Immunochromatographic POC-CCA Test for the diagnosis of intestinal schistosomiasis in a high endemic region in Brazil: Differences in the interpretation of results.

The POC-CCA test is subject to variations in reading interpretations depending on the intensity of its results, and trace test reading have implications for determining prevalence. The aim of this study was to assess whether the readings obtained from the POC-CCA tests, conducted using a semi-quantitative scale (the G-score classification for test determination), exhibited concurrence with the direct visual interpretation (positive, negative, or trace) performed by two distinct analysts, using photographs from previously performed POC-CCA test carried out in the municipality of Maruim, in the state of Sergipe-Brazil, a region of high endemicity. The devices used to read the photographs were smartphones, so as to simulate field usage, and a desktop, a tool with higher image quality that would help the researchers in the evaluation and establishment of the final result at a later. In direct visual interpretation of the POC-CCA photographs, the most discordant results occurred in the identification of the trace response (T). The Kappa index established for the direct visual interpretation between the two analysts, in which T is considered as positive, in the desktop was κ=0.826 and in the smartphone, κ=0.950. When we use the G-score as a reading standardization technique and classify the results according to the manufacturer, with trace being evaluated as positive, the highest level of agreement was obtained. Some disagreement remains between the direct visual interpretation and the G-score when performed on the desktop, with more individuals being classified as negative in the direct visual interpretation, by both analysts. However, this result was not statistically significant. The use of the G-score scale proved to be an excellent tool for standardizing the readings and classifying the results according to the semi-quantitative scale showed greater concordance of results both among analysts and among the different devices used to view the photographs.

Systematic review and meta-analysis: assessing the accuracy of rapid immunochromatographic tests in dengue diagnosis.

The objective of this systematic review is to analyze the diagnostic accuracy of rapid dengue diagnostic tests. The search was conducted in the following databases: LILACS, Medline (Pubmed), CRD, The Cochrane Library, Trip Medical Database and Google Scholar. ELISA and PCR assays were adopted as reference methods. Thirty-four articles were included in this systematic review. Receiver operating characteristic (ROC) and Forest Plot were performed to evaluate sensitivity and specificity for each parameter analyzed (NS1, IgM and IgG). The results revealed that the combined analysis of the IgM antibody with the NS1 antigen resulted in greater sensitivity than the isolated analysis of IgM. The three analytes together showed the best performance, with a combined sensitivity of 90 % (95 % CI: 89-92 %) using ELISA as a comparator. Thus, the present review provides relevant knowledge for decision-making between the available rapid diagnostic tests.

Purification of pineapple bromelain by IMAC chromatography using chlorophyll-activated macroporous matrices.

This study investigated the purification of bromelain obtained from pineapple fruit using a new adsorbent for immobilized metal ion affinity chromatography (IMAC), with chlorophyll obtained from plant leaves as a chelating agent. The purification of bromelain was evaluated in batches from the crude extract of pineapple pulp (EXT), and the extract precipitated with 50 % ammonium sulfate (EXT.PR), the imidazole buffer (200 mM, pH 7.2) being analyzed and sodium acetate buffer, pH 5.0 + 1.0 NaCl as elution solutions. All methods tested could separate forms of bromelain with molecular weights between ±21 to 25 kDa. Although the technique using EXT.PR stood out in terms of purity, presenting a purification factor of around 3.09 ± 0.31 for elution with imidazole and 4.23 ± 0.12 for acetate buffer solution. In contrast, the EXT methods obtained values between 2.44 ± 0.23 and 3.21 ± 0.74 for elution with imidazole and acetate buffer, respectively, for purification from EXT.PR has lower yield values (around 5 %) than EXT (around 15 %). The number of steps tends to reduce yield and increase process costs, so the purification process in a monolithic bed coupled to the chromatographic system using the crude extract was evaluated. The final product obtained had a purification factor of 6, with a specific enzymatic activity of 59.61 ± 0.00 U·mg-1 and a yield of around 39 %, with only one band observed in the SDS-PAGE electrophoresis analysis, indicating that the matrix produced can separate specific proteins from the total fraction in the raw material. The IMAC matrix immobilized with chlorophyll proved promising and viable for application in protease purification processes.

Porous polymer monolithic columns to investigate the interaction of humic substances with herbicides and emerging pollutants by affinity chromatography.

BACKGROUND: Understanding the interaction mechanisms and the relevant binding constants between humic acids and emerging or regulated pollutants is of utmost importance in predicting their geochemical mobility, bioavailability, and degradation. Fluorescence spectroscopy, UV-vis spectroscopy, equilibrium dialysis, and solid-phase extraction combined with liquid chromatography-mass spectrometry have been employed to elucidate interactions of humic acids with organic micropollutants, especially pharmaceutical drugs. These methods demand large sample volumes, long equilibration times, and laborious extraction steps which may imply analytical errors. Monolithic high-performance affinity chromatography is an alternative and simpler method to investigate these interactions and determine the binding constants. RESULTS: Polymer monoliths based on aminated glycidyl methacrylate and ethylene glycol dimethacrylate served to immobilize Cu(II) and then humic acid to produce monolithic affinity chromatography columns with humic acid as the active interaction phase. About 86.5 mg of humic acid was immobilized per gram of polymer. The columns enabled a comparison of the binding strength of humic acid with herbicides and emerging pollutants at 25 °C and pH 6.0 ± 0.1. Paracetamol, acetylsalicylic acid, and salicylic acid did not retain. Among the compounds that interacted with humic acid, the order of increasing affinity, estimated by the global affinity constant (nKa) or partition coefficient (KD) was: caffeine < simazine < atrazine âˆ¼ propazine < benzophenone. The nKa (L mol-1) values ranged from (4.9 ± 0.3) × 102 for caffeine to (1.9 ± 0.3) × 103 for benzophenone, whereas KD (L kg-1) varied from 14 ± 1 to 56 ± 8 for the same compounds. SIGNIFICANCE AND NOVELTY: To our knowledge, this is the first paper demonstrating the use of a monolithic platform to immobilize supramolecular structures of humic acids exploiting immobilized metal affinity to comparatively evaluate their affinity towards emerging pollutants exploiting the concepts of high-performance affinity chromatography. The proposed approach needs only small amounts of humic acid, which is a relevant feature in preparing columns with humic substances isolated and purified from remote areas.

Synthesis and characterization of supermacroporous cryogel with immobilized p-aminobenzenesulfonamide as affinity ligand for the purification of lactoperoxidase from whey.

This study proposed the development of a monolithic supermacroporous affinity column for direct capture of lactoperoxidase, a glycoprotein present in milk, whey, and colostrum, with several applications due to its wide antimicrobial activity. A poly(acrylamide)-based cryogel was produced by radical co-polymerization of monomers in frozen aqueous solution and activated with p-aminobenzenesulfonamide as a ligand for specific interaction with the lactoperoxidase. The axial liquid dispersion coefficients at different liquid flow rates were determined by measuring residence time distributions using the tracer pulse-response method. The axial dispersion coefficient was low and the height equivalent to theoretical plate was not dependent on the flow velocity. The adsorptive capacity of affinity cryogel was studied as a function of flow velocity and the best condition was 0.9 cm/min. The response surface methodology was applied to optimize the capture of the enzyme, as a function of pH and salt concentration. Higher purification factor value was found at a salt concentration of 80 mmol/L and pH of 8.0 (p < 0.05). There was no influence of the variables under study on the yield (p > 0.05). The results indicated that affinity cryogel is a promising chromatography support for the use in high-throughput one-step purification of lactoperoxidase from whey.

Antibody-Based Affinity Capture Combined with LC-MS Analysis for Identification of COVID-19 Disease Serum Biomarkers.

Blood serum or plasma proteins are potentially useful in COVID-19 research as biomarkers for risk prediction, diagnosis, stratification, and treatment monitoring. However, serum protein-based biomarker identification and validation is complicated due to the wide concentration range of these proteins, which spans more than ten orders of magnitude. Here we present a combined affinity purification-liquid chromatography mass spectrometry approach which allows identification and quantitation of the most abundant serum proteins along with the nonspecifically bound and interaction proteins. This led to the reproducible identification of more than 100 proteins that were not specifically targeted by the affinity column. Many of these have already been implicated in COVID-19 disease.

Understanding the adsorption of plasmid DNA and RNA molecules onto arginine-agarose chromatographic resin.

BACKGROUND: The production of nucleic acids (plasmid DNA or mRNA) in response to the development of new advanced vaccine platforms has greatly increased recently, mostly resulting from the pandemic situation. Due to the intended pharmaceutical use, nucleic acids preparations must fulfill all the required specifications in terms of purity and quality. Chromatography is a standard operation used to isolate these molecules from impurities, playing a central role in the manufacturing processes. However, the mechanism of nucleic acid adsorption in chromatographic resins is poorly understood, often leading to low adsorption capacities and a lack of specificity. METHODS AND RESULTS: Here we investigated the adsorption of plasmid DNA and RNA molecules onto arginine-agarose, a resin with potential for large-scale application. Equilibrium batch studies were performed through pre-purified samples, using arginine-based ligands by varying the adsorption conditions in the pH value range from 6.0 to 9.0. Langmuir and Freundlich isotherm models were used to describe the adsorption equilibrium. The best fit for both nucleic acids was achieved using the Freundlich model. The correct choice of pH showed critical for controlling the efficacy of arginine-nucleic acid interaction, due to its influence on the nucleic acid structures. This type of analysis is necessary for the improvement of the selectivity and binding capacities of the resins used for plasmid DNA or mRNA purification. CONCLUSIONS: The results presented here indicate that adsorption conditions can be tuned to enhance separation between pDNA and RNA, an important feature in the purification of nucleic acids for vaccine production.

Optimization of Expression and Purification of Schistosoma mansoni Antigens in Fusion with Rhizavidin.

Schistosomiasis causes significant morbidity and mortality. Vaccine efforts to date indicate the need to increase the immunogenicity of Schistosoma antigens. The multiple antigen-presenting system, whereby proteins are genetically fused to rhizavidin and affinity linked to biotinylated templates, enables the generation of robust immune responses. The objective of this work was to express and purify the S. mansoni antigens, SmTSP-2 and SmCD59.2, in fusion with rhizavidin. The fusion with rhizavidin greatly decreased the expression level of rSmTSP-2, but not rSmCD59.2, and both were expressed in the insoluble fraction, requiring optimization of culture conditions. Evaluation of different E. coli strains and media showed that BL21-DE3 cultured in Terrific Broth provided the highest expression levels of both proteins. Investigation of a range of time and temperature of induction showed that E. coli strains expressing rRzv:SmTSP-2 and rRzv:SmCD59.2 showed the highest protein production at 23 °C for 15 h. Recombinant proteins were purified by a single step of affinity chromatography allowing isolation of these proteins in high concentration and purity. The optimization process increased final soluble protein yield of rRzv:SmTSP-2 by fourfold and rRzv:SmCD59.2 by tenfold, providing ~ 20 mg/L of each protein. Optimized fusion protein production will allow antigen use in biotin-rhizavidin affinity platforms.

Prognosis of hospitalized children under 2 years of age with co-detection of influenza A and respiratory syncytial virus at the healthcare facility / Prognóstico de crianças hospitalizadas menores de 2 anos com codetecção de influenza A e vírus sincicial respiratório no local de atendimento

Abstract Objectives: the aim of this study is to evaluate the impact of co-detection of Flu A and RSV using rapid immunochromatographic tests at the point of care, in pediatric patients under 2 years of age in a general hospital. Methods: a retrospective cohort study was conducted to analyze clinical outcomes in hospitalized infants with viral respiratory disease with positive results of rapid immunochromatographic test for RSV and/or Flu-A, from 2013 to 2018. A logistic regression model was adjusted to analyze predictors of orotracheal intubation during hospitalization. Results: we analyzed 220 cases: RSV (192), Flu-A (9), co-detection (19). Lethality rate was 1.8% (2 cases), and 88% (194) were under 1 year of age. Mean time of hospitalizations was higher in patients with co-detection. Variables significantly associated with orotracheal intubation were: younger age in months, comorbidities, RSV and Flu-A co-detection, and bacterial pneumonia during hospitalization. Conclusions: RSV and Flu-Aco-detection was associated with the least favorable clinical prognoses in this study. Rapid test diagnosis may provide important information at the point of care, because molecular panels are not widely accessible in general hospitals. Rapid diagnosis allows timely evaluation and treatment.

Resumo Objetivos: avaliar o impacto da codetecção de Influenza A (FluA) e Vírus Sincicial Respiratório (VSR) por meio de testes imunocromatográficos rápidos em tempo real, em pacientes menores de 2 anos em hospital público e universitário. Métodos: estudo de coorte retrospectivo foi conduzido para analisar os desfechos clínicos de crianças hospitalizadas com doença respiratória viral com resultados positivos do teste rápido imunocromatográfico para VSR e/ou FluA, de 2013 a 2018. Um modelo de regressão logística foi ajustado para analisar preditores de intubação orotraqueal durante a internação. Resultados: foram analisados 220 casos: RSV (192), FluA (9) eco-detecção (19). A letalidade foi de 1,8% (2 casos) e 88% (194) casos em menores de 1 ano. O tempo médio de internação foi maior nos pacientes com codetecção. As variáveis significativamente associadas à intubação orotraqueal foram: menor idade em meses, comorbidades, codetecção de VSR e Flu-A e pneumonia bacteriana durante a internação. Conclusões: codetecção VSR e FluA foi associada a prognósticos clínicos desfavoráveis. O teste rápido fornece informações importantes a beira-leito, pois os painéis moleculares não são amplamente acessíveis em hospitais públicos. O diagnóstico rápido permite a avaliação e tratamento oportunos.

Improved Performance of ELISA and Immunochromatographic Tests Using a New Chimeric A2-Based Protein for Human Visceral Leishmaniasis Diagnosis.

METHODS: A total of 1028 sera samples were used for the development and validation of ELISA (321 samples from L. infantum-infected patients, 62 samples from VL/AIDS coinfected patients, 236 samples from patients infected with other diseases, and 409 samples from healthy donors). A total of 520 sera samples were used to develop and validate ICT (249 samples from L. infantum-infected patients, 46 samples from VL/AIDS coinfected patients, 40 samples from patients infected with other diseases, and 185 samples from healthy donors). Findings. Using the validation sera panels, DTL-4-based ELISA displayed an overall sensitivity of 94.61% (95% CI: 89.94-97.28), a specificity of 99.41% (95% CI: 96.39-99.99), and an accuracy of 97.02% (95% CI: 94.61-98.38), while for ICT, sensitivity, specificity, and accuracy values corresponded to 91.98% (95% CI: 86.65-95.39), 100.00% (95% CI: 96.30-100.00), and 95.14% (95% CI: 91.62-97.15), respectively. When testing sera samples from VL/AIDS coinfected patients, DTL-4-ELISA displayed a sensitivity of 77.42% (95% CI: 65.48-86.16), a specificity of 99.41% (95% CI: 96.39-99.99), and an accuracy of 93.51% (95% CI: 89.49%-96.10%), while for DTL-4-ICT, sensitivity was 73.91% (95% CI: 59.74-84.40), specificity was 90.63% (95% CI: 81.02-95.63), and accuracy was 82.00% (95% CI: 73.63-90.91). CONCLUSION: DTL-4 is a promising candidate antigen for serodiagnosis of VL patients, including those with VL/AIDS coinfection, when incorporated into ELISA or ICT test formats.

Human Blood Plasma Investigation Employing 2D UPLC-UDMSE Data-Independent Acquisition Proteomics.

Proteomic tools are especially useful when it comes to investigating complex samples such as human blood plasma, in which protein quantities can span across up to ten orders of magnitude. Ultra definition mass spectrometry, in combination with two-dimensional liquid chromatography, provides better coverage of complex proteomes and allows for better control of collision energy, keeping the fragmentation benefits of high collision energy associated with drift time measurements from ion mobility separation. Here, we present a protocol to assist in the identification of proteins in human blood plasma and other similar samples with a large dynamic range.

LC-HRMS and acetylcholinesterase affinity assay as a workflow for profiling alkaloids in Annona salzmannii extract.

Structure-based molecular networking is useful as a dereplication strategy to identify known molecules, unknown close analogues, or compound families. On the other hand, the ligand fishing assay is a remarkable alternative to accelerate the screening process and to overcome the drawbacks of laborious experiments usually adopted in natural product research. The combination of these approaches contributes to high productivity in disclosing active metabolites and a decrease in lead time identification. To provide a valuable data base for the alkaloids of A. salzmannii bark herein we disclose thirty-one isoquinoline alkaloids including benzyltetrahydroisoquinolines, aporphines, proaporphines, and protoberberines. Among these, twenty-six have not been described for A. salzmannii including the unprecedented alkaloid N,O-dimethylcoclaurine N-oxide. In addition, norcoclaurine (1), norreticuline (13), N,O-dimethylcoclaurine N-oxide (15), and N-acetylasimilobine (24) are now reported for the first time as ligand for acetylcholinesterase.

Preparation of a novel EGFR specific immunotoxin and its efficacy of anti-colorectal cancer in vitro and in vivo.

OBJECTIVES: Epithelial growth factor receptor (EGFR), as a malignancy marker, is overly expressed in multiple solid tumors including colorectal neoplasms, one of the most prevalent malignancies worldwide. The main objective of this study is to enhance the efficacy of anti-tumor therapy targeting EGFR by constructing a novel EGFR-specific immunotoxin (C-CUS245C) based on Cetuximab and recombinant Cucurmosin (CUS245C). METHODS: E. coli BL21 (DE3) PlysS (E. coli) was used to express CUS245C with a cysteine residue inserting to the C-terminus of Cucurmosin. Then immobilized metal ion affinity chromatography (IMAC) was used to purify CUS245C. The chemical conjugation method was used for the preparation of C-CUS245C. Then dialysis and IMAC were used to purify C-CUS245C. Western blot as well as SDS-PAGE was carried out to characterize the formation of C-CUS245C. At last the anti-colorectal cancer activity of C-CUS245C was investigated in vitro and in vivo. RESULTS: CUS245C with high purity could be obtained from the prokaryotic system. C-CUS245C was successfully constructed and highly purified. The cytotoxicity assays in vitro showed a significant proliferation inhibition of C-CUS245C on EGFR-positive cells for 120 h with IC50 values less than 0.1 pM. Besides, the anti-tumor efficacy of C-CUS245C was remarkably more potent than that of Cetuximab, CUS245C, and C + CUS245C (P < 0.001). Whereas the cytotoxicity of C-CUS245C could hardly be detected on EGFR-null cell line. Our results also showed that C-CUS245C had efficacy of anti-colorectal cancer in mouse xenograft model, indicating the therapeutic potential of C-CUS245C for the targeted therapy of colorectal neoplasms. CONCLUSIONS: C-CUS245C exhibits potent and EGFR-specific cytotoxicity. Insertional mutagenesis technique is worthy to be adopted in the preparation of immunotoxin. Immunotoxin can be highly purified through dialysis followed by IMAC.

Diagnóstico de cinomose canina por meio de teste imunocromatográfico e sua correlação com achados clínicos e hematológicos no semiárido da Paraíba / Diagnosis of canine distemper by immunochromatographic test and its correlation with clinical and hematological findings in the semiarid region of Paraíba

Objetivou-se através deste trabalho, determinar a prevalência de cinomose canina no semiárido da Paraíba, através de testes rápidos imunocromatográficos, correlacionando-a com os principais achados clínicos e hematológicos. Foram analisadas 67 fichas de animais em que foram realizados testes rápidos para pesquisa de antígeno em amostras nasais e oculares no período de janeiro a dezembro de 2019. Observou-se que 47% (32/67) dos cães analisados foram positivos para cinomose canina. As variáveis que apresentaram diferença estatística significativa (p<0,05) para a infecção foram animais sem raça definida 60% (21/35), animais não vacinados 70% (29/42), e período seco do ano, sendo o mês de agosto (40%; 13/32), com maior ocorrência. Os principais sistemas afetados foram o respiratório 61% (17/28), oftalmológico 70% (22/31), nervoso 69% (13/19), dermatológico 45% (9/20), e gastrintestinal 42% (6/14). As principais alterações hematológicas foram anemia 66% (23/32), leucopenia 76% (19/25) e linfopenia 48% (15/31). Concluiu-se que foi elevada a ocorrência de cinomose canina em animais com suspeita clínica no Semiárido Paraibano, e animais sem raça definida, não vacinados, no período seco do ano foram mais diagnosticados com a enfermidade.

The objective of this study was to determine the prevalence of distemper canine distemper vírus (CDV) infection in the semi-arid region of Paraíba, using rapid immunochromatographic tests, correlating it with the main clinical and hematological findings. 67 records of animals were analyzed in which rapid tests were performed for antigen research in nasal and ocular from January to December 2019. It was observed that 47% (32/67) of compulsory dogs were positive for canine distemper. The variables that defined difference difference (p <0.05) for infection were mixed breed animals 60% (21/35), unvaccinated animals 70% (29/42), and dry period of the year, being the August (40%; 13/32), with greater occurrence. The main affected systems were the respiratory 61% (17/28), ophthalmological 70% (22/31), nervous 69% (13/19), dermatological 45% (9/20), and gastrointestinal 42% (6/14 )) The main changes were hematological, anemia 66% (23/32), leukopenia 76% (19/25) and lymphopenia 48% (15/31). It was concluded that the occurrence of canine distemper in animals with clinical suspicion in the Semiarid Paraibano was high, and non-vaccinated mixed-breed animals in the dry period of the year were more diagnosed with the disease.

Development of a lateral flow immunochromatography test for the rapid detection of bovine tuberculosis.

Detection of specific antibodies would be a useful test strategy for bovine tuberculosis (bTB) as a complement to the single skin test. We developed a lateral flow immunochromatography (LFIC) test for rapid bTB detection based on the use of a conjugate of gold nanoparticles with a recombinant G protein. After evaluating 3 Mycobacterium bovis (MB) antigens: ESAT-6, CFP-10 and MPB83 for the control line, we selected MPB83 given it was the most specific. The performance of the test was analyzed with 820 bovine sera, 40 sera corresponding to healthy animals, 5 sera from animals infected with Mycobacterium avium subsp. paratuberculosis (MAP) and 775 sera of animals from herds with bTB. All these sera were also submitted to a validated bTB-ELISA using whole-cell antigen from MB. From the 775 sera of animals from herds with bTB, 87 sera were positive by the bTB-ELISA, 45 were positive by LFIC and only 5 animals were positives by skin test (TST). To confirm bTB infection in the group of TST (-), bTB-ELISA (+) and LFIC (+) animals, we performed postmortem examination in 15 randomly selected animals. Macroscopically, these 15 animals had numerous small and large yellow-white granulomas, characteristic of bTB, and the infection was subsequently confirmed by PCR in these tissues with lesions (gold standard). No false positive test result was detected with the developed LFIC either with the sera from healthy animals or from animals infected with MAP demonstrating that it can be a useful technique for the rapid identification of animals infected with bTB.

Diagnóstico de cinomose canina por meio de teste imunocromatográfico e sua correlação com achados clínicos e hematológicos no semiárido da Paraíba / Diagnosis of canine distemper by immunochromatographic test and its correlation with clinical and hematological findings in the semiarid region of Paraíba

Objetivou-se através deste trabalho, determinar a prevalência de cinomose canina no semiárido da Paraíba, através de testes rápidos imunocromatográficos, correlacionando-a com os principais achados clínicos e hematológicos. Foram analisadas 67 fichas de animais em que foram realizados testes rápidos para pesquisa de antígeno em amostras nasais e oculares no período de janeiro a dezembro de 2019. Observou-se que 47% (32/67) dos cães analisados foram positivos para cinomose canina. As variáveis que apresentaram diferença estatística significativa (p<0,05) para a infecção foram animais sem raça definida 60% (21/35), animais não vacinados 70% (29/42), e período seco do ano, sendo o mês de agosto (40%; 13/32), com maior ocorrência. Os principais sistemas afetados foram o respiratório 61% (17/28), oftalmológico 70% (22/31), nervoso 69% (13/19), dermatológico 45% (9/20), e gastrintestinal 42% (6/14). As principais alterações hematológicas foram anemia 66% (23/32), leucopenia 76% (19/25) e linfopenia 48% (15/31). Concluiu-se que foi elevada a ocorrência de cinomose canina em animais com suspeita clínica no Semiárido Paraibano, e animais sem raça definida, não vacinados, no período seco do ano foram mais diagnosticados com a enfermidade.(AU)

The objective of this study was to determine the prevalence of distemper canine distemper vírus (CDV) infection in the semi-arid region of Paraíba, using rapid immunochromatographic tests, correlating it with the main clinical and hematological findings. 67 records of animals were analyzed in which rapid tests were performed for antigen research in nasal and ocular from January to December 2019. It was observed that 47% (32/67) of compulsory dogs were positive for canine distemper. The variables that defined difference difference (p <0.05) for infection were mixed breed animals 60% (21/35), unvaccinated animals 70% (29/42), and dry period of the year, being the August (40%; 13/32), with greater occurrence. The main affected systems were the respiratory 61% (17/28), ophthalmological 70% (22/31), nervous 69% (13/19), dermatological 45% (9/20), and gastrointestinal 42% (6/14 )) The main changes were hematological, anemia 66% (23/32), leukopenia 76% (19/25) and lymphopenia 48% (15/31). It was concluded that the occurrence of canine distemper in animals with clinical suspicion in the Semiarid Paraibano was high, and non-vaccinated mixed-breed animals in the dry period of the year were more diagnosed with the disease.(AU)

Avaliação do perfil clínico da soro persistência de anticorpos em trabalhadores de saúde durante a resposta a infecção por SARS-CoV-2 / Evaluation of the clinical profile of serum antibody persistence in healthcare workers during the response to SARS-CoV-2 infection

A doença por coronavírus 2019 (COVID-19), causada por síndrome respiratória aguda grave coronavírus 2 (SARS-CoV-2), foi declarada uma pandemia pela Organização Mundial da Saúde (OMS) em 11 de março de 2020 (1). O conhecimento da resposta imune inata e adaptativa do hospedeiro e eficiência de infecção do vírus são cruciais para controle da infecção. Estudos recentes sugerem que os anticorpos contra SARS-CoV-2 diminuem após algumas semanas do início dos sintomas. O objetivo deste estudo foi descrever as características clínicas e laboratoriais dos trabalhadores de saúde que mantiveram o resultado positivo na avaliação sorológica de anticorpos Imunoglobulina (Ig) G anti- nucleocapsídeo (anti-N) para SARS-Cov-2. Este estudo foi realizado de forma transversal, descritivo e analítico. A coleta de dados foi efetuada através de questionário autoaplicável e teste de imunocromatografia de fluxo lateral para avaliação de anticorpo IgM e IgG específico para proteína N do SARS-COV 2. A análise dos resultados ocorreu utilizando os dados de três avaliações distintas dos trabalhadores de saúde no IFF-Fiocruz, entre junho e novembro de 2020. A maior produção de IgG foi relacionada a trabalhadores não brancos, com Reação quantitativa de transcrição reversa acoplada à reação em cadeia da polimerase (RT - PCR) confirmados e que relataram sintomas como dor no peito, dispneia, fadiga e ageusia. A chance de soro persistência foi 56,9% maior dentre os sintomáticos, porém não foi significativa do ponto de vista estatístico (OR=1,569, IC 95%: 0,908-2,711). O tempo mediano de manutenção da soro persistência foi de 211 dias. Este estudo demonstrou que cerca de metade dos trabalhadores que tiveram seus exames reagentes em uma primeira coleta não mantiveram estes níveis.

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was declared a pandemic by World Health Organization (WHO) on March 11, 2020(1). Knowledge of the host's innate and adaptive immune response and virus infection efficiency are crucial for infection control. Recent studies suggest that antibodies to SARS-CoV-2 decline weeks after symptom onset. This study describes the clinical and laboratory characteristics of health workers who maintained a positive result in the serological evaluation of IgG anti-N antibodies to SARS-Cov-2. This study was carried out in a transversal, descriptive and analytical way. Data collection was performed using a self-administered questionnaire and lateral flow immunochromatography test to assess IgM and IgG antibodies specific for SARS-COV 2 N protein. The analysis of the results was made from three distinct assessments of health workers at the IFF-Fiocruz, between June and November 2020. The highest production of IgG was related to non-white workers, with confirmed RT- PCR and who reported symptoms such as chest pain, dyspnea, fatigue and ageusia. The chance of sero persistence was 56.9% higher among the symptomatic ones, but it was not statistically significant (OR=1.569, 95% CI: 0.908-2.711). The symptom most related to sero persistence was dyspnea, followed by cough, arthralgia and anosmia.The median time of maintenance of serum persistence was 211 days. This study showed that about half of the professionals who had their exams reactive in a first collection, did not maintain their reactive levels.

Purification of Recombinant Galectins Expressed in Bacteria.

Galectins are soluble lectins that participate in many physiological and pathological functions. Since they can act extracellularly, the use of the recombinant protein is a recurrent strategy for studying their biological functions. Here, we provide a general protocol for the production of Galectins and their isolated or chimeric domains. We take advantage of their lectin activity and the 6xHis-tag addition for purification, thus obtaining a highly pure and active Galectin to use in both in vitro and in vivo assays. For complete details on the use and execution of this protocol, please refer to Cattaneo et al. (2011), Tribulatti et al. (2012), and Prato et al. (2020).

Amino acid-based hydrophobic affinity cryogel for protein purification from ora-pro-nobis (Pereskia aculeata Miller) leaves.

The surfaces of the polyacrylamide cryogels were coated with L-tryptophan (cryogel-Trp) or L-phenylalanine (cryogel-Phe) to enhance crude leaf extract-derived ora-pro-nobis (OPN) protein binding via pseudo-specific hydrophobic interactions. Cryogels functionalized with amino acids were prepared and characterized through morphological, hydrodynamic, and thermal analyses. The adsorption capacities of cryogel-Phe and cryogel-Trp were evaluated in terms of type (sodium sulfate or sodium phosphate) and concentration (0.02 or 0.10 mol∙L-1) of saline solution, pH (4.0, 5.5, or 7.0), and NaCl concentration (0.0 or 0.5 mol∙L-1). The cryogel-Phe presented a higher adsorptive capacity, achieving its maximum value (q = 92.53 mg∙g-1) when the crude OPN crude leaf extract was diluted in sodium sulfate 0.02 mol∙L-1 + NaCl 0.50 mol∙L-1, at pH = 7.0. The dilution rate significantly (p < 0.05) affected the recovered protein amount after the adsorption and elution processes, reaching 94.45% when the feedstock solution was prepared with a crude extract 5 times. The zeta potential for the eluted OPN proteins was 5.76 mV (pH = 3.23) for both dilution rates. The secondary structure composition mainly included ß-sheets (46.50%) and α-helices (13.93%). The cryogel-Phe exhibited interconnected pores ranging 20-300 µm in size, with a Young modulus of 1.51 MPa, and thermal degradation started at 230 °C. These results indicate that the cryogel-Phe exhibited satisfactory properties as promising chromatography support for use in high-throughput purification of crude leaf extract-derived OPN proteins.