Foot drop - an uncommon presentation of FOLFOX toxicity

A quimioterapia com FOLFOX (oxaliplatina, leucovorina e 5-fluorouracilo) é frequentemente utilizada em doentes com cancro colorretal. Os sais de platina são conhecidos por serem uma classe de quimioterápicos que comumente induzem neurotoxicidade periférica. Na toxicidade induzida pela oxaliplatina, os sintomas sensitivos são os mais frequentes. Neste artigo, apresentamos dois casos clínicos de pacientes com adenocarcinoma de cólon, ambos submetidos à quimioterapia com FOLFOX4, e que desenvolveram neurotoxicidade incomum, apresentando pé pendente após o terceiro ciclo de tratamento. Esta manifestação clínica pode ser explicada por dano axonal nos neurônios motores periféricos do nervo peroneal comum (fibular), que fornece inervação motora aos músculos do pé. A paralisia do nervo fibular causa fraqueza súbita nos músculos do pé, que parece ser temporária. Ambos os doentes recuperaram completamente do evento sem necessidade de ajustes no tratamento, nem introdução de medicamentos diferentes. A apresentação de pé pendente como toxicidade da quimioterapia ainda é pouco compreendida. Os casos relatados mostram o pé pendente como uma manifestação grave e incomum de neuropatia induzida por FOLFOX, que pode ser transitória, e não requer necessariamente intervenção específica.

Chemotherapy based on FOLFOX (oxaliplatin, leucovorin, and 5-fluorouracil) regimen is frequently used in colorectal cancer patients. Oxaliplatin and other platinum agents are known to be a class of chemotherapy drugs that commonly induce peripheral neurotoxicity. The most frequent oxaliplatin related neurotoxicity is sensitive symptoms. Here, we present two cases of patients with colon adenocarcinoma, both undergoing chemotherapy with FOLFOX4, who developed uncommon neurotoxicity, presenting with foot drop after the third treatment cycle. Foot drop may be explained by axonal damage of peripheral motor neurons of the common peroneal (fibular) nerve, which provides motor innervation to the foot muscles. Peroneal nerve palsy causes sudden weakness in the muscles of the foot that seems to be temporary. Both patients completely recovered from the event. There was no need for treatment adjustments, neither introduction of different drugs. Foot drop as chemotherapy toxicity is still poorly understood. The reported cases show foot drop as a severe and uncommon manifestation of FOLFOX-induced neuropathy, that might be transitory, and does not necessarily requires specific intervention.

Widow spiders in the New World: a review on Latrodectus Walckenaer, 1805 (Theridiidae) and latrodectism in the Americas

Humankind has always been fascinated by venomous animals, as their toxic substances have transformed them into symbols of power and mystery. Over the centuries, researchers have been trying to understand animal venoms, unveiling intricate mixtures of molecules and their biological effects. Among venomous animals, Latrodectus Walckenaer, 1805 (widow spiders) have become feared in many cultures worldwide due to their extremely neurotoxic venom. The Latrodectus genus encompasses 32 species broadly spread around the globe, 14 of which occur in the Americas. Despite the high number of species found in the New World, the knowledge on these spiders is still scarce. This review covers the general knowledge on Latrodectus spp. from the Americas. We address widow spiders' taxonomy; geographical distribution and epidemiology; symptoms and treatments of envenomation (latrodectism); venom collection, experimental studies, proteome and transcriptome; and biotechnological studies on these Latrodectus spp. Moreover, we discuss the main challenges and limitations faced by researchers when trying to comprehend this neglected group of medically important spiders. We expect this review to help overcome the lack of information regarding widow spiders in the New World.(AU)

Toxic plants affecting the nervous system of ruminants and horses in Brazil / Plantas tóxicas que afetam o sistema nervoso de ruminantes e equinos no Brasil

This review updates information about neurotoxic plants affecting ruminants and equidae in Brazil. Currently in the country, there are at least 131 toxic plants belonging to 79 genera. Thirty one of these poisonous plants affect the nervous system. Swainsonine-containing plants (Ipomoea spp., Turbina cordata and Sida carpinifolia) cause numerous outbreaks of poisoning, mainly in goats, but cattle and horses are occasionally affected. The poisoning by Ipomoea asarifolia, a tremorgenic plant, is very common in sheep, goats and cattle in the Northeastern region and in the Marajo island. Poisoning by the pods of Prosopis juliflora are frequent in cattle in Northeastern Brazil; occasionally this poisoning affects goats and more rarely sheep. Some poisonings by plants, such as Hybanthus calceolaria, Ipomoea marcellia and Talisia esculenta in ruminants and Indigofera lespedezioides in horses were recently described and needs to be accurately investigated about its occurrence and importance. Other plants poisonings causing nervous signs in ruminants and equidae are less important, but should be considered for the differential diagnosis of neurologic diseases.(AU)

Esta revisão tem por objetivo atualizar as informações sobre plantas neurotóxicas que afetam ruminantes e equinos no Brasil. Atualmente sabe-se que existe no país pelo menos 131 plantas tóxicas pertencentes a 79 gêneros. Trinta e uma espécies afetam o sistema nervoso. As plantas quem contém swainsonina (Ipomoea spp., Turbina cordata and Sida carpinifolia) causam numerosos surtos de intoxicação, principalmente em caprinos, mas bovinos e cavalos são ocasionalmente afetados. A intoxicação por Ipomoea asarifolia, uma planta tremorgênica, é muito comum em ovinos, caprinos e bovinos na região Nordeste e na ilha de Marajó. A intoxicação pelas vagens de Prosopis juliflora é frequente em bovinos no Nordeste do Brasil; ocasionalmente são afetados caprinos e mais raramente ovinos. Algumas intoxicações por plantas, como Hybanthus calceolaria, Ipomoea marcellia e Talisia esculenta em ruminantes e Indigofera lespedezioides em equinos foram recentemente descritas e precisam ser investigadas com precisão sobre sua ocorrência e importância. Outras intoxicações por plantas que causam sinais nervosos em ruminantes e equídeos são menos importantes, todavia devem ser consideradas para o diagnóstico diferencial de doenças neurológicas.(AU)

Actualización sobre manejo de araneismo en Perú / Update management on araneism in Peru

La mordedura de araña es un accidente muy común e importante problema de salud pública en lugares con clima tropical y se presenta como un problema muy frecuente en algunas regiones de Latinoamérica. En Perú las especies de araña que presentan más casos de esta problemática son Loxosceles laeta, Latrodectus mactans and Phoneutria spp. El presente trabajo pretende explicar, clarificar y categorizar estas mordeduras de arañas, con el fin de dar a conocerlas para ayudar a que los profesionales de la salud tengan un mayor conocimiento sobre las mismas para un mejor manejo de los casos que se les presenten. (AU)

Spider bites are a common and important public health issue in tropical climates, and become a frequent problem in certain Latin American regions. In Peru, the main species of spiders that represent this problematic are Loxosceles laeta, Latrodectus mactans and Phoneutria spp. The present article intends to explain, clarify and categorize these spider bites, in order to make them known by every health professional to its better management. (AU)

El costo de ignorar el signo de Carnett: Reporte de caso y revisión de la literatura / The Cost Of Ignoring Carnett’s Sign: A Case Report and Literature Review

El dolor abdominal crónico es un motivo frecuente de consulta externa y de urgencias. Los médicos tradicionalmente consideran que el origen del mismo son las estructuras intraabdominales, incluido el tracto gastrointestinal. Rara vez tienen en cuenta la pared abdominal como la causa de la molestia y someten a los pacientes a numerosos e interminables procedimientos diagnósticos, como laparoscopias y cirugías, entre otros. Por lo menos el 50% de estos pacientes tiene dolor de la pared abdominal por lesión del nervio cutáneo anterior y el diagnóstico se hace identificando el signo de Carnett. Se presenta un caso típico con esta patología, cuyo enfoque inicial ilustra los errores y altos costos en el abordaje de esta patología

Chronic abdominal pain is a frequent cause of outpatient and emergency visits. Doctors traditionally consider that its origin is in intra-abdominal structures, including the gastrointestinal tract. They rarely take into account the abdominal wall as a cause of discomfort and subject patients to numerous and endless diagnostic procedures, including laparoscopy and surgery. At least 50% of these patients have abdominal wall pain due to injuries to the anterior cutaneous vein the diagnosis of which is made by identifying Carnett’s sign. A typical case of this pathology is here. The initial approach illustrates the errors and high costs that can be involved in the approach to this pathology

Envenomation by the red-tailed coral snake (Micrurus mipartitus) in Colombia

Background Although the red-tailed coral snake (Micrurus mipartitus) is widely distributed in Colombia and its venom is highly neurotoxic and life threatening, envenomation by this species is rare. Therefore, this report may shed some light on the clinical presentation of M. mipartitus bites. Case presentations Herein, we describe two cases of patients bitten by red-tailed coral snakes, illustrating the clinical presentation of the victims, the outcomes and treatment provided. Conclusion Envenomation caused by M. mipartitus provokes predicable neurotoxicity, and its treatment should be based on respiratory support and use of specific antivenom.(AU)

Fatal neurotoxic envenomation following the bite of a greater black krait (Bungarus niger) in Nepal: a case report

Neurotoxic envenomation following bites by kraits (Bungarus species) is a leading cause of snakebite mortality in South Asia. Over a long time, this had been attributed only to one species, the common krait (Bungarus caeruleus). However, recent research has provided increasing evidence of the involvement of several krait species. Here, we report a fatal case of neurotoxic envenomation following the bite of a greater black krait (Bungarus niger) in Nepal. Case presentation A 33-year-old man was bitten in the outdoor corridor of his home in the eastern hills of Ilam district while handling a snake he thought to be non-venomous. He subsequently developed severe abdominal pain, frequent vomiting, and signs of neurotoxic envenomation leading to respiratory paralysis. The patient did not respond to Indian polyvalent antivenom given 4 h after the bite and died under treatment 8 h after the bite. This is the second time that a B. niger was observed in Nepal, the first documented case of envenomation by this species in the country and the sixth reported case worldwide. Conclusions Previous distribution records from eastern India and western Nepal, from western hills in Nepal, and from lowland localities in India and Bangladesh indicate risk of envenomation by B. niger throughout the low and intermediate elevations of Nepal up to at least 1,500 m above sea level. As very few people in Nepal bring killed snakes to healthcare centers and because there is a general belief among local people that there are no kraits in the hills, bites by B. niger are likely to be misdiagnosed and underreported.

Developmental neurotoxicity: methylmercury and prenatal exposure protection in the context of the Minamata Convention / Neurotoxicidad durante el desarrollo: metilmercurio y protección frente a la exposición prenatal a este contaminante en el contexto del Convenio de Minamata

Mercury is a global pollutant of public environmental health concern due to its long-range atmospheric distribution, environmental distribution, and neurotoxic effects. Following biological methylation, methylmercury (MeHg) can be un-evenly bioaccumulated within aquatic food chains. Fish consumption can be a significant route of human exposure to MeHg. MeHg exposure in the prenatal stage, at relatively low levels, has recently been established as harmful during neurological development, potentially leading to intellectual disability. The Minamata Convention on Mercury is a global agreement, currently under ratification, to protect human health and the environment from anthropogenic emissions and releases of mercury and mercury compounds. The resolution regarding the role of the World Health Organization and ministries of health in the implementation of the Convention includes protection of human health from critical exposures to MeHg. Riverside populations living in areas with artisanal small-scale gold mining, and relying heavily on fish consumption, have been identified as the most vulnerable population in terms of MeHg exposure and developmental neurotoxicity. This article focuses on the proper design and dissemination of fish advisories within the context of implementation of the Convention.

El mercurio es un contaminante global motivo de preocupación en materia de salud pública ambiental como consecuencia de su amplia distribución atmosférica, su distribución ambiental y sus efectos neurotóxicos. Tras su metilación biológica, el metilmercurio (MeHg) se puede bioacumular de manera desigual en las cadenas alimentarias acuáticas. El consumo de pescado puede ser una ruta significativa de exposición humana al MeHg. Recientemente, se ha establecido que la exposición a niveles relativamente bajos de MeHg en la etapa prenatal es perjudicial para el neurodesarrollo, pudiendo ocasionar discapacidad intelectual. El Convenio de Minamata sobre el Mercurio es un acuerdo a escala mundial, actualmente en fase de ratificación, cuyo objeto es proteger la salud humana y el medio ambiente de las emisiones antropogénicas y los vertidos de mercurio y sus compuestos. La resolución referente a la función de la Organización Mundial de la Salud y los ministerios de salud en la aplicación del Convenio incluye la protección de la salud humana de exposiciones importantes al MeHg. Se ha establecido que las poblaciones ribereñas que residen en zonas de extracción artesanal de oro a pequeña escala, y que dependen en gran medida del consumo de pescado, son las más vulnerables en términos de exposición al MeHg y neurotoxicidad durante el desarrollo. Este artículo se centra en el diseño y la difusión adecuados de las recomendaciones relativas al consumo de pescado en el contexto de la aplicación del Convenio.

Caracterización por cromatografía de gases-espectrometría de masas del thinner comercialmente disponible en la ciudad de Cartagena / Characterization by Gas Chromatography-Mass Spectrometry of Commercially Available Thinner in the City of Cartagena / Caracterização por cromatografia gasosa-espectrometria de massas do Tíner comercialmente disponível na cidade de Cartagena

El thinner es uno de los productos de mayor utilización en la industria de las pinturas, lubricantes y pegamentos. Su composición es variable de acuerdo con su uso y calidad. Sin embargo, la exposición crónica es una preocupación debido a que puede afectar órganos principales tales como pulmones, hígado, riñón y glándulas suprarrenales. En este estudio fue caracterizada la composición de varias muestras de thinner, disponibles comercialmente en la ciudad de Cartagena, que fueron recolectadas en diferentes almacenes y analizadas por cromatografía de gases acoplada a espectrometría de masas (GC/MS). Los resultados mostraron que no solo la composición, sino también la distribución relativa de los componentes presentes en las muestras son variables. Treinta y dos compuestos fueron detectados, entre los que se encuentran: tolueno, o-xileno, p-xileno y etilbenceno, con frecuencias de aparición de 91,7%, 66,7%, 75,0% y 66,7%, respectivamente. El desconocimiento del riesgo de intoxicación, generado al manipular este tipo de mezclas, puede ser la causa de muchos de los problemas de salud en personas expuestas al thinner, tanto en actividades laborales como domésticas. Una minería de datos mostró la asociación potencial entre los componentes del thinner y manifestaciones clínicas, las cuales incluyen daño renal y hepático, pérdida de cabello, alteraciones hematológicas, dermatitis, ansiedad y problemas de equilibrio, entre otras. En conclusión, el thinner posee gran variabilidad tanto en sus componentes como en la proporción relativa de los mismos. Los efectos perjudiciales en la salud por exposición directa o indirecta a estos componentes han sido ampliamente descritos en la literatura.

Thinner is a widely used product in the industry of paints, lubricants and adhesives. Its composition varies according to its use and quality. However, its chronic exposure is a concern, because it can affect major organs such as lungs, liver, kidney and the adrenal glands. This study characterizes the composition of several thinner samples commercially available in the city of Cartagena. Twelve samples were collected in different stores, these were then analyzed through gas chromatography coupled to mass spectrometry (GC/MS). The results showed that not only the composition but also the relative distribution of the components present in the samples are variable. Thirty two compounds were detected: toluene, o-xylene, p-xylene and ethylbenzene -among others- with occurrence frequencies of 91.7, 66.7, 75, and 66.7%, respectively. The lack of knowledge regarding the risk of poisoning, produced when handling this type of mixtures, may be the cause of many health problems in people exposed to thinner, both in workplace and domestic activities. A data mining showed the potential association between thinner components and clinical manifestations, which include kidney and liver damage, hair loss, haematological disorders, dermatitis, anxiety and balance problems, among others. In conclusion, thinner has large variability, both in terms of components and of their relative composition. The adverse health effects of direct or indirect exposure to these components have been widely described in the literature.

O Tíner é um dos produtos de maior utilização na indústria das pinturas, lubrificantes e colas. Sua composição é variável conforme a seu uso e qualidade. No entanto, a exposição crônica é uma preocupação devido a que pode afetar órgãos principais tais como pulmões, fígados, rins e glândulas suprarrenais. Neste estudo foi caracterizada a composição de várias amostras de Tíner, disponíveis comercialmente na cidade de Cartagena. Doze amostras de Tíner foram recoletadas em diferentes lojas e analisadas por cromatografia gasosa acoplada a espectrometria de massas (GC/MS). Os resultados mostraram que não só a composição, más também a distribuição relativa dos componentes presentes nas amostras são variáveis. Trinta e dois compostos foram detectados, entre os que se encontram: tolueno, o-xileno, p-xileno e etilbenceno, com frequências de aparição de 91.7, 66.7, 75.0 e 66.7%, respectivamente. O desconhecimento do risco de intoxicação, gerado ao manipular este tipo de misturas, pode ser a causa de muitos dos problemas de saúde em pessoas expostas ao Tíner, tanto nas atividades laborais quanto domésticas. Uma mineração de dados mostrou a associação potencial entre os componentes do Tíner e manifestações clínicas, as quais incluem dano renal e hepático, perda de cabelo, alterações hematológicas, dermatite, ansiedade e problemas de equilíbrio, entre outras. Em conclusão, o Tíner possui grande variabilidade tanto em seus componentes quanto na proporção relativa dos mesmos. Os efeitos prejudiciais na saúde por exposição direta ou indireta a estes componentes têm sido amplamente descritos na literatura.

Situación de los neurotóxicos ambientales en Quito / Situation of environmental neurotoxic agents in Quito

La contaminación del aire tiene un considerable inpacto en la salud humana. En Quito, aproximadamente el 80% de ella proviene de los emisores de los vehículos se han estudiado la evolución de dos contaminantes del aire que son neurotóxicos: plomo y monóxido de carbono. En 1991 el nivel de plomo en sangre de los niños era tres veces mayor de lo normal lo que provocaba una disminución de la velocidad de respuesta cerebral. Dos estudios fueron efectuados 7 y 10 años más tarde, en el periodo que se eliminó el uso de tetraetilo de plomo en la gasolina. Los dos demuestran una mejoría en los niveles sanguíneos. En el año 2000, una muestra de 300 niños fue estudiada para determinar la contaminación por CO. El 92% de los niños del centro de la cuidad presentaron niveles tóxicos de COHB. Los últimos reportes del monitoreo del aire, efactuados en los años 2004 y 2005 reportan niveles menores a la norma en cuanto al CO, principalmente debido a que actualmente los vehículos están equipados con convertidores catalíticos.

Air pollution has a considerable impact on human health. In Quito, approximately 80% of it comes from vehicle emitters. The evolution of two neurotoxic air pollutants has been studied: lead and carbon monoxide. In 1991, children's blood lead level was three times higher than normal, causing a decrease in the speed of brain response. Two studies were conducted 7 and 10 years later, in the period that the use of tetraethyl lead in gasoline was eliminated. Both demonstrate an improvement in blood levels. In 2000, a sample of 300 children was studied to determine CO contamination. 92% of the downtown children had toxic levels of COHB. The latest air monitoring reports, carried out in 2004 and 2005, report lower levels than the norm in terms of CO, mainly because the vehicles are currently equipped with catalytic converters.