1,527 research outputs found
Non-perturbative QEG Corrections to the Yang-Mills Beta Function
We discuss the non-perturbative renormalization group evolution of the gauge
coupling constant by using a truncated form of the functional flow equation for
the effective average action of the Yang-Mills-gravity system. Our result is
consistent with the conjecture that Quantum Einstein Gravity (QEG) is
asymptotically safe and has a vanishing gauge coupling constant at the
non-trivial fixed point.Comment: To appear in the proceedings of CORFU 200
Atrial fibrillation and left atrial size and function:a Mendelian randomization study
Atrial fibrillation (AF) patients have enlarged left atria (LA), but prior studies suggested enlarged atria as both cause and consequence of AF. The aim of this study is to investigate the causal association between AF and LA size and function. In the UK Biobank, all individuals with contoured cardiovascular magnetic resonance data were selected. LA maximal volume (LA max), LA minimal volume (LA min), LA stroke volume and LA ejection fraction were measured and indexed to body surface area (BSA). Two-sample Mendelian randomization analyses were performed using 84 of the known genetic variants associated with AF to assess the association with all LA size and function in individuals without prevalent AF. A total of 4274 individuals (mean age 62.0 ± 7.5 years, 53.2% women) were included. Mendelian randomization analyses estimated a causal effect between genetically determined AF and BSA-indexed LA max, LA min, and LA ejection fraction, but not between AF and LA stroke volume. Leave-one-out analyses showed that the causal associations were attenuated after exclusion of rs67249485, located near PITX2 gene. Our results suggest that AF causally increases LA size and decreases LA ejection fraction. The AF risk allele of rs67249485, located near the PITX2 gene, contributes strongly to these associations
Peroxiredoxin 4, a novel circulating biomarker for oxidative stress and the risk of incident cardiovascular disease and all-cause mortality
BACKGROUND: Oxidative stress has been suggested to play a key role in the development of cardiovascular disease (CVD). The aim of our study was to investigate the associations of serum peroxiredoxin 4 (Prx4), a hydrogen peroxide-degrading peroxidase, with incident CVD and all-cause mortality. We subsequently examined the incremental value of Prx4 for the risk prediction of CVD compared with the Framingham risk score (FRS). METHODS AND RESULTS: We performed Cox regression analyses in 8141 participants without history of CVD (aged 28 to 75 years; women 52.6%) from the Prevention of Renal and Vascular End-stage Disease (PREVEND) study in Groningen, The Netherlands. Serum Prx4 was measured by an immunoluminometric assay in baseline samples. Main outcomes were: (1) incident CVD events or CVD mortality and (2) all-cause mortality during a median follow-up of 10.5 years. In total, 708 participants (7.8%) developed CVD events or CVD mortality, and 517 participants (6.3%) died. Baseline serum Prx4 levels were significantly higher in participants with incident CVD events or CVD mortality and in those who died than in participants who remained free of outcomes (both P<0.001). In multivariable models with adjustment for Framingham risk factors, hazard ratios were 1.16 (95% CI 1.06 to 1.27, P<0.001) for incident CVD events or CVD mortality and 1.17 (95% CI 1.06 to 1.29, P=0.003) for all-cause mortality per doubling of Prx4 levels. After the addition of Prx4 to the FRS, the net reclassification improvement was 2.7% (P=0.01) using 10-year risk categories of CVD. CONCLUSIONS: Elevated serum Prx4 levels are associated with a significantly higher risk of incident CVD events or CVD mortality and all-cause mortality after adjustment for clinical risk factors. The addition of Prx4 to the FRS marginally improved risk prediction of future CVD
Development and first results of a dedicated chronic total occlusion programme
Objective To describe the development and first results of a dedicated chronic total occlusion (CTO) programme in a tertiary medical centre. Background Because of the complexity and the increased risk of complications during percutaneous coronary intervention (PCI) for CTO, it is essential that less experienced and evolving CTO centres perform regular quality analyses. Methods We therefore performed analyses to describe the results during the first 3 years of a dedicated CTO programme at a high-volume PCI centre. In addition, we discuss the strategies employed to develop such a programme. Results A total of 179 consecutive patients undergoing 187 CTO procedures were included in the study. The complexity of the CTO lesions increased from a mean J-CTO (Japanese Multicentre CTO Registry) score of 1.3 in 2015 to 2.1 in 2017. In the majority of cases, the antegrade wire escalation technique was performed. Final technical success rate was 78.5% in 175 patients with a single CTO and 80.2% of all 187 CTO procedures. No peri-procedural or in-hospital deaths occurred. One peri-procedural myocardial infarction occurred. Cardiac tamponade occurred in 2 cases, both managed by pericardiocentesis. No urgent cardiac surgery was necessary. Survival and revascularisation rates at 30 days and 1 year were excellent. Conclusion Following initiation of a dedicated CTO programme, using up-to-date techniques and strategies, procedural and clinical outcome were comparable with current standards in established centres
Sex differences in leukocyte profile in ST-elevation myocardial infarction patients
BACKGROUND: Whether sex differences exist in the inflammatory response after ST-elevation myocardial infarction (STEMI) remains to be elucidated. We studied leukocyte profiles and their prognostic value in men and women presenting with STEMI. METHODS: From a total of 552 consecutive STEMI patients, blood samples were collected at hospital admission. Linear regression was used to assess the relationship between leukocyte profiles and enzymatic infarct size. Cox regression was used to assess the association between leukocyte profiles and one-year mortality. RESULTS: Women presented with higher lymphocyte counts (2.3·109 cells/L (IQR 1.6-3.1) vs. 1.8·109 cells/L (IQR 1.4-2.5), p = 3.00 ∙ 10-4) and percentages (21.1% (IQR 14.4-28.1) vs. 17.1% (IQR 12.3-24.3), p = 0.004). Lymphocyte to monocyte ratio (LMR) was also higher in women (3.25 (IQR 2.56-4.5) vs. 2.68 (IQR 2.08-3.59), p = 7.28 ∙ 10-7). Higher LMR was associated with lower peak CK-MB (β = -0.27 (95% CI: -0.50, -0.03), p = 0.026), lower peak troponin T (β = -0.45 (95% CI: -0.77, -0.13), p = 0.006) and lower one-year mortality risk (HR 0.35 (95% CI: 0.13, 0.96), p = 0.042). CONCLUSION: At admission for STEMI, women present with higher lymphocyte count and LMR. Higher LMR is associated with smaller infarct size and decreased one-year mortality risk and could be used as a biomarker to predict outcome
Genetically Determined ABO Blood Group and its Associations With Health and Disease
Objective: To determine the spectrum of phenotypes linked to the ABO blood group system, using genetic determinants of the ABO blood group system. Approach and Results: We assessed the risk of 41 health and disease outcomes, and 36 linear traits associated with the ABO blood group system in the UK Biobank cohort. A total of 406 755 unrelated individuals were included in this study. Blood groups A, B, and O were determined based on allele combinations of previously established single-nucleotide polymorphisms rs8176746, rs8176719 in the ABO gene. Group AB was excluded because of its relative small sample size. Overall, 187 387 (46%) were male with a mean (SD) age of 57±8.1 years and a median total exposure of 64 person-years (interquartile range, 57-70). Of 406 755 individuals, 182 621 (44.9%) participants had blood group O, 182 786 (44.9%) had blood group A, and 41 348 (10.2%) had blood group B. ABO blood groups were associated with 11 health and disease outcomes (P<2.19×10-4). ABO blood groups were primarily associated with cardiovascular outcomes. Compared with individuals with blood group O, blood groups A and B were associated with increased odds of up to 1.56 (95% CI, 1.43-1.69) for thromboembolic events and decreased odds for hypertension (0.94 [95% CI, 0.92-0.97]). Conclusions: The ABO blood group system is associated with several parameters of healthy aging and disease development. Knowledge of ABO blood groups might be of interest for more personalized approaches towards health maintenance and the prevention of diseases
Intrathecal Morphine for Laparoscopic Segmental Colonic Resection as Part of an Enhanced Recovery Protocol: A Randomized Controlled Trial
Background and Objectives: Management of postoperative pain after laparoscopic segmental colonic resections remains controversial. We compared 2 methods of analgesia within an Enhanced Recovery After Surgery (ERAS) program. The goal of the study was to investigate whether admin
Low Hartmann’s procedure or intersphincteric proctectomy for distal rectal cancer: a retrospective comparative cohort study
Purpose: Two non-restorative options for low rectal cancer not invading the sphincter are the low Hartmann’s procedure (LH) or intersphincteric proctectomy (IP). The aim of this study was to compare postoperative morbidity with emphasis on pelvic abscesses after LH and IP. Methods: All patients that had LH or IP for low rectal cancer were included in three centres between 2008 and 2014 in this retrospective cohort study. Follow-up was performed for at least 12 months. Results: A total of 52 patients were included: 40 LH and 12 IP. Median follow-up was 29 months (IQR 23). There were no differences between groups in gender, age and ASA classification. Seven patients in the LH group (18%) and four patients in the IP group (33%) developed a complication within 30-day postoperative with a Clavien-Dindo classification grade III or higher (P = 0.253). Four out of 40 patients (10%) in the LH group and two out of 12 patients (17%) in the IP group developed a pelvic abscess (P = 0.612). Reinterventions were performed in 11 (28%) patients in the LH group and five (42%) patients in the IP group (P = 0.478), with a total number of reinterventions of 13 and 20, respectively. Six and 15 interventions were related to pelvic abscesses, respectively. Conclusion: Pelvic abscesses seem to occur in a similar rate after both LH and IP. Previous reports from the literature suggesting that IP might be associated with less infectious pelvic complications compared to LH are not supported by this study, although numbers are small
PROMISE:effect of protein supplementation on fat-free mass preservation after bariatric surgery, a randomized double-blind placebo-controlled trial
Introduction: Protein malnutrition after bariatric surgery is a severe complication and leads to significant morbidity. Previous studies have shown that protein intake and physical activity are the most important factors in the preservation of fat-free mass during weight loss. Low protein intake is very common in patients undergoing bariatric surgery despite dietary counseling. Protein powder supplements might help patients to achieve the protein intake recommendations after bariatric surgery and could therefore contribute to preserve fat-free mass. This double-blind randomized placebo-controlled intervention study aims to assess the effect of a daily consumed clear protein powder shake during the first 6 months after bariatric surgery on fat-free mass loss in the first 12 months after laparoscopic Roux-en-Y gastric bypass (LRYGB). Methods and analysis:Inclusion will take place at the outpatient clinic of the bariatric expertise center for obesity of the Maasstad Hospital. Patients will be randomly assigned to either the intervention or control group before surgery. The intervention group will receive a clear protein powder shake of 200 ml containing 20 g of whey protein dissolved in water which should be taken daily during the first 6 months after LRYGB on top of their normal postoperative diet. The control group will receive an isocaloric, clear, placebo shake containing maltodextrine. Postoperative rehabilitation and physiotherapeutical guidance will be standardized and similar in both groups. Also, both groups will receive the same dietary advice from specialized dieticians. The main study parameter is the percentage of fat-free mass loss 6 months after surgery, assessed by multi-frequency bioelectrical impedance analysis (MF-BIA). Ethics and dissemination: The protocol, version 2 (February 20, 2022) has been approved by the Medical Research Ethics Committees United (MEC-U) (NL 80414.100.22). The results of this study will be submitted to peer-reviewed journals. Trial registration: ClinicalTrials.gov NCT05570474. Registered on October 5, 2022.</p
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