Retrospective analysis of adverse effects associated with pyrethrins-containing products

The Pyrethrins Stewardship Program (PSP) was established to better understand adverse effects following exposure to pyrethrins-containing insecticide products. Running from April 2010 through December 2016, symptomatic dermal and inhalation exposures were entered into Phase I of the PSP and analyzed for exposure details and nature of the effects reported. Phase II consisted of an in-depth telephone interview using an enhanced questionnaire to investigate additional exposure details. Phase III scored the association between exposure and reported effects. Based on the data collected and analyzed, we conclude that: (1) Both in absolute number and relative to the wide distribution and use by consumers, adverse respiratory or dermal events after product exposure were rare; (2) Most outcomes for the reported events involving either dermal or respiratory effects were of minor severity and self-limiting; (3) None of the data collected and analyzed indicate that pyrethrins-containing products, including those formulated with synthetic pyrethroids and/or synergists, pose a significant risk of serious dermal or respiratory reactions even in cases where the exposed individual reported having allergies or asthma; (4) No additional label warnings or other mitigation techniques are warranted with pyrethrins-containing products formulated with or without synthetic pyrethroids and/or synergists.

A survey of aerosol exposure systems relative to the analysis of cytotoxicity: A Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA) perspective

During a Cooperation Centre for Scientific Research Relative to Tobacco (CORESTA) meeting, the in vitro toxicity testing Sub-Group (IVT SG) met to discuss the evolving field of aerosol exposure research. Given the diversity of exposure parameters and biological endpoints being used, it was considered a high priority to investigate and contextualise the responses obtained. This is particularly driven by the inability to compare between studies on different exposure systems due to user preferences and protocol differences. Twelve global tobacco and contract research companies met to discuss this topic and formulate an aligned approach on how this diverging field of research could be appropriately compared. Something that is becoming increasingly important, especially in the light of more focused regulatory scrutiny. A detailed and comprehensive survey was conducted on over 40 parameters ranging from aerosol generation, dilution and data analysis across eight geographically independent laboratories. The survey results emphasise the diversity of in vitro exposure parameters and methodologies employed across the IVT SG and highlighted pockets of harmonisation. For example, many of the biological protocol parameters are consistent across the Sub-Group. However, variables such as cell type and exposure time remain largely inconsistent. The next steps for this work will be to map parameters and system data against biological findings and investigate whether the observed inconsistencies translate into increased biological variability. The results from the survey provide improved awareness of parameters and nuances, that may be of substantial benefit to scientists in intersecting fields and in the development of harmonised approaches.

An analysis of heavy metals contamination and estimating the daily intakes of vegetables from Uganda

Background: Environmental contamination with elevated levels of copper (Cu), cobalt (Co), iron (Fe), zinc (Zn), lead (Pb), chromium (Cr6+), cadmium (Cd), and nickel (Ni)—all states of which are found in Uganda—raises health risk to the public. Pb, Cr6+, Cd, and Ni for instance are generally considered nonessential to cellular functions, notwithstanding the importance of the oxidative state of the metals in bioavailability. As such, we aimed in this study (i) to evaluate heavy metal concentrations in four vegetables from a typical open-air market in Uganda, (ii) to assess the safety of consuming these vegetables against the World Health Organization (WHO) recommended limits of heavy metals consumption, and (iii) to formulate a model of estimated daily intake (EDI) among consumers in the country. Methods: This was a cross-sectional study conducted in five georeferenced markets of Bushenyi district in January 2020. Amaranthus, cabbages, scarlet eggplants, and tomatoes were collected from open markets, processed, and analyzed by atomic absorption spectrometry. Modeled EDI, principal component (PCA) and cluster analysis (CA) were conducted to identify relationships in the samples. Results: The levels of essential elements in the four vegetables were found to fall from Co > Cu > Fe > Zn. Those of non-essential metals were significantly higher and followed the pattern Cd > Cr > Pb > Ni. The highest EDI values were those of Cu in scarlet eggplants, Zn in amaranthus, Fe in amaranthus, Co in amaranthus, Pb in cabbages, total Cr in scarlet eggplant, Cd in cabbages and tomatoes, and Ni in cabbages. In comparison to international limits, EDIs for Zn, Cu, Co and Fe were low while Ni in cabbages were high. PCA showed high variations in scarlet eggplant and amaranthus. The study vegetables were found to be related with each other, not according to the location of the markets from where they were obtained, but according to their species by CA. Conclusion: The presence of non-essential elements above WHO limits raises policy challenges for the consumption and marketing of vegetables in the study area. Furthermore, low EDIs of essential elements in the vegetables create demand for nutritious foods to promote healthy communities.

A 7-month inhalation toxicology study in C57BL/6 mice demonstrates reduced pulmonary inflammation and emphysematous changes following smoking cessation or switching to e-vapor products

Cigarette smoking causes serious diseases, including lung cancer, atherosclerotic coronary artery disease, peripheral vascular disease, chronic bronchitis, and emphysema. While cessation remains the most effective approach to minimize smoking-related disease, alternative non-combustible tobacco-derived nicotine-containing products may reduce disease risks among those unable or unwilling to quit. E-vapor aerosols typically contain significantly lower levels of smoke-related harmful and potentially harmful constituents; however, health risks of long-term inhalation exposures are unknown. We designed a 7-month inhalation study in C57BL/6 mice to evaluate long-term respiratory toxicity of e-vapor aerosols compared to cigarette smoke and to assess the impact of smoking cessation (Cessation group) or switching to an e-vapor product (Switching group) after 3 months of exposure to 3R4F cigarette smoke (CS). There were no significant changes in in-life observations (body weights, clinical signs) in e-vapor groups compared to the Sham Control. The 3R4F CS group showed reduced respiratory function during exposure and had lower body weight and showed transient signs of distress post-exposure. Following 7 months of exposure, e-vapor aerosols resulted in no or minimal increase in pulmonary inflammation, while exposure to 3R4F CS led to impairment of lung function and caused marked lung inflammation and emphysematous changes. Biological changes observed in the Switching group were similar to the Cessation group. 3R4F CS exposure dysregulated the lung and nasal tissue transcriptome, while these molecular effects were substantially lower in the e-vapor group. Results from this study demonstrate that in comparison with 3R4F CS, e-vapor aerosols induce substantially lower biological responses including pulmonary inflammation and emphysematous changes, and that complete switching from CS to e-vapor products significantly reduces biological changes associated with CS in C57BL/6 mice.

Acute electronic vapour product whole aerosol exposure of 3D human bronchial tissue results in minimal cellular and transcriptomic responses when compared to cigarette smoke

The use of electronic vapour products (EVPs) continues to increase worldwide and with advances in cell culture systems, molecular biology and the computational sciences there is also accumulating evidence of their potential reduced toxicity and reduced potential harm when compared to cigarette smoke. To further understand the potential risks and health effects associated with exposure to EVP aerosols we have assessed the cellular and transcriptomic response from a commercially available lung tissue culture system (MucilAirTM) following a single sub-cytotoxic exposure to cigarette smoke and the equivalent nicotine delivered dose of EVP aerosol. The transcriptomic, cellular (cilia beat frequency (CBF) and percent active area (%AA), trans epithelial electrical resistance (TEER), histology) and cytokine release were assessed at 4- and 48- hours following recovery from air, EVP aerosol (8.4% V/V: mybluTM blueberry flavour, 2.4% nicotine) and 3R4F smoke (3.5% V/V: exposure). No pathological changes were observed at either recovery time point from any exposure. Air and EVP aerosol exposure had no effect on CBF, %AA nor TEER at 48 hours. Exposure to cigarette smoke resulted in a decrease in TEER, an increase in CBF and the release of proinflammatory cytokines at both recovery time points. Although the number of significantly expressed genes was minimal following exposure to EVP aerosol, exposure to 3R4F smoke resulted in a significant upregulation of several disease relevant pathways. These data provide evidence that following an acute exposure to EVP aerosol there is significantly less damage to lung cells in culture than the equivalent, nicotine based, dose of cigarette smoke.

The use of vitreous renal chemistries in the discrimination of postmortem fresh water drowning

Background: The World Health Organization (WHO) has estimated drowning as the leading cause of unintentional death in the world, with 372,000 deaths reported annually. Not all drowning are unintentional; some could be disguised to cover up an act of heinous criminality. This study was aimed at using some vitreous renal function biochemical parameters as a discriminant of postmortem fresh water drowning. Twelve albino rabbits constituted the sample size as validated by Mead’s formula. The study was divided into three groups; the control, postmortem-drowned and truly drowned as mimicked using an artificial fresh water pond. Vitreous humours were extracted using Coe method. The vitreous renal chemistries were analysed using diacetyl monoxime, Jaffe’s test, uricase and ion-selective electrode (ISE) methods respectively. Result: The mean of vitreous creatinine, urea, uric acid, Na+, K+, Cl−, Ca2+, glucose and CO2 of the control, postmortem-drowned and truly drowned groups were compared using One-way Anova (post-hoc-LSD) with the aid of SPSS Inc., Chicago, IL, USA; Version 18–21 package. The findings revealed a significant increase in concentrations of vitreous creatinine, glucose, Ca2+ and K+ of the drowned death group, whereas vitreous concentrations of CO2 and urea significantly decreased when compared to the controls and/or postmortem-drowned death. Conclusion: The study has shown that some of the studied vitreous biochemical parameters could be used as an ancillary tool in discriminating death due to fresh water drowning from that of disguised or postmortem-drowned death.

Impacts of three glyphosate formulations on gonadal development of Xenopus laevis

The emergence of widespread morphological malformations in the reproductive system of wildlife is generating increasing concerns. This concern is because the observed malformities may be linked to pollution by pesticides and other chemicals. The amphibian declines, for example, have been linked to pesticide pollution among other factors. Using an extended Xenopus Metamorphosis Assay protocol, until the tadpoles metamorphosized, the exposure impacts of three glyphosate formulations, namely, Roundup, Kilo Max and Enviro Glyphosate, were assessed on the reproductive system of Xenopus laevis, vis-a-vis the body mass, sex ratios and morphological malformations as endpoints. The exposure concentrations ranged between 0.2–0.6 mg/L, 0.9–28 mg/L and 90–280 mg/L for Roundup, Enviro Glyphosate, and Kilo Max, respectively. Both Kilo Max and Enviro Glyphosate formulations significantly reduced the body mass of the metamorphs compared to the control. In sex ratios, only Kilo Max altered the percentage sex ratio of the treated frogs at a ratio of 68:32 (F:M) compared to 50:50 ratio in the control. In reproductive malformations, the three formulations showed abnormality index range of 22.3–49%, 17.5–37.5% and 20–30% for the Kilo Max, Enviro Glyphosate and Roundup formulations, respectively, compared to 7.5% in the control. Observed reproductive malformations include mixed sex, translucence, aplasia, segmented hypertrophy and segmented aplasia and translucence. This result indicates that some of the glyphosate formulations have the capacity to cause widespread reproductive malformations in a way that could reduce the reproductive fitness of the amphibian. Care must therefore be taken to reduce the application rate of these formulations, particularly in aquatic environments.

Safety assessment of purine nucleosidase from Aspergillus luchuensis

Purine nucleosidase (EC 3.2.2.1) catalyzes the N-riboside hydrolysis of purine nucleosides to D-ribose and a purine base. This enzyme may be used in the production of beer and other alcoholic beverages to reduce the purine content of these products. Purine nucleosidase was obtained from Aspergillus luchuensis naturally occurring in grain sources. The safety profile of purine nucleosidase is not well documented in the scientific literature, and a series of toxicological studies were undertaken to investigate the safety of its use in food production. Purine nucleosidase from A. luchuensis was non-mutagenic and non-clastogenic in a standard Ames test and in vitro mammalian chromosome aberration assay. Administration of purine nucleosidase in a 90-day subchronic toxicity study in Sprague-Dawley rats did not elicit adverse findings on any hematology, clinical chemistry, urinalysis, organ weight, or histopathological parameter at doses up to 1700 mg total organic solids (TOS)/kg body weight/day, the highest dose tested. The results suggest purine nucleosidase to lack systemic toxic effect. The no-observed-adverse-effect level was concluded to be 1700 mg TOS/kg body weight/day. The results of the toxicology studies support the safety of purine nucleosidase from a non-genetically modified strain of A. luchuensis when used in food production.

A commentary on drug safety and genomics: Promising new agents may require expansion of guidelines for subject screening in clinical trials

The fatty acid amide hydrolase (FAAH) inhibitors likely represent a novel therapeutic yet complex target with the potential to impact various disease processes that present significant unmet medical needs. Despite a history of significant adverse events and still ill-defined risks associated with FAAH inactivation, potential clinical results of FAAH inhibitors for the management of human diseases suggest strongly that the research not be abandoned. In the present commentary we argue that the way to move forward safely and effectively may lie in universal expansion of clinical trials guidelines and toxicology protocols to include targeted genomic screening of clinical trial subjects. Generalization to the safety testing of many new pharmaceutical agents may be the silver lining of an otherwise dark cloud.

An interlaboratory in vitro aerosol exposure system reference study

Given the complexity of inhaled substances, the aerosol exposure environment has seen diversification and development of setups in conjunction with the evolving in vitro toxicology space. Each laboratory uses its in vitro exposure system differently (different protocols, adaptations, and biological analysis). Unfortunately, as systems diversify, so does the complexity of comparing multiple systems in a “standardized” manner. As yet, no one has compared simply whether these diverse systems can all generate a consistent aerosol stream, which is paramount prior to transit and exposure. This study has compared, at source, aerosol generation (using nicotine as an exposure marker) in nine in vitro whole-aerosol exposure setups (seven different systems) across five distinct geographically independent locations, including the UK, the USA, Switzerland, Germany, and Japan. The results demonstrate that, despite system-wide differences (adaptations, nuances, and application), these systems—when appropriately maintained and used under a prescribed set of established conditions can all generate a consistent and statistically comparable aerosol stream. These data will be invaluable for new researchers and established laboratories, so they may benchmark against this study. Finally, this interlaboratory comparison combined with the wealth of transit and exposure interface data, may help the environment move towards a truly validated and consistent approach to aerosol exposure. Such an approach could be replicated for other aerosolized products, such as e-cigarettes and heated tobacco products.