Poisons affecting the neurological system

2020 ◽  
Vol 25 (2) ◽  
pp. 83-91
Author(s):  
Nicola Bates
Keyword(s):  
Seizure Activity ◽  
Companion Animals ◽  
Rapid Onset ◽  
Secondary Damage ◽  
Other Substances ◽  
Prolonged Sedation ◽  
Neurological Effects ◽  
Cns Stimulation ◽  
Risk Of Aspiration ◽  
Cns Depression

The brain is susceptible to a variety of poisons. Sedating drugs and chemicals can cause central nervous system (CNS) depression while other substances can cause CNS stimulation, including seizures. These are of particular concern since intractable seizure activity may cause complications, with pyrexia resulting in secondary damage to other organs. The common poisons discussed here that cause neurological effects are metaldehyde and tremorgenic mycotoxins, which can cause rapid onset seizures; cannabis, which can cause prolonged sedation in companion animals; permethrin, which is associated with prolonged seizures, particularly in cats; and ivermectin, which can cause CNS depression, blindness and seizures. Treatment is supportive in most cases; care should be taken when considering the use of emetics since there is a risk of aspiration in seizuring animals. Control of seizure activity is a priority, while intravenous lipid emulsion may also be useful.

Poisons affecting the neurological system

2020 ◽  
Vol 11 (3) ◽  
pp. 116-125
Author(s):  
Nicola Bates
Keyword(s):  
Seizure Activity ◽  
Companion Animals ◽  
Rapid Onset ◽  
Secondary Damage ◽  
Other Substances ◽  
Prolonged Sedation ◽  
Neurological Effects ◽  
Cns Stimulation ◽  
Risk Of Aspiration ◽  
Cns Depression

The brain is susceptible to a variety of poisons. Sedating drugs and chemicals can cause central nervous system (CNS) depression while other substances can cause CNS stimulation, including seizures. These are of particular concern since intractable seizure activity may cause complications, with pyrexia resulting in secondary damage to other organs. The common poisons discussed here that cause neurological effects are metaldehyde and tremorgenic mycotoxins, which can cause rapid onset seizures; cannabis, which can cause prolonged sedation in companion animals; permethrin, which is associated with prolonged seizures, particularly in cats; and ivermectin, which can cause CNS depression, blindness and seizures. Treatment is supportive in most cases; care should be taken when considering the use of emetics since there is a risk of aspiration in seizuring animals. Control of seizure activity is a priority, while intravenous lipid emulsion may also be useful.

scholarly journals Environmental Substances Associated with Alzheimer’s Disease—A Scoping Review

2021 ◽  
Vol 18 (22) ◽  
pp. 11839
Author(s):  
Hanna Maria Elonheimo ◽  
Helle Raun Andersen ◽  
Andromachi Katsonouri ◽  
Hanna Tolonen
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Scoping Review ◽  
Cognitive Abilities ◽  
Human Biomonitoring ◽  
Chemical Exposure ◽  
Priority Substances ◽  
Environmental Chemical ◽  
Other Substances ◽  
Neurological Effects

Alzheimer’s disease (AD) is the most common form of dementia, prevalent in approximately 50–70% of the dementia cases. AD affects memory, and it is a progressive disease interfering with cognitive abilities, behaviour and functioning of the person affected. In 2015, there were 47 million people affected by dementia worldwide, and the figure was estimated to increase to 75 million in 2030 and to 132 million by 2050. In the framework of European Human Biomonitoring Initiative (HBM4EU), 18 substances or substance groups were prioritized for investigation. For each of the priority substances, a scoping document was prepared. Based on these scoping documents and complementary review of the recent literature, a scoping review of HBM4EU-priority substances which might be associated with AD was conducted. A possible association between risk of AD and pesticides was detected. For mercury (Hg), association is possible but inconsistent. Regarding cadmium (Cd) and arsenic (As), the results are inconsistent but inclined towards possible associations between the substances and the risk of disease. The evidence regarding lead (Pb) was weaker than for the other substances; however, possible associations exist. Although there is evidence of adverse neurological effects of environmental substances, more research is needed. Environmental chemical exposure and the related hazards are essential concerns for public health, and they could be preventable.

Spring poisoning hazards

Livestock ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 78-85
Author(s):  
Nicola Bates
Keyword(s):  
Treatment Options ◽  
Clinical Signs ◽  
Rapid Onset ◽  
Food Sources ◽  
Poisonous Plants ◽  
Allium Species ◽  
Cardiac Effects ◽  
Conium Maculatum ◽  
Toxic Plants ◽  
Neurological Effects

Poisoning in the spring may occur in livestock from exposure to glyphosate which is used prior to sowing of plant crops or from ingestion of poisonous plants. Glyphosate is of low toxicity but many products contain a carrier which is irritant to tissues. Plant poisoning may occur because other forage is unavailable and hungry animals will eat unpalatable toxic plants if other food sources are scare. Some plants such as bluebell (Hyacinoides species) and ransom (wild garlic, Allium urinsum) grow in profusion in the spring. Bluebells cause gastrointestinal and cardiac effects and Allium species cause anaemia. Some plants are more toxic in the spring as concentrations of toxic compounds are high compared with other times of the year. This is the case with hemlock (Conium maculatum) and water hemlock (Cicuta virosa). Both these plants cause neurological effects and water hemlock, in particular, causes very rapid onset of clinical signs. Spring flowering plants such as Rhododendron and Pieris species are commonly associated with poisoning, particularly in ruminants. Both these species contain grayanotoxins which cause gastrointestinal and cardiac effects. Access to areas where poisonous plants are known to grow should be restricted and good quality forage provided. Treatment options for management of poisoning in livestock are limited and, in some cases, the only sign of exposure is sudden death.

Pharmacology of the myogenic heart of the pond snail Lymnaea stagnalis

1990 ◽  
Vol 63 (6) ◽  
pp. 1413-1425 ◽  
Author(s):  
K. J. Buckett ◽  
G. J. Dockray ◽  
N. N. Osborne ◽  
P. R. Benjamin
Keyword(s):  
Lymnaea Stagnalis ◽  
Isolated Heart ◽  
Rapid Onset ◽  
Heart Tissue ◽  
Pond Snail ◽  
Low Concentrations ◽  
Other Substances ◽  
Heart Preparation ◽  
High Concentrations ◽  
Alpha Bungarotoxin

1. We have used pharmacologic, immunologic, and biochemical techniques to examine the role of neurochemicals in modulating the myogenic heart of the snail, Lymnaea. 2. 5-HT [high-pressure liquid chromatography (HPLC) and immunocytochemistry], dopamine (HPLC), FMRFamide-related peptides (radioimmunoassay and immunocytochemistry) and substance P-related peptides (immunocytochemistry) were shown to be localized within heart tissue. 3. The pharmacologic actions of these substances on the auricle from an isolated heart preparation were examined together with other putative modulators, acetylcholine (ACh), small cardioactive peptides A and B (SCPA and SCPB), [Arg]8vasotocin (AVT), and Lymnaea native FMRFamide-related peptides [Phe-Met-Arg-Phe-NH2 (FMRFamide), Ser-Asp-Pro-Phe-Leu-Arg-Phe-NH2 (SDPFLRFamide) and Gly-Asp-Pro-Phe-Leu-Arg-Phe-NH2 (GDPFLRFamide)]. 4. The response to each substance could be distinguished by different effect on beat rate, amplitude, and diastolic tonus, as well as by the duration of responses to standard 1-min applications. ACh was inhibitory at low concentrations (threshold less than 10(-10) M) but excitatory at high concentrations (10(-6) M). AVT was alone in producing no dose-dependent response. At high concentrations (10(-4) M), AVT caused a massive tonic contraction and cessation of auricle beat. All other substances examined were excitatory. 5. Antagonists to 5-HT (cinanserin), dopamine (ergonovine), and ACh (alpha-bungarotoxin) were identified. 6. ACh, 5-HT, dopamine, and FMRFamide-related peptides all acted on the auricle at low concentrations, and the rapid onset and short duration of their excitatory effects (ACh inhibitory at low concentrations) suggested that they may have roles as neurotransmitters. SCPA and SCPB were also potent (threshold less than 10(-10) M) but produced long-duration responses suggesting a modulatory or hormonal role.

5-Fluorouracil toxicosis in cats and dogs

2019 ◽  
Vol 24 (6) ◽  
pp. 288-292
Author(s):  
Nicola Bates
Keyword(s):  
Bone Marrow ◽  
Companion Animals ◽  
Skin Lesions ◽  
Therapeutic Window ◽  
Bone Marrow Depression ◽  
Malignant Skin ◽  
Neurological Effects ◽  
And Control ◽  
Supportive Management ◽  
Gastrointestinal Ulceration

5-Fluorouracil is an antineoplastic drug with a narrow therapeutic window. Pets are commonly exposed to the cream used for pre-malignant and malignant skin lesions in humans. 5-Fluorouracil poisoning is characterised by severe gastrointestinal (vomiting; diarrhoea; and gastrointestinal ulceration and haemorrhage) and neurological effects (ataxia, tremors and convulsions), and from 4–7 days bone marrow depression. Progression of signs can be rapid and control of neurological effects can be refractory to treatment. There is no specific antidote suitable for companion animals with 5-fluorouracil toxicosis, and aggressive supportive management is required. Filgrastim (a human granulocyte colony stimulating factor) can be used in the management of severe bone marrow depression, but prognosis is generally poor in dogs and cats with pronounced signs from 5-fluorouracil poisoning.

scholarly journals CNS Stimulation and PGE2 Release. III. Pentamethylenetetrazole-Induced Seizures

1989 ◽  
Vol 9 (2) ◽  
pp. 180-186 ◽  
Author(s):  
E. Navarro ◽  
S. D. Romero ◽  
T. L. Yaksh
Keyword(s):  
Low Dose ◽  
Seizure Activity ◽  
Prostaglandin E ◽  
Pge2 Release ◽  
Time Courses ◽  
High Doses ◽  
Cns Stimulation ◽  
Dose Dependent ◽  
Secretion Rates ◽  
Energy Failure

Measurement of prostaglandin E2 (PGE2) in the ventriculocisternal perfusate of the halothane anesthetized, artificially ventilated cat has revealed low but measurable levels of the prostanoid (64 ± 5 pg/min). Administration of pentamethylenetetrazole (PTZ) resulted in a rapid appearance of paroxysmal bursting, the magnitude and duration of which was dose dependent. During the 30-min interval after seizure initiation, PGE2 secretion rates into the ventriculocisternal perfusate rose by five- to sevenfold. Though the initial rate of PGE2 secretion correlated closely with the initial magnitude of bursting, there were significant differences, viz. the time courses. Thus, after a low dose of PTZ (200 mg/kg) the increase and return to normal of PGE2 secretion was time locked with the onset and offset of seizures. In contrast, after high doses of PTZ (250 mg/kg i. v.), seizure activity returned to near baseline by 90 min, while the levels of PGE2 secretion remained elevated for periods in excess of 150 min. Pretreatment with clonazepam (CLP: 3 mg/kg i. v. infusion) blocked seizures otherwise induced by PTZ (250 mg/kg) and the increase in PGE2 secretion. CLP administration 60 min after the initiation of seizures, blocked further seizure activity but did not alter the elevated secretion of PGE2. We thus believe these data jointly support the hypothesis that under intense paroxysmal bursting there is a change in neuronal state such that large stores of free fatty acids are available either because they have accumulated during the seizure because of a continued Ca2+ influx or the presence of large and continuing concentrations of Ca2+ accumulating in the cytosol secondary to energy failure.

scholarly journals 61 Nutritive feed ingredients that pose toxicological potential

2019 ◽  
Vol 97 (Supplement_3) ◽  
pp. 66-66
Author(s):  
Ray A Matulka
Keyword(s):  
Adverse Effects ◽  
Bone Mineralization ◽  
Average Daily Gain ◽  
Companion Animals ◽  
Intestinal Barrier ◽  
Intestinal Morphology ◽  
Reproductive Capacity ◽  
Feed Composition ◽  
Other Substances ◽  
Safety Studies

Abstract A variety of different substances can promote adverse effects on livestock and companion animals, varying from a decrease in overall growth, to frank toxicological response and death. Many substances that are the cause of adverse effects are either components in feed, part of the forage landscape for grazing animals, or even a part of the nutritive feed composition for pets. It has been well-known that vitamin D intake increases bone mineralization, but methionine consumption may also positively impact bone density. Excess consumption of other nutrients may lead to adverse effects, as current research found that excess tryptophan consumption in weaned pigs adversely affects intestinal morphology and tight junction proteins in other species. However, some studies have found that different animals can have opposing effects from consuming the same substances. For example, a study in mice has found that consumption of chitosan impairs intestinal barrier integrity, while twice the intake by weaned piglets improved the average daily gain. This presentation will discuss examples of nutrients and other substances that may adversely impact the growth and reproductive capacity of companion animals and livestock, underscoring the need for the completion of safety studies of potentially new ingredients to evaluate their long-term use in commercial feed formulations.

Review of the Radiation Damage Problem of Organic Specimens in Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 476-477
Author(s):  
L. Reimer
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Irradiation Time ◽  
Dose Effect ◽  
Primary Process ◽  
Thin Specimen ◽  
Secondary Damage ◽  
Small Doses ◽  
Micro Organisms ◽  
Damage Processes

Most information about a specimen is obtained by elastic scattering of electrons, but one cannot avoid inelastic scattering and therefore radiation damage by ionisation as a primary process of damage. This damage is a dose effect, being proportional to the product of lectron current density j and the irradiation time t in Coul.cm−2 as long as there is a negligible heating of the specimen.Therefore one has to determine the dose needed to produce secondary damage processes, which can be measured quantitatively by a chemical or physical effect in the thin specimen. The survival of micro-organisms or the decrease of photoconductivity and cathodoluminescence are such effects needing very small doses (see table).

Abstract #549 A Case of Rapid Onset Quadriparesis

2019 ◽  
Vol 25 ◽  
pp. 277-278
Author(s):  
Alberto Franco-Akel ◽  
Janpreet Bhandohal ◽  
Mohammad Saeed ◽  
Devendra Tripathi
Keyword(s):  
Rapid Onset
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