WorldWideScience

Sample records for bothrops alternatus modulates

  1. A transcriptomic analysis of gene expression in the venom gland of the snake Bothrops alternatus (urutu

    Directory of Open Access Journals (Sweden)

    Menossi Marcelo

    2010-10-01

    Full Text Available Abstract Background The genus Bothrops is widespread throughout Central and South America and is the principal cause of snakebite in these regions. Transcriptomic and proteomic studies have examined the venom composition of several species in this genus, but many others remain to be studied. In this work, we used a transcriptomic approach to examine the venom gland genes of Bothrops alternatus, a clinically important species found in southeastern and southern Brazil, Uruguay, northern Argentina and eastern Paraguay. Results A cDNA library of 5,350 expressed sequence tags (ESTs was produced and assembled into 838 contigs and 4512 singletons. BLAST searches of relevant databases showed 30% hits and 70% no-hits, with toxin-related transcripts accounting for 23% and 78% of the total transcripts and hits, respectively. Gene ontology analysis identified non-toxin genes related to general metabolism, transcription and translation, processing and sorting, (polypeptide degradation, structural functions and cell regulation. The major groups of toxin transcripts identified were metalloproteinases (81%, bradykinin-potentiating peptides/C-type natriuretic peptides (8.8%, phospholipases A2 (5.6%, serine proteinases (1.9% and C-type lectins (1.5%. Metalloproteinases were almost exclusively type PIII proteins, with few type PII and no type PI proteins. Phospholipases A2 were essentially acidic; no basic PLA2 were detected. Minor toxin transcripts were related to L-amino acid oxidase, cysteine-rich secretory proteins, dipeptidylpeptidase IV, hyaluronidase, three-finger toxins and ohanin. Two non-toxic proteins, thioredoxin and double-specificity phosphatase Dusp6, showed high sequence identity to similar proteins from other snakes. In addition to the above features, single-nucleotide polymorphisms, microsatellites, transposable elements and inverted repeats that could contribute to toxin diversity were observed. Conclusions Bothrops alternatus venom gland

  2. Effect of Bothrops alternatus snake venom on macrophage phagocytosis and superoxide production: participation of protein kinase C

    Directory of Open Access Journals (Sweden)

    SS Setubal

    2011-01-01

    Full Text Available Envenomations caused by different species of Bothrops snakes result in severe local tissue damage, hemorrhage, pain, myonecrosis, and inflammation with a significant leukocyte accumulation at the bite site. However, the activation state of leukocytes is still unclear. According to clinical cases and experimental work, the local effects observed in envenenomation by Bothrops alternatus are mainly the appearance of edema, hemorrhage, and necrosis. In this study we investigated the ability of Bothrops alternatus crude venom to induce macrophage activation. At 6 to 100 ¼g/mL, BaV is not toxic to thioglycollate-elicited macrophages; at 3 and 6 ¼g/mL, it did not interfere in macrophage adhesion or detachment. Moreover, at concentrations of 1.5, 3, and 6 ¼g/mL the venom induced an increase in phagocytosis via complement receptor one hour after incubation. Pharmacological treatment of thioglycollate-elicited macrophages with staurosporine, a protein kinase (PKC inhibitor, abolished phagocytosis, suggesting that PKC may be involved in the increase of serum-opsonized zymosan phagocytosis induced by BaV. Moreover, BaV also induced the production of anion superoxide (O2_ by thioglycollate-elicited macrophages. This BaV stimulated superoxide production was abolished after treating the cells with staurosporine, indicating that PKC is an important signaling pathway for the production of this radical. Based on these results, we suggest that phagocytosis and reactive oxygen species are involved in the pathogenesis of local tissue damage characteristic of Bothrops spp. envenomations.

  3. Treatment of Bothrops alternatus envenomation by Curcuma longa and Calendula officinalis extracts and ar-turmerone Tratamento local do envenenamento por Bothrops alternatus com extrato de Curcuma longa e Calendula officinalis e ar-turmerone

    Directory of Open Access Journals (Sweden)

    M.M. Melo

    2005-02-01

    Full Text Available It was investigated the efficiency of two extracts of plants and one fraction of their properties against the local effects of bothropic envenomation. Bothrops alternatus venom (1.25µg diluted in 100µl of sterile saline solution was inoculated (intradermally into the shaved dorsal back skin of 30 New Zealand rabbits. The animals were divided in six groups receiving the following treatments: group I: subcutaneous application of Curcuma longa extract (1.0ml; group II: topic treatment of Curcuma longa hydroalcoholic extract (1.0ml; group III: topic application of ar-turmerone in vaseline (1.0g; group IV: topic application of Curcuma longa methanolic extract (1.0ml; group V: topic application of Calendula officinalis ointment (1.0g; group VI: topic application of saline (1.0ml. These treatments were done at 30 minutes, and at 2, 4, 24 and 72 hours after venom inoculation. Intensity of local edema, hemorrhagic halo and necrosis were evaluated until 168h after that. Additionally, seven days after the Bothrops venom inoculation, blood was collected from heart with and without EDTA (10% for hemogram and biochemical parameters (total protein, blood urea nitrogen, creatinine, and fibrinogen and all the animals were anesthetized, sacrificed by ether inhalation and submitted to necropsy. Fragments of tissues were taken for histopathological evaluation. The most efficient treatment for inhibition of edema, necrosis and local hemorrhage after Bothrops alternatus venom was the topic application of ar-turmerone.Investigou-se a eficácia do extrato de plantas no tratamento local do envenenamento botrópico. Veneno de serpentes Bothrops alternatus (1,25µg diluído em 100µl de solução salina estéril foi inoculado (via intradérmica entre as escápulas de 30 coelhos. Os animais foram divididos em seis grupos (tratamentos: grupo I: tratamento subcutâneo com extrato de Curcuma longa; grupo II: tratamento tópico com extrato hidroalcoólico de Curcuma longa

  4. Perfil clínico e imunológico de bovinos experimentalmente inoculados com veneno bruto e iodado de Bothrops alternatus Clinical and immunological characteristics in cattle experimentally inoculated with crude and iodinated Bothrops alternatus venom

    OpenAIRE

    N.J. F. Oliveira; M. M. de Melo; E.R. Lara; M. Lúcia; Z.I.P. Lobato

    2007-01-01

    Dez novilhas mestiças, distribuídas em dois grupos experimentais (n=5) receberam na altura média da face cranial do membro anterior direito, entre as articulações umerorradioulnar e do carpo, por via intramuscular superficial, 0,15mg/kg de veneno de Bothrops alternatus bruto ou iodado. Todos os animais foram avaliados clinicamente antes - tempo zero - e às 6 e 10h, no 2º, 3º, 4º, 5º, 8º, 11º, 18º e 25º dias após a inoculação dos venenos. Dois animais do grupo que recebeu veneno bruto foram a ...

  5. Perfil clínico e imunológico de bovinos experimentalmente inoculados com veneno bruto e iodado de Bothrops alternatus Clinical and immunological characteristics in cattle experimentally inoculated with crude and iodinated Bothrops alternatus venom

    Directory of Open Access Journals (Sweden)

    N.J.F. Oliveira

    2007-06-01

    Full Text Available Dez novilhas mestiças, distribuídas em dois grupos experimentais (n=5 receberam na altura média da face cranial do membro anterior direito, entre as articulações umerorradioulnar e do carpo, por via intramuscular superficial, 0,15mg/kg de veneno de Bothrops alternatus bruto ou iodado. Todos os animais foram avaliados clinicamente antes - tempo zero - e às 6 e 10h, no 2º, 3º, 4º, 5º, 8º, 11º, 18º e 25º dias após a inoculação dos venenos. Dois animais do grupo que recebeu veneno bruto foram a óbito às 53h e 78h e os sobreviventes apresentaram apatia, letargia, anorexia, postura indicativa de dor, melena, petéquias e sufusões nas mucosas, aumento do tempo de preenchimento capilar, enfartamento ganglionar regional, aumento das freqüências respiratória e cardíaca, redução da freqüência de pulsação arterial periférica, elevação da temperatura retal e diminuição da movimentação ruminal. No local da inoculação do veneno bruto houve sangramento e ulceração dérmica, além de aumento significativo na circunferência e dobra da pele do membro inoculado, revelando formação de edema. Todos os animais também foram avaliados imunologicamente no 17º, 24º, 31º, 45º, 60º e 180º dia. Somente os que receberam veneno bruto produziram anticorpos, detectados até o 45º dia. Os que receberam veneno botrópico iodado apresentaram alterações gerais e locais de menor intensidade, porém sem produção de IgG nos tempos pesquisados, demonstrando que a iodação alterou a composição bioquímica do veneno, diminuindo sua toxicidade e imunogenicidade.The effects of bothropic envenomation in 10 crossbred heifers, randomly divided into two groups, that received 0.15mg/kg of body weight of Bothrops alternatus crude or iodinated venom were studied. Behavior; attitude; appetite; defecation; urination; mucous membranes; capillary perfusion time; lymph nodes; respiratory, cardiac and pulse frequencies; rectal temperature and

  6. Aspectos clínico-patológicos e laboratoriais do envenenamento experimental por Bothrops alternatus em bovinos Clinic and pathological and laboratory aspects of experimental poisoning by Bothrops alternatus venom in cattle

    Directory of Open Access Journals (Sweden)

    Saulo A. Caldas

    2008-06-01

    Full Text Available Esse estudo teve como objetivo determinar as alterações clínico-patológicas e os achados laboratoriais em bovinos inoculados com a peçonha de Bothrops alternatus, no intuito de fornecer subsídios para o estabelecimento do diagnóstico e do diagnóstico diferencial, bem como esclarecer pontos obscuros da literatura pertinente. O veneno liofilizado foi diluído em 1 ml de solução fisiológica e administrado a cinco bovinos, por via subcutânea, nas doses de 0,0625, 0,125 e 0,25 mg/kg e a dois outros, por via intramuscular, nas doses de 0,25 e 0,45 mg/kg. Seis bovinos foram a óbito e um que recebeu a dose de 0,0625mg/kg, por via subcutânea, recuperou-se. Os sinais clínicos tiveram início entre 25 minutos a 5 horas 30 minutos após a inoculação. O período de evolução variou de 7 horas 18 minutos a 66 horas 12 minutos. Um animal recuperou-se após 92 horas. O quadro clínico, independentemente das doses, caracterizou-se por aumento de volume (hemorragia/hematoma no local da inoculação, tempo de sangramento aumentado, mucosas hipocoradas e apatia. O exame laboratorial revelou progressiva anemia normocítica normocrômica, trombocitopenia, redução de fibrinogênio e proteínas plasmáticas totais, hematócrito e hemoglobina diminuídos, além de leve aumento dos níveis de creatinaquinase e desidrogenase lática. Á necropsia, havia, a partir do local da inoculação, extensos hematomas e áreas de hemorragia no tecido celular subcutâneo dos animais que receberam o veneno por via subcutânea; nos animais inoculados por via intramuscular, adicionalmente, havia hemorragia intramuscular. O endocárdio esquerdo apresentava extensas hemorragias e verificaram-se petéquias na serosa do rúmen e do omaso e na mucosa do abomaso e da vesícula biliar. Em cinco animais, o cólon, reto e região perirrenal estavam envoltos por coágulos de sangue. Ao exame histológico observou-se, além do quadro hemorragíparo, necrose muscular coagulativa

  7. Heterologous expression and biochemical and functional characterization of a recombinant alpha-type myotoxin inhibitor from Bothrops alternatus snake.

    Science.gov (United States)

    Santos-Filho, Norival A; Boldrini-França, Johara; Santos-Silva, Ludier K; Menaldo, Danilo L; Henrique-Silva, Flávio; Sousa, Tiago S; Cintra, Adélia C O; Mamede, Carla C N; Oliveira, Fábio; Arantes, Eliane C; Antunes, Lusânia M Greggi; Cilli, Eduardo M; Sampaio, Suely V

    2014-10-01

    Venomous and non-venomous snakes possess phospholipase A2 (PLA2) inhibitory proteins (PLIs) in their blood serum. This study shows the expression and biochemical and functional characterization of a recombinant alpha inhibitor from Bothrops alternatus snake, named rBaltMIP. Its expression was performed in Pichia pastoris heterologous system, resulting in an active recombinant protein. The expressed inhibitor was tested regarding its ability to inhibit the phospholipase activity of different PLA2s, showing slight inhibitions especially at the molar ratios of 1:1 and 1:3 (PLA2:PLI). rBaltMIP was also effective in decreasing the myotoxic activity of the tested toxins at molar ratios greater than 1:0.4 (myotoxin:PLI). The inhibition of the myotoxic activity of different Asp49 (BthTX-II and PrTX-III) and Lys49 (BthTX-I and PrTX-I) myotoxins was also performed without the prior incubation of myotoxins/inhibitor in order to analyze the real possibility of using snake plasma inhibitors or recombinant inhibitors as therapeutic agents for treating envenomations. As a result, rBaltMIP was able to significantly inhibit the myotoxicity of Lys49 myotoxins. Histopathological analysis of the gastrocnemius muscles of mice showed that the myotoxins are able to induce severe damage to the muscle fibers of experimental animals by recruiting a large number of leukocyte infiltrates, besides forming an intense accumulation of intercellular fluid, leading to local edema. When those myotoxins were incubated with rBaltMIP, a reduction of the damage site could be observed. Furthermore, the cytotoxic activity of Asp49 PLA2s and Lys49 PLA2-like enzymes on C2C12 cell lines was decreased, as shown by the higher cell viabilities after preincubation with rBaltMIP. Heterologous expression would enable large-scale obtainment of rBaltMIP, thus allowing further investigations for the elucidation of possible mechanisms of inhibition of snake PLA2s, which have not yet been fully clarified. PMID:25047442

  8. Caracterização individual do veneno de Bothrops alternatus Duméril, Bibron & Duméril em função da distribuição geográfica no Brasil (Serpentes,Viperidae Individual characterization of Bothrops alternatus Duméril, Bibron & Duméril venoms, according to their geographic distribution in Brazil (Serpentes, Viperidae

    Directory of Open Access Journals (Sweden)

    Marisa M. T. da Rocha

    2005-06-01

    Full Text Available Bothrops alternatus Duméril, Bibron & Duméril, 1854 é uma serpente de importância em saúde pública, com ampla distribuição geográfica, desde o Mato Grosso do Sul até o sudeste do Brasil, chegando até a Argentina e Uruguai, ocupando vários domínios morfoclimáticos. Neste trabalho investigou-se a variação do veneno de adultos de Bothrops alternatus, em função de sua distribuição geográfica no Brasil, comparativamente ao veneno elaborado sob a forma de "pool" desta espécie (veneno referência, que inclui serpentes, em sua maioria, da região do estado de São Paulo. Foram analisadas as atividades letal, coagulante sobre o plasma, proteolítica sobre a caseína e miotóxica, bem como os padrões eletroforéticos de 61 amostras individuais de veneno contrapostas ao "pool". Os resultados mostraram que o veneno de B. alternatus é pouco ativo, comparativamente ao de outros Bothrops Wagler, 1824. A variação individual prevaleceu, não apresentando correlação com as áreas de distribuição geográfica e domínios morfoclimáticos, porém a atividade coagulante das amostras de veneno provenientes do nordeste da distribuição geográfica apresentaram-se menos ativas comparativamente às da porção central da distribuição. Os venenos provenientes das bordas da distribuição apresentaram ações proteolíticas e miotóxicas mais intensas, que estatisticamente não foram significativamente diferentes. As variações individuais prevaleceram.Bothrops alternatus Duméril, Bibron & Duméril, 1854 snakebites are an important public health problem in Brazil. Such snakes are found from Mato Grosso do Sul (central Brazil to southeastern Brazil, reaching even Argentina and Uruguay and thereby occupying different morphoclimatic domains. This work investigated venom variation occurring in adult specimens of B. alternatus specimens, according to their geographic distribution in Brazil. The standard venom pool (reference venom produced by

  9. [Hemolytic activity of venoms from snakes of the genera Bothrop, Lachesis, Crotalus, and Micrurus (Serpentes: Viperidae and Elapidae].

    Science.gov (United States)

    Martínez Cadillo, E; Bonilla Ferreyra, C; Zvealeta, A

    1991-11-01

    Hemolytic activity of eight Peruvian snake venoms from the families Viperidae and Elapidae (Bothrops atrox, B. pictus, B. hyoprorus, B. bilineatus, B. neuwedii, Lachesis m. muta, Crotalus d. terrificus, Micrurus tschudi), and three Brazilian viperids (B. jararacussu, B. alternatus and C. d. collilineatus) is described. None of the venoms caused direct lysis on washed human erythrocytes. However, all of them caused indirect hemolysis provided that the incubation medium contains an exogenous source of lecithin. Venom of Micrurus tschudi was the most hemolytic (HD50 2.8 ug/ml) while that of B. bilineatus was the least (HD50 681.3 ug/ml). Only six of eleven venoms showed parallel curves of hemolytic activity, and the HD50 varied from 198 to 681 ug/ml and the following decreasing order of hemolytic activity was obtained: L. muta, C. d. terrificus, C. d. collilineatus, B. hyoprorus, B. bilineatus, B. alternatus. PMID:1844159

  10. Therapeutic possibilities of Bothrops jararaca in high dilution

    Directory of Open Access Journals (Sweden)

    Eduardo Costa Gaia Nazareth

    2011-09-01

    the therapeutic indications such as modulation of the complement system, action on the cardiovascular system, among other uses, by Bothrops jararaca in high dilution. Conclusion: This evaluation can be used for different sources of products and allows the rational use of Bothrops jararaca in high dilution. The results can and should be complemented by clinical studies and pathogenetic. Bacterial infectious diseases such as tuberculosis and leprosy, and autoimmune disease LES and may receive treatment studies with the drug based on Bothrops jararaca snake venom because they are indirectly associated with them via similarity of the failure of complement, an important marker for bacterial the defense of mammals. Action on clinical aspects like hypertension, sweating, hypothermia and necrosis shall be seen. Perhaps the search for the stimulation of complement show a new pathway for the harmonization, long-predicted by Hahnemann, Hering and searched for among the many that followed the creator of this therapy.

  11. Preclinical testing of Peruvian anti-bothropic anti-venom against Bothrops andianus snake venom.

    Science.gov (United States)

    Schneider, Francisco S; Starling, Maria C; Duarte, Clara G; Machado de Avila, Ricardo; Kalapothakis, Evanguedes; Silva Suarez, Walter; Tintaya, Benigno; Flores Garrido, Karin; Seraylan Ormachea, Silvia; Yarleque, Armando; Bonilla, César; Chávez-Olórtegui, Carlos

    2012-11-01

    Bothrops andianus is a venomous snake found in the area of Machu Picchu (Peru). Its venom is not included in the antigenic pool used for production of the Peruvian anti-bothropic anti-venom. B. andianus venom can elicit many biological effects such as hemorrhage, hemolysis, proteolytic activity and lethality. The Peruvian anti-bothropic anti-venom displays consistent cross-reactivity with B. andianus venom, by ELISA and Western Blotting and is also effective in neutralizing the venom's toxic activities. PMID:22796381

  12. Effects of methamidophos and deltamethrin on in vitro protein phosphorylation in Monochamus alternatus

    Institute of Scientific and Technical Information of China (English)

    Jie Liu; Xi-Wu Gao; Yi-Jun Wu; Wei Li; Qi-Lian Qin; Jiang-Hua Sun

    2008-01-01

    Monochamus alternatus Hope(Coleoptera:Cerambycidae)is not onlY a serious Dest insect to pine trees but alSO the main vector of pine wood nemadote Bursaphelenchus xylophilus,which causes pine wilt disease.To explore the insecticidal mechanism of insecticides to M alternatus,we chose methamidophos and deltamethrin as the representa-tives of two groups of insecticides(organophosphates and pyrethroids),which arc widely used for pest controlin China and investigated their effects on phosphorylation of proteins from the insect.Phosphorylation of proteins from the insect fat body and head was determined by fn vitro 32P-labelling.In the fat body,deltamethtin obviously reduced basal phosphorylation levels of proteins at 111,95,77,and 44 kDa,but enhanced the basal phosphorylation level of a protein at 138 kDa.However,in the presence of calmodulin but not cyclic adenosine monophosphate(cAMP),deitamethrin increased phosphorylation of the protein at 111 kDa.In the head,deltamethrin inhibited basal phosphorylation levels of proteins at 113,98,and 51 kDa,but potentiated phosphorylation of a protein at 167 kDa activated by cAMP.Methamidophos inhibited phosphorylation of a protein at 44 kDa in the fat body.Although methamidophos did not impact basal phosphorylation levels of any proteins in the head,it inhibiled calcium/calmodulin(Ca2+/CAM) stimulated phosphoryla-tion of a protein at 5 1 kDa.Together.our dam indicate that methamidophos and deltamethrin altered phosphorylation levels of various proteins in thc head and fat body of the pine insect and these two kinds of inseeticides acted on the proteins that call be phosphorylated in the tissues respectively,Which is possibly related to their toxicity.

  13. Trichomoniasis in Bothrops jararaca (serpentes, viperidae)

    OpenAIRE

    F.C. Vilela; M.G. da Silva; T. H. Barrella; R. J. DA SILVA

    2003-01-01

    We describe a case of trichomoniasis in a Bothrops jararaca (Serpentes, Viperidae) donated to the Center for the Study of Venoms and Venomous Animals - CEVAP/UNESP. The animal had diarrhea with great quantity of flagellated protozoa in the feces. Microscopic examination of fecal smears stained with Giemsa revealed the presence of trichomonads, morphologically similar to Trichomonas acosta. Trichomonads were not detected in fecal exams after treatment with a single dose of 40 mg/kg metronidazo...

  14. Trichomoniasis in Bothrops jararaca (serpentes, viperidae

    Directory of Open Access Journals (Sweden)

    F. C. Vilela

    2003-01-01

    Full Text Available We describe a case of trichomoniasis in a Bothrops jararaca (Serpentes, Viperidae donated to the Center for the Study of Venoms and Venomous Animals - CEVAP/UNESP. The animal had diarrhea with great quantity of flagellated protozoa in the feces. Microscopic examination of fecal smears stained with Giemsa revealed the presence of trichomonads, morphologically similar to Trichomonas acosta. Trichomonads were not detected in fecal exams after treatment with a single dose of 40 mg/kg metronidazole (Flagyl®.

  15. Acute kidney injury caused by bothrops snake venom.

    Science.gov (United States)

    Rodrigues Sgrignolli, Lívia; Florido Mendes, Glória Elisa; Carlos, Carla Patricia; Burdmann, Emmanuel A

    2011-01-01

    Medically important venomous snakes in Latin America belong to the genus Bothrops, Crotalus, Lachesis and Micrurus. The Bothrops genus is responsible for the majority of accidents. The WHO globally estimates 2,500,000 poisonous snakebites and 125,000 deaths annually. In its last report in 2001, the Brazilian Ministry of Health accounted 359 deaths due to snakebites, of which the Bothrops genus was responsible for 185. Snake venoms cause local and systemic damage, including acute kidney injury, which is the most important cause of death among patients surviving the early effects of envenoming by the Crotalus and Bothrops genuses. Venom-induced acute kidney injury is a frequent complication of Bothrops snakebite, carrying relevant morbidity and mortality. PMID:21757950

  16. Metabolic Profiling of Somatic Tissues from Monochamus alternatus (Coleoptera: Cerambycidae Reveals Effects of Irradiation on Metabolism

    Directory of Open Access Journals (Sweden)

    Liangjian Qu

    2014-06-01

    Full Text Available A high-level of sexual sterility is of importance for the sterile insect technique (SIT. However, the use of high-dose-intensity gamma radiation to induce sterility has negative impacts not only on reproductive cells but also on somatic cells. In this study, we investigated the metabolite differences in somatic tissues between non-irradiated, 20-Gy-irradiated, and 40-Gy-irradiated male Monochamus alternatus, an important vector of the pathogenic nematode, Bursaphelenchus xylophilus, which kills Asian pines. The results showed that metabolite levels changed moderately in the 20-Gy samples but were markedly altered in the 40-Gy samples compared with the non-irradiated samples. Twenty-six and 53 metabolites were disturbed by 20-Gy and 40-Gy radiation, respectively. Thirty-six metabolites were found to be markedly altered in the 40-Gy samples but were not changed significantly in the 20-Gy samples. The comprehensive metabolomic disorders induced by 40-Gy radiation dysregulated six metabolic pathways involved in the life process. The findings presented in this manuscript will contribute to our knowledge of the characteristic metabolic changes associated with gamma-radiation-induced damage to somatic cells and will allow for better exploration of the SIT for the control of this target pest.

  17. Metabolic profiling of somatic tissues from Monochamus alternatus (Coleoptera: Cerambycidae) reveals effects of irradiation on metabolism.

    Science.gov (United States)

    Qu, Liangjian; Wang, Lijuan; Wang, Qinghua; Wang, Yuzhu; Zhang, Yongan

    2014-01-01

    A high-level of sexual sterility is of importance for the sterile insect technique (SIT). However, the use of high-dose-intensity gamma radiation to induce sterility has negative impacts not only on reproductive cells but also on somatic cells. In this study, we investigated the metabolite differences in somatic tissues between non-irradiated, 20-Gy-irradiated, and 40-Gy-irradiated male Monochamus alternatus, an important vector of the pathogenic nematode, Bursaphelenchus xylophilus, which kills Asian pines. The results showed that metabolite levels changed moderately in the 20-Gy samples but were markedly altered in the 40-Gy samples compared with the non-irradiated samples. Twenty-six and 53 metabolites were disturbed by 20-Gy and 40-Gy radiation, respectively. Thirty-six metabolites were found to be markedly altered in the 40-Gy samples but were not changed significantly in the 20-Gy samples. The comprehensive metabolomic disorders induced by 40-Gy radiation dysregulated six metabolic pathways involved in the life process. The findings presented in this manuscript will contribute to our knowledge of the characteristic metabolic changes associated with gamma-radiation-induced damage to somatic cells and will allow for better exploration of the SIT for the control of this target pest. PMID:24937685

  18. Influence of 60Co γ irradiation on fertility of Japanese pine sawyer beetle Monochamus alternatus hope (Coleoptera: Cerambycidae)

    International Nuclear Information System (INIS)

    The fertility of the Japanese pine sawyer beetle Monochamus alternatus (Coleoptera: Cerambycidae) irradiated with 60Co γ-rays was remarkable reduced at the doses of 30Gy, 35Gy and 40Gy, especially at 40Gy. When the non-irradiated females were coupled with the irradiated males first, and then coupled with non-irradiated males, the hatchability and the fertility had little higher but lower than the control. It explained that radiation has certain influence to the female gonad. It also has difference between the hatching rate and the amount of eggs in different match. (authors)

  19. [Toxicity and neutralization of venoms from Peruvian snakes of the genera Bothrops and Lachesis (Serpentes: Viperidae)].

    Science.gov (United States)

    Incio Ruiz, R; Incio Ruiz, L; Martínez-Vargas, A Z; Salas Arruz, M; Gutiérrez, J M

    1993-12-01

    The lethal potencies (Median Lethal Dose) of the venoms of Peruvian snakes (Bothrops atrox, Bothrops barnetti, Bothrops pictus and Lachesis muta muta) were determined in mice by using intravenous and intraperitoneal routes of injection. In addition, the neutralizing ability of three antivenoms (bothropic polyvalent, bothropic bivalent and lachetic) was studied by preincubation-type experiments. B. pictus venom had the highest lethality by the intraperitoneal route whereas B. atrox venom had the highest lethality when tested by the intravenous route. The three antivenoms were effective in neutralizing lethality of the homologous venoms. Bivalent antivenom was more effective than polyvalent antivenom in the neutralization of B. pictus venom. On the basis of these findings, the use of bivalent bothropic antivenom is recommended in the Pacific coastal regions of Perú, whereas polyvalent bothropic antivenom is recommended in the oriental jungle regions of the country. PMID:7701074

  20. Evaluation of antivenoms in the neutralization of hyperalgesia and edema induced by Bothrops jararaca and Bothrops asper snake venoms

    Directory of Open Access Journals (Sweden)

    Picolo G.

    2002-01-01

    Full Text Available Neutralization of hyperalgesia induced by Bothrops jararaca and B. asper venoms was studied in rats using bothropic antivenom produced at Instituto Butantan (AVIB, 1 ml neutralizes 5 mg B. jararaca venom and polyvalent antivenom produced at Instituto Clodomiro Picado (AVCP, 1 ml neutralizes 2.5 mg B. aspar venom. The intraplantar injection of B. jararaca and B. asper venoms caused hyperalgesia, which peaked 1 and 2 h after injection, respectively. Both venoms also induced edema with a similar time course. When neutralization assays involving the independent injection of venom and antivenom were performed, the hyperalgesia induced by B. jararaca venom was neutralized only when bothropic antivenom was administered iv 15 min before venom injection, whereas edema was neutralized when antivenom was injected 15 min or immediately before venom injection. On the other hand, polyvalent antivenom did not interfere with hyperalgesia or edema induced by B. asper venom, even when administered prior to envenomation. The lack of neutralization of hyperalgesia and edema induced by B. asper venom is not attributable to the absence of neutralizing antibodies in the antivenom, since neutralization was achieved in assays involving preincubation of venom and antivenom. Cross-neutralization of AVCP or AVIB against B. jararaca and B. asper venoms, respectively, was also evaluated. Only bothropic antivenom partially neutralized hyperalgesia induced by B. asper venom in preincubation experiments. The present data suggest that hyperalgesia and edema induced by Bothrops venoms are poorly neutralized by commercial antivenoms even when antibodies are administered immediately after envenomation.

  1. First report of hepatic hematoma after presumed Bothrops envenomation

    Directory of Open Access Journals (Sweden)

    Fernanda Cristina Cunha

    2015-10-01

    Full Text Available ABSTRACTIn Latin America, Bothrops envenomation is responsible for the majority of accidents caused by venomous snakes. Patients usually present local edema, bleeding and coagulopathy. Visceral hemorrhage is extremely rare and considered a challenge for diagnosis and management. We report the first case of hepatic hematoma owing to the bothropic envenomation in a 66-year-old man who was bitten in the left leg. He presented local edema, coagulopathy, and acute kidney injury. Radiological findings suggested hepatic hematoma, with a volume of almost 3 liters. The hepatic hematoma was gradually absorbed without the need for surgical intervention with complete resolution in 8 months.

  2. First report of hepatic hematoma after presumed Bothrops envenomation.

    Science.gov (United States)

    Cunha, Fernanda Cristina; Heerdt, Maike; Torrez, Pasesa Pascuala Quispe; França, Francisco Oscar de Siqueira; Molin, Graziela Zibetti Dal; Battisti, Rúbia; Zannin, Marlene

    2015-01-01

    In Latin America, Bothrops envenomation is responsible for the majority of accidents caused by venomous snakes. Patients usually present local edema, bleeding and coagulopathy. Visceral hemorrhage is extremely rare and considered a challenge for diagnosis and management. We report the first case of hepatic hematoma owing to the bothropic envenomation in a 66-year-old man who was bitten in the left leg. He presented local edema, coagulopathy, and acute kidney injury. Radiological findings suggested hepatic hematoma, with a volume of almost 3 liters. The hepatic hematoma was gradually absorbed without the need for surgical intervention with complete resolution in 8 months. PMID:26516980

  3. Postprandial thermogenesis in Bothrops moojeni (Serpentes: Viperidae

    Directory of Open Access Journals (Sweden)

    DR Stuginski

    2011-01-01

    Full Text Available Snakes that can ingest prey that are proportionally large have high metabolic rates during digestion. This great increase in metabolic rate (specific dynamic action - SDA may create a significant augment in the animal's body temperature. The present study investigated postprandial thermogenesis in Bothrops moojeni. Briefly, two groups of snakes were fed meals equivalent to 17 ± 3% and 32 ± 5% of their body weight and were observed for 72 hours, in which thermal images of each snake were taken with an infrared camera in a thermostable environment with a constant air temperature of 30°C. The results showed a significant increase in snake surface temperature, with a thermal peak between 33 and 36 hours after feeding. The meal size had a great impact on the intensity and duration of the thermogenic response. Such increase in temperature appears to be connected with the huge increase in metabolic rates during digestion of relatively large prey by snakes that feed infrequently. The ecologic implication of the thermogenic response is still not well understood; however, it is possible that its presence could affect behaviors associated with the snake digestion, such as postprandial thermophily.

  4. Neuromuscular activity of Bothrops alcatraz snake venom in chick biventer cervicis preparations.

    Science.gov (United States)

    de Moraes, Delkia Seabra; Aparecido de Abreu, Valdemir; Rostelato-Ferreira, Sandro; Leite, Gildo B; Alice da Cruz-Höfling, Maria; Travaglia-Cardoso, Silvia R; Hyslop, Stephen; Rodrigues-Simioni, Léa

    2012-02-01

    Venom (10-100 μg/ml) from Bothrops alcatraz, a pitviper from the Alcatrazes Archipelago off the coast of southeastern Brazil, caused progressive, irreversible neuromuscular blockade in chick isolated biventer cervicis preparations. The venom also inhibited contractures to exogenous ACh (110 μM) and KCl (20 mM), caused myofiber damage and increased creatine kinase release. Commercial bothropic antivenom raised against mainland Bothrops species neutralized the neuromuscular activity, depending on the venom concentration. PMID:22155137

  5. Bothrops sanctaecrucis Hoge 1966 (Squamata: Viperidae

    Directory of Open Access Journals (Sweden)

    Miranda Calle, Alejandro Bruno

    2011-05-01

    Full Text Available Seis ejemplares de la especie Bothrops sanctaecrucis presentes en la Colección Boliviana de Fauna (CBF, La Paz- Bolivia fueron examinados y comparados con sus congéneres (Tabla 1. Departamento de Cochabamba, Provincia Carrasco, Sección Quinta, Municipio Puerto Villarroel, Localidad Yuquis, 16º47’00.0"S, 64º56’50.0"O; 216 msnm. (CBF 673 Fecha de colecta: 11 mayo 1988. Colector: K.H. Redford. (200 mm LHC, 31.4 mm LCC. (CBF 776 Fecha de colecta: abril 1991. Colector: Allyn Maclean Sterman. (481.8 mm LHC, 85.8 mm LCC. Ambos individuos fueron colectados en la ecoregión Bosque Amazónico Preandino (Ibisch et al., 2003, y evaluados por Harvey et al. (2005. Departamento del Beni, Provincia General José Ballivián, Sección Segunda, Municipio San Borja, Localidad Quiquibey, 15º22’30.8"S, 67º06’17.4"O; 300 msnm. Fecha de colecta: 28 noviembre 1989. Colector: Efraín Peñaranda. Colectado en la ecoregión Bosque Amazónico Subandino (Ibisch et al., 2003. (CBF 814. Individuo con 921.8 mm LHC, 159.8 mm LCC. Departamento del Beni, Provincia Moxos, Sección Primera, Municipio San Ignacio, Localidad Oromomo, 16º01’58.7"S, 66º11’12.5"O; 250 msnm. (CBF 1009 Fecha de colecta: 17 mayo 1992. Colectores: Sergio Otazú y Fernando Guerra. (552.2 mm LHC, 119.0 mm LCC. (CBF 1023 Fecha de colecta: 18 mayo 1992. Colectores: Sergio Otazú y Fernando Guerra. (997.0 mm LHC, 151.4 mm LCC. Ambos individuos fueron colectados en la ecoregión Bosque Amazónico Subandino (Ibisch et al., 2003, y evaluados por Harvey et al. (2005. Ambos ejemplares corresponden a la localidad tipo de la especie descrita por Hoge (1966. Departamento de La Paz, Provincia Nor Yungas, Sección Primera, Municipio Coroico, Lo calidad Bajo Hornuni (Parque Nacional y Área Natural de Manejo Integrado Cotapata, 16º12’54.4"S, 67º53’09.8"O; 1935 msnm. Sin fecha de colecta. Colector: Amira Apaza. Colectado en la ecoregión Yungas (Ibisch et al., 2003. (CBF 3359. Individuo con 843

  6. Accidente ofídico causado por Bothrops Asper

    Directory of Open Access Journals (Sweden)

    Galofre-Ruiz Mario David

    2013-12-01

    Full Text Available Introduction: The snake bite of the genus Bothrops is an important cause of ophidic accident in Colombia, with high morbidity and mortality. Clinical case: A case of bite by the snake Bothrops Asper, which was classified as mild grade of poisoning at the entrance of the hospital center is presented. It was managed with antiophidic serum in doses lower than the recommended one, with progression of the symptoms of poisoning. Adjustments in the doses were done and total recovery was reached in five days. Conclusions: Antiophidic serums, named also antivenins, are the cornerstone of the treatment to minimize the local tissue damage and the systemic complications. Rev. cienc.biomed. 2013;4(2:353-357

  7. Bothrops lanceolatus Bites: Guidelines for Severity Assessment and Emergent Management

    OpenAIRE

    Resiere, Dabor; Mégarbane, Bruno; Valentino, Ruddy; Mehdaoui, Hossein; Thomas, Laurent

    2010-01-01

    Approximately 20-30 declared snakebite cases occurin Martinique each year. Bothrops lanceolatus, a member of the Crotalidae family, is considered to be the only involved snake. B. lanceolatus, commonly named “Fer-de-Lance”, is endemic and only found on this Caribbean island. Envenomation local features include the presence of fang marks, swelling, pain, bleeding from punctures, and ecchymosis. Severe envenomation is associated with multiple systemic thromboses appearing within 48 h of the bit...

  8. Tissue necrosis after canine bothropic envenoming: a case report

    Directory of Open Access Journals (Sweden)

    R. S. FERREIRA JÚNIOR

    2001-12-01

    Full Text Available The authors report a case of bothropic envenoming in a male Cocker Spaniel. The animal was bitten in the ventral thoracic region, receiving treatment 4 hours later. Clinical examination revealed an extensive, painful and area of firm edema, absence of local or systemic hemorrhage, without evident neurological alterations. Clinical diagnosis was mild bothropic envenoming. Treatment consisted of 5 vials of polyvalent snake antivenom, two vials administered intravenously and three subcutaneously. Blood clotting time was always within normal values. Two days after envenoming, the animal showed hyperthermia and received enrofloxacin (5mg/kg/24h for 10 days and ketoprofen (1mg/kg/24h for 5 days. Seventy-two hours after envenoming, extensive subcutaneous, muscle fiber, and skin necrosis of approximately 10 cm in diameter was observed. After débridement of necrotic tissues, the area was cleaned with antiseptic solutions. Complete healing was observed 55 days after envenoming. The authors discuss whether heterologous serotherapy is effective in preventing tissue necrosis after bothropic envenoming.

  9. PRODUCTION OF AN EFFECTIVE ANTI-Bothrops-TETANUS MIXED HYPERIMMUNE SERUM OF EQUINE ORIGIN

    OpenAIRE

    R. GUIDOLIN; M. A. STEPHANO; J.F. Morais; E. H. SAKAGUTI; S. M. A. PRADO; F. FRATELLI; M. D. C. VANCETTO; H. G. HIGASHI

    1998-01-01

    The present investigation reveals the possibility of simultaneous immunization of horses with Bothrops or Crotalus snake venoms and Tetanus antigens for the production of anti-Bothrops-Tetanus or anti-Crotalus-Tetanus mixed serum, with high titers of the respective specific antibodies. Bothrops antivenoms with an average neutralizing titer of 4.16 mg venom/ml were obtained from plasma of horses with titers lower than 0.5 mg venom/ml when Tetanus antigens were not used. This suggests the exist...

  10. Action of anti-bothropic factor isolated from Didelphis marsupialis on renal effects of Bothrops erythromelas venom.

    Science.gov (United States)

    Martins, Alice M C; Sousa, Fabiola C M; Barbosa, Paulo S F; Toyama, Marcos H; Toyama, Daniela O; Aprígio, Cleidiana C; Queiroz, Maria G R; Guarnieri, Mirian C; Havt, Alexandre; de Menezes, Dalgimar B; Fonteles, Manassés C; Monteiro, Helena S A

    2005-11-01

    Acute renal failure is the most common complication in the lethal cases caused by snakebites in Brazil. Among the Brazilian venom snakes, Bothrops erythromelas is responsible for the majority of accidents in Northeastern Brazil. Didelphis marsupialis serum could inhibit myonecrotic, hemorrhagic, edematogenic hyperalgesic and lethal effects of envenomation determined by ophidian bites. In the present study, we evaluated the action of the anti-bothropic factor isolated from D. marsupialis on the renal effects promoted by B. erythromelas venom without systemic interference. Isolated kidneys from Wistar rats were perfused with Krebs-Henseleit solution containing 6% bovine serum albumin. We analyzed renal perfusion pressure (PP), renal vascular resistance (RVR), glomerular filtration rate (GFR), urinary flow (UF), and the percentages of sodium and potassium tubular transport (%TNa+, %TK+). The B. erythromelas venom (10 microg mL(-1)) decreased the PP (ct = 108.71+/-5.09 mmHg; BE = 65.21+/-5.6 mmHg*) and RVR (ct = 5.76+/-0.65 mmHg mL(-1) g(-1) min(-1); BE = 3.10+/-0.45 mmHg mL(-1) g(-1) min(-1)*). On the other hand, the GFR decreased at 60 min (ct60 = 0.76+/-0.07 mL g(-1) min(-1); BE60 = 0.42+/-0.12 mL g(-1) min(-1)*) and increased at 120 min (ct120 = 0.72+/-0.01 mL g(-1) min(-1); BE120 = 1.24+/-0.26 mL g(-1) min(-1)*). The UF increased significantly when compared with the control group (ct = 0.14+/-0.01 mL g(-1) min(-1); BE = 0.47+/-0.08 mL g(-1) min(-1)*). The venom reduced the %TNa(+) (ct90 = 79.18+/-0.88%; BE90 = 58.35+/-4.86%*) and %TK+ (ct90 = 67.20+/-4.04%; BE90 = 57.32+/-5.26%*) The anti-bothropic factor from D. marsupialis (10 microg mL(-1)) incubated with B. erythromelas venom (10 microg mL(-1)) blocked the effects on PP, RVR, %TNa+, and %TK+, but was not able to reverse the effects in UF and GFR promoted by venom alone. However, the highest concentration of D. marsupialis serum (30 microg mL(-1)) reversed all the renal effects induced by the venom. In

  11. In vitro hemolytic activity of Bothrops lanceolatus (fer-de-lance) venom

    OpenAIRE

    LJ Martins; PMF de Araújo; Bon, C.; S. HYSLOP; AL de Araújo

    2009-01-01

    Bothrops lanceolatus venom contains a variety of enzymatic and biological activities. The present work investigated the hemolytic activity of this venom and its phospholipase A2 (PLA2). Bothrops lanceolatus venom (6.7 µg/mL) caused indirect hemolysis of cow, horse, rat and sheep erythrocytes, with horse erythrocytes being the most sensitive; no direct hemolysis was observed. Hemolysis in sheep erythrocytes was concentration-dependent (5-11.7 µg/mL) and markedly attenuated by heating the venom...

  12. ELISA assays for the detection of Bothrops lanceolatus venom in envenomed patient plasmas.

    Science.gov (United States)

    Rodriguez-Acosta, A; Uzcategui, W; Azuaje, R; Giron, M E; Aguilar, I

    1998-01-01

    A double antibody sandwich enzyme linked immunosorbant assay (ELISA) was carried out to detect Bothrops Ianceolatus venom in plasma from envenomed patients at various time intervals (0, 6, 12, 18 and 24 hrs). The test could detect Bothrops lanceolatus levels up to 12 ng/mL of envenomed patient plasmas. Elaboration of an easy, fast and species-diagnostic based on this ELISA technique useful to physicians is discussed. PMID:11845439

  13. Clinical and immunological aspects of envenomations by Bothrops snakes

    Directory of Open Access Journals (Sweden)

    KPO Luna

    2011-01-01

    Full Text Available Accidents caused by snakes, especially in tropical and subtropical countries, still constitute a serious public health problem due to the lack of knowledge of health professionals and the precariousness of health systems in the regions where most accidents occur. Snake venoms contain a range of molecules that may provoke local swelling, pain, renal and respiratory insufficiencies. The study of the effects of each molecule on humans can help the development of complementary therapy. Similarly, the knowledge of clinical aspects of envenomations provides a better identification and implementation of appropriate treatment. In addition, to understand Bothrops envenomations and improve the therapeutic strategy, it is necessary to understand and study the role of important inflammatory mediators, particularly nitric oxide (NO, cytokines and the complement system.

  14. Occipital infarction revealed by quadranopsia following snakebite by Bothrops lanceolatus.

    Science.gov (United States)

    Merle, Harold; Donnio, Angélique; Ayeboua, Lucas; Plumelle, Yves; Smadja, Didier; Thomas, Laurent

    2005-09-01

    We report a case of snakebite in which envenomation was manifested through impairment of the visual field. The patient, a 46-year-old man, was bitten on the right thumb by Bothrops lanceolatus. Treatment with a specific equine antivenom (Bothrofav) was administered one hour after the bite. With the exception of fang marks, the results of a clinical examination, particularly the neurologic component, were normal. The day after the bite, the patient developed an inferior left lateral homonymous quadranopsia with macular epargne. T2 magnetic resonance imaging showed a right occipital infarction. His condition improved clinically and biologically. This observation of snakebite is the first in which envenomation was accompanied exclusively by an impairment of the visual field. Envenomation by B. lanceolatus is distinct in its incidence of significant thrombotic complications at a distance from the site of the bite. PMID:16172485

  15. Reproductive Biology of Bothrops erythromelas from the Brazilian Caatinga

    Directory of Open Access Journals (Sweden)

    Verônica Alberto Barros

    2014-01-01

    Full Text Available The reproductive biology of Bothrops erythromelas, a small pit viper from the Caatinga, a semiarid biome in Brazil, is described based on analysis of individuals deposited in zoological collections. Males are smaller and also attain sexual maturity at a smaller size than females. Female reproductive cycle is seasonal with an extended period of secondary vitellogenesis and births occurring in a restricted period from late spring to early summer. Sperm storage in females may probably occur in infundibular tubular glands and uterine muscular twisting (UMT, which is a polymorphic condition within B. erythromelas. Seasonal spermatogenesis in males is variable with some intraspecific variation regarding the male reproductive stage per season. Most males are reproductively active during spring/summer and reproductively quiescent during autumn/winter, although some individuals vary (e.g., show testicular spermatogenesis and active sexual segment of the kidneys (SSK during winter. The SSK could be identified in every male. Most males showed highly hypertrophied SSK in spring/summer and moderately hypertrophied SSK in autumn/winter. The ampulla ductus deferentis was observed and histochemical reactions were conducted. We discuss the probable influence of the unique environmental conditions of the Caatinga region and phylogenetic inertia in the reproductive patterns of this snake species.

  16. Fatal bothropic snakebite in a horse: a case report

    Directory of Open Access Journals (Sweden)

    NS Silva

    2011-01-01

    Full Text Available The present study reports a snakebite in a horse in the state of Pará, Brazil. At initial evaluation the animal was reluctant to walk and had tachycardia, tachypnea, severe lameness, bleeding on the pastern and swelling around the left hind leg. Blood samples from the bleeding sites, took on the first day, showed leukocytosis and neutrophilia, whereas biochemical values of urea and creatinine were significantly increased. The chosen treatment was snake antivenom, fluid therapy, antibiotics, anti-inflammatory agents and diuretic drugs. On the fourth day of therapy, the hematological values were within normal parameters. There was improvement related to the clinical lameness and swelling of the limb. However, a decrease in water intake and oliguria were observed. On the seventh day the animal died. Necropsy revealed areas of hemorrhagic edema in the left hind limb and ventral abdomen; the kidneys presented equimosis in the capsule, and when cut they were wet. Moreover, the cortex was pale, slightly yellow and the medullary striae had the same aspect. Based on these data, we concluded that the snakebite in the present study was caused by Bothrops spp. and that renal failure contributed to death.

  17. Bothrops lanceolatus bites: guidelines for severity assessment and emergent management.

    Science.gov (United States)

    Resiere, Dabor; Mégarbane, Bruno; Valentino, Ruddy; Mehdaoui, Hossein; Thomas, Laurent

    2010-01-01

    Approximately 20-30 declared snakebite cases occurin Martinique each year. Bothrops lanceolatus, a member of the Crotalidae family, is considered to be the only involved snake. B. lanceolatus, commonly named "Fer-de-Lance", is endemic and only found on this Caribbean island. Envenomation local features include the presence of fang marks, swelling, pain, bleeding from punctures, and ecchymosis. Severe envenomation is associated with multiple systemic thromboses appearing within 48 h of the bite and resulting in cerebral, myocardial or pulmonary infarctions. Diagnosis requires first of all identification of the snake. Coagulation tests are helpful to identify thrombocytopenia or disseminated intravascular coagulation. A clinical score based on 4 grades is helpful to assess envonimation severity. A specific monovalent equine anti-venom (Bothrofav(®), Sanofi-Pasteur, France) to neutralize B. lanceolatus venom is available. Its early administration within 6h from the biting in case of progressive local injures, general signs or coagulation disturbances is effective to prevent severe thrombosis and coagulopathy. Its tolerance is considered to be good. Despite an increasing incidence of bites, no deaths have been recently attributed to B. lanceolatus in Martinique, probably due to the currently recommended strategy of early antivenom administration when required. PMID:22069552

  18. NAA TECHNIQUE FOR CLINICAL INVESTIGATION OF MICE IMMUNIZED WITH BOTHROP VENOM

    International Nuclear Information System (INIS)

    In the present study Neutron Activation Analysis (NAA) technique was used to determine sodium concentration in whole blood of mice immunized with Bothrops venom. With this value it was possible to perform clinical investigation in this animal model using whole blood.

  19. Biological and immunological characteristics of the poison of Bothrops cotiara (Serpentes: Viperidae)

    International Nuclear Information System (INIS)

    Bothrops cotiara is a venomous snake sporadically found in the province of Misiones in Argentina, South of Brazil and Paraguay. Data on the clinics of the poisoning produced by its bite and on its venom are scarce. There is no information on the neutralizing capacity of the antivenoms available. In this study, the lethal potency, hemorrhagic, necrotizing, coagulant and thrombin-like, defibrinogenasing, indirect hemolytic and fibrinolytic activities of the venom of B. cotiara specimens from the province of Misiones were determined. The toxic activities were within the range of those described for the other Bothrops species from Argentina, and the electrophoretic and chromatographic studies showed similarities with those described for the other bothropic venoms. The immunochemical reactivity of six South American anti Viper antivenoms (ELISA) have a strong reactivity with all the antivenoms studied. The neutralizing capacity of three of these therapeutic antivenoms against the lethal potency and hemorrhagic, necrotizing, coagulant, thrombin-like and hemolytic activities showed a very close neutralizing capacity. Our data strongly suggest that the antivenoms for therapeutic use available in this area of South America are useful to neutralize the toxic and enzymatic activities of the venom of this uncommon specie of Bothrops. (author)

  20. Natural resistance of opossum (Didelphis marsupialis) to the mapanare (Bothrops lanceolatus) snake venom.

    Science.gov (United States)

    Pifano, F; Aguilar, I; Giron, M E; Gamboa, N; Rodriguez-Acosta, A

    1993-01-01

    The inactivation of local and general effects of the Mapanare (Bothrops lanceolatus) venom by Opossum's (Didelphis marsupialis) serum fractions was tested using an in vivo assay and an in vitro preincubation experiment. A serum fraction of the Opossum serum has been obtained by immunochemical purification. It is only present in opossum's protective opossum serum fraction (F-0.1). PMID:8186456

  1. Purification and characterization of a hemorrhagic metalloproteinase from Bothrops lanceolatus (Fer-de-lance) snake venom.

    Science.gov (United States)

    Stroka, Alessandra; Donato, José L; Bon, Cassian; Hyslop, Stephen; de Araújo, Albetiza Lôbo

    2005-03-15

    Bothrops snake venoms contain metalloproteinases that contribute to the local effects seen after envenoming. In this work, a hemorrhagic metalloproteinase (BlaH1) was purified from the venom of the snake Bothrops lanceolatus by a combination of gel filtration, affinity (metal chelating) and hydrophobic interaction chromatographies. The hemorrhagin was homogeneous by SDS-PAGE and had a molecular mass of 28 kDa that was unaltered by treatment with beta-mercaptoethanol. BlaH1 gave a single band in immunoelectrophoresis and immunoblotting using commercial bothropic antivenom. BlaH1 had hemorrhagic, caseinolytic, fibrinogenolytic, collagenolytic and elastinolytic activities, but no phospholipase A(2) activity. The hemorrhagic and caseinolytic activities were inhibited by EDTA, indicating that they were metal ion-dependent. In contrast, aprotinin, benzamidine and PMSF did not affect these activities. The caseinolytic activity of BlaH1 had a pH optimum of 8.0 and was stable in solution at up to 40 degrees C; activity was completely lost at > or =70 degrees C. The hemorrhagic activity was neutralized by commercial bothropic antivenom. These properties suggest that this new hemorrhagin belongs to class P-I snake venom metalloproteinases. PMID:15733562

  2. Biochemical and immunological alterations of 60 Co irradiated Bothrops jararacussu venom

    International Nuclear Information System (INIS)

    Proteins irradiation leads to structural alterations resulting in activity and function loss. This process has been useful to detoxify animal venoms and toxins, resulting in low toxicity products which increased immunogenicity. The Bothrops jararacussu venom behaves as a weak immunogen and its lethal activity in not neutralized by either autologous, heterologous or bothropic polyvalent antisera. This venom is markedly myotoxic and and the commercial bothropic antiserum does not neutralize this activity, because of this low immunogenicity of the myotoxins. This present work was done in order to evaluate the possibility of irradiating Bothrops jararacussu, intending to increase the immunogenicity of the myotoxic components, leading to productions of myotoxins neutralizing antibodies. Bothrops jararacussu venom samples were irradiated with 500, 1000 and 2000 Gy of 60 Co gamma rays. A 2.3 folds decrease of toxicity was observed for the 1000 Gy irradiated samples while the 2000 Gy irradiated sample was at least 3.7 folds attenuated. On the other hand, the 500 Gy did not promote any detoxification. Electrophoresis and HPLC data indicate that the irradiation lead to the formation of high molecular weight products (aggregates). The proteolytic and phospholipasic activities decreased in a dose dependent manner, the phospholipases being more resistant than the proteases. Both the animals (rabbit) immunized with either native or 2000 Gy irradiated venom produced native venom binding antibodies, a slightly higher titer being obtained in the serum of the rabbit immunized with the irradiated samples. Western blot data indicate that the anti-irradiated venom Ig Gs recognised a greater amount of either autologous or heterologous venom bands, both sera behaving as genus specific. The anti-native serum did not neutralize the myotoxic activity of native venom, while the anti-irradiated one was able to neutralize this activity. (author)

  3. The distribution and elimination of Bothrops erythromelas venom labeled with {sup 131} I after intravenous injection in mice

    Energy Technology Data Exchange (ETDEWEB)

    Rocha, M.L. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Zoologia]. E-mail: rocha@cascavel.uefs.br

    1999-07-01

    Pharmacokinetic studies can be used to study the systemic effects of snake venoms and to develop standard serotherapy protocols for envenomation. Bothrops erythromelas is probably responsible for most of the snakebite in Pernambuco. The objective of this study was to investigate the pharmacokinetics of B. erythromelas venom (BeV) in mice, and to evaluate the efficacy of bothropic antivenom. BeV showed bicompartmental distribution in the blood of the experimental animals. (author)

  4. The distribution and elimination of Bothrops erythromelas venom labeled with 131 I after intravenous injection in mice

    International Nuclear Information System (INIS)

    Pharmacokinetic studies can be used to study the systemic effects of snake venoms and to develop standard serotherapy protocols for envenomation. Bothrops erythromelas is probably responsible for most of the snakebite in Pernambuco. The objective of this study was to investigate the pharmacokinetics of B. erythromelas venom (BeV) in mice, and to evaluate the efficacy of bothropic antivenom. BeV showed bicompartmental distribution in the blood of the experimental animals. (author)

  5. Human neutrophil migration and activation by BJcuL, a galactose binding lectin purified from Bothrops jararacussu venom

    Directory of Open Access Journals (Sweden)

    Fernandes Luiz

    2011-01-01

    Full Text Available Abstract Background Neutrophil migration to an inflamed site constitutes the first line of the innate immune response against invading microorganisms. Given the crucial role of endogenous lectins in neutrophil mobilization and activation, lectins from exogenous sources have often been considered as putative modulators of leukocyte function. Lectins purified from snake venom have been described as galactoside ligands that induce erythrocyte agglutination and platelet aggregation. This study evaluated human neutrophil migration and activation by C-type lectin BJcuL purified from Bothrops jararacussu venom. Results Utilizing fluorescence microscopy, we observed that biotinylated-BJcuL was evenly distributed on the neutrophil surface, selectively inhibited by D-galactose. Lectin was able to induce modification in the neutrophil morphology in a spherical shape for a polarized observed by optical microscopy and exposure to BJcuL in a Boyden chamber assay resulted in cell migration. After 30 minutes of incubation with BJcuL we found enhanced neutrophil functions, such as respiratory burst, zymozan phagocytosis and an increase in lissosomal volume. In addition, BJcuL delays late apoptosis neutrophils. Conclusion These results demonstrate that BJcuL can be implicated in a wide variety of immunological functions including first-line defense against pathogens, cell trafficking and induction of the innate immune response since lectin was capable of inducing potent neutrophil activation.

  6. Distribution of 131 I- labeled Bothrops erythromelas venom in mice

    International Nuclear Information System (INIS)

    Bothrops erythromelas is responsible for many snake bites in northeastern Brazil. In the present study we determined the in vivo distribution of the venom following its subcutaneous injection into mice. B. erythromelas venom and albumin were labeled individually with 131 I by the chloramine T method, and separated in a Sephacryl S-200 column. The efficiency of labeling was 68%.Male Swiss mice (40-45 g), which had been provided with drinking water containing 0.05% KI over a period of 10 days prior to the experiment, were inoculated dorsally (sc) with 0.3 ml (2.35 x 105 cpm/mouse) of 131 I-venom (N = 42), 131 -albumin or 131 I (controls, N = 28 each). Thirty minutes and 1,3, 6, 12, 18 and 24 h after inoculation, the animals were perfused with 0.85% Na Cl and skin and various organs were collected in order to determine radioactivity content. There was a high rate of venom absorption int he skin (51%) within the first 30 min compared to albumin (20.1%) and free iodine (8.2%). Up to the third hour after injection there was a tendency for venom and albumin to concentrate in the stomach ( 3 rd h),small intestine (3 rd h) and large intestine (6th h). Both control groups had more radioactivity in the digestive tract, especially in the stomach, but these levels decreased essentially to baseline by 12-18 h postinjection. In the kidneys, the distribution profiles of venom, albumin and iodine were similar. Counts at 30 min postinjection were low in all three groups (1.37, 1.86 and 0.77, respectively), and diminished to essentially 0% by 12-18 h. Albumin tended to concentrate in muscle until the 3 rd h postinjection (1.98%).There was a low binding of labeled venom in the liver (B. erythromelas venom does not specifically target most internal organs. That is, the systemic effects of envenomation ar mainly due to an indirect action. (author)

  7. Detection of an antibothropic fraction in opossum (Didelphis marsupialis) milk that neutralizes Bothrops jararaca venom.

    Science.gov (United States)

    Jurgilas, P B; Neves-Ferreira, A G; Domont, G B; Moussatché, H; Perales, J

    1999-01-01

    An antibothropic fraction (ABF) from Didelphis marsupialis (opossum) serum, which is responsible for the neutralization of Bothrops jararaca venom was isolated by Perales et al. [Perales, J., Moussatché, H., Marangoni, S., Oliveira, B. and Domont, G. B. (1994). Isolation and partial characterization of an antibothropic complex from the serum of South American Didelphidae. Toxicon 32, 1237-1249]. The aim of this work was to verify the presence of this factor in opossum's milk, which could represent an additional protection for the neonatal opossum against bothropic venoms. An active milk fraction was isolated and showed similar physicochemical, structural, antigenic and biological properties when compared to ABF, indicating that they are probably the same protein. PMID:9920488

  8. Tissue damage caused by Bothrops sp envenoming evaluated by magnetic resonance imaging (MRI)

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, M.G. [Faculdade do Norte Paulista, Bebedouro, SP (Brazil); Matias, M.R.C. [UNESP, Botucatu, SP (Brazil). Hospital Universitario. Unidade de Ressonancia Magnetica; Yamashita, S.; Morceli, J. [UNESP, Botucatu, SP (Brazil). Faculdade de Medicina. Dept. de Doencas Tropicais e Diagnostico por Imagem; Barraviera, B. [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil). Centro de Estudos de Venenos e Animais Venenosos (CEVAP)]. E-mail: marilucefonseca@hotmail.com

    2002-07-01

    The objective of this clinical study was to evaluate local tissue damage caused by Bothrops sp envenoming in relation to lesion type and damaged tissues using magnetic resonance imaging (MRI). Fifteen patients bitten by Bothrops snakes were treated at the Emergency Unit of the Tropical Diseases Unit at the University Hospital, Botucatu School of Medicine, UNESP, Sao Paulo State, Brazil. After receiving specific sero therapy, the patients were submitted to MR of the bite site. T 1 spin-echo MRI were obtained revealing the following lesions: edema (n=9), edema associated with hemorrhage (n=5), and hemorrhage (n=1). Peri muscular areas (n=6) and subcutaneous tissues (n=5) were the most affected, followed by muscular tissues (n=4). It is important to mention that MRI did not show myonecrosis of the bite site, a widely reported finding in anatomical and histopathological experimental studies. (author)

  9. ACUTE-PHASE REACTIONS, INCLUDING CYTOKINES, IN PATIENTS BITTEN BY BOTHROPS AND CROTALUS SNAKES IN BRAZIL

    Directory of Open Access Journals (Sweden)

    B. BARRAVIERA

    1995-01-01

    Full Text Available Thirty-one patients bitten by venomous snakes in Botucatu area (State of São Paulo - Brazil, sixteen by Bothrops spp. and fifteen by Crotalus durissus terrificus, were studied. The group comprised twenty-nine males and two females, ranging from fourteen to sixty-three years of age (mean 33 ± 15. Leukocytosis with neutrophilia and lymphopenia, increase of mucoproteins and C-reactive protein, decrease of total serum protein and albumin, were observed on the first day after the accident. In addition, increased serum levels of the cytokines IL-6 and IL-8, but not of IL-1b and TNF-a, were observed. The alterations were generally more intense in patients bitten by Crotalus durissus terrificus than by Bothrops spp. It is concluded that these snakebite envenomations closely resemble an acute trauma, inducing a typical acute-phase response.

  10. Snake Venomics and Antivenomics of Bothrops diporus, a Medically Important Pitviper in Northeastern Argentina

    Science.gov (United States)

    Gay, Carolina; Sanz, Libia; Calvete, Juan J.; Pla, Davinia

    2015-01-01

    Snake species within genus Bothrops are responsible for more than 80% of the snakebites occurring in South America. The species that cause most envenomings in Argentina, B. diporus, is widely distributed throughout the country, but principally found in the Northeast, the region with the highest rates of snakebites. The venom proteome of this medically relevant snake was unveiled using a venomic approach. It comprises toxins belonging to fourteen protein families, being dominated by PI- and PIII-SVMPs, PLA2 molecules, BPP-like peptides, L-amino acid oxidase and serine proteinases. This toxin profile largely explains the characteristic pathophysiological effects of bothropic snakebites observed in patients envenomed by B. diporus. Antivenomic analysis of the SAB antivenom (Instituto Vital Brazil) against the venom of B. diporus showed that this pentabothropic antivenom efficiently recognized all the venom proteins and exhibited poor affinity towards the small peptide (BPPs and tripeptide inhibitors of PIII-SVMPs) components of the venom. PMID:26712790

  11. Accidents caused by Bothrops and Bothropoides in the State of Paraiba: epidemiological and clinical aspects Acidentes causados por serpentes dos gêneros Bothrops e Bothropoides no Estado da Paraíba: aspectos clínicos e epidemiológicos

    OpenAIRE

    Fagner Neves Oliveira; Monalisa Taveira Brito; Isabel Cristina Oliveira de Morais; Sayonara Maria Lia Fook; Helder Neves de Albuquerque

    2010-01-01

    INTRODUCTION: Bothrops and Bothropoides snakes cause 70% of the ophidic accidents in Brazil. The species that cause ophidic accidents in State of Paraíba are Bothropoides erythromelas, Bothrops leucurus and Bothropoides neuwiedi. METHODS: This is a prospective and transverse study, following a quantitative approach of accidents involving Bothrops and Bothropoides admitted to the Toxicological Assistance and Information Centers of Campina Grande and João Pessoa (Ceatox-CG and Ceatox-JP), aimed...

  12. Cell adhesion molecules involved in the leukocyte recruitment induced by venom of the snake Bothrops jararaca

    OpenAIRE

    Catarina F. P. Teixeira; Stella R. Zamuner

    2002-01-01

    It has been shown that Bothrops jararaca venom (BjV) induces a significant leukocyte accumulation, mainly neutrophils, at the local of tissue damage. Therefore, the role of the adhesion molecules intercellular adhesion molecule-1 (ICAM-1), LECAM-1, CD18, leukocyte function-associated antigen-1 (LFA-1) and platelet endothelial cell adhesion molecule-1 (PECAM-1) on the BjV-induced neutrophil accumulation and the correlation with release of LTB4, TXA2, tumor necrosis factor-alpha, interleukin (I...

  13. A C-Type Lectin from Bothrops jararacussu Venom Disrupts Staphylococcal Biofilms

    OpenAIRE

    Raphael Contelli Klein; Mary Hellen Fabres-Klein; Leandro Licursi de Oliveira; Renato Neves Feio; François Malouin; Andréa de Oliveira Barros Ribon

    2015-01-01

    Bovine mastitis is a major threat to animal health and the dairy industry. Staphylococcus aureus is a contagious pathogen that is usually associated with persistent intramammary infections, and biofilm formation is a relevant aspect of the outcome of these infections. Several biological activities have been described for snake venoms, which led us to screen secretions of Bothrops jararacussu for antibiofilm activity against S. aureus NRS155. Crude venom was fractionated by size-exclusion chro...

  14. Intraspecific variation of biological activities in venoms from wild and captive Bothrops jararaca.

    Science.gov (United States)

    Saad, Eduardo; Curtolo Barros, Luciana; Biscola, Natalia; Pimenta, Daniel C; Barraviera, Silvia R C S; Barraviera, Benedito; Seabra Ferreira, Rui

    2012-01-01

    The venom of Bothrops jararaca is composed of complex mixture of molecules, mainly lectins, metalloproteinases, serinoproteinases, desintegrins, phospholipases, and peptides. This composition may vary according to the snake's age, gender, and region of origin. The aim of the was to determine individual variation in Bothrops jararaca venom in the Botucatu region, Sao Paulo State, Brazil, by means of enzymatic, biochemical, and pharmacological characterization, utilizing in vitro tests and biological assays. The activities were compared with those of Brazilian Reference Venom (BRV). Protein concentration varied between adult and juvenile groups. The electrophoretic profiles were similar, with molecular masses ranging between 25 and 50 kD, but with intraspecific variations. Reverse-phase high-performance liquid chromatography (RP-HPLC) revealed protein concentration differences. Coagulant activity did not differ significantly among adult groups, but there was a large variation between juvenile venom and BRV, which coagulated more extensively. Venoms from adults displayed greater hemorrhagic activity, especially in males recently obtained from the wild. In contrast, juveniles kept in captivity and adult males showed higher values. Edematogenic activity displayed an increase in edema in all groups. At the mean lethal dose (LD₅₀), toxicity varied significantly between groups, with venom from captive females being threefold more toxic than juvenile venom. Data illustrate the intra- and interspecific complexity that occurs in snake venoms, which may be attributed to ontogenetic, sexual, and environmental factors that affect variability in Bothrops jararaca venom. Further, it is proposed that Brazilian public health authorities document the constitution of pooled venom employed in the immunization of serum-producing animals due to this variability in venom properties. Given the large Brazilian territory, this variability requires regional monitoring and evaluation of

  15. Immunological assessment of mice hyperimmunized with native and Cobalt-60-irradiated Bothrops venoms

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira Junior, R.S.; Meira, D.A. [UNESP, Botucatu, SP (Brazil). Dept. de Doencas Tropicais; Barraviera, B. [UNESP, Botucatu, SP (Brazil). Center for the Study of Venoms and Venomous Animals - CEVAP; Nascimento, N.; Alves, J.B. [Instituto de Pesquisas Energeticas (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Martinez, J.C. [UNESP, Botucatu, SP (Brazil). Escola de Engenharia]. E-mail: rseabra@cevap.org.br

    2005-10-15

    ELISA was used to evaluate, accompany, and compare the humoral immune response of Swiss mice during hyperimmunization with native and Cobalt-60-irradiated ({sup 60}Co) venoms of Bothrops jararaca, Bothrops jararacussu and Bothrops moojeni. Potency and neutralization were evaluated by in vitro challenges. After hyperimmunization, immunity was observed by in vivo challenge, and the side effects were assessed. The animals immunization with one LD50 of each venom occurred on days 1, 15, 21, 30, and 45, when blood samples were collected; challenges happened on the 60th day. Results showed that ELISA was efficient in evaluating, accompanying and comparing mouse immune response during hyperimmunization. Serum titers produced with natural venom were similar to those produced with irradiated venom. Immunogenic capacity was maintained after {sup 60} Co-irradiation. The sera produced with native venom showed neutralizing potency and capacity similar to those of the sera produced with irradiated venom. All antibodies were able to neutralize five LD50 from these venoms. Clinical alterations were minimum during hyperimmunization with irradiated venom, however, necrosis and death occurred in animals inoculated with native venom. (author)

  16. Immunological assessment of mice hyperimmunized with native and Cobalt-60-irradiated Bothrops venoms

    International Nuclear Information System (INIS)

    ELISA was used to evaluate, accompany, and compare the humoral immune response of Swiss mice during hyperimmunization with native and Cobalt-60-irradiated (60Co) venoms of Bothrops jararaca, Bothrops jararacussu and Bothrops moojeni. Potency and neutralization were evaluated by in vitro challenges. After hyperimmunization, immunity was observed by in vivo challenge, and the side effects were assessed. The animals immunization with one LD50 of each venom occurred on days 1, 15, 21, 30, and 45, when blood samples were collected; challenges happened on the 60th day. Results showed that ELISA was efficient in evaluating, accompanying and comparing mouse immune response during hyperimmunization. Serum titers produced with natural venom were similar to those produced with irradiated venom. Immunogenic capacity was maintained after 60 Co-irradiation. The sera produced with native venom showed neutralizing potency and capacity similar to those of the sera produced with irradiated venom. All antibodies were able to neutralize five LD50 from these venoms. Clinical alterations were minimum during hyperimmunization with irradiated venom, however, necrosis and death occurred in animals inoculated with native venom. (author)

  17. Biochemical and hematological study of goats envenomed with natural and 60Co-irradiated bothropic venom

    Energy Technology Data Exchange (ETDEWEB)

    Lucas de Oliveira, P.C.; Madruga, R.A.; Barbosa, N.P.U. [Uberaba School of Veterinary Medicine (UNIUBE), MG (Brazil)]. E-mail: pedrolucaso@uol.com.br; Sakate, M. [UNESP, Botucatu, SP (Brazil). School of Veterinary Medicine and Animal Husbandry

    2007-07-01

    Venoms from snakes of the Bothrops genus are proteolytic, coagulant, hemorrhagic and nephrotoxic, causing edema, necrosis, hemorrhage and intense pain at the bite site, besides systemic alterations. Many adjuvants have been added to the venom used in the sensitization of antiserum-producer animals to increase antigenic induction and reduce the envenomation pathological effects. Gamma radiation from {sup 60}Co has been used as an attenuating agent of the venoms toxic properties. The main objective was to study, comparatively, clinical and laboratory aspects of goats inoculated with bothropic (Bothrops jararaca) venom, natural and irradiated from a {sup 60}Co source. Twelve goats were divided into two groups of six animals: GINV, inoculated with 0.5 mg/kg of natural venom; and GIIV, inoculated with 0.5 mg/kg of irradiated venom. Blood samples were collected immediately before and one, two, seven, and thirty days after venom injection. Local lesions were daily evaluated. The following exams were carried out: blood tests; biochemical tests of urea, creatinine, creatine kinase, aspartate amino-transferase and alanine amino-transferase; clotting time; platelets count; and total serum immunoglobulin measurement. In the conditions of the present experiment, irradiated venom was less aggressive and more immunogenic than natural venom. (author)

  18. Biochemical and hematological study of goats envenomed with natural and 60Co-irradiated bothropic venom

    International Nuclear Information System (INIS)

    Venoms from snakes of the Bothrops genus are proteolytic, coagulant, hemorrhagic and nephrotoxic, causing edema, necrosis, hemorrhage and intense pain at the bite site, besides systemic alterations. Many adjuvants have been added to the venom used in the sensitization of antiserum-producer animals to increase antigenic induction and reduce the envenomation pathological effects. Gamma radiation from 60Co has been used as an attenuating agent of the venoms toxic properties. The main objective was to study, comparatively, clinical and laboratory aspects of goats inoculated with bothropic (Bothrops jararaca) venom, natural and irradiated from a 60Co source. Twelve goats were divided into two groups of six animals: GINV, inoculated with 0.5 mg/kg of natural venom; and GIIV, inoculated with 0.5 mg/kg of irradiated venom. Blood samples were collected immediately before and one, two, seven, and thirty days after venom injection. Local lesions were daily evaluated. The following exams were carried out: blood tests; biochemical tests of urea, creatinine, creatine kinase, aspartate amino-transferase and alanine amino-transferase; clotting time; platelets count; and total serum immunoglobulin measurement. In the conditions of the present experiment, irradiated venom was less aggressive and more immunogenic than natural venom. (author)

  19. Intradermal injection of Bothrops cotiara venom in mice in an experimental wound model

    Directory of Open Access Journals (Sweden)

    JA Lopes

    2012-01-01

    Full Text Available Bothropic envenomation induces hemorrhage, coagulant disturbances and necrosis. Regarding therapies against the local damage caused by the venom, there is little information on tissue changes until the complete healing. In the current study, local damage was evaluated by examination of morphological inflammatory alterations, mast cell count, and analysis of collagen deposition. Bleeding was evident four hours after inoculation. After 24 hours, a large area of injury appeared presenting disorganized tissue, significant hemorrhage and acute inflammation. After three days, the damaged area was extensive, with a large amount of inflammatory cells and the presence of scab. In seven days, healing and reepithelization process started. And, 21 days later, the epithelium showed less infiltration and no skin appendages. The number of mast cells was similar to control after four hours, with a drop of 50% at 24 hours, followed by an increase until the 21st day. No differences of collagen deposition were observed among experimental groups. Taken together, wound healing after intradermal injection of Bothrops cotiara venom in mice follows similar parameters to wounds caused by other bothropic venoms. The present work reveals the importance of experimental wound models to the study of neutralizing agents against venom toxins.

  20. Effects of Schizolobium parahyba extract on experimental Bothrops venom-induced acute kidney injury.

    Directory of Open Access Journals (Sweden)

    Monique Silva Martines

    Full Text Available BACKGROUND: Venom-induced acute kidney injury (AKI is a frequent complication of Bothrops snakebite with relevant morbidity and mortality. The aim of this study was to assess the effects of Schizolobium parahyba (SP extract, a natural medicine with presumed anti-Bothrops venom effects, in an experimental model of Bothrops jararaca venom (BV-induced AKI. METHODOLOGY: Groups of 8 to 10 rats received infusions of 0.9% saline (control, C, SP 2 mg/kg, BV 0.25 mg/kg and BV immediately followed by SP (treatment, T in the doses already described. After the respective infusions, animals were assessed for their glomerular filtration rate (GFR, inulin clearance, renal blood flow (RBF, Doppler, blood pressure (BP, intra-arterial transducer, renal vascular resistance (RVR, urinary osmolality (UO, freezing point, urinary neutrophil gelatinase-associated lipocalin (NGAL, enzyme-linked immunosorbent assay [ELISA], lactate dehydrogenase (LDH, kinetic method, hematocrit (Hct, microhematocrit, fibrinogen (Fi, Klauss modified and blinded renal histology (acute tubular necrosis score. PRINCIPAL FINDINGS: BV caused significant decreases in GFR, RBF, UO, HcT and Fi; significant increases in RVR, NGAL and LDH; and acute tubular necrosis. SP did not prevent these changes; instead, it caused a significant decrease in GFR when used alone. CONCLUSION: SP administered simultaneously with BV, in an approximate 10∶1 concentration, did not prevent BV-induced AKI, hemolysis and fibrinogen consumption. SP used alone caused a decrease in GFR.

  1. Duvernoy's gland secretion of Philodryas olfersii and Philodryas patagoniensis (Colubridae): neutralization of local and systemic effects by commercial bothropic antivenom (Bothrops genus).

    Science.gov (United States)

    Rocha, Marisa M Teixeira; Paixão-Cavalcante, Danielle; Tambourgi, Denise V; Furtado, Maria de Fátima D

    2006-01-01

    Colubrids involved in human envenomation in Brazil are mainly from the genera Helicops, Oxyrhopus, Thamnodynastes and Philodryas. There is a relatively large number of clinical descriptions involving the Xenodontinae snakes, Philodryas olfersii and Philodryas patagoniensis, in human accidents. The most common manifestations of envenomation are local pain, swelling, erythema and ecchymosis and regional lymphadenopathy with normal coagulation. The aims of this study were to characterize the biochemical and biological properties of P. olfersii and P. patagoniensis venoms, and to investigate their immunological cross-reactivities by using both specific antisera and anti-Bothrops sp serum used for human serum therapy in Brazil, in neutralizing the lethal and hemorrhagic effects of these venoms. We show here that P. olfersii e P. patagoniensis venoms present proteolytic and haemorrhagic activities but are devoid of phospholipase A2 activity. Haemorrhage and lethality induced by P. olfersii and P. patagoniensis are associated with metal-dependent proteinases, since EDTA could block these toxic activities. P. olfersii and P. patagoniensis venoms were immunogenic and the antisera produced were able to recognize several bands in P. olfersii, P. patagoniensis venoms in Bothrops jararaca venom. PMID:16360723

  2. Acidente vascular cerebral hemorrágico associado à acidente ofídico por serpente do gênero bothrops: relato de caso Hemorrhagic stroke related to snakebite by bothrops genus: a case report

    Directory of Open Access Journals (Sweden)

    Amanda Silva Machado

    2010-10-01

    Full Text Available Este trabalho tem como objetivo relatar um caso de acidente vascular cerebral hemorrágico, associado à acidente ofídico por serpente do gênero bothrops e hipertensão arterial sistêmica grave. Apesar do ofidismo botrópico ser frequente no Estado do Pará, tais associações são incomuns, necessitando de uma abordagem especializada e precoce, visando menores complicações.This research reports a clinical case of hemorrhagic stroke due to envenomation by bothrops snakebite associated with severe hypertension. Although bothrops snakebites are frequent in the State of Pará, such associations are uncommon, requiring specialized and early management to avoid severe complications.

  3. [Pulmonary embolism and disseminated intravascular coagulation after being bitten by a Bothrops lanceolatus snake. Apropos of a case].

    Science.gov (United States)

    Estrade, G; Garnier, D; Bernasconi, F; Donatien, Y

    1989-11-01

    The authors report the case of a Bothrops lanceolatus snake bite complicated by severe pulmonary embolism a few hours after admission. This thromboembolic complication developed despite heparin therapy and was followed by disseminated intravascular coagulation (DIC). Vascular thrombosis and pulmonary embolism are rare after Bothrops lanceolatus snake bite as patients are usually hypocoagulable due to DIC. In this case, the thromboembolism was probably caused by the procoagulant effect of the thrombin-like enzymes of the snake venom which may have been injected directly into the vein of a young woman taking a contraceptive pill. A specific antivenin which has recently become available fort treatment may decrease the complications of Bothrops lanceolatus snake bite. PMID:2514645

  4. Venomics and antivenomics of Bothrops erythromelas from five geographic populations within the Caatinga ecoregion of northeastern Brazil.

    Science.gov (United States)

    Jorge, Roberta Jeane B; Monteiro, Helena S A; Gonçalves-Machado, Larissa; Guarnieri, Míriam C; Ximenes, Rafael M; Borges-Nojosa, Diva M; Luna, Karla P de O; Zingali, Russolina B; Corrêa-Netto, Carlos; Gutiérrez, José María; Sanz, Libia; Calvete, Juan J; Pla, Davinia

    2015-01-30

    The Caatinga lancehead, Bothrops erythromelas, is a medically relevant species, responsible for most of the snakebite accidents in most parts of its distribution range in northeastern Brazil. The spectrum and geographic variability of its venom toxins were investigated applying a venomics approach to venom pools from five geographic areas within the Caatinga ecoregion. Despite its wide habitat, populations of B. erythromelas from Ceará, Pernambuco, Juazeiro, Paraiba, and Ilha de Itaparica exhibit highly conserved venom proteomes. Mirroring their compositional conservation, the five geographic venom pools also showed qualitatively and quantitatively overlapping antivenomic profiles against antivenoms generated in Vital Brazil (BR) and Clodomiro Picado (CR) Institutes, using different venoms in the immunization mixtures. The paraspecificity exhibited by the Brazilian SAB and the Costa Rican BCL antivenoms against venom toxins from B. erythromelas indicates large immunoreactive epitope conservation across genus Bothrops during the last ~14 million years, thus offering promise for the possibility of generating a broad-spectrum bothropic antivenom. Biological Significance Accidental snakebite envenomings represent an important public health hazard in Brazil. Ninety per cent of the yearly estimated 20-30,000 snakebite accidents are caused by species of the Bothrops genus. Bothrops erythromelas, a small, moderately stocky terrestrial venomous snake, is responsible for most of the snakebite accidents in its broad distribution range in the Caatinga, a large ecoregion in northeastern Brazil. To gain a deeper insight into the spectrum of medically important toxins present in the venom of the Caatinga lancehead, we applied a venomics approach to define the proteome and geographic variability of adult B. erythromelas venoms from five geographic regions. Although intraspecific compositional variation between venoms among specimens from different geographic regions has long been

  5. Pharmacological characterization of the rat paw edema induced by Bothrops lanceolatus (Fer de lance) venom.

    Science.gov (United States)

    de Faria L; Antunes, E; Bon, C; de Araújo, A L

    2001-06-01

    The inflammatory response induced by Bothrops lanceolatus venom (BLV) in the rat hind-paw was studied measuring paw edema. Non-heated BLV (75microg/paw) caused a marked paw edema accompanied by intense haemorrhage whereas heated venom (97 degrees C, 30s; 12.5-100microg/paw) produced a dose- and time-dependent non-haemorrhagic edema. The response with heated BLV was maximal within 15min disappearing over 24h. Heated venom was then routinely used at the dose of 75microg/paw. The prostacyclin analogue iloprost (0.1microg/paw) potentiated by 125% the venom-induced edema. The histamine H(1) receptor antagonist mepyramine (6mg/kg) or the serotonin/histamine receptor antagonist cyproheptadine (6mg/kg) partially inhibited BLV-induced edema whereas the combination of both compounds virtually abolished the edema. The lipoxygenase inhibitor BWA4C (10mg/kg), but not the cyclooxygenase inhibitor indomethacin (10mg/kg), significantly inhibited the edema (35% reduction; P<0.05). Dexamethasone (1mg/kg) also markedly (P<0.001) reduced venom-induced edema. The bradykinin B(2) receptor antagonist Hoe 140 (0.6mg/kg) reduced by 30% (P<0.05) the venom induced edema, whereas the angiotensin-converting enzyme inhibitor captopril (300microg/paw) potentiated by 42% (P<0.05) the edema. Bothrops lanceolatus antivenon (anti-BLV) reduced by 28% (P<0.05) the venom-induced edema while intravenous administration of antivenom failed to affect the edema. In conclusion, BLV-induced rat paw edema involves mast cell degranulation causing local release of histamine and serotonin, a phenomenon mediated mainly by kinins and lipoxygenase metabolites. Additionally, the use of a specific Bothrops lanceolatus antivenom, given subplantarily or intravenously, revealed to be little effective to prevent BLV-induced edema. PMID:11137542

  6. Thrombin-like activity in snake venoms from Peruvian Bothrops and Lachesis genera.

    Science.gov (United States)

    Orejuela, P; Zavaleta, A; Salas, M; Marsh, N

    1991-01-01

    Venoms from Lachesis muta muta, Bothrops pictus, B. barnetti, B. atrox and B. hyoprorus coagulate in vitro canine fibrinogen, and both bovine fibrinogen and bovine plasma. B. barnetti and L. muta muta venoms have greater activity on canine fibrinogen and B. atrox and B. hyoprorus venoms, a greater activity on bovine fibrinogen. Gel filtration showed one peak of coagulant activity in all venoms except B. atrox venom which possessed two peaks. The apparent mol. wt of these enzymes ranged from 45,000 to 69,000. PMID:1796478

  7. Inactivation and fragmentation of lectin from Bothrops leucurus snake venom by gamma irradiation

    Science.gov (United States)

    Nunes, E. S.; Souza, M. A. A.; Vaz, A. F. M.; Coelho, L. C. B. B.; Aguiar, J. S.; Silva, T. G.; Guarnieri, M. C.; Melo, A. M. M. A.; Oliva, M. L. V.; Correia, M. T. S.

    2012-04-01

    Gamma radiation alters the molecular structure of biomolecules and is able to mitigate the action of snake venoms and their isolated toxins. The effect of γ-radiation on the folding of Bothrops lecurus venom lectin was measured by a hemagglutinating assay, intrinsic and bis-ANS fluorescence. Intrinsic and bis-ANS fluorescence analyses indicated that irradiation caused unfolding followed by aggregation of the lectin. Our results suggest that irradiation can lead to significant changes in the protein structure, which may promote the loss of its binding property and toxic action.

  8. Variação entre filhotes de representantes do complexo Bothrops newied (Serpentes, Viperidae, Crotalinae

    Directory of Open Access Journals (Sweden)

    Vinícius Xavier

    2002-01-01

    Full Text Available External morphological characters of 141 young specimens (69 males and 72 femalesof the Bothrops newied complex were analyzed. Regression analysis was used in the study of morphometric characters and principal components analysis was used in the study of meristic and qualitative characters. Sexual dimorphism was confirmed in the meristic and morphometric characters. Males showed higher counts of subcaudals and longer tails. Females showed eventually higher number of ventrals and dorsal rows, and larger heads. Six different drawing patterns were diagnosed and can indicate the existence of different species. Ontogenetic variation was described.

  9. ACUTE-PHASE REACTIONS, INCLUDING CYTOKINES, IN PATIENTS BITTEN BY BOTHROPS AND CROTALUS SNAKES IN BRAZIL

    OpenAIRE

    B. Barraviera; B. Lomonte; Tarkowski, A; L. Å. HANSON; D. A. Meira

    1995-01-01

    Thirty-one patients bitten by venomous snakes in Botucatu area (State of São Paulo - Brazil), sixteen by Bothrops spp. and fifteen by Crotalus durissus terrificus, were studied. The group comprised twenty-nine males and two females, ranging from fourteen to sixty-three years of age (mean 33 ± 15). Leukocytosis with neutrophilia and lymphopenia, increase of mucoproteins and C-reactive protein, decrease of total serum protein and albumin, were observed on the first day after the accident. In ad...

  10. Fatores associados à incoagulabilidade sangüínea no envenenamento por serpentes do gênero Bothrops Risk factors associated with coagulation abnormalities in Bothrops envenoming

    Directory of Open Access Journals (Sweden)

    Ricardo Borges de Oliveira

    2003-12-01

    Full Text Available Com o objetivo de conhecer fatores associados à incoagulabilidade sangüínea no envenenamento botrópico, foram obtidas informações de 2.991 prontuários médicos de pacientes atendidos no Instituto Butantan de 1981 a 1990. Associaram-se positivamente à incoagulabilidade sangüínea (p0,05: horário do acidente; presença de presa recém-deglutida no tubo digestivo da serpente; sexo e idade do paciente; ocorrência de bolha, necrose, abscesso e incisão local, amputação, insuficiência renal e óbito. Pode-se concluir que, embora a incoagulabilidade sangüínea apresente associação com manifestações precoces do envenenamento, não tem boa associação com a evolução clínica do paciente.This study aimed at assessing, in the envenoming by Bothrops, factors that are associated with blood incoagulability. Information was obtained from the charts of 2,991 patients admitted to Instituto Butantan, from 1981 to 1990. Factors positively associated with blood incoagulability (p0.05 were: time of the bite; presence of recently swallowed prey in the snake gut; gender and age of the patient; blister, necrosis, and abscess at the bite site; occurrence of amputation, renal failure and death; presence of an incision at the bite site. We conclude that although blood incoagulability is associated with early manifestations of Bothrops envenoming, it is not associated with the clinical outcome.

  11. Snake venomics of the Lesser Antillean pit vipers Bothrops caribbaeus and Bothrops lanceolatus: correlation with toxicological activities and immunoreactivity of a heterologous antivenom.

    Science.gov (United States)

    Gutiérrez, José María; Sanz, Libia; Escolano, José; Fernández, Julián; Lomonte, Bruno; Angulo, Yamileth; Rucavado, Alexandra; Warrell, David A; Calvete, Juan J

    2008-10-01

    The venom proteomes of the snakes Bothrops caribbaeus and Bothrops lanceolatus, endemic to the Lesser Antillean islands of Saint Lucia and Martinique, respectively, were characterized by reverse-phase HPLC fractionation, followed by analysis of each chromatographic fraction by SDS-PAGE, N-terminal sequencing, MALDI-TOF mass fingerprinting, and collision-induced dissociation tandem mass spectrometry of tryptic peptides. The venoms contain proteins belonging to seven ( B. caribbaeus) and five ( B. lanceolatus) types of toxins. B. caribbaeus and B. lanceolatus venoms contain phospholipases A 2, serine proteinases, l-amino acid oxidases and zinc-dependent metalloproteinases, whereas a long disintegrin, DC-fragments and a CRISP molecule were present only in the venom of B. caribbaeus, and a C-type lectin-like molecule was characterized in the venom of B. lanceolatus. Compositional differences between venoms among closely related species from different geographic regions may be due to evolutionary environmental pressure acting on isolated populations. The venoms of these two species differed in the composition and the relative abundance of their component toxins, but they exhibited similar toxicological and enzymatic profiles in mice, characterized by lethal, hemorrhagic, edema-forming, phospholipase A 2 and proteolytic activities. The venoms of B. caribbaeus and B. lanceolatus are devoid of coagulant and defibrinogenating effects and induce only mild local myotoxicity in mice. The characteristic thrombotic effect described in human envenomings by these species was not reproduced in the mouse model. The toxicological profile observed is consistent with the abundance of metalloproteinases, PLA 2s and serine proteinases in the venoms. A polyvalent (Crotalinae) antivenom produced in Costa Rica was able to immunodeplete approximately 80% of the proteins from both B. caribbaeus and B. lanceolatus venoms, and was effective in neutralizing the lethal, hemorrhagic, phospholipase

  12. Preliminary studies of the effects of a Peruvian snake Bothrops pictus (jergon of the coast) venom upon fibrinogen.

    Science.gov (United States)

    Olascoaga, M E; Zavaleta, A; Marsh, N A

    1988-01-01

    Bothrops pictus (jergon of the coast) venom has a coagulant effect in vitro on both canine fibrinogen and on human and canine plasma, with a greater affinity for canine plasma. In vivo a single dose of venom produced partial defibrinogenation in conscious dogs, plasma fibrinogen being reduced to about 60% of control values after 6 hr. PMID:3188056

  13. Biological and immunological properties of the venom of Bothrops alcatraz, an endemic species of pitviper from Brazil.

    Science.gov (United States)

    Furtado, M F D

    2005-06-01

    Bothrops alcatraz is a new pitviper species derived from the Bothrops jararaca group, whose natural habitat is situated in Alcatrazes Archipelago, a group of marine islands near São Paulo State coast in Brazil. Herein, the biological and biochemical properties of venoms of four adult specimens of B. alcatraz were examined comparatively to a reference pool of Bothrops jararaca venom. Both venoms showed similar activities and electrophoretic patterns, but B. alcatraz venom showed three protein bands of molecular masses of 97, 80 and 38 kDa that were not present in B. jararaca reference venom. The i.p. median lethal dose of B. alcatraz venom ranged from 5.1 to 6.6 mg/kg, while it was 1.5 mg/kg for B. jararaca venom. The minimum hemorrhagic dose of B. jararaca venom was 0.63, whereas 2.28 mug/mouse for B. alcatraz venom. In contrast, B. alcatraz venom was more potent in regard to procoagulant and proteolytic activities. These differences were supported by western blotting and neutralization tests, employing commercial bothropic antivenom, which showed that hemorrhagic and lethal activities of B. alcatraz venom were less effectively inhibited than B. jararaca venom. Such results evidence that B. alcatraz shows quantitative and qualitative differences in venom composition in comparison with its B. jararaca relatives, which might represent an optimization of venom towards a specialized diet. PMID:16002343

  14. Purification and biological effects of a C-type lectin isolated from Bothrops moojeni

    Directory of Open Access Journals (Sweden)

    PSF Barbosa

    2010-01-01

    Full Text Available Snake venom proteins from the C-type lectin family have very distinct biological activities despite their highly conserved primary structure, which is homologous to the carbohydrate recognition region of true C-type lectins. We purified a lectin-like protein (BmLec from Bothrops moojeni venom and investigated its effect on platelet aggregation, insulin secretion, antibacterial activity, and isolated kidney cells. The BmLec was purified using two chromatographic steps: affinity chromatography and reverse phase high performance liquid chromatography (HPLC. BmLec showed a dose-dependent platelet aggregation and significantly decreased the bacterial growth rate in approximately 15%. During scanning electron microscopy, the profile of Xanthomonas axonopodis pv. passiflorae treated with lectin disclosed a high vesiculation and membrane rupture. BmLec induced a strong and significant increase in insulin secretion at 2.8 and 16.7 mM glucose concentrations, and this effect was seen in the presence of EGTA in both experiments. BmLec (10 µg/mL increased the perfusion pressure, renal vascular resistance and urinary flow. The glomerular filtration rate and percentages of sodium, potassium and chloride tubular transport were reduced at 60 minutes of perfusion. Renal alterations caused by BmLec were completely inhibited by indomethacin in all evaluated parameters. In conclusion, the C-type lectin isolated from Bothrops moojeni affected platelet aggregation, insulin secretion, antibacterial activity and isolated kidney function.

  15. Effects of Co60 gamma radiation on the immunogenic and antigenic properties of Bothrops jararacussu venom

    International Nuclear Information System (INIS)

    Ionizing radiation has been successfully employed to attenuate animals toxins and venoms for immunizing antisera producing animals. However, the radiation effects on antigenicity and immunogenecity have not yet been elucidated. In the present work, we investigated the effects of gamma rays on the antigenic and immunogenicity have not yet been elucidated. In the present work, we investigated the effects of gamma rays on the antigenic and immunogenic behaviour of Bothrops jararacussu venon. Venom samples (2mg/ml in 150 mM NaCl) were irradiated with 500, 1000 and 2000 Gy of 60 Co gamma rays. These samples were submitted to antigen capture ELISA on plates coated with commercial bothropic antiserum. Results suggest a loss of reactivity of the 1000 and 2000 Gy irradiated samples. Antibodies against native and 2000 Gy irradiated venoms were produced in rabbits. Both sera able to bind native venom with a slightly higher titer for anti-irradiated serum. These data suggest that radiation promoted structural modification on the antigen molecules. However since the antibodies produced against irradiated antivenom were able to recognize native venom, there must have been preservation of some antigenic determinants. It has already been demosntrated that irradiation of proteins leads to structural modifications and unfolding of the molecules. Our data suggest that irradiation led to conformational epitopes destruction with preservation of linear epitopes and that the response against irradiated venom may be attributed to these linear antigenic determinants. (author). 8 refs., 3 figs

  16. The Triterpenoid Betulin Protects against the Neuromuscular Effects of Bothrops jararacussu Snake Venom In Vivo

    Directory of Open Access Journals (Sweden)

    Miriéle Cristina Ferraz

    2015-01-01

    Full Text Available We confirmed the ability of the triterpenoid betulin to protect against neurotoxicity caused by Bothrops jararacussu snake venom in vitro in mouse isolated phrenic nerve-diaphragm (PND preparations and examined its capability of in vivo protection using the rat external popliteal/sciatic nerve-tibialis anterior (EPSTA preparation. Venom caused complete, irreversible blockade in PND (40 μg/mL, but only partial blockade (~30% in EPSTA (3.6 mg/kg, i.m. after 120 min. In PND, preincubation of venom with commercial bothropic antivenom (CBA attenuated the venom-induced blockade, and, in EPSTA, CBA given i.v. 15 min after venom also attenuated the blockade (by ~70% in both preparations. Preincubation of venom with betulin (200 μg/mL markedly attenuated the venom-induced blockade in PND; similarly, a single dose of betulin (20 mg, i.p., 15 min after venom virtually abolished the venom-induced decrease in contractility. Plasma creatine kinase activity was significantly elevated 120 min after venom injection in the EPSTA but was attenuated by CBA and betulin. These results indicate that betulin given i.p. has a similar efficacy as CBA given i.v. in attenuating the neuromuscular effects of B. jararacussu venom in vivo and could be a useful complementary measure to antivenom therapy for treating snakebite.

  17. In vitro hemolytic activity of Bothrops lanceolatus (fer-de-lance venom

    Directory of Open Access Journals (Sweden)

    LJ Martins

    2009-01-01

    Full Text Available Bothrops lanceolatus venom contains a variety of enzymatic and biological activities. The present work investigated the hemolytic activity of this venom and its phospholipase A2 (PLA2. Bothrops lanceolatus venom (6.7 µg/mL caused indirect hemolysis of cow, horse, rat and sheep erythrocytes, with horse erythrocytes being the most sensitive; no direct hemolysis was observed. Hemolysis in sheep erythrocytes was concentration-dependent (5-11.7 µg/mL and markedly attenuated by heating the venom for 30 minutes at ≥ 40°C and by the PLA2 inhibitor p-bromophenacyl bromide. An acidic PLA2 (5 µg/mL purified from B. lanceolatus venom also caused hemolysis. This PLA2 showed immunoprecipitin lines with antivenom against B. lanceolatus, which suggests that the enzymatic and hemolytic activities of this enzyme may be neutralized during antivenom therapy. These results indicate that B. lanceolatus venom and its PLA2 can cause hemolysis in vitro.

  18. Screening of Bothrops snake venoms for L-amino acid oxidase activity

    Energy Technology Data Exchange (ETDEWEB)

    Pessati, M.L.; Fontana, J.D.; Guimaraes, M.F. [Federal Univ. of Parana, Curitiba (Brazil)

    1995-12-31

    Toxins, enzymes, and biologically active peptides are the main components of snake venoms from the genus Bothrops. Following the venom inoculation, the local effects are hemorrhage, edema, and myonecrosis. Nineteen different species of Brazilian Bothrops were screened for protein content and L-amino acid oxidase activity. B. cotiara, formerly found in the South of Brazil, is now threatened with extinction. Its venom contains a highly hemorrhagic fraction and, as expected from the deep yellow color of the corresponding lyophilized powder, a high L-amino acid oxidase (LAO) activity was also characterized. Flavin adenine dinucleotide (FAD) is its associate coenzyme. B. cotiara venom LAO catalyzed the oxidative deamination of several L-amino acids, and the best substrates were methionine, leucine, tryptophan, and phenylalanine, hence, its potential application for the use in biosensors for aspartame determination and for the removal of amino acids from plasma. High levels for LAO were also found in other species than B. cotiara. In addition, the technique of isoelectric focusing (IEF) was employed as a powerful tool to study the iso- or multi-enzyme distribution for LAO activity in the B. cotiara snake venom.

  19. Local inflammation, lethality and cytokine release in mice injected with Bothrops atrox venom

    Directory of Open Access Journals (Sweden)

    S. F. Barros

    1998-01-01

    Full Text Available We have provided evidence that: (a lethality of mice to crude Bothrops venom varies according the isogenic strain (A/J > C57Bl/6 > A/Sn > BALB/c > C3H/ HePas > DBA/2 > C3H/He; (bBALB/c mice (LD50=100.0 μg were injected i.p. with 50 μg of venom produced IL-6, IL-10, INF-γ, TNF-α and NO in the serum. In vitro the cells from the mice injected and challenged with the venom only released IL-10 while peritoneal macrophages released IL-10, INF-γ and less amounts of IL-6; (c establishment of local inflammation and necrosis induced by the venom, coincides with the peaks of TNF-α, IFN-γ and NO and the damage was neutralized when the venom was incubated with a monoclonal antibody against a 60 kDa haemorrhagic factor. These results suggest that susceptibility to Bothrops a trox venom is genetically dependent but MHC independent; that IL-6, IL10, TNF-α, IFN-γ and NO can be involved in the mediation of tissue damage; and that the major venom component inducers of the lesions are haemorrhagins.

  20. Preclinical assessment of the neutralizing capacity of antivenoms produced in six Latin American countries against medically-relevant Bothrops snake venoms.

    Science.gov (United States)

    Segura, A; Castillo, M C; Núñez, V; Yarlequé, A; Gonçalves, L R C; Villalta, M; Bonilla, C; Herrera, M; Vargas, M; Fernández, M; Yano, M Y; Araújo, H P; Boller, M A A; León, P; Tintaya, B; Sano-Martins, I S; Gómez, A; Fernández, G P; Geoghegan, P; Higashi, H G; León, G; Gutiérrez, J M

    2010-11-01

    Species of the genus Bothrops induce the vast majority of snakebite envenomings in Latin America. A preclinical study was performed in the context of a regional network of public laboratories involved in the production, quality control and development of antivenoms in Latin America. The ability of seven polyspecific antivenoms, produced in Argentina, Brazil, Peru, Bolivia, Colombia and Costa Rica, to neutralize lethal, hemorrhagic, coagulant, defibrinogenating and myotoxic activities of the venoms of Bothrops neuwiedi (diporus) (Argentina), Bothrops jararaca (Brazil), B. neuwiedi (mattogrossensis) (Bolivia), Bothrops atrox (Peru and Colombia) and Bothrops asper (Costa Rica) was assessed using standard laboratory tests. Despite differences in the venom mixtures used in the immunization of animals for the production of these antivenoms, a pattern of extensive cross-neutralization was observed between these antivenoms and all the venoms tested, with quantitative differences in the values of effective doses. This study reveals the capacity of these antivenoms to neutralize, in preclinical tests, homologous and heterologous Bothrops venoms in Central and South America, and also highlight quantitative differences in the values of Median Effective Doses (ED50s) between the various antivenoms. PMID:20621114

  1. Purification, crystallization and preliminary X-ray diffraction analysis of a class P-III metalloproteinase (BmMP-III) from the venom of Bothrops moojeni

    International Nuclear Information System (INIS)

    The P-III metalloproteinase from B. moojeni was crystallized and diffraction data were collected to a maximum resolution of 3.3 Å. Snake-venom metalloproteinases (SVMPs) comprise a family of haemostatically active toxins which can cause haemorrhage, coagulopathy, inhibition of platelet aggregation and inflammatory response. These effects are attributed to the proteolytic action of SVMPs on extracellular matrix components, plasma proteins and cell-surface proteins. SVMPs are classified into four classes (P-I to P-IV) based on their domain structures. In order to understand the multiple roles played by the domains of P-III SVMPs, a P-III SVMP (BmMP-III) from the venom of Bothrops moojeni was purified, characterized and crystallized. The crystals belonged to space group I4122, with unit-cell parameters a = b = 108.16, c = 196.09 Å. Initially, flash-cooled crystals diffracted poorly to a resolution of about 10 Å. However, a significant improvement in the diffraction resolution was observed upon annealing and a complete data set was collected to 3.3 Å resolution. The asymmetric unit contained one molecule and the structure was determined and partially refined to an R factor of 34%. Structural comparisons indicated that the cysteine-rich domain can adopt different conformations in relation to the catalytic domain, which may modulate the enzyme activity

  2. Cross-reactivity and phospholipase A2 neutralization of anti-irradiated Bothrops jararaca venom antibodies

    International Nuclear Information System (INIS)

    The detoxified Bothrops jararaca venom, immunized rabbits with the toxoid obtained and investigated cross-reactivity of the antibodies obtained against autologous and heterelogous venoms was presented. It was also investigated the ability of the IgGs, purified by affinity chromatography, from those sera to neutralize phospholipase. A2, an ubiquous enzyme in animal venoms. Results indicate that venom irradiation leads to an attenuation of toxicity of 84%. Cross-reactivity was investigated by ELISA and Western blot and all venoms were reactive to the antibodies. On what refers to phospholipase A2 activity neutralization, the antibodies neutralized autologous venoms efficiently and, curiously, other venoms from the same genus were not neutralized, while Lachesis muta venom, a remote related specier, was neutralized by this serum. These data suggest that irradiation preserve important epitopes for induction of neutralizing antibodies and that these epitopes are not shared by all venoms assayed. (author). 8 refs, 2 figs, 3 tabs

  3. Bothrops pauloensis snake venom toxins: the search for new therapeutic models.

    Science.gov (United States)

    Rodrigues, Veridiana M; Lopes, Daiana S; Castanheira, Leticia E; Gimenes, Sarah N C; Naves de Souza, Dayane L; Ache, David C; Borges, Isabela P; Yoneyama, Kelly A G; Rodrigues, Renata S

    2015-01-01

    Snake venoms constitute a mixture of bioactive components that are involved not only in envenomation pathophysiology but also in the development of new drugs to treat many diseases. Different enzymatic and non-enzymatic proteins, such as phospholipases A2, hyaluronidases, L-amino acid oxidases, metalloproteinases, serine proteinases, lectins and disintegrins have been isolated and their functional and structural properties described in the literature. Many of these studies have also explored their medicinal potential focusing mainly on anticancer, antithrombotic and microbicide therapies. Bothrops pauloensis is a species found in Brazil, whose venom has been the focus of our studies in order to explore the biochemical and functional characteristics of their components. In this review, we have presented the main results of years of research on different toxins from B. pauloensis emphasizing their therapeutic potential. Studies concerning snake venom toxins to search for new therapeutic models open perspectives for new drug discovery. PMID:25686731

  4. Glial cells of the central nervous system of Bothrops jararaca (Reptilia, Ofidae: an ultrastructural study

    Directory of Open Access Journals (Sweden)

    Eduardo F. Bondan

    2015-07-01

    Full Text Available Abstract Although ultrastructural characteristics of mature neuroglia in the central nervous system (CNS are very well described in mammals, much less is known in reptiles, especially serpents. In this context, two specimens of Bothrops jararaca were euthanized for morphological analysis of CNS glial cells. Samples from telencephalon, mesencephalon and spinal cord were collected and processed for light and transmission electron microscopy investigation. Astrocytes, oligodendrocytes, microglial cells and ependymal cells, as well as myelin sheaths, presented similar ultrastructural features to those already observed in mammals and tended to maintain their general aspect all over the distinct CNS regions observed. Morphological similarities between reptilian and mammalian glia are probably linked to their evolutionary conservation throughout vertebrate phylogeny.

  5. Molecular Cloning and Pharmacological Properties of an Acidic PLA2 from Bothrops pauloensis Snake Venom

    Directory of Open Access Journals (Sweden)

    Francis Barbosa Ferreira

    2013-12-01

    Full Text Available In this work, we describe the molecular cloning and pharmacological properties of an acidic phospholipase A2 (PLA2 isolated from Bothrops pauloensis snake venom. This enzyme, denominated BpPLA2-TXI, was purified by four chromatographic steps and represents 2.4% of the total snake venom protein content. BpPLA2-TXI is a monomeric protein with a molecular mass of 13.6 kDa, as demonstrated by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF analysis and its theoretical isoelectric point was 4.98. BpPLA2-TXI was catalytically active and showed some pharmacological effects such as inhibition of platelet aggregation induced by collagen or ADP and also induced edema and myotoxicity. BpPLA2-TXI displayed low cytotoxicity on TG-180 (CCRF S 180 II and Ovarian Carcinoma (OVCAR-3, whereas no cytotoxicity was found in regard to MEF (Mouse Embryonic Fibroblast and Sarcoma 180 (TIB-66. The N-terminal sequence of forty-eight amino acid residues was determined by Edman degradation. In addition, the complete primary structure of 122 amino acids was deduced by cDNA from the total RNA of the venom gland using specific primers, and it was significantly similar to other acidic D49 PLA2s. The phylogenetic analyses showed that BpPLA2-TXI forms a group with other acidic D49 PLA2s from the gender Bothrops, which are characterized by a catalytic activity associated with anti-platelet effects.

  6. Isolation and biological characterization of a basic phospholipase A2 from Bothrops jararacussu snake venom

    Directory of Open Access Journals (Sweden)

    S.L. Maruñak

    2007-12-01

    Full Text Available A phospholipase A2 has been isolated from Bothrops jararacussu venom from snakes that inhabit the northeast region of Argentina. The present study describes in vivo and in vitro biological activities of phospholipase A2 from B. jararacussu as well as isolation details of its. Venom was obtained by milking of adult snakes which were housing in wood reptile cages of varying dimensions in heated (20-30ºC rooms. Snakes received a weekly diet of mice and water was available ad libitum for drinking and soaking. The enzyme was purified by gel filtration on a Sephadex G-75 column followed by ion exchange chromatography on a SP-Sephadex C25 column. The major peak belonging to proteins was retained in the cation exchanger and then eluted using a concentration gradient of KCl that exhibited phospholipase activity. This basic PLA2 consists of a single polypeptide chain with a molecular mass of 15.6 kDa. It had a high indirect hemolytic activity and produced a significant paw edema reaction in mice. The enzyme showed a low lethality (LD50 148.6 mg when was administered i.p. but exhibited elevated myotoxic effects in vivo by increasing plasma CK activity of injected mice, corroborated results by the histological observations of samples of gastrocnemius muscle. Myonecrosis is the result of intense destruction of muscular fibers that involves local infiltration of inflammatory cells and leads to the highest peak of CK level just after 1 hour mice injection. Moreover, the isolated enzyme showed anticoagulant activity, evaluated on sheep platelet-poor plasma which recalcification time was prolonged after incubation with the isolated phospholipase A2. These findings showed that this phospholipase, isolated by only two simple chromatographic steps, possesses high edematogenic and myotoxic activities. However, despite the low lethal activity, this enzyme would contribute markedly to the pathophysiology of the bothropic envenomation.

  7. Low-level laser therapy decreases local effects induced by myotoxins isolated from Bothrops jararacussu snake venom

    Directory of Open Access Journals (Sweden)

    AM Barbosa

    2010-01-01

    Full Text Available The prominent myotoxic effects induced by Bothrops jararacussu crude venom are due, in part, to its polycationic myotoxins, BthTX-I and BthTX-II. Both myotoxins have a phospholipase A2 structure: BthTX-II is an active enzyme Asp-49 PLA2, while BthTX-I is a Lys-49 PLA2 devoid of enzymatic activity. In this study, the effect of low-level laser therapy (LLLT, 685 nm laser at a dose of 4.2 J/cm2 on edema formation, leukocyte influx and myonecrosis caused by BthTX-I and BthTX-II, isolated from Bothrops jararacussu snake venom, was analyzed. BthTX-I and BthTX-II caused a significant edema formation, a prominent leukocyte infiltrate composed predominantly by neutrophils and myonecrosis in envenomed gastrocnemius muscle. LLLT significantly reduced the edema formation, neutrophil accumulation and myonecrosis induced by both myotoxins 24 hours after the injection. LLLT reduced the myonecrosis caused by BthTX-I and BthTX-II, respectively, by 60 and 43%; the edema formation, by 41 and 60.7%; and the leukocyte influx, by 57.5 and 51.6%. In conclusion, LLLT significantly reduced the effect of these snake toxins on the inflammatory response and myonecrosis. These results suggest that LLLT should be considered a potential therapeutic approach for treatment of local effects of Bothrops species venom.

  8. Phylogeography of the Bothrops jararaca complex (Serpentes: Viperidae): past fragmentation and island colonization in the Brazilian Atlantic Forest.

    Science.gov (United States)

    Grazziotin, Felipe G; Monzel, Markus; Echeverrigaray, Sergio; Bonatto, Sandro L

    2006-11-01

    The Brazilian Atlantic Forest is one of the world's major biodiversity hotspots and is threatened by a severe habitat loss. Yet little is known about the processes that originated its remarkable richness of endemic species. Here we present results of a large-scale survey of the genetic variation at the mitochondrial cytochrome b gene of the pitviper, jararaca lancehead (Bothrops jararaca), and two closely related insular species (Bothrops insularis and Bothrops alcatraz), endemic of this region. Phylogenetic and network analyses revealed the existence of two well-supported clades, exhibiting a southern and a northern distribution. The divergence time of these two phylogroups was estimated at 3.8 million years ago, in the Pliocene, a period of intense climatic changes and frequent fragmentation of the tropical rainforest. Our data also suggest that the two groups underwent a large size expansion between 50,000 and 100,000 years ago. However, the southern group showed a more marked signal of population size fluctuation than the northern group, corroborating evidences that southern forests may have suffered a more pronounced reduction in area in the late Pleistocene. The insular species B. alcatraz and B. insularis presented very low diversity, each one sharing haplotypes with mainland individuals placed in different subclades. Despite their marked morphological and behavioural uniqueness, these two insular species seem to have originated very recently and most likely from distinct costal B. jararaca populations, possibly associated with late Pleistocene or Holocene sea level fluctuations. PMID:17054497

  9. Purification of an acidic phospholipase A2 from Bothrops lanceolatus (fer de lance) venom: molecular and enzymatic properties.

    Science.gov (United States)

    de Araújo, A L; Radvanyi, F; Bon, C

    1994-09-01

    The acidic phospholipase A2 from Bothrops lanceolatus venom has been purified by gel filtration on Sephadex G-50 and ion exchange chromatography on CM-cellulose. Analysis by FPLC on Mono-Q column of the purified phospholipase A2 indicated that it is a mixture of several isoenzymes. The two major isoforms consist of a single polypeptide chain with mol. wts of 14,500 and 15,000, which slightly differ in their isoelectric point (4.9 and 5.3) and amino acid composition. However, enzymatic and pharmacological properties of the various isoenzymes are identical. The phospholipase from B. lanceolatus venom is characterized by a progressive increase in the rate of hydrolysis when enzymatic activity is determined with crude egg yolk as substrate in the absence of detergent. This phenomenon, which is not observed with mixed micelles of lecithin-detergent, is not due to the presence of a phospholipase A2 inhibitor in the venom, as previously suggested by several investigators in the case of other Bothrops and Cobra venoms. It is rather a catalytic characteristics of B. lanceolatus venom phospholipase, the enzymatic activity of which depends on the physical state of phospholipids. Bothrops lanceolatus acidic phospholipase A2 is non-toxic. PMID:7801343

  10. Myonecrosis induced in rat by a myotoxin isolated from the venom of Bothrops neuwiedifrom Alfenas, MG

    Directory of Open Access Journals (Sweden)

    V.L. Leite

    2001-01-01

    Full Text Available Bothrops venoms are composed by several protein fractions. Among these fractions there are myotoxins which induce an important muscle lesion. The purification of this component involves some steps, although providing a pure material, is time consuming. In the present study, we describe a quick method for myotoxin fraction isolation from the venom of Bolhrops nsuwiedi using one-step high performance liquid chromatography (HPLC. The complete procedure took 30 min. The pur6+y of the two myotoxic fractions isolated was assessed by SDS-PAGE. Upon i.m. injection into rat tibialis anterior, both toxins induced early morphological changes, indicating that the plasma membrane was the first cellular structure affected. Afterwards, the lesion was typically myonecrotic and inflammatory infiltrate was present.Os venenos de Bolhrops são compostos por várias frações protéicas. Dentre elas, as miotoxinas induzem lesões musculares importantes. A purificação deste componente envolve várias etapas e, embora forneça frações puras, é muito trabalhosa. Neste trabalho foi descrito um método rápido para o isolamento da fração miotóxica do veneno de Bothrops neuwiedi (jararaca pintada, utilizando-se uma etapa única de purificação por Cromatografia Liquida de Alta Eficiência (CLAE. O procedimento completo demorou apenas 30 min. Foram isoladas duas frações com atividade miotóxica, cuja pureza foi verificada por eletroforese em gel de poliacrilamida-SDS. A injeção intramuscular no músculo tibial anterior de ratos induziu alterações morfológicas precoces, indicando que a membrana plasmática foi a primeira estrutura celular afetada pela fração miotóxica. A lesão muscular obtida foi tipicamente mionecrótica e foi observado infiltrado inflamatório.

  11. IgG antibodies against phospholipase A2 from Crotalus durissus terrificus: cross-reaction with venoms from Bothrops species from Argentina

    OpenAIRE

    JP Rodríguez; MC De Marzi; S Maruñak; P Teibler; O Acosta; EL Malchiodi; LC Leiva

    2009-01-01

    We examined the ability of IgG anti-crotalic PLA2 to cross-react with Bothrops spp. venoms, from snakes found in the northeast of Argentina. Immunoblotting and ELISA tests showed that IgG anti-crotalic PLA2 recognize antigens of bothropic venoms. Indirect hemolytic activity tests showed that the quantity of antibodies that neutralized 50% of Crotalus durissus terrificus venom (ED50: 2.1 mg IgG anti-crotalic PLA2/100 µg of venom) were also able to neutralize venom from other snakes in the foll...

  12. Anti-parasitic effect on Toxoplasma gondii induced by BnSP-7, a Lys49-phospholipase A2 homologue from Bothrops pauloensis venom.

    Science.gov (United States)

    Borges, Isabela Pacheco; Castanheira, Letícia Eulalio; Barbosa, Bellisa Freitas; de Souza, Dayane Lorena Naves; da Silva, Rafaela José; Mineo, José Roberto; Tudini, Kelly Aparecida Yoneyama; Rodrigues, Renata Santos; Ferro, Eloísa Amália Vieira; de Melo Rodrigues, Veridiana

    2016-09-01

    Toxoplasmosis affects a third of the global population and presents high incidence in tropical areas. Its great relevance in public health has led to a search for new therapeutic approaches. Herein, we report the antiparasitic effects of BnSP-7 toxin, a Lys49 phospholipase A2 (PLA2) homologue from Bothrops pauloensis snake venom, on Toxoplasma gondii. In an MTT assay, BnSP-7 presented significant cytotoxicity against host HeLa cells at higher doses (200 μg/mL to 50 μg/mL), whereas lower doses (25 μg/mL to 1.56 μg/mL) produced low cytotoxicity. Furthermore, the toxin showed no effect on T. gondii tachyzoite viability when evaluated by trypan blue exclusion, but decreased both adhesion and parasite proliferation when tachyzoites were treated before infection. We also measured cytokines in supernatants collected from HeLa cells infected with T. gondii tachyzoites previously treated with RPMI or BnSP-7, which revealed enhancement of only MIF and IL-6 cytokines levels in supernatants of HeLa cells after BnSP-7 treatment. Our results showed that the BnSP-7 PLA2 exerts an anti-Toxoplasma effect at a lower dose than that required to induce cytotoxicity in HeLa cells, and also modulates the immune response of host cells. In this sense, the anti-parasitic effect of BnSP-7 PLA2 demonstrated in the present study opens perspectives for use of this toxin as a tool for future studies on toxoplasmosis. PMID:27212627

  13. Appraisal of antiophidic potential of marine sponges against Bothrops jararaca and Lachesis muta venom.

    Science.gov (United States)

    Faioli, Camila Nunes; Domingos, Thaisa Francielle Souza; de Oliveira, Eduardo Coriolano; Sanchez, Eládio Flores; Ribeiro, Suzi; Muricy, Guilherme; Fuly, Andre Lopes

    2013-10-01

    Snakebites are a health problem in many countries due to the high incidence of such accidents. Antivenom treatment has regularly been used for more than a century, however, this does not neutralize tissue damage and may even increase the severity and morbidity of accidents. Thus, it has been relevant to search for new strategies to improve antiserum therapy, and a variety of molecules from natural sources with antiophidian properties have been reported. In this paper, we analyzed the ability of ten extracts from marine sponges (Amphimedon viridis, Aplysina fulva, Chondrosia collectrix, Desmapsamma anchorata, Dysidea etheria, Hymeniacidon heliophila, Mycale angulosa, Petromica citrina, Polymastia janeirensis, and Tedania ignis) to inhibit the effects caused by Bothrops jararaca and Lachesis muta venom. All sponge extracts inhibited proteolysis and hemolysis induced by both snake venoms, except H. heliophila, which failed to inhibit any biological activity. P. citrina inhibited lethality, hemorrhage, plasma clotting, and hemolysis induced by B. jararaca or L. muta. Moreover, other sponges inhibited hemorrhage induced only by B. jararaca. We conclude that Brazilian sponges may be a useful aid in the treatment of snakebites caused by L. muta and B. jararaca and therefore have potential for the discovery of molecules with antiophidian properties. PMID:24141284

  14. INTRASPECIFIC VARIATION IN NEUROTOXIC AND MYOTOXIC ACTIVITIES OF Bothrops neuwiedii VENOMS

    Directory of Open Access Journals (Sweden)

    C. R. BORJA-OLIVEIRA

    2002-01-01

    Full Text Available Snake venoms frequently vary in composition. In this work, we compared the neurotoxic and myotoxic activities of 16 lots of Bothrops neuwiedii venoms from different regions of Brazil, using chick biventer cervicis preparations. The neuromuscular blockade varied from 2% to 100% after 120 min incubation with venoms (50 mug/ml. In all cases, this blockade was irreversible and concentration-dependent; at low concentrations (10-20 mug/ml, 15 of the 16 venom lots failed to abolish responses to acetylcholine (110 muM, but blocked responses to KCl (13.4 muM, and induced contracture. At 5-20 mug/ml, the most active venom totally blocked twitch-tension without affecting responses to acetylcholine and KCl. Polyacrylamide gel electrophoresis for basic proteins showed that the most active samples contained a band that was absent in the less active venoms. These results indicate that there may be considerable intraspecific variation in the neurotoxic activity of B. neuwiedii venoms, whereas myotoxic activity is less variable.

  15. The effects of low-level laser on muscle damage caused by Bothrops neuwiedi venom

    International Nuclear Information System (INIS)

    The present study aimed to assess the effects of low-level laser (660 nm) on myonecrosis caused by the insertion of Bothrops neuwiedi venom in the gastrocnemius muscle of rats. Male Wistar rats were divided into three groups (n = 24 each): Group S (0.9% saline solution); Group V (venom) and Group VLLL (venom plus low-level laser). These categories were subdivided into four additional groups (n = 6) based on the euthanasia timing (3 hours, 24 hours, 3 days and 7 days). The groups V and VLLL were inoculated with 100 μL of concentrated venom (40 μg/mL) in the gastrocnemius muscle. The muscle was irradiated using a gallium-aluminum-arsenide laser (GaAlAs) at 35 mW power and 4 J/cm2 energy density for 3 hours, 24 hours, 3 days or 7 days after venom inoculation. To evaluate the myotoxic activity of the venom, CK activity was measured and the muscle was histologically analyzed. The low-level laser reduced venom-induced CK activity in the groups euthanized at 3 hours, 24 hours and 3 days (p < 0.0001). Histological analysis revealed that low-level laser reduced neutrophilic inflammation as well as myofibrillar edema, hemorrhage and myonecrosis following B. neuwiedi envenomation. These results suggest that low-level laser can be useful as an adjunct therapy following B. neuwiedi envenomation. (author)

  16. Pulsed ultrasound therapy accelerates the recovery of skeletal muscle damage induced by Bothrops jararacussu venom

    Directory of Open Access Journals (Sweden)

    J. Saturnino-Oliveira

    2012-06-01

    Full Text Available We studied the effect of pulsed ultrasound therapy (UST and antibothropic polyvalent antivenom (PAV on the regeneration of mouse extensor digitorum longus muscle following damage by Bothrops jararacussu venom. Animals (Swiss male and female mice weighing 25.0 ± 5.0 g; 5 animals per group received a perimuscular injection of venom (1 mg/kg and treatment with UST was started 1 h later (1 min/day, 3 MHz, 0.3 W/cm², pulsed mode. Three and 28 days after injection, muscles were dissected and processed for light microscopy. The venom caused complete degeneration of muscle fibers. UST alone and combined with PAV (1.0 mL/kg partially protected these fibers, whereas muscles receiving no treatment showed disorganized fascicules and fibers with reduced diameter. Treatment with UST and PAV decreased the effects of the venom on creatine kinase content and motor activity (approximately 75 and 48%, respectively. Sonication of the venom solution immediately before application decreased the in vivo and ex vivo myotoxic activities (approximately 60 and 50%, respectively. The present data show that UST counteracts some effects of B. jararacussu venom, causing structural and functional improvement of the regenerated muscle after venom injury.

  17. Isolation, functional, and partial biochemical characterization of galatrox, an acidic lectin from Bothrops atrox snake venom

    Institute of Scientific and Technical Information of China (English)

    Elaine de Paula Mendonca-Franqueiro; Eliane Candiani Arantes; Marcelo Dias-Baruffi; Suely Vilela Sampaio; Raquel de Melo Alves-Paiva; Marco Aurélio Sartim; Daniel Roberto Callejon; Helder Henrique Paiva; Gilmara Ausech Antonucci; José César Rosa; Adélia Cristina Oliveira Cintra; Jo(a)o José Franco

    2011-01-01

    Snake venom lectins have been studied in regard to their chemical structure and biological functions. However, little is known about lectins isolated from Bothrops atrox snake venom. We report here the isolation and partial functional and biochemical characterization of an acidic glycanbinding protein called galatrox from this venom. This lectin was purified by affinity chromatography using a lactosyl-sepharose column, and its homogeneity and molecular mass were evaluated by high-performance liquid chromatography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry. The purified galatrox was homogeneous and characterized as an acidic protein (pI 5.2) with a monomeric and dimeric molecular mass of 16.2 and 32.5 kDa, respectively. Alignment of N-terminal and internal amino acid sequences of galatrox indicated that this protein exhibits high homology to other C-type snake venom lectins. Galatrox showed optimal hemagglutinating activity at a concentration of 100 μg/ml and this effect was drastically inhibited by lactose, ethylenediaminetetraacetic acid, and heating, which confirmed galatrox's lectin activity. While galatrox failed to induce the same level of paw edema or mast cell degranulation as B. atrox crude venom, galatrox did alter cellular viability,which suggested that galatrox might contribute to venom toxicity by directly inducing cell death.

  18. Detection of proteins antigenically related to Bothrops asper myotoxin in crotaline snake venoms.

    Science.gov (United States)

    Lomonte, B; Moreno, E; Gutiérrez, J M

    1987-01-01

    The presence of components antigenically related to Bothrops asper myotoxin was investigated by Western blotting and immunoelectrophoretic techniques. B. asper myotoxin is a non-glycosylated monomeric phospholipase A with a molecular weight by SDS-PAGE of 16,000 and isoelectric point of pH 9.8-10.0. Results showed that proteins in the venoms of B. nummifer, B. godmani, B. schlegelii, B. picadoi, and Agkistrodon bilineatus were recognized by monospecific antibodies to B. asper myotoxin raised in rabbit and sheep. Western blotting indicated that cross-reacting proteins have a molecular weight of 16,000, with the exception of that of B. picadoi, which is of 24,000 mol. wt. However, immunoelectrophoresis indicated that these components are highly heterogeneous in charge, ranging from basic to acidic proteins. The cross-reacting component(s) present in newborn B. asper venom has a different charge from that of the 'adult-type'. Venoms from newborn specimens showed an additional cross-reacting band of 18,000 mol. wt. Myotoxin is an abundant component in adult B. asper venom. Myotoxin-antimyotoxin complexes had different electrophoretic mobilities in rocket immunoelectrophoresis depending upon the species in which monospecific immune sera were produced. PMID:2448918

  19. Evaluation of anti-Bothrops asper venom activity of ethanolic extract of Brownea rosademonte leaves

    Directory of Open Access Journals (Sweden)

    Salazar Marcos

    2014-12-01

    Full Text Available Significant inhibition of the coagulant and hemorrhagic effects of Bothrops asper venom was demonstrated by ethanolic extract prepared from the leaves of Brownea rosademonte. In vitro experiments preincubating 5.5 mg of extract kg-1 b.m. for 30 min with a minimum hemorrhagic dose of venom (273.8 ± 16.1 μg of venom kg-1 b.m. lowered the hemorrhagic activity of the venom alone in CD-1 mice by 51.5 ± 2.6 %. Additionally, 1.7 mg extract L-1 plasma prolonged 5.1 times the plasma coagulation time. Fractionation of the extract led to the isolation of two compounds: ononitol (1 and quercetrin (2. The structure of compounds 1 and 2 was established by spectroscopic analyses, including APCI-HRMS and NMR (1H, 13C, HSQC, HMBC and COSY. A quercetrin concentration of 0.11 μmol L-1 prolonged the plasma coagulation time 2.6 times demonstrating that this compound was one of the active constituents of the Brownea rosademonte extract.

  20. The effects of low-level laser on muscle damage caused by Bothrops neuwiedi venom

    Directory of Open Access Journals (Sweden)

    DM Dourado

    2008-01-01

    Full Text Available The present study aimed to assess the effects of low-level laser (660 nm on myonecrosis caused by the insertion of Bothrops neuwiedi venom in the gastrocnemius muscle of rats. Male Wistar rats were divided into three groups (n = 24 each: Group S (0.9% saline solution; Group V (venom and Group VLLL (venom plus low-level laser. These categories were subdivided into four additional groups (n = 6 based on the euthanasia timing (3 hours, 24 hours, 3 days and 7 days. The groups V and VLLL were inoculated with 100 µL of concentrated venom (40 µg/mL in the gastrocnemius muscle. The muscle was irradiated using a gallium-aluminum-arsenide laser (GaAlAs at 35 mW power and 4 J/cm² energy density for 3 hours, 24 hours, 3 days or 7 days after venom inoculation. To evaluate the myotoxic activity of the venom, CK activity was measured and the muscle was histologically analyzed. The low-level laser reduced venom-induced CK activity in the groups euthanized at 3 hours, 24 hours and 3 days (p < 0.0001. Histological analysis revealed that low-level laser reduced neutrophilic inflammation as well as myofibrillar edema, hemorrhage and myonecrosis following B. neuwiedi envenomation. These results suggest that low-level laser can be useful as an adjunct therapy following B. neuwiedi envenomation.

  1. The effects of low-level laser on muscle damage caused by Bothrops neuwiedi venom

    Energy Technology Data Exchange (ETDEWEB)

    Dourado, D.M.; Matias, R.; Almeida, M.F.; Paula, K.R. de; Carvalho, P.T.C. [University for the Development of the State and of the Region of Pantanal (UNIDERP), Campo Grande, MS (Brazil). Lab. of Experimental Histopathology]. E-mail: ccfi@uniderp.br; Vieira, R.P. [University of Sao Paulo (USP), SP (Brazil). School of Medicine. Dept. of Pathology and Physical Therapy; Oliveira, L.V.F. [Nove de Julho University (UNINOVE), Sao Paulo, SP (Brazil). Masters Program in Rehabilitation Sciences

    2008-07-01

    The present study aimed to assess the effects of low-level laser (660 nm) on myonecrosis caused by the insertion of Bothrops neuwiedi venom in the gastrocnemius muscle of rats. Male Wistar rats were divided into three groups (n = 24 each): Group S (0.9% saline solution); Group V (venom) and Group VLLL (venom plus low-level laser). These categories were subdivided into four additional groups (n = 6) based on the euthanasia timing (3 hours, 24 hours, 3 days and 7 days). The groups V and VLLL were inoculated with 100 {mu}L of concentrated venom (40 {mu}g/mL) in the gastrocnemius muscle. The muscle was irradiated using a gallium-aluminum-arsenide laser (GaAlAs) at 35 mW power and 4 J/cm{sup 2} energy density for 3 hours, 24 hours, 3 days or 7 days after venom inoculation. To evaluate the myotoxic activity of the venom, CK activity was measured and the muscle was histologically analyzed. The low-level laser reduced venom-induced CK activity in the groups euthanized at 3 hours, 24 hours and 3 days (p < 0.0001). Histological analysis revealed that low-level laser reduced neutrophilic inflammation as well as myofibrillar edema, hemorrhage and myonecrosis following B. neuwiedi envenomation. These results suggest that low-level laser can be useful as an adjunct therapy following B. neuwiedi envenomation. (author)

  2. Appraisal of Antiophidic Potential of Marine Sponges against Bothrops jararaca and Lachesis muta Venom

    Directory of Open Access Journals (Sweden)

    Guilherme Muricy

    2013-10-01

    Full Text Available Snakebites are a health problem in many countries due to the high incidence of such accidents. Antivenom treatment has regularly been used for more than a century, however, this does not neutralize tissue damage and may even increase the severity and morbidity of accidents. Thus, it has been relevant to search for new strategies to improve antiserum therapy, and a variety of molecules from natural sources with antiophidian properties have been reported. In this paper, we analyzed the ability of ten extracts from marine sponges (Amphimedon viridis, Aplysina fulva, Chondrosia collectrix, Desmapsamma anchorata, Dysidea etheria, Hymeniacidon heliophila, Mycale angulosa, Petromica citrina, Polymastia janeirensis, and Tedania ignis to inhibit the effects caused by Bothrops jararaca and Lachesis muta venom. All sponge extracts inhibited proteolysis and hemolysis induced by both snake venoms, except H. heliophila, which failed to inhibit any biological activity. P. citrina inhibited lethality, hemorrhage, plasma clotting, and hemolysis induced by B. jararaca or L. muta. Moreover, other sponges inhibited hemorrhage induced only by B. jararaca. We conclude that Brazilian sponges may be a useful aid in the treatment of snakebites caused by L. muta and B. jararaca and therefore have potential for the discovery of molecules with antiophidian properties.

  3. The pharmacological effect of Bothrops neuwiedii pauloensis (jararaca-pintada snake venom on avian neuromuscular transmission

    Directory of Open Access Journals (Sweden)

    C.R. Borja-Oliveira

    2003-05-01

    Full Text Available The neuromuscular effects of Bothrops neuwiedii pauloensis (jararaca-pintada venom were studied on isolated chick biventer cervicis nerve-muscle preparations. Venom concentrations of 5-50 µg/ml produced an initial inhibition and a secondary increase of indirectly evoked twitches followed by a progressive concentration-dependent and irreversible neuromuscular blockade. At venom concentrations of 1-20 µg/ml, the responses to 13.4 mM KCl were inhibited whereas those to 110 µM acetylcholine alone and cumulative concentrations of 1 µM to 10 mM were unaffected. At venom concentrations higher than 50 µg/ml, there was pronounced muscle contracture with inhibition of the responses to acetylcholine, KCl and direct stimulation. At 20-24ºC, the venom (50 µg/ml produced only partial neuromuscular blockade (30.7 ± 8.0%, N = 3 after 120 min and the initial inhibition and the secondary increase of the twitch responses caused by the venom were prolonged and pronounced and the response to KCl was unchanged. These results indicate that B.n. pauloensis venom is neurotoxic, acting primarily at presynaptic sites, and that enzyme activity may be involved in this pharmacological action.

  4. The crystal structure of a phospholipase-like from Bothrops godmani venom

    International Nuclear Information System (INIS)

    Full text. Phospho lipases A2 are common components of bothropic venoms responsible for disruption of the cell membrane integrity via hydrolysis of its phospholipids, culminating with cell death. These enzymes have an Asp at position 49 (D49) which is a part of the Ca++ loop which promotes the catalytic activity on phosphatidylcholine (lecithin) from egg yolk. More recently however, a new class of PLA2-like proteins has been described which, although devoid of PLA2 activity on phosphatidylcholine, due to a mutation D49K, are still highly myonecrotic, their effect being Ca++ independent and still not completely understood. In this work we show the X-ray structure determination and refinement process of this toxin. The crystals were obtained by hanging drop, a vapour diffusion method. The data collection was made using a image plate detector R-AXIS IIC from RIGAKU (IFSC/USP), Cu Kα radiation at room temperature. Data was collected up to 2.8 A resolution and the merging of all equivalent reflections resulted in a dataset which is about 80 % complete. The crystals belong to the space group P43212 with cell constants a= b=60.56 A and c=84.72 A. The structure was solved by Molecular Replacement method using AMORE program. The structure refinement process have been made using he X-PLOR program; the final R-factor was 17.9 % and free R-factor is 25.8 % including 69 water molecules. (author)

  5. Purification and functional characterization of a new metalloproteinase (BleucMP) from Bothrops leucurus snake venom.

    Science.gov (United States)

    Gomes, Mário Sérgio R; de Queiroz, Mayara R; Mamede, Carla C N; Mendes, Mirian M; Hamaguchi, Amélia; Homsi-Brandeburgo, Maria I; Sousa, Marcelo V; Aquino, Elaine Nascimento; Castro, Mariana S; de Oliveira, Fábio; Rodrigues, Veridiana M

    2011-04-01

    A fibrino(geno)lytic nonhemorrhagic metalloproteinase (BleucMP) was purified from Bothrops leucurus snake venom by two chromatographic steps procedure on DEAE-Sephadex A-25 followed by CM-Sepharose Fast Flow column. BleucMP represented 1.75% (w/w) of the crude venom and was homogeneous on SDS-PAGE. BleucMP analyzed by MALDI TOF/TOF, showed a molecular mass of 23,057.54Da and when alkylated and reduced, the mass is 23,830.40Da. Their peptides analyzed in MS (MALDI TOF\\TOF) showed significant score when compared with those of other proteins by NCBI-BLAST2 alignment display. As regards their proteolytic activities, BleucMP efficiently acted on fibrinogen, fibrin, and was inhibited by EDTA and 1.10-phenanthroline. This enzyme was also able to decrease significantly the plasma fibrinogen level provoking blood incoagulability, however was devoid of hemorrhagic activity when tested in the mice skin and did not induce relevant biochemical, hematological and histopathological alterations in mice. The aspects addressed in this paper provide data on the effect of BleucMP in envenomation from B. leucurus snakes in order to better understand the effects caused by snake venom metalloproteinase. PMID:21130897

  6. Envenomations by Bothrops and Crotalus snakes induce the release of mitochondrial alarmins.

    Directory of Open Access Journals (Sweden)

    Irene Zornetta

    Full Text Available Skeletal muscle necrosis is a common manifestation of viperid snakebite envenomations. Venoms from snakes of the genus Bothrops, such as that of B. asper, induce muscle tissue damage at the site of venom injection, provoking severe local pathology which often results in permanent sequelae. In contrast, the venom of the South American rattlesnake Crotalus durissus terrificus, induces a clinical picture of systemic myotoxicity, i.e., rhabdomyolysis, together with neurotoxicity. It is known that molecules released from damaged muscle might act as 'danger' signals. These are known as 'alarmins', and contribute to the inflammatory reaction by activating the innate immune system. Here we show that the venoms of B. asper and C. d. terrificus release the mitochondrial markers mtDNA (from the matrix and cytochrome c (Cyt c from the intermembrane space, from ex vivo mouse tibialis anterior muscles. Cyt c was released to a similar extent by the two venoms whereas B. asper venom induced the release of higher amounts of mtDNA, thus reflecting hitherto some differences in their pathological action on muscle mitochondria. At variance, injection of these venoms in mice resulted in a different time-course of mtDNA release, with B. asper venom inducing an early onset increment in plasma levels and C. d. terrificus venom provoking a delayed release. We suggest that the release of mitochondrial 'alarmins' might contribute to the local and systemic inflammatory events characteristic of snakebite envenomations.

  7. Expression and partial biochemical characterization of a recombinant serine protease from Bothrops pauloensis snake venom.

    Science.gov (United States)

    Isabel, Thais F; Costa, Guilherme Nunes Moreira; Pacheco, Isabela B; Barbosa, Luana G; Santos-Junior, Célio D; Fonseca, Fernando P P; Boldrini França, Johara; Henrique-Silva, Flávio; Yoneyama, Kelly A G; Rodrigues, Renata S; Rodrigues, Veridiana de Melo

    2016-06-01

    Snake venom serine proteases (SVSPs) are enzymes capable of interfering at several points of hemostasis. Some serine proteases present thrombin-like activity, which makes them targets for the development of therapeutics agents in the treatment of many hemostatic disorders. In this study, a recombinant thrombin-like serine protease, denominated rBpSP-II, was obtained from cDNA of the Bothrops pauloensis venom gland and was characterized enzymatically and biochemically. The enzyme rBpSP-II showed clotting activity on bovine plasma and proteolytic activity on fibrinogen, cleaving exclusively the Aα chain. The evaluation of rBpSP-II activity on chromogenic substrates demonstrated thrombin-like activity of the enzyme due to its capacity to hydrolyze the thrombin substrate. These characteristics make rBpSP-II an attractive molecule for additional studies. Further research is needed to verify whether rBpSP-II can serve as a template for the synthesis of therapeutic agents to treat hemostatic disorders. PMID:26965926

  8. Neuromuscular action of Bothrops lanceolatus (Fer de lance) venom and a caseinolytic fraction.

    Science.gov (United States)

    Lôbo de Araújo, Albetiza; Donato, José Luiz; Leite, Gildo Bernardo; Prado-Franceschi, Júlia; Fontana, Marcos Dias; Bon, Cassian; Rodrigues Simioni, Léa

    2002-09-01

    A protein capable of inducing neuromuscular blockade in avian preparations and of depolarizing mouse diaphragm muscle was isolated from Bothrops lanceolatus venom using gel filtration and ion-exchange chromatography. The purified protein was a single chain polypeptide with an estimated molecular mass of 27.5 kDa by SDS-PAGE and had caseinolytic activity (13.3 units/mg), but no phospholipase A(2). B.lanceolatus venom (50 micro g/ml) and the caseinolytic protein (20 micro g/ml) produced contracture and progressive irreversible blockade (50% in 25+/-5 min (SEM) and 45+/-15 min, respectively), in indirectly stimulated chick biventer cervicis preparations. The contractile responses to acetylcholine (ACh; 37 and 74 micro M, n=6) were inhibited by venom and the caseinolytic protein, whereas those to potassium (13.4mM, n=6) were not. Membrane resting potential measurements in mouse hemidiaphragm preparations showed that B.lanceolatus venom and the purified protein caused depolarization which was prevented by D-tubocurarine (14.6mM). The venom produced a slight increase in the amplitude and frequency of miniature end-plate potentials, but this effect was not seen with the purified fraction. These results suggest that the purified protein acts exclusively post-synaptically. PMID:12220713

  9. Hyperbaric oxygen therapy after Bothrops lanceolatus snake bites in Martinique: a brief report.

    Science.gov (United States)

    Hochedez, P; Thomas, L; Mehdaoui, H

    2010-01-01

    Every year 10 to 20 cases of snake bites are reported on the Caribbean island of Martinique. The only snake involved, Bothrops lanceolatus, is endemic on the island, and its bite may lead to systemic multifocal thrombotic complications in the'absence of the monospecific antivenom. Between January 1988 and January 2009, more than 250 snake bites have been reported, and five patients were treated with hyperbaric oxygen (HBO2) therapy for local complications. The patients were male, bitten on the leg or the hand, and presented with severe complications such as necrotizing soft tissue infections, compartment syndrome or abscesses despite prompt wound care and administration of antivenomous serum. Outcomes were favorable for these five patients, except for one who was left with a functional defect of the hand. Although snake bites are not part of the currently recommended indications for HBO2 therapy, local complications, namely compartment syndrome, necrotizing soft tissue infections and enhancement of healing in selected problem wounds, are approved uses of HBO2 therapy as defined by the Hyperbaric Oxygen Therapy Committee and would benefit from prospective studies. PMID:21226390

  10. Coagulant and anticoagulant activities of Bothrops lanceolatus (Fer de lance) venom.

    Science.gov (United States)

    Lôbo de Araújo, A; Kamiguti, A; Bon, C

    2001-01-01

    Bothrops lanceolatus venom contains caseinolytic, phospholipase, esterase and haemorrhagic activities. We have investigated the coagulant and anticoagulant actions of B. lanceolatus venom on human citrated plasma and on purified plasma components. Although B. lanceolatus venom up to 50 microg/ml was unable to clot citrated plasma, at concentrations > or = 5 microg/ml the venom dose-dependently clotted purified human fibrinogen, indicating the presence of a thrombin-like enzyme. Human plasma (final concentration > or = 12.5%) dose-dependently inhibited the venom-induced fibrinogen clotting. This finding suggested that endogenous plasma protease inhibitors can affect the venom's action on fibrinogen. To investigate this possibility, B. lanceolatus venom was incubated with different plasma protease inhibitors and the activity on fibrinogen tested. alpha(2)-Macroglobulin and alpha(1)-antitrypsin did not interfere with the coagulant activity of the venom whereas the antithrombin-III/heparin complex partially inhibited this activity. A non-toxic, acidic phospholipase A(2) purified from B. lanceolatus venom prolonged the activated partial thromboplastin time in human plasma from 39.7+/-0.5 s (control with saline) to 60.2+/-0.9 s with 50 microg of PLA(2) (p<0.001), suggesting an anticoagulant activity associated with this enzyme. This anticoagulant activity may account for some of the effects of the venom on blood coagulation. PMID:10978756

  11. Análisis inmunoenzimático (ELISA) para determinar niveles de IgG anti Bothrops atrox en accidente ofídico Immunoenzymatic determination of IgG anti bothrops atrox levels after snake bites

    OpenAIRE

    John J. Estrada; Rafael Otero Patiño; Luz E. Posada; Sadoh Molina

    1993-01-01

    Se desarrolló un método de inmunización de conejos con veneno de Bothrops atrox con el fin de preparar antisueros y estandarizar un inmunoanálisis (ELISA) para medir niveles de IgG en pacientes con accidente ofídico. La respuesta Inmune de los conejos se siguió por inmunodifusión en doble dimensión (Ouchterlony) e inmunoelectroforesis, demostrando la presencia de bandas nítidas desde el día 60 y en todas las sangrias posteriores; se comprobó que hay variabilidad individual en su respuesta inm...

  12. Low-level laser therapy decreases local effects induced by myotoxins isolated from Bothrops jararacussu snake venom

    OpenAIRE

    AM Barbosa; AB Villaverde; L Guimarães-Sousa; AM Soares; SF Zamuner; JC Cogo; SR Zamuner

    2010-01-01

    The prominent myotoxic effects induced by Bothrops jararacussu crude venom are due, in part, to its polycationic myotoxins, BthTX-I and BthTX-II. Both myotoxins have a phospholipase A2 structure: BthTX-II is an active enzyme Asp-49 PLA2, while BthTX-I is a Lys-49 PLA2 devoid of enzymatic activity. In this study, the effect of low-level laser therapy (LLLT), 685 nm laser at a dose of 4.2 J/cm2 on edema formation, leukocyte influx and myonecrosis caused by BthTX-I and BthTX-II, isolated from Bo...

  13. Inhibition of the hyperalgesic activity of Bothrops jararaca venom by an antibothropic fraction isolated from opossum (Didelphis marsupialis) serum.

    Science.gov (United States)

    Rocha, S L; Frutuoso, V S; Domont, G B; Martins, M A; Moussatché, H; Perales, J

    2000-06-01

    The antibothropic fraction (ABF) already isolated from Didelphis marsupialis serum, inhibits the haemorrhagic, oedematogenic, myonecrotic and lethal activities of Bothrops jararaca venom (Bjv). The aim of this work was to verify the capability of ABF to inhibit the hyperalgesic activity of Bjv. Intraplantar injection of Bjv induced hyperalgesia in a time- and dose-dependent manner and ABF administered in situ concomitantly with Bjv or i.v. 30 min before venom injection reduced the induced hyperalgesia. This same effect was observed when ABF was intravenously injected at 5 and 15 min after Bjv. Our results show that ABF inhibits also the hyperalgesia induced by Bjv. PMID:10695972

  14. Características biológicas e inmunológicas del veneno de Bothrops cotiara (Serpentes: Viperidae)

    OpenAIRE

    Adolfo Rafael de Roodt; Judith Estévez; Jorge Adrián Dolab; Marcelo Víctor Manzanelli; Nicolás Piñeiro; Jorge Francisco Paniagua; Alejandro Urs Vogt

    2006-01-01

    Bothrops cotiara es una serpiente que se encuentra en la provincia de Misiones (Argentina), el Sur de Brasil y Paraguay. La información sobre las características clínicas de los accidentes por esta serpiente es muy escasa y existen pocos datos sobre su veneno y la capacidad neutralizante de las actividades tóxicas del mismo por antivenenos terapéuticos. En este trabajo se estudiaron características bioquímicas, actividades tóxicas y la reactividad inmunoquímica del veneno de B. cotiara. Seis ...

  15. Neutralization of four Peruvian Bothrops sp. snake venoms by polyvalent antivenoms produced in Perú and Costa Rica: preclinical assessment.

    Science.gov (United States)

    Rojas, Ermila; Quesada, Lil; Arce, Viviana; Lomonte, Bruno; Rojas, Gustavo; Gutiérrez, José María

    2005-01-01

    Envenomations after bites inflicted by snakes of the genus Bothrops constitute a public health hazard in Perú, and the intravenous administration of equine-derived antivenoms represents the only scientifically validated treatment. This study presents a preclinical assessment of the efficacy of two whole IgG antivenoms, prepared in Perú and Costa Rica, to neutralize the most relevant toxic effects induced by the venoms of Bothrops atrox, B. brazili, B. barnetti and B. pictus from Perú. Peruvian antivenom is produced by immunizing horses with Bothrops sp. venoms from this country, whereas the production of Costa Rican antivenom involves immunization with venoms from Central American snakes. The neutralization of lethal, hemorrhagic, edema-forming, myotoxic, coagulant and defibrinating activities was evaluated in assays involving incubation of venom and antivenom prior to testing. Both antivenoms were effective in the neutralization of these effects, with quantitative variations in the values of effective dose 50% depending on the effects being studied. Peruvian antivenom was more effective in the neutralization of lethality induced by B. atrox and B. barnetti venoms. However, Peruvian antivenom failed to neutralize coagulant activity of B. barnetti venom and edema-forming activity of B. brazili venom, whereas neutralization was achieved by Costa Rican antivenom. It is concluded that an extensive immunological cross-reactivity exists between Bothrops sp. venoms from Perú and Costa Rica, and that both antivenoms are effective in the neutralization of these four venoms in a rodent model of envenoming. PMID:15589801

  16. Effects of irradiated Bothropstoxin-1 and Bothrops jararacussu crude venom on the immune system

    International Nuclear Information System (INIS)

    Ionizing radiation has been successfully employed to modify the immunological properties of biomolecules and has been proven to be a powerful tool to attenuate snake venoms toxicity without affecting and even increasing their immunogenic properties. Very promising results were obtained when crude animal venoms, as well as isolated toxins, were treated with 60Co gamma rays, yielding toxoids with good immunogenicity, however, little is known about the modifications that irradiated molecules undergo and even less about the immunological response that such antigens elicit. At the present work, we have evaluated the effects on immune system of B10.PL and BALB/c mice of Bothrops jararacussu crude venom and isolated bothropstoxin-1 (Bthx-1), before and after gamma radiation exposition. According to our data, irradiation process promoted structural modifications on both isolated toxin and crude venom, characterized by higher molecular weight protein (aggregates and oligomers) formation. Irradiated samples were immunogenic and the antibodies elicited by them were able to recognize the native toxin in ELISA. These results indicate that irradiation of toxic proteins can promote significant modifications in their structures, but still retain many of the original antigenic and immunological properties. Also, our data indicate that the irradiated protein induced higher titers of IgG2b, suggesting that Th1 cells were predominantly involved. Results from Western blot assay showed that antibodies raised against irradiated bothropstoxin-1 recognize both native isolated toxin or crude venom. Cytotoxicity assay showed that irradiated toxin and crude venom were less toxic than their native counterpart. Thus, the viability of the macrophages cultured in the presence of irradiated Bthx-1 or crude venom was higher if compared with their native forms. LDH Assay showed that irradiated Bthx-1 promotes less muscular damage than the native form. Our data confirm a potential use of ionizing

  17. Cell adhesion molecules involved in the leukocyte recruitment induced by venom of the snake Bothrops jararaca

    Directory of Open Access Journals (Sweden)

    Stella R. Zamuner

    2002-01-01

    Full Text Available It has been shown that Bothrops jararaca venom (BjV induces a significant leukocyte accumulation, mainly neutrophils, at the local of tissue damage. Therefore, the role of the adhesion molecules intercellular adhesion molecule-1 (ICAM-1, LECAM-1, CD18, leukocyte function-associated antigen-1 (LFA-1 and platelet endothelial cell adhesion molecule-1 (PECAM-1 on the BjV-induced neutrophil accumulation and the correlation with release of LTB4, TXA2, tumor necrosis factor-α, interleukin (IL-1 and IL-6 have been investigated. Anti-mouse LECAM-1, LFA-1, ICAM-1 and PECAM-1 monoclonal antibody injection resulted in a reduction of 42%, 80%, 66% and 67%, respectively, of neutrophil accumulation induced by BjV (250 μg/kg, intraperitoneal injection in male mice compared with isotype-matched control injected animals. The anti-mouse CD18 monoclonal antibody had no significant effect on venom-induced neutrophil accumulation. Concentrations of LTB4, TXA2, IL-6 and TNF-α were significant increased in the peritoneal exudates of animals injected with venom, whereas no increment in IL-1 was detected. This results suggest that ICAM-1, LECAM-1, LFA-1 and PECAM-1, but not CD18, adhesion molecules are involved in the recruitment of neutrophils into the inflammatory site induced by BjV. This is the first in vivo evidence that snake venom is able to up-regulate the expression of adhesion molecules by both leukocytes and endothelial cells. This venom effect may be indirect, probably through the release of the inflammatory mediators evidenced in the present study.

  18. Annual changes in seminal variables of golden lanchead pitvipers (Bothrops insularis) maintained in captivity.

    Science.gov (United States)

    Silva, K B; Zogno, M A; Camillo, A B; Pereira, R J G; Almeida-Santos, S M

    2015-12-01

    Bothrops insularis is an endemic and critically endangered snake with an estimated population of 2000 individuals restricted to Queimada Grande Island, in southeastern Brazil. Brazilian researchers established a captive breeding program for the species that includes the application of assisted reproductive technologies. The present study, therefore, aimed to evaluate semen samples from captive B. insularis throughout the year to ascertain seasonal differences in semen traits as well as correlations with body size and weight. Eighteen males with snout-vent length (SVL) ranging from 43.5 to 73.7 cm were collected at quarterly basis between August 2012 and May 2013. Macroscopic analysis revealed semen volumes ranging from 0.5 to 6.0 μL with samples featuring whitish to yellowish color and creamy and thick consistency. Viable sperm was obtained from all males indicating that individuals with SVL equal to or greater than 43.5 cm are sexually developed. However, adult and immature males (estimated by SVL) exhibited different seasonal profiles for motility and progressive motility. Adult males had a decrease in sperm motility and progressive motility during summer and spring, respectively, whereas the same variables did not vary throughout the year in immature snakes. Sperm concentration in all individuals was less (0.5 × 10(9) μL) during the winter, but no seasonal fluctuations were detected in semen volume. These findings are of particular importance to the development of reproductive tools such as male selection, artificial insemination and sperm freezing for the genetic management of this critically endangered snake. PMID:26559333

  19. A C-type lectin from Bothrops jararacussu venom disrupts Staphylococcal biofilms.

    Directory of Open Access Journals (Sweden)

    Raphael Contelli Klein

    Full Text Available Bovine mastitis is a major threat to animal health and the dairy industry. Staphylococcus aureus is a contagious pathogen that is usually associated with persistent intramammary infections, and biofilm formation is a relevant aspect of the outcome of these infections. Several biological activities have been described for snake venoms, which led us to screen secretions of Bothrops jararacussu for antibiofilm activity against S. aureus NRS155. Crude venom was fractionated by size-exclusion chromatography, and the fractions were tested against S. aureus. Biofilm growth, but not bacterial growth, was affected by several fractions. Two fractions (15 and 16 showed the best activities and were also assayed against S. epidermidis NRS101. Fraction 15 was identified by TripleTOF mass spectrometry as a galactose-binding C-type lectin with a molecular weight of 15 kDa. The lectin was purified from the crude venom by D-galactose affinity chromatography, and only one peak was observed. This pure lectin was able to inhibit 75% and 80% of S. aureus and S. epidermidis biofilms, respectively, without affecting bacterial cell viability. The lectin also exhibited a dose-dependent inhibitory effect on both bacterial biofilms. The antibiofilm activity was confirmed using scanning electron microscopy. A pre-formed S. epidermidis biofilm was significantly disrupted by the C-type lectin in a time-dependent manner. Additionally, the lectin demonstrated the ability to inhibit biofilm formation by several mastitis pathogens, including different field strains of S. aureus, S. hyicus, S. chromogenes, Streptococcus agalactiae, and Escherichia coli. These findings reveal a new activity for C-type lectins. Studies are underway to evaluate the biological activity of these lectins in a mouse mastitis model.

  20. BbrzSP-32, the first serine protease isolated from Bothrops brazili venom: Purification and characterization.

    Science.gov (United States)

    Zaqueo, Kayena D; Kayano, Anderson M; Domingos, Thaisa F S; Moura, Laura A; Fuly, André L; da Silva, Saulo L; Acosta, Gerardo; Oliveira, Eliandre; Albericio, Fernando; Zanchi, Fernando B; Zuliani, Juliana P; Calderon, Leonardo A; Stábeli, Rodrigo G; Soares, Andreimar M

    2016-05-01

    Snake venom toxins are related not only in detention, death and the promotion of initial digestion of prey but also due to their different biochemical, structural and pharmacological effects they can result in new drugs. Among these toxins snake venom serine proteases (SVSPs) should be highlighted because they are responsible for inducing changes in physiological functions such as blood coagulation, fibrinolysis, and platelet aggregation. This article presents the first serine protease (SP) isolated from Bothrops brazili: BbrzSP-32. The new SP showed 36kDa of relative molecular mass and its absolute mass was confirmed by mass spectrometry as 32,520Da. It presents 79.48% identity when compared to other SVSPs and was able to degrade the α-chain of fibrinogen, in in vitro models, because of this it is considered a SVTLE-A. It showed dose-dependent activity in the process of degradation of fibrin networks demonstrating greater specificity for this activity when compared to its thrombolytic action. BbrzSP-32 demonstrated proteolytic activity on gelatin and chromogenic substrates for serine proteases and thrombin-like enzymes (S-2288 and S-2238 respectively), besides having coagulant activity on human plasma. After pre-incubation with PMSF and benzamidine the coagulant and proteolytic activities on the S-2288 and S-2238 substrates were reduced. BbrzSP-32 shows stability against pH and temperature variations, demonstrating optimum activity between 30 and 40°C and in the pH range 7.5 to 8.5. A new SP with potential biotechnological application was isolated. PMID:26827743

  1. Bothrops jararaca venom metalloproteinases are essential for coagulopathy and increase plasma tissue factor levels during envenomation.

    Directory of Open Access Journals (Sweden)

    Karine M Yamashita

    2014-05-01

    Full Text Available BACKGROUND/AIMS: Bleeding tendency, coagulopathy and platelet disorders are recurrent manifestations in snakebites occurring worldwide. We reasoned that by damaging tissues and/or activating cells at the site of the bite and systemically, snake venom toxins might release or decrypt tissue factor (TF, resulting in activation of blood coagulation and aggravation of the bleeding tendency. Thus, we addressed (a whether TF and protein disulfide isomerase (PDI, an oxireductase involved in TF encryption/decryption, were altered in experimental snake envenomation; (b the involvement and significance of snake venom metalloproteinases (SVMP and serine proteinases (SVSP to hemostatic disturbances. METHODS/PRINCIPAL FINDINGS: Crude Bothrops jararaca venom (BjV was preincubated with Na2-EDTA or AEBSF, which are inhibitors of SVMP and SVSP, respectively, and injected subcutaneously or intravenously into rats to analyze the contribution of local lesion to the development of hemostatic disturbances. Samples of blood, lung and skin were collected and analyzed at 3 and 6 h. Platelet counts were markedly diminished in rats, and neither Na2-EDTA nor AEBSF could effectively abrogate this fall. However, Na2-EDTA markedly reduced plasma fibrinogen consumption and hemorrhage at the site of BjV inoculation. Na2-EDTA also abolished the marked elevation in TF levels in plasma at 3 and 6 h, by both administration routes. Moreover, increased TF activity was also noticed in lung and skin tissue samples at 6 h. However, factor VII levels did not decrease over time. PDI expression in skin was normal at 3 h, and downregulated at 6 h in all groups treated with BjV. CONCLUSIONS: SVMP induce coagulopathy, hemorrhage and increased TF levels in plasma, but neither SVMP nor SVSP are directly involved in thrombocytopenia. High levels of TF in plasma and TF decryption occur during snake envenomation, like true disseminated intravascular coagulation syndrome, and might be implicated in

  2. Effects of Bothrops asper snake venom on lymphatic vessels: insights into a hidden aspect of envenomation.

    Directory of Open Access Journals (Sweden)

    Javier Mora

    Full Text Available BACKGROUND: Envenomations by the snake Bothrops asper represent a serious medical problem in Central America and parts of South America. These envenomations concur with drastic local tissue pathology, including a prominent edema. Since lymph flow plays a role in the maintenance of tissue fluid balance, the effect of B. asper venom on collecting lymphatic vessels was studied. METHODOLOGY/PRINCIPAL FINDINGS: B. asper venom was applied to mouse mesentery, and the effects were studied using an intravital microscopy methodology coupled with an image analysis program. B. asper venom induced a dose-dependent contraction of collecting lymphatic vessels, resulting in a reduction of their lumen and in a halting of lymph flow. The effect was reproduced by a myotoxic phospholipase A(2 (PLA(2 homologue isolated from this venom, but not by a hemorrhagic metalloproteinase or a coagulant thrombin-like serine proteinase. In agreement with this, treatment of the venom with fucoidan, a myotoxin inhibitor, abrogated the effect, whereas no inhibition was observed after incubation with the peptidomimetic metalloproteinase inhibitor Batimastat. Moreover, fucoidan significantly reduced venom-induced footpad edema. The myotoxic PLA(2 homologue, known to induce skeletal muscle necrosis, was able to induce cytotoxicity in smooth muscle cells in culture and to promote an increment in the permeability to propidium iodide in these cells. CONCLUSIONS/SIGNIFICANCE: Our observations indicate that B. asper venom affects collecting lymphatic vessels through the action of myotoxic PLA(2s on the smooth muscle of these vessels, inducing cell contraction and irreversible cell damage. This activity may play an important role in the pathogenesis of the pronounced local edema characteristic of viperid snakebite envenomation, as well as in the systemic biodistribution of the venom, thus representing a potential therapeutical target in these envenomations.

  3. A transcriptomic view of the proteome variability of newborn and adult Bothrops jararaca snake venoms.

    Directory of Open Access Journals (Sweden)

    André Zelanis

    Full Text Available BACKGROUND: Snake bite is a neglected public health problem in communities in rural areas of several countries. Bothrops jararaca causes many snake bites in Brazil and previous studies have demonstrated that the pharmacological activities displayed by its venom undergo a significant ontogenetic shift. Similarly, the venom proteome of B. jararaca exhibits a considerable variation upon neonate to adult transition, which is associated with changes in diet from ectothermic prey in early life to endothermic prey in adulthood. Moreover, it has been shown that the Brazilian commercial antibothropic antivenom, which is produced by immunization with adult venom, is less effective in neutralizing newborn venom effects. On the other hand, venom gland transcripts of newborn snakes are poorly known since all transcriptomic studies have been carried out using mRNA from adult specimens. METHODS/PRINCIPAL FINDINGS: Here we analyzed venom gland cDNA libraries of newborn and adult B. jararaca in order to evaluate whether the variability demonstrated for its venom proteome and pharmacological activities was correlated with differences in the structure of toxin transcripts. The analysis revealed that the variability in B. jararaca venom gland transcriptomes is quantitative, as illustrated by the very high content of metalloproteinases in the newborn venom glands. Moreover, the variability is also characterized by the structural diversity of SVMP precursors found in newborn and adult transcriptomes. In the adult transcriptome, however, the content of metalloproteinase precursors considerably diminishes and the number of transcripts of serine proteinases, C-type lectins and bradykinin-potentiating peptides increase. Moreover, the comparison of the content of ESTs encoding toxins in adult male and female venom glands showed some gender-related differences. CONCLUSIONS/SIGNIFICANCE: We demonstrate a substantial shift in toxin transcripts upon snake development and a

  4. Snake venomics of Bothrops punctatus, a semiarboreal pitviper species from Antioquia, Colombia

    Directory of Open Access Journals (Sweden)

    Maritza Fernández Culma

    2014-01-01

    Full Text Available Bothrops punctatus is an endangered, semi-arboreal pitviper species distributed in Panamá, Colombia, and Ecuador, whose venom is poorly characterized. In the present work, the protein composition of this venom was profiled using the ‘snake venomics’ analytical strategy. Decomplexation of the crude venom by RP-HPLC and SDS-PAGE, followed by tandem mass spectrometry of tryptic digests, showed that it consists of proteins assigned to at least nine snake toxin families. Metalloproteinases are predominant in this secretion (41.5% of the total proteins, followed by C-type lectin/lectin-like proteins (16.7%, bradykinin-potentiating peptides (10.7%, phospholipases A2 (93%, serine proteinases (5.4%, disintegrins (38%, L-amino acid oxidases (3.1%, vascular endothelial growth factors (17%, and cysteine-rich secretory proteins (1.2%. Altogether, 6.6% of the proteins were not identified. In vitro, the venom exhibited proteolytic, phospholipase A2, and L-amino acid oxidase activities, as well as angiotensin-converting enzyme (ACE-inhibitory activity, in agreement with the obtained proteomic profile. Cytotoxic activity on murine C2C12 myoblasts was negative, suggesting that the majority of venom phospholipases A2 likely belong to the acidic type, which often lack major toxic effects. The protein composition of B. punctatus venom shows a good correlation with toxic activities here and previously reported, and adds further data in support of the wide diversity of strategies that have evolved in snake venoms to subdue prey, as increasingly being revealed by proteomic analyses.

  5. Rabbit antivenom efficacy against myotoxic and neurotoxic activities of Bothrops jararacussu venom and bothropstoxin-I

    Directory of Open Access Journals (Sweden)

    Y. Oshima-Franco

    2002-01-01

    Full Text Available Bothrops jararacussu venom and its major toxin bothropstoxin-I (BthTX-I possess myotoxic and neurotoxic properties. The efficacy of a rabbit antivenom raised against B. jararacussu venom in the neutralization of physiological, biochemical, and morphological changes induced by the venom and its major toxin BthTX-I was studied in mouse isolated phrenic nerve-diaphragm (PND and extensor digitorum longus (EDL preparations. The times required for 50% neuromuscular blockade in PND and EDL preparations for venom were 70+11.5 (S.E.M., n=5 min and 58+8 (n=16 (50 mu g/mL, and for BthTX-I 31+6 (n=3 min and 30+3 (n=5 min (20 mu g/mL, respectively. After 120 min incubation, creatine kinase (CK concentrations in solution containing the EDL preparations were 3464+346 U/L after exposure to venom (50 mu g/mL, n=5 and 3422+135 U/L to BthTX-I (20mu g/mL, n=4, respectively. Rabbit antivenom dose-dependently neutralized venom and toxin-induced neuromuscular blockade in both preparations and effectively prevented venom and toxin-induced CK release from EDL. Histological analysis showed that rabbit antivenom neutralized morphological damage caused by B. jararacussu venom and BthTX-I in EDL preparations. These results indicate that rabbit antivenom effectively neutralized the biological activities of B. jararacussu venom and BthTX-I.

  6. Crystal structure of myotoxin-II: a myotoxic phospholipase A2 - homologue from Bothrops moojeni venom

    International Nuclear Information System (INIS)

    Full text. Phospho lipases A2 (PLA2; E C 3.1.1.4, phosphatides s n-2 acyl hydrolases) hydrolysis the s n-2 ester bond of phospholipids showing enhanced activity at lamellar or membrane surfaces. Intracellular PLA2 s are involved at phospholipid metabolism and signal transduction, whereas extracellular PLA2 s are found in mammalian pancreatic juices, the venoms of snakes, lizards and insects. Based on their high primary sequence similarity, extracellular PLA2 s are separated into Classes I, II and III. Class II PLA2 s are found in snake venoms of Crotalidae an Viperidae species, and include the sub-family of Lys PLA2 s homologue. he coordination of the Ca2+ ion in the PLA2 calcium-binding loop includes and aspartate at position 49. In the catalytically active PLA2 s, this calcium ion plays a critical role in the stabilization of the tetrahedral transition state intermediate in the catalytic mechanism. The conservative substitution Asp49-Lys results in a decreased calcium affinity with a concomitant loss of catalytic activity, and naturally occurring PLA2 s-homologues showing the same substitution are catalytically inactive. However, the Lys PLA2 s possess cytolytic and myotoxic activities and furthermore retain the ability to disrupt the integrity of both plasma membranes and model lipid layers by a ca2+-independent mechanism for which there is no evidence of lipid hydrolysis. Lys 49 PLA2 homologues have been isolated from several Bothrops spp. venoms including B. moojeni. Therefore, in order to improve our understanding of the molecular basis of the myotoxic and Ca2+ independent membrane damaging activities we have determined the crystal structure of MjTX-II, a Lys 49 homologue from the venom of B. moojeni. The model presented has been determined at 2.0 A resolution and refined to a crystallographic residual of 19.7% (Rfree=28.1%). (author)

  7. Bothrops lanceolatus (Fer de lance) venom stimulates leukocyte migration into the peritoneal cavity of mice.

    Science.gov (United States)

    Arruda, Vanessa Alves; de Queiroz Guimarães, Alessandra; Hyslop, Stephen; de Araújo, Paulo Maria Ferreira; Bon, Cassian; de Araújo, Albetiza Lôbo

    2003-01-01

    The ability of Bothrops lanceolatus venom to induce neutrophil migration into the peritoneal cavity of mice was investigated. Intraperitoneal injection of venom caused dose- and time-dependent neutrophil migration, which peaked with 750 ng of venom/cavity 4h after venom injection. The neutrophil migration was significantly reduced by pretreatment with dexamethasone (0.5 mg/kg, s.c.), an indirect inhibitor of phospholipase A(2) (PLA(2)), and AA861 (0.01 mg/kg, s.c.), a 5-lipoxygenase inhibitor, but in contrast, was not modified by pretreatment with indomethacin (2 mg/kg, s.c.), an inhibitor of the cyclooxygenase pathway, meloxicam (5 mg/kg, s.c.), an inhibitor of the cyclooxygenase-2 pathway, or the PAF inhibitor WEB2086 (40 mg/kg, s.c.). Dexamethasone and AA861 also inhibited the neutrophil migration by 60% when administered immediately after venom injection, and the coadministration of these two drugs caused a 75% reduction in migration. BLV-induced neutrophil migration was not due to contamination by endotoxin since polymyxin B-treated venom retained its activity. Heating the venom (97 degrees C, 2 min) reduced the PLA(2) activity by 64% and this was accompanied by a corresponding reduction (68%) in neutrophil migration. These results suggest that arachidonate-derived lipoxygenase metabolites (possibly leukotriene B(4)) are involved in the chemotaxis observed. Macrophages may be an important source of these metabolites since the migratory response to venom was potentiated in mice pretreated with thioglycollate, but reduced when the peritoneal cavity was washed with sterile saline. PMID:12467667

  8. Radioiodination and biodistribution of Leucurolysin-B isolated from Bothrops Leucurus in mice bearing Ehrlich

    International Nuclear Information System (INIS)

    Integrins are family of heterodimeric cell surface adhesion receptors able to recognize and bind to proteins in the extracellular matrix (ECM). This recognition is mainly through the RGD domain present in both the cell surface as the protein in the ECM. Various integrins have been identified as regulators of tumor progression. The RGD domain is also found in some snake venoms named disintegrins. Disintegrins inhibit cell-matrix and a cell-cell interaction mediated by integrin and has been shown that these proteins are able to inhibit metastasis in processes dependent on integrin. The disintegrin-like (ECD), as well as RGD-disintegrin are also able to bind to cell surface integrins and inhibit their adherence to the natural ligands. Leucurolysin-B (Leuc-B) is a metalloproteinase class P-III isolated from Bothrops leucurus (BLV) and possesses a disintegrin-like domain (ECD). The goals of this work were to synthesize a radioactive probe analog to Leuc-B using radioiodine 125I and evaluate the interaction of 125I-Leuc-B in tumor cells through the study of biodistribution in animals bearing Ehrlich tumor.125I-Leuc-B was synthesized using lactoperoxidase with high yield (90%) and specific activity of 1.2x10-7Bq/mmol. It was observed that 125I-Leuc-B had very fast clearance from the blood stream (T1/2= 0.01 h). Tumor uptake of 125I-Leuc-B gradually increased up to (2 min) and remained for a quite long period. The tumor/normal tissue uptake ratios of 125I-Leuc-B were 1.77 (tumor/normal paw) and 8.44 tumor/skeletal muscle. The results suggest that 125I-Leuc- B may constitute a good template for development of a tool for detection of solid tumors. (author)

  9. Exploring the proteomes of the venoms of the Peruvian pit vipers Bothrops atrox, B. barnetti and B. pictus.

    Science.gov (United States)

    Kohlhoff, Markus; Borges, Marcia H; Yarleque, Armando; Cabezas, Cesar; Richardson, Michael; Sanchez, Eladio F

    2012-04-01

    We report the comparative proteomic characterization of the venoms of Bothrops atrox, B. barnetti and B. pictus. The venoms were subjected to RP-HPLC and the resulting fractions analyzed by SDS-PAGE. The proteins were cut from the gels, digested with trypsin and identified via peptide mass fingerprint and manual sequencing of selected peptides by MALDI-TOF/TOF mass spectrometry. Around 20-25 proteins were identified belonging to only 6-7 protein families. Metalloproteinases of the classes P-I and P-III were the most abundant proteins in all venoms (58-74% based on peak area A214 nm), followed by phospholipases-A(2) (6.4-14%), disintegrins (3.2-9%) and serine proteinases (7-11%), and some of these proteins occurred in several isoforms. In contrast cysteine-rich secretory proteins and L-amino acid oxidases appeared only as single isoforms and were found only in B. atrox and B. barnetti. C-type lectins were also detected in all venoms but at low levels (~ 5%). Furthermore, the venoms contain variable numbers of peptides (Bothrops species is in agreement with their pharmacological and pathological effects. PMID:22300577

  10. Inflammation induced by Bothrops asper venom: release of proinflammatory cytokines and eicosanoids, and role of adhesion molecules in leukocyte infiltration.

    Science.gov (United States)

    Zamuner, Stella Regina; Zuliani, Juliana Pavan; Fernandes, Cristina Maria; Gutiérrez, José Maria; de Fátima Pereira Teixeira, Catarina

    2005-12-01

    Bothrops asper venom (BaV) causes systemic and local effects characterized by an acute inflammatory reaction with accumulation of leukocytes and release of endogenous mediators. In this study, the effects of BaV on the release of the cytokines IL-1, IL-6 and TNF-alpha and the eicosanoids LTB4 and TXA2 in the peritoneal cavity of mice were analyzed. We also investigated the participation of beta2 integrin chain, l-selectin, LFA-1, ICAM-1 and PECAM-1 adhesion molecules in the BaV-induced leukocyte accumulation. Levels of proinflammatory cytokines IL-6 and TNF-alpha, as well as eicosanoids LTB4 and TXA2 were significantly increased after BaV injection (250 microg/kg), whereas no increment in IL-1 was observed. Anti-mouse l-selectin, LFA-1, ICAM-1, PECAM-1 and beta2 integrin chain monoclonal antibodies resulted in a reduction of neutrophil accumulation induced by BaV injection compared with isotype-matched control injected animals. These data suggest that BaV is able to induce the activation of leukocytes and endothelium to express adhesion molecules involved in the recruitment of neutrophils into the inflammed site. Furthermore, these results showed that BaV induces the release of cytokines and eicosanoids in the local of the venom injection; these inflammatory mediators may be important for the initiation and amplification of the inflammatory reaction characteristic from Bothrops sp envenomation. PMID:16198389

  11. Isolation and Biochemical Characterization of a New Thrombin-Like Serine Protease from Bothrops pirajai Snake Venom

    Directory of Open Access Journals (Sweden)

    Kayena D. Zaqueo

    2014-01-01

    Full Text Available This paper presents a novel serine protease (SP isolated from Bothrops pirajai, a venomous snake found solely in Brazil that belongs to the Viperidae family. The identified SP, named BpirSP-39, was isolated by three chromatographic steps (size exclusion, bioaffinity, and reverse phase chromatographies. The molecular mass of BpirSP-39 was estimated by SDS-PAGE and confirmed by mass spectrometry (39,408.32 Da. The protein was able to form fibrin networks, which was not observed in the presence of serine protease inhibitors, such as phenylmethylsulfonyl fluoride (PMSF. Furthermore, BpirSP-39 presented considerable thermal stability and was apparently able to activate factor XIII of the blood coagulation cascade, unlike most serine proteases. BpirSP-39 was capable of hydrolyzing different chromogenic substrates tested (S-2222, S-2302, and S-2238 while Cu2+ significantly diminished BspirSP-39 activity on the three tested substrates. The enzyme promoted platelet aggregation and also exhibited fibrinogenolytic, fibrinolytic, gelatinolytic, and amidolytic activities. The multiple alignment showed high sequence similarity to other thrombin-like enzymes from snake venoms. These results allow us to conclude that a new SP was isolated from Bothrops pirajai snake venom.

  12. Evaluation of platelet number and function and fibrinogen level in patients bitten by snakes of the Bothrops genus

    Directory of Open Access Journals (Sweden)

    Fábio Cardoso Luan

    1995-03-01

    Full Text Available Platelet function and plasma fibrinogen levels were evaluated in 14 patients, 10 males and 4females, aged 13-59years bitten by Bothrops genus snakes. There was a statistical difference (p Foram avaliadas a função plaquetária e os níveis séricos de fibrinogênio em 14 doentes picados por serpentes do gênero Bothrops, sendo 10 do sexo masculino e 4 do sexo feminino, com idades compreendidas entre 13 e 59 anos. Houve diferença estatística (p < 0,05 entre os níveis séricos defibrinogênio avaliados 24 e 48 horas após o acidente. Houve tendência à normalização após 48 horas do tratamento. A plaquetopenia foi evidente nas avaliações de 24 e 48 horas. Houve tendência à nomalização no 8o dia após o tratamento (p <0,05. Os níveis de produtos de degradação defibrina (PDF mostraram-se alterados em 83,33 % dos pacientes avaliados. Os autores sugerem que a hipoagregação esteja relacionada com níveis baixos de fibrinogênio e elevados de PDF.

  13. Spectroscopic and thermal characterization of alternative model biomembranes from shed skins of Bothrops jararaca and Spilotis pullatus

    Directory of Open Access Journals (Sweden)

    André Rolim Baby

    2009-09-01

    Full Text Available Recently, there has been an interest in the use of shed snake skin as alternative model biomembrane for human stratum corneum. This research work presented as objective the qualitative characterization of alternative model biomembranes from Bothrops jararaca and Spilotis pullatus by FT-Raman, PAS-FTIR and DSC. The employed biophysical techniques permitted the characterization of the biomembranes from shed snake skin of B. jararaca and S. pullatus by the identification of vibrational frequencies and endothermic transitions that are similar to those of the human stratum corneum.Existe atualmente interesse no uso da muda de pele de cobra como modelos alternativos de biomembranas da pele humana. O presente trabalho apresentou como objetivo a caracterização qualitativa de modelos alternativos de biomembranas provenientes de mudas de pele de cobra da Bothrops jararaca e Spilotis pullatus por espectroscopia Raman (FT-Raman, espectroscopia fotoacústica no infravermelho (PAS-FTIR e calorimetria exploratória diferencial (DSC. As técnicas biofísicas FT-Raman, PAS-FTIR e DSC permitiram caracterizar qualitativamente os modelos alternativos de biomembranas provenientes das mudas de pele de cobra da B. jararaca e S. pullatus e identificar freqüências vibracionais e transições endotérmicas similares ao estrato córneo humano.

  14. Isolation and characterization of a myotoxin from Bothrops brazili Hoge, 1953 Hoge, 1953 snake venom (Ophidia: Viperidae.

    Directory of Open Access Journals (Sweden)

    Carmen Pantigoso

    2014-06-01

    Full Text Available A myotoxin from the venom of the snake Bothrops brazili has been purified by ion-exchange chromatography on CM-Sephadex C-50 with 0,05 M ammonium acetate buffer pH 7. The homogeneity was evaluated by PAGE with and without SDS, immunodiffusion and immunoelectrophoresis. The myotoxin is a basic protein with 15,6% of Lys+Arg; it is not a glicoprotein, has not enzymatic activity, and corresponds to 25% of the whole venom protein. The molecular weight of the myotoxin was determined by PAGE-SDS and gel filtration chromatography. The myotoxin has 30 KDa of molecular weight and two polypeptide chains of 15 KDa each. Myotoxin produces a severe necrosis on the gastrocnemius muscle of white mice. The myotoxin does not have hemolytic nor anticoagulant activity. However, produces edema with a DEM of 32,6 mg of protein.

  15. Another new and threatened species of lancehead genus Bothrops (Serpentes, Viperidae) from Ilha dos Franceses, Southeastern Brazil.

    Science.gov (United States)

    Barbo, Fausto E; Gasparini, João Luiz; Almeida, Antonio P; Zaher, Hussam; Grazziotin, Felipe G; Gusmão, Rodrigo B; Ferrarini, José Mário G; Sawaya, Ricardo J

    2016-01-01

    A new insular species of the genus Bothrops is described from Ilha dos Franceses, a small island off the coast of Espírito Santo State, in southeastern Brazil. The new species differs from mainland populations of B. jararaca mainly by its small size, relative longer tail, relative smaller head length, and relative larger eyes. The new species is distinguished from B. alcatraz, B. insularis and B. otavioi by the higher number of ventral and subcaudal scales, relative longer tail and smaller head. The new species is highly abundant on the island, being nocturnal, semiarboreal, and feeding on small lizards and centipeds. Due its unique and restricted area of occurrence, declining quality of habitat, and constant use of the island for tourism, the new species may be considered as critically endangered. PMID:27394563

  16. Purification and Characterization of Jararassin-I,A Thrombin-like Enzyme from Bothrops jararaca Snake Venom

    Institute of Scientific and Technical Information of China (English)

    Débora F. VIEIRA; Leandra WATANABE; Carolina D. SANT'ANA; Silvana MARCUSSI; Suely V. SAMPAIO; Andreimar M. SOARES; Raghuvir K. ARNI

    2004-01-01

    A thrombin-like serine protease, jararassin-I, was isolated from the venom of Bothrops jararaca. The protein was obtained in high yield and purity by a single chromatographic step using the affinity resin Benzamidine-Sepharose CL-6B. SDS-PAGE and dynamic light scattering analyses indicated that the molecular mass of the enzyme was about 30 kD. The enzyme possessed fibrinogenolytic and coagulant activities. The jararassin-I degraded the Bβ chain of fibrinogen while the Aα chain and γ chain were unchanged.Proteases inhibitors, PMSF and benzamidine inhibited the coagulant activity. These results showed jararassinI is a serine protease similar to coagulating thrombin-like snake venom proteases, but it specifically cleaves Bβ chain of bovine fibrinogen. Single crystals of enzyme were obtained (0.2 mm×0.2 mm×0.2 mm) and used for X-ray diffraction experiments.

  17. Aqueous leaf extract of Jatropha gossypiifolia L. (Euphorbiaceae inhibits enzymatic and biological actions of Bothrops jararaca snake venom.

    Directory of Open Access Journals (Sweden)

    Juliana Félix-Silva

    Full Text Available Snakebites are a serious public health problem due their high morbi-mortality. The main available specific treatment is the antivenom serum therapy, which has some disadvantages, such as poor neutralization of local effects, risk of immunological reactions, high cost and difficult access in some regions. In this context, the search for alternative therapies is relevant. Therefore, the aim of this study was to evaluate the antiophidic properties of Jatropha gossypiifolia, a medicinal plant used in folk medicine to treat snakebites. The aqueous leaf extract of the plant was prepared by decoction and phytochemical analysis revealed the presence of sugars, alkaloids, flavonoids, tannins, terpenes and/or steroids and proteins. The extract was able to inhibit enzymatic and biologic activities induced by Bothrops jararaca snake venom in vitro and in vivo. The blood incoagulability was efficiently inhibited by the extract by oral route. The hemorrhagic and edematogenic local effects were also inhibited, the former by up to 56% and the latter by 100%, in animals treated with extract by oral and intraperitoneal routes, respectively. The inhibition of myotoxic action of B. jararaca reached almost 100%. According to enzymatic tests performed, it is possible to suggest that the antiophidic activity may be due an inhibitory action upon snake venom metalloproteinases (SVMPs and/or serine proteinases (SVSPs, including fibrinogenolytic enzymes, clotting factors activators and thrombin like enzymes (SVTLEs, as well upon catalytically inactive phospholipases A2 (Lys49 PLA2. Anti-inflammatory activity, at least partially, could also be related to the inhibition of local effects. Additionally, protein precipitating and antioxidant activities may also be important features contributing to the activity presented. In conclusion, the results demonstrate the potential antiophidic activity of J. gossypiifolia extract, including its significant action upon local effects

  18. Bothrops asper snake venom and its metalloproteinase BaP–1 activate the complement system. Role in leucocyte recruitment

    Directory of Open Access Journals (Sweden)

    Sandra H. P. Farsky

    2000-01-01

    Full Text Available The venom of the snake Bothrops asper, the most important poisonous snake in Central America, evokes an inflammatory response, the mechanisms of which are not well characterized. The objectives of this study were to investigate whether B. asper venom and its purified toxins – phospholipases and metalloproteinase – activate the complement system and the contribution of the effect on leucocyte recruitment. In vitro chemotaxis assays were performed using Boyden's chamber model to investigate the ability of serum incubated with venom and its purified toxins to induce neutrophil migration. The complement consumption by the venom was evaluated using an in vitro haemolytic assay. The importance of complement activation by the venom on neutrophil migration was investigated in vivo by injecting the venom into the peritoneal cavity of C5-deficient mice. Data obtained demonstrated that serum incubated with crude venom and its purified metalloproteinase BaP–1 are able to induce rat neutrophil chemotaxis, probably mediated by agent(s derived from the complement system. This hypothesis was corroborated by the capacity of the venom to activate this system in vitro. The involvement of C5a in neutrophil chemotaxis induced by venom-activated serum was demonstrated by abolishing migration when neutrophils were pre-incubated with antirat C5a receptor antibody. The relevance of the complement system in in vivo leucocyte mobilization was further demonstrated by the drastic decrease of this response in C5-deficient mice. Pre-incubation of serum with the soluble human recombinant complement receptor type 1 (sCR 1 did not prevent the response induced by the venom, but abolished the migration evoked by metalloproteinase-activated serum. These data show the role of the complement system in bothropic envenomation and the participation of metalloproteinase in the effect. Also, they suggest that the venom may contain other component(s which can cause direct activation

  19. Biochemical Characterization, Action on Macrophages, and Superoxide Anion Production of Four Basic Phospholipases A2 from Panamanian Bothrops asper Snake Venom

    Directory of Open Access Journals (Sweden)

    Aristides Quintero Rueda

    2013-01-01

    Full Text Available Bothrops asper (Squamata: Viperidae is the most important venomous snake in Central America, being responsible for the majority of snakebite accidents. Four basic PLA2s (pMTX-I to -IV were purified from crude venom by a single-step chromatography using a CM-Sepharose ion-exchange column (1.5 × 15 cm. Analysis of the N-terminal sequence demonstrated that pMTX-I and III belong to the catalytically active Asp49 phospholipase A2 subclass, whereas pMTX-II and IV belong to the enzymatically inactive Lys49 PLA2s-like subclass. The PLA2s isolated from Panama Bothrops asper venom (pMTX-I, II, III, and IV are able to induce myotoxic activity, inflammatory reaction mainly leukocyte migration to the muscle, and induce J774A.1 macrophages activation to start phagocytic activity and superoxide production.

  20. Biochemical characterization, action on macrophages, and superoxide anion production of four basic phospholipases A2 from Panamanian Bothrops asper snake venom.

    Science.gov (United States)

    Rueda, Aristides Quintero; Rodríguez, Isela González; Arantes, Eliane C; Setúbal, Sulamita S; Calderon, Leonardo de A; Zuliani, Juliana P; Stábeli, Rodrigo G; Soares, Andreimar M

    2013-01-01

    Bothrops asper (Squamata: Viperidae) is the most important venomous snake in Central America, being responsible for the majority of snakebite accidents. Four basic PLA2s (pMTX-I to -IV) were purified from crude venom by a single-step chromatography using a CM-Sepharose ion-exchange column (1.5 × 15 cm). Analysis of the N-terminal sequence demonstrated that pMTX-I and III belong to the catalytically active Asp49 phospholipase A2 subclass, whereas pMTX-II and IV belong to the enzymatically inactive Lys49 PLA2s-like subclass. The PLA2s isolated from Panama Bothrops asper venom (pMTX-I, II, III, and IV) are able to induce myotoxic activity, inflammatory reaction mainly leukocyte migration to the muscle, and induce J774A.1 macrophages activation to start phagocytic activity and superoxide production. PMID:23509779

  1. Neutralization of the edema-forming, defibrinating and coagulant effects of Bothrops asper venom by extracts of plants used by healers in Colombia

    OpenAIRE

    Núñez V.; Otero R.; Barona J.; Saldarriaga M.; Osorio R.G.; Fonnegra R.; Jiménez S.L.; Díaz A.; Quintana J.C.

    2004-01-01

    We determined the neutralizing activity of 12 ethanolic extracts of plants against the edema-forming, defibrinating and coagulant effects of Bothrops asper venom in Swiss Webster mice. The material used consisted of the leaves and branches of Bixa orellana (Bixaceae), Ficus nymphaeifolia (Moraceae), Struthanthus orbicularis (Loranthaceae) and Gonzalagunia panamensis (Rubiaceae); the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); the whole plant of Pleop...

  2. An Isoflavone from Dipteryx alata Vogel is Active against the in Vitro Neuromuscular Paralysis of Bothrops jararacussu Snake Venom and Bothropstoxin I, and Prevents Venom-Induced Myonecrosis

    OpenAIRE

    Miriéle C. Ferraz; Edson H. Yoshida; Renata V.S. Tavares; Cogo, José C; Adélia C.O. Cintra; Dal Belo, Cháriston A.; Franco, Luiz M.; dos Santos, Márcio G; Flávia A Resende; Eliana A. Varanda; Stephen Hyslop; Pilar Puebla; Arturo San Feliciano; Yoko Oshima-Franco

    2014-01-01

    Snakebite is a neglected disease and serious health problem in Brazil, with most bites being caused by snakes of the genus Bothrops. Although serum therapy is the primary treatment for systemic envenomation, it is generally ineffective in neutralizing the local effects of these venoms. In this work, we examined the ability of 7,8,3'-trihydroxy-4'-methoxyisoflavone (TM), an isoflavone from Dipteryx alata, to neutralize the neurotoxicity (in mouse phrenic nerve-diaphragm preparations) and myoto...

  3. Sexual dimorphism in development and venom production of the insular threatened pit viper Bothrops insularism (Serpentes: Viperidae) of Queimada Grande Island, Brazil

    OpenAIRE

    S.R. Travaglia-Cardoso; A. Zelanis; M. F. D. Furtado

    2010-01-01

    Bothrops insularis is a threatened snake endemic to Queimada Grande Island, southern coast of São Paulo, Brazil, and the occurrence of sexual abnormalities in females (females with functional ovaries and rudimentary hemipenis) has been reported in this population. To date there are few data regarding developmental features of this particular species. The aim of this study was to follow some developmental features in specimens maintained in captivity for seven years in the Herpetology Labora...

  4. Daño renal en ratas inducido por veneno de Bothrops neuwiedii diporus de Argentina Renal injury in rats poisoned by venom of Bothrops neuwiedii diporus from Argentina

    Directory of Open Access Journals (Sweden)

    Patricia Koscinczuk

    2004-08-01

    Full Text Available La insuficiencia renal aguda es una de las complicaciones sistémicas más frecuentes después de un accidente ofídico. En este estudio se evalúan los efectos que el veneno de Bothrops neuwiedii diporus produce en el riñón de ratas machos de la cepa Wistar. La histopatología permitió comprobar el desarrollo de necrosis tubular aguda; las lesiones iniciales se observaron a las 3 horas de la inoculación de una dosis de 700 µg del veneno, observándose en corteza renal congestión y degeneración granulohialina de las células epiteliales tubulares, acompañadas de dilatación y cilindros hialinos en la luz tubular. A las 24 horas se presentó necrosis tubular aguda en una superficie extensa de la corteza sin daño de la membrana basal tubular. Las lesiones de degeneración turbia de células epiteliales tubulares, dilatación de la luz tubular y cilindros hialinos se mantuvieron presentes hasta las 4 semanas post-inoculación. Si bien los parámetros de la bioquímica clínica asociados con insuficiencia renal aguda aumentaron a las 6 horas de la administración del veneno (urea: 1.10±0.22 g/dl; creatinina: 19.60±1.51mg/dl, a la semana descendieron a valores normales. Las densidades urinarias, en cambio, a la semana se mantuvieron más bajas que lo normal, 1.005 ± 0.001 (pAcute renal failure is one of the systemic complications that can be found in bothropic accidents. In this study the effects on male Wistar rats induced by the venom of Bothrops neuwiedii diporus were evaluated. The histopathology revealed acute tubular necrosis, lesions firstly were observed 3 hours post inoculation of 700 µg of venom. Cortical kidney congestion and granulohialin degeneration of tubular epithelial cells were observed, these lesions achieved a maximum at 24 hours after inoculation. Tubular epithelial hidropic degeneration and dilatation of tubular lumen with hyalin casts were present inclusive up to 4 weeks after inoculation. Biochemical parameter

  5. Análisis inmunoenzimático (ELISA para determinar niveles de IgG anti Bothrops atrox en accidente ofídico Immunoenzymatic determination of IgG anti bothrops atrox levels after snake bites

    Directory of Open Access Journals (Sweden)

    John J. Estrada

    1993-01-01

    Full Text Available Se desarrolló un método de inmunización de conejos con veneno de Bothrops atrox con el fin de preparar antisueros y estandarizar un inmunoanálisis (ELISA para medir niveles de IgG en pacientes con accidente ofídico. La respuesta Inmune de los conejos se siguió por inmunodifusión en doble dimensión (Ouchterlony e inmunoelectroforesis, demostrando la presencia de bandas nítidas desde el día 60 y en todas las sangrias posteriores; se comprobó que hay variabilidad individual en su respuesta inmune. El ELISA para detección de IgG humana anti B. atrox en los indígenas del Chocó fue una prueba simple y sensible (83.3% pero inespecífica por las reacciones cruzadas en individuos que habían sufrido accidentes por B. nasutus. La técnica para detectar IgG equina anti B. atrox en pacientes tratados con antiveneno fue tambIén simple y muy sensible. We developed an immunization method for the production of rabbit antisera against Bothrops atroxvenoms. An enzyme-Ilnked assay (ELISA was standardized in order to measure IgG levels after snake bites. The immune response of rabbits, as determined by Ouchterlony and immunoelectrophoresis techniques, revealed bands of precipitation from the sixtieth day on. Individual variability in the immune response of rabbits was demonstrated. For the measurement of IgG levels In Indians from the Department of Choco (Colombia, ELISA proved to be a sensitive (83.3% and simple but not an specific procedure, since there were cross-reactions in those previously bitten by B. nasutus. ELISA was also simple and sensitive (100% for the determination of equine anti B. atrox IgG antibodies in patients treated with antivenom

  6. Linear B-cell epitopes in BthTX-1, BthTX-II and BthA-1, phospholipase A₂'s from Bothrops jararacussu snake venom, recognized by therapeutically neutralizing commercial horse antivenom.

    Science.gov (United States)

    De-Simone, Salvatore G; Napoleão-Pego, Paloma; Teixeira-Pinto, Luiz A L; Santos, Jonathas D L; De-Simone, Thatiane S; Melgarejo, Anibal R; Aguiar, Aniesse S; Marchi-Salvador, Daniela P

    2013-09-01

    The benefits from treatment with antivenom sera are indubitable. However, the mechanism for toxin neutralization has not been completely elucidated. A mixture of anti-bothropic and anti-crotalic horse antivenom has been reported to be more effective in neutralizing the effects of Bothrops jararacussu snake venom than anti-bothropic antivenom alone. This study determined which regions in the three PLA₂s from B. jararacussu snake venom are bound by antibodies in tetravalent anti-bothropic and monovalent anti-crotalic commercial horse antivenom. Mapping experiments of BthTX-I, BthTX-II and BthA-I using two small libraries of 69 peptides each revealed six major IgG-binding epitopes that were recognized by both anti-bothropic and anti-crotalic horse antivenom. Two epitopes in BthTX-I were only recognized by the anti-bothropic horse antivenom, while anti-crotalic horse antivenom recognized four unique epitopes across the three PLA₂s. Our studies suggest that the harmful activities of the PLA₂s present in the venom of B. jararacussu are neutralized by the combinatorial treatment with both antivenom sera through their complementary binding sites, which provides a wide coverage on the PLA₂s. This is the first peptide microarray of PLA₂s from B. jararacussu snake venom to survey the performance of commercial horse antiophidic antivenom. Regions recognized by the protective antivenom sera are prime candidates for improved venom cocktails or a chimeric protein encoding the multiple epitopes to immunize animals as well as for designing future synthetic vaccines. PMID:23792452

  7. Crystal structure of a Bothrops toxin I, a Myotoxin K 49 like Phospholipase A{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Giotto, M.T.S.; Azevedo, W.F.; Horjales, E.; Oliva, G.; Mascarenhas, Y.P.; Garratt, R.C. [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica]|[Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Medicina

    1996-12-31

    Full text. Bothrops toxin-I (BthTX-I) is a mytoxin isolated from the Brazilian snake Bothrops jararacussu which is a member of the phospholipase A{sub 2} but presents no catalytic activity due to a D49K substitution. Protein was provided by Prof. Dr. J.R. Giglio and Prof{sup a}. Dr{sup a}. A.C.O. Cintra from the Departamento de Medicina de Ribeirao Preto and used in crystallization experiments which were performed using the vapor diffusion technique in hanging drops at 18{sup 0}C. The BthTX-I crystallized in 0.1 M HEPES, pH ranging from 7.0 to 7.6. The precipitant was (NH{sub 4})SO{sub 4} in concentrations ranging from 7.0 to 7.6. The precipitant was (NH{sub 4})SO{sub 4} in concentrations ranging from 57 to 62%. The data collection was initially performed using the automatic difractometer R-AXIS IIC from the Rigaku Co. at the Laboratorio de Cristalografia of IFESC-USP. Subsequently a second data set was collected at SERC Daresbury Laboratory in England using synchrotron radiation. BthTX-I crystallizes in space group P3{sub 1} 21 with a=b=57.58 A, c=131.27 A, {alpha}={beta}=900{sup 0}C and {gamma}=120{sup 0}C. Processing of the data was performed with the MOSFLM program yielding an R{sub merge}= 6.3% and completeness of 99.6% at 2.1 A of resolution. The structure was solved by Molecular Replacement using the package AMoRe with the Agksitrodon piscivorus piscivorus enyme as search model and refined using the refinement program X-PLOR to a final R=18.7% and R{sub free}=27.4%. The assymetric unit contains two monomers, which can be chosen such that they present similar interactions to those described for the homogeneous myotoxin II from B. asper. The interface is, however, surprisingly small when compared to other dimeric structures and is less complementary than expected. A theoretical model for phospholipid building to BthTX-I suggests that no direct interactions between the sn-2 ester bond and K49 would be expected, thus explaining the lack of catalytic activity.

  8. Alteraciones estructurales y ultraestructurales del encéfalo ocasionados por veneno de la serpiente mapanare (Bothrops colombiensis

    Directory of Open Access Journals (Sweden)

    A. Rodríguez Acosta

    2003-01-01

    Full Text Available Las actividades tóxicas y enzimáticas del veneno deserpiente mapanare (Bothrops colombiensis, cuya acción abar-ca casi todos los tejidos de mamíferos, no han sido estudiadas,estructural o ultraestructuralmente de manera exhaustiva, en elSistema Nervioso Central (SNC.Se inocularon ratones adultos C57/Bl por vía endovenosa conconcentraciones de veneno de 0,25 mg/kg de peso. Se sacrifica-ron a las 24 horas después de la inoculación de veneno y se hizoextracción del encéfalo, se fijó inmediatamente con paraformal-dehído y se realizaron cortes vértico-tranversales, tomando áreasrepresentativas de corteza cerebral y cerebelosa, asta de Amón,núcleos grises basales y tallo encefálico. Se prepararon paraestudio de histología convencional (hematoxilina y eosina ypara microscopía electrónica, en un equipo de transmisiónHitachi HS-500. Al extraer el encéfalo y hacer cortes coronalesno se observaron lesiones macroscópicas, a pesar de verse inten-sa hemorragia en las áreas dérmicas. A la microscopía óptica,los cerebros de ratones mostraron eritrocitos extravasados en lasleptomeninges y pericapilares, en los núcleos grises centrales,así como ligera espongiosis subpial, pericapilar y en el neuropi-lo. En el ámbito ultrastructural, las células endoteliales de loscapilares corticales se encontraban tumefactas con algunas vesí-culas de pinocitosis en la superficie luminal, la luz capilar oclui-da y mitocondrias hinchadas. Además se observó tumefacciónde las prolongaciones astrogliales pericapilares. El endotelio delos capilares de los plexos coroideos mostró algunas figurasmielínicas citoplasmáticas y engrosamiento de la membranabasal.En conclusión, la actividad En conclusión, la actividad del veneno de Bothrops colombien-sisno fue de la intensidad que se observa en otros tejidos delorganismo, probablemente por el efecto protector de la barrerahematoencefálica, que pudiera bloquear la acción de muchoscomponentes tóxicos y

  9. Biology and conservation status of Piraja’s Lancehead Snake Bothrops piraña Amaral, 1923 (Serpentes: Viperidae, Brazil

    Directory of Open Access Journals (Sweden)

    M.A.D. Freitas

    2014-09-01

    Full Text Available The venomous snake Bothrops pirajai (Amaral, 1923 is endemic to Brazil. Despite being described almost a century ago, very little is known about this species, which has never been studied in situ. Here, we present new data on the biology and natural history of B. pirajai based on a review of existing museum specimens and a field study (1504 man hours carried out throughout the species range. The distribution of B. pirajai was found to be restricted to the eastern Atlantic forest of the state of Bahia, Brazil, between Todosos Santos Bay, Itabuna and Ilhéus (12050’S-14050’S, 88-835 m. We recommend the species be uplisted to Endangered in the International Union for the Conservation of Nature’s global Red List of Threatened Species as its estimated extent of occurrence is under 5000km2. The effective conservation of B. pirajai will rely on addressing two key issues: improving our knowledge of the species and successfully mitigating habitat loss and fragmentation.

  10. Crystallization and preliminary X-ray diffraction analysis of three myotoxic phospholipases A2 from Bothrops brazili venom

    International Nuclear Information System (INIS)

    Two myotoxic and noncatalytic Lys49-phospholipases A2 (braziliantoxin-II and MT-II) and a myotoxic and catalytic phospholipase A2 (braziliantoxin-III) from B. brazili were crystallized. X-ray diffraction data sets were collected and molecular-replacement solutions were obtained. Two myotoxic and noncatalytic Lys49-phospholipases A2 (braziliantoxin-II and MT-II) and a myotoxic and catalytic phospholipase A2 (braziliantoxin-III) from the venom of the Amazonian snake Bothrops brazili were crystallized. The crystals diffracted to resolutions in the range 2.56–2.05 Å and belonged to space groups P3121 (braziliantoxin-II), P6522 (braziliantoxin-III) and P21 (MT-II). The structures were solved by molecular-replacement techniques. Both of the Lys49-phospholipases A2 (braziliantoxin-II and MT-II) contained a dimer in the asymmetric unit, while the Asp49-phospholipase A2 braziliantoxin-III contained a monomer in its asymmetric unit. Analysis of the quaternary assemblies of the braziliantoxin-II and MT-II structures using the PISA program indicated that both models have a dimeric conformation in solution. The same analysis of the braziliantoxin-III structure indicated that this protein does not dimerize in solution and probably acts as a monomer in vivo, similar to other snake-venom Asp49-phospholipases A2

  11. Isolation and characterization of a serine proteinase with thrombin-like activity from the venom of the snake Bothrops asper

    Directory of Open Access Journals (Sweden)

    A.V Pérez

    2008-01-01

    Full Text Available A serine proteinase with thrombin-like activity was isolated from the venom of the Central American pit viper Bothrops asper. Isolation was performed by a combination of affinity chromatography on aminobenzamidine-Sepharose and ion-exchange chromatography on DEAE-Sepharose. The enzyme accounts for approximately 0.13% of the venom dry weight and has a molecular mass of 32 kDa as determined by SDS-PAGE, and of 27 kDa as determined by MALDI-TOF mass spectrometry. Its partial amino acid sequence shows high identity with snake venom serine proteinases and a complete identity with a cDNA clone previously sequenced from this species. The N-terminal sequence of the enzyme is VIGGDECNINEHRSLVVLFXSSGFL CAGTLVQDEWVLTAANCDSKNFQ. The enzyme induces clotting of plasma (minimum coagulant dose = 4.1 µg and fibrinogen (minimum coagulant dose = 4.2 µg in vitro, and promotes defibrin(ogenation in vivo (minimum defibrin(ogenating dose = 1.0 µg. In addition, when injected intravenously in mice at doses of 5 and 10 µg, it induces a series of behavioral changes, i.e., loss of the righting reflex, opisthotonus, and intermittent rotations over the long axis of the body, which closely resemble the `gyroxin-like' effect induced by other thrombin-like enzymes from snake venoms.

  12. Morphometric studies on venom secretory cells from Bothrops jararacussu (Jararacuçu) before and after venom extraction.

    Science.gov (United States)

    Carneiro, S M; Pinto, V R; Jared, C; Lula, L A; Faria, F P; Sesso, A

    1991-01-01

    A comparative morphometrical analysis was carried out on secretory cells from Bothrops jararacussu venom glands, before manual extraction of the venom (milking) and 4 and 8 days after milking. At the 8th day after milking, the cytoplasmic volume increased by 160%. The rough endoplasmic reticulum (RER) volume density increase, up to the 8th day after milking, is mainly due to widening of the intra-scisternal space. The total volume and membrane surface of the RER. Golgi apparatus and subcomponents, secretory vesicles and mitochondria, increased during the experimental period while the volume and surface densities of these organelles, with the exception of the RER, did not vary. The numerical density of Golgi-associated microvesicles per Golgi volume unit also increased. The greatest relative increments in these parameters occurred within the first 4 days. These results are compatible with an increased rate of membrane synthesis and transport in the milked glands and suggest that the membrane biogenesis, degradation and circulation that takes place in the first week after milking is achieved through coordinated cellular mechanisms that maintain the rate between total membrane surface and total cytoplasmic volume unaltered. PMID:1926160

  13. New methodology for the obtainment of antibothropic factors from the South American opossum (Didelphis marsupialis) and jararaca snake (Bothrops jararaca).

    Science.gov (United States)

    Neves-Ferreira, A G; Valente, R H; Sá, P G; Rocha, S L; Moussatché, H; Domont, G B; Perales, J

    1999-10-01

    The antibothropic factor (ABF) from D. marsupialis was collected from perforated hollow plastic golf balls which were surgically implanted subcutaneously in anesthetized opossums, a technique originally described for the production of polyclonal antibodies. Two months after the implantation of the balls, approximately 15 ml of seromatous fluid from D. marsupialis (SFDm-50 mg total protein/ml) could be recovered monthly. Opossum serum as well as SFDm showed similar SDS-PAGE profiles and antihemorrhagic potencies against Bothrops jararaca snake venom (Bjv). The presence of ABF in SFDm was confirmed by immunoblotting, using rabbit polyclonal antibodies raised against ABF isolated from opossum serum. ABF isolated from SFDm or from serum by ion-exchange chromatography showed identical chromatographic and electrophoretic profiles. ABF fromboth sources displayed very similar antihemorrhagic and anticaseinolytic activities against Bjv. In the case of B. jararaca, polyethylene perforated tubes were inserted in the abdominal cavity and two months after implantation, approximately 4 ml of seromatous fluid from B. jararaca (SFBj-23 mg total protein/ml) were recovered. B.jararaca serum and SFBj showed the same native and SDS-PAGE band pattern. Both serum and SFBj inhibited Bjv hemorrhagic activity. We conclude that this new methodology is very suitable for continuously obtaining opossum ABF and SFBj, in large scale and in an easier way, avoiding animal suffering and eventual sacrifice. PMID:10414866

  14. Isolation of bothrasperin, a disintegrin with potent platelet aggregation inhibitory activity, from the venom of the snake Bothrops asper

    International Nuclear Information System (INIS)

    The venom of Bothrops asper induces severe coagulation disturbances in accidentally envenomed humans. However, only few studies have been conducted to identify components that interact with the hemostatic system in this venom. In the present work, we fractionated B. asper venom in order to investigate the possible presence of inhibitors of platelet aggregation. Using a combination of gel filtration, anion-exchange chromatography, and reverse-phase high performance liquid chromatography, we isolated an acidic protein which shows a single chain composition, with a molecular mass of ∼8 kDa, estimated by SDS-polyacrylamide gel electrophoresis. Its N-terminal sequence has high similarity to disintegrins isolated from different snake venoms, which are known to bind to cellular integrins such as the GPIIb/IIIa fibrinogen receptor on platelets. The purified protein exerted potent aggregation inhibitory activity on ADP-stimulated human platelets in vitro, with an estimated IC50 of 50 nM. This biological activity, together with the biochemical characteristics observed, demonstrate that the protein isolated from B. asper venom is a disintegrin, hereby named bothrasperin. This is the first disintegrin isolated from Central American viperid snake species. (Author)

  15. Bothrops asper envenoming in cattle: Clinical features and management using equine-derived whole IgG antivenom.

    Science.gov (United States)

    Rodríguez, C; Estrada, R; Herrera, M; Gómez, A; Segura, Á; Vargas, M; Villalta, M; León, G

    2016-01-01

    Snakebite envenoming is an important problem in the livestock industry in Costa Rica. Of the 22 species of venomous snakes in the country, Bothrops asper is involved in most animal envenomings. Envenomation is typically characterised by swelling and bleeding at the bite site, coagulopathy, systemic haemorrhage, and, in some cases, death. The aims of the present study were to describe the clinical manifestations of B. asper envenomation in cattle and to evaluate the treatment efficacy of antivenom administration. The clinical effects of naturally occurring envenomation were reproduced experimentally in cattle by giving an intramuscular injection of either 10 mg or 50 mg venom to replicate mild and severe envenomings, respectively. Intravenous antivenom given 6 h after experimental venom injection controlled the symptoms; a dose of 120 mL was found to be appropriate for moderate and 200 mL for severe naturally occurring envenomings. Although administration of antivenom within the first 6 h following a snakebite prevented systemic effects, it did not reduce the extent of swelling at the bite site. Delayed administration of antivenom was not effective in saving naturally envenomed animals. The results indicate that, when promptly administered, antivenom constitutes an effective treatment for B. asper snakebite envenomation in cattle. PMID:27152384

  16. Crystal structure of pira toxin-I: a calcium-independent, myotoxic phospholipase A2 - homologue from Bothrops pirajai venom

    International Nuclear Information System (INIS)

    Full text. Phospho lipases A2 (PLA2) are small enzymes that specifically hydrolysed the sn-2 ester bond of phospholipids, preferentially in lamellar or micellar aggregates at membrane surfaces. These enzymes are widely distributed in nature and have been extensively studied. Toxic proteins from venoms from Bothrops species include catalytically active PLA2s and calcium independent PLA2Lys 49 homologues. The substitution of Asp49 by Lys greatly diminishes the ability of these PLA2 to bind calcium, an ion that plays a critical role in the stabilization of the tetrahedral transition state intermediate in the catalytic mechanism. The Lys 49 PLA2 homologues and therefore catalytically inactive yet maintain cytolytic and myotoxic activities and furthermore retain the ability to disrupt the integrity of both plasma membranes and model lipid bilayers by a poorly understood Ca 2+ independente mechanism. Lys49 PLA2 homologues demonstrate a specific toxic activity against skeletal muscle, affecting only muscle fibers and leaving other tissue structure such as connective tissue, nerves and vessels essentially unharmed. In order to improve our understanding of the molecular basis of the myotoxic and Ca 2+ -independent membrane damaging activities, we have determined the crystal structure of Pr TX-I, a Lys49 variant from the venom of B. pirajai. The model presented has been determined at 2.8 angstrom resolution and refined to a crystallographic residual of 19.7% (Rfree=29.7%). (author)

  17. The effect of a lectin from the venom of the snake, Bothrops jararacussu, on tumor cell proliferation.

    Science.gov (United States)

    Pereira-Bittencourt, M; Carvalho, D D; Gagliardi, A R; Collins, D C

    1999-01-01

    Lectins have been used extensively as histochemical probes to describe changes in tumor cell surface and are known to influence the growth of cancer cells. In this study, we determined the effect of a lectin from the venom of Bothrops jararacussu (BJcuL) on the proliferation of a number of established human cancer cell lines. The growth of eight cancer cell lines was inhibited in a dose-related manner in the presence of BJcuL lectin. This lectin was most potent as an inhibitor of growth in renal (Caki-1 and A-498) and pancreatic (CFPAC-1) cancer cell lines with 50% inhibitory concentrations (IC50) of 1-2 mM. Melanoma (Wm115) and prostate (PC-3) cancer cells showed IC50 values of 7.9 and 8.5 mM, respectively, in the presence of BjcuL lectin whereas colon (Caco-2) and breast (MCF7) cancer cell lines showed no effect. Our results suggest that BJcuL lectin is an effective inhibitor of cell growth in some cancer cell lines. PMID:10628348

  18. Purification from Bothrops lanceolatus (fer de lance) venom of a fibrino(geno)lytic enzyme with esterolytic activity.

    Science.gov (United States)

    Lôbo de Araújo, A; Donato, J L; Bon, C

    1998-05-01

    Bothrops lanceolatus venom has high caseinolytic, phospholipasic, esterolytic and hemorrhagic activities. In spite of having no coagulant effect on plasma, this venom contains a thrombin-like enzyme. Using gel filtration and ion-exchange chromatographies, we have purified an esterolytic fraction (F-II-1a) from this venom with a protein yield of 4% and a 58% recovery in enzyme activity. SDS-PAGE in the presence of beta-mercaptoethanol showed that the enzyme is a single chain polypeptide with a MW=38,100. Immunodiffusion and immunoelectrophoresis of fraction F-II-1a against serum from horses immunized with B. lanceolatus venom and against rabbit antiserum prepared using fraction F-II-1a both showed a single immunoprecipitin line. The Km and Vmax values for TAME hydrolysis were 0.85 mM and 38.6 micromol/min/mg, respectively. The esterolytic activity was completely inhibited by PMSF (10 mM) but not by EDTA (20 mM). Fraction F-II-1a hydrolyzed the alpha and beta chains of fibrinogen. Degradation of the alpha chain occurred within 10 min while that of the beta-chain was slower. The enzyme had no effect on the gamma-chain even after 4 h of hydrolysis. PMID:9655635

  19. Fatal diffuse thrombotic microangiopathy after a bite by the "Fer-de-Lance" pit viper (Bothrops lanceolatus) of Martinique.

    Science.gov (United States)

    Malbranque, Stéphane; Piercecchi-Marti, Marie Dominique; Thomas, Laurent; Barbey, Christophe; Courcier, Dominique; Bucher, Bernard; Ridarch, Alex; Smadja, Didier; Warrell, David A

    2008-06-01

    In Martinique, a man bitten two days earlier by a pit viper (Bothrops lanceolatus) was hospitalized with impaired consciousness and tetraplegia. Investigations confirmed cerebral and myocardial infarctions. Resolving thrombocytopenia was associated with virtually normal blood prothrombin time/activated partial thromboplastin time but increasing hyperfibrinogenemia. Despite specific antivenom treatment, he developed fatal left ventricular failure six days after the bite. At autopsy, multiple cerebral, myocardial and mesenteric infarctions were found. Rupture of mitral chordae tendinae was the likely cause of death. Histopathologic examination showed multi-focal thrombotic microangiopathy with intimal-medial dissection by thrombi extending from foci of endothelial damage in small cerebral, myocardial, pulmonary, mesenteric, and interlobular renal arteries and arterioles. These findings were the causes of infarctions. There was intense angiogenesis in organizing cerebral infarcts. Immunohistochemical analysis showed platelet aggregates and endothelial cells within microthrombi. Viperidae venoms contain vascular endothelial toxins, notably metalloproteinase hemorrhagins, but von Willebrand factor activators or vascular endothelial growth factor-type factors are more likely to have been implicated in this case. PMID:18541759

  20. Purification and Characterization of BmooAi: A New Toxin from Bothrops moojeni Snake Venom That Inhibits Platelet Aggregation

    Directory of Open Access Journals (Sweden)

    Mayara Ribeiro de Queiroz

    2014-01-01

    Full Text Available In this paper, we describe the purification/characterization of BmooAi, a new toxin from Bothrops moojeni that inhibits platelet aggregation. The purification of BmooAi was carried out through three chromatographic steps (ion-exchange on a DEAE-Sephacel column, molecular exclusion on a Sephadex G-75 column, and reverse-phase HPLC chromatography on a C2/C18 column. BmooAi was homogeneous by SDS-PAGE and shown to be a single-chain protein of 15,000 Da. BmooAi was analysed by MALDI-TOF Spectrometry and revealed two major components with molecular masses 7824.4 and 7409.2 as well as a trace of protein with a molecular mass of 15,237.4 Da. Sequencing of BmooAi by Edman degradation showed two amino acid sequences: IRDFDPLTNAPENTA and ETEEGAEEGTQ, which revealed no homology to any known toxin from snake venom. BmooAi showed a rather specific inhibitory effect on platelet aggregation induced by collagen, adenosine diphosphate, or epinephrine in human platelet-rich plasma in a dose-dependent manner, whereas it had little or no effect on platelet aggregation induced by ristocetin. The effect on platelet aggregation induced by BmooAi remained active even when heated to 100°C. BmooAi could be of medical interest as a new tool for the development of novel therapeutic agents for the prevention and treatment of thrombotic disorders.

  1. Inhibition of the Myotoxicity Induced by Bothrops jararacussu Venom and Isolated Phospholipases A2 by Specific Camelid Single-Domain Antibody Fragments

    Science.gov (United States)

    Prado, Nidiane D. R.; Pereira, Soraya S.; da Silva, Michele P.; Morais, Michelle S. S.; Kayano, Anderson M.; Moreira-Dill, Leandro S.; Luiz, Marcos B.; Zanchi, Fernando B.; Fuly, André L.; E. F. Huacca, Maribel; Fernandes, Cleberson F.; Calderon, Leonardo A.; Zuliani, Juliana P.; Soares, Andreimar M.; Stabeli, Rodrigo G.; F. C. Fernandes, Carla

    2016-01-01

    Antivenoms, produced using animal hyperimmune plasma, remains the standard therapy for snakebites. Although effective against systemic damages, conventional antivenoms have limited efficacy against local tissue damage. Additionally, the hypersensitivity reactions, often elicited by antivenoms, the high costs for animal maintenance, the difficulty of producing homogeneous lots, and the instability of biological products instigate the search for innovative products for antivenom therapy. In this study, camelid antibody fragments (VHH) with specificity to Bothropstoxin I and II (BthTX-I and BthTX-II), two myotoxic phospholipases from Bothrops jararacussu venom, were selected from an immune VHH phage display library. After biopanning, 28 and 6 clones recognized BthTX-I and BthTX-II by ELISA, respectively. Complementarity determining regions (CDRs) and immunoglobulin frameworks (FRs) of 13 VHH-deduced amino acid sequences were identified, as well as the camelid hallmark amino acid substitutions in FR2. Three VHH clones (KF498607, KF498608, and KC329718) were capable of recognizing BthTX-I by Western blot and showed affinity constants in the nanomolar range against both toxins. VHHs inhibited the BthTX-II phospholipase A2 activity, and when tested for cross-reactivity, presented specificity to the Bothrops genus in ELISA. Furthermore, two clones (KC329718 and KF498607) neutralized the myotoxic effects induced by B. jararacussu venom, BthTX-I, BthTX-II, and by a myotoxin from Bothrops brazili venom (MTX-I) in mice. Molecular docking revealed that VHH CDRs are expected to bind the C-terminal of both toxins, essential for myotoxic activity, and to epitopes in the BthTX-II enzymatic cleft. Identified VHHs could be a biotechnological tool to improve the treatment for snake envenomation, an important and neglected world public health problem. PMID:27028872

  2. Inhibition of the Myotoxicity Induced by Bothrops jararacussu Venom and Isolated Phospholipases A2 by Specific Camelid Single-Domain Antibody Fragments.

    Science.gov (United States)

    Prado, Nidiane D R; Pereira, Soraya S; da Silva, Michele P; Morais, Michelle S S; Kayano, Anderson M; Moreira-Dill, Leandro S; Luiz, Marcos B; Zanchi, Fernando B; Fuly, André L; E F Huacca, Maribel; Fernandes, Cleberson F; Calderon, Leonardo A; Zuliani, Juliana P; Pereira da Silva, Luiz H; Soares, Andreimar M; Stabeli, Rodrigo G; F C Fernandes, Carla

    2016-01-01

    Antivenoms, produced using animal hyperimmune plasma, remains the standard therapy for snakebites. Although effective against systemic damages, conventional antivenoms have limited efficacy against local tissue damage. Additionally, the hypersensitivity reactions, often elicited by antivenoms, the high costs for animal maintenance, the difficulty of producing homogeneous lots, and the instability of biological products instigate the search for innovative products for antivenom therapy. In this study, camelid antibody fragments (VHH) with specificity to Bothropstoxin I and II (BthTX-I and BthTX-II), two myotoxic phospholipases from Bothrops jararacussu venom, were selected from an immune VHH phage display library. After biopanning, 28 and 6 clones recognized BthTX-I and BthTX-II by ELISA, respectively. Complementarity determining regions (CDRs) and immunoglobulin frameworks (FRs) of 13 VHH-deduced amino acid sequences were identified, as well as the camelid hallmark amino acid substitutions in FR2. Three VHH clones (KF498607, KF498608, and KC329718) were capable of recognizing BthTX-I by Western blot and showed affinity constants in the nanomolar range against both toxins. VHHs inhibited the BthTX-II phospholipase A2 activity, and when tested for cross-reactivity, presented specificity to the Bothrops genus in ELISA. Furthermore, two clones (KC329718 and KF498607) neutralized the myotoxic effects induced by B. jararacussu venom, BthTX-I, BthTX-II, and by a myotoxin from Bothrops brazili venom (MTX-I) in mice. Molecular docking revealed that VHH CDRs are expected to bind the C-terminal of both toxins, essential for myotoxic activity, and to epitopes in the BthTX-II enzymatic cleft. Identified VHHs could be a biotechnological tool to improve the treatment for snake envenomation, an important and neglected world public health problem. PMID:27028872

  3. Inhibition of the Myotoxicity Induced by Bothrops jararacussu Venom and Isolated Phospholipases A2 by Specific Camelid Single-Domain Antibody Fragments.

    Directory of Open Access Journals (Sweden)

    Nidiane D R Prado

    Full Text Available Antivenoms, produced using animal hyperimmune plasma, remains the standard therapy for snakebites. Although effective against systemic damages, conventional antivenoms have limited efficacy against local tissue damage. Additionally, the hypersensitivity reactions, often elicited by antivenoms, the high costs for animal maintenance, the difficulty of producing homogeneous lots, and the instability of biological products instigate the search for innovative products for antivenom therapy. In this study, camelid antibody fragments (VHH with specificity to Bothropstoxin I and II (BthTX-I and BthTX-II, two myotoxic phospholipases from Bothrops jararacussu venom, were selected from an immune VHH phage display library. After biopanning, 28 and 6 clones recognized BthTX-I and BthTX-II by ELISA, respectively. Complementarity determining regions (CDRs and immunoglobulin frameworks (FRs of 13 VHH-deduced amino acid sequences were identified, as well as the camelid hallmark amino acid substitutions in FR2. Three VHH clones (KF498607, KF498608, and KC329718 were capable of recognizing BthTX-I by Western blot and showed affinity constants in the nanomolar range against both toxins. VHHs inhibited the BthTX-II phospholipase A2 activity, and when tested for cross-reactivity, presented specificity to the Bothrops genus in ELISA. Furthermore, two clones (KC329718 and KF498607 neutralized the myotoxic effects induced by B. jararacussu venom, BthTX-I, BthTX-II, and by a myotoxin from Bothrops brazili venom (MTX-I in mice. Molecular docking revealed that VHH CDRs are expected to bind the C-terminal of both toxins, essential for myotoxic activity, and to epitopes in the BthTX-II enzymatic cleft. Identified VHHs could be a biotechnological tool to improve the treatment for snake envenomation, an important and neglected world public health problem.

  4. Combined venomics, venom gland transcriptomics, bioactivities, and antivenomics of two Bothrops jararaca populations from geographic isolated regions within the Brazilian Atlantic rainforest.

    Science.gov (United States)

    Gonçalves-Machado, Larissa; Pla, Davinia; Sanz, Libia; Jorge, Roberta Jeane B; Leitão-De-Araújo, Moema; Alves, Maria Lúcia M; Alvares, Diego Janisch; De Miranda, Joari; Nowatzki, Jenifer; de Morais-Zani, Karen; Fernandes, Wilson; Tanaka-Azevedo, Anita Mitico; Fernández, Julián; Zingali, Russolina B; Gutiérrez, José María; Corrêa-Netto, Carlos; Calvete, Juan J

    2016-03-01

    Bothrops jararaca is a slender and semi-arboreal medically relevant pit viper species endemic to tropical and subtropical forests in southern Brazil, Paraguay, and northern Argentina (Misiones). Within its geographic range, it is often abundant and is an important cause of snakebite. Although no subspecies are currently recognized, geographic analyses have revealed the existence of two well-supported B. jararaca clades that diverged during the Pliocene ~3.8Mya and currently display a southeastern (SE) and a southern (S) Atlantic rainforest (Mata Atlântica) distribution. The spectrum, geographic variability, and ontogenetic changes of the venom proteomes of snakes from these two B. jararaca phylogroups were investigated applying a combined venom gland transcriptomic and venomic analysis. Comparisons of the venom proteomes and transcriptomes of B. jararaca from the SE and S geographic regions revealed notable interpopulational variability that may be due to the different levels of population-specific transcriptional regulation, including, in the case of the southern population, a marked ontogenetic venom compositional change involving the upregulation of the myotoxic PLA2 homolog, bothropstoxin-I. This population-specific marker can be used to estimate the proportion of venom from the southern population present in the B. jararaca venom pool used for the Brazilian soro antibotrópico (SAB) antivenom production. On the other hand, the southeastern population-specific D49-PLA2 molecules, BinTX-I and BinTX-II, lend support to the notion that the mainland ancestor of Bothrops insularis was originated within the same population that gave rise to the current SE B. jararaca phylogroup, and that this insular species endemic to Queimada Grande Island (Brazil) expresses a pedomorphic venom phenotype. Mirroring their compositional divergence, the two geographic B. jararaca venom pools showed distinct bioactivity profiles. However, the SAB antivenom manufactured in Vital Brazil

  5. Identificación molecular y actividad sobre sustratos cromogénicos de la venombina A del veneno de la serpiente peruana Bothrops atrox

    OpenAIRE

    Gustavo A. Sandoval; Fanny Lazo; Edith Rodriguez; Armando Yarlequé; Russolina B. Zingali

    2011-01-01

    En el presente trabajo se ha realizado la identificación molecular de la enzima similar a trombina (EST) del veneno de Bothrops atrox y se ha evaluado su actividad enzimática sobre diversos sustratos sintéticos. La enzima fue purificada utilizando tres pasos cromatrográficos, sobre Sephadex G-75, CM-Sephadex C-50 y Agarosa-PAB, determinándose su peso molecular por PAGE-SDS. La identificación molecular de la enzima aislada se realizó por la técnica de peptide mass fingerprinting basada en espe...

  6. Pharmacological characterisation of arthritis induced by Bothrops jararaca venom in rabbits: a positive cross talk between bradykinin, nitric oxide and prostaglandin E2.

    OpenAIRE

    Suzana B. V. Mello; Maria Luiza Guzzo; Luiz Filipe Santiago Lisboa; Farsky, Sandra H P

    2002-01-01

    BACKGROUND: Our previous results showed that nitric oxide (NO) and bradykinin (BK) mediate the arthritis induced by Bothrops jararaca venom (BjV) in rabbits. In this study, we investigated the contribution of each receptor of BK as well as the inter-relationship between NO and eicosanoids in BjV-induced arthritis. METHODS: The arthritis was induced in rabbits with 16 microg of BjV injected intra-articularly. Prostaglandin E2 (PGE2), thromboxane B2 (TxB2), leukotriene B4 (LTB4) (radioimmunoass...

  7. Efecto de plantas usadas etnomédicamente sobre la actividad hemorrágica y proteolítica inducida por Bothrops asper

    OpenAIRE

    Beatriz Badilla Baltodano; Fernando Chaves Mora; Luis Jorge Poveda Álvarez; Sandra Jiménez Castro; Gina Rodríguez Rodríguez

    2006-01-01

    Se evaluó la capacidad para neutralizar la acción hemorrágica y proteolítica causada por el veneno de la serpiente Bothrops asper de extractos acuosos de 5 plantas utilizadas etnomédicamente para tratar este problema. Este trabajo forma parte de un estudio de tamizaje farmacológico sobre las plantas usadas por los curanderos para tratar las mordeduras de serpientes. Se usaron extractos liofilizados de las hojas de Buddleja americana H.B.& K. (Buddlejaceae), Mikania guaco Humb. & Bonpl. (Aster...

  8. INHIBICIÓN IN VITRO DEL VENENO DE Bothrops asper CON EXTRACTOS ETANÓLICOS DE Brownea ariza B. (CAESALPINIACEAE IN VITRO INHIBITION OF Bothrops asper VENOM BY ETHANOL EXTRACTS FROM Brownea ariza B. (CAESALPINIACEAE

    Directory of Open Access Journals (Sweden)

    Viviana L MACK-WEN G

    2011-04-01

    Full Text Available En Colombia, cerca del 90% de los accidentes ofídicos son ocasionados por serpientes del género Bothrops, cuyos venenos provocan alteraciones locales y sistémicas, como edema, anticoagulación, hemorragia y mionecrosis. El suero antiofídico es el único tratamiento efectivo, pero su limitada acción local y escasa disponibilidad en zonas geográficas aisladas hace necesaria la búsqueda y validación de alternativas terapéuticas que actúen como recurso y disminuyan el porcentaje de secuelas de estos accidentes. Recientes estudios han reportado acción inhibitoria del extracto etanólico de Brownea rosademonte (Caesalpiniaceae sobre algunos efectos locales de estos venenos. Así, en el presente estudio in vitro se evaluó la capacidad inhibitoria de extractos etanólicos de hojas y corteza de Brownea ariza sobre las actividades proteolítica, fosfolipasa A2 y coagulante del veneno de B. asper; esta última según el efecto de coagulación in vitro, se relaciona con anticoagulación observada in vivo. Los resultados mostraron que los extractos de corteza inhiben la acción de fosfolipasas A2 (93,2 ± 0,4%, prolongan el tiempo de coagulación (más de 10 min, e inhiben la actividad proteolítica, aunque ésta última con menores efectos que el extracto foliar (77 ± 0,6% y 93,8 ± 0,6% respectivamente.In Colombia, about 90% of snakebites are caused by Bothrops snakes, whose venoms cause in vivo, local and systemic disturbances, such as edema, myonecrosis, blood-clotting disorders and hemorrhage. Antivenom is the only effective treatment to manage these poisonings, but its limited action at local level and little availability in geographically isolated areas makes necessary the validation and search for therapeutic alternatives acting as an immediate resource to reduce the percent of sequels caused in these snakebites. Recent studies have reported the inhibitory action of the Brownea rosademonte (Caesalpiniaceae extract against some local

  9. Muscle Tissue Damage Induced by the Venom of Bothrops asper: Identification of Early and Late Pathological Events through Proteomic Analysis

    Science.gov (United States)

    Herrera, Cristina; Macêdo, Jéssica Kele A.; Feoli, Andrés; Escalante, Teresa; Rucavado, Alexandra; Gutiérrez, José María; Fox, Jay W.

    2016-01-01

    The time-course of the pathological effects induced by the venom of the snake Bothrops asper in muscle tissue was investigated by a combination of histology, proteomic analysis of exudates collected in the vicinity of damaged muscle, and immunodetection of extracellular matrix proteins in exudates. Proteomic assay of exudates has become an excellent new methodological tool to detect key biomarkers of tissue alterations for a more integrative perspective of snake venom-induced pathology. The time-course analysis of the intracellular proteins showed an early presence of cytosolic and mitochondrial proteins in exudates, while cytoskeletal proteins increased later on. This underscores the rapid cytotoxic effect of venom, especially in muscle fibers, due to the action of myotoxic phospholipases A2, followed by the action of proteinases in the cytoskeleton of damaged muscle fibers. Similarly, the early presence of basement membrane (BM) and other extracellular matrix (ECM) proteins in exudates reflects the rapid microvascular damage and hemorrhage induced by snake venom metalloproteinases. The presence of fragments of type IV collagen and perlecan one hour after envenoming suggests that hydrolysis of these mechanically/structurally-relevant BM components plays a key role in the genesis of hemorrhage. On the other hand, the increment of some ECM proteins in the exudate at later time intervals is likely a consequence of the action of endogenous matrix metalloproteinases (MMPs) or of de novo synthesis of ECM proteins during tissue remodeling as part of the inflammatory reaction. Our results offer relevant insights for a more integrative and systematic understanding of the time-course dynamics of muscle tissue damage induced by B. asper venom and possibly other viperid venoms. PMID:27035343

  10. Isotopic change in the tissues of Bothrops atrox in captivity collected from environments of the eastern Amazon

    Science.gov (United States)

    Martinez, M. G.; Chalkidis, H. D.; Amazonas, D. R.; da Silva, A. M.; De Oliveira, R., Jr.; Camargo, P. B.

    2013-12-01

    The Bothrops atrox is little studied because it is sympatric Amazonian animals, and very little is known about the ecology and natural history of this species. It has a generalist diet and the distribution of this species is very wide. The adult animals forage mostly on the ground, while the younger animals prefer to stay on the vegetation. They are easily find in the rainy months in areas near lakes and seasonally flooded and are difficult to find in the driest months, a period where there is less availability of preys in these environments. Due to its aggressiveness, is considered one of the most feared snakes in South America and in the eastern Amazon, being responsible for the largest number of snakebites in the region. Through stable isotope carbon-13 and nitrogen-15, is intended to characterize the variations of the feeding habits of these collected animals in different environments and also when they are kept in captivity, feeding the animal's bioterium. The serpents were collected in environments with different land uses, such as native forest, savannah, pasture and have been brought to the serpentarium Integrated College Tapajos (FIT), being retained in order to Samplings throughout the experiment with feeding mice's own bioterium. When these snakes came from different locations, samples were collected scales and blood (T0), before receiving the new supply (captive), and every time we fed the mice the vivarium, new tissue samples were collected, (T1, T2, T3) to exchange all the nature of food for the food captivity.Based on the results of δ13C and δ15N, the samples collected in the tissues of snakes of different environments (nature and captivity), it was observed that changes in food sources reflect changes in tissues (blood and scales), also reflecting the production of poison different periods of turnover of absorbed material in those tissues, contributing to the study of animal ecology and behavior in relation to habitat.

  11. N-terminal domain of Bothrops asper Myotoxin II Enhances the Activity of Endothelin Converting Enzyme-1 and Neprilysin

    Science.gov (United States)

    Smith, A. Ian; Rajapakse, Niwanthi W.; Kleifeld, Oded; Lomonte, Bruno; Sikanyika, Nkumbu L.; Spicer, Alexander J.; Hodgson, Wayne C.; Conroy, Paul J.; Small, David H.; Kaye, David M.; Parkington, Helena C.; Whisstock, James C.; Kuruppu, Sanjaya

    2016-01-01

    Neprilysin (NEP) and endothelin converting enzyme-1 (ECE-1) are two enzymes that degrade amyloid beta in the brain. Currently there are no molecules to stimulate the activity of these enzymes. Here we report, the discovery and characterisation of a peptide referred to as K49-P1-20, from the venom of Bothrops asper which directly enhances the activity of both ECE-1 and NEP. This is evidenced by a 2- and 5-fold increase in the Vmax of ECE-1 and NEP respectively. The K49-P1-20 concentration required to achieve 50% of maximal stimulation (AC50) of ECE-1 and NEP was 1.92 ± 0.07 and 1.33 ± 0.12 μM respectively. Using BLITZ biolayer interferometry we have shown that K49-P1-20 interacts directly with each enzyme. Intrinsic fluorescence of the enzymes change in the presence of K49-P1-20 suggesting a change in conformation. ECE-1 mediated reduction in the level of endogenous soluble amyloid beta 42 in cerebrospinal fluid is significantly higher in the presence of K49-P1-20 (31 ± 4% of initial) compared with enzyme alone (11 ± 5% of initial; N = 8, P = 0.005, unpaired t-test). K49-P1-20 could be an excellent research tool to study mechanism(s) of enzyme stimulation, and a potential novel drug lead in the fight against Alzheimer’s disease. PMID:26931059

  12. Poor regenerative outcome after skeletal muscle necrosis induced by Bothrops asper venom: alterations in microvasculature and nerves.

    Directory of Open Access Journals (Sweden)

    Rosario Hernández

    Full Text Available BACKGROUND: Viperid snakebite envenoming is characterized by prominent local tissue damage, including muscle necrosis. A frequent outcome of such local pathology is deficient skeletal muscle regeneration, which causes muscle dysfunction, muscle loss and fibrosis, thus provoking permanent sequelae that greatly affect the quality of life of patients. The causes of such poor regenerative outcome of skeletal muscle after viperid snakebites are not fully understood. METHODOLOGY/PRINCIPAL FINDINGS: A murine model of muscle necrosis and regeneration was adapted to study the effects of the venom and isolated toxins of Bothrops asper, the medically most important snake in Central America. Gastrocnemius muscle was injected with either B. asper venom, a myotoxic phospholipase A(2 (Mtx, a hemorrhagic metalloproteinase (SVMP, or saline solution. At various time intervals, during one month, tissue samples were collected and analyzed by histology, and by immunocytochemical and immunohistochemical techniques aimed at detecting muscle fibers, collagen, endothelial cells, myoblasts, myotubes, macrophages, TUNEL-positive nuclei, and axons. A successful regenerative response was observed in muscle injected with Mtx, which induces myonecrosis but does not affect the microvasculature. In contrast, poor regeneration, with fibrosis and atrophic fibers, occurred when muscle was injected with venom or SVMP, both of which provoke necrosis, microvascular damage leading to hemorrhage, and poor axonal regeneration. CONCLUSIONS/SIGNIFICANCE: The deficient skeletal muscle regeneration after injection of B. asper venom is likely to depend on the widespread damage to the microvasculature, which affects the removal of necrotic debris by phagocytes, and the provision of nutrients and oxygen required for regeneration. In addition, deficient axonal regeneration is likely to contribute to the poor regenerative outcome in this model.

  13. Snakebites and ethnobotany in the northwest region of Colombia. Part III: neutralization of the haemorrhagic effect of Bothrops atrox venom.

    Science.gov (United States)

    Otero, R; Núñez, V; Barona, J; Fonnegra, R; Jiménez, S L; Osorio, R G; Saldarriaga, M; Díaz, A

    2000-11-01

    Thirty-one of 75 extracts of plants used by traditional healers for snakebites, had moderate or high neutralizing ability against the haemorrhagic effect of Bothrops atrox venom from Antioquia and Chocó, north-western Colombia. After preincubation of several doses of every extract (7.8-4000 microg/mouse) with six minimum haemorrhagic doses (10 microg) of venom, 12 of them demonstrated 100% neutralizing capacity when the mixture was i.d. injected into mice (18-20 g). These were the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); the whole plants of Pleopeltis percussa (Polypodiaceae), Trichomanes elegans (Hymenophyllaceae) and Senna dariensis (Caesalpiniaceae); rhizomes of Heliconia curtispatha (Heliconiaceae); leaves and branches of Bixa orellana (Bixaceae), Philodendron tripartitum (Araceae), Struthanthus orbicularis (Loranthaceae) and Gonzalagunia panamensis (Rubiaceae); the ripe fruits of Citrus limon (Rutaceae); leaves, branches and stem of Ficus nymphaeifolia (Moraceae). Extracts of another 19 species showed moderate neutralization (21-72%) at doses up to 4 mg/mouse, e.g. the whole plants of Aristolochia grandiflora (Aristolochiaceae), Columnea kalbreyeriana (Gesneriaceae), Sida acuta (Malvaceae), Selaginella articulata (Selaginellaceae) and Pseudoelephantopus spicatus (Asteraceae); rhizomes of Renealmia alpinia (Zingiberaceae); the stem of Strychnos xinguensis (Loganiaceae); leaves, branches and stems of Hyptis capitata (Lamiaceae), Ipomoea cairica (Convolvulaceae), Neurolaena lobata (Asteraceae), Ocimum micranthum (Lamiaceae), Piper pulchrum (Piperaceae), Siparuna thecaphora (Monimiaceae), Castilla elastica (Moraceae) and Allamanda cathartica (Apocynaceae); the macerated ripe fruits of Capsicum frutescens (Solanaceae); the unripe fruits of Crescentia cujete (Bignoniaceae); leaves and branches of Piper arboreum (Piperaceae) and Passiflora quadrangularis (Passifloraceae). When the extracts were independently administered

  14. Muscle Tissue Damage Induced by the Venom of Bothrops asper: Identification of Early and Late Pathological Events through Proteomic Analysis.

    Science.gov (United States)

    Herrera, Cristina; Macêdo, Jéssica Kele A; Feoli, Andrés; Escalante, Teresa; Rucavado, Alexandra; Gutiérrez, José María; Fox, Jay W

    2016-04-01

    The time-course of the pathological effects induced by the venom of the snake Bothrops asper in muscle tissue was investigated by a combination of histology, proteomic analysis of exudates collected in the vicinity of damaged muscle, and immunodetection of extracellular matrix proteins in exudates. Proteomic assay of exudates has become an excellent new methodological tool to detect key biomarkers of tissue alterations for a more integrative perspective of snake venom-induced pathology. The time-course analysis of the intracellular proteins showed an early presence of cytosolic and mitochondrial proteins in exudates, while cytoskeletal proteins increased later on. This underscores the rapid cytotoxic effect of venom, especially in muscle fibers, due to the action of myotoxic phospholipases A2, followed by the action of proteinases in the cytoskeleton of damaged muscle fibers. Similarly, the early presence of basement membrane (BM) and other extracellular matrix (ECM) proteins in exudates reflects the rapid microvascular damage and hemorrhage induced by snake venom metalloproteinases. The presence of fragments of type IV collagen and perlecan one hour after envenoming suggests that hydrolysis of these mechanically/structurally-relevant BM components plays a key role in the genesis of hemorrhage. On the other hand, the increment of some ECM proteins in the exudate at later time intervals is likely a consequence of the action of endogenous matrix metalloproteinases (MMPs) or of de novo synthesis of ECM proteins during tissue remodeling as part of the inflammatory reaction. Our results offer relevant insights for a more integrative and systematic understanding of the time-course dynamics of muscle tissue damage induced by B. asper venom and possibly other viperid venoms. PMID:27035343

  15. Bothrops lanceolatus (Fer de lance) venom induces oedema formation and increases vascular permeability in the mouse hind paw.

    Science.gov (United States)

    de Araújo, A L; de Souza, A O; da Cruz-Höfling, M A; Flores, C A; Bon, C

    2000-02-01

    The ability of snake venoms to increase vascular permeability and to induce oedema through the release of pharmacologically active substances is well known. We have studied the oedema and vascular permeability induced by Bothrops lanceolatus venom in male Swiss white mice. Paw oedema was induced by the subplantar injection of B. lanceolatus venom (125-1000 ng/paw) and was quantified as the increase in paw weight. Changes in vascular permeability were assessed by measuring the amount of Evans blue dye extravasation. The oedema and the increase in vascular permeability were maximal within 2 h and had resolved after 24 h. The administration of the vasodilator iloprost (20 ng/paw) immediately after B. lanceolatus venom potentiated the oedema and the increase in vascular permeability by approximately four-fold. Pretreating the mice with indomethacin, dexamethasone, NDGA or BW A4C inhibited the venom-induced oedema and the increase in vascular permeability. In contrast, histamine, serotonin and PAF-acether antagonists (mepyramine, cyproheptadine and WEB 2086, respectively) were ineffective. Histological examination showed that B. lanceolatus venom (250 ng and 500 ng/paw) caused thickening of the inner dermal layers which was accompanied by extensive intercellular spaces indicative of oedema. In addition, there was a marked infiltration of inflammatory cells, particularly neutrophils, into the underlying muscle layer. The latter, however, remained morphologically unaffected during the 3 h of observation. Venom doses larger than 500 ng/paw produced intense haemorrhage. These results indicate that B. lanceolatus venom induces oedema and increases vascular permeability in the mouse hind paw. The principal mediators of this inflammatory response are cyclooxygenase and lipoxygenase products. PMID:10665802

  16. Effect of Diterpenes Isolated of the Marine Alga Canistrocarpus cervicornis against Some Toxic Effects of the Venom of the Bothrops jararaca Snake

    Directory of Open Access Journals (Sweden)

    Thaisa Francielle Souza Domingos

    2015-02-01

    Full Text Available Snake venoms are composed of a complex mixture of active proteins and peptides which induce a wide range of toxic effects. Envenomation by Bothrops jararaca venom results in hemorrhage, edema, pain, tissue necrosis and hemolysis. In this work, the effect of a mixture of two secodolastane diterpenes (linearol/isolinearol, previously isolated from the Brazilian marine brown alga, Canistrocarpus cervicornis, was evaluated against some of the toxic effects induced by B. jararaca venom. The mixture of diterpenes was dissolved in dimethylsulfoxide and incubated with venom for 30 min at room temperature, and then several in vivo (hemorrhage, edema and lethality and in vitro (hemolysis, plasma clotting and proteolysis assays were performed. The diterpenes inhibited hemolysis, proteolysis and hemorrhage, but failed to inhibit clotting and edema induced by B. jararaca venom. Moreover, diterpenes partially protected mice from lethality caused by B. jararaca venom. The search for natural inhibitors of B. jararaca venom in C. cervicornis algae is a relevant subject, since seaweeds are a rich and powerful source of active molecules which are as yet but poorly explored. Our results suggest that these diterpenes have the potential to be used against Bothropic envenomation accidents or to improve traditional treatments for snake bites.

  17. Structural and biophysical studies with the MjTX-I, a Lys49-phospholipase A{sub 2} homologue from Bothrops moojeni venom

    Energy Technology Data Exchange (ETDEWEB)

    Salvador, G.H.M.; Fernandes, C.A.H.; Fernandez, R.M.; Fontes, M.R.M. [UNESP, Universidade Estadual Paulista, Botucatu, SP (Brazil); Marchi-Salvador, D.P. [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil); Soares, A.M. [Universidade de Sao Paulo (USP-RP), Ribeirao Preto, SP (Brazil); Oliveira, C.L.P [Universidade de Sao Paulo (USP), SP (Brazil)

    2012-07-01

    Full text: Phospholipases A{sub 2} (PLA{sub 2}) are small proteins found in a great diversity of organisms and belong to a superfamily of proteins involved in many important pharmacological processes, such as neurotoxicity, myotoxicity, platelet aggregation, and anticoagulant activity. Ophidic accidents caused by snakes from Bothrops genus are not efficiently neutralized by conventional serum therapy, and then detailed studies with this class of proteins may be very important to supplement this conventional therapy. Miotoxin-I (MjTX-I) is a basic Lys49-PLA{sub 2}, isolated from Bothrops moojeni snake venom, which induces a drastic local myonecrosis. Crystal structure of MjTX-I shows four molecules in the asymmetric unit, an unusually oligomeric conformation for snake venom Lys49-PLA{sub 2}s. However, bioinformatics techniques indicate a dimer as the biological oligomeric conformation. To get additional information of its biological conformation, we also performed Dynamic Light Scattering, Size Exclusion Chromatography and Small Angle X-ray Scattering experiments. These techniques showed a monomer as the most probable biological conformation in water; however small changes in pH and ionic strength result in different oligomeric assemblies. These novel information for Lys49-PLA{sub 2}s may result in important conclusions for this intriguing class of toxins. (author)

  18. Neutralization of pharmacological and toxic activities of Bothrops jararacussu snake venom and isolated myotoxins by Serjania erecta methanolic extract and its fractions

    Directory of Open Access Journals (Sweden)

    RS Fernandes

    2011-01-01

    Full Text Available Most of the snakebites recorded in Brazil are caused by the Bothrops genus. Given that the local tissue damage caused by this genus cannot be treated by antivenom therapy, numerous studies are focusing on supplementary alternatives, such as the use of medicinal plants. Serjania erecta has already demonstrated anti-inflammatory, antiseptic and healing properties. In the current study, the aerial parts of S. erecta were extracted with methanol, then submitted to chromatographic fractionation on a Sephadex LH20 column and eluted with methanol, which resulted in four main fractions. The crude extract and fractions neutralized the toxic activities of Bothrops jararacussu snake venom and isolated myotoxins (BthTX-I and II. Results showed that phospholipase A2, fibrinogenolytic, myotoxic and hemorrhagic activities were inhibited by the extract. Moreover, the myotoxic and edematous activities induced by BthTX-I, and phospholipase A2 activity induced by BthTX-II, were inhibited by the extract of S. erecta and its fraction. The clotting time on bovine plasma was significantly prolonged by the inhibitory action of fractions SF3 and SF4. This extract is a promising source of natural inhibitors, such as flavonoids and tannins, which act by forming complexes with metal ions and proteins, inhibiting the action of serineproteases, metalloproteases and phospholipases A2.

  19. Structural and biophysical studies with the MjTX-I, a Lys49-phospholipase A2 homologue from Bothrops moojeni venom

    International Nuclear Information System (INIS)

    Full text: Phospholipases A2 (PLA2) are small proteins found in a great diversity of organisms and belong to a superfamily of proteins involved in many important pharmacological processes, such as neurotoxicity, myotoxicity, platelet aggregation, and anticoagulant activity. Ophidic accidents caused by snakes from Bothrops genus are not efficiently neutralized by conventional serum therapy, and then detailed studies with this class of proteins may be very important to supplement this conventional therapy. Miotoxin-I (MjTX-I) is a basic Lys49-PLA2, isolated from Bothrops moojeni snake venom, which induces a drastic local myonecrosis. Crystal structure of MjTX-I shows four molecules in the asymmetric unit, an unusually oligomeric conformation for snake venom Lys49-PLA2s. However, bioinformatics techniques indicate a dimer as the biological oligomeric conformation. To get additional information of its biological conformation, we also performed Dynamic Light Scattering, Size Exclusion Chromatography and Small Angle X-ray Scattering experiments. These techniques showed a monomer as the most probable biological conformation in water; however small changes in pH and ionic strength result in different oligomeric assemblies. These novel information for Lys49-PLA2s may result in important conclusions for this intriguing class of toxins. (author)

  20. Biotechnological application of protein Leuc-B isolated from Bothrops leucurus venom as a prototype for antitumoral radiopharmaceutical;Aplicacao biotecnologica da proteina Leuc-B isolada da peconha de Bothrops leucurus como prototipo de radiofarmaco antitumoral

    Energy Technology Data Exchange (ETDEWEB)

    Gabriel, Lucilene Marcia

    2010-07-01

    According to the report of the International Agency for Research on Cancer, the growth of this disease implies the death of 17 million people a year by 2030. Although the knowledge on development of cancer is growing considerably, just a few advances in the diagnosis and therapy has been achieved. Faced with this scenario, it is clear the need for new substances more specifics with low toxicity to the patient, which can be used for diagnosis and treatment of cancer. Membrane receptors over expressed in tumor cells are promising target candidates for development of diagnostic and therapeutical tools. Integrins are a family of hetero dimeric cell surface adhesion receptors able to recognize and bind to proteins in the extracellular matrix (ECM). This recognition is mainly through the RGD domains presents in both the cell surface as in the protein from the ECM. Various integrins have been identified as regulators of tumor progression. The RGD domain is also found in some snake venoms named disintegrins. Disintegrins inhibit cell-matrix and a cell-cell interactions mediated by integrins and it has been shown that these proteins are able to inhibit metastasis in processes dependent on integrin. The disintegrin-like (ECD), as well as RGD-disintegrin are also able to bind to cell surface integrins and inhibit their adhesion to the natural ligands. In this work it was purified from Bothrops leucurus venom (VBL), a metalloproteinase-class P-III with disintegrin-like domain (ECD), Leucurolisina B (Leuc-B). This metalloproteinase and the crude venom were used to evaluate their applicability in the differential detection of tumors. In vitro results demonstrated that both VBL and Leuc-B have potent antitumoral effect on several cancer cell lines: U87, T98, RT2 (glioblastoma), MCF7 (breast), Ehrlich and UACC (melanoma) with IC{sub 50} values of approximately 0.6 muM. The morphological changes observed in these strains when treated with Leuc-B, and data from the DAPI staining

  1. Power Module

    OpenAIRE

    Gang Fang

    2009-01-01

    Abstract: In this paper, we discuss the upgrade problem of module, and introduce the concepts of the power module, regular power module and uniform power module. We give some results of them. Key words: power group; power module; regular power module; uniform power module

  2. Biotechnological application of protein Leuc-B isolated from Bothrops leucurus venom as a prototype for antitumoral radiopharmaceutical

    International Nuclear Information System (INIS)

    According to the report of the International Agency for Research on Cancer, the growth of this disease implies the death of 17 million people a year by 2030. Although the knowledge on development of cancer is growing considerably, just a few advances in the diagnosis and therapy has been achieved. Faced with this scenario, it is clear the need for new substances more specifics with low toxicity to the patient, which can be used for diagnosis and treatment of cancer. Membrane receptors over expressed in tumor cells are promising target candidates for development of diagnostic and therapeutical tools. Integrins are a family of hetero dimeric cell surface adhesion receptors able to recognize and bind to proteins in the extracellular matrix (ECM). This recognition is mainly through the RGD domains presents in both the cell surface as in the protein from the ECM. Various integrins have been identified as regulators of tumor progression. The RGD domain is also found in some snake venoms named disintegrins. Disintegrins inhibit cell-matrix and a cell-cell interactions mediated by integrins and it has been shown that these proteins are able to inhibit metastasis in processes dependent on integrin. The disintegrin-like (ECD), as well as RGD-disintegrin are also able to bind to cell surface integrins and inhibit their adhesion to the natural ligands. In this work it was purified from Bothrops leucurus venom (VBL), a metalloproteinase-class P-III with disintegrin-like domain (ECD), Leucurolisina B (Leuc-B). This metalloproteinase and the crude venom were used to evaluate their applicability in the differential detection of tumors. In vitro results demonstrated that both VBL and Leuc-B have potent antitumoral effect on several cancer cell lines: U87, T98, RT2 (glioblastoma), MCF7 (breast), Ehrlich and UACC (melanoma) with IC50 values of approximately 0.6 μM. The morphological changes observed in these strains when treated with Leuc-B, and data from the DAPI staining solution

  3. Diversity of metalloproteinases in Bothrops neuwiedi snake venom transcripts: evidences for recombination between different classes of SVMPs

    Directory of Open Access Journals (Sweden)

    Valente Richard H

    2011-11-01

    Full Text Available Abstract Background Snake venom metalloproteinases (SVMPs are widely distributed in snake venoms and are versatile toxins, targeting many important elements involved in hemostasis, such as basement membrane proteins, clotting proteins, platelets, endothelial and inflammatory cells. The functional diversity of SVMPs is in part due to the structural organization of different combinations of catalytic, disintegrin, disintegrin-like and cysteine-rich domains, which categorizes SVMPs in 3 classes of precursor molecules (PI, PII and PIII further divided in 11 subclasses, 6 of them belonging to PII group. This heterogeneity is currently correlated to genetic accelerated evolution and post-translational modifications. Results Thirty-one SVMP cDNAs were full length cloned from a single specimen of Bothrops neuwiedi snake, sequenced and grouped in eleven distinct sequences and further analyzed by cladistic analysis. Class P-I and class P-III sequences presented the expected tree topology for fibrinolytic and hemorrhagic SVMPs, respectively. In opposition, three distinct segregations were observed for class P-II sequences. P-IIb showed the typical segregation of class P-II SVMPs. However, P-IIa grouped with class P-I cDNAs presenting a 100% identity in the 365 bp at their 5' ends, suggesting post-transcription events for interclass recombination. In addition, catalytic domain of P-IIx sequences segregated with non-hemorrhagic class P-III SVMPs while their disintegrin domain grouped with other class P-II disintegrin domains suggesting independent evolution of catalytic and disintegrin domains. Complementary regions within cDNA sequences were noted and may participate in recombination either at DNA or RNA levels. Proteins predicted by these cDNAs show the main features of the correspondent classes of SVMP, but P-IIb and P-IIx included two additional cysteines cysteines at the C-termini of the disintegrin domains in positions not yet described. Conclusions In

  4. Caracterización de la enzima similar a trombina del veneno de Bothrops pictus "jergón de costa

    OpenAIRE

    Dan Vivas-Ruiz; Gustavo A Sandoval; Fanny Lazo; Edith Rodríguez; Armando Yarlequé; Eladio Flores-Sánchez

    2015-01-01

    Objetivos. Realizar una caracterización bioquímica y molecular del principio coagulante del veneno de Bothrops pictus. Materiales y métodos. Se realizó la amplificación del gen a partir de cDNA, se analizó la homología de la secuencia nucleotídica y de la proteína deducida. Se procedió a purificar la enzima para los análisis de secuenciación directa N terminal de los primeros 20 aminoácidos y los ensayos de coagulación sobre plasma humano y fibrinógeno humano, por otro lado, se evaluó el patr...

  5. Sarcophagidae and Calliphoridae related to Rhinella schneideri (Anura, Bufonidae, Bothrops moojeni (Reptilia, Serpentes and Mabuya frenata (Reptilia, Lacertilia carcasses in Brasília, Brazil

    Directory of Open Access Journals (Sweden)

    Roger Maia Dias Ledo

    2012-09-01

    Full Text Available Sarcophagidae and Calliphoridae related to Rhinella schneideri (Anura, Bufonidae, Bothrops moojeni (Reptilia, Serpentes and Mabuya frenata (Reptilia, Lacertilia carcasses in Brasília, Brazil. This paper presents a list of necrophagous insects associated with small size carrions of two reptiles and one amphibian, found in areas of riparian forests and Cerrado sensu stricto physiognomies in a Conservation Unit located in Brasilia, Distrito Federal. We found seven species of insects related to these carcasses, being five Sarcophagidae, one Calliphoridae and one Braconidae parasitoid wasp. Lucilia eximia and Peckia (Pattonella intermutans were the most abundant species in the study, corroborating with other studies that suggests that these species have specializations for colonization of small size animal carcasses.

  6. Immunological studies on BaH1 and BaP1, two hemorrhagic metalloproteinases from the venom of the snake Bothrops asper.

    Science.gov (United States)

    Rucavado, A; Borkow, G; Ovadia, M; Gutiérrez, J M

    1995-08-01

    No immunological cross-reactivity was observed between BaH1 and BaP1, two hemorrhagic metalloproteinases isolated from B. asper venom, by gel immunodiffusion, Western blotting and neutralization studies. Cross-reactivity was detected with antisera against these toxins in several crotaline and viperine snake venoms by ELISA, whereas no reactivity was observed with either antiserum against the venoms of Bothrops nummifer, Crotalus durissus terrificus, Vipera russelli and several elapid venoms. Antiserum against native BaH1 neutralized hemorrhagic activity of the venoms of B. asper, B. atrox, B. jararaca, Crotalus atrox, C. durissus durissus, Echis carinatus and Trimeresurus flavoviridis, being ineffective against the venoms of Agkistrodon bilineatus and Lachesis muta. PMID:8533144

  7. Clinical indicators of envenoming and serum levels of venom antigens in patients bitten by Bothrops lanceolatus in Martinique. Research Group on Snake Bites in Martinique.

    Science.gov (United States)

    Bucher, B; Canonge, D; Thomas, L; Tyburn, B; Robbe-Vincent, A; Choumet, V; Bon, C; Ketterlé, J; Lang, J

    1997-01-01

    An enzyme-linked immunosorbent assay was developed to measure venom antigen levels in the serum of 40 patients bitten by Bothrops lanceolatus. The grading system used for the severity of envenomation (grades 1 to 4, minor to major) was predominantly based on the presence of local signs. Serum venom levels increased with the grade of severity (P or = 15 ng/mL were observed in all patients with progressive aggravation of swelling despite the use of early antivenom therapy. No venom was detectable in blood samples taken after completion of serotherapy. All patients recovered. These results confirm the efficacy of both the clinical severity scoring system used and the therapeutic regimen. PMID:9196765

  8. Caracterización de la enzima similar a trombina del veneno de Bothrops pictus "jergón de costa

    Directory of Open Access Journals (Sweden)

    Dan Vivas-Ruiz

    2015-10-01

    Full Text Available Objetivos. Realizar una caracterización bioquímica y molecular del principio coagulante del veneno de Bothrops pictus. Materiales y métodos. Se realizó la amplificación del gen a partir de cDNA, se analizó la homología de la secuencia nucleotídica y de la proteína deducida. Se procedió a purificar la enzima para los análisis de secuenciación directa N terminal de los primeros 20 aminoácidos y los ensayos de coagulación sobre plasma humano y fibrinógeno humano, por otro lado, se evaluó el patrón de corte del fibrinógeno por medio de PAGE SDS y la actividad defibrinogenante en roedores albinos (18-22 g. Se determinó el contenido de carbohidratos asociados, el efecto de inhibidores clásicos de proteasas y el efecto de iones bajo la forma de cloruros. Resultados. La enzima mostró homología en la estructura primaria con otras TLEs reportadas para la familia Viperidae, la dosis coagulante mínima (DCM sobre plasma y fibrinógeno humano fue de 18 y 6 µg respectivamente y su potencia coagulante fue de 131,1 NHI unidades de trombina. La enzima se mostró estable a condiciones fisiológicas y prescinde de iones para su actividad. Los carbohidratos asociados detectados fueron hexosas (25,76%, hexosaminas (13,1% y ácido siálico (0,76%. Los agentes fluoruro de fenil metil sulfonil floruro (PMSF ditiotreitol (DTT fueron los principales inhibidores de la actividad enzimática en tanto que la heparina no tuvo efecto inhibidor. Conclusiones. El principio coagulante del veneno de Bothrops pictus es una enzima similar a trombina

  9. Caracterización de la enzima similar a trombina del veneno de Bothrops pictus "jergón de costa

    Directory of Open Access Journals (Sweden)

    Dan Vivas-Ruiz

    2015-12-01

    Full Text Available Objetivos. Realizar una caracterización bioquímica y molecular del principio coagulante del veneno de Bothrops pictus. Materiales y métodos. Se realizó la amplificación del gen a partir de cDNA, se analizó la homología de la secuencia nucleotídica y de la proteína deducida. Se procedió a purificar la enzima para los análisis de secuenciación directa N terminal de los primeros 20 aminoácidos y los ensayos de coagulación sobre plasma humano y fibrinógeno humano, por otro lado, se evaluó el patrón de corte del fibrinógeno por medio de PAGE SDS y la actividad defibrinogenante en roedores albinos (18-22 g. Se determinó el contenido de carbohidratos asociados, el efecto de inhibidores clásicos de proteasas y el efecto de iones bajo la forma de cloruros. Resultados. La enzima mostró homología en la estructura primaria con otras TLEs reportadas para la familia Viperidae, la dosis coagulante mínima (DCM sobre plasma y fibrinógeno humano fue de 18 y 6 µg respectivamente y su potencia coagulante fue de 131,1 NHI unidades de trombina. La enzima se mostró estable a condiciones fisiológicas y prescinde de iones para su actividad. Los carbohidratos asociados detectados fueron hexosas (25,76%, hexosaminas (13,1% y ácido siálico (0,76%. Los agentes fluoruro de fenil metil sulfonil floruro (PMSF ditiotreitol (DTT fueron los principales inhibidores de la actividad enzimática en tanto que la heparina no tuvo efecto inhibidor. Conclusiones. El principio coagulante del veneno de Bothrops pictus es una enzima similar a trombina

  10. An Isoflavone from Dipteryx alata Vogel is Active against the in Vitro Neuromuscular Paralysis of Bothrops jararacussu Snake Venom and Bothropstoxin I, and Prevents Venom-Induced Myonecrosis

    Directory of Open Access Journals (Sweden)

    Miriéle C. Ferraz

    2014-05-01

    Full Text Available Snakebite is a neglected disease and serious health problem in Brazil, with most bites being caused by snakes of the genus Bothrops. Although serum therapy is the primary treatment for systemic envenomation, it is generally ineffective in neutralizing the local effects of these venoms. In this work, we examined the ability of 7,8,3'-trihydroxy-4'-methoxyisoflavone (TM, an isoflavone from Dipteryx alata, to neutralize the neurotoxicity (in mouse phrenic nerve-diaphragm preparations and myotoxicity (assessed by light microscopy of Bothrops jararacussu snake venom in vitro. The toxicity of TM was assessed using the Salmonella microsome assay (Ames test. Incubation with TM alone (200 μg/mL did not alter the muscle twitch tension whereas incubation with venom (40 μg/mL caused irreversible paralysis. Preincubation of TM (200 μg/mL with venom attenuated the venom-induced neuromuscular blockade by 84% ± 5% (mean ± SEM; n = 4. The neuromuscular blockade caused by bothropstoxin-I (BthTX-I, the major myotoxic PLA2 of this venom, was also attenuated by TM. Histological analysis of diaphragm muscle incubated with TM showed that most fibers were preserved (only 9.2% ± 1.7% were damaged; n = 4 compared to venom alone (50.3% ± 5.4% of fibers damaged; n = 3, and preincubation of TM with venom significantly attenuated the venom-induced damage (only 17% ± 3.4% of fibers damaged; n = 3; p < 0.05 compared to venom alone. TM showed no mutagenicity in the Ames test using Salmonella strains TA98 and TA97a with (+S9 and without (−S9 metabolic activation. These findings indicate that TM is a potentially useful compound for antagonizing the neuromuscular effects (neurotoxicity and myotoxicity of B. jararacussu venom.

  11. Isolation, structural and functional characterization of a new Lys49 phospholipase A2 homologue from Bothrops neuwiedi urutu with bactericidal potential.

    Science.gov (United States)

    Corrêa, Edailson A; Kayano, Anderson M; Diniz-Sousa, Rafaela; Setúbal, Sulamita S; Zanchi, Fernando B; Zuliani, Juliana P; Matos, Najla B; Almeida, José R; Resende, Letícia M; Marangoni, Sérgio; da Silva, Saulo L; Soares, Andreimar M; Calderon, Leonardo A

    2016-06-01

    Snake venom is a complex mixture of active compounds consisting of 80-90% proteins and peptides that exhibit a variety of biological actions that are not completely clarified or identified. Of these, phospholipase A2 is one of the molecules that has shown great biotechnological potential. The objectives of this study were to isolate, biochemically and biologically characterize a Lys49 phospholipase A2 homologue from the venom of Bothrops neuwiedi urutu. The protein was purified after two chromatographic steps, anion exchange and reverse phase. The purity and relative molecular mass were assessed by SDS-PAGE, observing a molecular weight typical of PLA2s, subsequently confirmed by mass spectrometry obtaining a mass of 13,733 Da. As for phospholipase activity, the PLA2 proved to be enzymatically inactive. The analyses by Edman degradation and sequencing of the peptide fragments allowed for the identification of 108 amino acid residues; this sequence showed high identity with other phospholipases A2 from Bothrops snake venoms, and identified this molecule as a novel PLA2 isoform from B. neuwiedi urutu venom, called BnuTX-I. In murine models, both BnuTX-I as well as the venom induced edema and myotoxic responses. The cytotoxic effect of BnuTX-I in murine macrophages was observed at concentrations above 12 μg/mL. BnuTX-I also presented antimicrobial activity against gram-positive and negative bacterial strains, having the greatest inhibitory effect on Pseudomonas aeruginosa. The results allowed for the identification of a new myotoxin isoform with PLA2 structure with promising biotechnological applications. PMID:26927324

  12. Snake population venomics and antivenomics of Bothrops atrox: Paedomorphism along its transamazonian dispersal and implications of geographic venom variability on snakebite management.

    Science.gov (United States)

    Calvete, Juan J; Sanz, Libia; Pérez, Alicia; Borges, Adolfo; Vargas, Alba M; Lomonte, Bruno; Angulo, Yamileth; Gutiérrez, José María; Chalkidis, Hipócrates M; Mourão, Rosa H V; Furtado, M Fatima D; Moura-Da-Silva, Ana M

    2011-04-01

    We describe two geographically differentiated venom phenotypes across the wide distribution range of Bothrops atrox, from the Colombian Magdalena Medio Valley through Puerto Ayacucho and El Paují, in the Venezuelan States of Amazonas and Orinoquia, respectively, and São Bento in the Brazilian State of Maranhão. Colombian and Venezuelan venoms show an ontogenetic toxin profile phenotype whereas Brazilian venoms exhibit paedomorphic phenotypes. Venoms from each of the 16 localities sampled contain both population-specific toxins and proteins shared by neighboring B. atrox populations. Mapping the molecular similarity between conspecific populations onto a physical map of B. atrox range provides clues for tracing dispersal routes that account for the current biogeographic distribution of the species. The proteomic pattern is consistent with a model of southeast and southwest dispersal and allopatric fragmentation northern of the Amazon Basin, and trans-Amazonian expansion through the Andean Corridor and across the Amazon river between Monte Alegre and Santarém. An antivenomic approach applied to assess the efficacy towards B. atrox venoms of two antivenoms raised in Costa Rica and Brazil using Bothrops venoms different than B. atrox in the immunization mixtures showed that both antivenoms immunodepleted very efficiently the major toxins (PIII-SVMPs, serine proteinases, CRISP, LAO) of paedomorphic venoms from Puerto Ayacucho (Venezuelan Amazonia) through São Bento, but had impaired reactivity towards PLA(2) and P-I SVMP molecules abundantly present in ontogenetic venoms. The degree of immunodepletion achieved suggests that each of these antivenoms may be effective against envenomations by paedomorphic, and some ontogenetic, B. atrox venoms. PMID:21278006

  13. Accidents caused by Bothrops and Bothropoides in the State of Paraiba: epidemiological and clinical aspects Acidentes causados por serpentes dos gêneros Bothrops e Bothropoides no Estado da Paraíba: aspectos clínicos e epidemiológicos

    Directory of Open Access Journals (Sweden)

    Fagner Neves Oliveira

    2010-12-01

    Full Text Available INTRODUCTION: Bothrops and Bothropoides snakes cause 70% of the ophidic accidents in Brazil. The species that cause ophidic accidents in State of Paraíba are Bothropoides erythromelas, Bothrops leucurus and Bothropoides neuwiedi. METHODS: This is a prospective and transverse study, following a quantitative approach of accidents involving Bothrops and Bothropoides admitted to the Toxicological Assistance and Information Centers of Campina Grande and João Pessoa (Ceatox-CG and Ceatox-JP, aimed at identifying the epidemiological and clinical profile of such accidents. All of the patients admitted had medical diagnoses and were monitored at Ceatox-CG or Ceatox-JP. RESULTS: The genera Bothrops and Bothropoides caused 91.7% of the ophidic accidents reported. Snake bites were frequent in men (75.1%, rural workers (65.1%, literate individuals (69% between 11 and 20 years-old (21.7%, and toes the most common area attacked (52.7%. Most (86.6% patients were admitted within 6 hours after the accident/bite, with a predominance of mild cases (64.6%. The annual occurrence in Paraíba was 5.5 accidents/100,000 inhabitants and lethality was 0.2%. CONCLUSIONS: Positive changes in the profiles of these accidents were verified, such as the non-application of inadequate solutions, including the use of tourniquet, coffee grounds, garlic, suction and/or cutting the bitten area. Moreover, the Itinerant Laboratory project, linked to Paraíba State University in partnership with Ceatox-CG, has contributed positively, providing several cities of the state with information regarding the prevention of accidents involving venomous animals. The local press has also contributed, reporting the educational work developed by the centers.INTRODUÇÃO: As serpentes Bothrops e Bothropoides são responsáveis por 70% dos acidentes ofídicos ocorridos no Brasil. As espécies causadoras de acidentes na Paraíba são Bothropoides erythromelas, Bothrops leucurus e Bothropoides neuwiedi

  14. Avaliação da eficácia do antiveneno botrópico administrado no local da inoculação intramuscular do veneno de Bothrops jararaca: estudo experimental em camundongos Assessment of the efficacy of antivenom injection at the site of the intramuscular inoculation of Bothrops jararaca venom in mice

    Directory of Open Access Journals (Sweden)

    Carla Lilian Agostini Utescher

    1994-06-01

    Full Text Available Foi determinada, em camundongos de 18 a 20 g, a dose efetiva 50% do antiveneno botrópico, por via intraperitoneal (ip, imediatamente (DE50 Oh e 30 minutos (DE50 30' após a inoculação de 2 DL50 do veneno de B. jararaca, por via intramuscular (im. A DE50 30' foi três vezes maior do que a DE50 Oh. A eficácia do antiveneno administrado no local da inoculação do veneno foi avaliada inoculando-se duas DL50 do veneno, por via im, e administrando-se a DE50 do antiveneno imediatamente (DE50 Oh e 30 minutos após (DE50 30', de duas formas a saber: totalmente por via ip (1ª e metade por via ip e metade por via im (2ª, no mesmo local da inoculação do veneno. O antiveneno ofereceu, por via ip, maior proteção aos camundongos (menor taxa de óbito em 48 horas do que quando metade do mesmo foi administrado, por via im, no local da inoculação do veneno. Conclui-se que, neste modelo experimental, quando se inicia o tratamento tardiamente há necessidade de maior dose de antiveneno botrópico e que não há benefício em administrá-lo no local da picada.The 50% effective intraperitoneal (ip dose of Bothrops jararaca antivenom (ED50 was assessed in mice immediately (ED50 Oh and thirty minutes (ED50 30' after the intramuscular (im injection of two 50% lethal dose (LD50 of Bothrops jararaca venom. The efficacy of the antivenom injected at the venom inoculation site was assessed by the inoculation of two LD50 of the venom by im route, followed immediately (ED50 Oh and 30 minutes later (ED50 30' by administration of the ED50 of the antivenom either entirely by the ip route or 50 percent ip plus 50 percent im, at the same inoculation site. It was shown that the ED50 30' was 3 times greater, than the ED50 Oh and that the antivenom was more protective to mice (lower death rate in 48 hours when given entirely ip. It was concluded that, in this experimental model, a higher dose of bothropic antivenom is needed when the treatment is started lately, and that

  15. Variaciones en las actividades enzimáticas del veneno de la serpiente Bothrops atrox "jergón", de tres zonas geográficas del Perú Variation of the enzymatic activity of Bothrops atrox "jergon" snake venom from three geographic regions, Peru

    Directory of Open Access Journals (Sweden)

    César Ortiz

    2012-06-01

    Full Text Available Objetivos. Estudiar la variabilidad en la composición y actividades enzimáticas entre venenos de ejemplares adultos de Bothrops atrox. Materiales y métodos. Se emplearon venenos de serpientes adultas procedentes de Amazonas, Junín y Ucayali. A cada una de las muestras se les realizó el análisis del contenido proteico y del número de bandas por PAGESDS, así como las actividades de fosfolipasa A2, hemolítica indirecta, amidolítica, coagulante, hemorrágica y proteolítica sobre caseína y mediante zimograma; además, se hicieron ensayos de inmunodifusión y neutralización in vitro con el suero antibotrópico polivalente del Instituto Nacional de Salud de Perú. Resultados. Las actividades amidolítica, coagulante, hemorrágica, proteolítica mediante zimograma, fosfolipasa A2 y hemolítica indirecta fueron variables, evidenciándose en las tres últimas una mayor actividad en los venenos de Amazonas, mientras que en la cantidad de proteína, bandas electroforéticas y actividad proteolítica sobre caseína no se observaron diferencias. Con respecto a las pruebas de neutralización, 0,5 dosis del antiveneno fueron suficientes para neutralizar con eficacia (más del 50% la actividad coagulante y fosfolipasa A2 de todas las muestras analizadas. Conclusiones. Algunas propiedades biológicas del veneno de ejemplares adultos de Bothrops atrox de Perú son variables, sin que ello afecte la neutralización in vitro por parte del suero antibotrópico polivalente sobre las actividades coagulante y fosfolipasa A2 del veneno.Objectives. To study the variability in the composition and enzymatic activity of venom from adult Bothrops atrox specimens. Materials and methods. We used venoms from adult snakes from Amazonas, Junín and Ucayali. Each of the venom samples underwent analysis for protein and number of bands by pagesds. Phospholipase A2, hemolytic, amidolytic, coagulant, hemorrhagic activity were analyzed, also and proteolytic activity on

  16. Abelian modules

    OpenAIRE

    S. Halıcıoğlu; Harmanci, A.; GÜNGÖROĞLU, G.; N. Agayev

    2009-01-01

    In this note, we introduce abelian modules as a generalization of abelian rings. Let R be an arbitrary ring with identity. A module M is called abelian if, for any m Î M and any a Î R, any idempotent e Î R, mae=mea. We prove that every reduced module, every symmetric module, every semicommutative module and every Armendariz module is abelian. For an abelian ring R, we show that the module MR is abelian iff M[x]R[x] is abelian. We produce an example to show that M[x, α] need not be abe...

  17. Sarcophagidae and Calliphoridae related to Rhinella schneideri (Anura, Bufonidae, Bothrops moojeni (Reptilia, Serpentes and Mabuya frenata (Reptilia, Lacertilia carcasses in Brasília, Brazil Sarcophagidae e Calliphoridae associados às carcaças de Rhinella schneideri (Anura, Bufonidae, Bothrops moojeni (Reptilia, Serpentes e Mabuya frenata (Reptilia, Lacertilia em Brasília, Distrito Federal, Brasil

    Directory of Open Access Journals (Sweden)

    Roger Maia Dias Ledo

    2012-09-01

    Full Text Available Sarcophagidae and Calliphoridae related to Rhinella schneideri (Anura, Bufonidae, Bothrops moojeni (Reptilia, Serpentes and Mabuya frenata (Reptilia, Lacertilia carcasses in Brasília, Brazil. This paper presents a list of necrophagous insects associated with small size carrions of two reptiles and one amphibian, found in areas of riparian forests and Cerrado sensu stricto physiognomies in a Conservation Unit located in Brasilia, Distrito Federal. We found seven species of insects related to these carcasses, being five Sarcophagidae, one Calliphoridae and one Braconidae parasitoid wasp. Lucilia eximia and Peckia (Pattonella intermutans were the most abundant species in the study, corroborating with other studies that suggests that these species have specializations for colonization of small size animal carcasses.Sarcophagidae e Calliphoridae associados às carcaças de Rhinella schneideri (Anura, Bufonidae, Bothrops moojeni (Reptilia, Serpentes e Mabuya frenata (Reptilia, Lacertilia em Brasília, Distrito Federal, Brasil. Este trabalho apresenta uma lista de insetos decompositores associados a carcaças de pequeno porte de dois répteis e de um anfíbio, encontrados em áreas de matas de galeria e de cerrado sensu stricto em unidades de conservação do Distrito Federal. Foram encontradas sete espécies de insetos associados a essas carcaças, sendo cinco sarcofagídeos, um califorídeo e uma vespa parasitóide Braconidae. Lucilia eximia e Peckia (Pattonella intermutans foram as espécies mais abundantes, corroborando com outros estudos que sugerem que estas espécies apresentam especializações para a colonização de carcaças menores.

  18. Crystallization and preliminary X-ray crystallographic studies of a Lys49-phospholipase A2 homologue from Bothrops pirajai venom complexed with rosmarinic acid

    International Nuclear Information System (INIS)

    PrTX-I, a noncatalytic and myotoxic Lys49-phospholipase A2 from B. pirajai venom, was cocrystallized with the inhibitor rosmarinic acid from C. verbenacea. The crystals diffracted X-rays to 1.8 Å resolution and the structure was solved, indicating a remarkable electronic density for the ligand at the entrance to the hydrophobic channel. PrTX-I, a noncatalytic and myotoxic Lys49-phospholipase A2 from Bothrops pirajai venom, was crystallized in the presence of the inhibitor rosmarinic acid (RA). This is the active compound in the methanolic extract of Cordia verbenacea, a plant that is largely used in Brazilian folk medicine. The crystals diffracted X-rays to 1.8 Å resolution and the structure was solved by molecular-replacement techniques, showing electron density that corresponds to RA molecules at the entrance to the hydrophobic channel. The crystals belong to space group P212121, indicating conformational changes in the structure after ligand binding: the crystals of all apo Lys49-phospholipase A2 structures belong to space group P3121, while the crystals of complexed structures belong to space groups P21 or P212121

  19. Purification and partial characterization of phospholipases A2 from Bothrops asper (barba amarilla snake venom from Chiriguaná (Cesar, Colombia

    Directory of Open Access Journals (Sweden)

    J. Ramírez-Avila

    2004-01-01

    Full Text Available Components with phospholipase A2 activity were isolated by gel filtration and cationic exchange chromatography from the venom of Bothrops asper snakes from Chiriguaná, Colombia (9°22´N; 73°37´W. Five fractions were obtained by the gel filtration, and PLA2 activity was found in fraction 3 (F3. In the cationic exchange chromatography, F3 showed eight components with PLA2 activity. Six of these components appeared as one band in polyacrylamide gel electrophoresis (SDS-PAGE. Fractions II and VII exhibited an optimal activity at pH 9 and 52ºC. The optimum calcium concentration for fraction II was 48 mM and for fraction VII, 384 mM. Both fractions showed thermal stability. Fraction II was stable at pH values between 2.5 and 9, and fraction VII, between 2.5 and 8. The Michaelis Menten constant (K M was 3.5x10-3 M for fraction II and 1.6x10-3 M for fraction VII. The molecular weight was 16,000 Dalton for fraction II and 17,000 Dalton for fraction VII. Both isoenzymes did not show any toxic activity (DL50 at 5.3 and 4 µg/g. The two fractions showed different kinetic constant (K M, calcium requirement, and substrate specificity for haemolytic activity.

  20. Extracts of Renealmia alpinia (Rottb. MAAS Protect against Lethality and Systemic Hemorrhage Induced by Bothrops asper Venom: Insights from a Model with Extract Administration before Venom Injection

    Directory of Open Access Journals (Sweden)

    Arley Camilo Patiño

    2015-04-01

    Full Text Available Renealmia alpinia (Rottb. MAAS, obtained by micropropagation (in vitro and wild forms have previously been shown to inhibit some toxic activities of Bothrops asper snake venom if preincubated before injection. In this study, assays were performed in a murine model in which extracts were administered for three days before venom injection. R. alpinia extracts inhibited lethal activity of B. asper venom injected by intraperitoneal route. Median Effective Dose (ED50 values were 36.6 ± 3.2 mg/kg and 31.7 ± 5.4 mg/kg (p > 0.05 for R. alpinia wild and in vitro extracts, respectively. At a dose of 75 mg/kg, both extracts totally inhibited the lethal activity of the venom. Moreover, this dose prolonged survival time of mice receiving a lethal dose of venom by the intravenous route. At 75 mg/kg, both extracts of R. alpinia reduced the extent of venom-induced pulmonary hemorrhage by 48.0% (in vitro extract and 34.7% (wild extract, in agreement with histological observations of lung tissue. R. alpinia extracts also inhibited hemorrhage in heart and kidneys, as evidenced by a decrease in mg of hemoglobin/g of organ. These results suggest the possibility of using R. alpinia as a prophylactic agent in snakebite, a hypothesis that needs to be further explored.

  1. In Vitro Antiplasmodial Activity of Phospholipases A2 and a Phospholipase Homologue Isolated from the Venom of the Snake Bothrops asper

    Directory of Open Access Journals (Sweden)

    Juan Carlos Alarcón Pérez

    2012-12-01

    Full Text Available The antimicrobial and antiparasite activity of phospholipase A2 (PLA2 from snakes and bees has been extensively explored. We studied the antiplasmodial effect of the whole venom of the snake Bothrops asper and of two fractions purified by ion-exchange chromatography: one containing catalytically-active phospholipases A2 (PLA2 (fraction V and another containing a PLA2 homologue devoid of enzymatic activity (fraction VI. The antiplasmodial effect was assessed on in vitro cultures of Plasmodium falciparum. The whole venom of B. asper, as well as its fractions V and VI, were active against the parasite at 0.13 ± 0.01 µg/mL, 1.42 ± 0.56 µg/mL and 22.89 ± 1.22 µg/mL, respectively. Differences in the cytotoxic activity on peripheral blood mononuclear cells between the whole venom and fractions V and VI were observed, fraction V showing higher toxicity than total venom and fraction VI. Regarding toxicity in mice, the whole venom showed the highest lethal effect in comparison to fractions V and VI. These results suggest that B. asper PLA2 and its homologue have antiplasmodial potential.

  2. Gamma radiation affects the anti-Leishmania activity of Bothrops moojeni venom and correlates with L-amino acid oxidase activity

    International Nuclear Information System (INIS)

    Leishmania causes human disfiguring skin disease in endemic areas of Amazon and North Eastern Brazil. Those parasites present a remarkable resistance to most treatments, except those using toxic antimonial salts. We detected a specific anti-Leishmania activity in snake venoms, using an in vitro promastigote assay. In this report, we analyzed the activity of Bothrops moojeni venom against L. Amazonensis, using whole venom or fractions of L-amino acid oxidase (L-AO). Crude venom of B.moojeni, was fractionated by molecular exclusion chromatography. Activity against promastigotes was detected by respiratory oxidative conversion of MTT in a colorimetric assay and L-AO activity was detected by a colorimetric assay with peroxidase and OPD as revealing reagents. Crude venom was irradiated with 500, 1000, and 2000 Gy in a 60 Co gamma radiation source. The venom had an anti-Leishmania activity of 33 pg/promastigote and the active fraction migrates as 100-150 kDa, close to the size described for L-AOs, and also presented L-AO activity. The radiation reduces both the L-AO and anti-Leishmania activity in a dose dependent effect. Those data suggests the anti-Leishmania activity in this venom is closely related to the L-amino acid oxidase activity and also that radiation could be used as a tool to detect specific activities reduction in water solutions, similarly to observed in dry preparations. (author)

  3. Sexual dimorphism in development and venom production of the insular threatened pit viper Bothrops insularism (Serpentes: Viperidae of Queimada Grande Island, Brazil

    Directory of Open Access Journals (Sweden)

    S.R. Travaglia-Cardoso

    2010-09-01

    Full Text Available Bothrops insularis is a threatened snake endemic to Queimada Grande Island, southern coast of São Paulo, Brazil, and the occurrence of sexual abnormalities in females (females with functional ovaries and rudimentary hemipenis has been reported in this population. To date there are few data regarding developmental features of this particular species. The aim of this study was to follow some developmental features in specimens maintained in captivity for seven years in the Herpetology Laboratory at Instituto Butantan, São Paulo, Brazil. We verified a pronounced sexual dimorphism in development and venom production in the specimens analyzed. In this regard, females showed greater length, mass and amount of venom in comparison to males. Our results suggest a possible niche partitioning between the sexes that reduces (or minimizes intraspecific disharmonic interactions (eg. competition on their small living area (Queimada Grande Island. Taken together, our data suggest that males and females probably are divergent in their diets, with females feeding preferentially on endothermic prey (such as migratory birds, while males maintain the juvenile diet (with the major items being ectothermic prey.

  4. Osteopontin, a chemotactic protein with cytokine-like properties, is up-regulated in muscle injury caused by Bothrops lanceolatus (fer-de-lance) snake venom.

    Science.gov (United States)

    Barbosa-Souza, Valéria; Contin, Daniel Kiss; Filho, Waldemar Bonventi; de Araújo, Albetiza Lôbo; Irazusta, Silvia Pierre; da Cruz-Höfling, Maria Alice

    2011-10-01

    Osteopontin (OPN) is a chemotactic, adhesive protein whose receptors include some integrins and matrix proteins known to have role in inflammatory and repair processes. We examined the time course of OPN expression at acute and chronic stages after intramuscular injection of Bothrops lanceolatus venom in rats. Additionally, we examined the expression of CD68 (a marker for phagocytic macrophages) and the myogenic factors, myoD and myogenin. There was a biphasic upregulation of OPN (6-48 h and 3-14 days post-venom), i.e., during acute inflammation and myogenic cell proliferation and differentiation phases. OPN was detected in CD68 + macrophages, fibroblasts, normal and damaged myofibers, myoblasts and myotubes. Myogenin was expressed in the cytoplasm (atypical pattern) and nucleus of myoblasts and myotubes from 18 h to 7 days, after which it was expressed only in nuclei. Macrophage numbers, OPN and myogenin expression were still elevated at 7, 14 and 7 days. At 3 days, when OPN achieved the peak, some clusters of myoblasts were within regions of intense collagen deposition. Fibrosis may represent limitation for repairing processes and may explain the small diameter of regenerated fibers at 21 days post-venom. The expression of OPN in the course of venom-induced damage and regeneration suggests stages-specific mediation role along the whole process. PMID:21839764

  5. Neutralization, by a monospecific Bothrops lanceolatus antivenom, of toxic activities induced by homologous and heterologous Bothírops snake venoms.

    Science.gov (United States)

    Bogarín, G; Romero, M; Rojas, G; Lutsch, C; Casadamont, M; Lang, J; Otero, R; Gutiérrez, J M

    1999-03-01

    A monospecific Bothrops lanceolatus antivenom, currently used in Martinique, was tested for its efficacy in the neutralization of several toxic and enzymatic activities of the venoms of B. lanceolatus, B. atrox and B. asper. When tested by the i.p. route in mice, B. lanceolatus venom had an LD50 of 12.8 microg/g. In addition, it induced local tissue damage (hemorrhage, edema and myotoxicity) and showed indirect hemolytic activity, but was devoid of coagulant effect on human plasma in vitro and of defibrinating activity in mice. Antivenom was fully effective in the neutralization of lethal, hemorrhagic, edema-forming, myotoxic and indirect hemolytic effects of B. lanceolatus venom in assays involving preincubation of venom and antivenom. When tested against the venoms of B. asper and B. atrox, the antivenom completely neutralized the lethal, hemorrhagic, myotoxic and indirect hemolytic effects, and was partially effective in neutralizing edema-forming activity. In contrast, the antivenom was ineffective in the neutralization of in vitro coagulant and in vivo defibrinating effects induced by these two venoms. PMID:10080358

  6. Prognostic significance of clinical grading of patients envenomed by Bothrops lanceolatus in Martinique. Members of the Research Group on Snake Bite in Martinique.

    Science.gov (United States)

    Thomas, L; Tyburn, B; Ketterlé, J; Biao, T; Mehdaoui, H; Moravie, V; Rouvel, C; Plumelle, Y; Bucher, B; Canonge, D; Marie-Nelly, C A; Lang, J

    1998-01-01

    The correlation between clinical grading of patients bitten by Bothrops lanceolatus and the subsequent development of their envenoming was examined. Severity of envenoming was graded using a 1-4 scale (minor to major). Patients were classified into 2 groups according to the time elapsed between bite and treatment with a specific purified equine F(ab')2 antivenom. The late/no treatment group (n = 33) was characterized by a systemic thrombotic complication rate of 14/33 (42.4%) leading to 4 deaths, which increased with the maximum severity assessed on the first day following the bite (P = 0.003). However, infarctions could develop in patients who presented initially with signs of moderate envenoming, normal blood clotting and low serum levels of venom antigens. No such complication of fatality occurred in the early (0.5-6 h) treatment group (n = 70). Multiple regression analysis showed that duration of stay in hospital in this group increased with the length of the snake (P = 0.017), venom antigenaemia (P = 0.016), initial grading (P < 0.001), and with the need for surgical debridement (n = 10/70, P < 0.001). Outcome was correlated with initial severity of envenoming. However, the only factor with a positive prognostic significance for the individual envenomed patient was the early infusion of specific antivenom, which led to 100% recovery in our series. PMID:9861375

  7. Quadros clínico-patológicos do envenenamento ofídico por Crotalus durissus terrificus e Bothrops spp. em animais de produção

    Directory of Open Access Journals (Sweden)

    Carlos Hubinger Tokarnia

    2014-04-01

    Full Text Available Foi realizada uma revisão dos quadros clínico-patológicos causados pelos venenos de Crotalus durissus terrificus e Bothrops spp. em bovinos, búfalos, ovinos equinos e suínos. Foram compilados os dados obtidos pela experimentação em animais de produção encontrados na literatura e os obtidos através de experimentação realizada por nossa equipe. Também foram revisados os casos naturais de envenenamento ofídico comunicados. Em dois Quadros foram lançados os mais importantes dados dessas revisões, que revelou diversos aspectos interessantes: 1 em nossos experimentos, o veneno de Crotalus durissus terrificus, quando injetado por via subcutânea em cavalos, causou um edema acentuado no local da aplicação, ao contrário do que tem sido observado em todas as outras espécies animais, aspecto não relatado na literatura; 2 em nossos experimentos, o veneno de diversas espécies de Bothrops, quando injetado por via subcutânea em bovinos, ovinos e equinos, não causou edema como em geral é relatado na literatura, e sim hemorragias subcutâneas acentuadas no local da aplicação. Nos casos não fatais este sangue era reabsorvido em poucos dias sem deixar sequelas. Exceção foi a reação ao veneno de Bothrops jararacussu, que causou edema nos ovinos experimentais, e tumefação acentuada que resultou em fístula com eliminação de líquido seroso nos equinos experimentais. O objetivo do presente estudo visa contribuir para o aperfeiçoamento do diagnóstico de acidentes ofídicos em animais de produção.

  8. Evaluación biológica preliminar de extractos vegetales utilizados en la medicina tradicional de la Sierra Nevada deSanta Marta contra el veneno de la Bothrops asper

    OpenAIRE

    Willinton Barranco Pérez; Vitelbina Nuñez; Mauricio Sanchez

    2013-01-01

    Title: Preliminary biological evaluation of plants extracts used in the Sierra Nevada de Santa Marta against the snake Bothrops asper venom.ResumenLa mordedura de serpientes constituye un problema de salubridad importante en muchos países tropicales y subtropicales, con un estimado de 2,5 millones de personas envenenadas cada año. En Colombia las especies Bothropsasper y Bothropsatrox son las causantes del 70 al 90 % de los accidentes registrados. Se estima que el 60% de estos accidentes son ...

  9. A influência dos ritmos circadianos no metabolismo da serpente Bothrops jararaca (Serpentes, Viperidae - DOI: 10.4025/actascibiolsci.v30i3.5030 The influence of circadian rhythms on the metabolism of the snake Bothrops jararaca (Serpentes, Viperidae - DOI: 10.4025/actascibiolsci.v30i3.5030

    Directory of Open Access Journals (Sweden)

    José Geraldo Pereira da Cruz

    2008-10-01

    Full Text Available A atividade termorreguladora conduziu a uma busca extensiva para o entendimento das correlações entre as variáveis fisiológicas, incluindo as funções metabólicas e a temperatura corporal. Frequentes observações mostram que algumas serpentes podem se aquecer, sendo este aumento de temperatura independente da temperatura ambiente, indicando a termorregulação bem sucedida. Bothrops jararaca foram expostas a dois ambientes com diferentes temperaturas (20 e 30oC durante três semanas, sendo mensuradas a temperatura corporal e o consumo de oxigênio. O aumento da temperatura corporal e consumo de oxigênio de Bothrops jararaca ocorreram na fase de escuro do fotoperíodo, consistente para espécies noturnas. Entretanto, antecedendo a fase de escuro, as serpentes em 20oC apresentaram os níveis mais elevados durante o dia para temperatura corporal e consumo de oxigênio. Estes resultados indicam pela primeira vez que animais termodependentes podem controlar a temperatura corporal por meio de ritmos fisiológicos circadianos, semelhante aos observados em termoindependentes. Os ritmos circadianos permitem que os animais antecipem as mudanças no ambiente: parâmetros fisiológicos como a temperatura corporal e as reservas de energia ou sua mobilização podem ser ajustadas antes que as mudanças ambientais previstas ocorram realmente.The thermoregulatory activity has led to an extensive search for correlations between physiological variables, including metabolic functions, and the ideal level of body temperature. Snakes were also often seen basking, when their body temperatures were relatively independent of ambient temperature, indicating successful thermoregulation. Bothrops jararaca were exposed to two different ambient temperatures (20 and 30ºC over a time course of three weeks and oxygen consumption and body temperature were measured. The snakes exhibited a freerunning rhythm of body temperature. Metabolic rate was increased at the same

  10. Neutralization of the edema-forming, defibrinating and coagulant effects of Bothrops asper venom by extracts of plants used by healers in Colombia

    Directory of Open Access Journals (Sweden)

    Núñez V.

    2004-01-01

    Full Text Available We determined the neutralizing activity of 12 ethanolic extracts of plants against the edema-forming, defibrinating and coagulant effects of Bothrops asper venom in Swiss Webster mice. The material used consisted of the leaves and branches of Bixa orellana (Bixaceae, Ficus nymphaeifolia (Moraceae, Struthanthus orbicularis (Loranthaceae and Gonzalagunia panamensis (Rubiaceae; the stem barks of Brownea rosademonte (Caesalpiniaceae and Tabebuia rosea (Bignoniaceae; the whole plant of Pleopeltis percussa (Polypodiaceae and Trichomanes elegans (Hymenophyllaceae; rhizomes of Renealmia alpinia (Zingiberaceae, Heliconia curtispatha (Heliconiaceae and Dracontium croatii (Araceae, and the ripe fruit of Citrus limon (Rutaceae. After preincubation of varying amounts of each extract with either 1.0 µg venom for the edema-forming effect or 2.0 µg venom for the defibrinating effect, the mixture was injected subcutaneously (sc into the right foot pad or intravenously into the tail, respectively, to groups of four mice (18-20 g. All extracts (6.2-200 µg/mouse partially neutralized the edema-forming activity of venom in a dose-dependent manner (58-76% inhibition, with B. orellana, S. orbicularis, G. panamensis, B. rosademonte, and D. croatii showing the highest effect. Ten extracts (3.9-2000 µg/mouse also showed 100% neutralizing ability against the defibrinating effect of venom, and nine prolonged the coagulation time induced by the venom. When the extracts were administered either before or after venom injection, the neutralization of the edema-forming effect was lower than 40% for all extracts, and none of them neutralized the defibrinating effect of venom. When they were administered in situ (sc at the same site 5 min after venom injection, the neutralization of edema increased for six extracts, reaching levels up to 64% for C. limon.

  11. Purification and n-terminal sequencing of two presynaptic neurotoxic PLA2, neuwieditoxin-I and neuwieditoxin-II, from Bothrops neuwiedi pauloensis (jararaca pintada venom

    Directory of Open Access Journals (Sweden)

    C. R. Borja-Oliveira

    2007-01-01

    Full Text Available Two presynaptic phospholipases A2 (PLA2, neuwieditoxin-I (NeuTX-I and neuwieditoxin-II (NeuTX-II, were isolated from the venom of Bothrops neuwiedi pauloensis (BNP. The venom was fractionated using molecular exclusion HPLC (Protein-Pak 300SW column, followed by reverse phase HPLC (µBondapak C18 column. Tricine-SDS-PAGE in the presence or absence of dithiothreitol showed that NeuTX-I and NeuTX-II had a molecular mass of approximately 14 kDa and 28kDa, respectively. At 10µg/ml, both toxins produced complete neuromuscular blockade in indirectly stimulated chick biventer cervicis isolated preparation without inhibiting the response to acetylcholine, but NeuTX-II reduced the response to KCl by 67.0±8.0% (n=3; p<0.05. NeuTX-I and NeuTX-II are probably responsible for the presynaptic neurotoxicity of BNP venom in vitro. In fact, using loose patch clamp technique for mouse phrenic nerve-diaphragm preparation, NeuTX-I produced a calcium-dependent blockade of acetylcholine release and caused appearance of giant miniature end-plate potentials (mepps, indicating a pure presynaptic action. The N-terminal sequence of NeuTX-I was DLVQFGQMILKVAGRSLPKSYGAYGCYCGWGGRGK (71% homology with bothropstoxin-II and 54% homology with caudoxin and that of NeuTX-II was SLFEFAKMILEETKRLPFPYYGAYGCYCGWGGQGQPKDAT (92% homology with Basp-III and 62% homology with crotoxin PLA2. The fact that NeuTX-I has Q-4 (Gln-4 and both toxins have F-5 (Phe-5 and Y-28 (Tyr-28 strongly suggests that NeuTX-I and NeuTX-II are Asp49 PLA2.

  12. Inflammatory effects of BaP1 a metalloproteinase isolated from Bothrops asper snake venom: leukocyte recruitment and release of cytokines.

    Science.gov (United States)

    Fernandes, Cristina Maria; Zamuner, Stella Regina; Zuliani, Juliana Pavan; Rucavado, Alexandra; Gutiérrez, José Maria; Teixeira, Catarina de Fátima Pereira

    2006-04-01

    The inflammatory events induced by BaP1, a 22.7 kDa metalloproteinase isolated from Bothrops asper snake venom, were studied. BaP1 i.p. injection in mice induced a marked inflammatory cell infiltrate into peritoneal cavity of animals with predominance of neutrophils in the early phase followed by mononuclear cells in the late period. Inhibition of enzymatic activity of BaP1 by chelation with EDTA resulted in a drastic reduction of this effect. In addition, BaP1 induced a significant increase of blood neutrophil numbers before its accumulation in peritoneal cavity, thus suggesting a stimulatory action of BaP1 on mechanisms of cell mobilization from bone marrow reserve compartments. A reduction in the number of neutrophils was observed in the exudate when antibodies against LECAM-1, CD18 and LFA-1 were used, suggesting the involvement of these adhesion molecules in the effects of BaP1. In contrast, there was no effect with antibodies against ICAM-1 and PECAM-1. Moreover, a conspicuous increment in the levels of IL-1 and TNF-alpha, but not of LTB4, was observed in peritoneal washes collected from mice injected with BaP1. It is concluded that BaP1 induces in vivo a marked leukocyte influx, which parallels an increased number of these cells in the blood, and is associated to the expression of specific leukocyte adhesion molecules and release of chemotactic inflammatory cytokines. Since BaP1 is a P-I class metalloproteinase, these results indicate that the proteolytic domain of metalloproteinases per se can trigger specific inflammatory events. PMID:16529786

  13. Action of Bothrops moojeni venom and its L-amino acid oxidase fraction, treated with 60Co gamma rays, in Leishmania spp

    International Nuclear Information System (INIS)

    Bothrops moojeni venom showed an anti leishmania activity in vitro, as determined by a cell viability assay using the reduction of MTT. After venom purification, by chromatography techniques, the fractions with anti leishmania and L-amino acid oxidase activities, eluted in the same positions. The molecular weight of the enzyme was estimated to be 140 kDa by molecular exclusion chromatography, and 69 kDa, by SDS-PAGE, migrating as a single band, with an isoelectric point of 4.8 as determined by isoelectric focusing. The purified LAO from B. moojeni venom, 135-fold more active than crude venom, showed homo dimeric constitution, and was active against Leishmania spp from the New World, with an effective concentration against L(L). amazonensis of 1.80 μg/ml (EC50), L.(V.) panamensis (0.78 |μg/ml) and L.(L.) chagasi (0.63 (μg/ml). Ultrastructural studies of promastigotes affected by LAO demonstrated cell death, with edema in several organelles such as mitochondria and nuclear membrane, before cell disruption and necrosis. The action of LAO was demonstrated to be hydrogen peroxide-dependent. Studies with LLCMK-2 cells, treated with LAO, showed a toxic effect, with an EC50 of 11|μg/ml. Irradiation of LAO with 60Co gamma rays, did not affect its whole oxidative activity, neither detoxified the enzyme. Amastigotes treated with LAO were not affected by its hydrogen peroxide, otherwise, the exogenous product, killed amastigotes with an EC50 of 0.67mM. These data could be of help in the development of alternative therapeutic approaches to the treatment of leishmaniasis. (author)

  14. Isolation and characterization of a new serine protease with thrombin-like activity (TLBm) from the venom of the snake Bothrops marajoensis.

    Science.gov (United States)

    Vilca-Quispe, Augusto; Ponce-Soto, Luis Alberto; Winck, Flavia Vischi; Marangoni, Sergio

    2010-04-01

    The thrombin-like serine protease TLBm from Bothrops marajoensis was isolated in one chromatographic step in reverse phase HPLC. Its molecular mass was 33239.95 Da, as based on the determined primary structure and confirmed experimentally by MALDI-TOF mass spectrometry (33332.5 Da) and it contains 12 half-cysteine residues. This TLBm exhibited high specificity for BArhoNA, Michaelis-Menten behavior with K(m) 2.3x10(-1)M and the V(max) 0.52x10(-1) nmoles rho-NA/lt/min for this substrate. TLBm also showed ability to coagulate bovine fibrinogen and was inhibited by soybean trypsin inhibitor, EDTA and S(Dm) from the serum of the species Didelphis marsupialis. The primary structure of TLBm showed the presence of His(45), Asp(103) and Ser(228) residues in the corresponding positions of the catalytic triad established in the serine proteases and Ser(228) are inhibited by phenylmethylsulfonyl fluoride (PMSF). Amino acid analysis showed a high content of Asp, Glu, Gly, Ser, Ala and Pro as well as 12 half-cysteine residues and calculated pI of 6.47; TLBm presented 285 amino acid residues. In this work, we investigated the ability of TLBm to degrade fibrinogen and we observed that it is able to cause alpha- and beta-chain cleavage. Enzymatic as well as the platelet aggregation activities were strongly inhibited when incubated with PMSF, a specific inhibitor of serine protease. Also, TLBm induced platelet aggregation in washed and platelet-rich plasma, and in both cases, PMSF inhibited its activity. PMID:19931298

  15. Neutralization of the edema-forming, defibrinating and coagulant effects of Bothrops asper venom by extracts of plants used by healers in Colombia.

    Science.gov (United States)

    Núñez, V; Otero, R; Barona, J; Saldarriaga, M; Osorio, R G; Fonnegra, R; Jiménez, S L; Díaz, A; Quintana, J C

    2004-07-01

    We determined the neutralizing activity of 12 ethanolic extracts of plants against the edema-forming, defibrinating and coagulant effects of Bothrops asper venom in Swiss Webster mice. The material used consisted of the leaves and branches of Bixa orellana (Bixaceae), Ficus nymphaeifolia (Moraceae), Struthanthus orbicularis (Loranthaceae) and Gonzalagunia panamensis (Rubiaceae); the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); the whole plant of Pleopeltis percussa (Polypodiaceae) and Trichomanes elegans (Hymenophyllaceae); rhizomes of Renealmia alpinia (Zingiberaceae), Heliconia curtispatha (Heliconiaceae) and Dracontium croatii (Araceae), and the ripe fruit of Citrus limon (Rutaceae). After preincubation of varying amounts of each extract with either 1.0 microg venom for the edema-forming effect or 2.0 microg venom for the defibrinating effect, the mixture was injected subcutaneously (sc) into the right foot pad or intravenously into the tail, respectively, to groups of four mice (18-20 g). All extracts (6.2-200 microg/mouse) partially neutralized the edema-forming activity of venom in a dose-dependent manner (58-76% inhibition), with B. orellana, S. orbicularis, G. panamensis, B. rosademonte, and D. croatii showing the highest effect. Ten extracts (3.9-2000 microg/mouse) also showed 100% neutralizing ability against the defibrinating effect of venom, and nine prolonged the coagulation time induced by the venom. When the extracts were administered either before or after venom injection, the neutralization of the edema-forming effect was lower than 40% for all extracts, and none of them neutralized the defibrinating effect of venom. When they were administered in situ (sc at the same site 5 min after venom injection), the neutralization of edema increased for six extracts, reaching levels up to 64% for C. limon. PMID:15264003

  16. Snakebites and ethnobotany in the northwest region of Colombia: Part II: neutralization of lethal and enzymatic effects of Bothrops atrox venom.

    Science.gov (United States)

    Otero, R; Núñez, V; Jiménez, S L; Fonnegra, R; Osorio, R G; García, M E; Díaz, A

    2000-08-01

    Twelve of 74 ethanolic extracts of plants used by traditional healers for snakebites in the northwest region of Colombia, were active against lethal effect of Bothrops atrox venom when they were i.p. injected into mice (18-20 g). After preincubation of sublethal doses of every extract (0.5-4.0 mg/mouse) with 1.5 i.p. lethal dose 50% (LD50) (99.3 microg) of venom, seven of them demonstrated 100% neutralizing capacity within 48 h. These were the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); rhizomes of Renealmia alpinia (Zingiberaceae) and Heliconia curtispatha (Heliconiaceae); the whole plants of Pleopeltis percussa (Polypodiaceae) and Trichomanes elegans (Hymenophyllaceae); and the ripe fruits of Citrus limon (Rutaceae). The other five extracts showing partial neutralization (45-80%; 10-30% survival rate in the control group receiving the venom alone; P<0.05) were: leaves, branches and stem of Costus lasius (Costaceae); the whole plant of Sida acuta (Malvaceae); rhizomes of Dracontium croatii (Araceae); leaves and branches of Bixa orellana (Bixaceae) and Struthanthus orbicularis (Loranthaceae). When the extracts were independently administered per oral or i.p. route 60 min before an i.m. venom injection (204 microg=1.5 i.m. LD50), C. limon, T. elegans, B. orellana and T. rosea extracts had partial and significant neutralizing capacity against B. atrox venom lethal effect. C. limon extract was also partially effective when it was administered either i.v. 15 min before or i.p. 5 min after an i.m. venom injection. Three of the 12 extracts with anti-lethal effect (C. limon, D. croatii and S. acuta) were devoid of antiphospholipase A2 activity, when they were tested against one minimum indirect hemolytic dose of B. atrox venom (2 microg) in agarose-erythrocyte-egg yolk gels. PMID:10940590

  17. Crystallization and preliminary X-ray diffraction studies of BmooPLA2-I, a platelet-aggregation inhibitor and hypotensive phospholipase A2 from Bothrops moojeni venom

    International Nuclear Information System (INIS)

    BmooPLA2-I, an acidic, catalytic and nontoxic phospholipase A2 from B. moojeni venom that is able to inhibit platelet aggregation and induce a hypotensive effect, has been crystallized. An X-ray diffraction data set was collected to 1.6 Å resolution and a molecular-replacement solution was obtained. Phospholipases A2 (PLA2s) are enzymes that cause the liberation of fatty acids and lysophospholipids by the hydrolysis of membrane phospholipids. In addition to their catalytic action, a wide variety of pharmacological activities have been described for snake-venom PLA2s. BmooPLA2-I is an acidic, nontoxic and catalytic PLA2 isolated from Bothrops moojeni snake venom which exhibits an inhibitory effect on platelet aggregation, an immediate decrease in blood pressure, inducing oedema at a low concentration, and an effective bactericidal effect. BmooPLA2-I has been crystallized and X-ray diffraction data have been collected to 1.6 Å resolution using a synchrotron-radiation source. The crystals belonged to space group C2221, with unit-cell parameters a = 39.7, b = 53.2, c = 89.2 Å. The molecular-replacement solution of BmooPLA2-I indicated a monomeric conformation, which is in agreement with nondenaturing electrophoresis and dynamic light-scattering experiments. A comparative study of this enzyme with the acidic PLA2 from B. jararacussu (BthA-I) and other toxic and nontoxic PLA2s may provide important insights into the functional aspects of this class of proteins

  18. A lectin from Bothrops leucurus snake venom raises cytosolic calcium levels and promotes B16-F10 melanoma necrotic cell death via mitochondrial permeability transition.

    Science.gov (United States)

    Aranda-Souza, Mary A; Rossato, Franco A; Costa, Rute A P; Figueira, Tiago R; Castilho, Roger F; Guarniere, Miriam C; Nunes, Erika S; Coelho, Luana C B B; Correia, Maria T S; Vercesi, Anibal E

    2014-05-01

    BlL, a galactose-binding C-type lectin purified from Bothrops leucurus snake venom, exhibits anticancer activity. The current study was designed to elucidate the cellular mechanisms by which BlL induces melanoma cell death. The viabilities of B16-F10 melanoma cells and HaCaT keratinocytes treated with BlL were evaluated. Necrotic and apoptotic cell death, cytosolic Ca(2+) levels, mitochondrial Ca(2+) transport and superoxide levels were assessed in B16-F10 melanoma cells exposed to BlL. We found that treatment with BlL caused dose-dependent necrotic cell death in B16-F10 melanoma cells. Conversely, the viability of non-tumorigenic HaCaT cells was not affected by similar doses of BlL. BlL-induced B16-F10 necrosis was preceded by a significant (2-fold) increase in cytosolic calcium concentrations and a significant (3-fold) increase in mitochondrial superoxide generation. It is likely that BlL treatment triggers B16-F10 cell death via mitochondrial permeability transition (MPT) pore opening because the pharmacological MPT inhibitors bongkrekic acid and Debio 025 greatly attenuated BlL-induced cell death. Experiments evaluating mitochondrial Ca(2+) transport in permeabilized B16-F10 cells strongly supported the hypothesis that BlL rapidly stimulates cyclosporine A-sensitive Ca(2+)-induced MPT pore opening. We therefore conclude that BlL causes selective B16-F10 melanoma cell death via dysregulation of cellular Ca(2+) homeostasis and Ca(2+)-induced opening of MPT pore. PMID:24593964

  19. Prevention of thromboses in human patients with Bothrops lanceolatus envenoming in Martinique: failure of anticoagulants and efficacy of a monospecific antivenom. Research Group on Snake Bites in Martinique.

    Science.gov (United States)

    Thomas, L; Tyburn, B; Bucher, B; Pecout, F; Ketterle, J; Rieux, D; Smadja, D; Garnier, D; Plumelle, Y

    1995-05-01

    Envenomation by the Bothrops lanceolatus, a snake found only in Martinique, leads to swelling and pain, and occasionally to systemic signs and/or coagulopathy. Severe thromboses at some distance from the site of the bite may appear within 48 hr. Uncertainties as to the actual development of thrombotic complications in patients appearing to be suffering from moderate poisoning and as to the availability and the toxicity of a monospecific antivenom (AVS) initially led us to reserve antivenom for the most severe cases, and to use anticoagulants to prevent thromboses in all patients. This approach was modified after we observed serious thromboses in patients with moderate poisoning. Of 50 adult snake bite cases hospitalized between June 1991 and August 1994, 11 developed serious thrombotic complications at 36 /+- 27 hr (mean +/- SD) (range 12-96) following envenomation, despite early preventive anticoagulant therapy. Those included pulmonary embolism (two cases), cerebral infarction (six cases), myocardial infarction (one case), and cerebral and myocardial infarctions (two cases). Sixteen patients were not treated with AVS: 10 of these recovered without complications and six developed systemic thrombosis causing permanent disability in three cases. Thirty were treated with an intravenous infusion of 2-6 vials of AVS given 2-48 hr after the bite. Of these, three died of cerebral infarction that developed before the initiation of serotherapy. All others recovered. Among patients treated with AVS, three presented with mild anaphylactic reactions, while one developed serum sickness that responded to steroids. These data indicate that preventive anticoagulant therapy is of limited efficacy in Martinique.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7771608

  20. Increments in cytokines and matrix metalloproteinases in skeletal muscle after injection of tissue-damaging toxins from the venom of the snake Bothrops asper

    Directory of Open Access Journals (Sweden)

    Alexandra Rucavado

    2002-01-01

    Full Text Available Envenomations by the snake Bothrops asper are characterized by prominent local tissue damage (i.e. myonecrosis, blistering, hemorrhage and edema. Various phospholipases A2 and metalloproteinases that induce local pathological alterations have been purified from this venom. Since these toxins induce a conspicuous inflammatory response, it has been hypothesized that inflammatory mediators may contribute to the local pathological alterations described. This study evaluated the local production of cytokines and matrix metalloproteinases (MMPs as a consequence of intramuscular injections of an Asp-49 myotoxic phospholipase A2 (myotoxin III (MT-III and a P-I type hemorrhagic metalloproteinase (BaP1 isolated from B. asper venom. Both enzymes induced prominent tissue alterations and conspicuous increments in interleukin (IL-1β, IL-6 and a number of MMPs, especially gelatinase MMP-9, rapidly after injection. In contrast, no increments in tumor necrosis factor-α (TNF-α and interferon-γ were detected. In agreement, MT-III and BaP1 did not induce the synthesis of TNF-α by resident peritoneal macrophages in vitro. Despite the conspicuous expression of latent forms of MMPs in muscle, evidenced by zymography, there were no increments in activated MMP-2 and only a small increase in activated MMP-9, as detected by a functional enzymatic assay. This suggests that MMP activity was regulated by a highly controlled activation of latent forms and, probably, by a concomitant synthesis of MMP inhibitors. Since no hemorrhage nor dermonecrosis were observed after injection of MT-III, despite a prominent increase in MMP expression, and since inflammatory exudate did not enhance hemorrhage induced by BaP1, it is suggested that endogenous MMPs released in the tissue are not responsible for the dermonecrosis and hemorrhage characteristic of B. asper envenomation. Moreover, pretreatment of mice with the peptidomimetic MMP inhibitor batimastat did not reduce myotoxic nor

  1. Identificación molecular y actividad sobre sustratos cromogénicos de la venombina A del veneno de la serpiente peruana Bothrops atrox

    Directory of Open Access Journals (Sweden)

    Gustavo A. Sandoval

    2011-05-01

    Full Text Available En el presente trabajo se ha realizado la identificación molecular de la enzima similar a trombina (EST del veneno de Bothrops atrox y se ha evaluado su actividad enzimática sobre diversos sustratos sintéticos. La enzima fue purificada utilizando tres pasos cromatrográficos, sobre Sephadex G-75, CM-Sephadex C-50 y Agarosa-PAB, determinándose su peso molecular por PAGE-SDS. La identificación molecular de la enzima aislada se realizó por la técnica de peptide mass fingerprinting basada en espectrometría de masas MALDI-TOF y posterior análisis in silico. Las actividades fibrinocoagulante y amidolítica fueron ensayadas sobre fibrinó- geno bovino y BApNA, respectivamente, así como la hidrólisis sobre los sustratos cromogénicos específicos S-2238, S-2251 y S-2266. Como resultado de los ensayos bioquímicos y estructurales, la EST del veneno de B. atrox, presentó un peso molecular de 29,6 kDa. El análisis mediante espectrometría de masas de los péptidos obtenidos, permitió identificar a esta enzima como una venombina A, presentando una identidad del 75%. Del análisis de actividad enzimática, se obtuvo que la EST de B. atrox produjo coagulación del fibrinógeno bovino y presentó actividad sobre BApNA, S-2238 y S-2266, siendo incapaz de hidrolizar el sustrato S-2251. El empleo de estas aproximaciones estructurales y funcionales ha permitido lograr la identificación molecular del principal componente del veneno de B. atrox relacionado con su acción coagulante, así como evaluar en detalle la naturaleza de su actividad enzimática sobre diversos sustratos.

  2. Evaluación biológica preliminar de extractos vegetales utilizados en la medicina tradicional de la Sierra Nevada deSanta Marta contra el veneno de la Bothrops asper

    Directory of Open Access Journals (Sweden)

    Willinton Barranco Pérez

    2013-10-01

    Full Text Available Title: Preliminary biological evaluation of plants extracts used in the Sierra Nevada de Santa Marta against the snake Bothrops asper venom.ResumenLa mordedura de serpientes constituye un problema de salubridad importante en muchos países tropicales y subtropicales, con un estimado de 2,5 millones de personas envenenadas cada año. En Colombia las especies Bothropsasper y Bothropsatrox son las causantes del 70 al 90 % de los accidentes registrados. Se estima que el 60% de estos accidentes son inicialmente tratados por curanderos tradicionales utilizando plantas medicinales en diferentes preparaciones. Este estudio evaluó la capacidad inhibitoria de cinco especies contra el efecto proteolítico y hemolítico indirecto inducido por el veneno de B. asper en ensayos in vitro.Las especies, que fueron seleccionadas de acuerdo a su uso en la medicina tradicional por parte de las comunidades campesinas de la Sierra Nevada de Santa Marta, fueron, Aristolochia máxima, Cissampelospareira, Equisetumbogotense, Mucunacfpruriens y una especie de la familia Asteraceae. La planta E. bogotense mostró los mayores porcentaje de inhibición contra la actividad de las fosfolipasas A2(42,29 %, así como la mayor precipitación de las proteínas en un rango de masas moleculares de 28,2 y 94,43 KDa. Al fraccionar el extracto de E. bogotense se obtuvieron cinco fracciones, las cuales presentaron un porcentaje de inhibición de 36,6 ± 1,07 a 46,1 ± 13,6. Adicionalmente se detectaron por métodos cualitativos núcleos como, alcaloides, esteroides y/o triterpenos, taninos, cumarinas y leucoantocianidinas. En estudio se reporta la actividad antiofídica en ensayos in vitro de la especie E. bogotense contra el veneno de la especie B.asper. (DUAZARY 2012 No. 2, 140 - 150AbstractIn Colombia the species Bothrops asper and Bothrops atrox are responsible for 70 to 90% of the snakebite accidents. Around 60% of these injuries are initially treated by traditional healers; they

  3. Action of Bothrops moojeni venom and its L-amino acid oxidase fraction, treated with {sup 60}Co gamma rays, in Leishmania spp; Acao do veneno de Bothrops moojeni e sua fracao L-aminoacido oxidase, submetida ao tratamento com raios gama de {sup 60}Co, em Leishmania spp

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Andre Gustavo Tempone

    1999-07-01

    Bothrops moojeni venom showed an anti leishmania activity in vitro, as determined by a cell viability assay using the reduction of MTT. After venom purification, by chromatography techniques, the fractions with anti leishmania and L-amino acid oxidase activities, eluted in the same positions. The molecular weight of the enzyme was estimated to be 140 kDa by molecular exclusion chromatography, and 69 kDa, by SDS-PAGE, migrating as a single band, with an isoelectric point of 4.8 as determined by isoelectric focusing. The purified LAO from B. moojeni venom, 135-fold more active than crude venom, showed homo dimeric constitution, and was active against Leishmania spp from the New World, with an effective concentration against L(L). amazonensis of 1.80 {mu}g/ml (EC{sub 50}), L.(V.) panamensis (0.78 |{mu}g/ml) and L.(L.) chagasi (0.63 ({mu}g/ml). Ultrastructural studies of promastigotes affected by LAO demonstrated cell death, with edema in several organelles such as mitochondria and nuclear membrane, before cell disruption and necrosis. The action of LAO was demonstrated to be hydrogen peroxide-dependent. Studies with LLCMK-2 cells, treated with LAO, showed a toxic effect, with an EC{sub 50} of 11|{mu}g/ml. Irradiation of LAO with 6{sup 0C}o gamma rays, did not affect its whole oxidative activity, neither detoxified the enzyme. Amastigotes treated with LAO were not affected by its hydrogen peroxide, otherwise, the exogenous product, killed amastigotes with an EC{sub 50} of 0.67mM. These data could be of help in the development of alternative therapeutic approaches to the treatment of leishmaniasis. (author)

  4. Reactividad inmunoquímica de sueros anti- Caiman yacare y Caiman latirostris frente a sueros de diferentes especies

    Directory of Open Access Journals (Sweden)

    de Roodt, Adolfo Rafael

    2010-06-01

    Full Text Available Se estudió la reactividad inmunoquímica entre los sueros de distintas especies de reptiles frente a sueros hiperinmunes experimentales anti-suero de Caiman yacare y anti-suero de Caiman latirostris. Los sueros que se probaron fueron los homólogos de Caiman yacare, Caiman latirostris y los heterólogos de Alligator missisipiensis, Tupinambis merinae, Tupinambis rufescens, Chelonoidis chilensis, Clelia rustica, Waglerophis merremii, Lystrophys dorbignyi, Phyton molurus, Boa constrictor occidentalis, Eunectes notaeus, Crotalus durissus terrificus, Bothrops alternatus, Bothrops diporus, Bothrops jararaca, Bothrops jararacussu, Bothrops moojeni, Pitangus sulphuratus y Gallus gallus. La reactividad inmunoquímica se determinó mediante las técnicas de doble inmunodifusión y ELISA, mostrándose importante entre los sueros de los crocodrílidos y baja entre estos y los de las otras especies de reptiles estudiadas. Se observó mayor reactividad entre los antisueros anti-Caiman respecto a los sueros de Caiman latirostris y Caiman yacare que frente al suero de Alligator missisipiensis. Además, se encontró una fuerte reactividad entre ambos sueros anti-Caiman y el de Gallus gallus poniendo en evidencia la fuerte reactividad entre los sueros de arcosaurios. In order to study the immunochemical reactivity among sera from different species of reptiles regarding sera from Caiman, the immunoreactivity of sera from reptiles against antisera to Caiman yacare or anti-Caiman latirostris sera was studied. These hiperimmune sera were tested against sera from Alligator missisipiensis, Tupinambis merinae, Tupinambis rufescens, Chelonoidis chilensis, Clelia rustica, Waglerophis merremii, Lystrophys dorbignyi, Phyton molurus, Boa constrictor occidentalis, Eunectes notaeus, Crotalus durissus terrificus, Bothrops alternatus, Bothrops neuwiedii, Bothrops jararaca, Bothrops jararacussu, Bothrops moojeni, Pitangus sulphuratus and Gallus gallus. The immunochemical

  5. Identificación de Bacterias en Cavidad Oral y Valores Hematológicos en Bothrops asper en el Serpentario de la Universidad de Antioquia -resumen-

    Directory of Open Access Journals (Sweden)

    C Martínez-Mejía

    2014-12-01

    Full Text Available La flora bacteriana de la cavidad oral de las serpientes en cautiverio ha sido asociada a infecciones por estomatitis y abscesos secundarios por auto-mordedura. Igualmente‚ su identificación es importante debido a las infecciones secundarias que pueden causar los accidentes ofídicos en humanos y animales. En particular el veneno de la serpiente mapaná‚ Bothrops asper‚ responsable del 70% de los accidentes ofídicos en Colombia‚ genera efectos sistémicos y locales incluyendo dermonecrosis y mionecrosis que puede complicarse con abscesos‚ celulitis y fascitis hasta en el 30% de los casos. En este estudio se realizaron cultivos bacteriológicos y antibiogramas para identificar las bacterias presentes en la cavidad oral‚ y se determinaron los valores hematológicos no reportados aún para B. asper‚ mantenidas en el serpentario de la Universidad de Antioquia. Mediante hisopados de cavidad oral (n=16 se aislaron 9 especies de bacterias pertenecientes a 4 familias: Enterobacteriaceae (Escherichia coli‚ Citrobacter sp.‚ Proteus sp.‚ Salmonella sp. y Enterobacter sp.‚ Enterococcaceae (Enterococcus sp.‚ Staphylococcaceae (Staphylococcus epidermidis‚ Staphylococcus haemolyticus y Bacillaceae (Bacillus licheniformis. De este total‚ la mayoría (55,5% resultaron Gram negativas y el resto (45,5% fueron Gram positivas. Se observó además una asociación entre los individuos con más tiempo en cautiverio (+ 60 meses‚ 4 ♀ y 3♂ y cultivos simultáneos de 2 bacterias‚ mientras que de los individuos con menos tiempo (- 50 meses‚ 4 ♀ y 5♂ se aisló solo una especie de bacteria. En acuerdo con la literatura‚ todas las bacterias aisladas fueron sensibles a la Amikacina y Enrofloxacina‚ mientras que el 66‚6% (n=9 de las bacterias fue resistente a la Ampicilina Sulbactam. Los parámetros hematológicos se determinaron a partir de 24 serpientes en buen estado de salud. El promedio del hematocrito (Hto‚ % fue de 27

  6. Alteraciones histológicas en riñones de ratas, inducidas por dosis bajas del veneno de la serpiente Bothrops asper. - Histological injuries in rat’s kidneys induced to low dose of snake’s poison Bothrops asper.

    Directory of Open Access Journals (Sweden)

    Reyes, Adriana

    2009-09-01

    Full Text Available ResumenEl objetivo del trabajo fue demostrar que dosis bajas del veneno deBothrops asper pueden causar patologías renales que se acentúancon el tiempo de exposición al veneno, especialmente a nivelglomérular. Se emplearon cinco grupos de ratas de cinco individuoscada uno, los cuales fueron inoculados con una dosis de veneno de2.1µg/g de peso (por vía intraperitoneal, con adición de un grupocontrol, al cual se le inyectó solución salina. A los animales se lespracticó la eutanasia secuencialmente (1, 48, 96, 144 y 288 horas.En cada tiempo se extrajeron los riñones del grupo seleccionado, paraprocesarlos con técnicas de coloración (HE – PAS. Con el diagnósticohistopatológico se evidenció en la primera hora gloméruloscongestionados con tumefacción, después de 48 horas se presentóuna glomérulonefritis, seguida de un colapso glomerular a las 96horas. Las patologías se evidenciaron mas en los últimos períodos deexperimentación; a las 144 horas se observó glomérulonefritismembranosa y proliferativa endocapilar culminando con la desaparición de la cápsula de Bowman y la estructura total del glomérulo a las 288 horas. Se concluye que cantidades bajas del veneno pueden causar patologías renales progresivas con el paso del tiempo.SummaryAim of this work was to demonstrate that low doses of Bothropsasper venom can cause pathologies that progress over time on therenal tissue, at the glomerular level especially. Five groups of ratsconsisting of five individuals were used and a single dose of poison2.1µg/g in weight was injected. Control group was injected withsaline solution. Euthanasia sequentially was practiced (1, 48, 96, 144and 288 hours. In each time was extracted the kidneys of groupselection, to procession with color’s techniques (HE – PAS.Histopathological diagnostic evidenced congested glomeruli withswelling in the first hour, after 48 hours a glomerulonephritis waspresented, followed by a collapsed glomerular at

  7. Fluorometric assay using naphthylamide substrates for assessing novel venom peptidase activities.

    Science.gov (United States)

    Gasparello-Clemente, Elaine; Silveira, Paulo Flávio

    2002-11-01

    In the present study we examined the feasibility of using the fluorometry of naphthylamine derivatives for revealing peptidase activities in venoms of the snakes Bothrops jararaca, Bothrops alternatus, Bothrops atrox, Bothrops moojeni, Bothrops insularis, Crotalus durissus terrificus and Bitis arietans, of the scorpions Tityus serrulatus and Tityus bahiensis, and of the spiders Phoneutria nigriventer and Loxosceles intermedia. Neutral aminopeptidase (APN) and prolyl-dipeptidyl aminopeptidase IV (DPP IV) activities were presented in all snake venoms, with the highest levels in B. alternatus. Although all examined peptidase activities showed relatively low levels in arthropod venoms, basic aminopeptidase (APB) activity from P. nigriventer venom was the exception. Compared to the other peptidase activities, relatively high levels of acid aminopeptidase (APA) activity were restricted to B. arietans venom. B. arietans also exhibited a prominent content of APB activity which was lower in other venoms. Relatively low prolyl endopeptidase and proline iminopeptidase activities were, respectively, detectable only in T. bahiensis and B. insularis. Pyroglutamate aminopeptidase activity was undetectable in all venoms. All examined peptidase activities were undetectable in T. serrulatus venom. In this study, the specificities of a diverse array of peptidase activities from representative venoms were demonstrated for the first time, with a description of their distribution which may contribute to guiding further investigations. The expressive difference between snake and arthropod venoms was indicated by APN and DPP IV activities while APA and APB activities distinguished the venom of B. arietans from those of Brazilian snakes. The data reflected the relatively uniform qualitative distribution of the peptidase activities investigated, together with their unequal quantitative distribution, indicating the evolutionary divergence in the processing of peptides in these different

  8. Q-modules

    OpenAIRE

    Q-modules,

    2009-01-01

    In this paper we characterize Q-modules and almost Q-modules. Next we estblish some equivalent conditions for an almost Q-module to be a Q-module. Using these results, some characterizations are given for Noetherian Q-modules.

  9. Bothrops jararaca venom (BjV) induces differential leukocyte accumulation in mice genetically selected for acute inflammatory reaction: the role of host genetic background on expression of adhesion molecules and release of endogenous mediators.

    Science.gov (United States)

    Carneiro, Adriana S; Ribeiro, Orlando G; Cabrera, Wafa H K; Vorraro, Francisca; De Franco, Marcelo; Ibañez, Olga M; Starobinas, Nancy

    2008-10-01

    The dynamics of the local inflammatory events induced by Bothrops jararaca venom (BjV) inoculation in footpad of mice genetically selected for maximal (AIRmax) and minimal (AIRmin) acute inflammatory reactivity (AIR) was investigated. The BjV injection induced a marked inflammatory cell infiltrate with predominance of neutrophils, with increased blood cell numbers before its accumulation, suggesting a stimulatory action of BjV on mechanisms of cell mobilization from bone marrow. The process of cell migration is regulated by different cell-adhesion molecules (CAM). Our results showed that neutrophil cells from both lines had the same pattern of response concerning CAMs expression, presenting the involvement of l-selectin, Mac-1 and PECAM-1 adhesion molecules in BjV-induced neutrophil accumulation. The effect of BjV on the release of pro-inflammatory cytokines and chemokines related with cellular migration was also studied and IL-1beta, IL-6, TNF-alpha and MIP-2 levels could be detected after venom injection. The AIRmax mice were shown to be more responsive than AIRmin with respect to leukocyte influx, expression of MIP-2 and release of IL-1beta and IL-6. These results demonstrate the importance of host genetic background in the local response and the involvement of alleles accumulated in AIRmax mice in the inflammatory events induced by BjV. PMID:18723041

  10. Purificación y caracterización de la l-amino ácido oxidasa del veneno de la serpiente Bothrops brazili "jergón shushupe"

    Directory of Open Access Journals (Sweden)

    Christian Solís

    2014-06-01

    Full Text Available Se ha purificado y caracterizado parcialmente la L-aminoácido oxidasa de la serpiente Bothrops brazili. El aislamiento se realizó usando técnicas cromatográficas en Sephadex G-100 y CM-Sephadex C-50, utilizando como eluyente buffer acetato de amonio 0,1M pH 6. La enzima fue purificada 29,3 veces con un rendimiento de 30,9%. Usando electroforesis en gel de poliacrilamida con dodecil sulfato de sodio (PAGE-SDS en condiciones reductoras y no reductoras, así como las técnicas de inmunodifusión e inmunoelectroforesis, se demostró la presencia de una sola banda proteica. La enzima fue caracterizada como una glicoproteína ácida con un peso molecular de 125,7 kd formada por dos subunidades de 59,9 kd unidas por enlaces débiles, con un pH óptimo entre 7,5 y 9, dependiendo del aminoácido usado como substrato; siendo termoestable hasta los 550 C y lábil a pH alcalino. Asimismo, los ensayos por el método del cilindro en placa de Grove demostraron el efecto antibacteriano de la proteína aislada en cepas estandarizadas de Staphylococcus aureus, Vibrio cholerae y Streptococcus faecalis.

  11. Module theory, extending modules and generalizations

    CERN Document Server

    Tercan, Adnan

    2016-01-01

    The main focus of this monograph is to offer a comprehensive presentation of known and new results on various generalizations of CS-modules and CS-rings. Extending (or CS) modules are generalizations of injective (and also semisimple or uniform) modules. While the theory of CS-modules is well documented in monographs and textbooks, results on generalized forms of the CS property as well as dual notions are far less present in the literature. With their work the authors provide a solid background to module theory, accessible to anyone familiar with basic abstract algebra. The focus of the book is on direct sums of CS-modules and classes of modules related to CS-modules, such as relative (injective) ejective modules, (quasi) continuous modules, and lifting modules. In particular, matrix CS-rings are studied and clear proofs of fundamental decomposition results on CS-modules over commutative domains are given, thus complementing existing monographs in this area. Open problems round out the work and establish the...

  12. An optical modulator

    OpenAIRE

    Thévenaz, Luc; Dainesi, Paolo

    2003-01-01

    An optical modulator is arranged to compensate for the thermo-optical modulating effects induced by charge-injection based phase modulators. It comprises first modulator means (3), that receive optical radiation (11, 21), direct it along an optical path, apply a first predetermined optical phase modulation by the injection of free charges into the optical path, and output optical radiation (13, 22) so modulated. Compensator means (4) apply, to optical radiation output from (13, 22), or to be ...

  13. Intensity modulated proton therapy

    OpenAIRE

    Kooy, H. M.; Grassberger, C

    2015-01-01

    Intensity modulated proton therapy (IMPT) implies the electromagnetic spatial control of well-circumscribed “pencil beams” of protons of variable energy and intensity. Proton pencil beams take advantage of the charged-particle Bragg peak—the characteristic peak of dose at the end of range—combined with the modulation of pencil beam variables to create target-local modulations in dose that achieves the dose objectives. IMPT improves on X-ray intensity modulated beams (intensity modulated radio...

  14. Moojenactivase, a novel pro-coagulant PIIId metalloprotease isolated from Bothrops moojeni snake venom, activates coagulation factors II and X and induces tissue factor up-regulation in leukocytes.

    Science.gov (United States)

    Sartim, Marco A; Costa, Tassia R; Laure, Helen J; Espíndola, Milena S; Frantz, Fabiani G; Sorgi, Carlos A; Cintra, Adélia C O; Arantes, Eliane C; Faccioli, Lucia H; Rosa, José C; Sampaio, Suely V

    2016-05-01

    Coagulopathies following snakebite are triggered by pro-coagulant venom toxins, in which metalloproteases play a major role in envenomation-induced coagulation disorders by acting on coagulation cascade, platelet function and fibrinolysis. Considering this relevance, here we describe the isolation and biochemical characterization of moojenactivase (MooA), a metalloprotease from Bothrops moojeni snake venom, and investigate its involvement in hemostasis in vitro. MooA is a glycoprotein of 85,746.22 Da, member of the PIIId group of snake venom metalloproteases, composed of three linked disulfide-bonded chains: an N-glycosylated heavy chain, and two light chains. The venom protease induced human plasma clotting in vitro by activating on both blood coagulation factors II (prothrombin) and X, which in turn generated α-thrombin and factor Xa, respectively. Additionally, MooA induced expression of tissue factor (TF) on the membrane surface of peripheral blood mononuclear cells (PBMC), which led these cells to adopt pro-coagulant characteristics. MooA was also shown to be involved with production of the inflammatory mediators TNF-α, IL-8 and MCP-1, suggesting an association between MooA pro-inflammatory stimulation of PBMC and TF up-regulation. We also observed aggregation of washed platelets when in presence of MooA; however, the protease had no effect on fibrinolysis. Our findings show that MooA is a novel hemostatically active metalloprotease, which may lead to the development of coagulopathies during B. moojeni envenomation. Moreover, the metalloprotease may contribute to the development of new diagnostic tools and pharmacological approaches applied to hemostatic disorders. PMID:26026608

  15. Variaciones ontogénicas y geográficas en los efectos tóxicos y en las características inmunoquímicas del veneno de serpientes del grupo Bothrops atrox del Meta y Antioquia

    Directory of Open Access Journals (Sweden)

    María Fabiola Toro

    2000-02-01

    Full Text Available

    El accidente ofídico es un problema de salud pública frecuente en algunos lugares del mundo. En Latinoamérica, el género Bothrops es el causante del 90% de los accidentes ofídicos y en Colombia el grupo Bothrops atrox es responsable del 50% o más de los casos que se reportan anualmente (2000 casos. Este grupo se encuentra distribuido en la mayor parte del territorio nacional colombiano, incluyendo el este y oeste de los Andes, vertiente Pacífica y Atlántica, además de los valles interandinos.

    El veneno del grupo Bothrops atrox induce un complejo cuadro de alteraciones fisiopatológicas locales y sistémicas, como mionecrosis, dermonecrosis, edema, hemorragia, dolor, coagulopatías, choque cardiovascular, nefrotoxicidad, actividad proteolítica y hemolítica indirecta.

    En diversos países se han realizado estudios sobre la variabilidad de los venenos de diferentes especies de serpientes. Se han encontrado diferencias en todos los niveles taxonómicos, siendo de mayor importancia la variabilidad intraespecífica. Con este estudio se pretende determinar la variabilidad ontogénica y geográfica del veneno de Bothrops atrox procedente de dos regiones colombianas, mediante pruebas biológicas e inmunoquímicas. Los resultados previos muestran que existe una variación ontogénica en el veneno de la especie Bothrops atrox del departamento del Meta con respecto a la letalidad, y a las actividades hemorrágica, coagulante y edematizante. Las serpientes recién nacidas tienen una mayor letalidad (DL50 = 51.8 ± 5.6 mg de veneno con respecto a los adultos (81.4±

  16. Modulating lignin in plants

    Science.gov (United States)

    Apuya, Nestor; Bobzin, Steven Craig; Okamuro, Jack; Zhang, Ke

    2013-01-29

    Materials and methods for modulating (e.g., increasing or decreasing) lignin content in plants are disclosed. For example, nucleic acids encoding lignin-modulating polypeptides are disclosed as well as methods for using such nucleic acids to generate transgenic plants having a modulated lignin content.

  17. Polarization modulators for CMBPol

    International Nuclear Information System (INIS)

    We review a number of technologies that are candidates for active polarization modulators for CMBPol. The technologies are appropriate for instruments that use bolometric detectors and include birefringent crystal-based and metal-mesh-based half-wave plates, variable phase polarization modulator, Faraday rotator, and photolithographed modulators. We also give a current account of the status of millimeter-wave orthomode transducers.

  18. Polarization modulators for CMBPol

    Energy Technology Data Exchange (ETDEWEB)

    Ade, P A R; Savini, G [Cardiff University, School of Physics and Astronomy, Queens Buildings, The Parade, Cardiff, CF24 3AA (United Kingdom); Chuss, D T [NASA Goddard Space Flight Center, Code 665, Greenbelt, MD, 20771 (United States); Hanany, S [School of Physics and Astronomy, University of Minnesota/Twin Cities, Minneapolis, MN, 55455 (United States); Haynes, V; Pisano, G [University of Manchester, School of Physics and Astronomy - Alan Turing Building, Upper Brooke street, Manchester, M13 4PL (United Kingdom); Keating, B G [Department of Physics, University of California, San Diego, La Jolla, CA 92093-0424 (United States); Kogut, A [Code 665 Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Ruhl, J E [Physics Department, Case Western Reserve University, Cleveland, OH, 44106 (United States); Wollack, E J [Observational Cosmology Laboratory, NASA/GSFC, Greenbelt, MD 20771 (United States)

    2009-03-01

    We review a number of technologies that are candidates for active polarization modulators for CMBPol. The technologies are appropriate for instruments that use bolometric detectors and include birefringent crystal-based and metal-mesh-based half-wave plates, variable phase polarization modulator, Faraday rotator, and photolithographed modulators. We also give a current account of the status of millimeter-wave orthomode transducers.

  19. CS-Rickart modules

    OpenAIRE

    Abyzov, A. N.; Nhan, T. H. N.

    2014-01-01

    In this paper, we introduce and study the concept of CS-Rickart modules, that is a module analogue of the concept of ACS rings. A ring $R$ is called a right weakly semihereditary ring if every its finitly generated right ideal is of the form $P\\oplus S,$ where $P_R$ is a projective module and $S_R$ is a singular module. We describe the ring $R$ over which $\\mathrm{Mat}_n (R)$ is a right ACS ring for any $n \\in \\mathbb {N}$. We show that every finitely generated projective right $R$-module wil...

  20. Reduced Multiplication Modules

    Indian Academy of Sciences (India)

    Karim Samei

    2011-05-01

    An -module is called a multiplication module if for each submodule of , = for some ideal of . As defined for a commutative ring , an -module is said to be reduced if the intersection of prime submodules of is zero. The prime spectrum and minimal prime submodules of the reduced module are studied. Essential submodules of are characterized via a topological property. It is shown that the Goldie dimension of is equal to the Souslin number of Spec (). Also a finitely generated module is a Baer module if and only if Spec () is an extremally disconnected space; if and only if it is a -module. It is proved that a prime submodule is minimal in if and only if for each $x\\in N,\\mathrm{Ann}(x)\

  1. Frequency modulation in nuclear magnetometer

    International Nuclear Information System (INIS)

    A version of the frequency-modulation magnetometer based on a particular design of the field-modulation nuclear magnetometer is proposed. Disadvantages of field modulation and advantages of frequency modulation are pointed out

  2. Modulation indices for volumetric modulated arc therapy

    International Nuclear Information System (INIS)

    The aim of this study is to present a modulation index (MI) for volumetric modulated arc therapy (VMAT) based on the speed and acceleration analysis of modulating-parameters such as multi-leaf collimator (MLC) movements, gantry rotation and dose-rate, comprehensively. The performance of the presented MI (MIt) was evaluated with correlation analyses to the pre-treatment quality assurance (QA) results, differences in modulating-parameters between VMAT plans versus dynamic log files, and differences in dose-volumetric parameters between VMAT plans versus reconstructed plans using dynamic log files. For comparison, the same correlation analyses were performed for the previously suggested modulation complexity score (MCSv), leaf travel modulation complexity score (LTMCS) and MI by Li and Xing (MI Li and Xing). In the two-tailed unpaired parameter condition, p values were acquired. The Spearman’s rho (rs) values of MIt, MCSv, LTMCS and MI Li and Xing to the local gamma passing rate with 2%/2 mm criterion were −0.658 (p < 0.001), 0.186 (p = 0.251), 0.312 (p = 0.05) and −0.455 (p = 0.003), respectively. The values of rs to the modulating-parameter (MLC positions) differences were 0.917, −0.635, −0.857 and 0.795, respectively (p < 0.001). For dose-volumetric parameters, MIt showed higher statistically significant correlations than the conventional MIs. The MIt showed good performance for the evaluation of the modulation-degree of VMAT plans. (paper)

  3. Directed network modules

    CERN Document Server

    Pálla, G; Farkas, I J; Pollner, P; Vicsek, T; Derenyi, Imre; Farkas, Illes J.; Palla, Gergely; Pollner, Peter; Vicsek, Tamas

    2007-01-01

    A search technique locating network modules, i.e., internally densely connected groups of nodes in directed networks is introduced by extending the Clique Percolation Method originally proposed for undirected networks. After giving a suitable definition for directed modules we investigate their percolation transition in the Erdos-Renyi graph both analytically and numerically. We also analyse four real-world directed networks, including Google's own webpages, an email network, a word association graph and the transcriptional regulatory network of the yeast Saccharomyces cerevisiae. The obtained directed modules are validated by additional information available for the nodes. We find that directed modules of real-world graphs inherently overlap and the investigated networks can be classified into two major groups in terms of the overlaps between the modules. Accordingly, in the word-association network and among Google's webpages the overlaps are likely to contain in-hubs, whereas the modules in the email and t...

  4. Bothrops bites in Colombia: a multicenter study on the efficacy and safety of Antivipmyn-Tri®, a polyvalent antivenom produced in Mexico Accidente bothrópico en Colombia: estudio multicéntrico de la eficacia y seguridad de Antivipmyn-Tri®, un antiveneno polivalente producido en México

    Directory of Open Access Journals (Sweden)

    María Eugenia Espinal Saldarriaga

    2007-08-01

    Full Text Available Introduction: Colombia is a country with two whole IgG antivenom producers, but the expectancy of all the market are not fulfilled by different technical reasons. Objectives: To evaluate the efficacy and safety of a F(ab´2 polyvalent antivenom produced in Mexico and of a new dosage regimen for Bothrops bites in Colombia. Methods: A clinical trial, including serum venom and antivenom measurements (ELISA, was performed during 9 months in 53 patients. Results: forty four patients were bitten by Bothrops asper in Antioquia and Chocó and 9 by B. atrox in Amazonas; on admission, all of them had nonclottable blood, 30 (56.6% presented local and 24 (45.3% systemic bleeding. The final envenoming grade was mild in 13 (24.5%, moderate in 30 (56.6% and severe in 10 patients (18.9%. At the antivenom doses used in this study (5 vials for mild / moderate and 10 for severe envenoming, Antivipmyn Triwas 100% efficient to decrease significantly serum venom concentrations within the first treatment hour, and to stop local and systemic bleeding within 6-12 hours, 96.2% efficient to restore blood coagulation within 24 hours and 100% within 48 hours. Two patients (3.8% had recurrence of coagulopathy without bleeding, and there were 12 recurrences of antigenaemia without clinical relevance. Ten (18.9% patients suffered early mild adverse reactions to fabotherapy. There were no deaths and four patients (7.5% presented sequelae. Conclusion: at the doses used in this study, Antivipmyn Tri® was efficient and safe for the treatment of Bothrops bites in Colombia. Introducción: Colombia es un país con dos productores de antivenenos de IgG, pero hay un mercado insatisfecho por diferentes razones técnicas. Objetivos: evaluar la eficacia y la seguridad de un antiveneno F(ab´2 polivalente (Antivipmyn-Tri® producido en México, y un nuevo esquema de dosis en accidente bothrópico en Colombia. Métodos: se realizaron durante 9 meses un ensayo clínico-terapéutico y

  5. Características bioquímicas y capacidad neutralizante de cuatro antivenenos polivalentes frente a los efectos farmacológicos y enzimáticos del veneno de Bothrops asper y Porthidium nasutum de Antioquia y Chocó

    Directory of Open Access Journals (Sweden)

    Mónica Saldarriaga

    2002-01-01

    Full Text Available En Colombia, el 90-95% de las 3000 mordeduras de serpientes informadas cada año, son ocasionadas por Bothrops spp, con una elevada mortalidad y secuelas. Siguiendo recomendaciones de la OMS, se evaluó la capacidad neutralizante de los efectos farmacológicos y enzimáticos de los venenos de Bothrops asper y Porthidium nasutum de Antioquia y Chocó por cuatro antivenenos; 2 de ellos de IgG completa (polivalente antibothrópico, anticrotálico del Instituto Nacional de Salud INS -Colombia; polivalente antibothrópico, anticrotálico, antilachésico de Laboratorios Probiol -Colombia y 2 antivenenos de fragmentos F(ab’2 (polivalente antibothrópico, anticrotálico del Centro de Biotecnología de la Universidad Central de Venezuela; y el polivalente antibothrópico, anticrotálico Antivipmyn® del Instituto Bioclón -México. Se determinó la actividad letal, hemorrágica, desfibrinante, edematizante, mionecrosante y hemolítica indirecta de cada veneno, siguiendo métodos ya estandarizados. Las pruebas de neutralización in vitro e in vivo se realizaron por el método de preincubación a 370C de dosis fijas de veneno y dosis variables de antiveneno. Los antivenenos Antivipmyn® de México y polivalente INS de Colombia tuvieron la mayor potencia neutralizante de todos los efectos farmacológicos y enzimáticos del veneno de B. asper y P. nasutum. El antiveneno polivalente Probiol fue el de menor capacidad neutralizante y mayor concentración de proteínas. Los antivenenos de fragmentos F(ab’2 tuvieron más baja concentración de proteínas y solo cantidades menores de proteínas no inmunes por electroforesis. Ninety to 95% of the snakebites reported yearly in Colombia are inflicted by Bothrops spp with high mortality and sequelae. Following recommendations of the World Health Organization, the neutralizing ability of four polyvalent antivenoms against several pharmacological and enzymatic effects of Bothrops asper and Porthidium nasutum snake

  6. A photovoltaic module

    OpenAIRE

    Krebs, Frederik C.; Sommer-Larsen, Peter

    2013-01-01

    The present invention relates to a photovoltaic module comprising a carrier substrate, said carrier substrate carrying a purely printed structure comprising printed positive and negative module terminals, a plurality of printed photovoltaic cell units each comprising one or more printed photovoltaic cells, wherein the plurality of printed photovoltaic cell units are electrically connected in series between the positive and the negative module terminals such that any two neighbouring photovolt...

  7. The ANTARES Optical Module

    OpenAIRE

    the ANTARES Collaboration

    2001-01-01

    The ANTARES collaboration is building a deep sea neutrino telescope in the Mediterranean Sea. This detector will cover a sensitive area of typically 0.1 km-squared and will be equipped with about 1000 optical modules. Each of these optical modules consists of a large area photomultiplier and its associated electronics housed in a pressure resistant glass sphere. The design of the ANTARES optical module, which is a key element of the detector, has been finalized following extensive R & D studi...

  8. Model theory and modules

    CERN Document Server

    Prest, M

    1988-01-01

    In recent years the interplay between model theory and other branches of mathematics has led to many deep and intriguing results. In this, the first book on the topic, the theme is the interplay between model theory and the theory of modules. The book is intended to be a self-contained introduction to the subject and introduces the requisite model theory and module theory as it is needed. Dr Prest develops the basic ideas concerning what can be said about modules using the information which may be expressed in a first-order language. Later chapters discuss stability-theoretic aspects of module

  9. Bracket for photovoltaic modules

    Science.gov (United States)

    Ciasulli, John; Jones, Jason

    2014-06-24

    Brackets for photovoltaic ("PV") modules are described. In one embodiment, a saddle bracket has a mounting surface to support one or more PV modules over a tube, a gusset coupled to the mounting surface, and a mounting feature coupled to the gusset to couple to the tube. The gusset can have a first leg and a second leg extending at an angle relative to the mounting surface. Saddle brackets can be coupled to a torque tube at predetermined locations. PV modules can be coupled to the saddle brackets. The mounting feature can be coupled to the first gusset and configured to stand the one or more PV modules off the tube.

  10. Delphi Accounts Receivable Module

    Data.gov (United States)

    Department of Transportation — Delphi accounts receivable module contains the following data elements, but are not limited to customer information, cash receipts, line of accounting details, bill...

  11. Silicon photonic heater-modulator

    Science.gov (United States)

    Zortman, William A.; Trotter, Douglas Chandler; Watts, Michael R.

    2015-07-14

    Photonic modulators, methods of forming photonic modulators and methods of modulating an input optical signal are provided. A photonic modulator includes a disk resonator having a central axis extending along a thickness direction of the disk resonator. The disk resonator includes a modulator portion and a heater portion. The modulator portion extends in an arc around the central axis. A PN junction of the modulator portion is substantially normal to the central axis.

  12. The Strip Module

    DEFF Research Database (Denmark)

    Pedersen, Tommy

    1996-01-01

    When the behaviour of a ship in waves is to be predicted it is convenient to have a tool which includes different approaches to the problem.The aim of this project is to develop such a tool named the strip theory module. The strip theory module will consist of submodules dependent on the I-ship c...

  13. The FPAX fastbus module

    International Nuclear Information System (INIS)

    The FPAX is a Fastbus module with 4 independent, 2 slave and 2 master, ports on two segments. It operates as a normal master on either segment or as a Block-Mover on both. The processor board is based on a 68020 microprocessor. A local/network switch allows operation as a host or as a normal module on the Fastbus network

  14. Cosmetology. Computerized Learning Modules.

    Science.gov (United States)

    Finnerty, Kathy, Ed.

    Intended to help reading-limited students meet course objectives, these 11 modules are based on instructional materials in cosmetology that have a higher readability equivalent. Modules cover bacteriology, chemical waving, scalp and hair massage, chemistry, hair shaping, hairstyling, chemical hair relaxing, hair coloring, skin and scalp,…

  15. Modulation gamma resonance spectroscopy

    International Nuclear Information System (INIS)

    Possibility to control dynamic processes in a matter through gamma-resonance modulation by high-frequency external variable fields in excess of inverse lifetimes of the Moessbauer nuclei excited states, that is, within the megahertz frequency range lies in the heart of the modulation gamma-resonance spectroscopy. Through the use of the gamma-resonance process theoretical analysis methods and of the equation solution method for the density matrix with the secondary quantization of gamma-radiation field one attacks the problems dealing with the effect of both variable fields and relaxation on gamma-resonance. One has studied the gamma-radiation ultrasound modulation stages. One points out a peculiar role of the gamma-magnetic resonance effect in modulation gamma resonance spectroscopy formation. One forecasts development of the modulation gamma-resonance spectroscopy into the nonlinear gamma-resonance spectroscopy

  16. Solar energy modulator

    Science.gov (United States)

    Hale, R. R. (Inventor); Mcdougal, A. R.

    1984-01-01

    A module is described with a receiver having a solar energy acceptance opening and supported by a mounting ring along the optic axis of a parabolic mirror in coaxial alignment for receiving solar energy from the mirror, and a solar flux modulator plate for varying the quantity of solar energy flux received by the acceptance opening of the module. The modulator plate is characterized by an annular, plate-like body, the internal diameter of which is equal to or slightly greater than the diameter of the solar energy acceptance opening of the receiver. Slave cylinders are connected to the modulator plate for supporting the plate for axial displacement along the axis of the mirror, therby shading the opening with respect to solar energy flux reflected from the surface of the mirror to the solar energy acceptance opening.

  17. Photovoltaic module and interlocked stack of photovoltaic modules

    Science.gov (United States)

    Wares, Brian S.

    2014-09-02

    One embodiment relates to an arrangement of photovoltaic modules configured for transportation. The arrangement includes a plurality of photovoltaic modules, each photovoltaic module including a frame. A plurality of individual male alignment features and a plurality of individual female alignment features are included on each frame. Adjacent photovoltaic modules are interlocked by multiple individual male alignment features on a first module of the adjacent photovoltaic modules fitting into and being surrounded by corresponding individual female alignment features on a second module of the adjacent photovoltaic modules. Other embodiments, features and aspects are also disclosed.

  18. On Modules Whose Singular Subgenerated Modules Are Weakly Injective

    Institute of Scientific and Technical Information of China (English)

    S. Dhompongsa; J. Sanwong; S.Plubtieng; H.Tansee

    2001-01-01

    Rings over which every singular right module is injective (briefly,right SI-rings) were introduced and investigated by Goodearl. Weakly injective modules, as a generalization of injective modules, were introduced by Jain and modules are weakly injective, which we call SwI-rings. This concept is extended to SwI-modules, i.e., modules whose singular subgenerated modules are weakly injective. Several characterizations and properties of SwI-rings and SwI-modules are obtained which generalize some earlier known results on SI-rings and weakly semisimple rings.

  19. VARIACIONES EN L COMPOSICIÓN PROTEICA, ACTIVIDADES ENZIMÁTICAS Y BIOLÓGICAS DEL VENENO DE LA SERPIENTE BOTHROPS ATROX (VIPEREIDAE EN RELACIÓN CON LA EDAD

    Directory of Open Access Journals (Sweden)

    O. Málaga

    2014-06-01

    Full Text Available La serpiente Bothrops atrox, que habita en la Selva Amazónica del Perú, es responsable del mayor número de accidentes ofídicos y constituye un problema de salud pública. Por esta razón, se ha realizado un estudio de las variaciones en la composición y actividad del veneno en tres grupos de especimenes en cautiverio, que corresponden a juveniles de 1 y 2 años, así como ejemplares adultos mayores de 5 años. Los venenos obtenidos fueron liofilizados para su conservación y diluidos en concentraciones iniciales de 1 mg/ml en solución salina o en el buffer apropiado. Con estas muestras se efectuaron los análisis de concentración de proteína por D. 0. 280 nm y por el método de Lowry, determinándose además el número de bandas proteicas por electroforesis en gel de poliacrilamida con dodecil sulfato de sodio (PAGE-SIDS. Con las mismas muestras se hicieron ensayos para medir las siguientes actividades enzimáticas: caseinolítica, amidolftica, coagulante, hialuronidasa, L-aminocácido oxidasa (LAO y fosfolipasa A, adicionalmente se determinó la actividad hemorrágica y el efecto edemático con ratones albinos. Los resultados mostraron que la mayor concentración proteica (0,938mg de proteína/mg de veneno así como el número máximo de bandas proteicas (8 bandas se obtuvieron con los venenos de juveniles de 2 años. Asimismo se encontró que algunas actividades enzimáticas como la amidolítica, fosfolipásica y L-aminoácido oxidasa fueron más altas en los juveniles de 2 años, además de los efectos hemorrágico y edemático. En cambio, las actividades coagulante y proteolítica sobre caseína se elevaron progresivamente con la edad de los ejemplares. Sin embargo, la enzima hialuronidasa tuvo su máximo valor en los juveniles de 1 año, decreciendo notablemente en los adultos. Es interesante señalar también que fosfolipasa A2 en los adultos sólo tuvo una actividad de 6,4% con respecto al valor más alto encontrado en el veneno

  20. The ANTARES optical module

    International Nuclear Information System (INIS)

    The ANTARES collaboration is building a deep sea neutrino telescope in the Mediterranean Sea. This detector will cover a sensitive area of typically 0.1 km2 and will be equipped with about 1000 optical modules. Each of these optical modules consists of a large area photomultiplier and its associated electronics housed in a pressure resistant glass sphere. The design of the ANTARES optical module, which is a key element of the detector, has been finalized following extensive R and D studies and is reviewed here in detail

  1. Optical modulator including grapene

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ming; Yin, Xiaobo; Zhang, Xiang

    2016-06-07

    The present invention provides for a one or more layer graphene optical modulator. In a first exemplary embodiment the optical modulator includes an optical waveguide, a nanoscale oxide spacer adjacent to a working region of the waveguide, and a monolayer graphene sheet adjacent to the spacer. In a second exemplary embodiment, the optical modulator includes at least one pair of active media, where the pair includes an oxide spacer, a first monolayer graphene sheet adjacent to a first side of the spacer, and a second monolayer graphene sheet adjacent to a second side of the spacer, and at least one optical waveguide adjacent to the pair.

  2. Functorial Test Modules

    OpenAIRE

    Blickle, Manuel; Stäbler, Axel

    2016-01-01

    In this article we introduce a slight modification of the definition of test modules which is an additive functor $\\tau$ on the category of coherent Cartier modules. We show that in many situations this modification agrees with the usual definition of test modules. Furthermore, we show that for a smooth morphism $f \\colon X \\to Y$ of $F$-finite schemes one has a natural isomorphism $f^! \\circ \\tau \\cong \\tau \\circ f^!$. If $f$ is quasi-finite and of finite type we construct a natural transfor...

  3. Water heater control module

    Science.gov (United States)

    Hammerstrom, Donald J

    2013-11-26

    An advanced electric water heater control system that interfaces with a high temperature cut-off thermostat and an upper regulating thermostat. The system includes a control module that is electrically connected to the high-temperature cut-off thermostat and the upper regulating thermostat. The control module includes a switch to open or close the high-temperature cut-off thermostat and the upper regulating thermostat. The control module further includes circuitry configured to control said switch in response to a signal selected from the group of an autonomous signal, a communicated signal, and combinations thereof.

  4. GREET Pretreatment Module

    Energy Technology Data Exchange (ETDEWEB)

    Adom, Felix K.; Dunn, Jennifer B.; Han, Jeongwoo

    2014-09-01

    A wide range of biofuels and biochemicals can be produced from biomass via different pretreatment technologies that yield sugars. This report documents the material and energy flows that occur when fermentable sugars from four lignocellulosic feedstocks (corn stover, miscanthus, switchgrass, and poplar) are produced via dilute acid pretreatment and ammonia fiber expansion. These flows are documented for inclusion in the pretreatment module of the Greenhouses Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. Process simulations of each pretreatment technology were developed in Aspen Plus. Material and energy consumption data from Aspen Plus were then compiled in the GREET pretreatment module. The module estimates the cradle-to-gate fossil energy consumption (FEC) and greenhouse gas (GHG) emissions associated with producing fermentable sugars. This report documents the data and methodology used to develop this module and the cradle-to-gate FEC and GHG emissions that result from producing fermentable sugars.

  5. A photovoltaic module

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention relates to a photovoltaic module comprising a carrier substrate, said carrier substrate carrying a purely printed structure comprising printed positive and negative module terminals, a plurality of printed photovoltaic cell units each comprising one or more printed...... photovoltaic cells, wherein the plurality of printed photovoltaic cell units are electrically connected in series between the positive and the negative module terminals such that any two neighbouring photovoltaic cell units are electrically connected by a printed interconnecting electrical conductor. The...... carrier substrate comprises a foil and the total thickness of the photovoltaic module is below 500 [mu]m. Moreover, the nominal voltage level between the positive and the negative terminals is at least 5 kV DC....

  6. Ultrasound Modulated Bioluminescence Tomography

    CERN Document Server

    Bal, Guillaume

    2013-01-01

    We propose a method to reconstruct the density of a luminescent source in a highly-scattering medium from ultrasound modulated optical measurements. Our approach is based on the solution to a hybrid inverse source problem for the diffusion equation.

  7. Isothermal Containment Module

    Science.gov (United States)

    1999-01-01

    Isothermal Containment Modules are the temperature-controlling carrier that BioServe built to carry Commercial Generic Bioprocessing Apparatus (CGBA) and in the future, Space Automated Bioproduct Lab (SABL) to the International Space Station.

  8. Electrical modulation of emissivity

    OpenAIRE

    Vassant, Simon; Moldovan Doyen, Ioana Cristina; Marquier, François; Pardo, F.; Gennser, Ulf; Cavanna, Antonella; Pelouard, Jean-Luc; Greffet, Jean-Jacques

    2013-01-01

    We demonstrate that it is possible to modulate the thermal emission through an electrical modulation of the emissivity. The basic idea is to design a device where absorption is due to a resonant phenomenon. If the resonance can be electrically controlled, then absorption and, therefore, thermal emission can be controlled. We demonstrate this general concept using THz resonant absorption by surface phonon polaritons coupled through a gold grating. In our device, absorption is mostly due to a s...

  9. Renewal, Modulation and Superstatistics

    OpenAIRE

    Allegrini, Paolo; Barbi, Francesco; Grigolini, Paolo; Paradisi, Paolo

    2005-01-01

    We consider two different proposals to generate a time series with the same non-Poisson distribution of waiting times, to which we refer to as renewal and modulation. We show that, in spite of the apparent statistical equivalence, the two time series generate different physical effects. Renewal generates aging and anomalous scaling, while modulation yields no aging and either ordinary or anomalous diffusion, according to the prescription used for its generation. We argue, in fact, that the ph...

  10. Groups, rings, modules

    CERN Document Server

    Auslander, Maurice

    2014-01-01

    This classic monograph is geared toward advanced undergraduates and graduate students. The treatment presupposes some familiarity with sets, groups, rings, and vector spaces. The four-part approach begins with examinations of sets and maps, monoids and groups, categories, and rings. The second part explores unique factorization domains, general module theory, semisimple rings and modules, and Artinian rings. Part three's topics include localization and tensor products, principal ideal domains, and applications of fundamental theorem. The fourth and final part covers algebraic field extensions

  11. Directed network modules

    Science.gov (United States)

    Palla, Gergely; Farkas, Illés J.; Pollner, Péter; Derényi, Imre; Vicsek, Tamás

    2007-06-01

    A search technique locating network modules, i.e. internally densely connected groups of nodes in directed networks is introduced by extending the clique percolation method originally proposed for undirected networks. After giving a suitable definition for directed modules we investigate their percolation transition in the Erdos Rényi graph both analytically and numerically. We also analyse four real-world directed networks, including Google's own web-pages, an email network, a word association graph and the transcriptional regulatory network of the yeast Saccharomyces cerevisiae. The obtained directed modules are validated by additional information available for the nodes. We find that directed modules of real-world graphs inherently overlap and the investigated networks can be classified into two major groups in terms of the overlaps between the modules. Accordingly, in the word-association network and Google's web-pages, overlaps are likely to contain in-hubs, whereas the modules in the email and transcriptional regulatory network tend to overlap via out-hubs.

  12. Second generation SLAC modulator

    International Nuclear Information System (INIS)

    The Stanford Linear Accelerator Laboratory has undertaken the construction of a single pass electron-positron collider. In order to reach required beam energy 235 new klystrons needed upgraded modulator systems. The collider will use 50 GeV electrons and positrons. The increase in accelerator energy from the present 30 GeV necessitates the replacement of existing 35 MW klystrons with new 67 MW units. The doubling of klystron output power required a redesign of the modulator system. The 67 MW klystron needs a 350 kV beam voltage pulse with a 3.7 μs pulse width. A new pulse transformer was designed to deliver the increased voltage and pulse width. Pulse cable design was evaluated to obtain increased reliability of that critical element. The modulator, with the exception of its power supply, was rebuilt to produce the required power increase while enhancing reliability and improving maintainability. An investigation of present thyratron switch tube performance under the new operating conditions resulted in agitation and some warranted panic but these conditions were mitigated after several successful experiments and some evolutionary narrowing of the klystron pulse width. The discussion will cover the upgraded modulator system specifications and some details of the new pulse transformer tank, pulse cable, modulator, and modulator switch tube

  13. Directed network modules

    International Nuclear Information System (INIS)

    A search technique locating network modules, i.e. internally densely connected groups of nodes in directed networks is introduced by extending the clique percolation method originally proposed for undirected networks. After giving a suitable definition for directed modules we investigate their percolation transition in the Erdos-Renyi graph both analytically and numerically. We also analyse four real-world directed networks, including Google's own web-pages, an email network, a word association graph and the transcriptional regulatory network of the yeast Saccharomyces cerevisiae. The obtained directed modules are validated by additional information available for the nodes. We find that directed modules of real-world graphs inherently overlap and the investigated networks can be classified into two major groups in terms of the overlaps between the modules. Accordingly, in the word-association network and Google's web-pages, overlaps are likely to contain in-hubs, whereas the modules in the email and transcriptional regulatory network tend to overlap via out-hubs

  14. Second generation SLAC modulator

    Energy Technology Data Exchange (ETDEWEB)

    Donaldson, A.R.; Cron, J.C.; Hanselman, R.R.

    1986-06-01

    The Stanford Linear Accelerator Laboratory has undertaken the construction of a single pass electron-positron collider. In order to reach required beam energy 235 new klystrons needed upgraded modulator systems. The collider will use 50 GeV electrons and positrons. The increase in accelerator energy from the present 30 GeV necessitates the replacement of existing 35 MW klystrons with new 67 MW units. The doubling of klystron output power required a redesign of the modulator system. The 67 MW klystron needs a 350 kV beam voltage pulse with a 3.7 ..mu..s pulse width. A new pulse transformer was designed to deliver the increased voltage and pulse width. Pulse cable design was evaluated to obtain increased reliability of that critical element. The modulator, with the exception of its power supply, was rebuilt to produce the required power increase while enhancing reliability and improving maintainability. An investigation of present thyratron switch tube performance under the new operating conditions resulted in agitation and some warranted panic but these conditions were mitigated after several successful experiments and some evolutionary narrowing of the klystron pulse width. The discussion will cover the upgraded modulator system specifications and some details of the new pulse transformer tank, pulse cable, modulator, and modulator switch tube.

  15. Photovoltaic module reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Mrig, L. (ed.)

    1990-01-01

    The paper and presentations compiled in this volume form the Proceedings of the fourth in a series of Workshops sponsored by Solar Energy Research Institute (SERI/DOE) under the general theme of photovoltaic module reliability during the period 1986--1990. The reliability Photo Voltaic (PV) modules/systems is exceedingly important along with the initial cost and efficiency of modules if the PV technology has to make a major impact in the power generation market, and for it to compete with the conventional electricity producing technologies. The reliability of photovoltaic modules has progressed significantly in the last few years as evidenced by warranties available on commercial modules of as long as 12 years. However, there is still need for substantial research and testing required to improve module field reliability to levels of 30 years or more. Several small groups of researchers are involved in this research, development, and monitoring activity around the world. In the US, PV manufacturers, DOE laboratories, electric utilities and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in this field were brought together under SERI/DOE sponsorship to exchange the technical knowledge and field experience as related to current information in this important field. The papers presented here reflect this effort.

  16. Photovoltaic module reliability workshop

    Science.gov (United States)

    Mrig, L.

    The paper and presentations compiled in this volume form the Proceedings of the fourth in a series of Workshops sponsored by Solar Energy Research Institute (SERI/DOE) under the general theme of photovoltaic module reliability during the period 1986 to 1990. The reliability photovoltaic (PV) modules/systems is exceedingly important along with the initial cost and efficiency of modules if the PV technology has to make a major impact in the power generation market, and for it to compete with the conventional electricity producing technologies. The reliability of photovoltaic modules has progressed significantly in the last few years as evidenced by warrantees available on commercial modules of as long as 12 years. However, there is still need for substantial research and testing required to improve module field reliability to levels of 30 years or more. Several small groups of researchers are involved in this research, development, and monitoring activity around the world. In the U.S., PV manufacturers, DOE laboratories, electric utilities and others are engaged in the photovoltaic reliability research and testing. This group of researchers and others interested in this field were brought together under SERI/DOE sponsorship to exchange the technical knowledge and field experience as related to current information in this important field. The papers presented here reflect this effort.

  17. Directed network modules

    Energy Technology Data Exchange (ETDEWEB)

    Palla, Gergely [Statistical and Biological Physics Research Group of HAS, Pazmany Peter Setany 1A, Budapest, H-1117 (Hungary); Farkas, Illes J [Statistical and Biological Physics Research Group of HAS, Pazmany Peter Setany 1A, Budapest, H-1117 (Hungary); Pollner, Peter [Statistical and Biological Physics Research Group of HAS, Pazmany Peter Setany 1A, Budapest, H-1117 (Hungary); Derenyi, Imre [Department of Biological Physics, Eoetvoes University, Pazmany Peter Setany 1A, Budapest, H-1117 (Hungary); Vicsek, Tamas [Statistical and Biological Physics Research Group of HAS, Pazmany Peter Setany 1A, Budapest, H-1117 (Hungary)

    2007-06-15

    A search technique locating network modules, i.e. internally densely connected groups of nodes in directed networks is introduced by extending the clique percolation method originally proposed for undirected networks. After giving a suitable definition for directed modules we investigate their percolation transition in the Erdos-Renyi graph both analytically and numerically. We also analyse four real-world directed networks, including Google's own web-pages, an email network, a word association graph and the transcriptional regulatory network of the yeast Saccharomyces cerevisiae. The obtained directed modules are validated by additional information available for the nodes. We find that directed modules of real-world graphs inherently overlap and the investigated networks can be classified into two major groups in terms of the overlaps between the modules. Accordingly, in the word-association network and Google's web-pages, overlaps are likely to contain in-hubs, whereas the modules in the email and transcriptional regulatory network tend to overlap via out-hubs.

  18. Strictly homogeneous laterally complete modules

    Science.gov (United States)

    Chilin, V. I.; Karimov, J. A.

    2016-03-01

    Let A be a laterally complete commutative regular algebra and X be a laterally complete A-module. In this paper we introduce a notion of homogeneous and strictly homogeneous A-modules. It is proved that any homogeneous A-module is strictly homogeneous A-module, if the Boolean algebra of all idempotents in A is multi-σ-finite.

  19. Separation film module. Bunri maku module

    Energy Technology Data Exchange (ETDEWEB)

    Ninomiya, Y.; Takada, N. (, Chiba (Japan))

    1990-10-09

    The separation film module used for the production of dry air by separating vapor from air and for the concentration of alcohol from a mixed gas of alcohol and water has hollow yarn of polyimide resin in a tubular container. The gas permeated through the separation film is discharged from the permeated gas exit provided at an end of the container, and the unpermeated gas is exhausted from the core pipe provided at the center of the tubulsr container. However, the module has a problem of poor airtightness at the connection when the machining is not accurate or when thermal expansion occurs because the core pipe is communicated with the unpermeated gas discharge pipe via a rigid joint pipe. This invention relates to a solution to the problem by providing an expansion joint between the discharge end of the core pipe and the unpermeated gas discharge pipe. A joint pipe with a bellows in the middle is used as the said joint pipe. 3 figs.

  20. Solar cell module. Taiyo denchi module

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, Akihiko; Matsumoto, Hitoshi.

    1989-09-06

    In the conventional solar cell module, the cell cost is elevated because the cross sections of the cell edge is surrounded with frames of various shape and the gap is filled with a sealant. In additionn, the top end of the module frame is placed roughly 1 mm above the glass surface; the photoelectromotive force part is covered with such deposits as soils and sands, thus badly affecting the photovoltaic generation. In this invention, weather-proof opaque paint is coated around the surface glass to interrupt the light irradiation to the adhesive resin layer between the glass and the back sheet, thus preventing the degradation of the resin layer. Cost is low because of using a thin film. The light interruption by the deposits can be prevented. The photoelectromotive force element is a n-type CdS film or CdS/CdTe. The resin layer around the glass is a thermoplastic polyolefin which is modified with acid anhydrides. 5 figs.

  1. Bunch identification module

    International Nuclear Information System (INIS)

    This module provides bunch identification and timing signals for the PEP Interaction areas. Timing information is referenced to the PEP master oscillator, and adjusted in phase as a function of region. Identification signals are generated in a manner that allows observers in all interaction regions to agree on an unambiguous bunch identity. The module provides bunch identification signals via NIM level logic, upon CAMAC command, and through LED indicators. A front panel ''region select'' switch allows the same module to be used in all regions. The module has two modes of operation: a bunch identification mode and a calibration mode. In the identification mode, signals indicate which of the three bunches of electrons and positrons are interacting, and timing information about beam crossing is provided. The calibration mode is provided to assist experimenters making time of flight measurements. In the calibration mode, three distinct gating signals are referenced to a selected bunch, allowing three timing systems to be calibrated against a common standard. Physically, the bunch identifier is constructed as a single width CAMAC module. 2 figs., 1 tab

  2. NREL module energy rating methodology

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, C.; Newmiller, J.; Kroposki, B. [National Renewable Energy Laboratory, Golden, CO (United States)] [and others

    1995-11-01

    The goals of this project were to develop a tool for: evaluating one module in different climates; comparing different modules; provide a Q&D method for estimating periodic energy production; provide an achievable module rating; provide an incentive for manufacturers to optimize modules to non-STC conditions; and to have a consensus-based, NREL-sponsored activity. The approach taken was to simulate module energy for five reference days of various weather conditions. A performance model was developed.

  3. Hilbert modules and their representation

    OpenAIRE

    Takahaschi, Alfonso

    2012-01-01

    A Hilbert module over a  C*-algebra A with identity is an unitary A-module H, endowed with an inner product taking values in A. We consider these modules and derive some of their elementary properties. Later we consider fields of Hilbert modules and obtain a representation of H by means of continuous sections. This result will be used in other papers ([7] and [8]) to get a duality  theorem and to study special Hilbert modules.

  4. Multilevel Modulation formats for Optical Communication

    DEFF Research Database (Denmark)

    Jensen, Jesper Bevensee

    2008-01-01

    This thesis studies the use of multilevel modulation formats for optical communication systems. Multilevel modulation is an attractive method of increasing the spectral efficiency of optical communication systems. Various modulation formats employing phase modulation, amplitude modulation or a...

  5. Phase modulated multiphoton microscopy

    CERN Document Server

    Karki, Khadga Jung; Pullerits, Tonu

    2015-01-01

    We show that the modulation of the phases of the laser beams of ultra-short pulses leads to modulation of the two photon fluorescence intensity. The phase modulation technique when used in multi-photon microscopy can improve the signal to noise ratio. The technique can also be used in multiplexing the signals in the frequency domain in multi-focal raster scanning microscopy. As the technique avoids the use of array detectors as well as elaborate spatiotemporal multiplexing schemes it provides a convenient means to multi-focal scanning in axial direction. We show examples of such uses. Similar methodology can be used in other non-linear scanning microscopies, such as second or third harmonic generation microscopy.

  6. Hollow dimension of modules

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In this paper, we are interested in the following general question: Given a module Mwhich has finite hollow dimension and which has a finite collection of submodules Ki (1≤i≤n) such that M=K1+... +Kn, can we find an expression for the hollow dimension of Min terms of hollow dimensions of modules built up in some way from K1 Kn? We prove the following theorem:Let Mbe an amply supplemented module having finite hollow dimension and let Ki (1≤i≤n) be a finite collection of submodules of Msuch that M=K1+...+Kn. Then the hollow dimension h(M) of Mis the sum of the hollow dimensions of Ki (1≤i≤n) ifand only if Ki is a supplement of K1+...+Ki-1+Ki+1+...+Kn in Mfor each 1≤i≤n.

  7. Flat covers of modules

    CERN Document Server

    Xu, Jinzhong

    1996-01-01

    Since the injective envelope and projective cover were defined by Eckmann and Bas in the 1960s, they have had great influence on the development of homological algebra, ring theory and module theory. In the 1980s, Enochs introduced the flat cover and conjectured that every module has such a cover over any ring. This book provides the uniform methods and systematic treatment to study general envelopes and covers with the emphasis on the existence of flat cover. It shows that Enochs' conjecture is true for a large variety of interesting rings, and then presents the applications of the results. Readers with reasonable knowledge in rings and modules will not have difficulty in reading this book. It is suitable as a reference book and textbook for researchers and graduate students who have an interest in this field.

  8. Quantitative velocity modulation spectroscopy

    Science.gov (United States)

    Hodges, James N.; McCall, Benjamin J.

    2016-05-01

    Velocity Modulation Spectroscopy (VMS) is arguably the most important development in the 20th century for spectroscopic study of molecular ions. For decades, interpretation of VMS lineshapes has presented challenges due to the intrinsic covariance of fit parameters including velocity modulation amplitude, linewidth, and intensity. This limitation has stifled the growth of this technique into the quantitative realm. In this work, we show that subtle changes in the lineshape can be used to help address this complexity. This allows for determination of the linewidth, intensity relative to other transitions, velocity modulation amplitude, and electric field strength in the positive column of a glow discharge. Additionally, we explain the large homogeneous component of the linewidth that has been previously described. Using this component, the ion mobility can be determined.

  9. Power module assembly

    Science.gov (United States)

    Campbell, Jeremy B.; Newson, Steve

    2011-11-15

    A power module assembly of the type suitable for deployment in a vehicular power inverter, wherein the power inverter has a grounded chassis, is provided. The power module assembly comprises a conductive base layer electrically coupled to the chassis, an insulating layer disposed on the conductive base layer, a first conductive node disposed on the insulating layer, a second conductive node disposed on the insulating layer, wherein the first and second conductive nodes are electrically isolated from each other. The power module assembly also comprises a first capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the first conductive node, and further comprises a second capacitor having a first electrode electrically connected to the conductive base layer, and a second electrode electrically connected to the second conductive node.

  10. Individualized training module

    International Nuclear Information System (INIS)

    An individualized training module is a device for providing an individual trainee with the training he needs in a format where he can proceed on his own, without regard for the capabilities or even the presence of other students. It is based on a pretest, each item of which is referenced to a training activity. Each activity also has a test or performance qualification to verify that the desired learning occurred. Typically, the module as a variety of training activities; the scope is purposely narrow; and the instructional materials combine commercial and instructor made materials. The instructor creates the activities based upon desired scope and depth and the training materials and budget available

  11. Photovoltaic concentrator module technology

    Science.gov (United States)

    Richards, Elizabeth H.; Chamberlin, Jay L.; Boes, Eldon C.

    Significant developments in the development of photovoltaic (PV) concentrator technology are described. Concentrator cell research, advances in PV concentrator cell technology, and PV concentrator module development are described. Reliability issues currently of concern, including the applicability of wet insulation resistance tests to concentrator modules, correlation of accelerated thermal cycling tests with life expectancy in the field, and the importance of quality assurance during manufacture, are discussed. Two PV concentrator power systems installed in 1989 are discussed. A PV concentrator initiative program established by the DOE is given, and the results of the latest cost study are presented.

  12. Instant node package module

    CERN Document Server

    Ali, Juzer

    2013-01-01

    Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. A practical exploration of the lifecycle of creating node modules as well as learning all of the top features that npm has to offer.Intended for readers who want to create their first node.js modules. The programming paradigm of JavaScript is not covered so a foundation in these concepts would be beneficial.

  13. Cadmium telluride module development

    Energy Technology Data Exchange (ETDEWEB)

    Albrigth, S.P.; Chamberlin, R.R.; Jordan, J.F. (Photon Energy, Inc., El Paso, TX (USA))

    1991-05-01

    Efficiencies of up to 12.3% have been achieved on small devices. It is expected that 14% efficiency will be exceeded on small devices by improving the fill factors on the present devices in the reasonably near future. Efficiencies in the range 16%-18% are expected to be achieved in the longer term. Modules of 6 W, approximately 929 cm{sup 2} in area with an active area efficiency of over 8% (aperture efficiency of 7.3%) have been achieved. The feasibility of producing 4 ft{sup 2} modules of CdS/CdTe has been shown and requires further efforts in order to realize the overall potentials. The structural integrity of the encapsulation design has been studied by thermal cycling and outdoor life testing. Submodules have been life tested for over 270 days with no observable degradation by the SERI Outdoor Reliability and Life Testing Laboratory. In addition to further optimization of materials and device structure, module output in the future will be increased by an improvement in the uniformity of the deposition process, and by minimizing the loss of active area due to cell division interconnections. Module output is expected to attain 135 W m{sup -2} in the mid 1990s and over 150 W m{sup -2} in the long term. (orig.).

  14. Modulated Luminescent Tomography

    OpenAIRE

    Stefanov, Plamen; Cong, Wenxiang; Wang, Ge

    2014-01-01

    We propose and analyze a mathematical model of Modulated Luminescent Tomography. We show that when single X-rays or focused X-rays are used as an excitation, the problem is similar to the inversion of weighted X-ray transforms. In particular, we give an explicit inversion in the case of Dual Cone X-ray excitation.

  15. Modelling the Photovoltaic Module

    DEFF Research Database (Denmark)

    Katsanevakis, Markos

    2011-01-01

    This paper refers into various ways in simulation the Photovoltaic (PV) module behaviour under any combination of solar irradiation and ambient temperature. There are three different approaches presented here briefly and one of them is chosen because of its good accuracy and relatively low...

  16. Special Attachments. Module 19.

    Science.gov (United States)

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on special attachments, one in a series dealing with industrial sewing machines, their attachments, and operation, covers four topics: gauges; cording attachment; zipper foot; and hemming, shirring, and binding. For each topic these components are provided: an introduction, directions, an objective, learning activities, student…

  17. Special Operation. Module 20.

    Science.gov (United States)

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on special operations, one in a series dealing with industrial sewing machines, their attachments, and operation, covers two topics: topstitching and mitering. For each topic these components are provided: an introduction, directions, an objective, learning activities, student information, a student self-check, and a check-out…

  18. ALICE silicon strip module

    CERN Multimedia

    Maximilien Brice

    2006-01-01

    This small silicon detector strip will be inserted into the inner tracking system (ITS) on the ALICE detector at CERN. This detector relies on state-of-the-art particle tracking techniques. These double-sided silicon strip modules have been designed to be as lightweight and delicate as possible as the ITS will eventually contain five square metres of these devices.

  19. Product Module Rig Test

    Science.gov (United States)

    Holdeman, James D. (Technical Monitor); Chiappetta, Louis, Jr.; Hautman, Donald J.; Ols, John T.; Padget, Frederick C., IV; Peschke, William O. T.; Shirley, John A.; Siskind, Kenneth S.

    2004-01-01

    The low emissions potential of a Rich-Quench-Lean (RQL) combustor for use in the High Speed Civil Transport (HSCT) application was evaluated as part of Work Breakdown Structure (WBS) 1.0.2.7 of the NASA Critical Propulsion Components (CPC) Program under Contract NAS3-27235. Combustion testing was conducted in cell 1E of the Jet Burner Test Stand at United Technologies Research Center. Specifically, a Rich-Quench-Lean combustor, utilizing reduced scale quench technology implemented in a quench vane concept in a product-like configuration (Product Module Rig), demonstrated the capability of achieving an emissions index of nitrogen oxides (NOx EI) of 8.5 gm/Kg fuel at the supersonic flight condition (relative to the program goal of 5 gm/Kg fuel). Developmental parametric testing of various quench vane configurations in the more fundamental flametube, Single Module Rig Configuration, demonstrated NOx EI as low as 5.2. All configurations in both the Product Module Rig configuration and the Single Module Rig configuration demonstrated exceptional efficiencies, greater than 99.95 percent, relative to the program goal of 99.9 percent efficiency at supersonic cruise conditions. Sensitivity of emissions to quench orifice design parameters were determined during the parametric quench vane test series in support of the design of the Product Module Rig configuration. For the rectangular quench orifices investigated, an aspect ratio (length/width) of approximately 2 was found to be near optimum. An optimum for orifice spacing was found to exist at approximately 0.167 inches, resulting in 24 orifices per side of a quench vane, for the 0.435 inch quench zone channel height investigated in the Single Module Rig. Smaller quench zone channel heights appeared to be beneficial in reducing emissions. Measurements were also obtained in the Single Module Rig configuration on the sensitivity of emissions to the critical combustor parameters of fuel/air ratio, pressure drop, and residence

  20. Fundamentals of spread spectrum modulation

    CERN Document Server

    Ziemer, Rodger E

    2007-01-01

    This lecture covers the fundamentals of spread spectrum modulation, which can be defined as any modulation technique that requires a transmission bandwidth much greater than the modulating signal bandwidth, independently of the bandwidth of the modulating signal. After reviewing basic digital modulation techniques, the principal forms of spread spectrum modulation are described. One of the most important components of a spread spectrum system is the spreading code, and several types and their characteristics are described. The most essential operation required at the receiver in a spread spect

  1. Lunar Module 5 mated with Spacecraft Lunar Module Adapter (SLA)

    Science.gov (United States)

    1969-01-01

    Interior view of the Kennedy Space Center's (KSC) Manned Spacecraft Operations Building showing Lunar Module 5 mated to its Spacecraft Lunar Module Adapter (SLA). LM-5 is scheduled to be flown on the Apollo 11 lunar landing mission.

  2. On Staggered Indecomposable Virasoro Modules

    CERN Document Server

    Kytölä, Kalle

    2009-01-01

    In this article, certain indecomposable Virasoro modules are studied. Specifically, the Virasoro mode L_0 is assumed to be non-diagonalisable, possessing Jordan blocks of rank two. Moreover, the module is further assumed to have a highest weight submodule, the "left module", and that the quotient by this submodule yields another highest weight module, the "right module". Such modules, which have been called staggered, have appeared repeatedly in the logarithmic conformal field theory literature, but their theory has not been explored in full generality. Here, such a theory is developed for the Virasoro algebra using rather elementary techniques. The focus centres on two different but related questions typically encountered in practical studies: How can one identify a given staggered module, and how can one demonstrate the existence of a proposed staggered module. The text is liberally peppered throughout with examples illustrating the general concepts. These have been carefully chosen for their physical relev...

  3. Prime Submodules and Flat Modules

    Institute of Scientific and Technical Information of China (English)

    A.AZIZI

    2007-01-01

    In this paper, some characterizations of prime submodules in fiat modules and, particularly,in free modules are given. Furthermore, the height of prime submodules and some saturated chain of prime submodules are also given.

  4. Generic ISIS Transport Module Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of the Generic ISIS Transport Module is to provide a means to bring living specimens to and from orbit. In addition to living specimens, the module can...

  5. Artinianness of local cohomology modules

    Science.gov (United States)

    Aghapournahr, Moharram; Melkersson, Leif

    2014-04-01

    Some uniform theorems on the artinianness of certain local cohomology modules are proven in a general situation. They generalize and imply previous results about the artinianness of some special local cohomology modules in the graded case.

  6. Modulational instability of nematic phase

    Indian Academy of Sciences (India)

    T Mithun; K Porsezian

    2014-02-01

    We numerically observe the effect of homogeneous magnetic field on the modulationally stable case of polar phase in = 2 spinor Bose–Einstein condensates (BECs). Also we investigate the modulational instability of uniaxial and biaxial (BN) states of polar phase. Our observations show that the magnetic field triggers the modulational instability and demonstrate that irrespective of the magnetic field effect the uniaxial and biaxial nematic phases show modulational instability.

  7. On closed weak supplemented modules

    Institute of Scientific and Technical Information of China (English)

    ZENG Qing-yi; SHI Mei-hua

    2006-01-01

    A module M is called closed weak supplemented if for any closed submodule N of M, there is a submodule K of M such that M=K+N and K(c)N<<M. Any direct summand of closed weak supplemented module is also closed weak supplemented.Any nonsingular image of closed weak supplemented module is closed weak supplemented. Nonsingular V-rings in which all nonsingular modules are closed weak supplemented are characterized in Section 4.

  8. Weighted network modules

    International Nuclear Information System (INIS)

    The inclusion of link weights into the analysis of network properties allows a deeper insight into the (often overlapping) modular structure of real-world webs. We introduce a clustering algorithm clique percolation method with weights (CPMw) for weighted networks based on the concept of percolating k-cliques with high enough intensity. The algorithm allows overlaps between the modules. First, we give detailed analytical and numerical results about the critical point of weighted k-clique percolation on (weighted) Erdos-Renyi graphs. Then, for a scientist collaboration web and a stock correlation graph we compute three-link weight correlations and with the CPMw the weighted modules. After reshuffling link weights in both networks and computing the same quantities for the randomized control graphs as well, we show that groups of three or more strong links prefer to cluster together in both original graphs

  9. Weighted network modules

    Science.gov (United States)

    Farkas, Illés; Ábel, Dániel; Palla, Gergely; Vicsek, Tamás

    2007-06-01

    The inclusion of link weights into the analysis of network properties allows a deeper insight into the (often overlapping) modular structure of real-world webs. We introduce a clustering algorithm clique percolation method with weights (CPMw) for weighted networks based on the concept of percolating k-cliques with high enough intensity. The algorithm allows overlaps between the modules. First, we give detailed analytical and numerical results about the critical point of weighted k-clique percolation on (weighted) Erdos Rényi graphs. Then, for a scientist collaboration web and a stock correlation graph we compute three-link weight correlations and with the CPMw the weighted modules. After reshuffling link weights in both networks and computing the same quantities for the randomized control graphs as well, we show that groups of three or more strong links prefer to cluster together in both original graphs.

  10. Lightweight Trauma Module - LTM

    Science.gov (United States)

    Hatfield, Thomas

    2008-01-01

    Current patient movement items (PMI) supporting the military's Critical Care Air Transport Team (CCATT) mission as well as the Crew Health Care System for space (CHeCS) have significant limitations: size, weight, battery duration, and dated clinical technology. The LTM is a small, 20 lb., system integrating diagnostic and therapeutic clinical capabilities along with onboard data management, communication services and automated care algorithms to meet new Aeromedical Evacuation requirements. The Lightweight Trauma Module is an Impact Instrumentation, Inc. project with strong Industry, DoD, NASA, and Academia partnerships aimed at developing the next generation of smart and rugged critical care tools for hazardous environments ranging from the battlefield to space exploration. The LTM is a combination ventilator/critical care monitor/therapeutic system with integrated automatic control systems. Additional capabilities are provided with small external modules.

  11. NEUROBIOLOGICAL MODULATORS OF ANXIETY

    Directory of Open Access Journals (Sweden)

    Mohale Deepak S.

    2012-01-01

    Full Text Available Anxiety can be a core symptom of various mental/ behavioral disorders such as major depressive disorders, obsessive-compulsive disorders, panic disorder, adaptive disorder, post-traumatic stress disorder, social withdrawal disorder, and various phobias. The neuroanatomic circuits that support fear and anxiety behavior are modulated by a variety of neurochemicals, these include the peptidergic neurotransmitters, Corticotrophin releasing factor (CRF, neuropeptide Y (NPY, and substance P, the monoaminergic transmitters, Norepinephrine (NE, serotonin (5-hydroxytryptamine or 5-HT, and dopamine (DA, and the amino acid transmitters, Gamma Aminobuteric Acid (GABA and glutamate and many more. These neurochemical systems subserve important adaptive functions in preparing the organism for responding to threat or stress, by increasing vigilance, modulating memory, mobilizing energy stores, and elevating cardiovascular function. Nevertheless, these biological responses to threat and stress can become maladaptive if they are chronically or inappropriately activated.

  12. Weighted network modules

    Energy Technology Data Exchange (ETDEWEB)

    Farkas, Illes [Department of Biological Physics, Eoetvoes University, Budapest, H-1117 (Hungary); Abel, Daniel [Department of Biological Physics, Eoetvoes University, Budapest, H-1117 (Hungary); Palla, Gergely [Department of Biological Physics, Eoetvoes University, Budapest, H-1117 (Hungary); Vicsek, Tamas [Department of Biological Physics, Eoetvoes University, Budapest, H-1117 (Hungary)

    2007-06-15

    The inclusion of link weights into the analysis of network properties allows a deeper insight into the (often overlapping) modular structure of real-world webs. We introduce a clustering algorithm clique percolation method with weights (CPMw) for weighted networks based on the concept of percolating k-cliques with high enough intensity. The algorithm allows overlaps between the modules. First, we give detailed analytical and numerical results about the critical point of weighted k-clique percolation on (weighted) Erdos-Renyi graphs. Then, for a scientist collaboration web and a stock correlation graph we compute three-link weight correlations and with the CPMw the weighted modules. After reshuffling link weights in both networks and computing the same quantities for the randomized control graphs as well, we show that groups of three or more strong links prefer to cluster together in both original graphs.

  13. FERMI multi-chip module

    CERN Multimedia

    This FERMI multi-chip module contains five million transistors. 25 000 of these modules will handle the flood of information through parts of the ATLAS and CMS detectors at the LHC. To select interesting events for recording, crucial decisions are taken before the data leaves the detector. FERMI modules are being developed at CERN in partnership with European industry.

  14. Thermal modulation for gas chromatography

    Science.gov (United States)

    Hasselbrink, Ernest F. (Inventor); Libardoni, Mark (Inventor); Stewart, Kristine (Inventor); Waite, J. Hunter (Inventor); Block, Bruce P. (Inventor); Sacks, Richard D. (Inventor)

    2007-01-01

    A thermal modulator device for gas chromatography and associated methods. The thermal modulator device includes a recirculating fluid cooling member, an electrically conductive capillary in direct thermal contact with the cooling member, and a power supply electrically coupled to the capillary and operable for controlled resistive heating of the capillary. The capillary can include more than one separate thermally modulated sections.

  15. Higher Level Orderings on Modules

    Institute of Scientific and Technical Information of China (English)

    Min WU; Guang Xing ZENG

    2005-01-01

    The aim of this paper is to investigate higher level orderings on modules over commutative rings. On the basis of the theory of higher level orderings on fields and commutative rings, some results involving existence of higher level orderings are generalized to the category of modules over commutative rings. Moreover, a strict intersection theorem for higher level orderings on modules is established.

  16. Physics. Module 1. Mechanics

    OpenAIRE

    Бовтрук, Алла Георгіївна; Мєняйлов, Сергій Миколайович; Максимов, Сергій Леонідович; Поліщук, Аркадій Петрович

    2009-01-01

    Ukraine’s joining Bologna process requires creating new books in physics (in English in particular). The book is developed for all forms of studying physics on the Credit-based Modular System basis in higher school. «Physics. Module 1. Mechanics» presents Newtonian mechanics and Special theory of relativity. It contains eight Study Units which include theoretical information, test questions, sample problems, laboratory works and individual home tasks. It is designed for students of engi...

  17. Chemical release module facility

    Science.gov (United States)

    Reasoner, D. L.

    1980-01-01

    The chemical release module provides the capability to conduct: (1) thermite based metal vapor releases; (2) pressurized gas releases; (3) dispersed liquid releases; (4) shaped charge releases from ejected submodules; and (5) diagnostic measurements with pi supplied instruments. It also provides a basic R-F and electrical system for: (1) receiving and executing commands; (2) telemetering housekeeping data; (3) tracking; (4) monitoring housekeeping and control units; and (5) ultrasafe disarming and control monitoring.

  18. Digital CAMAC modules

    International Nuclear Information System (INIS)

    Data sheets and block diagrams of new CAMAC modules are presented. These consist of a RS232C serial interface, a crate controller for the personnel computer IBM PC/AT, a 24-bit word to 16-bit word converter, a 4K of 16-bit words buffer memory, an input register for ECL logical level signals, a tester for the type A1 crate controllers and a multichannel analyzer tester. 15 refs.; 8 figs.; 1 tab

  19. Weighted network modules

    OpenAIRE

    Farkas, Illes J.; Abel, Daniel; Palla, Gergely; Vicsek, Tamas

    2007-01-01

    The inclusion of link weights into the analysis of network properties allows a deeper insight into the (often overlapping) modular structure of real-world webs. We introduce a clustering algorithm (CPMw, Clique Percolation Method with weights) for weighted networks based on the concept of percolating k-cliques with high enough intensity. The algorithm allows overlaps between the modules. First, we give detailed analytical and numerical results about the critical point of weighted k-clique per...

  20. Modulating aging and longevity

    DEFF Research Database (Denmark)

    Rattan, Suresh

    Provides information and an evaluation of a variety of approaches tried for modulating aging and longevity, including dietary supplementation with antioxidants, vitamins and hormones, genetic engineering, life-style alterations, and hormesis through mild stress. After decades of systematic...... mild stress. The goal of research on ageing is not to increase human longevity regardless of the consequences, but to increase active longevity free from disability and functional dependence...

  1. Adaptive modulations of martensites

    Czech Academy of Sciences Publication Activity Database

    Kaufmann, S.; Roßler, U.K.; Heczko, Oleg; Wuttig, M.; Buschbeck, J.; Schultz, L.; Fähler, S.

    2010-01-01

    Roč. 104, č. 14 (2010), 145702/1-145702/4. ISSN 0031-9007 Institutional research plan: CEZ:AV0Z10100520 Keywords : adaptive concept of modulated martensite * martensitic Ni-Mn-Ga films * austenite * 14M martensite Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 7.621, year: 2010 http://link.aps.org/doi/10.1103/PhysRevLett.104.145702

  2. COMBINING MODULES FOR MOVEMENT

    OpenAIRE

    Bizzi, E; Cheung, V.C.K.; d’Avella, A.; Saltiel, P.; Tresch, M.

    2007-01-01

    We review experiments supporting the hypothesis that the vertebrate motor system produces movements by combining a small number of units of motor output. Using a variety of approaches such as microstimulation of the spinal cord, NMDA iontophoresis, and an examination of natural behaviors in intact and deafferented animals we have provided evidence for a modular organization of the spinal cord. A module is a functional unit in the spinal cord that generates a specific motor output by imposing ...

  3. Modulated reheating by curvaton

    CERN Document Server

    Choi, Ki-Young

    2012-01-01

    There might be a light scalar field during inflation which is not responsible for the accelerating inflationary expansion. Then, its quantum fluctuation is stretched during inflation. This scalar field could be a curvaton, if it decays at a late time. In addition, if the inflaton decay rate depends on the light scalar field expectation value by interactions between them, density perturbations could be generated by the quantum fluctuation of the light field when the inflaton decays. This is modulated reheating mechanism. We study curvature perturbation in models where a light scalar field does not only play a role of curvaton but also induce modulated reheating at the inflaton decay. We calculate the non-linearity parameters as well as the scalar spectral index and the tensor-to-scalar ratio. We find that there is a parameter region where non-linearity parameters are also significantly enhanced by the cancellation between the modulated effect and the curvaton contribution. For the simple quadratic potential mo...

  4. Solar Module Fabrication

    Directory of Open Access Journals (Sweden)

    A. El Amrani

    2007-04-01

    Full Text Available One of the most important steps in the photovoltaic industry is the encapsulation of the solar cells. It consists to connect the cells in order to provide useful power for any application and also protect them from environmental damages which cause corrosion, and mechanical shocks. In this paper, we present the encapsulation process we have developed at Silicon Technology Unit (UDTS for monocrystalline silicon solar cells. We will focus particularly on the thermal treatment, the most critical step in the process, which decides on the quality and the reliability of the module. This thermal treatment is conducted in two steps: the lamination and the polymerization. Several tests of EVA reticulation have been necessary for setting technological parameters such as the level of vacuum, the pressure, the temperature, and the time. The quality of our process has been confirmed by the tests conducted on our modules at the European Laboratory of Joint Research Centre (JRC of ISPRA (Italy. The electrical characterization of the modules has showed that after the encapsulation the current has been improved by a factor of 4% to 6% and the power gain by a factor of 4% to 7%. This is mainly due to the fact of using a treated glass, which reduces the reflection of the light at a level as low as 8%.

  5. Allosteric modulation of caspases.

    Science.gov (United States)

    Häcker, Hans-Georg; Sisay, Mihiret Tekeste; Gütschow, Michael

    2011-11-01

    Caspases are proteolytic enzymes mainly involved in the induction and execution phases of apoptosis. This type of programmed cell death is an essential regulatory process required to maintain the integrity and homeostasis of multicellular organisms. Inappropriate apoptosis is attributed a key role in many human diseases, including neurodegenerative disorders, ischemic damage, autoimmune diseases and cancer. Allosteric modulation of the function of a protein occurs when the regulatory trigger, such as the binding of a small effector or inhibitor molecule, takes place some distance from the protein's active site. In recent years, several caspases have been identified that possess allosteric sites and binding of small molecule to these sites resulted in the modulation of enzyme activities. Regulation of caspase activity by small molecule allosteric modulators is believed to be of great therapeutic importance. In this review we give brief highlights on recent developments in identifying and characterizing natural and synthetic allosteric inhibitors as well as activators of caspases and discuss their potential in drug discovery and protein engineering. PMID:21807025

  6. Receiver Gain Modulation Circuit

    Science.gov (United States)

    Jones, Hollis; Racette, Paul; Walker, David; Gu, Dazhen

    2011-01-01

    A receiver gain modulation circuit (RGMC) was developed that modulates the power gain of the output of a radiometer receiver with a test signal. As the radiometer receiver switches between calibration noise references, the test signal is mixed with the calibrated noise and thus produces an ensemble set of measurements from which ensemble statistical analysis can be used to extract statistical information about the test signal. The RGMC is an enabling technology of the ensemble detector. As a key component for achieving ensemble detection and analysis, the RGMC has broad aeronautical and space applications. The RGMC can be used to test and develop new calibration algorithms, for example, to detect gain anomalies, and/or correct for slow drifts that affect climate-quality measurements over an accelerated time scale. A generalized approach to analyzing radiometer system designs yields a mathematical treatment of noise reference measurements in calibration algorithms. By treating the measurements from the different noise references as ensemble samples of the receiver state, i.e. receiver gain, a quantitative description of the non-stationary properties of the underlying receiver fluctuations can be derived. Excellent agreement has been obtained between model calculations and radiometric measurements. The mathematical formulation is equivalent to modulating the gain of a stable receiver with an externally generated signal and is the basis for ensemble detection and analysis (EDA). The concept of generating ensemble data sets using an ensemble detector is similar to the ensemble data sets generated as part of ensemble empirical mode decomposition (EEMD) with exception of a key distinguishing factor. EEMD adds noise to the signal under study whereas EDA mixes the signal with calibrated noise. It is mixing with calibrated noise that permits the measurement of temporal-functional variability of uncertainty in the underlying process. The RGMC permits the evaluation of EDA by

  7. Bent Electro-Absorption Modulator

    DEFF Research Database (Denmark)

    2002-01-01

    The present invention relates to a method and a device for modulating optical signals based on modulating bending losses in bend, quantum well semiconductor waveguide sections. The complex refractive index of the optical active semiconducting components of the waveguide section is modulated by...... applying a variable electric or electronmagnetic field. The modulation of the complex refractive index results in a modulation of the refractive index contrast and the absorption coefficient for the waveguide at the frequency of the light. By carefully adjusting the composition of the semiconducting...... components and the applied electric field in relation to the frequency of the modulated radiation, the bending losses (and possibly coupling losses) will provide extinction of light guided by the bent waveguide section. The refractive index contract may be modulated while keeping the absorption coefficient...

  8. Extension closure of relative syzygy modules

    Institute of Scientific and Technical Information of China (English)

    黄兆泳

    2003-01-01

    In this paper we introduce the notion of relative syzygy modules. We then study the extensionclosure of the category of modules consisting of relative syzygy modules (resp. relative k-torsionfree modules).

  9. On staggered indecomposable Virasoro modules

    International Nuclear Information System (INIS)

    In this article, certain indecomposable Virasoro modules are studied. Specifically, the Virasoro mode L0 is assumed to be non-diagonalisable, possessing Jordan blocks of rank two. Moreover, the module is further assumed to have a highest weight submodule, the ''left module'', and that the quotient by this submodule yields another highest weight module, the ''right module''. Such modules, which have been called staggered, have appeared repeatedly in the logarithmic conformal field theory literature, but their theory has not been explored in full generality. Here, such a theory is developed for the Virasoro algebra using rather elementary techniques. The focus centres on two different but related questions typically encountered in practical studies: How can one identify a given staggered module, and how can one demonstrate the existence of a proposed staggered module. Given just the values of the highest weights of the left and right modules, themselves subject to simple necessary conditions, invariants are defined which together with the knowledge of the left and right modules uniquely identify a staggered module. The possible values of these invariants form a vector space of dimension zero, one or two, and the structures of the left and right modules limit the isomorphism classes of the corresponding staggered modules to an affine subspace (possibly empty). The number of invariants and affine restrictions is purely determined by the structures of the left and right modules. Moreover, in order to facilitate applications, the expressions for the invariants and restrictions are given by formulae as explicit as possible (they generally rely on expressions for Virasoro singular vectors). Finally, the text is liberally peppered throughout with examples illustrating the general concepts. These have been carefully chosen for their physical relevance or for the novel features they exhibit. (orig.)

  10. On staggered indecomposable Virasoro modules

    Energy Technology Data Exchange (ETDEWEB)

    Kytoelae, Kalle [Geneve Univ. (Switzerland); Ridout, David [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2009-06-15

    In this article, certain indecomposable Virasoro modules are studied. Specifically, the Virasoro mode L0 is assumed to be non-diagonalisable, possessing Jordan blocks of rank two. Moreover, the module is further assumed to have a highest weight submodule, the ''left module'', and that the quotient by this submodule yields another highest weight module, the ''right module''. Such modules, which have been called staggered, have appeared repeatedly in the logarithmic conformal field theory literature, but their theory has not been explored in full generality. Here, such a theory is developed for the Virasoro algebra using rather elementary techniques. The focus centres on two different but related questions typically encountered in practical studies: How can one identify a given staggered module, and how can one demonstrate the existence of a proposed staggered module. Given just the values of the highest weights of the left and right modules, themselves subject to simple necessary conditions, invariants are defined which together with the knowledge of the left and right modules uniquely identify a staggered module. The possible values of these invariants form a vector space of dimension zero, one or two, and the structures of the left and right modules limit the isomorphism classes of the corresponding staggered modules to an affine subspace (possibly empty). The number of invariants and affine restrictions is purely determined by the structures of the left and right modules. Moreover, in order to facilitate applications, the expressions for the invariants and restrictions are given by formulae as explicit as possible (they generally rely on expressions for Virasoro singular vectors). Finally, the text is liberally peppered throughout with examples illustrating the general concepts. These have been carefully chosen for their physical relevance or for the novel features they exhibit. (orig.)

  11. Modulation of whistlers

    Science.gov (United States)

    Sivokon', V. P.; Bogdanov, V. V.; Druzhin, G. I.; Cherneva, N. V.; Kubyshkin, A. V.; Sannikov, D. V.; Agranat, I. V.

    2014-11-01

    Analysis of the experimental data obtained at Paratunka observatory (53.02° N, 158.65° E; L = 2.3) has revealed a nonstandard form of whistlers involving spectral lines that are symmetric with respect to the whistler. We have shown that this form is most likely due to the amplitude modulation of whistlers by electromagnetic pulses with a length of around 1 s and carrier frequency of around 1.1 kHz. We have suggested that these pulses could be emitted by the auroral electrojet modified by heating radiation from the HAARP facility (62.30° N, 145.30° W; L > 4.2).

  12. A photoelectrical module

    Energy Technology Data Exchange (ETDEWEB)

    Zhukov, K.V.; Nevezhin, O.A.; Rosstokinskiy, V.V.; Ryabikov, S.V.; Strebkov, D.S.; Tveryanovich, E.V.

    1983-01-01

    The photoelectric module, which contains an optical element with trapezoidal transverse cross section, whose lateral facets reflect radiation and different sized bases serve as the facets for input and output of radiation, and photoconverters installed in contact with the output facet, is distinguished by the fact that in order to increase the specific power, the optical element is made of a material transparent to solar radiation in the form of a prism of full internal reflection, where the lesser base of the optical element serves as the output facet for the radiation.

  13. CCDTL conditioning report: Module 2 and Module 3

    CERN Document Server

    Muranaka, T; Giguet, J M; Marques Balula, J; Delrieux, M

    2014-01-01

    Two CCDTL modules for Linac4 have been conditioned at SM18. The modules were tuned for resonance at 352.2 MHz, and stable operation has been achieved with 800 μs RF pulses with a repetition rate of 2 Hz. Maximum power of 700 kW loaded in cells has been achieved with a nominal Linac4 klystron and modulator setup. Since those were the first CCDTL modules to be conditioned, both hardware and software have been developed along with the conditionings.

  14. Influence of module requirements on flat plate module design evolution

    Science.gov (United States)

    Arnett, J. C.; Ross, R. G., Jr.

    1980-01-01

    Photovoltaic module design features and performance characteristics have undergone significant evolutionary changes between pre-1975 First Generation configurations and current Third Generation design technology. A major contributor to this evolution was an iterative process of continuing design guideline and specification development for major module procurements. Module manufacturers have actively responded to these evolving requirements through progressively improving designs. This iterative/feedback process is described. Interim design guidelines and preliminary design options reflecting the LSA 1982 Module Technical Readiness Specification (November 1979) are described with respect to previous design and performance requirements.

  15. Steam generator module

    International Nuclear Information System (INIS)

    The module of the steam generator is arranged such that the first working medium flows through the tubes of the heat exchange bundle and the second working medium flows through the intertube space. At least one side of the module is provided with a lid which is provided with a system of through-flow apertures. The apertures are expanded and provided with a thread in the direction of the outer side of the lid. They are coaxial with the tubes of the heat exchange bundle at the point of their anchorage in the tube plate. The apertures are closed with plugs with a male thread and the sealing surfaces are formed between the thread joint and the space of the first working medium. The plugs extend into the space of the heat exchange bundle and form a throttle which replaces the classical stop and allow for dismantling. This arrangement of the modular steam generator allows the control of the inner surfaces of heat exchange pipes and also the cleaning of these inner surfaces. (E.S.)

  16. Semiconductor-laser modulation techniques

    International Nuclear Information System (INIS)

    Three simple modulation techniques for semiconductor lasers have been described. The first technique employs a single constant current source and is suitable for low frequency modulation up to 500 Khz. The second and third techniques employ two constant current sources each with current summing of subtraction and are suitable for higher frequency modulation up to several MHz. Schematic diagrams of designed, developed and tested circuits, implementing each of the above mentioned schemes, have also been presented. (author)

  17. Lehmer problem and Drinfeld modules

    OpenAIRE

    Demangos, Luca

    2013-01-01

    We propose a lower bound estimate in Dobrowolski's style of the canonical height on a certain family of Drinfeld modules of characteristic 0, including under some hypothesis on their degree and their base field, the complex multiplication case, extending so a previous result of L. Denis on Carlitz modules. Our study is focused on the highest possible level of precision on the parameters involved with rapport to the main values which characterize the Drinfeld module (height, base field degree ...

  18. Developments in Directional Modulation Technology

    OpenAIRE

    Ding, Yuan; Fusco, Vincent F.

    2016-01-01

    Directional modulation (DM), as a promising physical-layer security technique, is able to secure wireless communications by virtue of the property of its direction-dependent signal modulation format transmission. Here modulated signal waveform signatures can only be detected by legitimate receiver(s) positioned along a-prior assigned directions. This paper reviews the development in DM technology over recent years, and provides some recommendations for future studies.

  19. Photovoltaic concentrator module improvements study

    Energy Technology Data Exchange (ETDEWEB)

    Levy, S.L.; Kerschen, K.A. (Black and Veatch, Kansas City, MO (United States)); Hutchison, G. (Solar Kinetics, Inc., Dallas, TX (United States)); Nowlan, M.J. (Spire Corp., Bedford, MA (United States))

    1991-08-01

    This report presents results of a project to design and fabricate an improved photovoltaic concentrator module. Using previous work as a baseline, this study conducted analyses and testing to select major module components and design features. The lens parquet and concentrator solar cell were selected from the highest performing, available components. A single 185X point-focus module was fabricated by the project team and tested at Sandia. Major module characteristics include a 6 by 4 compression-molded acrylic lens parquet (0.737 m{sup 2} area), twenty-four 0.2 ohms-cm, FZ, p-Si solar cells (1.56 cm{sup 2} area) soldered to ceramic substrates and copper heat spreaders, and an aluminized steel housing with corrugated bottom. This project marked the first attempt to use prismatic covers on solar cells in a high-concentration, point-focus application. Cells with 15 percent metallization were obtained, but problems with the fabrication and placement of prismatic covers on these cells lead to the decision not to use covers in the prototype module. Cell assembly fabrication, module fabrication, and module optical design activities are presented here. Test results are also presented for bare cells, cell assemblies, and module. At operating conditions of 981 watts/m{sup 2} DNI and an estimated cell temperature of 65{degrees}C, the module demonstrated an efficiency of 13.9 percent prior to stressed environmental exposure. 12 refs., 56 figs., 7 tabs.

  20. Adjustable extender for instrument module

    International Nuclear Information System (INIS)

    A blank extender module used to mount an instrument module in front of its console for repair or test purposes has been equipped with a rotatable mount and means for locking the mount at various angles of rotation for easy accessibility. The rotatable mount includes a horizontal conduit supported by bearings within the blank module. The conduit is spring-biased in a retracted position within the blank module and in this position a small gear mounted on the conduit periphery is locked by a fixed pawl. The conduit and instrument mount can be pulled into an extended position with the gear clearing the pawl to permit rotation and adjustment of the instrument

  1. Hybrid grapheme plasmonic waveguide modulators

    Science.gov (United States)

    Ansell, D.; Thackray, B. D.; Aznakayeva, D. E.; Thomas, P.; Auton, G. H.; Marshall, O. P.; Rodriguez, F. J.; Radko, I. P.; Han, Z.; Bozhevolnyi, S. I.; Grigorenko, A. N.

    2016-03-01

    The unique optical and electronic properties of graphene allow one to realize active optical devices. While several types of graphene-based photonic modulators have already been demonstrated, the potential of combining the versatility of graphene with sub-wavelength field confinement of plasmonic/metallic structures is not fully realized. Here we report fabrication and study of hybrid graphene-plasmonic modulators. We consider several types of modulators and identify the most promising one for light modulation at telecom and near-infrared. Our proof-of-concept results pave the way towards on-chip realization of efficient graphene-based active plasmonic waveguide devices for optical communications.

  2. Water-module interaction studies

    Science.gov (United States)

    Mon, G.; Wen, L.; Ross, R., Jr.

    Mechanisms by which moisture enters photovoltaic modules and techniques for reducing such interactions are reported. Results from a study of the effectiveness of various module sealants are given. Techniques for measuring the rate and quantity of moisture ingress are discussed. It is shown that scribe lines and porous frit bridging conductors provide preferential paths for moisture ingress and that moisture diffusion by surface/interfacial paths is considerably more rapid than diffusion by bulk paths, which implies that thin-film substrate and supersubstrate modules are much more vulnerable to moist environments than are bulk-encapsulated crystalline-silicon modules. Design approaches that reduce moisture entry are discussed.

  3. Modulated differential scanning calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Sauerbrunn, S.R.; Crowe, B.S.; Reading, M. [TA Instruments Inc., New Castle, DE (United States)

    1993-12-31

    Modulated DSC (MDSC){sup tm} is a new patent-pending extension to conventional DSC which provides information about the reversing and nonreversing characteristics of thermal events. This additional information aids interpretation and allows unique insights into the structure and behavior of materials. Data presented will demonstrate three uses of MDSC. First, the overlapping crystallization peak and glass transition in a bilayer film of polycarbonate and PET are separated by MDSC. Second, the glass transition and endothermic relaxation of epoxy are separated. Third, MDSC gives a direct measurement of the sample heat capacity. The ability to separate reversing and nonreversing transitions, as well as the ability to directly measure heat capacity, offers thermal analysis another tool for solving tough materials characterization problems.

  4. Modulated structure of nepheline

    OpenAIRE

    Friese, K.; Grzechnik, A.; Petricek, V.; Schönleber, A.; Smaalen, S. van; Morgenroth, W.

    2011-01-01

    The incommensurately modulated structure of a natural nepheline of composition K(0.54)Na(3.24)Ca(0.03)Al(3.84)Si(4.16)O(16) has been determined in superspace. The compound crystallizes in the trigonal centered superspace group X3(00γ)0 with γ = 0.2048 (10), X = (0, 0, 0, 0), (1/3, 2/3, 0, 2/3), (2/3, 1/3, 0, 1/3), a = 17.2889 (8) and c = 8.3622 (10) Å. The structure is characterized by a framework of corner-connected (Al,Si)O(4) tetrahedra. The additional cations are incorporated in two diffe...

  5. Digital Communication and Modulation

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    2011-01-01

    communication system.   Sessions in class with active participation by the students. The time will be divided between lectures and the students solving problems, including simulating digital communication building blocks in Matlab. Combines lectures and hands-on work. Semester: E2011 Extent: 7.5 ects......, the fundamental principles for modulation and detection in Gaussian noise is treated. This includes the principles for the determination of the bit-error rate for a digital communication system. During the course, a selection of small Matlab exercises are prepared, for simulation of parts of a....... Performance of a Digital Comunication System. Prepare and explain a model for bit-error probability versus the energy used per bit and channel noise, corresponding to the specific course contents. System Simulation. Prepare and explain a simulation program in Matlab for simulating a minor part of a digital...

  6. Digital Communication and Modulation

    DEFF Research Database (Denmark)

    Sørensen, John Aasted

    2011-01-01

    communication system. Sessions in class with active participation by the students. The time will be divided between lectures and the students solving problems, including simulating digital communication building blocks in Matlab. Combines lectures and hands-on work. Semester: F2011 Extent: 7.5 ects......, the fundamental principles for modulation and detection in Gaussian noise is treated. This includes the principles for the determination of the bit-error rate for a digital communication system. During the course, a selection of small Matlab exercises are prepared, for simulation of parts of a....... Performance of a Digital Comunication System. Prepare and explain a model for bit-error probability versus the energy used per bit and channel noise, corresponding to the specific course contents. System Simulation. Prepare and explain a simulation program in Matlab for simulating a minor part of a digital...

  7. Whistler modulational instability.

    Science.gov (United States)

    Brinca, A. L.

    1973-01-01

    Derivation of the modulational instability characteristics of whistlers in cold and hot plasmas. The cold-plasma analysis considers both ion motion and relativistic effects; the unstable band, with a growth rate proportional to (B/B sub zero)squared, is contiguous to Omega sub e/4 and, depending on the plasma density, lies above or below that frequency (Omega sub e is the electron cyclotron frequency of the static magnetic field; B and B sub zero are the whistler and static magnetic fields). In hot plasmas, stability occurs between Omega sub e/4 and Omega prime (less than Omega sub e), with Omega prime depending mainly on the mean energy and anisotropy of the energetic electron population; the complementary unstable band has a growth rate proportional to (B/B sub zero) to the 1/2 power. The relevance of the instability to whistlers in the magnetosphere is discussed.

  8. Transient heliosheath modulation

    Science.gov (United States)

    Quenby, J. J.; Webber, W. R.

    2015-10-01

    Voyager 1 has explored the solar wind-interstellar medium interaction region between the terminal shock and heliopause, following the intensity distribution of Galactic cosmic ray protons above 200 MeV energy. Before this component reached the expected galactic flux level at 121.7 au from the Sun, four episodes of rapid intensity change occurred with a behaviour similar to that found in Forbush Decreases in the inner Solar system, rather than that expected from a mechanism related to models for the long-term modulation found closer to the Sun. Because the mean solar wind flow is both expected and observed to be perpendicular to the radial direction close to the heliopause, an explanation is suggested in terms of transient radial flows related to possible heliopause boundary flapping. It is necessary that the radial flows are of the order either of the sound speed found for conditions downstream of the terminal shock or of the fluctuations found near the boundary by the Voyager 1 Low Energy Charged Particle detector and that the relevant cosmic ray diffusion perpendicular to the mean field is controlled by `slab' fluctuations accounting for about 20 per cent of the total power in the field variance. However, additional radial drift motion related to possible north to south gradients in the magnetic field may allow the inclusion of some diffusion according to the predictions of a theory based upon the presence of 2D turbulence. The required field gradients may arise due to field variation in the field carried by solar plasma flow deflected away from the solar equatorial plane. Modulation amounting to a total 30 per cent drop in galactic intensity requires explanation by a combination of transient effects.

  9. New pulse modulator with low switching frequency

    OpenAIRE

    Golub V. S.

    2014-01-01

    The author presents an integrating pulse modulator (analog signal converter) with the pulse frequency and duration modulation similar to sigma-delta modulation (with low switching frequency), without quantization. The modulator is characterized by the absence of the quantization noise inherent in sigma-delta modulator, and a low switching frequency, unlike the pulse-frequency modulator. The modulator is recommended, in particular, to convert signals at the input of the class D power amplifier.

  10. Aligned natural inflation with modulations

    Science.gov (United States)

    Choi, Kiwoon; Kim, Hyungjin

    2016-08-01

    The weak gravity conjecture applied for the aligned natural inflation indicates that generically there can be a modulation of the inflaton potential, with a period determined by sub-Planckian axion scale. We study the oscillations in the primordial power spectrum induced by such modulation, and discuss the resulting observational constraints on the model.

  11. Aligned natural inflation with modulations

    CERN Document Server

    Choi, Kiwoon

    2015-01-01

    The weak gravity conjecture applied for the aligned natural inflation indicates that generically there can be a modulation of the inflaton potential, with a period determined by sub-Planckian axion scale. We study the oscillations in the primordial power spectrum induced by such modulation, and discuss the resulting observational constraints on the model.

  12. Aligned natural inflation with modulations

    Directory of Open Access Journals (Sweden)

    Kiwoon Choi

    2016-08-01

    Full Text Available The weak gravity conjecture applied for the aligned natural inflation indicates that generically there can be a modulation of the inflaton potential, with a period determined by sub-Planckian axion scale. We study the oscillations in the primordial power spectrum induced by such modulation, and discuss the resulting observational constraints on the model.

  13. Aligned natural inflation with modulations

    OpenAIRE

    Kiwoon Choi; Hyungjin Kim

    2016-01-01

    The weak gravity conjecture applied for the aligned natural inflation indicates that generically there can be a modulation of the inflaton potential, with a period determined by sub-Planckian axion scale. We study the oscillations in the primordial power spectrum induced by such modulation, and discuss the resulting observational constraints on the model.

  14. Modular crystals as modulated structures

    DEFF Research Database (Denmark)

    Elcoro, L.; Perez-Mato, J.M.; Friese, K.; Petricek, V.; Balic Zunic, Tonci; Olsen, L.A.

    2008-01-01

    The use of the superspace formalism is extended to the description and refinement of the homologous series of modular structures with two symmetry-related modules with different orientations. The lillianite homologous series has been taken as a study case. Starting from a commensurate modulated...

  15. Input/output interface module

    Science.gov (United States)

    Ozyazici, E. M.

    1980-01-01

    Module detects level changes in any of its 16 inputs, transfers changes to its outputs, and generates interrupts when changes are detected. Up to four changes-in-state per line are stored for later retrieval by controlling computer. Using standard TTL logic, module fits 19-inch rack-mounted console.

  16. Voice recording module in PACS

    International Nuclear Information System (INIS)

    This paper discusses the development and implementation of picture archiving and communications system (PACS) modules and their value in reducing the burden of storage, transmission, and access to patient image files. The authors describe the integration of a voice-recording module in the existing PACS system. The implementation procedure is presented and the benefits are given

  17. Modulational instability of two waves

    International Nuclear Information System (INIS)

    The stability of a plasma in the presence of two propagating waves (modulation interaction) is considered. It is shown under what circumstances it is necessary to use open-quotes renormalizedclose quotes expressions for both the linear dielectric function and the effective third-order response. The typical behavior of both kinds of interaction are found for the specific case of Langmuir waves in a uniform and isotropic collisionless plasma. Criteria are established under which it is possible to disregard the effect of the interference terms in both the zeroth approximation and in the equations for the modulational perturbations when studying the modulational interaction of two pump waves. The calculated modulational instability growth rates are compared with the growth rates of the modulational instability for a single monochromatic mode. 13 refs

  18. Force Modulator System

    Energy Technology Data Exchange (ETDEWEB)

    Redmond Clark

    2009-04-30

    Many metal parts manufacturers use large metal presses to shape sheet metal into finished products like car body parts, jet wing and fuselage surfaces, etc. These metal presses take sheet metal and - with enormous force - reshape the metal into a fully formed part in a manner of seconds. Although highly efficient, the forces involved in forming metal parts also damage the press itself, limit the metals used in part production, slow press operations and, when not properly controlled, cause the manufacture of large volumes of defective metal parts. To date, the metal-forming industry has not been able to develop a metal-holding technology that allows full control of press forces during the part forming process. This is of particular importance in the automotive lightweighting efforts under way in the US automotive manufacturing marketplace. Metalforming Controls Technology Inc. (MC2) has developed a patented press control system called the Force Modulator that has the ability to control these press forces, allowing a breakthrough in stamping process control. The technology includes a series of hydraulic cylinders that provide controlled tonnage at all points in the forming process. At the same time, the unique cylinder design allows for the generation of very high levels of clamping forces (very high tonnages) in very small spaces; a requirement for forming medium and large panels out of HSS and AHSS. Successful production application of these systems testing at multiple stamping operations - including Ford and Chrysler - has validated the capabilities and economic benefits of the system. Although this technology has been adopted in a number of stamping operations, one of the primary barriers to faster adoption and application of this technology in HSS projects is system cost. The cost issue has surfaced because the systems currently in use are built for each individual die as a custom application, thus driving higher tooling costs. This project proposed to better

  19. ABSOLUTELY E-PURE MODULES AND E-PURE SPLIT MODULES

    Institute of Scientific and Technical Information of China (English)

    Yan Hangyu

    2011-01-01

    We first introduce the concepts of absolutely E-pure modules and Epure split modules. Then, we characterize the IF rings in terms of absolutely E-pure modules. The E-pure split modules are also characterized.

  20. Programmable Thermostat Module Upgrade for the Multipurpose Logistics Module

    Science.gov (United States)

    Clark, D. W.; Glasgow, S. d.; Reagan, S. E.; Presson, K. H.; Howard, D. E.; Smith, D. A.

    2007-01-01

    The STS-121/ULF 1.1 mission was the maiden flight of the programmable thermostat module (PTM) system used to control the 28 V shell heaters on the multi-purpose logistics module (MPLM). These PTMs, in conjunction with a data recorder module (DRM), provide continuous closed loop temperature control and data recording of MPLM on-orbit heater operations. This Technical Memorandum discusses the hardware design, development, test, and verification (DDT&V) activities performed at the Marshall Space Flight Center as well as the operational implementation and mission performance.

  1. OCGen Module Mooring Project

    Energy Technology Data Exchange (ETDEWEB)

    McEntee, Jarlath [Ocean Renewable Power Company, LLC, Portland, ME (United States)

    2015-02-06

    Ocean Renewable Power Company's OCGen Module Mooring Project provided an extensive research, design, development, testing and data collection effort and analysis conducted with respect to a positively buoyant, submerged MHK device secured to the seabed using a tensioned mooring system. Different analytic tools were evaluated for their utility in the design of submerged systems and their moorings. Deployment and testing of a prototype OCGen® system provided significant data related to mooring line loads and system attitude and station keeping. Mooring line loads were measured in situ and reported against flow speeds. The Project made a significant step in the development of designs, methodologies and practices related to floating and mooring of marine hydrokinetic (MHK) devices. Importantly for Ocean Renewable Power Company, the Project provided a sound basis for advancing a technically and commercially viable OCGen® Power System. The OCGen® Power System is unique in the MHK industry and, in itself, offers distinct advantages of MHK devices that are secured to the seabed using fixed structural frames. Foremost among these advantages are capital and operating cost reductions and increased power extraction by allowing the device to be placed at the most energetic level of the water column.

  2. Living Systems Energy Module

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-26

    The Living Systems Energy Module, renamed Voyage from the Sun, is a twenty-lesson curriculum designed to introduce students to the major ways in which energy is important in living systems. Voyage from the Sun tells the story of energy, describing its solar origins, how it is incorporated into living terrestrial systems through photosynthesis, how it flows from plants to herbivorous animals, and from herbivores to carnivores. A significant part of the unit is devoted to examining how humans use energy, and how human impact on natural habitats affects ecosystems. As students proceed through the unit, they read chapters of Voyage from the Sun, a comic book that describes the flow of energy in story form (Appendix A). During the course of the unit, an ``Energy Pyramid`` is erected in the classroom. This three-dimensional structure serves as a classroom exhibit, reminding students daily of the importance of energy and of the fragile nature of our living planet. Interactive activities teach students about adaptations that allow plants and animals to acquire, to use and to conserve energy. A complete list of curricular materials and copies of all activity sheets appear in Appendix B.

  3. Fiber Attachment Module Experiment

    Science.gov (United States)

    Agostini, Reinaldo J.

    2014-01-01

    Hollow Fiber Membrane Bioreactors (HFMB) are ideal systems for biological pretreatment of wastewater, however, optimization is still underway. The Fiber Attachment Module Experiment (FAME) allows the simultaneous testing of potential materials, treatments on these and varying inoculums. Polydimethylsiloxane (PDMS), the material chosen for its ideal oxygen permeation properties, was treated with 1 sodium hydroxide 0.1 M ether for 18 seconds and ultraviolet (UV) irradiation oxygen plasma (OP) exposure for 1 hour. Preliminary chemistry and visual data indicate promising treatments when using OP and sodium hydroxide as treatments for PDMS fibers; however, due to the biological nature of the experiment, time is a constraint. Sodium hydroxide treatment chemistry data shows nitrification is occurring as urea and ammonia are decreasing and nitrite is increasing. A higher amount of biofilm can also be observed for this particular case. During the final two weeks of the internship x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and acridine orange (AO) cell counts will be employed for treatment effectiveness on the first batch of treatments (ether and sodium hydroxide). These same strategies will be used for the second batch of experiments due in four weeks (2nd week of August).

  4. Transient Heliosheath Modulation

    CERN Document Server

    Quenby, J J

    2014-01-01

    Voyager 1 has explored the solar wind-interstellar medium interaction region between the terminal shock and heliopause following the intensity distribution of galactic cosmic ray protons above 200 MeV energy. Before this component reached the galactic level at 121.7 AU, 4 episodes of rapid intensity change occured similar to the Forbush Decreases found near the sun, rather than the expected result of models related to those describing Long Term Modulation in the inner solar system. Because the mean solar wind flow is both expected and observed to be perpendicular to the radial direction close to the heliopause, explanation is given in terms of transient radial flows related to possible heliopause boundary flapping. It is necessary that radial flows are at the sound speed found for conditions downstream of the teminal shock and that the relevant perpendicular cosmic ray diffusion is controlled by 'slab' field fluctuations accounting for 20 percent or less of the total power in field variance. However, addition...

  5. Quadratic and 2-Crossed Modules of Algebras

    Institute of Scientific and Technical Information of China (English)

    Z. Arvasi; E. Ulualan

    2007-01-01

    In this work, we define the quadratic modules for commutative algebras and give relations among 2-crossed modules, crossed squares, quadratic modules and simplicial commutative algebras with Moore complex of length 2.

  6. High-Efficiency Power Module

    Science.gov (United States)

    Simons, Rainee N. (Inventor); Wintucky, Edwin G. (Inventor)

    2015-01-01

    One or more embodiments of the present invention pertain to an all solid-state microwave power module. The module includes a plurality of solid-state amplifiers configured to amplify a signal using a low power stage, a medium power stage, and a high power stage. The module also includes a power conditioner configured to activate a voltage sequencer (e.g., bias controller) when power is received from a power source. The voltage sequencer is configured to sequentially apply voltage to a gate of each amplifier and sequentially apply voltage to a drain of each amplifier.

  7. Photovoltaic module with adhesion promoter

    Science.gov (United States)

    Xavier, Grace

    2013-10-08

    Photovoltaic modules with adhesion promoters and methods for fabricating photovoltaic modules with adhesion promoters are described. A photovoltaic module includes a solar cell including a first surface and a second surface, the second surface including a plurality of interspaced back-side contacts. A first glass layer is coupled to the first surface by a first encapsulating layer. A second glass layer is coupled to the second surface by a second encapsulating layer. At least a portion of the second encapsulating layer is bonded directly to the plurality of interspaced back-side contacts by an adhesion promoter.

  8. Matching polytopes and Specht modules

    CERN Document Server

    Liu, Ricky Ini

    2009-01-01

    We prove that the dimension of the Specht module of a forest $G$ is the same as the normalized volume of the matching polytope of $G$. We also associate to $G$ a symmetric function $s_G$ (analogous to the Schur symmetric function $s_\\lambda$ for a partition $\\lambda$) and investigate its combinatorial and representation-theoretic properties in relation to the Specht module and Schur module of $G$. We then use this to define notions of standard and semistandard tableaux for forests.

  9. Induced modules over group algebras

    CERN Document Server

    Karpilovsky, Gregory

    1990-01-01

    In 1898 Frobenius discovered a construction which, in present terminology, associates with every module of a subgroup the induced module of a group. This construction proved to be of fundamental importance and is one of the basic tools in the entire theory of group representations.This monograph is designed for research mathematicians and advanced graduate students and gives a picture of the general theory of induced modules as it exists at present. Much of the material has until now been available only in research articles. The approach is not intended to be encyclopedic, rather each topic is

  10. Modulational instabilities in discrete lattices

    International Nuclear Information System (INIS)

    We study analytically and numerically modulational instabilities in discrete nonlinear chains, taking the discrete Klein-Gordon model as an example. We show that discreteness can drastically change the conditions for modulational instability; e.g., at small wave numbers a nonlinear carrier wave is unstable to all possible modulations of its amplitude if the wave amplitude exceeds a certain threshold value. Numerical simulations show the validity of the analytical approach for the initial stage of the time evolution, provided that the harmonics generated by the nonlinear terms are considered. The long-term evolution exhibits chaoticlike states

  11. Modulation of lymphopoiesis

    Energy Technology Data Exchange (ETDEWEB)

    Rosse, C.

    1991-01-01

    During the current project period we have demonstrated correspondence between animal models and in vitro models of modulated lymphopoiesis. Our finding that G-CSF, a growth factor for neutrophil granulocytes, suppresses lymphopoiesis in long term bone marrow cultures (LTBMC) has important implications both for understanding the regulatory mechanisms of hemopoiesis and for clinical use of recombinant growth factors that are beginning to be widely used for the treatment of a variety of diseases. During the present project period we adopted LTBMC systems developed by others for the purposes of our specific aims. Also we developed a novel long term culture system for NK cells. The discovery of a new growth factor, O-CSF, specific for osteoclasts and the establishment of a clonal assay system that provides evidence for a new class of hemopoietic progenitor cells, the osteoclast progenitor, are important contributions. Given the important role T cells play in the immune response and in the regulation of other lymphohemopoietic cell lineages through the lymphokines they secrete, the need for an in vitro system that lends itself to the analysis of T cell maturation and to the testing of factors that may adversely affect T lymphopoiesis cannot be overemphasized. We believe that we can exploit an advantageous set of circumstances that present an excellent opportunity for initiating a focused experimental program for developing such a system. By a systematic and selective analysis of molecular interactions between heterogenous thymic stromal cells and T cell progenitors at different stages of maturation, it will be possible for our program to define the complement of critical cellular interactions on which successive stages of T lymphopoiesis depend. The experiments we propose will lay a rational foundation for the development of a long term culture system for T lymphopoiesis. 24 refs., 7 figs.

  12. An Embedded Reconfigurable Logic Module

    Science.gov (United States)

    Tucker, Jerry H.; Klenke, Robert H.; Shams, Qamar A. (Technical Monitor)

    2002-01-01

    A Miniature Embedded Reconfigurable Computer and Logic (MERCAL) module has been developed and verified. MERCAL was designed to be a general-purpose, universal module that that can provide significant hardware and software resources to meet the requirements of many of today's complex embedded applications. This is accomplished in the MERCAL module by combining a sub credit card size PC in a DIMM form factor with a XILINX Spartan I1 FPGA. The PC has the ability to download program files to the FPGA to configure it for different hardware functions and to transfer data to and from the FPGA via the PC's ISA bus during run time. The MERCAL module combines, in a compact package, the computational power of a 133 MHz PC with up to 150,000 gate equivalents of digital logic that can be reconfigured by software. The general architecture and functionality of the MERCAL hardware and system software are described.

  13. Photovoltaic Module Qualification Plus Testing

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, S.; Wohlgemuth, J.; Kempe, M.; Bosco, N.; Hacke, P.; Jordan, D.; Miller, D. C.; Silverman, T. J.; Phillips, N.; Earnest, T.; Romero, R.

    2013-12-01

    This report summarizes a set of test methods that are in the midst of being incorporated into IEC 61215 for certification of a module design or other tests that go beyond certification to establish bankability.

  14. Flip-Flop Digital Modulator

    Science.gov (United States)

    Eno, R. F.

    1984-01-01

    Clock switched on and off in response to data signal. Flip-flop modulator generates square-wave carrier frequency that is half clock frequency and turns carrier on and off. Final demodulator output logical inverse of data input.

  15. Ultrasound-modulated bioluminescence tomography

    Science.gov (United States)

    Bal, Guillaume; Schotland, John C.

    2014-03-01

    We propose a method to reconstruct the density of a luminescent source in a highly scattering medium from ultrasound-modulated optical measurements. Our approach is based on the solution to a hybrid inverse source problem for the diffusion equation.

  16. Defining Modules, Modularity and Modularization

    DEFF Research Database (Denmark)

    Miller, Thomas Dedenroth; Pedersen, Per Erik Elgård

    The paper describes the evolution of the concept of modularity in a historical perspective. The main reasons for modularity are: create variety, utilize similarities, and reduce complexity. The paper defines the terms: Module, modularity, and modularization....

  17. Compact energy conversion module Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This STTR project delivers a compact vibration-based Energy Conversion Module (ECM) that powers sensors for purposes like structural health monitoring (SHM). NASA...

  18. Factors Modulating Software Design Quality

    OpenAIRE

    S., Poornima. U.; V, Suma.

    2014-01-01

    Object oriented approach is one of the popular software development approach for managing complex systems with massive set of requirements. Unlike procedural approach, this approach captures the requirements as set of data rather than services. Further, class is considered as a key unit of the solution-domain with data and services wrapped together, representing architectural design of a basic module. Thus, system complexity is directly related to the number of modules and the degree of inter...

  19. Installing Python Modules with pip

    OpenAIRE

    Fred Gibbs

    2013-01-01

    This lesson shows you how to download and install Python modules. There are many ways to install external modules, but for the purposes of this lesson, we’re going to use a program called pip. As of Python 2.7.9 and newer, pip is installed by default. This tutorial will be helpful for anyone using older versions of Python (which are still quite common).

  20. Wideband Sigma-Delta Modulators

    OpenAIRE

    Yuan, Xiaolong

    2010-01-01

    Sigma-delta modulators (SDM) have come up as an attractive candidatefor analog-to-digital conversion in single chip front ends thanks to the continuousimproving performance. The major disadvantage is the limited bandwidthdue to the need of oversampling. Therefore, extending these convertersto broadband applications requires lowering the oversampling ratio (OSR) inorder. The aim of this thesis is the investigation on the topology and structureof sigma-delta modulators suitable for wideband app...

  1. Installing Python Modules with pip

    Directory of Open Access Journals (Sweden)

    Fred Gibbs

    2013-05-01

    Full Text Available This lesson shows you how to download and install Python modules. There are many ways to install external modules, but for the purposes of this lesson, we’re going to use a program called pip. As of Python 2.7.9 and newer, pip is installed by default. This tutorial will be helpful for anyone using older versions of Python (which are still quite common.

  2. Attentional Modulation of Binocular Rivalry

    OpenAIRE

    Chris ePaffen; David eAlais

    2011-01-01

    Ever since Wheatstone initiated the scientific study of binocular rivalry, it has been debated whether the phenomenon is under attentional control. In recent years, the issue of attentional modulation of binocular rivalry has seen a revival. Here we review the classical studies as well as recent advances in the study of attentional modulation of binocular rivalry. We show that (1) voluntary control over binocular rivalry is possible, yet limited, (2) both endogenous and exogenous attention in...

  3. Flavonoid modulation of GABAA receptors

    OpenAIRE

    Jane R. Hanrahan; Chebib, Mary; Johnston, Graham A. R.

    2011-01-01

    There has been a resurgence of interest in synthetic and plant-derived flavonoids as modulators of γ-amino butyric acid-A (GABAA) receptor function influencing inhibition mediated by the major inhibitory neurotransmitter GABA in the brain. Areas of interest include (i) flavonoids that show subtype selectivity in recombinant receptor studies in vitro consistent with their behavioural effects in vivo, (ii) flumazenil-insensitive modulation of GABAA receptor function by flavonoids, (iii) the abi...

  4. Hybrid graphene plasmonic waveguide modulators

    Science.gov (United States)

    Ansell, D.; Radko, I. P.; Han, Z.; Rodriguez, F. J.; Bozhevolnyi, S. I.; Grigorenko, A. N.

    2015-11-01

    The unique optical and electronic properties of graphene make possible the fabrication of novel optoelectronic devices. One of the most exciting graphene characteristics is the tunability by gating which allows one to realize active optical devices. While several types of graphene-based photonic modulators have already been demonstrated, the potential of combining the versatility of graphene with subwavelength field confinement of plasmonic waveguides remains largely unexplored. Here we report fabrication and study of hybrid graphene-plasmonic waveguide modulators. We consider several types of modulators and identify the most promising one for telecom applications. The modulator working at the telecom range is demonstrated, showing a modulation depth of >0.03 dB μm-1 at low gating voltages for an active device area of just 10 μm2, characteristics which are already comparable to those of silicon-based waveguide modulators while retaining the benefit of further device miniaturization. Our proof-of-concept results pave the way towards on-chip realization of efficient graphene-based active plasmonic waveguide devices for optical communications.

  5. Customized PEC modules. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Soerensen, Martin B. (DTI, Taastrup (Denmark))

    2012-07-01

    The purpose of the project ''Customized PEC modules'' was to move from the production hand-made individual DSCs (dye-sensitized solar cells) in the laboratory to the production of DSC modules in a semi-automated process. At the same time allowing sufficient variation in the product's specification for real tailoring of the product to the application. The tailoring can be related to the module's electrical output and size, but also to the possibility of designing patterns for decoration or communication purposes by playing around with the shape, size and layout of the individual cells forming the module. This was to be accomplished mainly by screen printing of DSC components on glass substrates at Mekoprint. For reaching this goal the work was divided into a number of steps. The central part of the work done was in the initial conception activity and the following manufacturing activity. An activity regarding optimization included several tasks of optimization and adaptation of the existing laboratory process for manufacturing of the DSCs. Finally, work focused on international activities was done. All the steps needed for the production of customized DSC modules have been demonstrated in this project. In combination with the development of a high performing printable sealant and sealing method all the prerequisites for producing customized DSC modules have been demonstrated. (LN)

  6. Intelligent spacecraft module

    Science.gov (United States)

    Oungrinis, Konstantinos-Alketas; Liapi, Marianthi; Kelesidi, Anna; Gargalis, Leonidas; Telo, Marinela; Ntzoufras, Sotiris; Paschidi, Mariana

    2014-12-01

    The paper presents the development of an on-going research project that focuses on a human-centered design approach to habitable spacecraft modules. It focuses on the technical requirements and proposes approaches on how to achieve a spatial arrangement of the interior that addresses sufficiently the functional, physiological and psychosocial needs of the people living and working in such confined spaces that entail long-term environmental threats to human health and performance. Since the research perspective examines the issue from a qualitative point of view, it is based on establishing specific relationships between the built environment and its users, targeting people's bodily and psychological comfort as a measure toward a successful mission. This research has two basic branches, one examining the context of the system's operation and behavior and the other in the direction of identifying, experimenting and formulating the environment that successfully performs according to the desired context. The latter aspect is researched upon the construction of a scaled-model on which we run series of tests to identify the materiality, the geometry and the electronic infrastructure required. Guided by the principles of sensponsive architecture, the ISM research project explores the application of the necessary spatial arrangement and behavior for a user-centered, functional interior where the appropriate intelligent systems are based upon the existing mechanical and chemical support ones featured on space today, and especially on the ISS. The problem is set according to the characteristics presented at the Mars500 project, regarding the living quarters of six crew-members, along with their hygiene, leisure and eating areas. Transformable design techniques introduce spatial economy, adjustable zoning and increased efficiency within the interior, securing at the same time precise spatial orientation and character at any given time. The sensponsive configuration is

  7. Linear frequency modulation with electronic-optics modulator

    Science.gov (United States)

    Cao, Changqing; Zeng, Xiaodong; Zheng, Yili; Liu, Huanhuan; Zhao, Xiaoyan

    2007-11-01

    The spatial resolution of a space communication system is constrained by the diffraction limit of the telescope aperture. In a frequency-modulated continuous wave (FMCW), the frequency of the laser is ramped, and the frequency difference between the reflected wave and a local-oscillator wave is monitored. For maximum performance the frequency ramping should be linear. Linear frequency modulation (LFM) of the laser emission is a commonly used method for improving the detection sensitivity. Because of the available technology, techniques that use relatively low modulation frequencies were implemented first. In the early 1980's, an elegant measurement method based on frequency modulation opened up new applications for spectroscopy with spectrally modulated laser light. In this paper we analyzed systematically the principles of saw tooth-wave optical FMCW. For optical FMCW, because all the practical optical waves are from single-mode lasers, and because the laser beam from a single-mode laser is coherent in space due to the nature of stimulated emission, the spatial coherence is always satisfied, and therefore only temporal coherence need be considered. The chip signal, experimental system, and results are analyzed and discussed.

  8. On generalized k-syzygy modules

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this paper, we first introduce the notion of generalized k-syzygy modules, and then give an equivalent characterization that the class of generalized k-syzygy modules coincides with that ofω-k-torsionfree modules. We further study the extension closure of the category consisting of generalized k-syzygy modules. Some known results are obtained as corollaries.

  9. Skein Modules and the Noncommutative Torus

    OpenAIRE

    Frohman, Charles; Gelca, Razvan

    1998-01-01

    We show that the Kauffman bracket skein module of a cylinder over the torus embeds as a subalgebra of the noncommutative torus. Using this we derive nice formulas for the Jones-Wenzl idempotents and analyze the structure of the Kauffman bracket skein module of the unknot as a module over the Kauffman bracket skein module of a cylinder over the torus.

  10. Tate cohomology with respect to semidualizing modules

    CERN Document Server

    Sather-Wagstaff, Sean; White, Diana

    2009-01-01

    We investigate Tate cohomology of modules over a commutative noetherian ring with respect to semidualizing modules. We identify classes of modules admitting Tate resolutions and analyze the interaction between the corresponding relative and Tate cohomology modules. As an application of our approach, we prove a general balance result for Tate cohomology. Our results are based on an analysis of Tate cohomology in abelian categories.

  11. Health Occupations Module. The Integumentary System.

    Science.gov (United States)

    Temple Univ., Philadelphia, PA. Div. of Vocational Education.

    This module on the integumentary system is one of eight modules designed for individualized instruction in health occupations education programs at both the secondary and postsecondary levels. This module contains an introduction to the module topic, objectives (e.g., list and describe the types of glands formed in the skin, and explain the…

  12. Language Parametric Module Management for IDEs

    NARCIS (Netherlands)

    Klint, P.; Kooiker, A.T.; Vinju, J.J.; Johnstone, A.; Sloane, A.M.

    2007-01-01

    An integrated development environment (IDE) monitors all the changes that a user makes to source code modules and responds accordingly by flagging errors, by reparsing, by rechecking, or by recompiling modules and by adjusting visualizations or other information derived from a module. A module manag

  13. On a Class of Semicommutative Modules

    Indian Academy of Sciences (India)

    Nazim Agayev; Tahire Özen; Abdullah Harmanci

    2009-04-01

    Let be a ring with identity, a right -module and $S=\\mathrm{End}_R(M)$. In this note, we introduce -semicommutative, -Baer, $S-q.$-Baer and $S-p.q.$-Baer modules. We study the relations between these classes of modules. Also we prove if is an -semicommutative module, then is an $S-p.q.$-Baer module if and only if $M[x]$ is an $S[x]-p.q.$-Baer module, is an -Baer module if and only if $M[x]$ is an $S[x]$-Baer module, is an $S-q.$-Baer module if and only if $M[x]$ is an $S[x]-q.$-Baer module.

  14. Optoelectronic Oscillator Based on Polarization Modulation

    Science.gov (United States)

    Pan, Shilong; Zhou, Pei; Tang, Zhenzhou; Zhang, Yamei; Zhang, Fangzheng; Zhu, Dan

    2015-07-01

    A polarization modulator together with a polarizer can implement phase modulation, intensity modulation with tunable chirp, and frequency-doubling intensity modulation. If an optical filter is incorporated, frequency-quadrupling and frequency-sextupling intensity modulations and a microwave photonic phase shifter can also be realized. By using a polarization modulator to replace the intensity modulator in an optoelectronic oscillator, various new features are enabled. In this article, an analytical model for the polarization modulator-based systems is established. The recent development in employing polarization modulators for constructing optoelectronic oscillators is discussed. The emerging applications enabled by the polarization modulator-based optoelectronic oscillators and the possible future development are also discussed.

  15. Module Amenability of Semigroup Algebras under Certain Module Actions

    Directory of Open Access Journals (Sweden)

    A. Sahleh

    2014-06-01

    Full Text Available In this paper we define a congruence ∼ on inverse semigroup S such that amenability of S is equivalent to amenability of S/ ∼. We study module amenability of semigroup algebra l 1 (S/ ∼ when S is an inverse semigroup with idempotents E and prove that it is equivalent to module amenability of l 1 (S. The main difference of this action with the more studied trivial action is that in this case the corresponding homomorphic image is a Clifford semigroup rather than a discrete group

  16. NEMS integrating module documentation report

    Energy Technology Data Exchange (ETDEWEB)

    1993-12-14

    The National Energy Modeling System (NEMS) is a computer modeling system that produces a general equilibrium solution for energy supply and demand in the US energy markets. The model achieves a supply and demand balance in the end-use demand regions, defined as the nine Census Divisions, by solving for the prices of each energy type such that the quantities producers are willing to supply equal the quantities consumers wish to consume. The system reflects market economics, industry structure, and energy policies and regulations that influence market behavior. The NEMS Integrating Module is the central integrating component of a complex modeling system. As such, a thorough understanding of its role in the modeling process can only be achieved by placing it in the proper context with respect to the other modules. To that end, this document provides an overview of the complete NEMS model, and includes brief descriptions of the modules with which the Integrating Module interacts. The emphasis and focus, however, is on the structure and function of the Integrating Module of NEMS.

  17. Compact nanomechanical plasmonic phase modulators

    Energy Technology Data Exchange (ETDEWEB)

    Dennis, B. S.; Haftel, M. I.; Czaplewski, D. A.; Lopez, D.; Blumberg, G.; Aksyuk, V. A.

    2015-03-30

    Highly confined optical energy in plasmonic devices is advancing miniaturization in photonics. However, for mode sizes approaching ≈10 nm, the energy increasingly shifts into the metal, raising losses and hindering active phase modulation. Here, we propose a nanoelectromechanical phase-modulation principle exploiting the extraordinarily strong dependence of the phase velocity of metal–insulator–metal gap plasmons on dynamically variable gap size. We experimentally demonstrate a 23-μm-long non-resonant modulator having a 1.5π rad range, with 1.7 dB excess loss at 780 nm. Analysis shows that by simultaneously decreasing the gap, length and width, an ultracompact-footprint π rad phase modulator can be realized. This is achieved without incurring the extra loss expected for plasmons confined in a decreasing gap, because the increasing phase-modulation strength from a narrowing gap offsets rising propagation losses. Such small, high-density electrically controllable components may find applications in optical switch fabrics and reconfigurable plasmonic optics.

  18. Photovoltaic module parameters acquisition model

    International Nuclear Information System (INIS)

    Highlights: • Photovoltaic five-parameter model is proposed using Matlab® and Simulink. • The model acquisits input sparse data matrix from stigmatic measurement. • Computer simulations lead to continuous I–V and P–V characteristics. • Extrapolated I–V and P–V characteristics are in hand. • The model allows us to predict photovoltaics exploitation in different conditions. - Abstract: This paper presents basic procedures for photovoltaic (PV) module parameters acquisition using MATLAB and Simulink modelling. In first step, MATLAB and Simulink theoretical model are set to calculate I–V and P–V characteristics for PV module based on equivalent electrical circuit. Then, limited I–V data string is obtained from examined PV module using standard measurement equipment at standard irradiation and temperature conditions and stated into MATLAB data matrix as a reference model. Next, the theoretical model is optimized to keep-up with the reference model and to learn its basic parameters relations, over sparse data matrix. Finally, PV module parameters are deliverable for acquisition at different realistic irradiation, temperature conditions as well as series resistance. Besides of output power characteristics and efficiency calculation for PV module or system, proposed model validates computing statistical deviation compared to reference model

  19. Linkage of finite Gorenstein dimension modules

    CERN Document Server

    Dibaei, Mohammad T

    2011-01-01

    For a horizontally linked module, over a commutative semiperfect Noetherian ring $R$, the connections of its invariants reduced grade, Gorenstein dimension and depth are studied. It is shown that under certain conditions the depth of a horizontally linked module is equal to the reduced grade of its linked module. The connection of the Serre condition $(S_n)$ on an $R$--module of finite Gorenstein dimension with the vanishing of the local cohomology groups of its linked module is discussed.

  20. Language Parametric Module Management for IDEs

    OpenAIRE

    Klint, Paul; Kooiker, Taeke; Vinju, Jurgen; Johnstone, A; Sloane, A.M.

    2007-01-01

    An integrated development environment (IDE) monitors all the changes that a user makes to source code modules and responds accordingly by flagging errors, by reparsing, by rechecking, or by recompiling modules and by adjusting visualizations or other information derived from a module. A module manager is the central component of the IDE that is responsible for this behavior. Although the overall functionality of a module manager in a given IDE is fixed, its actual behavior strongly depends on...

  1. Progress of MICE RFCC Module

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.; Bowring, D.; DeMello, A.; Gourlay, S.; Green, M.; Li, N.; Niinikoski, T.; Pan, H.; Prestemon, S.; Virostek, S.; Zisman, M.; Bross, A.; Carcagno, R.; Kashikhin, V.; Sylvester, C.; Chen, A. B.; Guo, Bin; Li, Liyi; Xu, Fengyu; Cao, Y.; Sun, S.; Wang, Li; Yin, Lixin; Luo, Tianhuan; Summers, Don; Smith, B.; Radovinsky, A.; Zhukovsky, A.; Kaplan, D.

    2012-05-20

    Recent progress on the design and fabrication of the RFCC (RF and superconducting Coupling Coil) module for the international MICE (Muon Ionization Cooling Experiment) are reported. The MICE ionization cooling channel has two RFCC modules, each having four 201- MHz normal conducting RF cavities surrounded by one superconducting coupling coil (solenoid) magnet. The magnet is designed to be cooled by three cryocoolers. Fabrication of the RF cavities is complete; preparation for the cavity electro-polishing, low power RF measurements, and tuning are in progress at Lawrence Berkeley National Laboratory (LBNL). Fabrication of the cold mass of the first coupling coil magnet has been completed in China and the cold mass arrived at LBNL in late 2011. Preparations for testing the cold mass are currently under way at Fermilab. Plans for the RFCC module assembly and integration are being developed and are described.

  2. Solid-state membrane module

    Science.gov (United States)

    Gordon, John Howard; Taylor, Dale M.

    2011-06-07

    Solid-state membrane modules comprising at least one membrane unit, where the membrane unit has a dense mixed conducting oxide layer, and at least one conduit or manifold wherein the conduit or manifold comprises a dense layer and at least one of a porous layer and a slotted layer contiguous with the dense layer. The solid-state membrane modules may be used to carry out a variety of processes including the separating of any ionizable component from a feedstream wherein such ionizable component is capable of being transported through a dense mixed conducting oxide layer of the membrane units making up the membrane modules. For ease of construction, the membrane units may be planar.

  3. Modulation classification based on spectrogram

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The aim of modulation classification (MC) is to identify the modulation type of a communication signal. It plays an important role in many cooperative or noncooperative communication applications. Three spectrogram-based modulation classification methods are proposed. Their reccgnition scope and performance are investigated or evaluated by theoretical analysis and extensive simulation studies. The method taking moment-like features is robust to frequency offset while the other two, which make use of principal component analysis (PCA) with different transformation inputs,can achieve satisfactory accuracy even at low SNR (as low as 2 dB). Due to the properties of spectrogram, the statistical pattern recognition techniques, and the image preprocessing steps, all of our methods are insensitive to unknown phase and frequency offsets, timing errors, and the arriving sequence of symbols.

  4. Cannabinoid modulation of neuroinflammatory disorders.

    Science.gov (United States)

    Saito, Viviane M; Rezende, Rafael M; Teixeira, Antonio L

    2012-06-01

    In recent years, a growing interest has been dedicated to the study of the endocannabinoid system. The isolation of Cannabis sativa main psychotropic compound, Δ(9)-tetrahydrocannabinol (THC), has led to the discovery of an atypical neurotransmission system that modulates the release of other neurotransmitters and participates in many biological processes, including the cascade of inflammatory responses. In this context, cannabinoids have been studied for their possible therapeutic properties in neuroinflammatory diseases. In this review, historic and biochemical aspects of cannabinoids are discussed, as well as their function as modulators of inflammatory processes and therapeutic perspectives for neurodegenerative disorders, particularly, multiple sclerosis. PMID:23204985

  5. Equivalence of Quotient Hilbert Modules

    Indian Academy of Sciences (India)

    Ronald G Douglas; Gadadhar Misra

    2003-08-01

    Let $\\mathcal{M}$ be a Hilbert module of holomorphic functions over a natural function algebra $\\mathcal{A}()$, where $ \\subseteq \\mathbb{C}^m$ is a bounded domain. Let $\\mathcal{M}_0 \\subseteq \\mathcal{M}$ be the submodule of functions vanishing to order on a hypersurface $\\mathcal{Z} \\subseteq $. We describe a method, which in principle may be used, to construct a set of complete unitary invariants for quotient modules $\\mathcal{Q} = \\mathcal{M} \\ominus \\mathcal{M}_0$. The invariants are given explicitly in the particular case of = 2.

  6. Transparent solar cell window module

    Energy Technology Data Exchange (ETDEWEB)

    Chau, Joseph Lik Hang; Chen, Ruei-Tang; Hwang, Gan-Lin; Tsai, Ping-Yuan [Nanopowder and Thin Film Technology Center, ITRI South, Industrial Technology Research Institute, Tainan County 709 (China); Lin, Chien-Chu [I-Lai Acrylic Corporation, Tainan City (China)

    2010-03-15

    A transparent solar cell window module based on the integration of traditional silicon solar cells and organic-inorganic nanocomposite material was designed and fabricated. The transparent solar cell window module was composed of a nanocomposite light-guide plate and traditional silicon solar cells. The preparation of the nanocomposite light-guide plate is easy without modification of the traditional casting process, the nanoparticles sol can be added directly to the polymethyl methacrylate (PMMA) monomer syrup during the process. The solar energy collected by this window can be used to power up small household electrical appliances. (author)

  7. Graphene Based Optical Phase Modulation

    CERN Document Server

    Midrio, Michele; Romagnoli, Marco; Kimerling, Lionel C; Michel, Jurgen

    2013-01-01

    In this paper we report phase modulation obtained by inducing a capacitive charge on graphene layers embedded in the core of a waveguide. There is a biasing regime in which graphene absorption is negligible but large index variations can be achieved with a voltage-length product as small as $V_\\pi\\,L_\\pi \\simeq 0.04 $\\,V\\,cm . Examples of phase induced changes are computed for straight waveguides and for microring resonators showing the possibility to implement several optoelectronic functionalities as modulators, tunable filters, and switches.

  8. Heegner modules and elliptic curves

    CERN Document Server

    Brown, Martin L

    2004-01-01

    Heegner points on both modular curves and elliptic curves over global fields of any characteristic form the topic of this research monograph. The Heegner module of an elliptic curve is an original concept introduced in this text. The computation of the cohomology of the Heegner module is the main technical result and is applied to prove the Tate conjecture for a class of elliptic surfaces over finite fields; this conjecture is equivalent to the Birch and Swinnerton-Dyer conjecture for the corresponding elliptic curves over global fields.

  9. Reward Modulates Adaptations to Conflict

    Science.gov (United States)

    Braem, Senne; Verguts, Tom; Roggeman, Chantal; Notebaert, Wim

    2012-01-01

    Both cognitive conflict (e.g. Verguts & Notebaert, 2009) and reward signals (e.g. Waszak & Pholulamdeth, 2009) have been proposed to enhance task-relevant associations. Bringing these two notions together, we predicted that reward modulates conflict-based sequential adaptations in cognitive control. This was tested combining either a single…

  10. Selective photoreceivers with modulated sensibility

    International Nuclear Information System (INIS)

    The paper presents new type of photoreceivers (photodiodes, photoresistor)(on the basis of semiconductor heterostructures of III-V compounds. As distinct from classic devices elaborated photoreceivers possesses new functional properties: selective spectrum, photo sensibility modulated by supply voltage, possibility to detect simultaneously two or more optic signals with different wavelength. Photoreceivers are elaborated for use in various optoelectronic systems. (authors)

  11. The ELETTRA Gun Trigger module

    International Nuclear Information System (INIS)

    The ELETTRA injector is a full energy Linac. The Linac and the pulsed magnets need to be synchronized with the beam in the storage ring in order to fill it with the proper bunch pattern. Most of the triggers for the timing system are generated by a module which is named Gun Trigger module. The gun is triggered in synchronism with a reference bucket of the storage ring. It can be programmed with a delay between 2 and 864 ns, a range which covers one revolution period of the storage ring, so any arbitrary bucket of the ring can be filled. The module generates also the gun trigger for working in FEL mode, which needs a repetition from 30 to 50 ns in a 10 μs window. The jitter of all these triggers is less than 50 ps. The Gun Trigger module is developed in VMEbus standard, using TTL and ECL technology. It is remotely programmable through the ELETTRA control system. The general architecture of the ELETTRA timing system is also described in the paper

  12. Can Arousal Modulate Response Inhibition?

    Science.gov (United States)

    Weinbach, Noam; Kalanthroff, Eyal; Avnit, Amir; Henik, Avishai

    2015-01-01

    The goal of the present study was to examine if and how arousal can modulate response inhibition. Two competing hypotheses can be drawn from previous literature. One holds that alerting cues that elevate arousal should result in an impulsive response and therefore impair response inhibition. The other suggests that alerting enhances processing of…

  13. Clothing and Textile Student Modules.

    Science.gov (United States)

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    Forty-seven performance-based instructional modules on six major topics are provided for the home economics content area of clothing and textiles. The six topics are (1) planning basics (psychological, physical, social, and behavioral aspects of clothing; elements of design; principles of design; and style and fashion in clothing), (2) buyership…

  14. Modules over discrete valuation domains

    CERN Document Server

    Tuganbaev, Askar A

    2008-01-01

    This book provides the first systematic treatment of modules over discrete valuation domains which plays an important role in various areas of algebra, especially in commutative algebra. Many important results representing the state of the art are presented in the text which is supplemented by exercises and interesting open problems. An important contribution to commutative algebra.

  15. Market Segmentation: An Instructional Module.

    Science.gov (United States)

    Wright, Peter H.

    A concept-based introduction to market segmentation is provided in this instructional module for undergraduate and graduate transportation-related courses. The material can be used in many disciplines including engineering, business, marketing, and technology. The concept of market segmentation is primarily a transportation planning technique by…

  16. WRAP module 1 treatment plan

    International Nuclear Information System (INIS)

    This document provides the methodology to treat waste in the Waste Receiving and Processing Module 1 facility to meet the Resource Conservation and Recovery Act (RCRA) land disposal restrictions or the Waste Isolation and Pilot Plant waste acceptance criteria. This includes Low-Level Mixed Waste, Transuranic Waste, and Transuranic Mixed Waste

  17. Optical DQPSK Modulation Performance Evaluation

    OpenAIRE

    Costa, Nelson; Cartaxo, Adolfo

    2010-01-01

    The performance evaluation of simulated optical DQPSK modulation has been analysed. The EDP of DQPSK signals is approximately Gaussian-distributed. Thus, a SASM for DQPSK systems performance evaluation based on the GA has been proposed. The SASM relies on the use of the closed-form expressions derived for the mean and STD of the EDP

  18. The Chainstitch Machine. Module 18.

    Science.gov (United States)

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on the chainstitch machine, one in a series dealing with industrial sewing machines, their attachments, and operation, covers one topic: performing special operations on the chainstitch machine. These components are provided: an introduction, directions, an objective, learning activities, student information, a student self-check, and…

  19. The Blindstitch Machine. Module 11.

    Science.gov (United States)

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on the purpose and use of the blindstitch machine, one in a series on clothing construction for industrial sewing machine operators designed for student self-study, contains three sections. Each section includes the following parts: an introduction, directions, an objective, learning activities, student information, student self-check,…

  20. Transportation Brokerage: An Instructional Module.

    Science.gov (United States)

    Hayden, Linda

    A concept-based introduction to transportation brokerage is provided in this instructional module for undergraduate and graduate transportation-related courses for disciplines such as engineering, business, marketing, and technology. The concept of transportation brokerage is defined as an assignment of the management of a specific element of a…

  1. Coherent states on Hilbert modules

    International Nuclear Information System (INIS)

    We generalize the concept of coherent states, traditionally defined as special families of vectors on Hilbert spaces, to Hilbert modules. We show that Hilbert modules over C*-algebras are the natural settings for a generalization of coherent states defined on Hilbert spaces. We consider those Hilbert C*-modules which have a natural left action from another C*-algebra, say A. The coherent states are well defined in this case and they behave well with respect to the left action by A. Certain classical objects like the Cuntz algebra are related to specific examples of coherent states. Finally we show that coherent states on modules give rise to a completely positive definite kernel between two C*-algebras, in complete analogy to the Hilbert space situation. Related to this, there is a dilation result for positive operator-valued measures, in the sense of Naimark. A number of examples are worked out to illustrate the theory. Some possible physical applications are also mentioned.

  2. Allosteric Modulation of Muscarinic Receptors

    Czech Academy of Sciences Publication Activity Database

    Jakubík, Jan; El-Fakahany, E. E.

    New York: Springer, 2016 - (Mysliveček, J.; Jakubík, J.), s. 95-130. (Neuromethods. 107). ISBN 978-1-4939-2857-6 R&D Projects: GA ČR(CZ) GBP304/12/G069 Institutional support: RVO:67985823 Keywords : muscarinic receptors * allosteric modulation * radioligand binding functional response Subject RIV: ED - Physiology

  3. Weakly Distributive Modules. Applications to Supplement Submodules

    Indian Academy of Sciences (India)

    Engin Büyükaşik; Yilmaz M Demirci

    2010-11-01

    In this paper, we define and study weakly distributive modules as a proper generalization of distributive modules. We prove that, weakly distributive supplemented modules are amply supplemented. In a weakly distributive supplemented module every submodule has a unique coclosure. This generalizes a result of Ganesan and Vanaja. We prove that -projective duo modules, in particular commutative rings, are weakly distributive. Using this result we obtain that in a commutative ring supplements are unique. This generalizes a result of Camillo and Lima. We also prove that any weakly distributive $\\oplus$-supplemented module is quasi-discrete.

  4. Nanosecond modulator of an electron gun

    International Nuclear Information System (INIS)

    The nanosecond modulator of an electron gun is developed for forming an electron beam with small emittance, necessary for generating the laser on free electrons. The block-diagram of the modulator is presented. The modulator consists of an optical receiver, two formers, two high-frequency power keys, diode with the DNZ charge storage and storage line. The modulator is positioned inside the timer container in the SF6 insulating gas medium under the 300 kV potential. The measured pulsation of the modulator output pulses is below 50 ps. The modulator operates reliably by the high-voltage breakdowns in the system

  5. Reliability and Energy Output of Bifacial Modules

    Energy Technology Data Exchange (ETDEWEB)

    Van Aken, B.B.; Jansen, M.J.; Dekker, N.J.J. [ECN Solar Energy, Petten (Netherlands)

    2013-06-15

    Although flash tests under standard test conditions yields lower power due to transmittance of the back sheet, bifacial modules are expected to outperform their monofacial equivalents in terms of yearly energy output in the field. We compare flash tests for bifacial modules with and without a light scattering panel directly behind the modules: 3% more power output is obtained. We also report on the damp-heat reliability of modules with transparent back sheet. Finally we will present the results of an outdoor study comparing modules with transparent back sheet and modules with state-of-the-art AR coating on the front glass.

  6. Perl Modules for Constructing Iterators

    Science.gov (United States)

    Tilmes, Curt

    2009-01-01

    The Iterator Perl Module provides a general-purpose framework for constructing iterator objects within Perl, and a standard API for interacting with those objects. Iterators are an object-oriented design pattern where a description of a series of values is used in a constructor. Subsequent queries can request values in that series. These Perl modules build on the standard Iterator framework and provide iterators for some other types of values. Iterator::DateTime constructs iterators from DateTime objects or Date::Parse descriptions and ICal/RFC 2445 style re-currence descriptions. It supports a variety of input parameters, including a start to the sequence, an end to the sequence, an Ical/RFC 2445 recurrence describing the frequency of the values in the series, and a format description that can refine the presentation manner of the DateTime. Iterator::String constructs iterators from string representations. This module is useful in contexts where the API consists of supplying a string and getting back an iterator where the specific iteration desired is opaque to the caller. It is of particular value to the Iterator::Hash module which provides nested iterations. Iterator::Hash constructs iterators from Perl hashes that can include multiple iterators. The constructed iterators will return all the permutations of the iterations of the hash by nested iteration of embedded iterators. A hash simply includes a set of keys mapped to values. It is a very common data structure used throughout Perl programming. The Iterator:: Hash module allows a hash to include strings defining iterators (parsed and dispatched with Iterator::String) that are used to construct an overall series of hash values.

  7. Spring-cleaning at the solar module; Fruehjahrsputz am Modul

    Energy Technology Data Exchange (ETDEWEB)

    Orben, Steffen [Orben Wasseraufbereitung, Wiesbaden (Germany)

    2013-04-15

    The solar power yield of a photovoltaic power plant can be reduced significantly by a natural pollution. The average loss in performance and yield at mild and moderate surface contaminations is between eight and sixteen percent. The self-cleaning effect due to wind, rain and snow is not sufficient in order to purify the solar panels. In contrast, the purification with desalinated water receives the performance of solar generators and ensures the yields. Desalinated water can be produced from tap water by reverse osmosis and ion exchange. The water consumption amounts ten liters for a performance of one kilowatt of the solar module. Other important factors are 0.23 Euro for a filter cartridge as well as 11.50 Euro for personnel costs for a performance of one kilowatt of the solar module.

  8. Silicon high speed modulator for advanced modulation: device structures and exemplary modulator performance

    Science.gov (United States)

    Milivojevic, Biljana; Wiese, Stefan; Whiteaway, James; Raabe, Christian; Shastri, Anujit; Webster, Mark; Metz, Peter; Sunder, Sanjay; Chattin, Bill; Anderson, Sean P.; Dama, Bipin; Shastri, Kal

    2014-03-01

    Fiber optics is well established today due to the high capacity and speed, unrivaled flexibility and quality of service. However, state of the art optical elements and components are hardly scalable in terms of cost and size required to achieve competitive port density and cost per bit. Next-generation high-speed coherent optical communication systems targeting a data rate of 100-Gb/s and beyond goes along with innovations in component and subsystem areas. Consequently, by leveraging the advanced silicon micro and nano-fabrication technologies, significant progress in developing CMOS platform-based silicon photonic devices has been made all over the world. These achievements include the demonstration of high-speed IQ modulators, which are important building blocks in coherent optical communication systems. In this paper, we demonstrate silicon photonic QPSK modulator based on a metal-oxide-semiconductor (MOS) capacitor structure, address different modulator configuration structures and report our progress and research associated with highspeed advanced optical modulation in silicon photonics

  9. Earth System Science Education Modules

    Science.gov (United States)

    Hall, C.; Kaufman, C.; Humphreys, R. R.; Colgan, M. W.

    2009-12-01

    The College of Charleston is developing several new geoscience-based education modules for integration into the Earth System Science Education Alliance (ESSEA). These three new modules provide opportunities for science and pre-service education students to participate in inquiry-based, data-driven experiences. The three new modules will be discussed in this session. Coastal Crisis is a module that analyzes rapidly changing coastlines and uses technology - remotely sensed data and geographic information systems (GIS) to delineate, understand and monitor changes in coastal environments. The beaches near Charleston, SC are undergoing erosion and therefore are used as examples of rapidly changing coastlines. Students will use real data from NASA, NOAA and other federal agencies in the classroom to study coastal change. Through this case study, learners will acquire remotely sensed images and GIS data sets from online sources, utilize those data sets within Google Earth or other visualization programs, and understand what the data is telling them. Analyzing the data will allow learners to contemplate and make predictions on the impact associated with changing environmental conditions, within the context of a coastal setting. To Drill or Not To Drill is a multidisciplinary problem based module to increase students’ knowledge of problems associated with nonrenewable resource extraction. The controversial topic of drilling in the Arctic National Wildlife Refuge (ANWR) examines whether the economic benefit of the oil extracted from ANWR is worth the social cost of the environmental damage that such extraction may inflict. By attempting to answer this question, learners must balance the interests of preservation with the economic need for oil. The learners are exposed to the difficulties associated with a real world problem that requires trade-off between environmental trust and economic well-being. The Citizen Science module challenges students to translate scientific

  10. Green card for solar modules; Die Green Card fuer Module

    Energy Technology Data Exchange (ETDEWEB)

    Petzold, Katrin

    2010-07-01

    Manufacturers intending to export solar modules must have them tested according to international safety standards. However, the world ends at the doors of North America. The USA have national safety standards which necessitate a separate test by the US test institute 'Underwriters Laboratories'. Some claim that this is important, while others view this as a strategy to protect the US industry. Now, another test institute has been commissioned near Frankfurt, Germany. (orig.)

  11. Thalamic Circuit Diversity: Modulation of the Driver/Modulator Framework

    Directory of Open Access Journals (Sweden)

    Martha E Bickford

    2016-01-01

    Full Text Available The idea that dorsal thalamic inputs can be divided into drivers, which provide the primary excitatory drive for the relay of information to cortex, and modulators, which alter the gain of signal transmission, has provided a valuable organizing principle for the study of thalamic function. This view further promoted the identification of first order and higher order thalamic nuclei, based on the origin of their driving inputs. Since the introduction of this influential terminology, a number of studies have revealed the existence of a wide variety of thalamic organizational schemes. For example, some thalamic nuclei are not innervated by typical driver inputs, but instead receive input from terminals which exhibit features distinct from those of either classic drivers or modulators. In addition, many thalamic nuclei contain unique combinations of convergent first order, higher order, and/or other driver-like inputs that do not conform with the driver/modulator framework. The assortment of synaptic arrangements identified in the thalamus are reviewed and discussed from the perspective that this organizational diversity can dramatically increase the computational capabilities of the thalamus, reflecting its essential roles in sensory, motor, and sensory-motor circuits.

  12. Mounting support for a photovoltaic module

    Science.gov (United States)

    Brandt, Gregory Michael; Barsun, Stephan K.; Coleman, Nathaniel T.; Zhou, Yin

    2013-03-26

    A mounting support for a photovoltaic module is described. The mounting support includes a foundation having an integrated wire-way ledge portion. A photovoltaic module support mechanism is coupled with the foundation.

  13. Fiber Acousto-Electro-Optic Modulator

    Institute of Scientific and Technical Information of China (English)

    Anen; Jiang

    2003-01-01

    A new kind of fiber acousto-electro-optic modulator is made by using Lithium Niobate crystal. This kind of modulator can be used in fiber communication, and its center frequency can be changed by directed current voltages.

  14. Plasma optical modulators for intense lasers

    CERN Document Server

    Yu, Lu-Le; Qian, Lie-Jia; Chen, Min; Weng, Su-Ming; Sheng, Zheng-Ming; Jaroszynski, D A; Mori, W B; Zhang, Jie

    2016-01-01

    Optical modulators can be made nowadays with high modulation speed, broad bandwidth, while being compact, owing to the recent advance in material science and microfabrication technology. However, these optical modulators usually work for low intensity light beams. Here, we present an ultrafast, plasma-based optical modulator, which can directly modulate high power lasers with intensity up to 10^16 W/cm^2 level to produce an extremely broad spectrum with a fractional bandwidth over 100%, extending to the mid-infrared regime in the low-frequency side. This concept relies on two co-propagating laser beams in a sub-mm-scale underdense plasma, where a drive laser pulse first excites an electron plasma wave in its wake while a following carrier laser beam is modulated by the plasma wave. The laser and plasma parameters suitable for the modulator to work are presented. Such optical modulators may enable new applications in the high field physics.

  15. Complex light modulation for lensless image projection

    Institute of Scientific and Technical Information of China (English)

    M. Makowski; A. Kolodziejczyk; A. Siemion; I. Ducin; K. Kakarenko; M. Sypek; A. M. Siemion; J. Suszek; D. Wojnowski; Z. Jaroszewicz

    2011-01-01

    We present a lensless projection of color images based on computer-generated Fourier holograms. Amplitude and phase modulation of three primary-colored laser beams is performed by a matched pair of spatial light modulators. The main advantage of the complex light modulation is the lack of iterative phase retrieval techniques. The advantage is the lack of speckles in the projected images. Experimental results are given and compared with the outcome of classical phase-only modulation.%We present a lensless projection of color images based on computer-generated Fourier holograms.Amplitude and phase modulation of three primary-colored laser beams is performed by a matched pair of spatial light modulators.The main advantage of the complex light modulation is the lack of iterative phase retrieval techniques.The advantage is the lack of speckles in the projected images.Experimental results are given and compared with the outcome of classical phase-only modulation.

  16. Implementing a module system for SICStus Prolog

    OpenAIRE

    Andersson, Stefan

    1991-01-01

    This report covers the specification and implementation of a predicate based module system for SICStus Prolog. There is also a brief background to the module issue for Prolog. The emphasis is put on the description of the implementation.

  17. Reliability Issues for Photovoltaic Modules (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, S.

    2009-10-01

    Si modules good in field; new designs need reliability testing. CdTe & CIGS modules sensitive to moisture; carefully seal. CPV in product development stage; benefits from expertise in other industries.

  18. A Dirichlet unit theorem for Drinfeld modules

    OpenAIRE

    Taelman, Lenny

    2009-01-01

    We show that the module of integral points on a Drinfeld module satisfies a an analogue of Dirichlet's unit theorem, despite its failure to be finitely generated. As a consequence, we obtain a construction of a canonical finitely generated sub-module of the module of integral points. We use the results to give a precise formulation of a conjectural analogue of the class number formula.

  19. Nonlinear approximation in alpha-modulation spaces

    DEFF Research Database (Denmark)

    Borup, Lasse; Nielsen, Morten

    2006-01-01

    The α-modulation spaces are a family of spaces that contain the Besov and modulation spaces as special cases. In this paper we prove that brushlet bases can be constructed to form unconditional and even greedy bases for the α-modulation spaces. We study m -term nonlinear approximation with brushlet...... bases, and give complete characterizations of the associated approximation spaces in terms of α-modulation spaces....

  20. Automatic modulation classification principles, algorithms and applications

    CERN Document Server

    Zhu, Zhechen

    2014-01-01

    Automatic Modulation Classification (AMC) has been a key technology in many military, security, and civilian telecommunication applications for decades. In military and security applications, modulation often serves as another level of encryption; in modern civilian applications, multiple modulation types can be employed by a signal transmitter to control the data rate and link reliability. This book offers comprehensive documentation of AMC models, algorithms and implementations for successful modulation recognition. It provides an invaluable theoretical and numerical comparison of AMC algo

  1. Tests Of Amorphous-Silicon Photovoltaic Modules

    Science.gov (United States)

    Ross, Ronald G., Jr.

    1988-01-01

    Progress in identification of strengths and weaknesses of amorphous-silicon technology detailed. Report describes achievements in testing reliability of solar-power modules made of amorphous-silicon photovoltaic cells. Based on investigation of modules made by U.S. manufacturers. Modules subjected to field tests, to accelerated-aging tests in laboratory, and to standard sequence of qualification tests developed for modules of crystalline-silicon cells.

  2. Steps in Modular Specifications for Concurrent Modules

    DEFF Research Database (Denmark)

    Da Rocha Pinto, Pedro; Dinsdale-Young, Thomas; Gardner, Philippa

    2015-01-01

    The specification of a concurrent program module is a difficult problem. The specifications must be strong enough to enable reasoning about the intended clients without reference to the underlying module implementation. We survey a range of verification techniques for specifying concurrent module......, in particular highlighting four key concepts: auxiliary state, interference abstraction, resource ownership and atomicity. We show how these concepts combine to provide powerful approaches to specifying concurrent modules....

  3. Host modulation by therapeutic agents

    Directory of Open Access Journals (Sweden)

    Sugumari Elavarasu

    2012-01-01

    Full Text Available Periodontal disease susceptible group present advanced periodontal breakdown even though they achieve a high standard of oral hygiene. Various destructive enzymes and inflammatory mediators are involved in destruction. These are elevated in case of periodontal destruction. Host modulation aims at bringing these enzymes and mediators to normal level. Doxycycline, nonsteroidal anti-inflammatory drugs (NSAIDs, bisphosphonates, nitrous oxide (NO synthase inhibitors, recombinant human interleukin-11 (rhIL-11, omega-3 fatty acid, mouse anti-human interleukin-6 receptor antibody (MRA, mitogen-activated protein kinase (MAPK inhibitors, nuclear factor-kappa B (NF-kb inhibitors, osteoprotegerin, and tumor necrosis factor antagonist (TNF-α are some of the therapeutic agents that have host modulation properties.

  4. Cavity Voltage Phase Modulation MD

    CERN Document Server

    Mastoridis, T; Butterworth, A; Molendijk, J; Tuckmantel, J

    2012-01-01

    The LHC RF/LLRF system is currently setup for extremely stable RF voltage to minimize transient beam loading eects. The present scheme cannot be extended beyond nominal beam current since the demanded power would push the klystrons to saturation. For beam currents above nominal (and possibly earlier), the cavity phase modulation by the beam will be not be corrected (transient beam loading), but the strong RF feedback and One-Turn Delay feedback will still be active for loop and beam stability in physics. To achieve this, the voltage set point will be adapted for each bunch. The goal of this MD was to test an iterative algorithm that would adjust the voltage set point to achieve the optimal phase modulation for klystron forward power considerations.

  5. Selforthogonal modules with finite injective dimension

    Institute of Scientific and Technical Information of China (English)

    黄兆泳

    2000-01-01

    The category consisting of finitely generated modules which are left orthogonal with a cotilting bimodule is shown to be functorially finite. The notion of left orthogonal dimension is introduced , and then a necessary and sufficient condition of selforthogonal modules having finite injective dimension and a characterization of cotilting modules are given.

  6. Selforthogonal modules with finite injective dimension

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The category consisting of finitely generated modules which are left orthogonal with a cotilting bimodule is shown to be functorially finite. The notion of left orthogonal dimension is introduced, and then a necessary and sufficient condition of selforthogonal modules having finite injective dimension and a characterization of cotilting modules are given.

  7. Permutation presentations of modules over finite groups

    OpenAIRE

    Katsura, Takeshi

    2006-01-01

    We introduce a notion of permutation presentations of modules over finite groups, and completely determine finite groups over which every module has a permutation presentation. To get this result, we prove that every coflasque module over a cyclic p-group is permutation projective.

  8. The staging system: Display and edit module

    Science.gov (United States)

    Edwards, E.; Bernier, L.

    1976-01-01

    The Display and Edit (D and E) Module described is one of six major modules being developed for the STAGING (STructural Analysis through Generalized INteractive Graphics) System. Several remarks are included concerning the computer environment and the architecture of the data base. The utility of this module is emphasized.

  9. Relative injectivity and CS-modules

    Directory of Open Access Journals (Sweden)

    Mahmoud Ahmed Kamal

    1994-01-01

    Full Text Available In this paper we show that a direct decomposition of modules M⊕N, with N homologically independent to the injective hull of M, is a CS-module if and only if N is injective relative to M and both of M and N are CS-modules. As an application, we prove that a direct sum of a non-singular semisimple module and a quasi-continuous module with zero socle is quasi-continuous. This result is known for quasi-injective modules. But when we confine ourselves to CS-modules we need no conditions on their socles. Then we investigate direct sums of CS-modules which are pairwise relatively inective. We show that every finite direct sum of such modules is a CS-module. This result is known for quasi-continuous modules. For the case of infinite direct sums, one has to add an extra condition. Finally, we briefly discuss modules in which every two direct summands are relatively inective.

  10. Applying Economics Using Interactive Learning Modules

    Science.gov (United States)

    Goma, Ophelia D.

    2010-01-01

    This article describes the use of web-based, interactive learning modules in the principles of economics course. The learning modules introduce students to important, historical economic events while providing real-world application of the economic theory presented in class. Each module is designed to supplement and complement the economic theory…

  11. Operator feedback system for the module builder

    Science.gov (United States)

    Seed cotton is compressed into modules after harvest for storage and transport. Inexperienced operators often construct modules with shapes that allow water to collect on the module cover. This water will penetrate the cover, especially if the cover is damaged by weathering or rough handling, and ...

  12. Twisted Cyclic Cohomology and Modular Fredholm Modules

    Science.gov (United States)

    Rennie, Adam; Sitarz, Andrzej; Yamashita, Makoto

    2013-07-01

    Connes and Cuntz showed in [Comm. Math. Phys. 114 (1988), 515-526] that suitable cyclic cocycles can be represented as Chern characters of finitely summable semifinite Fredholm modules. We show an analogous result in twisted cyclic cohomology using Chern characters of modular Fredholm modules. We present examples of modular Fredholm modules arising from Podleś spheres and from SUq(2).

  13. Optical Electronics. Electronics Module 9. Instructor's Guide.

    Science.gov (United States)

    Franken, Bill

    This module is the ninth of 10 modules in the competency-based electronics series. Introductory materials include a listing of competencies addressed in the module, a parts/equipment list, and a cross reference table of instructional materials. Five instructional units cover: fiber optic cable; optical coupler; lasers and masers; optical displays;…

  14. Synthetic circuits, devices and modules

    OpenAIRE

    Zhang, Hong; Jiang, Taijiao

    2010-01-01

    The aim of synthetic biology is to design artificial biological systems for novel applications. From an engineering perspective, construction of biological systems of defined functionality in a hierarchical way is fundamental to this emerging field. Here, we highlight some current advances on design of several basic building blocks in synthetic biology including the artificial gene control elements, synthetic circuits and their assemblies into devices and modules. Such engineered basic buildi...

  15. Optical interconnects for multichip modules

    Science.gov (United States)

    Haas, Franz; Honey, David A.

    1994-06-01

    A 16-channel plane-to-plane optical interconnect suitable for a multilayer multichip module computer system was demonstrated. a single diffractive optic element was used to focus the outputs from a 4 X 4 array of LEDs son one plane to a corresponding array of photodetectors on a second plane. This architecture can be used to overcome the speed, interconnect number and density, and power limitations of traditional electronic interconnects.

  16. Spontaneous Vesicles Modulated by Polymers

    OpenAIRE

    Francisco Ortega; M. Mercedes Velázquez; Margarita Valero

    2011-01-01

    Vesicles are widely used in technological applications including cosmetic products, in microencapsulation for drug delivery, as anticancer agents and in the technology of adhesives, paints and inks. The vesicle size and the surface charge are very important properties from a technological point of view. Thus, the challenge in formulation is to find inexpensive stable vesicles with well-defined sizes and to modulate the surface charge of these aggregates. In this work we analyze the effect of ...

  17. Cannabinoid Modulation of Neuroinflammatory Disorders

    OpenAIRE

    Saito, Viviane M; Rezende, Rafael M; Teixeira, Antonio L.

    2012-01-01

    In recent years, a growing interest has been dedicated to the study of the endocannabinoid system. The isolation of Cannabis sativa main psychotropic compound, Δ9-tetrahydrocannabinol (THC), has led to the discovery of an atypical neurotransmission system that modulates the release of other neurotransmitters and participates in many biological processes, including the cascade of inflammatory responses. In this context, cannabinoids have been studied for their possible therapeutic properties i...

  18. Complex Wavelet Based Modulation Analysis

    DEFF Research Database (Denmark)

    Luneau, Jean-Marc; Lebrun, Jérôme; Jensen, Søren Holdt

    2008-01-01

     polynomial trends. Moreover an analytic Hilbert-like transform is possible with complex wavelets implemented as an orthogonal filter bank. By working in an alternative transform domain coined as “Modulation Subbands”, this transform shows very promising denoising capabilities and suggests new approaches for joint...... spectro-temporal analytic processing of slow frequency and phase varying signals....

  19. Pulse amplitude modulated chlorophyll fluorometer

    Energy Technology Data Exchange (ETDEWEB)

    Greenbaum, Elias; Wu, Jie

    2015-12-29

    Chlorophyll fluorometry may be used for detecting toxins in a sample because of changes in micro algae. A portable lab on a chip ("LOAC") based chlorophyll fluorometer may be used for toxin detection and environmental monitoring. In particular, the system may include a microfluidic pulse amplitude modulated ("PAM") chlorophyll fluorometer. The LOAC PAM chlorophyll fluorometer may analyze microalgae and cyanobacteria that grow naturally in source drinking water.

  20. Intensity-modulated radiation therapy.

    Science.gov (United States)

    Goffman, Thomas E; Glatstein, Eli

    2002-07-01

    Intensity-modulated radiation therapy (IMRT) is an increasingly popular technical means of tightly focusing the radiation dose around a cancer. As with stereotactic radiotherapy, IMRT uses multiple fields and angles to converge on the target. The potential for total dose escalation and for escalation of daily fraction size to the gross cancer is exciting. The excitement, however, has greatly overshadowed a range of radiobiological and clinical concerns. PMID:12071811

  1. Attention modulates visual size adaptation.

    OpenAIRE

    Kreutzer, Sylvia; Fink, G R; R. Weidner

    2015-01-01

    The current study determined in healthy subjects (n = 16) whether size adaptation occurs at early, i.e., preattentive, levels of processing or whether higher cognitive processes such as attention can modulate the illusion. To investigate this issue, bottom-up stimulation was kept constant across conditions by using a single adaptation display containing both small and large adapter stimuli. Subjects' attention was directed to either the large or small adapter stimulus by means of a luminance ...

  2. Last ATLAS TRT module installed

    CERN Multimedia

    2005-01-01

    The ATLAS transition radiation tracker (TRT) consists of 96 modules and will join the pixel detector and silicon tracker at the heart of the experiment to map the trajectories of particles and identify electrons produced when proton beams collide. Images with the team responsible for assembly : Kirill Egorov (Petersburg Nuclear Physics Institute), Pauline Gagnon (Indiana University), Ben Legeyt (University of Pennsylvania), Chuck Long (Hampton University), John Callahan (Indiana University) and Alex High (University of Pennsylvania).

  3. Development of GREET Catalyst Module

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhichao [Argonne National Lab. (ANL), Argonne, IL (United States); Benavides, Pahola T. [Argonne National Lab. (ANL), Argonne, IL (United States); Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States); Cronauer, Donald C. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-09-01

    In this report, we develop energy and material flows for the production of five different catalysts (tar reforming, alcohol synthesis, Zeolite Socony Mobil-5 [ZSM-5], Mo/Co/ γ-Al2O3, and Pt/ γ-Al2O3) and two chemicals (olivine, dimethyl ether of polyethylene glycol [DEPG]). These compounds and catalysts are now included in the Greenhouse Gases, Regulated Emissions and Energy Use in Transportation (GREET™) catalyst module.

  4. Tabletability Modulation Through Surface Engineering.

    Science.gov (United States)

    Osei-Yeboah, Frederick; Sun, Changquan Calvin

    2015-08-01

    Poor powder tabletability is a common problem that challenges the successful development of high-quality tablet products. Using noncompressible microcrystalline cellulose beads, we demonstrate that surface coating is an effective strategy for modulating tabletability, almost at will, through judicious selection of coating material. This strategy has broad applicability as tabletability of such particles is dictated by the properties of the outermost layer coat regardless the nature of the core. PMID:26059496

  5. Cerebral cortex modulation of pain

    Institute of Scientific and Technical Information of China (English)

    Yu-feng XIE; Fu-quan HUO; Jing-shi TANG

    2009-01-01

    Pain is a complex experience encompassing sensory-discriminative, affective-motivational and cognitiv e-emotional com-ponents mediated by different mechanisms. Contrary to the traditional view that the cerebral cortex is not involved in pain perception, an extensive cortical network associated with pain processing has been revealed using multiple methods over the past decades. This network consistently includes, at least, the anterior cingulate cortex, the agranular insular cortex, the primary (SⅠ) and secondary somatosensory (SⅡ) cortices, the ventrolateral orbital cortex and the motor cortex. These corti-cal structures constitute the medial and lateral pain systems, the nucleus submedius-ventrolateral orbital cortex-periaque-ductal gray system and motor cortex system, respectively. Multiple neurotransmitters, including opioid, glutamate, GABA and dopamine, are involved in the modulation of pain by these cortical structures. In addition, glial cells may also be in-volved in cortical modulation of pain and serve as one target for pain management research. This review discusses recent studies of pain modulation by these cerebral cortical structures in animals and human.

  6. Solar Modulation of Cosmic Rays

    Directory of Open Access Journals (Sweden)

    Marius S. Potgieter

    2013-06-01

    Full Text Available This is an overview of the solar modulation of cosmic rays in the heliosphere. It is a broad topic with numerous intriguing aspects so that a research framework has to be chosen to concentrate on. The review focuses on the basic paradigms and departure points without presenting advanced theoretical or observational details for which there exists a large number of comprehensive reviews. Instead, emphasis is placed on numerical modeling which has played an increasingly significant role as computational resources have become more abundant. A main theme is the progress that has been made over the years. The emphasis is on the global features of CR modulation and on the causes of the observed 11-year and 22-year cycles and charge-sign dependent modulation. Illustrative examples of some of the theoretical and observational milestones are presented, without attempting to review all details or every contribution made in this field of research. Controversial aspects are discussed where appropriate, with accompanying challenges and future prospects. The year 2012 was the centennial celebration of the discovery of cosmic rays so that several general reviews were dedicated to historical aspects so that such developments are briefly presented only in a few cases.

  7. Development of the module inspection system for new standardized radiation monitoring modules

    International Nuclear Information System (INIS)

    This report mentions about the module inspection system which does the maintenance check of the monitoring modules adapted the new monitoring standard, as well as the result of the verification of the modules. The module inspection system is the automatic measurement system with the computer. The system can perform the functional and the characteristic examination of the monitoring modules, the calibration with radiation source and inspection report. In the verification of the monitoring module, three major items were tested, the adaptability for the new monitoring standard, the module functions and each characteristics. All items met the new monitoring standard. (author)

  8. Multilevel phase and amplitude modulation method for holographic memories with programmable phase modulator

    Science.gov (United States)

    Honma, Satoshi; Sekiguchi, Toru

    2014-09-01

    The utilization of spatial quadrature amplitude modulation (SQAM) signals with amplitude and phase modulation is a simple method used to improve storage capacity in a holographic data storage system. We propose a multilevel phase and amplitude modulation method for holographic memories with a programmable phase modulator (PPM). In this method, holographic page data is recorded by a two-step exposure process for different phase-modulated data. There is no need to adjust the positions of spatial light modulators (SLM) with high accuracy because we use only one spatial modulator. We estimate the quality of 16 SQAM signals produced by our technique.

  9. Modulated pulse bathymetric lidar Monte Carlo simulation

    Science.gov (United States)

    Luo, Tao; Wang, Yabo; Wang, Rong; Du, Peng; Min, Xia

    2015-10-01

    A typical modulated pulse bathymetric lidar system is investigated by simulation using a modulated pulse lidar simulation system. In the simulation, the return signal is generated by Monte Carlo method with modulated pulse propagation model and processed by mathematical tools like cross-correlation and digital filter. Computer simulation results incorporating the modulation detection scheme reveal a significant suppression of the water backscattering signal and corresponding target contrast enhancement. More simulation experiments are performed with various modulation and reception variables to investigate the effect of them on the bathymetric system performance.

  10. Tensor product of quotient Hilbert modules

    OpenAIRE

    Chattopadhyay, Arup; Das, B. Krishna; Sarkar, Jaydeb

    2013-01-01

    In this paper, we present a unified approach to problems of tensor product of quotient modules of Hilbert modules over $\\mathbb{C}[z]$ and corresponding submodules of reproducing kernel Hilbert modules over $\\mathbb{C}[z_1, \\ldots, z_n]$ and the doubly commutativity property of module multiplication operators by the coordinate functions. More precisely, for a reproducing kernel Hilbert module $\\clh$ over $\\mathbb{C}[z_1, \\ldots, z_n]$ of analytic functions on the polydisc in $\\mathbb{C}^n$ wh...

  11. Modules d'endo-p-permutation

    OpenAIRE

    Urfer, Jean-Marie

    2006-01-01

    This dissertation is concerned with the study of a new family of representations of finite groups, the endo-p-permutation modules. Given a prime number p, a finite group G of order divisible by p and an algebraically closed field k of characteristic p, we say that a kG-module M is an endo-p-permutation module if its endomorphism algebra Endk(M) is a p-permutation kG-module, that is a direct summand of a permutation kG-module. This generalizes the notion, first introduced by E. Dade in 1978, o...

  12. Modules d'endo-p-permutation

    OpenAIRE

    Urfer, Jean-Marie; Thévenaz, Jacques

    2007-01-01

    This dissertation is concerned with the study of a new family of representations of finite groups, the endo-p-permutation modules. Given a prime number p, a finite group G of order divisible by p and an algebraically closed field k of characteristic p, we say that a kG-module M is an endo-p-permutation module if its endomorphism algebra Endk(M) is a p-permutation kG-module, that is a direct summand of a permutation kG-module. This generalizes the notion, first introduced by E. Dade in 1978, o...

  13. Detection of Modulated Tones in Modulated Noise by Non-human Primates

    OpenAIRE

    Bohlen, Peter; Dylla, Margit; Timms, Courtney; Ramachandran, Ramnarayan

    2014-01-01

    In natural environments, many sounds are amplitude-modulated. Amplitude modulation is thought to be a signal that aids auditory object formation. A previous study of the detection of signals in noise found that when tones or noise were amplitude-modulated, the noise was a less effective masker, and detection thresholds for tones in noise were lowered. These results suggest that the detection of modulated signals in modulated noise would be enhanced. This paper describes the results of experim...

  14. Laser space communication experiment: Modulator technology

    Science.gov (United States)

    Goodwin, F. E.

    1973-01-01

    Results are presented of a contractual program to develop the modulator technology necessary for a 10.6 micron laser communication system using cadmium telluride as the modulator material. The program consisted of the following tasks: (1) The growth of cadmium telluride crystals of sufficient size and purity and with the necessary optical properties for use as laser modulator rods. (2) Develop a low loss antireflection coating for the cadmium telluride rods. (3) Design and build a modulator capable of 300 MHz modulation. (4) Develop a modulator driver capable of a data rate of 300 MBits/sec, 12 W rms output power, and 40 percent efficiency. (5) Assemble and test the modulator system. All design goals were met and the system was built and tested.

  15. On λ-Finitely Embedded Modules

    Institute of Scientific and Technical Information of China (English)

    O.A.S. Karamzadeh; Sh. Rahimpour

    2005-01-01

    In this article, we introduce and study the notion of λ-finitely embedded modules (a O-finitely embedded module is just a finitely embedded module). We extend some of the basic results of f.e. modules to λ-f.e. modules. We use this concept to give a new proof of a known result which essentially says that a module M has Krull dimension α if and only if each factor module of M is λ-f.e. for some λ≤α and α is the least ordinal with this property. It is observed that a semiprime ring R has Krull dimension λ if and only if R is λ-f.e. We improve the theorem of Matlis-Papp and some of its consequences.Finally, some known results in the literature are restated in terms of the above notion.

  16. Plasma optical modulators for intense lasers

    Science.gov (United States)

    Yu, Lu-Le; Zhao, Yao; Qian, Lie-Jia; Chen, Min; Weng, Su-Ming; Sheng, Zheng-Ming; Jaroszynski, D. A.; Mori, W. B.; Zhang, Jie

    2016-01-01

    Optical modulators can have high modulation speed and broad bandwidth, while being compact. However, these optical modulators usually work for low-intensity light beams. Here we present an ultrafast, plasma-based optical modulator, which can directly modulate high-power lasers with intensity up to 1016 W cm−2 to produce an extremely broad spectrum with a fractional bandwidth over 100%, extending to the mid-infrared regime in the low-frequency side. This concept relies on two co-propagating laser pulses in a sub-millimetre-scale underdense plasma, where a drive laser pulse first excites an electron plasma wave in its wake while a following carrier laser pulse is modulated by the plasma wave. The laser and plasma parameters suitable for the modulator to work are based on numerical simulations. PMID:27283369

  17. Plasma optical modulators for intense lasers

    Science.gov (United States)

    Yu, Lu-Le; Zhao, Yao; Qian, Lie-Jia; Chen, Min; Weng, Su-Ming; Sheng, Zheng-Ming; Jaroszynski, D. A.; Mori, W. B.; Zhang, Jie

    2016-06-01

    Optical modulators can have high modulation speed and broad bandwidth, while being compact. However, these optical modulators usually work for low-intensity light beams. Here we present an ultrafast, plasma-based optical modulator, which can directly modulate high-power lasers with intensity up to 1016 W cm-2 to produce an extremely broad spectrum with a fractional bandwidth over 100%, extending to the mid-infrared regime in the low-frequency side. This concept relies on two co-propagating laser pulses in a sub-millimetre-scale underdense plasma, where a drive laser pulse first excites an electron plasma wave in its wake while a following carrier laser pulse is modulated by the plasma wave. The laser and plasma parameters suitable for the modulator to work are based on numerical simulations.

  18. Automatic modulation recognition of communication signals

    CERN Document Server

    Azzouz, Elsayed Elsayed

    1996-01-01

    Automatic modulation recognition is a rapidly evolving area of signal analysis. In recent years, interest from the academic and military research institutes has focused around the research and development of modulation recognition algorithms. Any communication intelligence (COMINT) system comprises three main blocks: receiver front-end, modulation recogniser and output stage. Considerable work has been done in the area of receiver front-ends. The work at the output stage is concerned with information extraction, recording and exploitation and begins with signal demodulation, that requires accurate knowledge about the signal modulation type. There are, however, two main reasons for knowing the current modulation type of a signal; to preserve the signal information content and to decide upon the suitable counter action, such as jamming. Automatic Modulation Recognition of Communications Signals describes in depth this modulation recognition process. Drawing on several years of research, the authors provide a cr...

  19. The modulational instability of colinear waves

    International Nuclear Information System (INIS)

    A brief review is given of the modulational instability of a single wave. Some aspects of the modulational instability of two colinear waves are then studied. In general, the waves are modulationally unstable with a maximal growth rate which is larger than the modulational growth rate of either wave alone. Moreover, waves which are modulationally stable by themselves are often unstable in the other's presence. This is true for both copropagating and counterpropagating waves. An important property of an instability is whether it is absolute of convective in nature. The modulational instability of two equal-amplitude copropagating waves is usually, but not always, convective. The modulational instability of two equal-amplitude counter-propagating waves is always absolute. Some applications of current interest are discussed. (orig.)

  20. Mini pressurized logistics module (MPLM)

    Science.gov (United States)

    Vallerani, E.; Brondolo, D.; Basile, L.

    1996-06-01

    The MPLM Program was initiated through a Memorandum of Understanding (MOU) between the United States' National Aeronautics and Space Administration (NASA) and Italy's ASI, the Italian Space Agency, that was signed on 6 December 1991. The MPLM is a pressurized logistics module that will be used to transport supplies and materials (up to 20,000 lb), including user experiments, between Earth and International Space Station Alpha (ISSA) using the Shuttle, to support active and passive storage, and to provide a habitable environment for two people when docked to the Station. The Italian Space Agency has selected Alenia Spazio to develop MPLM modules that have always been considered a key element for the new International Space Station taking benefit from its design flexibility and consequent possible cost saving based on the maximum utilization of the Shuttle launch capability for any mission. In the frame of the very recent agreement between the U.S. and Russia for cooperation in space, that foresees the utilization of MIR 1 hardware, the Italian MPLM will remain an important element of the logistics system, being the only pressurized module designed for re-entry. Within the new scenario of anticipated Shuttle flights to MIR 1 during Space Station phase 1, MPLM remains a candidate for one or more missions to provide MIR 1 resupply capabilities and advanced ISSA hardware/procedures verification. Based on the concept of Flexible Carriers, Alenia Spazio is providing NASA with three MPLM flight units that can be configured according to the requirements of the Human-Tended Capability (HTC) and Permanent Human Capability (PHC) of the Space Station. Configurability will allow transportation of passive cargo only, or a combination of passive and cold cargo accommodated in R/F racks. Having developed and qualified the baseline configuration with respect to the worst enveloping condition, each unit could be easily configured to the passive or active version depending upon the

  1. [Selective estrogen receptor modulators (SERMs)].

    Science.gov (United States)

    Chaki, Osamu

    2015-10-01

    Selective estrogen receptor modulators (SERMs) have the potential to provide the skeletal benefits of estrogen without the increased risk of uterine and breast cancer. Raloxifene, second generation SERM has been approved for the prevention and treatment of post-menopausal osteoporosis. Bazedoxifene, third generation SERM acts as a tissue selective estrogen antagonist or agonist. These SERMs inhibited bone turnover and prevented bone loss caused estrogen deficiency. Furthermore, these SERMs did not affect the uterine endometrial thickness and reduced serum cholesterol. These data suggest that SERMs are potential drug for the prevention of osteoporosis in postmenopausal women. PMID:26529929

  2. [Photodynamic modulation of cellular functions].

    Science.gov (United States)

    Li, Yuan; Jiang, Hong-Ning; Cui, Zong-Jie

    2016-08-25

    Photodynamic action, due to the rather limited lifetime (1 μs) and effective reactive distance of singlet oxygen (lysosomes or endoplasmic reticulum can modulate photodynamically subcellular functions and fine-tune protein activity by targeted photooxidation. With the newly emerged active illumination technique, simultaneous photodynamic action localized at multiple sites is now possible, and the contribution of subcellular regions to the whole cell or individual cells to a cell cluster could be quantitated. Photodynamic action with protein photosensitiser will be a powerful tool for nano-manipulation in cell physiology research. PMID:27546513

  3. Angiogenesis: Future of pharmacological modulation

    Directory of Open Access Journals (Sweden)

    Bisht Manisha

    2010-01-01

    Full Text Available Angiogenesis is a fundamental biological process that is regulated by a fine balance between pro- and antiangiogenic molecules, and is deranged in various diseases. Historically, angiogenesis was only implicated in few diseases, such as, cancer, arthritis, and psoriasis. However, in recent years, it has been increasingly evident that excessive, insufficient or abnormal angiogenesis contributes to the pathogenesis of many more disorders. Research in angiogenesis offers a potential to cure a variety of diseases such as Alzheimer′s and AIDS. Modulation of angiogenesis may have an impact on diseases in the twenty-first century similar to that which the discovery of antibiotics had in the twentieth century.

  4. Highly Sensitive Electro-Optic Modulators

    Energy Technology Data Exchange (ETDEWEB)

    DeVore, Peter S [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-26

    There are very important diagnostic and communication applications that receive faint electrical signals to be transmitted over long distances for capture. Optical links reduce bandwidth and distance restrictions of metal transmission lines; however, such signals are only weakly imprinted onto the optical carrier, resulting in low fidelity transmission. Increasing signal fidelity often necessitates insertion of radio-frequency (RF) amplifiers before the electro-optic modulator, but (especially at high frequencies) RF amplification results in large irreversible distortions. We have investigated the feasibility of a Sensitive and Linear Modulation by Optical Nonlinearity (SALMON) modulator to supersede RF-amplified modulators. SALMON uses cross-phase modulation, a manifestation of the Kerr effect, to enhance the modulation depth of an RF-modulated optical wave. This ultrafast process has the potential to result in less irreversible distortions as compared to a RF-amplified modulator due to the broadband nature of the Kerr effect. Here, we prove that a SALMON modulator is a feasible alternative to an RFamplified modulator, by demonstrating a sensitivity enhancement factor greater than 20 and significantly reduced distortion.

  5. Bag-like contaminant control work module

    International Nuclear Information System (INIS)

    A bag-like contaminant control work module is formed from a flexible impervious membrane which is inflated inside of an enclosed workspace to protect workers in the module from contaminants. The workspace, such as in a nuclear power steam generator, has a portal or manway opening into the workspace into which the module is secured by a module passageway. The module includes one or more glove boxes, in which the workers perform their assigned tasks after passing through the passageway and portal. The module includes one or more absolute filters allowing passage of air flow through the module passageway and into the workspace only through the filters. The module may include an auxiliary passageway secured to the outside of the module passageway and also secured in the portal opening and through which items can be passed back and forth to the worker in the glove box from outside the portal. The module is invertible so that it can be pulled out of the workspace trapping all the contaminants therein and disposed of without handling the contaminants

  6. Hybrid multinary modulation using a phase modulating spatial light modulator and a low-pass spatial filter.

    Science.gov (United States)

    Göröcs, Zoltán; Erdei, Gábor; Sarkadi, Tamás; Ujhelyi, Ferenc; Reményi, Judit; Koppa, Pál; Lorincz, Emoke

    2007-08-15

    We propose a method for performing binary intensity and continuous phase modulation of beams with a spatial light modulator (SLM) and a low-pass spatial filtering 4-f system. With our method it is possible to avoid the use of phase masks in holographic data storage systems or to enhance the phase encoding of the SLM by making it capable of binary amplitude modulation. The data storage capabilities and the limitations of the method are studied. PMID:17700777

  7. Polyphosphate as a haemostatic modulator.

    Science.gov (United States)

    Mutch, Nicola J

    2016-02-15

    Platelets are small anuclear cells that play a central role in haemostasis. Platelets become activated in response to various stimuli triggering release of their granular contents into the surrounding milieu. One of these types of granules, termed dense granules, have been found to contain polyphosphate (polyP) in addition to other inorganic biomolecules, such as serotonin, ADP, ATP, PPi. Individuals deficient in dense granules exhibit bleeding tendencies, emphasizing their importance in haemostasis. Platelet polyP is of a relatively defined size, approximately 60-100 phosphate monomers in length. These linear polymers act at various points in the coagulation and fibrinolytic systems thereby modulating the haemostatic response. Due to its highly anionic nature, polyP lends itself to being a natural activator of the contact system. The contact system functions in multiple pathways including coagulation, fibrinolysis, inflammation and complement. Activation of the contact system accelerates thrombin generation, the terminal enzyme in the coagulation cascade. PolyP also modulates factors further downstream in the coagulation cascade to augment thrombin generation. The net effect is increased fibrin formation and platelet activation resulting in faster clot formation. PolyP is incorporated into the forming clot thereby modifying the structure of the resulting fibrin network and its susceptibility to degradation by certain plasminogen activators. In conclusion, release of platelet polyP at the site of injury may facilitate clot formation and augment clot stability thereby promoting wound healing. PMID:26862183

  8. EXOMARS Descent Module GNC Performance

    Science.gov (United States)

    Portigliotti, S.; Capuano, M.; Montagna, M.; Martella, P.; Venditto, P.

    2007-08-01

    The ExoMars mission is the first ESA led robotic mission of the Aurora Programme and combines technology development with investigations of major scientific interest. Italy is by far the major contributor to the mission through the strong support of the Italian Space Agency (ASI). ExoMars will search for traces of past and present life, characterize the Mars geochemistry and water distribution, improve the knowledge of the Mars environment and geophysics, and identify possible surface hazards to future human exploration missions. ExoMars will also validate the technology for safe Entry, Descent and Landing (EDL) of a large size Descent Module (DM) carrying a Rover with medium range surface mobility and the access to subsurface. The ExoMars project is presently undergoing its Phase B1 with Thales Alenia Space-Italia as Industrial Prime Contractor. Additionally, as Descent Module responsible, a dedicated simulation tool is under development in Thales Alenia Space-Italia, Turin site, for the end-to-end design and validation / verification of the DM Entry Descent and Landing.

  9. Nutritional Modulation of Insulin Resistance

    Directory of Open Access Journals (Sweden)

    Martin O. Weickert

    2012-01-01

    Full Text Available Insulin resistance has been proposed as the strongest single predictor for the development of Type 2 Diabetes (T2DM. Chronic oversupply of energy from food, together with inadequate physical activity, have been recognized as the most relevant factors leading to overweight, abdominal adiposity, insulin resistance, and finally T2DM. Conversely, energy reduced diets almost invariably to facilitate weight loss and reduce abdominal fat mass and insulin resistance. However, sustained weight loss is generally difficult to achieve, and distinct metabolic characteristics in patients with T2DM further compromise success. Therefore, investigating the effects of modulating the macronutrient composition of isoenergetic diets is an interesting concept that may lead to additional important insights. Metabolic effects of various different dietary concepts and strategies have been claimed, but results from randomized controlled studies and particularly from longer-term-controlled interventions in humans are often lacking. However, some of these concepts are supported by recent research, at least in animal models and short-term studies in humans. This paper provides an update of the current literature regarding the role of nutrition in the modulation of insulin resistance, which includes the discussion of weight-loss-independent metabolic effects of commonly used dietary concepts.

  10. Natural Compounds Modulating Mitochondrial Functions

    Directory of Open Access Journals (Sweden)

    Lara Gibellini

    2015-01-01

    Full Text Available Mitochondria are organelles responsible for several crucial cell functions, including respiration, oxidative phosphorylation, and regulation of apoptosis; they are also the main intracellular source of reactive oxygen species (ROS. In the last years, a particular interest has been devoted to studying the effects on mitochondria of natural compounds of vegetal origin, quercetin (Qu, resveratrol (RSV, and curcumin (Cur being the most studied molecules. All these natural compounds modulate mitochondrial functions by inhibiting organelle enzymes or metabolic pathways (such as oxidative phosphorylation, by altering the production of mitochondrial ROS and by modulating the activity of transcription factors which regulate the expression of mitochondrial proteins. While Qu displays both pro- and antioxidant activities, RSV and Cur are strong antioxidant, as they efficiently scavenge mitochondrial ROS and upregulate antioxidant transcriptional programmes in cells. All the three compounds display a proapoptotic activity, mediated by the capability to directly cause the release of cytochrome c from mitochondria or indirectly by upregulating the expression of proapoptotic proteins of Bcl-2 family and downregulating antiapoptotic proteins. Interestingly, these effects are particularly evident on proliferating cancer cells and can have important therapeutic implications.

  11. Spontaneous Vesicles Modulated by Polymers

    Directory of Open Access Journals (Sweden)

    Francisco Ortega

    2011-08-01

    Full Text Available Vesicles are widely used in technological applications including cosmetic products, in microencapsulation for drug delivery, as anticancer agents and in the technology of adhesives, paints and inks. The vesicle size and the surface charge are very important properties from a technological point of view. Thus, the challenge in formulation is to find inexpensive stable vesicles with well-defined sizes and to modulate the surface charge of these aggregates. In this work we analyze the effect of different polymers on the structural properties of vesicles of the biodegradable surfactant sodium bis(2-ethyl-hexyl sulfosuccinate, Aerosol OT. Using fluorescence, conductivity, electrophoretic mobility and dynamic light scattering measurements we study the effect of the polymer nature, molecular weight and polymer concentration on the stability and the vesicle size properties. Results demonstrate that it is possible to modulate both the size and the electric surface charge of spontaneous vesicles of Aerosol OT by the addition of very small percentages of poly(allylamine and poly(maleic anhydride-alt-1-octadecen.

  12. Bioelectric modulation of macrophage polarization

    Science.gov (United States)

    Li, Chunmei; Levin, Michael; Kaplan, David L.

    2016-02-01

    Macrophages play a critical role in regulating wound healing and tissue regeneration by changing their polarization state in response to local microenvironmental stimuli. The native roles of polarized macrophages encompass biomaterials and tissue remodeling needs, yet harnessing or directing the polarization response has been largely absent as a potential strategy to exploit in regenerative medicine to date. Recent data have revealed that specific alteration of cells’ resting potential (Vmem) is a powerful tool to direct proliferation and differentiation in a number of complex tissues, such as limb regeneration, craniofacial patterning and tumorigenesis. In this study, we explored the bioelectric modulation of macrophage polarization by targeting ATP sensitive potassium channels (KATP). Glibenclamide (KATP blocker) and pinacidil (KATP opener) treatment not only affect macrophage polarization, but also influence the phenotype of prepolarized macrophages. Furthermore, modulation of cell membrane electrical properties can fine-tune macrophage plasticity. Glibenclamide decreased the secretion and gene expression of selected M1 markers, while pinacidil augmented M1 markers. More interestingly, glibencalmide promoted macrophage alternative activation by enhancing certain M2 markers during M2 polarization. These findings suggest that control of bioelectric properties of macrophages could offer a promising approach to regulate macrophage phenotype as a useful tool in regenerative medicine.

  13. Rogue Waves and Modulational Instability

    Science.gov (United States)

    Zakharov, V. E.; Dyachenko, A.

    2015-12-01

    The most plausible cause of rogue wave formation in a deep ocean is development of modulational instability of quasimonochromatic wave trains. An adequate model for study of this phenomenon is the Euler equation for potential flow of incompressible fluid with free surface in 2-D geometry. Numerical integration of these equations confirms completely the conjecture of rogue wave formation from modulational instability but the procedure is time consuming for determination of rogue wave appearance probability for a given shape of wave energy spectrum. This program can be realized in framework of simpler model using replacement of the exact interaction Hamiltonian by more compact Hamiltonian. There is a family of such models. The popular one is the Nonlinear Schrodinger equation (NLSE). This model is completely integrable and suitable for numerical simulation but we consider that it is oversimplified. It misses such important phenomenon as wave breaking. Recently, we elaborated much more reliable model that describes wave breaking but is as suitable as NLSE from the point of numerical modeling. This model allows to perform massive numerical experiments and study statistics of rogue wave formation in details.

  14. Constructions of Rank Modulation Codes

    CERN Document Server

    Mazumdar, Arya; Zémor, Gilles

    2011-01-01

    Rank modulation is a way of encoding information to correct errors in flash memory devices as well as impulse noise in transmission lines. Modeling rank modulation involves construction of packings of the space of permutations equipped with the Kendall tau distance. We present several general constructions of codes in permutations that cover a broad range of code parameters. In particular, we show a number of ways in which conventional error-correcting codes can be modified to correct errors in the Kendall space. Codes that we construct afford simple encoding and decoding algorithms of essentially the same complexity as required to correct errors in the Hamming metric. For instance, from binary BCH codes we obtain codes correcting $t$ Kendall errors in $n$ memory cells that support the order of $n!/(\\log_2n!)^t$ messages, for any constant $t= 1,2,...$ We also construct families of codes that correct a number of errors that grows with $n$ at varying rates, from $\\Theta(n)$ to $\\Theta(n^{2})$. One of our constr...

  15. An Example of an Indecomposable Module Without Non-Zero Hollow Factor Modules

    OpenAIRE

    Lomp, Christian

    2007-01-01

    A module M is called hollow-lifting if every submodule N of M such that M/N is hollow contains a direct summand D \\subseteq N such that N/D is a small submodule of M/D. A module M is called lifting if such a direct summand D exists for every submodule N. We construct an indecomposable module M without non-zero hollow factor modules, showing that there are hollow-lifting modules which are not lifting. The existences of such modules had been left open in a recent work by N. Orhan, D. Ke...

  16. Optical modulators with 2D layered materials

    Science.gov (United States)

    Sun, Zhipei; Martinez, Amos; Wang, Feng

    2016-04-01

    Light modulation is an essential operation in photonics and optoelectronics. With existing and emerging technologies increasingly demanding compact, efficient, fast and broadband optical modulators, high-performance light modulation solutions are becoming indispensable. The recent realization that 2D layered materials could modulate light with superior performance has prompted intense research and significant advances, paving the way for realistic applications. In this Review, we cover the state of the art of optical modulators based on 2D materials, including graphene, transition metal dichalcogenides and black phosphorus. We discuss recent advances employing hybrid structures, such as 2D heterostructures, plasmonic structures, and silicon and fibre integrated structures. We also take a look at the future perspectives and discuss the potential of yet relatively unexplored mechanisms, such as magneto-optic and acousto-optic modulation.

  17. Modelling of Photovoltaic Module Using Matlab Simulink

    Science.gov (United States)

    Afiqah Zainal, Nurul; Ajisman; Razlan Yusoff, Ahmad

    2016-02-01

    Photovoltaic (PV) module consists of numbers of photovoltaic cells that are connected in series and parallel used to generate electricity from solar energy. The characteristics of PV module are different based on the model and environment factors. In this paper, simulation of photovoltaic module using Matlab Simulink approach is presented. The method is used to determine the characteristics of PV module in various conditions especially in different level of irradiations and temperature. By having different values of irradiations and temperature, the results showed the output power, voltage and current of PV module can be determined. In addition, all results from Matlab Simulink are verified with theoretical calculation. This proposed model helps in better understanding of PV module characteristics in various environment conditions.

  18. Temperature Effect on Photovoltaic Modules Power Drop

    Directory of Open Access Journals (Sweden)

    Qais Mohammed Aish

    2015-06-01

    Full Text Available In order to determine what type of photovoltaic solar module could best be used in a thermoelectric photovoltaic power generation. Changing in powers due to higher temperatures (25oC, 35oC, and 45oC have been done for three types of solar modules: monocrystalline , polycrystalline, and copper indium gallium (di selenide (CIGS. The Prova 200 solar panel analyzer is used for the professional testing of three solar modules at different ambient temperatures; 25oC, 35oC, and 45oC and solar radiation range 100-1000 W/m2. Copper indium gallium (di selenide module has the lowest power drop (with the average percentage power drop 0.38%/oC while monocrystalline module has the highest power drop (with the average percentage power drop 0.54%/oC, while polycrystalline module has a percentage power drop of 0.49%/oC.

  19. Induction accelerator test module for HIF

    International Nuclear Information System (INIS)

    An induction linac test module suitable for investigating the drive requirements and the longitudinal coupling impedance of a high-power ion induction linac has been constructed by the Heavy Ion Fusion (HIF) group at LBL. The induction linac heavy ion driver for inertial confinement fusion (ICF) as presently envisioned uses multiple parallel beams which are transported in separate focusing channels but accelerated together in the induction modules. The resulting induction modules consequently have large beam apertures-1--2 meters in diameter- and correspondingly large outside diameters. The module geometry is related to a low-frequency ''gap capacity'' and high-frequency structural resonances, which are affected by the magnetic core loading and the module pulser impedance. A description of the test module and preliminary results are presented. 3 figs

  20. Allosteric Modulation of Muscarinic Acetylcholine Receptors

    Directory of Open Access Journals (Sweden)

    Esam E. El-Fakahany

    2010-08-01

    Full Text Available An allosteric modulator is a ligand that binds to an allosteric site on the receptor and changes receptor conformation to produce increase (positive cooperativity or decrease (negative cooperativity in the binding or action of an orthosteric agonist (e.g., acetylcholine. Since the identification of gallamine as the first allosteric modulator of muscarinic receptors in 1976, this unique mode of receptor modulation has been intensively studied by many groups. This review summarizes over 30 years of research on the molecular mechanisms of allosteric interactions of drugs with the receptor and for new allosteric modulators of muscarinic receptors with potential therapeutic use. Identification of positive modulators of acetylcholine binding and function that enhance neurotransmission and the discovery of highly selective allosteric modulators are mile-stones on the way to novel therapeutic agents for the treatment of schizophrenia, Alzheimer’s disease and other disorders involving impaired cognitive function.