bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endovenous laser treatment to promote venous occlusion
Authors: Parente Eric J. , Rosenblatt Melvin 
Published: August 2003

AbstractBackground and ObjectivesCurrent treatment methods of superficial venous insufficiency (SVI) can be painful or result in incomplete occlusion. The objective of this study was to evaluate a technique for laser endovenous ablation with a newly developed diffuser fiber.Study Design/Materials and MethodsSix lateral saphenous veins in three goats were used. A specifically designed diffuser laser fiber tip was employed in all trials to deliver a wavelength of 1,064 nm. Each segment was treated with a different energy fluence by changing the power setting of the laser or the withdrawal rate of the fiber. Energy fluence was calculated by dividing the Joules employed for each segment over the internal surface area of the vessel. Segments were evaluated with ultrasound and histologically.ResultsSeventy‐five percent of the segments were occluded when an energy fluence of greater than 85 J/cm2 was employed. No perforations were observed, but perivascular changes were more common at higher energy fluence.ConclusionsEndovenous laser occlusion of veins with minimal perivascular effects can be achieved with laser wavelengths of 1,064 nm if an energy fluence of 84.9–224 J/cm2 is employed and circumferential effect is achieved. Lasers Surg. Med. 33:115–118, 2003. © 2003 Wiley‐Liss, Inc.
Preimplantation genetic diagnosis of chromosome abnormalities: implications from the outcome for couples with chromosomal rearrangements
Authors: Simopoulou M. , Harper J. C. , Fragouli E. , Mantzouratou A. , Speyer B. E. , Serhal P. , Ranieri D. M. , Doshi A. , Henderson J. , Rodeck C. H. , Delhanty J. D. A. 
Published: August 2003

AbstractObjectivesChromosomal rearrangements can lead to infertility or repeated spontaneous or induced abortions. The use of preimplantation genetic diagnosis (PGD) allows the selected transfer of chromosomally balanced embryos. The aim of this study was to carry out detailed analysis of the outcome of 11 PGD cycles for 8 patients carrying various chromosomal rearrangements.MethodsPatients underwent routine in vitro fertilisation with biopsy of embryos on day 3. Specific fluorescent in situ hybridisation protocols were developed for each couple. Embryo transfer was possible in all 11 cycles.ResultsThe outcome was four pregnancies, leading to three live births and one biochemical pregnancy. Post‐zygotic mosaicism was detected in 75% of untransferred embryos, the majority of which were chaotic. Detailed follow‐up and analysis provided evidence for the co‐existence of chromosomally balanced and abnormal cells in six embryos. The mechanisms involved included chromosome breakage and loss of material.ConclusionsBiopsy and analysis of two blastomeres, where possible, reduced the risk of misdiagnosis in cases of balanced/aneuploid mosaics. The three live births achieved for the eight couples treated in this series, despite the poor history in almost all cases, is further proof that a policy of biopsying two cells from embryos consisting of six or more cells and a single cell from four‐ or five‐cell embryos is compatible with a positive outcome. Copyright © 2003 John Wiley & Sons, Ltd.
Prioritizing patients for elective surgery: a systematic review
Authors: MacCormick Andrew D. , Collecutt Wayne G. , Parry Bryan R. 
Published: August 2003

Background:  Priority scoring tools are mooted as means for dealing with burgeoning elective surgical waiting lists. There is ongoing development work in New Zealand, Canada and the UK. This emerging international perspective is invaluable in determining the application of these tools and addressing any pitfalls.Methods:  A systematic electronic literature review was performed. Information was also retrieved using a search of reference lists of all papers included in the review and contact with those who were involved in the development of such criteria.Results:  The ethical basis of prioritization differed among priority scoring tools and in a number was not stated. The majority of tools covered criteria for specific procedures. Delphi consensus methods and regression were the predominant methods for ­deter­mining ­specific criteria. Authors’ opinions were the main source of generic criteria. Linear and non‐linear models or matrices sum­mated criteria.Conclusion:  There is debate over the ethical basis for prioritization. It is a concern that it is not addressed in many studies. The development of generic criteria showed a dearth of consensus approaches that represents a significant gap in our knowledge. On the aspects of summation and weighting, the impact of assumptions on the prioritization of patients may not have been fully explored.
Long‐term review of a breast conservation series and patterns of care over 18 years
Authors: Pendlebury Susan C. , Ivanov Olga , Renwick Stuart , Stevens Graham N. 
Published: August 2003

Background:  Multiple randomized trials of breast conservation compared with mastectomy in early breast cancer have validated equivalence of survival. Overwhelmingly the standard management of breast conservation includes surgical removal of the tumour, axillary dissection, postoperative breast irradiation, and adjuvant systemic therapy as appropriate. The outcomes are reviewed of 832 women with early breast cancer treated by local resection and irradiation at Royal Prince Alfred Hospital over an 18 year period, with particular emphasis on the changing patterns of practice.Methods:  Between September 1978 and May 1996, 832 women with early stage breast cancer were treated with conservative surgery and radiation therapy. The changes in patient, tumour and treatment factors were analysed over this time period. The outcomes of local recurrence and survival were recorded. Trends in patterns of these variables were evaluated by dividing the 18 years accrual period into three consecutive periods (1978−1983, n = 28; 1984−1990, n = 392; 1991−1996, n = 412).Results:  At a median follow up of 76 months, the 5 and 10 year actuarial local recurrence rates were 4% and 6%, respectively. Half of the local recurrences were at the primary site. Young age, extensive intraduct carcinoma, oestrogen receptor (ER) status and extranodal spread were predictive of local recurrence on multivariate analysis. The 5 and 10 year overall survival rates were 88% and 73%, respectively. Actuarial 5 year local recurrence (4%, 6%, 2%) and survival (96%, 88%, 92%) rates varied little across the three time intervals. There was an increase in median age from 46 to 56 years over the accrual period, with no change in median primary tumour size (1.5 cm). There were significant histopathological improvements in reporting margin status and ER status. Surgically, the median number of axillary lymph nodes retrieved (14) did not alter significantly. With respect to adjuvant therapies, irradiation of lymph nodes regions decreased over time. The proportion of patients receiving adjuvant hormones or chemotherapy increased sig­nificantly (18%, 35%, 54%).Conclusions:  The low local recurrence rate and high survival are consistent with published literature for early breast cancer. Changes in practice during the accrual period included improvements in histopathological reporting, a reduction in irradiation of lymph node regions, and an increase in the use of systemic therapy. These changes parallel international recommendations regarding the optimal management of early breast cancer.
A Likelihood Based Estimating Equation for the Clayton–Oakes Model with Marginal Proportional Hazards
Authors: Pipper Christian Bressen , Martinussen Torben 
Published: August 2003

AbstractMultivariate failure time data arise when data consist of clusters in which the failure times may be dependent. A popular approach to such data is the marginal proportional hazards model with estimation under the working independence assumption. In this paper, we consider the Clayton–Oakes model with marginal proportional hazards and use the full model structure to improve on efficiency compared with the independence analysis. We derive a likelihood based estimating equation for the regression parameters as well as for the correlation parameter of the model. We give the large sample properties of the estimators arising from this estimating equation. Finally, we investigate the small sample properties of the estimators through Monte Carlo simulations.
The Use of Replicates in Logistic Measurement Error Modelling
Authors: Thoresen Magne , Laake Petter 
Published: August 2003

AbstractThe use of replicates is essential in logistic measurement error models with random, additive error, as it gives a consistent estimate of the variance of the measurement error. In this paper, we investigate two different aspects of the use of replicates. We look into the efficiency gain in using more than two replicates in situations where the replicates are correlated. We find that, unlike the situation with independent replicates, the efficiency gain is an almost linear function of the number of replicates. Further, we study the allocation of replicates among study subjects, and find that the optimal way of doing this is to allocate few replicates to as many subjects as possible, rather than allocating many replicates to fewer subjects.
Linear Regression Models under Conditional Independence Restrictions
Authors: Causeur David , Dhorne Thierry 
Published: August 2003

AbstractMaximum likelihood estimation is investigated in the context of linear regression models under partial independence restrictions. These restrictions aim to assume a kind of completeness of a set of predictors Z in the sense that they are sufficient to explain the dependencies between an outcome Y and predictors X: ℒ(Y|Z, X) = ℒ(Y|Z), where ℒ(·|·) stands for the conditional distribution. From a practical point of view, the former model is particularly interesting in a double sampling scheme where Y and Z are measured together on a first sample and Z and X on a second separate sample. In that case, estimation procedures are close to those developed in the study of double‐regression by Engel & Walstra (1991) and Causeur & Dhorne (1998). Properties of the estimators are derived in a small sample framework and in an asymptotic one, and the procedure is illustrated by an example from the food industry context.
On the Distribution of Cash Flows Using Esscher Transforms
Authors: Vyncke D. , Goovaerts M. J. , De Schepper A. , Kaas R. , Dhaene J. 
Published: August 2003

AbstractIn their seminal paper, Gerber and Shiu (1994) introduced the concept of the Esscher transform for option pricing. As examples they considered the shifted Poisson process, the random walk, a shifted gamma process, and a shifted inverse Gaussian process to describe the logarithm of the stock price. In the present article it is shown how upper and lower bounds in convex order can be obtained when we use these types of models to describe the stochastic accumulation factors for a given cash flow.
Much Ado about Nothing? Political Representation Policies and the Influence of Women Parliamentarians in Germany
Authors: MEYER BIRGIT 
Published: August 2003

AbstractUp to the early 1980s, the percentage of women in the West German parliament remained under 10%—no more than in the very first election in which women were allowed to participate in 1918. The election of the Green Party to the Bundestag in 1983, with the aid of the party's 50% quota‐policy, increased this figure dramatically. Since this watershed election, the number of female parliamentarians has risen continuously: at the federal level reaching 32% in 2002 and at the state levels varying between 21% and 42%. In Germany, political representation policies are the exclusive domain of the political parties. This article, therefore, first analyses the aims and the performances of the main German political parties: the Christian Democrats, the Social Democrats, the Liberals, the Greens, and the Party of Democratic Socialism in the field of equal representation of women in politics, and it endeavors to shed light on their perceptions of women and gender equality. To determine whether women actually make a difference in elected office, the article next analyses the role of women parliamentarians in some of the major policies that affected the legal status of women and families in postwar Germany from 1949 to the 1990s. It concludes that women members of parliament (MPs), supported by other women's groups, have greatly influenced these policy‐making processes and, thus, the political culture in Germany.
Comparison of the use of endoscopic and radiologic gastrostomy in a single head and neck cancer unit
Authors: Neeff Michel , Crowder Victoria L. , McIvor Nicholas P. , Chaplin John M. , Morton Randall P. 
Published: August 2003

Background:  Head and neck cancer patients frequently require gastrostomy feeding. Different insertion techniques have been described. The aim of the present study was to compare clinical results of percutaneous endoscopic and radiological gastrostomies in patients treated in a regional head and neck cancer unit.Methods:  The records of patients who received either percutaneous endoscopic gastrostomy (PEG) or percutaneous radiological gastrostomy (PRG) between August 1997 and February 2001 were reviewed retrospectively. Documented complications (leak, infection, nausea and vomiting, ileus, bleeding, peritonitis) were recorded, compared and evaluated.Results:  There were 74 patients (56 PEG, 18 PRG), most with stage III and IV head and neck malignancy. There was a sig­nificantly lower incidence of complications in PEG than PRG (11% vs 44%, P = 0.004). There was a delay of feeding due to tube placement in 4% of PEG and 22% of PRG (P < 0.025). Major complications occurred in 3.6% and 5.6% of PEG and PRG, respectively. Generally the complication rate for either form of gastrostomy was comparable with other studies. No procedure‐related deaths occurred.Conclusion:  Selection bias, technique and tube type appeared to influence the complication rate in the present review. Percutaneous endoscopic gastrostomy will remain the authors’ preferred method while PRG will be reserved for those cases for whom endoscopic placement is deemed to be impractical.
Congenital diaphragmatic hernia: an evaluation of the prognostic value of the lung‐to‐head ratio and other prenatal parameters
Authors: Laudy J. A. M. , Van Gucht M. , Van Dooren M. F. , Wladimiroff J. W. , Tibboel D. 
Published: August 2003

AbstractObjectivesA retrospective analysis of the prognostic significance of the lung‐to‐head ratio (LHR) and other prenatal parameters on the outcome of fetuses with left‐sided congenital diaphragmatic hernia (CDH).MethodsA total of 26 fetuses with isolated left CDH without chromosomal abnormalities were included. Twenty‐one LHR measurements could retrospectively be calculated from the last available ultrasonographic recordings before birth. The relationship between LHR and fetal outcome and the gestational age dependency of this relation was tested. Cutoff levels as previously published were applied to determine their predictive value in this population. The association between other prenatal predictive variables and fetal outcome was also determined. Survival was defined as discharge from the hospital.ResultsThe overall survival rate was 50%. There was a statistically significant difference between the mean LHR of the survivors compared to the mean LHR of the nonsurvivors (1.78 vs 1.02), whereas the mean gestational age of these two groups did not differ. LHR was not gestational age dependent in the prediction of fetal outcome. The cutoff levels LHR <1, 1–1.4, >1.4 showed a good applicability in the prediction of fetal outcome within the present study population with a 100% survival if LHR >1.4 and a 100% mortality if LHR <1. An intrathoracic position of the stomach, mediastinal shift, polyhydramnios as individual variables and early diagnosis (<25 weeks' gestation) revealed to be poor sonographic predictors for fetal outcome.ConclusionLHR proved to be a good predictor for fetal outcome, independent of gestational age at the time of the measurement. To substantiate our observation, a prospective multicenter study is warranted. Copyright © 2003 John Wiley & Sons, Ltd.
Kinetics and mechanism of (salen)MnIII‐catalysed oxidation of organic sulfides with sodium hypochlorite
Authors: Chellamani Arunachalam , Harikengaram Sivalingam 
Published: August 2003

AbstractThe oxidation of organic sulfides with several substituted oxo(salen)manganese(V) complexes was investigated in 90% acetonitrile–10% water and the reaction is second‐order overall, first‐order each in sulfide and complex. Electron‐releasing substituents in sulfides and electron‐withdrawing substituents in oxo(salen)manganese(V) complexes accelerate the rate of oxidation. The second‐order rate constants for the oxidation of p‐substituted phenyl methyl sulfides follow a linear Hammett relationship with ρ = −1.85. However, correlation between log k2 and 2σ is excellent with ρ = 0.48 for the oxidation of thioanisole by substituted oxomanganese(V) complexes. The rate of oxidation of alkyl phenyl sulfides and dialkyl sulfides with oxo complexes was also examined and the reactions show a moderate steric effect. Substituent, acid and solvent effect studies reveal the operation of an SN2 mechanism. Copyright © 2003 John Wiley & Sons, Ltd.
Equity Risk, Conversion Risk, and the Demand for Insurance
Authors: Garratt Rod , Marshall John M. 
Published: August 2003

AbstractExisting insurance theory fails when applied to real property because it does not account for variations in the economic environment. The article studies optimal property insurance in the presence of two sources of variation: equity risk and conversion risk. Equity risk is randomness of the value of a property. It tends to raise demand for conventional insurance. In contrast, conversion risk is randomness in the value the property would have if, after severe damage, it were converted to the highest‐valued use. It is distinct from equity risk because the highest‐valued use is typically not the current one. Under independent conversion risk, the optimum upper limit is a compromise among underlying conversion thresholds. Absent independence, the optimum can be quite different. Conversion risk can raise or lower the demand for property insurance. Insurance contracts that fail to address conversion tend to undermine the orderly disposition of obligations and reduce the gains from reallocation of risks through insurance.
Screening for Speech and Language Delay and Disorders in Children
Authors:   US Preventive Services Task Force, Barry Michael J. , Nicholson Wanda K. , Silverstein Michael , Chelmow David , Coker Tumaini Rucker , Davis Esa M. , Donahue Katrina E. , Jaén Carlos Roberto , Li Li , Mangione Carol M. , Ogedegbe Gbenga , Rao Goutham , Ruiz John M. , Stevermer James , Tsevat Joel , Underwood Sandra Millon , Wong John B. 
Published: January 2024

ImportanceSpeech and language delays and disorders can pose significant problems for children and their families. Evidence suggests that school-aged children with speech or language delays may be at increased risk of learning and literacy disabilities, including difficulties with reading and writing.ObjectiveThe US Preventive Services Task Force (USPSTF) commissioned a systematic review to evaluate benefits and harms of screening for speech and language delay and disorders in children 5 years or younger.PopulationAsymptomatic children 5 years or younger whose parents or clinicians do not have specific concerns about their speech, language, hearing, or development.Evidence AssessmentThe USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for speech and language delay and disorders in children who do not present with signs or symptoms or parent/caregiver concerns.RecommendationThe USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for speech and language delay and disorders in children 5 years or younger without signs or symptoms. (I statement)
Platelet Transfusion and Death or Neurodevelopmental Impairment in Children Born Extremely Preterm
Authors: Davenport Patricia E. , Wood Thomas R. , Heagerty Patrick J. , Sola-Visner Martha C. , Juul Sandra E. , Patel Ravi M. 
Published: January 2024

ImportanceInfants born extremely preterm receive transfusions at higher platelet count thresholds than older children and adults due to concerns for intracranial hemorrhage. A recent randomized trial comparing 2 platelet transfusion thresholds showed the higher threshold was associated with increased risk of long-term adverse neurodevelopmental outcomes.ObjectiveTo evaluate the association of platelet transfusion exposure with death and severe neurodevelopmental impairment (NDI) at 2 years’ corrected age in a cohort of infants born extremely preterm.Design, Setting, and ParticipantsAn observational cohort study and secondary analysis of the Preterm Erythropoietin Neuroprotection Trial, a randomized, placebo-controlled clinical trial of erythropoietin neuroprotection in neonates born extremely preterm, was conducted in 30 neonatal intensive care units in the US from December 1, 2013, to September 31, 2016. This analysis included 819 infants born extremely preterm at 24 to 27 completed weeks of gestation who had a documented outcome (death or neurodevelopmental assessment). Analysis was performed in April 2023.ExposuresAny platelet transfusion during neonatal intensive care unit hospitalization.Main Outcomes and MeasuresThe primary composite outcome was death or severe NDI evaluated at 2 years’ corrected age using the Bayley Scales of Infant Development–Third Edition (BSID-III) and the Gross Motor Function Classification System and was defined as the presence of severe cerebral palsy or a BSID-III composite motor or cognitive score 2 SDs below the mean. Confounding by indication for platelet transfusion was addressed with covariate adjustment and propensity score methods.ResultsOf the 819 infants included in the analysis (429 [52.4%] male; mean [SD] gestational age, 25.5 [1.1] weeks), 245 (30.0%) received at least 1 platelet transfusion during their initial hospitalization. The primary outcome occurred in 46.5% (114 of 245) of infants exposed to a platelet transfusion and 13.9% (80 of 574) of nonexposed infants with a corresponding odds ratio of 2.43 (95% CI, 1.24-4.76), adjusted for propensity score, gestational age at birth, and trial treatment group. The individual components of death and severe NDI were directionally consistent with the overall composite outcome.Conclusions and RelevanceThe findings of this study suggest that platelet transfusion in infants born extremely preterm may be associated with an increased risk of death or severe NDI at 2 years’ corrected age, although the possibility of residual confounding by indication cannot be excluded.