Function Overtime Research Articles

#2145 Sexual dimorphism in kidney regenerative capacity decline and in progressive tubular cell polyploidization during aging

Abstract Background and Aims Aging is characterized by a progressive kidney function decline, resulting in chronic kidney disease (CKD), which is steeper in men than in women. However, sex-related differences in mechanisms underpinning CKD development during aging still remain to be clarified. In most organs regenerative capacity declines overtime from a pool of resident stem cells leading to tissue aging. In the kidney, we have revealed that two adaptive responses co-exist to recover kidney function after injury. On one hand a population of renal progenitors (RPC), which is interspersed among parietal epithelial cells of Bowman's capsule and tubular cells (TC) of nephron segments, proliferate and generate new podocytes and TC to recover structural integrity during the regenerative processes occurring in glomerular and tubular diseases. On the other, TC enter the alternative cell cycles to become polyploid in order to increase their functional capacity and maintain the residual kidney function after injury. However, a continuous TC polyploidization comes with the long term trade-offs (fibrosis and senescence), driving CKD. Here, we aimed to investigate the role of sexual dimorphism in these two different adaptive responses during aging. Method To trace RPC (Pax2+cells) we used the inducible Pax2/Confetti or Pax2/mTmG mice (RPC are randomly labelled by one of the four fluorescent reporter genes or with GFP respectively). To study polyploid TC, we used the inducible Pax8/FUCCI2aR mice (polyploid TC are identified by expression of cell cycle fluorescent proteins in combination with DNA content analysis). Mice were analyzed at 2, 5, 12 and 20 months of age. scRNA sequencing was performed at 2 and 20 months of age. Results Pax2/Confetti mice revealed that the number of Pax2+RPC either of the Bowman's capsule or in tubules was higher in female than in male mice at all ages. Specifically, tracing analysis during aging showed that in females Pax2+RPC of the Bowman's capsule generated new podocytes, resulting in glomeruli with a better integrity of the slit-diaphragm compared with aged males. Moreover, tubular Pax2+RPC in females clonally expanded, generating a higher number of clones, which were longer than those in males. scRNAseq analysis on kidneys showed that females were endowed with a greater number of Pax2+RPC with a higher expression of Pax2 than males, suggesting that RPC in females kept a higher regenerative capacity than males during aging. Simultaneously, analysis of tubular polyploidy demonstrated that, whereas in females the polyploid fraction progressively increased, it was drastically reduced in males during aging. These results suggested that whereas in females the increase of polyploid TC provided a better maintenance of kidney function overtime, loss of polyploid response in males made them more susceptible to develop CKD. Indeed, aged male mice showed a higher percentage of polyploid TC undergoing further cycles of polyploidization, which were associated with fibrosis and senescence. In agreement with these findings, we observed a progressive kidney function decline along with an increase of glomerulosclerosis, interstitial fibrosis and blood pressure, which were significantly greater in males than in females. Conclusion Female mice showed a higher regenerative and polyploid response compared to male mice, aimed likely to cope kidney function decline during aging. These results reveal the intriguing role of a new kidney adaptive response, which may explain the higher susceptibility of males to develop a more premature CKD during aging.

Abstract 79: Twelve-Year Trends in Ninety-Day Stroke Outcomes and Ethnic Differences From a Population-Based Study

Background: Stroke outcomes may be changing over time with improved acute stroke therapy, secondary prevention, and post-acute care. At the same time, stroke mortality has declined suggesting more people are living with stroke disability. No US population-based data exists on trends in outcomes. The objective was to investigate trends and ethnic differences in 90-day stroke outcomes in a population-based study. Methods: First-ever ischemic strokes in the population-based Brain Attack Surveillance in Corpus Christi Project (2009-2020, n=1,449) were included. 90-day outcomes included function (activities of daily living (ADL)/instrumental ADL), cognition (modified mini-mental state exam), NIHSS, and quality of life (Stroke-Specific Quality of Life (SS-QoL)). Linear regression with multiple imputation and inverse probability weighting was used to model adjusted associations between time, ethnicity, the interaction of time and ethnicity and outcomes. Results: Median age was 66; 61% Mexican American (MA). Trends in 90-day function overtime were roughly quadratic (Figure) and the change in the ethnic difference was significant among reference groups (p-value&lt0.01). Trends in NIHSS were linear with no change in the ethnic difference (p-value=0.51). Trends in cognition were approximately cubic and the change in the ethnic difference was significant within reference groups (p-value=0.03). Trends in QOL were stable with no change in the ethnic difference. Conclusion: Recent improvements in 90-day post-stroke functional and cognitive outcomes in MAs have resulted in reduced disparities. Factors contributing to favorable trends in outcomes in this group should be further studied.

Abstract P2176: Development Of Integrated Transparent Transgenic Zebrafish Modeling System For Experimental Cardio-oncology Therapeutics

The zebrafish model has provided an excellent platform to study the genetic and molecular approach of basic and translational cardiac research. Zebrafish heart cells are similar to human heart cells at the molecular level and determine the function of genes that control cardiac function and dysfunction. In zebrafish, myl7 is myosin light chain-7 gene and identified as a regulatory gene of heart orthologs to human MYL7. In vertebrates, including zebrafish, murine and human systems, the in-vivo spatial resolution is limited due to the normal opacification of skin and subdermal structures. For in-vivo imaging the skin transparency is primary requirement and to maintain the transparency, blocking the pigmentation needs to maintain. Chemical inhibition treatment is temporary and possible till the organism treated with the chemical inhibitor agent. Zebrafish casper mutant maintain transparency throughout the life and serve as ideal combination of sensitivity and resolution for in-vivo stem cell analyses and in-vivo imaging. To maintain the skin transparency, in this study, we have developed transparent transgenic zebrafish model and established of time lapse in-vivo confocal microscopy to study of cellular phenotype/pathologies of the cardiomyocytes to quantify changes in cardiomyocyte morphology and function overtime by comparing control and cardiac injury by generating casper/ myl7:RFP; annexin-5:YFP transgenic zebrafish. In the field of cardio-oncology, we are developing in-vivo transparent transgenic cellular phenotype model of zebrafish to study of the cell death process (Annexin5) and Inflammatory activity (NFkB) in the microglia, and the resident macrophage of the brain and cardiomyocytes) homozygous casper/ myl7:RFP; annexin-5:YFP/NF-kB:GFP/mpeg1:mcherryFP transgenic strain zebrafish. By using this novel model our lab establishing the role of NFkB and microglia function under normal healthy status and in glioblastomas Our strategist approach to yield crucial new insights into in-vivo cardiomyocyte imaging by confocal microscopy to observe and track the cell death pattern and cardio inflammatory pathways in cardiomyocyte and develop novel therapeutic approaches to treat cardio inflammatory pathology and glioblastoma

Effect of patisiran on stroke volume in hereditary transthyretin-mediated amyloidosis: insights from pressure-volume analysis of the APOLLO study.

Transthyretin-mediated (ATTR) amyloidosis is caused by deposition of transthyretin protein fibrils in the heart, nerves, and other organs. Patisiran, an RNA interference therapeutic that inhibits hepatic synthesis of transthyretin, was approved for the treatment of hereditary ATTR amyloidosis with polyneuropathy based on the phase 3 APOLLO study. We use left ventricular (LV) stroke volume (SV) to quantify LV function overtime and non-invasive pressure-volume techniques to delineate the effects of patisiran on LV mechanics in the pre-specified cardiac subpopulation of the APOLLO study. Left ventricular SV was assessed by transthoracic echocardiography at baseline, and after 9 and 18 months of therapy. To determine the mechanisms underlying changes in LV SV, non-invasive pressure-volume parameters, including the end-systolic and end-diastolic pressure-volume relationship, were derived using single beat techniques. At baseline, the mean SV was 51 ± 14ml. At 9months, the least-squares mean change in SV was -0.3 ± 1.2ml for patisiran and -5.4 ± 1.9ml for placebo (p= 0.021). At 18 months, the least-squares mean change in SV was -1.7 ± 1.3ml for patisiran and - 8.1 ± 2.3ml for placebo (p= 0.016). Decline in LV SV was driven by diminished LV capacitance in placebo relative to patisiran. Patisiran may delay progression of LV chamber dysfunction starting at 9months of therapy. These data elucidate the mechanisms by which transthyretin-reducing therapies modulate progression of cardiac disease and need to be confirmed in ongoing phase 3 trials.

Is Renal Function Equally Impacted By Hypomethylating Agents during Acute Myelogenous Leukemia Induction Therapy?

Background: Hypomethylating agents (HMA), such as azacitidine (AZA) /decitabine (DAC) plus BCL2 inhibitors are increasingly used as acute myelogenous leukemia (AML) therapy. However, side effects such as neutropenic fever, tumor lysis syndrome and acute kidney injury (AKI) are described. Although AKI induced by HMAs is infrequent, severity can result in permanent renal damage. Previous reports suggest that kidneys clear more than 50% of AZA with renal tubular acidosis and electrolytes abnormalities developing after drug exposure. To date, it is unknown whether concurrent comorbid conditions increase risk of AKI in AML patients. This study aimed to evaluate renal function overtime in patients receiving a HMAs plus venetoclax to determine each agent's ability to induce AKI. Methods: A single center retrospective, descriptive study from January 2018 to March 2022 was conducted at Baylor St. Luke's Medical Center. Patients with a confirmed diagnosis of AML, who received at least 1 cycle of venetoclax and a HMA, who were not eligible for intensive chemotherapy were included. Primary objective was incidence of AKI in AZA vs DAC during first week induction. Given potential additive impact of BCL2 inhibition on renal function, secondary objective was a subgroup analysis of patients in AZA group receiving venetoclax ≤ or >14 days. Descriptive and paired-t-test comparing baseline and daily sequential creatinine and glomerular filtration rate (GFR) were analyzed using SAS. Results: 40 AML patients were included. 25/40 (62.5%) and 15/40 (37.5%) received AZA and DAC. Baseline patient characteristics were well balanced between groups, except for differential absolute lymphocyte count (ALC) expression [3.4 K/uL vs 1.3 K/uL, in AZA treated vs DAC, p=0.01]. Patients receiving AZA developed significantly higher incidence of AKI from day 1 to day7. DAC was associated with transient significant AKI detectable only during day 5 (Fig 1A). At last follow up, incidence of irreversible renal failure was observed in 1/40 (2.5%) of AML patients. In further subgroup analysis, we sought to understand the possible nephrotoxic BCL2- inhibitor effect while combining with AZA. Patients exposed >14 days of BCL2- inhibitors developed sustained AKI throughout day 3 to day 7 [p=<0.05 for all time points], as compared to those receiving ≤14 days. No detectable differences on incidence of diabetes, heart failure, infections, and use of diuretics were found in patients exposed or not to 14 days of BCL-2 inhibitor. Conclusions: Our study demonstrates more severe and sustained worsening renal function in patients exposed to AZA than those receiving DAC. While our report recapitulates similar previous observations, we describe an important synergistic BCL-2 inhibitor effect on renal function when combined with AZA. It would be interesting to investigate whether higher than expected ALC cooperates to induce renal damage via enhanced T-cell immunity. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Novel mutation of IFT140 in an infant with Mainzer-Saldino syndrome presenting with retinal dystrophy

A seven-month-old girl presented with bilateral roving nystagmus, hyperopia, and retinal dystrophy, and was brought to our ophthalmology clinic. Visual-evoked potentials (VEPs) were non-recordable in both the eyes. No other systemic symptoms or abnormalities were observed. Whole exome sequencing (WES) identified a compound heterozygous mutation in the IFT140 gene: c.1990G > A (p. Glu664Lys) and c.2214_2217del (p.Asp738GlufsTer47). The genetic results support a diagnosis of Mainzer-Saldino syndrome (MSS). Importantly, c.2214_2217del is a novel mutation in the IFT140 gene. Although the patient presents with isolated retinal dystrophy, it is crucial to monitor renal function overtime. Taken together, our results reinforce the role of IFT140 in syndromic ciliopathies. This report also highlights the role of combined WES approaches in identifying underlying mutations in infants presenting with isolated retinal dystrophy, considering MSS may present differently over time.

Relationship between GDF-15, urinary sodium and markers of renal function in patients with chronic heart failure

Abstract Background Patients with heart failure (HF) often have altered renal function. Urinary sodium is a marker of diuretic resistance and is associated with a worse prognosis in HF. Growth differentiation factor-15 (GDF-15) is a marker of oxidative stress and inflammation and is a prognostic predictor in HF. Objectives We sought to assess the relationship of GDF-15 with renal function parameters and with urinary sodium in patients with chronic HF. Methods We undertook a cross-sectional study of patients with HF from specialized outpatient clinic. Patients with signs and symptoms of HF and LVEF &amp;lt;50% were included. An echocardiogram was performed and blood samples were collected, which were frozen for the final study, where the performance of GDF-15 in the prediction of renal outcomes in HF will be evaluated. The dosage of NT-proBNP was performed using the Elecsys® system (Roche, Basel, Switzerland) and GDF-15 by the sandwich immunoassay method with monoclonal antibodies (Elecsys®, Roche, Basel, Switzerland). Analysis of the relationship between GDF-15 and baseline renal parameters was performed. Correlation analysis was performed between GDF-15 and continuous variables, using the Spearman method. Results Sixty-seven patients were included. The etiologies of HF were hypertension, diabetes mellitus, alcoholic cardiomyopathy and idiopathic cardiomyopathy. Forty-one (61.2%) individuals were male, with a mean age of 61±13 years. Median GDF-15 values were 1413 pg/mL (interquartile range 1044–2554). Patients with GDF-15 values above the median had lower urinary sodium values (88 mEq/L [53–121] vs 112 [76–171], p=0.06), lower glomerular filtration rate (GFR) (63.9±29.1 vs 91.2±25 mL/min/1.73 m2, p=0.001) and higher creatinine levels (1.32 mg/dL [0.85–1.71] vs 0.91 [0.78–1.08], p&amp;lt;0.001). There was no significant difference in relation to urinary albumin (21 mg/L [7–126] vs 15.1 [5.8–41], p=0.30). The urinary albumin/creatinine ratio was higher in the group above the median, but did not reach statistical significance (38 mg/g [11–110] vs 12.5 [4.9–29], p=0.13). There was a direct correlation between GDF-15 and creatinine (r=0.56, p&amp;lt;0.001) and an inverse correlation with urinary sodium (r=−0.39, p=0.005) and with GFR (r=−0.55, p&amp;lt;0.001). Conclusion GDF-15 correlated with lower urinary sodium levels and worse kidney function in patients with chronic HF. Future studies should address whether GDF-15 is a predictor of worsening renal function overtime. Funding Acknowledgement Type of funding sources: None.

Abstract P303: Development Of Casper/myl7/annexin-5 Transparent Transgenic In-vivo Zebrafish Model To Study The Cardiomyocyte Function

The Zebrafish provided an excellent platform to study the genetic and molecular approach ofcardiac research. Zebrafish heart cells similar to human heart cells at the molecular level anddetermine gene functions that control cardiac function and dysfunction. In zebrafish heart, myl7is myosin 7 gene and identified as a regulatory gene orthologs to human MYL7. In the heart,Annexin5 activities contribute to cardiomyocyte dedifferentiation, proliferation and epicardial injuryresponses which leads to cardiac cell death by apoptosis and narcosis pathways. We aredeveloping annexin-5 activity in the cardiovascular function under normal and in metabolicaberration by generating homozygous Casper/ myl7:RFP; annexin-5:YFP transgenic zebrafish.By developing Casper/myl7/Annexin-5 transparent transgenic zebrafish model, we establish time-lapse in-vivo confocal microscopy to study of cellular phenotype/pathologies of thecardiomyocytes over time in newly developed strain to quantify changes in cardiomyocytemorphology and function overtime, comparing control and cardiac injury and cardio-oncologymodels. Transgenic zebrafish has normal type skin pigmentation background. In zebrafish,tracking of transgenic reporter activity in in-vivo is only possible in transparent stage. To maintaintransparency throughout the life, these strains crossbred with the skin transparent mutant Casper.Casper contributes to the study by integrating a transparent characteristic in adult zebrafish thatallows for simpler transparent visualization and observation. We develop casper transgenicprogenies through cross breeding with the transgenic strain of myl7:RFP;annexin-5:YFP .Confocal and fluorescent microscopy used to get accurate, precise imaging and to determinefluorescent protein being activated. 1.1: Generation of homozygous casper / myl7:RFP;annexin-5:YFP zebrafish (Generation F01-F05). 1.2: Screening and sorting the transgenic progeny andIn vivo imaging to validate cardiac morphology through in-vivo confocal imaging. Generation ofhomozygous casper / myl7:RFP;annexin-5:YFP zebrafish: Casper-Annexin5 homozygous stain:Cross breed casper and myl7/Annexin5 fish; F01: Generate the eggs from breeder and grow theembryo to attenuate larvae to screen for transgenic expression. F01 generation, larvae showtransgenic expression (47%). F02: transgenic expression larvae (39%). F02 heterozygous shownormal skin pattern; F03, larval show transgenic expression (43%). F04, transgenic larvae(90%).F04; 100% fishes are phenotypically casper; F05: heterozygous transgenic progeny togrow and continue to generate until achieve 100% homozygous casper-myl7-Annexin5 strain.These novel results provide in-vivo whole organism-based platform to design high throughputscreening and establish new horizon for drug discovery in the Cardiac Disease and Cardio-oncology.

LONGITUDINAL EVALUATION OF RIGHT VENTRICLE FUNCTION USING SPECKLE TRACKING ECHOCARDIOGRAPHY IN PATIENTS WITH ACUTE HYPOXEMIC RESPIRATORY FAILURE

SESSION TITLE: Critical Care Posters SESSION TYPE: Original Investigation Posters PRESENTED ON: October 18-21, 2020 PURPOSE: Right ventricle (RV) dysfunction occurs in approximately 22-25% of ARDS patients despite lung protective ventilation and is associated with increased mortality. This mortality increase is thought due to acute cor pulmonale wherein increased pulmonary vascular resistance (PVR) causes RV chamber dilation and systolic dysfunction. Distorted RV geometry compromises cardiac output and can lead to circulatory failure. Determination of PVR directly by pulmonary artery catheter is difficult to apply uniformly at bedside and previous beside echocardiography measurements such as acute cor pulmonale have failed to demonstrate consistent accuracy in predicting mortality. Speckle tracking echocardiography (STE) is a validated technique used to detect subclinical LV dysfunction before global ejection fraction is measurably impaired. STE is easily applied at beside and could prove useful for monitoring RV function in patients with ARDS on positive pressure ventilation. METHODS: We studied 9 patients with acute hypoxemic respiratory failure (PF ratio <300, PEEP >5) admitted to our ICU within 96 hours of intubation. We performed an RV focused echocardiogram with speckle tracking software (ECHOPAC) using GE Vivid 9.5 machines to assess RV function every 2-3 days until the patient was extubated, received tracheostomy or expired. TAPSE, TDI, right atrial pressure (calculated from TR jet maximum velocity and IVC % change), and 2 dimensional EF were also performed on each study. RESULTS: 4/9 patients had new RV dysfunction (RV FWLS >-23%) identified by STE at baseline echocardiogram. 5/9 patients died during the study and those that died had either abnormal RV function at baseline or had worsening function worsened over time despite stable PEEP settings and plateau pressure <30 cm H20. In survivors (4/9), RV function generally improved or remained stable. TDI and TAPSE did not correlate well with predicting mortality. In total, 24 RV echocardiograms were performed; RV dysfunction by strain was identified in 11/24 (44%) compared to TDI 1/24 (4%) and TAPSE 6/24 (25%). CONCLUSIONS: In mechanically ventilated patients with ARDS 5/9 patients died and were found to have either impaired RV function at baseline echocardiogram or had worsening in function overtime. Traditional markers such as TAPSE and TDI, that assess only longitudinal motion of RV performed poorly. CLINICAL IMPLICATIONS: This is the first study to date using speckle tracking echocardiography (STE) to prospectively evaluate RV function over time in patient with acute hypoxemic respiratory failure. STE of RV function correlated better with survivors and non-survivors compared to conventional measurements (TDI and TAPSE). A larger cohort of patients is needed to further characterize the relationship of RV function overtime in ARDS. DISCLOSURES: No relevant relationships by Alice Gallo De Moraes, source=Web Response No relevant relationships by Cameron Long, source=Web Response No relevant relationships by Richard Oeckler, source=Web Response No relevant relationships by Brandon Wiley, source=Web Response

Long term follow up of biomarkers of podocyte damage and renal function in patients with and without preeclampsia

ABSTRACTIntroduction:preeclampsia can be associated with future renal disease.Objectives:To measure changes in renal function overtime in patients with preeclampsia.Methods:urine and serum samples from eleven patients with preeclampsia and eight patients with a normal pregnancy were obtained during pregnancy, postpartum, and 3 years after delivery. Urine podocalyxin, protein, and serum creatinine were measured.Results:after 3 years, there were no significant differences in urinary podocalyxin in patients with or without preeclampsia: 4.34 ng/mg [2.69, 8.99] vs. 7.66 ng/mg [2.35, 13], p = 0.77. The same applied to urinary protein excretion: 81.5 mg/g [60.6, 105.5] vs. 43.2 mg/g [20.9, 139.3] p = 0.23. Serum creatinine was 0.86 mg/dL [0.7, 0.9] vs. 0.8 mg/dL [0.68, 1] p = 0.74 in those with and without preeclampsia. In normal patients, urinary podocalyxin decreased from 54.4 ng/mg [34.2, 76.9] during pregnancy to 7.66 ng/mg [2.35, 13] three years after pregnancy, p = 0.01. Proteinuria decreased from 123.5 mg/g [65.9, 194.8] to 43.2 mg/g [20.9, 139.3], p = 0.12. In preeclampsia patients, urinary podocalyxin decreased from 97.5 ng/mg [64.9, 318.4] during pregnancy to 37.1 ng/mg within one week post-partum [21.3, 100.4] p = 0.05 and 4.34 ng/mg [2.69, 8.99] three years after, p = 0.003. Proteinuria was 757.2 mg/g [268.4, 5031.7] during pregnancy vs. 757.2 mg/g [288.2, 2917] postpartum, p = 0.09 vs. 81.5 mg/g [60.6, 105.5] three years later, p = 0.01. Two patients still had proteinuria after 3 years.Conclusions:in preeclampsia patients, postpartum urinary podocalyxin decreased before proteinuria. After three years, serum creatinine, urinary podocalyxin, and protein tended to normalize, although some patients still had proteinuria.

Bendamustine plus rituximab for indolent B-cell lymphoma of renal significance.

Treatment of indolent B-cell non-Hodgkin lymphomas (iNHL) of renal significance is challenging given the need for deep and prolonged hematological response to restore and control renal function overtime, yet to be balanced with the risk of adverse drug-related events. This prospective single-center study included 20 patients with iNHL of renal significance (tubulointerstitial presentation [n = 8], glomerulopathy with or without monoclonal Ig deposits [n = 12]) who received a steroid-sparing regimen of rituximab plus bendamustine (BR), with either no or <1 month of steroid intake (as a first line therapy in 80%). Seventeen patients (85%) achieved a complete (CHR, n = 12) or a partial (PHR, n = 5) hematological response. Nine out of the 12 patients (75%) with iNHL-related glomerulopathy had a complete (CRR) or a partial (PRR) renal response. Among the six patients with glomerulopathy and CHR, five had a CRR (83%) compared to 1/6 (17%) that did not reach CHR. eGFR increased from 38 to 58 mL/min/1.73 m2 , and returned to baseline in five patients. Among the eight patients with a tubulointerstitial presentation, six (75%) had a renal response (5 CRR), and eGFR increased from 29 to 48 mL/min/1.73 m2 . One patient with a PHR had a renal relapse. Mortality rate was 10% at 12 months. The BR regimen was well tolerated overall. Thus, despite severe renal disease at presentation, a relapsing iNHL in 20% of patients and several comorbidities, the BR regimen was efficient and safe in our series. It should be further assessed as a first line therapy for patients with iNHL of renal significance.

Five-year follow-up after live donor nephrectomy - cross-sectional and longitudinal analysis of a prospective cohort within the era of extended donor eligibility criteria.

To establish the outcome of live kidney donors 5 years after donation, we investigated the risk for progressive renal function decline and quality of life (QoL). Data on estimated glomerular filtration rate (eGFR), creatinine, hypertension, QoL and survival were assessed in a prospective cohort of 190 donors, who donated between 2008 and 2010. Data were available for >90%. The mean age predonation was 52.8 ± 11.5 years, 30 donors having pre-existent hypertension. The mean follow-up was 5.1 ± 0.9 years. Eight donors had died due to non-donation-related causes. After 5 years, the mean eGFR was 60.2 (95% CI 58.7-62.7) ml/min/1.73 m2 , with a median serum creatinine of 105.1 (95% CI 102.5-107.8) μmol/l. eGFR decreased to 33.6% and was longitudinally lower among men than women and declining with age (P < 0.001), without any association on QoL. Donors with pre-existent and new-onset hypertension demonstrated no progressive decline of renal function overtime compared to nonhypertensives. No donors were found with proteinuria, microalbuminuria or at risk for end-stage renal disease. After an initial decline postdonation, renal function remained unchanged overtime. Men and ageing seem to affect renal function overtime, while decreased renal function did not affect QoL. These data support further stimulation of living kidney donation programmes as seen from the perspective of donor safety.

Effect of weight loss on renal function in overweight and obese patients with heart failure

AimsThe effect of intentional weight loss on glomerular filtration rate (GFR) in overweight and obese patients with heart failure (HF), diabetes mellitus (DM) and/or metabolic syndrome (MS) has not been studied. The purpose of the present study is to assess the short term effects of intentional weight loss on renal function in this population. Materials and methodsFifty nine patients were recruited to participate in a 3-month intensive behavioral weight management intervention and received one of two standard structured energy-restricted meal plans (1200 or 1500kcal/day) based on their computed calorie deficit. Weight and renal function (serum creatinine, BUN and estimated glomerular filtration rate based on two formulas – Modification in Renal Disease Study (MDRD), and modified version of Cockcroft-Gault formula reported by Salazar Corcoran for obese patients (absolute and relative formulas) – were evaluated at baseline and at 3 months. ResultsParticipants had eGFR in the normal range at baseline and lost an average of 7.56±14.9 pounds (p<0.0001) over 3 months; however, there was no significant reduction in serum creatinine, BUN or eGFR. ConclusionThis study provides evidence that intentional weight loss in overweight and obese patients with HF along with DM, and/or MS and normal baseline renal function does not adversely affect renal function overtime.

LDL-cholesterol lowering and renal outcomes

Patients with chronic kidney disease (CKD) are at high risk for cardiovascular events. Statins reduce cardiovascular risk in a broad spectrum of patients. This article summarizes the evidence that statins reduce risk in CKD patients, and that statins have a small but favorable effect on renal function. Current guidelines for lipid management in patients with CKD are also reviewed. Two well conducted randomized trials showed no significant benefit for statins among patients receiving dialysis. One large trial demonstrated that simvastatin/ezetimibe reduced cardiovascular events in a broad spectrum of CKD patients. A recent meta-analysis concluded that CKD patients benefit from statins, and that the relative benefit decreases as the severity of CKD worsens. In large trials, statin-treated patients have slightly less worsening of renal function overtime, and there are data to suggest that statins actually do not only preserve, but also increase renal function. Recent guidelines recommend a statin for CKD patients aged 50 years or older, for younger patients with known vascular disease, diabetes, or a 10-year risk greater than 10%, and for adult renal transplant recipients. Statins should be prescribed to older patients with CKD, and to younger patients with CKD who are at high CVD risk.

The level of antigen expression in the liver predicts the fate and functional outcome of antigen-specific CD8 T cells (LYM5P.706)

Abstract A wide spectrum of CD8 T cell responses can be elicited against antigens (Ag) expressed in the liver, ranging from tolerance to full effector function. Identifying the factors involved would allow us to predict the outcome of liver transplantation and viral hepatitis. To investigate how CD8 T cells respond to liver Ags, we have developed recombinant adeno-associated viral vectors that, when injected into mice, allow de novo Ag expression in a variable number of hepatocytes. Within the first day of Ag expression by at least 70% of hepatocytes, most naïve Ag-specific CD8 T cells were activated in the liver via direct presentation by hepatocytes. CD8 T cell activation in lymph nodes and spleen via cross presentation was detected a day later, suggesting that primary activation of CD8 T cells against hepatocyte-expressed Ag is compartmentalised. These T cells proliferated, developed into CTLs in the first week but were unable to kill all Ag-expressing hepatocytes. Most effector T cells were rapidly deleted while those surviving became exhausted and unresponsive over time. In contrast, when less than 10% of hepatocytes expressed the targeted Ag, CD8 T cell were gradually activated in liver and lymphoid tissues but were not deleted. Instead, they eliminated all Ag-expressing hepatocytes and maintained their effector function overtime. In summary, this study shows that intrahepatic Ag load dictates both the fate and function of CD8 T cells recognising hepatocyte-expressed Ags.

Renal function in recipients of pancreas transplant alone

Pancreas transplant alone (PTA) has become an accepted therapy for selected nonuremic patients with type 1 diabetes mellitus. We report a literature review, as well as data from the McGill University pancreas transplant program. The published literature suggests that there is reversibility of diabetic nephropathy when normoglycemia is maintained for 5-10 years after successful PTA. There is also evidence of development and progression of histological lesions compatible with calcineurin inhibitor nephrotoxicity, as well as a decline in renal function overtime, with an increased risk of end-stage renal disease (ESRD). We studied 43 patients with PTA. Nine patients had a pretransplant estimated glomerular filtration rate (eGFR) less than 60 ml/min/1.73 m, and 34 patients had an eGFR greater than 60 ml/min/1.73 m. The actuarial incidence of ESRD at 1, 3 and 5 years was 0, 28.57 and 61.9% in patients with pretransplant eGFR less than 60 ml/min/1.73 m, and 0, 8.2 and 12.5% in patients with pretransplant eGFR greater than 60 ml/min/1.73 m, respectively (P=0.006). Multivariate analysis confirmed that age, sex, duration of diabetes prior to PTA and eGFR pretransplant were significant predictors of ESRD. The ideal management of candidates for PTA with eGFR less than 60 ml/min/1.73 m remains to be determined. Future studies should focus on determining potentially reversible predictive factors of progression to ESRD after PTA, as well as the outcomes of these patients on chronic dialysis.

Upper limb kinetic analysis of three sitting pivot wheelchair transfer techniques

BackgroundThe objective of this study was to investigate differences in shoulder, elbow and hand kinetics while performing three different SPTs that varied in terms of hand and trunk positioning. MethodsFourteen unimpaired individuals (8 male and 6 female) performed three variations of sitting pivot transfers in a random order from a wheelchair to a level tub bench. Two transfers involved a forward flexed trunk (head–hips technique) and the third with the trunk remaining upright. The two transfers involving a head hips technique were performed with two different leading hand initial positions. Motion analysis equipment recorded upper body movements and force sensors recorded hand reaction forces. Shoulder and elbow joint and hand kinetics were computed for the lift phase of the transfer. FindingsTransferring using either of the head hips techniques compared to the trunk upright style of transferring resulted in reduced superior forces at the shoulder (P<0.002), elbow (P<0.004) and hand (P<0.013). There was a significant increase in the medial forces in the leading elbow (P=0.049) for both head hip transfers and the trailing hand for the head hip technique with the arm further away from the body (P<0.028). The head hip techniques resulted in higher shoulder external rotation, flexion and extension moments compared to the trunk upright technique (P<0.021). InterpretationVarying the hand placement and trunk positioning during transfers changes the load distribution across all upper limb joints. The results of this study may be useful for determining a technique that helps preserve upper limb function overtime.

Effect of hypoxia-inducible VEGF gene expression on revascularization and graft function in mouse islet transplantation

For gene transfer strategies to improve islet engraftment, vascular endothelial growth factor (VEGF) expression should be regulated in a way that matches the transient nature of revascularization with simultaneously avoiding undesirable effects of overexpression. The aim of this study was to investigate the effects of hypoxia-inducible VEGF gene transfer using the RTP801 promoter on islet grafts. We implanted pSV-hVEGF transfected, pRTP801-hVEGF transfected or nontransfected mouse islets under the kidney capsule of streptozotocin-induced diabetic syngeneic mice. Human VEGF immunostaining of day 3 grafts revealed that the pRTP801-hVEGF transfected group had higher hVEGF expression compared with the pSV-hVEGF transfected group. BS-1 staining of day 3 grafts from the pRTP801-hVEGF transfected group showed the highest vascular density, which was comparable with day 6 grafts from the nontransfected group. In 360 islet equivalent (IEQ)-transplantation which reverted hyperglycemia in all mice, the area under the curve of glucose levels during intraperitoneal glucose tolerance test 7 weeks post-transplant was lower in mice transplanted with pRTP801-hVEGF transfected grafts compared with mice transplanted with nontransfected grafts. In 220 IEQ-transplantations, diabetic mice transplanted with pRTP801-hVEGF islets became normoglycemic more rapidly compared with mice transplanted with pSV-hVEGF or nontransfected islets, and diabetes reversal rate after 50 days was 90%, 68%, and 50%, respectively. In conclusion, our results indicate that regulated overexpression of hVEGF in a hypoxia-inducible manner enhances islet vascular engraftment and preserves islet function overtime in transplants.

The effect of ADT on objective cognitive performance and self-reported cognitive functionin men with prostate cancer.

4560 Background: ADT is used to treat almost 50% of prostate cancer (PC) patients. Despite slowing disease progression and prolonging survival, ADT is associated with numerous side effects. However, the impact of ADT on self-reported and objective cognitive function remains unclear. Methods: Three groups of males age 50+ were included; PC patients starting continuous ADT (n=77), PC controls not receiving ADT (n=85), and healthy controls (n=83). A self-reported cognitive function questionnaire (FACT-Cog) and a battery of neuropsychological tests examining 8 cognitive domains were administered at baseline, 6 months and 12 months later. The FACT-Cog scores and the battery test scores were compared between groups at baseline, and change scores over the 12 month period were analyzed using ANOVA and multi-variable linear regression. To examine whether changes in objective cognitive scores correlated with changes in FACT-Cog scores, Pearson correlations were calculated. Results: FACT- Cog scores obtained at baseline did not significantly differ between the 3 groups (p>0.05). ADT users did not report a greater decline in self-cognitive function overtime compared to PC controls or healthy controls (p=0.21). Attention and Processing Speed, Visual Memory, Language and Executive Function scores did not significantly differ between groups (p>0.05). At 12 months, ADT users had significantly declined on the Longest Digit Span Forwards (Immediate Memory), Spatial Span Backwards (Working Memory), and Card Rotations tasks (Visuospatial Ability) (p<0.05). Correlations between FACT-Cog and objective cognitive test scores were weak at baseline and overtime (all r<0.20). Conclusions: Preliminary analyses suggest little or no deleterious effect of ADT on self-reported cognitive function over 12 months. Objective cognitive performance of ADT users declined over 12 months on 3 cognitive tests, indicating a possibility of ADT's long-term impact on selected cognitive domains. Correlations between FACT-Cog scores and objective cognitive performance were poor. No significant financial relationships to disclose.

MR Imaging of Pancreatic Islets: Tracking Isolation, Transplantation and Function

The increasing global incidence of diabetes and advancements in clinical pancreatic islet transplantation for the treatment of Type I diabetes have renewed the interest in understanding the variations of beta cell mass and function relative not only to transplant outcome but also to the onset and progression of diabetes. A deeper comprehension of the molecular and cellular processes involved in pancreatic islet inflammation and cytotoxicity is necessary to further improve efficacy of islet transplantation and to develop new therapies aimed at preserving beta cell function in pathological conditions. Available diagnostic methods based on metabolic response are unsuitable as they lack correlation to islet mass, viability and function. Great emphasis has been placed on developing noninvasive imaging technologies which enable the tracking of both endogenous and transplanted islet mass and potentially function overtime, the characterization of changes in islet vasculature and the degree of T-cell infiltration during insulitis. Among the more relevant modalities are magnetic resonance, positron emitted tomography, single photon emission computed tomography, bioluminescence and fluorescence optical imaging. This review focuses on the most recent advancements in magnetic resonance imaging (MRI) of pancreatic islets. In-vitro approaches aimed at characterizing the potency of isolated islets as well as in-vivo advancements in the assessment of transplanted beta cell mass are presented together with the significant progress made in the in-vivo imaging of the endocrine pancreas and islet vasculature and inflammation. Different experimental approaches are compared via their advantages and limitations with respect to their clinical implementation.