648 research outputs found

    Estimating genetic and non-genetic components of variance for fasting glucose levels in pedigrees ascertained through non-insulin dependent diabetes

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    Fasting glucose levels measured on 337 individuals in 14 pedigrees ascertained through a proband with non-inuslin dependent diabetes were used to estimate genetic and non-genetic components of variance under a multifactorial model of inheritance. In this sample genetic factors were important in controlling variation in basal carbohydrate metabolism, as represented by age-adjusted log-fasting glucose. There was no evidence that arbitrary sib common environments or arbitrary parent common environments accounted for significant portions of the variability in fasting glucose in these data. An arbitrary environment shared by parent and offspring, however, had a marginally significant impact on the likelihood. Parameter estimates obtained from multifactorial models analysed in this manner are sensitive to extreme phenotypic values, however, and caution must be exerciese in estimating total genetic variation. While additive genetic factors did account for a significant proportion of the total variation in fasting glucose, a large proportion remained unexplained.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66167/1/j.1469-1809.1982.tb01586.x.pd

    The definition of chemical diabetes

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    The natural history of diabetes mellitus can be arbitrarily divided into four stages based on the presence or absence of abnormal carbohydrate metabolism. Overt diabetes is the most advanced stage, characterized by elevated fasting blood glucose concentration and classical symptoms. This stage is divided into ketotic and nonketotic forms. Preceding overt diabetes is the latent or chemical diabetic stage, with no symptoms of diabetes but demonstrable abnormality of oral or intravenous glucose tolerance. Subclinical diabetes is an earlier stage when glucose tolerance is abnormal only with stress, such as pregnancy or the administration of cortisone. The earliest stage, prediabetes, extends from conception until the first demonstrable abnormality in glucose tolerance. In groups of presumed prediabetic individuals, delayed and/or decreased plasma insulin response to glucose has been noted. Progression of the diabetes may not occur, may occur very slowly or very rapidly, and regression to an earlier stage of abnormality may also occur.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33955/1/0000225.pd

    Using stochastic acceleration to place experimental limits on the charge of antihydrogen

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    Assuming hydrogen is charge neutral, CPT invariance demands that antihydrogen also be charge neutral. Quantum anomaly cancellation also demands that antihydrogen be charge neutral. Standard techniques based on measurements of macroscopic quantities of atoms cannot be used to measure the charge of antihydrogen. In this paper, we describe how the application of randomly oscillating electric fields to a sample of trapped antihydrogen atoms, a form of stochastic acceleration, can be used to place experimental limits on this charge

    Treatment of chemical diabetes mellitus with sulfonylurea compounds

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    Abnormality in glucose tolerance appears to correlate with arteriosclerotic disease, even when the abnormality is quite mild. Though there is no evidence for prevention of these vascular problems by correction of the carbohydrate abnormality, it seems reasonable to attempt such a correction in an investigational setting. We have used sulfonylurea (tolbutamide, chlorpropamide) in children and young adults (9-35 yr) without obesity, who have chemical diabetes. No apparent effect on insulin output has been noted, even with normalization of glucose tolerance.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33962/1/0000232.pd

    Wave profile modification (optical guiding) induced by the free electron laser interaction

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    METABOLIC STUDIES OF CHLORPROPAMIDE IN NORMAL MEN AND IN DIABETIC SUBJECTS

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72472/1/j.1749-6632.1959.tb39585.x.pd

    Production of antihydrogen at reduced magnetic field for anti-atom trapping

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    We have demonstrated production of antihydrogen in a 1,,T solenoidal magnetic field. This field strength is significantly smaller than that used in the first generation experiments ATHENA (3,,T) and ATRAP (5,,T). The motivation for using a smaller magnetic field is to facilitate trapping of antihydrogen atoms in a neutral atom trap surrounding the production region. We report the results of measurements with the ALPHA (Antihydrogen Laser PHysics Apparatus) device, which can capture and cool antiprotons at 3,,T, and then mix the antiprotons with positrons at 1,,T. We infer antihydrogen production from the time structure of antiproton annihilations during mixing, using mixing with heated positrons as the null experiment, as demonstrated in ATHENA. Implications for antihydrogen trapping are discussed

    Antihydrogen formation dynamics in a multipolar neutral anti-atom trap

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    Antihydrogen production in a neutral atom trap formed by an octupole-based magnetic field minimum is demonstrated using field-ionization of weakly bound anti-atoms. Using our unique annihilation imaging detector, we correlate antihydrogen detection by imaging and by field-ionization for the first time. We further establish how field-ionization causes radial redistribution of the antiprotons during antihydrogen formation and use this effect for the first simultaneous measurements of strongly and weakly bound antihydrogen atoms. Distinguishing between these provides critical information needed in the process of optimizing for trappable antihydrogen. These observations are of crucial importance to the ultimate goal of performing CPT tests involving antihydrogen, which likely depends upon trapping the anti-atom
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