240 research outputs found

    Characterization of left and right atrial function in healthy volunteers by cardiovascular magnetic resonance.

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    BACKGROUND: Left and right atrial function show a different pattern in advanced age in order to maintain adequate ventricular filling. It has been shown that left atrial (LA) function has a prognostic value in a number of heart conditions. Cardiovascular magnetic resonance (CMR) provides high quality images of the left and right atria using high temporal resolution steady state free precession (SSFP) cine sequences. We used SSFP cines to characterize atrial function in healthy, normotensive, volunteers. METHODS: We measured maximum, preatrial contraction and minimum left and right atrial volumes in 120 healthy subjects after careful exclusion of cardiovascular abnormality (60 men, 60 women; 20 subjects per age decile from 20 to 80 years). Data were generated from 3-dimensional modeling, including tracking of the atrioventricular ring motion and time-volume curves analysis. With those measurements, all the usual parameters for left and right atrial function were calculated. RESULTS: Gender had significant influence on some parameters of left and right atrial conduit and booster pump function. Age significantly influenced the majority of parameters of both left and right atrial function, with typically lower reservoir and conduit functions and higher booster pump function, both in males and females belonging to older age groups. CMR normal ranges were modelled for clinical use with normalization, where appropriate, for body surface area and gender, displaying parameters with respect to age. CONCLUSIONS: CMR normal reference ranges for components of left and right atrial function are provided for males and females for a wide age range

    Prediction of the response of chronic hepatitis C to interferon alfa: a statistical analysis of pretreatment variables

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    Pretreatment variables that could predict the response of chronic hepatitis C to interferon alfa treatment have not been fully assessed. Eighteen baseline variables were evaluated in a series of 100 consecutive patients treated with a 12 month course of interferon alfa. For the purposes of this study, response was defined as the return to normal of aminotransferase activities before the third month of treatment. Seventy per cent of the patients responded to treatment. Six variables were associated with an increased likelihood of response assessed by univariate analysis. With stepwise multiple regression analysis assessment, however, only three variables remained independently predictive of response: low gamma glutamyltransferase (gamma GT) activities (p 0.66 mu kat/l (n = 45) (p = 0.048). Response was attained in 75% of non-obese patients (n = 80), compared with only 50% of obese patients (n = 20) (p = 0.03). Finally, 80% of patients without cirrhosis (n = 76) responded, while among those with cirrhosis (n = 24) the response rate was only 37% (p 40 years old, and with gamma GT activities >0.66 mu kat/l responded to interferon alfa (p<0.001). Those findings may be useful when evaluating interferon alfa trials and it is suggested that this treatment should be applied early in the course of chronic hepatitis C

    Disminución de la reserva de flujo coronario en pacientes con insuficiencia cardíaca no isquémica

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    Introduction and objectives. Coronary flow reserve (CFR) is impaired not only in ischemic heart disease, but also in cardiac diseases that may or may not course with heart failure. The aim of the present study was to determine if the severity of heart failure can influence CFR impairment. Methods. Forty patients with non-ischemic heart disease and heart failure were studied 41 times. Four groups were established: 1. 10 patients in functional class III-IV; 2. 10 patients in functional class II not taking beta-blockers; 3. 11 patients in class II treated with carvedilol, and 4. 10 patients in class I. These patients had a history of heart failure and systolic dysfunction. Myocardial blood flow (MBF) was measured with positron emission tomography (PET) and N-13 ammonia at rest (r) and during adenosine triphosphate (ATP) infusion. Results. MBF and CFR were significantly higher in group 4 (1.95 ± 0.58 and 2.40 ± 0.95 ml/min/g) than in group 1 (1.02 ± 0.52 and 1.46 ± 0.48 ml/min/g). CFR tended to be higher in groups 2 (1.73 ± 0.72), and 3 (1.89 ± 0.75) vs group 1. No significant correlation was found between CFR and the following variables: age, systolic blood pressure, ventricular mass index, ventricular volume indexes, and ejection fraction. Conclusions. Coronary microvascular function is impaired in non-ischemic heart failure, and the impairment is related to functional class, regardless of the underlying responsible heart disease

    High dietary folate in pregnant mice leads to pseudo-MTHFR deficiency and altered methyl metabolism, with embryonic growth delay and short-term memory impairment in offspring

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    Methylenetetrahydrofolate reductase (MTHFR) generates methyltetrahydrofolate for methylation reactions. Severe MTHFR deficiency results in homocystinuria and neurologic impairment. Mild MTHFR deficiency (677C > T polymorphism) increases risk for complex traits, including neuropsychiatric disorders. Although low dietary folate impacts brain development, recent concerns have focused on high folate intake following food fortification and increased vitamin use. Our goal was to determine whether high dietary folate during pregnancy affects brain development in murine offspring. Female mice were placed on control diet (CD) or folic acid-supplemented diet (FASD) throughout mating, pregnancy and lactation. Three-week-old male pups were evaluated for motor and cognitive function. Tissues from E17.5 embryos, pups and dams were collected for choline/methyl metabolite measurements, immunoblotting or gene expression of relevant enzymes. Brains were examined for morphology of hippocampus and cortex. Pups of FASD mothers displayed short-term memory impairment, decreased hippocampal size and decreased thickness of the dentate gyrus. MTHFR protein levels were reduced in FASD pup livers, with lower concentrations of phosphocholine and glycerophosphocholine in liver and hippocampus, respectively. FASD pup brains showed evidence of altered acetylcholine availability and Dnmt3a mRNA was reduced in cortex and hippocampus. E17.5 embryos and placentas from FASD dams were smaller. MTHFR protein and mRNA were reduced in embryonic liver, with lower concentrations of choline, betaine and phosphocholine. Embryonic brain displayed altered development of cortical layers. In summary, high folate intake during pregnancy leads to pseudo-MTHFR deficiency, disturbed choline/methyl metabolism, embryonic growth delay and memory impairment in offspring. These findings highlight the unintended negative consequences of supplemental folic acid

    The unconscious in social explanation

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    The proper range and content of the unconscious in the human sciences should be established by reference to its conceptual relationship to the folk psychology that informs the standard form of explanation therein. A study of this relationship shows that human scientists should appeal to the unconscious only when the language of the conscious fails them, that is typically when they find a conflict between people's self-understanding and their actions. This study also shows that human scientists should adopt a broader concept of the unconscious than the one developed by Freud, that is, one free from his ahistorical concept of the instincts and his ahistorical emphasis on the sexual experiences of childhood. The unconscious, understood in this way, has an ambiguous relationship to more recent linguistic and narrativist strands of psycho-analysis

    Neumatosis intestinal y gas portomesentérico: a propósito de un caso

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    La neumatosis intestinal (presencia de gas en el interior de la pared intestinal y en el complejo venoso portomesentérico) es una situación clínica poco frecuente que ha sido característicamente relacionada con la isquemia intestinal y con un desenlace fatal. Existen otras causas que pueden justifi car estos hallazgos y cuya repercusión para el paciente no es inevitablemente trágica. Los avances recientes en técnicas de imagen, sobre todo en tomografía computarizada multicorte (TCMC), permiten un diagnóstico preciso fi able y precoz de estos hallazgos. En este artículo, repasamos las manifestaciones radiológicas de la neumatosis intestinal en TC así como las distintas causas relacionadas con esta entidad, en relación con los hallazgos presentes en un paciente diagnosticado de carcinoma de esófago y en tratamiento quimioterápico. INGLÉS: Intestinal pneumatosis (presence of gas in the intestinal wall and in the portomeseteric veins) is an infrequent clinical situation that has been associated with extended bowel necrosis and fatal outcome. However, there are other reasons that can justify these findings without such an outcome. Recent advances in diagnostic imaging techniques, especially multislice computerized tomography (MSCT), have allowed precise and quick diagnosis of these entities. In this article, we review the MSCT radiological manifestations of intestinal pneumatosis, as well as the different diagnoses related with the findings observed in a patient diagnosed with esophageal carcinoma under chemotherapy treatment

    Early lung cancer detection using spiral computed tomography and positron emission tomography

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    RATIONALE: Lung cancer screening using computed tomography (CT) is effective in detecting lung cancer in early stages. Concerns regarding false-positive rates and unnecessary invasive procedures have been raised. OBJECTIVE: To study the efficiency of a lung cancer protocol using spiral CT and F-18-fluorodeoxyglucose positron emission tomography (FDG-PET). METHODS: High-risk individuals underwent screening with annual spiral CTs. Follow-up CTs were done for noncalcified nodules of 5 mm or greater, and FDG-PET was done for nodules 10 mm or larger or smaller (> 7 mm), growing nodules. RESULTS: A total of 911 individuals completed a baseline CT study and 424 had at least one annual follow-up study. Of the former, 14% had noncalcified nodules of 5 mm or larger, and 3.6% had nodules of 10 mm or larger. Eleven non-small cell lung cancers (NSCLC) and one small cell lung cancer (SCLC) were diagnosed in the baseline study (prevalence rate, 1.32%), and two NSCLCs in the annual study (incidence rate, 0.47%). All NSCLCs (92% of prevalence cancers) were diagnosed in stage I (12 stage IA, 1 stage IB). FDG-PET was helpful for the correct diagnosis in 19 of 25 indeterminate nodules. The sensitivity, specificity, positive predictive value, and negative predictive value of FDG-PET for the diagnosis of malignancy were 69, 91, 90, and 71%, respectively. However, the sensitivity and negative predictive value of the screening algorithm, which included a 3-month follow-up CT for nodules with a negative FDG-PET, was 100%. CONCLUSION: A protocol for early lung cancer detection using spiral CT and FDG-PET is useful and may minimize unnecessary invasive procedures for benign lesions

    Utilización de células madre en terapia regenerativa cardíaca

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    One of the most important challenges in modern medicine is the use of stem cells for the treatment of human disease such as diabetes, Parkinson ́s disease or isquemic cardiomyopathy. A number of problems need to be solved before stem cells can be applied clinically. In this paper we will review some concepts related to the potential of stem cells, focusing on adult stem cells as they have recently been described by the group of Catherine Verfaillie. We will also present our initial clinical results using adult stem cells for cardiac regenerative therapy. In the studies mentioned above, autologous muscle stem cells (satelite cells) were infused directly in the periphery of the scar tissue of the infarct. We describe the technique for ex vivo expansion and purification of muscle stem cells.La posibilidad de utilizar células madre en el tratamiento de diversas enfermedades humanas como la diabetes, la enfermedad de Parkinson, la cardiopatía isquémica constituye uno de los retos mas importantes de la medicina moderna. Sin embargo, antes de que los resultados de los estudios con células madre se traduzcan clínicamente existen múltiples problemas que deben ser resueltos. A continuación trataremos de exponer algunos conceptos relacionados con las células madre y su potencial, centrándonos principalmente en las células madre adultas tal como han sido recientemente descritas por el grupo de Catherine Verfaillie. Además presentaremos resultados de alguno de los primeros estudios clínicos realizados con células madre adultas como forma de terapia regenerativa cardíaca. En dichos tra- bajos se han empleado células madre de músculo (células satélite) autólogas en pacientes con infarto de miocardio, inyectándose direc- tamente dichas células en la periferia de la cicatriz secundaria al infarto

    Can serum hyaluronic acid replace simple non-invasive indexes to predict liver fibrosis in HIV/Hepatitis C coinfected patients?

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    <p>Abstract</p> <p>Background</p> <p>Hyaluronic acid (HA) serum levels correlate with the histological stages of liver fibrosis in hepatitis C virus (HCV) monoinfected patients, and HA alone has shown very good diagnostic accuracy as a non-invasive assessment of fibrosis and cirrhosis. The aim of this study was to evaluate serum HA levels as a simple non-invasive diagnostic test to predict hepatic fibrosis in HIV/HCV-coinfected patients and to compare its diagnostic performance with other previously published simple non-invasive indexes consisting of routine parameters (HGM-1, HGM-2, Forns, APRI, and FIB-4).</p> <p>Methods</p> <p>We carried out a cross-sectional study on 201 patients who all underwent liver biopsies and had not previously received interferon therapy. Liver fibrosis was determined via METAVIR score. The diagnostic accuracy of HA was assessed by area under the receiver operating characteristic curves (AUROCs).</p> <p>Results</p> <p>The distribution of liver fibrosis in our cohort was 58.2% with significant fibrosis (F≥2), 31.8% with advanced fibrosis (F≥3), and 11.4% with cirrhosis (F4). Values for the AUROC of HA levels corresponding to significant fibrosis (F≥2), advanced fibrosis (F≥3) and cirrhosis (F4) were 0.676, 0.772, and 0.863, respectively. The AUROC values for HA were similar to those for HGM-1, HGM-2, FIB-4, APRI, and Forns indexes. The best diagnostic accuracy of HA was found for the diagnosis of cirrhosis (F4): the value of HA at the low cut-off (1182 ng/mL) excluded cirrhosis (F4) with a negative predictive value of 99% and at the high cut-off (2400 ng/mL) confirmed cirrhosis (F4) with a positive predictive value of 55%. By utilizing these low and high cut-off points for cirrhosis, biopsies could have theoretically been avoided in 52.2% (111/201) of the patients.</p> <p>Conclusions</p> <p>The diagnostic accuracy of serum HA levels increases gradually with the hepatic fibrosis stage. However, HA is better than other simple non-invasive indexes using parameters easily available in routine clinical practice only for the diagnosing of cirrhosis.</p
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