopyrgus antipodarum (Tateidae, Mollusca) and its recovery after exposure. Four treatments were used: a control and three nominal concentrations of unionized ammonia (0.25, 0.5 and 1 mg N-NH3/L). Each treatment was replicated eight times, with six animals in each replicate. Animals were exposed to unionized ammonia for 48 h (exposure period) and, subsequently, to control water for 144 h (post-exposure period). Two movement variables were monitored without food and five feeding behavioral variables were monitored in the presence of food. Some of the feeding behavioral variables showed higher sensitivity (LOEC = 0.25–0.5 mg N-NH3/L) than the movement behavior variables monitored without food (LOEC = 1 mg N-NH3/L). After exposure to unionized ammonia, animals showed a recovery of most behavioral endpoints. The inclusion of post-exposure period and feeding behaviors in bioassays may make studies more realistic, which is crucial for a proper ecotoxicological risk assessment.

Neopterin as a biomarker showing risks of developing pathology in bronchi and lungs among workers who have occupational contacts with industrial aerosols

Our research goal was to estimate neopterin level in blood serum of workers occupationally exposed to industrial aerosols with predominantly fibrogenic effects; to establish a relationship between this level and workers’ age, working experience in hazardous working conditions, spirometric parameters and the level of C-reactive protein. We also aimed to assess neopterin as a possible biomarker showing risks of the developing inflammatory process in the bronchi and lungs at its early stage. Our observation covered the following groups: workers employed at a metallurgic plant who had occupational contacts with industrial aerosols (exposure factors included welding and silicon-containing aerosols with predominantly fibrogenic effects in concentrations exceeding maximum permissible ones in workplace air); people suffering from chronic obstructive pulmonary disease of occupational etiology (COPD OE) in their post-exposure period; workers who didn’t have any occupational contacts with industrial aerosols. We determined neopterin contents in blood serum with ELISA test using “Neopterin ELISA” reagent kit (IBL, Hamburg). Elevated neopterin levels were detected in blood serum of 56.1 % workers who were occupationally exposed to industrial aerosols and 53.3 % of patients with COPD OE; we also found a direct correlation between levels of neopterin and interferon gamma. Only 18.7 % workers without any occupational contacts with industrial aerosols had elevated neopterin levels in their blood serum and there were no authentic correlations between these levels and interferon gamma contents in this group. Workers who were occupationally exposed to industrial aerosols had a more apparent increase in the average level of neopterin at an age younger than 40 years and working experience shorter than 20 years in comparison with workers without any such exposure. Neopterin can be used as a potential sensitive biomarker showing risks of an early inflammatory reaction in the lungs occurring in workers who are occupationally exposed to industrial aerosols. People with elevated neopterin levels in blood, especially those who are occupationally exposed to industrial aerosols, can be recommended to have their bronchi and lungs monitored in dynamics.

Неоптерин как биомаркер риска развития бронхолегочной патологии у работающих в контакте с промышленными аэрозолями Главные вкладки Просмотр(активная вкладка) Редактировать

Our research goal was to estimate neopterin level in blood serum of workers occupationally exposed to industrial aerosols with predominantly fibrogenic effects; to establish a relationship between this level and workers’ age, working experience in hazardous working conditions, spirometric parameters and the level of C-reactive protein. We also aimed to assess neopterin as a possible biomarker showing risks of the developing inflammatory process in the bronchi and lungs at its early stage. Our observation covered the following groups: workers employed at a metallurgic plant who had occupational contacts with industrial aerosols (exposure factors included welding and silicon-containing aerosols with predominantly fibrogenic effects in concentrations exceeding maximum permissible ones in workplace air); people suffering from chronic obstructive pulmonary disease of occupational etiology (COPD OE) in their post-exposure period; workers who didn’t have any occupational contacts with industrial aerosols. We determined neopterin contents in blood serum with ELISA test using “Neopterin ELISA” reagent kit (IBL, Hamburg). Elevated neopterin levels were detected in blood serum of 56.1 % workers who were occupationally exposed to industrial aerosols and 53.3 % of patients with COPD OE; we also found a direct correlation between levels of neopterin and interferon gamma. Only 18.7 % workers without any occupational contacts with industrial aerosols had elevated neopterin levels in their blood serum and there were no authentic correlations between these levels and interferon gamma contents in this group. Workers who were occupationally exposed to industrial aerosols had a more apparent increase in the average level of neopterin at an age younger than 40 years and working experience shorter than 20 years in comparison with workers without any such exposure. Neopterin can be used as a potential sensitive biomarker showing risks of an early inflammatory reaction in the lungs occurring in workers who are occupationally exposed to industrial aerosols. People with elevated neopterin levels in blood, especially those who are occupationally exposed to industrial aerosols, can be recommended to have their bronchi and lungs monitored in dynamics.

Insects as Chemical Sensors: Detection of Chemical Warfare Agent Simulants and Hydrolysis Products in the Blow Fly Using LC-MS/MS.

In this work, blow flies were investigated as environmental chemical sample collectors following a chemical warfare attack (CWA). Blow flies sample the environment as they search for water and food sources and can be trapped from kilometers away using baited traps. Three species of blow flies were exposed to CWA simulants to determine the persistence and detectability of these compounds under varying environmental conditions. A liquid chromatography mass spectrometry (LC-MS/MS) method was developed to detect CWA simulants and hydrolysis products from fly guts. Flies were exposed to the CWA simulants dimethyl methylphosphonate and diethyl phosphoramidate as well as the pesticide dichlorvos, followed by treatment-dependent temperature and humidity conditions. Flies were sacrificed at intervals within a 14 day postexposure period. Fly guts were extracted and analyzed with the LC-MS/MS method. The amount of CWA simulant in fly guts decreased with time following exposure but were detectable 14 days following exposure, giving a long window of detectability. In addition to the analysis of CWA simulants, isopropyl methylphosphonic acid, the hydrolysis product of sarin, was also detected in blow flies 14 days post exposure. This work demonstrates the potential to obtain valuable samples from remote or access-restricted areas without risking lives.

Soil Contamination and Bioaccumulation of Heavy Metals by a Tropical Earthworm Species (Alma nilotica) at Informal E‐Waste Recycling Sites in Douala, Cameroon

Soil contamination at electronic waste (e-waste) recycling sites is pervasive, though many locations have yet to be studied. While such contamination can present risks to soil organisms, little is known on the risks to native species. The objective of the present study was to assess soil contamination by heavy metals at e-waste recycling sites, and the potential of Alma nilotica, a native earthworm species, to bioaccumulate these metals. Soil samples collected from eight informal e-waste recycling sites and two non-e-waste sites in Douala, Cameroon, were analyzed for metal content. Metal concentrations in earthworm juveniles exposed to the soils for 21 days followed by a 14-day post-exposure period were measured weekly. Mean soil metal concentrations at e-waste sites ranked as Cu > Pb > Zn > Hg > Ni > As > Cd > Co > Cr. Based on contamination factors, soil contamination ranged from "moderate" (Cr), through "considerable" (Co and Cd), to "very high" for the rest of the metals. Based on the modified degree of contamination and risk index, all e-waste sites had "ultra-high" contamination with Ni, Pb, and Zn posing very high ecological risks and Bonaberi being the most contaminated site. There was a positive correlation between soil metal concentrations and metal accumulation (retention) by eathworms, but Hg and Co had the highest bioaccumulation factors (BAFs) despite having low soil concentrations. These results document that e-waste sites in Douala are contaminated with metals and that native earthworm species can bioaccumulate the studied metals at levels that could account for the toxic effects earlier recorded. With e-waste recycling growing worldwide, there is a need for more data, especially from understudied locations. Environ Toxicol Chem 2022;41:356-368. © 2021 SETAC.

Occupational exposure to severe acute respiratory coronavirus virus 2 (SARS-CoV-2) and risk of infection among healthcare personnel.

To assess the rate and factors associated with healthcare personnel (HCP) testing positive for severe acute respiratory coronavirus virus 2 (SARS-CoV-2) after an occupational exposure. Retrospective cohort study. Academic medical center with sites in Minnesota, Wisconsin, Arizona, and Florida. HCP with a high or medium risk occupational exposure to a patient or other HCP with SARS-CoV-2. We reviewed the records of HCP with significant occupational exposures from March 20, 2020, through December 31, 2020. We then performed regression analysis to assess the impact of demographic and occupational variables to assess their impact on the likelihood of testing positive for SARS-CoV-2. In total, 2,253 confirmed occupational exposures occurred during the study period. Employees were the source for 57.1% of exposures. Overall, 101 HCP (4.5%) tested positive in the postexposure period. Of these, 80 had employee sources of exposure and 21 had patient sources of exposure. The postexposure infection rate was 6.2% when employees were the source, compared to 2.2% with patient sources. In a multivariate analysis, occupational exposure from an employee source had a higher risk of testing positive compared to a patient source (odds ratio [OR], 3.22; 95% confidence interval [CI], 1.72-6.04). Sex, age, high-risk exposure, and HCP role were not associated with an increased risk of testing positive. The risk of acquiring coronavirus disease 2019 (COVID-19) following a significant occupational exposure has remained relatively low, even in the prevaccination era. Exposure to an infectious coworker carries a higher risk than exposure to a patient. Continued vigilance and precautions remain necessary in healthcare settings.

Therapeutic potential of Mucuna pruriens (Linn.) on high-fat diet-induced testicular and sperm damage in rats.

Objective: Mucuna pruriens Linn., a leguminous plant, is identified as a herbal medicine for improving fertility-related disorders in the alternative and complementary systems of medicine. The study was focused on evaluating the therapeutic potential of M. pruriens on testis and sperm parameters in a high-fat-induced hypercholesterolemia model. Materials and Methods:Male rats were divided as normal-control rats (NCR); normal-control rats + M.pruriens (200 mg/kg b.w. of ethanolic extract of M. pruriens seed) treated (NCRD); hypercholesterolemic rats (HCR) and hypercholesterolemic rats + M. pruriens (HCRD). Groups were further divided into three post-exposure periods (subgroups) of 9, 18, and 36 days, and the progressive changes in testis histology and sperm were analyzed. Results:The study showed a significant impairment in testicular histoarchitecture, depletion of antioxidant enzyme levels, increased oxidative stress and lipid peroxidation in the HCR group. The study indicated severe structural and functional damage in sperm parameters and diminished chromatin integrity in the HCR group. In the HCR rats, the follicular stimulating hormone (FSH) and luteinizing hormone (LH) and testosterone were significantly reduced. There was a significant improvement in sperm parameters and testis histology in the HCRD group. Conclusion:The study reveals the potential efficacy of M. pruriens to improve spermatogenesis, sperm parameters and hormone levels in hypercholesterolemic rats.