Cardiac transplantation: five years' activity

OBJECTIVE: To analyze the initial five years experience of the new heart transplant program of Coimbra University Hospitals. METHODS: Between November 2003 aid December 2008, 132 patients were transplanted, with a mean age of 52.0 years (range 3-71 years), of whom 98 were male (74%). Half of the patients had dilated cardiomyopathy and 33% ischemic cardiomyopathy. The mean age of donors was 31.7 years and 102 were male (77%). Donor hearts were harvested at a distance in 62% of cases. There was a gender mismatch between donor and recipient (F:M) in 19% of cases and ABO blood type disparity (not identical but compatible) in 11%. In all cases we used the technique of total transplantation with bicaval anastomosis, modified in this center. Mean ischemia time was 88.9 +/- 32.2 minutes. All patients received induction therapy with basiliximab and methylprednisolone. RESULTS: Six patients (4.5%) died within 30 days or during hospitalization, due to graft failure in four and hyperacute rejection in two. Two patients required prolonged ventilation, ten (8%) required inotropic support for more than 48 hours, and four required pacemaker implantation. Mean hospital stay was 15.6 +/- 15.2 days (median 13 days). Ninety percent of patients (116/129) were maintained on triple immunosuppressive therapy, including cyclosporine, the remainder receiving tacrolimus. In 23 patients it was necessary to change the immunosuppressive regimen due to renal and/or tumoral complications, or humoral rejection. All patients are followed regularly in the Surgical Center. Thirteen patients (10%) died late of cancer (6 patients), infection (4 patients), and pancreatitis, pulmonary hypertension and suicide (one patient each). Twenty-two patients (17%) had 25 episodes of cellular rejection (> or = 2R), with clinical consequences in only one case, and five had humoral rejection (3.9%). No patients died of late rejection, but there is evidence of mild graft vascular disease in one. Actuarial survival (Kaplan-Meier) at one and five years was 90% and 82%, respectively. CONCLUSION: In this initial series of five years we obtained results equivalent to or bette than those in centers with wider and longer experience, aided by self-correction arising from our own experience. This program has increased the rate of cardiac transplantation in Portugal to above the European average

Cardiac allograft systolic function. Is the aetiology (ischaemic or idiopathic) a determinant of ventricular function in the heart transplant patient?

The natural history of the LV systolic function (LV-SF) and functional capacity of survivors of heart transplantation (Htx) has not been defined. Some investigators suggest that SF may be different in recipients with different pre-transplant aetiologies: ischaemic or dilated, idiopathic disease. Routine transthoracic echocardiograms (TTE) were performed during a 1-year follow-up in 48 Htx recipients (total 864 examinations; mean 18/patient). Patients were divided into two groups based on pre-transplant diagnosis: ischaemic (CAD-CMP: n=13, age 54+/-1.7 years, 23% females) and idiopathic dilated cardiomyopathy (ID-CMP: n=35, age 51+/-2.3 years, 26% females). Patients with valvular and toxic aetiology were excluded. All patients underwent left ventriculography (VENT) 12-15 months after Htx. The majority of 1-year survivors of Htx maintained normal LV-SF: mean LVEF 65+/-4% by echocardiography and 68+/-3% by ventriculography, but in the ID-CMP group LVEF was significantly higher: 67+/-4% vs. 62+/-4% (TTE) and 77+/-4% vs. 60+/-4% (VENT), without significant differences in functional capacity (NYHA). 82.9% of ID-CMP patients had LVEF >65% vs. 39% in CAD-CMP. The incidence of acute cellular rejection, freedom from cardiac vasculopathy, renal failure, diabetes, hypertension and pre-transplant alloantibody level was similar. Our study shows a strong correlation between pre-transplant heart disease and the systolic function of the cardiac allograft at 1-year follow-up

A decade of cardiac transplantation in Coimbra: the value of experience

INTRODUCTION AND OBJECTIVES: To analyze the experience gained in 10 years of the heart transplantation program of the University Hospital of Coimbra. METHODS: Between November 2003 and December 2013, 258 patients with a mean age of 53.0±12.7 years (3-72 years) and predominantly male (78%) were transplanted. Over a third of patients had ischemic (37.2%) and 36.4% idiopathic cardiomyopathy. The mean age of donors was 34.4±1.3 years and 195 were male (76%), with gender difference between donor and recipient in 32% of cases and ABO disparity (non-identical groups but compatible) in 18%. Harvest was distant in 59% of cases. In all cases total heart transplantation with bicaval anastomoses, modified at this center, was used. Mean ischemia time was 89.7±35.4 minutes. All patients received induction therapy. RESULTS: Early mortality was 4.7% (12 patients) from graft failure and stroke in five patients each, and hyperacute rejection in two. Thirteen patients (5%) required prolonged ventilation, 25 (11.8%) required inotropic support for more than 48 hours, and seven required pacemaker implantation. Mean hospital stay was 15.8±15.3 days (median 12 days). Ninety percent of patients were maintained on triple immunosuppressive therapy including cyclosporine, the remainder receiving tacrolimus. In 23 patients it was necessary to change the immunosuppression protocol due to renal and/or neoplastic complications and humoral rejection. All but two patients have been followed in the Surgical Center. Fifty patients (19.4%) subsequently died from infection (18), cancer (10), vascular (eight), neuropsychiatric (four), cardiac (two) or other causes (eight). Forty-six patients (17.8%) had episodes of cellular rejection (>2 R on the ISHLT classification), eight had humoral rejection (3.1%), and 22 have evidence of graft vascular disease (8.5%). Actuarial survival at 1, 5, and 8 years was 87±2%, 78±3% and 69±4%, respectively. CONCLUSION: This 10-year series yielded results equivalent or superior to those of centers with wider and longer experience, and have progressively improved following the introduction of changes prompted by experience. This program has made it possible to raise and maintain the rate of heart transplantation to values above the European average

Tobacco smoking is associated with DNA methylation of diabetes susceptibility genes.

AIMS/HYPOTHESIS: Tobacco smoking, a risk factor for diabetes, is an established modifier of DNA methylation. We hypothesised that tobacco smoking modifies DNA methylation of genes previously identified for diabetes. METHODS: We annotated CpG sites available on the Illumina Human Methylation 450K array to diabetes genes previously identified by genome-wide association studies (GWAS), and investigated them for an association with smoking by comparing current to never smokers. The discovery study consisted of 630 individuals (Bonferroni-corrected p = 1.4 × 10(-5)), and we sought replication in an independent sample of 674 individuals. The replicated sites were tested for association with nearby genetic variants and gene expression and fasting glucose and insulin levels. RESULTS: We annotated 3,620 CpG sites to the genes identified in the GWAS on type 2 diabetes. Comparing current smokers to never smokers, we found 12 differentially methylated CpG sites, of which five replicated: cg23161492 within ANPEP (p = 1.3 × 10(-12)); cg26963277 (p = 1.2 × 10(-9)), cg01744331 (p = 8.0 × 10(-6)) and cg16556677 (p = 1.2 × 10(-5)) within KCNQ1 and cg03450842 (p = 3.1 × 10(-8)) within ZMIZ1. The effect of smoking on DNA methylation at the replicated CpG sites attenuated after smoking cessation. Increased DNA methylation at cg23161492 was associated with decreased gene expression levels of ANPEP (p = 8.9 × 10(-5)). rs231356-T, which was associated with hypomethylation of cg26963277 (KCNQ1), was associated with a higher odds of diabetes (OR 1.06, p = 1.3 × 10(-5)). Additionally, hypomethylation of cg26963277 was associated with lower fasting insulin levels (p = 0.04). CONCLUSIONS/INTERPRETATION: Tobacco smoking is associated with differential DNA methylation of the diabetes risk genes ANPEP, KCNQ1 and ZMIZ1. Our study highlights potential biological mechanisms connecting tobacco smoking to excess risk of type 2 diabetes

Pharmacological Primary Cardiovascular Prevention and Subclinical Atherosclerosis in Men: Evidence from the Aragon Workers' Health Study.

The objective of this study is to describe the profile of primary preventive treatment for cardiovascular disease in adult males and to analyze the association between treatment profile and subclinical atherosclerosis. We selected male workers who had undergone ultrasound imaging and had no previous history of cardiovascular disease (n = 2138). Data on the consumption of primary cardiovascular drugs from the previous year were obtained. We performed bivariate analyses to compare patient characteristics according to cardiovascular treatment and the presence of subclinical atherosclerosis, and logistic regression models to explore the association between these two variables. Among participants with no personal history of cardiovascular disease, subclinical atherosclerosis was present in 77.7% and 31.2% had received some form of preventive treatment. Of those who received no preventive treatment, 73.6% had subclinical atherosclerosis. Cardiovascular preventive treatment was associated only with CACS > 0 (odds ratio (OR), 1.37; 95% confidence interval (95% CI), 1.06-1.78). Statin treatment was associated with a greater risk of any type of subclinical atherosclerosis (OR, 1.73) and with CACS > 0 (OR, 1.72). Subclinical atherosclerosis existed in almost 75% of men who had no personal history of cardiovascular disease and had not received preventive treatment for cardiovascular disease

Quantitative super-resolution imaging of pathological aggregates reveals distinct toxicity profiles in different synucleinopathies.

Protein aggregation is a hallmark of major neurodegenerative disorders. Increasing data suggest that smaller aggregates cause higher toxic response than filamentous aggregates (fibrils). However, the size of small aggregates has challenged their detection within biologically relevant environments. Here, we report approaches to quantitatively super-resolve aggregates in live cells and ex vivo brain tissues. We show that Amytracker 630 (AT630), a commercial aggregate-activated fluorophore, has outstanding photophysical properties that enable super-resolution imaging of α-synuclein, tau, and amyloid-β aggregates, achieving ∼4 nm precision. Applying AT630 to AppNL-G-F mouse brain tissues or aggregates extracted from a Parkinson's disease donor, we demonstrate excellent agreement with antibodies specific for amyloid-β or α-synuclein, respectively, confirming the specificity of AT630. Subsequently, we use AT630 to reveal a linear relationship between α-synuclein aggregate size and cellular toxicity and discovered that aggregates smaller than 450 ± 60 nm (aggregate450nm) readily penetrated the plasma membrane. We determine aggregate450nm concentrations in six Parkinson's disease and dementia with Lewy bodies donor samples and show that aggregates in different synucleinopathies demonstrate distinct potency in toxicity. We further show that cell-penetrating aggregates are surrounded by proteasomes, which assemble into foci to gradually process aggregates. Our results suggest that the plasma membrane effectively filters out fibrils but is vulnerable to penetration by aggregates of 450 ± 60 nm. Together, our findings present an exciting strategy to determine specificity of aggregate toxicity within heterogeneous samples. Our approach to quantitatively measure these toxic aggregates in biological environments opens possibilities to molecular examinations of disease mechanisms under physiological conditions

Baryonic symmetries and M5 branes in the AdS_4/CFT_3 correspondence

We study U(1) symmetries dual to Betti multiplets in the AdS_4/CFT_3 correspondence for M2 branes at Calabi-Yau four-fold singularities. Analysis of the boundary conditions for vector fields in AdS_4 allows for a choice where wrapped M5 brane states carrying non-zero charge under such symmetries can be considered. We begin by focusing on isolated toric singularities without vanishing six-cycles, and study in detail the cone over Q^{111}. The boundary conditions considered are dual to a CFT where the gauge group is U(1)^2 x SU(N)^4. We find agreement between the spectrum of gauge-invariant baryonic-type operators in this theory and wrapped M5 brane states. Moreover, the physics of vacua in which these symmetries are spontaneously broken precisely matches a dual gravity analysis involving resolutions of the singularity, where we are able to match condensates of the baryonic operators, Goldstone bosons and global strings. We also argue more generally that theories where the resolutions have six-cycles are expected to receive non-perturbative corrections from M5 brane instantons. We give a general formula relating the instanton action to normalizable harmonic two-forms, and compute it explicitly for the Q^{222} example. The holographic interpretation of such instantons is currently unclear.Comment: 92 pages, 10 figure

Waves on the surface of the Orion molecular cloud

Massive stars influence their parental molecular cloud, and it has long been suspected that the development of hydrodynamical instabilities can compress or fragment the cloud. Identifying such instabilities has proved difficult. It has been suggested that elongated structures (such as the `pillars of creation') and other shapes arise because of instabilities, but alternative explanations are available. One key signature of an instability is a wave-like structure in the gas, which has hitherto not been seen. Here we report the presence of `waves' at the surface of the Orion molecular cloud near where massive stars are forming. The waves seem to be a Kelvin-Helmholtz instability that arises during the expansion of the nebula as gas heated and ionized by massive stars is blown over pre-existing molecular gas.Comment: Preprint of publication in Natur