Luis Mariúba - Academia.edu (original) (raw)

Papers by Luis Mariúba

Experimental Biology and Medicine

Microsphere-based flow cytometry is a highly sensitive emerging technology for specific detection... more Microsphere-based flow cytometry is a highly sensitive emerging technology for specific detection and clinical analysis of antigens, antibodies, and nucleic acids of interest. In this review, studies that focused on the application of flow cytometry as a viable alternative for the investigation of infectious diseases were analyzed. Many of the studies involve research aimed at epidemiological surveillance, vaccine candidates and early diagnosis, non-infectious diseases, specifically cancer, and emphasize the simultaneous detection of biomarkers for early diagnosis, with accurate results in a non-invasive approach. The possibility of carrying out multiplexed assays affords this technique high versatility and performance, which is evidenced in a series of clinical studies that have verified the ability to detect several molecules in low concentrations and with minimal sample volume. As such, we demonstrate that microsphere-based flow cytometry presents itself as a promising technique ...

Parasite Immunology, 2011

Previous studies have implicated reactive antibodies to the low molecular weight rhoptry-associat... more Previous studies have implicated reactive antibodies to the low molecular weight rhoptry-associated proteins (RAP-1, RAP-2/RSP-2 and RAP-3) in erythroid cell destruction during Plasmodium falciparum infection. In this pilot study, the frequency, specificity and functional capacity of naturally acquired anti-RAP-2/RSP-2 antibodies were investigated in the sera of anaemic and nonanaemic malaria-infected Cameroonian children. All sera recognized RAP-2/RSP-2 by FACS, irrespective of the clinical status of the subjects. However, the anaemic children showed higher levels of IgG antibodies than the nonanaemic group, while both groups showed similar levels of IgM antibodies. Only few individuals had detectable levels of RAP-2/RSP-2-specific IgG1 and IgG3 subclass antibodies, while no IgG2 and IgG4 subclass antibodies were detected in these subjects. By ELISA, the anaemic group tended to show higher levels of antibodies to RAP-2/RSP-2 regarding all antibody classes tested, except for IgG4 and IgE. Unexpectedly, sera from the nonanaemic group activated complement to a greater extent than those from the anaemic group. These results need to be confirmed in extended studies but indicate that the effector functions of the RAP-2/RSP-2-reactive antibodies may be more important than their amounts. Such antibodies could play a role in both immunity and pathogenesis during P. falciparum infection.

BMC Infectious Diseases, 2014

Background Immunoassays for Plasmodium detection are, presently, most frequently based on monoclo... more Background Immunoassays for Plasmodium detection are, presently, most frequently based on monoclonal antibodies (MAbs); Polyclonal antibodies (PAbs), which are cheaper to develop and manufacture, are much less frequently used. In the present study we describe a sandwich ELISA assay which is capable of detecting P. vivax Lactate Dehydrogenase (LDH) in clinical blood samples, without cross reacting with those infected with P. falciparum. Methods Two recombinant proteins were produced from different regions of the P. vivax LDH gene. Two sandwich ELISA assay were then designed: One which uses mouse anti-LDH 1-43aa PAbs as primary antibodies (“Test 1”) and another which uses anti-LDH 35-305aa PAbs (“Test 2”) as the primary antibodies. Rabbit anti-LDH 1-43aa PAbs were used as capture antibodies in both ELISA assays. Blood samples taken from P. vivax and P. falciparum infected patients (confirmed by light microscopy) were analysed using both tests. Results “Test 2” performed better at dete...

Rotavirus genotyping in gastroenteritis cases of an infantile population from Western Brazilian A... more Rotavirus genotyping in gastroenteritis cases of an infantile population from Western Brazilian Amazonia Genotipagem de rotavírus em casos de gastrenterites de uma população infantil do oeste da Amazônia brasileira

RSC Advances, 2021

One-step enzyme-free dual electrochemical immunosensor for Malaria biomarker determination.

Memórias do Instituto Oswaldo Cruz, 2008

Rhoptry-associated protein 2 (RAP2) is known to be discharged from rhoptry onto the membrane surf... more Rhoptry-associated protein 2 (RAP2) is known to be discharged from rhoptry onto the membrane surface of infected and uninfected erythrocytes (UEs) ex vivo and in vitro and this information provides new insights into the understanding of the pathology of severe anemia in falciparum malaria. In this study, a hexahistidine-tagged recombinant protein corresponding to residues 5-190 of the N-terminal of Plasmodium falciparum RAP2 (rN-RAP2) was produced using a new method of solubilization and purification. Expression was induced with D-lactose, a less expensive alternative inducer to the more common isopropyl-β-d-thio-galactopyranosidase. The recombinant protein was purified using two types of commercially-available affinity columns, iminodiacetic and nitrilotriacetic. rN-RAP2 had immunogenic potential, since it induced high titers of anti-RAP2 antibodies in mice. These antibodies recognized full-length RAP2 prepared from Triton X-100 extracts from two strains of P. falciparum. In fact, the antibody recognized a 29-kDa product of RAP2 cleavage as well as 82 and 70-kDa products of RAP1 cleavage. These results indicate that the two antigens share sequence epitopes. Our expressed protein fragment was shown to contain a functional epitope that is also present in rhoptry-derived ring surface protein 2 which attaches to the surface of both infected and UEs and erythroid precursor cells in the bone marrow of malaria patients. Serum from malaria patients who developed anemia during infection recognized rN-RAP2, suggesting that this protein fragment may be important for epidemiological studies investigating whether immune responses to RAP2 exacerbate hemolysis in falciparum malaria patients.

Fibers and Polymers, 2018

Cellulose was isolated from plant material for the first time in 1839 by the French chemist Ansel... more Cellulose was isolated from plant material for the first time in 1839 by the French chemist Anselme Payen. In recent years, due to the need in reduce the world's environmental problems, there has been an increase in studies related to the physical and chemical factors of cellulose. It is important to emphasize that experiments and studies with a cellulose occur individually, because of the variation in the amount of cellulose and the extraction method that differs from plant to plant. In the present study, we determined the optimal conditions for cellulose extraction of jute fiber, using the response surface method. The Box-Behnken Design (BBD) was used statistically evaluate the ratio effects of sodium hydroxide (NaOH) and sodium hypochlorite (NaClO), temperature and extraction time in the process used. The analysis of the results showed a significant variable in the linear and quadratic terms of the temperature and also a significant level of interaction in the effect between the variables of temperature and time. Besides this, the BBD used for the analysis of the extraction yield, resulted in a polynomial regression of second order, in complete agreement with experimental results, with R 2 =0.9627 (p<0.05). The optimal condition was obtained in a ratio of 1.3 at 45 o C for 2 h. Under the best possible conditions, the obtained experimental value is in accordance with the value predicted by the model, thus indicating a model combination and success to optimize the extraction conditions of the jute fiber pulp in the response surface methodology.

Supplemental Material, Slide1 for Solubilization, characterization, and protein coupling analysis... more Supplemental Material, Slide1 for Solubilization, characterization, and protein coupling analysis to multiwalled carbon nanotubes by Juliane Glória, Walter Brito, Ariamna Gandarilla, Duniesky Larrude, Jacqueline Carlos, Felipe Araújo, Maria Edilene Almeida, Lizandro Manzato and Luis André Morais Mariúba in High Performance Polymers

Materials Science and Engineering: C, 2021

We report the synthesis of magnetite nanoparticles (MNP) and their functionalization with glycine... more We report the synthesis of magnetite nanoparticles (MNP) and their functionalization with glycine (MNPGly), β-alanine (MNPAla), L-phenylalanine (MNPPhAla), D-(-)-α-phenylglycine (MNPPhGly) amino acids. The functionalized nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), electron paramagnetic resonance (EPR), vibrating sample magnetometry (VSM), Mössbauer spectroscopy (MS), magnetic hyperthermia (MH), dynamic light scattering and zeta potential. The functionalized nanoparticles had isoelectric points (IEP) at pH ≃ 4.4, 5.8, 5.9 and 6.8 for samples MNPGly, MNPAla, MNPPhGly and MNPPhAla, respectively, while pure magnetite had an IEP at pH 5.6. In the MH experiments, the samples showed specific absorption rate (SAR) of 64, 71, 74, 81 and 66 W/g for MNP, MNPGly, MNPAla, MNPPhGly, and MNPPhAla, respectively. We used a flow cytometric technique to determine the cellular magnetic nanoparticles plus amino acids content. Magnetic fractionation and characterization of Resovist® magnetic nanoparticles were performed for applications in magnetic particle imaging (MPI). We have also studied the antiproliferative and antiparasitic effects of functionalized MNPs. Overall, the data showed that the functionalized nanoparticles have great potential for using as environmental, antitumor, antiparasitic agents and clinical applications.

Biotechnology & Biotechnological Equipment, 2020

Revista de Ciencias Agrícolas, 2021

The iota toxin (ITX) is a binary enterotoxin produced as a protoxin by Clostridium perfringens (C... more The iota toxin (ITX) is a binary enterotoxin produced as a protoxin by Clostridium perfringens (C. perfringens) type E that is activated by proteolytic enzymes in the small intestine of infected animals. By depolymerization of the actin filaments, ITX causes cytoskeleton disorganization of cells promoting the increase of the cell permeability. Here, we conducted this review aiming to advance the understanding of enteric clostridial diseases caused by C. perfringens toxins and the specificity of ITX in the intestinal mucosa lesions. ITX consists of an enzymatic component (Ia) and a binding component (Ib). We screened the recently published histological findings of the ITX effects and its relationship with intestinal enteric diseases. Histologically, hemorrhagic necrosis and multifocal hemorrhage have been observed in the jejunum-ileum mucosa, the small intestine, and the abomasum. Although the diagnosis is still based on the presence of toxins in the intestinal contents and the clini...

Tradicionalmente, o diagnostico confirmatorio da malaria e feito pelo exame microscopico do sangu... more Tradicionalmente, o diagnostico confirmatorio da malaria e feito pelo exame microscopico do sangue. Logo, o diagnostico da doenca pode ser complicado com a falta de pessoas ou equipamentos necessarios para a obtencao de um diagnostico confiavel e rapido. Por esta e outras razoes, metodos rapidos, praticos e sensiveis vem sendo desenvolvidos, como, por exemplo, as fitas imunocromatograficas. Este trabalho teve como objetivo o desenvolvimento de um sistema em fluxo lateral para o diagnostico de malaria causada por Plasmodium falciparum. Logo, anticorpos policlonais e monoclonais contra a proteina HRP2 (“Histidine rich protein 2”) de Plasmodium falciparum foram produzidos utilizando para isso uma proteina recombinante desta fusionada a uma cauda de glutationa-S-transferase (rHRP2-GST, obtida em trabalhos anteriores). Apos a obtencao dos hibridomas, apenas 20 responderam contra a proteina rHRP2-GST, e dentre estes apenas 4 apresentaram alguma reatividade contra a proteina nativa. O anti...

Revista do Instituto de Medicina Tropical de São Paulo, 2021

This is an open-access article distributed under the terms of the Creative Commons Attribution Li... more This is an open-access article distributed under the terms of the Creative Commons Attribution License.

Malaria remains a widespread public health problem in tropical and subtropical regions around the... more Malaria remains a widespread public health problem in tropical and subtropical regions around the world, and there is still no vaccine available for full protection. In recent years, it has been observed that spores of Bacillus subtillis can act as a vaccine carrier and adjuvant, promoting an elevated humoral response after co-administration with antigens either coupled or integrated to their surface. In our study, B. subtillis spores from the KO7 strain were used to couple the recombinant CSP protein of P. falciparum (rPfCSP), and the nasal humoral-induced immune response in Balb/C mice was evaluated. Our results demonstrate that the spores coupled to rPfCSP increase the immunogenicity of the antigen, which induces high levels of serum IgG, and with balanced Th1/Th2 immune response, being detected antibodies in serum samples for 250 days. Therefore, the use of B. subtilis spores appears to be promising for use as an adjuvant in a vaccine formulation.

Aquaculture International, 2020

The use of probiotics can beneficially improve the water quality in the biofloc technology (BFT) ... more The use of probiotics can beneficially improve the water quality in the biofloc technology (BFT) system consequently enhancing the fish performance. This study focused on the effect of Bacillus subtilis on a clear water static system compared to the BFT system on the productive performance, proximate body composition, and diversity of intestinal bacterial communities of tambaqui ( Colossoma macropomum ) juveniles submitted to four treatments: clear water static system with (CW + BS) or without (CW) B. subtilis and BFT with (BFT + BS) or without (BFT) B. subtilis . For the study, 20 juveniles (five replicates) per treatment were used for 60 days. For the B. subtilis treatments, water was inoculated at weekly intervals with a 4 × 10 8 -cell mL −1 culture suspension. Results revealed that regardless of B. subtilis supplementation, fish reared in BFT displayed better zootechnical performance than those in CW—weight gain (BFT 33.57 ± 4.08 g; CW 19.97 ± 5.42 g), protein efficiency (BFT 0.16 ± 0.02; CW 0.11 ± 0.02), feed conversion ratio (BFT 0.71 ± 0.08; CW 0.84 ± 0.40), and relative growth rate (BFT 1.52 ± 0.12; CW 1.06 ± 0.15)—which suggests that biofloc consumption was 31.9% crude protein. Moreover, fish reared in BFT + BS had a higher condition factor (2.30 ± 0.09). In conclusion, BFT is regarded as a promising system to save water, decrease aquaculture effluents, and promote tambaqui farming. Although B. subtilis is a common bacterium found in tambaqui gut, its supplementation in the BFT system improved the fish condition factor.

Genetics and Molecular Research, 2020

Since 2012, CRISPR/Cas technologies have revolutionized the field of modern molecular biology and... more Since 2012, CRISPR/Cas technologies have revolutionized the field of modern molecular biology and biotechnology due to their ability to direct a Cas nuclease to cleave specific nucleic acid sequences with a guide RNA (crRNA), providing dynamic tools for many applications, being naturally derived from the adaptive immune system of prokaryotes. The most widely used toolbox for genome editing, modulation, and detection contains types II, V and VI of class 2 systems, categorized and characterized by Cas9, Cas12, and Cas13, respectively. In recent years, given the wide application of Class 2 CRISPR-Cas systems as molecular tools, there has been a focus on the discovery, characterization, and specificity of Cas effector nucleases from these systems, generating even more possibilities for the development of new applications. We reviewed the scientific literature on current knowledge of CRISPR-Cas systems and recent advances in biotechnology involving class 2 systems between 2000 and 2019. For this, we searched for original articles indexed in the following databases: PubMed, Scopus, SciELO, Periodicos Capes and Google Scholar, and used keyword combinations such as "CRISPR / Cas Class 2 systems", "Cas9", "Cas12", "Cas13", "Genome editing" and "diagnostic detection". Eighty original articles were obtained, 55 of ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 19 (1): gmr18478 D.S. Mota et al. 2 them were selected for this review because they match with the keywords and the years of publication.

Journal of Molecular Structure, 2017

Highlights  New approach for Cellulose type II extraction.  The first reported Cellulose type I... more Highlights  New approach for Cellulose type II extraction.  The first reported Cellulose type II extraction from Tucumã's endocarp.  Nanocrystals of cellulose have been observed in the XRD pattern.  Apparent average crystallite size and microstrain were, respectively, 20.0 Å and 0.1 %.

Emirates Journal of Food and Agriculture, Jun 12, 2011

Malaria Journal, 2013

Background Plasmodium vivax has the potential to infect 2.85 billion individuals worldwide. Never... more Background Plasmodium vivax has the potential to infect 2.85 billion individuals worldwide. Nevertheless, the limited number of studies investigating the immune status of individuals living in malaria-endemic areas, as well as the lack of reports investigating serological markers associated with clinical protection, has hampered development of vaccines for P. vivax. It was previously demonstrated that naturally total IgG against the N-terminus of P. vivax merozoite surface protein 1 (Pv-MSP1) was associated with reduced risk of malarial infection. Methods Immune response against Pv-MSP1 (N-terminus) of 313 residents of the Rio Pardo rural settlement (Amazonas State, Brazil) was evaluated in a cross-sectional and longitudinal follow up over two months (on site) wherein gold standard diagnosis by thick blood smear and rRNA gene-based nested real-time PCR were used to discriminate symptomless Plasmodium vivax-infected individuals who did not develop clinical symptoms during a 2-months ...