Sequela fibrótica na paracoccidioidomicose pulmonar: aspectos histopatológicos em camundongos BALB/c infectados com propágulos viáveis e não viáveis do Paracoccidioides brasiliensis

Patients with paracoccidioidomycosis often present pulmonary fibrosis and exhibit important respiratory limitations. Based on an already established animal model, the contribution of viable and non-viable P. brasiliensis propagules to the development of fibrosis was investigated. BALB/c male mice, 4-6 weeks old were inoculated intranasally either with 4x10(6 )viable conidia (Group I), or 6.5x10(6) fragmented yeast cells (Group II). Control animals received PBS. Six mice per period were sacrificed at 24, 48, 72h (initial) and 1, 2, 4, 8, 12 and 16 weeks post-challenge (late). Paraffin embedded lungs were sectioned and stained with H&E, trichromic (Masson), reticulin and Grocott´s. During the initial period PMNs influx was important in both groups and acute inflammation involving 34% to 45% of the lungs was noticed. Later on, mononuclear cells predominated. In group I, the inflammation progressed and granulomas were formed and by the 12th week they fussed and became loose. Thick collagen I fibers were observed in 66.6% and 83.3% of the animals at 8 and 12 weeks, respectively. Collagen III, thick fibers became apparent in some animals at 4weeks and by 12 weeks, 83% of them exhibited alterations in the organization and thickness of these elements. In group II mice, this pattern was different with stepwise decrease in the number of inflammatory foci and lack of granulomas. Although initially most animals in this group had minor alterations in thin collagen I fibers, they disappeared by the 4th week. Results indicate that tissue response to fragmented yeast cells was transitory while viable conidia evoked a progressive inflammatory reaction leading to granuloma formation and to excess production and/or disarrangement of collagens I and III; the latter led to fibrosis.Pacientes com paracoccidioidomicose apresentam, algumas vezes, fibrose pulmonar e exibem limitações respiratórias importantes. Baseados num modelo animal já estabelecido da micose, estudamos a possível contribuição de propágulos viáveis e não viáveis do Paracoccidioides brasiliensis ao desenvolvimento da fibrose. Assim, camundongos BALB/c, machos de 4 a 6 semanas de idade, foram inoculados intranasalmente com 4 x 10(6) conídios viáveis (Grupo I), ou com 6,5 x 10(6) fragmentos não viáveis de células leveduriformes (Grupo II). Animais controles (Grupo III) receberam unicamente PBS. Seis camundongos por período foram sacrificados 24, 48, 72h (inicial) e 1, 2, 4, 8, 12 e 16 semanas pós-inoculação (tardio). Os pulmões dos animais foram fixados, incluidos em parafina, cortados e corados com H & E, Tricrômico (Masson), reticulina e Grocott. Durante o período inicial houve afluxo importante de PMNs em ambos os grupos I e II, e a inflamação aguda comprometeu entre 34 a 45% dos pulmões. Depois, foram as células mononucleares as que predominaram. No grupo I, a inflamação progrediu e formaram-se granulomas os quais, às 12 semanas, ficaram confluentes e frouxos. Adicionalmente, se observaram fibras de colágeno tipo I muito densas em 66,6% e 83,3% dos animais após 8 e 12 semanas, respectivamente. As fibras do colágeno tipo III foram observadas nos animais a partir das 4 semanas pós-infecção, e 83% deles exibiram, às 12 semanas, alterações na sua distribuição e organização. Nos animais do grupo II o padrão foi diferente, pois mostraram diminuição gradual no número de focos inflamatórios e não houve formação dos granulomas. Embora animais deste grupo tivessem no período inicial pequenas alterações nas fibras de colágeno tipo I, estas desapareceram por volta da 4a semana. Os resultados indicam que a resposta tissular aos fragmentos de leveduras foi transitória, enquanto que os conídios induzem resposta inflamatória progressiva permitindo a formação de granuloma e um excesso na produção e desorganização dos colágenos I e III, permitindo finalmente a fibrose

Potential use of antibodies to provide an earlier indication of lymphatic filariasis resurgence in post–mass drug ad ministration surveillance in American Samoa

Background: Under the Global Programme to Eliminate Lymphatic Filariasis (LF), American Samoa conducted 7 rounds of mass drug administration (MDA) between 2000 and 2006. The territory passed transmission assessment surveys (TASs) in 2011 (TAS-1) and 2015 (TAS-2). In 2016, the territory failed TAS-3, indicating resurgence. This study aims to determine if antibodies (Abs) may have provided a timelier indication of LF resurgence in American Samoa. Methods: We examined school-level antigen (Ag) and Ab status (presence/absence of Ag- and Ab-positive children) and prevalence of single and combined Ab responses to Wb123, Bm14, and Bm33 Ags at each TAS. Pearson chi-square test and logistic regression were used to examine associations between school-level Ab prevalence in TAS-1 and TAS-2 and school-level Ag status in TAS-3. Results: Schools with higher prevalence of Wb123 Ab in TAS-2 had higher odds of being Ag-positive in TAS-3 (odds ratio [OR] 24.5, 95% confidence interval [CI] 1.2–512.7). Schools that were Ab-positive for WB123 plus Bm14, Bm33, or both Bm14 and Bm33 in TAS-2 had higher odds of being Ag-positive in TAS-3 (OR 16.0–24.5). Conclusion: Abs could provide earlier signals of resurgence and enable a timelier response. The promising role of Abs in surveillance after MDA and decision making should be further investigated in other settings

Design and methods for a randomized clinical trial of a diabetes self-management intervention for low-Income Latinos: Latinos en Control

<p>Abstract</p> <p>Background</p> <p>US Latinos have greater prevalence of type 2 diabetes (diabetes), uncontrolled diabetes and diabetes co-morbidities compared to non-Latino Whites. They also have lower literacy levels and are more likely to live in poverty. Interventions are needed to improve diabetes control among low-income Latinos.</p> <p>Methods and design</p> <p>This randomized clinical trial tested the efficacy of a culturally- and literacy-tailored diabetes self-management intervention (<it>Latinos en Control</it>) on glycemic control among low-income Latinos with diabetes, compared to usual care (control). Participants were recruited from five community health centers (CHCs) in Massachusetts. The theory-based intervention included an intensive phase of 12 weekly sessions and a follow-up maintenance phase of 8 monthly sessions. Assessments occurred at baseline, and at 4 and 12 months. The primary outcome was glycosylated hemoglobin (HbA1c). Secondary outcomes were self-management behaviors, weight, lipids and blood pressure. Additional outcomes included diabetes knowledge, self-efficacy, depression and quality of life. The study was designed for recruitment of 250 participants (estimated 20% dropout rate) to provide 90% power for detecting a 7% or greater change in HbA1c between the intervention and control groups. This is a difference in change of HbA1c of 0.5 to 0.6%.</p> <p>Discussion</p> <p>Low-income Latinos bear a great burden of uncontrolled diabetes and are an understudied population. Theory-based interventions that are tailored to the needs of this high-risk population have potential for improving diabetes self-management and reduce health disparities. This article describes the design and methods of a theory driven intervention aimed at addressing this need.</p> <p>Trial registration</p> <p><url>http://www.clinicaltrials.gov</url> # NCT00848315</p

Clonaje y caracterización molecular de dos genes homólogos hsp70 del hongo dimórficoParacoccidioides brasilensis.

Paracoccidioides brasiliensis, a dimorphic fungus, is the etiologic agent of Paracoccidioidomycosis (PCM), one of the most important systemic mycosis in Latin America. Two genes (2.2 and 1DB5) were cloned, characterized and sequenced; they showed homology with members of hsp70 gene family. By using several probe fragments derived from these genes, levels of expression for each gene were determined by Northern blot during transition to the yeast phase. The highest level of hsp70 transcript occurred between 30 min to 6 hours after temperature shift, with significant reduction after 36-48 hours. However, after 72 hours, the level of the transcription increased until yeast phase was reached. As a response to temperature increase, hsp 70 genes are expressed during the transition phase and possibly play a role in the differentiation process.Paracoccidiodes brasiliensis es el agente etiológico de la Paracoccidioidomicosis (PCM), una de las micosis sistémicas mas importantes en Latinoamérica. Dos genes hsp70 (Clones 2.2 y 1DB5) fueron clonados, caracterizados y secuenciados. El análisis de secuencia mostró que los clones 2.2 y 1DB5 poseen una alta homología con la familia de genes de choque térmico hsp70. Mediante la utilización de fragmentos de ADN provenientes de ambos clones, se determinó la expresión por Northern blot durante la fase de transición a levadura. Nosotros encontramos los niveles mas altos de transcriptos ocurre entre los 30 min y 6 h después de cambiar la temperatura a 37°C. Entre las 36 y 48 h, se reducen los niveles de ARNm. Sin embargo, los niveles de ARNm aumentan a las 72 h hasta alcanzar la fase de levadura. Como resultado del aumento de la temperatura durante la fase de transición micelio a levadura, se incrementa la expresión de genes hsp70 sugiriendo que las proteínas de choque térmico tienen un papel durante el proceso de diferenciación

Pulmonary Abnormalities in Mice with Paracoccidioidomycosis: A Sequential Study Comparing High Resolution Computed Tomography and Pathologic Findings

Paracoccidioidomycosis (PCM) is a fungal infection caused by the dimorphic fungus Paracoccidioides brasiliensis. It occurs preferentially in rural workers in whom the disease is severe and may cause incapacitating pulmonary sequelae. Assessment of disease progression and treatment outcome normally includes chest x-rays or CT studies. Existing experimental PCM models have focused on several aspects, but none has done a radiologic or image follow-up evaluation of pulmonary lesions considered as the fungus primary target. In this study, the lungs of mice infected with fungal conidia were studied sequentially during the chronic stage of their experimental mycosis by noninvasive high resolution medical computed tomography, and at time of sacrifice, also by histopathology to characterize pulmonary abnormalities. Three basic lung lesion patterns were revealed by both techniques: nodular-diffuse, confluent and pseudo-tumoral which were located mainly around the hilus thus accurately reflecting the situation in human patients. The experimental design of this study decreases the need to sacrifice a large number of animals, and serves to monitor treatment efficacy by means of a more rational approach to the study of human pulmonary diseases. The findings we are reporting open new avenues for experimental research, increase our understanding of the mycosis pathogenesis and consequently have repercussions in patients' care

Structural and Topographic Dynamics of Pulmonary Histopathology and Local Cytokine Profiles in Paracoccidioides brasiliensis Conidia-Infected Mice

Paracoccidioidomycosis (PCM), an endemic fungal infection of pulmonary origin resulting in severe disseminated disease, occurs in rural areas of most South American countries and presents several clinical forms. The infection is acquired by inhalation of specific fungal propagules, called conidia. Considering the difficulties encountered when studying the infection in humans, this work was done in mice infected by inhalation of infective fungal conidia thus mimicking the human natural infection. The lungs of mice were sequentially studied by histopathological and multiplex cytokine methods from 2 h to 16 weeks after infection to verify the course of the disease. The mycosis presented different morphologic aspects during the course of time, affecting several pulmonary compartments. Otherwise and based on the analysis of 30 cytokines, the immune response also showed heterogeneous responses, which were up or down regulated depending on the time of infection. By recognizing the different stages that correspond to the evolution of pulmonary lesions, the severity (benign, chronic or fibrotic) of the disease could be predicted and the probable prognosis of the illness be inferred

Alternative Oxidase Mediates Pathogen Resistance in Paracoccidioides brasiliensis Infection

Thermally dimorphic pathogenic fungi are responsible for potentially life-threatening diseases of immunocompetent and immunocompromised individuals. These microorganisms grow as conidia-producing mycelia in the environment, which when inhaled by the host convert to the pathogenic yeast form at 37°C. During adaptation and growth, fungi interact with host immune cells and must cope with defense mechanisms such as imposed-oxidative stress (e.g., reactive oxygen species; ROS). Alternative oxidase (AOX) is an enzyme recently implicated in the reduction of ROS production by the mitochondria when triggered by external stimuli, such as temperature and ROS. During this work we have evaluated the relevance of AOX during infection with Paracoccidioides brasiliensis, the etiological agent of one of the most prevalent mycoses in Latin America, paracoccidioidomycosis. We show that PbAOX gene expression is stimulated after interaction with alveolar macrophages or in the presence of H2O2 and is essential for survival against fungicidal activity of both the immune cells and the ROS compound. Moreover, decreasing PbAOX gene expression in P. brasiliensis led to increased survival of infected mice. Altogether, our data supports a relevant role for AOX in the virulence of P. brasiliensis

Spatial prediction of the risk of exposure to Echinococcus spp. among schoolchildren and dogs in Ningxia Hui Autonomous Region, People’s Republic of China

The geographical distribution of Echinococcus spp. infections in Ningxia Hui Autonomous Region (NHAR) has been reported to be expanding in response to environmental change. The aim of the present study was to predict and compare the spatial distribution of human seropositivity for Echinococcus granulosus and Echinococcus multilocularis and infections with these parasites in dogs in four counties in the south of NHAR to identify communities where targeted prevention and control efforts are required. Predicted seroprevalence of E. granulosus in schoolchildren and E. granulosus infections in dogs concurred spatially, whereas predicted seroprevalence of E. multilocularis in schoolchildren and E. multilocularis infections in dogs differed spatially. Enhanced vegetation index was significantly associated with E. multilocularis seropositivity among schoolchildren, and infections with E. granulosus and E. multilocularis in dogs. A positive association was also found between dog infection with E. granulosus and cultivated land, and a negative association between human seropositivity for E. granulosus and bare-land/artificial surfaces. The findings of this study support the importance of land cover and climatic variables in determining habitat suitability for Echinococcus spp. infections, and suggest that definitive hosts other than dogs (e.g. foxes) are important in defining the geographical risk of human seropositivity for E. multilocularis in NHAR