Coinfection with Different Trypanosoma cruzi Strains Interferes with the Host Immune Response to Infection

A century after the discovery of Trypanosoma cruzi in a child living in Lassance, Minas Gerais, Brazil in 1909, many uncertainties remain with respect to factors determining the pathogenesis of Chagas disease (CD). Herein, we simultaneously investigate the contribution of both host and parasite factors during acute phase of infection in BALB/c mice infected with the JG and/or CL Brener T. cruzi strains. JG single infected mice presented reduced parasitemia and heart parasitism, no mortality, levels of pro-inflammatory mediators (TNF-α, CCL2, IL-6 and IFN-γ) similar to those found among naïve animals and no clinical manifestations of disease. On the other hand, CL Brener single infected mice presented higher parasitemia and heart parasitism, as well as an increased systemic release of pro-inflammatory mediators and higher mortality probably due to a toxic shock-like systemic inflammatory response. Interestingly, coinfection with JG and CL Brener strains resulted in intermediate parasitemia, heart parasitism and mortality. This was accompanied by an increase in the systemic release of IL-10 with a parallel increase in the number of MAC-3+ and CD4+ T spleen cells expressing IL-10. Therefore, the endogenous production of IL-10 elicited by coinfection seems to be crucial to counterregulate the potentially lethal effects triggered by systemic release of pro-inflammatory mediators induced by CL Brener single infection. In conclusion, our results suggest that the composition of the infecting parasite population plays a role in the host response to T. cruzi in determining the severity of the disease in experimentally infected BALB/c mice. The combination of JG and CL Brener was able to trigger both protective inflammatory immunity and regulatory immune mechanisms that attenuate damage caused by inflammation and disease severity in BALB/c mice

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

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

Piomiosite no lúpus eritematoso sistêmico juvenil

Resumo A piomiosite é uma infecção piogênica da musculatura esquelética, decorrente da disseminação hematogênica e geralmente acompanhada de formação de abscesso localizado. Esta infecção da musculatura é raramente descrita em adultos com lúpus eritematoso sistêmico (LES) e, até onde se sabe, ainda não o foi em pacientes com LES juvenil (LESJ). De nossos 289 pacientes com LESJ, uma apresentou piomiosite. Diagnosticada com LESJ aos 10 anos de idade e após seis anos de tratamento com prednisona, azatioprina e hidroxicloroquina, a paciente foi hospitalizada em razão de um histórico de 30 dias de dor insidiosa na coxa esquerda, sem relato algum de trauma aparente ou febre. O exame físico mostrou músculos sensíveis e com endurecimento lenhoso. Os exames laboratoriais revelaram anemia, aumento de reagentes de fase aguda e enzimas musculares normais. A tomografia computadorizada da coxa esquerda mostrou coleção no terço médio do vasto intermédio, sugerindo estágio purulento de piomiosite. Iniciou-se tratamento com antibiótico de largo espectro, que levou à resolução clínica completa. Em suma, descreveu-se o primeiro caso de piomiosite em pacientes com LESJ encontrado neste serviço. Este relato reforça que a presença de dor muscular localizada em pacientes imunocomprometidos, ainda que sem aumento de enzimas musculares, deve sugerir o diagnóstico de piomiosite. Recomenda-se tratamento imediato com antibióticos

Morphology and immunohistochemistry of the myenteric plexus of valves constructed in the colon of rats submitted to abdominoperineal amputation and perineal colostomy

PURPOSE: To investigate immunohistochemical aspects of the myenteric plexus of valves constructed in the colon of rats to verify whether any denervation occurs both at the operative site and in those areas adjacent to the third valve. METHODS: Thirty six male Wistar rats divided into the following three groups were used: Control Group (CG); Amputated Group (AG); Amputated Group with Valves (AGWV). In AG was held in the rectum amputation and the colon was sutured to the skin elaborating the perineal colostomy. In AGWV was held in the rectum amputation. A laparotomy was performed for the manufacture of valves (seromyotomy) in the colon. After this step, the colon was sutured to the skin elaborating the perineal colostomy. The density of the neural elements in the muscular wall as marked specifically using Protein Gene Product (PGP) 9.5 and utilising the proper tools of the KS300 software for measuring the area. From these measurements, a relation and three proportions were drawn and analysed according to the mean of the averages obtained from the measured images. RESULTS: Immunoexpression of PGP 9.5 demonstrated a total absence of neural elements and myenteric plexus at the valve site. The density of the neural elements in the circular muscular layer at sites adjacent to the 3rd valve was lesser, however, was not significantly different. CONCLUSION: The immunohistochemical study of valves constructed in the colon of rats submitted to abdominoperineal amputation and perineal colostomy revealed denervation at the seromyotomy site

Histopathology of Leishmania major infection: revisiting L. major histopathology in the ear dermis infection model

We describe the relationship between lesion outcome and histopathological hallmarks in susceptible (BALB/c) and resistant (C57BL/6 and IL-4-deficient BALB/c) mouse strains over the course of a 12-week-infection with Leishmania major in the ear. The infiltration of mononuclear cells and polymorphonuclear cells occurred within 6 h and mononuclear cells predominated one week post-infection. Permissive intracellular growth of the pathogen was associated with non-healing lesions. In contrast, tissue damage and clearance of the parasite was observed in healing lesions and was associated with inducible nitric oxide synthase expression. The identification of the structural components of tissue reaction to the parasite in this study furthers our understanding of subjacent immune effector mechanisms

NÍVEIS DE ENXOFRE NA ASSOCIAÇÃO DE ADUBOS NITROGENADOS NA PRODUÇÃO DOS CAPINS ANGOLA E PIATÃ

A adubação nitrogenada pode ser limitada por baixos níveis de enxofre nos solos. Com isso haverá o comprometimento da produtividade das forrageiras. Assim, objetivou-se neste estudo o de avaliar o efeito da associação de duas fontes de nitrogênio (uréia e sulfato de amônio), com níveis crescentes de enxofre. Usou-se a dosagem equivalente a 100 kg ha-1 ano-1, parcelados a cada corte de 28 dias, na produção de matéria seca de Baquiária (Brachiaria brizantha cv. Piatã) e capim angola (Brachiaria mutica). O estudo consistiu na adição de doses crescentes de S (0, 6, 12, 18 e 24 kg ha-1), mantendo-se o nível de N constante, usando-se a uréia (U) e o sulfato de amônio (SA), sendo os tratamentos: 100% SA – 0% U; T2: 75% SA – 25% U; T3: 50% SA – 50% U; T4: 25% SA– 75% U e T5: 0% SA – 100% U. Os resultados em produção não geraram diferenças significativas