Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 31
Filtrar
1.
Nephrol Dial Transplant ; 39(1): 114-121, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-37715343

RESUMO

BACKGROUND: Ischemia-reperfusion injury (IRI) upon transplantation is one of the most impactful events that the kidney graft suffers during its life. Its clinical manifestation in the recipient, delayed graft function (DGF), has serious prognostic consequences. However, the different definitions of DGF are subject to physicians' choices and centers' policies, and a more objective tool to quantify IRI is needed. Here, we propose the use of donor-derived cell-free DNA (ddcfDNA) for this scope. METHODS: ddcfDNA was assessed in 61 kidney transplant recipients of either living or deceased donors at 24 h, and 7, 14 and 30 days after transplantation using the AlloSeq cfDNA Kit (CareDx, San Francisco, CA, USA). Patients were followed-up for 6 months and 7-year graft survival was estimated through the complete and functional iBox tool. RESULTS: Twenty-four-hour ddcfDNA was associated with functional DGF [7.20% (2.35%-15.50%) in patients with functional DGF versus 2.70% (1.55%-4.05%) in patients without it, P = .023] and 6-month estimated glomerular filtration rate (r = -0.311, P = .023). At Day 7 after transplantation, ddcfDNA was associated with dialysis duration in DGF patients (r = 0.612, P = .005) and worse 7-year iBox-estimated graft survival probability (ß -0.42, P = .001) at multivariable analysis. Patients with early normalization of ddcfDNA (<0.5% at 1 week) had improved functional iBox-estimated probability of graft survival (79.5 ± 16.8%) in comparison with patients with 7-day ddcfDNA ≥0.5% (67.7 ± 24.1%) (P = .047). CONCLUSIONS: ddcfDNA early kinetics after transplantation reflect recovery from IRI and are associated with short-, medium- and long-term graft outcome. This may provide a more objective estimate of IRI severity in comparison with the clinical-based definitions of DGF.


Assuntos
Ácidos Nucleicos Livres , Transplante de Rim , Humanos , Função Retardada do Enxerto , Diálise Renal , Transplante de Rim/efeitos adversos , Doadores de Tecidos , Sobrevivência de Enxerto , Rejeição de Enxerto/diagnóstico , Fatores de Risco
2.
Transpl Int ; 36: 11507, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37901296

RESUMO

In our prospective, unicenter cohort study, we collected blood samples from 30 newly kidney transplanted patients, at month 1, 2, 3, and 5 for dd-cfDNA analysis, along with creatinine/eGFR and DSA monitoring, and from 32 patients who underwent an indication biopsy and whose dd-cfDNA levels were measured at the time of biopsy and 1 month afterwards. Fourteen of 32 (43.8%) patients in the biopsy group were diagnosed with TCMR and 5 of 32 (15.6%) with ABMR. Dd-cfDNA proved to be better than creatinine in diagnosing rejection from non-rejection in patients who were biopsied. When a dd-cfDNA threshold of 0.5% was chosen, sensitivity was 73.7% and specificity was 92.3% (AUC: 0.804, 0.646-0.961). In rejection patients, levels of dd-cfDNA prior to biopsy (0.94%, 0.3-2.0) decreased substantially after initiation of treatment with median returning to baseline already at 1 month (0.33%, 0.21-0.51, p = 0.0036). In the surveillance group, high levels of dd-cfDNA (>0.5%) from second month post-transplantation were correlated with non-increasing eGFR 1 year post-transplantation. The study used AlloSeq kit for kidney transplant surveillance for first time and confirmed dd-cfDNA's ability to detect rejection and monitor treatment, as well as to predict worse long-term outcomes regarding eGFR.


Assuntos
Ácidos Nucleicos Livres , Transplante de Rim , Humanos , Estudos de Coortes , Creatinina , Estudos Prospectivos
3.
Clin Transplant ; 36(11): e14785, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35894263

RESUMO

BACKGROUND: BK polyomavirus-associated nephropathy (BKPyVAN) carries a risk of irreversible allograft injury. While detection of BK viremia and biopsy assessment are the current diagnostic gold standard, the diagnostic value of biomarkers reflecting tissue injury (donor-derived cell-free DNA [dd-cfDNA]) or immune activation (C-X-C motif chemokine ligand [CXCL]9 and CXCL10) remains poorly defined. METHODS: For this retrospective study, 19 cases of BKPyVAN were selected from the Vienna transplant cohort (biopsies performed between 2012 and 2019). Eight patients with T cell-mediated rejection (TCMR), 17 with antibody-mediated rejection (ABMR) and 10 patients without polyomavirus nephropathy or rejection served as controls. Fractions of dd-cfDNA were quantified using next-generation sequencing and CXCL9 and CXCL10 were detected using multiplex immunoassays. RESULTS: BKPyVAN was associated with a slight increase in dd-cfDNA (median; interquartile range: .38% [.27%-1.2%] vs. .21% [.12%-.34%] in non-rejecting control patients; p = .005). Levels were far lower than in ABMR (1.2% [.82%-2.5%]; p = .004]), but not different from TCMR (.54% [.26%-3.56%]; p = .52). Within the BKPyVAN cohort, we found no relationship between dd-cfDNA levels and the extent of tubulo-interstitial infiltrates, BKPyVAN class and BK viremia/viruria, respectively. In some contrast to dd-cfDNA, concentrations of urinary CXCL9 and CXCL10 exceeded those detected in ABMR, but similar increases were also found in TCMR. CONCLUSION: BKPyVAN can induce moderate increases in dd-cfDNA and concomitant high urinary excretion of chemokines, but this pattern may be indistinguishable from that of TCMR. Our results argue against a significant value of these biomarkers to reliably distinguish BKPyVAN from rejection.


Assuntos
Vírus BK , Ácidos Nucleicos Livres , Nefropatias , Transplante de Rim , Infecções por Polyomavirus , Humanos , Vírus BK/genética , Estudos Retrospectivos , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/etiologia , Transplante de Rim/efeitos adversos , Nefropatias/complicações , Viremia/complicações , Anticorpos , Biomarcadores/urina
4.
Transpl Int ; 34(9): 1689-1702, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34448270

RESUMO

Circulating donor-specific antibodies (DSA) do not necessarily indicate antibody-mediated rejection (ABMR). Here, we evaluated the diagnostic value of donor-derived cell-free DNA (dd-cfDNA) as an add-on to DSA detection. The study included two independent cohorts of DSA+ kidney allograft recipients, 45 subclinical cases identified by cross-sectional antibody screening (cohort 1), and 30 recipients subjected to indication biopsies (cohort 2). About 50% of the DSA+ recipients had ABMR and displayed higher dd-cfDNA levels than DSA+ ABMR- recipients (cohort 1: 1.90% [median; IQR: 0.78-3.90%] vs. 0.52% [0.35-0.72%]; P < 0.001); (cohort 2: 1.20% [0.82-2.50%] vs. 0.59% [0.28-2.05%]; P = 0.086). Receiver operating characteristic (ROC) analysis revealed an area under the curve (AUC) of 0.89 and 0.69 for dd-cfDNA, and 0.88 and 0.77 for DSA mean fluorescence intensity (MFI), respectively. In combined models, adding dd-cfDNA to DSA-MFI or vice versa significantly improved the diagnostic accuracy. Limited diagnostic performance of dd-cfDNA in cohort 2 was related to the frequent finding of other types of graft injury among ABMR- recipients, like T cell-mediated rejection or glomerulonephritis. For dd-cfDNA in relation to injury of any cause an AUC of 0.97 was calculated. Monitoring of dd-cfDNA in DSA+ patients may be a useful tool to detect ABMR and other types of injury.


Assuntos
Ácidos Nucleicos Livres , Transplante de Rim , Aloenxertos , Anticorpos , Estudos Transversais , Rejeição de Enxerto/diagnóstico , Humanos , Isoanticorpos , Rim , Transplante de Rim/efeitos adversos
5.
Clin Chem Lab Med ; 57(7): 999-1005, 2019 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-30739097

RESUMO

Background Isolated antibodies to DFS70 have been described in healthy individuals and are rarely found in patients with antinuclear antibody-associated autoimmune rheumatic diseases (AARD). However, no data is available on geographic differences in the prevalence of anti-DFS70 antibodies. We aimed to study the prevalence of anti-DFS70 antibodies in blood donor samples from several countries representing various ethnical backgrounds and geographic regions in the world. Methods Sera from apparently healthy blood donors (n≥300 per site) were collected in seven countries (USA, Italy, Spain, Germany, UK, Belgium and Brazil). All samples (n=2628) were tested for anti-DFS70 antibodies by QUANTA Flash DFS70 (Inova Diagnostics, Inc., San Diego, CA, USA). Results The prevalence of anti-DFS70 antibodies varied from 4/321 (1.2%, Italy) to 42/497 (8.5%, USA). Consequently, the prevalence of the antibodies was significantly higher in USA compared to all other countries (p<0.05). In addition, the prevalence in the combined cohort (all sites) was higher in young blood donors (<35 years; 5.0% vs. 2.7%; p=0.0017) and among females (4.5% vs. 3.0%; p=0.0446). However, when cohorts from different countries were corrected for age and gender, no significant difference between the countries were found. Conclusions This is the first study to analyze the prevalence of anti-DFS70 antibodies in different geographic areas using a standardized assay. Our findings show that the antibodies are most prevalent in young females.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/imunologia , Autoanticorpos/sangue , Doenças Autoimunes/diagnóstico , Doenças Reumáticas/diagnóstico , Fatores de Transcrição/imunologia , Adulto , Doenças Autoimunes/epidemiologia , Doadores de Sangue , Feminino , Humanos , Imunoensaio , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Prevalência , Doenças Reumáticas/epidemiologia
6.
Environ Res ; 159: 355-361, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28843166

RESUMO

INTRODUCTION: High mammographic density is one of the main risk factors for breast cancer. Although several occupations have been associated with breast cancer, there are no previous occupational studies exploring the association with mammographic density. Our objective was to identify occupations associated with high mammographic density in Spanish female workers. METHODS: We conducted a population-based cross-sectional study of occupational determinants of high mammographic density in Spain, based on 1476 women, aged 45-68 years, recruited from seven screening centers within the Spanish Breast Cancer Screening Program network. Reproductive, family, personal, and occupational history data were collected. The latest occupation of each woman was collected and coded according to the 1994 National Classification of Occupations. Mammographic density was assessed from the cranio-caudal mammogram of the left breast using a semi-automated computer-assisted tool. Association between mammographic density and occupation was evaluated by using mixed linear regression models, using log-transformed percentage of mammographic density as dependent variable. Models were adjusted for age, body mass index, menopausal status, parity, smoking, alcohol intake, educational level, type of mammography, first-degree relative with breast cancer, and hormonal replacement therapy use. Screening center and professional reader were included as random effects terms. RESULTS: Mammographic density was higher, although non-statistically significant, among secondary school teachers (eß = 1.41; 95%CI = 0.98-2.03) and nurses (eß = 1.23; 95%CI = 0.96-1.59), whereas workers engaged in the care of people (eß = 0.81; 95%CI = 0.66-1.00) and housewives (eß = 0.87; 95%CI = 0.79-0.95) showed an inverse association with mammographic density. A positive trend for every 5 years working as secondary school teachers was also detected (p-value = 0.035). CONCLUSIONS: Nurses and secondary school teachers were the occupations with the highest mammographic density in our study, showing the latter a positive trend with duration of employment. Future studies are necessary to confirm if these results are due to chance or are the result of a true association whose causal hypothesis is, for the moment, unknown.


Assuntos
Densidade da Mama , Ocupações/classificação , Idoso , Estudos Transversais , Feminino , Humanos , Modelos Lineares , Mamografia , Pessoa de Meia-Idade , Espanha
7.
HLA ; 103(5): e15518, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38733247

RESUMO

Donor-derived cell-free DNA (dd-cfDNA) has been widely studied as biomarker for non-invasive allograft rejection monitoring. Earlier rejection detection enables more prompt diagnosis and intervention, ultimately improving patient treatment and outcomes. This multi-centre study aims to verify analytical performance of a next-generation sequencing-based dd-cfDNA assay at end-user environments. Three independent laboratories received the same experimental design and 16 blinded samples to perform cfDNA extraction and the dd-cfDNA assay workflow. dd-cfDNA results were compared between sites and against manufacturer validation to evaluate concordance, reproducibility, repeatability and verify analytical performance. A total of 247 sample libraries were generated across 18 runs, with completion time of <24 h. A 96.0% first pass rate highlighted minimal failures. Overall observed versus expected dd-cfDNA results demonstrated good concordance and a strong positive correlation with linear least squares regression r2 = 0.9989, and high repeatability and reproducibility within and between sites, respectively (p > 0.05). Manufacturer validation established limit of blank 0.18%, limit of detection 0.23% and limit of quantification 0.23%, and results from independent sites verified those limits. Parallel analyses illustrated no significant difference (p = 0.951) between dd-cfDNA results with or without recipient genotype. The dd-cfDNA assay evaluated here has been verified as a reliable method for efficient, reproducible dd-cfDNA quantification in plasma from solid organ transplant recipients without requiring genotyping. Implementation of onsite dd-cfDNA testing at clinical laboratories could facilitate earlier detection of allograft injury, bearing great potential for patient care.


Assuntos
Ácidos Nucleicos Livres , Rejeição de Enxerto , Sequenciamento de Nucleotídeos em Larga Escala , Transplante de Órgãos , Doadores de Tecidos , Transplantados , Humanos , Ácidos Nucleicos Livres/sangue , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Reprodutibilidade dos Testes , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/sangue , Rejeição de Enxerto/genética , Biomarcadores/sangue
8.
J Biomol Struct Dyn ; 40(21): 11448-11459, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34315332

RESUMO

N-(2-Hydroxyphenyl)-2-propylpentanamide (HO-AAVPA) is a valproic acid (VPA) derivative that has shown promising antiproliferative effects in different cancer cell lines, such as A204, HeLa, and MDA-MB-231. However, its low water solubility could reduce its therapeutic effectiveness. To solve this problem, in this work, we incorporated HO-AAVPA into dimyristoyl-phosphatidylcholine (DMPC) liposomes in the presence or absence of cholesterol (CHOL). Using differential scanning calorimetry (DSC), we found that the transition enthalpy (ΔHtr) of DMPC liposomes is reduced in the presence of CHOL and/or HO-AAVPA, indicating the favorable interactions between CHOL and/or HO-AAVPA and DMPC. Further, by molecular dynamics simulations it was possible to observed that HO-AAVPA migrates from the center of the bilayer toward the water and lipid interface of the DPMC bilayer systems exposing the amine group to water and the aliphatic chain toward the interior of the bilayer. As a consequence, we observed an ordering of the lipid bilayer. Moreover, CHOL harbors into the inner bilayer membrane, increasing the order parameter of the system. The liposomal solutions loaded with HO-AAVPA were tested in the NIH3T3 cell line, showing a reduction in cell proliferation compared to those cells presented without liposomes.Communicated by Ramaswamy H. Sarma.


Assuntos
Dimiristoilfosfatidilcolina , Lipossomos , Camundongos , Animais , Dimiristoilfosfatidilcolina/química , Dimiristoilfosfatidilcolina/metabolismo , Lipossomos/química , Células NIH 3T3 , Bicamadas Lipídicas/química , Colesterol/química , Água
9.
Transplant Direct ; 8(12): e1406, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36382130

RESUMO

Targeting interleukin-6 (IL-6) was shown to counteract donor-specific antibody production and antibody-mediated rejection (AMR) activity. It is not known whether, or to what extent, IL-6 antagonism modulates biomarkers indicative of tissue damage (donor-derived cell-free DNA [dd-cfDNA]) and parenchymal inflammation (C-X-C motif chemokine ligand [CXCL] 10). Methods: We report a secondary endpoint analysis of a phase 2 trial of anti-IL-6 antibody clazakizumab in late AMR (ClinicalTrials.gov, NCT03444103). Twenty kidney transplant recipients were randomized to treatment with clazakizumab or placebo over 12 wk (part A), followed by an extension in which all recipients received clazakizumab through week 52 (part B). Biomarkers were evaluated at day 0 and after 12 and 52 wk, respectively. Results: Fractional dd-cfDNA (dd-cfDNA[%]) did not significantly change under clazakizumab, with no differences between study arms (clazakizumab versus placebo) at week 12 (1.65% [median; interquartile range: 0.91%-2.78%] versus 0.97% [0.56%-2.30%]; P = 0.25) and no significant decrease from weeks 12 to 52 (1.15% [0.70%-2.38%] versus 1.0% [0.61%-1.70%]; P = 0.25). Similarly, urine CXCL10 was not different between groups at week 12 (55.7 [41.0-91.4] versus 60.2 [48.8-208.7.0] pg/mg creatinine; P = 0.44) and did not change over part B (CXCL10 [pg/mg creatinine]: from 58 [46.3-93.1] to 67.4 [41.5-132.0] pg/mL creatinine; P = 0.95). Similar results were obtained for serum CXCL10. There was no association between biomarker levels and resolution of molecular and morphologic AMR activity. Conclusions: Our results suggest that IL-6 blockade does not significantly affect levels of dd-cfDNA[%] and CXCL10. Subtle responses to this therapeutic principle may be overlooked by early biomarker surveillance.

10.
Am J Physiol Endocrinol Metab ; 299(6): E1087-95, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20943756

RESUMO

BACE1 (ß-site amyloidogenic cleavage of precursor protein-cleaving enzyme 1) is a ß-secretase protein that plays a central role in the production of the ß-amyloid peptide in the brain and is thought to be involved in the Alzheimer's pathogenesis. In type 2 diabetes, amyloid deposition within the pancreatic islets is a pathophysiological hallmark, making crucial the study in the pancreas of BACE1 and its homologous BACE2 to understand the pathological mechanisms of this disease. The objectives of the present study were to characterize the localization of BACE proteins in human pancreas and determine their function. High levels of BACE enzymatic activity were detected in human pancreas. In normal human pancreas, BACE1 was observed in endocrine as well as in exocrine pancreas, whereas BACE2 expression was restricted to ß-cells. Intracellular analysis using immunofluorescence showed colocalization of BACE1 with insulin and BACE2 with clathrin-coated vesicles of the plasma membrane in MIN6 cells. When BACE1 and -2 were pharmacologically inhibited, BACE1 localization was not altered, whereas BACE2 content in clathrin-coated vesicles was increased. Insulin internalization rate was reduced, insulin receptor ß-subunit (IRß) expression was decreased at the plasma membrane and increased in the Golgi apparatus, and a significant reduction in insulin gene expression was detected. Similar results were obtained after specific BACE2 silencing in MIN6 cells. All these data point to a role for BACE2 in the IRß trafficking and insulin signaling. In conclusion, BACE2 is hereby presented as an important enzyme in ß-cell function.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Ácido Aspártico Endopeptidases/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Pâncreas/metabolismo , Receptor de Insulina/metabolismo , Adulto , Animais , Western Blotting , Linhagem Celular , Células Cultivadas , Vesículas Revestidas por Clatrina/metabolismo , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Transporte Proteico , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Frações Subcelulares/metabolismo
11.
Autoimmun Rev ; 19(10): 102641, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32801044

RESUMO

Patients with antiphospholipid syndrome (APS) present with clinical features of recurrent thrombosis and pregnancy morbidity and persistently test positive for the presence of antiphospholipid antibodies (aPL). At least one clinical (vascular thrombosis or pregnancy morbidity) and one lab-based (positive test result for lupus anticoagulant, anticardiolipin antibodies and/or anti-ß2-glycoprotein 1 antibodies) criterion have to be met for a patient to be classified as having APS. Nevertheless, the clinical variety of APS encompasses additional signs and symptoms, potentially affecting any organ, that cannot be explained exclusively by a prothrombotic state. Those manifestations, also known as extra-criteria manifestations, include haematologic (thrombocytopenia and haemolytic anaemia), neurologic (chorea, myelitis and migraine) manifestations as well as the presence of livedo reticularis, nephropathy and valvular heart disease. The growing body of evidence describing the clinical aspect of the syndrome has been paralleled over the years by emerging research interest focusing on the development of novel biomarkers that might improve the diagnostic accuracy for APS when compared to the current aPL tests. This review will focus on the clinical utility of extra-criteria aPL specificities. Besides, the promising role of a new technology using particle based multi-analyte testing that supports aPL panel algorithm testing will be discussed. Diagnostic approaches to difficult cases, including real-world case studies investigating the diagnostic added value of extra criteria aPL, particularly anti-phosphatidylserine/prothrombin, will also be examined.


Assuntos
Síndrome Antifosfolipídica , Autoanticorpos , Anticorpos Anticardiolipina , Anticorpos Antifosfolipídeos , Síndrome Antifosfolipídica/diagnóstico , Autoanticorpos/análise , Feminino , Humanos , Inibidor de Coagulação do Lúpus , Gravidez
12.
Autoimmun Rev ; 19(8): 102583, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32553611

RESUMO

Systemic sclerosis (SSc) is a rare chronic disease of unknown etiology characterized by vascular abnormalities and fibrosis involving the skin and internal organs, especially the gastrointestinal tract, lung, heart and kidneys. Although the disease was historically stratified according to the extent of skin involvement, more recent approaches place more emphasis on patterns and extent of internal organ involvement. Despite numerous clinical trials, disease-modifying treatment options are still limited resulting in persistent poor quality of life and high mortality. This review provides an overview of autoantibodies in SSc and novel approaches to stratify the disease into clinically actionable subsets.


Assuntos
Autoanticorpos , Escleroderma Sistêmico , Autoanticorpos/sangue , Autoanticorpos/imunologia , Humanos , Qualidade de Vida , Escleroderma Sistêmico/imunologia , Escleroderma Sistêmico/patologia , Escleroderma Sistêmico/terapia
13.
J Clin Endocrinol Metab ; 92(4): 1446-50, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17213278

RESUMO

CONTEXT: Amylin has been linked to the development of hypertension in several pathological states related to hypertension and insulin resistance, although there is scant data regarding its potential mechanisms of action. The -132 G/A mutation located within an activator domain of the amylin gene's promoter was first identified in a small cohort of Spanish patients with type 2 diabetes. OBJECTIVE: The objective of the study was to test the interference of amylin peptide with endothelium-dependent responses as an added potential mechanism for amylin-induced hypertension. DESIGN: A total of 384 patients with type 2 diabetes and 207 healthy controls were subjected to clinical analysis and genetic screening for the -132 G/A mutation of the amylin gene. The effect of amylin on endothelium-dependent responses was analyzed in aortic rings and mesenteric microvessels from nondiabetic rats. RESULTS: The prevalence of the mutation was 10.1 vs. 0.9% in the control population (P<0.001). Hypertension was higher in a diabetic population carrying the mutation than in diabetic noncarriers (74 vs. 57%; P<0.05). Diabetic carriers showed higher fasting amylin levels than diabetic noncarriers (11.4+/-7 vs. 8.2+/-3 pmol/liter; P<0.05). Preincubation with 20 pmol/liter amylin impaired the relaxant responses induced by acetylcholine in rat aorta and mesenteric microvessels. This effect was abolished in both vascular beds in the presence of 100 micromol/liter NG-nitro-L-arginine methyl ester. CONCLUSIONS: We propose that amylin levels and hypertension may be linked by a novel mechanism involving the capacity of amylin to induce endothelial dysfunction by interfering with nitric oxide-mediated responses.


Assuntos
Amiloide/genética , Amiloide/farmacologia , Diabetes Mellitus Tipo 2/genética , Endotélio Vascular/fisiopatologia , Hipertensão/genética , Mutação , Idoso , Animais , Diabetes Mellitus Tipo 2/complicações , Endotélio Vascular/efeitos dos fármacos , Feminino , Humanos , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Ratos , Ratos Sprague-Dawley , Valores de Referência
14.
J Phys Chem B ; 111(39): 11497-505, 2007 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-17850130

RESUMO

An analysis scheme for the formation of the inclusion complexes in water is presented. It is exemplified for the case where the host is alpha-cyclodextrin and the guest is a linear alcohol (1-propanol to 1-octanol) or the isomers of 1-pentanol. Eight transfer isobaric heat capacities, DeltatCp, involving different initial and final states are evaluated at infinite dilution of the guest using both data determined in this work and from the literature. Apart from the usual definition for the inclusion heat capacity change, three inclusion transfers are used. The sign of each DeltatCp indicates if the transfer is an order-formation or an order-destruction process. From the DeltatCp data, the main contributions to the heat capacity of cyclodextrin complexation, namely, those due to dehydration of the hydrophobic section of the guest molecule, H-bond formation, formation of hydrophobic interactions, and release of water molecules from the cyclodextrin cavity, are estimated. The relative weight of each of these contributions to the DeltatCp values is discussed, providing a better characterization of the molecular recognition process involved in the inclusion phenomena.


Assuntos
Álcoois/química , Temperatura Alta , Substâncias Macromoleculares/química , alfa-Ciclodextrinas/química , Ligação de Hidrogênio , Água/química
15.
J Phys Chem B ; 111(17): 4383-92, 2007 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-17428087

RESUMO

Three host-guest systems have been characterized using surface tension (sigma), calorimetry, and molecular dynamics simulations (MD). The hosts were three native cyclodextrins (CD) and the guest the non-ionic carbohydrate surfactant octyl-beta-d-glucopyranoside. It is shown that, for any host-guest system, a rough screening of the most probable complex stoichiometries can be obtained in a model free form, using only calorimetric data. The sigma data were analyzed using a model that includes a newly proposed adsorption isotherm. The equilibrium constants for several stoichiometries were simultaneously obtained through fitting the sigma data. For alpha- and beta-CD, the predominant species is 1:1 and to a lesser extent 2:1, disregarding the existence of the 1:2. For gamma-CD, the 1:2 species dominates, the other two being also present. In an attempt to confirm these results, 10 ns MD simulations for each CD were performed using seven different starting conformations. The MD stable conformations agree with the results found from the experimental data. In one case, the spontaneous dissociation-formation of a complex was observed. Analysis of the trajectories indicates that hydrophobic interactions are primarily responsible for the formation and stability of the inclusion complexes. For the 2:1 species, intermolecular H-bonds between CD molecules result in a tight packed structure where their original truncated cone shape is lost in favor of a cylindrical geometry. Together, the results clearly demonstrate that the often used assumption of considering only a 1:1 species is inappropriate.


Assuntos
Ciclodextrinas/química , Tensoativos/química , Calorimetria , Simulação por Computador , Íons/química , Modelos Químicos , Modelos Moleculares , Conformação Molecular , Transição de Fase , Propriedades de Superfície , Termodinâmica , Água/química
16.
Int J Pharm ; 500(1-2): 11-9, 2016 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-26795192

RESUMO

Supramolecular gels of poloxamer-hydroxyethyl cellulose (HEC)-α-cyclodextrin (αCD) were developed aiming to obtain synergisms regarding solubilization and sustained release of griseofulvin for topical application. The effects of αCD concentration (0-10%w/w) on the phase behavior of aqueous dispersions of Pluronic(®) P123 (14%w/w) mixed with HEC (2%w/w) were evaluated at 4, 20 and 37°C. The cooperative effects of the inclusion complex formation between poly(ethylene oxide) (PEO) blocks and HEC with αCD prevented phase separation and led to supramolecular networks that solubilize the antifungal drug. Rheological and bioadhesive properties of gels with and without griseofulvin could be easily tuned modulating the polymers proportions. Supramolecular gels underwent sol-gel transition at lower temperature than P123 solely dispersions and enabled drug sustained release for at least three weeks. All gels demonstrated good biocompatibility in the HET-CAM test. Furthermore, the drug-loaded gels showed activity against Trichophyton rubrum and Trichophyton mentagrophytes and thus may be useful for the treatment of tinea capitis and other cutaneous fungal infections.


Assuntos
Antifúngicos/química , Celulose/análogos & derivados , Griseofulvina/química , Poloxâmero/química , alfa-Ciclodextrinas/química , Antifúngicos/administração & dosagem , Antifúngicos/farmacologia , Celulose/química , Preparações de Ação Retardada/administração & dosagem , Preparações de Ação Retardada/química , Liberação Controlada de Fármacos , Géis , Griseofulvina/administração & dosagem , Griseofulvina/farmacologia , Reologia , Solubilidade , Trichophyton/efeitos dos fármacos
17.
Rev Esp Geriatr Gerontol ; 51(3): 154-8, 2016.
Artigo em Espanhol | MEDLINE | ID: mdl-26304636

RESUMO

BACKGROUND AND AIM: Shared decision-making between patients and healthcare professionals is crucial to guarantee adequate coherence between patient values and preferences, caring aims and treatment intensity, which is key for the provision of patient-centred healthcare. The assessment of such interventions are essential for caring continuity purposes. To do this, reliable and easy-to-use assessment systems are required. This study describes the results of the implementation of a hospital treatment intensity assessment tool. MATERIAL AND METHODS: The pre-implementation and post-implementation results were compared between two cohorts of patients assessed for one month. RESULTS: Some record of care was registered in 6.1% of patients in the pre-implementation group (n=673) compared to 31.6% of patients in the post-implementation group (n=832) (P<.01), with differences between services. Hospital mortality in both cohorts is 1.9%; in the pre-implementation group, 93.75% of deceased patients had treatment intensity assessment. CONCLUSIONS: In hospital settings, the availability of a specific tool seems to encourage very significantly shared decision-making processes between patients and healthcare professionals -multiplying by more than 5 times the treatment intensity assessment. Moreover, such tools help in the caring continuity processes between different teams and the personalisation of caring interventions to be monitored. More research is needed to continue improving shared decision-making for hospital patients.


Assuntos
Tomada de Decisões , Idoso , Humanos , Pacientes Internados
19.
Neotrop. ichthyol ; 19(3): e210027, 2021. tab, graf, mapas, ilus
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1340229

RESUMO

Because dams block migratory routes of potamodromous fish to their spawning areas, and energy generation changes natural flow seasonality, it is necessary to identify spawning areas and their conditions. This information will help in management decisions in the Magdalena River basin regarding the future hydropower development. We identified which characteristics of the tributaries to the Magdalena River are important for determining potamodromous fish spawning grounds, and we estimated the percentage of future loss of spawning areas because of dam development. Ichthyoplankton density is directly related to the floodplain area, and inversely related with channel slope. Low channel slopes offer adult fish a longer distance for their upstream migration and a longer time for embryo development during their drift downstream from the spawning areas to nursery habitats (floodplain lakes). These features could increase the migration distance of the adults, the time for initial embryo development, and, because of its relationship with nursery habitats access, the offspring survival. The potential loss of the actual spawning grounds in the river network was estimated to be nearly 70% because of new dams. Our findings will help to reduce conflicts between hydropower and ecological interests.(AU)


La construcción de hidroeléctricas puede afectar la reproducción de los peces migratorios potamódromos, ya sea porque las represas bloquean las rutas migratorias a sus áreas de desove, o porque la generación de energía cambia la estacionalidad del flujo natural. Esto hace necesario generar información sobre las áreas de desove y sus características, que permitan tomar decisiones de manejo, teniendo en cuenta el desarrollo hidroeléctrico propuesto a futuro en la cuenca del río Magdalena. Identificamos qué características de algunos afluentes del río Magdalena son importantes para los desoves y estimamos el porcentaje de pérdida futura de áreas de desoves debido al desarrollo hidroeléctrico. La densidad del ictioplancton se relacionó directamente con el área de la llanura aluvial e inversamente con la pendiente del canal. Estas características aumentan la distancia de migración de los adultos maduros, el tiempo para el desarrollo inicial del embrión y la supervivencia de la descendencia debido a la proximidad y/o conectividad con los hábitats de cría. La pérdida potencial de las zonas de desove en la red fluvial se estimó en casi el 70% debido a las nuevas presas. Nuestros hallazgos ayudarán a tomar decisiones sostenibles para reducir los conflictos entre intereses de desarrollo hidroeléctrico y ecológicos.(AU)


Assuntos
Animais , Migração Animal , Energia Hidrelétrica , Peixes/embriologia , Desenvolvimento Embrionário
20.
Haematologica ; 88(6): 654-8, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12801841

RESUMO

BACKGROUND AND OBJECTIVES: The lymphotoxin beta (LTB) gene, localized to the major histocompatibility complex region on chromosome 6p21.3, has an important role in the formation of germinal center reactions and regulation of immune response and apoptosis. Our aim was to determine LTB gene expression in different hematologic neoplasias. DESIGN AND METHODS: We determined the expression of LTB using quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR) on a series of RNA samples from CD3(+) T cells and CD19(+) B cells isolated from peripheral blood (n=7); CD19(+) B cells isolated from lymph nodes (n=11) and from patients with acute lymphoblastic leukemia (ALL; n=16), acute myeloid leukemia (AML; n=43), chronic myeloid leukemia (CML; n=12), mantle cell lymphoma (MCL; n=19), chronic lymphocytic leukemia (CLL; n=32) and small lymphocytic lymphoma (SLL; n=22). RESULTS: The expression level of LTB in CD3(+) T cells and CD19(+) B cells isolated from blood was ten to forty times lower than that in normal CD19(+) B cells isolated from lymph nodes. In malignant myeloid cells the expression levels were very low, whereas in malignant lymphoid cells the expression was higher than in myeloid cells, being highest in MCL and CLL (20.2+/-14.0 ng/microL and 81.0+/-116.3 ng/microL) and low in SLL (4.5+/-3.6 ng/microL; p=0.001). We did not find correlations between LTB expression and hematoclinical parameters (risk groups, immunophenotypes and overall survival). INTERPRETATION AND CONCLUSIONS: A distinct difference in expression of LTB in CLL and SLL indicates that these morphologically similar B-cell malignancies are molecularly different. Further studies are needed to investigate the prognostic value of LTB and any role that LTB may have in determining whether the malignant B cells manifest a leukemia or lymphoma.


Assuntos
Leucemia Linfocítica Crônica de Células B/imunologia , Linfotoxina-alfa/metabolismo , Proteínas de Membrana/metabolismo , Adulto , Idoso , Linfócitos B/imunologia , Pré-Escolar , Feminino , Humanos , Leucemia/diagnóstico , Leucemia/genética , Leucemia/imunologia , Leucemia Linfocítica Crônica de Células B/diagnóstico , Leucemia Linfocítica Crônica de Células B/genética , Linfoma/diagnóstico , Linfoma/genética , Linfoma/imunologia , Linfotoxina-alfa/genética , Linfotoxina-beta , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Linfócitos T/imunologia , Transcrição Gênica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA