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1.
Pathogens ; 13(8)2024 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-39204231

RESUMO

BACKGROUND: Leishmaniasis is a significant global public health issue that is caused by parasites from Leishmania genus. With limited treatment options and rising drug resistance, there is a pressing need for new therapeutic approaches. Molecular chaperones, particularly Hsp90, play a crucial role in parasite biology and are emerging as promising targets for drug development. OBJECTIVE: This study evaluates the efficacy of 17-DMAG in treating BALB/c mice from cutaneous leishmaniasis through in vitro and in vivo approaches. MATERIALS AND METHODS: We assessed 17-DMAG's cytotoxic effect on bone marrow-derived macrophages (BMMΦ) and its effects against L. braziliensis promastigotes and intracellular amastigotes. Additionally, we tested the compound's efficacy in BALB/c mice infected with L. braziliensis via intraperitoneal administration to evaluate the reduction in lesion size and the decrease in parasite load in the ears and lymph nodes of infected animals. RESULTS: 17-DMAG showed selective toxicity [selective index = 432) towards Leishmania amastigotes, causing minimal damage to host cells. The treatment significantly reduced lesion sizes in mice and resulted in parasite clearance from ears and lymph nodes. It also diminished inflammatory responses and reduced the release of pro-inflammatory cytokines (IL-6, IFN-γ, TNF) and the regulatory cytokine IL-10, underscoring its dual leishmanicidal and anti-inflammatory properties. CONCLUSIONS: Our findings confirm the potential of 17-DMAG as a viable treatment for cutaneous leishmaniasis and support further research into its mechanisms and potential applications against other infectious diseases.

2.
Vet Parasitol Reg Stud Reports ; 53: 101060, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39025553

RESUMO

Snakes of the genus Bothrops inhabit tropical forests in Central and South America and are important for the biomedical and pharmaceutical industries because of the chemical properties of their venom. They serve as either definitive or intermediate hosts for many parasitic helminths. The Marajó Island (Brazil) is the natural habitat of venomous snakes, Bothrops atrox and Bothrops marajoensis, which are often found around rural and peri-urban areas and are known to bite humans. Samples of helminths parasitizing the oral cavity, subcutaneous tissues, coelomic cavity, and intestine of four B. atrox from Marajó Island (Pará-Brazil) were collected. The specimens studied were taxonomically classified as trematodes of the species Stycholecitha serpentis, nematodes of the genera Eustrongylides and Camallanus and cystacanths of an acanthocephalan of the genus Centrorhynchus. The aims of the present study were: to record helminths found in B. atrox from the Marajó Island; to discuss their role as definitive, intermediate, or paratenic hosts; and to compile a list of helminths that have been recorded in snakes of the genus Bothrops of the Neotropical region.


Assuntos
Bothrops , Helmintíase Animal , Animais , Bothrops/parasitologia , Brasil/epidemiologia , Helmintíase Animal/parasitologia , Helmintíase Animal/epidemiologia , Masculino , Helmintos/classificação , Helmintos/isolamento & purificação , Feminino , Bothrops atrox
3.
PLoS Negl Trop Dis ; 18(6): e0011877, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38843306

RESUMO

The spleen plays a pivotal role in the pathogenesis of visceral leishmaniasis. In severe forms of the disease, the spleen undergoes changes that can compromise its function in surveilling blood-circulating pathogens. In this study, we present an integrated analysis of the structural and gene expression alterations in the spleens of three patients with relapsing visceral leishmaniasis, two of whom were coinfected with HIV. Our findings reveal that the IL6 signaling pathway plays a significant role in the disorganization of the white pulp, while BCL10 and ICOSLG are associated with spleen organization. Patients coinfected with HIV and visceral leishmaniasis exhibited lower splenic CD4+ cell density and reduced expression of genes such as IL15. These effects may contribute to a compromised immune response against L. infantum in coinfected individuals, further impacting the structural organization of the spleen.


Assuntos
Coinfecção , Infecções por HIV , Leishmaniose Visceral , Baço , Humanos , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/genética , Baço/patologia , Infecções por HIV/complicações , Coinfecção/virologia , Masculino , Adulto , Feminino , Linfócitos T CD4-Positivos/imunologia , Leishmania infantum/genética , Expressão Gênica
4.
Parasitol Res ; 123(2): 125, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38326631

RESUMO

During bacterial and viral pathogen investigation of 30 specimens of bats captured in periurban forest areas in the city of Belém, Pará, Brazil, a case of cerebral filariasis was observed. In the course of histopathological examination, adult filariae were found in pseudocystic cavities brain of Molossus barnesi (Molossidae) and classified morphologically as Litomosoides by the shape of the spicules-left spicule with a handle longer than the blade; right spicule curved, with a sclerotized heel supporting a dorsal notch; the area rugosa constituted by a ventral band of small longitudinal crests; tail rounded in males; long esophagus with a slightly glandular distal portion; and a muscular bent vagina. All the specimens lack a stoma (buccal capsule). We compared our filarioids with the description of specimens of Molossinema wimsatti. Morphological characteristics of M. wimsatti resemble the genus Litomosoides. Thus, we believe that M. wimsatti is a synonym of L. molossi Esslinger, 1973, and filarioid specimens from material reported by Lichtenfels et al. (Trans Am Micros Soc 100:216-219, 1981) and from de Souto et al. (J. Helminthol 1195:e65, 2021) most probably correspond to Litomosoides. We suggest that the reduction of the buccal capsule may be attributable to the ectopic location. No evidence of tissue responses by the host was observed. This is the first record of Litomosoides infecting brain tissue of Molossus barnesi from Brazil, representing a record of a new host species. More specimens of bats should be examined in order to find filarioids in the brain and verify its taxonomic position using molecular techniques.


Assuntos
Quirópteros , Filariose , Filarioidea , Animais , Feminino , Masculino , Brasil , Meio Ambiente , Filariose/veterinária
5.
Front Cell Dev Biol ; 11: 1206049, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37576604

RESUMO

Background: Leishmaniasis results in a wide spectrum of clinical manifestations, ranging from skin lesions at the site of infection to disseminated lesions in internal organs, such as the spleen and liver. While the ability of Leishmania-infected host cells to migrate may be important to lesion distribution and parasite dissemination, the underlying mechanisms and the accompanying role of host cells remain poorly understood. Previously published work has shown that Leishmania infection inhibits macrophage migration in a 2-dimensional (2D) environment by altering actin dynamics and impairing the expression of proteins involved in plasma membrane-extracellular matrix interactions. Although it was shown that L. infantum induces the 2D migration of dendritic cells, in vivo cell migration primarily occurs in 3-dimensional (3D) environments. The present study aimed to investigate the migration of macrophages and dendritic cells infected by Leishmania using a 3-dimensional environment, as well as shed light on the mechanisms involved in this process. Methods: Following the infection of murine bone marrow-derived macrophages (BMDM), human macrophages and human dendritic cells by L. amazonensis, L. braziliensis, or L. infantum, cellular migration, the formation of adhesion complexes and actin polymerization were evaluated. Results: Our results indicate that Leishmania infection inhibited 3D migration in both BMDM and human macrophages. Reduced expression of proteins involved in adhesion complex formation and alterations in actin dynamics were also observed in Leishmania-infected macrophages. By contrast, increased human dendritic cell migration in a 3D environment was found to be associated with enhanced adhesion complex formation and increased actin dynamics. Conclusion: Taken together, our results show that Leishmania infection inhibits macrophage 3D migration, while enhancing dendritic 3D migration by altering actin dynamics and the expression of proteins involved in plasma membrane extracellular matrix interactions, suggesting a potential association between dendritic cells and disease visceralization.

6.
Pathog Dis ; 812023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-37401145

RESUMO

Cutaneous leishmaniasis is an infectious disease that may lead to a single or multiple disseminated cutaneous lesions. The mechanisms involved in Leishmania dissemination to different areas of the skin and the internal organs remain poorly understood. Evidence shows that Very Late Antigen-4 (VLA-4)-dependent phagocyte adhesion is impaired by Leishmania infection, which may be related to the mechanisms of parasite dissemination. We investigated factors potentially associated with decreased VLA-4-mediated adhesion in Leishmania-infected macrophages, including lipid raft-mediated VLA-4 mobilization along the cellular membrane, integrin cluster formation at the cell base (adhesion site), and focal adhesion complex assembly. Phagocytes treated with Methyl-ß-Cyclodextrin (MßCD) demonstrated reduced adhesion, similarly to Leishmania amazonensis-infected J774 cells. Infected and MßCD-treated macrophages presented decreased VLA-4 mobilization to the adhesion plane, as well as reduced integrin clustering. Leishmania amazonensis-infected cells exhibited talin depletion, as well as a decreased mobilization of adhesion complex proteins, such as talin and viculin, which were associated with lower VLA-4 concentrations at the adhesion site and limited cell-spreading. Our results suggest that Leishmania infection may modulate the firm adhesion phase of the cell-spreading process, which could contribute to the bloodstream dissemination of infected cells.


Assuntos
Leishmania mexicana , Leishmania , Leishmaniose Cutânea , Humanos , Integrina alfa4beta1 , Talina , Leishmaniose Cutânea/parasitologia , Análise por Conglomerados
7.
J Med Primatol ; 52(4): 272-275, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37329235

RESUMO

We report two cases of disseminated hyperinfection by filariae in free-living primates Saimiri sciureus and Saguinus niger from eastern Amazon. Histopathological examination showed the presence of Dipetalonema gracile microfilariae in blood, liver, lungs, spleen, small intestine, kidney, brain, liver, and adults in peritoneal thoracic cavity.


Assuntos
Dipetalonema , Animais , Saimiri
8.
Pharmaceuticals (Basel) ; 16(5)2023 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-37242472

RESUMO

Margaritaria nobilis L.f. (Phyllanthaceae), a native Brazilian tree occurring mainly in the Amazon, is used in folk medicine for the treatment of abscesses (bark) and cancer-like symptoms (leaves). The present study evaluates the safety of its acute oral administration and its effects on nociception and plasma leakage. The chemical constitution of the leaf's ethanolic extract is determined by ultra-performance liquid chromatography-high-resolution mass spectrometry (LC-MS. Its acute oral toxicity is evaluated in female rats at a dose of 2000 mg/kg, evaluating the occurrence of deaths and Hippocratic, behavioral, hematological, biochemical, and histopathological changes, as well as food and water consumption and weight gain. Antinociceptive activity is evaluated in male mice with acetic-acid-induced peritonitis (APT) and formalin (FT) tests. An open field (OF) test is performed to verify possible interferences in the animals' consciousness or locomotion. LC-MS analysis shows the presence of 44 compounds classified as phenolic acid derivatives, flavonoids and O-glycosylated derivatives, and hydrolyzable tannins. No deaths or significant behavioral, histological, or biochemical changes are observed in the toxicity assessment. In nociception tests, M. nobilis extract significantly reduces abdominal contortions in APT, demonstrating selectivity for inflammatory components (FT second phase), not interfering in neuropathic components (FT first phase) or consciousness and locomotion levels in OF. Additionally, M. nobilis extract inhibits plasma acetic-acid-induced leakage. These data demonstrate the low toxicity of M. nobilis ethanolic extract, as well as its effectiveness in modulating inflammatory nociception and plasma leakage, possibly related to the flavonoids and tannins present in its composition.

10.
Environ Sci Pollut Res Int ; 30(9): 23047-23059, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36316547

RESUMO

Slow-release urea fertilisers have been shown to present acceptable values for plant yield and mitigate the harmful effect of soil emission gases. This study synthesises a slow-release fertiliser containing fumed-nanosilica, nanofibrillated cellulose as well as sodium alginate as a urea carrier to analyse the growth parameters of Eucalyptus urograndis seedlings and potential emission of soil gases, N2O, CH4, CO2 and ammonia volatilisation. The developed supraparticles, arranged layered nanoparticle structure, presented a decrease in the normal nitrogen content of urea of 19%, which is attributed to the binding of this element. A good electrostatic interaction between the elements was confirmed by the FTIR with 20% of nitrogen content from its chemical composition and an increase in thermal degradation of the main components when synthesised. The profile of urea release presented to be as first-order with 85% of this compound was released only after 60 days. These characteristics led to statistically increased growth of Eucalyptus seedlings compared to the controls, which improves with higher dosages of urea. Values of biomass and characteristics of the plant were used for principal component analysis which resulted in good cluster formation based on the upward concentration of urea added to the plant. Nevertheless, flux gases were statistically higher for certain time periods on lower urea particle concentration, while increased concentration presented N2O emissions within standard rates with no significant variation in the other measured gases, which was attributed to the soil microbial targeted consumption. Therefore, this material can be beneficial in the agriculture industry.


Assuntos
Eucalyptus , Gases de Efeito Estufa , Gases de Efeito Estufa/análise , Fertilizantes/análise , Eucalyptus/metabolismo , Plântula/metabolismo , Óxido Nitroso/análise , Metano/análise , Gases/análise , Agricultura/métodos , Solo/química , Nitrogênio/análise , Ureia/química
11.
Biota Neotrop. (Online, Ed. ingl.) ; 23(4): e20231520, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1527942

RESUMO

Abstract It is repeatedly stressed the need to characterize the extant biodiversity in tropical ecosystems. However, inventory studies are still progressing slowly in dry ecosystems, leading to the underestimation of their true biodiversity and hindering conservation efforts. In this study, we present primary and secondary data, along with an updated list of amphibians and reptiles from two localities in the São Francisco-Gurguéia region in Piauí. Additionally, we compare the species composition between nine areas within the Caatinga, which were sampled using standardized methods over the past ten years, to examine broader spatial patterns of community composition. To survey reptiles and amphibians, we employed similar methods and sampling efforts in two areas within the Serra das Confusões National Park (SCNP) region. Our surveys recorded a total of 73 species of amphibians and reptiles, of which 24 are new distribution records for the SCNP region. Consequently, our findings increase the known herpetofauna in the region to 94 species. Despite their proximity, the two sites in the SCNP region exhibited only 42% similarity in species composition, and they differed significantly from other areas within the Caatinga. Furthermore, even the closer Caatinga areas presented differences in species composition, highlighting the necessity to evaluate biodiversity across the landscape and contribute to understanding biogeographic patterns.


Resumo É repetidamente enfatizada a necessidade de caracterizar a biodiversidade vivente em ecossistemas tropicais. No entanto, os estudos de inventário ainda estão progredindo lentamente em ecossistemas secos, levando à subestimação de sua verdadeira biodiversidade e dificultando os esforços de conservação. Neste estudo, apresentamos dados primários e secundários, juntamente com uma lista atualizada de anfíbios e répteis de duas localidades na região de São Francisco-Gurguéia, do Piauí. Além disso, comparamos a composição de espécies entre nove áreas dentro da Caatinga, que foram amostradas usando métodos padronizados nos últimos dez anos, para examinar padrões espaciais mais amplos de composição da comunidade. Para estudar répteis e anfíbios, utilizamos métodos e esforços de amostragem semelhantes em duas áreas na região do Parque Nacional da Serra das Confusões (PNSC). Nossos levantamentos registraram um total de 73 espécies de anfíbios e répteis, das quais 24 são novos registros de distribuição para a região do PNSC. Consequentemente, nossos resultados aumentam a herpetofauna conhecida na região para 94 espécies. Apesar da proximidade, os dois locais na região do PNSC exibiram apenas 42% de similaridade na composição de espécies e diferiram significativamente de outras áreas dentro da Caatinga. Mesmo áreas mais próximas da Caatinga apresentaram diferenças na composição de espécies, destacando a necessidade de avaliar a biodiversidade em toda a paisagem e contribuir para a compreensão de padrões biogeográficos.

12.
Int J Biol Macromol ; 222(Pt B): 2535-2544, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36240896

RESUMO

The cosmetics market has recently undergone changes as consumers increasingly seek sustainable products. In this context, agro-derived lignins have the potential for cosmetics applications. Thus, this study investigated the photoprotective activity and skin irritation potential (OECD TG 439 with SkinVitro-RHE, an in-house reconstructed human epidermis (RHE) model) of a kraft lignin (LE) and two LE-derived lignins modified by enzymatic reactions to achieve higher molecular weight (Mw) (R1: intermediate Mw and E60: highest Mw). Results showed that LE and R1 lignins present adequate photoprotective activity with averages Sun Protection Factor (SPF) of 33.8 ± 0.02 and 22.7 ± 0.04, respectively. The E60 also present adequate SPF (22.4 ± 0.2); however, due to its poor solubility, this lignin has potential application as a physical filter. In terms of safety, these lignins did not cause skin irritation or cellular and structural damage to the epidermis. Additionally, using an analysis based on the autofluorescence feature of lignin, no sign of the tested lignins was found in exposed RHE models, indicating that these three lignins did not penetrate the skin. Altogether, the results indicate a promising application of kraft lignins for sunscreen products regarding safer alternatives and product sustainability. Also, the SkinVitro-RHE showed to be a good model for evaluating the skin irritation potential of substances, including natural cosmetic ingredients.


Assuntos
Cosméticos , Lignina , Humanos , Lignina/farmacologia , Cosméticos/farmacologia , Epiderme , Pele
13.
Am J Trop Med Hyg ; 107(2): 342-348, 2022 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-35895427

RESUMO

Some patients with visceral leishmaniasis (VL), or kala-azar, suffer relapses and low quality of life despite adequate drug therapy, especially those co-infected with HIV. Occasionally, physicians indicate splenectomy, but the benefit of the procedure needs to be analyzed systematically. Therefore, a retrospective open cohort study was conducted in Teresina, Brazil. Inpatients from a reference hospital with relapsing VL who had a rescue splenectomy between 2012 and 2019 after the nationally recommended drug therapy failed were studied. The procedure's risks and benefits were assessed in a limited-resource setting. The primary outcomes were surgical complications, complete blood count, CD4+ cell count, hospitalizations, survival time, and medical complications preceding death. Thirteen adult patients received medical and surgical indications of splenectomy (12 men and one woman). Eleven had HIV infection. Two had early and two had late complications. Four died, all of whom were infected with HIV. An additional HIV-coinfected patient, apart from the cohort, died just before surgery. The death rate after surgery was 13.3 overall and 22.1 per 100 person-years among HIV-infected patients (31% overall and 36%, respectively). The impressive rise of complete blood counts and reduction of blood transfusions and hospitalizations were observed among all patients. Also, a meaningful increase in CD4+ cells in HIV-infected patients was noted. Splenectomy may benefit patients with relapsing VL. However, before performing splenectomy, available combined drug therapy for VL should be tried.


Assuntos
Infecções por HIV , Leishmaniose Visceral , Adulto , Masculino , Feminino , Humanos , Leishmaniose Visceral/complicações , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/cirurgia , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Estudos Retrospectivos , Estudos de Coortes , Esplenectomia , Qualidade de Vida , Recidiva
14.
Front Immunol ; 13: 833560, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35154155

RESUMO

Chagas disease is accompanied by a multisystem inflammatory disorder that follows Trypanosoma cruzi infection. Alpha-tocopherol has been described as an antioxidant and a potential adjuvant to enhance immune responses to vaccines. Therefore, we have evaluated the immune response to T. cruzi infection upon alpha-tocopherol pre-administration. The results show that administration of alpha-tocopherol before the infection results in lower parasitemia and lower mortality of C57BL/6 mice infected with the Tulahuen T. cruzi strain. Alpha-tocopherol administration in normal C57BL/6 mice resulted in higher levels of IFN-γ production by T and NK cells before and after the infection with T. cruzi. More importantly, previous administration of alpha-tocopherol increased the production of IL-10 by T and myeloid suppressor cells and the formation of effector memory T cells while decreasing the expression of PD-1 on T cells. These results suggest that alpha-tocopherol may limit the appearance of dysfunctional T cells during the acute and early chronic phases of T. cruzi infection, contributing to control infection. In addition, alpha-tocopherol could diminish tissue inflammation and fibrosis in late acute disease. These results strongly suggest that alpha-tocopherol may be a helpful agent to be considered in Chagas disease.


Assuntos
Doença de Chagas/prevenção & controle , Parasitemia/prevenção & controle , alfa-Tocoferol/farmacologia , Animais , Doença de Chagas/patologia , Fibrose/prevenção & controle , Inflamação/prevenção & controle , Interferon gama/fisiologia , Interleucina-10/fisiologia , Células Matadoras Naturais/imunologia , Células T de Memória/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Receptor de Morte Celular Programada 1/metabolismo
15.
BMC Nephrol ; 23(1): 23, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-35012461

RESUMO

INTRODUCTION: Here we report estimates of glomerular basement membrane (GBM) thickness in the Brazilian population performed using direct (DM) and orthogonal interception methods (OIM), and comment on potential sources of variation among estimates made by different laboratories. METHODOLOGY: A total of 38 patients, ranging from 3 to 78 years of age, 26 (68%) males and 12 (32%) females, were submitted to kidney biopsy procedures for renal disease diagnosis. Glomeruli were diagnosed with minor histological changes by conventional, immunofluorescence and electron microscopy. GBM thickness was estimated using both DM and OIM methods. RESULTS: Estimates of GBM thickness obtained using DM were higher than those obtained by OIM. However, the application of a correction for non-perpendicular membrane sectioning to DM estimates yielded similar results to those obtained under OIM. The estimated GMB thickness using DM after correction was 289 + 44 nm, versus 287 + 48 nm by OIM. No statistically significant differences were detected in GMB thickness, nor with respect to patient age or sex. CONCLUSIONS: GBM thickness in the studied Brazilian population measured approximately 290 nm. The application of criteria for estimating the shortest distance between the endothelial and podocyte cell membranes with correction for non-perpendicular membrane sectioning can increase the accuracy of GBM thickness estimates using DM and OIM.


Assuntos
Membrana Basal Glomerular/patologia , Nefropatias/patologia , Adolescente , Adulto , Idoso , Biópsia , Brasil , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Adulto Jovem
16.
Pathogens ; 10(12)2021 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-34959592

RESUMO

The spleen is involved in visceral leishmaniasis immunopathogenesis, and presents alterations in white-pulp microenvironments that are associated with an increased susceptibility to coinfections and patient death. Plasmacytosis in splenic red pulp (RP) is one observed alteration, but the specificity of antibody-secreting cells and the distribution of them has not yet been evaluated. We biotinylated soluble L. infantum membrane antigens (bSLMA) used as probes in modified immunohistochemistry, and detected the presence of anti-L. infantum antibody-secreting cells. Were used spleens from eight dogs from the endemic area for canine visceral leishmaniasis (CanL), and three healthier controls. The spleen sections were cryopreserved, and we performed modified immunohistochemistry. The ratio of plasma cells which were reactive to bSLMA (Anti-Leish-PC) in the spleen RP and periarteriolar lymphatic sheath (PALS) were calculated. Dogs with CanL present hyperglobulinemia and more plasma cells in their RP than the controls. Furthermore, dogs with CanL presented a lower proportion of Anti-Leish-PC in their RP than in PALS. Likewise, dysproteinemia was related to RP and PALS plasmacytosis, and a more severe clinical profile.

17.
Front Immunol ; 12: 716314, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34804009

RESUMO

Structural changes in the spleen have been reported in several infectious diseases. In visceral leishmaniasis (VL), a severe parasitic disease caused by Leishmania spp., the loss of white pulp accompanies a severe clinical presentation. Hamster model reproduces aspects of human VL progression. In the early stages, a transcriptomic signature of leukocyte recruitment was associated with white pulp hyperplasia. Subsequently, impaired leukocyte chemotaxis with loss of T lymphocytes in the periarteriolar lymphoid sheath occurred. This differential gene expression was subsequently corroborated by transcriptomic profiling of spleens in severe human VL. At the latest stage, spleen disorganization was associated with increasing clinical signs of VL. White pulp disruption was accompanied by decreased DLK1 expression. The expression of CXCL13, CCR5, CCL19, CCR6, CCR7 and LTA decreased, likely regulated by CDKN2A overexpression. Our findings enlighten a pathway implying cell cycle arrest and decreased gene expression involved in spleen organization.


Assuntos
Pontos de Checagem do Ciclo Celular/genética , Quimiotaxia de Leucócito/genética , Leishmaniose Visceral/imunologia , Baço/imunologia , Baço/parasitologia , Animais , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Cricetinae , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Hiperplasia/patologia , Leishmaniose Visceral/patologia , Leucócitos/parasitologia , Leucócitos/patologia , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Baço/patologia , Transcriptoma
19.
Microorganisms ; 9(8)2021 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-34442696

RESUMO

Visceral leishmaniasis is associated with a variety of hematological abnormalities. In this study, we correlated the hematological changes in the peripheral blood of dogs naturally infected with Leishmania infantum (L. infantum) with the distribution of cell lineages and cytokine gene expression patterns in the bone marrow. Samples from 63 naturally semidomiciled dogs living in an endemic area of visceral leishmaniasis were analyzed. L. infantum infection was detected in 50 dogs (79.3%). Among those, 18 (32%) had positive splenic cultures and showed more clinical signs. They also had lower red blood cell counts and leukocytosis with an increased number of neutrophils and monocytes in peripheral blood compared to dogs negative to this test. L. infantum DNA was detected in the bone marrow of 8/14 dogs with positive splenic culture. Dogs with L. infantum infection in the bone marrow presented with histiocytosis (p = 0.0046), fewer erythroid cell clusters (p = 0.0127) and increased gene expression levels of IFN-γ (p = 0.0015) and TNF (p = 0.0091). The data shown herein suggest that inflammatory and cytokine gene expression changes in bone marrow may contribute to the peripheral blood hematological changes observed in visceral leishmaniasis.

20.
Biomed Mater ; 16(5)2021 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-34330112

RESUMO

This work investigates peripheral nerve regeneration using membranes consisting of pure chitosan (CHI), which was further blended with nanofibrillated cellulose, with citric acid as crosslinker, with posterior addition of polyvinyl alcohol, with subsequent freeze thawing. Nanocellulose improves the mechanical and thermal resistance, as well as flexibility of the film, which is ideal for the surgical procedure. The hydrogel presented a slow rate of swelling, which is adequate for cell and drug delivery. A series ofin vitrotests revealed to be non-toxic for neuronal Schwann cell from the peripheral nervous system of Rattus norvegicus, while there was a slight increase in toxicity if crosslink is performed-freeze-thaw. Thein vivoresults, using rabbits with a 5 mm gap nerve defect, revealed that even though pure CHI was able to regenerate the nerve, it did not present functional recovery with only the deep pain attribute being regenerated. When autologous implant was used jointly with the biomaterial membrane, as a covering agent, it revealed a functional recovery within 15 d when cellulose and the hydrogel were introduced, which was attributed to the film charge interaction that may help influence the neuronal axons growth into correct locations. Thus, indicating that this system presents ideal regeneration as nerve conduits.


Assuntos
Celulose , Quitosana , Ácido Cítrico/química , Nanofibras/química , Regeneração Nervosa/efeitos dos fármacos , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biocompatíveis/toxicidade , Celulose/química , Celulose/farmacologia , Quitosana/química , Quitosana/farmacologia , Reagentes de Ligações Cruzadas/química , Hidrogéis/química , Hidrogéis/farmacologia , Nervos Periféricos/efeitos dos fármacos , Álcool de Polivinil/química , Coelhos , Ratos , Células de Schwann
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