1,033 research outputs found

    Effects of intrauterine food restriction and long-term dietary supplementation with L-arginine on age-related changes in renal function and structure of rats

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    We have previously demonstrated that restricting intrauterine food by 50% in 3-mo-old rats produced lower nephron numbers and early-onset hypertension, the latter being normalized by L-arginine administration. in 18-mo-old rats, such restriction increased glomerulosclerosis. in this study, we expanded our investigation, evaluating functional, morphologic, and immunohistochemical parameters in intrauterine-food-restricted 18-mo-old rats, either receiving L-arginine (RA18) or not (R18). Age-matched, non-food-restricted controls were assigned to similar groups with L-arginine (CA18) and without (C18). After weaning, L-arginine was given daily for 17 mo. No functional or morphologic changes were observed in C IS rats. the R18 rats developed early-onset hypertension, which persisted throughout the observation period, as well its significant proteinuria from 12 mo on. in RA18 rats, L-arginine decreased both blood pressure levels and proteinuria, and glomerular diameter was si,significantly smaller than in R18 rats (115.63 +/- 2.2 versus 134.8 +/- 1.0 mu m, p < 0.05). However, in RA18 rats, glomerular filtration rate remained depressed. Although L-arginine prevented glomerulosclerosis (R18 = 14%, RA18 = 4%; p < 0.05), glomerular expression of fibronectin and desmin was still greater in RA18 rats than in controls. Our data show that, although L-arginine prevented hypertension and proteinuria, glomerular injury still occurred, suggesting that intrauterine food restriction may be one of the leading causes of impaired renal function in adult life.Universidade Federal de São Paulo, Dept Physiol, EPM, Dept Physiol, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, EPM, Dept Morphol,Embrol Div, BR-04023900 São Paulo, BrazilUniv São Paulo, Ribeirao Preto Sch Med, Dept Physiol & Biophys, Brookline, MA 02146 USAUniversidade Federal de São Paulo, Dept Physiol, EPM, Dept Physiol, BR-04023900 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, EPM, Dept Morphol,Embrol Div, BR-04023900 São Paulo, BrazilWeb of Scienc

    Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

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    The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

    ALS-associated VRK1 R321C mutation causes proteostatic imbalance and mitochondrial defects in iPSC-derived motor neurons

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    Vaccinia-related kinase 1 (VRK1) is a gene which has been implicated in the pathological process of a broad range of neurodevelopmental disorders as well as neuropathies, such as Amyotrophic Lateral Sclerosis (ALS). Here we report a family presenting ALS in an autosomal recessive mode of inheritance, segregating with a homozygous missense mutation located in VRK1 gene (p.R321C; Arg321Cys). Proteomic analyses from iPSC-derived motor neurons identified 720 proteins eligible for subsequent investigation, and our exploration of protein profiles revealed significant enrichments in pathways such as mTOR signaling, E2F, MYC targets, DNA repair response, cell proliferation and energetic metabolism. Functional studies further validated such alterations, showing that affected motor neurons presented decreased levels of global protein output, ER stress and downregulation of mTOR signaling. Mitochondrial alterations also pointed to decreased reserve capacity and increased non-mitochondrial oxygen consumption. Taken together, our results present the main pathological alterations associated with VRK1 mutation in ALS

    Biallelic UBE4A loss-of-function variants cause intellectual disability and global developmental delay

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    Purpose: To identify novel genes associated with intellectual disability (ID) in four unrelated families. Methods: Here, through exome sequencing and international collaboration, we report eight individuals from four unrelated families of diverse geographic origin with biallelic loss-of-function variants in UBE4A. Results: Eight evaluated individuals presented with syndromic intellectual disability and global developmental delay. Other clinical features included hypotonia, short stature, seizures, and behavior disorder. Characteristic features were appreciated in some individuals but not all; in some cases, features became more apparent with age. We demonstrated that UBE4A loss-of-function variants reduced RNA expression and protein levels in clinical samples. Mice generated to mimic patient-specific Ube4a loss-of-function variant exhibited muscular and neurological/behavioral abnormalities, some of which are suggestive of the clinical abnormalities seen in the affected individuals. Conclusion: These data indicate that biallelic loss-of-function variants in UBE4A cause a novel intellectual disability syndrome, suggesting that UBE4A enzyme activity is required for normal development and neurological function
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