Acute toluene intoxication--clinical presentation, management and prognosis: a prospective observational study

Toxic leukoencephalopathies

Toxic-metabolic encephalopathies are a group of disorders in which an exogenous or endogenous substance leads to transient or permanent neuronal damage. It is an important cause of potentially reversible acute encephalopathy syndrome. The signs and symptoms of toxic encephalopathies may be relatively nonspecific, and toxicologic tests are not always widely available. Imaging plays a key role in determining the most probable diagnosis, pointing to the next steps of investigation, and providing prognostic information. In this chapter, we review the main acquired toxic-metabolic leukoencephalopathies, commenting on their pathophysiology, imaging patterns, and rationale for an adequate diagnosis in detail.

The Experience of Using Urinary Liver-Type Fatty Acid-Binding Protein for Follow-Up of Toluene Poisoning: A Case Report

Toluene poisoning is diagnosed based on toluene exposure history and the level of hippuric acid in the urine. Regular blood and urine tests are performed for follow-up. A 54-year-old man collided with a utility pole while driving a car and was rushed to our hospital with a complaint of loss of consciousness. Although the trauma was minor, toluene poisoning was suspected based on the presence of impaired consciousness, occupation is a painting job that involves toluene, and the presence of metabolic acidosis of the normal anion gap. Urinary hippuric acid and urinary liver-type fatty acid-binding protein (L-FABP) were measured, and a diagnosis of renal tubular acidosis (RTA) due to toluene toxicity was made. Urinary L-FABP levels decreased as the condition improved. Urinary L-FABP is a practical and rapid diagnostic and follow-up tool for toluene-induced RTA, and it is helpful to measure it in addition to conventional methods.

The pathophysiology of distal renal tubular acidosis

The kidneys have a central role in the control of acid-base homeostasis owing to bicarbonate reabsorption and production of ammonia and ammonium in the proximal tubule and active acid secretion along the collecting duct. Impaired acid excretion by the collecting duct system causes distal renal tubular acidosis (dRTA), which is characterized by the failure to acidify urine below pH 5.5. This defect originates from reduced function of acid-secretory type A intercalated cells. Inherited forms of dRTA are caused by variants in SLC4A1, ATP6V1B1, ATP6V0A4, FOXI1, WDR72 and probably in other genes that are yet to be discovered. Inheritance of dRTA follows autosomal-dominant and -recessive patterns. Acquired forms of dRTA are caused by various types of autoimmune diseases or adverse effects of some drugs. Incomplete dRTA is frequently found in patients with and without kidney stone disease. These patients fail to appropriately acidify their urine when challenged, suggesting that incomplete dRTA may represent an intermediate state in the spectrum of the ability to excrete acids. Unrecognized or insufficiently treated dRTA can cause rickets and failure to thrive in children, osteomalacia in adults, nephrolithiasis and nephrocalcinosis. Electrolyte disorders are also often present and poorly controlled dRTA can increase the risk of developing chronic kidney disease.

Molecular evidence of the amelioration of toluene induced encephalopathy by human breast milk mesenchymal stem cells

Toluene was widely used volatile organic compound that accumulates in tissues with high lipid content. Stem cells have been proposed as an increasingly attractive approach for repair of damaged nervous system, we aimed to evaluate the ability of breast milk mesenchymal stem cells (MSc) to ameliorate toluene-induced encephalopathy. Sixty adult male albino rats were assigned to 3 groups, control, toluene, and toluene/breast milk-MSc. Neurological assessment was evaluated as well as serum levels of glial fibrillary acidic protein (GFAP), tumor necrosis factor-alpha (TNF-α), nerve growth factor (NGF), vascular endothelial growth factor (VEGF), tissue dopamine and oxidative markers. Gene expression of peroxisome Proliferator-Activated Receptor-Gamma (PPAR-ɣ), nuclear factor-kappaB (NF-kB), and interleukin-6 (IL-6) were evaluated. Moreover, histological and immunohistochemical investigation were done. Results revealed that toluene caused cerebral injury, as evidenced by a significant increase in serum GFAP, TNF-α, malondialdehyde (MDA) and nitric oxide (NO), a significant decrease in serum NGF, tissue dopamine and oxidative markers, besides, a non-significant change in VEGF. Toluene also caused changes in normal cerebral structure and cellular degeneration, including a significant decrease in the total number of neurons and thickness of frontal cortex. Meninges showing signs of inflammation with inflammatory cell infiltration and exudation, a significant decrease in MBP immunoreactivity, and increase in the percent of high motility group box protein-1 (HMGB1) positive cells. PPAR- ɣ, NF-kB, and IL-6 gene expression were all considerably elevated by toluene. These changes were greatly improved by breast milk MSc. Therefore, we conclude that breast milk MSc can attenuate toluene-induced encephalopathy.

Toxic benzyl alcohol inhalation: Altered mental status with metabolic acidosis and hyperammonemia

This report presents the case of a patient whose inhalation exposure to benzyl alcohol led to clinical manifestations similar to toluene intoxication, including sudden altered mental status, metabolic acidosis, hypokalemia, hypophosphatemia, and hyperammonemia. Toxicity from benzyl alcohol inhalation is quite rare, and hyperammonemia associated with renal tubular dysfunction in poisoning cases has not been reported in the past.

In Silico Prediction and Insights Into the Structural Basis of Drug Induced Nephrotoxicity

Drug induced nephrotoxicity is a major clinical challenge, and it is always associated with higher costs for the pharmaceutical industry and due to detection during the late stages of drug development. It is desirable for improving the health outcomes for patients to distinguish nephrotoxic structures at an early stage of drug development. In this study, we focused on in silico prediction and insights into the structural basis of drug induced nephrotoxicity, based on reliable data on human nephrotoxicity. We collected 565 diverse chemical structures, including 287 nephrotoxic drugs on humans in the real world, and 278 non-nephrotoxic approved drugs. Several different machine learning and deep learning algorithms were employed for in silico model building. Then, a consensus model was developed based on three best individual models (RFR_QNPR, XGBOOST_QNPR, and CNF). The consensus model performed much better than individual models on internal validation and it achieved prediction accuracy of 86.24% external validation. The results of analysis of molecular properties differences between nephrotoxic and non-nephrotoxic structures indicated that several key molecular properties differ significantly, including molecular weight (MW), molecular polar surface area (MPSA), AlogP, number of hydrogen bond acceptors (nHBA), molecular solubility (LogS), the number of rotatable bonds (nRotB), and the number of aromatic rings (nAR). These molecular properties may be able to play an important part in the identification of nephrotoxic chemicals. Finally, 87 structural alerts for chemical nephrotoxicity were mined with f-score and positive rate analysis of substructures from Klekota-Roth fingerprint (KRFP). These structural alerts can well identify nephrotoxic drug structures in the data set. The in silico models and the structural alerts could be freely accessed via https://ochem.eu/article/140251 and http://www.sapredictor.cn, respectively. We hope the results should provide useful tools for early nephrotoxicity estimation in drug development.

Management of hydrocarbon burns: Considering mental health and biochemical abnormalities

Volatile substance misuse, particularly the inhalation of hydrocarbons, is a growing issue globally. Consequences of VSM, both acute or chronic, causes cardiovascular, respiratory, renal, metabolic and central nervous system damage. Whilst the effects of hydrocarbon abuse have been reported, the combination of intoxication with hydrocarbon and burns sustained has not yet been presented. A retrospective case series of patients who presented in the last 5 years to the Royal Adelaide Hospital with hydrocarbon-related burns in the context of illicit use was undertaken. Our aims are to present to the wider scientific community the high morbidity and mortality of hydrocarbon burn injuries and why this tertiary Burns Unit feel it most appropriate to medically stabilise these patients prior to definitive surgery for their burn. All patients that presented with acute hydrocarbon intoxication and sustained concomitant burns had significant psychiatric disorder and substance abuse history and three of five had either not eaten in several days resulting in acute malnourishment, refeeding syndrome or had evidence of chronic malnourishment with deranged electrolytes and hypoalbuminaemia. Their definitive burns surgery was delayed where appropriate in order to facilitate medical stabilisation as they were too high risk of cardiac membrane instability, electrolyte derangement and/or respiratory compromise to undergo safe general anaesthetic and burns debridement. We propose a multidisciplinary team approach, utilising not only our Burns Unit care model of physiotherapists, psychologists, social work and burns trained nurses and surgeons but also Intensive Care, Toxicology, Addiction medicine and General Medical physicians in the management of these patients.

ACUTE EXPOSURE TO ABUSE-LIKE CONCENTRATIONS OF TOLUENE INDUCES INFLAMMATION IN MOUSE LUNGS AND BRAIN

Toluene is an aromatic hydrocarbon commonly abused by young adolescents for its central nervous system depressant effects. While toluene's pharmacological effects at high concentrations are relatively well known, few studies have assessed toluene's effects on lung and brain tissues. The present study characterized the pathological effects of acute inhaled toluene exposure in the lungs and brains of male Swiss-Webster mice (N = 68). Using a static vapor exposure chamber, mice (PND 28) received a single 30-min toluene administration (0, 1000, 2000, or 4000 ppm). Lung and brain tissues were extracted 24 hrs post-exposure. Histology results revealed significant changes in the morphology lung tissue (e.g., irregular cellular architecture) with the 2000 and 4000 ppm exposures expressing greater signs of pathology than control 0-ppm exposure. Markers of immune system activity (F4/80 and Ly-6G) and cellular proliferation (Ki-67) in the lung revealed no significant differences. Additionally, brain tissues were analyzed for changes of astrogliosis (GFAP) and oxidative stress (GPx). GFAP showed increased astrogliosis in the striatum with 2000 ppm toluene showing significantly higher expression than control (p < 0.05), and a marginal effect in the hippocampus. No other markers showed significant changes. The increased signs of inflammation and cellular damage suggest that exposure to a single high concentration of toluene, typical of abuse, are capable of producing pathology in both lung and brain tissue.

Targeted and Nontargeted Detection and Characterization of Trace Organic Chemicals in Human Serum and Plasma Using QuEChERS Extraction

Humans are exposed to a broad range of organic chemicals. Although targeted gas chromatography mass spectrometry techniques are used to quantify a limited number of persistent organic pollutants and trace organic contaminants in biological samples, nontargeted, high-resolution mass spectrometry (HRMS) methods assess the human exposome more extensively. We present a QuEChERS extraction for targeted and nontargeted analysis of trace organic contaminants using HRMS and compare this method to a traditional, cartridge-based solid-phase extraction (SPE). Following validation using reference and spiked serum samples, the method was applied to plasma samples (n = 75) from the Prospective investigation of Obesity, Energy, and Metabolism (POEM) study. We quantified 44 analytes using targeted analysis and 6247 peaks were detected using the nontargeted approach. Over 90% of targeted analytes were at least 90% recovered using the QuEChERS method in spiked serum samples. In nontargeted analysis, 84% of the peaks were above the method detection limit with area counts up to 3.0 × 105 times greater using the QuEChERS method. Of the targeted compounds, 88% were also identified in the nontargeted analysis. We categorized the 4212 chemicals assigned an identity in using EPA's CompTox Dashboard and 1076 chemicals were found in at least one list. The category with the highest number of chemicals was "androgen or estrogen receptor activity." The findings demonstrate that a QuEChERS technique is suitable for both targeted and nontargeted analysis of trace organic contaminants in biological samples.

19-year-old Woman with Intermittent Weakness

Introduction

Systemic weakness is a common chief complaint of patients presenting to the emergency department (ED). A well thought out approach to the assessment and workup of these patients is key to diagnostic accuracy and definitive therapy.

Case Presentation

In this case, a 19-year-old female presented to the ED with generalized weakness and near syncope. She had global weakness in her extremities and multiple electrolyte abnormalities.

Discussion

This case takes the reader through the differential diagnosis and evaluation of a patient with weakness and profound electrolyte derangements. It includes a discussion of the diagnostic studies and calculations that ultimately led to the patient’s diagnosis.

Inhalants

Toxic inhalants include various xenobiotics. Irritants cause upper and lower respiratory tract injuries. Highly water-soluble agents injure the upper respiratory tract, while low water-soluble inhalants injure the lower track. Asphyxiants are divided into simple asphyxiants and chemical asphyxiants. Simple asphyxiants displace oxygen, causing hypoxia, while chemical asphyxiants also impair the body's ability to use oxygen. Cyanide is a classic chemical asphyxiant. Treatment includes hydroxocobalamin. Electronic cigarette or vaping use-associated lung injury (EVALI) is a relatively new illness. Patients present with respiratory symptoms and gastrointestinal distress. EVALI appears to be associated with vaping cannabinoids. Treatment is supportive and may include steroids.

Smoking and Neuropsychiatric Disease-Associations and Underlying Mechanisms

Despite extensive efforts to combat cigarette smoking/tobacco use, it still remains a leading cause of global morbidity and mortality, killing more than eight million people each year. While tobacco smoking is a major risk factor for non-communicable diseases related to the four main groups—cardiovascular disease, cancer, chronic lung disease, and diabetes—its impact on neuropsychiatric risk is rather elusive. The aim of this review article is to emphasize the importance of smoking as a potential risk factor for neuropsychiatric disease and to identify central pathophysiological mechanisms that may contribute to this relationship. There is strong evidence from epidemiological and experimental studies indicating that smoking may increase the risk of various neuropsychiatric diseases, such as dementia/cognitive decline, schizophrenia/psychosis, depression, anxiety disorder, and suicidal behavior induced by structural and functional alterations of the central nervous system, mainly centered on inflammatory and oxidative stress pathways. From a public health perspective, preventive measures and policies designed to counteract the global epidemic of smoking should necessarily include warnings and actions that address the risk of neuropsychiatric disease.

The last two decades on preclinical and clinical research on inhalant effects

This paper reviews the scientific evidence generated in the last two decades on the effects and mechanisms of action of most commonly misused inhalants. In the first section, we define what inhalants are, how they are used, and their prevalence worldwide. The second section presents specific characteristics that define the main groups of inhalants: (a) organic solvents; (b) aerosols, gases, and volatile anesthetics; and (c) alkyl nitrites. We include a table with the molecular formula, structure, synonyms, uses, physicochemical properties and exposure limits of representative compounds within each group. The third and fourth sections review the direct acute and chronic effects of common inhalants on health and behavior with a summary of mechanisms of action, respectively. In the fifth section, we address inhalant intoxication signs and available treatment. The sixth section examines the health effects, intoxication, and treatment of nitrites. The seventh section reviews current intervention strategies. Finally, we propose a research agenda to promote the study of (a) solvents other than toluene; (b) inhalant mixtures; (c) effects in combination with other drugs of abuse; (d) age and (e) sex differences in inhalant effects; (f) the long-lasting behavioral effects of animals exposed in utero to inhalants; (g) abstinence signs and neurochemical changes after interrupting inhalant exposure; (h) brain networks involved in inhalant effects; and finally (i) strategies to promote recovery of inhalant users.

A 20-Year-Old Man with e-Cigarette or Vaping Product Use-Associated Lung Injury (EVALI) and Thrombotic Coagulopathy

BACKGROUND In 2019, the US Centers for Disease Control and Prevention (CDC) described the criteria for the diagnosis of e-cigarette or vaping product use-associated lung injury (EVALI), which may be caused by contamination of delta-9-tetrahydrocannabinoid (THC) e-liquids with vitamin E acetate. This report describes a case of a 20-year-old man with a history of recreational drug use that included vaping, who presented with EVALI and a coagulopathy associated with thrombotic events. CASE REPORT We present a 20-year-old patient who worked at a cannabidiol (CBD) manufacturing facility with a history of e-cigarette use and polysubstance abuse in remission who presented with respiratory and gastrointestinal symptoms accompanied by 50-pound weight loss over 6 months. The patient had been vaping with nicotine and THC-containing e-cigarettes multiple times per day for 1.5 years. He met the CDC surveillance criteria for EVALI, consisting of respiratory symptoms and infiltrates on imaging within 90 days of vaping, and was found to have eosinophilic pneumonia secondary to THC-containing e-cigarette use. Additionally, thrombi were detected in the pulmonary arteries, right saphenous vein, and right ventricle. A segmental infarct was noted in the inferior pole of the left kidney. CONCLUSIONS We present the second case report potentially linking e-cigarette use with clinically significant thrombogenesis, the first with both arterial and venous thromboses. This report demonstrates the importance of taking a history of e-cigarette use in patients presenting with lung injury. Although EVALI and the diagnostic criteria have only recently been described, systemic effects, including coagulopathy, are now being reported.

Effects of tobacco cigarettes, e-cigarettes, and waterpipe smoking on endothelial function and clinical outcomes

Tobacco smoking is a leading cause of non-communicable disease globally and is a major risk factor for cardiovascular disease (CVD) and lung disease. Importantly, recent data by the World Health Organizations (WHO) indicate that in the last two decades global tobacco use has significantly dropped, which was largely driven by decreased numbers of female smokers. Despite such advances, the use of e-cigarettes and waterpipes (shisha, hookah, narghile) is an emerging trend, especially among younger generations. There is growing body of evidence that e-cigarettes are not a harm-free alternative to tobacco cigarettes and there is considerable debate as to whether e-cigarettes are saving smokers or generating new addicts. Here, we provide an updated overview of the impact of tobacco/waterpipe (shisha) smoking and e-cigarette vaping on endothelial function, a biomarker for early, subclinical, atherosclerosis from human and animal studies. Also their emerging adverse effects on the proteome, transcriptome, epigenome, microbiome, and the circadian clock are summarized. We briefly discuss heat-not-burn tobacco products and their cardiovascular health effects. We discuss the impact of the toxic constituents of these products on endothelial function and subsequent CVD and we also provide an update on current recommendations, regulation and advertising with focus on the USA and Europe. As outlined by the WHO, tobacco cigarette, waterpipe, and e-cigarette smoking/vaping may contribute to an increased burden of symptoms due to coronavirus disease 2019 (COVID-19) and to severe health consequences.

Toxicological Study and Genetic Basis of BTEX Susceptibility in Drosophila melanogaster

Benzene, toluene, ethylbenzene and xylene, also known as BTEX, are released into environmental media by petroleum product exploratory and exploitative activities and are harmful to humans and animals. Testing the effects of these chemicals on a significantly large scale requires an inexpensive, rapidly developing model organism such as Drosophila melanogaster. In this study, the toxicological profile of benzene, toluene, ethylbenzene, p-xylene, m-xylene, and o-xylene in D. melanogaster was evaluated. Adult animals were monitored for acute toxicity effects. Similarly, first instar larvae reared separately on the same compounds were monitored for the ability to develop into adult flies (eclosion). Further, the impact of fixed concentrations of benzene and xylene on apoptosis and mitosis were investigated in adult progenitor tissues found in third instar larvae. Toluene is the most toxic to adult flies with an LC₅₀ of 0.166 mM, while a significant and dose-dependent decrease in fly eclosion was observed with benzene, p-xylene, and o-xylene. An increase in apoptosis and mitosis was also observed in animals exposed to benzene and p-xylene. Through Genome Wide Association Screening (GWAS), 38 regions of the D. melanogaster genome were identified as critical for responses to p-xylene. This study reveals the strength of D. Melanogaster genetics as an accessible approach to study BTEX compounds.

Toxin-Induced Cerebellar Disorders

The cerebellum plays an important role in motor and nonmotor systems, with damage resulting in clinical manifestations presenting as weakness, ataxia, dysarthria, and nystagmus. There are numerous environmental and industrial agents as well as medications that, through either accidental or intentional use, can result in a range of neurologic presentations. The variability in the presentation is important to recognize promptly so that early cessation in exposure, use, or abuse can be initiated to reduce the severity of symptoms. Recognition of an agent causing the particular pathology is important so that the route of exposure, and subsequent treatment options can be identified.

Assessment of kidney health and exposure to mixture pollutants in the Mexican indigenous population

The indigenous population is one of the most vulnerable to suffer from contaminated environments. One of the target organs to suffer early deterioration from exposure to toxins is the kidney. The objective of this article was to evaluate biomarkers of exposure to organic and inorganic toxins and biomarkers of early kidney damage in urine from an indigenous Tenek population in Mexico. The biomarkers of exposure were Li, Be, Al, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Mo, Sn, Ba, and Pb evaluated by ICP-MS and hippuric acid for toluene exposure evaluated by UV-coupled with liquid chromatography; the biomarkers of kidney damage were cystatin C (Cys-C), osteopontin (OPN), retinol-binding protein-4 (RPB-4), and neutrophil gelatinase-associated lipocalin (NGAL). Thirty-one urine samples were obtained from indigenous people; 16, 42, 45.1, and 45.2% of the population exceeded the reference values for Pb, Zn, As, and hippuric acid respectively. Our results demonstrate significant correlations between the metals tested and the proteins associated with renal damage; Cys-C, OPN, and RPB4 showed a significant correlation with Li, B, and Mo, as well as hippuric acid in the case of Cys-C and Zn in OPN and RPB-4; NGAL did not present significant correlations with any of the pollutants of the study. This pilot study contributes to the evidence of great inequity in health associated to environmental pollution matters faced by indigenous people and addresses the need of initiatives for mitigation under the perspective that health is a fundamental human right.

Self-Administration of Toluene Vapor in Rats

Inhalants, including volatile organic solvents such as toluene, continue to be one of the most prevalent, and often first substances abused by adolescents. Like other drugs of abuse, toluene affects the function of neurons within key brain reward circuits including the prefrontal cortex, ventral tegmental area, and nucleus accumbens. However, preclinical models used to study these toluene-induced adaptations generally employ passive exposure paradigms that do not mirror voluntary patterns of solvent exposure observed in humans. To address this shortcoming, we developed an inhalation chamber containing active and inactive nose pokes, cue lights, flow-through vaporizers, and software-controlled valves to test the hypothesis that rats will voluntarily self-administer toluene vapor. Following habituation and self-administration (SA) training rats achieve vapor concentrations associated with rewarding effects of toluene, and maintain responding for toluene vapor, but not for air. During extinction trials, rats showed an initial burst of drug-seeking behavior similar to that of other addictive drugs and then reduced responding to Air SA levels. Responding on the active nose poke recovered during cue-induced reinstatement but not following a single passive exposure to toluene vapor. The results from these studies establish a viable toluene SA protocol that will be useful in assessing toluene-induced changes in addiction neurocircuitry.

Toluene Toxicity: A Case Report of Transdermal Exposure Causing Hypokalemic Paralysis

Rationale:

Hypokalemia is a common finding. Typically asymptomatic presentations of neuromuscular weakness emerge at levels below 2.5 mmol/L. Causes include gastrointestinal losses, renal losses, or intracellular shift, with gastrointestinal losses and diuretics accounting for the majority. Although the cause is often apparent on clinical assessment, a systematic approach incorporating urine biochemistry can aid in narrowing the differential in obscure cases.

Presentation:

We describe a case of a previously healthy 27-year-old man who presented with acute ascending paralysis, with an associated severe hypokalemia and metabolic acidosis. There were no apparent causes on clinical assessment.

Diagnosis:

Based on analysis of urine biochemistry, we concluded that a pathologic kaluresis was present, and given his acidemia and transient pathology, we diagnosed the patient with hypokalemic paralysis secondary to toluene toxicity.

Interventions:

We provided supportive care and electrolyte repletion for our patient; no specific therapies for toluene were required. Our patient was counseled regarding appropriate protective measures when handling toluene.

Outcomes:

Complete neurologic recovery and biochemical normalization occurred within 48 hours of presentation with supportive care. He continued to use proper precautions when handling toluene, and experienced no symptom relapse, or further abnormalities on both blood and urine chemistry.

Lessons learned:

Using this case, we review an algorithmic approach incorporating urine biochemistries to aid in the workup of hypokalemia. We review toluene as a toxicologic entity and highlight its role as a cause of hypokalemia.

Targeted GC-MS analysis of firefighters' exhaled breath: Exploring biomarker response at the individual level

Biomarker measurements can provide unambiguous evidence of environmental exposures as well as the resultant biological responses. Firefighters have a high rate of occupational cancer incidence, which has been proposed to be linked in part to their increased environmental exposure to byproducts of combustion and contaminants produced during fire responses. In this article, the uptake and elimination of targeted volatile organic compounds were investigated by collecting the exhaled breath of firefighters on sorbent tubes before and after controlled structure burns and analyzing samples using automated thermal desorption-gas chromatography (ATD-GC/MS). Volatile organic compounds exposure was assessed by grouping the data according to firefighting job positions as well as visualizing the data at the level of the individual firefighter to determine which individuals had expected exposure responses. When data were assessed at the group level, benzene concentrations were found to be elevated post-exposure in both fire attack, victim search, and outside ventilation firefighting positions. However, the results of the data analysis at the individual level indicate that certain firefighters may be more susceptible to post-exposure volatile organic compounds increases than others, and this should be considered when assessing the effectiveness of firefighting protective gear. Although this work focuses on firefighting activity, the results can be translated to potential human health and ecological effects from building and forest fires.

Toluene abuse markers in marginalized populations

Toluene abuse is one of the most common addictions among marginalized Roma. The aim of the study was the comparison of urinary toluene metabolite levels in marginalized population of Eastern Slovakia as compared to the majority population, and to verify the validity of the answers, given in the questionnaires, regarding toluene abuse. The study was carried out as part of the HEPA-META project aiming to map the prevalence of health problems in marginalized Roma. The majority of people living outside the area of the segregated Roma communities comprised the control group. The total number of study participants was 770. Statistically significant differences in the levels of hippuric acid and o-cresol were found between Roma and the majority population. Variations in urinary hippuric acid levels in addition to toluene abuse can be caused also by dietary factors, medical treatment as well as alcohol consumption, which is frequent (not only) in marginalized communities.

Hypokalemic Distal Renal Tubular Acidosis

Distal renal tubular acidosis (DRTA) is defined as hyperchloremic, non-anion gap metabolic acidosis with impaired urinary acid excretion in the presence of a normal or moderately reduced glomerular filtration rate. Failure in urinary acid excretion results from reduced H⁺ secretion by intercalated cells in the distal nephron. This results in decreased excretion of NH₄⁺ and other acids collectively referred as titratable acids while urine pH is typically above 5.5 in the face of systemic acidosis. The clinical phenotype in patients with DRTA is characterized by stunted growth with bone abnormalities in children as well as nephrocalcinosis and nephrolithiasis that develop as the consequence of hypercalciuria, hypocitraturia, and relatively alkaline urine. Hypokalemia is a striking finding that accounts for muscle weakness and requires continued treatment together with alkali-based therapies. This review will focus on the mechanisms responsible for impaired acid excretion and urinary potassium wastage, the clinical features, and diagnostic approaches of hypokalemic DRTA, both inherited and acquired.

When good times go bad: managing 'legal high' complications in the emergency department

Patients can use numerous drugs that exist outside of existing regulatory statutes in order to get "legal highs." Legal psychoactive substances represent a challenge to the emergency medicine physician due to the sheer number of available agents, their multiple toxidromes and presentations, their escaping traditional methods of analysis, and the reluctance of patients to divulge their use of these agents. This paper endeavors to cover a wide variety of "legal highs," or uncontrolled psychoactive substances that may have abuse potential and may result in serious toxicity. These agents include not only some novel psychoactive substances aka "designer drugs," but also a wide variety of over-the-counter medications, herbal supplements, and even a household culinary spice. The care of patients in the emergency department who have used "legal high" substances is challenging. Patients may misunderstand the substance they have been exposed to, there are rarely any readily available laboratory confirmatory tests for these substances, and the exact substances being abused may change on a near-daily basis. This review will attempt to group legal agents into expected toxidromes and discuss associated common clinical manifestations and management. A focus on aggressive symptom-based supportive care as well as management of end-organ dysfunction is the mainstay of treatment for these patients in the emergency department.

Expanding the differential: toluene-induced toxicity

A 31-year-old woman presented to the hospital with generalised weakness and lower back and abdominal pain. The only significant finding on physical examination was the weakness of the legs. Laboratory analysis in the emergency department revealed that she was hypokalaemic with metabolic acidosis. She was treated with oral and intravenous potassium, which resolved her weakness. During the search for an explanation for her renal tubular acidosis, she said she was exposed to paint exposure while working on a friend's house. She was discharged on correction of her hypokalaemia, and a subsequent test revealed elevated blood toluene level.

Rhabdomyolysis with acute tubular necrosis following occupational inhalation of thinners

Thinners are mixtures of organic solvents commonly containing toluene, xylene, acetone, hexane, benzene and methyl isobutyl ketone. This report describes a case of rhabdomyolysis with acute tubular necrosis and renal failure, most likely attributable to toluene, following occupational exposure to thinners while cleaning a steel water tank. These adverse health effects have previously been reported following acute poisoning or intentional inhalation by drug abusers, but rarely in the occupational setting. Poor working conditions, lack of health and safety training and delayed treatment contributed to the onset and severity of the patient's complications. This case emphasizes the need for strict control measures, including adequate ventilation, training on working in confined spaces, appropriate personal protective equipment and emergency rescue procedures in such settings. In addition, rhabdomyolysis, acute tubular necrosis and renal failure should be added to safety data material as possible complications of excessive inhalation of thinners.

Tubulointerstitial Injury and Drugs of Abuse

Drug abuse is widespread in many populations, and patients abusing illicit substances are at a significantly increased risk of kidney injury. The tubulointerstitial compartment is a common target of these nephrotoxic agents. This review will cover some of the common illicit drugs and will focus on the tubulointerstitial injuries seen in the setting of drug abuse. Agents addressed in this review are synthetic cannabinoids, "bath salts," ecstasy, anabolic steroids, inhaled solvents, heroin, and cocaine. The most frequent biopsy findings are those of acute tubular necrosis and acute interstitial nephritis. Unfortunately, histology is often unable to sufficiently narrow the differential diagnosis and point to a single likely cause. A high suspicion for drug abuse as a potential cause of kidney injury is needed to identify the patients for whom this is the cause of their kidney failure. Toxicology screens are often of little use in identifying patients using emerging drugs of abuse.

Challenges in Laboratory Detection of Unusual Substance Abuse: Issues with Magic Mushroom, Peyote Cactus, Khat, and Solvent Abuse

Drug abuse is a worldwide problem. Although commonly abused drugs can be identified during routine urine drug testing, less commonly abused drugs may escape detection. These less commonly abused drugs not only include some designer drugs such as synthetic cannabinoid but also include abuse of psychedelic magic mushroom (active ingredients: psilocybin and psilocin), peyote cactus (active ingredient: mescaline), and khat plants (active ingredient: cathinone). Moreover, solvent and glue abuse is gaining popularity among teenagers and young adults which may even cause fatality. Amphetamine/methamphetamine immunoassay has a low cross-reactivity with psilocin. Cathinone, if present in the urine, can be detected by amphetamine/methamphetamine immunoassay due to cross-reactivity of cathinone with assay antibody. Currently there is one commercially available immunoassay which is capable of detecting synthetic cathinone known as bath salts as well as mescaline. However, gas chromatography combined with mass spectrometry as well as liquid chromatography combined with tandem mass spectrometry (LC/MS/MS)-based method is available for confirmation of the active ingredients present in magic mushroom, peyote cactus, and khat plant. Such chromatography-based methods also offer more sensitivity and specificity compared to an immunoassay.

The protective effect of Buffalo's milk against toluene induced-nephrotoxicity in rats

Background:

Toluene is widely used in different activities of industrial, commercial and household applications. It can cause damage to the human body. Buffalos’ milk has a good nutritive value.

Objectives:

The aim of this study is to examine the negative effects of toluene on kidney tissues and to investigate the protective effects of buffalo’s milk against toluene-induced nephrotoxicity in rats.

Materials and Methods:

Forty adult male Wistar rats (180-220 g weight) were randomly assigned to eight groups (n = 5). Animals in groups I to IV received oral gavage 1 mL distilled water (DH₂O) and groups V to VIII received oral gavage 1 mL buffalo’s milk. Ten minutes later, animals were received toluene (i.p) at doses of 300 mg/kg (groups I and V), 600 mg/kg (groups of II and VI), and 900 mg/kg (groups of III and VII), respectively. The animals in groups IV (control) and VIII were injected vehicle (corn oil) only. The experiment repeated for seven consecutive days. Twenty-four hours after the last administration, animals were killed with overdose of sodium pentobarbital. Blood samples were analyzed for blood urea nitrogen (BUN) and creatinine (Cr). One part of the kidney tissues were excised for measuring the activities of superoxide dismutase (SOD), glutathione reductase (GR) and catalase (CAT) and the level of malondialdehyde (MDA). Another parts were excised for histopatholgical examination.

Results:

Administration of toluene to male rats produced dose-dependent damage in the kidney. This was noted by elevation of BUN, Cr and MDA levels. In contrast, diminished the CAT, GR and SOD enzyme activities in rats treated with toluene when compared to those in control animals. Histopathological manifestations were also observed in dose related manner in toluene-treated rats. Buffalo’s milk had no effect on the biochemical parameters and kidney morphology when compared to those in control. However, it was able to prevent rat kidney against toluene toxicity.

Conclusions:

The results of this study demonstrated that toluene damages kidney tissue and is a nephrotoxic substance. Buffalo’s milk was able to prevent the renal damage as an antioxidant and a nephroprotective agent.