Toxic Constituents Research Articles

Extending the Near-Infrared Emission Range of Indium Phosphide Quantum Dots for Multiplexed In Vivo Imaging.

This report of the reddest emitting indium phosphide quantum dots (InP QDs) to date demonstrates tunable, near-infrared (NIR) photoluminescence (PL) as well as PL multiplexing in the first optical tissue window while avoiding toxic constituents. This synthesis overcomes the InP "growth bottleneck" and extends the emission peak of InP QDs deeper into the first optical tissue window using an inverted QD heterostructure, specifically ZnSe/InP/ZnS core/shell/shell nanoparticles. The QDs exhibit InP shell thickness-dependent tunable emission with peaks ranging from 515-845 nm. The high absorptivity of InP yields effective photoexcitation of the QDs with UV, visible, and NIR wavelengths. These nanoparticles extend the range of tunable direct-bandgap emission from InP-based nanostructures, effectively overcoming a synthetic barrier that has prevented InP-based QDs from reaching their full potential as NIR imaging agents. Multiplexed lymph node imaging in a mouse model demonstrates the potential of the NIR-emitting InP particles for in vivo imaging.

Pterocephin A, a novel Triterpenoid Saponin from Pterocephalus hookeri induced liver injury by activation of necroptosis

BackgroundPterocephalus hookeri (C. B. Clarke) Höeck, a Tibetan medicine widely used for treatment of rheumatoid arthritis, was recorded in Chinese Pharmacopoeia (2020 version) with slight toxicity. The liver injury was observed in mice with administration of n-butanol extract (BUE) in our previously study. However, the toxic components and the mechanism were still unrevealed. PurposeThe present study was aimed to isolate and structural elucidate of the toxic compound pterocephin A (PA), as well as evaluate its liver toxicity and investigate its mechanism. MethodsPA was isolated from the BUE of P. hookeri. Its structure was determined by analysis of HRMS, NMR and ECD data. L-02 cellular viability, LDH, ALT, AST, ROS, intracellular Ca2+ and the fluidity of cell membrane were assessed by multifunctional microplate reader. The PI staining, cell membrane permeability assessment, and mitochondrial fluorescence staining analysis were determined through the fluorescence microscope. Liver samples for mice were assessed by pathological and immunohistochemistry analysis. Expression levels of indicated proteins were measured by western blotting assays. ResultsPA was determined as a previously undescribed oleanolane-type triterpenoid saponin. In vitro study revealed PA significantly induced hepatotoxicity by inhibition of L-02 cell growth, abnormally elevation of ALT and AST. Mechanically, PA induced the damage of cell membrane, fragmentation of mitochondria, and subsequently increase of intracellular Ca2+ and ROS levels, which trigged by necroptosis with the activation of RIP1 and NF-κB signaling pathways. In vivo study confirmed PA could induce liver injury in mice with observation of the body weight loss, increasing of serum ALT and AST, and the histopathological changes in liver tissues. ConclusionOur present study indicated that PA was an undescribed toxic constituent in P. hookeri to induce liver injury in mice by activation of necroptosis and inflammation. And the findings are of great significance for the clinical use safely of this herb.

Enhanced Hepatotoxicity of Extract of Polygoni Multiflori Radix after Inhibition of CYP2E1 and Screening of Toxic Constituents

Enhanced Hepatotoxicity of Extract of Polygoni Multiflori Radix after Inhibition of CYP2E1 and Screening of Toxic Constituents

The adverse effect of toxic plant constituent found in India: Forensic approach

There are various plant originated active chemical constituents which are toxicologically significant includes proteins, phenolic compounds, alkaloids, glycosides, and resins, etc. Out of these huge numbers of plants in the environment, few cause acute toxicity, severe illness if it is consumed. The diversity of active chemical constituent in plants is quite amazing. Natural poisons are those chemicals that kill without violence, mysteriously, secretly destroy life. Some of the common plant families and its toxic constituent are easily available like Euphorbiaceae (cleistanthin, toxalbumin, curcin), Solanaceae (capsicin, atropine, dutarin), Apocyanacae (uscharin, odolotoxin, neriodorin), Leguminosae (cytisine sparteine), Fabaceae (abrasine, diaminopropionic acid), Papaveraceae (narcotine, dihydrosangunarine). The natural poisons are also used by criminals for stupefying people that facilitate robbery, murder and other cases. These natural poisons are readily accessible and very cheap, so skilful poisoners prefer this toxic plant for a crime. In this work author revised literature related to the classification of plant’s chemical constituents, its lethal dose and metabolic effects on the body. It has been thoroughly received and collected from journals and textbooks to make this review useful to all specialists of different discipline and it also has significant forensic importance.

Chronotoxicity of Semen Strychni is associated with circadian metabolism and transport in mice.

We aimed to determine the circadian responses of mice to Semen Strychni and to investigate the role of pharmacokinetics in generating chronotoxicity. Total extract of Semen Strychni was administered by oral gavage to wild-type (WT) and Bmal1-/- (a circadian clock-deficient model) mice at different circadian time points for toxicity (including survival) and pharmacokinetic characterization. Nephrotoxicity and neurotoxicity were evaluated by measuring plasma creatinine and creatine kinase BB (CK-BB), respectively. Drug metabolism and transport assays were performed using liver/intestine microsomes and everted gut sacs, respectively. Semen Strychni nephrotoxicity and neurotoxicity as well as animal survival displayed significant circadian rhythms (the highest level of toxicity was observed at ZT18 and the lowest level at ZT2 to ZT6). According to pharmacokinetic experiments, herb dosing at ZT18 generated higher plasma concentrations (and systemic exposure) of strychnine and brucine (two toxic constituents) compared with ZT6 dosing. This was accompanied by reduced formation of both dihydroxystrychnine and strychnine glucuronide (two strychnine metabolites) at ZT18. Bmal1 ablation sensitized mice to Semen Strychni-induced toxicity (with increased levels of plasma creatinine and CK-BB) and abolished the time dependency of toxicity. Metabolism of Semen Strychni (strychnine and brucine) in the liver and intestine microsomes of WT mice was more extensive at ZT6 than at ZT18. These time differences in hepatic and intestinal metabolism were lost in Bmal1-/- mice. Additionally, the intestinal efflux transport of Semen Strychni (strychnine and brucine) was more extensive at ZT6 than ZT18 in WT mice. However, the time-varying transport difference was abolished in Bmal1-/- mice. Circadian responses of mice to Semen Strychni are associated with time-varying efflux transport and metabolism regulated by the circadian clock (Bmal1). Our findings may have implications for optimizing phytotherapy with Semen Strychni via timed delivery.

Bioremediation of various aromatic and emerging pollutants by Bacillus cereus sp. isolated from petroleum sludge.

The accumulation of toxic chemical constituents in sludge and wastewater has fuelled an interest in investigating efficient and eco-friendly wastewater remediation approaches. In this study, a set of bacterial samples were isolated from petroleum sludge and tested for their ability to degrade different aromatic pollutants, including azo dyes and emerging pollutants. Although exhibiting differential specificity, all bacterial isolates were able to degrade different classes of aromatic dyes efficiently. Ribosomal 16S rRNA sequencing of the 12 bacterial isolates showed that they belonged to two different bacterial genera: Bacillus cereus and Pseudomonas guariconensis. Of these 12 strains, MA1 (B. cereus) was the most promising and was chosen for further optimization and biochemical studies. The optimum culture and remediation conditions for MA1 was found to be at pH 7, with 100 ppm dye concentration, and under aerobic condition. In addition to efficiently degrading various aromatic dyes (e.g. Congo Red, Reactive Black 5, PBS, and Toluidine Blue), MA1 was also found to be capable of degrading various emerging pollutants (e.g. prometryn, fluometuron and sulfamethoxazole). Preliminary transcriptome analysis shows that MA1 grown on media containing a mixture of aromatic dyes appears to differentially express a number of genes. Data shown here strongly suggests that petroleum sludge is a rich reservoir of bacteria with powerful remediation abilities.

Influence of sprouting on proximate composition, dietary fiber, nutrient availability, antinutrient, and antioxidant activity of flaxseed varieties

The present study evaluated the effect of sprouting on nutritional characteristics of flaxseed varieties Neelam, Garima, Shekhar, and Kusum. It was found that moisture and ash contents of sprouted flaxseeds were higher, while the crude protein, fat, and fiber content of sprouted flaxseeds were significantly lower than that of raw. The highest protein content among all the four raw and sprouted flaxseed varieties was in Neelam while lowest protein content was of Kusum variety. After sprouting of flaxseeds their soluble dietary fiber increased while insoluble dietary fiber decreased. There was less change in total calcium content even after germination as compared to raw. On mean basis, the total iron and magnesium contents of sprouted flaxseed varieties were significantly (p < 0.05) lower as compared to raw varieties. Sprouting caused increase in available mineral contents (calcium, iron, zinc, magnesium, and phosphorus), in vitro protein and starch digestibilities and antioxidant activity of processed flaxseeds. Practical applications Flaxseeds are nutritious oilseeds being a rich source of dietary fibers (lignans), essential fatty acids, protein, minerals like iron, calcium, zinc, phosphorus, and magnesium and antioxidants which are important for human nutrition and development. Sprouting resulted in a decrease in anti-nutritional factor in flaxseeds thereby removing the toxic constituents present in flaxseeds and rendering them safe for human consumption. Sprouting is a very easy economical and efficient technique which can be followed at household level to obtain safe, pro-health, nutritionally, and functionally superior flaxseeds; which can be further utilized for product development, value addition, and combating nutritional deficiencies.

Origin, distribution, and perspective health benefits of particulate matter in the air of underground salt mine: a case study from Bochnia, Poland

The composition and distribution of airborne particles in different locations in a salt mine were determined in terms of their origin, the distance from the air inlet, and the adaptation of post-mining chambers and corridors for tourists and general audience. The composition of aerosols in air was also evaluated from the perspective of human health. Air samples were collected on filters by using portable air pumps, in a historical underground salt mine in Bochnia (Poland), which is currently a touristic and recreation attraction and sanatorium. The particulate matter (PM) concentration was determined using the gravimetric method by weighing quartz filters. The content of carbon, water-soluble constituents, trace elements, and minerals was also determined. A genetic classification of the suspended matter was proposed and comprised three groups: geogenic (fragments of rock salt and associated minerals from the deposit), anthropogenic (carbon-bearing particles from tourist traffic and small amounts of fly ash, soot, and rust), and biogenic particles (occasional pollen). The total PM concentration in air varied between 21 and 79 μg/m3 (with PM4 constituting 4–24 μg/m3). The amount of atmospheric dust components coming from the surface was low and decreased with the distance from the intake shaft, thus indicating the self-cleaning process. NaCl dominated the water-soluble constituents, while Fe, Al, Ag, Mn, and Zn dominated the trace elements, with the concentration of majority of them below 30 ng/m3. These metals are released into air from both natural sources and the wear or/and corrosion of mining and tourists facilities in the underground functional space. No potentially toxic elements or constituents were detected. The presence of salt particles and salty spray in the atmosphere of salt mine, which may have anti-inflammatory and antiallergic properties, is beneficial to human health. This study will allow for a broader look at the potential of halotherapy in underground salt mines from a medical and regulatory point of view.

Chemical and Toxicological Properties of Emissions from a Light-Duty Compressed Natural Gas Vehicle Fueled with Renewable Natural Gas

Biogas consisting primarily of methane (CH4) and carbon dioxide (CO2) can be upgraded to a transportation fuel referred to as renewable natural gas (RNG) by removing CO2 and other impurities. RNG has energy content comparable to fossil compressed natural gas (CNG) but with lower life-cycle greenhouse gas (GHG) emissions. In this study, a light-duty cargo van was tested with CNG and two RNG blends on a chassis dynamometer in order to compare the toxicity of the resulting exhaust. Tests for reactive oxygen species (ROS), biomarker expressions (CYP1A1, IL8, COX-2), and mutagenicity (Ames) show that RNG exhaust has toxicity that is comparable or lower than CNG exhaust. Statistical analysis reveals associations between toxicity and tailpipe emissions of benzene, dibenzofuran, and dihydroperoxide dimethyl hexane (the last identification is considered tentative/uncertain). Further gas-phase toxicity may be associated with tailpipe emissions of formaldehyde, dimethyl sulfide, propene, and methyl ketene. CNG exhaust contained higher concentrations of these potentially toxic chemical constituents than RNG exhaust in all of the current tests. Photochemical aging of the vehicle exhaust did not alter these trends. These preliminary results suggest that RNG adoption may be a useful strategy to reduce the carbon intensity of transportation fuels without increasing the toxicity of the vehicle exhaust.

Short-term personal PM2.5 exposure and change in DNA methylation of imprinted genes: Panel study of healthy young adults in Guangzhou city, China.

DNA methylation (DNAm) plays a significant role in deleterious health effects inflicted by fine particulate matter (PM2.5) on the human body. Recent studies have reported that DNAm of imprinted control regions (ICRs) in imprinted genes may be a sensitive biomarker of environmental exposure. Less is known about specific biomarkers of imprinted genes after PM2.5 exposure. The relationship between PM2.5 and its chemical constituents and DNAm of ICRs in imprinted genes after short-term exposure was investigated to determine specific human biomarkers of its adverse health effects. A panel study was carried out in healthy young people in Guangzhou, China. Mixed-effects models were used to evaluate the influence of PM2.5 and its constituent exposure on DNAm while controlling for potential confounders. There was no significant correlation between DNAm and personal PM2.5 exposure mass. DNAm changes in eight ICRs (L3MBTL1, NNAT, PEG10, GNAS Ex1A, MCTS2, SNURF/SNRPN, IGF2R, and RB1) and a non-imprinted gene (CYP1B1) were significantly associated with PM2.5 constituents. Compared to non-imprinted genes, imprinted gene methylation was more susceptible to interference with PM2.5 constituent exposure. Among those genes, L3MBTL1 was the most sensitive to personal PM2.5 constituent exposure. Moreover, transition metals derived from traffic sources (Cd, Fe, Mn, and Ni) significantly influenced DNAm of the imprinted genes, suggesting the importance of more targeted measures to reduce toxic constituents. Bioinformatics analysis indicated that imprinted genes (RB1) may be correlated with pathways and diseases (non-small cell lung cancer, glioma, and bladder cancer). The present study suggests that screening the imprinted gene for DNAm can be used as a sensitive biomarker of PM2.5 exposure. The results will provide data for prevention of PM2.5 exposure and a novel perspective on potential mechanisms on an epigenetic level.

A comprehensive overview of vaccines developed for pandemic viral pathogens over the past two decades including those in clinical trials for the current novel SARS-CoV-2.

The unprecedented coronavirus disease 2019 (COVID-19) is triggered by a novel strain of coronavirus namely, Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2). Researchers are working around the clock to control this pandemic and consequent waves of viral reproduction, through repurposing existing drugs as well as designing new vaccines. Several countries have hastened vaccine design and clinical trials to quickly address this outbreak. Currently, more than 250 aspirants against SARS-CoV-2 are in progress, including mRNA-replicating or non-replicating viral vectored-, DNA-, autologous dendritic cell-based-, and inactivated virus-vaccines. Vaccines work by prompting effector mechanisms such as cells/molecules, which target quickly replicating pathogens and neutralize their toxic constituents. Vaccine-stimulated immune effectors include adjuvant, affinity, avidity, affinity maturation, antibodies, antigen-presenting cells, B lymphocytes, carrier protein, CD4+ T-helper cells. In this review, we describe updated information on the various vaccines available over the last two decades, along with recent progress in the ongoing battle developing 63 diverse vaccines against SARS-CoV-2. The inspiration of our effort is to convey the current investigation focus on registered clinical trials (as of January 08, 2021) that satisfy the safety and efficacy criteria of international wide vaccine development.

Effects of psoralen on hepatic bile acid transporters in rats.

Fructus Psoraleae (FP), widely used in traditional medicine, is increasingly reported to cause serious hepatotoxicity in recent years. However, the main toxic constituents responsible for hepatotoxicity and the underlying mechanisms are poorly understood. In the present study, psoralen, a main and quality-control constituent of FP, was intragastrically administered to Sprague-Dawley rats at a dose of 60 mg/kg for 1, 3 and 7 days. Blood and selected tissue samples were collected and analyzed for biochemistry and histopathology to evaluate hepatotoxicity. The results showed that psoralen could induce hepatotoxicity by enhanced liver-to-body weight ratio and alterations of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total cholesterol after administration for 3 days. In addition, histopathological examinations also indicated the hepatotoxicity induced by psoralen. Furthermore, the mRNA and protein levels of hepatic bile acid transporters were significantly changed, in which MRP4, ABCG5 and ABCG8 were repressed, while the protein level of NTCP tended to increase in the rat liver. Taken together, psoralen caused liver injury possibly through affecting bile acid transporters, leading to the disorder of bile acid transport and accumulation in hepatocytes.

Circadian clock regulates hepatotoxicity of Tripterygium wilfordii through modulation of metabolism.

We aimed to determine the diurnal rhythm of Tripterygium wilfordii (TW) hepatotoxicity and to investigate a potential role of metabolism and pharmacokinetics in generating chronotoxicity. Hepatotoxicity was determined based on assessment of liver injury after dosing mice with TW at different circadian time points. Circadian clock control of metabolism, pharmacokinetics and hepatotoxicity was investigated using Clock-deficient (Clock-/- ) mice. Hepatotoxicity of TW displayed a significant circadian rhythm (the highest level of toxicity was observed at ZT2 and the lowest level at ZT14). Pharmacokinetic experiments showed that oral gavage of TW at ZT2 generated higher plasma concentrations (and systemic exposure) of triptolide (a toxic constituent) compared with ZT14 dosing. This was accompanied by reduced formation of triptolide metabolites at ZT2. Loss of Clock gene sensitized mice to TW-induced hepatotoxicity and abolished the time-dependency of toxicity that was well correlated with altered metabolism and pharmacokinetics of triptolide. Loss of Clock gene also decreased Cyp3a11 expression in mouse liver and blunted its diurnal rhythm. Tripterygium wilfordii chronotoxicity was associated with diurnal variations in triptolide pharmacokinetics and circadian expression of hepatic Cyp3a11 regulated by circadian clock. Our findings may have implications for improving TW treatment outcome with a chronotherapeutic approach.

Current status of biomethane production using aqueous liquid from pyrolysis and hydrothermal liquefaction of sewage sludge and similar biomass

Pyrolysis and hydrothermal liquefaction (HTL) are potential technologies for renewable energy production and waste valorization using municipal wastewater sewage sludge and other lignocellulosic biomass. However, the organic-rich aqueous pyrolysis liquid (APL) and HTL aqueous phase (HTL-AP) produced currently have no apparent use and are challenging to manage. Furthermore, the toxic organic compounds in them can be harmful to the environment. Anaerobic digestion (AD) may be a viable method to manage the liquids and recover energy in APL and HTL-AP in form of methane-rich biogas. Integrating thermochemical processes with AD could promote a circular economy by recovering resources and reducing environmental pollution. The challenge, however, is the presence of toxic compounds recalcitrant to anaerobic biodegradation such as phenols and nitrogen-containing organics that can inhibit methane-producing microbes. This review presents information on APL and HTL-AP characterization and biodegradability. Feedstock composition and process operational parameters are major factors affecting APL and HTL-AP composition, subsequent toxicity, and degradability. Feedstocks with high nitrogen content as well as increased thermochemical processing temperature and retention time result in a more toxic aqueous liquid and lower methane yield. Dilution and low AD organic loading are required to produce methane. More comprehensive APL and HTL-AP chemical characterization is needed to adopt suitable treatment strategies. Pretreatments such as overliming, air stripping, partial chemical oxidation, adsorption, and solvent extraction of toxic constituents as well as co-digestion and microbial acclimatization successfully reduce toxicity and increase methane yield.

Clarifying the in-situ cytotoxic potential of electronic waste plastics

Plastics in waste electronics (E-plastics) account for approximately 20% of the entire global electronic waste (E-waste) stream. Most of the E-plastics are not recycled as the presence of toxic additives (e.g. heavy metals, brominated flame retardants (BFRs), antimony, etc.) have associated environmental and health concerns. However, the majority of the studies are focused on quantitative assessment of the toxic constituents in E-plastics, while empirical information regarding the potential toxic effects in humans is largely lacking. To gain a deeper appreciation into the toxicological profile of E-plastics, in situ time-dependent exposures of 6 different human cell lines to a panel of 8 representative E-plastics recovered from liquid crystal displays (LCD), keyboards, screen frames, and wire insulators were conducted. Although several hazardous elements (e.g. Pb, As, Sb, Zn, Cu, etc) were detected at concentrations that far exceed the limit values permitted by the Restriction of Hazardous Substances Directive and EU Directives in the panel E-plastics, in-depth analysis of the 144 unique cell viability data points and live-dead staining experiments suggest that the acute and sub-chronic toxic effects of E-plastics in direct contact with human cells are negligible. These observations agreed with the inductively coupled plasma-optical emission spectrometry data, which revealed that leaching of these toxic additives into the biological milieu is not sufficiently high to trigger a cytotoxic response up to a continuous culture period of 2 weeks. The novel insights gained from this study are posited to further clarify the uncertainty associated with the safety and circular economy implementation of E-plastics.

Mine spoil remediation via biochar addition to immobilise potentially toxic elements and promote plant growth for phytostabilisation

There are thousands of disused and abandoned mining sites around the world with substantial accumulations of exposed mine spoil materials that pose a direct threat to their surrounding environment. Management of such sites, and neutralisation of the environmental threats they pose, is therefore extremely important and is an issue of global significance. Low cost management and remediation strategies need to be developed because many abandoned mine sites are in remote and/or economically challenged areas. One promising option is the incorporation of biochar into spoil materials, which has the potential to immobilise leachable toxic constituents and facilitate revegetation and thereby stabilisation of spoil heaps. This study investigated the capacity of readily available biochar materials made from wheat and rice waste products to immobilise and retain key metallic contaminants Pb and Zn from solution, and also investigated the utility of biochar application for remediating mine spoil heaps from different mine types in terms of facilitating establishment of vegetation coverage and minimising porewater element mobility within spoil heaps. The results demonstrated the high sorption capacity of the biochars (typically >97% of Pb or Zn in solution) and their ability to retain the metals despite an active desorption procedure (>93% of sorbed Pb retained and >75% of sorbed Zn). The remediation trial revealed that biochar application increased plant yield and decreased plant assimilation of many potentially toxic elements and also decreased spoil porewater concentrations of Al, Cd, Pb and Zn in most cases. In some spoil types investigated biochar addition also significantly decreased porewater concentrations of As (e.g. from ~30 mg/L to ~5 mg/L), demonstrating its potential utility for low cost environmental remediation across a range of mine spoil types.

Electrophilic reactivity of the Busulfan metabolite, EdAG, towards cellular thiols and inhibition of human thioredoxin-1

Busulfan is an alkylating agent used in chemotherapy conditioning regimens prior to hematopoietic stem cell transplantation (HSCT). However, its administration is associated with a great risk of adverse toxicities, which have been historically attributed to busulfan’s mechanism of non-specific DNA alkylation. A phase II generated metabolite of busulfan, EdAG (γ-glutamyldehydroalanylglycine), is a dehydroalanine analog of glutathione (GSH) with an electrophilic moiety, suggesting it may bind to proteins and disrupt biological function. However, EdAG’s reactions with common cellular thiols such as glutathione (GSH) and l-cysteine are understudied, along with possible inhibition of glutathionylation-dependent enzymes (with active site cysteine residues). We established a physiologically-relevant in vitro model to readily measure thiol loss over time. Using this model, we compared the apparent rates of thiol depletion in the presence of EdAG or arecoline, a toxic constituent of the areca (betel) nut and known GSH depletor. Simulated kinetic modeling revealed that the mean (±SE) alpha (α) second order rate constants describing GSH and l-cysteine depletion in the presence of EdAG were 0.00522 (0.00845) μM−1∙min−1 and 0.0207 (0.00721) μM−1∙min−1, respectively; in the presence of arecoline, the apparent rates of depletion were 0.0619 (0.009) μM−1∙min−1 and 0.2834 (0.0637) μM−1∙min−1 for GSH and l-cysteine, respectively. Under these experimental conditions, we conclude that EdAG was a weaker electrophile than arecoline. Arecoline and EdAG both depleted apparent l-cysteine concentrations to a much greater extent than GSH, approximately 4.58-fold and 3.97-fold change greater, respectively. EdAG modestly inhibited (∼20%) the human thioredoxin-1 (hTrx-1) catalyzed reduction of insulin with a mean IC50 of 93 μM [95% CI: 78.6–110 μM). In summary, EdAG’s ability to spontaneously react with endogenous thiols and inhibit hTrx-1 are potentially biochemically relevant in humans. These findings continue to support the growing concept that EdAG, an underrecognized phase II metabolite of busulfan, plays a role in untoward cellular toxicities during busulfan pharmacotherapy.

Occupational exposure and health risks of volatile organic compounds of hotel housekeepers: Field measurements of exposure and health risks.

Hotel housekeepers represent a large, low-income, predominantly minority, and high-risk workforce. Little is known about their exposure to chemicals, including volatile organic compounds (VOCs). This study evaluates VOC exposures of housekeepers, sources and factors affecting VOC levels, and provides preliminary estimates of VOC-related health risks. We utilized indoor and personal sampling at two hotels, assessed ventilation, and characterized the VOC composition of cleaning agents. Personal sampling of hotel staff showed a total target VOC concentration of 57±36µg/m3 (mean±SD), about twice that of indoor samples. VOCs of greatest health significance included chloroform and formaldehyde. Several workers had exposure to alkanes that could cause non-cancer effects. VOC levels were negatively correlated with estimated air change rates. The composition and concentrations of the tested products and air samples helped identify possible emission sources, which included building sources (for formaldehyde), disinfection by-products in the laundry room, and cleaning products. VOC levels and the derived health risks in this study were at the lower range found in the US buildings. The excess lifetime cancer risk (average of 4.1×10-5 ) still indicates a need to lower exposure by reducing or removing toxic constituents, especially formaldehyde, or by increasing ventilation rates.

Study of hypocholesterolemic and antiatherosclerotic properties of Medicago sativa L. cultivated in Egypt

Alfalfa was reported to be hypocholesterolemic and antiatherosclerotic. Saponin glycosides were suggested to be responsible for this activity by neutralizing cholesterol in the stomach, enabling it to be excreted from the body. This makes alfalfa superior to the current anti-cholesterol medications which act by blocking cholesterol synthesizing apparatus. This study was undertaken in an attempt to prepare an alfalfa extract with high saponin content and free or low content of other toxic constituents found in alfalfa (canavanine and coumestrol), which causes serious side effects. A patent process was used to render alfalfa toxin free and to produce a drug present in the international market. Our study is based on monitoring the Egyptian crop at two different localities for its saponin, canavanine and coumestrol contents at different growth stages. The study showed that the tested extract of the chosen stage to be biologically studied (hypocholesterolemic and antiatherosclerotic effects) on the basis of the highest saponin content was just before fruiting stage of the locality A. This stage was free from both coumestrol and canavanine. The study proved that the Egyptian crop of alfalfa was found to safely reduce natural cholesterol and to possess a strong antiatherosclerotic activity. This extract (1) produced the most significant decrease in total cholesterol and LDL-cholesterol by 85.1 and 88%, respectively, of the corresponding levels in hypercholesterolemic rabbits. This decrease is more significant than that produced by gemfibrozil (73 and 74%) upon concomitant administration with a cholesterol enriched diet using the same animal model at the tested dose level. Also, it was obvious that all alfalfa preparations produced significant antioxidant properties. All alfalfa extracts possessed antiatherosclerotic activity as observed by the almost normalization of the aortic sections upon concomitant use of alfalfa extracts with cholesterol-enriched diet.

Recent Developments of PFAS-Detecting Sensors and Future Direction: A Review.

Per- and poly-fluoroalkyl substances (PFASs) have recently been labeled as toxic constituents that exist in many aqueous environments. However, traditional methods used to determine the level of PFASs are often not appropriate for continuous environmental monitoring and management. Based on the current state of research, PFAS-detecting sensors have surfaced as a promising method of determination. These sensors are an innovative solution with characteristics that allow for in situ, low-cost, and easy-to-use capabilities. This paper presents a comprehensive review of the recent developments in PFAS-detecting sensors, and why the literature on determination methods has shifted in this direction compared to the traditional methods used. PFAS-detecting sensors discussed herein are primarily categorized in terms of the detection mechanism used. The topics covered also include the current limitations, as well as insight on the future direction of PFAS analyses. This paper is expected to be useful for the smart sensing technology development of PFAS detection methods and the associated environmental management best practices in smart cities of the future.