Publications by authors named "J V de Oliveira"

5,258 Publications

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An efficient and user-friendly method for cytohistological analysis of organoids.

J Tissue Eng Regen Med 2021 Sep 23. Epub 2021 Sep 23.

Digestive Diseases Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, 518107, China.

Organoid culture is a recently developed in-vitro three-dimensional (3D) cell culture technology. It has wide applications in tissue engineering studies. However, histological analysis of organoid is quite complex and tedious for researchers. This study proposes a user-friendly, affordable and efficient method for making formalin-fixed paraffin embedded (FFPE) organoid blocks and Optimal Cutting Temperature compound (OCT) embedded frozen organoid blocks. This method implements a key pre-embedding step for preparing paraffin embedded organoid blocks, which could concentrate organoid togethor without damaging or loss of samples. This method could be used to process even a small number of organoids with high efficiency. In addition, with minor modifications, the method is readily applied for OCT embedded organoid blocks. The slides generated were ready for H&E staining, immunohistochemistry staining and immunofluorescent staining. The method described in this study can be easily used for routine histological analysis of organoid, and could be performed in general pathology labs and requires no dedicated equipment and reagent. This article is protected by copyright. All rights reserved.
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http://dx.doi.org/10.1002/term.3248DOI Listing
September 2021

Tick-borne zoonotic agents infecting horses from an urban area in Midwestern Brazil: epidemiological and hematological features.

Trop Anim Health Prod 2021 Sep 22;53(5):475. Epub 2021 Sep 22.

Laboratory Insana Huna, Interface Between Animal, Environmental and Human Health, Department of Biosaúde, University Católica Dom Bosco, Campo Grande, Mato Grosso Do Sul, Brazil.

The emergence of tick-borne diseases has been reported as a serious problem in public health worldwide and many aspects of its epidemiology and effects on the health of its hosts are unclear. We aimed to perform an epidemiological study of tick-borne zoonotic Rickettsia, Borrelia, and Anaplasmataceae in horses from Midwestern Brazil. We also evaluated whether Borrelia spp. and Anaplasmataceae may be associated with hematological disorders in the sampled animals. Blood and serum samples as well as ticks were collected from 262 horses. Serum samples were used to perform serological tests, and hematological analyses were made using whole blood. Furthermore, DNA extracted from whole blood and ticks was used for molecular tests. Campo Grande is enzootic for tick-borne studied bacteria, since we found an overall exposure of 59.9% of the sampled horses, 28.7% of them presented co-exposure. Seropositivity rates of 20.6% for Borrelia spp., 25.6% for Rickettsia spp., and 31.6% for Anaplasmataceae were found in the sampled horses. Considering both molecular and serological tests for Borrelia spp., the infection rate was 48.0% (126/262). None of the tested horses showed molecular positivity for Anaplasma phagocytophilum. The horses sampled displayed 7.2% of parasitism by ixodid ticks in single and coinfestations. We did not find DNA of any studied bacteria in the sampled ticks. Positive horses for Borrelia spp. and Anaplasmataceae agents displayed leukopenia, monocytopenia, and lymphopenia. Together, our results suggest that horses may play a role as sentinel host for zoonotic bacteria and Borrelia spp. and Anaplasmataceae agents can impair the health of horses.
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http://dx.doi.org/10.1007/s11250-021-02887-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8457776PMC
September 2021

Gut and faecal bacterial community of the terrestrial isopod Porcellionides pruinosus: potential use for monitoring exposure scenarios.

Ecotoxicology 2021 Sep 22. Epub 2021 Sep 22.

CESAM- Centre for Environmental and Marine Studies, Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.

This work aimed to characterize the gut and faeces bacterial communities (BC) of Porcellionides pruinosus using high-throughput sequencing. Isopods were collected from the field and kept in laboratory conditions similar to those normally applied in ecotoxicology tests. Faeces and purged guts of isopods (n = 3 × 30) were analysed by pyrosequencing the V3-V4 region of 16 S rRNA encoding gene. Results showed that gut and faecal BCs were dominated by Proteobacteria, particularly by an OTU (Operational Taxonomic Unit) affiliated to genus Coxiella. Diversity and richness values were statistically higher for faecal BC, mainly due to the occurrence of several low-abundance phylotypes. These results may reflect faecal carriage of bacterial groups that cannot settle in the gut. BCs of P. pruinosus comprised: (1) common members of the soil microbiota, (2) bacterial symbionts, (3) bacteria related to host metabolic/ecological features, and (4) bacterial etiological agents. Comparison of BC of this isopod species with the BC from other invertebrates revealed common bacterial groups across taxa. The baseline information provided by this work will assist the design and data interpretation of future ecotoxicological or biomonitoring assays where the analysis of P. pruinosus BC should be included as an additional indicator. CAPSULE: Terrestrial isopods bacterial communities might support ecotoxicological assays and biomonitoring processes as a valuable tool.
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http://dx.doi.org/10.1007/s10646-021-02477-4DOI Listing
September 2021

Physicochemical characterization of monazite sand and its associated bacterial species from the beaches of southeastern Brazil.

Environ Sci Pollut Res Int 2021 Sep 22. Epub 2021 Sep 22.

Universidade de São Paulo, São Paulo, SP, Brazil.

Beaches with monazitic sands show high natural radiation, and the knowledge of this radiation is fundamental to simulate the effects of natural terrestrial radiation on biological systems. Monazite-rich sand from a beach in the southeastern Brazil were collected and analyzed by X-ray fluorescence, X-ray diffraction, and magnetic susceptibility. The natural terrestrial radiation of the beach sand showed a positive correlation with the Th and Y elements, which are closely associated with Ce, Nd, Ca, and P, suggesting that this grouping is mainly associated with local natural radiation. Based on the sand characterization, a physical simulator of natural gamma radiation was built with parameters similar to those of the monazite beach sand, considering areas with high natural radiation levels. The simulation revealed that the natural radiation of the monazite sands has a significant effect on reducing the growth of the bacteria strains of E. coli and S. aureus present in the beach sand, with a reduction of 23.8% and 18.4%, respectively.
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http://dx.doi.org/10.1007/s11356-021-16523-5DOI Listing
September 2021

Magnetic lipid nanovehicles synergize the controlled thermal release of chemotherapeutics with magnetic ablation while enabling non-invasive monitoring by MRI for melanoma theranostics.

Bioact Mater 2022 Feb 17;8:153-164. Epub 2021 Jun 17.

Advanced (Magnetic) Theranostic Nanostructures Lab. International Iberian Nanotechnology Laboratory, Avda. Mestre José Veiga s/n, 4715-330, Braga, Portugal.

Nowadays, a number of promising strategies are being developed that aim at combining diagnostic and therapeutic capabilities into clinically effective formulations. Thus, the combination of a modified release provided by an organic encapsulation and the intrinsic physico-chemical properties from an inorganic counterpart opens new perspectives in biomedical applications. Herein, a biocompatible magnetic lipid nanocomposite vehicle was developed through an efficient, green and simple method to simultaneously incorporate magnetic nanoparticles and an anticancer drug (doxorubicin) into a natural nano-matrix. The theranostic performance of the final magnetic formulation was validated and , in melanoma tumors. The systemic administration of the proposed magnetic hybrid nanocomposite carrier enhanced anti-tumoral activity through a synergistic combination of magnetic hyperthermia effects and antimitotic therapy, together with MRI reporting capability. The application of an alternating magnetic field was found to play a dual role, (i) acting as an extra layer of control (remote, on-demand) over the chemotherapy release and (ii) inducing a local thermal ablation of tumor cells. This combination of chemotherapy with thermotherapy establishes a synergistic platform for the treatment of solid malignant tumors under lower drug dosing schemes, which may realize the dual goal of reduced systemic toxicity and enhanced anti-tumoral efficacy.
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http://dx.doi.org/10.1016/j.bioactmat.2021.06.009DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8424388PMC
February 2022
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