749 research outputs found

    High-protein-low-carbohydrate diet: deleterious metabolic and cardiovascular effects depend on age

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    High-protein-low-carbohydrate (HP-LC) diets have become widespread. Yet their deleterious consequences, especially on glucose metabolism and arteries, have already been underlined. Our previous study (2) has already shown glucose intolerance with major arterial dysfunction in very old mice subjected to an HP-LC diet. The hypothesis of this work was that this diet had an age-dependent deleterious metabolic and cardiovascular outcome. Two groups of mice, young and adult (3 and 6 mo old), were subjected for 12 wk to a standard or to an HP-LC diet. Glucose and lipid metabolism was studied. The cardiovascular system was explored from the functional stage with Doppler-echography to the molecular stage (arterial reactivity, mRNA, immunohistochemistry). Young mice did not exhibit any significant metabolic modification, whereas adult mice presented marked glucose intolerance associated with an increase in resistin and triglyceride levels. These metabolic disturbances were responsible for cardiovascular damages only in adult mice, with decreased aortic distensibility and left ventricle dysfunction. These seemed to be the consequence of arterial dysfunctions. Mesenteric arteries were the worst affected with a major oxidative stress, whereas aorta function seemed to be maintained with an appreciable role of cyclooxygenase-2 to preserve endothelial function. This study highlights for the first time the age-dependent deleterious effects of an HP-LC diet on metabolism, with glucose intolerance and lipid disorders and vascular (especially microvessels) and cardiac functions. This work shows that HP-LC lead to equivalent cardiovascular alterations, as observed in very old age, and underlines the danger of such diet

    Aggressive surgical management in localized pulmonary mycotic and nonmycotic infections for neutropenic patients with acute leukemia: Report of eighteen cases

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    AbstractObjective: To prevent hemoptysis and relapse during subsequent chemotherapy-induced neutropenia in patients with localized forms of invasive pulmonary aspergillosis, we adopted an aggressive surgical approach. Methods: From 1988 to 1996, 18 patients with hematologic diseases were referred with the diagnosis of localized invasive pulmonary aspergillosis. The diagnosis was based on clinical features, failure to respond to antibiotic therapy, an air crescent sign suggestive of aspergillosis on the computed tomographic scan (39%), and retrieval of fungi by bronchoalveolar lavage (44%). Results: The following procedures were done: one pneumonectomy, four bilobectomies, seven lobectomies, six wedge resections, and one lobectomy with wedge resection (one patient had two procedures). No perioperative deaths or complications occurred. The histologic examination confirmed the diagnosis of invasive pulmonary aspergillosis in 12 patients. The six other diagnoses were as follows: one case of classic aspergilloma, one case of pneumonia, and four cases of pulmonary abscess. According to univariate analysis, thoracic pain was less common in the group with noninvasive pulmonary aspergillosis (1/6) than in the group with invasive pulmonary aspergillosis (8/12) (p < 0.05). Sixteen patients required subsequent hematologic treatments. Sixty-six percent of the patients are alive with a mean follow-up of 29.1 ¹ 27.8 months (range 2 to 103 months), with no statistically significant difference between the invasive and the noninvasive pulmonary aspergillosis groups. Five patients died of a recurrence of their malignant disease at a mean of 17.2 ¹ 12.5 months (range 2 to 30 months), and one had a cerebral recurrence of Aspergillus infection during a bone marrow transplantation 3 months later. Conclusion: Aggressive surgical management radically improves the prognosis of invasive pulmonary aspergillosis, even if the surgical indications include some nonmycotic infections because of the difficulty in establishing the clinical diagnosis. (J Thorac Cardiovasc Surg 1997;115:63-9

    Resveratrol Decreases TXNIP mRNA and Protein Nuclear Expressions With an Arterial Function Improvement in Old Mice

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    Aging leads to a high prevalence of glucose intolerance and cardiovascular diseases, with oxidative stress playing a potential role. Resveratrol has shown promising effects on glucose tolerance and tends to improve endothelial function in elderly patients. Thioredoxin-interacting protein (TXNIP) was recently proposed as a potential link connecting glucose metabolism to oxidative stress. Here, we investigated the resveratrol-induced improvement of arterial aging phenotype in old mice and the expression of aortic TXNIP. Using an in vivo model of old mice with or without 3-month resveratrol treatment, we investigated the effects of resveratrol on age-related impairments from a cardiovascular Doppler analysis, to a molecular level, by studying inflammation and oxidative stress factors. We found a dual effect of resveratrol, with a decrease of age-related glucose intolerance and oxidative stress imbalance leading to reduced matrix remodeling that forestalls arterial aging phenotype in terms of intima-media thickness and arterial distensibility. These results provide the first evidence that aortic TXNIP mRNA and protein nuclear expressions are increased in the arterial aging and decreased by resveratrol treatment. In conclusion, we demonstrated that resveratrol helped to restore several aging impaired processes in old mice, with a decrease of aortic TXNIP mRNA and protein nuclear expression

    Strain mapping at the nanoscale using precession electron diffraction in transmission electron microscope with off axis camera

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    International audiencePrecession electron diffraction is an efficient technique to measure strain in nanostructures by precessing the electron beam, while maintaining a few nanometre probe size. Here, we show that an advanced diffraction pattern treatment allows reproducible and precise strain measurements to be obtained using a default 512 x 512 DigiSTAR off-axis camera both in advanced or non-corrected transmission electron microscopes. This treatment consists in both projective geometry correction of diffraction pattern distortions and strain Delaunay triangulation based analysis. Precision in the strain measurement is improved and reached 2.7 x 10(-4) with a probe size approaching 4.2 nm in diameter. This method is applied to the study of the strain state in InGaAs quantum-well (QW) devices elaborated on Si substrate. Results show that the GaAs/Si mismatch does not induce in-plane strain fluctuations in the InGaAs QW region. (C) 2014 AIP Publishing LLC

    Study of temperature dependent atomic correlations in MgB2_{2}

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    We have studied the evolution with temperature of the local as well as the average crystal structure of MgB2_2 using the real-space atomic pair distribution function (PDF) measured by high resolution neutron powder diffraction. We have investigated the correlations of the B-B and B-Mg nearest neighbor pair motion by comparing, in the wide temperature range from T=10 K up to T=600 K, the mean-square displacements (MSD) of single atoms with the mean-square relative displacements (MSRD) obtained from the PDF peak linewidths. The results show that the single atom B and Mg vibrations are mostly decoupled from each other, with a small predominance of positive (in phase) correlation factor for both the B-B and B-Mg pairs. The small positive correlation is almost temperature independent, in contrast with our theoretical calculations; this can be a direct consequence of the strong decay processes of the E2gE_{2g} anharmonic phonons

    Patterns of Sociodemographic and Clinicopathologic Characteristics of Stages II and III Colorectal Cancer Patients by Age: Examining Potential Mechanisms of Young-Onset Disease

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    Background and Aims. As a first step toward understanding the increasing incidence of colorectal cancer (CRC) in younger (age < 50) populations, we examined demographic, clinicopathologic, and socioeconomic characteristics and treatment receipt in a population-based sample of patients newly diagnosed with stages II and III CRC. Methods. Patients were sampled from the National Cancer Institute's Patterns of Care studies in 1990/91, 1995, 2000, 2005, and 2010 (n=6,862). Tumor characteristics and treatment data were obtained through medical record review and physician verification. We compared sociodemographic and clinicopathologic characteristics and treatment patterns of younger (age < 50) and older (age 50-69, age ≥ 70) CRC patients. Results. Younger patients were more likely to be black (13%) and Hispanic (15%) than patients aged 50-69 years (11% and 10%, resp.) and ≥70 years (7% each). A larger proportion of young white (41%) and Hispanic (33%) patients had rectal tumors, whereas tumors in the right colon were the most common in young black patients (39%). The majority of younger patients received chemotherapy and radiation therapy, although receipt of microsatellite instability testing was suboptimal (27%). Conclusion. Characteristics of patients diagnosed with young-onset CRC differ considerably by race/ethnicity, with a higher proportion of black and Hispanic patients diagnosed at the age of < 50 years

    RE: Colorectal Cancer Incidence Patterns in the United States, 1974–2013

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    In the latest issue of the Journal, Siegel et al. report that young adults born around 1990 (and so currently age 20 to 29 years) have double and quadruple the risk of colon and rectal cancer (CRC), respectively, compared with the same age group born in 1950. We believe presenting relative increases in incidence isolated from the absolute risk of CRC in younger adults can be misleading. Using relative or ratio measures to communicate risk of young-onset CRC may lead the casual reader or popular press to misinterpret the extent to which incidence is increasing

    Autism as a disorder of neural information processing: directions for research and targets for therapy

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    The broad variation in phenotypes and severities within autism spectrum disorders suggests the involvement of multiple predisposing factors, interacting in complex ways with normal developmental courses and gradients. Identification of these factors, and the common developmental path into which theyfeed, is hampered bythe large degrees of convergence from causal factors to altered brain development, and divergence from abnormal brain development into altered cognition and behaviour. Genetic, neurochemical, neuroimaging and behavioural findings on autism, as well as studies of normal development and of genetic syndromes that share symptoms with autism, offer hypotheses as to the nature of causal factors and their possible effects on the structure and dynamics of neural systems. Such alterations in neural properties may in turn perturb activity-dependent development, giving rise to a complex behavioural syndrome many steps removed from the root causes. Animal models based on genetic, neurochemical, neurophysiological, and behavioural manipulations offer the possibility of exploring these developmental processes in detail, as do human studies addressing endophenotypes beyond the diagnosis itself
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