52 research outputs found
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Metabolism and gastrointestinal absorption of neptunium and protactinium in adult baboons
The metabolism of neptunium and protactinium was studied in adult female baboons following intravenous injection and intragastric intubation. Immediately following intravenous injection (10/sup -1/ to 10/sup -10/ mg Np per kg body wt), neptunium cleared rapidly from blood, deposited primarily in the skeleton (54 +- 5%) and liver (3 +- 0.2%), and was excreted predominantly via urine (40 +- 3%). For the first year post injection, neptunium was retained with a biological half-time of approx.100 days in liver and 1.5 +- 0.2 yr in bone. In comparison, injected protactinium (10/sup -9/ mg/kg) was retained in blood in higher concentrations and was initially eliminated in urine to a lesser extent (6 +- 3%). In vivo measurements indicated that protactinium was retained in bone (65 +- 0.3%) with a half-time of 3.5 +- 0.6 yr. Differences in the physicochemical states of the neptunium or protactinium solutions injected did not alter the metabolic behavior of these nuclides. The gastrointestinal absorption value for neptunium in two fasted baboons, sacrificed at 1 day post administration, was determined to be 0.92 +- 0.04%. Of the total amount of neptunium absorbed, 52 +- 3% was retained in bone, 6 +- 2% was in liver, and 42 +- 0.1% was excreted in urine. A method was developed to estimate GI absorption values for both nuclides in baboons which were not sacrificed. Absorption values calculated by this method for neptunium and protactinium in fasted baboons were 1.8 +- 0.8% and 0.65 +- 0.01%, respectively. Values for fed animals were 1 to 2 orders of magnitude less than those for fasted animals. 14 refs., 3 figs., 4 tabs. (DT
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Influence of chemical form, feeding regimen, and animal species on the gastrointestinal absorption of plutonium
We evaluated the effect of chemical form and feeding regimen on the gastrointestinal (GI) absorption of plutonium in adult mice at plutonium concentrations relevant to the establishment of drinking water standards. Mean fractional GI absorption values in fasted adult mice were: Pu(VI) bicarbonate, 15 x 10/sup -4/; Pu(IV) bicarbonate, 20 x 10/sup -4/; Pu(IV) nitrate (pH2), 17 x 10/sup -4/; Pu(IV) citrate, 24 x 10/sup -4/; and Pu(IV) polymer, 3 x 10/sup -4/. Values in fed adult mice were: Pu(VI) bicarbonate, 1.4 x 10/sup -4/; Pu(IV) polymer, 0.3 x 10/sup -4/. Pu(VI) is the oxidation state in chlorinated drinking waters and Pu(IV) is the oxidation state in many untreated natural waters. To assess the validity of extrapolating data from mice to humans, we also determined the GI absorption of Pu(VI) bicarbonate in adult baboons with a dual-isotope method that does not require animal sacrifice. Fractional GI absorption values obtained by this method were 23 +- 10 x 10/sup -4/ for fasted baboons (n=5) and 1.4 +- 0.9 x 10/sup -4/ for fed baboons (n=3). We have so far validated this method in one baboon and are currently completing validation in two additional animals. At low plutonium concentrations, plutonium oxidation state (Pu(VI) vs Pu(IV)) and administration medium (bicarbonate vs nitrate vs citrate) had little effect on the GI absorption of plutonium in mice. Formation of Pu(IV) polymers and animal feeding decreased the GI absorption of plutonium 5- to 10-fold. The GI absorption of Pu(VI) bicarbonate in both fed and fasted adult baboons appeared to be the same as in fed and fasted adult mice, respectively. 17 refs., 2 tabs
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Plutonium - its behavior in natural-water systems and assimilation by man
There are a number of factors which must be considered in establishing whether or not the inadvertent intrusion of a sizable amount of plutonium-bearing material into a natural-water system may have a significant impact on the health of those individuals who use that system as a drinking-water resource. These factors include the chemical form(s) and solubility of plutonium in natural waters, its behavior in relation to natural processes (geochemical and biological), its fate in water-treatment systems, and its uptake by man from drinking water. From the results obtained of the behavior in natural-water systems, it appears that (1) the chemical forms of plutonium dissolved in natural waters are Pu(IV) and Pu(V), (2) the soluble plutonium in many waters is bound to the organic constituents which probably enhance plutonium solubility, (3) the natural process responsible for the removal of plutonium from water is adsorption onto sediments, and (4) in water-treatment systems, soluble plutonium is oxidized to the VI state and this form is not removed. From investigations of gastrointestinal absorption, it appears that the value for f/sub 1/, the fraction transferred from the gut to blood, is greater than 1 x 10/sup -3/ and may be as high as 2 x 10/sup -1/
Proposed changes in personality and personality disorder assessment and diagnosis for DSM-5 part I: description and rationale
A major reconceptualization of personality psychopathology has been proposed for DSM-5 that identifies core impairments in personality functioning, pathological personality traits, and prominent pathological personality types. A comprehensive personality assessment consists of four components: levels of personality functioning, personality disorder types, pathological personality trait domains and facets, and general criteria for personality disorder. This four-part assessment focuses attention on identifying personality psychopathology with increasing degrees of specificity, based on a clinician’s available time, information, and expertise. In Part I of this two-part article, we describe the components of the new model and present brief theoretical and empirical rationales for each. In Part II, we will illustrate the clinical application of the model with vignettes of patients with varying degrees of personality psychopathology, to show how assessments might be conducted and diagnoses reached
Personality disorder types proposed for DSM-5
The Personality and Personality Disorders Work Group has proposed five specific personality disorder (PD) types for DSM-5, to be rated on a dimension of fit: antisocial/psychopathic, avoidant, borderline, obsessive-compulsive, and schizotypal. Each type is identified by core impairments in personality functioning, pathological personality traits, and common symptomatic behaviors. The other DSM-IV-TR PDs and the large residual category of personality disorder not otherwise specified (PDNOS) will be represented solely by the core impairments combined with specification by individuals’ unique sets of personality traits. This proposal has three main features: (1) a reduction in the number of specified types from 10 to 5; (2) description of the types in a narrative format that combines typical deficits in self and interpersonal functioning and particular configurations of traits and behaviors; and (3) a dimensional rating of the degree to which a patient matches each type. An explanation of these modifications in approach to diagnosing PD types and their justifications—including excessive co-morbidity among DSM-IV-TR PDs, limited validity for some existing types, lack of specificity in the definition of PD, instability of current PD criteria sets, and arbitrary diagnostic thresholds—are the subjects of this review
Proposed changes in personality and personality disorder assessment and diagnosis for DSM-5 part II: clinical application
The four-part assessment of personality psychopathology proposed for DSM-5 focuses attention on identifying personality psychopathology with increasing degrees of specificity, based on a clinician's available time, information, and expertise. In Part I of this two-part article, we described the components of the new model and presented brief rationales for them. In Part II, we illustrate the clinical application of the model with vignettes of patients with varying degrees of personality psychopathology, selected from the DSM-IV-TR Casebook, to show how assessments might be conducted and diagnoses reached
Proposed changes in personality and personality disorder assessment and diagnosis for DSM-5 part I: description and rationale
A major reconceptualization of personality psychopathology has been proposed for DSM-5 that identifies core impairments in personality functioning, pathological personality traits, and prominent pathological personality types. A comprehensive personality assessment consists of four components: levels of personality functioning, personality disorder types, pathological personality trait domains and facets, and general criteria for personality disorder. This four-part assessment focuses attention on identifying personality psychopathology with increasing degrees of specificity, based on a clinician’s available time, information, and expertise. In Part I of this two-part article, we describe the components of the new model and present brief theoretical and empirical rationales for each. In Part II, we will illustrate the clinical application of the model with vignettes of patients with varying degrees of personality psychopathology, to show how assessments might be conducted and diagnoses reached
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