Diphtheria toxin fused to granulocyte-macrophage colony-stimulating factor eliminates acute myeloid leukemia cells with the potential to initiate leukemia in immunodeficient mice, but spares normal hemopoietic stem cells

We studied the cell kill induced by granulocyte-macrophage colony-stimulating factor (GM-CSF ) fused to Diphtheria Toxin (DT-GM-CSF ) in acute myeloid leukemia (AML) samples and in populations of normal primitive hemopoietic progenitor cells. AML samples from three patients were incubated in vitro with 100 ng/mL DT-GM-CSF for 48 hours, and AML cell kill was determined in a proliferation assay, a clonogenic assay colony-forming unit-AML (CFU-AML) and a quantitative long-term bone marrow (BM) culture ie, the leukemic-cobblestone area forming cell assay (L-CAFC). To measure an effect on cells with in vivo leukemia initiating potential DT-GM-CSF exposed AML cells were transplanted into immunodeficient mice. In two out of three samples it was shown that all AML subsets, including those with long-term abilities in vivo (severe combined immunodeficient mice) and in vitro (L-CAFC assay) were reduced in number by DT-GM-CSF. Cell kill induced by DT-GM-CSF could be prevented by coincubation with an excess of GM-CSF, demonstrating that sensitivity to DT-GM-CSF is specifically mediated by the GM-CSF receptor. Therefore, binding and internalization of GM-CSF probably occur in immature AML precursors of these two cases of AML. The third AML sample was not responsive to either GM-CSF or DT-GM-CSF. The number of committed progenitors of normal bone marrow (burst-forming unit-erythroid, colony-forming unit granulocyte- macrophage, and cobble stone area forming cell [CAFC] week 2) and also the number of cells with long-term repopulating ability, assayed as week 6 CAFC, were unchanged after exposure to DT-GM-CSF (100 ng/mL, 48 hours). These studies show that DT-GM-CSF may be used to eliminate myeloid leukemic cells with long-term potential in vitro and in immunodeficient mice, whereas normal hemopoietic stem cells are spared.     

Characterization and frequency distribution of species of lactic acid bacteria involved in the processing of mawè, a fermented maize dough from Benin

Lactic acid bacteria involved in the natural fermentation of both home-produced and commercial mawè were investigated during a 72 h fermentation period. Lactobacillus spp. constitute the majority (94%) of the strains of the lactic acid bacteria isolated, among which 89% represent the Betabacterium group. They include L. fermentum (biotype cellobiosus) (41%), L. fermentum or L. reuteri (19%), L. brevis (26%), L. confusus (less than 2%), L. curvatus (less than 1%) and L. buchneri (less than 1%). Other isolated lactic acid bacteria were L. salivarius, Lactococcus lactis, Pediococcus pentosaceus, Pediococcus acidilactici and Leuconostoc mesenteroides. Several species were detected at the early stage of fermentation, but the final stage was dominated by L. fermentum (biotype cellobiosus) and L. fermentum or L. reuteri totalling 90% of the isolated strains. The trend was the same for both home-produced and commercial mawè. No strains of L. plantarum, generally reported as dominating lactic acid bacteria at the final stage of fermentation of most plant foods, were isolated.     

An Unconstrained Architecture for Systematic Design of Higher Order $SigmaDelta$ Force-Feedback Loops

Nowadays, $SigmaDelta$ -modulation is a widely used technique for analog-to-digital (A/D) conversion, especially when aiming for high resolutions. While being applied initially for purely electrical A/D converters, its application has been expanded to mixed mechanical–electrical systems. This has led to the use of $SigmaDelta$ force-feedback for digital readout of high-performance inertial sensors. However, compared with their electrical counterpoint, $SigmaDelta$ force-feedback loops often have to deal with three additional issues: 1) an increased stability problem due to phase-lag occurring in the sensor; 2) the injection of relatively high levels of readout noise in the loop; and 3) the lack of degrees-of-freedom of many $SigmaDelta$ force-feedback architectures for implementing an arbitrary noise transfer function. As a result, $SigmaDelta$ force-feedback loops found in literature are designed in a much less systematic way as compared with electrical $SigmaDelta$ modulators. In this paper, we address these issues and propose a new unconstrained architecture. Based on this architecture, we are able to present a systematic approach for designing $SigmaDelta$ force-feedback loops. Additionally, the main strengths and weaknesses of different $SigmaDelta$ force-feedback architectures are discussed.      

Nonparametric density estimation for positive time series

The Gaussian kernel density estimator is known to have substantial problems for bounded random variables with high density at the boundaries. For independent and identically distributed data, several solutions have been put forward to solve this boundary problem. In this paper, we propose the gamma kernel estimator as a density estimator for positive time series data from a stationary α-mixing process. We derive the mean (integrated) squared error and asymptotic normality. In a Monte Carlo simulation, we generate data from an autoregressive conditional duration model and a stochastic volatility model. We study the local and global behavior of the estimator and we find that the gamma kernel estimator outperforms the local linear density estimator and the Gaussian kernel estimator based on log-transformed data. We also illustrate the good performance of the h-block cross-validation method as a bandwidth selection procedure. An application to data from financial transaction durations and realized volatility is provided.     

GM-CSF receptor targeted treatment of primary AML in SCID mice using Diphtheria toxin fused to huGM-CSF

The severe combined immunodeficient (SCID) mouse model may be used to evaluate new approaches for the treatment of acute myeloid leukemia (AML). We have previously demonstrated the killing of SCID mouse leukemia initiating cells by in vitro incubation with human GM-CSF fused to Diphtheria toxin (DT-huGM-CSF). In this report, we show that in vivo treatment with DT-huGM-CSF eliminates AML growth in SCID mice. Seven cases of AML were studied. SCID mice were treated intraperitoneally with the maximally tolerated dose of 75 microg/kg/day for 7 days. Antileukemic efficacy was determined at days 40 and 80 after transplantation, by enumerating the percentages of human cells in SCID bone marrow using flow cytometry and short tandem repeat polymerase chain reaction (STR-PCR) analysis. Four out of seven AML cases were sensitive to in vivo treatment with DT-huGM-CSF at both evaluation time points. In three of these cases, elimination of human cells was demonstrated by flow cytometry and STR-PCR. One AML case showed moderate sensitivity for DT-huGM-CSF, and growth of the two remaining AML cases was not influenced by DT-huGM-CSF. Sensitivity was correlated with GM-CSFR expression. Our data show that DT-huGM-CSF can be used in vivo to reduce growth of AML and warrant further development of DT-huGM-CSF for the treatment of human AML.     

Conditions Governing Food Protein Amyloid Fibril Formation. Part II: Milk and Legume Proteins

Both intrinsic and extrinsic factors impact amyloid formation of food proteins. We here review the impact of various conditions and food constituents on amyloid fibrillation of milk and legume proteins. Much less is known about casein and legume protein amyloid‐like fibril formation than about that of whey proteins such as β‐lactoglobulin, α‐lactalbumin, and bovine serum albumin. Proteins of both sources are often studied after heating under strong acidic (pH < 3) conditions. The latter induces changes in protein conformation and often peptide hydrolysis. At higher pH values, alcohols, chaotropic and/or reducing agents induce the conformational changes required to enhance fibrillation. Different types of food proteins can impact each other's fibrillation. Also, the presence of other food constituents can enhance or reduce it. No general conclusions on the mechanisms or impact of different food constituents on food proteins can be made. Optimal conditions for AF formation, that is, heating for several days at low pH, are rare in food processing. However, this does not exclude the possibility of AF formation in food products. For example, slow cooking of hydrolyzed proteins may enhance it. Future research should focus on the prevalence of AFs in complex food systems or model systems relevant for food processing.     

Behavior of Clostridium perfringens at low temperatures

Refrigerated storage is an important step in the preparation of foods and inadequate storage is one of the main causes of food poisoning outbreaks of Clostridium perfringens. Therefore, growth and germination characteristics of C. perfringens in a temperature range of 3-42 degrees C were determined in fluid thioglycollate broth (FTG) and Dutch pea soup. To study the effect of adaptation, cells were either inoculated from a 37 degrees C pre-culture or from a temperature-adapted pre-culture. Membrane fatty acid patterns were determined at all temperatures to examine the effect of temperature on membrane composition. Spores were either inoculated with and without heat treatment. Adaptation of cells did not influence growth rate nor lag phase. Growth in pea soup, however, was slower and lag phases tended to be more extended compared to FTG. No growth was observed at temperatures < or =10 degrees C and death rates in pea soup were higher than those in FTG at these low temperatures. Cells preserved the membrane fluidity by reducing the arachidic acid content and increasing the lauric acid content when the temperature dropped. This resulted in a net reduction in chain length. Microscopic analysis of cells grown at 15 degrees C revealed a morphological change: cells were elongated compared to those grown at 37 degrees C. These data demonstrate the ability of C. perfringens to adapt to lower temperatures. However, this did not influence growth characteristics compared to non-adapted cells. Spores of C. perfringens did germinate at all temperatures with and without heat-activation. Combining this fact with the extended survival at low temperatures emphasizes the need for adequate heating of refrigerated foods before consumption to eliminate health risks due to C. perfringens.     

Topology optimization of fail-safe structures using a simplified local damage model

Topology optimization of mechanical structures often leads to efficient designs which resemble statically determinate structures. These economical structures are especially vulnerable to local loss of stiffness due to material failure. This paper therefore addresses local failure of continuum structures in topology optimization in order to design fail-safe structures which remain operable in a damaged state.

A simplified model for local failure in continuum structures is adopted in the robust approach. The complex phenomenon of local failure is modeled by removal of material stiffness in patches with a fixed shape. The damage scenarios are taken into account by means of a minimax formulation of the optimization problem which minimizes the worst case performance.

The detrimental influence of local failure on the nominal design is demonstrated in two representative examples: a cantilever beam optimized for minimum compliance and a compliant mechanism. The robust approach is applied successfully in the design of fail-safe alternatives for the structures in these examples.

     

Acetylsalicylic Acid Reduces Passive Aortic Wall Stiffness and Cardiovascular Remodelling in a Mouse Model of Advanced Atherosclerosis

Acetylsalicylic acid (ASA) is widely used in secondary prevention of cardiovascular (CV) disease, mainly because of its antithrombotic effects. Here, we investigated whether ASA can prevent the progression of vessel wall remodelling, atherosclerosis, and CV complications in apolipoprotein E deficient (ApoE^−/−) mice, a model of stable atherosclerosis, and in ApoE^−/− mice with a mutation in the fibrillin-1 gene (Fbn1^C1039G+/−), which is a model of elastic fibre fragmentation, accompanied by exacerbated unstable atherosclerosis. Female ApoE^−/− and ApoE^−/−Fbn1^C1039G+/− mice were fed a Western diet (WD). At 10 weeks of WD, the mice were randomly divided into four groups, receiving either ASA 5 mg/kg/day in the drinking water (ApoE^−/− (n = 14), ApoE^−/−Fbn1^C1039G+/− (n = 19)) or plain drinking water (ApoE^−/− (n = 15), ApoE^−/−Fbn1^C1039G+/− (n = 21)) for 15 weeks. ApoE^−/−Fbn1^C1039G+/− mice showed an increased neutrophil–lymphocyte ratio (NLR) compared to ApoE^−/− mice, and this effect was normalised by ASA. In the proximal ascending aorta wall, ASA-treated ApoE^−/−Fbn1^C1039G+/− mice showed less p-SMAD2/3 positive nuclei, a lower collagen percentage and an increased elastin/collagen ratio, consistent with the values measured in ApoE^−/− mice. ASA did not affect plaque progression, incidence of myocardial infarction and survival of ApoE^−/−Fbn1^C1039G+/− mice, but systolic blood pressure, cardiac fibrosis and hypertrophy were reduced. In conclusion, ASA normalises the NLR, passive wall stiffness and cardiac remodelling in ApoE^−/−Fbn1^C1039G+/− mice to levels observed in ApoE^−/− mice, indicating additional therapeutic benefits of ASA beyond its classical use.     

A 8?mW 72?dB ΣΔ-modulator ADC with 2.4?MHz BW in 130?nm CMOS

A double-sampling split ????-ADC with bilinear integrators and a 7-level quantizer is presented. It achieves third order noise shaping with a second order modulator through quantization noise-coupling. The modulator is integrated in a 130?nm CMOS technology. For a clock frequency of 48?MHz and an oversampling ratio of 20 (2.4?MHz signal bandwidth), it achieves 72?dB DR and 68?dB SNR. The prototype consumes 8?mW from a 1.2?V voltage supply.