Thermal tolerance in the keystone species Daphnia magna-a candidate gene and an outlier analysis approach.

Changes in temperature have occurred throughout Earth's history. However, current warming trends exacerbated by human activities impose severe and rapid loss of biodiversity. Although understanding the mechanisms orchestrating organismal response to climate change is important, remarkably few studies document their role in nature. This is because only few systems enable the combined analysis of genetic and plastic responses to environmental change over long time spans. Here, we characterize genetic and plastic responses to temperature increase in the aquatic keystone grazer Daphnia magna combining a candidate gene and an outlier analysis approach. We capitalize on the short generation time of our species, facilitating experimental evolution, and the production of dormant eggs enabling the analysis of long-term response to environmental change through a resurrection ecology approach. We quantify plasticity in the expression of 35 candidate genes in D. magna populations resurrected from a lake that experienced changes in average temperature over the past century and from experimental populations differing in thermal tolerance isolated from a selection experiment. By measuring expression in multiple genotypes from each of these populations in control and heat treatments, we assess plastic responses to extreme temperature events. By measuring evolutionary changes in gene expression between warm- and cold-adapted populations, we assess evolutionary response to temperature changes. Evolutionary response to temperature increase is also assessed via an outlier analysis using EST-linked microsatellite loci. This study provides the first insights into the role of plasticity and genetic adaptation in orchestrating adaptive responses to environmental change in D. magna.

Functional scaffold-free 3-D cardiac microtissues: a novel model for the investigation of heart cells.

To bridge the gap between two-dimensional cell culture and tissue, various three-dimensional (3-D) cell culture approaches have been developed for the investigation of cardiac myocytes (CMs) and cardiac fibroblasts (CFs). However, several limitations still exist. This study was designed to develop a cardiac 3-D culture model with a scaffold-free technology that can easily and inexpensively generate large numbers of microtissues with cellular distribution and functional behavior similar to cardiac tissue. Using micromolded nonadhesive agarose hydrogels containing 822 concave recesses (800 µm deep × 400 µm wide), we demonstrated that neonatal rat ventricular CMs and CFs alone or in combination self-assembled into viable (Live/Dead stain) spherical-shaped microtissues. Importantly, when seeded simultaneously or sequentially, CMs and CFs self-sorted to be interspersed, reminiscent of their myocardial distribution, as shown by cell type-specific CellTracker or antibody labeling. Microelectrode recordings and optical mapping revealed characteristic triangular action potentials (APs) with a resting membrane potential of -66 ± 7 mV (n = 4) in spontaneously contracting CM microtissues. Under pacing, optically mapped AP duration at 90% repolarization and conduction velocity were 100 ± 30 ms and 18.0 ± 1.9 cm/s, respectively (n = 5 each). The presence of CFs led to a twofold AP prolongation in heterogenous microtissues (CM-to-CF ratio of 1:1). Importantly, Ba(2+)-sensitive inward rectifier K(+) currents and Ca(2+)-handling proteins, including sarco(endo)plasmic reticulum Ca(2+)-ATPase 2a, were detected in CM-containing microtissues. Furthermore, cell type-specific adenoviral gene transfer was achieved, with no impact on microtissue formation or cell viability. In conclusion, we developed a novel scaffold-free cardiac 3-D culture model with several advancements for the investigation of CM and CF function and cross-regulation.

Alkaline phosphatase (alp) levels in multiple myeloma and solid cancers with bone lesions: Is there any difference?

INTRODUCTION: Bone involvement in Multiple Myeloma results from increased osteoclast formation and activity that occurs in proximity to myeloma cells. The role of Alkaline Phosphatse (ALP) in this process and the diagnostic significance of plasma levels in patients with MM are unclear. AIM: To compare plasma ALP levels in patients with MM and solid cancers and metastatic lesions to the bone. RESULTS: In this observational retrospective study we enrolled 901 patients were enrolled: 440 patients (49%) with Multiple Myeloma, 461 (51%) with solid cancers. All 901 patients had bone lesions. Among patients with Multiple Myeloma, ALP values were mainly in the range of normality than those observed in patients with solid cancers and bone lesions. This difference is independent of stage, number and type of bone lesions. CONCLUSION: This study suggests that plasma ALP has a different clinical significance in MM than in other neoplasms and could be used as a discriminating marker in presence of bone lesions. In particular, lower or normal values, should suggest further investigations such as urinary and serum electrophoresis, associated with bone marrow aspirate in case of the presence of a monoclonal component, in order to confirm or exclude a MM diagnosis.

Prevalence of allo-immunization anti-HLA and anti-integrin alphaIIbbeta3 in Glanzmann Thromboasthenia patients.

SUMMARY: Platelet transfusions, main therapy of Glanzmann Thromboasthenia (GT), can induce an allo-immunization against human leucocyte antigen and integrin alphaIIbbeta3. We have investigated in our GT patients the rate of allo-immunization and of refractoriness to platelet transfusions. From 1975 until December 2005, we have followed 17 GT patients: 14 type 1, 3 variant type; nine females, eight males; median age at diagnosis 9.8 years (range 1-44.5); median age at the time of the study 35.5 years (range 23.6-68.5). In our patients, 121 bleeding episodes occurred (24 severe, 37 moderate, and 60 mild). Ten major and 22 minor surgical procedures have been performed. Two spontaneous deliveries and three caesarian sections with five live births were performed; moreover, one late foetal loss occurred, and one voluntary abortion was performed. Sixteen of 17 patients have been transfused at least once in life with platelets and/or red blood cells (RBC). All transfused patients have been investigated for the presence of anti-HLA and anti-integrin alphaIIbbeta3 allo-antibodies. The positiveness of allo-antibodies has been demonstrated in 4/16 transfused patients (25%): isolated for anti-HLA in two; isolated for anti-integrin alphaIIbbeta3 in one; and combined in one. In spite of the presence of allo-antibodies, platelet transfusions have always been effective and the haemostasis was not compromised.

Paroxysmal atrial fibrillation in myotonic dystrophy type 1 patients: P wave duration and dispersion analysis.

OBJECTIVE: Myotonic dystrophy type 1 (MD1) is characterized by cardiac involvement, in about 80% of case, that predominantly affects the conduction system. Aim of our study was to evaluate the P-wave duration and dispersion (PD) in MD1 patients underwent pacemaker implantation with conserved systolic and diastolic function. PATIENTS AND METHODS: We enrolled 60 MD1 patients (age 51.3 ± 5 years; 11 females) underwent dual chamber pacemaker implantation for various grade of atrioventricular (AV) block. Sixty sex-and age matched non-MD1 subjects were recruited as controls. P-wave duration and dispersion were carefully measured using 12-lead electrocardiogram. RESULTS: Compared with healthy control group, MD1 patients presented increased maximum P wave duration (106.4 ± 20.9 vs 65.9 ± 8.2 ms, p = 0.03) and PD values (40.1 ± 11 vs 27.1 ± 4.2 ms, p = 0.003). No statistically significant difference was found in minimum P wave duration (69.7 ± 11.8 vs 65.4 ± 8.1 ms, p = 0.4). The MD1 patients with paroxysmal atrial fibrillation, compared with MD1 patients without evidence of atrial fibrillation, presented increased maximum P wave duration (108.1 ± 10.4 vs 78.1 ± 7.9 ms, p = 0.001) and PD values (41.1 ± 8.5 vs 33.2 ± 4.2 ms, p = 0.003). Minimum P wave duration (68.4 ± 8.2 vs 67.1 ± 4.9 ms, p = 0.5) didn't differ between the two groups. CONCLUSIONS: Our data showed a significantly increased P wave duration and dispersion in MD1 patients compared with age and sex-matched healthy controls. We showed a statistically significant increase in PD and P max in MD1 patients subgroup with AF compared to MD1 patients with no arrhythmias.

Diagnostic and prognostic role of PET/CT in patients with chronic lymphocytic leukemia and progressive disease.

In order to evaluate the predictive value of positron emission tomography-computed tomography (PET/CT) in discriminating the presence of a Richter's syndrome (RS) or a second malignancy (SM), as well as to evaluate its prognostic value in patients with chronic lymphocytic leukemia (CLL), we retrospectively analyzed the data of 90 patients who, in the suspicion of a RS or a SM, underwent PET/CT followed by the biopsy of the involved tissue. The median maximum Standardized Uptake Value (SUV max) in the presence of a CLL/small lymphocytic lymphoma, a diffuse large B-cell lymphoma (DLBCL), a Hodgkin lymphoma (HL), a SM were 3.5, 14.6, 7.0 and 6.3, respectively (P ⩽ 0.0001). A SUV max cutoff value ⩾ 5 showed a sensitivity, specificity, positive and negative predictive values of 88.2, 71.2, 51.3 and 94%, respectively, for the presence of a more aggressive disease (DLBCL, HL and SM). A SUV max ⩾ 5 identified also a subset of treatment naive patients with an inferior progression-free survival (P = 0.011) and overall survival (P = 0.067). These findings suggest that PET/CT may helpfully integrate the biologically-based prognostic stratification of CLL. Prospective clinical trials including larger cohorts of patients are needed to conclusively define the role and prognostic impact of PET/CT in the routine management of CLL patients.

[Value of the transcranial Doppler examination in the diagnosis of brain death]. / Valor del examen Doppler transcraneal en el diagnóstico de la muerte cerebral.

BACKGROUND: Transcranial Doppler examination (TCD) is a non invasive method capable of detecting the interruption of cerebral flow in patients with criteria of brain death. Its recognition as an alternative to isoelectric EEG for the diagnosis of brain death requires previous validation. METHODS: Twenty-six patients in profound coma were examined by TCD. Of 23 patients with technically adequate study 13 manifested clinical criteria and EEG of brain death. Of these patients 9 had received barbiturate treatment and 4 had not. RESULTS: Changes in the flow waves of the TCD were observed in the form of diastolic reflux or systolic points of slight amplitude without diastolic flow in at least 2 arteries in 12 of 13 patients with criteria of brain death (sensitivity = 92%) and in none of the 10 patients without criteria of brain death (specificity = 100%). The use of barbiturates did not modify the normal anterograde flow detected by TCD in the absence of criteria of brain death. CONCLUSIONS: Transcranial Doppler is a good method for confirming the clinical diagnosis of brain death, fundamentally in patients undergoing treatment with drugs depressing the central nervous system.

The effect of aortic coarctation surgical repair on QTc and JTc dispersion in severe aortic coarctation newborns: a short-term follow-up study.

Sudden death is a possible occurrence for newborns younger than 1 year with severe aortic coarctation (CoA) before surgical correction. In our previous study, we showed a significant increase of QTc-D and JTc-D in newborns with isolated severe aortic coarctation, electrocardiographic parameters that clinical and experimental studies have suggested could reflect the physiological variability of regional and ventricular repolarization and could provide a substrate for life-threatening ventricular arrhythmias. The aim of the current study was to evaluate the effect of surgical repair of CoA on QTc-d, JTc-d in severe aortic coarctation newborns with no associated congenital cardiac malformations. The study included 30 newborns (18M; 70+/-12 h old) affected by severe congenital aortic coarctation, without associated cardiac malformations. All newborns underwent to classic extended end-to-end repair. Echocardiographic and electrocardiographic measurements were performed in each patient 24 h before and 24 h after the interventional procedure and at the end of the follow-up period, 1 month after the surgical correction. All patients at baseline, 24 h and one month after CoA surgical repair did not significantly differ in terms of heart rate, weight, height, and echocardiographic parameters. There were no statistically significant differences in QTc-D (111.7+/-47.4 vs 111.9+/-63.8 ms vs 108.5+/-55.4 ms; P=0.4) and JTc-D (98.1+/-41.3 vs 111.4+/-47.5 vs 105.1+/-33.4 ms; P=0.3) before, 24 h and 1 month after CoA surgical correction. In conclusions, our study did not show a statistically significant decrease in QTc-D and JTc-D, suggesting the hypothesis that the acute left ventricular afterload reduction, related to successful CoA surgical correction, may not reduce the ventricular electrical instability in the short-term follow-up.

Subacute combined degeneration without nutritional anemia.

Subacute combined degeneration (SCD) is a rare neurological complication of cobalamin deficiency, characterized by demyelination of the dorsal and lateral spinal cord. The diagnosis and treatment of SCD can be delayed if a patient does not present with clear clinical and laboratory signs of nutritional anemia, which has a marked effect on neurological recovery. We report a 62-year-old man with SCD with a history of gastric cancer and chronic alcoholism who presented with ataxia, gait disturbance, urinary incontinence, and limb weakness, but without other clinical or laboratory signs of cobalamin deficiency. The SCD diagnosis was confirmed by 3-Tesla MRI, which showed intramedullary signal alteration in the posterior columns of the entire spinal cord.

The biocompatibility of rapidly degrading polymeric stents in porcine carotid arteries.

The goal of this study was to evaluate the biocompatibility of materials for use in fully bioabsorbable vascular stents. 10:90 poly(L-lactic-co-glycolic acid) (10:90 L-PLGA), 85:15 poly(L-lactic-co-glycolic acid) (85:15 L-PLGA), polydioxanone (PDO), and poly-L-lactic acid (L-PLA) polymers were chosen as materials. Polymeric fibers were woven into a braided structure with a mass equivalent to or greater than that expected for a vascular stent, secured to balloon-expandable bare metal stents and implanted into porcine carotid arteries. The in vivo response was analyzed at 30 and 90 days by angiography, histopathology, and histomorphometry. All vessels were patent at 30 and 90 days. Injury score and neointima formation was mild for all samples. The faster-degrading 10:90 L-PLGA had the highest inflammatory response at 30 days, but was completely absorbed with minimal inflammation and neointimal formation at 90 days. PDO showed signs of partial absorption at 90 days, while 85:15 L-PLGA and L-PLA demonstrated minimal absorption at 30 and 90 days. The inflammatory response to these three groups was similar over the experimental period. Using a robust materials-testing platform, we demonstrated long-term patency and intravascular biocompatibility of bioabsorbable polymers with varying rates of resorption. The data point to biocompatibility of a polymeric stent in the vascular space that is fully absorbable in less than a year.

[Budd-Chiari syndrome and splanchnic vein thrombosis: masked myeloproliferative neoplasms and JAK2V617F]. / Sindrome di Budd-Chiari e trombosi delle vene splancniche: neoplasie mieloproliferative mascherate e mutazione di JAK2V617F.

The Budd-Chiari Syndrome (BCS) and the splanchnic vein thrombosis are characterized by hepatic venous outflow obstruction, generally due to venous thrombosis. These rare diseases are usually caused by multiple concurrent factors, including acquired and inherited thrombophilias. Since the diagnosis of myeloproliferative neoplasms (MPNs) is often difficult in patients with BCS and splanchnic vein thrombosis because of spleen enlargement, secondary pancytopenia and bleeding disorders, recent observations have included in the diagnostic work-up the analysis of the JAK2 mutation. The revision of several recent reports clarify the importance of the JAK2V617F detection in the diagnostic work-up of the BCS and splanchnic vein thrombosis, allowing the demonstration of masked MPNs among these cases that may benefit, in the near future, of target molecular therapies directed toward the JAK2 mutation.