Margem de segurança do meloxicam em cães: efeitos deletérios nas células sangüíneas e trato gastrintestinal Margin of safety of meloxicam in dogs: deleterious effects on blood cells and gastrointestinal tract

Este trabalho investigou a margem de segurança do inibidor COX-2, meloxicam, em cães, enfocando seus efeitos deletérios nas células sangüíneas e no trato gastrintestinal. Para tanto, após uma avaliação clínico-laboratorial, os cães foram distribuídos nos seguintes grupos: I (placebo; n= 3), II (piroxicam; 1,0mg kg-1; n= 5), III (meloxicam; 0,2mg kg-1; n= 5), IV (meloxicam;1,0mg kg-1; n= 5) e V (meloxicam; 2,0mg kg-1; n= 5). Os fármacos foram usados, por via oral, por 16 dias. No 17&ordm; dia, repetiu-se o hemograma completo e, então, procedeu-se a eutanásia seguida pela necrópsia. No grupo I, não houve alterações dignas de nota. No grupo II, todos os cães apresentaram episódios moderados de vômito e diarréia. O perfil celular sangüíneo não foi significativamente modificado. Em dois cães, houve redução no hematócrito e na hemoglobina. Na necropsia, observaram-se focos hemorrágicos e lesões gastriduodenais moderadas. A análise microscópica revelou a presença de gastrite e enterite ulcerativa. No grupo III, quatro cães (80%) apresentaram vômito e diarréia, sem alteração no perfil celular sangüíneo. Na análise macroscópica, observaram-se lesões brandas na mucosa gástrica e focos hemorrágicos no duodeno em quatro cães. Na histopatologia, observaram-se lesões sugestivas de discreta gastroenterite. No grupo IV, os cinco cães tiveram vômito e diarréia sanguinolenta. Quatro deles (80%) apresentaram anemia (p < 0,05). Quatro e cinco cães apresentaram redução no hematócrito e hemoglobina, respectivamente. Ocorreram, ainda, leucocitose, neutrofilia e linfopenia significantes (p < 0,05), em 60% dos cães. Na necrópsia, evidenciaram-se hiperemia, hemorragia e úlceras gástricas severas em 100% dos animais. Verificou-se na microscopia um quadro de gastroenterite ulcerativa nos cinco cães. No grupo V, todos os cães apresentaram sérios episódios de vômito, diarréia e melena. Os quatro (80%) cães que suportaram o tratamento apresentaram anemia e leucocitose com neutrofilia e linfopenia significativas (p< 0,05). Houve, ainda, uma redução no hematócrito e hemoglobina desses cães. Na necropsia, foram visualizadas hemorragias e graves ulcerações gastroduodenais. À histopatologia, evidenciou-se severa gastroenterite. Conclui-se que o meloxicam, mesmo sendo COX-2 seletivo, induz efeitos deletérios no trato gastrintestinal e células sangüíneas de cães, quando administrado em concentrações cinco e dez vezes a dose terapêutica, que demonstram sua estreita margem de segurança nesta espécie.<br>This study investigated the margin of safety of the COX-2e inhibitor, meloxicam on blood cells and gastrointestinal tract of dogs. After a clinical and laboratorial examination, the dogs were distributed in the following groups: I (placebo; n=3), II (piroxicam: 1.0mg kg-1; n=5), III (meloxicam: 0.2mg kg-1; n=5), IV (meloxican: 1.0mg kg-1; n=5) and V (meloxican: 2.0mg kg-1; n=5). The drugs were given orally for 16 days. On the 17th day the complete hemogram was repeated and the euthanasia and necropsy were then accomplished. In group I there were no significative alterations. In group II, all the dogs showed moderate episodes of vomit and diarrhea. The blood-cell profile was not modified. Two dogs had hematocrit and hemoglobin reduction. In the necropsy, hemorrhagic spots and moderate gastroduodenal lesions were seen. The microscopic analysis revealed the presence of gastritis and ulcerative enteritis. In group III, four dogs (80%) showed vomit and diarrhea, without alteration in blood-cell profile. The microscopic analysis showed mild lesions in the gastric mucosa and hemorrhagic spots in the duodenum of four dogs. Histology showed lesions suggesting mild gastroenteritis. In group IV, all the dogs (n=5) showed vomit and blood diarrhea. Four of them showed anemia (p <0.05). Four and five dogs, respectively, had hematocrit and hemoglobin reduction. In addition, there was a significant (p<0.05) leukocytosis, neutrophilia and linfopenia in 60% of the dogs. The necropsy showed hiperemia, hemorrhage and severe gastric ulcers in all the dogs. In the microscopic analyses, gastroenteritis ulcerative was present in all the animals. In group V, the dogs (n=5) had serious vomit, diarrhea and melena episodes. The dogs that bore the treatment (n=4) had anemia and leukocytosis with neutrophilia and linfopenia significatives (p<0.05). All the dogs had hematocrit and hemoglobin reduction. In the necropsy, hemorrhages and severe gastroduodenal ulceration were seen. The microscopic analysis showed severe gastroenteritis. It can be concluded that, although meloxicam is a COX-2 selective inhibitor, it induces deleterious effects on gastrointestinal tract and blood cells of dogs, when given five or ten times the therapeutic dose, which demonstrate its low margin of safety in this animal specie

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora