Acidentes com animais peçonhentos no Brasil: uma revisão integrativa / Accidents with venomous animals in Brazil: an integrative review

Considerados como doenças negligenciadas pela Organização Mundial de Saúde, os acidentes com animais peçonhentos são de grande relevância média por apresentarem altos índices de mortalidade e morbidade. Objetivo - O objetivo desta revisão é apresentar os aspectos epidemiológicos e clínicos dos acidentes com animais peçonhentos no Brasil nos últimos dez anos. Métodos - Foram utilizadas publicações que compreendessem os aspectos clínicos e epidemiológicos de estados, regiões ou municípios brasileiros. Para a revisão foram os artigos foram selecionados em maio de 2020, compreendendo os anos de 2010 a 2020. Resultados e Discussão - Os principais acidentes foram relacionados às serpentes peçonhentas e escorpiões. Nas regiões Sudeste, Norte, Centro-Oeste os acidentes ofídicos foram os mais recorrentes, enquanto que, na região Nordeste, os acidentes com escorpiões e um estudo da região Sul um estudo destacou o araneísmo como principal acidente. Os sinais e sintomas do ofidismo variaram de acordo com o gênero das serpentes, sendo os acidentes com o gênero Bothrops predominante. Os sintomas recorrentes foram: dor, edema, equimose, hemorragia local e sistêmica e alterações na coagulação. O escorpionismo foi causado principalmente pelo gênero Tityus, sendo os casos graves relacionados ao comprometimento pulmonar. Conclusão - Os tipos de acidentes, bem como os sinais e sintomas do envenenamento apresentam muitas variáveis, como região geográfica, gênero e espécie dos animais. A melhoria da qualidade dos dados epidemiológicos e ampliação da assistência em saúde são fatores essenciais para a redução no número de casos de mortalidade e morbidades decorrentes do envenenamento por animais peçonhentos.

Considered as neglected by the World Health Organization, accidents with venomous animals are of great relevance because they have high mortality and morbidity rates. Purpose - This review has the purpose to present the epidemiological and clinical aspects of accidents with venomous animals in Brazil in the past ten years. Methods - Publications were used that understood the clinical and epidemiological aspects of Brazilian states, regions or municipalities. For the review, articles were selected in May 2020, covering the years 2010 to 2020. Results and Discussion - The main accidents were related to venomous snakes and scorpions. In the Southeast, North, and Center-West regions, snakebite accidents were the most recurrent, while in the Northeast region, accidents involving scorpions and a study in the Southern region highlighted accidents with arachnids as the most frequent type of incident. Signs and symptoms of snakebite varied according to the gender of the snakes, with predominance for accidents with the Bothrops genus. Recurring symptoms included pain, edema, ecchymosis, local and systemic hemorrhage, and changes in coagulation. Scorpionism was mainly caused by the Tityus genus, with severe cases presenting pulmonary involvement. Conclusion - The types of accidents, as well as the signs and symptoms of envenomation, present many variables which included geographic region, gender and species of animals. Improving the quality of epidemiological data and expanding health care are essential factors for reducing the number of mortality and morbidity cases resulting from envenomation by venomous animals.

Merging catalysis and supramolecular aggregation features of triptycene based Zn(salphen)s.

A series of trinuclear, triptycene-based metallosalphen complexes (M = Zn, Ni) have been prepared incorporating various peripheral substituents. The introduction of Zn metal centres into these triptycene based salphen ligands gives rise to cross-linking between different triptycene molecules through µ-phenoxo bridges between the Zn metal centres, and variation in the peripheral groups allows the control of the self-assembling properties as shown by UV-Vis titration data. The strong association of these trinuclear Zn3 complexes under relatively apolar conditions has been exploited to recover the complex after its application as a catalyst in the cycloaddition of carbon dioxide to 1,2-epoxyhexane. The catalysis results and recycling studies show that the co-catalyst structure is important for efficient recovery of the binary system, demonstrating that reversible supramolecular aggregation may become a useful tool for recycling homogeneous catalysts.

Supramolecular bulky phosphines comprising 1,3,5-triaza-7-phosphaadamantane and Zn(salphen)s: structural features and application in hydrosilylation catalysis.

The use of the commercially available, bifunctional phosphine 1,3,5-triaza-7-phosphaadamantane (abbreviated as PN3) in conjunction with a series of Zn(salphen) complexes leads to sterically encumbered phosphine ligands as a result of (reversible) coordinative Zn-N interactions. The solid state and solution phase behaviour of these supramolecular ligand systems have been investigated in detail and revealed their stoichiometries in the solid state observed by X-ray crystallography, and those determined in solution by NMR and UV-Vis spectroscopy. Also, upon application of these supramolecular bulky phosphines in hydrosilylation catalysis employing 1-hexene as a substrate, the catalysis data infer the presence of an active Rh species with two coordinated, bulky PN3/Zn(salphen) assembly units having a maximum of three Zn(salphen)s associated per PN3 scaffold, with an excess of bulky phosphines hardly affecting the overall activity.

Metal-directed assembly of chiral bis-Zn(II) Schiff base structures.

Tetra-Schiff bases derived from (chiral) bis-salphen ligand scaffolds furnish, upon metalation with appropriate metal reagents, their multinuclear structures with associated Zn(OAc)(2) or Zn(OH)(2) fragments. The tendency of retaining these salts was investigated using four different (chiral) bis-salphen scaffolds. The presence of the additional Zn ions was supported by NMR studies, mass determinations and X-ray crystallography showing in two cases the possible mode of coordination within these multinuclear structures. In one case, dimerization of the Zn(3) complex leads to a unique hexanuclear Zn(6) complex being a mixture of diastereoisomeric complexes as revealed by NMR spectroscopy.

Isolation and characterization of a new type of mu-hydroxo-bis-Zn(salphen) assembly.

A series of assemblies comprising hydroxo-bridged dinuclear Zn(salphen) structures have been isolated and fully characterized in solution and by X-ray crystallography. The solution stability of these assembled species was evaluated in polar media, in the presence of excess of building blocks and competing ligands. The catalytic potential of this type of complex was investigated in phosphoester cleavage reactions.

Self-assembly of Zn(salphen) complexes: steric regulation, stability studies and crystallographic analysis revealing an unexpected dimeric 3,3'-t-Bu-substituted Zn(salphen) complex.

The self-assembly features of a series of (non)symmetrical Zn(salphen) complexes have been studied in detail by X-ray crystallography, NMR and UV-vis techniques. The combined data demonstrate that the stability of these dimeric assemblies and the relative position of each monomeric unit within the dinuclear structure depend on the location and combination of the aromatic ring substituents.

Assembly of unusual Zn-cluster compounds based on pyridinealcohol platforms.

The assembly formation of Zn cluster compounds comprising pyridinealcohol ligands is described and their solution and solid state features have been determined using NMR spectroscopy and X-ray diffraction. The di-Zn complex 5 and tetra-Zn complex 7 may serve as accessible structural models for the active site of various multinuclear Zn-containing metalloenzymes. Their phosphoester cleavage activity was tested and correlated with their dynamic structural features.

The interaction of native DNA with Zn(II) and Cu(II) complexes of 5-triethyl ammonium methyl salicylidene orto-phenylendiimine.

The interaction of native calf thymus DNA with the Zn(II) and Cu(II) complexes of 5-triethyl ammonium methyl salicylidene orto-phenylendiimine (ZnL(2+) and CuL(2+)), in 1 mM Tris-HCl aqueous solutions at neutral pH, has been monitored as a function of the metal complex-DNA molar ratio by UV absorption spectrophotometry, circular dichroism (CD) and fluorescence spectroscopy. The results support for an intercalative interaction of both ZnL(2+) and CuL(2+) with DNA, showing CuL(2+) an affinity of approximately 10 times higher than ZnL(2+). In particular, the values of the binding constant, determined by UV spectrophotometric titration, equal to 7.3x10(4) and 1.3x10(6)M(-1), for ZnL(2+) and CuL(2+), respectively, indicate the occurrence of a marked interaction with a binding size of about 0.7 in base pairs. The temperature dependence of the absorbance at 258 nm suggests that both complexes strongly increase the DNA melting temperature (Tm) already at metal complex-DNA molar ratios equal to 0.1. As evidenced by the quenching of the fluorescence of ethidium bromide-DNA solutions in the presence of increasing amounts of metal complex, ZnL(2+) and CuL(2+) are able to displace the ethidium cation intercalated into DNA. A tight ZnL(2+)-DNA and CuL(2+)-DNA binding has been also proven by the appearance, in both metal complex-DNA solutions, of a broad induced CD band in the range 350-450 nm. In the case of the CuL(2+)-DNA system, the shape of the CD spectrum, at high CuL(2+) content, is similar to that observed for psi-DNA solutions. Such result allowed us to hypothesize that CuL(2+) induces the formation of supramolecular aggregates of DNA in aqueous solutions.