bluuebunny/crossref_metadata_2025 huggingface dataset:
Nontransferrin-bound iron uptake by hepatocytes is increased in the Hfe knockout mouse model of hereditary hemochromatosis
Authors: Chua Anita C. G. , Olynyk John K. , Leedman Peter J. , Trinder Debbie
Published: May 2004

Hereditary hemochromatosis (HH) is an iron-overload disorder caused by a C282Y mutation in the HFE gene. In HH, plasma nontransferrin-bound iron (NTBI) levels are increased and NTBI is bound mainly by citrate. The aim of this study was to examine the importance of NTBI in the pathogenesis of hepatic iron loading in Hfe knockout mice. Plasma NTBI levels were increased 2.5-fold in Hfe knockout mice compared with control mice. Total ferric citrate uptake by hepatocytes isolated from Hfe knockout mice (34.1 ± 2.8 pmol Fe/mg protein/min) increased by 2-fold compared with control mice (17.8 ± 2.7 pmol Fe/mg protein/min; P < .001; mean ± SEM; n = 7). Ferrous ion chelators, bathophenanthroline disulfonate, and 2′,2-bipyridine inhibited ferric citrate uptake by hepatocytes from both mouse types. Divalent metal ions inhibited ferric citrate uptake by hepatocytes, as did diferric transferrin. Divalent metal transporter 1 (DMT1) mRNA and protein expression was increased approximately 2-fold by hepatocytes from Hfe knockout mice. We conclude that NTBI uptake by hepatocytes from Hfe knockout mice contributed to hepatic iron loading. Ferric ion was reduced to ferrous ion and taken up by hepatocytes by a pathway shared with diferric transferrin. Inhibition of uptake by divalent metals and up-regulation of DMT1 expression suggested that NTBI uptake was mediated by DMT1.
Renal venous thrombosis in neonates: prothrombotic risk factors and long-term follow-up
Authors: Kosch Andrea , Kuwertz-Bröking Eberhard , Heller Christine , Kurnik Karin , Schobess Rosemarie , Nowak-Göttl Ulrike ,   for the Childhood Thrombophilia Study Group
Published: May 2004

The present study was designed to evaluate prothrombotic risk profiles in 59 consecutively recruited white neonates with renal venous thrombosis (RVT). The rates of prothrombotic risk factors (PRs)—for example, the factor V (FV) 1691G> A mutation, the factor II (FII) 20210G> A variant, antithrombin (AT), protein C (PC), protein S (PS), elevated lipoprotein(a) (Lp(a)), total fasting plasma homocysteine (tHcy) levels, and anticardiolipin antibodies (ACAs)—were compared with those of 118 healthy control children. At onset, 32 (54.2%) of the 59 neonates showed underlying clinical conditions; 40 (67.8%) of them and 23 (85.2%) of the 27 infants with idiopathic RVT showed at least one PR. Univariate analysis revealed significantly elevated odds ratios/95% confidence intervals (ORs/95% CIs) for FV and Lp(a). Additionally, PC/AT deficiency and ACAs were found significantly more often in the patient group (P = .04). Multivariate analysis calculated significant ORs/95% CIs only for FV (OR, 9.4; 95% CI, 3.3-26.6) and elevated Lp(a) (OR, 7.6; 95% CI, 2.4-23.8). Of the 59 neonates investigated, 53 revealed renal atrophy, and 13 children additionally suffered from severe arterial hypertension. In conclusion, the present study demonstrates the significance of genetic PR—especially the FV mutation and elevated Lp(a)—for the etiology of neonatal RVT.
Cell-intrinsic requirement for pRb in erythropoiesis
Authors: Clark Allison J. , Doyle Kathryn M. , Humbert Patrick O.
Published: May 2004

Retinoblastoma (Rb) and family members have been implicated as key regulators of cell proliferation and differentiation. In particular, accumulated data have suggested that the Rb gene product pRb is an important controller of erythroid differentiation. However, current published data are conflicting as to whether the role of pRb in erythroid cells is cell intrinsic or non–cell intrinsic. Here, we have made use of an in vitro erythroid differentiation culture system to determine the cell-intrinsic requirement for pRb in erythroid differentiation. We demonstrate that the loss of pRb function in primary differentiating erythroid cells results in impaired cell cycle exit and terminal differentiation. Furthermore, we have used coculture experiments to establish that this requirement is cell intrinsic. Together, these data unequivocally demonstrate that pRb is required in a cell-intrinsic manner for erythroid differentiation and provide clarification as to its role in erythropoiesis.
Morbidity and mortality with nonmyeloablative compared with myeloablative conditioning before hematopoietic cell transplantation from HLA-matched related donors
Authors: Diaconescu Razvan , Flowers Christopher R. , Storer Barry , Sorror Mohamed L. , Maris Michael B. , Maloney David G. , Sandmaier Brenda M. , Storb Rainer
Published: May 2004

Nonmyeloablative regimens for allogeneic hematopoietic cell transplantation (HCT) have been developed for patients ineligible for myeloablative conditioning. We compared regimen-related toxicities (RRTs) and nonrelapse mortality (NRM) in 73 nonmyeloablative and 73 myeloablative recipients of HLA-matched related donor HCT, using the National Cancer Institute (NCI) Common Toxicity Criteria. Nonmyeloablative regimens were 2 Gy total body irradiation (TBI), either alone (n = 40) or combined with fludarabine, 30 mg/m2/d for 3 days (n = 33). Posttransplantation immunosuppression included mycophenolate mofetil and cyclosporine. Myeloablative regimens consisted mostly of cyclophosphamide + TBI or busulfan + cyclophosphamide, followed by posttransplantation methotrexate and cyclosporine. Nonmyeloablative patients were at higher risk than ablative patients because of greater age, longer time from diagnosis to HCT, more frequent preceding high-dose HCT, and higher pretransplantation Charlson comorbidity scores. Nevertheless, they experienced significantly less severe toxicities in 7 organs/systems: hematologic, gastrointestinal, hepatic, hemorrhage, infection, metabolic, and pulmonary. This translated into less NRM at day 100 (3% versus 23%, P = 10-4) and 1 year (16% versus 30%, P = .04). In multivariate analysis, the strongest factor predicting lessened RRT and NRM was nonmyeloablative conditioning, whereas high pretransplantation comorbidity scores predicted higher NRM. In conclusion, nonmyeloablative regimens had lower RRT and NRM and could be considered for comparative studies, including younger patients with more favorable Charlson comorbidity scores.
Bedside to bench and back again: how animal models are guiding the development of new immunotherapies for cancer
Authors: Finkelstein Steven E , Heimann David M , Klebanoff Christopher A , Antony Paul A , Gattinoni Luca , Hinrichs Christian S , Hwang Leroy N , Palmer Douglas C , Spiess Paul J , Surman Deborah R , Wrzesiniski Claudia , Yu Zhiya , Rosenberg Steven A , Restifo Nicholas P
Published: May 2004

Immunotherapy using adoptive cell transfer is a promising approach that can result in the regression of bulky, invasive cancer in some patients. However, currently available therapies remain less successful than desired. To study the mechanisms of action and possible improvements in cell-transfer therapies, we use a murine model system with analogous components to the treatment of patients. T cell receptor transgenic CD8+ T cells (pmel-1) specifically recognizing the melanocyte differentiation antigen gp100 are adoptively transferred into lympho-depleted mice bearing large, established, 14-day subcutaneous B16 melanoma (0.5–1 cm in diameter) on the day of treatment. Adoptive cell transfer in combination with interleukin interleukin-2 or interleukin-15 cytokine administration and vaccination using an altered form of the target antigen, gp100, can result in the complete and durable regression of large tumor burdens. Complete responders frequently develop autoimmunity with vitiligo at the former tumor site that often spreads to involve the whole coat. These findings have important implications for the design of immunotherapy trials in humans.
Pricing path-dependent options in a Black-Scholes market from the distribution of homogeneous Brownian functionals
Authors: Fujita T. , Petit F. , Yor M.
Published: May 2004

We give some explicit formulae for the prices of two path-dependent options which combine Brownian averages and penalizations. Because these options are based on both the maximum and local time of Brownian motion, obtaining their prices necessitates some involved study of homogeneous Brownian functionals, which may be of interest in their own right.
On max-sum equivalence and convolution closure of heavy-tailed distributions and their applications
Authors: Cai Jun , Tang Qihe
Published: May 2004

In this paper, we discuss max-sum equivalence and convolution closure of heavy-tailed distributions. We generalize the well-known max-sum equivalence and convolution closure in the class of regular variation to two larger classes of heavy-tailed distributions. As applications of these results, we study asymptotic behaviour of the tails of compound geometric convolutions, the ruin probability in the compound Poisson risk process perturbed by an α-stable Lévy motion, and the equilibrium waiting-time distribution of the M/G/k queue.
A note on the asymptotic behaviour of the extinction probability in supercritical population-size-dependent branching processes with independent and identically distributed random environments
Authors: Zhunwei Lu , Jagers Peter
Published: May 2004

In supercritical population-size-dependent branching processes with independent and identically distributed random environments, it is shown that under certain regularity conditions there exist constants 0 < α1 ≤α0 < + ∞ and 0 < C1, C2 < + ∞ such that the extinction probability starting with k individuals is bounded below by C1k-α0 and above by C2k-α1 for sufficiently large k. Moreover, a similar conclusion, which follows from a result of Höpfner, is presented along with some remarks.
A note on two-level superprocesses
Authors: Hong Wen-Ming
Published: May 2004

We prove some central limit theorems for a two-level super-Brownian motion with random immigration, which lead to limiting Gaussian random fields. The covariances of those Gaussian fields are explicitly characterized.
The critical probability for the frog model is not a monotonic function of the graph
Authors: Fontes L. R. , Machado F. P. , Sarkar A.
Published: May 2004

We show that the critical probability for the frog model on a graph is not a monotonic function of the graph. This answers a question of Alves, Machado and Popov. The nonmonotonicity is unexpected as the frog model is a percolation model.
Quasi-likelihood-based higher-order spectral estimation of random fields with possible long-range dependence
Authors: Anh V. V. , Leonenko N. N. , Sakhno L. M.
Published: May 2004

This paper provides a quasi-likelihood or minimum-contrast-type method for the parameter estimation of random fields in the frequency domain based on higher-order information. The estimation technique uses the spectral density of the generalkth order and allows for possible long-range dependence in the random fields. To avoid bias due to edge effects, data tapering is incorporated into the method. The suggested minimum contrast functional is linear with respect to the periodogram ofkth order, hence kernel estimation for the spectral densities is not needed. Furthermore, discretization is not required in the estimation of continuously observed random fields. The consistency and asymptotic normality of the resulting estimators are established. Illustrative applications of the method to some problems in mathematical finance and signal detection are given.
On finite exponential moments for branching processes and busy periods for queues
Authors: Nakayama Marvin K. , Shahabuddin Perwez , Sigman Karl
Published: May 2004

Using a known fact that a Galton–Watson branching process can be represented as an embedded random walk, together with a result of Heyde (1964), we first derive finite exponential moment results for the total number of descendants of an individual. We use this basic and simple result to prove analogous results for the population size at time t and the total number of descendants by time t in an age-dependent branching process. This has applications in justifying the interchange of expectation and derivative operators in simulation-based derivative estimation for generalized semi-Markov processes. Next, using the result of Heyde (1964), we show that, in a stable GI/GI/1 queue, the length of a busy period and the number of customers served in a busy period have finite exponential moments if and only if the service time does.
Scoring probability forecasts for point processes: the entropy score and information gain
Authors: Daley Daryl J. , Vere-Jones David
Published: May 2004

The entropy score of an observed outcome that has been given a probability forecast p is defined to be –log p. If p is derived from a probability model and there is a background model for which the same outcome has probability π, then the log ratio log(p/π) is the probability gain, and its expected value the information gain, for that outcome. Such concepts are closely related to the likelihood of the model and its entropy rate. The relationships between these concepts are explored in the case that the outcomes in question are the occurrence or nonoccurrence of events in a stochastic point process. It is shown that, in such a context, the mean information gain per unit time, based on forecasts made at arbitrary discrete time intervals, is bounded above by the entropy rate of the point process. Two examples illustrate how the information gain may be related to realizations with a range of values of ‘predictability'.
The eigenvalues of the empirical transition matrix of a Markov chain
Authors: Pritchard Geoffrey , Scott David J.
Published: May 2004

This paper investigates the probabilistic behaviour of the eigenvalue of the empirical transition matrix of a Markov chain which is of largest modulus other than 1, loosely called the second-largest eigenvalue. A central limit theorem is obtained for nonmultiple eigenvalues of the empirical transition matrix. When the Markov chain is actually a sequence of independent observations the distribution of the second-largest eigenvalue is determined and a test for independence is developed. The independence case is considered in more detail when the Markov chain has only two states, and some applications are given.
Representations of continuous-time ARMA processes
Authors: Brockwell Peter J.
Published: May 2004

Using the kernel representation of a continuous-time Lévy-driven ARMA (autoregressive moving average) process, we extend the class of nonnegative Lévy-driven Ornstein–Uhlenbeck processes employed by Barndorff-Nielsen and Shephard (2001) to allow for nonmonotone autocovariance functions. We also consider a class of fractionally integrated Lévy-driven continuous-time ARMA processes obtained by a simple modification of the kernel of the continuous-time ARMA process. Asymptotic properties of the kernel and of the autocovariance function are derived.
Asymptotics of the sample mean and sample covariance of long-range-dependent series
Authors: Dai Wen
Published: May 2004

An asymptotic distribution is given for the partial sums of a stationary time-series with long-range dependence. The law of large numbers for the sample covariance of the series is also derived. The results differ from those given elsewhere in relaxing the assumption of the independence of the innovations of the series.
Distribution of the amount of genetic material from a chromosomal segment surviving to the following generation
Authors: Stefanov Valeri T.
Published: May 2004

A method is provided for numerical evaluation, with any given accuracy, of the probability that at least p% of the genetic material from an individual's chromosomal segment survives to the next generation. Relevant MAPLE® V codes, for automated implementation of such evaluation, are also provided. The genomic continuum model, with Haldane's model for the crossover process, is assumed.
On the role played by extreme summands when a sum of independent and identically distributed random vectors is asymptotically α-stable
Authors: Davydov Yu. , Nagaev A. V.
Published: May 2004

The focus of our attention is the limit distribution of the sum of independent and identically distributed random vectors from which all the extreme summands are removed. The problem is rather trivial if the summands are ordered by their norms. It is of much more interest when the vertices of the convex hull generated by the vectors are taken as the extremes.
Modelling long-range-dependent Gaussian processes with application in continuous-time financial models
Authors: Gao Jiti
Published: May 2004

This paper considers a class of continuous-time long-range-dependent Gaussian processes. The corresponding spectral density is assumed to have a general and flexible form, which covers some important and special cases. For example, the spectral density of a continuous-time fractional stochastic differential equation is included. A modelling procedure is then established through estimating the parameters involved in the spectral density by using an extended continuous-time version of the Gauss–Whittle objective function. The resulting estimates are shown to be strongly consistent and asymptotically normal. An application of the modelling procedure to the identification and modelling of a fractional stochastic volatility is discussed in some detail.
Infinite- and finite-buffer Markov fluid queues: a unified analysis
Authors: Akar Nail , Sohraby Khosrow
Published: May 2004

In this paper, we study Markov fluid queues where the net fluid rate to a single-buffer system varies with respect to the state of an underlying continuous-time Markov chain. We present a novel algorithmic approach to solve numerically for the steady-state solution of such queues. Using this approach, both infinite- and finite-buffer cases are studied. We show that the solution of the infinite-buffer case is reduced to the solution of a generalized spectral divide-and-conquer (SDC) problem applied on a certain matrix pencil. Moreover, this SDC problem does not require the individual computation of any eigenvalues and eigenvectors. Via the solution for the SDC problem, a matrix-exponential representation for the steady-state queue-length distribution is obtained. The finite-buffer case, on the other hand, requires a similar but different decomposition, the so-called additive decomposition (AD). Using the AD, we obtain a modified matrix-exponential representation for the steady-state queue-length distribution. The proposed approach for the finite-buffer case is shown not to have the numerical stability problems reported in the literature.
A bold strategy is not always optimal in the presence of inflation
Authors: Chen Robert W. , Shepp Larry A. , Zame Alan
Published: May 2004

A gambler, with an initial fortune less than 1, wants to buy a house which sells today for 1. Due to inflation, the price of the house tomorrow will be 1 + α, where α is a nonnegative constant, and will continue to go up at this rate, becoming (1 + α)n on the nth day. Once each day, he can stake any amount of fortune in his possession, but no more than he possesses, on a primitive casino. It is well known that, in a subfair primitive casino without the presence of inflation, the gambler should play boldly. The presence of inflation would motivate the gambler to recognize the time value of his fortune and to try to reach his goal as quickly as possible; intuitively, we would conjecture that the gambler should again play boldly. However, in this note we will show that, unexpectedly, bold play is not necessarily optimal.
Characterization by orthogonal polynomial systems of finite Markov chains
Authors: Seneta E.
Published: May 2004

The paper characterizes matrices which have a given system of vectors orthogonal with respect to a given probability distribution as its right eigenvectors. Results of Hoare and Rahman are unified in this context, then all matrices with a given orthogonal polynomial system as right eigenvectors under the constraint a0j = 0 for j ≥ 2 are specified. The only stochastic matrices P = {pij} satisfying p00 + p01 = 1 with the Hahn polynomials as right eigenvectors have the form of the Moran mutation model.
The detection of words and an ordering for Markov chains
Authors: Irle Albrecht , Gani Joseph
Published: May 2004

This paper considers the occurrence of patterns in sequences of independent trials from a finite alphabet; Gani and Irle (1999) have described a finite state automaton which identifies exactly those sequences of symbols containing the specific pattern, which may be thought of as the word of interest. Each word generates a particular Markov chain. Motivated by a result of Guibas and Odlyzko (1981) on stochastic monotonicity for the random times when a particular word is completed for the first time, a new level-crossing ordering is introduced for stochastic processes. A process {Yn : n = 0, 1, …} is slower in level-crossing than a process {Zn}, if it takes {Yn} stochastically longer than {Zn} to exceed any given level. This relation is shown to be useful for the comparison of stochastic automata, and is used to investigate this ordering for Markov chains in discrete time.
Roles of theC. eleganscyclophilin-like protein MOG-6 in MEP-1 binding and germline fates
Authors: Belfiore Marco , Pugnale Paolo , Saudan Zarifja , Puoti Alessandro
Published: May 2004

The switch from spermatogenesis to oogenesis in the Caenorhabditis elegans hermaphrodite requires mog-6, which post-transcriptionally represses the fem-3 RNA. In this study, we show that mog-6 codes for a divergent nuclear cyclophilin, in that a conserved domain is not required for its function in the sperm-oocyte switch. MOG-6 binds to the nuclear zinc finger protein MEP-1 through two separate domains that are essential for the role of MOG-6 in the sperm-oocyte switch. We propose that MOG-6 has a function distinct from that of prevailing cyclophilins and that its binding to MEP-1 is essential for germline sex determination. Finally, we found that gld-3 mog-6 mutants develop germline tumors, suggesting that mog-6 might function in the decision between mitosis and meiosis.
Axonal mitochondrial transport and potential are correlated
Authors: Miller Kyle E. , Sheetz Michael P.
Published: May 2004

Disruption of axonal transport leads to a disorganized distribution of mitochondria and other organelles and is thought to be responsible for some types of neuronal disease. The reason for bidirectional transport of mitochondria is unknown. We have developed and applied a set of statistical methods and found that axonal mitochondria are uniformly distributed. Analysis of fast axonal transport showed that the uniform distribution arose from the clustering of the stopping events of fast axonal transport in the middle of the gaps between stationary mitochondria. To test whether transport was correlated with ATP production, we added metabolic inhibitors locally by micropipette. Whereas applying CCCP (a mitochondrial uncoupler) blocked mitochondrial transport, as has been previously reported, treatment with antimycin (an inhibitor of electron transport at complex III) caused increases in retrograde mitochondrial transport. Application of 2-deoxyglucose did not decrease transport compared with the mannitol control. To determine whether mitochondrial transport was correlated with mitochondrial potential, we stained the neurons with the mitochondrial potential-sensing dye JC-1. We found that ∼90% of mitochondria with high potential were transported towards the growth cone and ∼80% of mitochondria with low potential were transported towards the cell body. These experiments show for the first time that a uniform mitochondrial distribution is generated by local regulation of the stopping events of fast mitochondrial transport, and that the direction of mitochondrial transport is correlated with mitochondrial potential. These results have implications for axonal clogging, autophagy, apoptosis and Alzheimer's disease.
Risk Sharing, Fiduciary Duty, and Corporate Risk Attitudes
Authors: Smith James E.
Published: May 2004

In this paper, we consider the problem of determining corporate risk preferences that reflect the preferences of the company's shareholders. Although we do not assume that the company necessarily has a utility function, we can use shareholder risk preferences to place bounds on the firm's risk tolerances and certainty equivalents. Using these bounds with published estimates for individual risk tolerances, we find that large companies with reasonably diversified shareholders should have risk tolerances that are much larger than those typically suggested in the decision analysis literature. We also find that, in contrast with what is commonly assumed in the finance literature, market prices for gambles generally do not reflect the interests of shareholders, and market-value maximization can lead to the selection of dominated alternatives.
SSRI Treatment—Associated Stroke: Causality Assessment in Two Cases
Authors: Ramasubbu Rajamannar
Published: May 2004

OBJECTIVE:

To assess the probability of cerebrovascular adverse drug reactions (CV-ADRs) due to treatment with selective serotonin-reuptake inhibitors (SSRIs) using 2 causality methods.

CASE SUMMARIES:

Two patients with the possibility of SSRI-related stroke were referred for causality assessment. Causality assessment was performed using an adverse drug reaction probability scale, as well as clinical and radiologic parameters. A 31–year-old white man, who had been receiving paroxetine 200 mg/day over a period of 3 years, developed ischemic stroke involving left middle cerebral artery. The second patient was a 46–year-old white woman with a history of recurrent depression who developed delirium and ischemic stroke while she was taking a combination of paroxetine 50 mg/day, trazodone 200 mg/day, and bupropion 150 mg/day.

DISCUSSION:

Carotid and cardiothromboembolism were found to be the major etiological factors for ischemic stroke. Accounting for the temporal relation, prior reports of SSRI treatment—associated CV-ADRs, and the pharmacologic action of serotonin on coagulation and the vascular system, the possible contribution of SSRIs to stroke in these patients was considered. An objective causality assessment using the Naranjo probability scale revealed that a CV-ADR was possible. However, the nature of the stroke, plus clinical and radiologic findings, were inconsistent with known pathophysiologic mechanisms linking SSRIs and stroke in these patients.

CONCLUSIONS:

Causality assessment may improve unbiased recognition, management, and voluntary reporting of infrequent adverse effects such as SSRI treatment—related cerebrovascular accident.
Awareness in early‐stage Alzheimer's disease: A review of methods and evidence
Authors: Clare Linda
Published: May 2004

Purpose: This review has three main aims:

(1) To illustrate the strengths and limitations of current approaches to assessing awareness of difficulties and impairments in people with early‐stage Alzheimer's disease (AD).

(2) To consider the evidence regarding factors associated with level of awareness.

(3) To highlight the implications for assessment and intervention.

Methods: A comprehensive range of literature on awareness in AD published in the past 20 years is critically reviewed.

Results: Four main approaches to the assessment of awareness can be discerned, each with significant conceptual and methodological limitations. These limitations affect the quality of the available evidence regarding factors associated with level of awareness, which is contradictory, with few clear findings emerging. Awareness does, however, appear to be related to the outcome of rehabilitation, and this has important implications for the selection of appropriate and sensitive interventions.

Conclusions: The review highlights the need for a broad conceptualization of awareness. Greater clarity about theoretical frameworks, and improved assessment methods, are required in order to enhance understanding of variations in awareness in early‐stage AD. Awareness is an important variable for clinicians to consider.
Apolipoprotein(a) Size and Lipoprotein(a) Concentration and Future Risk of Angina Pectoris with Evidence of Severe Coronary Atherosclerosis in Men: The Physicians’ Health Study
Authors: Rifai Nader , Ma Jing , Sacks Frank M , Ridker Paul M , Hernandez Wendy Jade L , Stampfer Meir J , Marcovina Santica M
Published: May 2004

Background: The relationship of lipoprotein (a) [Lp(a)] concentrations with risk of coronary heart disease needs clarification, especially for threshold values for increased risk and for possible interactions with LDL-cholesterol concentrations and apolipoprotein (a) [apo(a)] size polymorphism. This study was designed to examine the ability of baseline Lp(a) concentration and apo(a) size to predict future severe angina pectoris in apparently healthy men.

Methods: Baseline Lp(a) concentration and apo(a) size were determined in 195 men who subsequently developed angina and in 195 men who remained free of cardiovascular disease for 5 years.

Results: Cases had higher median Lp(a) concentrations than did controls (30.6 vs 22.5 nmol/L; P = 0.02). Lp(a) concentration was predictive of angina [relative risk (RR) from lowest to highest quintiles: 1.0, 1.5, 1.0, 1.8, and 2.6; P for trend = 0.015]. The increased risk was ∼4-fold (95% confidence interval, 1.4- to 11-fold) among men who had Lp(a) above the 95th percentile (>158 nmol/L). Men with Lp(a) concentrations in the highest quintile and LDL-cholesterol concentrations >1600 mg/L had a 12-fold increased risk (95% confidence interval, 1.5- to 43-fold). Small apo(a) size isoforms also significantly predicted risk of angina (RR for lowest quintile = 4.1; P for trend = 0.004). When the independent effect of Lp(a) concentration and apo(a) size was assessed by including them in the same multivariate model, only the association between apo(a) size and risk remained significant.

Conclusions: High Lp(a) predicts risk of angina, and the risk is substantially increased with high concomitant LDL-cholesterol. Small apo(a) size predicts angina with greater strength and independence than Lp(a) concentration.
Evaluation of Two Nonisotopic Immunoassays for Determination of Glutamic Acid Decarboxylase and Tyrosine Phosphatase Autoantibodies in Serum
Authors: Palomer Xavier , Mauricio Dídac , Rodríguez-Espinosa José , Zapico Edgar , Mayoral Carme , González-Sastre Francesc , de Leiva Alberto , Blanco-Vaca Francisco
Published: May 2004

Background: Autoantibodies for the 65-kDa form of glutamic acid decarboxylase (GAD65) and protein tyrosine phosphatase-like protein (IA-2) are measured for risk prediction and diagnosis of autoimmune diabetes mellitus. There is a lack of adequate nonisotopic alternatives to the most widely used method for both autoantibodies, which is a radiobinding assay (RBA).

Methods: We compared two commercially available immunoassays, an ELISA and a time-resolved immunofluorometric assay (TR-IFMA), with RBA.

Results: We found excellent agreement between the RBA and ELISA for measurement of GAD65 autoantibodies (GADAs); they showed comparable analytical precision in the cutoff range and achieved similar diagnostic specificity. The ELISA identified more GADA-positive individuals among patients with new-onset type 1 diabetes than did the RBA [89% (95% confidence interval, 78–95%), vs 71% (58–82%); P <0.03]. For IA-2 autoantibodies (IA-2As), only the TR-IFMA achieved analytical performance and diagnostic accuracy comparable to that of the RBA. These results with the GADA ELISA and IA-2A TR-IFMA were consistent with those obtained blindly in the Diabetes Antibody Standardization Program 2003. The performance of the GADA TR-IFMA and IA-2A ELISA was unsatisfactory, and these tests were not subjected to clinical evaluation.

Conclusions: The GADA ELISA and IA-2A TR-IFMA behave comparably with RBA and are thus suitable for use in the clinical laboratory.
Universal RNA Reference Materials for Gene Expression
Authors: Cronin Maureen , Ghosh Krishna , Sistare Frank , Quackenbush John , Vilker Vincent , O’Connell Catherine
Published: May 2004

A workshop entitled “Metrology and Standards Needs for Gene Expression Technologies: Universal RNA Standards” was held in March 2003 to define the requirements for standardizing RNA-based molecular assays, specifically microarray and quantitative reverse-transcriptase-PCR technologies. NIST sponsored the workshop, and participants represented government, industry, academia, and clinic. Workshop participants concluded that as a first step, two RNA reference materials could be defined that would help in standardization of gene-expression technologies: an Assay Process Reference Material, and a Universal Array Hybridization Reference Material. The specific characteristics of these two standardized materials were broadly outlined. The Assay Process Material was proposed to be a pool of 96 expressed human sequences of defined composition, cloned in a defined vector and pooled in prescribed ways. The Universal Array Hybridization Material was defined as a pool of 12 “alien” synthetic sequences not expressed in any known genome to be used to control for variability in array hybridization methods. Work is underway at NIST and among members of the gene expression array community to further define these materials and make them available.
Relationship Between Particle Shape and Void Content of Fine Aggregate
Authors: Dilek U , Leming ML
Published: May 2004

Fine aggregate characteristics have an important influence on water demand and related properties of concrete. Several test methods for measurement of fine aggregate angularity are reported in the literature. These tests typically provide a single number that represents the bulk, or average angularity of the sand. An understanding of the relationship between bulk measures of angularity, individual particle geometry and shape characteristics, and concrete properties is important to aggregate producers, concrete suppliers, consulting engineers, other design professionals, particularly as existing deposits of sand are consumed and alternate sources must be developed. As part of a comprehensive research program on manufactured sand properties and their effects on fresh and hardened concrete properties, an image analysis technique was developed to determine the shape characteristics by photographing and analyzing sets of individual grains of sand. The outlines of the grains were analyzed using a variety of geometrically derived characteristics. The relationship between particle shape characteristics and a common measure of bulk angularity, void content (ASTM C 1252), was then examined. Results of the study indicated that void content was significantly influenced by the presence of deep indentations in the surface of the sand particle and deviations from a cubical particle shape.
Anthropological Data in Individualization of Skeletal Remains from a Forensic Context in Kosovo—A Case History
Authors: Djurić MP
Published: May 2004

There are many reports relating to victims and mass graves in the former Yugoslavia. They emphasize the importance of creating local skeletal identification standards. In this paper we deal with the first mass grave examined since the Kosovo crisis started and discuss problems regarding the identification process, especially the coincidence of antemortem with postmortem data. Twelve persons out of 39 bodies were identified using interviews with relatives and correspondence of biological data with personal effects and/or documents. Previous pathology was of crucial importance in the identification of three persons.
Linking Crime Guns: The Impact of Ballistics Imaging Technology on the Productivity of the Boston Police Department's Ballistics Unit
Authors: Braga AA , Pierce GL
Published: May 2004

Ballistics imaging technology has received national attention as a potent tool for moving the law enforcement response to violent gun criminals forward by linking multiple crime scenes to one firearm. This study examines the impact of ballistics imaging technology on the productivity of the Boston Police Department's Ballistics Unit. Using negative binomial regression models to analyze times series data on ballistics matches, we find that ballistics imaging technology was associated with a more than sixfold increase in the monthly number of ballistics matches made by the Boston Police Department's Ballistics Unit. Cost-effectiveness estimates and qualitative evidence also suggest that ballistics imaging technology allows law enforcement agencies to make hits that would not have been possible using traditional ballistics methods.
Sexual Dimorphism of the Calcaneus of South African Blacks
Authors: Bidmos MA , Asala SA
Published: May 2004

Forensic anthropology is a rapidly growing field in South Africa and skeletal biologists are often called upon by the police to assist in personal identification from skeletal remains, which are recovered in suspected cases of homicide and suicide and in mass disaster. Measurements of the calcaneus have been shown to be sexually dimorphic in South African whites. Since the validity of discriminant function equations in sex determination is population specific, the aim of the present study was to derive similar equations for the calcanei of the South African blacks. The bones that were used in this study were obtained from the Raymond A. Dart Collection of Human Skeletons, School of Anatomical Sciences, University of the Witwatersrand, Johannesburg. One hundred and sixteen (116) intact and non-pathological calcanei, consisting of 58 males and 58 females and belonging to individuals whose age at death ranged between 22 and 75 years, were selected by the simple random sampling technique. The measured variables included the maximum length, the load arm length, the dorsal articular facet length, the body height, the maximum height, the cuboidal facet height, the middle breadth, the dorsal articular facet breadth and the maximum breadth. Discriminant function analyses were done using the Statistical Product and Service Solutions (SPSS) program. All measured parameters of the calcaneus showed significant sexual differences. Length measurements were found to be the most sexually dimorphic. Combinations of variables provided better estimate of sex (79%–86%) than individual variables (64%–79%).
The Effect of Time After Body Discovery on the Accuracy of Retrospective Weather Station Ambient Temperature Corrections in Forensic Entomology
Authors: Archer MS
Published: May 2004

Weather station data are used by forensic entomologists to estimate ambient temperatures at body discovery sites. Correlation data from sites may also be collected to correct for site and station differences. This experiment tested the accuracy over time of retrospective weather data correction using linear regression between stations and sites. Temperatures were logged at six hypothetical body discovery sites during a seven-day period for which a hypothetical body lay in situ, and a further four correlation periods. The accuracy of weather data for hypothetical body in situ periods improved after correction in 22 of 24 correlations; however, mean predicted body in situ temperatures for sites differed significantly between correlation periods. Predicted temperatures generally rose with time after body removal, which correlated with rising site temperatures accompanying seasonal change. Therefore, practitioners should be cautious in making correlations if weather patterns during correlation differ greatly from those while the body was in situ.
Fifteen-Year Retrospective Study of Infant Organ Weights and Revision of Standard Weight Tables
Authors: Thompson WS , Cohle SD
Published: May 2004

No recent studies of organ weights of normal infants exist. We completed a 15-year retrospective study of organ weights of normal infants who died between 1986 and 2000 in an effort to update the “normal” weight standards for infants up to one year of age. Additionally, we compared organ weights of infants whose deaths were ruled Sudden Infant Death Syndrome (SIDS) with those of other natural or non-natural causes within the same age groups, length and total body weight at autopsy, total organ weight as a percentage of total body weight, and with weight standards based on previous studies. This study included 453 autopsied infants in Kent County, Michigan, and who were referred to our facility by surrounding counties. All subjects were autopsied at Spectrum Health Blodgett Campus in Grand Rapids, Michigan.
Evaluation of Three Rapid Detection Methods for the Forensic Identification of Seminal Fluid in Rape Cases
Authors: Khaldi N , Miras A , Botti K , Benali L , Gromb S
Published: May 2004

We sought to discover whether spermatozoa concentration and the delay between ejaculation and test influence the results of seminal fluid fast detection tests. Two hundred and twenty-seven anonymous sam ples divided into four groups (normospermia, oligospermia, azoospermia, and controls) after a semen analysis were subjected to three fast detection semen tests: Diff-Quick® fast coloration, Phosphatesmo Km Paper® for acid phosphatases (AP) detection, and PSA-Check 1® for prostate specific antigen (PSA) detection. The study was performed at three time points (0, 48, and 72 h). Unlike cytology, results obtained with AP and PSA were not influenced by spermatozoa concentration. PSA detection results remained constant up to 72 h and were more reliable after 48 h than those obtained by AP detection.
Age Calculation Using X-ray Microfocus Computed Tomographical Scanning of Teeth: A Pilot Study
Authors: Vandevoort FM , Bergmans L , Cleynenbreugel JV , Bielen DJ , Lambrechts P , Wevers M , Peirs A , Willems G
Published: May 2004

To correlate dental age with an individual's chronological age based on the calculated volume ratio of pulp versus tooth volume measured, an X-ray microfocus computed tomography unit (μCT) with 25μm spatial resolution was used to non-destructively scan 43 extracted single root teeth of 25 individuals with well-known chronological age. Custom-made analysis software was used by two examiners to obtain numerical values for pulpal and tooth volume. The ratio of both was calculated and statistically processed. No significant intra-orinter-examiner differences were found. In fact,a very strong concordance correlation coefficient was found. Linear regression analysis showed a coefficient of determination (r) of 0.31 which suggests that there is a rather weak correlation between the volume ratio of pulp versus tooth and biological age. Although rather time consuming, this technique shows promising results for dental age estimation in a non-destructive manner using X-ray microfocus computed tomography.
Laboratory Impulse Tests for Soil-Underground Structure Interactions
Authors: Helwany SMB , Chowdhury A
Published: May 2004

The dynamic lateral earth pressures resulting from underground detonation can cause severe damage to underground structures. The shock exerted on an underground structure caused by an underground explosion will vary with the detonation depth, the intensity of detonation force, and distance of detonation source from the underground structure. This paper describes four large-scale impulse tests on a 1-m-high pro-totype subsection of an underground structure subjected to controlled impulsive lateral loadings propagating through a 0.75-m-thick backfill soil. The response of the subsection to the impulsive loading is carefully monitored utilizing an extensive instrumentation program. The test results provide insight into the phenomenon of shock wave propagation caused by an impulsive loading emanating from an underground source adjacent to the underground structure. The tests indicated that the damaging effect of impulse loading increased with surcharge pressure (depth) until a threshold surcharge pressure is reached above which the damaging effect of impulse loading decreased.
Numerical Analysis for Small Punch Creep Tests by Finite-Element Method
Authors: Zhai PC , Hashida T , Komazaki S , Zhang QJ
Published: May 2004

A numerical study is presented that simulates small punch creep (SP-C) tests using a finite-element method (FEM). The objective of the present study is to develop a miniaturized testing methodology for high-temperature creep properties. The numerical simulations have been shown to produce deflection versus time curves that are quantitatively similar to the experimental results obtained on tungsten-alloyed 9 % Cr ferritic steels. It is also demonstrated that the numerically predicted curves show the steady state (secondary) creep stage. Furthermore, the numerical simulations reveal that the magnitude of the equivalent stress in the central region of the SP-C specimen shows no significant change with respect to time at the secondary creep stage, supporting the use of the present SP-C testing method to characterize the secondary creep deformation rate. Finally, an approximate equation is proposed for the assessment of the equivalent stress in the SP-C specimen in terms of the load and testing parameters.
Review of Steelwork Corrosion Control—Second Edition
Authors: Hack HP
Published: May 2004

This book is a thorough review of corrosion control methods for steel structures, with a major emphasis on painting. The contents include chapters on the corrosion of steel, surface preparation, paints and paint coatings, pain application, specialist coating and applications, metal coating, writings effective specifications, quality control of coating operations, designing for corrosion control, maintenance painting, control methods other than coatings, coating defects and failures, the selection of coating systems, protective systems for different situations, and testing of coatings.
Osteoporosis Screening and Treatment in Women with Schizophrenia: A Controlled Study
Authors: Bishop Jeffrey R. , Alexander Bruce , Lund Brian C. , Klepser Teresa B.
Published: May 2004

Study Objective. As patients with a major psychiatric disorder such as schizophrenia generally are less likely to have their medical illnesses diagnosed and medically managed, we investigated whether osteoporosis screening, prevention management, and/or drug therapy (i.e., clinical services for osteoporosis) are provided consistently to both women with schizophrenia and those without the disease.

Design. Retrospective medical record review.

Setting. Three Midwest Veterans Affairs medical centers and clinics.

Patients. Forty‐six women aged 45 years or older who had schizophrenia and 46 female control subjects who were frequency matched on age.

Measurements and Main Results. Twelve months of progress notes were reviewed for osteoporosis clinical services. In addition, smoking status, smoking cessation counseling, alcohol consumption, and fracture rates were compared between the groups. Overall, significantly fewer patients with schizophrenia (28 patients [61%]) received a clinical service for osteoporosis compared with the control group (37 patients [80%]). This difference was due to a significantly fewer number of patients with schizophrenia who received any osteoporosis agent (22 patients [48%]) compared with the control group (36 patients [78%]). Only 13 patients (28%) with schizophrenia received hormone replacement therapy compared with 25 control patients (54%).

Conclusion. Women with schizophrenia in three Midwest Veterans Affairs medical centers did not receive the same level of osteoporosis care as that of age‐matched control patients. This was primarily due to a lower utilization of osteoporosis agents, specifically hormone replacement therapy. Further research is necessary to determine the reason for this difference. Clinicians should be aware of medical management issues in patients with major psychiatric diagnoses and, specifically, osteoporosis care of women with schizophrenia.