3,899 research outputs found

    Variation in the Thyrotropic Activity of Human Chorionic Gonadotropin in Chinese Hamster Ovary Cells Arises from Differential Expression of the Human Thyrotropin Receptor and Microheterogeneity of the Hormone.

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    The role of hCG as a stimulator of the human thyroid has been a subject of controversy, because discrepant results have been obtained in different in vitro assays. In an attempt to explain the variation observed in the thyroid response to hCG, we investigated the ability of hCG and that of its isoforms and glycosylation variants to inhibit [125I]bovine (b) TSH binding and stimulate adenylate cyclase in two clones, JP09 and JP26, of Chinese hamster ovary cells stably transfected with the human TSH receptor (hTSHr). The two clones differed with respect to the number of hTSHr expressed per cell (34,000 in JP09 and 2,000 in JP26 cells). Both responded extremely well to bTSH; the cAMP response to 0.001 IU/L bTSH was distinguishable from basal values. Interestingly, JP09 cells were readily stimulated by hCG (20-100 mg/L; 0.52-2.6 x 10(-6) mol/L) to release cAMP, whereas JP26 cells showed little if any response. Also, cAMP stimulation produced by asialo-hCG was 12-fold in JP09 cells and only 4-fold in JP26 cells compared to 45- and 67-fold stimulations by bTSH, respectively. Stimulation by asialo-hCG was approximately 30% that of bTSH in JP09 cells, but less than 6% in JP26 cells. When assessing the thyrotropic activity of the microheterogeneous isoforms of hCG, more alkaline pI forms were found to be more active than those of a more acidic pI regardless of whether they were derived from normal or molar pregnancy urine. Further studies with hCG, asialo-hCG, asialoagalacto-hCG, and deglycosylated hCG revealed that removal of sialic acid caused a marked increase in both its affinity for hTSHr and its cAMP-releasing potency, whereas removal of further carbohydrate, although it slightly enhanced receptor binding, was detrimental to adenylate cyclase activation. In conclusion, differences in hTSHr expression may cause a variation in the cAMP response to hCG or its glycosylation variants, as does the microheterogeneity of the hormone itself. These mechanisms may be responsible at least in part for the divergent responses of different cell types to hCG and render interpretation of the physiological meaning of the data obtained in recombinant receptor systems difficult

    J0811+4730: the most metal-poor star-forming dwarf galaxy known

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    We report the discovery of the most metal-poor dwarf star-forming galaxy (SFG) known to date, J0811+4730. This galaxy, at a redshift z=0.04444, has a Sloan Digital Sky Survey (SDSS) g-band absolute magnitude M_g = -15.41 mag. It was selected by inspecting the spectroscopic data base in the Data Release 13 (DR13) of the SDSS. LBT/MODS spectroscopic observations reveal its oxygen abundance to be 12 + log O/H = 6.98 +/- 0.02, the lowest ever observed for a SFG. J0811+4730 strongly deviates from the main-sequence defined by SFGs in the emission-line diagnostic diagrams and the metallicity - luminosity diagram. These differences are caused mainly by the extremely low oxygen abundance in J0811++4730, which is ~10 times lower than that in main-sequence SFGs with similar luminosities. By fitting the spectral energy distributions of the SDSS and LBT spectra, we derive a stellar mass of M* = 10^6.24 - 10^6.29 Msun (statistical uncertainties only), and we find that a considerable fraction of the galaxy stellar mass was formed during the most recent burst of star formation.Comment: 12 pages, 5 figures, accepted for publication in MNRA

    Improved quality of life in patients with refractory or recidivant ascites after insertion of transjugular intrahepatic portosystemic shunts

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    Background. We have recently shown that the transjugular intrahepatic portosystemic shunt (TIPS) is more effective than paracentesis in the treatment of cirrhotic patients with severe ascites and can prolong survival in selected patients. Although an improved quality of life (QOL) has been suggested in these patients after the TIPS procedure, so far there are no data available to substantiate this assumption. Therefore, the aim of this study was to determine the effect of TIPS on the QOL in cirrhotic patients with refractory or recidivant ascites. Methods: 21 cirrhotic patients who underwent TIPS for refractory or recidivant ascites were investigated. All patients were pretreated with repeated paracentesis for at least 1 year. Before the procedure and at 3 and 6 months during follow-up, the patients themselves rated QOL, fatigue and physical performance on a visual analogue scale (range 0-100). Furthermore, QOL was determined by the QOL index (range 0-10) according to Spitzer. Results: Patients' rating of the QOL on the visual analogue scale significantly increased from 35 +/- 25 (baseline) to 64 +/- 28 (3 months), and 66 +/- 24 (6 months; p = 0.02). Similarly, the QOL index significantly increased from 6.9 +/- 2.0 (baseline) to 8.3 +/- 2.1 (3 months), and 8.6 +/- 1.7 (6 months; p < 0.001). The increase of QOL was more pronounced in patients with complete response to TIPS. Conclusions: We demonstrate that TIPS for refractory or recidivant ascites improves the QOL in patients with cirrhosis. Our data indicates that this improvement is dependent on the response to therapy. Copyright (C) 2002 S. Karger AG, Basel

    Heterogeneous Catalysis under pressure - In-situ neutron diffraction under industrial conditions

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    The present work describes the application of a tubular reactor that allows in-situ neutron diffraction on working catalysts at high pressures. The designed reactor enables the application to a sample of industrially-relevant reaction conditions, i.e., in a temperature range up to 330° C and 60 bar pressure, coupled with online gas-analysis. Application of the cell is demonstrated by ammonia synthesis over a commercial catalyst with diffraction data obtained from the high-resolution powder diffractometer, Echidna, at the Australian Nuclear Science and Technology Organisation, ANSTO

    Effects of a Home-Based Exercise Program on Inflammatory Cytokines and Functional Capacity in Men with Prostate Cancer Under Active Surveillance

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    Regular exercise can improve physical fitness, functional performance, and quality of life in men with prostate cancer (PCa); however, few men with PCa meet national physical activity guidelines. Structured, home-based exercise programs may bridge this gap and increase physical activity in men with PCa. PURPOSE: This pilot study aimed to investigate the impact of a home-based exercise program on cytokines associated with tumor progression in men with PCa. METHODS: A single group, self-controlled study design was used. Fifteen men with PCa under active surveillance were recruited to complete 24 weeks of a home-based exercise program, combining aerobic and body-weight based exercises. The aerobic portion of the intervention included 5 days of light-to-moderate intensity walking for 30 minutes at 40-60% of the participant’s heart rate reserve as calculated using the Karvonen formula. Body-weight based exercises were performed 3 times per week consisting of 3 sets of 15 reps of bodyweight squats, inclined push-ups, and hip thrusts. Serum was collected at baseline and end of study to measure circulating eotaxin, interferon (IFN)γ, interleukin (IL)-12, IL-1a, IL-5, IL-6, tumor necrosis factor (TNF)-α, and vascular endothelial growth factor (VEGF) cytokines using an 8-protein multiplex (Millipore Sigma, Billerica, MA). A 6-minute walk test (MWT)was completed at the beginning and end of study to measure physical function. T-tests were performed with significance set to p \u3c0.05. RESULTS: A total of 15 men were consented with 9 men completing the intervention (40% attrition due to COVID). At baseline, participants were 70.11 ± 5.42 years of age, weighted 85.31 ± 6.41 kg with a body mass index of 27.77 ± 2.93 kg/m2. A non-significant tendency was observed for improved 6MWT distance (meters) (Pre: 382.7 ± 108.1; Post: 466.7 ± 73.78; p=0.08). Analysis of circulating cytokines showed tendencies for reduced circulating concentrations (pg/mL) of IFNγ (Pre: 152.9 ± 312.7; Post: 118.9 ± 258.8; p=0.08), and VEGF (Pre: 125.2 ± 198.7; Post: 80.29 ± 124.3; p=0.06) following the intervention. Several other biomarkers showed relevant, though not significant, decreases as well, including IL-12 (Pre: 28.69 ± 32.06; Post: 23.92 ± 19.38; -16.6%), IL-1a (Pre: 78.76 ± 183.3; Post: 65.55 ± 147.7; -16.8%), IL-6 (Pre: 23.71 ± 45.64; Post: 21.24 ± 45.18; -10.4%), and TNF-α (Pre: 24.58 ± 35.4; Post: 19.71 ± 20.76; -19.8%). CONCLUSION: Due to institutional COVID-19 protocols limiting in person research visits, six participants declined to continue the study. The small sample size likely accounts for the lack of statistically significant findings. Although the study did not yield statistically significant outcomes, the results of this study show promising indications that a home-based exercise program could be effective in reducing inflammatory cytokines and increasing functional capacity in men with PCa. Further investigation is needed to confirm these results with a powered sample

    Impact of a Home-Based Exercise Program on Cardiovascular Disease Biomarkers in Men with Prostate Cancer

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    Patients with prostate cancer (PCa) tend to live a sedentary lifestyle and fail to meet national physical activity requirements putting them at a greater risk for developing weight-related co-morbidities and cancer recurrence. Physical activity after cancer diagnosis is known to improve body composition, physical function, and overall quality of life. The inclusion of a home-based exercise regimen may increase their physical activity and reduce the risk of weight-related illness. PURPOSE: To gather preliminary data regarding the impact of a home-based exercise program on body composition and cardiovascular disease (CVD) biomarkers. METHODS: A single group self-controlled study design was used to test the hypothesis that a home-based exercise program can reduce CVD risk in men with PCa. Fifteen men with PCa under active surveillance were recruited to complete a 24-week home-based exercise program consisting of both aerobic and strength-based exercises. Each week, participants were asked to complete 5 days of light-to-moderate intensity walking at a heart rate reserve of 40-60% and 3 days of bodyweight-based exercises including 3 sets of 15 reps of squats, incline push-ups, and hip thrusts. Serum was collected at baseline and end of study to quantify circulating CVD biomarkers: a-2 macroglobulin (A2M), C-reactive protein (CRP), fetuin-A, a-1 acid glycoprotein (AGP), fibrinogen, L-selectin, serum amyloid P (SAP), platelet factor 4 (PF4/CXCL4), and adipsin using an 8-protein multiplex (Millipore Sigma, Billerica, MA). T-tests were performed with significance established at pRESULTS: A total of 15 men consented and 9 men saw the trial to completion (Age: 72.0 ± 8.52; Weight: 85.31 ± 6.41 kg; BMI: 27.77 ± 2.93 kg/m2). There was a 40% rate of attrition observed due to COVID-19. No significant changes occurred in average weights and BMI from pre to post trial visits. Though not significant, tendencies for increased concentrations of the anticoagulant, A2M (Pre: 99.83 ± 81.19 pg/mL; Post: 126.7 ± 102.5; p=0.064) and the inflammatory protein, SAP (Pre: 0.63 ± 0.32 pg/mL; Post: 0.86 ± 0.46; p=0.09) were seen. We also observed a 1.5-fold increase in CRP (Pre: 0.47 ± 0.38 pg/mL; Post: 1.19 ± 2.209) perhaps, as a result of an increase in SAP, or indicative of increased levels of stress due to COVID-19. No other significant differences were found. CONCLUSION: The reduced sample size may have contributed to the lack of significance found in the analysis. Although there were no statistically significant findings, the tendencies seen in A2M suggest that a home-based exercise program may protect against certain facets of CVD in this overweight population. However, our enthusiasm is blunted by the observed increases in SAP and CRP. Further investigation is necessary to validate these results

    OppvekstvilkĂĄr og rusavhengighet : hvilken betydning har oppvektsvilkĂĄr for utvikling av rusavhengighet?

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    Studentarbeid i sosialt arbeid (bachelorgrad) - Universitetet i Nordland, 201

    First normal stress difference and crystallization in a dense sheared granular fluid

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    The first normal stress difference (N1{\mathcal N}_1) and the microstructure in a dense sheared granular fluid of smooth inelastic hard-disks are probed using event-driven simulations. While the anisotropy in the second moment of fluctuation velocity, which is a Burnett-order effect, is known to be the progenitor of normal stress differences in {\it dilute} granular fluids, we show here that the collisional anisotropies are responsible for the normal stress behaviour in the {\it dense} limit. As in the elastic hard-sphere fluids, N1{\mathcal N}_1 remains {\it positive} (if the stress is defined in the {\it compressive} sense) for dilute and moderately dense flows, but becomes {\it negative} above a critical density, depending on the restitution coefficient. This sign-reversal of N1{\mathcal N}_1 occurs due to the {\it microstructural} reorganization of the particles, which can be correlated with a preferred value of the {\it average} collision angle θav=π/4±π/2\theta_{av}=\pi/4 \pm \pi/2 in the direction opposing the shear. We also report on the shear-induced {\it crystal}-formation, signalling the onset of fluid-solid coexistence in dense granular fluids. Different approaches to take into account the normal stress differences are discussed in the framework of the relaxation-type rheological models.Comment: 21 pages, 13 figure

    A diagnosis of prostate cancer and pursuit of active surveillance is not followed by weight loss: potential for a teachable moment

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    BACKGROUND: Obesity is a risk factor for incident prostate cancer (PC) as well as risk of disease progression and mortality. We hypothesized that men diagnosed with lower-risk PC and who elected active surveillance (AS) for their cancer management would likely initiate lifestyle changes that lead to weight loss. METHODS: Patients were enrolled in the Prostate Active Surveillance Study (PASS), a multicenter prospective biomarker discovery and validation study of men who have chosen AS for their PC. Data from 442 men diagnosed with PC within 1 year of study entry who completed a standard of care 12-month follow-up visit were analyzed. We examined the change in weight and body mass index (BMI) over the first year of study participation. RESULTS: After 1 year on AS, 7.5% (33/442) of patients had lost 5% or more of their on-study weight. The proportion of men who lost 5% or more weight was similar across categories of baseline BMI: normal/underweight (8%), overweight (6%) and obese (10%, χ2 test P=0.44). The results were similar for patients enrolled in the study 1 year or 6 months after diagnosis. By contrast, after 1 year, 7.7% (34/442) of patients had gained >5% of their weight. CONCLUSIONS: Only 7.5% of men with low-risk PC enrolled in AS lost a modest (⩾5%) amount of weight after diagnosis. Given that obesity is related to PC progression and mortality, targeted lifestyle interventions may be effective at this 'teachable moment', as men begin AS for low-risk PC

    Silencing alanine transaminase 2 in diabetic liver attenuates hyperglycemia by reducing gluconeogenesis from amino acids

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    Hepatic gluconeogenesis from amino acids contributes significantly to diabetic hyperglycemia, but the molecular mechanisms involved are incompletely understood. Alanine transaminases (ALT1 and ALT2) catalyze the interconversion of alanine and pyruvate, which is required for gluconeogenesis from alanine. We find that ALT2 is overexpressed in the liver of diet-induced obese and db/db mice and that the expression of the gene encoding ALT2 (GPT2) is downregulated following bariatric surgery in people with obesity. The increased hepatic expression of Gpt2 in db/db liver is mediated by activating transcription factor 4, an endoplasmic reticulum stress-activated transcription factor. Hepatocyte-specific knockout of Gpt2 attenuates incorporation o
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