27 research outputs found
Effect of a hyperlipidic diet rich in omegas 3, 6 and 9 on aberrant crypt formation in rat colonic mucosa
Carbon sequestration potential of second-growth forest regeneration in the Latin American tropics
Regrowth of tropical secondary forests following complete or nearly complete removal of forest vegetation actively stores carbon in aboveground biomass, partially counterbalancing carbon emissions from deforestation, forest degradation, burning of fossil fuels, and other anthropogenic sources. We estimate the age and spatial extent of lowland second-growth forests in the Latin American tropics and model their potential aboveground carbon accumulation over four decades. Our model shows that, in 2008, second-growth forests (1 to 60 years old) covered 2.4 million km2 of land (28.1%of the total study area).Over 40 years, these lands can potentially accumulate a total aboveground carbon stock of 8.48 Pg C (petagrams of carbon) in aboveground biomass via low-cost natural regeneration or assisted regeneration, corresponding to a total CO2 sequestration of 31.09 Pg CO2. This total is equivalent to carbon emissions from fossil fuel use and industrial processes in all of Latin America and the Caribbean from1993 to 2014. Ten countries account for 95% of this carbon storage potential, led by Brazil, Colombia, Mexico, and Venezuela. We model future land-use scenarios to guide national carbon mitigation policies. Permitting natural regeneration on 40% of lowland pastures potentially stores an additional 2.0 Pg C over 40 years. Our study provides information and maps to guide national-level forest-based carbon mitigation plans on the basis of estimated rates of natural regeneration and pasture abandonment. Coupled with avoided deforestation and sustainable forestmanagement, natural regeneration of second-growth forests provides a low-costmechanism that yields a high carbon sequestration potential with multiple benefits for biodiversity and ecosystem services. © 2016 The Authors
Biodiversity recovery of Neotropical secondary forests
Old-growth tropical forests harbor an immense diversity of tree species but are rapidly being cleared, while secondary forests that regrow on abandoned agricultural lands increase in extent. We assess how tree species richness and composition recover during secondary succession across gradients in environmental conditions and anthropogenic disturbance in an unprecedented multisite analysis for the Neotropics. Secondary forests recover remarkably fast in species richness but slowly in species composition. Secondary forests take a median time of five decades to recover the species richness of old-growth forest (80% recovery after 20 years) based on rarefaction analysis. Full recovery of species composition takes centuries (only 34% recovery after 20 years). A dual strategy that maintains both old-growth forests and species-rich secondary forests is therefore crucial for biodiversity conservation in human-modified tropical landscapes. Copyright © 2019 The Authors, some rights reserved
Enxerto composto de artéria torácica interna esquerda e veia safena magna: estudo angiográfico após oito anos
O uso de enxerto composto de artéria torácica interna esquerda (ATIE) com segmentos arteriais ou segmentos de veia safena magna (VSM) pode permitir a revascularização completa do sistema coronariano esquerdo (SCE) sem circulação extracorpórea (CEC) e sem manuseio da aorta ascendente (MAA), como forma de tentar reduzir alguns riscos e complicações no pós-operatório imediato. Neste trabalho, relatamos os resultados angiográficos, após oito anos, de dois pacientes submetidos à cirurgia de revascularização do SCE com enxerto composto de ATIE e VSM, sem CEC e sem MAA
Case Report: Prolapsed Ureterocele—A Differential Diagnosis of Urethral Cists
Ureterocele is a cystic dilatation of submucosal distal ureter. It presents a higher incidence in infants and young children but is rare in adults. The urethral prolapse of ureterocele is extremely rare, and its clinical presentation includes vulvar mass, hematuria, and urinary tract dysfunction. We present a case of ureterocele prolapse in a 45-year-old woman who has a 3-day-evolution vulvar mass and intense urethral bleeding. The patient underwent armed cystoscopy and ureteroscopy, ureterocele resection, and biopsy. She evolved with good postoperative condition and was then discharged
Effect of a hyperlipidic diet rich in omegas 3, 6 and 9 on aberrant crypt formation in rat colonic mucosa Efeito de uma dieta hiperlipídica rica em ômegas 3, 6 e 9 na formação de criptas aberrantes em mucosa cólica de ratos
PURPOSE: To determine whether a hypercaloric and hyperlipidic diet enriched with polyunsaturated fatty acids influences the formation of aberrant crypt foci (ACF) in colonic mucosa of Wistar rats treated with azoxymethane (AOM). METHODS: At eight weeks of life, the rats were assigned to four groups: Group I―standard diet (STD) not treated with AOM; Group II―hypercaloric and hyperlipidic diet (FED), not treated with AOM; Group III―STD, treated with AOM; Group IV―FED, treated with AOM. At 16 weeks, the animals were injected intraperitoneal with 0.9% saline solution (Group I and II) or AOM at 15mg/Kg (Groups III and IV) once a week for two weeks. Fifteen weeks later, the animals were euthanized. RESULTS: FED promoted weight gain in Groups II and IV compared to Groups I and III, respectively. The groups did not differ with regard to the total number of ACF. The Chi-square test revealed no predominance of the presence of foci with <4 crypts. However, foci with ≥5 crypts were proportionally more prevalent in Group III than in Group IV (p=0.043). CONCLUSION: The administration of polyunsaturated fatty acids did not interfere with the formation of aberrant crypt foci, but reduced ACF multiplicity, exercising an attenuating effect on carcinogenesis.<br>OBJETIVO: Determinar se uma dieta hipercalórica, hiperlipídica, rica em ácidos graxos poliinsaturados (FED) tem influência na formação de focos de cripta aberrante (FCA) em mucosa cólica de ratos Wistar expostos ao azoximetano (AOM). MÉTODOS: Com oito semanas de vida, os ratos foram distribuídos em quatro grupos: Grupo I: Dieta padrão (SD) sem AOM; Grupo II: FED, sem AOM; Grupo III: SD, com AOM; Grupo IV: FED com AOM. Com 16 semanas, os animais dos grupos I e II receberam injeções intraperitoneais de solução salina 0,9%, enquanto os dos grupos III e IV receberam AOM na dose de 15mg/Kg de peso, 1 vez por semana por duas semanas. Quinze semanas após, os animais foram mortos. RESULTADOS: FED promoveu aumento de peso nos grupos II e IV em relação aos grupos I e III. Não houve aumento significante no número total de FCA entre os grupos. Em relação à multiplicidade das criptas por FCA, o teste do qui-quadrado mostrou que não houve predominância da presença <4 criptas por foco. Contudo, focos ≥5 criptas foram proporcionalmente mais prevalentes no grupo III que no grupo IV (p=0,043). CONCLUSÃO: Os ácidos graxos poliinsaturados não interferem na formação de focos de cripta aberrante, contudo reduz sua multiplicidade, exercendo efeito atenuador na carcinogênese
Optimization of visibility and quantification of aberrant crypt foci in colonic mucosa in Wistar rats Otimização da visibilidade e quantificação de focos de criptas aberrantes em mucosa cólica de ratos Wistar
PURPOSE: Test immersion of microscopy samples in water as an aid to visualizing and quantifying aberrant crypt foci (ACF) in rat colon mucosa. METHODS: Carcinogenesis was induced with azoxymethane in Wistar rats kept on a conventional diet or a hypercaloric diet containing unsaturated fat. Fifteen weeks after induction, colon samples were retrieved and fixated in a 10% formaldehyde solution. The samples were divided into segments (distal, middle, proximal) and stained with 1% toluidine blue. The technique tested in the study consisted of immersing microscopy samples in distilled water in order to eliminate the problem of light reflection known from conventional microscopy. RESULTS: When samples were immersed in water during microscopy, significantly more ACF could be visualized in all colon segments than with the conventional method proposed by Bird. CONCLUSION: Immersing microscopy samples in water aids the visualization and quantification of aberrant crypt foci in rat colon mucosa fixed in formaldehyde.<br>OBJETIVO: Otimizar a visibilização de focos de criptas aberrantes (FCA) em mucosa cólica de ratos Wistar. MÉTODOS: Colo de rato Wistar, sob diferentes dietas e submetidos a iniciação de carcinogênese pelo azoximetano há 4 meses, foram previamente lavados, abertos e fixados em solução de formalina a 10% por 24 horas. Após serem corados em azul de toluidina a 1%, foram divididos em segmentos distal, médio e proximal e imersos em água destilada para quantificação de FCA. RESULTADOS: No método de imersão foi visibilizado maior quantidade de focos de criptas aberrantes em todos os segmentos cólicos, com diferença significante, quando comparado com o método de Bird. CONCLUSÃO: O método de imersão otimiza a visibilização e quantificação de focos de criptas aberrantes em mucosa cólica (ratos Wistar) fixada em solução de formalina a 10%
Multiple Site Fracture of Both Rods in a Malleable Penile Implant
Penile prosthesis implant is the definitive treatment for refractory erectile dysfunction. Fracture of malleable prosthesis is rarely described due to its low incidence. We describe a case of multiple, bilateral fracture of a malleable penile implant, ten years after implantation. After the diagnosis, a review surgery was performed and the implants were replaced. No corporal rupture or urethral lesion was observed. Review of the literature shows few articles reporting penile implant fractures, and to our knowledge no other article has described multiple, bilateral fractures of a penile prosthesis
Do despotismo da gentalha à democracia da gravata lavada: história do conceito de democracia no Brasil (1770-1870)
The voting rate in Brazil only reached 40% (considered consistent with a modern democracy) in the 1980s. However, the bibliography always refers to the 1986, 1945, and 1933 elections as moments of "re-democratization", when explicitly or implicitly the original "democracy" could only have existed during the fraudulent and oligarchic First Republic (1889-1930). This article focuses on the process by which the 19th century Brazilian elites slowly forged this purely liberal-institutional concept of democracy, with extensive repercussions during the following century. The concept found its symbol in the "starched collar democracy" to which Teófilo Ottoni referred in his campaign in 1860, limited to the educated and moneyed stratum of the population, and reclaimed by the UDN party in the 1945 presidential campaign