bluuebunny/crossref_metadata_2025_split huggingface dataset:
A postulated granite near Builth Wells, Mid‐Wales, and its local and regional significance
Authors: Goddard P. , Kearey P. 
Published: August 2002

AbstractNew gravity measurements taken to the northeast of Builth Wells reveal, after removal of a regional field, a negative gravity anomaly of 28 gravity units magnitude and some 7 km × 5 km in extent. The anomaly can be modelled in terms of a near‐surface, three‐dimensional body some 1.7 km in thickness with a density contrast of − 0.30 Mg m−3, which corresponds to an actual density of 2.45 Mg m−3. We interpret this body as a granite whose low density is the result of the percolating fluids which it heated and ultimately gave rise to the hydrothermal system near Builth Wells. This is the first indication of the possible presence of a granite that is associated with the back‐arc basin that formed during the subduction of the lapetus Ocean beneath Eastern Avalonia. Copyright © 2002 John Wiley & Sons, Ltd.
Modelling large areas of demyelination in the rat reveals the potential and possible limitations of transplanted glial cells for remyelination in the CNS
Authors: Blakemore W.F. , Chari D.M. , Gilson J.M. , Crang A.J. 
Published: August 2002

AbstractTransplantation of myelin‐forming glial cells may provide a means of achieving remyelination in situations in which endogenous remyelination fails. For this type of cell therapy to be successful, cells will have to migrate long distances in normal tissue and within areas of demyelination. In this study, 40 Gy of X‐irradiation was used to deplete tissue of endogenous oligodendrocyte progenitors (OPCs). By transplanting neonatal OPCs into OPC‐depleted tissue, we were able to examine the speed with which neonatal OPCs repopulate OPC‐depleted tissue. Using antibodies to NG‐2 proteoglycan and in situ hybridisation to detect platelet‐derived growth factor alpha‐receptor Rα (PDGFRα) mRNA to visualise OPCs, we were able to show that neonatal OPCs repopulate OPC‐depleted normal tissue 3–5 times more rapidly than endogenous OPCs. Transplanted neonatal OPCs restore OPC densities to near‐normal values and when demyelinating lesions were made in tissue into which transplanted OPCs had been incorporated 1 month previously, we were able to show that the transplanted cells retain a robust ability to remyelinate axons after their integration into host tissue. In order to model the situation that would exist in a large OPC‐depleted area of demyelination such as may occur in humans; we depleted tissue of its endogenous OPC population and placed focal demyelinating lesions at a distance (≤1 cm) from a source of neonatal OPCs. In this situation, cells would have to repopulate depleted tissue in order to reach the area of demyelination. As the repopulation process would take time, this model allowed us to examine the consequences of delaying the interaction between OPCs and demyelinated axons on remyelination. Using this approach, we have obtained data that suggest that delaying the time of the interaction between OPCs and demyelinated axons restricts the expression of the remyelinating potential of transplanted OPCs. GLIA 38:155–168, 2002. © 2002 Wiley‐Liss, Inc.
Neuropsychiatric disturbance in Alzheimer's disease clusters into three groups: the Cache County study
Authors: Lyketsos Constantine G. , Sheppard Jeannie‐Marie E. , Steinberg Martin , Tschanz Jo Ann T. , Norton Maria C. , Steffens David C. , Breitner John C. S. 
Published: August 2002

AbstractObjectiveWe investigated the frequency and inter‐relationship of neuropsychiatric disturbances in a population sample of persons suffering from Alzheimer's disease (AD).MethodScreening 5,092 elderly residents (90% of the population aged 65 and older) of Cache County, Utah, for dementia, we identified 198 persons with AD using a comprehensive neuropsychiatric examination protocol. This examination included the Neuropsychiatric Inventory (NPI), a widely used measure of dementia‐associated neuropsychiatric disturbances.ResultsOverall, 60% of individuals with AD reported one or more neuropsychiatric symptoms. A latent class analysis revealed that these participants could be classified into three groups (classes) based on their neuropsychiatric symptom profile. The largest class included cases with no neuropsychiatric symptoms (40%) or with a mono‐symptomatic disturbance (19%). A second class (28%) exhibited a predominantly affective syndrome, while a third class (13%) had a psychotic syndrome.ConclusionData from this first US population‐based study of AD‐associated neuropsychiatric disturbances suggest that a significant majority of persons with AD suffer from one or more neuropsychiatric disturbance. Based on phenomenological study, the spectrum of neuropsychiatric symptoms in AD can be empirically classified into three groups: an affective syndrome, a psychotic syndrome and other neuropsychiatric disturbance. The biologic and predictive validity of this classification merits further investigation. Copyright © 2001 John Wiley & Sons, Ltd.
Prophylactic therapy with lithium in elderly patients with unipolar major depression
Authors: Wilkinson David , Holmes Clive , Woolford Janet , Stammers Susan , North Janine 
Published: August 2002

AbstractObjectivesTo compare the relapse rate of elderly depressed patients taking low dose lithium as an additional therapy with antidepressant medication to those receiving antidepressant medication alone.MethodsFifty elderly subjects recovering from a major depressive illness taking continuation antidepressants were randomised, in a double blind study, to receive additional lithium carbonate or placebo and followed up over a two year period for evidence of relapse.ResultsRelapse rate was significantly greater in those subjects taking antidepressant medication alone compared to subjects taking additional lithium therapy. After six months four (17%) subjects taking antidepressant medication alone had relapsed, whereas none of the subjects taking additional lithium had relapsed. After two years eight (33%) subjects taking antidepressant medication alone had relapsed, whereas only one (4%) of the subjects taking additional lithium had relapsed.ConclusionThis preliminary study suggests that long‐term low dose lithium therapy is well tolerated and protects elderly patients from a relapse of depressive illness. Copyright © 2002 John Wiley & Sons, Ltd.
Enantioselective reduction of dialkyl 4‐(dialkoxyphosphoryl)‐3‐oxobutanoates by baker's yeast
Authors: Yuan Chengye , Wang Ke , Li Jinfeng , Li Zuyi 
Published: August 2002

AbstractDialkyl 4‐(dialkoxyphosphoryl)‐3‐oxobutanoates (1), upon yeast‐mediated bioreduction, afforded chiral dialkyl 4‐(dialkoxyphosphoryl)‐3‐hydroxybutanoates (2) in moderate to good yields and ee values. Significant improvement was reported for the preparation of dialkyl 4‐(dialkoxyphosphoryl)‐3‐oxobutanoates (1), the key substrates of this bioreductive conversion. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:153–156, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10011
Autoxidation of acridanyl and benzhydryl carbanions adjacent to sulfur groups leading to CS bond cleavage with weak chemiluminescence
Authors: Motoyoshiya Jiro , Inoue Hisashi , Takaguchi Yutaka , Aoyama Hiromu 
Published: August 2002

AbstractAutoxidation of acridanyl and benzhydryl carbanions stabilized by sulfur groups gave the corresponding ketones via radical intermediates, being accompanied by a weak light emission. While oxidation of 9‐sulfenylacridanes (1a and 1b) in the presence of tert‐BuOK showed direct chemiluminescence (CL) due to excited 10‐methylacridone, that of benzhydryl phenyl sulfide (2) and benzhydryldimethylsulfomium bromide (3) displayed CL in the presence of a fluorescer, 9,10‐dibromoanthracene (DBA), due to excited benzophenone. The yields of excited species in the present oxidation are low but comparable to acyclic peroxide systems. The bimolecular energy transfer from triplet benzophenone to DBA was established in CL of the sulfonium ylide from 3. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:252–257, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10025
Comparison of computational studies of internal stabilization of 1‐butadienyllithiums and representative 1‐chloro‐1‐lithio‐2‐phenylalkenes
Authors: Nelson Donna J. , Brammer Christopher 
Published: August 2002

AbstractComparison of molecular orbital calculations of 1‐butadienyllithiums and representative 1‐chloro‐1‐lithio‐2‐phenylalkenes, carried out by using MNDO and AM1, reveals that the major stabilizing interaction with lithium in these systems is predicted to be agostic bonding between lithium and hydrogen. MNDO and AM1 calculations for 1‐chloro‐1‐lithio‐2‐phenylethenes give evidence for agostic bonding between lithium and the ortho H, such as compressed pertinent bond angles and increased pertinent bond lengths. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:263–269, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10027
Syntheses of some new azolopyrido‐[4′,3′:4,5]thieno[2,3‐d]pyrimidines
Authors: Ahmed Essam Kh. 
Published: August 2002

AbstractDiethyl 2‐[(ethoxythioxomethyl)amino]‐4,5,6,7‐tetrahydrothieno[2,3‐c]‐pyridine‐3,6‐dicarboxylate 2, prepared from diethyl 2‐isothiocyanato‐4,5,6,7‐tetrahydrothieno[2,3‐c]pyridine‐3,6‐dicarboxylate 1 by boiling in anhydrous ethanol, was converted into pyrido[4′,3′:4,5]thieno[2,3‐d]pyrimidine derivatives 3, 4 by treatment with hydrazine hydrate. The tetracyclic systems imidazo[1,2‐a]pyrido‐[4′,3′:4,5]thieno[2,3‐d]pyrimidine 9 and pyrido[4′,3′:4,5]thieno[2,3‐d][1,3]thiazolo‐[3,2‐a]pyrimidine 10 were synthesized by the reaction of 2 with 1,2‐diaminoethane and aminoethanethiol, respectively. The hydrazino derivative 4 underwent cyclization reactions with orthoesters and nitrous acid to give the corresponding pyrido[4′,3′:4,5]thieno[2,3‐d][1,2,4]triazolo[1,5‐a]pyrimidines 5, 6 and pyrido[4′,3′:4,5]thieno[3,2‐e][1,2,3,4]tetrazolo[1,5‐a]pyrimidine 8, respectively. Moreover, reactions of 3 with cyanogen bromide, N‐carbethoxyhydrazine, carbon disulfide, and ethylchloroformate resulted in the formation of the new pyrido[4′,3′:4,5]thieno[2,3‐d][1,3,4]thiadiazolo[3,2‐a]pyrimidine derivatives 12–15. © 2002 Wiley Periodicals, Inc. Heteroatom Chem 13:280–286, 2002; Published online in Wiley Interscience (www.interscience.wiley.com). DOI 10.1002/hc.10030
A convenient synthesis of N‐t‐butyl‐N′‐aminocarbonyl‐N‐(substituted)benzoyl‐hydrazine containing α‐aminoalkylphosphonate groups in a one‐pot procedure
Authors: Wang Qingmin , Li Zaiguo , Huang Runqiu , Cheng Junran 
Published: August 2002

AbstractA variety of novel N‐t‐butyl‐N′‐aminocarbonyl‐N‐(substituted)benzoylhydrazines containing α‐aminoalkylphosphonate groups were synthesized. Treatment of α‐aminoalkylphosphonates with triphosgene yielded α‐isocyanatoalkylphosphonates, and subsequent addition with N‐t‐butyl‐N‐substituted benzoylhydrazines provided the title compounds in a one‐pot procedure with good yields. The triphosgene‐mediated reaction for the synthesis of α‐isocyanatoalkylphosphonates enjoys a number of advantages: the reaction is carried out under mild condition in good yield, triphosgene is relatively safe to handle because of its low vapor pressure and high stability, and the experimental procedure is simple. This method can be applicable to the synthesis of other α‐isocyanatoalkyl‐phosphonates and urylenediphosphonates. The structures of all of the products and by‐products were confirmed by 1H NMR, 31P NMR, IR and mass spectroscopy, and elemental analysis. We also found that some of the compounds possess potential antitobacco mosaic virus (TMV) activities and anticancer activities. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:68–72, 2001
Testing efficacy with detection controlled estimation: an application to telemedicine
Authors: Bradford W. David , Kleit Andrew N. , Krousel‐Wood M. A. , Re Richard N. 
Published: August 2002

AbstractDetection controlled estimation (DCE) is a powerful new econometric estimator in the family of missing data estimators. By collecting measures from a variety of inspectors or inspection technologies, DCE is able to make inferences about the entire population, even when that population is not directly observed. Using this innovative method, we were able to assess whether telemedicine technology could be substituted for in‐person visits when providing maintenance care for patients with hypertension. Our findings indicate that there is no support for the proposition that telemedicine is less effective than in‐person visits for determining whether patients have high blood pressure. Indeed, our results imply that telemedicine misses 7% fewer cases of high blood pressure than in‐person visits do. The results of this study indicate that DCE may be an effective tool for use in cost‐effectiveness or cost‐benefit analysis in health care. Copyright © 2001 John Wiley & Sons, Ltd.
Econometric issues in testing the age neutrality of health care expenditure
Authors: Salas Christian , Raftery James P. 
Published: August 2002

AbstractA recent study by Zweifel et al. (Zweifel P, Felder S, Meiers M. Ageing of the population and health care expenditure: a red herring? Health Economics 1999; 8: 485–496) suggests that age is not related to health care expenditure among the elderly once ‘closeness to death’ is controlled for. If correct, this finding has major policy implications, but flaws in the econometric analysis undermine its credibility. We highlight two in particular, and propose methods to deal with them. Copyright © 2001 John Wiley & Sons, Ltd.
Estimation of the transition matrix of a discrete‐time Markov chain
Authors: Craig Bruce A. , Sendi Peter P. 
Published: August 2002

AbstractDiscrete‐time Markov chains have been successfully used to investigate treatment programs and health care protocols for chronic diseases. In these situations, the transition matrix, which describes the natural progression of the disease, is often estimated from a cohort observed at common intervals. Estimation of the matrix, however, is often complicated by the complex relationship among transition probabilities. This paper summarizes methods to obtain the maximum likelihood estimate of the transition matrix when the cycle length of the model coincides with the observation interval, the cycle length does not coincide with the observation interval, and when the observation intervals are unequal in length. In addition, the bootstrap is discussed as a method to assess the uncertainty of the maximum likelihood estimate and to construct confidence intervals for functions of the transition matrix such as expected survival. Copyright © 2002 John Wiley & Sons, Ltd.
Statistical determination of cost‐effectiveness frontier based on net health benefits
Authors: Laska Eugene M. , Meisner Morris , Siegel Carole , Wanderling Joseph 
Published: August 2002

AbstractStatistical methods are given for producing a cost‐effectiveness frontier for an arbitrary number of programs. In the deterministic case, the net health benefit (NHB) decision rule is optimal; the rule funds the program with thelargest positiveNHB at eachλ, the amount a decision‐maker is willing to pay for an additional unit of effectiveness. For bivariate normally distributed cost and effectiveness variables and a specifiedλ, a statistical procedure is presented, based on the method ofconstrained multiple comparisons with the best(CMCB), for determining the program with the largest NHB. A one‐tailedttest is used to determine if the NHB is positive. To obtain a statistical frontier in theλ‐NHB plane, we develop a method to produce the region in which each program has the largest NHB, by pivoting a CMCB confidence interval. A one‐sided version of Fieller's theorem is used to determine the region where the NHB of each program is positive. At eachλ, the pointwise error rate is bounded by a prespecifiedα. Upper bounds on the familywise error rate, the probability of an error at any value ofλ, are given. The methods are applied to a hypothetical clinical trial of antipsychotic agents. Copyright © 2002 John Wiley & Sons, Ltd.
Discounting and clinical decision making: Physicians, patients, the general public, and the management of asymptomatic abdominal aortic aneurysms
Authors: Höjgård S. , Enemark U. , Lyttkens C. H. , Lindgren A. , Troëng T. , Weibull H. 
Published: August 2002

AbstractClinical decisions often entail in intertemporal trade‐off. Moreover, they often involve physicians of different specialities. In an experiment dealing with the management of small asymptomatic abdominal aortic aneurysms (a clinically relevant problem) we find that specialists in internal medicine exhibit higher implicit discount rates than vascular surgeons, general practitioners, and actual and prospective patients. Several personal characteristics expected to be directly related to pure time‐preference and risk aversion (gender, smoking habits, age, place of employment) have the hypothesised effects. Additionally, financial incentives appear to affect the estimated implicit discount rates of physicians, but are unlikely to have caused the inter‐group differences. Differences in discount rates could lead to variations in clinical practice, which may conflict with equality of treatment or equal access to health care. Copyright © 2002 John Wiley & Sons, Ltd.
Squamous cell carcinoma of the head and neck in solid organ transplant recipients
Authors: Preciado Diego A. , Matas Arthur , Adams George L. 
Published: August 2002

AbstractBackgroundThe increased incidence of cancer after solid organ transplantation is well established in the literature, yet outcome studies in this population are rare. Excluding skin cancers, squamous cell carcinomas make up most head and neck cancers in transplant recipients.MethodsAt our institution, of 5300 solid organ transplant recipients, 34 have had head and neck cancer develop. We reviewed the records of the 23 recipients whose cancer was treated here.ResultsOnly 6 of the 23 recipients were alive at the time of our chart review. Of these, three had already survived 5 years. The 10 recipients diagnosed early (stage I or II) had significantly longer survival after cancer diagnosis than the 13 diagnosed at an advanced stage (stage III or IV) (96.0 mo vs 9.0 mo,p< .001). In all, 14 (60.8%) of the 23 recipients died of cancer within 2 years after diagnosis, 12 (50.2%) within 12 months. The sum of the daily doses of immunosuppressive drugs at cancer diagnosis was significantly greater for recipients who died within 2 years (p= .02). Furthermore, the difference in average doses of both prednisone (p= .001) and azathioprine (p= .028) was also significantly greater for those who died within 2 years. The average dose of cyclosporine was also greater, but this difference did not reach statistical significance (p= .18). The average dose of prednisone was significantly lower for recipients diagnosed early (p= .001). This correlation between high immunosuppressive drug doses and worse outcome has not been shown previously.ConclusionsSolid organ transplant recipients who are diagnosed with advanced head and neck cancer while receiving high doses of immunosuppressive drugs fare extremely poorly. High doses of immunosuppressive drugs, most notably prednisone, correlate significantly with advanced diagnosis of head and neck cancer and earlier death. © 2002 Wiley Periodicals, Inc. Head Neck 24: 319–325, 2002; DOI 10.1002/hed.10055
Survival in patients with recurrent squamous cell head and neck carcinoma treated with bio‐chemotherapy
Authors: Airoldi Mario , De Stefani Antonella , Marchionatti Sara , Pedani Fulvia , Gabriele Pietro , Ragona Riccardo , Cortesina Giorgio , Bumma Cesare 
Published: August 2002

AbstractBackgroundWe have shown that rIL‐2 administration in recurrent head and neck cancers induces a tumor‐specific T‐lymphocyte reactivity and tumor regression; in a pilot study we have shown a safe and effective administration of rIL2 after cisplatin + 5‐fluorouracil. Long‐term results are not known.MethodsThirty patients with recurrent‐persistent head and neck cancer were treated with cisplatin (100 mg‐m2) d.1,5‐fluorouracil (1 gr‐m2‐d c.i. 96 h), and SQ rIL‐2 (4.5 M IU day 8 to 12 and 15 to 19) every 3 weeks.ResultsThe overall response rate was 53.3% (95% CI; 34.4–72.3%): 26.6% complete response (CR) (8 patients) and 26.6% partial response (PR) (8 patients); 6 patients had SD (20%), 8 had PD (26.6%). The median follow‐up was 36 months (range, 28–44).The median CR duration is 16.2 months (8.5–39+); the median survival duration of this group has not been reached. The median PR duration was 7.2 months (3–10); the median survival was 13.3 months (10–26). The median overall survival was 14 months.ConclusionsThe most impressive finding is the very long survival of CRs patients. This outcome has been reported in other cancer patients with a CR after IL‐2 therapy. © 2001 John Wiley & Sons, Inc. Head Neck 23: 298–304, 2001.
Treatment of early stage squamous‐cell carcinoma of the glottic larynx: Endoscopic surgery or cricohyoidoepiglottopexy versus radiotherapy
Authors: Bron Lue P. , Soldati Daniela , Zouhair Ahmed , Ozsahin Mahmut , Brossard Edgar , Monnier Philippe , Pasche Philippe 
Published: August 2002

AbstractBackgroundBoth surgery and radiotherapy are recognized treatments of T1‐T2 squamous cell carcinoma of the larynx. We retrospectively analyze and compare the oncological outcome of patients treated in a single institution, either by endoscopic surgery or partial supracricoid laryngectomy versus radiation therapy.MethodsThe medical records of 156 patients treated between 1983 and 1996 with either surgery (n= 75) or radiotherapy (n= 81) were reviewed. Male to female ratio, median age, and T‐stage distribution were comparable.ResultsWith a median follow‐up time of 59 months, the 5‐year cause‐specific survival rate of 93% was identical for both groups. The actuarial incidence of metachronous second primaries was 7% at 5 years. Local control at 5 years remained 84% after surgery and 77% after radiotherapy. Anterior commissure infiltration was shown to represent a negative predictive factor of local control for radiotherapy (p= .01). Salvage treatment brought ultimate local control to 96% of patients after surgery and 94% after radiation therapy with long‐term laryngeal preservation rate altered significantly (p= .05) in the group of patients who received radiotherapy (90.1% vs 97.4%).ConclusionThe treatment of laryngeal cancer is always a compromise between oncological efficiency and preservation of function. Our data suggest that, assuming proper selection of patients, radiation therapy and surgery yield similar local control and survival rates. The functional disadvantages after surgery are moderate and clearly counterbalanced by a significant decrease in long‐term laryngeal preservation rate after radiotherapeutic treatment. © 2001 John Wiley & Sons, Inc. Head Neck 23: 823–829, 2001.