Hydrogen cyanamide exposure: a case series from Pavia Poison Control Centre

BACKGROUND

Hydrogen cyanamide is a plant growth regulator introduced in Italy as Dormex in 2000, but recalled from the market in 2008. It's currently not authorized in Europe. Inhalation/dermal contact may cause irritation/caustic burns, ingestion of severe organ damage and concomitant alcohol consumption disulfiram-like reaction due to aldehyde-dehydrogenase inhibition by hydrogen cyanamide.

AIMS

To study all exposure cases referred to our centre, evaluating temporal and geographic distribution and analysing clinical manifestations, including the ones after alcohol consumption.

METHODS

We retrospectively evaluated all hydrogen cyanamide exposures referred to our Poison Control Centre (January 2007-December 2021). For each case, age, sex, exposure route/year, geographical location, intent of exposure, alcohol co-ingestion, emergency department-admission Poison Severity Score, signs/symptoms and treatment were analysed.

RESULTS

Thirty subjects were included. Median case/year was 1 [1; 2]: 79% occurred after market withdrawal, 92% in Sicily. All exposures were unintentional and work related; 41% of patients also co-ingested alcohol. Mean poison severity score at emergency department admission was 1.54, more severe when ingestion occurred. The most common signs/symptoms were flushing, secondary to peripheral vasodilation (41%), hyperaemia/erythema (29%), dyspnoea (25%), nausea (20%), vomiting (12%), oedema (12%), II-III degrees burns (12%) and pharyngodynia (12%). All patients were treated symptomatically and fully recovered.

CONCLUSIONS

Hydrogen cyanamide exposure can lead to severe clinical manifestations. Despite its withdrawal from the Italian market, hydrogen cyanamide is still used: through PCC's crucial role in monitoring exposure to agricultural products efforts should be made to contrast illegal trade and increase awareness of its potential toxicity in those countries in which it's still legal.

MAM-2201, One of the Most Potent-Naphthoyl Indole Derivative-Synthetic Cannabinoids, Exerts Toxic Effects on Human Cell-Based Models of Neurons and Astrocytes

Considering the consequences on human health, in general population and workplace, associated with the use of new psychoactive substances and their continuous placing on the market, novel in vitro models for neurotoxicology research, applying human-derived CNS cells, may provide a means to understand the mechanistic basis of molecular and cellular alterations in brain. Cytotoxic effects of MAM-2201, a potent-naphthoyl indole derivative-synthetic cannabinoid, have been evaluated applying a panel of human cell-based models of neurons and astrocytes, testing different concentrations (1-30 µM) and exposure times (3-24-48 h). MAM-2201 induced toxicity in primary neuron-like cells (hNLCs), obtained from transdifferentiation of mesenchymal stem cells derived from human umbilical cord. Effects occurred in a concentration- and time-dependent manner. The lowest concentration affecting cell viability, metabolic function, apoptosis, morphology, and neuronal markers (MAP-2, NSE) was 5 μM, and even 1 μM induced apoptosis. Effects appeared early (3 h) and persisted after 24 and 48 h. Similar behavior was evidenced for human D384-astrocytes treated with MAM-2201. Differently, human SH-SY5Y-neurons, both differentiated and undifferentiated, were not sensitive to MAM-2201. On D384, the different altered endpoints were reversed, attenuated, or not antagonized by AM251 indicating that CB1 receptors may partially mediate MAM-2201-induced cytotoxicity. While in hNLCs, all toxic effects caused by MAM-2201 were apparently unrelated to CB-receptors since they were not evidenced by immunofluorescence. The present in vitro findings demonstrate the cytotoxicity of MAM-2201 on human primary neurons (hNLCs) and astrocytes cell line (D384), and support the use of these cellular models as species-specific in vitro tools suitable to clarify the neurotoxicity mechanisms of synthetic cannabinoids.

Neurotoxicity of European viperids in Italy: Pavia Poison Control Centre case series 2001-2011

CONTEXT

Some clinical aspects about neurotoxicity after snakebites by European viper species remain to be elucidated.

OBJECTIVE

This observational case series aims to analyze neurological manifestations due to viper envenomation in Italy in order to describe the characteristic of neurotoxicity and to evaluate the clinical response to the antidotic treatment, the outcome, and the influence of individual variability in determining the appearance of neurotoxic effects.

MATERIALS AND METHODS

All cases of snakebite referred to Pavia Poison Centre (PPC) presenting peripheral neurotoxic effects from 2001 to 2011 were included. Cases were assessed for time from bite to PPC evaluation, Grade Severity Score (GSS), onset/duration of clinical manifestations, severity/time course of local, non-neurological and neurological effects, and antidotic treatment.

RESULTS

Twenty-four were included (age, 3-75 years) and represented on average of 2.2 cases/year (about 5% of total envenomed patients). The mean interval time of PPC evaluation from snakebite was 10.80 ± 19.93 hours. GSS at ED-admission was 0 (1 case), 1 (10 cases), and 2 (13 cases). All patients showed local signs: 41.6%, minor; 58.4%, extensive swelling and necrosis. The main systemic non-neurological effects were as follows: vomiting (86.7%), diarrhea (66.7%), abdominal discomfort (53.3%), and hypotension (20%). Neurotoxic effects were accommodation troubles and diplopia (100%), ptosis (91.7%), ophtalmoplegia (58.3%), dysphagia (20.8%), drowsiness (16.6%), cranial muscle weakness (12.5%), and dyspnea (4.2%). Neurotoxicity was the unique systemic manifestation in 9 cases; in 4 cases, they were associated with only mild local swelling. In 10 patients the onset of neurotoxic effects followed the resolution of systemic non-neurological effects. Antidote was intravenously administered in 19 (79.2%) patients. The mean duration of manifestations in untreated versus treated groups was 53.5 ± 62.91 versus 41.75 ± 21.18 hours (p = 0.68, local effects) and 9.77 ± 3.29 versus 8.25 ± 12.23 hours (p = 0.1, systemic non-neurological effects) and 43.4 ± 14.69 versus 26.58 ± 20.62 hours (p = 0.03, neurotoxic effects).

CONCLUSIONS

Neurotoxicity may appear late (11 hours after the bite in 58.3% of cases), in contrast with the data reported in medical literature. Neurotoxic effects have been reversible in all cases and may be the unique systemic manifestation of envenomation. Neurotoxic effects are shorter in treated group. The antidotic treatment of patients considered as GSS 2 only for neurotoxic effects (with mild local effects) may not be necessary. Variable factors such as different amount of venom injected, concentration of PLA2 component, and individual susceptibility may explain the less percentage of patients presenting neurotoxic effects.