242 research outputs found

    Hormone specific regulation of natural killer cells by cortisol Direct inactivation of the cytotoxic function of cloned human NK cells without an effect on cellular proliferation

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    AbstractCorticosteroids have previously been reported to partially inhibit the natural cytotoxic activity of peripheral blood lymphocytes. However, since only a few percent of peripheral lymphocytes are natural killer (NK) cells, it has not been possible to determine whether corticosteroids directly inhibit NK cells or mediate this effect via other cell types. This report documents direct functional inactivation, but unimpeded proliferation, of cloned human NK cells by subphysiologic levels of cortisol. In contrast, high concentrations of testosterone, progesterone or estradiol had no significant effect on proliferation or cytotoxic activity of the cloned NK cells. The kinetics of inhibition of NK function by cortisol are consistent with a transcription-dependent mechanism

    Short communication: relationship between body growth and mammary development in dairy heifers

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    Our objective was to determine if prepubertal rate of body weight (BW) gain, independent of diet, was related to mammary development of dairy heifers. Data from two studies recently conducted at Michigan State University were used to identify factors, within a dietary treatment group, that would account for variation in first lactation milk production or amount of mammary parenchymal DNA at the time of puberty. Factors analyzed for variation in milk production during first lactation were: postpartum BW, prepubertal BW gain, gestational BW gain, postpartum BW gain, body condition score (BCS) at breeding, and BCS at calving. Factors analyzed for variation in mammary parenchymal DNA at puberty were: BW at slaughter, age at puberty, prepubertal BW gain and body protein and body fat content at slaughter. For both analyses, prepubertal BW gain did not account for any of the variation in mammary development. The only significant covariate for the milk production model (r2 = 0.44) was BCS at breeding. Similarly, the only significant covariate in the parenchymal DNA model (r2 = 0.22) was body fat content at slaughter. These results suggest that, within a dietary treatment, heifers that grow faster do not have impaired mammary development, and increased body fatness may be a better predictor of impaired mammary development than BW gain

    Short communication: relationship between body growth and mammary development in dairy heifers

    Get PDF
    Our objective was to determine if prepubertal rate of body weight (BW) gain, independent of diet, was related to mammary development of dairy heifers. Data from two studies recently conducted at Michigan State University were used to identify factors, within a dietary treatment group, that would account for variation in first lactation milk production or amount of mammary parenchymal DNA at the time of puberty. Factors analyzed for variation in milk production during first lactation were: postpartum BW, prepubertal BW gain, gestational BW gain, postpartum BW gain, body condition score (BCS) at breeding, and BCS at calving. Factors analyzed for variation in mammary parenchymal DNA at puberty were: BW at slaughter, age at puberty, prepubertal BW gain and body protein and body fat content at slaughter. For both analyses, prepubertal BW gain did not account for any of the variation in mammary development. The only significant covariate for the milk production model (r2 = 0.44) was BCS at breeding. Similarly, the only significant covariate in the parenchymal DNA model (r2 = 0.22) was body fat content at slaughter. These results suggest that, within a dietary treatment, heifers that grow faster do not have impaired mammary development, and increased body fatness may be a better predictor of impaired mammary development than BW gain

    Does the load-sharing classification predict ligamentous injury, neurological injury, and the need for surgery in patients with thoracolumbar burst fractures?: Clinical article.

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    OBJECT: The load-sharing score (LSS) of vertebral body comminution is predictive of results after short-segment posterior instrumentation of thoracolumbar burst fractures. Some authors have posited that an LSS \u3e 6 is predictive of neurological injury, ligamentous injury, and the need for surgical intervention. However, the authors of the present study hypothesized that the LSS does not predict ligamentous or neurological injury. METHODS: The prospectively collected spinal cord injury database from a single institution was queried for thoracolumbar burst fractures. Study inclusion criteria were acute (\u3c 24 hours) burst fractures between T-10 and L-2 with preoperative CT and MRI. Flexion-distraction injuries and pathological fractures were excluded. Four experienced spine surgeons determined the LSS and posterior ligamentous complex (PLC) integrity. Neurological status was assessed from a review of the medical records. RESULTS: Forty-four patients were included in the study. There were 4 patients for whom all observers assigned an LSS \u3e 6, recommending operative treatment. Eleven patients had LSSs ≤ 6 across all observers, suggesting that nonoperative treatment would be appropriate. There was moderate interobserver agreement (0.43) for the overall LSS and fair agreement (0.24) for an LSS \u3e 6. Correlations between the LSS and the PLC score averaged 0.18 across all observers (range -0.02 to 0.34, p value range 0.02-0.89). Correlations between the LSS and the American Spinal Injury Association motor score averaged -0.12 across all observers (range -0.25 to -0.03, p value range 0.1-0.87). Correlations describing the relationship between an LSS \u3e 6 and the treating physician\u27s decision to operate averaged 0.17 across all observers (range 0.11-0.24, p value range 0.12-0.47). CONCLUSIONS: The LSS does not uniformly correlate with the PLC injury, neurological status, or empirical clinical decision making. The LSSs of only one observer correlated significantly with PLC injury. There were no significant correlations between the LSS as determined by any observer and neurological status or clinical decision making

    Coherent States of the SU(N) groups

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    Coherent states (CS)(CS) of the SU(N)SU(N) groups are constructed explicitly and their properties are investigated. They represent a nontrivial generalization of the spining CSCS of the SU(2)SU(2) group. The CSCS are parametrized by the points of the coset space, which is, in that particular case, the projective space CPN1CP^{N-1} and plays the role of the phase space of a corresponding classical mechanics. The CSCS possess of a minimum uncertainty, they minimize an invariant dispersion of the quadratic Casimir operator. The classical limit is ivestigated in terms of symbols of operators. The role of the Planck constant playes h=P1h=P^{-1}, where PP is the signature of the representation. The classical limit of the so called star commutator generates the Poisson bracket in the CPN1CP^{N-1} phase space. The logarithm of the modulus of the CSCS overlapping, being interpreted as a symmetric in the space, gives the Fubini-Study metric in CPN1CP^{N-1}. The CSCS constructed are useful for the quasi-classical analysis of the quantum equations of the SU(N)SU(N) gauge symmetric theories.Comment: 19pg, IFUSP/P-974 March/199

    Association of Accelerometry-Measured Physical Activity and Cardiovascular Events in Mobility-Limited Older Adults: The LIFE (Lifestyle Interventions and Independence for Elders) Study.

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    BACKGROUND:Data are sparse regarding the value of physical activity (PA) surveillance among older adults-particularly among those with mobility limitations. The objective of this study was to examine longitudinal associations between objectively measured daily PA and the incidence of cardiovascular events among older adults in the LIFE (Lifestyle Interventions and Independence for Elders) study. METHODS AND RESULTS:Cardiovascular events were adjudicated based on medical records review, and cardiovascular risk factors were controlled for in the analysis. Home-based activity data were collected by hip-worn accelerometers at baseline and at 6, 12, and 24 months postrandomization to either a physical activity or health education intervention. LIFE study participants (n=1590; age 78.9±5.2 [SD] years; 67.2% women) at baseline had an 11% lower incidence of experiencing a subsequent cardiovascular event per 500 steps taken per day based on activity data (hazard ratio, 0.89; 95% confidence interval, 0.84-0.96; P=0.001). At baseline, every 30 minutes spent performing activities ≥500 counts per minute (hazard ratio, 0.75; confidence interval, 0.65-0.89 [P=0.001]) were also associated with a lower incidence of cardiovascular events. Throughout follow-up (6, 12, and 24 months), both the number of steps per day (per 500 steps; hazard ratio, 0.90, confidence interval, 0.85-0.96 [P=0.001]) and duration of activity ≥500 counts per minute (per 30 minutes; hazard ratio, 0.76; confidence interval, 0.63-0.90 [P=0.002]) were significantly associated with lower cardiovascular event rates. CONCLUSIONS:Objective measurements of physical activity via accelerometry were associated with cardiovascular events among older adults with limited mobility (summary score >10 on the Short Physical Performance Battery) both using baseline and longitudinal data. CLINICAL TRIAL REGISTRATION:URL: http://www.clinicaltrials.gov. Unique identifier: NCT01072500

    Comparison of alternative risk adjustment measures for predictive modeling: high risk patient case finding using Taiwan's National Health Insurance claims

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    <p>Abstract</p> <p>Background</p> <p>Predictive modeling presents an opportunity to contain the expansion of medical expenditures by focusing on very few people. Evaluation of how risk adjustment models perform in predictive modeling in Taiwan or Asia has been rare. The aims of this study were to evaluate the performance of different risk adjustment models (the ACG risk adjustment system and prior expenditures) in predictive modeling, using Taiwan's National Health Insurance (NHI) claims data, and to compare characteristics of potentially high-expenditure subjects identified through different models.</p> <p>Methods</p> <p>A random sample of NHI enrollees continuously enrolled in 2002 and 2003 (n = 164,562) was selected. Health status measures and total expenditures derived from 2002 NHI claims data were used to predict the possibility of becoming 2003 top users. Statistics-based indicators (C-statistics, sensitivity, & Predictive Positive Value) and characteristics of identified top groups by different models (expenditures and prevalence of manageable diseases) were presented.</p> <p>Results</p> <p>Both diagnosis-based and prior expenditures models performed much better than the demographic model. Diagnosis-based models were better in identifying top users with manageable diseases; prior expenditures models were better in statistics-based indicators and identifying people with higher average expenditures. Prior expenditures status could correctly identify more actual top users than diagnosis-based or demographic models. The proportions of actual top users that could be identified by diagnosis-based models alone were much lower than that identified by prior expenditures status.</p> <p>Conclusions</p> <p>Predicted top users identified by different models have different characteristics and there is little agreement between modes regarding which groups would be potentially top users; therefore, which model to use should depend on the purpose of predictive modeling. Prior expenditures are a more powerful tool than diagnosis-based risk adjusters in terms of correctly identifying more actual high expenditures users. There is still much room left for improvement of diagnosis-based models in predictive modeling.</p

    Apelin Attenuates the Osteoblastic Differentiation of Vascular Smooth Muscle Cells

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    Vascular calcification, which results from a process osteoblastic differentiation of vascular smooth muscle cells (VSMCs), is a major risk factor for cardiovascular morbidity and mortality. Apelin is a recently discovered peptide that is the endogenous ligand for the orphan G-protein-coupled receptor, APJ. Several studies have identified the protective effects of apelin on the cardiovascular system. However, the effects and mechanisms of apelin on the osteoblastic differentiation of VSMCs have not been elucidated. Using a culture of calcifying vascular smooth muscle cells (CVMSCs) as a model for the study of vascular calcification, the relationship between apelin and the osteoblastic differentiation of VSMCs and the signal pathway involved were investigated. Alkaline phosphatase (ALP) activity and osteocalcin secretion were examined in CVSMCs. The involved signal pathway was studied using the extracellular signal-regulated kinase (ERK) inhibitor, PD98059, the phosphatidylinositol 3-kinase (PI3-K) inhibitor, LY294002, and APJ siRNA. The results showed that apelin inhibited ALP activity, osteocalcin secretion, and the formation of mineralized nodules. APJ protein was detected in CVSMCs, and apelin activated ERK and AKT (a downstream effector of PI3-K). Suppression of APJ with siRNA abolished the apelin-induced activation of ERK and Akt. Furthermore, inhibition of APJ expression, and the activation of ERK or PI3-K, reversed the effects of apelin on ALP activity. These results showed that apelin inhibited the osteoblastic differentiation of CVSMCs through the APJ/ERK and APJ/PI3-K/AKT signaling pathway. Apelin appears to play a protective role against arterial calcification
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