Use of Polymer Casts or Metal Particle Infusion of Ducts to Study Antigen Uptake in the Guinea Pig Mammary Gland

Microcorrosion casts were made of the duct system of guinea pig mammary glands by intramammary infusion of Mercox® polyester resin following involution of the glands after the first lactation. The acinar configuration of the involuted gland was apparent on examination of the casts by scanning electron microscopy (SEM). Surface features, which were readily identified as those of imprints of duct al epithelium, were visible at higher magnifications. The morphology of these casts corresponded to the patterns observed by SEM of ethanol cryofractured specimens of mammary tissue. Cryofractured specimens of guinea pig mammary glands were also examined by SEM following intramammary infusion of tantalum. Tantalum particles were observed within the lumina of many ducts. Large phagocytic cells within the lumina were shown to contain tantalum by using back scatter imaging in conjunction with secondary imaging

Trans-sialidase delivered as a naked DNA vaccine elicits an immunological response similar to a Trypanosoma cruzi infection

Trypanosoma cruzi, the protozoan parasite that causes Chagas' disease, does not synthesize sialic acid, but expresses a trans-sialidase (TS) that catalyzes the transfer of sialic acid from host glycoconjugates to the parasite surface. Here, we review studies that characterize the immune response to the catalytic domain of the enzyme in humans during Chagas' disease or in mice following immunization with the TS gene. In both cases, there are antibodies that strongly inhibit the enzymatic activity and generation of interferon-g-producing T cells.Universidade Federal de São Paulo (UNIFESP)Instituto Dante Pazzanese de Cardiologia do Estado de São PauloUNIFESPSciEL

The impact of COVID-19 on community-based exercise classes for people with Parkinson disease

OBJECTIVE: he purpose of the study was to determine the impact of novel coronavirus 2019 (COVID-19) restrictions on community-based exercise classes for people with Parkinson disease (PD) and their instructors. METHODS: Data were collected via custom-designed electronic surveys for people with PD and class instructors who reported attending or teaching PD-specific exercise class ≥1 time/week for ≥3 months prior to pandemic restrictions (March 2020). The PD group also completed the Godin Leisure-Time Questionnaire, Self-Efficacy for Exercise scale, Schwab-England scale, and Parkinson\u27s Disease Questionnaire 8. RESULTS: Eighty-seven people with PD (mean = 70 [7.3] years old) and 43 instructors (51 [12.1] years old) from the United States completed surveys (October 2020 to February 2021). Mean Schwab-England (84 [16]) and Parkinson\u27s Disease Questionnaire 8 (21 [15]) scores indicated low-to-moderate disability in the PD group. Ninety-five percent of the PD group had COVID-19 exposure concerns, and 54% reported leaving home ≤1 time/week. Although 77% of the PD group scored active on the Godin Leisure-Time Questionnaire, the mean Self-Efficacy for Exercise Scale score (55 [24]) indicated only moderate exercise self-efficacy, and \u3e50% reported decreased exercise quantity/intensity compared with pre-COVID. There was decreased in-person and increased virtual class participation for both groups. The top in-person class barrier for the PD (63%) and instructor (51%) groups was fear of participant COVID-19 exposure. The top virtual class barriers were lack of socialization (20% of PD group) and technology problems (74% of instructor group). CONCLUSION: During COVID-19, there has been less in-person and more virtual exercise class participation in people with PD and decreased exercise quantity and intensity. Virtual classes may not fully meet the needs of people with PD, and primary barriers include technology and lack of socialization. IMPACT: As COVID-19 restrictions wane, it is imperative to help people with PD increase exercise and activity. The barriers, needs, and facilitators identified in this study might help inform approaches to increase participation in exercise and activity for people with PD. LAY SUMMARY: During COVID-19, there has been less in-person and more virtual exercise class participation in people with PD and a decrease in exercise quantity and intensity. If you have PD, virtual classes might not fully meet your needs. Primary barriers may include technology problems and lack of social interaction

Trypanosoma cruzi DNA replication includes the sequential recruitment of pre-replication and replication machineries close to nuclear periphery

In eukaryotes, many nuclear processes are spatially compartmentalized. Previously, we have shown that in Trypanosoma cruzi, an early-divergent eukaryote, DNA replication occurs at the nuclear periphery where chromosomes remain constrained during the S phase of the cell cycle. We followed Orc1/Cdc6, a pre-replication machinery component and the proliferating cell nuclear antigen (PCNA), a component of replication machinery, during the cell cycle of this protozoon. We found that, at the G(1) stage, TcOrc1/Cdc6 and TcPCNA are dispersed throughout the nuclear space. During the G(1)/S transition, TcOrc1/Cdc6 migrates to a region close to nuclear periphery. At the onset of S phase, TcPCNA is loaded onto the DNA and remains constrained close to nuclear periphery. Finally, in G(2), mitosis and cytokinesis, TcOrc1/Cdc6 and TcPCNA are dispersed throughout the nuclear space. Based on these findings, we propose that DNA replication in T. cruzi is accomplished by the organization of functional machineries in a spatial-temporal manner.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Universidade Federal de São Paulo, Parasitol Lab, Inst Butantan, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilUniv Fed Rio de Janeiro, Inst Biofis Carlos Chagas Filho, Lab Ultraestrutura Celular Hertha Meyer, BR-21941 Rio de Janeiro, BrazilUniversidade Federal de São Paulo, Parasitol Lab, Inst Butantan, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Microbiol Imunol & Parasitol, São Paulo, BrazilWeb of Scienc

Reduction of Tubulin Expression in Angomonas deanei by RNAi Modifies the Ultrastructure of the Trypanosomatid Protozoan and Impairs Division of Its Endosymbiotic Bacterium

In the last two decades, RNA interference pathways have been employed as a useful tool for reverse genetics in trypanosomatids. Angomonas deanei is a non-pathogenic trypanosomatid that maintains an obligatory endosymbiosis with a bacterium related to the Alcaligenaceae family. Studies of this symbiosis can help us to understand the origin of eukaryotic organelles. The recent elucidation of both the A. deanei and the bacterium symbiont genomes revealed that the host protozoan codes for the enzymes necessary for RNAi activity in trypanosomatids. Here we tested the functionality of the RNAi machinery by transfecting cells with dsRNA to a reporter gene (green fluorescent protein), which had been previously expressed in the parasite and to α-tubulin, an endogenous gene. In both cases, protein expression was reduced by the presence of specific dsRNA, inducing, respectively, a decreased GFP fluorescence and the formation of enlarged cells with modified arrangement of subpellicular microtubules. Furthermore, symbiont division was impaired. These results indicate that the RNAi system is active in A. deanei and can be used to further explore gene function in symbiont-containing trypanosoma tids and to clarify important aspects of symbiosis and cell evolution. This article is protected by copyright. All rights reserved

The translational challenge in chagas disease drug development

Chagas disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi. There is an urgent need for safe, effective, and accessible new treatments since the currently approved drugs have serious limitations. Drug development for Chagas disease has historically been hampered by the complexity of the disease, critical knowledge gaps, and lack of coordinated R&D efforts. This review covers some of the translational challenges associated with the progression of new chemical entities from preclinical to clinical phases of development, and discusses how recent technological advances might allow the research community to answer key questions relevant to the disease and to overcome hurdles in R&D for Chagas disease.Fil: Kratz, Jadel M.. No especifíca;Fil: Gonçalves, Karolina R.. Universidade de Sao Paulo; BrasilFil: Romera, Lavínia M. D.. Universidade de Sao Paulo; BrasilFil: Borsoi Moraes, Carolina. Universidade Federal de Sao Paulo; BrasilFil: Bittencourt Cunha, Paula. Universidade de Sao Paulo; Brasil. Universidade Federal de Sao Paulo; BrasilFil: Schenkman, Sergio. Universidade Federal de Sao Paulo; BrasilFil: Chatelain, Eric. No especifíca;Fil: Sosa-Estani, Sergio Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Centro de Investigaciones en Epidemiología y Salud Pública. Instituto de Efectividad Clínica y Sanitaria. Centro de Investigaciones en Epidemiología y Salud Pública; Argentin

Nitroheterocyclic compounds are more efficacious than CYP51 inhibitors against Trypanosoma cruzi: implications for Chagas disease drug discovery and development

Advocacy for better drugs and access to treatment has boosted the interest in drug discovery and development for Chagas disease, a chronic infection caused by the genetically heterogeneous parasite, Trypanosoma cruzi. in this work new in vitro assays were used to gain a better understanding of the antitrypanosomal properties of the most advanced antichagasic lead and clinical compounds, the nitroheterocyclics benznidazole, nifurtimox and fexinidazole sulfone, the oxaborole AN4169, and four ergosterol biosynthesis inhibitors -posaconazole, ravuconazole, EPL-BS967 and EPL-BS1246. Two types of assays were developed: one for evaluation of potency and efficacy in dose-response against a panel of T. cruzi stocks representing all current discrete typing units (DTUs), and a time-kill assay. Although less potent, the nitroheterocyclics and the oxaborole showed broad efficacy against all T. cruzi tested and were rapidly trypanocidal, whilst ergosterol biosynthesis inhibitors showed variable activity that was both compoundand strain-specific, and were unable to eradicate intracellular infection even after 7 days of continuous compound exposure at most efficacious concentrations. These findings contest previous reports of variable responses to nitroderivatives among different T. cruzi strains and further challenge the introduction of ergosterol biosynthesis inhibitors as new single chemotherapeutic agents for the treatment of Chagas disease.DNDiInstitut Pasteur Korea (IPK)Reconstruction Credit Institution-Federal Ministry of Education and Research (KfW-BMBF)/GermanyMedecins Sans Frontieres (Doctors without Borders)/InternationalKorean government (MSIP), Gyeonggi-doKISTIInst Pasteur Korea, Ctr Neglected Dis Drug Discovery CND3, Songnam, South KoreaCtr Nacl Pesquisa Energia & Mat, Lab Nacl Biociencias LNBio, Campinas, SP, BrazilUniversidade Federal de São Paulo UNIFESP, Depto Microbiol Imunol & Parasitol, São Paulo, BrazilDrugs Neglected Dis Initiat DNDi, Geneva, SwitzerlandUniversidade Federal de São Paulo UNIFESP, Depto Microbiol Imunol & Parasitol, São Paulo, BrazilKorean government (MSIP), Gyeonggi-do: 2007-00559Web of Scienc

A conceptual exoskeleton shoulder design for the assistance of upper limb movement

© Springer International Publishing AG, part of Springer Nature 2018. There is an increased interest on wearable technologies for rehabilitation and human augmentation. Systems focusing on the upper limbs are attempting to replicate the musculoskeletal structures found in humans, reproducing existing behaviors and capabilities. The current work is expanding on existing systems with a novel design that ensures the maximum range of motion while at the same time allowing for lockable features ensuring higher manipulation payloads at minimum energy and fatigue costs. An analysis of the biomechanics of the shoulder is being done and a detailed system design for structural as well actuation elements of a parallel mechanism is given. The benefits for the use are discussed of reduced weight, maximum range of motion at minimum energy cost