Intoxicação por êxtase: bases toxicológicas para o tratamento

Youngsters are increasingly using 3,4 methylenedioxymethamphetamine, known as ecstasy, because it is wrongly believed that it does not induce harm. However, there are many reports of adverse effects, including acute intoxication, abuse potential, and possible neurotoxic effects. Therefore, health care providers need to promptly recognize the symptoms of systemic intoxication in order to initiate early treatment. The drug is used by the oral route for long hours during crowded dance parties. Acutely, ecstasy increases the release of serotonin and decreases its reuptake, leading to hypertension, hyperthermia, trismus, and vomiting. There is debate on whether recreational doses of ecstasy cause permanent damage to human serotonergic neurons. Ecstasy users showed a high risk of developing psychopathological disturbances. The prolonged use of ecstasy might induce dependence, characterized by tolerance and hangover. Acute ecstasy intoxication needs emergency-type treatment to avoid the dose-dependent increase in adverse reactions and in severity of complications. There are no specific antidotes to be used during acute intoxication. Supportive measures and medical treatment for each one of the complications should be implemented, keeping in mind that symptoms originate mainly from the central nervous system and the cardiovascular system.Os jovens estão cada vez mais usando o 3,4-metilenodioximetanfetamina, conhecido como êxtase, pois acreditam que não causa danos. Entretanto, existem muitos relatos de efeitos adversos, incluindo a intoxicação aguda, abuso potencial e possíveis efeitos neurotóxicos. Portanto, profissionais da área da saúde necessitam reconhecer prontamente os sintomas da intoxicação a fim de iniciar o tratamento o mais breve possível. A droga é usada via oral durante várias horas de festas com danças. Agudamente, o êxtase aumenta a liberação do serotonina e diminui sua recaptação, levando a hipertensão, hipertermia, trismo e vômitos. Há discussão se as doses recreacionais causam danos permanentes aos neurônios serotonérgicos em humanos. Os usuários apresentam risco elevado de desenvolver distúrbios psicopatológicos, além disso, o uso prolongado pode induzir a dependência, caracterizada pela tolerância e ressaca. A intoxicação aguda necessita de tratamento de emergência, para se evitar reações adversas e complicações graves. Não há antidotos específicos para tratar a intoxicação aguda. Medidas de suporte e tratamento médico para cada uma das complicações devem ser executados, mantendo-se em mente que os sintomas a serem tratados originam-se principalmente do sistema nervoso central e do sistema cardiovascular

Modelling the scope to conserve an endemic-rich mountain butterfly taxon in a changing climate

Taxa restricted to mountains may be vulnerable to global warming, unless local-scale topographic variation and conservation actions can protect them against expected changes to the climate. We tested how climate change will affect the 19 mountain-restricted Erebia species of the Iberian Peninsula, of which 7 are endemic. To examine the scope for local topographic variation to protect against warming, we applied species distribution models (HadGEM2 and MPI) at two spatial scales (10 × 10 and 1 × 1 km) for two representative concentration pathways (RCP4.5 and RCP8.5) in 2050 and 2070. We also superimposed current and future ranges on the protected area (PA) network to identify priority areas for adapting Erebia conservation to climate change. In 10 × 10 km HadGEM2 models, climatically suitable areas for all species decreased in 2050 and 2070 (average −95.7%). Modelled decreases at 1 × 1 km were marginally less drastic (−95.3%), and 14 out of 19 species were still expected to lose their entire climatically favourable range by 2070. The PA network is well located to conserve the species that are expected to retain some climatically suitable areas in 2070. However, we identify 25 separate 10 × 10 km squares where new PAs would help to adapt the network to expected range shifts or contractions by Erebia. Based on our results, adapting the conservation of range-restricted mountain taxa to projected climate change will require the implementation of complementary in situ and ex situ measures alongside urgent climate change mitigationBiology Department from Universidad Autonoma de Madrid, Grant/Award Number: SBPLY/17/180501/000492; European Regional Development Fund; MCIU/AEI/ FEDER, UE, Grant/Award Number: RTI2018-096739-B-C21; NexTdive project, Grant/Award Number: PID2021-124187NBI00; Spanish Ministry of Science and Innovatio

Quantum to Classical Transition in a Single-Ion Laser

Stimulated emission of photons from a large number of atoms into the mode of a strong light field is the principle mechanism for lasing in "classical" lasers. The onset of lasing is marked by a threshold which can be characterised by a sharp increase in photon flux as a function of external pumping strength. The same is not necessarily true for the fundamental building block of a laser: a single trapped atom interacting with a single optical radiation mode. It has been shown that such a "quantum" laser can exhibit thresholdless lasing in the regime of strong coupling between atom and radiation field. However, although theoretically predicted, a threshold at the single-atom level could not be experimentally observed so far. Here, we demonstrate and characterise a single-atom laser with and without threshold behaviour by changing the strength of atom-light field coupling. We observe the establishment of a laser threshold through the accumulation of photons in the optical mode even for a mean photon number substantially lower than for the classical case. Furthermore, self-quenching occurs for very strong external pumping and constitutes an intrinsic limitation of single-atom lasers. Moreover, we find that the statistical properties of the emitted light can be adjusted for weak external pumping, from the quantum to the classical domain. Our observations mark an important step towards fundamental understanding of laser operation in the few-atom limit including systems based on semiconductor quantum dots or molecules.Comment: 19 pages, 4 figures, 10 pages supplement, accepted by Nature Physic

PHYTOPLANKTON BIOMASS INCREASES IN A SILT-IMPACTED AREA IN AN AMAZONIAN FLOOD-PLAIN LAKE OVER 15 YEARS

Funding Information: We thank Mineração Rio do Norte S.A. and Limnologia/UFRJ for fieldwork support, Dr. Janet W. Reid (JWR Associates) for language revision, and Leonardo Preza Rodrigues for map charting. VLMH, JCN, FAE, RLB, and FR are partially supported by the National Council for Scientific and Technological Development (CNPq), Brazil, RLB, and FAE by FAPERJ, Brazil, and CGR financially supported by Sakari Alhopuro Foundation, Finland. Publisher Copyright: © 2022, Universidade Federal do Rio de Janeiro. All rights reserved.Tailings from bauxite mining in Porto Trombetas (Pará state, Central Amazonia, Brazil) was discharged (1979–1989) into Batata Lake affecting about 30% of its area. The lake belongs to a clear-water flood-plain system along the Trombetas River, a tributary of the Amazon River. Siltation is the main perceived factor impacting aquatic and flooded communities. Besides natural regeneration, a program to restore a section of igapó forest in the impacted area (IA) has been conducted since 1991. Decreased light is the main factor reducing total phytoplankton biomass (PhyBM) in IA. We hypothesized that PhyBM in IA increases over time because of the improvement of the underwater light conditions due to the natural regeneration and restoration. We sampled quarterly PhyBM and limnological variables (depth, transparency, temperature, pH, conductivity, dissolved oxygen, turbidity, suspended solids, total Kjeldahl nitrogen, and total phosphorus), over 15 years (2005–2019) at eight sampling sites in the two areas (N = 349). We also obtained daily climatic and hydrologic data. PhyBM was higher in NIA than in IA. The temporal trend in the annual mean of PhyBM increased significantly over time only in the IA, approximating the NIA values, confirming our general hypothesis. The increase of PhyBM in the IA was negatively related to the residual light attenuation caused by non-phytoplankton turbidity and to total phosphorus, and positively to air temperature and site depth (p < 0.05; Marginal r2 = 0.18; Conditional r2 = 0.29). Instead, in NIA, PhyBM was explained only by the increase in air temperature (p < 0.05; Marginal r2 = 0.15; Conditional r2 = 0.34). We concluded that the PhyBM in the IA positively responds to the synergy between increasing light availability, air temperature, and site depth, and decreasing total phosphorus concentrations, regardless of hydrologic phase.Peer reviewe

Antioxidant activity and acute toxicity of Neoglaziovia variegata (Bromeliaceae)

Antioxidant activities of Neoglaziovia variegata were evaluated by using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and β-carotene-linoleic acid bleaching and was compared with ascorbic acid, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT). The total phenolics content of the extracts was determined by the Folin-Ciocalteu method. Total flavonoid was also determined. The most significant total phenolic content was of 543.50 ± 9.38 mg of gallic acid equivalent/g for ethyl acetate extract (AcOEt), which presented the best antioxidant activity (IC50 5.08 ± 0.20 μg/ml) for DPPH scavenging. The acute toxicity of Nv-EtOH was performed 2.0 g/kg intraperitoneally and 5.0 g/kg orally in mice. No mortality and no toxicity signs were observed, indicating low toxicity of the extract. Blood was removed after 14 days for laboratory analysis of hematological and biochemical parameters. Alterations of aspartate aminotransferase (AST) and creatinine were observed. The data obtained showed that the doses induced microscopic alterations in the liver and kidney. In conclusion, the Nv-EtOH can be considered of low toxicity.Keywords: Antioxidant activity, acute toxicity, Neoglaziovia variegata, Bromeliacea

ACALASIA NA DOENÇA DE CHAGAS É DIFERENTE DE ACALASIA IDIOPÁTICA? EXPERIÊNCIA DO HOSPITAL DE CLÍNICAS DE PORTO ALEGRE

Objetive: The objective of this study is to evaluate the differences between achalasia in Chagas’ disease and idiopathic achalasia in patients admitted to the Hospital de Clínicas de Porto Alegre, by analyzing epidemiologic, clinic, radiologic and manometric findings.Methods: Patients referred to the Hospital de Clinicas de Porto Alegre between November 1996 and December 2001 with suspicion of achalasia, later confirmed by esophageal manometry, were included in the study. In addition to manometric and radiologic findings, patients were assessed for age, sex, symptomsand symptomatic period.Results: Among 51 patients, nine (18%) presented positive serology for Chagas’ disease and 42 (82%) presented negative serology. The latter were considered carriers of idiopathic achalasia. The mean age of patients with achalasia in Chagas’ disease was 62 ± 15 years, while the mean age in the idiopathic group was 43 ± 18 years (P &lt; 0.02). The symptomatic period for patients with achalasia in Chagas’ disease was 74 ± 47 months, and in the idiopathic group, 49 ± 35 months (P &lt; 0.05). Dysphagia, regurgitation, thoracic pain and weight loss, values at the lower esophageal sphincter (basal pressure, post-deglutitive relaxation pressure/duration and total length) and at the esophageal body (amplitude and duration of the post-deglutitive waves) were similar in both groups.Conclusions: The only statistically significant differences found between the two groups were age and length of the symptomatic period, significantly greater in patients with achalasia in Chagas’ disease. These data suggest a greater resistance to the symptoms in older patients.Objetivo: O presente trabalho tem como objetivo avaliar as diferenças entre a acalasia chagásica e a idiopática em pacientes do Hospital de Clínicas de Porto Alegre, através da análise de achados epidemiológicos, clínicos, radiológicos e manométricos.Métodos: Foram estudados pacientes encaminhados ao Hospital de Clínicas de Porto Alegre, entre novembro de 1996 e dezembro de 2001, com suspeita de acalasia, posteriormente, confirmada por manometria esofágica. Além das características manométricas e radiológicas, os pacientes foram avaliados quanto a idade, sexo, sintomas e tempo de evolução.Resultados: Entre 51 pacientes, nove (18%) tiveram sorologia positiva para doença de Chagas e 42 (82%) sorologia negativa. Indivíduos com sorologia negativa foram considerados portadores de acalasia idiopática. Pacientes com acalasia chagásica tinham média de idade de 62 ± 15 anos e os com idiopática 43 ± 18 anos (P &lt; 0,02). O período de evolução dos sintomas em pacientes com acalasia chagásica foi de 74 ± 47 meses e nos idiopáticos 49 ± 35 meses (P &lt; 0,05). Disfagia, regurgitação, dor torácica e emagrecimento, valores do esfíncter esofágico inferior (pressão basal, pressão e duração de relaxamento pós-deglutição e comprimento total) e do corpo esofágico (amplitude e duração das ondas pós-deglutição) foram similares em ambos os grupos.Conclusões: As únicas diferenças estatisticamente significativas encontradas entre os dois grupos foram a média de idade e o período de evolução dos sintomas, maiores nos pacientes chagásicos. Esses dados permitem especular sobre uma maior tolerância aos sintomas nos pacientes com idade mais avançada