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81.
Degradation of collagen by fibroblast phagocytosis is an important pathway for physiological remodelling of soft connective tissues. Perturbations of this pathway may provide a mechanism for the development of fibrotic lesions. As collagen phagocytosis may be regulated by either a change of the proportions or the activity of phagocytic cells, we quantified phagocytosis with an in vitro model system. Collagen-coated fluorescent latex beads were incubated with human gingival fibroblasts and the fluorescence associated with internalized beads was measured by flow cytometry. Cells from normal tissues that had been incubated with beads for 3 hours contained a mean of 64% phagocytic cells; however, a small subpopulation (10% of phagocytic cells) contained more than threefold higher numbers of beads per cell than the mean. In contrast, cells from fibrotic lesions exhibited a large reduction of the proportions of phagocytic cells (mean = 13.8%) and there were no cells with high numbers of beads. On the basis of 3H-Tdr labeling, cells from fibrotic lesions that had internalized beads failed to proliferate, in contrast to phagocytic cells from normal tissues, which underwent repeated cell divisions. This result was not due to variations of cell cycle phase as there was no preferential internalization of beads during different phases of the cell cycle. The low phagocytic rate of cells from fibrotic lesions was also not due to asymmetric partitioning of phagosomes at mitosis as videocinemicrography of bead-labeled phagosomes in single, pre-mitotic cells demonstrated that > 90% of phagocytic cells equally partitioned beads to daughter cells. To investigate if inhibition of phagocytosis could be replicated in vitro, cells were incubated with the fibrosis-inducing drugs nifedipine or dilantin. These cultures exhibited marked (15–75%), dose-dependent reductions in the proportions of phagocytic cells, but there was no reduction in bead number per cell. Fibrotic lesions appear to contain fibroblasts with marked deficiencies in phagocytosis and the reduced phagocytic activity of these cells may contribute to unbalanced degradation and fibrosis. © 1993 Wiley-Liss, Inc. 相似文献
82.
Camila V. Molina Marcos B. Heinemann Cecilia Kierulff Alcides Pissinatti Tiago F. da Silva Danilo G. de Freitas Gisele O. de Souza Bruno A. Miotto Adriana Cortez Beatriz de P. Semensato Luisa Z. Moreno Jos L. Cato‐Dias Marina G. Bueno 《American journal of primatology》2019,81(3)
The world currently faces severe biodiversity losses caused by anthropogenic activities such as deforestation, pollution, the introduction of exotic species, habitat fragmentation, and climate changes. Disease ecology in altered environments is still poorly understood. The golden‐headed lion tamarin (GHLT, Leontopithecus chrysomelas) is an endangered species that became invasive in an urban park in Niterói, Rio de Janeiro, Brazil. The initially few invasive GHLT individuals became hundreds, adapted to living in proximity to humans and domestic animals. These GHLTs were captured as part of a conservation project; some animals were translocated to Bahia and some were kept in captivity. This study tested 593 GHLT for Leptospira serology; 100 and 95 GHLT for polymerase chain reaction (PCR) toLeptospira and hepatitis E virus genotype 3 (HEV‐3), respectively, and 101 familiar groups for PCR to viruses (rotavirus A, norovirus GI and GII, and HEV‐3). One animal had antibodies for Leptospira serovar Shermani and another for serovar Hebdomadis. One saprophyticLeptospira was found by the 16S PCR and sequencing. Viruses were not detected in samples tested. Findings suggest that the epidemiological importance of such pathogens in this GHLT population is either low or nonexistent. These data are important to understand the local disease ecology, as well as monitoring a translocation project, and to contribute data for species conservation. 相似文献
83.
Adriana da Silva Rezende Moreira Gisele Huf Maria Armanda Monteiro da Silva Vieira Paulo Albuquerque da Costa Fábio Aguiar Anna Grazia Marsico Leila de Souza Fonseca M?nica Ricks Martha Maria Oliveira Anne Detjen Paula Isono Fujiwara Stephen Bertel Squire Afranio Lineu Kritski 《PloS one》2015,10(6)
Background
The use of liquid medium (MGIT960) for tuberculosis (TB) diagnosis was recommended by WHO in 2007. However, there has been no evaluation of its effectiveness on clinically important outcomes.Methods and Findings
A pragmatic trial was carried out in a tertiary hospital and a secondary health care unit in Rio de Janeiro City, Brazil. Participants were 16 years or older, suspected of having TB. They were excluded if only cerebral spinal fluid or blood specimens were available for analysis. MGIT960 technique was compared with the Lowenstein-Jensen (LJ) method for laboratory diagnosis of active TB. Primary outcome was the proportion of patients who had their initial medical management changed within 2 months after randomisation. Secondary outcomes were: mean time for changing the procedure, patient satisfaction with the overall treatment and adverse events. Data were analysed by intention-to-treat. Between April 2008 and September 2011, 693 patients were enrolled (348 to MGIT, 345 to LJ). Smear and culture results were positive for 10% and 15.7% of participants, respectively. Patients in the MGIT arm had their initial medical management changed more frequently than those in the LJ group (10.1% MGIT vs 3.8% LJ, RR 2.67 95% CI 1.44–.96, p = 0.002, NNT 16, 95% CI 10–39). Mean time for changing the initial procedure was greater in LJ group at both sites: 20.0 and 29.6 days in MGIT group and 52.2 and 64.3 in LJ group (MD 33.5, 95% CI 30.6–36.4, p = 0.0001). No other important differences were observed.Conclusions
This study suggests that opting for the MGIT960 system for TB diagnosis provides a promising case management model for improving the quality of care and control of TB.Trial Registration
Controlled-Trials.com ISRCTN79888843 相似文献84.
Raul Hernandes Bortolin Bento Jo?o da Gra?a Azevedo Abreu Marcela Abbott Galv?o Ururahy Karla Simone Costa de Souza Jo?o Felipe Bezerra Melina Bezerra Loureiro Flávio Santos da Silva Dáfiny Emanuele da Silva Marques Angélica Amanda de Sousa Batista Gisele Oliveira André Ducati Luchessi Valéria Morgiana Gualberto Duarte Moreira Lima Carlos Eduardo Saraiva Miranda Marcus Vinicius Lia Fook Maria das Gra?as Almeida Luciana Augusto de Rezende Adriana Augusto de Rezende 《PloS one》2015,10(5)
Several studies have established an association between diabetes and alterations in bone metabolism; however, the underlying mechanism is not well established. Although zinc is recognized as a potential preventive agent against diabetes-induced bone loss, there is no evidence demonstrating its effect in chronic diabetic conditions. This study evaluated the effects of zinc supplementation in a chronic (90 days) type 1 diabetes-induced bone-loss model. Male Wistar rats were distributed in three groups: control, type 1 diabetes mellitus (T1DM), and T1DM plus zinc supplementation (T1DMS). Serum biochemical analysis; tibia histomorphometric, biomechanical, and collagen-content analyses; and femur mRNA expression were evaluated. Relative to T1DM, the zinc-supplemented group showed increased histomorphometric parameters such as TbWi and BAr and decreased TbSp, increased biomechanical parameters (maximum load, stiffness, ultimate strain, and Young’s modulus), and increased type I collagen content. Interestingly, similar values for these parameters were observed between the T1DMS and control groups. These results demonstrate the protective effect of zinc on the maintenance of bone strength and flexibility. In addition, downregulation of OPG, COL1A, and MMP-9 genes was observed in T1DMS, and the anabolic effects of zinc were evidenced by increased OC expression and serum ALP activity, both related to osteoblastogenesis, demonstrating a positive effect on bone formation. In contrast, T1DM showed excessive bone loss, observed through reduced histomorphometric and biomechanical parameters, characterizing diabetes-associated bone loss. The bone loss was also observed through upregulation of OPG, COL1A, and MMP-9 genes. In conclusion, zinc showed a positive effect on the maintenance of bone architecture and biomechanical parameters. Indeed, OC upregulation and control of expression of OPG, COL1A, and MMP-9 mRNAs, even in chronic hyperglycemia, support an anabolic and protective effect of zinc under chronic diabetic conditions. Furthermore, these results indicate that zinc supplementation could act as a complementary therapy in chronic T1DM. 相似文献
85.
Viviane A. V. N. Braga Gisele K. Couto Mariana C. Lazzarin Luciana V. Rossoni Alessandra Medeiros 《PloS one》2015,10(4)
Objective
Previous studies have shown that estrogen deficiency, arising in postmenopause, promotes endothelial dysfunction. This study evaluated the effects of aerobic exercise training on endothelial dependent vasodilation of aorta in ovariectomized rats, specifically investigating the role of nitric oxide (NO) and reactive oxygen species (ROS).Methods
Female Wistar rats ovariectomized (OVX – n=20) or with intact ovary (SHAM – n=20) remained sedentary (OVX and SHAM) or performed aerobic exercise training on a treadmill 5 times a week for a period of 8 weeks (OVX-TRA and SHAM-TRA). In the thoracic aorta the endothelium-dependent and –independent vasodilation was assessed by acetylcholine (ACh) and sodium nitroprusside (SNP), respectively. Certain aortic rings were incubated with L-NAME to assess the NO modulation on the ACh-induced vasodilation. The fluorescence to dihydroethidium in aortic slices and plasma nitrite/nitrate concentrations were measured to evaluate ROS and NO bioavailability, respectively.Results
ACh-induced vasodilation was reduced in OVX rats as compared SHAM (Rmax: SHAM: 86±3.3 vs. OVX: 57±3.0%, p<0.01). Training prevented this response in OVX-TRA (Rmax: OVX-TRA: 88±2.0%, p<0.01), while did not change it in SHAM-TRA (Rmax: SHAM-TRA: 80±2.2%, p<0.01). The L-NAME incubation abolished the differences in ACh-induced relaxation among groups. SNP-induced vasodilation was not different among groups. OVX reduced nitrite/nitrate plasma concentrations and increased ROS in aortic slices, training as effective to restore these parameters to the SHAM levels.Conclusions
Exercise training, even in estrogen deficiency conditions, is able to improve endothelial dependent vasodilation in rat aorta via enhanced NO bioavailability and reduced ROS levels. 相似文献86.
Milton Pereira Chrislaine Soares Gisele André Baptista Canuto Marina Franco Maggi Tavares Walter Colli Maria Julia M. Alves 《PLoS neglected tropical diseases》2015,9(4)
Background
Adhesion of the Trypanosoma cruzi trypomastigotes, the causative agent of Chagas'' disease in humans, to components of the extracellular matrix (ECM) is an important step in host cell invasion. The signaling events triggered in the parasite upon binding to ECM are less explored and, to our knowledge, there is no data available regarding •NO signaling.Methodology/Principal Findings
Trypomastigotes were incubated with ECM for different periods of time. Nitrated and S-nitrosylated proteins were analyzed by Western blotting using anti-nitrotyrosine and S-nitrosyl cysteine antibodies. At 2 h incubation time, a decrease in NO synthase activity, •NO, citrulline, arginine and cGMP concentrations, as well as the protein modifications levels have been observed in the parasite. The modified proteins were enriched by immunoprecipitation with anti-nitrotyrosine antibodies (nitrated proteins) or by the biotin switch method (S-nitrosylated proteins) and identified by MS/MS. The presence of both modifications was confirmed in proteins of interest by immunoblotting or immunoprecipitation.Conclusions/Significance
For the first time it was shown that T. cruzi proteins are amenable to modifications by S-nitrosylation and nitration. When T. cruzi trypomastigotes are incubated with the extracellular matrix there is a general down regulation of these reactions, including a decrease in both NOS activity and cGMP concentration. Notwithstanding, some specific proteins, such as enolase or histones had, at least, their nitration levels increased. This suggests that post-translational modifications of T. cruzi proteins are not only a reflex of NOS activity, implying other mechanisms that circumvent a relatively low synthesis of •NO. In conclusion, the extracellular matrix, a cell surrounding layer of macromolecules that have to be trespassed by the parasite in order to be internalized into host cells, contributes to the modification of •NO signaling in the parasite, probably an essential move for the ensuing invasion step. 相似文献87.
Gisele C. Amorim David A. Cisneros Muriel Delepierre Olivera Francetic Nadia Izadi-Pruneyre 《Biomolecular NMR assignments》2014,8(1):43-46
Bacterial type 4 pili (T4P) are long flexible fibers involved in adhesion, DNA uptake, phage transduction, aggregation and a flagella-independent movement called “twitching motility”. T4P comprise thousands of copies of the major pilin subunit, which is initially inserted in the plasma membrane, processed and assembled into dynamic helical filaments. T4P are crucial for host colonization and virulence of many Gram-negative bacteria. In enterohemorrhagic Escherichia coli the T4P, called hemorrhagic coli pili (HCP) promote cell adhesion, motility, biofilm formation and signaling. To understand the mechanism of HCP assembly and function, we analyzed the structure of the major subunit prepilin peptidase-dependent protein D (PpdD) (also called HcpA), a 15 kDa pilin with two potential disulfide bonds. Here we present the 1H, 15N and 13C backbone and side chain resonance assignments of the C-terminal globular domain of PpdD as a first step to its structural determination. 相似文献
88.
Giorgini Augusto Venturieri Adenilse Ribeiro Venturieri Gisele Leopoldo 《In vitro cellular & developmental biology. Plant》2013,49(2):137-144
Production of orchid seedlings often requires complex laboratory infrastructure; therefore, a simple and low-cost method would be of general benefit to many small-scale producers and orchid enthusiasts. This article describes a protocol for preparing culture media using a domestic microwave oven. Two alternative culture media were evaluated for a range of factors, including the duration of boiling, the efficacy of antiseptics applied to jars and media, the concentration of the antiseptic hydrogen peroxide required for sterilization, and the growth of Oncidium cebolleta and Phalaenopsis amabilis plantlets in media prepared using a microwave oven compared with conventionally autoclaved media. It was found that addition of 2 mL of 30% hydrogen peroxide (Peridrol® solution) per liter of culture medium, an 8-min boiling time in the microwave oven, and 8 g/L agar were sufficient to produce solidified culture media, which facilitated orchard seed germination and growth without contamination. Furthermore, the microwaved media exhibited superior plantlet growth to autoclaved media. 相似文献
89.
Daniel Pens Gelain Luiz Fernando de Souza Gisele Roncheti Ribeiro Marcelo Zim Fernanda Rafaela Jardim José Cláudio Fonseca Moreira 《Free radical research》2013,47(1):37-47
Extracellular purines are involved in the regulation of a wide range of physiological processes, including cytoprotection, ischemic preconditioning, and cell death. These actions are usually mediated via triggering of membrane purinergic receptors, which may activate antioxidant enzymes, conferring cytoprotection. Recently, it was demonstrated that the oxidative stress induced by cisplatin up-regulated A1 receptor expression in rat testes, suggesting an involvement of purinergic signaling in the response of testicular cells to oxidant injury. In this article, we report the effect of hydrogen peroxide on purinergic agonist release by cultured Sertoli cells. Extracellular inosine levels are strongly increased in the presence of H2O2, suggesting an involvement of this nucleoside on Sertoli cells response to oxidant treatment. Inosine was observed to decrease H2O2-induced lipoperoxidaton and cellular injury, and it also preserved cellular ATP content during H2O2 exposure. These effects were abolished in the presence of nucleoside uptake inhibitors, indicating that nucleoside internalisation is essential for its action in preventing cell damage. 相似文献
90.
Leprosy is an ancient disease and the focus of the researchers' scrutiny for more than a century. However, many of the molecular aspects related to transmission, virulence, antigens and immune responses are far from known. Initially, the implementation of recombinant DNA library screens raised interesting antigen candidates. Finally, the availability of Mycobacterium leprae genomic information showed an intriguing genome reduction which is now largely used in comparative genomics. While predictive in silico tools are commonly used to identify possible antigens, proteomic approaches have not yet been explored fully to study M. leprae biology. Quantitative information obtained at the protein level, and its analysis as part of a complex system, would be a key feature to be used to help researchers to validate and understand many of such in silico predictions. Through a re-analysis of data from a previous publication of our group, we could easily tackle many questions regarding antigen prediction and pseudogene expression. Several well known antigens are among the quantitatively dominant proteins, while several major proteins have not been explored as antigens. We argue that combining proteomic approaches together with bioinformatic workflows is a required step in the characterization of important pathogens. 相似文献