776 research outputs found
Editorial - Emerging talents in alloimmunity and transplantation: 2022
In modern transplant and biomedicine, a proper understanding of both allo- and auto-immune processes is of key importance to minimize acute and chronic graft failure and consecutive rejection/pathology through both cellular and humoral effector mechanisms . .
Association between duration of delayed graft function, acute rejection and allograft outcome after deceased donor kidney transplantation
Prolonged duration of delayed graft function (DGF) may be associated with adverse allograft outcomes, but the association between threshold duration of DGF, acute rejection and long-term allograft loss remains undefined. We aimed to determine the impact of DGF duration on allograft outcomes and to assess whether this association was mediated by acute rejection.Using data from the Australian and New Zealand Dialysis and Transplant (ANZDATA) registry, Cox proportional modelling was used to determine the association between quartiles of DGF duration, acute rejection at 6 months and death-censored graft loss (DCGL). Mediation analysis was conducted to determine whether acute rejection was a causal intermediate between DGF and DCGL.Of 7668 deceased donor kidney transplants between 1997-2014, 1497 (19.5%) recipients experienced DGF requiring dialysis. The median (interquartile range) duration of DGF was 7(9) days, with 25% requiring dialysis for ≥14 days. Among recipients who had experienced DGF duration of 1-4 days, the adjusted HR for duration of 5-7, 8-13 and ≥14 days were 1.13 (95%CI 0.83-1.55;p=0.43), 1.44 (1.08-1.91;p=0.013), and 1.99 (1.50-2.65;
Association between plasma neutrophil gelatinase-associated lipocalin and cardiac disease hospitalizations and deaths in older women
Background Neutrophil gelatinase-associated lipocalin ( NGAL ) or lipocalin 2 may promote atherosclerosis and plaque instability leading to increased risk of cardiac events. We investigated the relationships between plasma NGAL , cardiovascular disease biomarkers, and long-term cardiac events. Methods and Results The study population consisted of 1131 ambulant older white women (mean age 75 years) without clinical coronary heart disease ( CHD ) and measures of plasma NGAL in the Perth Longitudinal Study of Ageing Women with 14.5-year CHD and heart failure hospitalizations or death (events) captured using linked records. Over 14.5 years, 256 women had CHD events, while 118 had heart failure events. Per SD increase in log-transformed NGAL there was a 35% to 37% increase in relative hazards for CHD and heart failure events in unadjusted analyses, which remained significant after adjustment for conventional risk factors for CHD events (hazard ratio 1.29, 95% CI 1.13-1.48, P0.05). Women in the highest 2 quartiles of NGAL had higher relative hazards for CHD events compared with women in the lowest quartile hazard ratio 1.61, 95% CI 1.08-2.39, P=0.019 and hazard ratio 1.97, 95% CI 1.33-3.93, P=0.001, respectively. These associations were independent of high-sensitivity cardiac troponin I, homocysteine, and estimated renal function. NGAL correctly reclassified 1 in 4 women who sustained a CHD event up in risk and 1 in 10 women without CHD events down in risk. Conclusions NGAL was associated with increased risk of long-term CHD events, independent of conventional risk factors and biomarkers. These findings provide mechanistic insight into the role of NGAL with cardiac events
Variables associated with successful vascular access cannulation in hemodialysis patients: A prospective cohort study
BACKGROUND: Successful vascular access (VA) cannulation is integral to the delivery of adequate dialysis, highlighting the importance of ensuring the viability of arteriovenous access in hemodialysis (HD) patients. Missed VA cannulation can lead to infection, infiltration, hematoma or aneurysm formation resulting in the need for access revision, central venous catheter (CVC) placement, or permanent loss of VA. Cannulation-related complications can also negatively impact on a patient\u27s dialysis experience and quality of life. This study aimed to identify patient, VA and nurse factors associated with unsuccessful VA cannulations.
METHODS: A prospective cohort study was conducted in HD patients with a permanent VA from three HD units. Data on patient, VA and nurse characteristics, plus, cannulation technique were collected for each episode of cannulation. General Estimating Equation was used to fit a repeated measures logistic regression to determine the odds of cannulation success.
RESULTS: We collected data on 1946 episodes of cannulation (83.9% fistula) in 149 patients by 63 nurses. Cannulation included use of tourniquet (62.9%), ultrasound (4.1%) and was by rope ladder (73.8%) or area (24.7%) technique. The miscannulation rate was 4.4% (n = 85) with a third of patients (n = 47) having at least one episode of miscannulation. Extravasation (n = 17, 0.9%) and use of an existing CVC (n = 6, 0.6%) were rare. Multivariable characteristics of successful cannulation included fistula compared with graft [OR 4.38; 95%CI, 1.89-10.1]; older access [OR 1.68; 95%CI, 1.32-2.14]; absence of stent [OR 3.37; 95%CI, 1.39-8.19]; no ultrasound [OR 13.7; 95%CI, 6.52-28.6]; no tourniquet [OR 2.32; 95%CI, 1.15-4.66]; and lack of post graduate certificate in renal nursing [OR 2.27; 95%CI, 1.31-3.93].
CONCLUSION: This study demonstrated a low rate of miscannulation. Further research is required on ultrasound-guided cannulation. Identifying variables associated with successful cannulation may be used to develop a VA cannulation complexity instrument that could be utilised to match to the cannulation skill of a competency-assessed nurse, thereby minimising the risk of missed cannulation and trauma
The engine reformer: Syngas production in an engine for compact gas-to-liquids synthesis
Methane (CH[subscript 4]) reforming was carried out in an internal combustion engine (an “engine reformer”). We successfully produced syngas from the partial oxidation of natural gas in the cylinder of a diesel engine that was reconfigured to perform spark ignition. Performing the reaction in an engine cylinder allows some of the exothermicity to be captured as useful work. Intake conditions of 110 kPa and up to 480 °C allowed low cycle-to-cycle variability (COV[subscript nimep] 2.4, but < 1 mg/L below these equivalence ratios. These results demonstrate that the engine reformer could be a key component of a compact gas-to-liquids synthesis plant by highlighting the operating conditions under which high gas conversion, high H[subscript 2]-to-CO ratios close to 2.0, and low soot production are possible.United States. Advanced Research Projects Agency-Energy (Award DE-AR0000506)Research Triangle InitiativeMIT Energy InitiativeMassachusetts Institute of Technology. Tata Center for Technology and Desig
Apolipoprotein ɛ4 is associated with increased risk of fall- and fracture-related hospitalisation: the Perth Longitudinal Study of Ageing Women
Apolipoprotein ɛ4 (APOE ɛ4) may be a genetic risk factor for reduced bone mineral density (BMD) and muscle function, which could have implications for fall and fracture risk. We examined the association between APOE ɛ4 status and long-term fall- and fracture-related hospitalisation risk in older women. 1276 community-dwelling women from the Perth Longitudinal Study of Ageing Women (mean age ± SD = 75.2 ± 2.7 years) were included. At baseline, women underwent APOE genotyping and detailed phenotyping for covariates including prevalent falls and fractures, as well as health and lifestyle factors. The association between APOE ɛ4 with fall-, any fracture-, and hip fracture-related hospitalisations, obtained over 14.5 years from linked health records, were examined using multivariable-adjusted Cox-proportional hazard models. Over 14.5 years, 507 (39.7%) women experienced a fall-related hospitalisation, 360 (28.2%) women experienced a fracture-related hospitalisation, including 143 (11.2%) attributed to a hip fracture. In multivariable-adjusted models, compared to non-carriers, APOE ɛ4 carriers (n=297, 23.3%) had greater risk for a fall- (HR 1.48 95%CI 1.22-1.81), fracture- (HR 1.28, 95%CI 1.01-1.63) or hip fracture-related hospitalisation (HR 1.83 95%CI 1.29-2.61). The estimates remained similar when specific fall and fracture risk factors (fear of falling, plasma 25-hydroxyvitamin D, grip strength, timed-up-and-go, hip BMD, vitamin K status, prevalent diabetes, HbA1c, cholesterol, abbreviated mental test score) were added to the multivariable model. In conclusion, APOE ɛ4 is a potential risk factor for fall- and fracture-related hospitalisation in community-dwelling older women. Screening for APOE ɛ4 could provide clinicians an opportunity to direct higher risk individuals to appropriate intervention strategies
Serum Midkine, estimated glomerular filtration rate and chronic kidney disease-related events in elderly women: Perth Longitudinal Study of Aging Women
© 2020, The Author(s). Midkine (MDK), a heparin-binding growth factor cytokine, is involved in the pathogenesis of kidney diseases by augmenting leukocyte trafficking and activation. Animal models and small case control studies have implicated MDK as a pathological biomarker in chronic kidney diseases (CKD), however this is yet to be confirmed in prospective human studies. In a prospective study of 499 elderly, predominantly Caucasian women aged over 70 years the association between serum MDK collected in 1998, and renal function change and the risk of CKD-related hospitalisations and deaths at 5 and 14.5 years, respectively, was examined. Baseline serum MDK was not associated with 5-year change in estimated glomerular filtration rate using the CKD Epidemiology Collaboration creatinine and cystatin C equation (Standardised β = − 0.09, 95% confidence interval − 3.76–0.48, p = 0.129), 5-year rapid decline in renal function (odds ratio = 0.97, 95% confidence interval 0.46–2.02, p = 0.927) or the risk of 14.5-year CKD-related hospitalisations and deaths (hazard ratio = 1.27, 95% confidence interval.66–2.46, p = 0.470) before or after adjusting for major risk factors. In conclusion, in this cohort of elderly women with normal or mildly impaired renal function, serum MDK was not associated with renal function change or future CKD-related hospitalisations and deaths, suggesting that MDK may not be an early biomarker for progression of CKD
Abdominal aortic calcification on lateral spine images captured during bone density testing and late-life dementia risk in older women: A prospective cohort study
Background: Dementia after the age of 80 years (late-life) is increasingly common due to vascular and non-vascular risk factors. Identifying individuals at higher risk of late-life dementia remains a global priority. Methods: In prospective study of 958 ambulant community-dwelling older women ( ≥ 70 years), lateral spine images (LSI) captured in 1998 (baseline) from a bone density machine were used to assess abdominal aortic calcification (AAC). AAC was classified into established categories (low, moderate and extensive). Cardiovascular risk factors and apolipoprotein E (APOE) genotyping were evaluated. Incident 14.5-year late-life dementia was identified from linked hospital and mortality records. Findings: At baseline women were 75.0 ± 2.6 years, 44.7% had low AAC, 36.4% had moderate AAC and 18.9% had extensive AAC. Over 14.5- years, 150 (15.7 %) women had a late-life dementia hospitalisation (n = 132) and/or death (n = 58). Compared to those with low AAC, women with moderate and extensive AAC were more likely to suffer late-life dementia hospitalisations (9.3 %, 15.5 %, 18.3 %, respectively) and deaths (2.8 %, 8.3 %, 9.4 %, respectively). After adjustment for cardiovascular risk factors and APOE, women with moderate and extensive AAC had twice the relative hazards of late-life dementia (moderate, aHR 2.03 95 % CI 1.38 – 2.97; extensive, aHR 2.10 95 % CI 1.33 – 3.32), compared to women with low AAC. Interpretation: In community-dwelling older women, those with more advanced AAC had higher risk of late-life dementia, independent of cardiovascular risk factors and APOE genotype. Given the widespread use of bone density testing, simultaneously capturing AAC information may be a novel, non-invasive, scalable approach to identify older women at risk of late-life dementia
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