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.

Uso potencial de componentes del veneno de serpiente en el tratamiento del cáncer / Potential use of snake venom components in cancer treatment

El desarrollo del cáncer es posible en la medida que las células tumorales proliferen, se dispersen e invadan otros tejidos del cuerpo. Las integrinas son una familia de receptores heterodiméricos de superficie celular que cumplen un papel crucial en el desarrollo de la angiogénesis, crecimiento y metástasis de un tumor señalándolas como un atractivo blanco terapéutico. Los venenos de serpientes contienen péptidos de bajo peso molecular conocidos como desintegrinas, las que se unen con una alta afinidad a las integrinas e inhiben su accionar en un proceso cancerígeno. En el siguiente articulo revisamos los resultados de investigaciones, tanto in vitro como in vivo, que han mostrado resultados promisorios, por lo cual el uso de las desintegrinas podrían constituir una alternativa promisoria para el tratamiento de diversas neoplasias.

Cancer can develop to the extent tumor cells grow, divide and grow into other body tissues. Integrins are a family of cell-surface heterodimeric receptors that play an important role in the development of tumor angiogenesis, growth and metastasis, thus being recognized as an attractive therapeutic target. Snake venom contains low-molecular weight peptides known as “disintegrins” that bind to integrins with high affinity, and prevent their action in cancer. In the next article, we go over the results of investigations, both in vitro and in vivo, which have shown promising results, thus revealing that the use of disintegrins could be a promising alternative for the treatment of different neoplasias.

Clonaje y caracterización molecular in silico de un transcrito de fosfolipasa A2 aislado del veneno de la serpiente peruana Lachesis muta / Molecular cloning and characterization in silico of phospholipase A2 transcripto isolated from Lachesis muta peruvian snake venom

Objetivo. Aislar y caracterizar in silico un transcrito del gen de fosfolipasa A2 (PLA2) aislado del veneno de Lachesis muta de la Amazonía peruana. Materiales y métodos. Se amplificó el transcrito del gen sPLA2 mediante la técnica de RT-PCR a partir de RNA total utilizando cebadores específicos, el producto de DNA amplificado se insertó en el vector pGEM para su posterior secuenciación. Mediante análisis bioinformático de la secuencia nucleotídica se determinó un marco de lectura abierta de 414 nucleótidos que codifica 138 aminoácidos, incluyendo16 aminoácidos del péptido señal, el peso molecular y el pI fueron de 13 976 kDa y 5,66 respectivamente. Resultados. La secuencia aminoacídica denominada Lm-PLA2- Perú, contiene Asp49, así como Tyr-28, Gly-30, Gly-32, His-48, Tyr52, Asp99 importantes para la actividad enzimática. La comparación de Lm-PLA2-Perú con las secuencias aminoacídicas de los bancos de datos mostró 93 por ciento de similitud con las sPLA2 de Lachesis stenophrys y más del 80 por ciento con otras sPLA2 de venenos de la familia Viperidae. El análisis filogenético de la secuencia nucleotídica del transcrito del gen sPLA2 indica que Lm-PLA2-Perú se agrupa con otras sPLA2 [Asp49] ácidas previamente aisladas del veneno de Bothriechis schlegelii con un 89 por ciento de identidad. El modelaje tridimensional de Lm-PLA2-Perú, presenta una estructura característica de sPLA2 del Grupo II formada por tres hélices-α, una lámina-β, una hélice corta y un lazo de unión con calcio. Conclusión. La secuencia nucleotídica corresponde al primer transcripto del gen de PLA2 clonado a partir del veneno de la serpiente Lachesis muta, que habita en la selva del Perú.

Objective. Isolate and characterize in silico gene phospholipase A2 (PLA2) isolated from Lachesis muta venom of the Peruvian Amazon. Material and methods. Technique RT-PCR from total RNA was using specific primers, the amplified DNA product was inserted into the pGEM vector for subsequent sequencing. By bioinformatic analysis identified an open reading frame of 414 nucleotides that encoded 138 amino acids including a signal peptide of 16 aminoacids, molecular weight and pI were 13 976 kDa and 5.66 respectively. Results. The aminoacid sequence was called Lm-PLA2-Peru, contains an aspartate at position 49, this aminoacid in conjunction with other conserved residues such as Tyr-28, Gly-30, Gly-32, His-48, Tyr52, Asp99 are important for enzymatic activity. The comparison with the amino acid sequence data banks showed of similarity between PLA2 from Lachesis stenophrys (93 percent) and other PLA2 snake venoms and over 80 percent of other sPLA2 family Viperidae venoms. A phylogenetic analysis showed that Lm-PLA2-Peru grouped with other acidic [Asp49] sPLA2 previously isolated from Bothriechis schlegelii venom showing 89 percent nucleotide sequence identity. Finally, the computer modeling indicated that enzyme had the characteristic structure of sPLA2 group II that consisted of three α-helices, a β-wing, a short helix and a calcium-binding loop. Conclusion. The nucleotide sequence corresponding to the first transcript of gene from PLA2 cloned of Lachesis muta venom, snake from the Peruvian rainforest.

Efectos de la irradiación neutrónica del uranio 235 sobre el veneno de Lachesis muta (Ofidia: Viperidae) / The effect neutron irradiation of Uranium 235 on the venom of Lachesis muta muta (Ofidia: Viperidae)

The effect of irradiation of the aqueous solution of L. m. muta venom was evaluated with thermic neutrons from Uranium-235 employing doses of 1.61 to 5.19 Gray. The venom was examined for protein content by the Folin Lowry Method modified by Stauffer; for acute toxicity by intraperitoneal route estimation in mice and for immunochemical tests by the antigen-antibody reactions evaluation. Neutronic radiation affects all evaluated parameters in venom (decrease in protein content levels, increase of LD50 values and decrease in the number of precipitating antigen-antibody) as shown by immunodiffusion and immunoelectrophoresis

Aislamiemto y algunas propiedades de la proteinasa I del veneno de la serpiente peruana Lachesis muta / Isolation and various properties of proteinase I from the venom of the Peruvian snake Lachesis muta

Se ha purificado una enzima proteolítica con elevada actividad sobre caseína a partir del veneno de la serpiente Lachesis muta. Esta proteína denominada "Proteinasa I" fue obtenida mediante una cromatografía de filtración sobre sephadex G-100 a pH 6.5 con buffer acetato de amonio 0.1 seguida de una cromatografía de intercambio iónico con DEAE-celulosa a pH 7.5 y una recromatografía en DEAE-celulosa a pH 9.0 y 7.8. La proteína aislada mostró un banda homogenea en electroforeis en gel de poliacrilamida. El peso molecular calculado por filtración en gel fue 26,100 y su pH óptimo 8.4. La ctividad enzimática no fue alterada depués de un calentamiento a 45-C por 10 minutos, mientras que a 70- sólo se registró un 4%de actividad. La enzima no ataca ésteres sintético como TAME y BAEE, no es afectada por lo iones de calcio y carecen de actividad hemorrágica