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1.
J Cardiovasc Pharmacol ; 83(5): 457-465, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38498600

RESUMO

ABSTRACT: Angiotensin (Ang)-(1-7) is a cardioprotective peptide of the renin-angiotensin system. Prepuberty has been considered as a later susceptible window of development, and stressful factors in this life phase can induce chronic diseases in adulthood. We aimed to investigate whether the treatment with Ang-(1-7) during the prepuberty could attenuate the development of hypertension and cardiac injury in adult spontaneously hypertensive rats (SHRs). SHRs were treated with Ang-(1-7) (24 µg/kg/h) from age 4 to 7 weeks. Systolic blood pressure was measured by tail-cuff plethysmography up to 17th week. Thereafter, echocardiography was performed, and the rats were euthanized for the collection of tissues and blood. Ang-(1-7) did not change the systolic blood pressure but reduced the septal and posterior wall thickness, and cardiomyocyte hypertrophy and fibrosis in SHR. In addition, Ang-(1-7) reduced the gene expression of atrial natriuretic peptide and brain natriuretic peptide, increased the metalloproteinase 9 expression, and reduced the extracellular signal-regulated kinases 1/2 phosphorylation. Ang-(1-7) also prevented the reduction of Mas receptor but did not change the protein expression of angiotensin-converting enzyme, angiotensin-converting enzyme 2, AT1, and AT2. The treatment with Ang-(1-7) decreased the malondialdehyde (MDA) levels and increased superoxide dismutase-1 and catalase activities and protein expression of catalase. Our findings demonstrate that the treatment of SHR with Ang-(1-7) for 3 weeks early in life promotes beneficial effects in the heart later in life, even without altering blood pressure, through mechanisms involving the reduction of oxidative stress and ERK1/2 phosphorylation. In addition, this study supports the prepuberty as an important programming window.


Assuntos
Angiotensina I , Pressão Sanguínea , Cardiomegalia , Hipertensão , Estresse Oxidativo , Fragmentos de Peptídeos , Ratos Endogâmicos SHR , Animais , Angiotensina I/farmacologia , Fragmentos de Peptídeos/farmacologia , Masculino , Hipertensão/fisiopatologia , Hipertensão/tratamento farmacológico , Hipertensão/prevenção & controle , Cardiomegalia/prevenção & controle , Cardiomegalia/fisiopatologia , Cardiomegalia/metabolismo , Cardiomegalia/tratamento farmacológico , Cardiomegalia/patologia , Estresse Oxidativo/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Fibrose , Modelos Animais de Doenças , Ratos , Fosforilação , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Miócitos Cardíacos/metabolismo , Peptídeo Natriurético Encefálico/metabolismo , Fatores Etários , Metaloproteinase 9 da Matriz/metabolismo , Fator Natriurético Atrial/metabolismo , Anti-Hipertensivos/farmacologia , Remodelação Ventricular/efeitos dos fármacos
2.
Fungal Genet Biol ; 144: 103446, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32822859

RESUMO

Oxygen is fundamental to the life of aerobic organisms and is not always available to Paracoccidioides cells. During the life cycle stages, reduced oxygen levels directly affect general metabolic processes and oxygen adaptation mechanisms may play a fundamental role on fungal ability to survive under such condition. Heme proteins can bind to oxygen and participate in important biological processes. Several fungi, including Paracoccidioides, express a heme-binding globin (fungoglobin - FglA) presumable to regulate fungal adaptation to hypoxia. However, the characterization of fungoglobin in Paracoccidioides spp. has not yet been performed. In this study, we predicted the structure of fungoglobin and determined its level of expression during hypoxic-mimetic conditions. Genomic screening revealed that the fungoglobin gene is conserved in all species of the Paracoccidioides genus. Molecular modeling showed biochemical and biophysical characteristics that support the hypothesis that FglA binds to the heme group and oxygen as well. The fungoglobin transcript and proteins are expressed at higher levels at the early treatment time, remaining elevated while oxygen is limited. A P. brasiliensis fglA knockdown strain depicted reduced growth in hypoxia indicating that this protein can be essential for growth at low oxygen. Biochemical analysis confirmed the binding of fungoglobin to heme. Initial analyzes were carried out to establish the relationship between FlglA and iron metabolism. The FglA transcript was up regulated in pulmonary infection, suggesting its potential role in the disease establishment. We believe that this study can contribute to the understanding of fungal biology and open new perspectives for scientific investigations.


Assuntos
Proteínas Fúngicas/genética , Heme/genética , Hemeproteínas/genética , Paracoccidioides/genética , Aerobiose/genética , Hipóxia Celular/genética , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica/genética , Heme/metabolismo , Hemeproteínas/metabolismo , Oxigênio/metabolismo , Paracoccidioides/metabolismo
3.
Microb Pathog ; 149: 104281, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32585293

RESUMO

Paracoccidioides complex is a genus that comprises pathogenic fungi which are responsible by systemic disease Paracoccidioidomycosis. In host tissues, pathogenic fungi need to acquire nutrients in order to survive, making the uptake of nitrogen essential for their establishment and dissemination. Nitrogen utilization is employed by the alleviation of Nitrogen Catabolite Repression (NCR) which ensures the use of non-preferential or alternative nitrogen sources when preferential sources are not available. NCR is controlled by GATA transcription factors which act through GATA binding sites on promoter regions in NCR-sensitive genes. This process is responsible for encoding proteins involved with the scavenge, uptake and catabolism of a wide variety of non-preferential nitrogen sources. In this work, we predict the existence of AreA GATA transcription factor and feature the zinc finger domain by three-dimensional structure in Paracoccidioides. Furthermore, we demonstrate the putative genes involved with NCR response by means of in silico analysis. The gene expression profile under NCR conditions was evaluated. Demonstrating that P. lutzii supported transcriptional regulation and alleviated NCR in non-preferential nitrogen-dependent medium. The elucidation of NCR in members of Paracoccidioides complex will provide new knowledge about survival, dissemination and virulence for these pathogens with regard to nitrogen-scavenging strategies in the interactions of host-pathogens.


Assuntos
Repressão Catabólica , Paracoccidioides , Regulação Fúngica da Expressão Gênica , Nitrogênio/metabolismo , Paracoccidioides/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
4.
J Appl Toxicol ; 37(9): 1098-1107, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28425566

RESUMO

Ecotoxicity of glyphosate (GLY) and its metabolite aminomethylphosphonic acid (AMPA) was investigated in guppies, Poecilia reticulata. We tested the effects of these chemicals on the gills and liver of both male and female guppies using qualitative and quantitative histopathological analyses associated with histopathological condition indexes. Both genders showed similar median lethal concentration (LC50 ) at 96 h for GLY (68.78 and 70.87 mg l-1 ) and AMPA (180 and 164.32 mg l-1 ). However, the histopathological assessment of both fish organs exposed to sublethal concentrations of GLY (35 mg l-1 ) and AMPA (82 mg l-1 ) for 96 h showed a tissue- and gender-specific histopathological response. In both exposure assays, fish presented mainly progressive changes, such as proliferation of the interlamellar epithelium, partial and total fusion of secondary lamellae. The liver showed mainly regressive changes, such as steatosis, pyknotic nuclei and high distribution of collagen fibers. Unusually large hepatocytes as degenerated cells were also detected. Histopathological changes in gills were similar for the males and females, but the liver response was different between the genders. The hepatic inflammatory changes were more common in males. The increase in the area of hepatocyte vacuoles is gender dependent with higher values in the male compared to the female guppies exposed to GLY and AMPA. Multiparametric analysis indicated that the male guppies are more sensitive than females, particularly in the presence of AMPA. Our study shows that the histopathological assessment associated with gender-specific response can be successfully used in ecotoxicological assessment of GLY and the metabolite AMPA. Copyright © 2017 John Wiley & Sons, Ltd.


Assuntos
Glicina/análogos & derivados , Isoxazóis/toxicidade , Poecilia/metabolismo , Fatores Sexuais , Tetrazóis/toxicidade , Animais , Feminino , Brânquias/efeitos dos fármacos , Brânquias/metabolismo , Glicina/toxicidade , Dose Letal Mediana , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Análise de Componente Principal , Glifosato
5.
Cureus ; 16(1): e52679, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38380218

RESUMO

The triad of diabetic ketoacidosis, hypertriglyceridemia, and acute pancreatitis is a rare presentation of diabetes mellitus type 2 in adults. We report a case of a 41-year-old male who presented at the emergency department with a sudden onset of severe abdominal pain. Diagnosis of diabetic ketoacidosis, hypertriglyceridemia, and acute pancreatitis was made. Triglyceride level was 6056 mg/dL and glycated hemoglobin was 12.6%. Vigorous fluid therapy and continuous infusion of insulin were started, but due to maintained symptoms, a single plasmapheresis session was performed, with significant clinical improvement. This case emphasizes the diagnostic challenges of the triad and highlights the potential role of plasmapheresis in rapidly reducing triglyceride levels.

6.
Biomol NMR Assign ; 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39269603

RESUMO

Research on camelid-derived single-domain antibodies (sdAbs) has demonstrated their significant utility in diverse biotechnological applications, including therapy and diagnostic. This is largely due to their relative simplicity as monomeric proteins, ranging from 12 to 15 kDa, in contrast to immunoglobulin G (IgG) antibodies, which are glycosylated heterotetramers of 150-160 kDa. Single-domain antibodies exhibit high conformational stability and adopt the typical immunoglobulin domain fold, consisting of a two-layer sandwich of 7-9 antiparallel beta-strands. They contain three loops, known as complementary-determining regions (CDRs), which are assembled on the sdAb surface and are responsible for antigen recognition. The single-domain antibody examined in this study, sdAb-mrh-IgG, was engineered to recognize IgG from rats, mice, but it also weakly recognizes IgG from humans (Pleiner et al. 2018). A search of the Protein Data Bank revealed only one NMR structure of a single-domain antibody, which is unrelated to sdAb-mrh-IgG. The NMR chemical shift assignments of sdAb-mrh-IgG will be utilized to study its molecular dynamics and interactions with antigens in solution, which is fundamental for the rational design of novel single-domain antibodies.

7.
PLoS Negl Trop Dis ; 18(9): e0012452, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39226308

RESUMO

The formamidase (FMD) enzyme plays an important role in fungal thriving by releasing a secondary nitrogen source as a product of its activity. In Paracoccidioides species, previous studies have demonstrated the upregulation of this enzyme in a wide range of starvation and infective-like conditions. However, Paracoccidioides lutzii formamidase has not yet been defined as a virulence factor. Here, by employing in vivo infections using an fmd-silenced strain in Galleria mellonella larvae model, we demonstrate the influence of formamidase in P. lutzii's immune stimulation and pathogenicity. The formamidase silencing resulted in improper arrangement of the nodules, poor melanogenesis and decreased fungal burden. Thus, we suggest that formamidase may be a piece composing the process of molecular recognition by Galleria immune cells. Furthermore, formamidase silencing doubled the observed survival rate of the larvae, demonstrating its importance in fungal virulence in vivo. Therefore, our findings indicate that formamidase contributes to Galleria's immune incitement and establishes the role of this enzyme as a P. lutzii virulence factor.


Assuntos
Larva , Mariposas , Paracoccidioides , Fatores de Virulência , Animais , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Larva/microbiologia , Mariposas/microbiologia , Paracoccidioides/patogenicidade , Paracoccidioides/enzimologia , Paracoccidioides/genética , Virulência , Paracoccidioidomicose/microbiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Modelos Animais de Doenças , Inativação Gênica
8.
PLoS One ; 18(11): e0288178, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38032879

RESUMO

Since angiotensin-converting enzyme 2, ACE2, was identified as the receptor for SARS-CoV-2 and considering the intense physiological interplay between the two angitensinases isoforms, ACE and ACE2, as counter-regulatory axis of the renin-angiotensin system, we proposed the evaluation of polymorphisms in these two key regulators in relation to COVID-19 severity. A genetic association study involving 621 COVID-19 hospitalized patients from Brazil was performed. All subjects had a confirmed diagnosis of COVID-19 via RT-PCR. Patients were categorized into two groups: the "mild" group (N = 296), composed of individuals hospitalized in ward beds who progressed to cure, and the "severe" group (N = 325), composed of individuals who required hospitalization in an intensive care unit (ICU), or who died. Blood samples were genotyped for ACE I/D polymorphism and ACE2 G8790A polymorphism by real-time PCR via TaqMan assay. The analysis of combined polymorphisms revealed a protective role for genotypic profile II/A_ (ORA = 0,26; p = 0,037) against the worsening of COVID-19 in women. The results indicate a protection profile to COVID-19 progression, in which the II/A_ carriers have almost four times less chance of a severe outcome. It is proposed that a decreased activity of ACE (deleterious effects) in conjunction with an increased ACE2 activity (protective effects), should be the underlying mechanism. The findings are unprecedented once other studies have not explored the genotypic combination analysis for ACE and ACE2 polymorphisms and bring perspectives and expectations for dealing with the COVID-19 pandemic based on definitions of genetically-based risk groups within the context of personalized medicine.


Assuntos
Enzima de Conversão de Angiotensina 2 , COVID-19 , Peptidil Dipeptidase A , Feminino , Humanos , Enzima de Conversão de Angiotensina 2/genética , Brasil/epidemiologia , COVID-19/genética , Estudos de Associação Genética , Pandemias , Peptidil Dipeptidase A/genética , Peptidil Dipeptidase A/metabolismo , Sistema Renina-Angiotensina/genética
9.
Artigo em Inglês | MEDLINE | ID: mdl-36674238

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic has changed the course of human history and killed millions of people worldwide. Its long-term consequences remain uncertain. This study aimed to describe the short- and long-term symptoms of COVID-19 among individuals in Goiás, central Brazil, who experienced acute mild or non-symptomatic SARS-CoV-2 infection during the first wave of the pandemic. This prospective cohort study included 110 healthcare workers, 18 safety workers, and 19 administrative support workers, who were followed up for 12 months after the onset of COVID-19. Most participants were healthy adult female healthcare professionals. At the onset of infection, the major symptoms were headache, myalgia, nasal congestion, cough, coryza, anosmia, ageusia, sore throat, fatigue, diarrhea, and dyspnea. Furthermore, 20.3% of the participants had three or more COVID-19 symptoms that persisted for at least 12 months. These included coryza, congestion, hair loss, sore throat, headache, myalgia, cough, memory loss, anosmia, and fatigue. This study revealed a high prevalence of persistent symptoms of COVID-19 in healthy individuals from central Brazil, which may present an additional burden on healthcare services. Further studies are required to investigate the sequelae of COVID-19 over periods greater than 12 months.


Assuntos
COVID-19 , Faringite , Adulto , Humanos , Feminino , COVID-19/epidemiologia , SARS-CoV-2 , Mialgia , Anosmia , Tosse/epidemiologia , Estudos Prospectivos , Cefaleia/epidemiologia , Cefaleia/etiologia , Faringite/epidemiologia , Pessoal de Saúde , Fadiga/epidemiologia , Fadiga/etiologia , Atenção à Saúde
10.
J Fungi (Basel) ; 9(11)2023 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-37998907

RESUMO

Members of the Paracoccidioides complex are the causative agents of Paracoccidioidomycosis (PCM), a human systemic mycosis endemic in Latin America. Upon initial contact with the host, the pathogen needs to uptake micronutrients. Nitrogen is an essential source for biosynthetic pathways. Adaptation to nutritional stress is a key feature of fungi in host tissues. Fungi utilize nitrogen sources through Nitrogen Catabolite Repression (NCR). NCR ensures the scavenging, uptake and catabolism of alternative nitrogen sources, when preferential ones, such as glutamine or ammonium, are unavailable. The NanoUPLC-MSE proteomic approach was used to investigate the NCR response of Paracoccidioides lutzii after growth on proline or glutamine as a nitrogen source. A total of 338 differentially expressed proteins were identified. P. lutzii demonstrated that gluconeogenesis, ß-oxidation, glyoxylate cycle, adhesin-like proteins, stress response and cell wall remodeling were triggered in NCR-proline conditions. In addition, within macrophages, yeast cells trained under NCR-proline conditions showed an increased ability to survive. In general, this study allows a comprehensive understanding of the NCR response employed by the fungus to overcome nutritional starvation, which in the human host is represented by nutritional immunity. In turn, the pathogen requires rapid adaptation to the changing microenvironment induced by macrophages to achieve successful infection.

11.
J Fungi (Basel) ; 9(6)2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37367569

RESUMO

Fungal infections represent a serious global health problem, causing damage to health and the economy on the scale of millions. Although vaccines are the most effective therapeutic approach used to combat infectious agents, at the moment, no fungal vaccine has been approved for use in humans. However, the scientific community has been working hard to overcome this challenge. In this sense, we aim to describe here an update on the development of fungal vaccines and the progress of methodological and experimental immunotherapies against fungal infections. In addition, advances in immunoinformatic tools are described as an important aid by which to overcome the difficulty of achieving success in fungal vaccine development. In silico approaches are great options for the most important and difficult questions regarding the attainment of an efficient fungal vaccine. Here, we suggest how bioinformatic tools could contribute, considering the main challenges, to an effective fungal vaccine.

12.
Pathogens ; 11(5)2022 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-35631090

RESUMO

Systemic mycoses have been viewed as neglected diseases and they are responsible for deaths and disabilities around the world. Rapid, low-cost, simple, highly-specific and sensitive diagnostic tests are critical components of patient care, disease control and active surveillance. However, the diagnosis of fungal infections represents a great challenge because of the decline in the expertise needed for identifying fungi, and a reduced number of instruments and assays specific to fungal identification. Unfortunately, time of diagnosis is one of the most important risk factors for mortality rates from many of the systemic mycoses. In addition, phenotypic and biochemical identification methods are often time-consuming, which has created an increasing demand for new methods of fungal identification. In this review, we discuss the current context of the diagnosis of the main systemic mycoses and propose alternative approaches for the identification of new targets for fungal pathogens, which can help in the development of new diagnostic tests.

13.
Microbes Infect ; 24(6-7): 104975, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35381358

RESUMO

The genus Paracoccidioides comprises the species complex causing paracoccidioidomycoses (PCM). These fungi are a serious public health problem due to the long-term drug therapy, follow-up treatment, and frequent sequelae generated by the infection, such as pulmonary fibrosis. In this sense, the objective of this work was to generate bioluminescent reporter strains of Paracoccidioides spp. harboring a thermostable, red-shifted luciferase gene under the control of different constitutive promoters. The strains were generated by the integration of a species-specific codon-optimized luciferase gene upon actin or enolase promoter's control. The insertion of the constructs in Paracoccidioides brasiliensis and Paracoccidioides lutzii yeast cells were performed through Agrobacterium tumefaciens-mediated transformation. The results demonstrated the presence of several transformants harboring the luciferase gene. These transformants were further confirmed by the expression of luciferase and by the presence of the hygromycin resistance gene. Moreover, the luciferase activity could be detected in in vitro bioluminescence assays and in vivo models of infection. In general, this work presents the methodology for the construction of bioluminescent strains of Paracoccidioides spp., highlighting potential promoters and proposing an in vivo model, in which those strains could be used for the systemic study of PCM.


Assuntos
Paracoccidioides , Paracoccidioidomicose , Actinas , Paracoccidioides/genética , Paracoccidioidomicose/microbiologia , Fosfopiruvato Hidratase
14.
Microorganisms ; 10(10)2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36296287

RESUMO

Nitrogen is a crucial nutrient for microorganisms that compose essential biomolecules. However, hosts limit this nutrient as a strategy to counter infections, therefore, pathogens use adaptive mechanisms to uptake nitrogen from alternative sources. In fungi, nitrogen catabolite repression (NCR) activates transcription factors to acquire nitrogen from alternative sources when preferential sources are absent. Formamidase has been related to nitrogen depletion in Aspergillus nidulans through formamide degradation to use the released ammonia as a nitrogen source. In Paracoccidioides spp., formamidase is highly expressed in transcriptomic and proteomic analyses. Here, we aim to investigate the importance of formamidase to Paracoccidioides lutzii. Thereby, we developed a P. lutzii silenced strain of fmd gene (AsFmd) by antisense RNA technology using Agrobacterium tumefaciens-mediated transformation (ATMT). The AsFmd strain led to increased urease expression, an enzyme related to nitrogen assimilation in other fungi, suggesting that P. lutzii might explore urease as an alternative route for ammonia metabolism as a nitrogen source. Moreover, formamidase was important for fungal survival inside macrophages, as fungal recovery after macrophage infection was lower in AsFmd compared to wild-type (WT) strain. Our findings suggest potential alternatives of nitrogen acquisition regulation in P. lutzii, evidencing formamidase influence in fungal virulence.

15.
J Bodyw Mov Ther ; 27: 535-542, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34391283

RESUMO

INTRODUCTION: There is controversy about the repercussions of high speed-low amplitude thrust (HVLAT) manipulation in the thoracic region on the autonomic nervous system. OBJECTIVE: To evaluate the immediate effects of the HVLAT in the high thoracic region on the heart rate autonomic modulation of judo athletes. METHODS: In the experimental study, thirty-eight healthy men divided into 2 groups (Judo athletes and non-athletes) having heart rate variability (HRV) collected beat-to-beat using a cardio-pacemater during all stages of the manipulation: i) rest, ii) time 1 (participant positioning), iii) time 2 (positioning of the participant together with the therapist), iv) HVLAT manipulation, v) post 5min, vi) post 10min and vii) post 15min HVLAT. Systolic blood pressure (SBP), diastolic blood pressure (DBP), breath frequency (BF), and HRV were also analyzed. RESULTS: A higher sympathetic modulation was observed with an increase in the standard deviation of successive normal R-R intervals (SDNN) and SD2 indices representing the total variability, however, there was no significant statistical difference in the root mean square of the mean squared differences (RMSSD), percentual of interval differences of successive NN intervals greater than 50 ms (pNN50), and SD1 variables, which represent the parasympathetic nervous system. CONCLUSION: HVLAT manipulation was able to decrease HRV during manipulation, reflecting sympathetic hyperactivity. However, the return of the HRV indices to the baseline conditions in the first minutes of recovery in Judo athletes and non-athletes reflected the safety of the application of the manipulation in these conditions studied.


Assuntos
Sistema Nervoso Autônomo , Artes Marciais , Atletas , Pressão Sanguínea , Frequência Cardíaca , Humanos , Masculino
16.
Eur J Case Rep Intern Med ; 8(3): 002360, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33768082

RESUMO

Hypercalcaemia is a frequent finding in malignancies including lymphomas. However, there are no reports of hypercalcaemia in hepatosplenic T-cell lymphoma (HSTCL). HSTCL is a rare and aggressive neoplasm which is usually difficult to diagnose. We present a case of HSTCL in which hypercalcaemia was the initial presentation. LEARNING POINTS: Hepatosplenic T-cell lymphoma (HSTCL) is difficult to diagnose, has a poor prognosis and usually presents with hepatosplenomegaly, B symptoms and cytopenias.Hypercalcaemia is an extremely rare clinical presentation of HSTCL.Severe hypercalcaemia is a life-threatening condition and should always be corrected and investigated.

17.
Front Neurosci ; 14: 551, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32655350

RESUMO

In this work, we present a neuromorphic architecture for head pose estimation and scene representation for the humanoid iCub robot. The spiking neuronal network is fully realized in Intel's neuromorphic research chip, Loihi, and precisely integrates the issued motor commands to estimate the iCub's head pose in a neuronal path-integration process. The neuromorphic vision system of the iCub is used to correct for drift in the pose estimation. Positions of objects in front of the robot are memorized using on-chip synaptic plasticity. We present real-time robotic experiments using 2 degrees of freedom (DoF) of the robot's head and show precise path integration, visual reset, and object position learning on-chip. We discuss the requirements for integrating the robotic system and neuromorphic hardware with current technologies.

18.
Fungal Biol ; 124(9): 766-780, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32883428

RESUMO

Fungi of the genus Paracoccidioides are the etiological agents of Paracoccidioidomycosis (PCM), the most prevalent mycosis in Latin America. Paracoccidioidomycosis infection is acquired by inhalation of Paracoccidioides conidia, which have first contact with the lungs and can subsequently spread to other organs/tissues. Until now, there have been no proteomic studies focusing on this infectious particle of Paracoccidioides. In order to identify the Paracoccidioides lutzii conidia proteome, conidia were produced and purified. Proteins were characterized by use of the nanoUPLC-MSE approach. The strategy allowed us to identify a total of 242 proteins in P. lutzii conidia. In the conidia proteome, proteins were classified in functional categories such as protein synthesis, energy production, metabolism, cellular defense/virulence processes, as well as other processes that can be important for conidia survival. Through this analysis, a pool of ribosomal proteins was identified, which may be important for the initial processes of dimorphic transition. In addition, molecules related to energetic and metabolic processes were identified, suggesting a possible basal metabolism during this form of resistance of the fungus. In addition, adhesins and virulence factors were identified in the P. lutzii conidia proteome. Our results demonstrate the potential role that these molecules can play during early cell-host interaction processes, as well as the way in which these molecules are involved in environmental survival during this form of propagation.


Assuntos
Paracoccidioides , Proteoma , Esporos Fúngicos , Paracoccidioides/metabolismo , Esporos Fúngicos/metabolismo
19.
IMA Fungus ; 11: 11, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32742914

RESUMO

Iron is an essential nutrient for all organisms. For pathogenic fungi, iron is essential for the success of infection. Thus, these organisms have developed high affinity iron uptake mechanisms to deal with metal deprivation imposed by the host. Siderophore production is one of the mechanisms that fungal pathogens employ for iron acquisition. Paracoccidioides spp. present orthologous genes encoding the enzymes necessary for the biosynthesis of hydroxamates, and plasma membrane proteins related to the transport of these molecules. All these genes are induced in iron deprivation. In addition, it has been observed that Paracoccidioides spp. are able to use siderophores to scavenge iron. Here we observed that addition of the xenosiderophore ferrioxamine B FOB) to P. brasiliensis culture medium results in repression (at RNA and protein levels) of the SidA, the first enzyme of the siderophore biosynthesis pathway. Furthermore, SidA activity was reduced in the presence of FOB, suggesting that P. brasiliensis blocks siderophores biosynthesis and can explore siderophores in the environment to scavenge iron. In order to support the importance of siderophores on Paracoccidioides sp. life and infection cycle, silenced mutants for the sidA gene were obtained by antisense RNA technology. The obtained AsSidA strains displayed decreased siderophore biosynthesis in iron deprivation conditions and reduced virulence to an invertebrate model.

20.
Pest Manag Sci ; 65(1): 34-40, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18785221

RESUMO

BACKGROUND: Avenaciolide, a natural product isolated from Aspergillus avenaceus H. Smith, possesses several interesting biological properties, such as antifungal and antibacterial activities and inhibition of glutamate transport in mitochondria. In a study aiming to discover new compounds with antifungal activity, a bis-gamma-lactone analogous to avenaciolide was prepared and characterized by elemental analysis, mass spectrometry, and infrared and NMR spectroscopy. RESULTS: The absolute structures of this compound and of the synthetic precursor (also a bis-gamma-lactone) were determined by X-ray diffraction analysis. The bis-gamma-lactones synthesized crystallize in the orthorhombic space group P2(1)2(1)2(1), and the crystal packings are supported by C--H...O hydrogen bonds. The compound showed antifungal activity against Colletotrichum gloeosporioides (Penz.) Penz. & Sacc., while the synthetic precursor was inactive under the in vitro test conditions employed. CONCLUSION: The results indicate that it is not only the bis-gamma-lactone skeleton that is important to antifungal activity. The latter also depends on the presence of the exocyclic double bond possibly due to a Michael addition type reaction with the fungal enzymes.


Assuntos
Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Lactonas/química , Lactonas/farmacologia , Colletotrichum/efeitos dos fármacos , Modelos Moleculares , Estrutura Molecular
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