Blanca Ramos-Cerrillo

Publications of Blanca Ramos-Cerrillo

• Neutralization of Vipera and Macrovipera venoms by two experimental polyvalent antisera: a study of paraspecificity.

  Authors: Irving G Archundia, Adolfo R de Roodt, Blanca Ramos-Cerrillo, Jean-Philippe Chippaux, Laura Olguín-Pérez, Alejandro Alagón, Roberto P Stock

  Toxicon : official journal of the International Society on Toxinology. 06/2011; 57(7-8):1049-56.

  We conducted an extensive study of neutralization of lethality of 11 species and one subspecies of snakes of the genus Vipera, and of five species of Macrovipera, by two experimental equine antisera.We conducted an extensive study of neutralization of lethality of 11 species and one subspecies of snakes of the genus Vipera, and of five species of Macrovipera, by two experimental equine antisera. One antiserum was a trivalent preparation raised against the venoms of Vipera aspis aspis, Vipera berus berus and Vipera ammodytes ammodytes; the other was a pentavalent preparation that also included venoms of Vipera (now Montivipera) xanthina and Macrovipera lebetina obtusa. We measured specific neutralization of lethality against all venoms included in the immunization schemes, and paraspecific neutralization against the venoms of Vipera ammodytes montandoni, Vipera (Montivipera) bornmuelleri, Vipera latastei, Vipera (Mo.) latifii, Vipera (Mo.) lotievi, Vipera (Daboia) palaestinae, Vipera (Mo.) raddei and Vipera seoanei, as well as against Macrovipera (D.) deserti, Macrovipera lebetina cernovi, Macrovipera lebetina turanica and Macrovipera schweitzeri. We found an important degree of paraspecific protection within each genera (omitting recent reclassification) that was quite independent of both the lethal potency of the venoms and their geographic origin. This information may be of use to clinicians charged with the treatment of Vipera or Macrovipera envenomations with non-specific antivenoms.

• Paraspecific neutralization of the venom of African species of cobra by an equine antiserum against Naja melanoleuca: a comparative study.

  Authors: Andrea Casasola, Blanca Ramos-Cerrillo, Adolfo R de Roodt, Alejandro Carbajal Saucedo, Jean-Philippe Chippaux, Alejandro Alagón, Roberto P Stock

  Toxicon : official journal of the International Society on Toxinology. 06/2009; 53(6):602-8.

  Venoms of snakes belonging to the same Genera tend to share biochemical, toxinological and antigenic characteristics. Accordingly, paraspecific neutralization of venom lethality by experimentalVenoms of snakes belonging to the same Genera tend to share biochemical, toxinological and antigenic characteristics. Accordingly, paraspecific neutralization of venom lethality by experimental antisera and commercial antivenoms has been reported. We studied the spectrum of neutralization of lethality of an experimental monovalent equine antiserum against the strongly neurotoxic African forest cobra (Naja melanoleuca) when tested against venoms of most species of African Naja, both neuro and cytotoxic as described by some authors. We report a comparison of the median lethal doses (LD50) of the venoms and the paraspecific median effective doses (ED50) of the antiserum calculated using three methods: Spearman-Kärber and Probit (currently recommended by the World Health Organization), and non-linear regression. An ample--but not complete--spectrum of paraspecific neutralization of lethality was observed against both spitting and non-spitting species of African Naja with a clearly more efficient neutralization of the more potent venoms, the implications of which are discussed. The median lethal and effective doses calculated by the three methods are remarkably consistent and may warrant consideration of non-linear regression methods for the calculation of venom lethality and antivenom potency by venom/antivenom researchers and producers.

• Characterization of a new polyvalent antivenom (Antivipmyn((R)) Africa) against African vipers and elapids.

  Authors: Blanca Ramos-Cerrillo, Adolfo R de Roodt, Jean-Philippe Chippaux, Laura Olguín, Andrea Casasola, Guadalupe Guzmán, Jorge Paniagua-Solís, Alejandro Alagón, Roberto P Stock

  Toxicon : official journal of the International Society on Toxinology. 10/2008;

  As a response to the antivenom shortage in Sub-Saharan Africa, evident for well over a decade, we developed a new polyvalent anti-ophidian antivenom (Antivipmyn((R)) Africa) designed for use in theAs a response to the antivenom shortage in Sub-Saharan Africa, evident for well over a decade, we developed a new polyvalent anti-ophidian antivenom (Antivipmyn((R)) Africa) designed for use in the region. We report a detailed characterization of its biochemical composition (protein content and profiling by size-exclusion chromatography and electrophoresis) as well as the specific and para-specific neutralization potencies (as median effective dose in the mouse lethality test). Additionally, we studied the neutralization of hemorrhagic, anti-hemostatic and necrotic activities of Echis ocellatus venom, responsible for a majority of severe envenomations in the continent according to existing epidemiological data. The antivenom is currently under production and has already been employed in the field in a pragmatic Phase III clinical trial in the Republic of Benin. It is a purified lyophilized polyvalent equine F(ab')(2)-based product obtained by immunization with the venoms of eleven species of African snakes of the Genera Echis, Bitis, Naja and Dendroaspis. The criteria for its design are discussed, particularly in terms of the implementation of realistic public health policies targeting mostly rural populations in the continent.

• Upregulation of IL-6, IL-8, CXCL1, and CXCL2 dominates gene expression in human fibroblast cells exposed to Loxosceles reclusa sphingomyelinase D: insights into spider venom dermonecrosis.

  Authors: Bojan Dragulev, Yongde Bao, Blanca Ramos-Cerrillo, Hilda Vazquez, Alejandro Olvera, Roberto Stock, Alejandro Algaron, Jay W Fox

  The Journal of investigative dermatology. 06/2007; 127(5):1264-6.

• Study of the efficacy of the black stone on envenomation by snake bite in the murine model.

  Authors: Jean-Philippe Chippaux, Blanca Ramos-Cerrillo, Roberto P Stock

  Toxicon : official journal of the International Society on Toxinology. 05/2007; 49(5):717-20.

  The black stone (BS) has been used since antiquity to treat envenomations. Since no actual clinical trial has ever been performed we used an experimental approach to evaluate its efficacy against theThe black stone (BS) has been used since antiquity to treat envenomations. Since no actual clinical trial has ever been performed we used an experimental approach to evaluate its efficacy against the venoms of Bitis arietans, Echis ocellatus and Naja nigricollis. Local application of BS after intramuscular venom injection had no demonstrable effect on the outcome of envenomationa and it did not change the LD(50) of B. arietans venom. Our results show that, contrary to widespread belief, no efficacy to treat envenomation may be expected of the BS.

• North and South American Loxosceles spiders: development of a polyvalent antivenom with recombinant sphingomyelinases D as antigens.

  Authors: Alejandro Olvera, Blanca Ramos-Cerrillo, Judith Estévez, Herlinda Clement, Adolfo de Roodt, Jorge Paniagua-Solís, Hilda Vázquez, Alfonso Zavaleta, María Salas Arruz, Roberto P Stock, Alejandro Alagón

  Toxicon : official journal of the International Society on Toxinology. 08/2006; 48(1):64-74.

  We report the cloning of sphingomyelinase D (SMD) cDNA from Loxosceles reclusa, Loxosceles boneti and Loxosceles laeta into bacterial expression systems, as well as optimization of expressionWe report the cloning of sphingomyelinase D (SMD) cDNA from Loxosceles reclusa, Loxosceles boneti and Loxosceles laeta into bacterial expression systems, as well as optimization of expression conditions so as to obtain soluble and active recombinant enzymes. The recombinant mature SMDs, tagged with a histidine tail at the N- or C-termini, were compared in terms of toxicity and enzymatic activity, and were used as immunogens for the production of monovalent antisera in rabbits and F(ab')(2) preparations in animals used for commercial antivenom production (horses). We performed studies on in vitro inhibition of enzymatic activity of natural venom preparations by antibodies generated against the tagged proteins. We also present and discuss the results of studies on the specific and para-specific in vivo protective potential of the rabbit and equine antibody preparations against the recombinant proteins themselves and natural venom preparations. Our conclusions support the feasibility of using recombinant SMDs for production and evaluation of polyvalent anti-Loxosceles antivenoms, and we offer data on the potential of paraspecific neutralization in the context of the antigenic groupings and the molecular phylogeny of those active SMDs for which amino acid sequence information is available.

• Genetic and enzymatic characterization of sphingomyelinase D isoforms from the North American fiddleback spiders Loxosceles boneti and Loxosceles reclusa.

  Authors: Blanca Ramos-Cerrillo, Alejandro Olvera, George V Odell, Fernando Zamudio, Jorge Paniagua-Solís, Alejandro Alagón, Roberto P Stock

  Toxicon : official journal of the International Society on Toxinology. 11/2004; 44(5):507-14.

  In this study we report the isolation and characterization of several sphingomyelinase D isoforms from the venoms of the North American spiders Loxosceles boneti and Loxosceles reclusa, from MexicoIn this study we report the isolation and characterization of several sphingomyelinase D isoforms from the venoms of the North American spiders Loxosceles boneti and Loxosceles reclusa, from Mexico and the United States, respectively. We have measured their enzymatic activity, their capacity to induce necrotic lesions in rabbits, cloned the cDNAs coding for the mature forms of two of the isoforms from L. boneti and two of L. reclusa based on N-terminal sequence information of the purified proteins, and performed a comprehensive comparison of the sequence data generated by us with that reported for other sphingomyelinase genes to date.

• Effectiveness of two common antivenoms for North, Central, and South American Micrurus envenomations.

  Authors: Adolfo R de Roodt, Jorge F Paniagua-Solis, Jorge A Dolab, Judith Estévez-Ramiréz, Blanca Ramos-Cerrillo, Silvana Litwin, José C Dokmetjian, Alejandro Alagón

  Journal of toxicology. Clinical toxicology. 02/2004; 42(2):171-8.

  Micrurus snakes (coral snakes) may produce severe envenomation that can lead to death by peripheral respiratory paralysis. Only few laboratories produce specific antivenoms, and despite theMicrurus snakes (coral snakes) may produce severe envenomation that can lead to death by peripheral respiratory paralysis. Only few laboratories produce specific antivenoms, and despite the cross-reactivity found in some Micrurus species venoms, the treatment is not always effective. To test two therapeutic antivenoms against the venom of four species of Micrurus from Southern America, North of South America, Central America, and North America, the determination of the lethal potency of the venoms, the study of some biochemical and immunochemical characteristics, and the determination of the neutralizing activity of both antivenoms were studied. North American and South American antivenoms neutralized well venoms from Micrurus species of the corresponding hemisphere but displayed lower effectiveness against venoms of species from different hemispheres. It was concluded that the neutralization of Micrurus venoms by regional antivenoms could be useful to treat the envenomation by some Micrurus snakes but is necessary to evaluate carefully the antivenoms to be used with the venoms from the snakes of the region. Also, considering the difficulties for coral snake antivenom production, the development of a polyvalent antivenom is useful to treat the envenomation by coral snakes from different regions is necessary.

• Study of the efficacy of the black stone on envenomation by snake bite in the murine model

  Authors: Jean-Philippe Chippaux, Blanca Ramos-Cerrillo, Roberto P. Stock

  Toxicon.

  The black stone (BS) has been used since antiquity to treat envenomations. Since no actual clinical trial has ever been performed we used an experimental approach to evaluate its efficacy against theThe black stone (BS) has been used since antiquity to treat envenomations. Since no actual clinical trial has ever been performed we used an experimental approach to evaluate its efficacy against the venoms of Bitis arietans, Echis ocellatus and Naja nigricollis. Local application of BS after intramuscular venom injection had no demonstrable effect on the outcome of envenomationa and it did not change the LD50 of B. arietans venom. Our results show that, contrary to widespread belief, no efficacy to treat envenomation may be expected of the BS.