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Ice-binding proteins (IBPs) from extremophile organisms can modulate ice formation and growth. There are many (bio)technological applications of IBPs, from cryopreservation to mitigating freeze-thaw damage in concrete to frozen food texture modifiers. Extraction or expression of IBPs can be challenging to scale up, and hence polymeric biomimetics have emerged. It is, however, desirable to use biosourced monomers and heteroatom-containing backbones in polymers for in vivo or environmental applications to allow degradation. Here we investigate high molecular weight polyproline as an ice recrystallization inhibitor (IRI). Low molecular weight polyproline is known to be a weak IRI. Its activity is hypothesized to be due to the unique PPI helix it adopts, but it has not been thoroughly investigated. Here an open-to-air aqueous N-carboxyanhydride polymerization is employed to obtain polyproline with molecular weights of up to 50000 g mol-1. These polymers were found to have IRI activity down to 5 mg mL-1, unlike a control peptide of polysarcosine, which did not inhibit all ice growth at up to 40 mg mL-1. The polyprolines exhibited lower critical solution temperature behavior and assembly/aggregation observed at room temperature, which may contribute to its activity. Single ice crystal assays with polyproline led to faceting, consistent with specific ice-face binding. This work shows that non-vinyl-based polymers can be designed to inhibit ice recrystallization and may offer a more sustainable or environmentally acceptable, while synthetically scalable, route to large-scale applications.
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Gelo , Peptídeos , Peso Molecular , Inibidores do CrescimentoRESUMO
To evaluate the effect of the phosphodiesterase 4 inhibitor apremilast in biologic-naïve patients with early peripheral PsA in terms of disease activity, clinical manifestations, patient-perceived outcomes, as well as apremilast's safety profile in routine care settings of Greece. Non-interventional, multicenter, 52-week prospective cohort study, enrolling biologic-naïve patients with early active peripheral PsA who started apremilast after intolerance or inadequate response (within the first 12 months of treatment) to an initial conventional synthetic (cs)DMARD treatment. Non-responder imputation was applied for missing data.In total, 167 consecutive patients (mean age: 52.5 years; median PsA duration: 0.9 years) were analyzed. At baseline, the median (interquartile range) clinical Disease Activity in Psoriatic Arthritis (cDAPSA) score was 22.0 (16.0-29.0), with 86.8% of patients having at least moderate (29.3% high) disease activity; 87.4% had skin psoriasis, 37.7% nail psoriasis, 30.7% enthesitis, and 12.4% dactylitis. At 16, 24, and 52 weeks, 28.7, 42.5, and 48.5% of patients, achieved ≥ 50% improvement in their baseline cDAPSA score, respectively. At week 52, 55.6, 50, and 26.8% of evaluable patients achieved complete resolution of enthesitis, dactylitis and nail psoriasis, respectively. Improvements were also observed in patient's health state assessed by the Psoriatic Arthritis Impact of Disease 12-item questionnaire, and health-related quality of life. The 52-week drug survival rate was 75%, while 13.8% of patients experienced at least one adverse drug reaction.Biologic-naïve patients with early PsA, treated with apremilast experienced significant improvements in disease activity, extra-articular manifestations and patient-centered outcomes, accompanied by a favorable tolerability profile.
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Anti-Inflamatórios não Esteroides , Artrite Psoriásica , Produtos Biológicos , Psoríase , Humanos , Pessoa de Meia-Idade , Artrite Psoriásica/tratamento farmacológico , Produtos Biológicos/uso terapêutico , Entesopatia , Estudos Prospectivos , Psoríase/tratamento farmacológico , Qualidade de VidaRESUMO
Current point-of-care lateral flow immunoassays, such as the home pregnancy test, rely on proteins as detection units (e.g. antibodies) to sense for analytes. Glycans play a fundamental role in biological signalling and recognition events such as pathogen adhesion and hence they are promising future alternatives to antibody-based biosensing and diagnostics. Here we introduce the potential of glycans coupled to gold nanoparticles as recognition agents for lateral flow diagnostics. We first introduce the concept of lateral flow, including a case study of lateral flow use in the field compared to other diagnostic tools. We then introduce glycosylated materials, the affinity gains achieved by the cluster glycoside effect and the current use of these in aggregation based assays. Finally, the potential role of glycans in lateral flow are explained, and examples of their successful use given.
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Técnicas Biossensoriais , Nanopartículas Metálicas , Anticorpos , Ouro , Imunoensaio , Sistemas Automatizados de Assistência Junto ao LeitoRESUMO
OBJECTIVE: Τo report outcomes of breakthrough COVID-19 in comparison with COVID-19 in unvaccinated patients with systemic rheumatic diseases (SRDs). METHODS: Patients with SRD with COVID-19 (vaccinated and unvaccinated) were included by their rheumatologists in a registry operated by the Greek Rheumatology Society in a voluntarily basis. Type, date and doses of SARS-CoV-2 vaccines were recorded, and demographics, type of SRD, concurrent treatment, comorbidities and COVID-19 outcomes (hospitalisation, need for oxygen supplementation and death) were compared between vaccinated and unvaccinated patients. RESULTS: Between 1 March 2020 and 31 August 2021, 195 patients with SRD with COVID-19 were included; 147 unvaccinated and 48 vaccinated with at least one dose of a SARS-CoV-2 vaccine (Pfizer n=38 or AstraZeneca n=10). Among vaccinated patients, 29 developed breakthrough COVID-19 >14 days after the second vaccine dose (fully vaccinated), while 19 between the first and <14 days after the second vaccine dose (partially vaccinated). Despite no differences in demographics, SRD type, treatment or comorbidities between unvaccinated and vaccinated patients, hospitalisation and mortality rates were higher in unvaccinated (29.3% and 4.1%, respectively) compared with partially vaccinated (21% and 0%) or fully vaccinated (10.3% and 0%) patients. CONCLUSIONS: Vaccinated patients with SRD with breakthrough COVID-19 have better outcomes compared with unvaccinated counterparts with similar disease/treatment characteristics.
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COVID-19 , Doenças Reumáticas , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Hospitalização , Humanos , Doenças Reumáticas/tratamento farmacológico , SARS-CoV-2RESUMO
Ice binding proteins (IBP) have evolved to limit the growth of ice but also to promote ice formation by ice-nucleating proteins (INPs). IBPs, which modulate these seemingly distinct processes, often have high sequence similarities, and molecular size/assembly is hypothesized to be a crucial determinant. There are only a few synthetic materials that reproduce INP function, and rational design of ice nucleators has not been achieved due to outstanding questions about the mechanisms of ice binding. Poly(vinyl alcohol) (PVA) is a water-soluble synthetic polymer well known to effectively block ice recrystallization, by binding to ice. Here, we report the synthesis of a polymeric ice nucleator, which mimics the dense assembly of IBPs, using confined ice-binding polymers in a high-molar-mass molecular bottlebrush. Poly(vinyl alcohol)-based molecular bottlebrushes with different side-chain densities were synthesized via a combination of ring-opening metathesis polymerization (ROMP) and reversible addition-fragmentation chain-transfer (RAFT) polymerization, using "grafting-to" and "grafting-through" approaches. The facile preparation of the PVA bottlebrushes was performed via selective hydrolysis of the acetate of the poly(vinyl acetate) (PVAc) side chains of the PVAc bottlebrush precursors. Ice-binding polymer side-chain density was shown to be crucial for nucleation activity, with less dense brushes resulting in colder nucleation than denser brushes. This bio-inspired approach provides a synthetic framework for probing heterogeneous ice nucleation and a route toward defined synthetic nucleators for biotechnological applications.
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Gelo , Álcool de Polivinil , Álcool de Polivinil/química , Polimerização , Polímeros/química , Peso MolecularRESUMO
The management of acute gout in the hospital setting may be challenging since most patients are elderly with multiple unstable comorbidities. However, there are no prospective clinical trials for hospitalized patients with gout to guide optimal management. Evidence indicates that steroids or adrenocorticotropic hormone (ACTH) may be effective and safe therapeutic options for these patients. This study aimed at directly comparing the efficacy and safety of ACTH vs betamethasone for the treatment of gout in hospitalized patients. This is the first prospective clinical trial for hospitalized patients with gout. We designed a randomized, open label study to assess the efficacy and safety of a single intramuscular injection of either ACTH or betamethasone in hospitalized patients with acute gout. Primary efficacy endpoints were the change in intensity of pain as recorded using a Visual Analogue Scale (VAS) at baseline compared to 24 h (ΔVAS24h), and 48 h. Moreover, we assessed safety and effects on the hypothalamic-pituitary-adrenal (HPA) axis, glucose and lipid homeostasis, bone metabolism, electrolytes and renal function. 38 patients were recruited. Both treatments were highly effective. The mean ± SE ΔVAS24h and ΔVAS48h for ACTH was 4.48 ± 0.29 and 5.58 ± 0.26, respectively. The mean ± SE ΔVAS24h and ΔVAS48h for betamethasone was 4.67 ± 0.32 and 5.67 ± 0.28, respectively. Direct comparison between the two groups at 24 h and 48 h did not show statistically significant differences. Both treatments were well tolerated and safe. The effects on all metabolic parameters were mostly minimal and transient for both treatments. However, ACTH may affect less the HPA axis and bone metabolism compared to betamethasone, thus leading to the conclusion that. ACTH and betamethasone are effective and safe for the management of acute gout in hospitalized patients but that ACTH may associate with less disturbance of the HPA axis and bone metabolism. Our data support the use of both drugs as first line treatments for hospitalized patients with gout.Clinical trial registration: ClinicalTrials.gov NCT04306653.
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Artrite Gotosa , Gota , Hormônio Adrenocorticotrópico/efeitos adversos , Idoso , Artrite Gotosa/tratamento farmacológico , Betametasona , Gota/tratamento farmacológico , Humanos , Sistema Hipotálamo-Hipofisário , Sistema Hipófise-Suprarrenal , Estudos Prospectivos , Esteroides/uso terapêuticoRESUMO
Ice binding proteins modulate ice nucleation/growth and have huge (bio)technological potential. There are few synthetic materials that reproduce their function, and rational design is challenging due to the outstanding questions about the mechanisms of ice binding, including whether ice binding is essential to reproduce all their macroscopic properties. Here we report that nanoparticles obtained by polymerization-induced self-assembly (PISA) inhibit ice recrystallization (IRI) despite their constituent polymers having no apparent activity. Poly(ethylene glycol), poly(dimethylacrylamide), and poly(vinylpyrrolidone) coronas were all IRI-active when assembled into nanoparticles. Different core-forming blocks were also screened, revealing the core chemistry had no effect. These observations show ice binding domains are not essential for macroscopic IRI activity and suggest that the size, and crowding, of polymers may increase the IRI activity of "non-active" polymers. It was also discovered that poly(vinylpyrrolidone) particles had ice crystal shaping activity, indicating this polymer can engage ice crystal surfaces, even though on its own it does not show any appreciable ice recrystallization inhibition. Larger (vesicle) nanoparticles are shown to have higher ice recrystallization inhibition activity compared to smaller (sphere) particles, whereas ice nucleation activity was not found for any material. This shows that assembly into larger structures can increase IRI activity and that increasing the "size" of an IRI does not always lead to ice nucleation. This nanoparticle approach offers a platform toward ice-controlling soft materials and insight into how IRI activity scales with molecular size of additives.
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OBJECTIVES: Predicting serious infections (SI) in patients with rheumatoid arthritis (RA) is crucial for the implementation of appropriate preventive measures. Here we aimed to identify risk factors for SI and to validate the RA Observation of Biologic Therapy (RABBIT) risk score in real-life settings. METHODS: A multi-centre, prospective, RA cohort study in Greece. Demographics, disease characteristics, treatments and comorbidities were documented at first evaluation and one year later. The incidence of SI was recorded and compared with the expected SI rate using the RABBIT risk score. RESULTS: A total of 1557 RA patients were included. During follow-up, 38 SI were recorded [incidence rate ratio (IRR): 2.3/100 patient-years]. Patients who developed SI had longer disease duration, higher HAQ at first evaluation and were more likely to have a history of previous SI, chronic lung disease, cardiovascular disease and chronic kidney disease. By multivariate analysis, longer disease duration (IRR: 1.05; 95% CI: 1.005, 1.1), history of previous SI (IRR: 4.15; 95% CI: 1.7, 10.1), diabetes (IRR: 2.55; 95% CI: 1.06, 6.14), chronic lung disease (IRR: 3.14; 95% CI: 1.35, 7.27) and daily prednisolone dose ≥10 mg (IRR: 4.77; 95% CI: 1.47, 15.5) were independent risk factors for SI. Using the RABBIT risk score in 1359 patients, the expected SI incidence rate was 1.71/100 patient-years, not different from the observed (1.91/100 patient-years; P = 0.97). CONCLUSION: In this large real-life, prospective study of RA patients, the incidence of SI was 2.3/100 patient-years. Longer disease duration, history of previous SI, comorbidities and high glucocorticoid dose were independently associated with SI. The RABBIT score accurately predicted SI in our cohort.
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Artrite Reumatoide/epidemiologia , Infecções/epidemiologia , Infecções Oportunistas/epidemiologia , Idoso , Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Comorbidade , Feminino , Glucocorticoides/uso terapêutico , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Fatores de RiscoRESUMO
Glycomaterials display enhanced binding affinity to carbohydrate-binding proteins due to the nonlinear enhancement associated with the cluster glycoside effect. Gold nanoparticles bearing glycans have attracted significant interest in particular. This is due to their versatility, their highly tunable gold cores (size and shape), and their application in biosensors and diagnostic tools. However, conjugating glycans onto these materials can be challenging, necessitating either multiple protecting group manipulations or the use of only simple glycans. This results in limited structural diversity compared to glycoarrays which can include hundreds of glycans. Here we report a method to generate glyconanoparticles from unprotected glycans by conjugation to polymer tethers bearing terminal amino-oxy groups, which are then immobilized onto gold nanoparticles. Using an isotope-labeled glycan, the efficiency of this reaction was probed in detail to confirm conjugation, with 25% of end-groups being functionalized, predominantly in the ring-closed form. Facile post-glycosylation purification is achieved by simple centrifugation/washing cycles to remove excess glycan and polymer. This streamlined synthetic approach may be particularly useful for the preparation of glyconanoparticle libraries using automation, to identify hits to be taken forward using more conventional synthetic methods. Exemplar lectin-binding studies were undertaken to confirm the availability of the glycans for binding and show this is a powerful tool for rapid assessment of multivalent glycan binding.
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Ouro/química , Nanopartículas Metálicas/química , Polímeros/química , Polissacarídeos/química , Aminação , Ligantes , Nanotecnologia , Polímeros/síntese química , Polissacarídeos/síntese químicaRESUMO
The preparation of a functional fluorine-containing block copolymer using reversible addition-fragmentation chain-transfer dispersion polymerization in DMSO as a "platform/scaffold" is explored. The nanostructures, comprised of poly(ethyleneglycol)-b-poly(pentafluorophenyl methacrylate) or PEG-b-P(PFMA), are formulated via photo-initiated polymerization-induced self-assembly (PISA) followed by post-polymerization modification using different primary amines. A combination of light scattering and microscopy techniques are used to characterize the resulting morphologies. It is found that upon varying the degree of polymerization of the core-forming block of PFMA, only uniform spheres (with textured surfaces) are obtained. These nanostructures are subsequently modified by cross-linking using a non-responsive and a redox-responsive diamine, thus imparting stability to the particles in water. In response to intracellular glutathione (GSH) concentration, destabilization of the micelles occurs as evidenced by dynamic light scattering. The well-defined size, inherent reactivity of the nanoparticles toward nucleophiles, and GSH-responsiveness of the nanospheres make them ideal scaffolds for drug delivery to intracellular compartments with reductive environments.
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Técnicas de Química Sintética/métodos , Luz , Metacrilatos/química , Nanoestruturas/química , Polimerização/efeitos da radiação , Polímeros/química , Aminas/química , Glutationa/química , Microscopia Eletrônica de Transmissão , Modelos Químicos , Estrutura Molecular , Nanoestruturas/ultraestrutura , Polímeros/síntese química , Água/químicaRESUMO
Poly(sarcosine) (PSar) is a non-ionic hydrophilic polypeptoid with numerous biologically relevant properties, making it an appealing candidate for the development of amphiphilic block copolymer nanostructures. In this work, the fabrication of poly(sarcosine)-based diblock copolymer nano-objects with various morphologies via aqueous reversible addition-fragmentation chain-transfer (RAFT)-mediated photoinitiated polymerization-induced self-assembly (photo-PISA) is reported. Poly(sarcosine) was first synthesized via ring-opening polymerization (ROP) of sarcosine N-carboxyanhydride, using high-vacuum techniques. A small molecule chain transfer agent (CTA) was then coupled to the active ω-amino chain end of the telechelic polymer for the synthesis of a poly(sarcosine)-based macro-CTA. Controlled chain-extensions of a commercially available water-miscible methacrylate monomer (2-hydroxypropyl methacrylate) were achieved via photo-PISA under mild reaction conditions, using PSar macro-CTA. Upon varying the degree of polymerization and concentration of the core-forming monomer, morphologies evolving from spherical micelles to worm-like micelles and vesicles were accessed, as determined by dynamic light scattering and transmission electron microscopy, resulting in the construction of a detailed phase diagram. The resistance of both colloidally stable empty vesicles and enzyme-loaded nanoreactors against degradation by a series of proteases was finally assessed. Overall, our findings underline the potential of poly(sarcosine) as an alternative corona-forming polymer to poly(ethylene glycol)-based analogues of PISA assemblies for use in various pharmaceutical and biomedical applications.
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Nanoestruturas/química , Peptídeo Hidrolases/metabolismo , Processos Fotoquímicos , Polímeros/química , Sarcosina/química , Técnicas de Química Sintética , Peroxidase do Rábano Silvestre/metabolismo , Polimerização , Propriedades de Superfície , ÁguaRESUMO
PURPOSE: The purpose of this study is to assess the value of extended (lateral) lymphadenectomy (EL) in the operative management of locally advanced and recurrent rectal cancer. METHODS: Patients that underwent exenterative surgery for locally advanced or recurrent rectal cancer between 2006 and 2009 were included in the study. A decision for EL was taken at the local multidisciplinary meeting based on the radiological findings. Perioperative and oncological outcomes were assessed and compared between the EL and non-EL group prospectively. RESULTS: Forty-one consecutive patients were included in the study (EL = 17). The median age was 57 (40-71) for EL and 66 (39-81) years for non-EL. Of patients, 27 (EL = 13) and 14 (EL = 4) underwent pelvic exenteration and abdominosacral resection, respectively. Twelve (EL = 7) patients were diagnosed with locally advanced primary rectal cancer. Thirty-one (EL = 12) patients received neoadjuvant radiotherapy. The median intraoperative time, blood loss and hospital stay were 9 h (3-13), 1.5 l (0.3-7) and 14 days (12-72), respectively, for the EL group, and 8 h (4-15), 1.6 l (0.25-17) and 14 days (10-86), respectively, for the non-EL (p ≥ 0.394). Morbidity was similar between the two groups (EL = 4, non-EL = 9; p = 0.344). Complete tumour resection (R0) was achieved in 30 (73.17%) patients, 12 (70.58%) in the EL group and 18 (75%) in the non-EL group (p = 0.649). There was no significant difference in 5-year survival (EL = 60.7%, non-EL = 75.2%; p = 0.447), local recurrence (EL = 53.6%, non-EL = 65.4%; p = 0.489) and disease-free survival (EL = 53.6%, non-EL = 51.4%; p = 0.814). CONCLUSIONS: The present study demonstrated that EL does not provide a statistically significant advantage in survival or recurrence rates, for patients with locally advanced primary or recurrent rectal cancer.
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Excisão de Linfonodo , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia , Neoplasias Retais/patologia , Neoplasias Retais/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Demografia , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico , Assistência Perioperatória , Resultado do TratamentoRESUMO
AIM: Ileal pouch-anal anastomosis (IPAA) is performed in ulcerative colitis or familial adenomatous polyposis with a view to restoration of GI continuity and prevention of permanent faecal diversion. Debate exists as to its safety in older patients. This review aims to assess functional outcomes and safety of restorative proctocolectomy (RPC) in older compared to younger patients. METHODS: Literature search was performed for age-stratified studies which assessed functional outcomes of IPAA. Twelve papers were included overall. Patients were categorized into 'older' and 'younger' groups. Analysis was split into three separate parts: 1. Age cut-off of 50 ± 5 years (with sensitivity analysis); 2. Age cut-off of 65 ± years; 3. Long-term outcomes (>10 years). RESULTS: With an age cut-off of 50 years (4327 versus 513 patients), complication rates were comparable with the exception of an increased rate of small-bowel obstruction in the younger patients (p = 0.034). At 1 year, 24-h stool frequency was significantly higher in the older patient group (p < 0.0001). Daytime (p < 0.0001) and night-time (p < 0.0001) incontinence rates were also significantly higher in older patients. Overall, function deteriorated with time across all ages; however, after 10 years, there was no significant difference in incontinence rates between age groups. Dehydration and electrolyte loss was a significant problem in patients over 65 (p < 0.0001). Despite differences in postoperative function, quality of life was comparable between groups; however, only a few studies reported quality of life data. CONCLUSION: IPAA is safe in older patients, although treating clinicians should bear in mind the increased risk of dehydration. Postoperative function is worse in older patients, but seems to level out with time and does not appear to significantly impact on overall quality of life and patient satisfaction. Assessment for suitability for RPC should not be based on chronological age in isolation. It is imperative that the correct support is given to older patients with worsened postoperative function in order to maintain patient satisfaction and adequate quality of life.
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Bolsas Cólicas/patologia , Fatores Etários , Idoso , Anastomose Cirúrgica , Demografia , Incontinência Fecal/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/fisiopatologia , Qualidade de Vida , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: Intravascular access routes are widely used for administering agents or taking blood samples in rodents. Vessel cannulation in rats is a technically challenging procedure with a risk for significant complications. The use of cumulative sum (CUSUM) analysis allows continuous monitoring of the performer's outcomes to evaluate the learning curve for a particular procedure. The aim of the present study was to assess a researcher's learning curve in the cannulation of the jugular and femoral vein in rats using CUSUM analysis. MATERIALS AND METHODS: A single researcher performed two hundred microsurgical operations between September 2012 and September 2013. The animals (male Wistar rats) were anesthetized with isoflurane whereas the right jugular vein and the left femoral vein were catheterized. Prospective data were collected and analyzed using CUSUM analysis. For the purposes of the study, the rat population was divided in four groups based on the order of studies; group 1 represents the first 50 animals cannulated, group 2 the next batch of 50 animals, and so forth. RESULTS: The operating times required for cannulation of the jugular vein for groups 1, 2, 3, and 4 were 24.6 ± 4.8, 15.9 ± 2.5, 15.2 ± 3.2, and 15.7 ± 3.3 min, respectively. Group 1's operating time was significantly longer than all the other groups (P < 0.001 compared with all other groups). The operating times for groups 2, 3, and 4 did not differ significantly (P > 0.05). The cannulation of the femoral vein required a mean of 32 ± 5.3 min for group 1, 24.9 ± 5.7 min for group 2, 18.4 ± 4 min for group 3, and 17.2 ± 3.4 min for group 4. The operating time of group 1 was significantly longer when compared with all groups (P < 0.001 for all groups). Group 2 also had a longer operating time than groups 3 and 4 (P < 0.001 compared with both groups). Groups 3 and 4 did not show any statistical significant difference when their operating time was compared (P > 0.05). CUSUM analysis suggested that the number of cases required to achieve the required experience to most effectively cannulate the jugular and femoral vein is approximately 50 and 100 cases, respectively. The adverse effects of the procedure included two unexpected deaths, both of which occurred in group 1 (0.5% in total). CONCLUSIONS: The authors' experience regarding the learning curve of the cannulation of the femoral and jugular vein in rats from 200 animals operated over a period of 1 y for the evaluation of the pharmacokinetic properties of drug candidates suggests significant experience is required to optimize the operating time required for the procedure.
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Coleta de Amostras Sanguíneas/métodos , Cateterismo/métodos , Educação Baseada em Competências/métodos , Procedimentos Cirúrgicos Vasculares/educação , Procedimentos Cirúrgicos Vasculares/métodos , Animais , Coleta de Amostras Sanguíneas/efeitos adversos , Cateterismo/efeitos adversos , Cateterismo Venoso Central/efeitos adversos , Cateterismo Venoso Central/métodos , Veia Femoral , Veias Jugulares , Masculino , Duração da Cirurgia , Ratos Wistar , Procedimentos Cirúrgicos Vasculares/efeitos adversosRESUMO
Glycoforms (and other post-translational modifications) of otherwise identical proteins can indicate pathogenesis/disease state and hence new tools to detect and sense a protein's glycosylation status are essential. Antibody-based assays against specific protein sequences do not typically discriminate between glycoforms. Here we demonstrate a 'sandwich' bio-assay approach, whereby antibodies immobilised onto biolayer interferometry sensors first select proteins, and then the specific glycoform is identified using gold nanoparticles functionalised with lectins which provide signal enhancement. The nanoparticles significantly enhance the signal relative to lectins alone, allowing glycoform specific detection as low as 0.04 µg mL-1 (1.4 nM) in buffer, and crucially there is no need for an enrichment step and all steps can be automated. Proof of concept is demonstrated using prostate specific antigen: a biomarker for prostate cancer, where glycoform analysis could distinguish between cancerous and non-cancerous status, rather than only detecting overall protein concentration.
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Lectinas , Nanopartículas Metálicas , Humanos , Masculino , Anticorpos , Glicosilação , Ouro , Lectinas/metabolismo , Neoplasias da Próstata/diagnóstico , Antígeno Prostático Específico/análiseRESUMO
INTRODUCTION: This study aimed to determine whether the introduction of anti-SARS-CoV-2 vaccines and the dominance of the omicron variant had a significant impact on the outcome of COVID-19 in patients with systemic autoimmune rheumatic diseases (SAIRDs). METHODS: Using data entered to the Greek Rheumatology Society COVID-19 registry, we investigated the incidence of hospitalization and death due to COVID-19, during the successive periods of the pandemic according to the prevalent strain (wild-type, Alpha, Delta, Omicron) in vaccinated and unvaccinated patients. Variables independently associated with hospitalization and death were explored using multivariate regression analyses, while Kaplan-Meier curves were used to depict survival data. RESULTS: From August 2020 until June 30, 2022, 456 cases (70.2% females) of COVID-19 with a mean age (± SD) of 51.4 ± 14.0 years were reported. In unvaccinated patients, the proportions of hospitalization and death were 24.5% and 4%, compared to 12.5% and 0.8% in the vaccinated group (p < 0.001 for both comparisons). The rates of hospitalization for the wild-type, Alpha, Delta, and Omicron periods were 24.7%, 31.3%, 25.9%, and 8.1% respectively (p < 0.0001), while the case fatality rates were 2.7%, 4%, 7%, and 0%, respectively (p = 0.001). Using multivariable regression analysis, factors independently associated with hospitalization were infection by a non-Omicron variant, being non-vaccinated, exposure to rituximab, older age, and respiratory and cardiovascular disease. Independent predictors for death were contracting COVID-19 during the Alpha or Delta period, pulmonary disease, and older age, while being vaccinated was protective. CONCLUSIONS: In this 2-year analysis, the rates of hospitalization and death among patients with SAIRDs have declined significantly. Vaccination and the dominance of the Omicron variant appear to be the major determinants for this shift. Key points ⢠During the late phase of the pandemic, the proportion of severe COVID-19 cases, defined as requiring hospitalization or resulting in death, in patients with systemic autoimmune rheumatic diseases has declined. ⢠Anti-SARS-CoV-2 vaccination and the dominance of the Omicron strain are the key factors that have independently contributed to this shift.
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COVID-19 , Doenças Reumáticas , Feminino , Humanos , Adulto , Pessoa de Meia-Idade , Idoso , Masculino , COVID-19/epidemiologia , COVID-19/prevenção & controle , SARS-CoV-2 , Vacinação , Doenças Reumáticas/epidemiologiaRESUMO
Conventional cryopreservation solutions rely on the addition of organic solvents such as DMSO or glycerol, but these do not give full recovery for all cell types, and innovative cryoprotectants may address damage pathways which these solvents do not protect against. Macromolecular cryoprotectants are emerging, but there is a need to understand their structure-property relationships and mechanisms of action. Here we synthesized and investigated the cryoprotective behavior of sulfoxide (i.e., "DMSO-like") side-chain polymers, which have been reported to be cryoprotective using poly(ethylene glycol)-based polymers. We also wanted to determine if the polarized sulfoxide bond (S+O- character) introduces cryoprotective effects, as this has been seen for mixed-charge cryoprotective polyampholytes, whose mechanism of action is not yet understood. Poly(2-(methylsulfinyl)ethyl methacrylate) was synthesized by RAFT polymerization of 2-(methylthio)ethyl methacrylate and subsequent oxidation to sulfoxide. A corresponding N-oxide polymer was also prepared and characterized: (poly(2-(dimethylamineoxide)ethyl methacrylate). Ice recrystallization inhibition assays and differential scanning calorimetry analysis show that the sulfoxide side chains do not modulate the frozen components during cryopreservation. In cytotoxicity assays, it was found that long-term (24 h) exposure of the polymers was not tolerated by cells, but shorter (30 min) incubation times, which are relevant for cryopreservation, were tolerated. It was also observed that overoxidation to the sulfone significantly increased the cytotoxicity, and hence, these materials require a precision oxidation step to be deployed. In suspension cell cryopreservation investigations, the polysulfoxides did not increase cell recovery 24 h post-thaw. These results show that unlike hydrophilic backboned polysulfides, which can aid cryopreservation, the installation of the sulfoxide group onto a polymer does not necessarily bring cryoprotective properties, highlighting the challenges of developing and discovering macromolecular cryoprotectants.
RESUMO
Upon exposure to biological fluids, the fouling of nanomaterial surfaces results in non-specific capture of proteins, which is particularly important when in contact with blood for in vivo and ex vivo applications. It is crucial to evaluate not just the protein components but also the glycans attached to those proteins. Polymer-tethered glycosylated gold nanoparticles have shown promise for use in biosensing/diagnostics, but the impact of the glycoprotein corona has not been established. Here we investigate how polymer-tethered glycosylated gold nanoparticles interact with serum proteins and demonstrate that the protein corona introduces new glycans and hence off-specific targeting capability. Using a panel of RAFT-derived polymers grafted to the gold surface, we show that the extent of corona formation is not dependent on the type of polymer. In lectin-binding assays, a glycan (galactose) installed on the chain-end of the polymer was available for binding even after protein corona formation. However, using sialic-acid binding lectins, it was found that there was significant off-target binding due to the large density of sialic acids introduced in the corona, confirmed by western blotting. To demonstrate the importance, we show that the nanoparticles can bind Siglec-2, an immune-relevant lectin post-corona formation. Pre-coating with (non-glycosylated) bovine serum albumin led to a significant reduction in the total glycoprotein corona. However, sufficient sialic acids were still present in the residual corona to lead to off-target binding. These results demonstrate the importance of the glycans when considering the protein corona and how 'retention of the desired function' does not rule out 'installation of undesired function' when considering the performance of glyco-nanomaterials.
Assuntos
Nanopartículas Metálicas , Nanopartículas , Coroa de Proteína , Galactose , Glicoproteínas , Ouro , Lectinas , Nanopartículas/metabolismo , Polímeros/metabolismo , Polissacarídeos , Ligação Proteica , Coroa de Proteína/metabolismo , Soroalbumina Bovina/metabolismo , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/metabolismo , Ácidos Siálicos/metabolismoRESUMO
Lateral flow devices are rapid (and often low cost) point-of-care diagnostics-the classic example being the home pregnancy test. A test line (the stationary phase) is typically prepared by the physisorption of an antibody, which binds to analytes/antigens such as viruses, toxins, or hormones. However, there is no intrinsic requirement for the detection unit to be an antibody, and incorporating other ligand classes may bring new functionalities or detection capabilities. To enable other (nonprotein) ligands to be deployed in lateral flow devices, they must be physiosorbed to the stationary phase as a conjugate, which currently would be a high-molecular-weight carrier protein, which requires (challenging) chemoselective modifications and purification. Here, we demonstrate that poly(vinylpyrrolidone), PVP, is a candidate for a polymeric, protein-free test line, owing to its unique balance of water solubility (for printing) and adhesion to the nitrocellulose stationary phase. End-functionalized PVPs were prepared by RAFT polymerization, and the model capture ligands of biotin and galactosamine were installed on PVP and subsequently immobilized on nitrocellulose. This polymeric test line was validated in both flow-through and full lateral flow formats using streptavidin and soybean agglutinin and is the first demonstration of an "all-polymer" approach for installation of capture units. This work illustrates the potential of polymeric scaffolds as anchoring agents for small-molecule capture agents in the next generation of robust and modular lateral flow devices and that macromolecular engineering may provide real benefit.