Avaliação da toxicidade oral subcrônica da bixina para ratos

The aim of the investigation was to determine the possible health hazards of bixin (30%) from annatto (Bixa orellana L.) origin to rats. A concentration of 0.01±0.006%/day of bixin in corn oil was administered to 20 Wistar rats (10 per sex), through the oral route (gavage) over a period of 13 weeks. A group of untreated animal (10 per sex) acting as a control (corn oil) was used for comparision. Body weight, body weight gain, feed consumption and feed efficiency were determined. The health of the animals was checked. At the end of the study a biochemistry (glucose, creatinine, total cholesterol, triglyceride, asparagine transaminase and g-glutamyl transaminase) and hematological examination was carried out. All the animals were subjected to a gross-pathological assessment followed by liver, kidney, adrenals, spleen and tests weight. A histopathological analysis (liver and kidney) was performed. From the weight parameters clinical, clinical chemistry and haematology, necroscopy and histology viewpoints, it can be said that annatto, under the chosen test condition, was no toxic to the rat.A bixina em pó (30% de bixina), proveniente das sementes de urucum (Bixa orellana L.), foi administrada, por gavagem, a ratos Wistar, 10 animais de cada sexo, na concentração de 0,01±0,006% de bixina/dia, em óleo de milho, cinco dias por semana, durante 13 semanas, com o objetivo de verificar a toxicidade da substância-teste para essa espécie animal. A grupos controle (10 animais por sexo), foi administrado óleo de milho, para comparação. Durante o período de exposição, foram registrados o peso absoluto corpóreo, o ganho de peso, o consumo de ração e a eficiência alimentar, bem como realizadas as avaliações clínica e oftalmoscópica. Antes da eutanásia, os animais foram anestesiados (éter etílico) e submetidos a exames hematológicos de rotina e bioquímicos (glicose, creatinina, colesterol total, triglicérides, asparagina transaminase e g-glutamil transaminase). Durante o exame necroscópico, fígado, rins, baço, adrenais e testículos foram excisados e pesados. O estudo histológico foi realizado em amostras de fígado e rins dos animais expostos e respectivos controles. A análise estatística dos parâmetros de peso, hematológicos e bioquímicos mostrou algumas diferenças significativas entre os grupos teste e controle, as quais não parecem estar relacionadas à exposição. Não foram observadas alterações clínicas, comportamentais, necroscópicas e histológicas. Nas condições do estudo, a bixina não produziu efeitos tóxicos nos animais expostos

Lumbar Malignant Peripheral Nerve Sheath Tumor in a Young Dog

Background: The most common location of malignant tumors of the peripheral nerve sheath in the spinal cord is the intradural-extramedullary region, and is rare in the spinal nerve roots in the lumbar region. They mainly affect large female dogs over six years of age. Imaging tests assist in the presumptive diagnosis, but confirmation requires histopathological and immunohistochemical examination. The prognosis is guarded. Diagnostic imaging, anatomopathological and immunohistochemical findings of a malignant tumor of the intradural-extramedullary peripheral nerve sheath with medullary infiltration in the lumbar region in a young dog are reported.Case: A body of a 6-year-old Poodle dog was donated for necropsy and diagnostic clarification. In the history, there was a suspicion of lumbar intramedullary neoplasia, detected by computed tomography (CT), with a 4 years progressive chronic evolution. Additionally, the dog had hidden spina bifida (L7 to S3), as detected by radiography and CT. On post mortem radiographic examination (X-ray), there was an enlargement of the vertebral canal (T10 to S2), intense osteolysis (L1 to S2), spinous processes (L5 to L7), and ankylosis (L3 to L7). Necropsy revealed ankylosis (L3 to L7) and intradural-extramedullary mass (9.5 × 2.6 × 2.3 cm) (L2 to L6). No metastases were identified. On microscopy, there was neoplastic proliferation of cells with intense pleomorphism, arranged in bundles interlaced in palisades and sometimes solid mantles. The mitotic index was high, ranging from 10 to 12 mitoses per field. There was also necrosis, hemorrhage, edema, and focal axonal demyelination of the adjacent white matter in the spinal cord. Masson Trichrome staining highlighted an intense diffuse conjunctive stroma. There was a suspicion of a malignant tumor of the peripheral nerve sheath and an immunohistochemical panel was performed for confirmation. There was strong and diffuse positivity for vimentin and S-100 and partial positivity for neuron-specific enolase (NSE), negative for anti-factor VIII, glial fibrillary acidic protein (GFAP), α-actin for smooth muscle, cytokeratin, neurofilament, and desmin. Thus, the diagnosis of malignant neoplasm of the peripheral nerve sheath was confirmed.Discussion: Peripheral nerve sheath tumors are classified as benign or malignant. In dogs, they are frequent in elderly, females, and large breeds. In this case report, the animal was young, female, and small breed. The location of the spinal nerve roots is uncommon, and is more commonly found in the brachial plexus. In the animal reported, the tumor was observed as lumbar swelling. Clinical signs vary with the affected region, however, neurogenic claudication and muscle atrophy are more frequent, as observed in this report. Imaging examinations such as X-rays and CT assist in the presumptive diagnosis. In this case report, spina bifida was identified on radiography, and CT suggested the presence of intramedullary neoplasia and allowed to monitor tumor growth. Post mortem X-ray imaging revealed intense osteolysis and ankylosis, which were confirmed at necropsy, which also elucidated its intradural-extramedullary location with infiltration into the spinal cord. The confirmation of the neoplasm was made by histopathological and immunohistochemical examination; the latter should be made a panel, not restricted to the use of antibodies S-100 and vimentin only. The prognosis of malignant peripheral nerve sheath tumors (MPNST) of the spinal cord is poor, and although there are palliative methods, there is no curative treatment, as complications can interfere with the quality of life of the animal. MPNST should be included in the differential diagnosis of spinal disorders, even in young dogs and small breeds. CT helps in early diagnosis to make decisions aimed at the animal's well-being

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

More than 10,000 pre-Columbian earthworks are still hidden throughout Amazonia

Indigenous societies are known to have occupied the Amazon basin for more than 12,000 years, but the scale of their influence on Amazonian forests remains uncertain. We report the discovery, using LIDAR (light detection and ranging) information from across the basin, of 24 previously undetected pre-Columbian earthworks beneath the forest canopy. Modeled distribution and abundance of large-scale archaeological sites across Amazonia suggest that between 10,272 and 23,648 sites remain to be discovered and that most will be found in the southwest. We also identified 53 domesticated tree species significantly associated with earthwork occurrence probability, likely suggesting past management practices. Closed-canopy forests across Amazonia are likely to contain thousands of undiscovered archaeological sites around which pre-Columbian societies actively modified forests, a discovery that opens opportunities for better understanding the magnitude of ancient human influence on Amazonia and its current state

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

AVALIAÇÃO DA TOXICIDADE AGUDA (DL50): PROPOSTA PARA HARMONIZAÇÃO DOS PROTOCOLOS ADOTADOS NO BRASIL

Nos testes para avaliação da toxicidade aguda (curto prazo) devem ser considerados os efeitos tóxicos e os achados da necropsia. A DL50 é apenas um dos parâmetros que pode ser obtido. Levando-se em conta que os diversos protocolos adotados no Brasil apresentam diferentes níveis de exigência com relação às observações dos referidos efeitos, foram relatados alguns resultados obtidos visando contribuir para a harmonização destes protocolos. Ratos adultos machos e fêmeas foram expostos pelas vias oral e cutânea a onze praguicidas e afins. Observou-se na maior dose onde não se verificou óbito, que dez produtos promoveram alterações comportamentais e quatro, na evolução ponderal. Esses resultados demonstram a necessidade de uma interpretação toxicológica