127 research outputs found
Evolutionary Conservation of the Role of CD4 as a Receptor for Interleukin-16
The interaction of CD4 with MHC class II during helper T-cell activation and effector function is required for the initiation of an adaptive immune response in all gnathostomes. CD4 is comprised of four immunoglobulin domains but most likely arose from an ancestral two-domain homolog. The distal, D1 domain of CD4 binds to non-polymorphic regions of the MHC molecule, but despite the absolute requirement for this interaction, the sequence and structure of this domain are not well conserved through phylogeny. Conversely, the proximal, D4 domain of CD4 contains the binding site of the cytokine IL-16 and is highly conserved in its amino acid structure. IL-16 is a cytokine that has been described in a wide variety of invertebrate and vertebrate species. The CD4-binding residues on IL-16 are highly conserved throughout phylogeny, allowing for promiscuous binding of IL-16 to CD4 between members of unrelated taxa. This chapter aims to present structural, and functional support for the hypothesis that the CD4 co-receptor of the TCR arose from a primordial receptor for IL-16
P216 Comparative Assessment C-reactive Protein Between a Point-of-Care Testing and Current Standard of Care (Immunonephelometric testing)
Abstract
Background
C-reactive protein (CRP) is widely used as a biomarker of inflammatory disease activity in hospitalized and non-hospitalized patients. In particular, CRP is commonly used in patients suspected to have an inflammatory bowel disease (IBD) or with a confirmed diagnosis of IBD diagnosis in order to drive the diagnostic approach, to monitor disease activity and to guide therapeutic adjustments. However, standard laboratory CRP testing (Immunonephelometric assays) present some drawbacks, including a turnaround time of 1–2 hours, and the need of specialized equipment, offices and laboratory personnel. Because of that, point-of care testing (POCT) was recently developed in order to provide results within 2 minutes from blood collection, enabling a rapid response to clinical condition.
Aim
To determine the degree of analytical correlation between a recently developed POCT (ProciseDx) using capillary whole blood and the comparative Immunonephelometric assay using serum samples.
Methods
From October to November 2020, consecutive patients hospitalized at Gastroenterology Unit, Padua University Hospital, aged > 18 years and with clinical evidence of active inflammatory disease or infection, who underwent to a standard of care CRP test (Dimension Vista – Siemens Healthineers) were included in the study (range 2.9–340 g/L). Within 1 hour from blood collection, in each patient, CRP quantitation from capillary whole blood collected by finger stick was performed using the ProciseDx CRP assay, with reportable range between 3.6–100 g/L. A Deming regression test was used to identify the correlation between the two methods.
Results
Eighty-three patients were enrolled (62.5% males with mean age ± SD: 60±18). The most common indications for hospitalisation were liver disease (34.9%), pancreatic disturbance (27.7%) and suspicious or recurrence of IBD (16.7%). ProciseDx POCT with finger prick samples required a turnaround time of 2±0.2 minutes, whereas serum samples analyzed in clinical laboratory with the reference method required a turnaround time of about 180±15 minutes (p<0.001). Overall, the correlation between the two tests was high (R squared of 0.899 (95% CI 0.916–0.968)). In particular, the correlation between the methods was even higher with CRP values between 0–100 g/L with R squared of 0.961 (95% CI 0.958–0.986).
Conclusion
The ProciseDx POCT allows a more rapid and comparable accuracy of CRP assessment in hospitalized patients as compared to the standard laboratory measurement. Moreover, the ProciseDx POCT does not require specialised personnel to be performed. The use of ProciseDx POCT may improve and accelerate the decision-making approach, further reducing the resources required for CRP assessment
Evidence for directional selection at a novel major histocompatibility class I marker in wild common frogs (Rana temporaria) exposed to a viral pathogen (Ranavirus).
(c) 2009 Teacher et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Whilst the Major Histocompatibility Complex (MHC) is well characterized in the anuran Xenopus, this region has not previously been studied in another popular model species, the common frog (Rana temporaria). Nor, to date, have there been any studies of MHC in wild amphibian host-pathogen systems. We characterise an MHC class I locus in the common frog, and present primers to amplify both the whole region, and specifically the antigen binding region. As no more than two expressed haplotypes were found in over 400 clones from 66 individuals, it is likely that there is a single class I locus in this species. This finding is consistent with the single class I locus in Xenopus, but contrasts with the multiple loci identified in axolotls, providing evidence that the diversification of MHC class I into multiple loci likely occurred after the Caudata/Anura divergence (approximately 350 million years ago) but before the Ranidae/Pipidae divergence (approximately 230 mya). We use this locus to compare wild populations of common frogs that have been infected with a viral pathogen (Ranavirus) with those that have no history of infection. We demonstrate that certain MHC supertypes are associated with infection status (even after accounting for shared ancestry), and that the diseased populations have more similar supertype frequencies (lower F(ST)) than the uninfected. These patterns were not seen in a suite of putatively neutral microsatellite loci. We interpret this pattern at the MHC locus to indicate that the disease has imposed selection for particular haplotypes, and hence that common frogs may be adapting to the presence of Ranavirus, which currently kills tens of thousands of amphibians in the UK each year
Low Temperature Magnetic Instabilities in Triply Charged Fulleride Polymers
The electronic properties of the C603- polymer in Na2Rb0.3Cs0.7C60 were studied by X-band and high field (109.056 GHz) ESR. They are characteristic of a strongly correlated quasi-one-dimensional metal down to 45 K. On further cooling, a pseudogap of magnetic origin opens at the Fermi level below 45 K with three-dimensional magnetic ordering occurring below TN≈15K, as confirmed by the observation of an antiferromagnetic resonance mode. The Na2Rb1-xCsxC60 family of polymers offers a unique way to chemically control the electronic properties, as the opening of the gap in this system of predominantly itinerant electrons is an extremely sensitive function of the interchain separation
Continuous pulse advances in the negative ion source NIO1
Consorzio RFX and INFN-LNL have designed, built and operated the compact
radiofrequency negative ion source NIO1 (Negative Ion Optimization phase 1)
with the aim of studying the production and acceleration of H- ions. In
particular, NIO1 was designed to keep plasma generation and beam extraction
continuously active for several hours. Since 2020 the production of negative
ions at the plasma grid (the first grid of the acceleration system) has been
enhanced by a Cs layer, deposited though active Cs evaporation in the source
volume. For the negative ion sources applied to fusion neutral beam injectors,
it is essential to keep the beam current and the fraction of co-extracted
electrons stable for at least 1 h, against the consequences of Cs sputtering
and redistribution operated by the plasma. The paper presents the latest
results of the NIO1 source, in terms of caesiation process and beam
performances during continuous (6{\div}7 h) plasma pulses. Due to the small
dimensions of the NIO1 source (20 x (diam.)10 cm), the Cs density in the volume
is high (10^15 \div 10^16 m^-3) and dominated by plasma-wall interaction. The
maximum beam current density and minimum fraction of co-extracted electrons
were respectively about 30 A/m^2 and 2. Similarly to what done in other
negative ion sources, the plasma grid temperature in NIO1 was raised for the
first time, up to 80 {\deg}C, although this led to a minimal improvement of the
beam current and to an increase of the co-extracted electron current.Comment: 11 pages, 7 figures. Contributed paper for the 8th International
symposium on Negative Ions, Beams and Sources - NIBS'22. Revision 1 of the
preprint under evaluation at Journal of Instrumentation (JINST
Logistica de coleta e transporte de material biologico e organizacao do laboratorio central no ELSA-Brasil
The ELSA (Estudo Longitudinal de Saúde do Adulto - Brazilian Longitudinal Study for Adult Health) is a multicenter cohort study which aims at the identification of risk factors associated with type 2 diabetes and cardiovascular diseases in the Brazilian population. The paper describes the strategies for the collection, processing, transportation, and quality control of blood and urine tests in the ELSA. The study decided to centralize the tests at one single laboratory. The processing of the samples was performed at the local laboratories, reducing the weight of the material to be transported, and diminishing the costs of transportation to the central laboratory at the Universidade de São Paulo Hospital. The study included tests for the evaluation of diabetes, insulin resistance, dyslipidemia, electrolyte abnormalities, thyroid hormones, uric acid, hepatic enzyme abnormalities, inflammation, and total blood cell count. In addition, leukocyte DNA, urine, plasma and serum samples were stored. The central laboratory performed approximately 375,000 tests.O Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil) é um estudo de coorte multicêntrico com o objetivo de identificar os fatores de risco associados ao diabetes tipo 2 e à doença cardiovascular na população brasileira. O artigo descreve as estratégias de coleta, processamento, transporte e de controle de qualidade dos exames de sangue e urina no ELSA. O estudo optou pela centralização dos exames em um único laboratório. O processamento das amostras foi realizado nos laboratórios locais, reduzindo o peso do material a ser transportado e diminuindo os custos do transporte para o laboratório central no Hospital da Universidade de São Paulo. O estudo incluiu exames para avaliação de diabetes, resistência à insulina, dislipidemias, alterações eletrolíticas, hormônios tireoidianos, ácido úrico, alterações de enzimas hepáticas, inflamação e hemograma completo. Além desses exames, foram estocados DNA de leucócitos, amostras de urina, plasma e soro. O laboratório central realizou aproximadamente 375.000 exames
Investigation and management of young-onset hypertension: British and Irish Hypertension Society position statement
National and international hypertension guidelines recommend that adults with young-onset hypertension (aged <40 years at diagnosis) are reviewed by a hypertension specialist to exclude secondary causes of hypertension and optimise therapeutic regimens. A recent survey among UK secondary care hypertension specialist physicians highlighted variations in the investigation of such patients. In this position statement, the British and Irish Hypertension Society seek to provide clinicians with a practical approach to the investigation and management of adults with young-onset hypertension. We aim to ensure that individuals receive consistent and high-quality care across the UK and Ireland, to highlight gaps in the current evidence, and to identify important future research questions
IFNG +874T/A polymorphism is not associated with American tegumentary leishmaniasis susceptibility but can influence Leishmania induced IFN-γ production
<p>Abstract</p> <p>Background</p> <p>Interferon-gamma is a key cytokine in the protective responses against intracellular pathogens. A single nucleotide polymorphism (SNP) located in the first intron of the human IFN-γ gene can putatively influence the secretion of cytokine with an impact on infection outcome as demonstrated for tuberculosis and other complex diseases. Our aim was to investigate the putative association of IFNG+874T/A SNP with American tegumentary leishmaniasis (ATL) and also the influence of this SNP in the secretion of IFN-γ <it>in vitro</it>.</p> <p>Methods</p> <p>Brazilian ATL patients (78 cutaneous, CL, and 58 mucosal leishmaniasis, ML) and 609 healthy volunteers were evaluated. The genotype of +874 region in the IFN-γ gene was carried out by Amplification Refractory Mutational System (ARMS-PCR). <it>Leishmania</it>-induced IFN-γ production on peripheral blood mononuclear cell (PBMC) culture supernatants was assessed by ELISA.</p> <p>Results</p> <p>There are no differences between +874T/A SNP frequency in cases and controls or in ML versus CL patients. Cutaneous leishmaniasis cases exhibiting AA genotype produced lower levels of IFN-γ than TA/TT genotypes. In mucosal cases, high and low IFN-γ producers were clearly demonstrated but no differences in the cytokine production was observed among the IFNG +874T or A carriers.</p> <p>Conclusion</p> <p>Our results suggest that +874T/A polymorphism was not associated with either susceptibility or severity to leishmaniasis. Despite this, IFNG +874T/A SNP could be involved in the pathogenesis of leishmaniasis by influencing the amount of cytokine released by CL patients, although it could not prevent disease development. On the other hand, it is possible that in ML cases, other potential polymorphic regulatory genes such as TNF-α and IL-10 are also involved thus interfering with IFN-γ secretion.</p
Combination Therapy Is Superior to Sequential Monotherapy for the Initial Treatment of Hypertension:A Double-Blind Randomized Controlled Trial
Background: Guidelines for hypertension vary in their preference for initial combination therapy or initial monotherapy, stratified by patient profile; therefore, we compared the efficacy and tolerability of these approaches.
Methods and Results: We performed a 1‐year, double‐blind, randomized controlled trial in 605 untreated patients aged 18 to 79 years with systolic blood pressure (BP) ≥150 mm Hg or diastolic BP ≥95 mm Hg. In phase 1 (weeks 0–16), patients were randomly assigned to initial monotherapy (losartan 50–100 mg or hydrochlorothiazide 12.5–25 mg crossing over at 8 weeks), or initial combination (losartan 50–100 mg plus hydrochlorothiazide 12.5–25 mg). In phase 2 (weeks 17–32), all patients received losartan 100 mg and hydrochlorothiazide 12.5 to 25 mg. In phase 3 (weeks 33–52), amlodipine with or without doxazosin could be added to achieve target BP. Hierarchical primary outcomes were the difference from baseline in home systolic BP, averaged over phases 1 and 2 and, if significant, at 32 weeks. Secondary outcomes included adverse events, and difference in home systolic BP responses between tertiles of plasma renin. Home systolic BP after initial monotherapy fell 4.9 mm Hg (range: 3.7–6.0 mm Hg) less over 32 weeks (P<0.001) than after initial combination but caught up at 32 weeks (difference 1.2 mm Hg [range: −0.4 to 2.8 mm Hg], P=0.13). In phase 1, home systolic BP response to each monotherapy differed substantially between renin tertiles, whereas response to combination therapy was uniform and at least 5 mm Hg more than to monotherapy. There were no differences in withdrawals due to adverse events.
Conclusions: Initial combination therapy can be recommended for patients with BP >150/95 mm Hg.
Clinical Trial Registration URL: http://www.ClinicalTrials.gov. Unique identifier: NCT00994617
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