The Effect of the Statewide Sharing Variance on Geographic Disparity in Kidney Transplantation in the United States

Background and objectives

The Statewide Sharing variance to the national kidney allocation policy allocates kidneys not used within the procuring donor service area (DSA), first within the state, before the kidneys are offered regionally and nationally. Tennessee and Florida implemented this variance. Known geographic differences exist between the 58 DSAs, in direct violation of the Final Rule stipulated by the US Department of Health and Human Services. This study examined the effect of Statewide Sharing on geographic allocation disparity over time between DSAs within Tennessee and Florida and compared them with geographic disparity between the DSAs within a state for all states with more than one DSA (California, New York, North Carolina, Ohio, Pennsylvania, Texas, and Wisconsin).

Design, setting, participants, & measurements

A retrospective analysis from 1987 to 2009 was conducted using Organ Procurement and Transplant Network data. Five previously used indicators for geographic allocation disparity were applied: deceased-donor kidney transplant rates, waiting time to transplantation, cumulative dialysis time at transplantation, 5-year graft survival, and cold ischemic time.

Results

Transplant rates, waiting time, dialysis time, and graft survival varied greatly between deceased-donor kidney recipients in DSAs in all states in 1987. After implementation of Statewide Sharing in 1992, disparity indicators decreased by 41%, 36%, 31%, and 9%, respectively, in Tennessee and by 28%, 62%, 34%, and 19%, respectively in Florida, such that the geographic allocation disparity in Tennessee and Florida almost completely disappeared. Statewide kidney allocations incurred 7.5 and 5 fewer hours of cold ischemic time in Tennessee and Florida, respectively. Geographic disparity between DSAs in all the other states worsened or improved to a lesser degree.

Conclusions

As sweeping changes to the kidney allocation system are being discussed to alleviate geographic disparity—changes that are untested run the risk of unintended consequences—more limited changes, such as Statewide Sharing, should be further studied and considered.     

The ErbB4 Ligand Neuregulin-4 Protects against Experimental Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) affects up to 10% of premature infants, has a mortality of 30%, and can leave surviving patients with significant morbidity. Neuregulin-4 (NRG4) is an ErbB4-specific ligand that promotes epithelial cell survival. Thus, this pathway could be protective in diseases such as NEC, in which epithelial cell death is a major pathologic feature. We sought to determine whether NRG4-ErbB4 signaling is protective in experimental NEC. NRG4 was used i) in the newborn rat formula feeding/hypoxia model; ii) in a recently developed model in which 14- to 16-day-old mice are injected with dithizone to induce Paneth cell loss, followed by Klebsiella pneumoniae infection to induce intestinal injury; and iii) in bacterially infected IEC-6 cells in vitro. NRG4 reduced NEC incidence and severity in the formula feed/hypoxia rat model. It also reduced Paneth cell ablation–induced NEC and prevented dithizone-induced Paneth cell loss in mice. In vitro, cultured ErbB4^−/− ileal epithelial enteroids had reduced Paneth cell markers and were highly sensitive to inflammatory cytokines. Furthermore, NRG4 blocked, through a Src-dependent pathway, Cronobacter muytjensii–induced IEC-6 cell apoptosis. The potential clinical relevance of these findings was demonstrated by the observation that NRG4 and its receptor ErbB4 are present in human breast milk and developing human intestine, respectively. Thus, NRG4-ErbB4 signaling may be a novel pathway for therapeutic intervention or prevention in NEC.Necrotizing enterocolitis (NEC) is a devastating intestinal disease primarily affecting premature infants. In the United States, NEC afflicts 7% of infants weighing <1500 g.¹ In addition to prematurity, risk factors include hypoxia, bacterial colonization of the intestine, and formula feeding.² The development of NEC seems to be multifactorial, and patients may have any combination of risk factors at the time of presentation. The current disease model is that the immature gut barrier, along with defects in endogenous antimicrobial activity,³ allows bacterial translocation across the epithelium, triggering an inflammatory response that further worsens gut barrier function. Pathogenic bacteria,^{4, 5} inflammatory cytokines such as tumor necrosis factor (TNF),^{6, 7, 8} and Paneth cell dropout³ have all been associated with human NEC and contribute to NEC-like injury in animal models.Available therapy for either prevention or treatment of NEC is limited, and patients currently face a mortality rate of approximately 30%.^{9, 10, 11} Breast-fed infants have a lower risk of NEC than their formula-fed peers,^{12, 13} and a variety of studies have attempted to identify and characterize factors in human milk that confer this protection. Candidate protective molecules to date include immunoglobulins, oligosaccharides, lactoferrin, and soluble growth factors, such as epidermal growth factor (EGF)¹⁴ and heparin-binding EGF-like growth factor (HB-EGF).¹⁵ In rat and mouse models, enteral administration of either EGF^{16, 17} or HB-EGF¹⁸ decreases the incidence and severity of NEC. The primary receptor for both EGF and HB-EGF is EGF receptor (EGFR), the prototypic member of the ErbB receptor tyrosine kinase family. However, HB-EGF also activates ErbB4, a member of the ErbB family whose potential role in the developing gut and NEC is not known.ErbB4 has unique biochemical properties distinguishing it from other ErbB family members. Compared with EGFR, ErbB2, or ErbB3, it recognizes a broader collection of ligands, including the EGF-like growth factors HB-EGF and betacellulin as well as the heregulin/neuregulin molecules.¹⁹ At the same time, the ErbB4 c-terminus contains a distinct and somewhat restricted set of functional docking sites for downstream effectors²⁰ and is thus predicted to elicit divergent cellular effects on activation versus other family members. In fact, we recently demonstrated that neuregulin-4 (NRG4), an ErbB4-specific ligand that does not bind or activate other family members, including EGFR,²¹ specifically promotes survival but not migration or proliferation of mouse colon epithelial cells.²² Thus, ErbB4 is a potentially unique and selective target for therapeutic protection in diseases in which intestinal epithelial cell death is a major pathologic feature.We previously reported that ErbB4 is up-regulated in adult human and murine colon inflammation in vivo²³ and that ErbB4 overexpression protects cultured colonocytes from cytokine-induced apoptosis in a ligand-dependent manner.²⁴ Furthermore, i.p. NRG4 administration reduces the severity of acute murine dextran sulfate sodium colitis.²² Thus, it seems that ErbB4 induction is a natural compensatory response meant to preserve the epithelium rather than part of disease pathology and that ErbB4 activation with exogenous ligand is protective against induced inflammation. However, the role of this signaling pathway in the small intestine, or during development, has not been described. We hypothesized that ErbB4 and its ligands have a protective role in the small bowel during postnatal development, particularly in the setting of NEC-associated acute injury and inflammation. To advance our understanding of ErbB4 biology in intestinal homeostasis and disease, we tested the hypothesis that NRG4-ErbB4 signaling is protective in experimental NEC.     

Parkinson’s disease: considerations for dental hygienists

Abstract: The prevalence of Parkinson’s disease (PD) is expected to double over the next 20 years owing to the increase in life expectancy. This progressive disease has several implications relating to oral health, and many are manageable with proper awareness and knowledge about the disease. This article reviews the epidemiology, pathophysiology, and characteristics of PD, as well as the treatments and oral health considerations to enable dental hygienists to undertake an informed approach to patient management strategies and provide optimal care.     

Reduction in length of stay for patients undergoing oesophageal and gastric resections with implementation of enhanced recovery packages

Introduction

The high mortality and morbidity associated with resection for oesophagogastric malignancy has resulted in a conservative approach to the postoperative management of this patient group. In August 2009 we introduced an enhanced recovery after surgery (ERAS) pathway tailored to patients undergoing resection for oesophagogastric malignancy. We aimed to assess the impact of this change in practice on standard clinical outcomes.

Methods

Two cohorts were studied of patients undergoing resection for oesophagogastric malignancy before (August 2008 – July 2009) and after (August 2009 – July 2010) the implementation of the ERAS pathway. Data were collected on demographics, interventions, length of stay, morbidity and in-hospital mortality.

Results

There were 53 and 55 oesophagogastric resections undertaken respectively for malignant disease in each of the study periods. The median length of stay for both gastric and oesophageal resection decreased from 15 to 11 days (Mann– Whitney U, p<0.001) following implementation of the ERAS pathway. There was no significant increase in morbidity (gastric resection 23.1% vs 5.3% and oesophageal resection 25.9% vs 16.7%) or mortality (gastric resection no deaths and oesophageal resection 1.8% vs 3.6%) associated with the changes. There was a significant decrease in the number of oral contrast studies used following oesophageal resection, with a reduction from 21 (77.8%) in 2008–2009 to 6 (16.7%) in 2009–2010 (chi-squared test, p<0.0001).

Conclusions

The introduction of an enhanced recovery programme following oesophagogastric surgery resulted in a significant decrease in length of median patient stay in hospital without a significant increase in associated morbidity and mortality.     

A Randomized‐Controlled Pilot Study Comparing ICD Implantation with and Without Intraoperative Defibrillation Testing in Patients with Heart Failure and Severe Left Ventricular Dysfunction: A Substudy of the RAFT Trial

Comparing ICD Implantation with and Without Intraoperative Defibrillation Testing. Introduction: The need to perform defibrillation testing (DT) at the time of implantable cardioverter defibrillator (ICD) insertion is controversial. In the absence of randomized trials, some regions now perform more than half of ICD implants without DT. Methods: During the last year of enrolment in the Resynchronization for Ambulatory Heart Failure Trial, a substudy randomized patients to ICD implantation with versus without DT. Results: Among 252 patients screened, 145 were enrolled; 75 randomized to DT and 70 to no DT. Patients were similar in terms of age (65.9 ± 9.3 years vs 67.9 ± 8.9 years); LVEF (24.7 ± 4.6% vs 23.6 ± 4.6%), QRS width (154.8 ± 23.5 vs 155.8 ± 23.6 ms), and history of atrial fibrillation (5% vs 6%). All 68 patients in the DT arm tested according to the protocol achieved a successful DT (≤25 J); 96% without requiring any system modification. No patient experienced perioperative stroke, myocardial infarction, heart failure (HF), intubation or unplanned ICU stay. The length of hospital stay was not prolonged in the DT group: 20.2 ± 26.3 hours versus 21.3 ± 23.0 hours, P = 0.79. One patient in the DT arm had a failed appropriate shock and no patient suffered an arrhythmic death. The composite of HF hospitalization or all‐cause mortality occurred in 10% of patients in the no‐DT arm and 19% of patients in the DT arm (HR = 0.53, 95% CI: 0.21–1.31, P = 0.14). Conclusions: In this randomized trial, perioperative complications, failed appropriate shocks, and arrhythmic death were all uncommon regardless of DT. There was a nonsignificant increase in the risk of death or HF hospitalization with DT. (J Cardiovasc Electrophysiol, Vol. 23, pp. 1313‐1316, December 2012)     

Enhanced Bone Regeneration Using Porcine Small Intestinal Submucosa

Small instestinal submucosa (SIS) is an easily produced material that has been used experimentally for tissue engineering. To evaluate the ability of SIS to facilitate bone growth within a long-bone defect, a segment of the radius was surgically removed in adult, female Sprague-Dawley rats. The defect was either left unfilled or implanted with SIS, demineralized cortical bone (DMCB), or ovalbumin. The defect was evaluated radiographically and histologically after 3, 6, 12, and 24 weeks. Tissue remodeling within the defect was evident by week 3 in SIS- and DMCB-treated rats. Filling was characterized initially by infiltration of mononuclear cells and extracellular material in SIS-implanted rats and multifocal remodeling bone particles and cartilage formation in DMCB implanted rats. Cartilage was observed as early as 3 weeks and bone as early as 6 weeks in SIS-implanted rats. Filling of the defect arose from multiple foci in DMCB-implanted rats, but was contiguous with and parallel to the ulnar shaft in SIS-implanted rats, suggesting that defect repair by SIS may be conductive rather than inductive. Rats in which the defect was left unfilled demonstrated slow but progressive filling of the defect, characterized by mononuclear cell infiltrates and fibrous extracellular material. In summary, SIS facilitated rapid filling of a longbone defect. These results suggest that SIS may be useful as a bone repair material.     

More stressors prior to and during the course of bipolar illness in patients from the United States compared with the Netherlands and Germany

Considerable data suggest that compared to some European countries, in the U.S. there are more childhood onset bipolar disorders, more adverse courses of illness, and greater treatment resistance. Psychosocial variables related to these findings have not been adequately explored. Therefore we analyzed psychosocial stressors in three time domains: childhood; the year prior to illness Onset; and the Last Episode from questionnaires in 968 outpatients (mean age 41) with bipolar I or II disorder; 676 from four sites in the U.S. and 292 from three in the Netherlands and Germany (abbreviated here as Europe). Compared to the Europeans, those from the U.S. had significantly more stressors in childhood and prior to the last episode. Stressors prior to the last episode were related to: childhood stressors; an earlier age at illness onset; anxiety and substance abuse comorbidity; lower income; both parents having an affective illness; and feeling more stigma. These data suggest a greater prevalence of adverse life events in childhood and over the course of bipolar illness in the U.S. compared to the Netherlands and Germany. Clinical, therapeutic, and public health approaches to these illness-relevant stressors require further exploration.     

Trends in kidney transplantation rates and disparities

OBJECTIVE: To examine the likelihood of transplantation and trends over time among persons with end-stage renal disease (ESRD) in Wisconsin. METHODS: We examined the influence of patient- and community-level characteristics on the rate of kidney transplantation in Wisconsin among 22,387 patients diagnosed with ESRD between January 1, 1982 and October 30, 2005. We grouped patients by the year of ESRD onset in order to model the change in transplantation rates over time. RESULTS: After multivariate adjustment, all other racial groups were significantly less likely to be transplanted compared with whites, and the racial disparity increased over calendar time. Older patients were less likely to be transplanted in all periods. Higher community income and education level and a greater distance from patients' residence to the nearest dialysis center significantly increased the likelihood of transplantation. Males also had a significantly higher rate of transplantation than females. CONCLUSION: These results demonstrate a growing disparity in transplantation rates by demographic characteristics and a consistent disparity in transplantation by socioeconomic characteristics. Future studies should focus on identifying specific barriers to transplantation among different subpopulations in order to target effective interventions.