590 research outputs found
Continued monitoring of acute kidney injury survivors might not be necessary in those regaining an estimated glomerular filtration rate > 60 mL/min at 1 year
Background. Severe acute kidney injury (AKI) among hospitalized patients often necessitates initiation of short-term dialysis. Little is known about the long-term outcome of those who recover to normal renal function. The aim of this study was to determine the long-term renal outcome of patients experiencing AKI requiring dialysis secondary to hypoperfusion injury and/or sepsis who recovered to apparently normal renal function.
Methods. All adult patients with AKI requiring dialysis in our centre between 1 January 1980 and 31 December 2010 were identified. We included patients who had estimated glomerular filtration rate (eGFR) >60 mL/min/1.73 m2 12 months or later after the episode of AKI. Patients were followed up until 3 March 2015. The primary outcome was time to chronic kidney disease (CKD) (defined as eGFR persistently <60 mL/min/1.73 m2) from first dialysis for AKI.
Results. Among 2922 patients with a single episode of dialysis-requiring AKI, 396 patients met the study inclusion criteria. The mean age was 49.8 (standard deviation 16.5) years and median follow-up was 7.9 [interquartile range (IQR) 4.8–12.7] years. Thirty-five (8.8%) of the patients ultimately developed CKD after a median of 5.3 (IQR 2.8–8.0) years from first dialysis for AKI giving an incidence rate of 1 per 100 person-years. Increasing age, diabetes and vascular disease were associated with higher risk of progression to CKD [adjusted hazard ratios (95% confidence interval): 1.06 (1.03, 1.09), 3.05 (1.41, 6.57) and 3.56 (1.80, 7.03), respectively].
Conclusions. Recovery from AKI necessitating in-hospital dialysis was associated with a very low risk of progression to CKD. Most of the patients who progressed to CKD had concurrent medical conditions meriting monitoring of renal function. Therefore, it seems unlikely that regular follow-up of renal function is beneficial in patients who recover to eGFR >60 mL/min/1.73 m2 by 12 months after an episode of AKI
Obstetric and long-term kidney outcomes in renal transplant recipients: a 40 year single-centre study
Female renal transplant recipients of childbearing age may ask what the outcomes are for pregnancy and whether pregnancy will affect graft function. We analyzed obstetric and transplant outcomes among renal transplant recipients in our center who have been pregnant between 1973 and 2013. A case−cohort study was performed identifying 83 pairs of pregnant and non-pregnant controls matched for sex, age, transplant vintage, and creatinine. There were 138 pregnancies reported from 89 renal transplant recipients. There were live births in 74% of pregnancies with high prevalence of prematurity (61%), low birth weight (52%), and pre-eclampsia (14%). Lower eGFR (OR 0.98; p = 0.05) and higher uPCR (OR 1.86; p = 0.02) at conception were independent predictors for poor composite obstetric outcome. Lower eGFR (OR 0.98; p = 0.04), higher uPCR (OR 1.50; p = 0.04), and live organ donation (OR 0.35; p = 0.02) were predictors of ≥20% loss of eGFR between immediately pre-pregnancy and one yr after delivery. There was no difference in eGFR at one, five, and 10 yr in pregnant women compared with non-pregnant controls and a pregnancy was not associated with poorer 10-yr transplant or 20-yr patient survival. Despite high rates of obstetric complications, most women had successful pregnancies with good long-term transplant function
Risk factors of ischemic stroke and subsequent outcome in hemodialysis patients
Background and purpose:
End stage renal disease (ESRD) requiring hemodialysis (HD) carries up to a 10-fold greater risk of stroke than normal renal function. Knowledge concerning risk factors and management strategies derived from the general population may not be applicable to those with ESRD. We studied a large ESRD population to identify risk factors and outcomes for stroke.
Methods:
All adult patients receiving HD for ESRD from 01/01/2007 to 31/12/2012 were extracted from the electronic patient record. Variables associated with stroke were identified by survival analysis; demographic, clinical, imaging and dialysis related variables were assessed and case-fatality determined. Follow-up was until 31/12/2013.
Results:
1382 patients were identified (mean age 60.5 years, 58.5% male). The prevalence of AF was 21.2% and 59.4% were incident HD patients. 160 (11.6%) experienced a stroke during 3471 patient-years of follow-up (95% ischemic). Stroke incidence was 41.5/1000 patient-years in prevalent and 50.1/1000 patient-years in incident HD patients. Factors associated with stroke on regression analysis were prior stroke, diabetes and age at starting renal replacement therapy. AF was not significantly associated with stroke and warfarin did not affect stroke risk in warfarin treated patients. Fatality was 18.8% at 7, 26.9% at 28 and 56.3% 365 days after stroke.<p></p>
Conclusions:
Incidence of stroke is high in patients with ESRD on HD with high case-fatality. Incident HD patients had the highest stroke incidence. Many, but not all, important risk factors commonly associated with stroke in the general population were not associated with stroke in patients receiving HD
Genetic Approach to Elucidate the Role of Cyclophilin D in Traumatic Brain Injury Pathology
Cyclophilin D (CypD) has been shown to play a critical role in mitochondrial permeability transition pore (mPTP) opening and the subsequent cell death cascade. Studies consistently demonstrate that mitochondrial dysfunction, including mitochondrial calcium overload and mPTP opening, is essential to the pathobiology of cell death after a traumatic brain injury (TBI). CypD inhibitors, such as cyclosporin A (CsA) or NIM811, administered following TBI, are neuroprotective and quell neurological deficits. However, some pharmacological inhibitors of CypD have multiple biological targets and, as such, do not directly implicate a role for CypD in arbitrating cell death after TBI. Here, we reviewed the current understanding of the role CypD plays in TBI pathobiology. Further, we directly assessed the role of CypD in mediating cell death following TBI by utilizing mice lacking the CypD encoding gene Ppif. Following controlled cortical impact (CCI), the genetic knockout of CypD protected acute mitochondrial bioenergetics at 6 h post-injury and reduced subacute cortical tissue and hippocampal cell loss at 18 d post-injury. The administration of CsA following experimental TBI in Ppif-/- mice improved cortical tissue sparing, highlighting the multiple cellular targets of CsA in the mitigation of TBI pathology. The loss of CypD appeared to desensitize the mitochondrial response to calcium burden induced by TBI; this maintenance of mitochondrial function underlies the observed neuroprotective effect of the CypD knockout. These studies highlight the importance of maintaining mitochondrial homeostasis after injury and validate CypD as a therapeutic target for TBI. Further, these results solidify the beneficial effects of CsA treatment following TBI
Correlates of depression in bipolar disorder
We analyse time series from 100 patients with bipolar disorder for correlates of depression symptoms. As the sampling interval is non-uniform, we quantify the extent of missing and irregular data using new measures of compliance and continuity. We find that uniformity of response is negatively correlated with the standard deviation of sleep ratings (ρ = -0.26, p = 0.01). To investigate the correlation structure of the time series themselves, we apply the Edelson-Krolik method for correlation estimation. We examine the correlation between depression symptoms for a subset of patients and find that self-reported measures of sleep and appetite/weight show a lower average correlation than other symptoms. Using surrogate time series as a reference dataset, we find no evidence that depression is correlated between patients, though we note a possible loss of information from sparse sampling
Improving die rework capability: Opportunities for using 3D non-contact measurement technology to reduce die tryout iterations to resolve dimensional issues
This report summarizes automotive body die tryout performance, based on a survey of and interviews with die manufacturing experts from automotive body manufacturers and die
suppliers, The report explores opportunities for more effectively integrating new 3D noncontact optical measurement technologies during the die tryout process to improve
performance. It provides basic guidelines for optical measurement data collection for
stamping dies and resultant parts as well as analysis methods.
For medium-complexity parts, the study participants estimate that a typical number of die tryout iterations is five to nine over a nine to 14 week period using typical North American tolerances and part acceptance criteria.
The key enablers to reduce die tryout time were advancements in die forming and
simulation software, particularly for complex materials, as well as advancements in virtual assembly tools.Center for Automotive Research, Ann Arbor, MINational Institute of Standards and Technology, Gaithersburg, MDhttp://deepblue.lib.umich.edu/bitstream/2027.42/61821/1/102174.pd
Integrating 3D non-contact measurement in the die tryout business process
Based on two surveys of manufacturers, this report summarizes several automotive body die tryout buyoff criteria, rework processes, and 3D non-contact measurement strategies. Relative to historical die tryout performance levels, a significant reduction in the number of iterations is clearly achievable through the following:
Improved ability to create die compensation models to create new machine files to rework parts closer to nominal without significant unintended consequences.
Changes to existing die and production source part approval processes to make better
decisions about when rework is needed to produce a dimensionally acceptable body.
Related to these improvements is the need for an effective business process integrating
3DNC measurement with new part approval processes to help manufacturers reduce the
number of die rework iterations. A cowl top case study demonstrates the application of this process in effective use of 3DNC measurement to reduce the number of tryout iterations to only one rework loop.Center for Automotive Research, Ann Arbor, MINational Institute of Standards and Technology, Gaithersburg, MDhttp://deepblue.lib.umich.edu/bitstream/2027.42/61820/3/102173.pd
The utility of anti-Müllerian hormone in women with chronic kidney disease, on haemodialysis and after kidney transplantation
Women with renal disease have menstrual and gonadal dysfunction manifesting as hormonal imbalance. Anti-Müllerian hormone (AMH) is a potential measure of ovarian reserve. We examined circulating AMH concentrations in young women with renal failure, determined associations with clinical characteristics, and compared AMH with age-matched healthy individuals. AMH was measured in 77 women: 26 had chronic kidney disease (CKD), 26 were on haemodialysis (HD), and 25 had a kidney transplant. Random AMH levels were highest in women on HD [HD 2.9 (1.1–5.2), CKD 1.6 (0.7–2.2), transplant 1.5 (1.0–4.2) ng/ml]. On multiple linear regression, AMH was 53% higher [95% CI 0.20–0.98, P = 0.002] in women on HD and decreased by 20% per 5-year increase in age (P < 0.001). AMH was 43% lower in women with renal failure compared with 600 age-matched controls [1.7 (0.9–3.8) versus 3.0 (1.9–5.0) ng/ml, P < 0.001]; however, we found no difference in AMH between those on HD and healthy individuals [2.9 (1.1–5.2) versus 3.0 (1.9–5.0) ng/ml]. AMH may be a useful biomarker in female renal patients with non-dialysis dependent renal disease pursuing pregnancy. In contrast, AMH levels are higher in HD but unlikely to reflect ovarian reserve
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