Identification of the myodural bridge in a venomous snake, the gloydius shedaoensis: what is the functional significance? / Identificación del puente miodural en una serpiente venenosa, gloydius shedaoensis: ¿cuál es el significado funcional?

SUMMARY: Myodural bridges (MDB) are anatomical connections between the suboccipital muscles and the cervical dura mater which pass through both the atlanto-occipital and the atlanto-axial interspaces in mammals. In our previous studies, we found that the MDB exists in seven terrestrial mammal species, two marine mammal species, two reptilian species, and one bird species. A recent study suggested that given the "ubiquity" of myodural bridges in terrestrial vertebrates, the MDB may also exist in snakes. Specifically, we focused on the Gloydius shedaoensis, a species of Agkistrodon (pit viper snake) that is only found on Shedao Island, which is in the southeastern sea of Dalian City in China. Six head and neck cadaveric specimens of Gloydius shedaoensis were examined. Three specimens were used for anatomical dissection and the remaining three cadaveric specimens were utilized for histological analysis. The present study confirmed the existence of the MDB in the Gloydius shedaoensis. The snake's spinalis muscles originated from the posterior edge of the supraoccipital bones and the dorsal facet of the exocciput, and then extended on both sides of the spinous processes of the spine, merging with the semispinalis muscles. On the ventral aspect of this muscular complex, it gave off fibers of the MDB. These MDB fibers twisted around the posterior margin of the exocciput and then passed through the atlanto-occipital interspace, finally terminating on the dura mater. We observed that the MDB also existed in all of the snakes' intervertebral joints. These same histological findings were also observed in the Gloydius brevicaudus, which was used as a control specimen for the Gloydius shedaoensis. In snakes the spinal canal is longer than that observed in most other animals. Considering the unique locomotive style of snakes, our findings contribute to support the hypothesis that the MDB could modulate cerebrospinal fluid (CSF) pulsations.

RESUMEN: Los puentes miodurales (MDB) son conexiones anatómicas entre los músculos suboccipitales y la duramadre cervical que pasan a través de los espacios intermedios atlanto-occipital y atlanto-axial en los mamíferos. En nuestros estudios anteriores, encontramos que el MDB existe en siete especies de mamíferos terrestres, dos especies de mamíferos marinos, dos especies de reptiles y una especie de ave. Un estudio reciente sugirió que dada la "ubicuidad" de los puentes miodurales en los vertebrados terrestres, el MDB también puede existir en las serpientes. Específicamente, nos enfocamos en Gloydius shedaoensis, una especie de Agkistrodon (serpiente víbora) que solo se encuentra en la isla Shedao, en el mar sureste de la ciudad de Dalian en China. Se examinaron seis especímenes cadavéricos de cabeza y cuello de Gloydius shedaoensis. Se utilizaron tres especímenes para la disección anatómica y los tres especímenes cadavéricos restantes se utilizaron para el análisis histológico. El presente estudio confirmó la existencia del MDB en Gloydius shedaoensis. Los músculos espinosos de la serpiente se originaron en el margen posterior de los huesos supraoccipital y la cara dorsal del exoccipucio, y luego se extendieron a ambos lados de los procesos espinosas de la columna vertebral, fusionándose con los músculos semiespinosos. En la cara ventral de este complejo muscular se desprendían fibras del MDB. Estas fibras MDB se ubican alrededor del margen posterior del exoccipucio y luego atraviesan el interespacio atlanto-occipital, terminando finalmente en la duramadre. Observamos que el MDB también existía en todas las articulaciones intervertebrales de las serpientes. Estos mismos hallazgos histológicos también se observaron en Gloydius brevicaudus, que se utilizó como muestra de control para Gloydius shedaoensis. En las serpientes, el canal espinal es más largo que el observado en la mayoría de los otros animales. Teniendo en cuenta el estilo único locomotor de las serpientes, nuestros hallazgos contribuyen a respaldar la hipótesis de que el MDB podría modular las pulsaciones del líquido cerebroespinal.

Reversible atrial fibrillation following Crotalinae envenomation

Background Cardiotoxicity is a documented complication of Crotalinae envenomation. Reported cardiac complications following snake envenomation have included acute myocardial infarction, electrocardiogram abnormalities and arrhythmias. Few reports exist describing arrhythmia induced by viper envenomation and to our knowledge none describe arrhythmia induced by Crotalinae envenomation. This report concerns the first known case of atrial fibrillation precipitated by rattlesnake bite. Case presentation A 73-year-old Caucasian man with a past medical history of hypertension, hyperlipidemia, type 1 diabetes mellitus, and a baseline first-degree atrioventricular block presented to the emergency department following a rattlesnake bite to his left lower leg. He developed pain and swelling in his left leg two-hour post-envenomation and subsequently received four vials of Crotalidae polyvalent immune fab (ovine). At three-hour post-envenomation following transfer to the intensive care unit, an electrocardiogram revealed new-onset atrial fibrillation. An amiodarone drip was started and the patient successfully converted to normal sinus rhythm approximately six hours after he was found to be in atrial fibrillation. A transthoracic echocardiogram revealed mild concentric left ventricular hypertrophy and an ejection fraction of 72%. He was discharged the following day with no hematological abnormalities and a baseline first-degree atrioventricular block. Conclusion This is the first documented case of reversible atrial fibrillation precipitated by Crotalinae envenomation. In patients with pertinent risk factors for developing atrial fibrillation, physicians should be aware of the potential for this arrhythmia. Direct toxic effects of venom or structural and electrophysiological cardiovascular abnormalities may predispose snakebite patients to arrhythmia, warranting extended and attentive cardiac monitoring.(AU)

Preparation and neutralization efficacy of IgY antibodies raised against Deinagkistrodon acutus venom

Background The five-paced pit viper (Deinagkistrodon acutus), endemic to China and northern Vietnam, is responsible for most snakebites in the Chinese territory. Antivenom produced from horses is the main treatment for snakebites, but it may cause numerous clinical side effects and have other disadvantages involved in their production such as the welfare of animals. The present study was conducted aiming to develop an alternative antibody (IgY) from the egg yolk of leghorn chickens immunized with snake venom. Methods IgY from the egg yolk of white leghorn chickens previously immunized intramuscularly with D. acutus venom was extracted by water, precipitated by ammonium sulfate and purified by affinity chromatographic system. IgY was identified by SDS-PAGE, ELISA and Western blot. Finally, IgY neutralization assays to test its efficacy against hemorrhagic, edema-forming and myotoxic activities of D. acutus venom were conducted on mice. Results For the first time, IgY antibodies against D. acutus venom were raised successfully in egg yolk of chickens injected with D. acutus venom multiple times. By three steps, including caprylic acid extraction, ammonium sulfate precipitation and affinity chromatography, IgY antibodies were isolated and purified from egg yolk, which exhibited a single protein band on SDS-PAGE and two bands (about 65 kDa and 35 kDa, respectively) under reducing conditions, and presented a high titer (1:40,000) tested by ELISA. Immunoblot analysis confirmed that these IgY were polyclonal antibodies since they bound to components of D. acutus venom. Furthermore, immunodiffusion assay showed that anti-D. acutus venom IgY cross-reacted with the venoms of Trimeresurus albolabris and D. saxatilis Emelianov, but did not react to the venoms of Bungarus multicinctus and Naja atra. In the neutralizing lethal assay, the median effective dose of anti-D. acutus venom IgY was 14.14 mg/kg of mouse body weight under the challenge dose (3 LD50 of D. acutus venom). In neutralizing the hemorrhagic, edema-forming and myotoxic activities of D. acutus venom, IgY showed the characteristic dose-dependent neutralization effects against all these toxic activities of D. acutus venom. Conclusion Anti-D. acutus venom IgY antibodies with high purity and titer were for the first time raised successfully in egg yolk of chickens immunized with D. acutus venom. They were effective in neutralizing the lethal effects, and the hemorrhagic, edema-forming and myotoxic acitivities of D. acutus venom. IgY could be an effective source to develop a treatment against snake bites in humans or animals in the future.(AU)

La producción científica de acta colombiana de psicología: análisis descriptivo del período 2010-2014 / Scientific production of Colombian act of psychology: descriptive analysis of the period 2010 -2014 / A produção científica da Acta Colombiana de Psicología: análise descritiva do período 2010-2014

Una de las estrategias para la elaboración de los planes de acción o mejoramiento de las publicaciones científicas parte de la mirada retrospectiva o de estudios de caracterización con respecto a la evolución de las mismas. Para ello se tienen en cuenta indicadores que exigen las bases e índices de datos, los cuales permiten evaluar la calidad científica y editorial, la visibilidad, la periodicidad o estabilidad, así como el impacto. En este sentido, el presente artículo tiene como objetivo realizar un análisis descriptivo de los artículos publicados en la Revista Acta Colombiana de Psicología entre los años 2010 y 2014. Se identificaron las variables a tener en cuenta para este análisis: variables categóricas y variables de tipo cuantitativo. El procesamiento y análisis de datos se realizó mediante el paquete IBM SPSS Statistics versión 23; se analizó cada una de las variables categóricas por medio de frecuencias y porcentajes, y las variables cuantitativas aplicando estadísticos descriptivos. Posteriormente se realizaron los cruces entre algunas variables, tanto categóricas como cuantitativas, mediante el uso de frecuencias, porcentajes, medidas descriptivas y algunos gráficos. Se resalta la información relacionada con el número de artículos publicados por año, procedencia de los artículos, tiempos entre la recepción y aceptación de los mismos, porcentajes de idioma de los artículos, tipo de investigaciones de los cuales se derivan los artículos, y tipo de análisis estadístico utilizado, entre otros.

One of the strategies for developing action plans or improving scientific publications originates from a retrospective view or characterization studies, regarding the evolution of such written productions. In order to achieve this, indicators that require databases and indexes are considered. They allow evaluating scientific quality, editorial quality, visibility, periodicity or stability and impact. In this sense, this article aims to make a descriptive analysis of articles published in the “Acta Colombiana de Psicología” (Colombian Act of Psychology) Journal between 2010 and 2014. The variables to be considered for this analysis were identified: categorical and quantitative variables. Processing and data analysis was performed using SPSS Statistics IBM package version 23. Each of the categorical variables was analyzed by frequencies and percentages, and quantitative variables using descriptive statistics. Later, crosses between some variables, both categorical and quantitative, were performed using frequencies, percentages, descriptive measures, and some graphics. Information related to the number of articles published per year was highlighted, as well as origin of the articles, time span between receipt and acceptance, language percentages of the articles, type of research from which articles are derived, and the type of statistical analysis used, among others.

Uma das estratégias para a elaboração dos planos de ação ou melhoramento das publicações científicas parte do olhar retrospectivo ou dos estudos da caracterização a respeito da evolução destas. Para isso, consideram-se os indicadores que exigem as bases e os índices de dados, os quais permitem avaliar a qualidade científica, a qualidade editorial, a visibilidade, a periodicidade ou a estabilidade bem como o impacto. Nesse sentido, o presente artigo tem como objetivo realizar uma análise descritiva dos artigos publicados na revista Acta Colombiana de Psicología entre 2010 e 2014. Identificaram-se as variáveis a considerar para esta análise: variáveis categóricas e variáveis de tipo quantitativo. O processamento e a análise de dados foi realizada mediante o IBM SPSS Statistics versão 23; foi analisada cada uma das variáveis categóricas por meio de frequências e porcentagens, e as variáveis quantitativas aplicando estatísticos descritivos. Em seguida, foram realizados os cruzamentos entre algumas variáveis, tanto categóricas quanto quantitativas, mediante o uso de frequências, porcentagens, medidas descritivas e alguns gráficos. Ressalta-se a informação relacionada com o número de artigos publicados por ano, a procedência dos artigos, o tempo entre a recepção e a aceitação deles, as porcentagens de idioma dos artigos, os tipos de pesquisa das quais se derivam os artigos e o tipo de análise estatística utilizada, entre outros.

Serum kinetics of Calloselasma rhodostoma (Malayan pit viper) venom components in a rabbit

The serum kinetics of Calloselasma rhodostoma (Malayan pit viper) venom - specifically two of its components, the major hemorrhagin (rhodostoxin) and a thrombin-like enzyme - was examined in a rabbit by double-sandwich enzyme-linked immunosorbent assay (ELISA). The animal received intramuscularly a 1.0-mg/kg dose of C. rhodostoma venom. The venom level in serum peaked 12 hours after the injection, followed by a gradual decline and finally reached low rates 72 hours after administration. The serum kinetic profile of venom components, however, did not correspond to the profile of the whole C. rhodostoma venom. The serum levels of the C. rhodostoma thrombin-like enzyme increased slowly and peaked only 48 hours post-injection. Then both thrombin-like enzyme and rhodostoxin remained at relatively high levels 72 hours after administration. Data suggest that various venom components bind to tissue at the injection site with different affinities and that conjugated venom components were continuously released into circulation at different rates. The prolonged high serum levels of both thrombin-like enzyme and hemorrhagin are consistent with the clinical picture of prolonged clotting deficiency in severe cases of C. rhodostoma envenomation. Our results also suggest that since venom components are being released into and eliminated from the circulation at different rates, the "average composition" of the venom antigen in the circulation changes over time. This implies that data from ELISA quantification of antigen levels from serum venom employing "whole venom" as reagent must be interpreted with care.(AU)