Studies of the use of L-leucyl-L-leucine methyl ester in canine allogeneic marrow transplantation

L-leucyl-L-leucine methyl ester (Leu-Leu-OMe) is a lysosomotropic agent that selectively kills cytotoxic T cells and their precursors, natural killer cells, and monocytes but not helper T cells or other cells of hematopoietic origin. In this study, the effects of treatment of bone marrow and peripheral blood buffy coat with Leu-Leu-OMe on the outcome of allogeneic marrow transplantation were studied in several canine models. Whereas incubation of autologous marrow with Leu-Leu-OMe had no adverse effects on subsequent engraftment, incubation of marrow from dog leukocyte antigen (DLA)-identical littermates resulted in a high rate of graft failure. Previous studies have demonstrated that the addition of peripheral blood buffy coat allows engraftment of unrelated DLA-nonidentical marrow, and in this study we found that incubation of buffy coat with Leu-Leu-OMe did not alter this graft promoting effect. In a final experiment it was demonstrated that incubation of both marrow and peripheral blood buffy coat did not prevent the development of graft-versus-host disease in recipients of marrow from DLA-haploidentical littermates. In considering the eventual application of Leu-Leu-OMe in the clinic, these results are less encouraging than those previously reported using murine models.     

Rapid colorimetric bioassay for screening of Fusarium mycotoxins

Ultrasound energy was applied to 137 segments of human cadaver atherosclerotic arteries, 90 with calcified and 47 with noncalcified atheromatous plaque, and to 100 segments of healthy swine aorta. The average depth of penetration was dependent on the forward force of the ultrasonic probe, the duration of treatment, and the degree of atherosclerosis. There was one perforation of a fibrous plaque using a forward force of 2 Newton and 45 sec of application time. Injury of healthy intima was minimal. It is concluded that catheter-delivered ultrasound is effective and safe for the disintegration of atherosclerotic plaques. Presently, the main limitations of the system are the lack of flexibility and steerability.     

Possible non-sexual transmission of genital human papillomavirus infections in young women

Human papillomaviruses were detected by an in vitro enzymatic DNA amplification method in cells obtained from vulvar swabs of 9 of 61 (14.8%) young women without prior experience of sexual intercourse and in 7 of 57 (12.3%) young women with prior experience. The prevalence of human papillomavirus DNA in these two groups of women was not significantly different (x2 = 0.16, p > 0.5; 95% confidence interval -0.165 to 0.215). These results suggest that genital human papillomavirus is not sexually transmitted in all cases and that it may be acquired by modes other than sexual contact.     

A hybrid model combining case-based reasoning and fuzzy decision tree for medical data classification

In this research, a hybrid model is developed by integrating a case-based data clustering method and a fuzzy decision tree for medical data classification. Two datasets from UCI Machine Learning Repository, i.e., liver disorders dataset and Breast Cancer Wisconsin (Diagnosis), are employed for benchmark test. Initially a case-based clustering method is applied to preprocess the dataset thus a more homogeneous data within each cluster will be attainted. A fuzzy decision tree is then applied to the data in each cluster and genetic algorithms (GAs) are further applied to construct a decision-making system based on the selected features and diseases identified. Finally, a set of fuzzy decision rules is generated for each cluster. As a result, the FDT model can accurately react to the test data by the inductions derived from the case-based fuzzy decision tree. The average forecasting accuracy for breast cancer of CBFDT model is 98.4% and for liver disorders is 81.6%. The accuracy of the hybrid model is the highest among those models compared. The hybrid model can produce accurate but also comprehensible decision rules that could potentially help medical doctors to extract effective conclusions in medical diagnosis.     

Prototype system for pursuing firm’s core capability

Core capabilities are critical abilities that enhance and sustain an organization’s competitive advantage in extremely competitive environments. In today’s complex and dynamic business environment, companies are often prevented from effectively and efficiently evaluating relevant factors necessary for developing their core capability strategic systems. These systems, with inherent human decision-making processes, should be fully considered when creating a method for determining a firm’s suitable or required core capabilities. It is helpful to implement IT-based group decision support systems (GDSS) with soft computing algorithms to assist managers in determining the appropriate core capabilities for the firm. Therefore, this study develops a holistic group decision support system in which similarity measures, fuzzy set theory, and fuzzy mathematics programming are implemented to facilitate managers in making decisions. Through evaluations done in actual cases, we have found that this system creates a flexible and user-friendly environment that aids top management and other relevant staff members in evaluating all relevant factors related to core capabilities.     

Microstructure and formability of ZnNi alloy electrodeposited sheet steel

ZnNi alloy electrodeposited sheet steels were made from a chloride bath using a high-speed flow cell. A Ni-rich flash coating was deposited first, upon which the ZnNi coating, with Ni contents ranging from 8 to 16 wt pct, was subsequently electrodeposited. It is demonstrated that the Ni content of the coating affects the forming properties and microstructure of the ZnNi coatings. The hardness of the ZnNi coating increased with Ni content, leading to poor formability and inferior adhesion of the coated steels, as evident from the large amount of coating loss during swift cupping and coating peel-off during low-temperature adhesion tests. On the other hand, the friction force between the coated steel and cupping die decreased with increasing Ni content. At low Ni contents of 8 wt pct, the coating had a porous equiaxed grain structure. As the Ni content increased, the coating surface changed to dense faceted morphologies. A pyramid morphology was observed for 16 wt pct ZnNi coatings. An X-ray diffraction (XRD) analysis showed that all coatings containing up to 16 wt pct Ni contained only γ phase. Transmission electron microscopy (TEM) observations showed the 8 wt pct Ni coating to have a fine-grained structure, which changed to a columnar structure at 16 wt pct Ni. The formation of the columnar structure is explained by the smaller amount of hydrogen discharge as the bath Ni ion concentration increased.     

Prediction model building with clustering-launched classification and support vector machines in credit scoring

Recently, credit scoring has become a very important task as credit cards are now widely used by customers. A method that can accurately predict credit scoring is greatly needed and good prediction techniques can help to predict credit more accurately. One powerful classifier, the support vector machine (SVM), was successfully applied to a wide range of domains. In recent years, researchers have applied the SVM-based in the prediction of credit scoring, and the results have been shown it to be effective. In this study, two real world credit datasets in the University of California Irvine Machine Learning Repository were selected. SVM and a new classifier, clustering-launched classification (CLC), were employed to predict the accuracy of credit scoring. The advantages of using CLC are that it can classify data efficiently and only need one parameter needs to be decided. In substance, the results show that CLC is better than SVM. Therefore, CLC is an effective tool to predict credit scoring.     

Enhanced ab initio protein folding simulations in Poisson-Boltzmann molecular dynamics with self-guiding forces

We have investigated the sampling efficiency in molecular dynamics with the PB implicit solvent when self-guiding forces are added. Compared with a high-temperature dynamics simulation, the use of self-guiding forces in room-temperature dynamics is found to be rather efficient as measured by potential energy fluctuation, gyration radius fluctuation, backbone RMSD fluctuation, number of unique clusters, and distribution of low RMSD structures over simulation time. Based on the enhanced sampling method, we have performed ab initio folding simulations of two small proteins, betabetaalpha1 and villin headpiece. The preliminary data for the folding simulations is presented. It is found that betabetaalpha1 folding proceeds by initiation of the turn and the helix. The hydrophobic collapse seems to be lagging behind or at most concurrent with the formation of the helix. The hairpin stability is weaker than the helix in our simulations. Its role in the early folding events seems to be less important than the more stable helix. In contrast, villin headpiece folding proceeds first by hydrophobic collapse. The formation of helices is later than the collapse phase, different from the betabetaalpha1 folding.     

Preparation of a DNA aptamer-Pt complex and its use in the colorimetric sensing of thrombin and anti-thrombin antibodies

DNA aptamers carrying Pt nanoparticles were prepared by the reaction of DNA aptamers (without functionalization with biotin, thiol, or other reactive groups) with K 2[PtCl 4] in solution at 60-90 degrees C. The DNA-Pt complexes possessed peroxidase enzymatic activity while retaining the specific binding ability of the aptamers. The enzymatic reaction of these complexes obeyed Michaelis-Menten kinetics. K M for the DNA-Pt complex was found to be on the same order as K M for hemin and hemin-DNA complex but 1 or 2 orders of magnitude higher than that of horseradish peroxidase. The rate of the reaction catalyzed by the DNA-Pt complex, k cat, was found to be on the same order as that of hemin and hemin-DNA complex but 2 or 3 orders of magnitude lower than that of horseradish peroxidase. Two types of DNAzyme-linked aptamer assays (DLAAs) were developed using these complexes, which successfully detected target proteins, with the sandwich type of DLAA targeting thrombin and the competitive type of DLAA targeting anti-thrombin IgA/G/M in serum. The DNA-Pt complexes retained their peroxidase enzymatic activity even after heat treatment. DLAAs having high thermal stability were developed using these complexes, which were free of animal and plant matter because neither antibodies nor horseradish peroxidase were used in their synthesis.