Binding sites and actions of Tx1, a neurotoxin from the venom of the spider Phoneutria nigriventer, in guinea pig ileum

Tx1, a neurotoxin isolated from the venom of the South American spider Phoneutria nigriventer, produces tail elevation, behavioral excitation and spastic paralysis of the hind limbs after intracerebroventricular injection in mice. Since Tx1 contracts isolated guinea pig ileum, we have investigated the effect of this toxin on acetylcholine release, as well as its binding to myenteric plexus-longitudinal muscle membranes from the guinea pig ileum. [125I]-Tx1 binds specifically and with high affinity (Kd = 0.36 ± 0.02 nM) to a single, non-interacting (nH = 1.1), low capacity (Bmax 1.1 pmol/mg protein) binding site. In competition experiments using several compounds (including ion channel ligands), only PhTx2 and PhTx3 competed with [125I]-Tx1 for specific binding sites (K0.5 apparent = 7.50 x 10-4 g/l and 1.85 x 10-5 g/l, respectively). PhTx2 and PhTx3, fractions from P. nigriventer venom, contain toxins acting on sodium and calcium channels, respectively. However, the neurotoxin PhTx2-6, one of the isoforms found in the PhTx2 pool, did not affect [125I]-Tx1 binding. Tx1 reduced the [3H]-ACh release evoked by the PhTx2 pool by 33%, but did not affect basal or KCl-induced [3H]-ACh release. Based on these results, as well as on the homology of Tx1 with toxins acting on calcium channels (w-Aga IA and IB) and its competition with [125I]-w-Cono GVIA in the central nervous system, we suggest that the target site for Tx1 may be calcium channels.

Extracellular matrix molecules as targets for brown spider venom toxins

Loxoscelism, the term used to describe lesions and clinical manifestations induced by brown spider's venom (Loxosceles genus), has attracted much attention over the last years. Brown spider bites have been reported to cause a local and acute inflammatory reaction that may evolve to dermonecrosis (a hallmark of envenomation) and hemorrhage at the bite site, besides systemic manifestations such as thrombocytopenia, disseminated intravascular coagulation, hemolysis, and renal failure. The molecular mechanisms by which Loxosceles venoms induce injury are currently under investigation. In this review, we focused on the latest reports describing the biological and physiopathological aspects of loxoscelism, with reference mainly to the proteases recently described as metalloproteases and serine proteases, as well as on the proteolytic effects triggered by L. intermedia venom upon extracellular matrix constituents such as fibronectin, fibrinogen, entactin and heparan sulfate proteoglycan, besides the disruptive activity of the venom on Engelbreth-Holm-Swarm basement membranes. Degradation of these extracellular matrix molecules and the observed disruption of basement membranes could be related to deleterious activities of the venom such as loss of vessel and glomerular integrity and spreading of the venom toxins to underlying tissues.

Letter from the Secretary of the Navy, transmitting the official account of the capture of the British sloop of War, Reindeer, by the United States sloop Wasp, commanded by Captain Johnston Blakeley, on the twenty-eighth June last.--

"A list of British vessels captured by the United States' sloop of War Wasp, J. Blakeley esg. commander, between May 1st and July 6th, 1814".Folded table at end.

Letter from the Secretary of the Navy, transmitting the official account of the capture of the British sloop of War, Reindeer, by the United States sloop Wasp, commanded by Captain Johnston Blakeley, on the twenty-eighth June last

"A list of British vessels captured by the United States' sloop of War Wasp, J. Blakeley esg. commander, between May 1st and July 6th, 1814".Folded table at end. October 17, 1814. Printed by order of the Senate of the United States.

Photograph - Group Return from Hunting

A photograph of a male holding a rifle by his side, with four females (varying ages) and another male is standing in the background. They are holding a long stick which is carrying their game.

Photograph - Percy Band Hunting with others

A photograph of Percy Band with a group of men with a pack of hunting dogs.

Photograph - Percy Band Hunting with others #2

Another photograph of the Percy Band with a group of hunters.

Photograph - Hunting Group with Percy Band

A group of men with rifles and hunting dogs. The photograph is dark and cloudy making it difficult to see details. Percy Band is sitting in front.

Samuel DeVeaux Woodruff's Pewter Hunting Flask

This is a 16 cm x 8 cm 19th century pewter flask which has 3 pieces including the flask, the screw-on cap and a cover/drinking cup. There is a W inscribed within the cap. This is well-worn and dented.

Los superhéroes, el deber moral y la obligación : el caso de Spider-man y los X-Men

La manera en que los superhéroes actúan como agentes morales, así como la forma en que asumen y justifican su deber moral se explora por medio del análisis de dos superhéroes de historieta: Spider-man y los X-Men. Una exploración de los mensajes mediáticos desde la filosofía moral.

Are you a spider?

Ofrece información a los niños más pequeños a través del ciclo de vida de una araña. Con un texto divertido se hace la comparación entre una araña y un niño y se examinan las diferencias que hay entre ambos para ayudar a entender los procesos de la vida y ver las similitudes y diferencias entre las arañas y los seres humanos.

A cheese and tomato spider.

Presenta las páginas divididas por la mitad en horizontal, con lo que las múltiples ilustraciones de animales, objetos y personas, se pueden combinar para dar origen a objetos y personas absurdos e inverosímiles.

Different interpretations of witch-hunting in early Modern Europe c. 1560-c. 1660.

Cumple con los requisitos para la especificación OCR A2 de Historia, unidad F986, opción B. Estudia las causas y desarrollo de la controversia, la Europa Moderna, la brujería y la caza de brujas, enfoques e interpretaciones estructurales y funcionales, enfoques e interpretaciones culturales y psicoanalíticas, aproximaciones e interpretaciones de carácter regional y general. Este recurso comprende actividades que ayudan a la comprensión del contenido y a desarrollar en los estudiantes habilidades con la historia, análisis de situaciones y acontecimientos, breves biografías de personajes clave de la época, definiciones de palabras nuevas y consejos prácticos para los exámenes.

Creació de l'empresa Mediterranean Hunting

Treball sobre la creació d'una empresa de turisme cinegètic. Es pretén aprofundir en la temàtica del turisme cinegètic; aprofundir en la temàtica del les agències de viatges; aprofundir en la temàtica de caça i fer una proposta novedosa i viable des del punt de vista empresarial