Recombinant multiepitope proteins expressed in Escherichia coli cells and their potential for immunodiagnosis.

Recombinant multiepitope proteins (RMPs) are a promising alternative for application in diagnostic tests and, given their wide application in the most diverse diseases, this review article aims to survey the use of these antigens for diagnosis, as well as discuss the main points surrounding these antigens. RMPs usually consisting of linear, immunodominant, and phylogenetically conserved epitopes, has been applied in the experimental diagnosis of various human and animal diseases, such as leishmaniasis, brucellosis, cysticercosis, Chagas disease, hepatitis, leptospirosis, leprosy, filariasis, schistosomiasis, dengue, and COVID-19. The synthetic genes for these epitopes are joined to code a single RMP, either with spacers or fused, with different biochemical properties. The epitopes' high density within the RMPs contributes to a high degree of sensitivity and specificity. The RMPs can also sidestep the need for multiple peptide synthesis or multiple recombinant proteins, reducing costs and enhancing the standardization conditions for immunoassays. Methods such as bioinformatics and circular dichroism have been widely applied in the development of new RMPs, helping to guide their construction and better understand their structure. Several RMPs have been expressed, mainly using the Escherichia coli expression system, highlighting the importance of these cells in the biotechnological field. In fact, technological advances in this area, offering a wide range of different strains to be used, make these cells the most widely used expression platform. RMPs have been experimentally used to diagnose a broad range of illnesses in the laboratory, suggesting they could also be useful for accurate diagnoses commercially. On this point, the RMP method offers a tempting substitute for the production of promising antigens used to assemble commercial diagnostic kits.

Cross-resistance of Leishmania infantum isolates to nitric oxide from patients refractory to antimony treatment, and greater tolerance to antileishmanial responses by macrophages.

Visceral leishmaniasis is a life-threatening disease characterized by intense parasitism of the spleen, liver, and bone marrow. Antimonials have served as front-line antileishmanial therapeutics for decades, but the increasing failure rates under antimonial treatment have challenged the continued use of these drugs. Pentavalent antimonials are known to reinforce the killing mechanisms of macrophages, although the associated mechanism remains unclear. Here, for the first time, we determined whether Leishmania infantum strains isolated from patients refractory to antimony treatment (relapse cases) were cross-resistant to antimonials, liposomal amphotericin B, and/or nitric oxide, and also whether these strains modulate macrophage infection. We selected four clinical isolates from relapse cases and two clinical isolates from antimony-responsive patients (control group) for the present study. The L. infantum promastigotes from all four relapse cases were resistant to trivalent antimonial treatment and nitric oxide, while only one isolate was resistant to liposomal amphotericin B. We evaluated whether the resistant strains from relapse cases showed enhanced infectivity and amastigote survival in macrophages, or macrophage-killing mechanisms in macrophages activated by lipopolysaccharide plus interferon gamma. Infection indexes calculated using macrophages infected with isolates from relapse were higher than those observed with control strains that were stimulated independently. Macrophage infection was higher with L. infantum isolates from relapse cases and correlated with enhanced interleukin 1-ß production but showed similar nitrite production. Our results demonstrate that L. infantum field isolates from relapse cases were resistant to antimonials and nitric oxide and that these parasites stimulated inflammatory cytokines and were resistant to macrophage-killing mechanisms, factors that may contribute to disease severity.

Nrf2 cell signaling pathway is responsible for the antioxidant effect of resveratrol in aging.

INTRODUCTION: One of the markers of aging is oxidative stress, a condition characterized by an increase in free radicals concomitant with a reduction in antioxidant defenses. Within this, resveratrol is a compound that has been shown to act as a potent antioxidant. However, few studies highlight the cellular signaling pathways that are activated or inhibited during aging and that are responsible for this biological effect. AIM: To verify the antioxidant profile of resveratrol (5 µM) in leukocytes from donors in different age groups. METHODS: The project was approved by the Ethics Committee. Individuals were divided into three groups: 20-39, 40-59, and 60-80 years old. After separating the leukocytes, assays were performed to evaluate the AMPK (AMP-activated protein kinase) and Nrf2 (erythroid nuclear factor 2-related factor 2) pathways. In addition, luciferase assay and enzyme-linked immunosorbent assay were performed to evaluate transcription factor activation and Nrf2 expression, respectively. The analysis between age and treatment was performed using Pearson correlation (*P < 0.05). RESULTS: There was a reduction in the antioxidant effect of resveratrol during the aging process. In leukocytes from donors over 60 years of age, the AMPK pathway was silenced. Nrf2 was active at all ages. There was an increase in the activation of the transcription factor and phosphorylated protein in all age groups. CONCLUSIONS: Nrf2 is an important biochemical mechanism responsible for the antioxidant effect of resveratrol. This effect diminishes with aging but is still observed. Geriatr Gerontol Int 2024; ••: ••-••.

Divergence in toxin antigenicity and venom enzymes in Tityus melici, a medically important scorpion, despite transcriptomic and phylogenetic affinities with problematic Brazilian species.

The Brazilian scorpion Tityus melici, native to Minas Gerais and Bahia, is morphologically related to Tityus serrulatus, the most medically significant species in Brazil. Despite inhabiting scorpion-envenomation endemic regions, T. melici venom remains unexplored. This work evaluates T. melici venom composition and function using transcriptomics, enzymatic activities, and in vivo and in vitro immunological analyses. Next-Generation Sequencing unveiled 86 components putatively involved in venom toxicity: 39 toxins, 28 metalloproteases, seven disulfide isomerases, six hyaluronidases, three phospholipases and three amidating enzymes. T. serrulatus showed the highest number of toxin matches with 80-100 % sequence similarity. T. melici is of medical importance as it has a venom LD50 of 0.85 mg/kg in mice. We demonstrated venom phospholipase A2 activity, and elevated hyaluronidase and metalloprotease activities compared to T. serrulatus, paralleling our transcriptomic findings. Comparison of transcriptional levels for T. serrulatus and T. melici venom metalloenzymes suggests species-specific expression patterns in Tityus. Despite close phylogenetic association with T. serrulatus inferred from COI sequences and toxin similarities, partial neutralization of T. melici venom toxicity was achieved when using the anti-T. serrulatus antivenom, implying antigenic divergence among their toxins. We suggest that the Brazilian therapeutic scorpion antivenom could be improved to effectively neutralize T. melici venom.

Toxic and antigenic characterization of Peruvian Micrurus surinamensis coral snake venom.

Micrurus surinamensis is a semi-aquatic coral snake found in primary forest region and can cause relevant human accidents. In this work we investigated the toxic and antigenic activities of the Peruvian Micrurus surinamensis venom (MsV). We found that MsV show hyaluronidase activity but lack LAAO and PLA2 enzymatic activities. Interestingly, MsV induce edematogenic responses but cannot cause nociceptive effects. Furthermore, MsV can reduce in vitro cell viability in MGSO-3 cell line derived from human breast cancer tissue. To evaluate its antigenic potential, rabbits were immunized with MsV, which proved to be immunogenic. ELISA, immunobloting and in vivo neutralization assays demonstrated that the specific rabbit anti-MsV antivenom is more efficient than the therapeutic Brazilian antivenom in recognizing and neutralizing the lethal activity of MsV. MsV differs in protein profile and biological activities from M. frontalis venom (MfV), used as control, which impairs its recognition and neutralization by Brazilian therapeutic anti-elapidic antivenom. We performed a SPOT immunoassay for the identification of B-cell linear epitopes in the main toxins described for MsV targeted by the elicited neutralizing antibodies previously produced. A membrane containing 15-mer peptides representing the sequences of five 3TFxs and five PLA2s was produced and probed with anti- MsV antibodies. Results revealed important regions in 3FTx toxins for venom neutralization. Identifying the main MsV components and its biological activities can be helpful in guiding the production of antivenoms and in the optimization of treatment for coral snake envenomation in Brazil.

Levels of inflammatory markers are differentially expressed in sickle cell anemia and sickle cell trait.

Although sickle cell anemia (SCA) is related to inflammation, the profile of inflammatory markers in sickle cell trait (SCT) is poorly studied. This is a cross-sectional study of inflammatory biomarkers carried out involving adults with SCA in steady state, SCT and controls. The SCA group had higher levels of lactato dehydrogenase, IL-1ß, IL-6, IL-10, and tumor necrosis factor alpha than the others, while the SCT group had similar levels to control group. In addition, SCA group had lower IL-8/IL-10 and soluble triggering receptor expressed on myeloid cells-1/IL-10 ratios. These findings indicate that individuals with SCT do not have a chronic inflammatory profile and reinforce that cytokines are involved in the maintenance of the inflammatory state in SCA.

Progressive disseminated histoplasmosis in HIV-positive patients.

BACKGROUND: Histoplasmosis is the most common endemic mycosis among people living with advanced HIV infection. PURPOSE: Describe general aspects and challenges of this disease and its association with HIV. RESEARCH DESIGN: Review of literature. STUDY SAMPLE: Articles found using different combinations of terms including "disseminated histoplasmosis" and AIDS/HIV or immunosuppression in PubMed, Scopus, WHO Global health library, and Scielo database. ANALYSIS: We look for information on epidemiology, pathogenesis, diagnosis, and treatment of histoplasmosis in AIDS patients. RESULTS: Histoplasmosis is caused by Histoplasma capsulatum, a dimorphic fungus encountered throughout the world, mainly in soil enriched with bat and bird excreta. Progressive disseminated histoplasmosis is the main presentation of this mycosis in people living with advanced HIV and is fatal if left untreated. Symptoms include a systemic disease characterized by fever, weight loss, night sweats, skin manifestations, hepatomegaly, splenomegaly, and septic shock. Diagnostic tests include culture, visualization of H. capsulatum by direct and histopathological examination, serology, antigen, molecular, and skin testing. Patients with disseminated disease require aggressive and prolonged treatment to eradicate the pathogen and include amphotericin B and itraconazole. In many low income countries of endemic regions, histoplasmosis in HIV-positive patients is often undiagnosed or misdiagnosed as another opportunistic infection, due to the similarity in clinical manifestations and to the paucity of better diagnostic tests. CONCLUSION: Histoplasmosis remains a neglected disease. Few studies about the disease and expensive treatments make it difficult to reduce the morbidity and mortality of this condition. Public health services and physicians must be aware of histoplasmosis' burden among the HIV-positive population.

COVID-19 presenting as an exanthematic disease: a case report.

Coronavirus disease (COVID-19) is caused by SARS-CoV-2 and has spread rapidly and caused a global pandemic. Knowledge about clinical and laboratory manifestations in the pediatric population is necessary to guide and monitor such patients. A 3-year-old female patient diagnosed with COVID-19 presented with high fever. After defervescence, she experienced a maculopapular rash that worsened by the sixth day of the disease with self-limited evolution without relevant laboratory changes. The identification of rashes in children with COVID-19 is an unusual and important condition that must be recognized in view of the high transmissibility shown.

Epidemiological profile of HIV older adults who are patients in a reference center in Aracaju-SE / Perfil epidemiológico dos pacientes idosos com HIV em um centro de referência de Aracaju-SE / Perfil epidemiológico de pacientes ancianos con VIH en un centro de referencia en Aracaju-SE

Background and objectives: Acquired Immunodeficiency Syndrome (AIDS) is a disease caused by HIV. 3% of the people living with HIV/AIDS in Brazil are 60 years old or over. Although older adults correspond to a small percentage, there has been a significant increase in the incidence in this group in recent years. Thus, HIV infection in older adults is a reality, however, literature hardly addresses this topic. The objective is to study the epidemiological clinical profile of older adults living with HIV monitored at a referral center. Methods:This is an observational, descriptive, cross-sectional study with data collection obtained from the medical records of the STI/AIDS outpatient clinic at a reference center. The data were sociodemographic, clinical and laboratory, collected from September 2018 to February 2019. Results:In the reference center, 309 older adults were registered, representing 6.7% of all patients registered in the service. Of these, 75.6% are men, 38% are married, 70% heterosexual and approximately 50% with low education. Comorbidities are associated, with dyslipidemia (54%) being the main one. At the time of diagnosis, 65.8% had detectable viral load and 62% had CD4 + cells <500 cls/mm³ and after therapeutic follow-up, only 20% had detectable viral load. Several therapeutic regimens are used, the main one being Tenofovir, Lamivudine and Efavirenz (35.3%). Conclusion: The epidemiological profile of the population served in the region follows national and global characteristics, with a predominance of men, heterosexuals, married and with low education.(AU)

Justificativa e Objetivos: A Síndrome da Imunodeficiência Adquirida (SIDA) é uma doença causada pelo HIV. Das pessoas vivendo com HIV(PVHIV)no Brasil, 3% apresentam 60 anos ou mais. Apesar dos idosos corresponderem a um pequeno percentual, há aumento significativo da incidência nesse grupo nos últimos anos. Dessa forma, a infecção pelo HIV em idosos é uma realidade, contudo, a literatura pouco aborda esse tema. O objetivo do trabalho é estudar o perfil clínico epidemiológico dos idosos vivendo com HIV acompanhados em um centro de referência. Métodos: Trata-se de um estudo observacional, descritivo, de corte transversal, com coleta de dados obtida através dos prontuários do ambulatório de IST/SIDA de um centro de referência. Os dados sociodemográficos, clínicos e laboratoriais, foram coletados no período setembro de 2018 a fevereiro de 2019. Resultados: No centro de referência, estão cadastrados 309 idosos, representando 6,7% de todos os pacientes matriculados no serviço. Destes, 75,6% são homens, 38% casados, 70% de orientação heterossexual e aproximadamente 50% com baixa escolaridade. Comorbidades estão associadas, sendo a dislipidemia (54%) a principal. No momento do diagnóstico, 65,8% apresentavam carga viral (CV) detectável,62% tinham células CD4+ < 500céls/mm³ e após seguimento terapêutico apenas 20% apresentavam CV detectável. Vários esquemas terapêuticos foram utilizados, sendo o principal Tenofovir, Lamivudina e Efavirenz (35,3%). Conclusão: O perfil epidemiológico da população atendida na região segue as características nacionais e mundiais, com predomínio de homens, heterossexuais, casados e de baixa escolaridade.(AU)

Justificación y Objetivos: El Síndrome de Inmunodeficiencia Adquirido(SIDA) es una enfermedad causada por el VIH. De las personas que viven con el VIH (PVVIH) en Brasil, el 3% tiene 60 años o más. Aunque los adultos mayor es corresponden a un pequeño porcentaje, en los últimos años se ha producido un aumento significativo de la incidencia en este grupo. La infección por VIH en los adultos mayores es una realidad; sin embargo, la literatura aborda poco este tema. El objetivo de este trabajo es estudiar el perfil clínico epidemiológico de adultos mayores que conviven con el VIH y se atienden en un centro de referencia. Métodos: Se trata de un estudio observacional, descriptivo, de corte transversal, con datos obtenidos de los registros de ETS/SIDA de un centro de referencia. Se recogieron datos sociodemográficos, clínicos y de laboratorio desde septiembre de 2018 hasta febrero de 2019. Resultados: En el centro de referencia están registrados309 adultos mayores, que representan el 6,7% de todos los pacientes inscriptos en el servicio. De ellos, el 75,6% es del sexo masculino, el 38%, casado, el 70% con orientación heterosexual y aproximadamente el 50% con baja escolaridad. De las comorbilidades asociadas, la dislipidemia esla principal (54%). En el momento del diagnóstico, el 65,8% tenía una carga viral detectable (CV), el 62%tenía células CD4+<500 células/mm³ y después del seguimiento terapéutico sólo el 20% tenía CV detectable. Se utilizaron varios esquemas terapéuticos, siendo los principales el Tenofovir, la Lamivudina y el Efavirenz (35,3%). Conclusión: El perfil epidemiológico de la población atendida en la región sigue las características nacionales e internacionales, con predominio de hombres heterosexuales, casados y de baja escolaridad.(AU)

COVID-19 presenting as an exanthematic disease: a case report

Abstract Coronavirus disease (COVID-19) is caused by SARS-CoV-2 and has spread rapidly and caused a global pandemic. Knowledge about clinical and laboratory manifestations in the pediatric population is necessary to guide and monitor such patients. A 3-year-old female patient diagnosed with COVID-19 presented with high fever. After defervescence, she experienced a maculopapular rash that worsened by the sixth day of the disease with self-limited evolution without relevant laboratory changes. The identification of rashes in children with COVID-19 is an unusual and important condition that must be recognized in view of the high transmissibility shown.

Alterações oftalmológicas em pacientes com COVID-19: revisão narrativa de estudos e séries de casos / Ophthalmic changes in patients with COVID-19: narrative review of studies and case series

O objetivo deste trabalho é descrever casos clínicos e séries de casos relacionados a alterações oftalmológicas em pacientes com diagnóstico de COVID-19. Foi realizada uma revisão narrativa/descritiva de casos clínicos e série de casos. A partir das buscas de dados com descritores pré-definidos, foram integrados na revisão, 17 estudos. Dentre os principais temas identificados, destacam-se: alterações conjuntivais, alterações retinianas e oftalmoparesias. O quadro de alterações da conjuntiva foi prevalente em relação aos demais. Essa revisão incluiu não apenas afecções oculares em adultos, mas também, em crianças e adolescentes. O estudo chama atenção para o fato de que as alterações oculares foram descritas como alteração isolada, alteração precipitante e alteração simultânea ao quadro respiratório. Conclui-se que as afecções oculares vão além de alterações conjuntivais, embora sejam essas preponderantes, havendo ainda alterações retinianas, quadro de oftalmoparesia e ainda a incomum síndrome de Miller Fisher. Novos ensaios irão poder avaliar, qual é de fato, a representatividade dos problemas oculares na cadeia epidemiológica da COVID-19. [au]

The objective of this work is to describe clinical cases and case series related to ophthalmological changes in patients diagnosed with COVID-19. A narrative/descriptive review of clinical cases and case series was performed. Based on data searches with pre-defined descriptors, 17 studies were integrated in the review. Among the main themes identified, the following stand out: conjunctival changes, retinal changes and ophthalmoparesis. The picture of changes in the conjunctiva was prevalent in relation to the others. This review included not only eye disorders in adults, but also in children and adolescents. The study draws attention to the fact that the ocular changes were described as isolated alteration, precipitating alteration and simultaneous alteration to the respiratory condition. It is concluded that ocular conditions go beyond conjunctival alterations, although these are predominant, with retinal alterations, ophthalmoparesis and the unusual Miller Fisher syndrome. New trials will be able to assess, in fact, the representativeness of eye problems in the epidemiological chain of COVID-19. [au]