Nonadaptive Amino Acid Convergence Rates Decrease over Time.

Convergence is a central concept in evolutionary studies because it provides strong evidence for adaptation. It also provides information about the nature of the fitness landscape and the repeatability of evolution, and can mislead phylogenetic inference. To understand the role of adaptive convergence, we need to understand the patterns of nonadaptive convergence. Here, we consider the relationship between nonadaptive convergence and divergence in mitochondrial and model proteins. Surprisingly, nonadaptive convergence is much more common than expected in closely related organisms, falling off as organisms diverge. The extent of the convergent drop-off in mitochondrial proteins is well predicted by epistatic or coevolutionary effects in our "evolutionary Stokes shift" models and poorly predicted by conventional evolutionary models. Convergence probabilities decrease dramatically if the ancestral amino acids of branches being compared have diverged, but also drop slowly over evolutionary time even if the ancestral amino acids have not substituted. Convergence probabilities drop-off rapidly for quickly evolving sites, but much more slowly for slowly evolving sites. Furthermore, once sites have diverged their convergence probabilities are extremely low and indistinguishable from convergence levels at randomized sites. These results indicate that we cannot assume that excessive convergence early on is necessarily adaptive. This new understanding should help us to better discriminate adaptive from nonadaptive convergence and develop more relevant evolutionary models with improved validity for phylogenetic inference.

Comparison of systemic reactions in rush, cluster, and standard-build aeroallergen immunotherapy.

BACKGROUND: Given the choice of standard, cluster, and rush build-up for aeroallergen immunotherapy, standard-build immunotherapy has generally been preferred because of a perceived high rate of systemic reactions (SRs) associated with cluster and rush immunotherapy. OBJECTIVE: To characterize the incidence of SRs during standard, cluster, and rush build-up immunotherapy in an allergy practice during a 5-year period. METHODS: A retrospective review was conducted among patients receiving standard-build, 8- to 10-step cluster, or 2-day rush immunotherapy from January 1, 2010, through December 31, 2014, at Family Allergy & Asthma clinics in Louisville, Kentucky. Investigators excluded reactions that occurred during skin prick testing, venom immunotherapy, and not-true SRs, and identified the build-up method, age, sex, date of reaction, vial concentration, and presence of asthma. Per-shot and per-patient incidence of SRs was computed from these data. RESULTS: During our review period, 2,549,643 injections were administered to 11,982 patients. Per-shot incidence of SR was 0.01%, 0.06%, and 0.33% for standard, cluster, and rush immunotherapy, respectively; per-patient incidence of SR was 2.84%, 2.52%, and 11.86% for standard, cluster, and rush immunotherapy, respectively. A total of 42% of SRs were grade 1, 43% were grade 2, 12% were grade 3, and 3% were grade 4. No fatalities were reported. A total of 70% of total SRs, 75% of cluster SR, and 55% of rush SR occurred in females, with an emergent peak in SR from May to October. CONCLUSION: Compared with previously published rates, we observed a decrease in the incidence of SR for standard, cluster, and rush immunotherapy, with peak seasonality from May to October and a female predominance.

Increased morbidity in overweight and obese liver transplant recipients: a single-center experience of 1325 patients from the United Kingdom.

Obesity levels in the United Kingdom have risen over the years. Studies from the United States and elsewhere have reported variable outcomes for obese liver transplant recipients in terms of post-liver transplant morbidity, mortality, and graft survival. This study was designed to analyze the impact of the body mass index (BMI) on outcomes following adult liver transplantation. Data from 1994 to 2009 were retrieved from a prospectively maintained database. Patients were stratified into 5 World Health Organization BMI categories: underweight (<18.5 kg/m(2)), normal weight (18.5-24.9 kg/m(2)), overweight (25.0-29.9 kg/m(2)), obese (30.0-34.9 kg/m(2)), and morbidly obese (≥35.0 kg/m(2)). The primary outcome was an evaluation of graft and patient survival, and the secondary outcome was an assessment of postoperative morbidity. Bonferroni correction was applied with statistical significance set at P < 0.012. Kaplan-Meier curves were used to study the effects of BMI on graft and patient survival. A total of 1325 patients were included in the study: underweight (n = 47 or 3.5%), normal-weight (n = 643 or 48.5%), overweight (n = 417 or 31.5%), obese (n = 145 or 10.9%), and morbidly obese patients (n = 73 or 5.5%). The rate of postoperative infective complications was significantly higher in the overweight (60.7%, P < 0.01) and obese recipients (65.5%, P < 0.01) versus the normal-weight recipients (50.4%). The morbidly obese patients had a longer mean intensive care unit (ICU) stay than the normal-weight patients (4.7 versus 3.2 days, P = 0.03). The mean hospital stay was longer for the overweight (22.4 days, P < 0.001), obese (21.3 days, P = 0.04), and morbidly obese recipients (22.4 days, P = 0.047) versus the normal-weight recipients (18.0 days). There was no difference in death-censored graft survival or patient survival between the groups. In conclusion, this is the largest and only reported UK series on BMI and outcomes following liver transplantation. Overweight and obese patients have significantly increased morbidity in terms of infective complications after liver transplantation and, consequently, longer ICU and hospital stays.

Liver transplantation for acute liver failure in Europe: outcomes over 20 years from the ELTR database.

BACKGROUND & AIMS: Liver transplantation for acute liver failure (ALF) still has a high early mortality. We evaluated changes during 20 years, and identified risk factors for poor outcome. METHODS: Donor, graft, and recipient variables from the European Liver Transplant Registry database (January 1988-June 2009), were analysed. Aetiologies and time periods were compared. Three and 12-month survival models were generated from separate training data sets, which were validated. A sub-analysis was performed for recipient older than 50 years. RESULTS: Four thousand nine hundred and three patients were evaluated. One, 5- and 10-year patient, and graft survival rates were 74%, 68%, 63%, and 63%, 57%, 50%, respectively. Survival was better in 2004-2009 compared to previous quinquennia (p<0.001), despite donors >60 years increased from 1.8% to 21%. A higher incidence of suicide or non-adherence occurred in paracetamol-related ALF (p<0.001). Death or graft loss were independently associated with male recipients (adjusted OR 1.25), recipient >50 years (1.26), incompatible ABO matching (1.93), donors >60 years (1.21), and reduced size graft (1.54). For both 3- and 12-month models, incompatible ABO matching, non-viral aetiology, reduced size graft, and non-UW preservation fluid were associated with increased mortality/graft loss, whereas male recipients and age >50 years were associated only at 12 months. Both models had reasonable discriminative ability with good calibration at 3 months. Recipients >50 years, combined with donors >60 years resulted in 57% mortality/graft loss within the first year. CONCLUSIONS: Survival after liver transplantation has improved despite increases in donor/recipient age. Recipients >50 years paired with donors >60 years had a very high mortality/graft loss within the first year.

Rectal epithelial cell mitosis and expression of macrophage migration inhibitory factor are increased 3 years after Roux-en-Y gastric bypass (RYGB) for morbid obesity: implications for long-term neoplastic risk following RYGB.

BACKGROUND: Rectal epithelial cell mitosis and crypt size, as well as expression of proinflammatory genes including macrophage migration inhibitory factor (MIF), are increased 6 months after Roux-en-Y gastric bypass (RYGB) in morbidly obese patients. Tests were carried out to determine whether these putative colorectal cancer risk biomarkers remained elevated long term after RYGB, and the mechanistic basis, as well as the functional consequences, of Mif upregulation in intestinal epithelial cells was investigated. METHODS: Rectal mucosa and blood were obtained a median of 3 years after RYGB from the original cohort of patients with RYGB (n = 19) for crypt microdissection, real-time PCR, immunohistochemistry for MIF and immunoassay of proinflammatory markers. Immunohistochemistry for Mif and bromodeoxyuridine labelling were performed on AhCre⁺ mouse and Apc(Min/⁺) mouse (with and without functional Mif alleles) intestine, respectively. RESULTS: Rectal epithelial cell mitosis and crypt size remained elevated 3 years after RYGB compared with preoperative values (1.7- and 1.5-fold, respectively; p < 0.05). There was a 40-fold (95% CI 13 to 125) increase in mucosal MIF transcript levels at 3 years associated with increased epithelial cell MIF protein levels. Conditional Apc loss in AhCre⁺ mice led to increased epithelial cell Mif content. Mif deficiency in Apc(Min/⁺) mice was associated with a combined defect in intestinal epithelial cell proliferation and migration, which was reflected by the longitudinal clinical data. CONCLUSIONS: Mucosal abnormalities persist 3 years after RYGB and include elevation of the protumorigenic cytokine MIF, which is upregulated following Apc loss and which contributes to intestinal epithelial cell homeostasis. These observations should prompt clinical studies of colorectal neoplastic risk after RYGB.

Primary liver transplantation for autoimmune hepatitis: a comparative analysis of the European Liver Transplant Registry.

The principal aim of this study was to compare the probability of and potential risk factors for death and graft loss after primary adult and pediatric liver transplantation in patients undergoing transplantation for autoimmune hepatitis (AIH) to those in patients undergoing transplantation for primary biliary cirrhosis (PBC; used as the reference group) or alcoholic cirrhosis (used as an example of a nonautoimmune liver disease). The 5-year survival of patients undergoing transplantation for AIH (n = 827) was 0.73 [95% confidence interval (CI) = 0.67-0.77]. This was similar to that of patients undergoing transplantation for alcoholic cirrhosis (0.74, 95% CI = 0.72-0.76, n = 6424) but significantly worse than that of patients undergoing transplantation for PBC (0.83, 95% CI = 0.80-0.85, n = 1588). Fatal infectious complications occurred at an increased rate in patients with AIH (hazard ratio = 1.8, P = 0.002 with PBC as the reference). The outcome of pediatric AIH patients was similar to that of adult patients undergoing transplantation up to the age of 50 years. However, the survival of AIH patients undergoing transplantation beyond the age of 50 years (0.61 at 5 years, 95% CI = 0.51-0.70) was significantly reduced in comparison with the survival of young adult AIH patients (0.78 at 18-34 years, 95% CI = 0.70-0.86) and in comparison with the survival of patients of the same age group with PBC or alcoholic cirrhosis. In conclusion, age significantly affects patient survival after liver transplantation for AIH. The increased risk of dying of infectious complications in the early postoperative period, especially above the age of 50 years, should be acknowledged in the management of AIH patients with advanced-stage liver disease who are listed for liver transplantation. It should be noted that not all risk factors relevant to patient and graft survival could be analyzed with the European Liver Transplant Registry database.

Liver transplantation following donation after cardiac death: an analysis using matched pairs.

Grafts from donation after cardiac death (DCD) donors are used to increase the number of organs available for liver transplantation. There is concern that warm ischemia may impair graft function. We compared our DCD recipients with a case-matched group of donation after brain death (DBD) recipients. Between January 2002 and April 2008, 39 DCD grafts were transplanted. These were matched with 39 DBD recipients on the basis of identified variables that had a significant impact on mortality. These were used to individually match DCD and DBD patients with similar predictive mortality. We compared patient/graft survival, primary non-function (PNF), and rates of complications. Of all liver transplants, 6.1% were DCD grafts. PNF occurred twice in the DCD group. The incidence of nonanastomotic biliary strictures (NABS; 20.5% versus 0%, P = 0.005) and hepatic artery stenosis (HAS; 12.8% versus 0%, P = 0.027) in the DCD group was higher. One-year (79.5% versus 97.4%, P = 0.029) and 3-year (63.6% versus 97.4%, P = 0.001) graft survival was lower in the DCD group. Three-year patient survival was also lower (68.2% versus 100%, P < 0.0001). Our study is the first to use case-matched patients and compare groups with similar predictive mortality. There was a higher incidence of NABS and HAS in the DCD group. NABS were likely a result of warm ischemia. HAS may have been due to ischemia or arterial injury during retrieval. The DCD group had significantly poorer outcomes, but DCD grafts remain a valuable resource. With careful donor/recipient selection, minimization of ischemia, and good postoperative care, acceptable results can be achieved.

Increased colorectal epithelial cell proliferation and crypt fission associated with obesity and roux-en-Y gastric bypass.

BACKGROUND AND AIMS: The relationship between obesity, weight reduction, and future risk of colorectal cancer is not well understood. Therefore, we compared mucosal biomarkers in normal weight individuals [body mass index (BMI), 18.5-24.9 kg/m(2)] with those in morbidly obese patients (BMI >40 kg/m(2)) before and 6 months after Roux-en-Y gastric bypass (RYGB). METHODS: Rectal epithelial cell mitosis, crypt area, and crypt branching were measured following whole crypt microdissection. Apoptosis was measured by immunohistochemistry for neo-cytokeratin 18 on fixed tissue sections. Serum levels of C-reactive protein and cytokines were assayed in combination with quantification of mucosal proinflammatory gene expression by real-time RT-PCR. RESULTS: Twenty-six morbidly obese patients (mean BMI, 54.4 kg/m(2)) had significantly increased mitosis, crypt area, and crypt branching (all P < 0.01) compared with 21 age- and sex-matched normal weight individuals (mean BMI, 22.5 kg/m(2)). Morbidly obese patients underwent a mean excess weight loss of 41.7% at a mean of 26 weeks after RYGB. Surprisingly, this was associated with a further increase in mitosis and decreased apoptosis of epithelial cells. At the same time, lower levels of serum C-reactive protein and interleukin-6 following RYGB were accompanied by a reduction in mucosal IL-6 protein content but elevated mucosal expression of other proinflammatory genes such as cyclooxygenase-1 and cyclooxygenase-2. CONCLUSIONS: Mucosal biomarkers, accepted as indicators of future colorectal cancer risk, are increased in morbidly obese patients compared with normal weight controls. The hyperproliferative state that exists 6 months after RYGB may have important implications for long-term colorectal cancer risk in bariatric surgery patients.

Poor tolerance of sirolimus in a steroid avoidance regimen for renal transplantation.

Vascular disease and chronic allograft nephropathy have prompted re-evaluation of steroids and calcineurin inhibitors (CNIs) in renal transplantation. Sirolimus (SRL) can facilitate early CNI withdrawal. We report on the Early CNI and Steroid Elimination in Leeds (ECSEL) study, which was terminated early due to poor tolerability of SRL. Basiliximab/methylprednisolone induction was used, then 2 months of tacrolimus (TAC) and mycophenolate mofetil (MMF) treatment. A total of 51 patients were randomized to continue TAC/MMF or switch to SRL/MMF. In ECSEL1, patients were switched at 2 months (n=10). In ECSEL2, SRL was introduced at months 4-6 and TAC was tapered (n=13). Median overall follow up was 701 days. All 10 ECSEL1 and 10 of 13 (77%) ECSEL2 patients discontinued SRL due to adverse events, including leucopenia, rash, mucosal ulceration, arthralgia, and possible pneumonitis. Mean end-of-study creatinine was comparable in all groups. Sirolimus should be used with caution in complete CNI and steroid withdrawal, due to the resultant intolerable adverse event profile.

3-month and 12-month mortality after first liver transplant in adults in Europe: predictive models for outcome.

BACKGROUND: Mortality after liver transplantation depends on heterogeneous recipient and donor factors. Our aim was to assess risk of death and to develop models to help predict mortality after liver transplantation. METHODS: We analysed data from 34,664 first adult liver transplants from the European Liver Transplant Registry to identify factors associated with mortality at 3-months (n=21,605 in training dataset) and 12-months (n=18,852 in training dataset) after transplantation. We used multivariable logistic regression models to generate mortality scores for each individual, and assessed model discrimination and calibration on an independent validation dataset (n=9489 for 3-month model and n=8313 for 12-month model). FINDINGS: 2540 of 21,605 (12%) individuals in the 3-month training sample had died by 3 months. Compared with those transplanted in 2000-03, those transplanted earlier had a higher risk of death. Increased mortality at 3-months post-transplantation was associated with acute liver failure (adjusted odds ratio 1.61), donor age older than 60 years (1.16), compatible (1.22) or incompatible (2.07) donor-recipient blood group, older recipient age (1.12 per 5 years), split or reduced graft (1.96), total ischaemia time of longer than 13 h (1.38), and low United Network for Organ Sharing score (score 1: 2.43; score 2: 1.67). However, cirrhosis with hepatocellular carcinoma, alcohol cirrhosis, hepatitis C or primary biliary cirrhosis, donor age 40 years or younger, or less, hepatitis B, and larger size of transplant centre (> or = 70 transplants per year) were associated with improved early outcomes. The 3-month mortality score discriminated well between those who did and did not die in the validation sample (C statistic=0.688). We noted similar findings for 12-month mortality, although deaths were generally underestimated at this timepoint. INTERPRETATION: The 3-month and 12-month mortality models can be effectively used to assess outcomes both within and between centres. Furthermore, the models provide a means of assessing the risk of post-transplantation mortality, giving clinicians important data on which to base strategic decisions about transplant policy in particular individuals or groups.

Genome of the pitcher plant Cephalotus reveals genetic changes associated with carnivory.

Carnivorous plants exploit animals as a nutritional source and have inspired long-standing questions about the origin and evolution of carnivory-related traits. To investigate the molecular bases of carnivory, we sequenced the genome of the heterophyllous pitcher plant Cephalotus follicularis, in which we succeeded in regulating the developmental switch between carnivorous and non-carnivorous leaves. Transcriptome comparison of the two leaf types and gene repertoire analysis identified genetic changes associated with prey attraction, capture, digestion and nutrient absorption. Analysis of digestive fluid proteins from C. follicularis and three other carnivorous plants with independent carnivorous origins revealed repeated co-options of stress-responsive protein lineages coupled with convergent amino acid substitutions to acquire digestive physiology. These results imply constraints on the available routes to evolve plant carnivory.

Endovascular management of arterial conduit pseudoaneurysm after liver transplantation: a report of two cases.

We describe two cases of pseudoaneurysms in liver-transplant iliac artery conduits, which were successfully treated with endovascular stent grafting.

Vascular access survival in children and young adults receiving long-term hemodialysis.

BACKGROUND: The delivery of long-term hemodialysis therapy in children is complicated by smaller vascular caliber and the potential lifelong requirement for hemodialysis access. Various factors have resulted in the increased use of cuffed central venous catheters (CVLs) in preference to autologous arteriovenous fistulae (AVFs) and arteriovenous synthetic grafts (AVGs). The aim of this study is to compare CVL, AVF, and AVG survival and determine factors affecting their survival. METHODS: A 20-year retrospective study was undertaken of pediatric patients receiving long-term hemodialysis therapy. Age, height, weight, body mass index, and sex were noted at each procedure, in addition to the presence of hypoalbuminemia, underlying diagnosis, type and site of vascular access, and effect of previous access surgery. The grade of operator also was noted. RESULTS: Three hundred four vascular access procedures were performed on 114 patients, with a median age at initial access formation of 12.0 years (range, 4 weeks to 21.9 years). The most common procedure was CVL insertion (182 procedures) and then AVF formation (107 procedures), with only 15 AVGs created. Median censored survival was 3.14 years (95% confidence interval, 1.22 to 5.06) for AVFs and 0.6 years (95% confidence interval, 0.20 to 1.00) for CVLs. Factors adversely affecting vascular access survival were younger age, trainee operator, presence of hypoalbuminemia, and type of access undertaken, with AVF better than CVL. CONCLUSION: This study shows increased survival of AVFs over CVLs and AVGs. Vascular access in children and adolescents may impact on future dialysis accessibility and should be undertaken by those most experienced in each technique.

A pharmacokinetic and clinical review of the potential clinical impact of using different formulations of cyclosporin A. Berlin, Germany, November 19, 2001.

A meeting of 14 transplant and pharmacokinetic specialists from Europe and North America was convened in November 2001 to evaluate scientific and clinical data regarding the use of different formulations of cyclosporin A (CsA). The following consensus was achieved. (1) CsA is a critical-dose drug with a narrow therapeutic window. Clinical outcomes after transplantation are affected by the pharmacokinetic properties of CsA, particularly by its bioavailability, and by intrapatient variability in CsA exposure. (2) Standard bioequivalence criteria do not address differences in CsA pharmacokinetics between transplant recipients and healthy volunteers, or between subpopulations of transplant recipients. (3) In some circumstances, currently available formulations of CsA that meet standard bioequivalence criteria are likely to be nonequivalent with respect to pharmacokinetic characteristics. (4) The choice of CsA formulation can affect the short- and long-term clinical outcome. Currently, there is a lack of clinical comparisons between generic CsA formulations and the Neoral formulation (Novartis Pharmaceuticals Corporation, East Hanover, New Jersey). Initial retrospective data from the Collaborative Transplant Study suggest that use of generic CsA formulations may result in reduced graft survival at 1 year. (5) Management of transplant recipients by monitoring Neoral concentrations 2 hours after dosing (C(2)) reduces the incidence and severity of acute rejection compared with monitoring of trough concentrations with no increase in toxicity. C(2) monitoring has been developed based on the pharmacokinetics of Neoral only and has not been evaluated or validated for generic formulations of CsA. (6) The major costs of care after transplantation relate to the management of poor clinical outcomes and toxicity. CsA formulations with different pharmacokinetic properties may be associated with varying clinical outcomes, which would be expected to affect total health care costs. (7) The transplant physician is responsible for selecting immunosuppressive agents and formulations for his or her patients. Any switch between CsA formulations in a particular patient should take place only in a controlled setting with adequate pharmacokinetic monitoring.

Caution in using a unique technique of banded revision gastric bypass: Successful endosopic and surgical management of a rare complication.

INTRODUCTION: Revision surgery is increasingly performed as result of the increase in primary bariatric procedures. We describe a new technique of revision Roux-en-Y gastric bypass (RYGB) acombining stapled gastroenterostomy with fixed band placement. We report two cases of unique complications and its successful endoscopic and surgical management. PRESENTATION OF CASE: Two out of twenty patients undergoing this revision RYGB procedure presented with gastric outlet obstruction due to band erosion within 10 weeks. Endoscopic band retrieval was successful in the first patient but the second patient required surgical removal. DISCUSSION: We report the new complication of band erosion in 10% patients using a unique revision RYGB technique combining restriction of the gastric outlet and band placement. We advise using one or the other technique but not both in combination. Surgeons need to be aware of this as erosion which occurs early due to close proximity of band with fresh staple line. We report successful endoscopic and surgical management. CONCLUSION: Revision surgery using this technique predisposes to bande erosion, presenting as gastric outlet obstruction. Endoscopic management should be attempted prior to surgical removal.

Alemtuzumab induction in renal transplantation permits safe steroid avoidance with tacrolimus monotherapy: a randomized controlled trial.

BACKGROUND: The use of alemtuzumab as induction immunosuppression for renal transplantation introduces the possibility of long-term tacrolimus monotherapy, avoiding maintenance with both corticosteroids and mycophenolate mofetil (MMF). METHODS: We conducted a single-center, prospective, open-label, randomized controlled trial comparing two steroid avoidance regimens between December 2006 and November 2010. One hundred and sixteen adult patients were randomized to either basiliximab induction followed by tacrolimus and MMF maintenance or to alemtuzumab induction followed by tacrolimus monotherapy. The primary endpoint was noninferiority of isotopic glomerular filtration rate at 1 year; secondary endpoints included patient and graft survival, incidence of delayed graft function, and incidence and severity of biopsy-proven acute rejection. RESULTS: The two groups were well matched for all baseline demographics. Isotopic glomerular filtration rate was comparable between the groups at 1 year (57±26 mL/min for alemtuzumab group and 53±21 mL/min for basiliximab group; P=0.42). Secondary endpoints were also similar between the groups. The rate of biopsy-proven acute rejection by 12 months was lower in the alemtuzumab group (n=6 vs. n=14 in basiliximab arm) just reaching statistical significance (P=0.049); however, a single extra case in the alemtuzumab arm included when considering clinically treated rejection removes this significance (P=0.082). Similar rates of cardiovascular, infective, and neoplastic complications were observed in both groups. Forty-seven (81.0%) of the patients in the alemtuzumab group remained on tacrolimus monotherapy at 12 months. CONCLUSIONS: Renal transplantation with alemtuzumab induction followed by tacrolimus monotherapy leads to good graft and patient outcomes, with no major differences detected compared with basiliximab induction and tacrolimus/MMF maintenance at 1 year.

Six steps to making your estate smarter.

Today, UK healthcare providers are under increasing pressure to cut costs, improve quality of care, and meet the changing needs of patients. However, asks Arup's Healthcare Business leader, UK, Middle East, and Africa, Stephen Pollard, are enough NHS Trusts using their estate effectively to overcome these new challenges?