Immunogenicity and safety of inactivated quadrivalent influenza vaccine compared with the trivalent vaccine for influenza infection: an overview of systematic reviews

Influenza infection is a highly preventable transmissible viral disease associated with mild upper respiratory symptoms and more severe conditions such as lethal pneumonia. Studies have shown that a broader spectrum influenza vaccine could reduce influenza’s burden of disease in low- and middle-income countries. A considerable number of systematic reviews reported that quadrivalent influenza vaccines are considered more effective compared to trivalent vaccines, hence, there is a need for an overview in order to synthesize the current evidence pertaining to the comparison between quadrivalent and trivalent inactivated influenza vaccines. Objective: The aim was to summarize the evidence from systematic reviews that investigated the immunogenicity and safety of the Influenza’s inactivated quadrivalent vaccine (QIV) compared to the trivalent vaccine (TIV), in the general population. Methods We searched articles up to December 2022 at: Web of Science, EMBASE, MEDLINE, Cochrane Library, and SCOPUS. The search strategy was conducted following the PICO model. We included systematic reviews comparing the primary outcomes of immunogenicity (seroprotection rate and seroconversion rate) and adverse events using risk ratios. The AMSTAR 2 and ROBIS were used for quality assessments, and GRADE was used for evidence certainty assessments. Findings We included five systematic reviews, totalling 47,740 participants. The Quadrivalent Inactivated Influenza Vaccine (QIV) exhibited enhanced immunogenicity in the context of B-lineage mismatch when compared to the Trivalent Inactivated Influenza Vaccine (TIV). While the safety profile of QIV was found to be comparable to that of TIV, the QIV showed a higher incidence of solicited local pain among children and adolescents, as well as an increased frequency of local adverse events within the adult population. Conclusion Our findings suggest that the QIV provides a superior immunogenicity response compared to the TIV in all age groups evaluated, especially when a lineage mismatch occurred. The safety of QIV was considered similar to the TIV, with no serious or systemic solicited or unsolicited adverse events; tough pain at the injection site was greater for QIV. We recommend caution owing to the high risk of bias in the selection process and no protocol registration.

A randomized, double-blind, non-inferiority trial comparing the immunogenicity and safety of two seasonal inactivated influenza vaccines in adults

Background To enhance the production and availability of influenza vaccines in different regions of the world is paramount to mitigate the global burden of this disease. Instituto Butantan developed and manufactured an embryonated egg-based inactivated split-virion trivalent seasonal influenza vaccine as part of a technology transfer partnership with Sanofi Pasteur. Methods This is a phase IV, randomized, double-blind, active-controlled, multicenter clinical trial including adults 18–60 and > 60 years recruited during the 2019 southern hemisphere influenza season. Subjects were randomized 1:1 to receive either the Sanofi Pasteur Trivalent Seasonal Influenza Vaccine (SP-TIV) or Instituto Butantan Trivalent Seasonal Influenza Vaccine (IB-TIV). Hemagglutinin inhibition antibody titers were assessed pre-vaccination and 21 days post-vaccination. Results 624 participants were randomized and vaccinated. In both intention-to-treat and per-protocol analysis, non-inferiority of the SP-TIV versus IB-TIV was demonstrated for the three influenza strains. In the per-protocol analysis, the SP-GMT/IB-GMT ratios for H1N1, H3N2, and B were 0.9 (95%CI, 0.7–1.1), 1.2 (95%CI, 1.0–1.4), and 1.1 (95%CI, 0.9–1.3), respectively. Across vaccination groups, the most common adverse reactions (AR) were limited to the injection-site, including pain and tenderness. The majority of the ARs were graded 1 and/or 2 and lasted less than one day. No serious adverse reaction was observed. Conclusion This study demonstrated the non-inferiority of the immunogenicity of a single-dose of Instituto Butantan versus a single dose of the Sanofi Pasteur Seasonal Trivalent Influenza Vaccine in adults. Both vaccines were well tolerated and presented similar safety profiles.

Dose-sparing effect of two adjuvant formulations with a pandemic influenza A/H7N9 vaccine: A randomized, double-blind, placebo-controlled, phase 1 clinical trial.

The emergence of potentially pandemic viruses has resulted in preparedness efforts to develop candidate vaccines and adjuvant formulations. We evaluated the dose-sparing effect and safety of two distinct squalene-based oil-in-water adjuvant emulsion formulations (IB160 and SE) with influenza A/H7N9 antigen. This phase I, randomized, double-blind, placebo-controlled, dose-finding trial (NCT03330899), enrolled 432 healthy volunteers aged 18 to 59. Participants were randomly allocated to 8 groups: 1A) IB160 + 15µg H7N9, 1B) IB160 + 7.5µg H7N9, 1C) IB160 + 3.75µg H7N9, 2A) SE + 15µg H7N9, 2B) SE + 7.5µg H7N9, 2C) SE + 3.75µg H7N9, 3) unadjuvanted vaccine 15µg H7N9 and 4) placebo. Immunogenicity was evaluated through haemagglutination inhibition (HI) and microneutralization (MN) tests. Safety was evaluated by monitoring local and systemic, solicited and unsolicited adverse events (AE) and reactions (AR) 7 and 28 days after each study injection, respectively, whereas serious adverse events (SAE) were monitored up to 194 days post-second dose. A greater increase in antibody geometric mean titers (GMT) was observed in groups receiving adjuvanted vaccines. Vaccinees receiving IB160-adjuvanted formulations showed the greatest response in group 1B, which induced an HI GMT increase of 4.7 times, HI titers ≥40 in 45.2% of participants (MN titers ≥40 in 80.8%). Vaccinees receiving SE-adjuvanted vaccines showed the greatest response in group 2A, with an HI GMT increase of 2.5 times, HI titers ≥40 in 22.9% of participants (MN titers ≥40 in 65.7%). Frequencies of AE and AR were similar among groups. Pain at the administration site and headache were the most frequent local and systemic solicited ARs. The vaccine candidates were safe and the adjuvanted formulations have a potential dose-sparing effect on immunogenicity against influenza A/H7N9. The magnitude of this effect could be further explored.

Dose-sparing effect of two adjuvant formulations with a pandemic influenza A/H7N9 vaccine: a randomized, double-blind, placebo-controlled, phase 1 clinical trial

The emergence of potentially pandemic viruses has resulted in preparedness efforts to develop candidate vaccines and adjuvant formulations. We evaluated the dose-sparing effect and safety of two distinct squalene-based oil-in-water adjuvant emulsion formulations (IB160 and SE) with influenza A/H7N9 antigen. This phase I, randomized, double-blind, placebo-controlled, dose-finding trial (NCT03330899), enrolled 432 healthy volunteers aged 18 to 59. Participants were randomly allocated to 8 groups: 1A) IB160 + 15μg H7N9, 1B) IB160 + 7.5μg H7N9, 1C) IB160 + 3.75μg H7N9, 2A) SE + 15μg H7N9, 2B) SE + 7.5μg H7N9, 2C) SE + 3.75μg H7N9, 3) unadjuvanted vaccine 15μg H7N9 and 4) placebo. Immunogenicity was evaluated through haemagglutination inhibition (HI) and microneutralization (MN) tests. Safety was evaluated by monitoring local and systemic, solicited and unsolicited adverse events (AE) and reactions (AR) 7 and 28 days after each study injection, respectively, whereas serious adverse events (SAE) were monitored up to 194 days post-second dose. A greater increase in antibody geometric mean titers (GMT) was observed in groups receiving adjuvanted vaccines. Vaccinees receiving IB160-adjuvanted formulations showed the greatest response in group 1B, which induced an HI GMT increase of 4.7 times, HI titers ≥40 in 45.2% of participants (MN titers ≥40 in 80.8%). Vaccinees receiving SE-adjuvanted vaccines showed the greatest response in group 2A, with an HI GMT increase of 2.5 times, HI titers ≥40 in 22.9% of participants (MN titers ≥40 in 65.7%). Frequencies of AE and AR were similar among groups. Pain at the administration site and headache were the most frequent local and systemic solicited ARs. The vaccine candidates were safe and the adjuvanted formulations have a potential dose-sparing effect on immunogenicity against influenza A/H7N9. The magnitude of this effect could be further explored.

Active pharmacovigilance of the seasonal trivalent influenza vaccine produced by Instituto Butantan: A prospective cohort study of five target groups.

INTRODUCTION: Active pharmacovigilance studies are pivotal to better characterize vaccine safety. METHODS: These are multicenter prospective cohort studies to evaluate the safety of the 2017 and 2018 seasonal trivalent influenza vaccines (TIVs) manufactured by Instituto Butantan, by means of active pharmacovigilance practices. Elderly, children, healthcare workers, pregnant women, and women in the puerperium period were invited to participate in the study during the 2017 and 2018 Brazilian national seasonal influenza vaccination campaigns. Following immunization, participants were observed for 30 minutes and they received a participant card to register adverse events information. All safety information registered were checked at a clinical site visit 14 days after immunization and by a telephone contact 42 days after immunization for unsolicited Adverse Events (AE) and Guillain-Barré Syndrome (GBS). RESULTS: A total of 942 volunteers participated in the two studies: 305 elderly, 109 children, 108 pregnant women, 32 women in the postpartum period, and 388 health workers. Overall, the median number of AR per participant ranged from 1 to 4. The lowest median number of AR per participant was observed among healthcare workers (1 AR per participant) and the highest among pregnant women (4 AR per participant). Overall, local pain (46.6%) was the most frequent solicited local AR. The most frequent systemic ARs were: headache (22.5%) followed by fatigue (16.0%), and malaise (11.0%). The majority of solicited ARs (96%) were mild, Grades 1 or 2), only 3% were Grade 3, and 1% was Grade 4. No serious AEs, including Guillain-Barré Syndrome, were reported up to 42 days postvaccination. CONCLUSION: The results from the two studies confirmed that the 2017 and 2018 seasonal trivalent influenza vaccines produced by Instituto Butantan were safe and that active pharmacovigilance studies should be considered, when it is feasible, as an important initiative to monitor vaccine safety in the post-marketing period.

Active pharmacovigilance of the seasonal trivalent influenza vaccine produced by Instituto Butantan: a prospective cohort study of five target groups

Active pharmacovigilance studies are pivotal to better characterize vaccine safety. Methods: These are multicenter prospective cohort studies to evaluate the safety of the 2017 and 2018 seasonal trivalent influenza vaccines (TIVs) manufactured by Instituto Butantan, by means of active pharmacovigilance practices. Elderly, children, healthcare workers, pregnant women, and women in the puerperium period were invited to participate in the study during the 2017 and 2018 Brazilian national seasonal influenza vaccination campaigns. Following immunization, participants were observed for 30 minutes and they received a participant card to register adverse events information. All safety information registered were checked at a clinical site visit 14 days after immunization and by a telephone contact 42 days after immunization for unsolicited Adverse Events (AE) and Guillain-Barré Syndrome (GBS). Results: A total of 942 volunteers participated in the two studies: 305 elderly, 109 children, 108 pregnant women, 32 women in the postpartum period, and 388 health workers. Overall, the median number of AR per participant ranged from 1 to 4. The lowest median number of AR per participant was observed among healthcare workers (1 AR per participant) and the highest among pregnant women (4 AR per participant). Overall, local pain (46.6%) was the most frequent solicited local AR. The most frequent systemic ARs were: headache (22.5%) followed by fatigue (16.0%), and malaise (11.0%). The majority of solicited ARs (96%) were mild, Grades 1 or 2), only 3% were Grade 3, and 1% was Grade 4. No serious AEs, including Guillain-Barré Syndrome, were reported up to 42 days postvaccination. Conclusion: The results from the two studies confirmed that the 2017 and 2018 seasonal trivalent influenza vaccines produced by Instituto Butantan were safe and that active pharmacovigilance studies should be considered, when it is feasible, as an important initiative to monitor vaccine safety in the post-marketing period.

Epidemiologia dos acidentes por animais peçonhentos e a distribuição de soros: estado de arte e a situação mundial / Epidemiology of accidents by venomous animals and distribution of antivenon: state of art and world status / Epidemiología de accidentes por animales venenosos y distribución de suero: estado de arte y situación mundial

RESUMO Acidentes por animais peçonhentos são discutidos sob perspectiva histórica de ações de estado. Considerados doenças negligenciadas eles causam prejuízos sociais e econômicos, em pessoas em idade produtiva de regiões rurais em países pobres. Poucos países dispõem de políticas públicas de saúde para profilaxia e tratamento adequados e as maiores perdas ocorrem na África e Ásia. Os 46 produtores mundiais de soros não suprem as necessidades globais e acesso ao tratamento é difícil, mesmo em países com produção própria. Sistemas de Notificação produzem levantamentos imprecisos sobre necessidades de soro e apesar da notificação compulsória. O Brasil carece de bancos de dados robustos de amplo acesso, que permita uma distribuição do soro em tempo seguro para o atendimento de qualidade. Muito se avançou em testes diagnóstico, porém sua aplicação em áreas pobres é inviabilizada pelos custos. Melhorias na qualidade de produção dos soros, via boas práticas laboratoriais e fabris, minimizam resultados insatisfatórios de tratamentos com produtos de origem e ação duvidosa. Desenvolvimento de soros empregando Biotecnologia e Ensaios Clínicos bem desenhados, são chave para tratamento de envenenamentos por agentes aparentados em diferentes regiões (soros continentais ou universais). Parcerias internacionais são fundamentais, além de estoques reguladores, semelhantes aos adotados em vacinas, para suprir a demanda mundial. A qualificação dos soros antivenenos certamente minimizará equívocos de uso. Apoio governamental à pesquisa é alavanca propulsora e a ferramenta mais eficiente de preservação da vida, evitando sobrecargas social e previdenciária principalmente em países em desenvolvimento.(AU)

ABSTRACT Accidents by venomous animals are discussed under the historical perspective of state actions. Considered as neglected diseases, they cause social and economic losses in the working age population from rural areas of poor countries, as few of them have public health policies for adequate prophylaxis and treatment; in fact, the largest life losses occur in Africa and Asia. The 46 world producers of antivenin do not meet the global needs, making access to treatment difficult, even in countries with own production. Notification systems lead to inaccurate surveillance surveys and antivenin needs. Despite mandatory notification, Brazil lacks robust databases with full open access in order to allow the timely distribution of antivenin for quality care of these patients. Progress has been made in diagnostic testing, but its application in poor areas is not feasible due to high costs. Improvements in quality antivenin production through good laboratory practices and manufacturing minimize unsatisfactory results of treatments carried out with products of dubious origin. Antivenin development using biotechnology and well-designed clinical trials are key for the treatment of envenoming by agents phylogenetically related from different regions (continental or universal antivenins). International partnerships are fundamental, besides regulatory stocks, similarly to those adopted for vaccines, to supply world demand. The qualification of antivenin will certainly minimize treatment mistakes. Government support to research is a driving force and the most efficient tool for preserving life and avoiding social security surcharges, particularly in developing countries.(AU)

RESUMEN Accidentes por animales venenosos se discuten desde una perspectiva histórica de acciones de estado. Consideradas enfermedades olvidadas, causan perjuicios sociales y económicos, en personas en edad productiva de regiones rurales en países pobres. Pocos países disponen de políticas públicas de salud para profilaxis y tratamiento adecuados y las mayores pérdidas ocurren en África y Asia. Los 46 productores mundiales de sueros no suplen las necesidades globales y el acceso al tratamiento es difícil, incluso en países con producción propia. Los sistemas de notificación generan levantamientos imprecisos sobre las necesidades de suero ya pesar de la notificación obligatoria, Brasil carece de bases de datos robustas de amplio acceso, permitiendo la llegada del suero en tiempo seguro para la atención de calidad. Se ha avanzado mucho en pruebas diagnósticas, pero su aplicación en áreas pobres es inviabilizada por los costos. Mejoras en la calidad de producción de los sueros, a través de buenas prácticas de laboratorio y fabril, minimizan resultados insatisfactorios de tratamientos con productos de origen y acción dudosa. El desarrollo de sueros empleando Biotecnología y Ensayos Clínicos bien diseñados, son clave para el tratamiento de envenenamientos por agentes emparentados en diferentes regiones (sueros continentales o universales). Las alianzas internacionales son fundamentales, además de stocks reguladores, similares a los adoptados en vacunas, para suplir la demanda mundial. La pre cualificación de los sueros antivenenos ciertamente minimizará equívocos de uso. El apoyo gubernamental a la investigación es la palanca propulsora y la herramienta más eficiente de preservación de la vida, evitando sobrecargas social y previsional principalmente en países en desarrollo.(AU)

Epidemiologia dos acidentes por animais peçonhentos e a distribuição de soros: estado de arte e a situação mundial / Epidemiology of accidents by venomous animals and distribution of antivenon / Epidemiología de accidentes por animales venenosos y distribución de suero

Acidentes por animais peçonhentos são discutidos sob perspectiva histórica de ações de estado. Considerados doenças negligenciadas eles causam prejuízos sociais e econômicos, em pessoas em idade produtiva de regiões rurais em países pobres. Poucos países dispõem de políticas públicas de saúde para profilaxia e tratamento adequados e as maiores perdas ocorrem na África e Ásia. Os 46 produtores mundiais de soros não suprem as necessidades globais e acesso ao tratamento é difícil, mesmo em países com produção própria. Sistemas de Notificação produzem levantamentos imprecisos sobre necessidades de soro e apesar da notificação compulsória. O Brasil carece de bancos de dados robustos de amplo acesso, que permita uma distribuição do soro em tempo seguro para o atendimento de qualidade. Muito se avançou em testes diagnóstico, porém sua aplicação em áreas pobres é inviabilizada pelos custos. Melhorias na qualidade de produção dos soros, via boas práticas laboratoriais e fabris, minimizam resultados insatisfatórios de tratamentos com produtos de origem e ação duvidosa. Desenvolvimento de soros empregando Biotecnologia e Ensaios Clínicos bem desenhados, são chave para tratamento de envenenamentos por agentes aparentados em diferentes regiões (soros continentais ou universais). Parcerias internacionais são fundamentais, além de estoques reguladores, semelhantes aos adotados em vacinas, para suprir a demanda mundial. A qualificação dos soros antivenenos certamente minimizará equívocos de uso. Apoio governamental à pesquisa é alavanca propulsora e a ferramenta mais eficiente de preservação da vida, evitando sobrecargas social e previdenciária principalmente em países em desenvolvimento.

Epidemiologia dos acidentes por animais peçonhentos e a distribuição de soros: estado de arte e a situação mundial / Epidemiology of accidents by venomous animals and distribution of antivenon

Acidentes por animais peçonhentos são discutidos sob perspectiva histórica de ações de estado. Considerados doenças negligenciadas eles causam prejuízos sociais e econômicos, em pessoas em idade produtiva de regiões rurais em países pobres. Poucos países dispõem de políticas públicas de saúde para profilaxia e tratamento adequados e as maiores perdas ocorrem na África e Ásia. Os 46 produtores mundiais de soros não suprem as necessidades globais e acesso ao tratamento é difícil, mesmo em países com produção própria. Sistemas de Notificação produzem levantamentos imprecisos sobre necessidades de soro e apesar da notificação compulsória. O Brasil carece de bancos de dados robustos de amplo acesso, que permita uma distribuição do soro em tempo seguro para o atendimento de qualidade. Muito se avançou em testes diagnóstico, porém sua aplicação em áreas pobres é inviabilizada pelos custos. Melhorias na qualidade de produção dos soros, via boas práticas laboratoriais e fabris, minimizam resultados insatisfatórios de tratamentos com produtos de origem e ação duvidosa. Desenvolvimento de soros empregando Biotecnologia e Ensaios Clínicos bem desenhados, são chave para tratamento de envenenamentos por agentes aparentados em diferentes regiões (soros continentais ou universais). Parcerias internacionais são fundamentais, além de estoques reguladores, semelhantes aos adotados em vacinas, para suprir a demanda mundial. A qualificação dos soros antivenenos certamente minimizará equívocos de uso. Apoio governamental à pesquisa é alavanca propulsora e a ferramenta mais eficiente de preservação da vida, evitando sobrecargas social e previdenciária principalmente em países em desenvolvimento.

Accidents by venomous animals are discussed under the historical perspective of state actions. Considered as neglected diseases, they cause social and economic losses in the working age population from rural areas of poor countries, as few of them have public health policies for adequate prophylaxis and treatment; in fact, the largest life losses occur in Africa and Asia. The 46 world producers of antivenin do not meet the global needs, making access to treatment difficult, even in countries with own production. Notification systems lead to inaccurate surveillance surveys and antivenin needs. Despite mandatory notification, Brazil lacks robust databases with full open access in order to allow the timely distribution of antivenin for quality care of these patients. Progress has been made in diagnostic testing, but its application in poor areas is not feasible due to high costs. Improvements in quality antivenin production through good laboratory practices and manufacturing minimize unsatisfactory results of treatments carried out with products of dubious origin. Antivenin development using biotechnology and well-designed clinical trials are key for the treatment of envenoming by agents phylogenetically related from different regions (continental or universal antivenins). International partnerships are fundamental, besides regulatory stocks, similarly to those adopted for vaccines, to supply world demand. The qualification of antivenin will certainly minimize treatment mistakes. Government support to research is a driving force and the most efficient tool for preserving life and avoiding social security surcharges, particularly in developing countries.

Accidentes por animales venenosos se discuten desde una perspectiva histórica de acciones de estado. Consideradas enfermedades olvidadas, causan perjuicios sociales y económicos, en personas en edad productiva de regiones rurales en países pobres. Pocos países disponen de políticas públicas de salud para profilaxis y tratamiento adecuados y las mayores pérdidas ocurren en África y Asia. Los 46 productores mundiales de sueros no suplen las necesidades globales y el acceso al tratamiento es difícil, incluso en países con producción propia. Los sistemas de notificación generan levantamientos imprecisos sobre las necesidades de suero ya pesar de la notificación obligatoria, Brasil carece de bases de datos robustas de amplio acceso, permitiendo la llegada del suero en tiempo seguro para la atención de calidad. Se ha avanzado mucho en pruebas diagnósticas, pero su aplicación en áreas pobres es inviabilizada por los costos. Mejoras en la calidad de producción de los sueros, a través de buenas prácticas de laboratorio y fabril, minimizan resultados insatisfactorios de tratamientos con productos de origen y acción dudosa. El desarrollo de sueros empleando Biotecnología y Ensayos Clínicos bien diseñados, son clave para el tratamiento de envenenamientos por agentes emparentados en diferentes regiones (sueros continentales o universales). Las alianzas internacionales son fundamentales, además de stocks reguladores, similares a los adoptados en vacunas, para suplir la demanda mundial. La pre cualificación de los sueros antivenenos ciertamente minimizará equívocos de uso. El apoyo gubernamental a la investigación es la palanca propulsora y la herramienta más eficiente de preservación de la vida, evitando sobrecargas social y previsional principalmente en países en desarrollo.

Topographical Anatomy of the Blunthead Treesnake, Imantodes cenchoa (Linnaeus, 1758) (Colubridae: Xenodontinae) / Anatomía Topográfica de la Serpiente Bejucillo Cabezona, Imantodes cenchoa (Linnaeus, 1758) (Colubridae: Xenodontinae)

Imantodes cenchoa (Duméril, 1853) is an arboreal, nocturnal and oviparous xenodontine snake, which feeds on amphibians and lizards. It is found in Central and South America, including northern and central Brazil. In this work, we investigated the relationship between topographic anatomy and habitat in I. cenchoa. Twenty specimens (13 non pregnant females and 7 males) were examined. The topographic anatomy study was realized through observations of the internal anatomy, particularly the position and size of lung, heart, liver, left and right gonads and left and right kidneys. Results showed that all the organs are located in a posterior position in relation to the snout vent length (SVL). The centre of gravity is found at about 74% of SVL in both males and females. In males, no positive allometry was observed among the positions of the organs. Negative allometry in females was observed regarding the position of the anterior tip of the left kidney, the anterior and posterior tips of the right kidney and in both ovaries. In males, negative allometry is present in the position of all the organs. The distance between the last follicle and the cloaca was 8.78% of SVL. Our data corroborate the idea that the posterior position of all internal organs is linked to a habitat specialization of a snake, linking the arboreal species I. cenchoa with a relatively posterior internal topography.

Imantodes cenchoa (Duméril, 1853) es una serpiente xenodontinea, arbórea, noctura y ovípara, que se alimenta de anfibios y largartos. Se encuenta en América Central y del Sur, incluyendo las partes Norte y Central de Brasil. En este trabajo, investigamos la relaciones entre la Anatomía Topográfica y hábitat en I. cenchoa. Fueron examinados 20 especímenes (13 hembras no preñadas y 7 machos). El estudio de la Anatomía Topográfica fue realizada a través de observaciones de la anatomía interna, particularmente la posición y tamaño del pulmón, corazón, hígado, gónadas y riñones derechos e izquierdos. Los resultados mostraron que todos los órganos están localizados en una posición posterior, en relación a la entrada de la longitud del hocico(SVL). El centro de gravedad se encuentra a 74% de SVL en machos y hembras. En los machos, no fue observada alometría positiva entre la posición de los órganos. Fue observada alometría negativa en las hembras, considerando la posición del extremo anterior del riñón izquierdo, los extremos anterior y posterior del riñón derecho y ambos ovarios. En machos, se presentó alometría negativa en la posición de todos los órganos. La distancia entre el último folículo y la cloaca fue 8.78% de SVL. Nuestros datos corroboran la idea que la posición posterior de todos los órganos internos está marcada por una especialización al hábitat de una serpiente, marcando la especie arbórea I. cenchoa con una especial topografía interna posterior.

Tracing an invasion: landbridges, refugia, and the phylogeography of the Neotropical rattlesnake (Serpentes: Viperidae: Crotalus durissus).

Abstract Pleistocene fragmentation of the Amazonian rainforest has been hypothesized to be a major cause of Neotropical speciation and diversity. However, the role and even the reality of Pleistocene forest refugia have attracted much scepticism. In Amazonia, previous phylogeographical studies have focused mostly on organisms found in the forests themselves, and generally found speciation events to have predated the Pleistocene. However, molecular studies of open-formation taxa found both north and south of the Amazonian forests, probably because of vicariance resulting from expansion of the rainforests, may provide novel insights into the age of continuous forest cover across the Amazon basin. Here, we analyse three mitochondrial genes to infer the phylogeography of one such trans-Amazonian vicariant, the Neotropical rattlesnake (Crotalus durissus), which occupies primarily seasonal formations from Mexico to Argentina, but avoids the rainforests of Central and tropical South America. The phylogeographical pattern is consistent with gradual dispersal along the Central American Isthmus, followed by more rapid dispersal into and across South America after the uplift of the Isthmus of Panama. Low sequence divergence between populations from north and south of the Amazon rainforest is consistent with mid-Pleistocene divergence, approximately 1.1 million years ago (Ma). This suggests that the Amazonian rainforests must have become fragmented or at least shrunk considerably during that period, lending support to the Pleistocene refugia theory as an important cause of distribution patterns, if not necessarily speciation, in Amazonian forest organisms. These results highlight the potential of nonforest species to contribute to an understanding of the history of the Amazonian rainforests themselves.

Hemorrhagic, fibrinogenolytic and edema-forming activities of the venom of the colubrid snake Philodryas olfersii (green snake)

The venom of P. olfersii has high hemorrhagic, edema-inducing and fibrin(ogen)olytic activities. It is devoid of thrombin-like, procoagulant, phospholipase A2 and platelet aggregating enzymes. The main activities are metalloproteinases inhibited by metal chelators (EDTA and 1,10-phenanthroline) and sulfhydryl compounds (DTT and cysteine). The hemorrhagic and fibrinogenolytic enzymes were partially purified by gel filtration on HPLC. The hemorrhagic activity of the venom was neutralized by commercial horse antivenoms to Bothrops species, as well as by rabbit antisera specific for hemorrhagic factors isolated from these Bothrops venoms. No immunoprecipitin reactions were obtained, indicating that the few epitopes of the P. olfersii hemorrhagin are involved in these neutralization reactions. The fibrinogenolytic enzyme cleaves A á-chain more quickly than the B â-chain of human fibrinogen. The venom also solubilizes fibrin. This solubilization appears to occur from the hydrolysis of unpolymerized á-chain and cross-linked ã-ã dimer. The fibrin peptide products are distinct from those produced by plasmin.