The accumulation of polyethylene terephthalate (PET) has become a major environmental in Malaysia.Disposal of PET in the local landfill has resulted in additional problems, as plastic leachate is known to cause cancer and neurological impairment in humans.Mycoremediation using fungi with vast hyphal network and broader metabolic competence is seen as an eco-friendlier approach to tackle this issue.The objective of this research is to evaluate fungi remediation of PET via the detection of manganese peroxidase and laccase activity.Biodegradation of PET is shown via the enzymatic activity of laccase and manganese peroxidase measured at the wavelength of 450 nm and 610 nm, respectively.Of the 14 species of fungi isolated from the Jeram landfill, only 7 fungal species were able to biodegrade PET to obtain the carbon that supports fungal growth.Only one species, P. janthinellum was able to express relatively high MnP and laccase activity consistently, demonstrating the ability to biodegrade PET.This shows that P. janthinellum has the highest potential to be further developed as an agent to biodegrade PET in an integrated plastic waste management to restore soil pollution.
Intramuscular injections of botulinum toxin A (BTX) are regularly used to treat skeletal muscle spasticity and relieve pain during rehabilitation therapy. However, while numerous preclinical studies have shown dramatic atrophic changes in muscle, little is known about the long-term effect of toxin on human skeletal muscle. In this study, muscle morphology was analyzed in biopsies taken from spastic upper extremity muscles of 8 cerebral palsy patients treated with BTX 5 months to 4 years prior sampling and was compared to muscles from 7 patients who had not ever received BTX treatment (overall 25 muscle biopsies obtained from 6 different muscles.). The most important (and surprising) finding was that BTX-treated muscles contained significantly larger fibers compared to untreated muscles. A strong correlation between fiber size and age was observed but the growth rate in the BTX group was larger. Pathological signs such as central nuclei, neonatal myosin heavy chain expression, angular fibers and hybrid fibers (expressing both slow and fast myosin heavy chain fibers) were significantly greater in BTX-treated muscles compared to untreated muscles. Capillarization was also increased in BTX-treated muscle compared to untreated muscles and was the best predictor of fiber size. We suggest that, in the context of spasticity, BTX may block negative, atrophy-inducing pressure of the central nervous system on skeletal muscle or may allow an altered use pattern that should be considered a positive adjuvant to current rehabilitation therapies.
Expression of TrkB receptors in the nucleus accumbens and prefrontal cortex of mice exposed to ethanol and voluntary physical activity ABSTRACT Alcohol use disorder (AUD) is known to be influenced by environmental factors.Voluntary physical activity (VPA) has been proven to be rewarding and to play a role in preventing drug relapse.In a previous study, we found that VPA mitigated ethanol-rewarding effects by preventing ethanol-induced conditioned place preference (CPP).There is evidence demonstrating alterations in the neurotrophic signaling of brain-derived neurotrophic factor (BDNF) in mice subjected to both CPP conditioning and VPA.Considering the putative participation of the BDNF signaling in ethanol-CPP and the high-affinity BDNF receptors TrkB 145 kDa and 90 kDa, we sought to address whether the expression of these receptors is changed in the nucleus accumbens (NAc) and prefrontal cortex (PFC) of ethanol-treated mice exposed to VPA.Mice were assigned into four groups.They were housed in home cages with locked ("Sedentary") or unlocked running wheels (VPA), and treated with saline or 1.8 g/kg ethanol during the conditioning phase.The groups are referred as Saline-Sedentary, Saline-VPA, Ethanol-Sedentary and Ethanol-VPA.TrkB receptors do not play a relevant role in ethanol-induced CPP or in VPA-induced protection against ethanol CPP.VPA and ethanol exposure decreased TrkB 145/90 ratio in the PFC.No differences were found among groups in the NAc.Considering that TrkB 90 kDa can counterbalance the excessive neurotrophic signaling mediated by BDNF-TrkB 145 kDa in the brain, the lower TrkB 145/90 ratio might represent a putative protection to stressful events involving BDNF-induced glutamatergic hyperexcitability and excitotoxicity.
Although penalties for violating Italy's laws on driving under the influence of drugs (DUID) are very strict, no national protocol is enforced in order to assess possible offences in traffic accidents and routine traffic patrols.We describe two protocols that were applied to assess 298 cases of potentially impaired drivers out of 1653 stopped in Perugia, a town in Central Italy.One protocol was the D.O.S. carried out by means of oral fluid and urine and blood for confirmatory analysis.The other "SALIVA" uses only oral fluid collected during the road checkpoints.Psychoactive drugs were present in about 30% of the suspected drivers under both protocols, with cannabis being most often detected.The number of drivers who were sanctioned for DUID was significantly higher under the SALIVA protocol.Because non-standardized procedures showed critical issues, it is necessary to harmonize DUID national protocols.Toxicological screening and confirmatory tests, with standard analytic procedures, should be developed.
Occupational or environmental exposure to malathion is known to increasingly cause cognitive or psychiatric disorders, since it damages brain tissue through inflammation and oxidative stress processes.Here, we examine the possible neuroprotective effects of some natural products such as argan and nigella oils against malathioninduced cognitive-behavioral deficits and cerebral tissue alterations.Male Wistar rats were used in the present study.The rats were pretreated either with virgin argan oil (2 ml/kg p.o.) or nigella oil (1 ml/kg p.o.) 1 hour before malathion (150 mg/kg p.o.) administration for 28 days.At the end of the experiment, the cognitive-behavioral tests were performed, followed by the biochemical and histological analysis.Our results confirmed significant recognition memory deficits, affective disorders such as anxiety-like behavior in malathion-exposed rats, as well as an increased acetylcholinesterase (AChE) inhibition rate and histological changes in the brain.However, the pretreatment with argan oil significantly reversed the memory and behavioral disorders, and prevented neurodegeneration in the hippocampus and prefrontal cortex (PFC), caused by the malathion.By contrast, nigella oil especially attenuated malathion-induced histopathological effects in the liver.The neuroprotective effects of argan oil against malathion-induced neurotoxicity could be attributed to antioxidant properties of its bioactive compounds such as tocopherol, caffeic acid or oleuropein, whereas nigella oil exerted anti-inflammatory action through its main bioactive component thymoquinone (30-40% approximately).
The comet assay or single-cell gel electrophoresis (SCGE) has been widely used over a decade as a simple, rapid, and sensitive way for determining deoxyribonucleic acid (DNA) strand breaks. The versatility of the SCGE assay is because of the fact that a wide range of fresh or frozen samples can be used, including peripheral blood, cultured cells, buccal mucosal cells, solid tumours, cancer cells, yeast cells, epithelial cells, bacteria etc. The most extensively used form of this method is the alkaline version as it detects a variety of damages in single cells, such as DNA double-strand breaks, single-strand breaks, alkali-labile sites and DNADNA/DNA-protein cross-linking. Thus, the human epithelial bladder cancer (RT112) cell line was incubated with hydrogen peroxide (H2O2), a DNAdamaging agent. The cells were embedded in a thin agarose gel on microscope slides. Cellular proteins were removed by lysing the cells, followed by unwinding the damaged DNA-forming comets using electrophoresis under alkaline conditions (pH >13). One hundred comet images per each concentration were captured by using a fluorescence microscope. There was a significant increase in DNA percentage in tail of the comets with a linear rising of the tail lengths. Additionally, there was a strong positive correlation between tail DNA percentage and the lengths of the tail comets (p < 0.05, r > 0.98). Overall, the results of this study indicate that by increasing the DNA damage by H2O2, the intensity of the comet tails becomes higher, and the alkaline form of the comet assay is an effective method for measuring this damage.
Toxicological changes in female Wistar albino rats exposed to Solignum: a permethrin
In modern agriculture, synthetic agrochemicals are still the main line of defense in most pest management programs.Insecticides can have lethal or sublethal impacts on non-target organisms (species that recycle nutrients in the soil, pollinators and predators of target species).They also can contaminate food sources of organisms of higher trophic levels.To achieve protection of non-target organisms from the effects caused by the continued development and use of agrochemicals in modern agriculture, the European Economic Community and the Environmental Pollutant Agency emphasize the necessity of developing bioassays on honeybees to approve an agrochemical registration.The toxicity of commercial formulations of two insecticides, α-endosulphan (organochlorine) and α-cypermethrin (piretroid), and a commercial formulation of the herbicide glyphosate (organophosphorus) was analyzed.The analysis was performed on the bees using the comet assay as a biomarker of damaged DNA.The assay performed demonstrated the mutagenic effects caused by agrochemicals in DNA cells of the hypopharingeal gland from the bees.
Municipal effluents are recognized as major sources of pollutants that could compromise fish health and reproduction. The purpose of this study was to examine and compare the reproductive toxicity of low-and high-risk municipal effluents to fathead minnows (Pimephales promelas) exposed for 12 weeks in the laboratory. After the exposure period, reproductive success was determined by following changes in the total number of eggs, egg hatchability/survival and time to hatch. In parallel, the expression of the following was also assessed in adults to gain insights into the pathways involved in toxicity: estrogen receptor alpha (ERα), androgen receptor (Ar1), pregnane X receptor (PXR1), vitellogenin (VTG), CYP3A4 and 17β-hydroxysteroid dehydrogenase (HSD). The results revealed that in the high-and low-risk effluents, egg laying followed a biphasic response, with an initial increase in egg laying followed by a decrease at higher concentrations and stronger amplitudes with the high-risk effluent. Hatching success (i.e., release of viable fish fry) was directly proportional to the decrease in egg production with no hatching of viable fish at 10% and 20% for both effluents. VTG gene expression was significantly increased in females, reaching levels 4 and 3 orders of magnitude greater than in the controls for the high-and low-risk effluent, respectively. VTG gene expression was also found in males but at lower expression levels than for the females. The expression of ERα was significantly correlated with VTG levels, which suggests the presence of estrogenic compounds in municipal effluents. This was further supported by the increased expression of CYP3A4, which is involved in the biotransformation of steroid-like and pharmaceutical compounds. In conclusion, municipal effluents have the capacity to reduce reproduction in fathead minnows and involve estrogenic effects. The high-risk effluent generally displayed stronger effects than the low-risk effluent.
Author(s): Carratt, SA; Flayer, CH; Kossack, ME; Last, JA | Abstract: In the past few decades, the frequency and severity of wildfires in California has increased. The majority of studies on wildfire-related human health effects have focused on the criteria pollutants in smoke. However, there are other minor constituents of smoke that may impact human health, particularly in specific geographic regions in California. This review summarizes what we currently know about the contribution of pesticides and wildfire suppression chemicals to wildfire-induced human health effects. In California there is heavy use of pesticides in agricultural settings and at the urban interface. When wildfires burn land treated with pesticide, these chemicals and their combustion products are volatilized and can be inhaled by humans. These constituents can be transported long distances in smoke, although those at the highest risk for exposure are near the wildfire source. Toxicity of some pesticides by inhalation has been demonstrated, although the health effects of pesticide combustion products in smoke have not been characterized. In order to effectively fight wildfires, large volumes of wildfire suppression chemicals are used. Wildfire suppression chemicals include retardants, for long-term application, and foams, for short term application. Based on the available data, foams are more likely to have an impact on human health than retardants. Moreover, foams tend to be applied at the urban interface, while the retardants are generally applied in remote areas. Understanding the health effects of the compounds we choose to introduce into our environment and how they alter and are altered by extreme events like wildfires is an important consideration for fire and land management. Our investigation has uncovered that there are significant data gaps in this area.
The purpose of this study was to compare the toxicity of two major municipal effluents subjected to different treatment processes: a physico-chemically treated effluent (high-risk effluent) and a biofiltered/ UV-disinfected effluent (low-risk effluent). Juvenile fathead minnows were exposed to increasing concentrations of the high-risk and low-risk effluents in semi-static conditions for 16 weeks at 25 °C. At the end of the exposure period, juveniles were collected for immunocompetence (leukocyte density and phagocytosis), oxidative stress (catalase and superoxide dismutase activity) and DNA damage (COMET assay) assessments. The data revealed that DNA damage was the most sensitive biomarker, with increases at concentrations between 3.5% and 5%, and that the treatment processes had no influence on the intensity of genotoxic effects. A greater increase in oxidative stress enzymes was observed with the high-risk effluent as compared to the low-risk effluent, suggesting that oxidative stress was dependent on the treatment process applied. At the immunocompetence level, a biphasic pattern of response was found in both the high-risk and low-risk effluents. Indeed, in fish exposed to the low-risk effluent, an initial increase in leukocyte density and phagocytosis activity was followed by a subsequent decrease in these effects with increasing concentrations of the effluent. In the high-risk effluent, the initial increase and subsequent drop in leukocyte density occurred at lower concentrations while phagocytosis activity increased only at the highest concentration. In conclusion, the occurrence of DNA damage was not affected by the 2 types of effluents; however, oxidative stress and immunocompetence were more strongly influenced by the high-risk effluent than the low-risk one.
DNA methylation of repeated elements and cancer-related genes in normal human liver, and in cancer and non-cancer liver cell lines, treated with 5adC or PCB126 ABSTRACT DNA methylation is an important epigenetic mechanism contributing to the regulation of gene expression and to the stability of DNA repeated sequences.Abnormal DNA methylation is a characteristic of cancer cells and there are scientific concerns that exposure to environmental contaminants (EC) might contribute to carcinogenesis by altering DNA methylation mechanisms.This study compared DNA methylation of repeated elements and cancerrelated genes in normal human liver, and in cancer (HepG2) and non-cancer (HC-04) cell lines, and investigated the effects of 5-aza-2'-deoxycytidine (5adC; a demethylation control) and polychlorinated biphenyl-126 (PCB126), a non-genotoxic rodent hepatocarcinogen.The results revealed striking celltype differences in DNA methylation of repeated elements (AluYb8, LINE-1, Sat-alpha) and 7/9 cancerrelated genes (CCND2, DAB2IP, DLEC1, GSTp1, OPCML, RASSF1, RUNX3, but not SFRP2 and SOCS1).In 72-h dose-response experiments, 5adC induced "U" shape demethylation responses in the nine investigated genes, but associated with elevated mRNA expression only in 6/9 and 3/9 genes in HC-04 and HepG2 cells, respectively.DNA methylation was resistant to PCB126 in most genes in both cell lines, except for reduced promoter methylation and increased expression of GSTp1 in HepG2 cells, which further support a role for oxidative stress in PCB126induced oncogenesis/toxicity. Finally, the different DNA methylation patterns and gene expression responses between the non-cancer HC-04 and cancer HepG2 cell lines provide alternative models to further explore epigenetic divergence in gene expression regulation.
Naphthalene is a polycyclic aromatic hydrocarbon that is commonly encountered in indoor and outdoor environments. There is growing awareness of the environmental health risks associated with inhalation exposure to naphthalene in the indoor environment. While there are numerous potential sources of naphthalene indoors, the use of mothballs can be a significant contributor to ambient concentrations. This review article describes recurring and emerging environmental health issues relating to mothballs containing naphthalene. The toxicology and health effects of naphthalene exposure are reviewed, with discussion of high-risk populations and risk mitigation strategies. Environmental health professionals should be aware of mothball use in the home, and recognize risks associated with accidental exposure and misuse.
