bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generalized Linear Models with a Coarsened Covariate
Authors: Lipsitz Stuart , Parzen Michael , Natarajan Sundar , Ibrahim Joseph , Fitzmaurice Garrett 
Published: December 2004

SummaryWe consider generalized linear models with a coarsened covariate. The term ‘coarsened’ is used here to refer to the case where the exact value of the covariate of interest is not fully observed. Instead, only some set or grouping that contains the exact value is observed. In particular, we propose a likelihood-based method for estimating regression parameters in a generalized linear model relating the mean of the outcome to covariates. We outline Newton–Raphson and EM algorithms for obtaining maximum likelihood estimates of the regression parameters. We also compare and contrast this likelihood-based approach with two somewhat ad hoc procedures: a complete-case analysis in which individuals with coarsened data are excluded and estimation is based on the remaining ‘complete cases’, and a coarsened data regression model in which the covariate values for all the complete cases are coarsened and then included in a regression model relating the mean to the coarsened covariate. The methodology that is presented is motivated by coarsened data on the racial–ethnicity categorization of patients in the US’s National Ambulatory Medical Care Survey, a study to examine the medical care that is provided to a patient in a physician’s office. In this study, the outcome of interest is the level of tests (none, non-invasive tests or invasive tests) ordered for the patient at the doctor’s visit. One of the covariates of interest is the patient’s four-level discrete covariate comprised of four racial–ethnicity categories: white–Hispanic, white–non-Hispanic, African-American–Hispanic and African-American–non-Hispanic. However, of the 19 095 patients in the sample, 14 955 (or 78%) have the exact category of race–ethnicity recorded and 4140 (or 22%) have race–ethnicity coarsened. For the latter group of 4140 individuals, the ethnicity is not recorded, but we know that 3683 are white and 457 are African-American.
Designing Fractional Factorial Split-Plot Experiments with Few Whole-Plot Factors
Authors: Bingham D. R. , Schoen E. D. , Sitter R. R. 
Published: December 2004

Summary
When it is impractical to perform the experimental runs of a fractional factorial design in a completely random order, restrictions on the randomization can be imposed. The resulting design is said to have a split-plot, or nested, error structure. Similarly to fractional factorials, fractional factorial split-plot designs can be ranked by using the aberration criterion. Techniques that generate the required designs systematically presuppose unreplicated settings of the whole-plot factors. We use a cheese-making experiment to demonstrate the practical relevance of designs with replicated settings of these factors. We create such designs by splitting the whole plots according to one or more subplot effects. We develop a systematic method to generate the required designs and we use the method to create a table of designs that is likely to be useful in practice.
A Hierarchical Modelling Approach for Measuring Reliability of and Agreement Between Two Types Of Magnetic Field Dosimeter
Authors: Brazzale Alessandra Rosalba , Salvan Alberto , Roletti Stefano 
Published: December 2004

SummaryThe paper describes how to use hierarchical models to assess the reliability of and agreement between two or more types of measurement device. The idea is illustrated by fitting a linear model with nested random effects to a set of data that was obtained from the calibration of two samples of extremely low frequency magnetic field meters. The paper focuses on the formulation of a suitable model that accounts for the various aspects of the calibration protocol and the subsequent interpretation of the parameter estimates. The approach is very flexible and can easily be tuned to the various needs arising in the measurement agreement framework. It can be seen as an extension of the common practice of using a one-way random-effects model to retrieve a measure of agreement.
Temporal Pattern in Number of Staff on Sick Leave: The Effect of Downsizing
Authors: Kauermann Göran , Ortlieb Renate 
Published: December 2004

SummaryThe pattern of absenteeism in the downsizing process of companies is a topic in focus in economics and social science. A general question is whether employees who are frequently absent are more likely to be selected to be laid off or in contrast whether employees to be dismissed are more likely to be absent for the remaining time of their working contract. We pursue an empirical and microeconomic investigation of these theses. We analyse longitudinal data that were collected in a German company over several years. We fit a semiparametric transition model based on a mixture Poisson distribution for the days of absenteeism per month. Prediction intervals are considered and the primary focus is on the period of downsizing. The data reveal clear evidence for the hypothesis that employees who are to be laid off are more frequently absent before leaving the company. Interestingly, though, no clear evidence is seen that employees being selected to leave the company are those with a bad absenteeism profile.
Computerized cardiotocography: predictive value of instant variability
Authors: Char Sang Choon , Yamasaki A. A. , Toma O. T. 
Published: December 2004

Introduction:  Computerized cardiotocography differs from classic method in measurement of instant variability, also named short‐term variation (STV) which is an important parameter of evaluation of fetal condition. While classic cardiotocography considers an active fetus when in the presence of two transitory accelerations (TA), in computerized method, value of STV is the most important parameter and it must be higher than 4 ms.Objective:  Correlation between STV and TA.Methods:  Two hundred and forty traces of computerized cardiotocography were analyzed (SYS 8002), in normal pregnant, between 30 and 36 weeks of gestation. They were divided into two groups: group I (n = 200) represented by pregnant whose exam did not show any TA but STV > 4 ms after 10 min; group II (n = 40) represented by pregnant with no TA and STV < 4 ms after 10 min. In all cases traces were continued until presence of TA, and the longest trace was 60 min of duration.Results:  In group I, all cases showed TA while in group II in 60% cases initial STV < 4 ms have become more than 4 ms and with presence of TA, showing fetal in good conditions. In the other hand, in 40% cases even after keeping trace until complete 60 min there were not changes in STV or presence of TA.Conclusion:  Fetuses with STV > 4 ms are related to active fetuses (presence of TA) and the ones with STV < 4 ms does ever not mean altered result as when prolonging trace until 60 min, 60% of these fetuses become active.
THE CLINICAL EPIDEMIOLOGY OF CARDIOVASCULAR DISEASES IN CHRONIC KIDNEY DISEASE: Cardiovascular Disease in Chronic Renal Failure: Pathophysiologic Aspects
Authors: London Gérard M. 
Published: December 2004

ABSTRACTCardiovascular complications are the leading cause of mortality in patients with end‐stage renal disease (ESRD). The excess cardiovascular risk and mortality is already demonstrable in early renal disease and in patients with chronic renal failure (CRF), with the highest relative risk of mortality in the youngest patients. The high risk for cardiovascular disease (CVD) results from the additive effect of multiple factors, including hemodynamic overload and several metabolic and endocrine abnormalities more or less specific to uremia. CVD includes disorders of the heart (left ventricular hypertrophy [LVH], cardiomyopathy) and disorders of the vascular system (atherosclerosis, arteriosclerosis), these two disorders being usually associated and interrelated. LVH is the most frequent cardiac alteration in ESRD, resulting from a combined pressure and volume overload. LVH in general is an ominous prognostic sign and an independent risk factor for arrhythmias, sudden death, heart failure, and myocardial ischemia. Regression of LVH needs a combined intervention to reduce hemodynamic overload and is associated with improved prognosis and survival. Clinical studies have shown that damage of large conduit arteries is a major contributing factor for the high incidence of congestive heart failure (CHF), LVH, ischemic heart disease (IHD), sudden death, cerebrovascular accidents, and peripheral artery diseases. Damage to large conduit arteries is principally related to highly calcified occlusive atherosclerotic lesions and to stiffening of large capacitive arteries. These two complications are independent risk factors for survival, and improvement of arterial stiffness is associated with better prognosis and survival. The present review summarizes the most recent works dealing with the pathophysiology of CVD and some aspects of the therapeutic approach.
THE CLINICAL EPIDEMIOLOGY OF CARDIOVASCULAR DISEASES IN CHRONIC KIDNEY DISEASE: Management of Heart Failure and Coronary Artery Disease in Patients with Chronic Kidney Disease
Authors: Murphy Sean W. 
Published: December 2004

ABSTRACTCardiovascular disease (CVD) is a major contributor to the mortality and morbidity of patients who suffer from chronic kidney disease (CKD). Heart failure and ischemic heart disease (IHD) are both highly prevalent in this population. The diagnosis of myocardial dysfunction is usually based on echocardiography. As in the general population, systolic dysfunction is treated with a combination of diuretics, renin‐angiotensin system blockade, and β‐receptor antagonists. Diastolic dysfunction is best managed by eliminating the cause. Non‐invasive tests for coronary artery disease (CAD) may be less reliable in patients with renal disease compared with nonuremic patients. Medical therapy of IHD in this population is generally similar to that for other patient groups, but surgical revascularization appears to carry a higher risk of complications with poorer clinical outcomes. The choice of revascularization procedure (coronary artery bypass grafting versus percutaneous transluminal angioplasty) should be based on the specific coronary anatomy of a given patient as well as a consideration of other comorbid factors.
Determinants of Factor VIII Recovery in Cryoprecipitate
Authors: Kasper C. K. , Myhre B. A. , McDonald J. D. , Nakasako Y. , Feinstein D. I. 
Published: December 2004

Many aspects of the production of cryoprecipitate were studied to determine which methods resulted in the greatest recovery of Factor VIII. The following recommendations resulted: 1) blood should be mixed with anticoagulant throughout phlebotomy; 2) blood should be centrifuged within a few hours of collection; 3) larger satellite bags should be used to contain the usual volume of plasma, for example, 200 ml of plasma should be frozen in a 600‐ml capacity bag; 4) plasma should be centrifuged as soon as thawing is complete; 5) cryoprecipitate should be refrozen on dry ice; 6) cryoprecipitate should be stored at or below –30 C; and 7) prolonged storage of frozen plasma or cryoprecipitate should be avoided.Variations in Factor VIII content from one bag of cryoprecipitate to another, under uniform production conditions, depends largely on two donor‐specific attributes which tend to remain constant from time to time, namely, the donor's plasma Factor VIII level and the cryoprecipitability of his Factor VIII.
Metabolic Changes during Platelet Storage
Authors: Rock G. , Figueredo A. 
Published: December 2004

Platelet concentrates (PC) were stored in plastic bags with continuous shaking at 4, 22, and 37 C. Various metabolic parameters were examined over a 72‐hour period. At 22 C, the pH and PO2 declined over 72 hours while the Pco2 and lactate increased. Hypotonic shock declined to 70 per cent. This differed from the small amounts of CO2 and lactate found at 4 C and the marked accumulation of metabolites and almost complete loss of shock response at 37 C. Aggregation was always better maintained with 4 C storage.The toxic effect of the accumulation of metabolites on the platelets was tested by adding lactate to fresh PC at zero time. This was effective in lowering the initial pH, markedly inhibiting the response to aggregation and decreasing the total accumulation of lactate during storage, but did not produce an inhibition of hypotonic shock response. The effect of accumulation of toxic metabolites was further investigated by using 72‐hour plasma and platelets and recombining each of them with fresh preparations.Platelets were tested under degassed conditions to outline the requirements for oxygen and gaseous exchange. Surprisingly, there was less accumulation of lactate and CO2 and better hypotonic shock response.These experiments have detected various changes in viability markers in platelets that are stored under actual blood bank conditions and indicate that the accumulation of lactate is not totally responsible for the toxic inhibition of platelet performance that is found upon storage at 22 C.
A “Normal” Individual with a Positive Direct Antiglobulin Test Case Complicated by Pregnancy and Unusual Autoantibody Specificity
Authors: Henry R. A. , Weber J. , Pavone B. G. , Issitt P. D. 
Published: December 2004

A “normal” individual with a positive direct anti‐globulin test is described. In common with many other “normal” persons in whom a similar finding has been made, there was no evidence of an increased rate of in vivo red blood cell destruction in this patient. The patient successfully completed a pregnancy during the time that detailed serologic studies on her autoantibodies were being performed. Although the maternal autoantibodies were demonstrable in both an eluate made from the red blood cells of her newborn infant, and in the cord serum, there was no reason to believe that the antibodies caused red blood cell destruction in the infant.The case was of further interest because of the specificities of some of the autoantibodies. Although the mother and child were both C‐negative, eluates from their red blood cells contained what ostensibly appeared to be anti‐C. Studies that showed that the antibody could be totally adsorbed with C‐negative, as well as C‐positive red blood cells, proved that this was another example of an autoantibody mimicking an alloantibody. Although this autoantibody appeared initially to have anti‐C specificity it was eventually shown to be more closely related to anti‐Hr or anti‐Rh34, than to anti‐C.
An Investigation of the Relationship between the V(hrv), VS, and hrH Antigens
Authors: Tregellas W. M. , Issitt P. D. 
Published: December 2004

The data from this investigation show that the anti‐VS sera studied cannot be separated into anti‐hrv (anti‐V) and anti‐hrH specificities. The antibody specificity is singular and is directed against an antigenic determinant present on VS positive red blood cells. That some anti‐VS sera appear to have a separable specificity may be due to the incomplete absorption of those antisera.It was shown that V–, VS+ red blood cells adsorb more anti‐VS than do those that are V+, VS+. Several absorption of anti‐VS serum with V +, VS + red blood cells may remove enough of the antibody that the absorbed serum will no longer (visibly) react with V +, VS+ red blood cells, though the same absorbed serum will react with V‐, VS+ red blood cells. That this is not a separable specificity can be demonstrated by subsequent absorption to exhaustion of the same serum with V +, VS+ red blood cells.Testing of the original Hernandez serum confirmed that it defines the antigenic specificity, hrH. The relationship of hrH to VS may be similar to the relationship of the Rho (D) antigen to the antigens of the Rho (D) mosaic.
Freezing in the Primary Polyvinylchloride Plastic Collection Bag: A New System for Preparing and Freezing Nonrejuvenated and Rejuvenated Red Blood Cells
Authors: Valeri C. R. , Valeri D. A. , Anastasi J. , Vecchione J. J. , Dennis R. C. , Emerson C. P. 
Published: December 2004

Red blood cells were stored at 4 C in the primary bag with an integrally attached empty transfer pack so that the red blood cells could be rejuvenated or not, as desired before glycerolization and freezing. The rejuvenation and glycerol solutions were added through ports in the system. After glycerolization, the red blood cells were concentrated by centrifugation to remove the supernatant glycerol before freezing with 40% w/v glycerol in the primary polyvinylchloride (PVC) plastic container at −80 C.After thawing, the red blood cells were washed using either the Haemonetics Blood Processor 115 or the IBM Blood Processor 2991‐1 or 2991‐2. In each system, 50 ml of 12% sodium chloride and 1.5 to 1.6 liters of 0.9% sodium chloride‐0.2% glucose‐25 meq/l disodium phosphate were used. Recovery of red blood cells in vitro was 91 per cent. After three days of postwash storage at 4 C, nonrejuvenated red blood cells had a mean 24‐hour posttransfusion survival of 88 per cent, and outdated‐rejuvenated red blood cells a value of 81 per cent. This new system is simpler and safer than methods previously used in this laboratory, and red blood cell recovery and 24‐ hour posttransfusion survivals were comparable or better.
Factors influencing yield of plateletpheresis by discontinuous centrifugation
Authors: Ogata H. , Nagashima K. , Iinuma N. , Hosogaya S. , Akabane T. 
Published: December 2004

Plateletphereses performed by the Haemonetics Model 30 Blood Processor under a fixed condition were retrospectively analyzed. The mean platelet yield was 5.97 × 10ll (± l.46 × 10ll. Prepheresis platelet count was significantly correlated to platelet yield (p < 0.001), but hematocrit was not (p > 0.1). Blood‐drawing time showed a significant correlation (p < 0.01) and may suggest than an infusion rate of 60 ml/minute is a technique of choice.A large number of platelets (% platelet recovery = 73.0 ± 14.1%) was discarded in order to remove erythrocytes and leukocytes from the initial product. The recovery was negatively correlated to the percentage removal of leukocytes (p < 0.01), which means that a platelet product of good quality not containing leukocytes can be prepared at the sacrifice of a large quantity of platelets. It is desirable to devise a simple and practical technique to obtain pure platelets without loss.
Defective energy metabolism in stored granulocytes
Authors: Lane T.A. , Lamkin G.E. 
Published: December 2004

Previous studies suggested that a general metabolic defect might be responsible for impaired chemotaxis of stored granulocytes (PMN). We studied PMN energy metabolism in fresh and stored PMN.Adenosine triphosphate (ATP) decreased slightly in unstimulated PMN after 48 hours of storage at room temperature. Exposure of fresh PMN to opsonized zymosan resulted in a 12 percent decrease in ATP. In contrast, PMN stored for 24 or 48 hours at room temperature and then exposed to opsonized zymosan, showed significant decreases in ATP. Incubation of fresh or stored, stimulated (opsonized zymosan) or resting PMN with potassium cyanide resulted in no change in the pattern of ATP decrements during storage. Likewise, incubation of fresh or stored, stimulated or resting PMN in the presence or absence of extracellular glucose, resulted in no change in the pattern of ATP decrements during storage. Preincubation of PMN with 2‐deoxy‐glucose obscured the differences in ATP maintenance between fresh and stored PMN. ATP decrements were also observed in unstimulated PMN which had been stored at high cell concentrations. Decrements in ATP correlated stronglywith decreased glucose (r = .82) and pH (r = .89) in the storage medium.These decrements were partially reversed by incubation of PMN in fresh buffer. The ATP decrements in stored, concentrated granulocyte preparations thus were prevented by maintenance of pH. ATP decrements were not prevented by additional glucose. Thus, in PMN stored for 24 or 48 hours at room temperature, there was a defect in ATP maintenance which was occult in unstimulated cells, but was evoked by the energy‐dependent process, phagocytosis. These findings are compatible with a major role for glycolysis and glycogenolysis in maintaining ATP in fresh and stored PMN. Storage of PMN at high cell concentrations was accompanied by impaired ATP maintenanceand decreased pH in the storage medium, both of which were preventable by addition of alkali to the PMN concentrate prior to storage.
Stability of red cell antigens and plasma coagulation factors stored in new formulation plastic blood containers
Authors: Snyder E. L. , Hezzey A. , Weirich F. , Mosher D. F. , Davisson W. , Buchholz D. H. 
Published: December 2004

The stability of red blood cell antigens and plasma coagulation factors stored in new plastic blood packs containing either citrate‐phosphate‐dextrose (CPD) or citrate‐phosphate‐dextrose‐adenine (CPDA‐2) was studied. The containers were made of either polyolefin (PL 732™) plastic without a plasticizer, or polyvinyl chloride with a non‐diethylhexyl phthalate (non‐DEHP) plasticizer (PL 1240). All studies were done in parallel using standard polyvinyl chloride (PL 146) bags containing DEHP plasticizer as controls. Red blood cell antigen scoring was performed for the A, B, c, D, K, Fya, Lea, Jka, M, and P antigens using cells obtained from both the blood container and tubing segments. Units of fresh frozen plasma and cryoprecipitate were prepared, and age and donor‐matched sets of each of these blood components were stored in both test and control plastic containers.The red blood cell antigens showed no decrease in reactivity over 21 (CPD) or 35 (CPDA‐2) days of storage in either test plastic compared with controls. For fresh frozen plasma (factors V, VIII, IX) and cryoprecipitate (factor VIII) the factor activity found for the test plastics ranged from 94 to 115 percent of that recorded for the age and donor‐matched control plastic. The concentration of fibronectin found in cryoprecipitate stored in the test plastics averaged 90 to 99 percent of the activity found in PL 146 plastic. We conclude that the red blood cell antigens and coagulation factors tested remain stable in the plastic‐anticoagulant combinations studied
Isolation and cryopreservation of monocytes from plateletapheresis cellular residues
Authors: Hunt S. M. , Lionetti F. J. , Valeri C. R. 
Published: December 2004

Human monocytes were isolated from the cellular residues remaining after plateletapheresis of donors using an automated blood cell processor. Mononuclear cells were obtained with density gradients and separated from lymphocytes by stepwise elutriation. The isolated cells were frozen using extracellular hydroxyethyl starch and intracellular dimethylsulfoxide.In three procedures, approximately 1 × 10° monocytes were obtained. Ninety‐nine percent of isolated monocytes were viable in a fluorescein diacetate (FDA)‐ethidium bromide (EB) test. Myeloperoxidase‐positive cells were 95 percent and 90 percent in the two chambers. Ninety‐four percent of monocytes ingested five or more opsonized polycyclic hydrocarbon particles and 95 percent ingested one or more ethidium‐treated zymosan particles.After storage in liquid nitrogen for up to 9 weeks, 99 percent of the cells were recovered after thawing. Of these, 95 percent were myeloperoxidase‐positive, 94 percent showed intact membranes in the FDA‐EB test, 95 percent ingested five or more opsonized polycyclic hydrocarbon particles, and 96 percent ingested one or more ethidium‐treated zymosan particles.