The Effect of Calcium Hydroxide Pastes on Isolated Vital Nerve Fibers

INTRODUCTION

Calcium hydroxide pastes (CHPs), commonly used for disinfecting root canals during endodontic treatment, are generally considered safe. However, accidental extrusions result in minimal injuries and little to no discomfort, except when extruded pastes come into contact with nerve bundles, such as the inferior alveolar nerve. Currently, there is a lack of information about the possible role of specific paste vehicles on the extent of nerve injury. The purpose of this study was to compare the role that paste vehicles, such as water or methylcellulose, may play when nerve fibers are exposed to CHP.

METHODS

Isolated sciatic nerves of Sprague-Dawley rats were exposed to either water-based or methylcellulose-based CHP for varying durations of time (30, 60, or 90 minutes). Histopathological changes, including axonal edema, myelin alterations, and loss of cellular outlines, were assessed, and the degrees of changes were compared using chi-square intraclass correlation coefficient tests.

RESULTS

Both groups exposed to the pastes demonstrated varying degrees of histopathologic changes, including axonal edema, myelin changes, and loss of cellular outlines, at different exposure times. The water-based calcium hydroxide paste induced these changes more rapidly than the methylcellulose-based paste. Similar patterns were observed in the scanning electron microscopic findings. Exposure time emerged as an important difference in the effects of the 2 pastes. In each of these tests, all observations of water-based paste exposure were rated as moderate to severe, whereas the observed cellular changes (axonal, myelin, and intact cellular outline) were rated as mild to moderate after exposure to methylcellulose-based paste for the same exposure durations. The chi-square tests indicated a statistically significant association between the material and each of the outcomes (axonal changes: χ²15 = 81.0, P < .001; myelin changes: χ²15 = 81.0, P < .001; intact cellular outline, χ²15 = 81.0, P < .001). The intraclass correlation coefficient value was 0.93.

CONCLUSIONS

The study demonstrates that axonal and myelin damage increase with longer exposure times, with water-based CHP causing more damage than methylcellulose-based CHP at each time point.

Perils and Problems in Bispecific T-Cell Engager Antibodies

Bispecific antibodies (BsAbs) are promising immunotherapies for cancer treatment designed to engage both tumour and immune cells. However, their use is associated with potential toxicities, including cytokine release syndrome (CRS), neurotoxicity, and on-target, off-tumour toxicity. CRS, characterized by cytokine release, is the most common, potentially life-threatening toxicity. Neurotoxicity presents as neurological symptoms and on-target, off-tumour toxicity damages healthy cells. Incidence and severity vary based on BsAb type, dose, patient factors, and tumor characteristics. For this study, articles pertaining to BsAb toxicity were searched on PubMed. Moreover, the management involves early recognition, dose modification, supportive care, and, in severe cases, immunosuppressive therapy or treatment discontinuation. Clinicians must carefully assess risks and benefits, considering individual patient profiles. Close monitoring and multidisciplinary collaboration are crucial for effective BsAb therapy. All in all, while toxicity is a concern, with vigilant management, BsAbs remain a valuable cancer treatment option.

Snake Bite-Induced Leukoencephalopathy: A Rare Case

Across the globe, snake envenomation causes significant morbidity and mortality. Although many clinical presentations and complications are observed in different types of snake bites, the incidence of leukoencephalopathy is rare. Although most cases of leukoencephalopathy are seen in viper bites, they are rarely seen in neurotoxic snake bites. In this report, we present a unique case of snake bite-induced leukoencephalopathy following a neurotoxic snake bite. The case highlights the importance of considering this rare complication in cases of snake bites presenting with neurological symptoms, particularly in those affecting higher mental functions.

Comparative Analysis of Alpha-1 Orthosteric-Site Binding by a Clade of Central American Pit Vipers (Genera Atropoides, Cerrophidion, Metlapilcoatlus, and Porthidium)

The distribution and relative potency of post-synaptic neurotoxic activity within Crotalinae venoms has been the subject of less investigation in comparison with Elapidae snake venoms. No previous studies have investigated post-synaptic neurotoxic activity within the Atropoides, Metlapilcoatlus, Cerrophidion, and Porthidium clade. Given the specificity of neurotoxins to relevant prey types, we aimed to uncover any activity present within this clade of snakes that may have been overlooked due to lower potency upon humans and thus not appearing as a clinical feature. Using biolayer interferometry, we assessed the relative binding of crude venoms to amphibian, lizard, bird, rodent and human α-1 nAChR orthosteric sites. We report potent alpha-1 orthosteric site binding in venoms from Atropoides picadoi, Metlapilcoatlus occiduus, M. olmec, M. mexicanus, M. nummifer. Lower levels of binding, but still notable, were evident for Cerrophidion godmani, C. tzotzilorum and C. wilsoni venoms. No activity was observed for Porthidium venoms, which is consistent with significant alpha-1 orthosteric site neurotoxicity being a trait that was amplified in the last common ancestor of Atropoides/Cerrophidion/Metlapilcoatlus subsequent to the split by Porthidium. We also observed potent taxon-selective activity, with strong selection for non-mammalian targets (amphibian, lizard, and bird). As these are poorly studied snakes, much of what is known about them is from clinical reports. The lack of affinity towards mammalian targets may explain the knowledge gap in neurotoxic activity within these species, since symptoms would not appear in bite reports. This study reports novel venom activity, which was previously unreported, indicating toxins that bind to post-synaptic receptors may be more widespread in pit vipers than previously considered. While these effects appear to not be clinically significant due to lineage-specific effects, they are of significant evolutionary novelty and of biodiscovery interest. This work sets the stage for future research directions, such as the use of in vitro and in vivo models to determine whether the alpha-1 orthosteric site binding observed within this study confers neurotoxic venom activity.

Early-Life Lead Exposure: Risks and Neurotoxic Consequences

Lead (Pb) does not have any biological function in a human, and there is likely no safe level of Pb in the human body. The Pb exposure impacts are a global concern for their potential neurotoxic consequences. Despite decreasing both the environmental Pb levels and the average blood Pb levels in the survey populations, the lifetime redistribution from the tissues-stored Pb still poses neurotoxic risks from the low-level exposure in later life. The growing fetus and children hold their innate high-susceptible to these Pb-induced neurodevelopmental and neurobehavioral effects. This article aims to evaluate the cumulative studies and insights on the topic of Pb neurotoxicology while assessing the emerging trends in the field. The Pb-induced neurochemical and neuro-immunological mechanisms are likely responsible for the high-level Pb exposure with the neurodevelopmental and neurobehavioral impacts at the initial stages. Early-life Pb exposure can still produce neurodegenerative consequences in later life due to the altered epigenetic imprints and the ongoing endogenous Pb exposure. Several mechanisms contribute to the Pb-induced neurotoxic impacts, including the direct neurochemical effects, the induction of oxidative stress and inflammation through immunologic activations, and epigenetic alterations. Furthermore, the individual nutritional status, such as macro-, micro-, or antioxidant nutrients, can significantly influence the neurotoxic impacts even at low-level exposure to Pb. The prevention of early-life Pb exposure is, therefore, the critical determinant for alleviating various Pb-induced neurotoxic impacts across the different age groups.

Tetrodotoxin Poisoning Due to Pufferfish Ingestion in the United Arab Emirates

Tetrodotoxin is a potent neurotoxin that is found in the ovaries and liver of pufferfish. This lethal toxin is heat stable and does not destroy by cooking that is why precaution should be taken when eating pufferfish. A 60-year-old male presented to the ED after eating pufferfish complaining of perioral and hand numbness, gait disturbance, and generalized body weakness. This presentation is due to a tetrodotoxin found in and not limited to the pufferfish he ingested. Despite having pufferfish with his family, he was the sole person to have symptoms because, unlike the other family members, he ate from the liver part of the fish. The patient was admitted for observation, received supportive care, and underwent multiple investigations that most came to be normal. He improved gradually and was discharged after staying for three nights in the hospital. Symptoms after eating the toxic parts of a pufferfish may progress to paralysis, and respiratory failure, and may lead to death. It is not common to have such fish eaten in the United Arab Emirates due to its limited availability.

Intraperitoneal pretreatment of ellagic acid and chrysin alleviate ifosfamide-induced neurotoxicity, but betanin induces death in male wistar rats

BACKGROUND

Ifosfamide (IFO) is a widely used antineoplastic drug with broad-spectrum efficacy against various types of cancer. However, different toxicities associated with IFO has limited its use. This study was to establish the prophylactic effects of betanin, chrysin and ellagic acid against IFO-induced neurotoxicity in rats.

METHODS

Animals were randomly divided into eight groups, control, IFO, IFO + betanin, IFO + chrysin, IFO + ellagic acid, betanin, chrysin and ellagic acid groups. Betanin (50 mg/kg, i.p.), chrysin (25 mg/kg, i.p.) and ellagic acid (25 mg/kg, i.p.) were administered to rats once daily for two consecutive days. IFO (500 mg/kg, i.p.) was administered on third day.

RESULTS

Results demonstrated that only ellagic acid markedly decreased the activity of acetylcholinesterase (AChE) and butrylcholinesterase (BChE) compared with IFO alone, while chrysin was only effective on BChE activity. Also, ellagic acid ameliorated IFO-induced lipid peroxidation and glutathione (GSH) depletion, while chrysin only decreased GSH depletion. Histopathological alteration in the IFO-induced brain tissues were decreased especially after administration of ellagic acid. Intraperitoneal pretreatment with betanin, followed by IFO resulted in death of all treated animals. In addition, all mitochondrial toxicity parameters induced by IFO in the rat brain tissue were ameliorated by ellagic acid, chrysin and even betanin.

CONCLUSION

Taken together, our results demonstrated that especially ellagic acid and to some extent chrysin show a typical neuroprotective effect on IFO-induced acute neurotoxicity through mitochondrial protection and antioxidant properties. Also, the results of our studies showed that pretreatment with betanin followed by IFO was lethal.

An Overview of the Relationship Between Occupational Manganese Exposure and Parkinsonism

Manganese (Mn) is an essential element used in many industries, such as welding, foundries, the production of metal alloys, especially stainless steel, and the production of dry batteries, pesticides, paints, and explosives. Individuals are exposed to Mn through inhalation of fumes, dermal absorption, and ingestion. This metal is an essential trace element required for normal growth, development, and cellular homeostasis. It has also toxic effects on the central nervous system and can cause Parkinsonism symptoms in exposed patients. Studies on human and animal models reveal that neurons of the globus pallidus, the cerebellum, pons, red nucleus, the thalamus, cortex, and the anterior horn of the spinal cord could be affected by Mn toxicity. Although the diagnosis of manganese-induced Parkinsonism is primarily clinical, there are some supporting features on brain MRI images that may be helpful to objectively distinguish it. This study was designed to review the ways of exposure to Mn, clinical symptoms in case of exposure, and discover the relationship between exposure to Mn and Parkinsonism in the working population.

The Use of Non-targeted Lipidomics and Histopathology to Characterize the Neurotoxicity of Bifenthrin to Juvenile Rainbow Trout (Oncorhynchus mykiss)

Due to the detection frequencies and measured concentrations in surface water, the type I pyrethroid insecticide, bifenthrin, has been of particular concern within the Sacramento-San Joaquin Delta in California. Concentrations have been detected above levels previously reported to impair neuroendocrine function and induce neurotoxicity to several species of salmonids. Metabolomic and transcriptomic studies indicated impairment of cellular signaling within the brain of exposed animals and potential alteration of lipid metabolism. To better understand the potential impacts of bifenthrin on brain lipids, juvenile rainbow trout (Oncorhynchus mykiss) were exposed to mean bifenthrin concentrations of 28 or 48 ng/L for 14 days, and non-targeted lipidomic profiling in the brain was conducted. Brain tissue sections were also assessed for histopathological insult following bifenthrin treatment. Bifenthrin-exposed trout had a concentration-dependent decrease in the relative abundance of triglycerides (TGs) with levels of phosphatidylcholines (PCs) and phosphatidylethanolamines (PEs) significantly altered following 48 ng/L bifenthrin exposure. An increased incidence of histopathological lesions, such as focal hemorrhages and congestion of blood vessels, was noted in the brains of bifenthrin-treated animals, suggesting an association between altered lipid metabolism and neuronal cell structure and integrity.

A review of potential neuropathological changes associated with ketamine

INTRODUCTION

: Ketamine is an established intervention for treatment resistant depression (TRD). However, long-term adverse effects with repeated doses remain insufficiently characterized. Although several animal models have shown N-methyl-D-aspartate glutamate receptor antagonists to produce various neuropathological reactions, attention surrounding the risk of brain lesions has been minimal.

AREAS COVERED

: The current review focuses on potential neuropathological changes associated with ketamine. Search terms included variations of ketamine, Olney lesions, tau hyperphosphorylation, and parvalbumin interneurons.

EXPERT OPINION

: Daily high-dose ketamine use in substance use disorder (SUD) populations was associated with clear neurotoxic effects, while no studies specifically evaluated effects of ketamine protocols used for TRD. It is difficult to discern effects directly attributable to ketamine due to methodological factors, such as comorbidities and dramatic differences in dose in SUD populations versus infrequent sub-anesthetic doses typically prescribed for TRD. Taken together, animal models and human ketamine SUD populations suggest potential neuropathology with chronic high-dose ketamine exposure exceeding those recommended for adults with TRD. It is unknown whether repeat sub-anesthetic dosing of ketamine in adults with TRD is associated with Olney lesions or other neuropathologies. In the interim, practitioners should be vigilant for this possibility recognizing that the condition itself is associated with neurodegenerative processes.

Treatment of Hyperammonemia by Transplanting a Symbiotic Pair of Intestinal Microbes

Hyperammonemia is a deleterious and inevitable consequence of liver failure. However, no adequate therapeutic agent is available for hyperammonemia. Although recent studies showed that the pharmabiotic approach could be a therapeutic option for hyperammonemia, its development is clogged with poor identification of etiological microbes and low transplantation efficiency of candidate microbes. In this study, we developed a pharmabiotic treatment for hyperammonemia that employs a symbiotic pair of intestinal microbes that are both able to remove ammonia from the surrounding environment. By a radioactive tracing experiment in mice, we elucidated how the removal of ammonia by probiotics in the intestinal lumen leads to lower blood ammonia levels. After determination of the therapeutic mechanism, ammonia-removing probiotic strains were identified by high-throughput screening of gut microbes. The symbiotic partners of ammonia-removing probiotic strains were identified by screening intestinal microbes of a human gut, and the pairs were administrated to hyperammonemic mice to evaluate therapeutic efficacy. Blood ammonia was in a chemical equilibrium relationship with intestinal ammonia. Lactobacillus reuteri JBD400 removed intestinal ammonia to shift the chemical equilibrium to lower the blood ammonia level. L. reuteri JBD400 was successfully transplanted with a symbiotic partner, Streptococcus rubneri JBD420, improving transplantation efficiency 2.3×10³ times more compared to the sole transplantation while lowering blood ammonia levels significantly. This work provides new pharmabiotics for the treatment of hyperammonemia as well as explains its therapeutic mechanism. Also, this approach provides a concept of symbiotic pairs approach in the emerging field of pharmabiotics.

Psychobiotics improve propionic acid-induced neuroinflammation in juvenile rats, rodent model of autism

This study aimed to evaluate the protective and therapeutic potency of bee pollen and probiotic mixture on brain intoxication caused by propionic acid (PPA) in juvenile rats. Five groups of six animals each, were used: the control group only receiving phosphate-buffered saline; the bee pollen and probiotic-treated group receiving a combination of an equal quantity of bee pollen and probiotic (0.2 kg/kg body weight); the PPA group being treated for 3 days with an oral neurotoxic dose of PPA (0.25 kg/kg body weight); the protective and therapeutic groups receiving bee pollen and probiotic mixture treatment right before and after the neurotoxic dose of PPA, respectively. The levels of interleukin (IL)-1ß, IL-6, IL-8, IL-10, IL-12, tumor necrosis factor α, and interferon γ (IFN-γ) were investigated to evaluate the neuroinflammatory responses in brain tissues from different animal groups. The much higher IL-1β, IL-8, and IFN-γ, as pro-inflammatory cytokines (P < 0.001), together with much lower IL-10, as anti-inflammatory cytokine (P < 0.001) compared to controls clearly demonstrated the neurotoxic effects of PPA. Interestingly, the mixture of bee pollen and probiotics was effective in alleviating PPA neurotoxic effects in both therapeutic and protective groups demonstrating highly significant changes in IL-1β, IL-8, IL-10, and IFN-γ levels together with non-significant reduction in IL-6 levels compared to PPA-treated rats. Overall, our findings demonstrated a new approach to the beneficial use of psychobiotics presenting as bee pollen and probiotic combination in neuroinflammation through cytokine changes as a possible role of glial cells in gut–brain axis.

Noninvasive disconnection of targeted neuronal circuitry sparing axons of passage and nonneuronal cells

OBJECTIVE

Surgery can be highly effective for the treatment of medically intractable, neurological disorders, such as drug-resistant focal epilepsy. However, despite its benefits, surgery remains substantially underutilized due to both surgical concerns and nonsurgical impediments. In this work, the authors characterized a noninvasive, nonablative strategy to focally destroy neurons in the brain parenchyma with the goal of limiting collateral damage to nontarget structures, such as axons of passage.

METHODS

Low-intensity MR-guided focused ultrasound (MRgFUS), together with intravenous microbubbles, was used to open the blood-brain barrier (BBB) in a transient and focal manner in rats. The period of BBB opening was exploited to focally deliver to the brain parenchyma a systemically administered neurotoxin (quinolinic acid) that is well tolerated peripherally and otherwise impermeable to the BBB.

RESULTS

Focal neuronal loss was observed in targeted areas of BBB opening, including brain regions that are prime objectives for epilepsy surgery. Notably, other structures in the area of neuronal loss, including axons of passage, glial cells, vasculature, and the ventricular wall, were spared with this procedure.

CONCLUSIONS

These findings identify a noninvasive, nonablative approach capable of disconnecting neural circuitry while limiting the neuropathological consequences that attend other surgical procedures. Moreover, this strategy allows conformal targeting, which could enhance the precision and expand the treatment envelope for treating irregularly shaped surgical objectives located in difficult-to-reach sites. Finally, if this strategy translates to the clinic, the noninvasive nature and specificity of the procedure could positively influence both physician referrals for and patient confidence in surgery for medically intractable neurological disorders.

PAC1 Receptor Mediates Electroacupuncture-Induced Neuro and Immune Protection During Cisplatin Chemotherapy

Platinum-based chemotherapy is an effective treatment used in multiple tumor treatments, but produces severe side effects including neurotoxicity, anemia, and immunosuppression, which limits its anti-tumor efficacy and increases the risk of infections. Electroacupuncture (EA) is often used to ameliorate these side effects, but its mechanism is unknown. Here, we report that EA on ST36 and SP6 prevents cisplatin-induced neurotoxicity and immunosuppression. EA induces neuroprotection, prevents pain-related neurotoxicity, preserves bone marrow (BM) hematopoiesis, and peripheral levels of leukocytes. EA activates sympathetic BM terminals to release pituitary adenylate cyclase activating polypeptide (PACAP). PACAP-receptor PAC1-antagonists abrogate the effects of EA, whereas PAC1-agonists mimic EA, prevent neurotoxicity, immunosuppression, and preserve BM hematopoiesis during cisplatin chemotherapy. Our results indicate that PAC1-agonists may provide therapeutic advantages during chemotherapy to treat patients with advanced neurotoxicity or neuropathies limiting EA efficacy.

The Bacterial Enzyme RfxCas13d Is Less Neurotoxic Than PspCas13b and Could Be a Promising RNA Editing and Interference Tool in the Nervous System

RNA therapies using RNA editing and interference are currently being developed for neurological diseases. The CRISPR-Cas13 system, based on bacterial enzymes, holds great promise for developing efficient tools for RNA therapies. However, neurotoxic activity has been reported for Cas13a, and recent studies have reported toxic effects of PspCas13b and RfxCas13d during zebrafish and Drosophila embryonic development. It is important to investigate the safety of these bacterial enzymes in the context of the nervous system and neuronal development. In this study, we used mouse cerebellar Purkinje cells as a complex neuron type to test for the potential neurotoxic actions of RfxCas13d and PspCas13b. We found that PspCas13b significantly impeded the dendritic development of cultured Purkinje cells, similar to the neurotoxic action of Cas13a. In contrast, RfxCas13d did not exhibit a significant inhibition of dendritic development. A similar trend was found for axonal outgrowth. These results suggest varying neurotoxic properties for different Cas13 ortholog enzymes. We call for more studies to investigate, and possibly mitigate, the neurotoxicity of Cas13 proteins in order to improve the safety of the CRISPR-Cas13 system for RNA therapies.

The Dragon's Paralysing Spell: Evidence of Sodium and Calcium Ion Channel Binding Neurotoxins in Helodermatid and Varanid Lizard Venoms

Bites from helodermatid lizards can cause pain, paresthesia, paralysis, and tachycardia, as well as other symptoms consistent with neurotoxicity. Furthermore, in vitro studies have shown that Heloderma horridum venom inhibits ion flux and blocks the electrical stimulation of skeletal muscles. Helodermatids have long been considered the only venomous lizards, but a large body of robust evidence has demonstrated venom to be a basal trait of Anguimorpha. This clade includes varanid lizards, whose bites have been reported to cause anticoagulation, pain, and occasionally paralysis and tachycardia. Despite the evolutionary novelty of these lizard venoms, their neuromuscular targets have yet to be identified, even for the iconic helodermatid lizards. Therefore, to fill this knowledge gap, the venoms of three Heloderma species (H. exasperatum, H. horridum and H. suspectum) and two Varanus species (V. salvadorii and V. varius) were investigated using Gallus gallus chick biventer cervicis nerve–muscle preparations and biolayer interferometry assays for binding to mammalian ion channels. Incubation with Heloderma venoms caused the reduction in nerve-mediated muscle twitches post initial response of avian skeletal muscle tissue preparation assays suggesting voltage-gated sodium (Na_V) channel binding. Congruent with the flaccid paralysis inducing blockage of electrical stimulation in the skeletal muscle preparations, the biolayer interferometry tests with Heloderma suspectum venom revealed binding to the S3–S4 loop within voltage-sensing domain IV of the skeletal muscle channel subtype, Na_V1.4. Consistent with tachycardia reported in clinical cases, the venom also bound to voltage-sensing domain IV of the cardiac smooth muscle calcium channel, Ca_V1.2. While Varanus varius venom did not have discernable effects in the avian tissue preparation assay at the concentration tested, in the biointerferometry assay both V. varius and V. salvadorii bound to voltage-sensing domain IV of both Na_V1.4 and Ca_V1.2, similar to H. suspectum venom. The ability of varanid venoms to bind to mammalian ion channels but not to the avian tissue preparation suggests prey-selective actions, as did the differential potency within the Heloderma venoms for avian versus mammalian pathophysiological targets. This study thus presents the detailed characterization of Heloderma venom ion channel neurotoxicity and offers the first evidence of varanid lizard venom neurotoxicity. In addition, the data not only provide information useful to understanding the clinical effects produced by envenomations, but also reveal their utility as physiological probes, and underscore the potential utility of neglected venomous lineages in the drug design and development pipeline.

The Footprint of Kynurenine Pathway in Neurodegeneration: Janus-Faced Role in Parkinson's Disorder and Therapeutic Implications

Progressive degeneration of neurons and aggravation of dopaminergic neurons in the substantia nigra pars compacta results in the loss of dopamine in the brain of Parkinson's disease (PD) patients. Numerous therapies, exhibiting transient efficacy have been developed; however, they are mostly accompanied by side effects and limited reliability, therefore instigating the need to develop novel optimistic treatment targets. Significant therapeutic targets have been identified, namely: chaperones, protein Abelson, glucocerebrosidase-1, calcium, neuromelanin, ubiquitin-proteasome system, neuroinflammation, mitochondrial dysfunction, and the kynurenine pathway (KP). The role of KP and its metabolites and enzymes in PD, namely quinolinic acid (QUIN), kynurenic acid (KYNA), 3-hydroxykynurenine (3-HK), 3-hydroxyanthranillic acid (3-HAA), kunurenine-3-monooxygenase (KMO), etc. has been reported. The neurotoxic QUIN, N-methyl-D-aspartate (NMDA) receptor agonist, and neuroprotective KYNA-which antagonizes QUIN actions-primarily justify the Janus-faced role of KP in PD. Moreover, KP has been reported to play a biomarker role in PD detection. Therefore, the authors detail the neurotoxic, neuroprotective, and immunomodulatory neuroactive components, alongside the upstream and downstream metabolic pathways of KP, forming a basis for a therapeutic paradigm of the disease while recognizing KP as a potential biomarker in PD, thus facilitating the development of a suitable target in PD management.

Nω-nitro-L-arginine, a nitric oxide synthase inhibitor, attenuates nickel-induced neurotoxicity

The various mediums of exposure to nickel (Ni) compounds have raised enormous public health concerns, as it has been illustrated to exert toxic effects in biological organs, including the brain. We have previously implicated the involvement of elevated nitric oxide (NO) in Ni-induced oxidative stress in the brain. Hence, the present study investigated the ameliorative potential of N^ω-nitro-L-arginine (L-NA), a NO synthase inhibitor, following Ni-induced neurotoxicity. Adult male rats were divided into four groups; control (normal saline), 10 mg/kg Ni chloride (NiCl₂) only, 1 mg/kg L-NA, or 2 mg/kg L-NA co-administered with NiCl₂. The administration was via daily intraperitoneal injections for three weeks. Neurobehavioural assessments performed thereafter ascertained short-term spatial memory and anxiety. Furthermore, histological evaluations of the cortex, hippocampus, and striatum were carried out using routine hematoxylin and eosin technique, while the phosphotungstic acid hematoxylin method was used to express the degree of astrogliosis. Biochemical analysis of NO levels was examined along with other oxidative stress markers (superoxide dismutase, catalase, glutathione, glutathione S transferase, glutathione peroxidase, myeloperoxidase, and lipid peroxidation). The results illustrated altered behavioral responses, a higher population of degenerating neurons, and astrocytes in the NiCl₂ group. There was also an elevation in the NO level and a corresponding reduction in antioxidant activities. However, these debilitating changes were ameliorated in the L-NA treated groups. These results demonstrate an association between alterations in NO synthesis pathway and Ni neurotoxicity, which may render neuronal cells susceptible to damage by oxidative stress. This may yet be another mechanism and useful therapeutic marker in deciphering Ni-induced neurotoxicity.

Ambispective study of clinical picture, management practices and outcome of snake bite patients at tertiary care centre in Northern India

Background

Snakebite is a common but neglected public health problem of tropical & subtropical regions worldwide. This study was conducted to look into profile, first aid measures, management strategy and outcomes of snake bite patients.

Methods

This was an ambispective study conducted in the Department of Medicine & Emergency Medicine at AIIMS, New Delhi from June 2011 to May 2017 and enrolled 54 patients. In retrospective part 33 case records of snake bite patients were retrieved and in prospective part 21 patients were recruited. All relevant information including demographic parameters, first aid measures, clinical and laboratory profile and outcomes were recorded in pre made proformas. All data were analysed using IBM Stata version 13 and Microsoft Excel 2011.

Results

Majority of patients were male, and the mean age was 27.6 years. Maximum numbers of bites 34 (63%) happened in the rainy season and Krait was the most common culprit species. Neurological manifestations were most common (70.4%) followed by haematological. Most common complication was ventilatory failure (78.6%), and median dose of ASV was 20 vials. Forty-nine (90.7%) patients were discharged successfully. There was significant association of sepsis and shock with non survivors of snake bite with respective P values of 0.02 and 0.007.

Conclusion

Neurotoxic snake bite (70.4%) was the most common type of envenomation. Most common complication was ventilatory failure and majority of patient (90.7%) successfully discharged. Sepsis and shock were significantly associated with non survivors of snake bite.

Extensive Variation in the Activities of Pseudocerastes and Eristicophis Viper Venoms Suggests Divergent Envenoming Strategies Are Used for Prey Capture

Snakes of the genera Pseudocerastes and Eristicophis (Viperidae: Viperinae) are known as the desert vipers due to their association with the arid environments of the Middle East. These species have received limited research attention and little is known about their venom or ecology. In this study, a comprehensive analysis of desert viper venoms was conducted by visualising the venom proteomes via gel electrophoresis and assessing the crude venoms for their cytotoxic, haemotoxic, and neurotoxic properties. Plasmas sourced from human, toad, and chicken were used as models to assess possible prey-linked venom activity. The venoms demonstrated substantial divergence in composition and bioactivity across all experiments. Pseudocerastes urarachnoides venom activated human coagulation factors X and prothrombin and demonstrated potent procoagulant activity in human, toad, and chicken plasmas, in stark contrast to the potent neurotoxic venom of P. fieldi. The venom of E. macmahonii also induced coagulation, though this did not appear to be via the activation of factor X or prothrombin. The coagulant properties of P. fieldi and P. persicus venoms varied among plasmas, demonstrating strong anticoagulant activity in the amphibian and human plasmas but no significant effect in that of bird. This is conjectured to reflect prey-specific toxin activity, though further ecological studies are required to confirm any dietary associations. This study reinforces the notion that phylogenetic relatedness of snakes cannot readily predict venom protein composition or function. The significant venom variation between these species raises serious concerns regarding antivenom paraspecificity. Future assessment of antivenom is crucial.

Effects of Cassava Juice (Manihot esculenta Crantz) on Renal and Hepatic Function and Motor Impairments in Male Rats

Cassava (Manihot esculenta Crantz) is a plant that contains neurotoxins such as linamarin and lotaustraline. Its long-term consumption is associated with neuronal damage and contributes to the development of motor impairment in humans and rats. We investigated the effects of the consumption of cassava juice on renal and hepatic function and motor impairments in male rats. The rats received the vehicle, non-toxic and toxic doses of cassava juice, or linamarin as a pharmacological control, over 35 consecutive days. The effects were evaluated in an open field test, rotarod, and swim test. The toxic cassava dose and linamarin resulted in motor impairments in the rotarod and swim test from day 7 of treatment. The toxic cassava dose and linamarin increased the parameters that indicate renal and hepatic damage, with the exception of total protein and albumin levels. Behavioral variables that show motor incoordination (i.e., latency to fall in the rotarod) were negatively correlated with biochemical parameters of renal and kidney damage, whereas spin behavior was positively correlated. Our data indicate that chronic oral consumption of cassava juice caused renal and hepatic damage that was correlated with motor coordination impairment in rats, similarly to their principal neurotoxic compound, linamarin.

Neuroprotective effect of rhaponticin against Parkinson disease: Insights from in vitro BV-2 model and in vivo MPTP-induced mice model

Parkinson's disease (PD) is a complex neurodegenerative illness associated with the loss or damage to neurons of the dopaminergic system in the brain. Few therapeutic approaches and considerable side effects of conventional drugs necessitate a new therapeutic agent to treat patients with PD. Rhaponticin is a natural hydroxystilbene, found in herbal plants such as Rheum rhaponticum, and known to have desirable biological activity including anti-inflammatory properties. However, the neuroinflammation on rhaponticin levels has only been investigated partially so far. So, the current study explored whether rhaponticin could ameliorate the pathophysiology observed in both the in vitro microglial BV-2 cells and the in vivo (1-methyl-4-phenyl-1,2,3,5-tetrahydropyridine [MPTP])-mediated PD model. The results show rhaponticin significantly attenuated lipopolysaccharide (LPS)-mediated microglial activation by suppressing nitric oxide synthase in conjunction with abridged reactive oxygen species production together with proinflammatory mediator reduction. In vivo rhaponticin treatment improves motor impairments as well as the loss of dopaminergic neurons in MPTP-treated mice possibly through suppression via mediators of inflammation. Taken together, these results offer evidence that rhaponticin exerts anti-inflammatory effects and neuroprotection in an LPS-induced microglial model and the MPTP-induced mouse models of PD.

Dietary monosodium glutamate altered redox status and dopamine metabolism in lobster cockroach (Nauphoeta cinerea)

Monosodium Glutamate (MSG) is the most commonly utilized food additive in the world. However, data on possible biochemical reasons underlying the neurotoxic effects of dietary MSG is limited. Therefore, this study investigated the effects of dietary supplementation of MSG on redox status and neurochemical indices in lobster cockroach nymph. These were evaluated via assessment of enzymatic and nonenzymatic antioxidants, acetylcholinesterase and monoamine oxidase activities, and dopamine content in the cockroach nymph head homogenate. MSG supplemented diet caused dose-dependent significant (p < .05) reduction in % survival, thiol, GSH, dopamine contents, and GST activity, increased ROS, NO, Fe²⁺ , MDA contents, and MAO activity but no significant (p < .05) difference was obtained in GSH and TBARS contents, and AChE activity. Increased oxidative, cholinergic, and monoaminergic activities coupled with decreased dopamine level might be the plausible biochemical explanation for the neurotoxic effects observed during sub-chronic consumption of large amounts of MSG in diet. PRACTICAL APPLICATIONS: This study suggests that consumption of monosodium glutamate should be reduced to the barest minimum due to its capability to induce oxidative stress and nervous toxicological effects at high dosage.

Insights into platinum-induced peripheral neuropathy-current perspective

Cancer is a global health problem that is often successfully addressed by therapy, with cancer survivors increasing in numbers and living longer world around. Although new cancer treatment options are continuously explored, platinum based chemotherapy agents remain in use due to their efficiency and availability. Unfortunately, all cancer therapies affect normal tissues as well as cancer, and more than 40 specific side effects of platinum based drugs documented so far decrease the quality of life of cancer survivors. Chemotherapy-induced peripheral neuropathy is a frequent side effects of platinum-based chemotherapy agents. This cluster of complications is often so debilitating that patients occasionally have to discontinue the therapy. Sensory neurons of dorsal root ganglia are at the core of chemotherapy-induced peripheral neuropathy symptoms. In these postmitotic cells, DNA damage caused by platinum chemotherapy interferes with normal functioning. Accumulation of DNA-platinum adducts correlates with neurotoxic severity and development of sensation of pain. While biochemistry of DNA-platinum adducts is the same in all cell types, molecular mechanisms affected by DNA-platinum adducts are different in cancer cells and non-dividing cells. This review aims to raise awareness about platinum associated chemotherapy-induced peripheral neuropathy as a medical problem that has remained unexplained for decades. We emphasize the complexity of this condition both from clinical and mechanistical point of view and focus on recent findings about chemotherapy-induced peripheral neuropathy in in vitro and in vivo model systems. Finally, we summarize current perspectives about clinical approaches for chemotherapy-induced peripheral neuropathy treatment.

Sex-specific behavioral effects following developmental exposure to tetrabromobisphenol A (TBBPA) in Wistar rats

Tetrabromobisphenol A (TBBPA) has become a ubiquitous indoor contaminant due to its widespread use as an additive flame retardant in consumer products. Reported evidence of endocrine disruption and accumulation of TBBPA in brain tissue has raised concerns regarding its potential effects on neurodevelopment and behavior. The goal of the present study was to examine the impact of developmental TBBPA exposure, across a wide range of doses, on sexually dimorphic non-reproductive behaviors in male and female Wistar rats. We first ran a pilot study using a single TBBPA dose hypothesized to produce behavioral effects. Wistar rat dams were orally exposed using cookie treats to 0 or 0.1 mg TBBPA/kg bw daily from gestational day (GD) 9 to postnatal day (PND) 21 to assess offspring (both sexes) activity and anxiety-related behaviors. Significant effects were evident in females, with exposure increasing activity levels. Thus, this dose was used as the lowest TBBPA dose in a subsequent, larger study conducted as part of a comprehensive assessment of TBBPA toxicity. Animals were exposed to 0, 0.1, 25, or 250 mg TBBPA/kg bw daily by oral gavage starting on GD 6 through PND 90 (dosed dams GD 6 - PND 21, dosed offspring PND 22 - PND 90). Significant behavioral findings were observed for male offspring, with increased anxiety-like behavior as the primary phenotype. These findings demonstrate that exposure to environmental contaminants, like TBBPA, can have sex-specific effects on behavior highlighting the vulnerability of the developing brain.

Anthropogenic Noise Aggravates the Toxicity of Cadmium on Some Physiological Characteristics of the Blood Clam Tegillarca granosa

Widespread applications of cadmium (Cd) in various products have caused Cd contamination in marine ecosystems. Meanwhile, human activities in the ocean have also generated an increasing amount of noise in recent decades. Although anthropogenic noise and Cd contaminants could be present simultaneously in marine environments, the physiological responses of marine bivalve mollusks upon coexposure to anthropogenic noise and toxic metal contaminants, including Cd remain unclear. Therefore, the combined effects of anthropogenic noise and Cd on the physiological characteristics of the blood clam Tegillarca granosa were investigated in this study. The results showed that 10 days of coexposure to anthropogenic noise and Cd can enhance adverse impacts on metabolic processes, as indicated by the clearance rate, respiration rate, ammonium excretion rate, and O:N ratio of T. granosa. In addition, both the ATP content, ATP synthase activity and genes encoding important enzymes in ATP synthesis significantly declined after coexposures to anthropogenic noise and Cd, which have resulted from reduced feeding activity and respiration. Furthermore, the expressions of neurotransmitter-related genes (MAO, AChE, and mAChR3) were all significantly down-regulated after coexposure to anthropogenic noise and Cd, which suggests an enhanced neurotoxicity under coexposure. In conclusion, our study demonstrated that anthropogenic noise and Cd would have synergetic effects on the feeding activity, metabolism, and ATP synthesis of T. granosa, which may be due to the add-on of stress responses and neurotransmitter disturbances.

In Vitro Cytotoxicity Induced by the Bufadienolides 1α,2α-Epoxyscillirosidine and Lanceotoxin B on Rat Myocardial and Mouse Neuroblastoma Cell Lines

Consumption of bufadienolide-containing plants are responsible for many livestock mortalities annually. Bufadienolides are divided into two groups; non-cumulative bufadienolides and cumulative bufadienolides. Cumulative bufadienolides are referred to as neurotoxic, as the chronic intoxication with this type of bufadienolide results in a paretic/paralytic syndrome known as ‘krimpsiekte’. The in vitro cytotoxicity of a non-cumulative bufadienolide, 1α,2α-epoxyscillirosidine, and a cumulative bufadienolide, lanceotoxin B, were compared using the MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction) assay after exposing rat myocardial (H9c2) and mouse neuroblastoma (Neuro-2a) cell lines. The effect of these two bufadienolides on cell ultrastructure was also investigated using transmission electron microscopy (TEM). H9c2 cells exhibited greater cytotoxicity when exposed to 1α,2α-epoxyscillirosidine, compared to lanceotoxin B. In contrast, Neuro-2a cells were more susceptible to lanceotoxin B. The EC₅₀ (half maximal effective concentration) of lanceotoxin B exposure of Neuro-2a cells for 24–72 h ranged from 4.4–5.5 µM compared to EC₅₀s of 35.7–37.6 µM for 1α,2α-epoxyscillirosidine exposure of Neuro-2a cells over the same period. 1α,2α-Epoxyscillirosidine induced extensive vacuolization in both cell types, with swollen RER (rough endoplasmic reticulum) and perinuclear spaces. Lanceotoxin B caused swelling of the mitochondria and sequestration of cytoplasmic material within autophagic vesicles. These results corroborate the notion that cumulative bufadienolides are neurotoxic.

Berg adder (Bitis atropos) envenoming: an analysis of 14 cases

INTRODUCTION

The berg adder (Bitis atropos) is a little-studied, lesser-known viperid snake found in southern Africa and there is limited information available regarding the manifestations of envenoming.

MATERIALS AND METHODS

This observational series of 14 cases documents features of berg adder envenoming over a period of 16 years (1987-2003). Clinical features of envenomed patients: All 14 patients developed local cytotoxic effects. Thirteen patients developed systemic effects manifesting and documented in varying degrees. These include (1) prominent vomiting (2) disturbances in cranial nerve function (anosmia and altered taste, an ophthalmological triad of ptosis, mydriasis and visual disturbances including loss of accommodation, and dysphagia) (3) a global decrease in motor power where mechanical ventilation was often required for respiratory failure and (4) hyponatraemia (lowest value recorded 111 mmol/L), sometimes with associated convulsions.

DISCUSSION

The full range of polypeptides present in berg adder venom is yet to be characterised. However, two closely related phospholipases A₂ (PLA₂; PLA₂-1 and PLA₂-2) have been purified from the venom of B. atropos and clinical evidence suggests that a natriuretic peptide is also possibly present. Envenoming results in distinctive, sometimes life-threatening, manifestations.

Clinical and epidemiologic profile and predictors of outcome of poisonous snake bites - an analysis of 1,500 cases from a tertiary care center in Malabar, North Kerala, India

Background

Snake bites are a neglected public health problem in all tropical countries, and particularly in Malabar region of Kerala, India. Demographic characteristics and clinical parameters vary in this part of the world, and studies based on them are scarce. Increased incidence of capillary leak syndrome (CLS) in hemotoxic snake bites and emergence of cases of hump-nosed pit viper (HNPV, Hypnale hypnale) envenomation are some notable features seen here.

Objectives

The study was conducted to assess the epidemiological profile and clinical features to identify factors contributing to outcome in patients with venomous snakebites.

Materials and methods

An observational cross-sectional study was done among patients with snakebite envenomation, admitted to Government Medical College, Kozhikode, Kerala, from January 2012 to October 2016.

Results

There were 1,500 cases of toxic snake bites, of which 65% of these cases were males. Forty eight percent of them were aged between 21 and 40 years. Hemotoxic snake bites predominated, accounting for 912 cases. Viperine bite was the most commonly observed snakebite, and 70% of this was due to Russell’s viper and 25% due to HNPV. Among the neurotoxic bites, common krait bites predominated. Overall mortality was 8.8%. CLS was the major cause of death (80%). The mean dose of antivenom given for neuroparalytic snakebite was 10.25 vials, and 18.5 vials for hemotoxic bites. Albuminuria, neutrophilic leucocytosis, thrombocytopenia, acute kidney injury (AKI), and early onset of symptoms were associated with poor outcome.

Conclusion

This study emphasizes the importance of snakebite as a significant threat to the community in the tropics. CLS in hemotoxic snake bites is the leading cause of mortality and is often refractory to any treatment measures. This study also brings to light the graveness of complications caused by HNPV envenomation. Anti-snake venom with activity against HNPV venom needs to be manufactured. Lack of awareness, delayed presentation to the hospital, and treatment by nonmedical personnel also add to the risk of mortality.

Fatal bromethalin intoxication in 3 cats and 2 dogs with minimal or no histologic central nervous system spongiform change

Use of the neurotoxic rodenticide bromethalin has steadily increased since 2011, resulting in an increased incidence of bromethalin intoxications in pets. Presumptive diagnosis of bromethalin toxicosis relies on history of possible rodenticide exposure coupled with compatible neurologic signs or sudden death, and postmortem examination findings that eliminate other causes of death. Diagnosis is confirmed by detecting the metabolite desmethylbromethalin (DMB) in tissues. In experimental models, spongiform change in white matter of the central nervous system (CNS) is the hallmark histologic feature of bromethalin poisoning. We describe fatal bromethalin intoxication in 3 cats and 2 dogs with equivocal or no CNS white matter spongiform change, illustrating that the lesions described in models can be absent in clinical cases of bromethalin intoxication. Cases with history and clinical signs compatible with bromethalin intoxication warrant tissue analysis for DMB even when CNS lesions are not evident.

Cauda equina syndrome following an uneventful spinal anesthesia in a patient undergoing drainage of the Bartholin abscess: A case report

RATIONALE

Neuraxial anesthesia is a commonly used type of regional anesthesia. Cauda equina syndrome is an unusual and severe complication of neuraxial anesthesia, and is caused by damage to the sacral roots of the neural canal. We present a case of cauda equina syndrome following spinal anesthesia in a patient who underwent Bartholin abscess drainage.

PATIENT CONCERNS

A 23-year old female scheduled to undergo surgical drainage of Bartholin abscess. Spinal anesthesia was performed with bupivacaine and fentanyl. There were no perioperative adverse events reported. On postoperative day 1, the patient went to the emergency department describing bilateral weakness and pain of the lower extremities (LE).

DIAGNOSES

Lumbar magnetic resonance imaging showed increased gadolinium accumulation in the neural sheath at the level of the cauda equina tracts, consistent with the diagnosis of arachnoiditis and the diagnosis of cauda equina was established.

INTERVENTIONS

The patient received the following emergent treatment: 75 mg pregabalin (oral) every 12 hours, 20 mg (8 drops) tramadol (oral) every 8 hours, and 4 mg dexamethasone (intravenous) every 6 hours. On postoperative day 4, the patient still experienced bilateral flaccid paraparesis (accentuated in the left side), neuropathic pain in low extremities, and left brachial monoparesis. Hence, dexamethasone was instantly replaced with 1 g methylprednisolone (intravenous) for 5 days.

OUTCOMES

After completing 5 days of methylprednisolone, on postoperative day 9, the patient experienced less pain in left extremities, osteotendinous reflexes were slightly diminished, and she was able to walk with difficulty for 3 to 5 minutes. Greater mobility was evidenced, with right proximal and distal low extremities Medical Research Council Scale grades of 2 and 3 and left proximal and distal low extremities Medical Research Council Scale grades 1 and 2, respectively. Oral prednisone was restarted. Consequently, she was discharged home in stable conditions on postoperative day 25 with a prescription for sertraline, clonazepam, pregabalin, paracetamol, and prednisone.

LESSON

The early detection and treatment of complications after neuraxial anesthesia is essential to minimize the risk of permanent damage.

Phenotypic Variation in Mojave Rattlesnake (Crotalus scutulatus) Venom Is Driven by Four Toxin Families

Phenotypic diversity generated through altered gene expression is a primary mechanism facilitating evolutionary response in natural systems. By linking the phenotype to genotype through transcriptomics, it is possible to determine what changes are occurring at the molecular level. High phenotypic diversity has been documented in rattlesnake venom, which is under strong selection due to its role in prey acquisition and defense. Rattlesnake venom can be characterized by the presence (Type A) or absence (Type B) of a type of neurotoxic phospholipase A2 (PLA2), such as Mojave toxin, that increases venom toxicity. Mojave rattlesnakes (Crotalus scutulatus), represent this diversity as both venom types are found within this species and within a single panmictic population in the Sonoran Desert. We used comparative venom gland transcriptomics of nine specimens of C. scutulatus from this region to test whether expression differences explain diversity within and between venom types. Type A individuals expressed significantly fewer toxins than Type B individuals owing to the diversity of C-type lectins (CTLs) and snake venom metalloproteinases (SVMPs) found in Type B animals. As expected, both subunits of Mojave toxin were exclusively found in Type A individuals but we found high diversity in four additional PLA2s that was not associated with a venom type. Myotoxin a expression and toxin number variation was not associated with venom type, and myotoxin a had the highest range of expression of any toxin class. Our study represents the most comprehensive transcriptomic profile of the venom type dichotomy in rattlesnakes and C. scutulatus. Even intra-specifically, Mojave rattlesnakes showcase the diversity of snake venoms and illustrate that variation within venom types blurs the distinction of the venom dichotomy.

Unmasking a Case of Asymptomatic Charcot-Marie-Tooth Disease (CMT1A) With Vincristine

Charcot-Marie-Tooth (CMT) disease is a hereditary demyelinating disease of the peripheral nervous system that results in sensory and motor dysfunction. CMT includes a spectrum of diseases with different types of mutations in the genes encoding myelin protein, resulting in a variety of dysfunctions in its life cycle. In CMT subtype 1A there is duplication mutation of peripheral myelin protein 22 gene on chromosome 17. Incomplete penetrance, gene-dosage effect, and variable expressivity can attribute to the asymptomatic nature of the disease in some subset of patients. Vincristine administration is contraindicated in patients who are alrea\dy diagnosed with CMT disease. We report a case of asymptomatic CMT disease unmasked only by the neurotoxic effects of vincristine. Genetic testing for a patient with a preexisting family background of inherited diseases before starting vincristine therapy can potentially prevent a disability.

Effect of Dooshivishari Agada over MSG-induced reproductive toxicity w.s.r. ovary and follicle count

Introduction:

Monosodium glutamate (MSG), an extensively used flavor enhancer, produces degenerative changes in cell and causes neural death which cause imbalance in endocrine system and disturb the body system. While taking consideration of its potency and affinity, it falls under the category of Dooshi Visha, which leads to various diseases among which Kshapayet Shukram is one and can be correlated with disturbance in reproductive system which may be endocrinological or related to gametes. Dooshivishari Agada (DVA) is a herbomineral formulation which is mentioned for the treatment of Dooshi Visha.

Aim:

The aim is to evaluate the efficacy of DVA in MSG-induced female reproductive toxicity in Wistar rats.

Materials and Methods:

DVA was prepared and analyzed for preliminary physicochemical, organic and inorganic tests. Twenty-four rats were divided into four groups. Up to 14 days, MSG (0.20g/kg) was given to all groups except control group. From days 15 to 42, DVA (216mg/200g) was given to the third group and in the fourth group no intervention was given to evaluate auto recovery. The second group was considered as disease control. At the end, Follicle-stimu`lating hormone test and histopathology of ovary were done.

Results:

There was a significant increase in primary follicle count and decrease in atretic follicle count in DVA group. Secondary follicle count, tertiary follicle count and Graafian follicle count were increased in DVA group but the increase was not statistically significant.

Conclusion:

MSG mainly acts as a neurotoxic component by oxidative stress. Mostly, the ingredients of DVA have anti-oxidant properties, which counteract the oxidative stress caused by MSG in cell. Many ingredients such as Pippali, Tagara and Kushtha have neuroprotective property which corrects the neurodegeneration and balances the endocrine system.

Neuroimmunology of the Interleukins 13 and 4

The cytokines interleukin 13 and 4 share a common heterodimeric receptor and are important modulators of peripheral allergic reactions. Produced primarily by T-helper type 2 lymphocytes, they are typically considered as anti-inflammatory cytokines because they can downregulate the synthesis of T-helper type 1 pro-inflammatory cytokines. Their presence and role in the brain is only beginning to be investigated and the data collected so far shows that these molecules can be produced by microglial cells and possibly by neurons. Attention has so far been given to the possible role of these molecules in neurodegeneration. Both neuroprotective or neurotoxic effects have been proposed based on evidence that interleukin 13 and 4 can reduce inflammation by promoting the M2 microglia phenotype and contributing to the death of microglia M1 phenotype, or by potentiating the effects of oxidative stress on neurons during neuro-inflammation. Remarkably, the heterodimeric subunit IL-13Rα1 of their common receptor was recently demonstrated in dopaminergic neurons of the ventral tegmental area and the substantia nigra pars compacta, suggesting the possibility that both cytokines may affect the activity of these neurons regulating reward, mood, and motor coordination. In mice and man, the gene encoding for IL-13Rα1 is expressed on the X chromosome within the PARK12 region of susceptibility to Parkinson’s disease (PD). This, together with finding that IL-13Rα1 contributes to loss of dopaminergic neurons during inflammation, indicates the possibility that these cytokines may contribute to the etiology or the progression of PD.

Potency of pre-post treatment of coenzyme Q10 and melatonin supplement in ameliorating the impaired fatty acid profile in rodent model of autism

BACKGROUND

Abnormalities in fatty acid metabolism and membrane fatty acid composition play a part in a wide range of neurodevelopmental and psychiatric disorders. Altered fatty acid homeostasis as a result of insufficient dietary supplementation, genetic defects, the function of enzymes involved in their metabolism, or mitochondrial dysfunction contributes to the development of autism.

OBJECTIVE

This study evaluates the association of altered brain lipid composition and neurotoxicity related to autism spectrum disorders in propionic acid (PA)-treated rats.

DESIGN

Forty-eight young male western albino rats were used in this study. They were grouped into six equal groups with eight rats in each. The first group received only phosphate buffered saline (control group). The second group received a neurotoxic dose of buffered PA (250 mg/kg body weight/day for 3 consecutive days). The third and fourth groups were intoxicated with PA as described above followed by treatment with either coenzyme Q (4.5 mg/kg body weight) or melatonin (10 mg/kg body weight) for 1 week (therapeutically treated groups). The fifth and sixth groups were administered both compounds for 1 week prior to PA (protected groups). Methyl esters of fatty acid were extracted with hexane, and the fatty acid composition of the extract was analyzed on a gas chromatography.

RESULTS

The obtained data proved that fatty acids are altered in brain tissue of PA-treated rats. All saturated fatty acids were increased while all unsaturated fatty acids were significantly decreased in the PA-treated group and relatively ameliorated in the pre-post melatonin and coenzyme Q groups.

CONCLUSIONS

Melatonin and coenzyme Q were effective in restoring normal level of most of the impaired fatty acids in PA-intoxicated rats which could help suggest both as supplements to ameliorate the autistic features induced in rat pups.

Voluntary warnings and the limits of good prescribing behavior: the case for de-adoption of meperidine

Background

Meperidine (pethidine) offers little to no therapeutic advantage over other opioids, may be more prone to abuse, and produces a neurotoxic metabolite with a long half-life. The Institute for Safe Medication Practices (ISMP) issued warnings in 2004 and 2005 suggesting that meperidine be avoided, and when used, it should be in limited doses (<600 mg/24 h) and for a limited duration (<48 hours). Hospitals have responded to these warnings, but much less is known about meperidine prescribing in the community setting. This study examined the potential impact of ISMP warnings on the prescribing of meperidine using time series analysis.

Methods

A population-based longitudinal cross-sectional study was conducted to examine oral meperidine utilization among persons 16 years of age and older in Manitoba, Canada, between April 1, 2001 and March 31, 2014. Amounts of meperidine were expressed using defined daily doses (DDDs), the equivalent of 400 mg of meperidine per day. The number of meperidine prescriptions and users per quarter were determined and analyzed using regression analysis.

Results

There were 49,063 prescriptions for 442,641 DDDs of meperidine dispensed to 9,374 distinct users. The number of DDDs of meperidine per 1,000 persons peaked in the second quarter of 2003 at 11.75, and then dropped to a low of 5.36 by 2014. This represented a marked decline in the numbers of users and prescriptions over the study period. The piecewise regression model revealed a significant breakpoint in the last quarter of 2004 (F_{(3, 48)}=337.00, P<0.0001). In contrast to these findings, among the remaining users, there was an increase in the amount of meperidine per prescription (increase of 0.34 DDDs/prescription/year; F(1, 50)=434, P<0.0001, R²=0.89) and the amount of meperidine per user (increase of 1.17 DDDs/user/year; F(1, 50)=653.5, P<0.0001, R²=0.93).

Conclusion

Following the ISMP warnings, meperidine use dramatically declined. Unfortunately, the remaining users of meperidine are using more meperidine and receiving more meperidine in each prescription. This pattern of results suggests that there may be limits to voluntary safety warnings. Policy action such as removal of medication insurance coverage may represent a logical next step to reverse or de-adopt meperidine and further enhance patient safety.

Persistent effects after camphor ingestion: a case report and literature review

BACKGROUND

Camphor is a well-known toxin responsible for thousands of poisonings per year. It can be found in many over-the-counter remedies and illegally imported substances. The toxidrome manifests within minutes and includes gastrointestinal, neurologic, pulmonary, and cardiac effects. Severe ingestions may progress to seizures, apnea, and coma. Most individuals are no longer symptomatic outside the 24-48 h window, but physiologic derangement may persist for far longer in some instances.

CASE REPORT

This is a case report of a 25-year-old Guatemalan woman with no past medical history who ingested a cube of camphor for a facial rash. She presented to the Emergency Department with persistent delirium and headache 6 days after ingestion. She had a protracted recovery but returned to her baseline state of health 19 days after ingestion. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Persistent toxic effects of camphor are not well described, and most sources state that the toxidrome resolves in 24-48 h. Given the frequency of camphor poisoning, it is crucial to increase public awareness of camphor toxicity, to understand the biological mechanism of the effects, and to develop more targeted treatments. From the emergency physician's perspective, it is important to realize that toxic effects of camphor poisoning may persist far beyond the 24-48 h window and require attention.

A standardized extract of Ginkgo biloba prevents locomotion impairment induced by cassava juice in Wistar rats

The long-term consumption of cassava (Manihot esculenta Crantz) juice produce neurotoxic effects in the rat, characterized by an increased motor activity in the open field test and presence of uncoordinated swim (i.e., lateral swimming), in the swim test; which has been associated with damage in the hippocampus (CA1). On the other hand, flavonoids content in the Ginkgo biloba extract has been reported to produces neuroprotective effects at experimental level; therefore we hypothesized that G. biloba extract may prevents the motor alterations produced by cassava juice and reduce cellular damage in hippocampal neurons of the rat. In present study the effect of vehicle, cassava juice (linamarin, 0.30 mg/kg), G. biloba extract (dry extract, 160 mg/kg), and combination of treatment were evaluated in the open field and swim tests to identify locomotor and hippocampal alterations in adult male Wistar rats. All treatments were administered once per day, every 24 h, for 28 days, by oral rout. The effect was evaluated at 0, 7, 14, 21, and 28 days of treatment. The results show that cassava group from day 14 of treatment increase crossing and rearing in the open field test, as compared with the vehicle group; while in the swim test produces an uncoordinated swim characterized by the lateral swim. In this same group an increase in the number of damage neurons in the hippocampus (CA1) was identified. Interestingly, both behavioral and neuronal alterations produced by cassava juice administration were prevented by treatment with G. biloba extract. The results shown that G. biloba extract exert a protective effect against behavioral and neuronal damage associated with consumption of cassava juice in the rat. These effects are possibly related with flavonoid content in the G. biloba extract.

Bromethalin poisoning in a raccoon (Procyon lotor): diagnostic considerations and relevance to nontarget wildlife

Submission of a raccoon (Procyon lotor) for necropsy following exhaustion at a California wildlife care center revealed minimal gross pathologic changes and only mild vacuolar changes in the white matter of the brain. Turquoise granular material was noted in the gastrointestinal tract and was submitted for toxicological testing along with portions of the brain, liver, kidney, and mesenteric and perirenal adipose tissues. Testing of the turquoise material for 7 anticoagulant rodenticides, strychnine, 4-aminopyridine, starlicide, and salts revealed none of these compounds; however, desmethylbromethalin was detected by high-performance liquid chromatography-tandem mass spectrometry. Other tissues were subsequently analyzed; the mesenteric and perirenal adipose tissues contained desmethylbromethalin. Desmethylbromethalin is the active metabolite of bromethalin, uncouples oxidative phosphorylation, and results in cerebral edema. Bromethalin is a rodenticide that is visually indistinguishable from many other rodenticides, making identification of poisonings by appearance alone nearly impossible. Based on the pathological and toxicological findings, a diagnosis of bromethalin toxicosis was established. In cases of wildlife species with unknown deaths or inconsistent clinical signs with normal or minimal histological findings, bromethalin toxicosis should be considered as a differential. Adipose tissue is the tissue of choice and can be easily harvested from a live or deceased animal to help confirm or rule out bromethalin exposure or intoxication.

Factors affecting outcome in children with snake envenomation: a prospective observational study

OBJECTIVES

To evaluate clinical outcome and factors affecting outcome in children with snake envenomation.

DESIGN

Prospective observational study.

SETTING

Paediatric intensive care unit of a tertiary care teaching hospital in India.

PATIENTS

We prospectively enrolled children ≤12 years of age admitted to our hospital with a definitive history of snake bite from August 2007 to June 2010.

MEASUREMENTS AND MAIN RESULTS

Demographic characteristics and clinical course of the enrolled children were recorded in a structured proforma and analysed using appropriate statistical methods. Children were treated as per the WHO guidelines (2005) on the management of snake bite in children. Of 110 children studied, 77 (69%) were male. Most (72; 64.2%) had features predominantly of haematotoxic envenomation while 20 (18%) and 18 (16%) children had features of neurotoxic envenomation and local involvement, respectively. 14 children (13%) died and 13 (12%) had major disabilities. On univariable analysis, the following prehospital and admission variables were found to be significantly associated with poor outcome: age, walking for >1 km after the bite, vomiting, haemoglobin ≤10 g/dl at admission and species of snake (cobra). On multivariable analysis, only younger age (adjusted OR 0.85; 95% CI 0.7 to 0.9), walking for >1 km after the bite (adjusted OR 57; 95% CI 4.2 to 782) and haemoglobin ≤10 g/dl at admission (adjusted OR 6; 95% CI 2 to 18.2) remained significant.

CONCLUSIONS

Younger age at presentation, anaemia (haemoglobin ≤10 g/dl) and distance walked after the bite may be independent predictors of mortality and morbidity in children with snake bite. These features in victims of snake bite warrant early referral to and management in tertiary care centres.

Investigation of neurotoxic and immunotoxic effects of some plant growth regulators at subacute and subchronic applications on rats

The present study was aimed to investigate the effects of subacute and subchronic treatment of some plant growth regulators (PGRs), such as abscisic acid (ABA) and gibberellic acid (GA3), on neurological and immunological biomarkers in various tissues of rats. The activities of acetylcholinesterase (AChE) and butrylcholinesterase (BChE) were selected as biomarkers for neurotoxic biomarkers. Adenosine deaminase (ADA) and myeloperoxidase (MPO) were measured as indicators for immunotoxic investigation purpose. Wistar albino rats were orally administered with 25 and 50 ppm of PGRs ad libitum for 25-50 days continuously with drinking water. The treatment of PGRs caused different effects on the activities of enzymes. Results showed that the administrations of ABA and GA3 increased AChE and BChE activities in some tissues of rats treated with both the dosages and periods of ABA and GA3. With regard to the immunotoxic effects, ADA activity fluctuated, while MPO activity increased after subacute and subchronic exposure of treated rat tissues to both dosages when compared with the controls. The observations presented led us to conclude that the administrations of PGRs at subacute and subchronic exposure increased AChE, BChE, and MPO activities, while fluctuating the ADA activity in various tissues of rats. This may reflect the potential role of these parameters as useful biomarkers for toxicity of PGRs.

sindanus) in Maharashtra, India

We report a case of severe envenoming with unusual complications and two anecdotal cases of fatalities following proven 17-scale-row ‘Sind krait’ (Bungarus cf. sindanus) bites on people sleeping in temporary huts at construction sites in Pune District, Maharashtra, India. A 25-yr-old male developed progressive neuromuscular paralysis, abdominal pain and autonomic disturbances complicated by four prolonged episodes of pulseless ventricular tachycardia requiring defibrillation, and followed by pulmonary edema secondary to impaired left ventricular systolic function and hyperfusion. There was no response to antivenom; mechanical ventilation was required for six days. Only one other case of fatal envenoming likely caused by this species had been reported previously in India. The distribution of B. sindanus sensu lato from eastern Afghanistan to India overlaps with that of the superficially very similar common krait (Bungarus caeruleus). Thus, B. cf. sindanus envenoming may be common but routinely overlooked or misdiagnosed.