Novel telomeric repeat elongation assay performed on zinc oxide nanorod array supports

We developed a highly sensitive and effective telomeric repeat elongation (TRE) assay by exploiting the fluorescence signal enhancing ability of ZnO nanorod (NR) platforms. We report that this novel ZnO NR-based TRE assay can be successfully used for detecting active telomerase. Our TRE assays enable complex biological reactions between many different biological components to take place effectively on various ZnO NR platforms. Therefore, ZnO NRs can effectively determine telomerase activity even at ultratrace concentration level, by functioning as excellent fluorescence enhancing biosupports. We also show the potential of ZnO NR-based TRE assays in a high-throughput and multiplexed screening of active telomerase in a large number of samples. As telomerase is a useful biomarker in cancer diagnosis and screening, our ZnO NR-based TRE assays may prove to be not only useful in basic biological research but also in clinical testing.     

Offset invariance in maximum-likelihood decoding for a class ofpartial response channels

In this letter we show that for a class of partial response channels with discrete-time pulse response of the form (1-D)P(D) whose output samples are corrupted by independent samples of additive white Gaussian noise with mean m, a maximum likelihood sequence detector designed for the case of m=0 is also the maximum likelihood sequence detector for an arbitrary value of m. The studied class of partial response channels is widely used for the characterization of digital magnetic recording channels where the DC offset is frequently an issue     

A spatial data handling system for retrieval of images by unrestricted regions of user interest

The Intelligent Data Management (IDM) project at NASA/GSFC has prototyped an Intelligent Information Fusion System (IIFS) that automatically ingests metadata from remote sensor observations into a large catalog. One of the challenges in the implementation of this catalog has been supporting spatially driven searches, where the user has a possibly complex region of interest and wishes to recover those images that overlap all or simply part of that region. A novel spatial data management system that is capable of storing and retrieving records of image data regardless of their source is described. This system has been designed and implemented as part of the IIFS catalog. A new data structure, the hypercylinder, is central to the design. The hypercylinder is specifically tailored for data distributed over the surface of a sphere, such as satellite observations of the Earth or space. Operations on the hypercylinder are regulated by two expert systems. The first governs the ingest of new metadata records, and maintains the efficiency of the data structure as it grows. The second translates, plans, and executes users' spatial queries, performing incremental optimization as partial query results are returned.     

Influence of the Plasma Treatment Regimes on the Surface Morphology and Properties of Films Applied to Steel from Heptane Plasma

Atomic force microscopy, x-ray photoelectron spectroscopy, chemical analysis, and the method of measuring the contact angle were used to reveal the correlation between the surface morphology, physicochemical properties, and texture of films applied to steel by glow discharge in heptane plasma. In the glow zone at low pressure and discharge power, the resulting thin layer is sticky, and its surface has protruding macromolecular conoidal and spheroidal formations. With an increase in the pressure and discharge power, this layer disappears, while the formations become more numerous and then coalesce. The maximum thickness, roughness, and strength of the films and their minimum permeability were found to correlate with the maximum number of the above conoids and spheroids at the film surface. Apparently, they are film growth centers; their formation is caused by the relaxation of internal stresses in the film or lengthy defects in the base metal. In the absence of glow, the sticky film contains no macromolecular formations.     

Monte Carlo validation of a multireader method for receiver operating characteristic discrete rating data: factorial experimental design

RATIONALE AND OBJECTIVES: The authors conducted a series of null-case Monte Carlo simulations to evaluate the Dorfman-Berbaum-Metz (DBM) method for comparing modalities with multireader receiver operating characteristic (ROC) discrete rating data. MATERIALS AND METHODS: Monte Carlo simulations were performed by using discrete ratings on fully crossed factorial designs with two modalities and three, five, and 10 hypothetical readers. The null hypothesis was true for all simulations. The population ROC areas, latent variable structures, case sample sizes, and normal/abnormal case sample ratios used in another study were used in these simulations. RESULTS: For equal allocation ratios and small (Az = 0.702) and moderate (Az = 0.855) ROC areas, the empirical type I error rate closely matched the nominal alpha level. For very large ROC areas (Az = 0.961), however, the empirical type I error rate was somewhat smaller than the nominal alpha level. This conservatism increased with decreasing case sample size and asymmetric normal/abnormal case allocation ratio. The empirical type I error rate was sometimes slightly larger than the nominal alpha level with many cases and few readers, where there was large residual, relatively small treatment-by-case interaction and relatively large treatment-by-reader interaction. CONCLUSION: The results suggest that the DBM method provides trustworthy alpha levels with discrete ratings when the ROC area is not too large and case and reader sample sizes are not too small. In other situations, the test tends to be somewhat conservative or slightly liberal.     

Structure of the ankyrin-binding domain of alpha-Na,K-ATPase

The ankyrin 33-residue repeating motif, an L-shaped structure with protruding beta-hairpin tips, mediates specific macromolecular interactions with cytoskeletal, membrane, and regulatory proteins. The association between ankyrin and alpha-Na,K-ATPase, a ubiquitous membrane protein critical to vectorial transport of ions and nutrients, is required to assemble and stabilize Na,K-ATPase at the plasma membrane. alpha-Na,K-ATPase binds both red cell ankyrin (AnkR, a product of the ANK1 gene) and Madin-Darby canine kidney cell ankyrin (AnkG, a product of the ANK3 gene) utilizing residues 142-166 (SYYQEAKSSKIMESFK NMVPQQALV) in its second cytoplasmic domain. Fusion peptides of glutathione S-transferase incorporating these 25 amino acids bind specifically to purified ankyrin (Kd = 118 +/- 50 nM). The three-dimensional structure (2.6 A) of this minimal ankyrin-binding motif, crystallized as the fusion protein, reveals a 7-residue loop with one charged hydrophilic face capping a double beta-strand. Comparison with ankyrin-binding sequences in p53, CD44, neurofascin/L1, and the inositol 1,4,5-trisphosphate receptor suggests that the valency and specificity of ankyrin binding is achieved by the interaction of 5-7-residue surface loops with the beta-hairpin tips of multiple ankyrin repeat units.     

Immunohistochemical staining for bcl-2 and mcl-1 in intrathyroidal epithelial thymoma (ITET)/carcinoma showing thymus-like differentiation (CASTLE) and cervical thymic carcinoma

Intrathyroidal epithelial thymoma (ITET)/carcinoma showing thymus-like differentiation (CASTLE), a rare thyroid neoplasm, was recently shown to be immunoreactive for CD5, providing immunophenotypic evidence of previously postulated thymic differentiation. To assess whether ectopic malignant neoplasms with thymic differentiation display other markers associated with thymic carcinoma, we studied five cases of ITET/CASTLE, two cases of cervical thymic carcinoma, and one case of cervical thymoma for bcl-2 and mcl-1 immunoreactivity. Both of these antiapoptosis proto-oncogenes have been reported to be expressed by the majority of true thymic carcinomas but only a minority of thymomas. All of the five cases of ITET/CASTLE, both CD5-positive cervical thymic carcinomas, and one CD5-negative cervical thymoma were immunoreactive for bcl-2, as were 10 (91%) of 11 thymic carcinomas arising in the thymus, in contrast to 6 (25%) of 24 benign and invasive thymomas arising in the thymus. Similarly, all of the five cases of ITET/CASTLE, both cervical thymic carcinomas, but not the cervical thymoma, were immunoreactive for mcl-1, as were 9 (90%) of 10 thymic carcinomas, in contrast to 6 (33%) of 18 benign and invasive thymomas. We conclude that dual immunoreactivity for bcl-2 and mcl-1 is a feature of malignant neoplasms with thymic differentiation in general, both within the thymus and at ectopic sites.     

The role of Ly49A and 5E6(Ly49C) molecules in hybrid resistance mediated by murine natural killer cells against normal T cell blasts

Due to affluence and a sedentary life style a great deal of people in the western countries are affected by coronary heart disease (CHD). The relation between CHD and certain risk factors pertaining to life style is evaluated in this study. A primary purpose is to study certain crucial risk factors for women. The main variables are age, smoking, overweight (measured by BMI), blood pressure and exercise. This prospective study is based on self-reported data from the nation-wide Swedish Level of Living Survey and on data from the national Cause of Death Register. The data were analysed separately by sex using a proportional hazards model. The sample was divided into two strata: those with heart disease and/or diabetes initially, and all the rest. A sample of 2546 men and 2760 women between 45 and 74 years of age was followed from 1980 to the end of 1990. During this period 189 men and 75 women died of coronary heart disease (CHD). It was found that high blood pressure raised the relative risk (RR) of death from CHD by almost 60% in both men and women. Male smokers (> 14 cigarettes a day) had about 60% (significant) and female smokers (> 10 cigarettes a day) 150% (significant) excessive mortality from CHD. Different levels of overweight among women were strongly related to excess mortality from CHD, ranging between 100 and 300%. Among men there was no such relation. Lack of physical activity showed only a weak (non-significant) increased risk of death due to CHD. Diabetes was also found to be an important risk factor for mortality from CHD, especially among women, being seven times as high as among non diabetics. A test of sex differences revealed that there were two significant interactions, namely between sex and overweight, and between sex and age. Background variables in relation to mortality from all cardiovascular diseases (CVD) were also studied. There were of course many similarities between the effects of the background variables in both the disease groups, but there were interesting differences too, e.g. overweight turned out to be a significant risk factor also for men and physical inactivity for women.