Factors influencing outcome and incidence of long-term complications in children who underwent autologous stem cell transplantation for acute myeloid leukemia in first complete remission

To evaluate factors influencing outcome and incidence of long-term complications, we analyzed, in a retrospective, multicenter study, 387 children who underwent autologous hematopoietic stem cell transplantation (HSCT) for acute myeloid leukemia (AML) in first complete remission (CR). Median follow-up time from transplantation was 60 months. Transplantation of bone marrow cells was performed in 318 children, whereas in 60 patients peripheral blood progenitor cells (PBPCs) were used. In multivariate analysis, we investigated the variables influencing probability of hematopoietic recovery, transplantation-related mortality (TRM), relapse, and leukemia-free survival (LFS). We found that use of PBPCs as stem cell sources and use of BCNU (N,N-bis[2-chloroethyl]-N-nitrosourea), amsacrine, VP-16, and cytosine arabinoside (BAVC) as a preparative regimen were associated with faster neutrophil recovery. Infusion of PBPCs, young age of patients, use of BAVCs, and absence of marrow purging predicted an accelerated platelet reconstitution. The 5-year Kaplan-Meier estimates of TRM, relapse, and LFS were 3% +/- 1%, 39% +/- 3% and 60% +/- 3%, respectively. Relapse probability was increased in children given the BAVC regimen, and it was decreased after in vitro purging of hematopoietic progenitors and in children with a French-American-British classification of M3 and a time interval of 170 days or more between CR and HSCT. These 2 latter variables favorably influenced the probability of LFS, which was, by contrast, reduced with the BAVC regimen. Thirty-three percent of patients surviving more than 18 months experienced at least one late sequela; use of total body irradiation was the only predictive factor. The results obtained in this analysis can be of help in designing prospective studies of autologous HSCT in children with AML in first CR.     

Hematopoietic stem cell transplantation for de novo erythroleukemia: a study of the European Group for Blood and Marrow Transplantation (EBMT)

De novo erythroleukemia (EL) is a rare disease. Reported median survival are poor and vary from 4 to 14 months. The value of hematopoietic stem cell transplantation (HSCT) for EL is unknown. This EBMT registry study reports on the largest series of patients with EL treated with HSCT in first complete remission-103 autologous and 104 HLA identical sibling allogeneic HSCT. Outcome and identification of prognostic factors for each type of transplantation were evaluated. For autologous HSCT, outcome at 5 years showed a leukemia-free survival (LFS) of 26% +/- 5%, a relapse incidence (RI) of 70% +/- 6%, and a transplant-related mortality (TRM) of 13% +/- 4%. By multivariate analysis, the only prognostic factor was age. For allogeneic HSCT, outcome at 5 years showed an LFS of 57% +/- 5%, an RI of 21% +/- 5%, and a TRM of 27% +/- 5%. By multivariate analysis, prognostic factors were graft-versus-host disease and age. This study represents the largest series of de novo EL treated with HSCT and shows that allogeneic HSCT is by far the most effective treatment.     

Hepatic gene expression profiling reveals perturbed calcium signaling in a mouse model lacking both LDL receptor and Apobec1 genes

Atherosclerosis is a complex disease that gene and environment interaction influences the progression of atherosclerotic lesion development. Our laboratory used mice lacking both the low density lipoprotein (LDL) receptor and Apobec1 genes (LDLR-/-Apobec1-/-, designated LDb) to investigate gene-gene interaction and the influence of an environmental factor (high-fat diet) on gene networks. LDb mice (males and females) at 5 months of age were fed a chow or high fat diet for 3-month. The mice on a chow diet had elevated plasma cholesterol and triglyceride levels and developed atherosclerosis. Feeding a high-fat diet accelerated the development of lesions >1.5-fold. We performed microarray analysis of the expression of 12442 murine genes in the livers of these animals, which identified 54 genes in males and 77 genes in females were significantly perturbed by the high-fat diet. Moreover, most of these genes (>70%) were upregulated. The results suggested that glycolysis, fat transport, and steroid hormone biosynthesis pathways were upregulated, probably to compensate for the high fat intake. Furthermore, a batch of stress-responsive genes was upregulated. The study also shows a dynamic cellular communication network including T cells, neutrophils, and monocytes/macrophages, which related to inflammatory and immune/complement responses. Importantly, this study discovered that many genes involved in calcium signaling and bone formation were up regulated. Alizarin Red S staining was used to detect calcium deposits in the region of atherosclerotic lesions. Real-time quantitative RT-PCR and Western blot analyses provided verification of the gene expression levels. In conclusion, this study demonstrated the global differential gene expression profiles, which are influenced by feeding a high fat diet to LDb mice. The results of the study provide new insights into the significance of calcification in atherogenesis.     

Chemical properties of lipids strongly affect the kinetics of the membrane-induced aggregation of α-synuclein

Intracellular α-synuclein deposits, known as Lewy bodies, have been linked to a range of neurodegenerative disorders, including Parkinson’s disease. α-Synuclein binds to synthetic and biological lipids, and this interaction has been shown to play a crucial role for both α-synuclein’s native function, including synaptic plasticity, and the initiation of its aggregation. Here, we describe the interplay between the lipid properties and the lipid binding and aggregation propensity of α-synuclein. In particular, we have observed that the binding of α-synuclein to model membranes is much stronger when the latter is in the fluid rather than the gel phase, and that this binding induces a segregation of the lipids into protein-poor and protein-rich populations. In addition, α-synuclein was found to aggregate at detectable rates only when interacting with membranes composed of the most soluble lipids investigated here. Overall, our results show that the chemical properties of lipids determine whether or not the lipids can trigger the aggregation of α-synuclein, thus affecting the balance between functional and aberrant behavior of the protein.The protein α-synuclein is mainly found in the presynaptic termini of neurons (1). The protein has been shown to populate a highly unstructured form in its unbound state both in vitro and in vivo and to adopt an α-helical conformation when bound to membranes (2). The balance between these two states has been found to play a role both in the proposed biological function of the protein, including the regulation of synaptic plasticity, and in the kinetics of its pathogenic aggregation; the latter is the hallmark of a range of diseases, known as synucleinopathies, of which the most common is Parkinson’s disease (3, 4). α-Synuclein has been shown to have its highest affinity for membranes containing either anionic lipids or so-called ”packing defects” (5–7), where the latter are defined as low-density regions in bilayers with high exposure of the lipid hydrophobic chains attributable to a mismatch between lipid shape and bilayer curvature (6, 7).Biological membranes are highly heterogeneous and differ from one cell or organelle to another in terms of the physical and chemical properties of the membranes, including curvature, charge, fluidity, and packing of the hydrophobic chains (8–10). The variety of membrane structures in cells can be directly related to differences in lipid (and protein) composition, where properties such as length and saturation of the hydrocarbon chain as well as the charge and size of the polar head group are crucial in determining the properties of the membrane (8, 9). In particular, most chemical and thermotropic properties of a lipid molecule are known to vary almost linearly with the length of its hydrophobic chain. As some examples, the standard change in free energy of transfer of a lipid molecule from water into a bilayer (i.e., its solubility in water), the melting temperature, and the enthalpy of melting have all been found to be proportional to the number of aliphatic carbons in the hydrophobic chain, which ranges from 8 to 18 (11). In addition, the adsorption and partitioning of small molecules and proteins to membranes can also affect the structural and thermotropic properties of the latter, and the magnitude and characteristics of these changes depend on the nature of the molecular interactions (e.g., electrostatic, hydrophobic) (12, 13).The interactions between amphipathic proteins and membranes have been extensively studied over the last three decades (7, 14–22). In general, the amino acid sequences of these peripheral proteins are characterized by patterns of hydrophobic and polar residues such that the proteins fold into amphipathic α-helices upon binding to hydrophobic patches exposed at the membrane interface (16, 17). In particular, molecular dynamics simulations and neutron reflectometry studies of deposited bilayers have shown that the amphipathic helix in α-synuclein is primarily located in the vicinity of the lipid phosphate groups and the glycerol backbone (16, 23–25).Although the binding of α-synuclein to membranes has been well characterized for different lipid systems (26–28), the observed modulation of the kinetics of the conversion of monomeric α-synuclein into amyloid fibrils by different membranes is less well understood (29–32). Most studies of this phenomenon have been performed under conditions of mechanical agitation (32) and/or in the presence of catalyzing polymer surfaces (31), where α-synuclein aggregates also in the absence of lipids and where the mechanism of aggregation has not yet been elucidated. Here, we take a different approach using an experimental procedure with protein-repellant surfaces and under quiescent conditions (33) that enables the systematic study of the manner in which a change in lipid properties can affect the ability of a model membrane to initiate α-synuclein aggregation. Indeed, we have previously shown that the presence of model membranes composed of 1,2-dimyristoyl-sn-glycero-3-phospho-l-serine (DMPS) triggers the aggregation of α-synuclein by specifically enhancing the rate of primary nucleation (33). In addition, this study showed how the protein:lipid (P:L) ratio modulates the kinetics of α-synuclein aggregation in the presence of DMPS; at low P:L ratios, effectively all of the protein molecules are adsorbed onto the surface of the membrane in a thermodynamically stable α-helical state and no aggregation is observed. At high P:L ratios, however, the protein molecules populate both the free monomeric state and the membrane-bound state, leading to rapid amyloid formation (33).In the present study, we have applied this experimental procedure to probe how changes in the chemical (charge and solubility) and physical (thermotropic) properties of lipids affect the binding of α-synuclein and the magnitude by which model membranes can trigger α-synuclein aggregation. The results reveal that the efficiency of the binding of α-synuclein to model membranes is correlated with their fluidity and, conversely, that the self-assembly of the lipids is affected by their association with the protein. In addition, although α-synuclein has a high affinity for all of the fluid anionic model membranes investigated here, this interaction is not sufficient for the efficient induction of aggregation. Rather, the rate of amyloid fibril formation is shown to be inversely correlated with the free energy of transfer of the lipid molecule from water into the bilayer. These results indicate that the chemical properties of the lipids are likely to play an important role in perturbing the balance between functional and deleterious interactions of α-synuclein with membranes.     

Maternal Self-confidence Postpartum and at Pre-school Age: The Role of Depression,Anxiety Disorders,Maternal Attachment Insecurity

The aim of this study was to analyze the impact of maternal postpartum depression and/or anxiety disorders according to DMS-IV on maternal self-confidence throughout infancy and early childhood. Exploratively, associations between maternal attachment insecurity and maternal self-confidence at pre-school age were examined. The sample (N = 54) of this prospective longitudinal study was comprised of n = 27 women with postpartum depression and/or anxiety disorders according to DSM-IV criteria and n = 27 healthy women without present or history of mental health disorders or psychotherapy. Data was collected in the postpartum period (M = 60.08 days) and at pre-school age (M = 4.7 years). Subjects were recruited between 2004 and 2011 in South Germany. Data revealed a significant difference in maternal self-confidence between clinical and control group at child′s pre-school age: Women with postpartum depression and/or anxiety disorder scored lower on maternal self-confidence than healthy controls, but only if they had current SCID-diagnoses or partly remitted symptoms. According to explorative analyses maternal attachment insecurity turned out to be the strongest predictor of maternal self-confidence at pre-school age besides maternal mental health status. The results emphasize the impact of attachment insecurity and maternal mental health regarding maternal self-confidence leading to potential adverse long-term consequences for the mother–child relationship. Attachment based interventions taking maternal self-confidence into account are needed.     

Care and prejudice: moving beyond mistrust in the care relationship with addicted patients

Social representations of addiction and the resulting stigmatization have been widely described and studied in the literature, but their effects are no less problematic. These representations, which also occur in care settings, generate a climate of distrust which damages the therapeutic relationship, and its ethical quality. This article, combining clinical experience and an ethical stance, offers an original, innovating approach to the existence of distrust in care relationships in the area of addiction. Pragmatic approaches deriving from the human sciences and analytical philosophy provide an invitation to escape from the demanding climate of mistrust, and to take the gamble on trust so as to improve the quality of interactions between protagonists in care. In complementary fashion, a sociology of action can combat the disquiet generated by distrust through a new commitment to innovating forms of action. This “poetic” mode of action is legitimized by the reflection that backs it up, and by its presentation to peers qualified to approve it. Finally, continental moral philosophy underlines the importance of a carefully weighed commitment on the part of caregivers and addicted patients towards promises aiming to support a sincere care relationship, without damaging the therapeutic dynamic or the ethical quality by providing too many safety nets. This reflection is intended to achieve better identification of the clinical and ethical issues raised by mistrust, and inclusion of these aspects in the training of personnel and in care provision planning.     

Regulation of senescence traits by MAPKs

GeroScience - A phenotype of indefinite growth arrest acquired in response to sublethal damage, cellular senescence affects normal aging and age-related disease. Mitogen-activated protein kinases...     

Construct validity of nine new inanimate exercises for robotic surgeon training using a standardized setup

Background

As more surgeons choose to complete procedures robotically, validated training tools are needed so that they can acquire and maintain the technical skills required to proficiently use robotic systems. The purpose of this study was to show construct validity of nine new inanimate training exercises for robot-assisted surgery. The inanimate training exercises were designed to span several core technical skills required to use a robotic system.

Methods

New (n = 30) and experienced (n = 11) robotic surgeons participated in the study. New robotic surgeons had not yet completed their first robotic surgery case and participated in this study before attending their robotic certification course. Experienced robotic surgeons had completed more than 200 robotic surgery cases. The raw scores from the exercises were reported so that other research groups could easily define custom proficiency levels. Example normalized scores that could be used in proficiency-based curricula were computed. These normalized scores balanced efficiency (completion time) and accuracy (exercise-specific errors) to measure performance. Finally, the setup was standardized using a custom docking model, which enabled consistent and repeatable completion of the inanimate exercises across surgeons.

Results

For all nine exercises, experienced robotic surgeons completed the exercises significantly faster than new robotic surgeons (p < 0.01). Similarly, experienced robotic surgeons achieved higher normalized scores than new robotic surgeons for all nine exercises (p < 0.01). Finally, consistent robot setup was achieved using the custom docking model based on an analysis of the robot kinematic data.

Conclusions

In summary, all nine inanimate exercises showed construct validity. The results suggest that the inanimate exercises along with the custom docking model can be used as part of proficiency-based curricula to improve robotic surgeon training.     

Breakdown of Phosphatidylserine Asymmetry Following Treatment of Erythrocytes with Lumefantrine

Background: Lumefantrine, a commonly used antimalarial drug, inhibits hemozoin formation in parasites. Several other antimalarial substances counteract parasitemia by triggering suicidal death or eryptosis of infected erythrocytes. Eryptosis is characterized by cell shrinkage and cell membrane scrambling leading to phosphatidylserine-exposure at the erythrocyte surface. Signaling involved in eryptosis include increase of cytosolic Ca²⁺-activity ([Ca²⁺]_i), formation of ceramide, oxidative stress and/or activation of p38 kinase, protein kinase C (PKC), or caspases. The present study explored, whether lumefantrine stimulates eryptosis. Methods: Cell volume has been estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, [Ca²⁺]_i from Fluo3-fluorescence, reactive oxygen species from 2'',7''-dichlorodihydrofluorescein-diacetate fluorescence, content of reduced glutathione (GSH) from mercury orange fluorescence, and ceramide abundance from binding of fluorescent antibodies in flow cytometry. Results: A 48 h exposure to lumefantrine (3 µg/mL) was followed by a significant increase of annexin-V-binding without significantly altering forward scatter, [Ca²⁺]_i, ROS formation, reduced GSH, or ceramide abundance. The annexin-V-binding following lumefantrine treatment was not significantly modified by p38 kinase inhibitors SB203580 (2 μM) and p38 Inh III (1 μM), PKC inhibitor staurosporine (1 µM) or pancaspase inhibitor zVAD (1 or 10 µM). Conclusions: Lumefantrine triggers cell membrane scrambling, an effect independent from entry of extracellular Ca²⁺, ceramide formation, ROS formation, glutathione content, p38 kinase, PKC or caspases.