Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 169
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
Phys Rev Lett ; 129(2): 027002, 2022 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-35867432

RESUMO

Superconductivity in infinite-layer nickelates holds exciting analogies with that of cuprates, with similar structures and 3d-electron count. Using resonant inelastic x-ray scattering, we studied electronic and magnetic excitations and charge density correlations in Nd_{1-x}Sr_{x}NiO_{2} thin films with and without an SrTiO_{3} capping layer. We observe dispersing magnons only in the capped samples, progressively dampened at higher doping. We detect an elastic resonant scattering peak in the uncapped x=0 compound at wave vector (∼⅓,0), remindful of the charge order signal in hole doped cuprates. The peak weakens at x=0.05 and disappears in the superconducting x=0.20 film. The role of the capping on the electronic reconstruction far from the interface remains to be understood.

2.
Reproduction ; 159(4): 437-451, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31990675

RESUMO

Human spermatogonial stem cells (SSCs) are an essential source to maintain spermatogenesis as an efficient process for daily sperm production with high self-renewal capacity along adulthood. However, the phenotype and the subpopulation that represent the real reserve SSC for the human testis remain unknown. Moreover, although SSC markers have been described for undifferentiated spermatogonia (Adark and Apale), the existence of a specific subtype that could be identified as the actual/true SSC has not yet been fully determined. Herein we evaluated spermatogonial morphology, kinetics, positioning regarding blood vasculature in relation to protein expression (UTF1, GFRA1, and KIT) as well as proliferative activity (MCM7) and identified a small subpopulation of Adark with nuclear rarefaction zone (AdVac) that behaves as the human reserve SSC. We show that AdVac is the smallest human spermatogonial population (10%), staying quiescent (89%) and positioned close to blood vessels throughout most of the stages of the seminiferous epithelium cycle (SEC) and divides only at stages I and II. Within this AdVac population, we found a smaller pool (2% of A undifferentiated spermatogonia) of entirely quiescent cells exhibiting a high expression of UTF1 and lacking GFRA1. This finding suggests them as the real human reserve SSC (AdVac UTF1+/GFRA1-/MCM7-). Additionally, Adark without nuclear vacuole (AdNoVac) and Apale have similar kinetic and high proliferative capacity throughout the SEC (47%), indicating that they are actively dividing undifferentiated spermatogonia. Identification of human stem cells with evident reserve SSC functionality may help further studies intending to sort SSCs to treat male diseases and infertility.


Assuntos
Células-Tronco Germinativas Adultas , Espermatogônias/fisiologia , Testículo/citologia , Adulto , Receptores de Fator Neurotrófico Derivado de Linhagem de Célula Glial/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Mitose , Proteínas Nucleares/metabolismo , Espermatogônias/citologia , Testículo/irrigação sanguínea , Transativadores/metabolismo
3.
J Hum Nutr Diet ; 27(3): 270-9, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24118227

RESUMO

BACKGROUND: The present study aimed to determine whether the δ(13)C and δ(15)N of fingernails (δ(13)CF and δ(15)NF, respectively) would exhibit differences between groups from different income levels in the city of Piracicaba, Brazil. METHODS: In 2010, the fingernails of 273 participants belonging to six income groups were analysed to determine isotopic composition. δ(13)CF and δ(15)NF were compared with the stable isotope of a putative diet (δ(13)CD and δ(15)ND , respectively), which was estimated via an isotopic mass balance using, as a weighting factor, macronutrient intake by the main food items, as obtained by the 2008-2009 household food purchases conducted by the Brazilian Institute of Geography and Statistics. RESULTS: δ(13)CF values showed a decreasing trend towards the lower income level groups, in accordance with the δ(13)CD values that showed the same trend. This isotopic change was mainly a result of the higher consumption of beef, bread, soft drinks and dairy by the highest income group; and also as a result of the higher consumption of soybean oil, rice and sugar by the lowest income group. The δ(15)NF values failed to capture differences in groups between income levels. This outcome was not expected because individuals in a higher income group tend to consume more animal protein and, as a result of the trophic fractionation, have higher δ(15)N values. CONCLUSIONS: The combination of household purchase surveys and stable isotopic composition in modern humans is found to be a valuable tool, especially with respect to determining the role of C3 and C4 plants through the complex modern food chain.


Assuntos
Isótopos de Carbono/análise , Dieta , Renda , Unhas/química , Isótopos de Nitrogênio/análise , Brasil , Pão , Bebidas Gaseificadas , Laticínios , Sacarose Alimentar/administração & dosagem , Alimentos , Humanos , Carne , Oryza , Pobreza , Óleo de Soja , População Urbana
4.
Nat Commun ; 15(1): 5348, 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38914556

RESUMO

Quantum fluctuations in low-dimensional systems and near quantum phase transitions have significant influences on material properties. Yet, it is difficult to experimentally gauge the strength and importance of quantum fluctuations. Here we provide a resonant inelastic x-ray scattering study of magnon excitations in Mott insulating cuprates. From the thin film of SrCuO2, single- and bi-magnon dispersions are derived. Using an effective Heisenberg Hamiltonian generated from the Hubbard model, we show that the single-magnon dispersion is only described satisfactorily when including significant quantum corrections stemming from magnon-magnon interactions. Comparative results on La2CuO4 indicate that quantum fluctuations are much stronger in SrCuO2 suggesting closer proximity to a magnetic quantum critical point. Monte Carlo calculations reveal that other magnetic orders may compete with the antiferromagnetic Néel order as the ground state. Our results indicate that SrCuO2-due to strong quantum fluctuations-is a unique starting point for the exploration of novel magnetic ground states.

5.
Rev Sci Instrum ; 93(12): 123505, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36586937

RESUMO

High resolution spectroscopy on the Tokamak à Configuration Variable (TCV) divertor plasma provided Doppler broadening measurements to infer the ion and neutral temperature of injected helium gas. This paper presents the Divertor Spectroscopy System's (DSS) access to He II ion temperature measurements over a broad range, ≈0.5-15 eV, with an uncertainty of <10% for most of the studied plasma discharges. TCV's shaping flexibility was employed to validate these measurements against Thomson scattering across the DSS lines of sight. In detachment-related experiments, Ti(He II) ≃ Te, making this diagnostic a reliable thermometer along the divertor leg plasma over the wide range of magnetic equilibria and divertor configurations achievable in TCV. A detailed description of the diagnostic hardware, data analysis, and sources of uncertainty is presented.

6.
Acta Crystallogr Sect F Struct Biol Cryst Commun ; 67(Pt 10): 1300-8, 2011 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-22102052

RESUMO

The use of relative humidity control of protein crystals to overcome some of the shortcomings of soaking ligands (i.e. inhibitors, substrate analogs, weak ligands) into pre-grown apoprotein crystals has been explored. Crystals of PurE (EC 4.1.1.21), an enzyme from the purine-biosynthesis pathway of Bacillus anthracis, were used as a test case. The findings can be summarized as follows: (i) using humidity control, it is possible to improve/optimize the diffraction quality of crystals soaked in solutions of organic solvent (DMSO, ethanol) containing ligands/inhibitors; (ii) optimization of the relative humidity can compensate for the deterioration of the diffraction pattern that is observed upon desalting crystals grown in high salt; (iii) combining desalting protocols with the addition of PEG it is possible to achieve very high concentrations of weak ligands (in the 5-10 mM range) in soaking solutions and (iv) fine control of the relative humidity of crystals soaked in these solutions can compensate for the deterioration of crystal diffraction and restore `high-resolution' diffraction for structure-based and fragment-based drug design. It is suggested that these experimental protocols may be useful in other protein systems and may be applicable in academic or private research to increase the probability of obtaining structures of protein-ligand complexes at high resolution.


Assuntos
Bacillus anthracis/enzimologia , Carboxiliases/química , Cristalização , Cristalografia por Raios X , Umidade , Soluções/química
7.
Int J STD AIDS ; 21(4): 267-72, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20378899

RESUMO

The aim of the study was to evaluate the cardiovascular risk factors associated with subclinical carotid atherosclerosis in antiretroviral therapy-naïve HIV-infected patients. The HERMES (HIV Exposure and Risk of Metabolic Syndrome) study enrolled therapy-naïve patients attending hospitals in the Italian coordination group for the study of allergies and HIV infection (CISAI [Coordinamento Italiano per lo Studio Allergia e Infezione da HIV]) in 2007. It was designed to identify metabolic syndrome (MS) and cardiovascular risk factors. The present analysis is a nested cross-sectional study with a subset of patients examined by carotid ultrasonography. Consecutive antiretroviral therapy-naïve HIV patients attending the facilities involved in the CISAI were included. Their 10-year probability of cardiovascular events was calculated using the Framingham Risk Score (FRS) and three other cardiovascular algorithms (the Global Framingham Risk Score - GFRS, 'Progetto Cuore' and 'SCORE'). Vascular age was estimated using a new model derived from GFRS and was compared with chronological age. The diagnosis of MS was based on the National Cholesterol Education Programme and International Diabetes Federation (IDF) definitions. Subclinical atherosclerosis was determined as ultrasound carotid intima-media thickness >0.9 mm. Out of 140 patients enrolled in the HERMES study by the four centres participating in the nested study, a total of 72 (51.4%) subjects, with no overt cardiovascular disease, were examined using carotid ultrasonography. The median age was 40 years, 79.2% men. The vascular age was 7.6 years higher than the chronological age. The factors associated with subclinical atherosclerosis were age (P < 0.0001), vascular age (P = 0.0002), body mass index (P = 0.003), waist circumference (P = 0.0002), MS (IDF definition, P = 0.004) and all the cardiovascular (CV) models (FRS, P = 0.01, GFRS, P = 0.002, Progetto Cuore, P = 0.018, SCORE, P = 0.03). Independent of other significant factors, waist circumference was significantly associated with pathological results (P = 0.007). The GFRS (area under the receiver-operating characteristic curves, 0.78; P < 0.001) had slightly better predictive accuracy than the other three CV models (FRS, areas under the curve [AUC] = 0.71, P = 0.003; Progetto Cuore, AUC = 0.74, P = 0.0005; SCORE, AUC = 0.77, P < 0.0001); 55% of patients at intermediate risk (6-20%) had subclinical carotid lesions. Subclinical carotid lesions had a highly significant direct association with all the CV risk predictors. The GFRS and vascular age were highly predictive. We recommend a carotid ultrasonographic examination at least among HIV patients with GFRS > or =6% or with an elevated waist circumference.


Assuntos
Aterosclerose/epidemiologia , Doenças das Artérias Carótidas/epidemiologia , Infecções por HIV/complicações , Adulto , Aterosclerose/diagnóstico por imagem , Aterosclerose/virologia , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/virologia , Estudos Transversais , Feminino , Humanos , Itália , Masculino , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/virologia , Pessoa de Meia-Idade , Curva ROC , Medição de Risco , Fatores de Risco , Túnica Íntima/diagnóstico por imagem , Túnica Média/diagnóstico por imagem , Ultrassonografia
8.
Reprod Toxicol ; 98: 82-91, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32916274

RESUMO

Bacterial infection alters placental ABC transporters expression. These transporters provide fetal protection against circulating xenobiotics and environmental toxins present in maternal blood. We hypothesized that lipopolysaccharide (LPS-bacterial mimic) alters the yolk sac morphology and expression of key ABC transporters in a gestational-age dependent manner. Yolk sac samples from C57BL/6 mice were obtained at gestational ages (GD) 15.5 and GD18.5, 4 or 24 h after LPS exposure (150ug/kg; n = 8/group). Samples underwent morphometrical, qPCR and immunohistochemistry analysis. The volumetric proportions of the histological components of the yolk sac did not change in response to LPS. LPS increased Abcg2 expression at GD15.5, after 4 h of treatment (p < 0.05). No changes in Abca1, Abcb1a/b, Abcg1, Glut1, Snat1, Il-1ß, Ccl2 and Mif were observed. Il-6 and Cxcl1 were undetectable in the yolk sac throughout pregnancy. Abca1, breast cancer resistance protein (Bcrp, encoded by Abcg2) and P-glycoprotein (P-gp/ Abcb1a/b) were localized in the endodermal (uterine-facing) epithelium and to a lesser extent in the mesothelium (amnion-facing), whereas Abca1 was also localized to the endothelium of the yolk sac blood vessels. LPS increased the labeling area and intensity of Bcrp in the yolk sac's mesothelial cells at GD15.5 (4 h), whereas at GD18.5, the area of Bcrp labeling in the mesothelium (4 and 24 h) was decreased (p < 0.05). Bacterial infection has the potential to change yolk sac barrier function by affecting Bcrp and Abcg2 expression in a gestational-age dependent-manner. These changes may alter fetal exposure to xenobiotics and toxic substances present in the maternal circulation and in the uterine cavity.


Assuntos
Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Lipopolissacarídeos/farmacologia , Saco Vitelino/efeitos dos fármacos , Animais , Feminino , Idade Gestacional , Camundongos Endogâmicos C57BL , Gravidez , Saco Vitelino/metabolismo
9.
Science ; 234(4781): 1256-8, 1986 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-17778007

RESUMO

Detritivorous fishes form an important part of the ichthyomass in the Amazon basin. Most of these fishes are contained in the orders Characiformes and Siluriformes (catfishes). The Characiformes constitute more than 30% of the total fish yield in the Amazon basin, whereas the catfishes are of minor importance. Stable isotope data indicate that Characiformes species receive most of their carbon through food chains originating with phytoplankton, while the Siluriformes receive a significant part of their energy from other plant sources.

10.
J Anim Ecol ; 78(4): 848-56, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19486381

RESUMO

1. Many natural populations exploiting a wide range of resources are actually composed of relatively specialized individuals. 2. This interindividual variation is thought to be a consequence of the invasion of 'empty' niches in depauperate communities, generally in temperate regions. If individual niches are constrained by functional trade-offs, the expansion of the population niche is only achieved by an increase in interindividual variation, consistent with the 'niche variation hypothesis'. 3. According to this hypothesis, we should not expect interindividual variation in species belonging to highly diverse, packed communities. 4. In the present study, we measured the degree of interindividual diet variation in four species of frogs of the highly diverse Brazilian Cerrado, using both gut contents and delta(13)C stable isotopes. 5. We found evidence of significant diet variation in the four species, indicating that this phenomenon is not restricted to depauperate communities in temperate regions. 6. The lack of correlations between the frogs' morphology and diet indicate that trade-offs do not depend on the morphological characters measured here and are probably not biomechanical. The nature of the trade-offs remains unknown, but are likely to be cognitive or physiological. 7. Finally, we found a positive correlation between the population niche width and the degree of diet variation, but a null model showed that this correlation can be generated by individuals sampling randomly from a common set of resources. Therefore, albeit consistent with, our results cannot be taken as evidence in favour of the niche variation hypothesis.


Assuntos
Anuros/fisiologia , Comportamento Alimentar/fisiologia , Animais , Brasil , Demografia , Dieta , Ecossistema , Feminino , Masculino
11.
J Cardiovasc Surg (Torino) ; 50(2): 205-12, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19329917

RESUMO

AIM: Outcomes after surgery for acute type A aortic dissection in the octogenarian are controversial. To analyze this issue further, the authors reviewed their experience in the hope of finding ways to improve results in these high-risk patients. METHODS: Between April 1990 and November 2006, 319 consecutive patients underwent emergency surgery for acute type A aortic dissection at the San Martino University Hospital of Genoa (Italy). Among them, 23 (7%) patients were aged 80 years or older (mean age 82 years, range 80 to 86 years) and represent the study population. On admission 7 patients (30%) had preoperative shock, 1 needed cardiopulmonary resuscitation, 7 (30%) had a neurological deficit, 2 (9%) had acute renal failure. Deep hypothermic circulatory arrest was performed in 19 patients (83%). Surgical procedures included isolated replacement of the ascending aorta in all patients associated with root replacement in 2 (9%) and total aortic arch replacement in 5 (22%). Median follow up was 4.1 years (range 3 to 83 months). RESULTS: Hospital mortality was 61% (14 of 23 patients). Late mortality was 11% (1 of 9 survivors). Stepwise logistic regression identified the extension of surgery to the arch as independent risk factors for hospital death. Fourteen patients (61%) had 1 or more postoperative complications. Overall survival was 39+/-10% and 33+/-10% after 1 and 5 years respectively. CONCLUSIONS: Surgery for acute type A aortic dissection in the octogenarian shows high hospital mortality but satisfactory long-term survival among discharged patients. A less aggressive approach should increase the outcomes of surgically managed patients.


Assuntos
Aneurisma Aórtico/cirurgia , Dissecção Aórtica/cirurgia , Implante de Prótese Vascular , Acessibilidade aos Serviços de Saúde , Serviços de Saúde para Idosos , Doença Aguda , Idoso de 80 Anos ou mais , Dissecção Aórtica/complicações , Dissecção Aórtica/mortalidade , Aneurisma Aórtico/complicações , Aneurisma Aórtico/mortalidade , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/mortalidade , Parada Circulatória Induzida por Hipotermia Profunda , Feminino , Mortalidade Hospitalar , Humanos , Itália/epidemiologia , Estimativa de Kaplan-Meier , Modelos Logísticos , Masculino , Reoperação , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
12.
Rev Sci Instrum ; 89(10): 10I134, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30399979

RESUMO

A new compact gamma-ray spectrometer was developed in order to optimise the measurement of bremsstrahlung radiation emitted from runaway electrons in the MeV range. The detector is based on a cerium doped lutetium-yttrium oxyorthosilicate (LYSO:Ce) scintillator coupled to a silicon photomultiplier and is insensitive to magnetic fields. A dedicated electronic board was developed to optimise the signal readout as well as for online control of the device. The detector combines a dynamic range up to 10 MeV with moderate energy non-linearity, counting rate capabilities in excess of 1 MHz, and an energy resolution that extrapolates to a few % in the MeV range, thus meeting the requirements for its application to runaway electron studies by bremsstrahlung measurements in the gamma-ray energy range.

13.
Neurology ; 40(11): 1797-8, 1990 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2234440

RESUMO

We report the lst case of neuroleptic malignant syndrome occurring in a patient receiving desipramine, a tricyclic antidepressant, with no exposure to neuroleptics. Our case suggests that this syndrome may be caused by a central imbalance between norepinephrine and dopamine, and not by dopamine depletion alone.


Assuntos
Desipramina/efeitos adversos , Síndrome Maligna Neuroléptica/etiologia , Bromocriptina/uso terapêutico , Dantroleno/uso terapêutico , Dopamina/metabolismo , Quimioterapia Combinada , Feminino , Humanos , Pessoa de Meia-Idade , Síndrome Maligna Neuroléptica/tratamento farmacológico , Síndrome Maligna Neuroléptica/metabolismo , Norepinefrina/metabolismo
14.
Transplantation ; 61(3): 418-27, 1996 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-8610354

RESUMO

The present study aimed to investigate the relationship between acute rejection and human cytomegalovirus (HCMV) infection, as well as the coexpression of HLA-DR and immediate-early (IE) viral antigens, in 143 transbronchial biopsies and bronchoalveolar lavage fluids of 32 lung transplant recipients. We investigated the occurrence of morphologically overt viral infection with conventional histopathology, the expression of IE antigens with single labeling immunohistochemistry, the coexpression of IE antigens and HLA-DR molecules with double labeling techniques, and the presence of viral IE genes with polymerase chain reaction. Histopathologic study showed overt viral infections (12.6%) in 18 of the 143 biopsies; 8 were in a context of pneumonia and 10 were localizations without surrounding inflammatory cells; immunohistochemistry showed IE viral antigen expression in 31 (21.67%); PCR detected viral IE genes in 73/143 lavage fluids and biopsies (51%). The double labeling immunohistochemical technique showed that most IE antigen-expressing, noncytopathic cells were either HLA-DR negative in areas without infiltrates, or HLA-DR positive in those areas where inflammatory infiltrates were consistent, in the absence of viral cytopathy, with acute rejection. The results indicate that, in transplanted lung, the frequency of morphologically occult HCMV infection (as detected by immunohistochemically and/or PCR) is much higher than that of morphologically overt viral infection. The occurrence of inflammatory infiltrates (consistent with acute rejection) around morphologically occult infected cells and the possible lack of inflammation around both early- and late-infected cells suggest that in biopsies with occult infection the infiltrates should be attributed to allograft reaction. This conclusion would be in keeping with the coexpression of HLA-DR and HCMV IE in infiltrate-rich biopsies that are consistent with acute rejection, as well as with the absence of HLA-DR expression in IE antigen-positive cells in infiltrate-free-areas.


Assuntos
Infecções por Citomegalovirus/etiologia , Rejeição de Enxerto/etiologia , Antígenos HLA-DR/metabolismo , Transplante de Pulmão/efeitos adversos , Transplante de Pulmão/imunologia , Pneumonia Viral/etiologia , Doença Aguda , Sequência de Bases , Estudos de Casos e Controles , Citomegalovirus/genética , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/diagnóstico , Efeito Citopatogênico Viral , Primers do DNA/genética , DNA Viral/genética , DNA Viral/isolamento & purificação , Rejeição de Enxerto/diagnóstico , Humanos , Proteínas Imediatamente Precoces/genética , Proteínas Imediatamente Precoces/isolamento & purificação , Imuno-Histoquímica , Dados de Sequência Molecular , Pneumonia Viral/diagnóstico , Reação em Cadeia da Polimerase
15.
Am J Cardiol ; 71(16): 1382-90, 1993 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-8517381

RESUMO

Low doses of acetylcholine induce "endothelium-dependent" dilatation in normal coronary arteries and constriction of diseased vessels. This study investigated morphologic changes induced by perfusion of normal and diseased coronary arteries with low and high doses of acetylcholine. Vessels were excised from a series of beating hearts explanted at transplantation for idiopathic dilated cardiomyopathy and coronary artery disease. Coronary arteries from other explanted hearts, perfused with saline solution under similar conditions were taken as controls. Samples were studied using conventional histopathologic and immunohistochemical methods. Coronary arteries were grouped according to presence or absence of histologically detectable structural modifications of any type and extent. Low doses of acetylcholine induced changes in all but 1 structurally diseased coronary artery, whereas no change was induced in any but 1 histologically normal coronary artery. High doses of acetylcholine induced contraction changes in both normal and diseased vessels. Changes observed in the wall of the contracted vessels were: (1) endothelial cell contraction with protruding nuclei and detachment of their intercellular junctions with exposure of subjacent collagen to flow, (2) contraction of plaque smooth muscle cells, (3) formation of cushions protruding into vessel lumens causing blunt microchannels. Contraction in both intimal and plaque cells occurred even in diseased vessel segments with intimal denudation. These effects seemed to be dose-dependent in structurally normal vessels because low doses of acetylcholine did not produce any morphologically detectable changes in histologically normal coronary arteries, while low doses of acetylcholine induced similar reactions in vessels affected by both atherosclerosis and subintimal fibrocellular thickening.


Assuntos
Acetilcolina/farmacologia , Cardiomiopatia Dilatada/patologia , Doença das Coronárias/patologia , Vasos Coronários/efeitos dos fármacos , Acetilcolina/administração & dosagem , Adolescente , Adulto , Cardiomiopatia Dilatada/fisiopatologia , Estudos de Casos e Controles , Doença das Coronárias/fisiopatologia , Vasos Coronários/anatomia & histologia , Vasos Coronários/patologia , Feminino , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade
16.
Am J Cardiol ; 72(7): 608-14, 1993 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-8103281

RESUMO

Proliferating cell nuclear antigen (PCNA) myocyte expression and histopathologic features related to its occurrence were investigated in normal and diseased hearts of adult humans using both immunohistochemical and Western blotting techniques. Ki67 Western blotting was also performed in the same samples used for PCNA blotting. Two hundred seventy-one endomyocardial biopsies, and 15 adult, 1 embryonic and 2 fetal hearts were studied. The biopsies were from normal donor hearts (n = 71), patients with cardiomyopathy and myocarditis (n = 64), and patients with transplantation with (n = 106) and without (n = 30) acute rejection of any grade. The 15 hearts were from 1 heart donor, and from patients with cardiomyopathy (n = 5), valvular heart disease (n = 2), ischemic heart disease (n = 4), amyloidosis (n = 1) and transplantation with acute rejection (n = 2). The PCNA labeling index was plotted against myocyte hypertrophy, inflammatory infiltrates and binucleation index. The PCNA labeling index ranged from 2 to 9% in embryonic and fetal hearts. PCNA was expressed by 1 to 2% of myocyte nuclei in 12% of normal heart biopsies, 1 to 5% of myocyte nuclei in 28% of cardiomyopathy and myocarditis biopsies, and by up to 8% of myocyte nuclei in 53% of biopsies of patients with transplantation, independently of the presence and degree of acute rejection. In the latter biopsies and in myocarditis, some inflammatory cells also showed PCNA expression. PCNA positive myocytes were both mono- and binucleated, and there was no correlation between binucleation and PCNA labeling indexes. Ki67 and PCNA blotting confirmed immunohistochemical results.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Cardiopatias/patologia , Miocárdio/citologia , Adulto , Autoantígenos/análise , Autoantígenos/metabolismo , Biópsia , Western Blotting , Divisão Celular , Núcleo Celular/química , Núcleo Celular/metabolismo , Endocárdio/patologia , Feminino , Coração/embriologia , Cardiopatias/metabolismo , Transplante de Coração/patologia , Transplante de Coração/fisiologia , Humanos , Imuno-Histoquímica , Antígeno Ki-67 , Masculino , Pessoa de Meia-Idade , Miocárdio/metabolismo , Proteínas de Neoplasias/análise , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/análise , Proteínas Nucleares/metabolismo , Antígeno Nuclear de Célula em Proliferação , Doadores de Tecidos
17.
Am J Cardiol ; 84(4): 459-61, A9, 1999 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-10468087

RESUMO

C-reactive protein was measured in 86 patients undergoing coronary artery bypass graft surgery. Patients were followed up for 3.2 years (range 1 to 6). Patients with C-reactive protein > or = 3 mg/L had significantly increased risk of recurrent ischemia at 1 to 6 years after intervention.


Assuntos
Angina Instável/sangue , Proteína C-Reativa/metabolismo , Ponte de Artéria Coronária , Idoso , Angina Instável/diagnóstico por imagem , Angina Instável/cirurgia , Biomarcadores/sangue , Angiografia Coronária , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Recidiva , Estudos Retrospectivos , Fatores de Risco
18.
Am J Cardiol ; 66(12): 973-80, 1990 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-2145740

RESUMO

Atrial natriuretic peptide (ANP) was immunohistochemically investigated in (1) right ventricular endomyocardial biopsy specimens from 87 apparently healthy donor hearts taken from victims of cerebral accidents; (2) 1 normal heart not suitable for transplantation (HBsAg carrier); (3) right ventricular endomyocardial biopsy specimens from 151 patients with dilated cardiomyopathy (DC); and (4) 57 explanted hearts, 26 with DC and 31 with ischemic heart disease. No ANP immunoreactivity was found in normal ventricles. Failing hearts showed ventricular positivity in 31% of the DC biopsy series, in 61% of the left ventricles, and in 30% of the right ventricles of the explanted heart series. An endoepicardial gradient was observed, because ANP positivity was greater and more extensive in the subendocardial layers. Ultrastructural studies were performed on biopsy specimens from 10 normal hearts and 132 DC biopsy samples. No ANP-storing granules were found in biopsy samples of normal ventricles, whereas ANP granules were seen in 15 of 132 (11.4%) DC cases. In parallel immunoblotting, investigation showed the same 13 kDa band protein in 1 normal atrium as well as in 8 failing atria and ventricles. ANP immunoreactivity was positively correlated with higher New York Heart Association functional classes as well as with higher left ventricular end-diastolic pressure (p less than 0.005), end-diastolic volume (p less than 0.005) and end-diastolic volume index (p less than 0.005). In conclusion, apparently healthy ventricles do not show ANP immunoreactivity, whereas failing ventricles do. ANP expression seems to be independent of the underlying disease, but positively related to the clinical status and the degree of left ventricular impairment and dilatation.


Assuntos
Fator Natriurético Atrial/biossíntese , Cardiomiopatia Dilatada/fisiopatologia , Insuficiência Cardíaca/fisiopatologia , Hemodinâmica/fisiologia , Miocárdio/metabolismo , Adulto , Cardiomiopatia Dilatada/metabolismo , Cardiomiopatia Dilatada/patologia , Feminino , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/patologia , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Valores de Referência
19.
Am J Cardiol ; 78(7): 795-800, 1996 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-8857485

RESUMO

We investigated at autopsy or at retransplantation the frequency and characteristics of coronary thrombosis in 76 cardiac allografts: 37 in place for < or = 2 months (early) and 39 in place >2 to 99 months (late). The 76 allografts were inserted in 69 patients: a single 1 in 56 patients and 2 allografts in 13 patients, 7 of whom subsequently died and had an autopsy. An average of 140 sections from 70 5-mm-long segments of 8 epicardial coronary arteries were examined from each of the 76 allografts with both hematoxylin-eosin and Movat pentachrome stains. Thrombus was found in only 1 coronary artery (3%) (the right one) of the 37 early allografts, and in 24 of 39 late allografts (61%). Of the latter 39 grafts, 29 (79%) had allograft vascular disease (AVD) and 24 (83%) of them had coronary thrombosis. Of the 312 epicardial coronary arteries (4 major and 4 minor) examined in the 39 late cases, 66 arteries (21%) contained thrombus. Of the 24 late cases with thrombus in at least 1 artery, thrombus was present in 66 (34%) of the 192 epicardial coronary arteries examined: in 6 of the 8 arteries in 3 patients; in 5 arteries in 2 patients; in 4 arteries in 1 patient; in 3 arteries in 5 patients; in 2 arteries in 6 patients, and in a single artery in 7 patients. In all 66 arteries with thrombus (24 patients) the thrombus was longer than 5 mm. The thrombus in the late cases was entirely nonocclusive (mural) in 51 (77%) of the 66 epicardial coronary arteries containing thrombus and entirely occlusive in 10 arteries (15%). It consisted exclusively of multiluminal channels in 6 arteries (9%) and combinations in 1 artery (2%). Acute myocardial infarcts were present in 3 patients, all of whom had occlusive thrombi. In all 10 arteries with occlusive thrombi, the thrombus was larger than the underlying plaque and no occlusive thrombi were located over ulcerated plaques. These observations demonstrate that thrombus is common in epicardial coronary arteries >2 months after cardiac transplantation.


Assuntos
Trombose Coronária/epidemiologia , Vasos Coronários/patologia , Transplante de Coração/efeitos adversos , Adolescente , Adulto , Idoso , Criança , Trombose Coronária/etiologia , Trombose Coronária/patologia , Feminino , Rejeição de Enxerto/patologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade
20.
Radiother Oncol ; 52(2): 185-90, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10577705

RESUMO

PURPOSE: This report proposes hypnosis as a valid alternative to general anaesthesia for immobilisation and set-up in certain cases in paediatric radiotherapy. METHODS: We report three cases of children who underwent radiotherapy in 1994 and were treated using hypnosis for set-up during irradiation. The first and the second were two cases of macroscopic resection of cerebellar medulloblastoma in which craniospinal irradiation was necessary, while the third patient suffered of an endorbitary relapse of retinoblastoma previously treated with bilateral enucleation, radiotherapy and chemotherapy; in this last situation the child needed radiation as palliative therapy. Hypnosis was used during treatment to obtain the indispensable immobility. Hypnotic conditioning was obtained by our expert psychotherapist while the induction during every single treatment was made by the clinician, whose voice was presented to the children during the conditioning. RESULTS: Every single fraction of the radiation therapy was delivered in hypnosis and without the need for narcosis. CONCLUSIONS: Hypnosis may be useful in particular situations to prepare paediatric cancer patients during irradiation, when lack of child collaboration might necessitate the use of general anaesthesia and when anaesthesia itself is not possible.


Assuntos
Hipnose Anestésica , Neoplasias/radioterapia , Anestesia Geral , Neoplasias Cerebelares/radioterapia , Pré-Escolar , Feminino , Humanos , Masculino , Meduloblastoma/radioterapia , Recidiva Local de Neoplasia/radioterapia , Neoplasias Orbitárias/radioterapia , Retinoblastoma/radioterapia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA