bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unit roots versus other types of time heterogeneity, parameter time dependence and superexogeneity
Authors: Caporale Guglielmo Maria , Pittis Nikitas 
Published: August 2002

AbstractThis paper stresses the restrictive nature of the standard unit root/cointegration assumptions and examines a more general type of time heterogeneity, which might characterize a number of economic variables, and which results in parameter time dependence and misleading statistical inference. We show that in such cases ‘operational’ models cannot be obtained, and the estimation of time‐varying parameter models becomes necessary. For instance, economic processes subject to endemic change can only be adequately modelled in a state space form. This is a very important point, because unstable models will break down when used for forecasting purposes. We also discuss a new test for the null of cointegration developed by Quintos and Phillips (1993), which is based on parameter constancy in cointegrating regressions. Finally, we point out that, if it is possible to condition on a subset of superexogenous variables, parameter instability can be handled by estimating a restricted system. Copyright © 2002 John Wiley & Sons, Ltd.
Forecasting European GNP data through common factor models and other procedures
Authors: García‐Ferrer Antonio , Poncela Pilar 
Published: August 2002

AbstractIn this paper we present an extensive study of annual GNP data for five European countries. We look for intercountry dependence and analyse how the different economies interact, using several univariate ARIMA and unobserved components models and a multivariate model for the GNP incorporating all the common information among the variables. We use a dynamic factor model to take account of the common dynamic structure of the variables. This common dynamic structure can be non‐stationary (i.e. common trends) or stationary (i.e. common cycles). Comparisons of the models are made in terms of the root mean square error (RMSE) for one‐step‐ahead forecasts. For this particular group of European countries, the factor model outperforms the remaining ones. Copyright © 2002 John Wiley & Sons, Ltd.
Mean Reversion and the Comovement of Equilibrium Spot and Futures Prices: Implications from Alternative Data‐Generating Processes
Authors: Zeng Tian 
Published: August 2002

AbstractThe comovements of spot and futures prices are characterized by six binary variables, including the term structure curvature of futures prices. These variables are used to uniquely identify 48 possible comovement patterns. Among them, 24 cases are associated with mean reversion, which is defined as a state when spreads between futures and spot prices are shrinking. These pattern frequencies are then calculated on a daily basis with the futures prices of 10 commodities, including precious metal, agricultural, and financial commodities. The results are further compared to simulation output from three data‐generating processes: a bivariate pure random walk, a mixed random walk with first‐order autoregression (AR(1)), and an error‐correction representation. The mean‐reverting frequencies for all 10 commodities are about 50%. Around half of the time, spot and futures prices are moving toward each other, and the rest of the time they move in the same direction. The symmetry of these results implies that the existence of substantial shocks originated from futures markets; thus, this is consistent with the risk premium view of futures trading. Also, although all simulation models produce similar mean‐reversion frequencies, the patterns of comovements of spot and futures prices are different, and the price dynamics depend heavily on whether the market is dominant contango or backwardation. Furthermore, the error‐correction model outperforms the random‐walk model for agricultural commodities, and the mixed random walk with AR(1) is hardly distinguishable from the pure random walk. © 2001 John Wiley & Sons, Inc. Jrl Fut Mark 21:769–796, 2001
Mutation analysis of the CDKN2A promoter in Australian melanoma families
Authors: Pollock Pamela M. , Stark Mitchell S. , Palmer Jane M. , Walters Marilyn K. , Aitken Joanne F. , Martin Nicholas G. , Hayward Nicholas K. 
Published: August 2002

AbstractApproximately 50% of all melanoma families worldwide show linkage to 9p21‐22, but only about half of these have been shown to contain germ line CDKN2A mutations. It has been hypothesized that a proportion of these families carry mutations in the noncoding regions of CDKN2A. Several Canadian families have been reported to carry a mutation in the 5′ UTR, at position −34 relative to the start site, which gives rise to a novel AUG translation initiation codon that markedly decreases translation from the wild‐type AUG (Liu et al., 1999). Haplotype sharing in these Canadian families suggested that this mutation is of British origin. We sequenced 1,327 base pairs (bp) of CDKN2A, making up 1,116 bp of the 5′ UTR and promoter, all of exon 1, and 61 bp of intron 1, in at least one melanoma case from 110 Australian families with three or more affected members known not to carry mutations within the p16 coding region. In addition, 431 bp upstream of the start codon was sequenced in an additional 253 affected probands from two‐case melanoma families for which the CDKN2A mutation status was unknown. Several known polymorphisms at positions −33, −191, −493, and −735 were detected, in addition to four novel variants at positions 120, −252, −347, and −981 relative to the start codon. One of the probands from a two‐case family was found to have the previously reported Q50R mutation. No family member was found to carry the mutation at position −34 or any other disease‐associated mutation. For further investigation of noncoding CDKN2A mutations that may affect transcription, allele‐specific expression analysis was carried out in 31 of the families with at least three affected members who showed either complete or “indeterminate” 9p haplotype sharing without CDKN2A exonic mutations. Reverse transcription polymerase chain reaction and automated sequencing showed expression of both CDKN2A alleles in all family members tested. The lack of CDKN2A promoter mutations and the absence of transcriptional silencing in the germ line of this cohort of families suggest that mutations in the promoter and 5′ UTR play a very limited role in melanoma predisposition. © 2001 Wiley‐Liss, Inc.
Chromosomal translocation t(8;12) induces aberrant HMGIC expression in aggressive angiomyxoma of the vulva
Authors: Nucci Marisa R. , Weremowicz Stanislawa , Neskey David M. , Sornberger Kris , Tallini Giovanni , Morton Cynthia C. , Quade Bradley J. 
Published: August 2002

AbstractBenign mesenchymal neoplasms associated with rearrangements of the DNA architectural factor gene HMGIC on chromosome 12 include lipomas, uterine leiomyomata, pulmonary chondroid hamartomas, endometrial polyps, salivary gland pleomorphic adenomas, and breast fibroadenomas. Although HMGIC also has been implicated in the pathobiology of aggressive angiomyxoma of the vulva, the molecular mechanisms pertaining to this neoplasm are unclear. Tissue from a recurrent aggressive angiomyxoma was investigated by cytogenetic and expression analysis for HMGIC and HMGIY. The trypsin‐Giemsa‐banded karyotype showed a clonal translocation between chromosomes 8 and 12 [46,XX,t(8;12)(p12;q15)]. Fluorescence in situ hybridization (FISH) analysis with whole chromosome paint probes for chromosomes 8 and 12 excluded cryptic involvement of other chromosomes. The chromosome 12 breakpoint was mapped with two‐color FISH analysis using cosmid probes at the 5′ and 3′ termini of HMGIC. Both cosmid probes showed hybridization to the normal chromosome 12 and the der(12) chromosome, indicating that the breakpoint was 3′ (telomeric) to the gene. Reverse transcriptase‐polymerase chain reaction (RT‐PCR) analysis revealed HMGIC expression in the tumor, and immunohistochemistry localized HMGIC expression to the tumor's spindle cells. Like numerous benign mesenchymal tumors, this locally aggressive tumor is associated with rearrangements near or within HMGIC, but chimeric gene formation was not required for tumorigenesis. Inappropriate expression of this DNA binding protein, however, may be important in the pathobiology of this tumor. Understanding the pathogenetic mechanism may also be helpful in developing new diagnostic tools for identifying residual disease. © 2001 Wiley‐Liss, Inc.
Genetics of the apnea hypopnea index in Caucasians and African Americans: I. Segregation analysis
Authors: Buxbaum Sarah G. , Elston Robert C. , Tishler Peter V. , Redline Susan 
Published: August 2002

AbstractDifferences in age of presentation and anatomic risk factors for obstructive sleep apnea (OSA) in Caucasians and African Americans suggest possible racial differences in the genetic underpinnings of the disorder. In this study, we assess transmission patterns in a Caucasian sample consisting of 177 families (N = 1,195) and in an African American sample consisting of 125 families (N = 720) for two variables: 1) apnea hypopnea index (AHI) log transformed and adjusted for age, and 2) AHI log transformed and adjusted for age and body mass index (BMI). We allowed for residual familial correlations and sex‐specific means in all models. Analysis of the Caucasian sample showed transmission patterns consistent with that of a major gene that were stronger in the age‐adjusted variable than in the age‐ and BMI‐adjusted variable. However, in the African American families, adjusting for BMI in addition to age gave stronger evidence for segregation of a codominant gene with an allele frequency of 0.14, accounting for 35% of the total variance. These results provide support for an underlying genetic basis for OSA that in African Americans is independent of the contribution of BMI. Genet. Epidemiol. 22:243–253, 2002. © 2002 Wiley‐Liss, Inc.
Human antibodies accelerate the rate of remyelination following lysolecithin‐induced demyelination in mice
Authors: Bieber Allan J. , Warrington Arthur , Asakura Kuni , Ciric Bogoljub , Kaveri Srini V. , Pease Larry R. , Rodriguez Moses 
Published: August 2002

AbstractImmunoglobulin‐based therapies are becoming increasingly common for the treatment of neurologic and autoimmune diseases in humans. In this study, we demonstrate that systemic administration of either polyclonal human immunoglobulins or specific human monoclonal antibodies can accelerate the rate of CNS remyelination following toxin‐induced demyelination. Injection of lysolecithin directly into the spinal cord results in focal demyelinated lesions. In contrast to other murine models of demyelinating disease, the mechanism of demyelination following lysolecithin injection is independent of immune system activation, and chronic inflammation at the site of the lesion is minimal. Administration of polyclonal human IgM (pHIgM) or a serum‐derived human monoclonal antibody (sHIgM22) resulted in approximately a twofold increase in remyelinating axons when compared to animals treated with saline or with antibodies that do not promote repair. Both pHIgM and sHIgM22 show strong binding to CNS white matter and oligodendrocytes, while antibodies that did not accelerate remyelination do not. This differential staining pattern suggests that enhanced remyelination may result from direct stimulation of oligodendrocyte remyelination by binding to surface receptors on oligodendrocytes or glial progenitor cells. We propose the use of human polyclonal IgM or specific human monoclonal IgM antibodies as potential therapies to enhance myelin repair following CNS injury and disease. GLIA 37:241–249, 2002. © 2002 Wiley‐Liss, Inc.
Mechanism of NMDA receptor contribution to axon‐to‐glia signaling in the crayfish medial giant nerve fiber
Authors: Gafurov Boris S. , Urazaev Albert K. , Grossfeld Robert M. , Lieberman Edward M. 
Published: August 2002

AbstractElectrical stimulation of crayfish giant axons at high frequency activates group II metabotropic and NMDA glutamate receptors on adjacent glial cells via release of N‐acetylaspartylglutamate and glutamate formed upon its hydrolysis. This produces a transient depolarization followed by a prolonged hyperpolarization of glial cells that involves nicotinic acetylcholine receptor activation. The hyperpolarization is nearly completely blocked by antagonists of metabotropic glutamate receptors but only slightly reduced by inhibition of NMDA receptors. We report that the NMDA‐induced hyperpolarization of glial cells is reduced by decreased calcium in the solution bathing the giant nerve fiber, while removal of sodium ions or block of voltage‐dependent calcium channels completely prevents the glial response to NMDA. Inhibition of nicotinic acetylcholine receptors or removal of extracellular Cl− converts the glial response from a hyperpolarization to a depolarization that is sensitive to NMDA receptor antagonist. We propose that NMDA receptor activation by glutamate, formed from extracellular N‐acetylaspartylglutamate during nerve stimulation, contributes to glial hyperpolarization by increasing intracellular Ca2+ via opening of voltage‐sensitive Ca2+ channels. Based on our previous work, we propose further that the added Ca2+ supplements that produced by N‐acetylaspartylglutamate and glutamate acting on group II metabotropic glutamate receptors to cause an increased release of acetylcholine and a larger hyperpolarization. GLIA 38:80–86, 2002. © 2002 Wiley‐Liss, Inc.
Inflammatory repertoire of Alzheimer's disease and nondemented elderly microglia in vitro
Authors: Lue Lih‐Fen , Rydel Russell , Brigham Elizabeth F. , Yang Li‐Bang , Hampel Harald , Murphy Greer M. , Brachova Libuse , Yan Shi‐Du , Walker Douglas G. , Shen Yong , Rogers Joseph 
Published: August 2002

AbstractWe have previously developed and characterized isolated microglia and astrocyte cultures from rapid (<4 h) brain autopsies of Alzheimer's disease (AD) and nondemented elderly control (ND) patients. In the present study, we evaluate the inflammatory repertoire of AD and ND microglia cultured from white matter (corpus callosum) and gray matter (superior frontal gyrus) with respect to three major proinflammatory cytokines, three chemokines, a classical pathway complement component, a scavenger cell growth factor, and a reactive nitrogen intermediate. Significant, dose‐dependent increases in the production of pro‐interleukin‐1β (pro‐IL‐1β), interleukin‐6 (IL‐6), tumor necrosis factor‐α (TNF‐α), monocyte chemoattractant protein‐1 (MCP‐1), macrophage inflammatory peptide‐1α (MIP‐1α), IL‐8, and macrophage colony‐stimulating factor (M‐CSF) were observed after exposure to pre‐aggregated amyloid β peptide (1–42) (Aβ1–42). Across constitutive and Aβ‐stimulated conditions, secretion of complement component C1q, a reactive nitrogen intermediate, and M‐CSF was significantly higher in AD compared with ND microglia. Taken together with previous in situ hybridization findings, these results demonstrate unequivocally that elderly human microglia provide a brain endogenous source for a wide range of inflammatory mediators. GLIA 35:72–79, 2001. © 2001 Wiley‐Liss, Inc.
How do memory clinics compare with traditional old age psychiatry services?
Authors: Luce Anna , McKeith Ian , Swann Alan , Daniel Sarah , O'Brien John 
Published: August 2002

AbstractMethods100 consecutive referrals to the Northern Memory Clinic (NMC) were compared with 100 referrals to a traditional Old Age Psychiatry (OAPsych) service in the same city in terms of demographic variables, cognitive function (assessed by the Mini‐Mental State Examination), and diagnosis. The study also examined the ability of psychometric assessments (CAMCOG, MMSE, Trail‐Making Tests A & B, Word Fluency) and CT scans included in the NMC assessment to differentiate between those with and without DSM‐IV dementia.ResultsNMC patients were significantly younger than OAPsych patients, had lower levels of cognitive impairment, and had a wider range of diagnoses. The NMC patients who were diagnosed as having dementia were found to be at least 2 years earlier in the course of the disease than those seen by the OAPsych team. The CAMCOG and MMSE were proved to be effective at distinguishing between patients diagnosed as dementing versus non‐dementing with cut‐offs of 82/83 and 23/24 respectively, confirming previous findings. The Memory subscale of the CAMCOG, though much shorter, was equally as effective using a cut‐off of 20/21. Trail‐Making Tests, Word Fluency (FAS), and measurement of the minimum width of the medial temporal lobe (MTL) on angled CT scans were poor indicators of dementia in this sample.ConclusionsThis study confirms that the memory clinic is targeting a distinct patient group compared to traditional old age psychiatry services, is identifying cases of dementia much earlier, and as such has potential to make valuable contributions to patient care. Copyright © 2001 John Wiley & Sons, Ltd.
Are the care levels of people with dementia correctly assessed for eligibility of the Japanese long‐term care insurance?
Authors: Ito Hiroto , Tachimori Hisateru , Miyamoto Yuki , Morimura Yasushi 
Published: August 2002

AbstractBackgroundA new long‐term care insurance system was launched in Japan in April 2000.ObjectivesWe performed the first national survey on special units of psychiatric hospitals for dementia patients to examine whether their disabilities were well reflected in the eligibility assessment.MethodsOf all 248 dementia special units of psychiatric hospitals in Japan, 180 units (72.6%) participated in the survey. Five patients were randomly selected in each unit, and we used data of 802 (89.1%) of 900 patients whose care levels were obtained by the primary computer assessment. These patients were assessed using the Mini‐Mental State Examination (MMSE), dementia rating scale by Gottfries et al. (1982) (GBS), and Activities of Daily Living (ADL). The mean score (SD) of the MMSE was 9.3 (6.9).ResultsMultiple regression analysis revealed that the scores of motor function in GBS, ADL, MMSE, and the degree of bedridden explained 73% of the variation of care level. The higher care levels were inversely related to lower MMSE scores. In the group of people who were not bedridden, the MMSE score sharply decreased even though their physical functions were maintained. There were no significant differences in the MMSE scores among the care level 1 and 5 groups except between care level 1 and 3 after controlling for the motor function scores in GBS.ConclusionsOur results suggest that care level and cognitive impairment are generally correlated in the primary assessment, but some adjustment measure for cognitive impairment is needed in mildly or moderately physically disabled patients. Copyright © 2001 John Wiley & Sons, Ltd.
The meaning of acute confusional state from the perspective of elderly patients
Authors: Andersson Edith M. , Hallberg Ingalill R. , Norberg Astrid , Edberg Anna‐Karin 
Published: August 2002

AbstractObjectivesThe aim of this study was to illuminate lived experience of having been in an acute confusional state (ACS) as narrated by elderly patients in orthopaedic care.MethodQualitative study with phenomenological hermeneutic method for analysing the data based on narrative interviews. Fifty patients (67–96 years of age) who developed ACS during hospitalisation and in all cases the ACS ceased during their stay on the ward were interviewed once lucid again regarding the course of the event, their experiences, memories and interpretation of what had happened during the ACS.ResultsThe meaning of the patients' lived experiences of being and having been confused was interpreted as ‘Being trapped in incomprehensible experiences and a turmoil of past and present and here and there’, comprising the themes trying to get a grip on the experience of the confusion, encountering past, present and the realm of the imagination as reality during the period of confusion and confronting the idea of having been confused. Contradictory to earlier research the patients remembered and could tell in great detail about their ACS. While confused, the confusional state means that impressions of all kinds invade the mind of the person and are experienced as reality, making him/her a victim of these impressions rather than the one who controls what comes into his/her mind. While in the middle of these experiences the person simultaneously senses that the impressions are unreal, thus indicating that he/she is in some sort of borderland between understanding and not understanding. The things that come into the mind of the person can either be frightening or neutral or enjoyable scenarios that seem to be mainly familiar but can also be unknown. These scenarios seem to be a mixture of past and present, of events and people while they seem to float from location to location.ConclusionsThe findings indicates that what takes place during the ACS is not nonsense but probably a mix of the patient's life history, their present situation and above all a form of communication concerning their emotional state and inner experiences in this new situation. The findings also indicated that one possible approach to the patients is to confirm and support the patients in narrating their experiences both during the confusion and also after the ACS had ceased. Copyright © 2002 John Wiley & Sons, Ltd.
The practicality and validity of directly elicited and SF‐36 derived health state preferences in patients with low back pain
Authors: Hollingworth William , Deyo Richard A. , Sullivan Sean D. , Emerson Scott S. , Gray Darryl T. , Jarvik Jeffrey G. 
Published: August 2002

AbstractRecent research has derived preference scores from the SF‐36. We compare the practicality and construct validity of SF‐36 derived preference scores with directly elicited time trade off (TTO) and visual analogue scale (VAS) scores. In this observational study, low back pain (LBP), patients were asked to complete disease specific, generic (SF‐36), and health state preference (VAS and TTO) instruments. Baseline SF‐36 responses were converted to preference scores using six published algorithms.Response rates for the SF‐36 derived and TTO preference values were 354 of 379 (93%) and 303 of 379 (80%), respectively. Thirty patients were excluded from the TTO exercise because of difficulties comprehending the scaling task. Choice based methods (standard gamble, TTO) yielded higher and more uniform estimates of preference (0.77–0.79) than non‐choice based methods (VAS) (0.42–0.70). Directly elicited TTO values were variable and had less power to distinguish among patients with differing severity of LBP. All SF‐36 derived preferences exhibited a minimum threshold implying a potential floor effect for severely ill patients. SF‐36 derived preferences demonstrated good practicality and construct validity in this setting, however different methods will yield disparate estimates of marginal benefit. This emphasises the need for a standardised algorithm for deriving SF‐36 preference scores. Copyright © 2001 John Wiley & Sons, Ltd.