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Physicochemical characterization of commercial freeze-dried snake antivenoms
(2016-02) Herrera Vega, María; Solano Centeno, Daniela; Gómez Argüello, Aarón; Villalta Arrieta, Mauren; Vargas Arroyo, Mariángela; Sánchez Brenes, Andrés; Gutiérrez, José María; León Montero, Guillermo
Freeze-drying is a process used to improve the stability of pharmaceutical proteins, including snake antivenoms. This additional step confers these with a higher stability in comparison to liquid formulations, especially in tropical regions where high temperatures could affect the activity of immunoglobulins. Currently, the knowledge about freeze-drying process conditions for snake antivenoms is very limited. Some of the scarce scientific works on this subject reported reconstitution times up to 90 min for these preparations, which could imply a delay in the beginning of the antivenom therapy at the clinical setting. Therefore there is a reasonable concern about whether freeze-dried antivenoms exhibit the desired attributes for solid pharmaceutical proteins. In this work, a physicochemical characterization of seven commercial freeze-dried snake antivenoms was performed based on tests recommended by the World Health Organization (WHO). No significant differences were observed between the products regarding macroscopic appearance of the solid cakes, reconstitution times, residual humidity and monomers content. On the other hand, total protein concentration, turbidity and electrophoretic profile were different among samples. Microscopic analysis by scanning electron microscopy showed no collapsed structure and, instead, most of the samples showed a characteristic protein morphology composed of smooth plates and channels. All the parameters tested in this study were according to literature recommendations and evidenced that, in spite of slight variations found for some products, formulation and freeze-drying conditions chosen by manufacturers are adequate to prevent aggregation and generate, in physicochemical terms, freeze-dried antivenoms of acceptable quality.
Role of nitric oxide and signaling pathways modulating the stimulatory effect of snake venom secretory PLA2S on non-opsonized zymosan phagocytosis by macrophages
(2024-05-28) Zuliani Trench de Souza, Juliana Pavan; Gutiérrez, José María; Pereira Teixeira, Catarina de Fátima
The phagocytic activity of macrophages activated with MT-II, a Lys-49 PLA2 homolog, and MT-III, an Asp-49 PLA2, from Bothrops asper snake venom, was investigated in this study using a pharmacological approach. Stimulating thioglycollate-elicited macrophages with both venom components enhanced their ability to phagocytose non-opsonized zymosan particles. MT-II and MT–III–induced phagocytosis was drastically inhibited by pretreating cells with L-NAME, aminoguanidine or L-NIL, cNOS or iNOS inhibitors, or with ODQ (sGC inhibitor) or Rp-cGMPS (PKG inhibitor). These results indicate that the NO/sGC/GMP/PKG pathway plays an essential role in the β-glucan-mediated phagocytosis induced in macrophages by these venom-secretory PLA2s.
PKC-α is involved in the signaling of phagocytosis induced by two snake venom secretory PLA2S in macrophages
(2024-08-28) Pavan Zuliani, Juliana; Yamanouye, Norma; Gutiérrez, José María; Pereira Teixeira, Catarina de Fátima
Phagocytosis, an essential process for host defense, requires the coordination of a variety of signaling reactions. MT-II, an enzymatically inactive Lys49 phospholipase A2 (PLA2) homolog, and MT-III, a catalytically-active Asp49 PLA2, are known to activate phagocytosis in macrophages. In this study, the signaling pathways mediating phagocytosis, focusing on protein kinases, were investigated. Macrophages from male Swiss mice peritoneum were obtained 96 h after intraperitoneal thioglycolate injection. Phagocytosis was evaluated using non-opsonized zymosan particles in the presence or absence of specific inhibitors, as well as PKC and PKC-α localization by confocal microscopy. Moreover, protein kinase C (PKC) activity was assessed by γP32 ATP in macrophages stimulated by both PLA2s. Data showed that both sPLA2s increased phagocytosis. Cytochalasin D, staurosporine/H7, wortmannin, and herbimycin, inhibitors of actin polymerization, PKC, phosphoinositide 3-kinase (PI3K), and protein tyrosine kinase (PTK), respectively, significantly reduced phagocytosis induced by both PLA2s. PKC activity was increased in macrophages stimulated by both PLA2s. Actin polymerization and talin were evidenced by immunofluorescence and talin was recruited 5 min after both PLA2s stimulation. PKC and PKC-α localization within the cell were increased after 60 min of MT-II and MT-III stimulation. These data suggest that the effect of both PLA2s depends on actin cytoskeleton rearrangements and the activation of PKC, PI3K, and PTK signaling events required for phagocytosis.
A new nothogenus and nothospecies in the Zygopetalinae (Orchidaceae), with a note on euglossine pollination in the subtribe
(2025-11-15) Pupulin, Franco; Karremans Lok, Adam Philip; Salas Hidalgo, Elvira
Natural hybridization in Neotropical orchids is summarized, and the frequency of notho genera in the subtribe Zygopetalinae is highlighted. A new nothogenus discovered in Costa Rica, formed by the cross between species of Benzingia and Chondroscaphe, is described, and the new nothospecies ×Benzoscaphe stelleri is described and illustrated.
Putative parents, as well as their derivative hybrid, are compared through composite digital plates. Cues are offered about the pollination mechanisms of the putative parents, based on the morphology of the flowers and pollinaria, which possibly led to the formation of the natural cross between different genera.
La tuba como amplificador de una voz: estudio auto-etnográfico de siete obras para tuba creadas por personas compositoras costarricenses
(2025) Jiménez Camacho, Diego; Chinchilla Meza, Iván
Esta monografía propone una reflexión sobre la relación entre la práctica interpretativa y la construcción del repertorio nacional para tuba en Costa Rica. A través de un enfoque auto-etnográfico, el estudio se centra en la experiencia del intérprete-investigador como punto de partida para comprender los procesos técnicos, estéticos y culturales que surgen al abordar obras contemporáneas costarricenses.
El objetivo de este trabajo es generar información mediante la experiencia adquirida en el proceso del montaje de las obras seleccionadas, para obtener una fuente de consulta sobre las obras, las personas compositoras y las técnicas usadas para resolver los distintos retos que se presentaron.
Por medio de la auto-etnografía se trabajaron siete obras compuestas por personas compositoras costarricenses. Usando métodos como la entrevista, la encuesta y la búsqueda de fuentes, se complemento el trabajo personal del interprete que, junto con su experiencia y conocimiento adquirido, llevo a cabo la exploración.
La investigación busca responder a la pregunta: ¿de qué manera la experiencia interpretativa de siete obras costarricenses para tuba contribuye al desarrollo técnico, estético y cultural del intérprete y, al mismo tiempo, al fortalecimiento del repertorio nacional? Los resultados evidencian que la interpretación de estas obras no solo amplía las posibilidades técnicas y expresivas del instrumento, sino que también fomenta una reflexión crítica sobre el lugar de la tuba en el contexto académico y cultural costarricense. Asimismo, el proceso auto-etnográfico permitió al intérprete profundizar en su identidad artística, reconociendo la interdependencia entre creación, ejecución y pertenencia cultural.