Measurement of an intestinal biomarker during poisonings from select toxicants and toxins.

INTRODUCTION: Intestinal toxicity can occur following ingestion of various drugs, chemicals, and toxins. Intestinal fatty acid binding protein is a cytosolic protein specific to intestinal epithelial cells released into the systemic circulation following intestinal injury. Understanding intestinal toxicity in poisoning has the potential to explain mechanisms of toxicity and gastrointestinal symptoms. METHODS: Plasma samples were retrospectively analysed for intestinal fatty acid binding protein in 25 healthy controls and in those poisoned with Gloriosa superba (n = 18), Thevetia peruviana (n = 26), organophosphates (in various solvents) (n = 17), paracetamol (n = 14), glyphosate (n = 20), 2-methyl-4-chlorophenoxyacetic acid (n = 18) and propanil (n = 19). RESULTS: Median peak plasma intestinal fatty acid binding protein concentrations were significantly higher in patients poisoned with Gloriosa superba (2,994.1 µg/L; interquartile range 600.0-5,158.2, P < 0.001), Thevetia peruviana (1,292.5 µg/L; interquartile range 760.3 - 2,076.2; P < 0.001), glyphosate (1,803.6 µg/L; interquartile range 225.7-8,927.7; P < 0.001), 2-methyl-4-chlorophenoxyacetic acid (1,236.2 µg/L; interquartile range 192.6 - 1,709.7; P = 0.010), paracetamol (1,066.5 µg/L; interquartile range 512.9 - 1,336.9; P = 0.035), and organophosphate poisoning (729.8 µg/L; interquartile range 431.5 - 1,588.2; P = 0.046) than in healthy controls (221.6 µg/L; interquartile range 134.8 - 460.1). Median intestinal fatty acid binding protein was not statistically significantly increased compared to controls after propanil poisoning (630.0 µg/L; interquartile range 23.5 - 1,390.3; P = 0.423). CONCLUSIONS: Our pilot study describes intestinal injury assessed by elevated plasma intestinal fatty acid binding protein concentrations following the ingestion of several poisons. This serves as a foundation for further exploration into enterocyte damage in toxicology.

High biosorption of cationic dye onto a novel material based on paper mill sludge.

The valorization of paper mill sludge (PMS) is the main goal of this study. The emissions of PMS continue to increase at global scale, especially from packaging paper and board sectors. The raw sludge was used to prepare an adsorbent to remove toxic pollutants from wastewater, the methylene blue (MB), an organic dye. Firstly, the physico-chemical characterization of PMS was done determining the crystalline phases of PMS fibers, the content of main elements, and the pH zero point charge, which was determined at around pH 7. The adsorption of MB on PMS powder was studied at 18 °C with an agitation of 200 rpm, being the best operating conditions 30 min of contact time, 250 mg L-1 of initial MB concentration and 0.05 g in 25 mL of adsorbent dose. Experimental data of MB adsorption was fitted to Langmuir and Freundlich isotherm equations. The Langmuir model was more accurate for the equilibrium data of MB adsorption at pH 5.1. The PFOM and PSOM were adjusted to experimental adsorption kinetics data, being PSOM, which describes better the MB adsorption by PMS powder. This was confirmed by calculating the maximum adsorption capacity with PSOM, which was 42.7 mg g-1, being nearly similar of the experimental value of 43.5 mg g-1. The analysis of adsorption thermodynamics showed that the MB was adsorbed exothermically with a ΔH0 = - 20.78 kJ mol-1, and spontaneously with ΔG0 from - 0.99 to - 6.38 kJ mol-1 in the range of temperature from 291 to 363 K, respectively. These results confirm that the sludge from paper industry can be used as biosorbent with remarkable adsorption capacity and low cost for the treatment of wastewater. PMS can be applied in the future for the depollution of the effluents from the textile industry, which are highly charged with dyes.

A prospective study of snakebite in a tertiary care hospital in south-western Nepal.

BACKGROUND: Snakebite is a neglected public health issue in Nepal. We aimed to characterize patients with snake envenoming admitted to hospital in south-western Nepal. METHODS: This was a prospective cohort study of 476 snakebite patients admitted to Bheri Hospital from May to December 2017. Data were collected on patient demographics, bite circumstances, snake type, treatment-seeking behavior, clinical effects, complications and treatment. RESULTS: There were 139/476 (29%) patients with clinical features of envenomation and 10 deaths (8%), of which six were prehospital deaths; 325/476 (68%) patients used non-recommended prehospital first aid, including 278 (58%) who applied a tourniquet and 43 (9%) consulting traditional healers. Median time to hospital arrival was 1.5 (IQR: 0.8-4) h. Also, 127 envenomated patients (91%) developed neurotoxicity and 12 (9%) hemotoxicity, while 124 patients (89%) received antivenom, with a median dose of 10 (4-30) vials. Three patients developed anaphylaxis following antivenom administration; 111 of 139 (80%) cases were admitted to the ICU and 48 (35%) were intubated. Median length of hospital stay for all cases was 0.5 (IQR: 0.5-1.2) d, but it was 2.2 (IQR: 1.5-3.8) d for envenomated cases. CONCLUSIONS: The majority of snakebite patients used non-recommended first aid or attended traditional healers. Almost one-third of patients developed systemic envenomation and required antivenom. The case fatality rate was high, but many died prior to arriving in hospital.

Dose ingested, vomiting, and outcome in patients ingesting a standard paraquat 20SL formulation.

BACKGROUND: FAO specifications for liquid paraquat dichloride SL formulations require the use of an emetic agent to stimulate vomiting within 30 min of ingestion. To date, there is no high-quality evidence of efficacy, despite use of the PP796 emetic since 1979. We first examined the validity of patients' self-reported dose of paraquat ingested by examining the relationship with blood paraquat concentration and time to death for patients ingesting the standard paraquat SL formulation in a Sri Lankan cohort. As a secondary outcome, we assessed whether ingestion resulted in vomiting within 30 min and whether vomiting was associated with good outcome. METHODS: Patients presenting with paraquat SL self-poisoning were prospectively studied in ten Sri Lankan hospitals in 2003-08. Data on reported dose ingested, incidence and timing of vomiting after ingestion, treatment received, plasma paraquat concentration, and outcome were collected prospectively on presentation to hospital. Time between ingestion and blood sampling was incorporated by covariate adjustment. RESULTS: 441 patients were recruited to the case series, presenting a median (IQR) of 3.0 (1.5-8.1] h post ingestion. Outcome was known for 435 patients of whom 322 (74.0%) died within 42 days, a median of 1.3 (0.6-4.4) days post ingestion. Median reported dose ingested was 15 to <30 mL. There was a highly significant linear trend between log plasma paraquat and reported dose ingested (p < .001); adjustment for the log of the time from ingestion to sampling further improved the model fit. Case fatality and median time to death also showed good agreement with estimated ingestion amount. 347/438 patients (79.2%) were stated to have vomited before reaching the study hospital with 300 (68.5%) vomiting within 30 min of ingestion; time to vomiting was unknown for a further 12 (2.7%). The proportion vomiting was strongly associated with reported dose ingested (p < .001); of note the proportion vomiting within 30 min only increased to 83.3% for the highest ingestion group. Patients vomiting within 30 min had higher plasma paraquat concentrations (p = .008), and higher hazard ratio in the adjusted Cox regression model of 2.01 (95% CI 1.45-2.77) compared to those who did not. Vomiting within 30 min was associated with a higher case fatality (241/295 [81.7%] vs 68/125 [54.4%], p < .001). Forty-three (47.3%) of the 91 patients who did not vomit before reaching hospital died (one had unknown outcome). CONCLUSION: Importantly, we found good agreement between reported dose ingested and plasma paraquat concentration, case fatality, and time to death, suggesting that the reported dose is a valid marker for the dose ingested. Vomiting occurred within 30 min for 68.5% of patients, exceeding the characteristics for a purported effective emetic in the FAO specifications. However, vomiting within 30 min was associated with approximately double the risk of death compared to those who did not vomit, larger paraquat ingestions, and higher blood paraquat concentrations. In addition, death occurred in many patients who did not vomit, and the proportion vomiting within 30 min only reached 82.1% for the highest ingested dose group. Overall, we found no evidence of benefit resulting from incorporation of the emetic, suggesting that the current FAO specification is not effective at preventing deaths after ingestion of the paraquat SL formulation.

Rapid determination of polyethoxylated tallow amine surfactants in human plasma by LC-MSMS.

The potential exposure to the widely used glyphosate-based herbicides, including attempted suicide by ingestion, is of world-wide concern. Whilst the major focus to date has been on managing exposure to the active ingredient glyphosate, it is now recognised that a common major 'inert' surfactant ingredient, polyethoxylated tallow amine (POEA) and related compounds, may be more toxic. However, the information on the toxicokinetics of POEA surfactants after exposure is limited, in part, due to the lack of suitable methods for their analysis in biological matrices. We therefore developed and validated a robust LC-MSMS method that allowed, for the first time, a rapid analysis of 11 POEA homologues in human plasma. Chromatographic separation was achieved on a Kinetex EVO C18 column under a 5 min gradient elution with mobile phase A containing water/acetonitrile/formic acid (95:5:0.1, v/v/v) and mobile phase B containing acetonitrile/water/formic acid (95:5:0.1, v/v/v). Amlodipine was chosen as the internal standard (IS) for this assay. Amlodipine-d4 would be an ideal alternative IS to expand the applicability of the established method especially in antihypertensive patients. Multiple reaction monitoring (MRM) methods were optimized for 11 POEA homologues and the IS. Sample pre-treatment was performed using simple protein precipitation with methanol at a ratio of 4:1, requiring only 20 µL plasma. The validated method showed good specificity, accuracy and precision with lower limits of quantification (LLOQ) ranging from 0.35 to 10.8 ng mL-1 for all selected POEA homologues. The method was then used to measure concentrations of the various POEA surfactants in more than 600 human plasma samples from 151 patients admitted to hospital with acute glyphosate intoxication. The highest concentrations ranged from 1.07 ng mL-1 for C18u(EO)4-362.70 ng mL-1 for C16s(EO)2. The analysis of POEA surfactants plasma concentrations as described here underpins the assessment of POEA internal exposure and the relationships between POEA related glyphosate toxicity and the extent of poisoning.

Relationship Between Alcohol Co-Ingestion and Clinical Outcome in Pesticide Self-Poisoning: A Systematic Review and Meta-Analysis.

AIM: Alcohol is a commonly co-ingested compound during self-poisoning with pesticides. Clinical experiences suggest alcohol co-ingestion (or withdrawal) makes patient management more difficult after self-poisoning and may contribute to poor clinical outcomes. We aimed to systematically review the world literature to explore the relationship between alcohol co-ingestion and outcome in pesticide self-poisoning. METHODS: We searched 13 electronic databases and Google scholar, conducted citation searching and a review of reference lists to find studies which investigated the relationship of alcohol with clinical outcome of pesticide self-poisoning in different countries. Thirteen studies, including 11 case series/reports and two cohort studies were considered for inclusion. RESULTS: Meta-analysis showed that alcohol co-ingestion in pesticide self-poisoning was associated with increased risk of death [odds ratio (OR) 4.9, 95% confidence interval (CI) 2.9-8.2 P<0.0001] and that alcohol co-ingested group required intubation eight times more often than non-co-ingested group in organophosphorus insecticide self-poisoning (OR 8.0, 95% CI 4.9-13.0 P<0.0001). Cases who co-ingested alcohol were older than non-alcohol group in two studies. One cohort study demonstrated that alcohol co-ingestion was associated with larger pesticide ingestions but did not itself affect the outcome. CONCLUSIONS: This systematic review indicates that alcohol co-ingestion may worsen clinical outcome in pesticide self-poisoning.

Epidemiology and renal injury following 2-methyl-4-chlorophenoxyacetic acid (MCPA) poisoning.

2-Methyl-4-chlorophenoxyacetic acid (MCPA) is a widely used chlorophenoxy herbicide. MCPA poisoning causes mitochondrial dysfunction, which can lead to kidney injury and death. The objective of this study is to describe the epidemiology, case fatality and extent of renal injury in a large cohort of MCPA self-poisonings. The study consists of two parts: (1) A report of epidemiological data and clinical outcomes in MCPA poisoned patients in Sri Lanka between 2002 and 2019; (2) Evaluation of acute kidney injury (AKI) using renal biomarkers in a subset from this cohort. Serum creatinine (sCr) and biomarkers were measured soon after hospitalization (2 [IQR 1-3] h) and at different time intervals. We measured serum biomarkers: sCr, cystatin C (sCysC), creatine kinase (CK), and urinary biomarkers: creatinine, kidney injury molecule-1 (KIM-1), clusterin, albumin, beta-2-microglobulin (ß2M), cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), osteopontin (OPN), trefoil factor 3 (TFF3) and cytochrome C (CytoC). Kidney Disease Improving Global Outcomes (KDIGO) criteria was used to define acute kidney injury (AKI). There were 1653 patients; 65% were male. The median time from ingestion to examination was 3:54 (IQR 2:19-6:57) h. The overall case-fatality rate was 5.3%. Patients who died were older (42 [IQR 33.5-54] vs 27 [IQR 20-37] for survivors). The median estimated amount of MCPA ingested by patients who died was also greater (88 [IQR 34-200] vs. 30 [IQR 15-63] ml in survivors). Moderate to severe AKI (AKI2/3) was uncommon (6/59 patients in the biomarker study had KDIGO stage 2 or 3). Most patients in AKI2/3 group with increased sCr were older (median age 35 years [IQR 27-41]) compared to No AKI (23 years (19-29) years) or AKI1 (26 years (21-40) years) group who had no or mild increase in sCr. These patients had no pre-existing kidney diseases. In these patients, serum creatinine (maximum medium concentration; 1.12 [IQR 0.93-1.67] mg/dl) and CK (maximum medium concentration; 284 [IQR 94-428] U/l) were increased but sCysC (maximum medium concentration; 0.79 [IQR 0.68-0.81] mg/l) remained in the normal range within 72 h. All urinary biomarkers performed poorly in diagnosing AKI (area under the receiver operating characteristic curve < 0.68). The higher numbers of men with MCPA poisoning likely reflects greater occupational access to pesticides. Fatal outcome and higher ingested dose were more common in the elderly. Significant AKI with tubular injury biomarkers was uncommon. Most people with raised sCr were older and appeared to have no pre-existing kidney disease.

Acute fungicide self-poisoning - a prospective case series.

BACKGROUND: Pesticide self-poisoning is a global clinical and public health problem. While self-poisoning with insecticides and herbicides has been extensively studied, there is minimal literature on acute fungicide self-poisoning. We aimed to study the clinical course and outcome of fungicide self-poisoned patients recruited to a prospective cohort in Sri Lanka. METHODS: We conducted a prospective study of patients presenting with fungicide self-poisoning to nine hospitals in Sri Lanka between 2002 and 2020. Patients were enrolled by clinical research assistants, with clinical outcomes being recorded at regular review for each patient. RESULTS: We identified 337 cases of self-poisoning with fungicides (alcohol as only co-ingestant), including 28 different fungicides across 5 different fungicide classes. Median time from ingestion to examination was 3.1 (1.8-5.7) h. Nearly all presented to hospital fully conscious (GCS 15, 15-15)- only 27 patients (8.0%) presented with reduced GCS (<15) and only 2 (0.6%) had GCS 3/15. Most patients (333/337, 98.8%) made a full recovery, of whom only eight (2.37%) required intubation and ventilation. Four patients died (case fatality rate: 1.2%; 95% CI 0.0-23.4) after ingestion of edifenphos (n = 2), propamocarb and pyraclostrobin. CONCLUSION: Fungicide self-poisoning appears to be less hazardous than insecticide or herbicide self-poisoning, with a substantially lower case fatality in the same cohort. Edifenphos is an exception to this 'less toxic' rule; as a WHO Class Ib highly hazardous pesticide, we recommend its withdrawal from, and replacement in, global agricultural practice. Propamocarb should be listed in the WHO hazard classification as propamocarb hydrochloride to reflect the higher toxicity of the common agricultural formulation. Pyraclostrobin currently has no WHO classification; one is urgently required now that its ingestion has now been linked the death of a patient. Additional prospective clinical data on fungicide self-poisoning is required to expand knowledge on the effects of these diverse compounds.

Acute phenthoate self-poisoning: a prospective case series.

BACKGROUND: The clinical characteristics following self-poisoning with organophosphorus (OP) insecticides differs according to the insecticide ingested. Phenthoate is a dimethoxy WHO Hazard Class II OP pesticide with limited literature on its clinical characteristics and outcome. We aimed to better understand its clinical characteristics by studying patients with phenthoate self-poisoning in Sri Lanka. METHODS: We conducted a prospective cohort study of patients presenting with phenthoate self-poisoning to eight hospitals in Sri Lanka between 2002 and 2018. Clinical outcomes were recorded for each patient. Blood samples for measuring plasma phenthoate concentration, cholinesterase activity, and response to oximes were available for a very small number of patients recruited to a clinical trial. RESULTS: Two hundred and ninety-two patients who ingested agricultural phenthoate formulations were included in the study. Median time to admission was 3.9 (IQR 2.4 - 6.8) h. Forty-two (14.4%) patients were intubated, mostly (30/37, 81%) within 24 h of ingestion (median time to intubation 7.2 [IQR 2.6-20.9] h). Median duration of intubation was 74.8 (IQR 26.8-232.5) h; the longest duration in a survivor was 592 h. Nineteen died (case fatality 6.5%, 95% CI 4.0-10.0); median time to death was 37 (IQR 16 - 101.7) h. Median plasma phenthoate concentration in patients with samples (n = 81) was 135 (IQR 62.7-356.5) ng/mL (0.42 µmol/mL [0.2 to 1.1 µmol/mL]). Five of six patients receiving pralidoxime chloride 2 g showed an initial increase in AChE and BuChE activity that was not sustained despite an infusion of pralidoxime. CONCLUSION: Phenthoate self-poisoning has a 6.5% case fatality rate. Most patients who experience respiratory failure undergo early intubation; most deaths occurred among those patients who were intubated less than 24 h after ingestion. There was a non-sustained increase in cholinesterase activity with pralidoxime, but further studies are required to analyse the extent to which oximes are clinically effective in phenthoate self-poisoning.

Circulating intestinal fatty acid binding protein and intestinal toxicity in Russell's viper envenomation.

OBJECTIVE: Abdominal pain is known to be an early clinical predictor of severe systemic Russell's viper (RV) envenomation and is often associated with the later development of coagulopathy and neurotoxicity. The mechanism of abdominal pain is unknown, but we postulated it might be due to intestinal microvascular endothelial gut damage. Gut-toxicity can be detected using the novel biomarker Intestinal Fatty Acid Binding Protein (IFABP). We also wanted to explore the mechanisms and consequences of this toxicity by measuring procalcitonin as a specific marker of sepsis triggered by bacterial endotoxin, and serum cystatin-C (CysC) as a measure of acute kidney injury. We hypothesised that severe gut-injury might lead to gut-barrier failure, translocation of gastrointestinal microorganisms, associated sepsis and systemic inflammatory response syndrome (SIRS), with a possible exacerbation of snake-bite severity, including acute kidney injury that was previously attributed to direct venom effects. METHODS: Serial plasma samples previously collected from 16 RV envenomations with abdominal pain, 15 RV envenomations without abdominal pain and 25 healthy controls were assayed for IFABP. A subgroup of these RV envenomations were assayed for procalcitonin (n = 24) and serum CysC (n = 11). RESULTS: The median peak IFABP for RV envenomations was much higher than healthy controls [3703.0 pg/mL (IQR 2250.1-13702.0 pg/mL) vs. 270.1 pg/mL (IQR 153.5-558.0 pg/mL) (p < 0.001)]. There was no difference in those with and without abdominal pain [3801.4 pg/mL (IQR 2080.5-22446.3 pg/mL) vs. 3696.6 pg/mL (IQR 2280.3-4664.7 pg/mL) (p = 1.0)]. Peak procalcitonin levels were elevated in envenomed patients 30.1 ng/ml (IQR: 13.1-59.7 ng/ml) with a level >2ng/mL indicative of severe sepsis] and also correlated with peak IFABP (r = 0.55, p = 0.006, n = 24). Peak serum CysC was also elevated and also correlated with IFABP (r = 0.71, p = 0.037, n = 9). CONCLUSION: IFABP is significantly elevated indicating enterocyte damage occurs in RV envenomation. IFABP correlated with markers of sepsis (procalcitonin) and acute kidney injury (serum CysC) suggesting that enterocyte damage resulting in translocation of microbial associated molecular patterns (MAMPs) contributes to RV envenomation associated SIRS and sepsis.

Two decades of chronic kidney disease of unknown aetiology (CKDu) research: Existing evidence and persistent gaps from epidemiological studies in Sri Lanka.

BACKGROUND: Chronic Kidney Disease of unknown origin (CKDu) excludes known primary renal conditions or systemic disease (such as diabetes mellitus or hypertension). Prominence of CKDu has been noted for some decades in Sri Lanka, especially among men in particular rural areas, prompting many studies directed towards environmental causation. This article critically reviews relevant primary studies. METHODS: Articles for this literature review (n = 86) were found by searching Medline, Embase, Global Health and ProQuest databases over 2000-2020 utilizing a standard algorithm. Articles were critiqued according to criteria for diagnosis of CKDu, aetiological agents investigated, analytic methods employed and findings. RESULTS: Criteria for diagnosis of CKDu varied significantly, including pre-selection by proteinuria, eGFR and biopsy proven interstitial nephritis. Prevalence studies have been largely conducted in the North Central Province, with recent studies demonstrating the presence of CKDu in other regions. Aetiological factors investigated in primary studies included water source, use of agrochemicals, agricultural work, heavy metals, snake bites, ayurvedic medication, heat stress, infectious diseases and usage of tobacco and betel leaf. There is no conclusive evidence for any one aetiological agent despite consistent evidence of distal factors such as male sex, rural residence and farming. CONCLUSIONS: The current body of evidence for any aetiological agent as the cause of CKDu in Sri Lanka is limited. Further research with stronger study designs is necessary to increase knowledge of aetiology of CKDu in Sri Lanka to identify and eliminate exposure to possible causative agent(s) prior to concluding that the disease is multifactorial.

Osmolal and anion gaps after acute self-poisoning with agricultural formulations of the organophosphorus insecticides profenofos and diazinon: A pilot study.

Self-poisoning with organophosphorus (OP) insecticides is an important means of global self-harm. The insecticides are formulated with solvents that may also contribute to toxicity. We set up a study to detect changes in osmolal and anion gaps following ingestion of OP insecticides. We recruited consecutive patients admitted to a Teaching Hospital, Sri Lanka, with a history of OP self-poisoning. The osmolal and anion gaps were calculated on admission and at 4, 24 and 72 h post-ingestion together with ethanol concentration. Forty-nine patients were recruited (28 profenofos, 10 diazinon, one coumaphos, one chlorpyrifos, one phenthoate and eight unknown OP). Only modest increases in osmolal and anion gaps were noted. Small rises in osmolal gap above the upper limit of normal were noted in 16/49 (32.7%) of all cases, 9/28 (32.1%) profenofos cases and 4/10 (40.0%) diazinon cases. The anion gap was raised in 24/49 (49.0%) of all cases, 15/28 (53.6%) profenofos cases and 5/10 (50.0%) diazinon cases. We observed a trend for a fall in osmolal gap during the first 24 h, followed by an increase up to 72 h. There was no correlation between the anion gap and serum lactate concentration, indicating that a lactic acidosis was not responsible for the anion gap. Formate, which could have explained the increased gap, was not detected in any of the samples; ketoacids (beta-hydroxybutyrate and acetoacetate) were not measured. This pilot study found that profenofos and diazinon poisoning caused only modest increases in the osmolal and anion gaps in a minority of cases.

Serum and urinary biomarkers for early detection of acute kidney injury following Hypnale spp. envenoming.

BACKGROUND: Hump-nosed pit viper (HNV; Hypnale spp.) bites account for most venomous snakebites in Sri Lanka. Acute kidney injury (AKI) is the most serious systemic manifestation (1-10%) following HNV envenoming. We aimed to identify the value of functional and injury biomarkers in predicting the development of AKI early following HNV bites. METHODS: We conducted a prospective cohort study of patients with confirmed HNV envenoming presenting to two large tertiary care hospitals in Sri Lanka. Demographics, bite details, clinical effects, complications and treatment data were collected prospectively. Blood and urine samples were collected from patients for coagulation and renal biomarker assays on admission, at 0-4h, 4-8h, 8-16h and 16-24h post-bite and daily until discharge. Follow-up samples were obtained 1 and 3 months post-discharge. Creatinine (sCr) and Cystatin C (sCysC) were measured in serum and kidney injury molecule-1 (uKIM-1), clusterin (uClu), albumin (uAlb), ß2-microglobulin (uß2M), cystatin C (uCysC), neutrophil gelatinase associated lipocalin (uNGAL), osteopontin (uOPN) and trefoil factor-3 (uTFF-3) were measured in urine. Definite HNV bites were based on serum venom specific enzyme immunoassay. Kidney Disease: Improving Global Outcomes (KDIGO) criteria were used to stage AKI. Two patients had chronic kidney disease at 3 month follow-up, both with pre-existing abnormal sCr, and one developed AKI following HNV envenoming. RESULTS: There were 52 patients with confirmed HNV envenoming; median age 48y (Interquartile range [IQR]:40-59y) and 29 (56%) were male. Median time to admission was 1.87h (IQR:1-2.75h). Twelve patients (23%) developed AKI (AKI stage 1 = 7, AKI stage 2 = 1, AKI stage 3 = 4). Levels of five novel biomarkers, the functional marker serum Cystatin C and the damage markers urinary NGAL, cystatin C, ß2-microglobulin and clusterin, were elevated in patients who developed moderate/severe acute kidney injury. sCysC performed the best at 0-4 h post-bite in predicting moderate to severe AKI (AUC-ROC 0.95;95%CI:0.85-1.0) and no biomarker performed better than sCr at later time points. CONCLUSIONS: sCysC appears to be a better marker than sCr for early prediction of moderate to severe AKI following HNV envenoming.

Urinary microRNAs as non-invasive biomarkers for toxic acute kidney injury in humans.

MicroRNAs in biofluids are potential biomarkers for detecting kidney and other organ injuries. We profiled microRNAs in urine samples from patients with Russell's viper envenoming or acute self-poisoning following paraquat, glyphosate, or oxalic acid [with and without acute kidney injury (AKI)] and on healthy controls. Discovery analysis profiled for 754 microRNAs using TaqMan OpenArray qPCR with three patients per group (12 samples in each toxic agent). From these, 53 microRNAs were selected and validated in a larger cohort of patients (Russell's viper envenoming = 53, paraquat = 51, glyphosate = 51, oxalic acid = 40) and 27 healthy controls. Urinary microRNAs had significantly higher expression in patients poisoned/envenomed by different nephrotoxic agents in both discovery and validation cohorts. Seven microRNAs discriminated severe AKI patients from no AKI for all four nephrotoxic agents. Four microRNAs (miR-30a-3p, miR-30a-5p, miR-92a, and miR-204) had > 17 fold change (p < 0.0001) and receiver operator characteristics area-under-curve (ROC-AUC) > 0.72. Pathway analysis of target mRNAs of these differentially expressed microRNAs showed association with the regulation of different nephrotoxic signaling pathways. In conclusion, human urinary microRNAs could identify toxic AKI early after acute injury. These urinary microRNAs have potential clinical application as early non-invasive diagnostic AKI biomarkers.

MicroRNAs in toxic acute kidney injury: Systematic scoping review of the current status.

Acute kidney injury induced by nephrotoxic agents is common, increasing in incidence and associated with considerable morbidity and mortality in developing countries. MicroRNAs are stable biomarkers that can be detected in extracellular fluids. This systematic scoping review aims to describe published research on urinary and circulating microRNAs in toxic acute kidney injury in both animal and human studies. We conducted a literature search, using EMBASE and Medline, for articles on urinary and circulating microRNA in nephrotoxic injuries to February 2020. A total of 21 publications studied acute kidney injury from 12 different toxic agents. Cisplatin was the most common nephrotoxic agent (n = 10), followed by antibiotics (n = 4). There were no randomized controlled trials. An increase in urinary miR-218 predicted acute kidney injury in six different studies, suggesting it is a promising biomarker for nephrotoxin-induced acute kidney injury. There were many factors that prevented a more comprehensive synthesis of microRNA performance including highly variable models, no consistent protocols for RNA isolation, cDNA synthesis and PCR amplification, and variability in normalization methods using reference controls. In conclusion, while microRNAs are promising biomarkers to study nephrotoxic acute kidney injury, the replication of most positive findings is not assessable due to deficient reporting of negative outcomes. A very narrow range of poisons have been studied, and more human data are required. In particular, further studies are needed on the most important causes of nephrotoxic injury, such as pesticides, chemicals, snake envenoming, and medicines other than aminoglycosides and cisplatin.

The clinical toxicity of imidacloprid self-poisoning following the introduction of newer formulations.

BACKGROUND: Self-poisoning with imidacloprid has been previously shown to have low toxicity in humans. Since 2007 newer formulations of Imidacloprid with unknown solvents have been introduced and the potential clinical consequences of these products have not been described. METHODS: Clinical and demographic data were prospectively collected from admissions following oral ingestion of imidacloprid from seven hospitals in Sri Lanka. Data was collected from 2002 to 2007 in an already published study. We compared this data on poisonings collected from 2010 to 2016 following the introduction of new formulations of imidacloprid. RESULTS: From 2002-2007, there were 56 patients with ingestion to imidacloprid compared to 67 patients post 2010 The median time to presentation prior to 2007 was 4 h (IQR 2.3-6.0 hrs) and post 2010 was only 2.0 hr (IQR 1.5 to 3.1 hrs). The median amount ingested was 15 ml (IQR 10.0-50.0mls) prior to 2007 and 27.5mls (IQR 5.0-71.8mls) post 2010. In both studies most patients developed non-specific symptoms including nausea, vomiting, epigastric pain and headache. However, prior to 2007 only 1.9% of the cohort required mechanical ventilation due to respiratory failure and there were no reported deaths. In contrast, post 2010; deaths occurred in 3.0% of the cohort and 6.0% required mechanical ventilation for respiratory failure. The cause of mortality was due to one case of cardiorespiratory failure and the other due to a prolonged admission complicated with lobar pneumonia leading to decompensated liver failure on the background of undiagnosed liver cirrhosis. CONCLUSION: Although acute exposure to imidacloprid is usually associated with mild non-specific symptoms, since the introduction of new formulations of imidacloprid, the toxic profile has changed with reported cases of death as well as an increase in cases requiring mechanical ventilation. The change in toxicity could be due to the solvents used in the newer formulations but also due to higher dose of imidacloprid described in our latter cohort. Further research into these solvents needs to be done and continued toxicovigilance is required.

Cellular injury leading to oxidative stress in acute poisoning with potassium permanganate/oxalic acid, paraquat, and glyphosate surfactant herbicide.

Previous studies on human acute kidney injury (AKI) following poisoning with potassium permanganate/oxalic acid (KMnO4/H2C2O4), paraquat, and glyphosate surfactant herbicide (GPSH) have shown rapid and large increases in serum creatinine (sCr) that cannot be entirely explained by direct nephrotoxicity. One plausible mechanism for a rapid increase in sCr is oxidative stress. Thus, we aimed to explore biomarkers of oxidative stress, cellular injury, and their relationship with sCr, after acute KMnO4/H2C2O4, paraquat, and GPSH poisonings. Serum biomarkers [sCr, creatine (sCn), cystatin C (sCysC)] and urinary biomarkers [cytochrome C (CytoC), 8-isoprostane (8-IsoPs)] were evaluated in 105 patients [H2C2O4/KMnO4 (N = 57), paraquat, (N = 21), GPSH (N = 27)] recruited to a multicenter cohort study. We used area under the receiver operating characteristics curve (AUC-ROC) to quantify the extent of prediction of moderate to severe AKI (acute kidney injury network stage 2/3 (AKIN2/3)). Patients with AKIN2/3 showed increased levels of CytoC. Early high CytoC predicted AKIN2/3 in poisoning with KMnO4/H2C2O4 (AUC-ROC4-8h: 0.81), paraquat (AUC-ROC4-8h: 1.00), and GPSH (AUC-ROC4-8h: 0.91). 8-Isoprostane levels were not significantly elevated. Reduced sCn and increased sCr/sCn ratios were observed for 48 h post KMnO4/H2C2O4 ingestion. Paraquat exhibited a similar pattern (N = 11), however only 3 were included in our study. Increased CytoC suggests there is mitochondrial injury coupled with energy depletion. The increased sCr within 24 h could be due to increased conversion of cellular creatine to creatinine during the process of adenosine triphosphate (ATP) generation and then efflux from cells. Later increases of sCr are more likely to represent a true decrease in kidney function.

Urinary versus serum microRNAs in human oxalic acid poisoning: Contrasting signals and performance.

MicroRNAs are key regulators of the normal kidney function and development, and altered in acute kidney injury (AKI). However, there is a lack of studies comparing serum and urine miRNA expression in toxic AKI in humans. We aimed to compare the global signature of urinary and serum microRNAs, with and without kidney injury, after human oxalic acid poisoning. We profiled urinary microRNAs in patients who ingested oxalic acid and developed no injury (No AKI n = 3), moderate injury (AKIN2 n = 3) or severe injury (AKIN3 n = 3) and healthy controls (n = 3). We validated a signature of 30 urinary microRNAs identified in the discovery profiling, in a second cohort of individuals exposed to oxalic acid (No AKI n = 15, AKIN2 n=11 & AKIN3 n= 18) and healthy controls (n=-27) and we compared the results with previously published serum data. Global profiling in toxic AKI patients showed a higher expression of urinary microRNAs and lower expression of serum microRNAs. Most urine microRNA in the validation cohort were significantly upregulated (25/30, fold change >2.8 and p < 0.05) in AKIN2/3 patients compared to No AKI. Four urinary microRNAs (miR-191, miR-19b, miR-20a and miR-30b) had good diagnostic performance (AUC greater than 0.8) to predict AKIN2/3 between 4-8 hours post ingestion. Poisoning irrespective of AKI led to significantly lower expression of many microRNAs in serum but relatively few changes in urinary miRNA expression. In conclusion, urinary microRNA signature provides a stronger measure of AKI in oxalic acid poisoning compared to serum microRNA. Kidney injury has the greatest impact on urinary microRNA, while poisoning itself was better reflected in serum miRNA. Plasma and urinary microRNAs signatures provide complementary information in toxic kidney injury.

A pilot clinical study of the neuromuscular blocker rocuronium to reduce the duration of ventilation after organophosphorus insecticide poisoning.

Background: A common manifestation of organophosphorus insecticide self-poisoning is prolonged respiratory failure due to neuromuscular junction dysfunction and likely nicotinic receptor overstimulation. We aimed at collecting preliminary data on whether addition of the competitive nicotinic antagonist rocuronium to standard early therapy might be clinically feasible and associated with reduced duration of ventilation.Methods: A pilot three-arm dose-response phase II trial was set up to compare bolus doses of rocuronium bromide titrated to produce initial >95% or 50% inhibition of neuromuscular function, measured using acceleromyography, plus standard treatment, versus standard treatment alone. After attaining inhibition, patients receiving bolus rocuronium then received rocuronium infusions for a maximum of 120 h. Primary outcome was duration of intubation; secondary outcome was case fatality. Plasma butyrylcholinesterase activity was measured throughout the inpatient stay. Blood was analysed to confirm the organophosphorus insecticide ingested.Results: Forty-five patients were randomised to receive: rocuronium to initially attain 95% inhibition (Roc>95, n = 15), rocuronium to initially attain 50% inhibition (Roc50, n = 14), or no rocuronium (control, n = 16). The most commonly ingested pesticide was profenofos (29/45, 64.4%). Butyrylcholinesterase activity remained severely inhibited for the duration of the study for most patients. Case fatality was 9/45 (20%) and similar across study arms: control 3/16 (18.8%), Roc50 4/14 (28.6%) and Roc>95 2/15 (13.3%) (p = .5842). When excluding patients who died, median [IQR] duration of intubation was significantly longer in the Roc50 (259.5 [176-385] h) and Roc>95 (226.8 [186-355] h) groups compared to controls (88.5 [47-160] h, p = .0162 and p = .0016, respectively).Conclusions: In this pilot dose-response study, we found no evidence that rocuronium in addition to standard therapy reduced the duration of intubation. It is possible that it worsened neuromuscular junction function. Further clinical research, including testing of shorter duration regimens, needs to be performed before nicotinic antagonists can be used in the clinical management of OP poisoning.

An LC-MS/MS method for creatine and creatinine analysis in paraquat-intoxicated patients.

A sudden increase in serum creatinine after paraquat intoxication has been reported in several clinical studies. However, this dramatic change of creatinine may be possibly due to an interconversion of creatine-creatinine in relation to paraquat toxicity. In order to investigate the creatine-creatinine relationship, a liquid chromatography tandem mass spectrometry in combination with electrospray ionization was developed and validated for simultaneous determination of creatine and creatinine in the serum. The chromatographic separation was achieved on a Gemini® C6-Phenyl column with a gradient elution consisting of 0.1% formic acid in ultrapure water and methanol as the mobile phase. The method yielded suitable levels of specificity and selectivity, and calibration curves of creatine and creatinine in serum were linear over the concentration range of 0.5-200 µg mL-1. The limit of quantification of both compounds was 0.5 µg mL-1, and the method was accurate within the recovery range of 96.23-102.75%, indicating the robustness of the method. The method was successfully applied to toxicological samples from paraquat-intoxicated patients, and the concentrations of creatine and creatinine were quantified. High creatine concentrations in serum samples were observed which may lead to high serum creatinine despite normal kidney function as creatine is converted to creatinine in proportion to its concentration.