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1.
Polymers (Basel) ; 16(11)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38891423

RESUMO

Galactomannans are polysaccharides obtained from legume seed extraction. They present a chemical structure consisting of D-mannose chains linked by glycosidic bonds and galactose branches. The main focus lies in their use as thickeners in the food industry, aimed at improving the dielectric properties of food during heating processes within the radiofrequency and microwave ranges. In this work, the prepared galactomannan samples were electrically analyzed through impedance spectroscopy, which is a powerful physical technique. From the experimental measurements, the dielectric permittivity and loss tangent of the galactomannan solutions were analyzed and the electrical modulus formalism was used to study the dielectric relaxations. Crude galactomannans exhibited higher values of permittivity, conductivity, and losses compared to purified galactomannans. Increasing ethanol concentration in galactomannan purification causes an increase in the permittivity and conductivity of galactomannan solutions. In a 1% solution, at 1 kHz, the permittivity increased from 378.56 to 538.09, while in the 2% solution, this increase was from 656.22 to 1103.24. Regarding the conductivity, at the same frequency, the increase was from 1.6 × 10-3 to 3.3 × 10-3 Ω-1m-1 and from 2.9 × 10-3 to 5.5 × 10-3 Ω-1m-1, respectively. The rise of the ethanol concentration in galactomannan purification led to a decrease in the relaxation time, from 448.56 to 159.15 µs and from 224.81 to 89.50 µs in the solution with 1 and 2%, respectively. The results suggest that galactomannan from Adenanthera pavonina L. has potential for use in the food industry.

2.
Viruses ; 15(4)2023 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-37112964

RESUMO

SARS-CoV-2 genome surveillance is important for monitoring risk groups and health workers as well as data on new cases and mortality rate due to COVID-19. We characterized the circulation of SARS-CoV-2 variants from May 2021 to April 2022 in the state of Santa Catarina, southern Brazil, and evaluated the similarity between variants present in the population and healthcare workers (HCW). A total of 5291 sequenced genomes demonstrated the circulation of 55 strains and four variants of concern (Alpha, Delta, Gamma and Omicron-sublineages BA.1 and BA.2). The number of cases was relatively low in May 2021, but the number of deaths was higher with the Gamma variant. There was a significant increase in both numbers between December 2021 and February 2022, peaking in mid-January 2022, when the Omicron variant dominated. After May 2021, two distinct variant groups (Delta and Omicron) were observed, equally distributed among the five Santa Catarina mesoregions. Moreover, from November 2021 to February 2022, similar variant profiles between HCW and the general population were observed, and a quicker shift from Delta to Omicron in HCW than in the general population. This demonstrates the importance of HCW as a sentinel group for monitoring disease trends in the general population.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , COVID-19/epidemiologia , Genômica , Pessoal de Saúde
3.
J Biomed Mater Res B Appl Biomater ; 111(6): 1247-1258, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-36786241

RESUMO

The development of bioactivity in bioinert metallic alloys is a field of interest aiming to improve some aspects of these materials for implant applications. New Co63 Cr28 W9-x Tax alloys with different Ta concentrations (x = 0, 2, 4, 6, and 9% w/w) were synthesized in the work reported here. The alloys were characterized by x-ray diffraction, volumetric density, Vickers microhardness, atomic force microscopy, scanning electron microscopy (SEM), and energy-dispersion x-ray spectroscopy (EDS). Bioactivity properties were evaluated by in vitro tests with simulated body fluid (SBF). In vivo assays were performed to assess biocompatibility. The influence of surface thermochemical treatment and Ta insertion on the bioactive properties of the alloys was investigated. The results showed that the alloy structure comprises εCo and αCo phases, with cobalt as a matrix with Cr, W, and Ta as a solid solution. TaCo2 phase is observed in the alloys with 4, 6, and 9% w/w of Ta, and its amount increase as Ta concentration increases. Volumetric density is reduced (from 8.78 ± 0.06 to 8.56 ± 0.09 g/cm3 ) as Ta concentration increases (from 0% to 9% w/w) mainly due to the lower density of the tantalum compared to the tungsten metal. On the other hand, the TaCo2 phase contributes to the increase of Vickers's hardness by ~17.6% for the alloy with 9% Ta (394.7 ± 8.1 HV) compared with Co63 Cr28 W9 (336 ± 5 HV). The topographic analysis showed increased roughness and adhesion due to the nucleation of Ta1.1 O1.05 and Ca2 Ta2 O7 crystals after surface thermochemical treatment. The roughness and adhesion increase from 16.9 ± 0.6 nm and 8.3 ± 1.8 nN (untreated surface) to 255.7 ± 17.7 nm and 24.1 ± 12.6 nN (treated surface), respectively, for the Co63 Cr28 Ta9 alloy. These results suggest that thermochemical treatment provides surface conditions favorable to hydroxyapatite (HA) nucleation. The SEM and EDS data showed the nucleation of spongy structures, consistent with HA, composed mainly of Ca and P, indicating that oxides tantalum promoted a bioactive response on the sample's surface. The biological assay corroborated the alloy's safety and applicability, highlighting its potential in biomedical application since no harmful effects were observed.


Assuntos
Ligas , Tantálio , Ligas/farmacologia , Tantálio/farmacologia , Durapatita/química , Metais , Próteses e Implantes , Propriedades de Superfície , Teste de Materiais
4.
Chem Biodivers ; 20(2): e202200888, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36703594

RESUMO

Aiming of self-sustainable production, the search for biodegradable and biocompatible materials has brought with it the need to know the physicochemical and dielectric characteristics of polysaccharide-based composite structures, which can be used as important and promising raw materials for biotechnology and electronic industries. Galactomannans are polysaccharides, extracted from seeds and microbiological sources, consisting of mannose and galactose. In this context, this work aimed to extract, purify and characterize by XRD, FTIR and impedance spectroscopy galactomannan obtained from seeds of Adenanthera pavonina L. The purification process was made with ethyl alcohol at concentrations of 70, 80 and 90 %. Polymeric films were prepared by solvent slow evaporation at low temperatures. XRD measurements revealed that Galactomannan from Adenanthera pavonina L., after purification, has a semi-crystalline structure due to the identification of two peaks the first between 5.849° and 6.118° and the second between 20.011° and 20.247°. FTIR spectra showed the functional groups associated with monosaccharides of the galactomannan from Adenanthera pavonina L. seeds, as well as the typical polysaccharide bands and peaks, confirmed by literature data. The impedance results give an increment on the state-of-the-art of this biomaterial by showing the existence of dielectric relaxations, independent of the degree of purification, using the dielectric modulus formalism. The permittivity analysis reveals the presence of water in the structure of the film, whose dipoles contribute to the relatively high value of the dielectric constant. From the results obtained, it can be concluded that purified galactomannan has the potential for possible applications in the electronics industry as a green and eco-friendly dielectric material.


Assuntos
Fabaceae , Mananas , Mananas/análise , Mananas/química , Fabaceae/química , Polissacarídeos/química , Galactose , Sementes/química , Materiais Biocompatíveis
5.
Biomedicines ; 10(9)2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36140252

RESUMO

Head and neck cancer (HNC) is one of the most common cancers worldwide. Alcohol and tobacco consumption, besides viral infections, are the main risk factors associated with this cancer. When diagnosed in advanced stages, HNC patients present a higher probability of recurrence or metastasising. The complexity of therapeutic options and post-treatment surveillance is associated with poor prognosis and reduced overall survival (OS). This review aims to explore immunotherapy (immune checkpoint inhibitors (ICI), therapeutic vaccines, and oncolytic viruses) in HNC patients' treatment, and to explore when, how, and why patients can benefit from it. The monotherapy with ICI or in combination with chemotherapy (QT) shows the most promising results. Compared to standard therapy, ICI are able to increase OS and patients' quality of life. QT in combination with ICI demonstrates significant response rates and considerable long-term clinical benefits. However, the toxicity associated with this approach is still a hurdle to overcome. In parallel, the therapeutic vaccines directed to the Human Papilloma Virus are also efficient in increasing the antitumour response, inducing cellular and humoral immunity. Although these results demonstrate clinical benefits compared to standard therapy, it is also important to unravel the resistance mechanisms in order to predict the clinical benefit of immunotherapy.

6.
Mol Biol Rep ; 49(1): 717-733, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34739691

RESUMO

Breast cancer is the most common cancer in women. It is a heterogeneous disease, encompassing different biological subtypes that differ in histological features, outcomes, clinical behaviour and different molecular subtypes. Therapy has progressed substantially over the past years with a reduction both for locoregional and systemic therapy. Endocrine therapies have considerably reduced cancer recurrence and mortality. Despite the major diagnostic and therapeutic innovations, resistance to therapy has become a main challenge, especially in metastatic breast cancer, and became a major factor limiting the use of endocrine therapeutic agents in ER positive breast cancers. Approximately 50% of patients with ER positive metastatic disease achieve a complete or partial response with endocrine therapy. However, in the remaining patients, the benefit is limited due to resistance, intrinsic or acquired, resulting in disease progression and poor outcome.Tumour heterogeneity as well as acquired genetic changes and therapeutics pressure have been involved in the endocrine therapy resistance. Nowadays, targeted sequencing of genes involved in cancer has provided insights about genomic tumour evolution throughout treatment and resistance driver mutations. Several studies have described multiple alterations in receptor tyrosine kinases, signalling pathways such as Phosphoinositide-3-kinase-protein kinase B/Akt/mTOR (PI3K/Akt/mTOR) and Mitogen-activated protein kinase (MAPK), cell cycle machinery and their implications in endocrine treatment failure.One of the current concern in cancer is personalized therapy. The focus has been the discovery of new potentially predictive biomarkers capable to identify reliably the most appropriate therapy regimen and which patients will experience disease relapse. The major concern is also to avoid overtreatment/undertreatment and development of resistance.This review focuses on the most promising predictive biomarkers of resistance in estrogen receptor-positive breast cancer and the emerging role of circulating free-DNA as a powerful tool for longitudinal monitoring of tumour molecular profile throughout treatment.


Assuntos
Neoplasias da Mama/sangue , Neoplasias da Mama/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Terapia de Alvo Molecular/métodos , Inibidores de Fosfoinositídeo-3 Quinase/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismo , Moduladores Seletivos de Receptor Estrogênico/uso terapêutico , Biomarcadores Tumorais/sangue , Neoplasias da Mama/diagnóstico , DNA Tumoral Circulante/sangue , Quinases Ciclina-Dependentes/antagonistas & inibidores , Feminino , Humanos , Sobretratamento , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase/farmacologia , Medicina de Precisão/métodos , Inibidores de Proteínas Quinases/farmacologia , Moduladores Seletivos de Receptor Estrogênico/farmacologia
8.
Biomedicines ; 9(11)2021 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-34829916

RESUMO

Breast Cancer (BC) is the second most frequent cause of cancer death among women worldwide and, although there have been significant advances in BC therapies, a significant percentage of patients develop metastasis and disease recurrence. Since BC was demonstrated to be an immunogenic tumor, immunotherapy has broken through as a significant therapy strategy against BC. Over the years, immunotherapy has improved the survival rate of HER2+ BC patients due to the approval of some monoclonal antibodies (mAbs) such as Trastuzumab, Pertuzumab and, recently, Margetuximab, along with the antibody-drug conjugates (ADC) Trastuzumab-Emtansine (T-DM1) and Trastuzumab Deruxtecan. Immune checkpoint inhibitors (ICI) showed promising efficacy in triple-negative breast cancer (TNBC) treatment, namely Atezolizumab and Pembrolizumab. Despite the success of immunotherapy, some patients do not respond to immunotherapy or those who respond to the treatment relapse or progress. The main causes of these adverse events are the complex, intrinsic or extrinsic resistance mechanisms. In this review, we address the different immunotherapy approaches approved for BC and some of the mechanisms responsible for resistance to immunotherapy.

10.
Mol Biol Rep ; 48(3): 2791-2802, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33733384

RESUMO

Bladder cancer (BC) is the most common cancer of the urinary tract and despite all innovations, remains a major challenge due to high morbidity and mortality. Genomic and epigenetic analyses allowed the discovery of new genes and pathways involved in the pathogenesis and regulation of BC. However, the effect on mortality has been modest and the development of new targets for BC treatment are needed. Recent evidence suggests that cancer cells are under increased stress associated with oncogenic transformation, with changes in metabolic activity and increased generation of reactive oxygen species (ROS). The increased amounts of ROS in cancer cells are associated with stimulation of cellular proliferation, promotion of mutations and genetic instability, as well as alterations in cellular sensitivity to anticancer agents. Since these mechanisms occur in cancer cells, there is a close link between oxidative stress (OS) and BC with implications in prevention, carcinogenesis, prognosis, and treatment. We address the role of OS as an enemy towards BC development, as well as an ally to fight against BC. This review promises to expand our treatment options for BC with OS-based therapies and launches this approach as an opportunity to improve our ability to select patients most likely to respond to personalized therapy.


Assuntos
Estresse Oxidativo , Neoplasias da Bexiga Urinária/patologia , Animais , Resistencia a Medicamentos Antineoplásicos , Humanos , Modelos Biológicos , Neoplasias da Bexiga Urinária/tratamento farmacológico
11.
Biology (Basel) ; 10(1)2021 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-33435434

RESUMO

Antitumor therapies based on Cold Atmospheric Plasma (CAP) are an emerging medical field. In this work, we evaluated CAP effects on bladder cancer. Two bladder cancer cell lines were used, HT-1376 (stage III) and TCCSUP (stage IV). Cell proliferation assays were performed evaluating metabolic activity (MTT assay) and protein content (SRB assay). Cell viability, cell cycle, and mitochondrial membrane potential (Δψm) were assessed using flow cytometry. Reactive oxygen and nitrogen species (RONS) and reduced glutathione (GSH) were evaluated by fluorescence. The assays were carried out with different CAP exposure times. For both cell lines, we obtained a significant reduction in metabolic activity and protein content. There was a decrease in cell viability, as well as a cell cycle arrest in S phase. The Δψm was significantly reduced. There was an increase in superoxide and nitric oxide and a decrease in peroxide contents, while GSH content did not change. These results were dependent on the exposure time, with small differences for both cell lines, but overall, they were more pronounced in the TCCSUP cell line. CAP showed to have a promising antitumor effect on bladder cancer, with higher sensitivity for the high-grade cell line.

12.
Pathobiology ; 88(2): 198-207, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33352574

RESUMO

Lung cancer is still the leading cause of cancer death worldwide. Despite the major diagnostic and therapeutic innovations, the effect on mortality has been modest and the overall survival is still poor. Better understanding of the pathology of these tumors is necessary in order to develop personalized therapeutic strategies in lung cancer patients. Human microbiome has been associated with normal physiology and function, and increasing evidence points towards a key role of the microbiome in promoting the progression of lung disease. Studies have shown that although poorly understood, lung has a distinctive microbiome that may an important role in lung cancer development and progression, and interactions between microbial populations have the potential to influence disease, suggesting that microbiome can be an emerging target in cancer therapeutics. We will review mechanisms how the lung microbiota influences carcinogenesis, focusing on the bacterial dysbiosis and inflammation. Moreover, we will discuss the link between the microbiome and cancer and the consequences induced by the immune system, as the host microbiota plays an essential role in activating and modulating the immune response. We summarize current research advances in the lung microbiome and demonstrate the potential to exploit microbiome as a mechanism to prevent carcinogenesis and modulate therapeutic strategy, suggesting microbiome as a valuable approach in lung cancer patients.


Assuntos
Disbiose/microbiologia , Neoplasias Pulmonares/microbiologia , Pulmão/microbiologia , Pulmão/patologia , Microbiota/imunologia , Animais , Carcinogênese , Disbiose/complicações , Humanos , Inflamação , Camundongos
13.
Artigo em Inglês | MEDLINE | ID: mdl-32635433

RESUMO

Empowering parents by actively engaging them in environmental prevention strategies is a promising approach that only a few programs use. Evidence suggests that when families and the wider community are engaged, alcohol prevention is more efficient. However, due to the novelty of this approach, no specific assessment tools for measuring this type of engagement are available. The objective of this study is to design a parental empowerment measurement tool to evaluate parents' self-efficacy when engaging in environmental and community actions and to analyze its psychometric properties. A total of 132 parents active in in-school parent associations from Spain (n = 77; 58.4%) and Portugal (n = 55; 41.7%) completed a pencil and paper battery of four questionnaires, including the developed scale COmmuNity iNtervention SElf-Efficacy SCale for ParenT LEaDers (CONNECTED). The scale showed a good reliability and good test-retest stability in a three-month period. The convergent validity with other well-established instruments that assess similar constructs was significant. A preliminary confirmatory factor analysis (CFA) showed an acceptable fit. Environmental prevention supported by families is a promising preventive strategy because the participation and involvement of families is an effective way to address some risks in adolescence; however, new assessment tools are needed in this field. The developed scale could be a first step to identify the areas of need in a community and to monitor the progress and evaluate the outcomes of the preventive interventions implemented.


Assuntos
Empoderamento , Pais/educação , Autoeficácia , Inquéritos e Questionários/normas , Consumo de Álcool por Menores/prevenção & controle , Adolescente , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Relações Pais-Filho , Pais/psicologia , Portugal , Poder Psicológico , Psicometria , Reprodutibilidade dos Testes , Espanha
14.
Glycobiology ; 30(11): 881-894, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-32280958

RESUMO

The FORS histo-blood group system is the most recently discovered carbohydrate-based human blood group system. FORS is a rare blood group system, and most individuals have naturally occurring anti-FORS1 antibodies in plasma. Screening for anti-FORS1 antibodies is often done by hemagglutination assays using FORS1-expressing sheep erythrocytes, since FORS1-positive human erythrocytes are most often not available. Here, we have characterized the non-acid glycosphingolipids from sheep erythrocytes and isolated subfractions, with mass spectrometry, binding of antibodies and lectins, and by enzymatic hydrolysis. This demonstrated the presence of Forssman and Galili pentaosylceramides, and a Galili heptaosylceramide. Two complex glycosphingolipids recognized by human anti-FORS1 antibodies were characterized as a Forssman neolacto hybrid hexaosylceramide (GalNAcα3GalNAcß3Galß4GlcNAcß3Galß4Glcß1Cer) and a Forssman Galili hybrid heptaosylceramide (GalNAcα3GalNAcß3Galα3Galß4GlcNAcß3Galß4Glcß1Cer). These are novel glycosphingolipid structures, and to our knowledge, the first case of an elongated Galili antigen. Thus, the anti-Forssman antibodies in human serum bind not only to the classical Forssman pentaosylceramide (GalNAcα3GalNAcß3Galα4Galß4Glcß1Cer), but also when the GalNAcα3GalNAcß3 sequence is presented on a neolacto core chain and even on a Galili carbohydrate sequence.


Assuntos
Anticorpos/química , Eritrócitos/química , Glicoesfingolipídeos/análise , Animais , Anticorpos/imunologia , Eritrócitos/imunologia , Glicoesfingolipídeos/imunologia , Humanos , Ovinos
15.
Nutrients ; 12(4)2020 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-32218109

RESUMO

Diabetic nephropathy (DN) is a major microvascular complication of diabetes. Obesity and hyperlipidemia, fueled by unhealthy food habits, are risk factors to glomerular filtration rate (GFR) decline and DN progression. Several studies recommend that diabetic patients should be screened early (in prediabetes) for kidney disease, in order to prevent advanced stages, for whom the current interventions are clearly inefficient. This ambition greatly depends on the existence of accurate early biomarkers and novel molecular targets, which only may arise with a more thorough knowledge of disease pathophysiology. We used a rat model of prediabetes induced by 23 weeks of high-sugar/high-fat (HSuHF) diet to characterize the phenotype of early renal dysfunction and injury. When compared with the control animals, HSuHF-treated rats displayed a metabolic phenotype compatible with obese prediabetes, displaying impaired glucose tolerance and insulin sensitivity, along with hypertriglyceridemia, and lipid peroxidation. Despite unchanged creatinine levels, the prediabetic animals presented glomerular crescent-like lesions, accompanied by increased kidney Oil-Red-O staining, triglycerides content and mRNA expression of IL-6 and iNOS. This model of HSuHF-induced prediabetes can be a useful tool to study early features of DN, namely crescent-like lesions, an early signature that deserves in-depth elucidation.


Assuntos
Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Dieta para Diabéticos/efeitos adversos , Glomérulos Renais/metabolismo , Glomérulos Renais/patologia , Estado Pré-Diabético/complicações , Animais , Biomarcadores , Peso Corporal , Colágeno Tipo IV/metabolismo , Nefropatias Diabéticas/etiologia , Modelos Animais de Doenças , Ingestão de Energia , Imuno-Histoquímica , Testes de Função Renal , Metabolismo dos Lipídeos , Masculino , Estado Pré-Diabético/etiologia , Estado Pré-Diabético/metabolismo , Ratos
17.
PLoS One ; 15(1): e0219105, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31918436

RESUMO

Infertility has been a common postoperative problem caused by peritoneal adhesions. Since several prophylactic agents have recently shown promising preliminary results, more complete studies comparing their real efficacy and safety are needed urgently. The aim of this study was to investigate and describe practical considerations of a porcine model that can be used to assess such prophylactic agents. First, 10 healthy 5½ months old female pigs (24.3-31.3 Kg) underwent a standardized laparoscopy to provoke peritubal adhesion formation without prophylactic agents. After 30 days, a second-look laparoscopy was performed to evaluate adhesions and perform adnexectomy for histopathological evaluation. Adhesions at different sites were classified by grade, for which the scores range from 0 (no adhesion) to 3 (very strong vascularized adhesions), and also by area, with scores ranging from 0 (no adhesion) to 4 (>75% of the injured area). The histopathological evaluation of the distal uterine horns, oviducts and ovaries were compared withthose from a control group of six healthy pigs with no previous surgery. Biological samples were collected to assess vitality, inflammation and renal, hepatic and hematopoietic systems. There were small (but significant) changes in serum albumin (P = 0.07), globulin (P = 0.07), C-reactive protein (P = 0.011), fibrinogen (P = 0.023) and bilirubin (P<0.01) after 30 days, but all values were within the normal range. No inflammation or abscess formation was observed, but different degrees of adhesion were identified. The estimated occurrence of adhesion (scores >0) and of strong / very strong adhesion (scores >1) was 75% (95% CI: 55-94.9) and 65% (95% CI: 45-85), respectively. The porcine model represents a useful animal platform that can be used to test the efficacy and safety of candidate prophylactic agents intended to prevent postoperative peritubal adhesions formation. We present several practical considerations and measures that can help to minimize animal suffering and avoid problems during such experiments.


Assuntos
Tubas Uterinas , Laparoscopia , Ovário , Complicações Pós-Operatórias , Aderências Teciduais , Animais , Feminino , Bilirrubina/sangue , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Modelos Animais de Doenças , Tubas Uterinas/metabolismo , Tubas Uterinas/patologia , Fibrinogênio/metabolismo , Laparoscopia/efeitos adversos , Ovário/metabolismo , Ovário/patologia , Complicações Pós-Operatórias/sangue , Complicações Pós-Operatórias/patologia , Albumina Sérica/metabolismo , Índice de Gravidade de Doença , Suínos , Aderências Teciduais/sangue , Aderências Teciduais/etiologia , Aderências Teciduais/patologia
19.
J Immunol Methods ; 478: 112722, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31816281

RESUMO

In 2012, the FORS system was accepted by the International Society of Blood Transfusion as the 31st blood group system. Forssman (Fs) antigen (Ag) expression is most commonly found on sheep red blood cells (RBC) but rare in human RBC. Anti-Fs antibodies (Ab) are naturally occurring in human sera and are predominantly IgM but they can also be IgG. To this day, the global prevalence of the FORS system is unknown. Currently, there is a lack of natural FORS1-positive RBC available to use for anti-Fs screening in large populations. This study was designed to produce FORS1-positive cells viable for 40 days use in the anti-Fs screening. Three to 5% FORS1-positive cells were produced using sheep's blood and CellStab stabilizer solution. The quality of the FORS1-positive cells was investigated in more than three independent experiments of ABO titration, osmotic fragility test and supernatant haemolysis. For each batch of FORS1-positive cells produced, an extended antibody panel was performed. To demonstrate that the FORS1-positive cells can be used for up to 40 days, anti-Fs screening and classification were carried out in a patient and donor population. Antigenic expression and membrane integrity of FORS1-positive cells remained stable for 40 days. Good FORS1 Ag preservation was established, and minimal haemolysis was observed. In conclusion, a novel and easy-to-produce reagent has been developed and submitted to a patent with stable FORS1 Ag expression. With this FORS1-positive cell suspension, it is now possible to screen and classify anti-Fs Ab in large populations.


Assuntos
Antígenos de Grupos Sanguíneos/isolamento & purificação , Tipagem e Reações Cruzadas Sanguíneas/métodos , Eritrócitos/metabolismo , Antígeno de Forssman/isolamento & purificação , Cultura Primária de Células/métodos , Animais , Antígenos de Grupos Sanguíneos/imunologia , Linhagem Celular , Sobrevivência Celular , Eritrócitos/imunologia , Antígeno de Forssman/imunologia , Antígeno de Forssman/metabolismo , Humanos , Ovinos/sangue , Ovinos/imunologia , Fatores de Tempo
20.
Transfus Med Hemother ; 46(6): 450-454, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31933576

RESUMO

BACKGROUND: The Forssman antigen (FORS1 Ag) is expressed on human red blood cells (RBCs). We investigated its presence on RBCs from Palestinian subjects and Swedish subjects by serological testing and by sequencing part of exon 7 of the GBGT1 gene, which encodes Forssman synthase. MATERIALS AND METHODS: Blood samples from Palestinian subjects (n = 211 adults and n = 73 newborns) and from Swedish subjects (n = 47 adults) were analyzed in the study. RBCs from the Palestinian samples were typed for the FORS1 Ag using a monoclonal anti-Forssman antibody. The GBGT1 gene was genotyped by DNA sequencing (all adult samples) or by using amplification refractory mutation system PCR (newborn samples). RESULTS: All of the studied samples were negative for the FORS1 Ag by serologic typing. DNA sequencing of the 3' end of exon 7 of the GBGT1 gene, which includes Arg296, showed that all samples had the wild-type Arg296 sequence, which is associated with an inactive form of Forssman synthase. We detected four single nucleotide polymorphisms in the adult samples; two were silent (p.Tyr232=, p. Gly290=), and two were missense (p. Arg243Cys, p. Arg243His). The allele frequencies ranged from 0.2 to 3.6%. The p. Arg243Cys SNP was a novel SNP that was detected in one Palestinian sample. CONCLUSION: Our results confirmed the allelic diversity of GBGT1 and identified a novel nucleotide polymorphism in this gene, p. Arg243Cys. Our results also confirmed that the FORS blood group system is a low-frequency system.

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