Front Cell Infect Microbiol
September 2025
Background: The protozoan , in addition to infecting phagocytic cells such as macrophages, can also invade non-professional phagocytic cells like fibroblasts, a process previously described in 2D models. In a bidimensional environment, its interaction with the extracellular matrix and manipulation of endocytic processes reveal a complex ability to alter cellular entry mechanisms. However, this process in fibroblasts, especially in three-dimensional (3D) models, remains poorly understood.
View Article and Find Full Text PDFspp. is an obligate intracellular parasite that primarily infects macrophages. During infection, leukocytes are activated, culminating in the formation of lipid droplets (LDs), which are sites for the synthesis of eicosanoids that modulate the immune response.
View Article and Find Full Text PDFLeishmaniasis is a parasitic infection caused by obligatory intracellular protozoa of the Leishmania genus. Macrophages are the main cell for Leishmania parasites that play a key role in immune response against it. Interestingly, both the promastigote and amastigote forms of the parasite have also been detected in fibroblasts, revealing the complex interactions during the infection.
View Article and Find Full Text PDFOdontology
July 2025
Teeth whitening is a procedure that, despite being less invasive and more affordable, can cause sensitivity and damage to the enamel. This study evaluated an experimental copaiba oil-resin gel associated with 35% hydrogen peroxide (HP 35%) teeth whitening. The biocompatibility of the experimental gel and the physicochemical, morphological, and mechanical properties of bovine enamel were assessed.
View Article and Find Full Text PDFJ Eukaryot Microbiol
July 2025
This study employs advanced three-dimensional electron microscopy techniques, including Transmission Electron Microscopy (TEM) tomography and freeze-fracture imaging via scanning electron microscopy (SEM), to investigate the ultrastructural organization of Cyrilia lignieresi-infected red blood cells (iRBCs) in the host fish Synbranchus marmoratus. The analysis focuses on the parasitophorous vacuole (PV) and reveals a highly complex intravacuolar membranous network (IVN) composed of vesicles, tubules, and interconnected membranous structures. These elements exhibit considerable diversity in size, morphology, and electron density, suggesting dynamic functional roles in the parasite-host interaction.
View Article and Find Full Text PDFObjective: This randomized clinical trial evaluated a copaiba oil-based gel in controlling dental sensitivity (DS) and color change after dental bleaching.
Materials And Methods: Seventy-five volunteers were randomized into three groups (n = 25): GC (placebo gel - negative control); GKF2% (gel of 5% potassium nitrate and 2% sodium fluoride - positive control); and GCO (copaiba oil gel). Three bleaching sessions were performed using 35% hydrogen peroxide (HP 35%), with 7-day intervals.
Juruaça virus (JUAV), previously unclassified, was isolated from bats and administered to neonatal and adult BALB/c mice to investigate acute and chronic disease progression. In this study, we conducted genomic sequencing to achieve taxonomic classification and utilized these models to explore the inflammatory response and sickness behavior in both neonatal and adult mice. Neonates received a single intranasal instillation of infected brain homogenate (20 µL), whereas 31-day-old mice were given the same volume intranasally for three consecutive days.
View Article and Find Full Text PDFParasitology
April 2024
Haemogregarine (Apicomplexa: Adeleorina) parasites are considered to be the most common and widespread haemoparasites in reptiles. The genus (Apicomplexa: Adeleorina: Hepatozoidae) can be found parasitizing a broad range of species and, in reptiles, they infect mainly peripheral blood erythrocytes. The present study detected and characterized a haemogregarine isolated from the lizard species, , collected from the municipality of Capanema, Pará state, north Brazil.
View Article and Find Full Text PDFLeishmaniasis encompasses a cluster of neglected tropical diseases triggered by kinetoplastid phatogens belonging to the genus Leishmania. Current therapeutic approaches are toxic, expensive, and require long-term treatment. Nanoparticles are emerging as a new alternative for the treatment of neglected tropical diseases.
View Article and Find Full Text PDF(1) Background: Leishmaniasis refers to a group of anthropozoonotic diseases caused by Leishmania. The major chemotherapeutic agent used for its treatment is Glucantime, but the search continues for new compounds that are economically viable and act on the protozoan without causing damage to the host cell. As an alternative approach, this study used a combination of copaiba oil (CO) and kojic acid (KA) to determine their in vitro action on host cells, on the protozoan and its interaction with macrophages.
View Article and Find Full Text PDFPolymers (Basel)
November 2023
Tissue engineering is vital in treating injuries and restoring damaged tissues, aiming to accelerate regeneration and optimize the complex healing process. In this study, multizonal scaffolds, designed to mimic tissues with bilayer architecture, were prepared using the rotary jet spinning technique (RJS scaffolds). Polycaprolactone and different concentrations of alginate hydrogel (2, 4, and 6% /) were used.
View Article and Find Full Text PDFSci Rep
November 2023
Bone tissue is one of the most important in the human body. In this study, scaffolds of poly (lactic acid) PLA reinforced with hydroxyapatite (HA) and carbon nanotubes (CNT) were manufactured, evaluating their mechanical and biological properties. HA was synthesized by wet method and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM).
View Article and Find Full Text PDFBMC Microbiol
August 2023
Metalloproteinases (MMPs) are remarkable zinc-dependent endopeptidases, critical for degrading components of the extracellular matrix, thus actively influencing cell migration. Their impact on intracellular parasites, such as the enigmatic protozoan Leishmania, elicits intriguing queries. This study explores into the untapped territory of MMP-2 and MMP-9 within Leishmania spp.
View Article and Find Full Text PDFChromoblastomycosis (CBM) is a chronic human subcutaneous mycosis caused by various aetiologic agents. CBM does not have an established treatment but may be managed using antifungal agents, surgical removal of the lesions, or cryotherapy. Kojic acid (KA), a known tyrosinase inhibitor with a variety of biological actions, including fungistatic action against the fungus Cryptococcus neoformans, mediated by inhibiting melanin production, seems to be an alternative to improve the treatment of CBM.
View Article and Find Full Text PDFThe Haemogregarinidae family (Apicomplexa: Adeleina) comprises hemoprotozoa that infect mammals, birds, amphibians, fish, and reptiles. Some morphological characteristics of the Cyrilia lignieresi have been described previously, but the parasite-erythrocyte relationship is still poorly understood. In order to understand the structural architecture of C.
View Article and Find Full Text PDFBackground: Leishmaniasis is an infectious disease caused by parasites of the genus Leishmania and presents different clinical manifestations. The adverse effects, immunosuppression and resistant strains associated with this disease necessitate the development of new drugs. Nanoparticles have shown potential as alternative antileishmanial drugs.
View Article and Find Full Text PDFLeishmania is an obligate intracellular parasite that primarily inhabits macrophages. The destruction of the parasite in the host cell is a fundamental mechanism for infection control. In addition, inhibition of the leishmanicidal activity of macrophages seems to be related to the ability of some species to inhibit the production of nitric oxide (NO) by depleting arginine.
View Article and Find Full Text PDFViruses
December 2020
We previously demonstrated, using the Piry virus model, that environmental enrichment promotes higher T-cell infiltration, fewer microglial changes, and faster central nervous system (CNS) virus clearance in adult mice. However, little is known about disease progression, behavioral changes, CNS cytokine concentration, and neuropathology in limbic encephalitis in experimental models. Using Cocal virus, we infected C57Bl6 adult mice and studied the neuroanatomical distribution of viral antigens in correlation with the microglial morphological response, measured the CNS cytokine concentration, and assessed behavioral changes.
View Article and Find Full Text PDFTrans R Soc Trop Med Hyg
November 2020
Background: It is well established that infection by Plasmodium vivax is a result of host-parasite interactions. In the present study, association with the IL1/IL2 cytokine profiles, anticircumsporozoite protein antibody levels and parasitic loads was evaluated in individuals naturally infected with P. vivax in an endemic area of the Brazilian Amazon.
View Article and Find Full Text PDFObjective: In the present study, we evaluated the effects of the aqueous extract of Physalis angulata root (AEPa) on Leishmania infantum proliferation, morphology, and the driving mechanism in leishmanicidal activity and modulatory action on macrophages.
Methods: L. infantum promastigotes were treated with 50 and 100 µg/mL AEPa for 72 h and then antipromastigote assay was performed by counts in a Newbauer chamber, morphological changes were analyzed by transmission electron microscopy and the mechanism of the leishmanicidal activity was detected.
Microbes Infect
May 2019
Leishmaniasis, a neglected disease caused by Leishmania protozoans, primarily affects people in tropical and subtropical areas. Chemotherapy based on the use of pentavalent antimonials, amphotericin B, paromomycin, miltefosine and liposomal amphotericin B is currently the only effective treatment. However, adverse effects, long-term treatment and the emergence of parasite resistance have led to the search for alternative treatments.
View Article and Find Full Text PDFMonocytes are mononuclear phagocytes in peripheral blood that can differentiate into macrophages and dendritic cells. Macrophages play a specific role in the inflammatory process and are essential for the innate response. Given the important role of monocytes/macrophages in the immune response, this study aimed to evaluate the activity of kojic acid (KA), a natural product of certain fungal species, on human peripheral blood monocytes in vitro.
View Article and Find Full Text PDFNanomedicine (Lond)
February 2018
Aim: Development of functionalized nanocomposites containing AgNPs-PVP-Glucantime to evaluate their leishmanicidal activity as a novel method for improving the pharmacological properties of the drug Glucantime against extracellular promastigotes and intracellular amastigotes of Leishmania amazonensis in vitro to treat cutaneous leishmaniasis.
Materials & Methods: The silver nanoparticles and nanocomposites prepared containing silver nanoparticles, polyvinylpyrrolidone and different amounts of Glucantime were characterized using transmission electron microscopy, x-ray diffraction, energy-dispersive x-ray spectroscopy and ζ potential analysis; in addition, the in vitro cytotoxicity was evaluated.
Results: The nanocomposites showed an inhibitory effect on the cellular viability of promastigote forms, with values of 47.