The COBE DIRBE Point Source Catalog

We present the COBE DIRBE Point Source Catalog, an all-sky catalog containing infrared photometry in 10 bands from 1.25 microns to 240 microns for 11,788 of the brightest near and mid-infrared point sources in the sky. Since DIRBE had excellent temporal coverage (100 - 1900 independent measurements per object during the 10 month cryogenic mission), the Catalog also contains information about variability at each wavelength, including amplitudes of variation observed during the mission. Since the DIRBE spatial resolution is relatively poor (0.7 degrees), we have carefully investigated the question of confusion, and have flagged sources with infrared-bright companions within the DIRBE beam. In addition, we filtered the DIRBE light curves for data points affected by companions outside of the main DIRBE beam but within the `sky' portion of the scan. At high Galactic latitudes (|b| > 5 degrees), the Catalog contains essentially all of the unconfused sources with flux densities greater than 90, 60, 60, 50, 90, and 165 Jy at 1.25, 2.2, 3.5, 4.9, 12, and 25 microns, respectively, corresponding to magnitude limits of approximately 3.1, 2.6, 1.7, 1.3, -1.3, and -3.5. At longer wavelengths and in the Galactic Plane, the completeness is less certain because of the large DIRBE beam and possible contributions from extended emission. The Catalog also contains the names of the sources in other catalogs, their spectral types, variability types, and whether or not the sources are known OH/IR stars. We discuss a few remarkable objects in the Catalog. [abridged]Comment: Accepted for publication in the Astrophysical Journal Supplement. The full tables are available at http://www.etsu.edu/physics/bsmith/dirbe

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Modelling the Cost-Effectiveness of Implementing a Dietary Intervention in Renal Transplant Recipients

Background: The Dietary Approach to Stop Hypertension (DASH) and potassium supplementation have been shown to reduce the risk of death with a functioning graft (DWFG) and renal graft failure in renal transplant recipients (RTR). Unfortunately, a key problem for patients is the adherence to these diets. The aim of this study is to evaluate the cost-effectiveness and budget impact of higher adherence to either the DASH or potassium supplementation. Methods: A Markov model was used to simulate the life course of 1000 RTR in the Netherlands. A societal perspective with a lifetime time horizon was used. The potential effect of improvement of dietary adherence was modelled in different scenarios. The primary outcomes are the incremental cost-effectiveness ratio (ICER) and the budget impact. Results: In the base case, improved adherence to the DASH diet saved 27,934,786 and gained 1880 quality-adjusted life years (QALYs). Improved adherence to potassium supplementation saved euro1,217,803 and gained 2901 QALYs. Both resulted in dominant ICERs. The budget impact over a five-year period for the entire Dutch RTR population was euro8,144,693. Conclusion: Improving dietary adherence in RTR is likely to be cost-saving and highly likely to be cost-effective compared to the current standard of care in the Netherlands

Urinary Excretion of 6-Sulfatoxymelatonin, the Main Metabolite of Melatonin, and Mortality in Stable Outpatient Renal Transplant Recipients

Melatonin is a multifaceted hormone which rises upon the onset of darkness. Pineal synthesis of melatonin is known to be disturbed in patients with end-stage renal disease, but it is not known if its production is restored to normal after successful renal transplantation. We hypothesized that urinary excretion of 6-sulfatoxymelatonin, the major metabolite of melatonin, is lower in renal transplant recipients (RTRs) compared to healthy controls and that this is associated with excess mortality. Urinary 6-sulfatoxymelatonin was measured via LC-MS/MS in 701 stable outpatient RTRs and 285 healthy controls. Median urinary 6-sulfatoxymelatonin in RTR was 13.2 nmol/24 h, which was 47% lower than in healthy controls. Urinary 6-sufatoxymelatonin appeared undetectable in the majority of 36 RTRs with diabetic nephropathy as primary renal disease. Therefore, this subgroup was excluded from further analyses. Of the remaining 665 RTRs, during 5.4 years of follow-up, 110 RTRs died, of whom 38 died due to a cardiovascular cause. In Cox-regression analyses, urinary 6-sulfatoxymelatonin was significantly associated with all-cause mortality (0.60 (0.44–0.81), p = 0.001) and cardiovascular mortality (0.49 (0.29–0.84), p = 0.009), independent of conventional risk factors and kidney function parameters. Based on these results, evaluation and management of melatonin metabolism could be considered for improvement of long-term outcomes in RTRs

PREhabilitation of CAndidates for REnal Transplantation (PreCareTx) study:protocol for a hybrid type I, mixed method, randomised controlled trial

INTRODUCTION: Kidney transplant candidates (KTCs) need to be in optimal physical and psychological condition prior to surgery. However, KTCs often experience compromised functional capacity which can be characterised as frailty. Prehabilitation, the enhancement of a person's functional capacity, may be an effective intervention to improve the health status of KTCs. The PREhabilitation of CAndidates for REnal Transplantation (PreCareTx) study aims to examine the effectiveness of a multimodal prehabilitation programme on the health status of KTCs, and to explore the potential of implementation of prehabilitation in daily clinical practice.METHODS AND ANALYSIS: This study uses a single centre, effectiveness-implementation hybrid type I study design, comprised of a randomised controlled trial and a mixed-methods study. Adult patients who are currently on the transplant waiting list or are waitlisted during the study period, at a university medical centre in The Netherlands, will be randomly assigned to either prehabilitation (n=64) or care as usual (n=64) groups. The prehabilitation group will undergo a 12-week home-based, tailored prehabilitation programme consisting of physical and/or nutritional and/or psychosocial interventions depending on the participant's deficits. This programme will be followed by a 12-week maintenance programme in order to enhance the incorporation of the interventions into daily life. The primary endpoint of this study is a change in frailty status as a proxy for health status. Secondary endpoints include changes in physical fitness, nutritional status, psychological well-being, quality of life and clinical outcomes. Tertiary endpoints include the safety, feasibility and acceptability of the prehabilitation programme, and the barriers and facilitators for further implementation.ETHICS AND DISSEMINATION: Medical ethical approval was granted by the Medical Ethics Committee Groningen, Netherlands (M22.421). Written informed consent will be obtained from all participants. The results will be disseminated at international conferences and in peer-reviewed journals.TRIAL REGISTRATION NUMBER: ClinicalTrials.gov, NCT05489432.</p

Urinary Excretion of N1-Methylnicotinamide, as a Biomarker of Niacin Status, and Mortality in Renal Transplant Recipients

Renal transplant recipients (RTR) commonly suffer from vitamin B6 deficiency and its functional consequences add to an association with poor long-term outcome. It is unknown whether niacin status is affected in RTR and, if so, whether this affects clinical outcomes, as vitamin B6 is a cofactor in nicotinamide biosynthesis. We compared 24-h urinary excretion of N1-methylnicotinamide (N1-MN) as a biomarker of niacin status in RTR with that in healthy controls, in relation to dietary intake of tryptophan and niacin as well as vitamin B6 status, and investigated whether niacin status is associated with the risk of premature all-cause mortality in RTR. In a prospective cohort of 660 stable RTR with a median follow-up of 5.4 (4.7–6.1) years and 275 healthy kidney donors, 24-h urinary excretion of N1-MN was measured with liquid chromatography-tandem mass spectrometry LC-MS/MS. Dietary intake was assessed by food frequency questionnaires. Prospective associations of N1-MN excretion with mortality were investigated by Cox regression analyses. Median N1-MN excretion was 22.0 (15.8–31.8) μmol/day in RTR, compared to 41.1 (31.6–57.2) μmol/day in healthy kidney donors (p < 0.001). This difference was independent of dietary intake of tryptophan (1059 ± 271 and 1089 ± 308 mg/day; p = 0.19), niacin (17.9 ± 5.2 and 19.2 ± 6.2 mg/day; p < 0.001), plasma vitamin B6 (29.0 (17.5–49.5), and 42.0 (29.8–60.3) nmol/L; p < 0.001), respectively. N1-MN excretion was inversely associated with the risk of all-cause mortality in RTR (HR 0.57; 95% CI 0.45–0.71; p < 0.001), independent of potential confounders. RTR excrete less N1-MN in 24-h urine than healthy controls, and our data suggest that this difference cannot be attributed to lower dietary intake of tryptophan and niacin, nor vitamin B6 status. Importantly, lower 24-h urinary excretion of N1-MN is independently associated with a higher risk of premature all-cause mortality in RTR. View Full-Tex

Estimation of functional connectivity from electromagnetic signals and the amount of empirical data required

An increasing number of neuroimaging studies are concerned with the identification of interactions or statistical dependencies between brain areas. Dependencies between the activities of different brain regions can be quantified with functional connectivity measures such as the cross-correlation coefficient. An important factor limiting the accuracy of such measures is the amount of empirical data available. For event-related protocols, the amount of data also affects the temporal resolution of the analysis. We use analytical expressions to calculate the amount of empirical data needed to establish whether a certain level of dependency is significant when the time series are autocorrelated, as is the case for biological signals. These analytical results are then contrasted with estimates from simulations based on real data recorded with magnetoencephalography during a resting-state paradigm and during the presentation of visual stimuli. Results indicate that, for broadband signals, 50–100 s of data is required to detect a true underlying cross-correlations coefficient of 0.05. This corresponds to a resolution of a few hundred milliseconds for typical event-related recordings. The required time window increases for narrow band signals as frequency decreases. For instance, approximately 3 times as much data is necessary for signals in the alpha band. Important implications can be derived for the design and interpretation of experiments to characterize weak interactions, which are potentially important for brain processing

Urinary Excretion of N1-Methylnicotinamide and N1-Methyl-2-Pyridone-5-Carboxamide and Mortality in Kidney Transplant Recipients

It is unclear whether niacin nutritional status is a target for improvement of long-term outcome after renal transplantation. The 24-h urinary excretion of N1-methylnicotinamide (N1-MN), as a biomarker of niacin status, has previously been shown to be negatively associated with premature mortality in kidney transplant recipients (KTR). However, recent evidence implies higher enzymatic conversion of N1-MN to N1-methyl-2-pyridone-5-carboxamide (2Py) in KTR, therefore the need exists for interpretation of both N1-MN and 2Py excretion for niacin status assessment. We assessed niacin status by means of the 24-h urinary excretion of the sum of N1-MN and 2Py (N1-MN + 2Py), and its associations with risk of premature mortality in KTR. N1-MN + 2Py excretion was measured in a longitudinal cohort of 660 KTR with LS-MS/MS. Prospective associations of N1-MN + 2Py excretion were investigated with Cox regression analyses. Median N1-MN + 2Py excretion was 198.3 (155.9-269.4) µmol/day. During follow-up of 5.4 (4.7-6.1) years, 143 KTR died, of whom 40 due to an infectious disease. N1-MN + 2Py excretion was negatively associated with risk of all-cause mortality (HR 0.61; 95% CI 0.47-0.79; p < 0.001), and infectious mortality specifically (HR 0.47; 95% CI 0.29-0.75; p = 0.002), independent of potential confounders. Secondary analyses showed effect modification of hs-CRP on the negative prospective association of N1-MN + 2Py excretion, and sensitivity analyses showed negative and independent associations of N1-MN and 2Py excretion with risk of all-cause mortality separately. These findings add further evidence to niacin status as a target for nutritional strategies for improvement of long-term outcome in KTR.</p

Urinary Excretion of N1-methyl-2-pyridone-5-carboxamide and N1-methylnicotinamide in Renal Transplant Recipients and Donors

N1-methylnicotinamide (N1-MN) and N1-methyl-2-pyridone-5-carboxamide (2Py) are successive end products of NAD+ catabolism. N1-MN excretion in 24-h urine is the established biomarker of niacin nutritional status, and recently shown to be reduced in renal transplant recipients (RTR). However, it is unclear whether 2Py excretion is increased in this population, and, if so, whether a shift in excretion of N1-MN to 2Py can be attributed to kidney function. Hence, we assessed the 24-h urinary excretion of 2Py and N1-MN in RTR and kidney donors before and after kidney donation, and investigated associations of the urinary ratio of 2Py to N1-MN (2Py/N1-MN) with kidney function, and independent determinants of urinary 2Py/N1-MN in RTR. The urinary excretion of 2Py and N1-MN was measured in a cross-sectional cohort of 660 RTR and 275 healthy kidney donors with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Linear regression analyses were used to investigate associations and determinants of urinary 2Py/N1-MN. Median 2Py excretion was 178.1 (130.3–242.8) μmol/day in RTR, compared to 155.6 (119.6–217.6) μmol/day in kidney donors (p < 0.001). In kidney donors, urinary 2Py/N1-MN increased significantly after kidney donation (4.0 ± 1.4 to 5.2 ± 1.5, respectively; p < 0.001). Smoking, alcohol consumption, diabetes, high-density lipoprotein (HDL), high-sensitivity C-reactive protein (hs-CRP) and estimated glomerular filtration rate (eGFR) were identified as independent determinants of urinary 2Py/N1-MN in RTR. In conclusion, the 24-h urinary excretion of 2Py is higher in RTR than in kidney donors, and urinary 2Py/N1-MN increases after kidney donation. As our data furthermore reveal strong associations of urinary 2Py/N1-MN with kidney function, interpretation of both N1-MN and 2Py excretion may be recommended for assessment of niacin nutritional status in conditions of impaired kidney function. View Full-Tex