Showing papers by "University of North Carolina at Chapel Hill published in 1990"

Anti-neutrophil cytoplasmic autoantibodies induce neutrophils to degranulate and produce oxygen radicals in vitro.

Abstract: Anti-neutrophil cytoplasmic autoantibodies (ANCA) are in the circulation of most patients with pauci-immune necrotizing vasculitis and pauci-immune crescentic glomerulonephritis. The current study demonstrates an effect of these autoantibodies on neutrophil function in vitro. ANCA cause normal human neutrophils to undergo an oxidative burst and degranulate. Both ANCA phenotypes (i.e., cytoplasmic-pattern ANCA and myeloperoxidase-specific ANCA) induce neutrophil activation. ANCA sera and purified immunoglobulins significantly increase the release of reactive oxygen species when compared with controls. ANCA, in a dose-dependent manner, induce the release of primary granule contents. These effects are markedly enhanced by priming neutrophils with tumor necrosis factor. Flow cytometry studies demonstrate the presence of myeloperoxidase on the surface of neutrophils after cytokine priming, indicating that primed neutrophils have ANCA antigens at their surfaces to interact with ANCA. These observations suggest an in vivo pathogenetic role for ANCA. We propose that, in patients with necrotizing vasculitis, ANCA-induced release of toxic oxygen radicals and noxious granule enzymes from cytokine-primed neutrophils could be mediating vascular inflammation.

Methodological Guidelines for Impedance Cardiography

Abstract: Impedance cardiography was introduced over 20 years ago as a noninvasive and unobtrusive technique for measuring systolic time intervals and cardiac output. Although our understanding of the physiological events reflected in the impedance cardiogram has become more refined, the technique's theoretical basis remains somewhat controversial and acceptance of its validity has relied heavily upon empirical validation. Largely as a consequence of this status, there have been inadequate grounds on which to develop sound methodological standardization. Currently, the methodological approaches that have been most frequently adopted may be viewed as representing the standard. The various aspects of impedance methodology are discussed, and alternative approaches described, with the objective of providing an informed basis for choosing among these methodological alternatives. It is recommended that studies utilizing impedance cardiography should be reported with clear and detailed methodological description. This should help clarify the extent to which methodological differences may underlie any discrepant research observations, as well as facilitate the emergence of improved methodological standards.

Efficient ray tracing of volume data

Abstract: Volume rendering is a technique for visualizing sampled scalar or vector fields of three spatial dimensions without fitting geometric primitives to the data. A subset of these techniques generates images by computing 2-D projections of a colored semitransparent volume, where the color and opacity at each point are derived from the data using local operators. Since all voxels participate in the generation of each image, rendering time grows linearly with the size of the dataset. This paper presents a front-to-back image-order volume-rendering algorithm and discusses two techniques for improving its performance. The first technique employs a pyramid of binary volumes to encode spatial coherence present in the data, and the second technique uses an opacity threshold to adaptively terminate ray tracing. Although the actual time saved depends on the data, speedups of an order of magnitude have been observed for datasets of useful size and complexity. Examples from two applications are given: medical imaging and molecular graphics.

Footprint evaluation for volume rendering

Abstract: This paper presents a forward mapping rendering algorithm to display regular volumetric grids that may not have the same spacings in the three grid directions. It takes advantage of the fact that convolution can be thought of as distributing energy from input samples into space. The renderer calculates an image plane footprint for each data sample and uses the footprint to spread the sample's energy onto the image plane. A result of the technique is that the forward mapping algorithm can support perspective without excessive cost, and support adaptive resampling of the three-dimensional data set during image generation.

Expression of C-fos-like protein as a marker for neuronal activity following noxious stimulation in the rat

Abstract: C-fos is a proto-oncogene that is expressed within some neurons following depolarization. The protein product, c-fos protein, can be identified by immunohistochemical techniques. Therefore, c-fos expression might be used as a marker for neuronal activity throughout the neuraxis following peripheral stimulation. This study has analyzed patterns of c-fos expression in both control and anesthetized animals and in anesthetized rats subjected to various forms of peripheral stimulation. Labeled cells were counted in the spinal cord, brainstem, hypothalamus, and thalamus. Little c-fos immunoreactivity was found in control animals. Prolonged inhalational anesthesia increased the number of labeled cells at several brainstem sites. Noxious stimulation of anesthetized rats induced c-fos within the neuraxis in patterns consistent with data obtained from electrophysiological studies and in additional locations for which few direct electrophysiological data are available, such as the ventrolateral medulla, the posterior hypothalamic nucleus, and the reuniens and paraventricular thalamic nuclei. Gentle mechanical stimulation was ineffective in inducing c-fos-like protein. The data suggest that c-fos can be used as a transynaptic marker for neuronal activity following noxious stimulation. However, c-fos is expressed only in some kinds of neurons following peripheral stimulation, and it therefore may be an incomplete marker for nociresponsive activity. In addition, at least a few neurons express c-fos protein in the absence of noxious stimulation. Experiments analyzing c-fos expression must be designed with care, as both extraneous stimuli and anesthetic depth influence the results.

PECAM-1 (CD31) cloning and relation to adhesion molecules of the immunoglobulin gene superfamily

Abstract: An antibody to a platelet integral membrane glycoprotein was found to cross-react with the previously identified CD31 myelomonocytic differentiation antigen and with hec7, an endothelial cell protein that is enriched at intercellular junctions. This antibody identified a complementary DNA clone from an endothelial cell library. The 130-kilodalton translated sequence contained six extracellular immunoglobulin (Ig)-like domains and was most similar to the cell adhesion molecule (CAM) subgroup of the Ig superfamily. This is the only known member of the CAM family on platelets. Its cell surface distribution suggests participation in cellular recognition events.

Normal development of mice deficient in beta 2M, MHC class I proteins, and CD8+ T cells

Abstract: Major histocompatibility class I proteins display viral and self antigens to potentially responsive cells and are important for the maturation of T cells; beta 2-microglobulin (beta 2M) is required for their normal expression. Mouse chimeras derived from embryonic stem cells with a disrupted beta 2M gene transmitted the inactivated gene to their progeny. Animals homozygous for the mutated beta 2M gene were obtained at expected frequencies after further breeding. The homozygotes appeared normal, although no class I antigens could be detected on their cells and the animals are grossly deficient in CD4- CD8+ T cells, which normally mediate cytotoxic T cell function.

Overall Fit in Covariance Structure Models: Two Types of Sample Size Effects

Abstract: A controversial area in covariance structure models is the assessment of overall model fit. Researchers have expressed concern over the influence of sample size on measures of fit. Many contradictory claims have been made regarding which fit statistics are affected by N. Part of the confusion is due to there being two types of sample size effects that are confounded. The first is whether N directly enters the calculation of a fit measure. The second is whether the means of the sampling distributions of a fit index are associated with sample size. I explain these types of sample size effects and illustrate them with the major structural equation fit indices. In addition, I examine the current debate on sample size influences in light of this distinction. Structural equation models, including confirmatory factor analyses, are becoming increasingly popular in psychology. Key to these procedures is the hypothesis that the population covariance matrix of observed variables is a function of the unknown free parameters of a model. Many measures of overall model fit have been proposed to assess the degree to which this hypothesis holds (e.g., Rentier B Bollen, 1986;Hoelter, 1983; Joreskog & Sorbom, 1986; Tucker & Lewis, 1973).

Sexual and physical abuse in women with functional or organic gastrointestinal disorders.

Abstract: This study aims to determine the prevalence of sexual and physical abuse among women seen in a gastroenterology clinic. A total of 206 patients, who completed a self-administered questionnaire, were included in the analysis. Results indicated that 89 patients (44%) reported a history of sexual abuse or physical abuse in childhood or later in life; and all except one of the physically abused were also sexually abused. Among them, only 17% had informed their doctors about the abuse. Moreover, the 75 patients (36%) with functional gastrointestinal disorders were more likely than those with organic disease diagnosis to report a history of forced intercourse, frequent physical abuse, chronic or recurrent abdominal pain, and more lifetime surgeries. They were also more likely to be receiving psychological counseling for emotional concerns. Furthermore, abused patients were more likely than nonabused patients to report pelvic pain, multiple somatic symptoms, and more lifetime surgeries. In conclusion, this study discovered that there is a high prevalence of a history of sexual and physical abuse among women seen in a referral-based gastroenterology clinic, particularly those with functional gastrointestinal disorders. Language: en

An interaction between alpha-actinin and the beta 1 integrin subunit in vitro.

Abstract: A number of cytoskeletal-associated proteins that are concentrated in focal contacts, namely alpha-actinin, vinculin, talin, and integrin, have been shown to interact in vitro such that they suggest a potential link between actin filaments and the membrane. Because some of these interactions are of low affinity, we suspect the additional linkages also exist. Therefore, we have used a synthetic peptide corresponding to the cytoplasmic domain of beta 1 integrin and affinity chromatography to identify additional integrin-binding proteins. Here we report our finding of an interaction between the cytoplasmic domain of beta 1 integrin and the actin-binding protein alpha-actinin. Beta 1-integrin cytoplasmic domain peptide columns bound several proteins from Triton extracts of chicken embryo fibroblasts. One protein at approximately 100 kD was identified by immunoblot analysis as alpha-actinin. Solid phase binding assays indicated that alpha-actinin bound specifically and directly to the beta 1 peptide with relatively high affinity. Using purified heterodimeric chicken smooth muscle integrin (a beta 1 integrin) or the platelet integrin glycoprotein IIb/IIIa complex (a beta 3 integrin), binding of alpha-actinin was also observed in similar solid phase assays, albeit with a lower affinity than was seen using the beta 1 peptide. alpha-Actinin also bound specifically to phospholipid vesicles into which glycoprotein IIb/IIIa had been incorporated. These results lead us to suggest that this integrin-alpha-actinin linkage may contribute to the attachment of actin filaments to the membrane in certain locations.

Corticocortical connections of anatomically and physiologically defined subdivisions within the inferior parietal lobule.

Abstract: The anatomical and functional organization of the inferior parietal lobule was investigated in macaque monkeys by using anterograde and retrograde anatomical tracing techniques and single cell recording techniques in awake, behaving monkeys. The connections of areas 7a and 7b, and of two previously unexplored areas, the lateral intraparietal area (LIP) and the dorsal prelunate area (DP), were examined in detail. Functional mapping experiments were performed in all four areas. Prior to this study the pathways for visual input to area 7a were unclear. In these experiments we found several direct projections from extrastriate visual areas, including the lateral intraparietal (LIP), dorsal prelunate (DP), parieto-occipital (PO), and medial superior temporal (MST) areas into area 7a. Using the observed laminar patterns of connections between areas 7a, LIP, and DP and other extrastriate cortical areas, we were able to construct a hypothetical flow of visual information processing from striate cortex to area 7a. A broader hierarchy was also produced, which relates the positions of areas 7a, 7b, LIP, and DP to various cortical fields in the parietal, temporal, and frontal lobes. By combining single cell recording techniques in trained monkeys with anatomical tracing techniques, we have parceled the inferior parietal lobule into several subdivisions on the basis of both anatomical and physiological grounds. A clear segregation of visual and somatosensory responses was found in the inferior parietal lobule with areas 7a, LIP, and DP being visual and visual-motor and area 7b being primarily somatosensory. A similar segregation was found anatomically with areas 7a, LIP, and DP being interconnected primarily with other visual cortical areas and area 7b being connected with several somatosensory areas. Area 7b was also found to connect to a few visual cortical areas, and these connections likely account for the small but consistent number of visually responsive cells that are found in this region. Areas LIP, DP, and 7a differed in receptive field and saccade-related properties. Area 7a visual receptive fields were very large and usually bilateral with a small but significant number of them having receptive field centers in the ipsilateral visual field. Area DP and LIP receptive fields were smaller and the receptive field peaks were almost always confined to the contralateral visual field. Areas 7a, DP, and LIP all contained cells with saccade-related responses; however, in area 7a there were fewer saccade cells than area LIP, and presaccadic responses were only observed in area LIP.(ABSTRACT TRUNCATED AT 400 WORDS)

Ten-Year Mortality from Cardiovascular Disease in Relation to Cholesterol Level among Men with and without Preexisting Cardiovascular Disease

Abstract: To determine the associations of total, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol with mortality from coronary heart disease and cardiovascular disease, we studied 2541 white men who were 40 to 69 years old at base line and followed them for an average of 10.1 years. Seventeen percent had some manifestation of cardiovascular disease at base line, whereas the others did not. Among the men who had cardiovascular disease at base line, we found, after multivariate adjustment, that those with "high" blood cholesterol levels (above 6.19 mmol per liter) had a risk of death from cardiovascular disease, including coronary heart disease, that was 3.45 times higher (95 percent confidence interval, 1.63 to 7.33) than that for men with "desirable" blood cholesterol levels (below 5.16 mmol per liter). The corresponding hazard ratios were 5.92 (95 percent confidence interval, 2.59 to 13.51) for LDL cholesterol levels above 4.13 mmol per liter as compared with those below 3.35 mmol per liter, and 6.02 (95 percent confidence interval, 2.73 to 13.28) for HDL cholesterol levels below 0.90 mmol per liter as compared with those above 1.16 mmol per liter. All three lipid levels were also significant predictors of death from coronary heart disease alone (P less than 0.005). Total cholesterol and LDL cholesterol levels were also significant predictors of death from cardiovascular and coronary heart disease in men without preexisting cardiovascular disease, although at a lower level of absolute risk of death. Thus, the 10-year risk of death from cardiovascular disease for a man with preexisting cardiovascular disease increased from 3.8 percent to almost 19.6 percent with increasing levels of total cholesterol from "desirable" to "high," whereas the corresponding risk for a man who was free of cardiovascular disease at base line increased from 1.7 percent to 4.9 percent. Our findings suggest that total, LDL, and HDL cholesterol levels predict subsequent mortality in men 40 to 69 years of age, especially those with preexisting cardiovascular disease.

A plant leucine zipper protein that recognizes an abscisic acid response element

Abstract: The mechanism by which phytohormones, like abscisic acid (ABA), regulate gene expression is unknown. An activity in nuclear extracts that interacts with the ABA response element (ABRE) from the 5' regulatory region of the wheat Em gene was identified. A complementary DNA clone was isolated whose product is a DNA binding protein (EmBP-1) that interacts specifically with an 8-base pair (bp) sequence (CACGTGGC) in the ABRE. A 2-bp mutation in this sequence prevented binding of EmBP-1. The same mutation reduced the ability of the ABRE to confer ABA responsiveness on a viral promoter in a transient assay. The 8-bp EmBP-1 target sequence was found to be conserved in several other ABA-responsive promoters and in promoters from plants that respond to signals other than ABA. Similar sequences are found in promoters from mammals, yeast, and in the major late promoter of adenovirus. The deduced amino acid sequence of EmBP-1 contains conserved basic and leucine zipper domains found in transcription factors in plants, yeast, and mammals. EmBP-1 may be a member of a highly conserved family of proteins that recognize a core sequence found in the regulatory regions of various genes that are integrated into a number of different response pathways.

Perceived Cohesion: A Conceptual and Empirical Examination

Abstract: Most existing measures of cohesion attempt to objectively measure cohesion while neglecting individual group members' perceptions of their cohesion to a particular group. We propose that group members' perceptions of cohesion are important for the behavior of the individual as well as the group as a whole. We offer a theoretical definition of perceived cohesion which says individuals' perceptions of their own cohesion to a group has two dimensions: sense of belonging and feelings of morale. We test this conceptualization and the adequacy of our Perceived Cohesion Scale in two random samples: students at a small college notedfor its strong "school spirit" and residents of a mnidsized city. Our confirmatory factor analyses indicate a two-factor model, with a high degree of invariance across the two samples, and with the two dimensions correlated over .90 in both. However, as anticipated, perceived cohesion is significantly higher in the college than the city sample.

Writing Space: The Computer, Hypertext, and the History of Writing

Abstract: Contents: Introduction. Part I: The Visual Writing Space. The Computer as a New Writing Space. Writing as Technology. The Elements of Writing. Seeing and Writing. Part II: The Conceptual Writing Space. The Electronic Book. The New Dialogue. Interactive Fiction. Critical Theory and the New Writing Space. Part III: The Mind as a Writing Space. Artificial Intelligence. Electronic Signs. Writing the Mind. Writing Culture. Conclusion.

Paxillin: a new vinculin-binding protein present in focal adhesions.

Abstract: The 68-kD protein (paxillin) is a cytoskeletal component that localizes to the focal adhesions at the ends of actin stress fibers in chicken embryo fibroblasts. It is also present in the focal adhesions of Madin-Darby bovine kidney (MDBK) epithelial cells but is absent, like talin, from the cell-cell adherens junctions of these cells. Paxillin purified from chicken gizzard smooth muscle migrates as a diffuse band on SDS-PAGE gels with a molecular mass of 65-70 kD. It is a protein of multiple isoforms with pIs ranging from 6.31 to 6.85. Using purified paxillin, we have demonstrated a specific interaction in vitro with another focal adhesion protein, vinculin. Cleavage of vinculin with Staphylococcus aureus V8 protease results in the generation of two fragments of approximately 85 and 27 kD. Unlike talin, which binds to the large vinculin fragment, paxillin was found to bind to the small vinculin fragment, which represents the rod domain of the molecule. Together with the previous observation that paxillin is a major substrate of pp60src in Rous sarcoma virus-transformed cells (Glenney, J. R., and L. Zokas. 1989. J. Cell Biol. 108:2401-2408), this interaction with vinculin suggests paxillin may be a key component in the control of focal adhesion organization.

Project GROPEHaptic displays for scientific visualization

Abstract: We began in 1967 a project to develop a haptic+display for 6-D force fields of interacting protein molecules. We approached it in four stages: a 2-D system, a 3-D system tested with a simple task, a 6-D system tested with a simple task, and a full 6-D molecular docking system, our initial goal. This paper summarizes the entire project---the four systems, the evaluation experiments, the results, and our observations. The molecular docking system results are new.Our principal conclusions are:• Haptic display as an augmentation to visual display can improve perception and understanding both of force fields and of world models populated with impenetrable objects.• Whereas man-machine systems can outperform computer-only systems by orders of magnitude on some problems, haptic-augmented interactive systems seem to give about a two-fold performance improvement over purely graphical interactive systems. Better technology may give somewhat more, but a ten-fold improvement does not seem to be in the cards.• Chemists using GROPE-III can readily reproduce the true docking positions for drugs whose docking is known (but not to them) and can find very good docks for drugs whose true docks are unknown. The present tool promises to yield new chemistry research results; it is being actively used by research chemists.• The most valuable result from using GROPE-III for drug docking is probably the radically improved situation awareness that serious users report. Chemists say they have a new understanding of the details of the receptor site and its force fields, and of why a particular drug docks well or poorly.• We see various scientific/education applications for haptic displays but believe entertainment, not scientific visualization, will drive and pace the technology.• The hardware-software system technology we have used is barely adequate, and our experience sets priorities for future development.• Some unexpected perceptual phenomena were observed. All of these worked for us, not against us.

Oligoribonucleoside and oligodeoxyribonucleoside boranophosphates

Abstract: Disclosed are oligonucleoside boranophosphates, or salts thereof, comprising a chain of natural or modified ribonucleotides or deoxyribonucleotides, containing at least one boronated internucleotide phospodiester linkage of formula (III), wherein W is selected from the group consisting of =O, =S, -OPr, and -SPr where Pr is a base-labile protecting group. X is selected from the group consisting of -BH3, -BH2R1, -BHR1R2 and -BR1R2R3. R1 is selected from the group consisting of -R4, -COOH, -COOR4, -CONHR4, -CON(R4)2, -CN+R4, -CN, carboxycholesteryl and carboxybenzyl, wherein R4 is C1 to C18 alkyl. R2 is selected from the group consisting of -R5, -COOH, COOR5, -CONHR5, -CON(R5)2, -CN+R5, -CN, carboxy- cholesteryl and carboxybenzyl, wherein R5 is C1 to C18 alkyl. R3 is selected from the group consisting of C1 to C3 alkyl. Most preferably, X is -BH3 and W is =O. Compounds of formula (III) are useful as antisense agents and probes in molecular biology, and have pharmacological activities including anti-inflammatory, antihyperlipidemic, and antineoplastic activity.

Preadolescent peer status, aggression, and school adjustment as predictors of externalizing problems in adolescence.

Abstract: The comparative effectiveness of preadolescent aggressive behavior, peer rejection, and school functioning were evaluated in the prediction of adolescent delinquency and school maladjustment. Fifth-grade children (n = 112, 69% white, 53% male, M = 11 years old) were followed forward for 7 years until the end of high school. Rejected children were more likely to have a nonspecific negative outcome and more types of negative outcomes than average, popular, or neglected children, particularly among the white students. However, in regression models containing sex, race, aggression, frequent school absences, low grades, and rejection, the only significant predictor of juvenile delinquency or of a nonspecific negative outcome was aggression toward peers. Both aggression and frequent school absences were significant predictors of early school withdrawal. Analyses for the white children in the sample revealed that both rejection and aggression best predicted to the nonspecific negative outcome, whereas aggression alone best predicted to school dropout and to having one or more police contacts. Implications for future longitudinal outcome research and for risk-group identification in racially heterogeneous samples are discussed.

Homologous recombination for universal donor cells and chimeric mammalian hosts

Abstract: Homologous recombination is employed to inactivate genes, particularly genes associated with MHC antigenes. Particularly, the β2-microglobulin gene is inactivated for reducing or eliminating Class I MHC antigenes. The resulting cells may be used as universal donors. In addition, embryonic stem cells may be modified by homologous recombination for use in producing chimeric or transgenic mammalian hosts.

Immunohistochemical Localization of the Androgen Receptor in Rat and Human Tissues

Abstract: Immunohistochemical localization of the androgen receptor (AR) was performed in reproductive tissues, submaxillary gland, pituitary, and brain of the rat and in human prostate. AR was visualized using either of two polyclonal antibodies raised against peptides with sequences derived from rat and human AR. Tissue sections of 6-8 microns, frozen in isopentane and fixed in paraformaldehyde, were stained using immunoglobulin G fractions of immune, preimmune, and peptide-adsorbed immune sera in the avidin-biotin peroxidase procedure. AR was prominent in nuclei of acinar epithelial cells of epididymis, ventral prostate, seminal vesicle, and ductus deferens from the intact rat. Androgen withdrawal, 3 days after castration, resulted in the loss of receptor immunostaining, which was restored within 15 min of androgen administration. Stromal cell staining was absent or weak in the ventral prostate of intact rats, but was more evident in the epididymis. AR was confined to nuclei of cells within and bordering the interstitial compartment of the testis, including Sertoli cells, peritubular myoid cells, and interstitial cells, and was undetectable in germ cells. Submaxillary gland epithelial cells and a population of rat anterior pituitary cells showed strong nuclear staining of AR. In rat brain, AR was present in the medial preoptic, arcurate, and ventromedial nuclei of the hypothalamus, the medial nucleus of the amygdala, the CA-1 hippocampus, and the cortex. AR was prominent in acinar epithelial cells in human benign prostatic hyperplasia and was also present in stroma of fibromuscular benign hyperplasia. Heterogeneous staining was observed in stromal and epithelial cells of prostatic adenocarcinoma. The results of these studies indicate that AR can be detected immunohistochemically in a variety of tissues and cell types using antipeptide polyclonal antibodies. The presence of AR in tissues correlated with their known androgen responsiveness.

Is vitamin D deficiency a risk factor for prostate cancer? (Hypothesis).

Abstract: Prostate cancer is a major cause of cancer death among males, yet little is known about its etiology. We hypothesize that Vitamin (Hormone) D deficiency may underlie the major risks for prostate cancer, including age, Black race, and northern latitudes. These factors all are associated with decreased synthesis of Vitamin D. Mortality rates from prostate cancer in the U.S. are inversely correlated with ultraviolet radiation, the principal source of Vitamin D. This hypothesis is consistent with known antitumor properties of Vitamin D, and may suggest new avenues for research in prostate cancer.

High density lipoprotein cholesterol as a predictor of cardiovascular disease mortality in men and women: the follow-up study of the lipid research clinics prevalence study

Abstract: With data from the Lipid Research Clinics Prevalence Study used as a baseline, an average of 8.4 years of mortality follow-up has been completed for 8,825 male and female participants who were at least 30 years of age at the time of the study. The participants were examined at 10 North American sites during 1972-1976. Univariate findings for high density lipoprotein (HDL) cholesterol in the 7,569 persons initially free of coronary heart disease indicate an inverse relation with cardiovascular disease mortality for men and women. Controlling for age, low density lipoprotein (LDL) cholesterol, triglycerides, body mass index, systolic blood pressure, and smoking, multivariate analysis results indicate inverse relations between HDL cholesterol and cardiovascular disease mortality. In men, the cardiovascular disease mortality rate ratio for HDL cholesterol increments of 10 mg/dl was similar to the cardiovascular disease mortality rate ratio for LDL cholesterol increments of 30 mg/dl. In women, HDL cholesterol is more closely related to cardiovascular disease than is LDL cholesterol. HDL cholesterol is inversely related to both coronary heart disease and other cardiovascular disease mortality in both sexes, though the relation of HDL cholesterol with coronary heart disease mortality in women approached statistical significance only for the combined end point of suspect and definite cases. No relation was observed in either sex group between HDL cholesterol and noncardiovascular disease mortality. This study, only the second large prospective study evaluating the role of HDL cholesterol in women, confirms both the importance and the independence in both men and women of HDL cholesterol in the epidemiology of coronary heart disease and other cardiovascular disease mortality.

Contrast-limited adaptive histogram equalization: speed and effectiveness

Abstract: An experiment intended to evaluate the clinical application of contrast-limited adaptive histogram equalization (CLAHE) to chest computer tomography (CT) images is reported. A machine especially designed to compute CLAHE in a few seconds is discussed. It is shown that CLAHE can be computed in 4 s after 5-s loading time using the specially designed parallel engine made from a few thousand dollars worth of off-the-shelf components. The processing appears to be useful for a wide range of medical images, but the limitations of observer calibration make it impossible to demonstrate such usefulness by agreement experiments. >

Comparison of Data-Driven Bandwidth Selectors

Abstract: This article compares several promising data-driven methods for selecting the bandwidth of a kernel density estimator. The methods compared are least squares cross-validation, biased cross-validation, and a plug-in rule. The comparison is done by asymptotic rate of convergence to the optimum and a simulation study. It is seen that the plug-in bandwidth is usually most efficient when the underlying density is sufficiently smooth, but is less robust when there is not enough smoothness present. We believe the plug-in rule is the best of those currently available, but there is still room for improvement.