bluuebunny/crossref_metadata_2025 huggingface dataset:
A relative survival regression model using B‐spline functions to model non‐proportional hazards
Authors: Giorgi Roch , Abrahamowicz Michal , Quantin Catherine , Bolard Philippe , Esteve Jacques , Gouvernet Joanny , Faivre Jean
Published: August 2003

Relative survival, a method for assessing prognostic factors for disease‐specific mortality in unselected populations, is frequently used in population‐based studies. However, most relative survival models assume that the effects of covariates on disease‐specific mortality conform with the proportional hazards hypothesis, which may not hold in some long‐term studies. To accommodate variation over time of a predictor's effect on disease‐specific mortality, we developed a new relative survival regression model using B‐splines to model the hazard ratio as a flexible function of time, without having to specify a particular functional form. Our method also allows for testing the hypotheses of hazards proportionality and no association on disease‐specific hazard. Accuracy of estimation and inference were evaluated in simulations. The method is illustrated by an analysis of a population‐based study of colon cancer. Copyright © 2003 John Wiley & Sons, Ltd.
Non‐parametric methods to predict HIV drug susceptibility phenotype from genotype
Authors: Gregory DiRienzo A. , DeGruttola Victor , Larder Brendan , Hertogs Kurt
Published: August 2003

Medical management of HIV infection requires an understanding of the relationship between viral genetic sequences and viral susceptibility to antiretroviral drugs. Because of the high dimensionality of the data on viral genotype, traditional statistical methods are not well suited for investigating this relationship. We develop non‐parametric methods specifically for the setting where high‐dimensional data provides a basis for predicting a low‐dimensional response variable. Our non‐recursive methods proceed in three stages: (i) build models, in a forward‐stepwise manner, that predict phenotype response from genotype sequence; (ii) identify specific patterns of amino acid sequence that are most influential in predicting phenotype, and (iii) identify combinations of codons that have either a concordant or a discordant association in the occurrence of a mutation. The methods are applied to a data set provided by the Virco Group that contains protease genome sequences and IC50 measurements on a drug from the protease inhibitor class, amprenavir, for 2747 patient samples. From these methods, we were able to identify eight codons from the protease region of the HIV genome that predict resistance to amprenavir, and to determine pairs of codons that tend either to occur together or to preclude the occurrence of the other member of the pair. Copyright © 2003 John Wiley & Sons, Ltd.
A global sensitivity analysis of performance of a medical diagnostic test when verification bias is present
Authors: Kosinski Andrzej S. , Barnhart Huiman X.
Published: August 2003

Current advances in technology provide less invasive or less expensive diagnostic tests for identifying disease status. When a diagnostic test is evaluated against an invasive or expensive gold standard test, one often finds that not all patients undergo the gold standard test. The sensitivity and specificity estimates based only on the patients with verified disease are often biased. This bias is called verification bias. Many authors have examined the consequences of verification bias and have proposed bias correction methods based on the assumption of independence between disease status and election for verification conditionally on the test result, or equivalently on the assumption that the disease status is missing at random using missing data terminology. This assumption may not be valid and one may need to consider adjustment for a possible non‐ignorable verification bias resulting from the non‐ignorable missing data mechanism. Such an adjustment involves ultimately uncheckable assumptions and requires sensitivity analysis. The sensitivity analysis is most often accomplished by perturbing parameters in the chosen model for the missing data mechanism, and it has a local flavour because perturbations are around the fitted model. In this paper we propose a global sensitivity analysis for assessing performance of a diagnostic test in the presence of verification bias. We derive a region of all sensitivity and specificity values consistent with the observed data and call this region a test ignorance region (TIR). The term ‘ignorance’ refers to the lack of knowledge due to the missing disease status for the not verified patients. The methodology is illustrated with two clinical examples. Copyright © 2003 John Wiley & Sons, Ltd.
Estimate of standard deviation for a log‐transformed variable using arithmetic means and standard deviations
Authors: Quan Hui , Zhang Ji
Published: August 2003

Analyses of study variables are frequently based on log transformations. To calculate the power for detecting the between‐treatment difference in the log scale, we need an estimate of the standard deviation of the log‐transformed variable. However, in many situations a literature search only provides the arithmetic means and the corresponding standard deviations. Without individual log‐transformed data to directly calculate the sample standard deviation, we need alternative methods to estimate it. This paper presents methods for estimating and constructing confidence intervals for the standard deviation of a log‐transformed variable given the mean and standard deviation of the untransformed variable. It also presents methods for estimating the standard deviation of change from baseline in the log scale given the means and standard deviations of the untransformed baseline value, on‐treatment value and change from baseline. Simulations and examples are provided to assess the performance of these estimates. Copyright 2003 John Wiley & Sons, Ltd.
Experimental evaluation and improvements to linear scan register allocation
Authors: Sagonas Konstantinos , Stenman Erik
Published: August 2003

We report our experience from implementing and experimentally evaluating the performance of various register allocation schemes, focusing on the recently proposed linear scan register allocator. In particular, we describe in detail our implementation of linear scan and report on its behavior both on register‐rich and on register‐poor computer architectures. We also extensively investigate how different options to the basic algorithm and to the compilation process as a whole affect compilation times and quality of the produced code.

In a nutshell, our experience is that a well‐tuned linear scan register allocator is a good choice on register‐rich architectures. It performs competitively with graph coloring based allocation schemes and results in significantly lower compilation times. When compilation time is a concern, such as in just‐in‐time compilers, it can also be a viable option on register‐poor architectures. Copyright © 2003 John Wiley & Sons, Ltd.
Efficient implementation of lazy suffix trees
Authors: Giegerich R. , Kurtz S. , Stoye J.
Published: August 2003

We present an efficient implementation of a write‐only top‐down construction for suffix trees. Our implementation is based on a new, space‐efficient representation of suffix trees that requires only 12 bytes per input character in the worst case, and 8.5 bytes per input character on average for a collection of files of different type. We show how to efficiently implement the lazy evaluation of suffix trees such that a subtree is evaluated only when it is traversed for the first time. Our experiments show that for the problem of searching many exact patterns in a fixed input string, the lazy top‐down construction is often faster and more space efficient than other methods. Copyright © 2003 John Wiley & Sons, Ltd.
Adapting traditional software processes to virtual environments development
Authors: Sánchez‐Segura María I. , Cuadrado Juan J. , de Antonio Angelica , de Amescua Antonio , García Luis
Published: August 2003

Virtual environments (VEs) are special kinds of interactive systems currently used in many fields such as education, training and medicine. However, as VE development is relatively recent, there is little experience in the area. Software engineering, the discipline which assures quality software, has not been successfully applied to date. In developing VEs, the object‐oriented software engineering paradigm is the most suitable even though principles and techniques are insufficient. In this paper, we will demonstrate this inadequacy through the development of two different VEs, identify the processes to be improved, offer a set of guidelines to improve them (coined SENDA), and present the results obtained with SENDA. Copyright © 2003 John Wiley & Sons, Ltd.
The directed Chinese Postman Problem
Authors: Thimbleby Harold
Published: August 2003

The Chinese Postman Problem has many applications, including robot exploration, and analysing interactive system and Web site usability. This paper reviews the wide range of applications of the problem and presents complete, executable code to solve it for the case of directed multigraphs. A variation called the ‘open Chinese Postman Problem’ is also introduced and solved. Although optimizations are possible, no substantially better algorithms are likely. Copyright © 2003 John Wiley & Sons, Ltd.
TNM: Evolution and relation to other prognostic factors
Authors: Sobin Leslie H.
Published: August 2003

The TNM Classification describes the anatomic extent of cancer. TNM's ability to separately classify the individual tumor (T), node (N), and metastasis (M) elements and then group them into stages differs from other cancer staging classifications (e.g., Dukes), which are only concerned with summarized groups. The objectives of the TNM Classification are to aid the clinician in the planning of treatment, give some indication of prognosis, assist in the evaluation of the results of treatment, and facilitate the exchange of information. During the past 50 years, the TNM system has evolved under the influence of advances in diagnosis and treatment. Radiographic imaging (e.g., endoscopic ultrasound for the depth of invasion of esophageal and rectal tumors) has improved the accuracy of the clinical T, N, and M classifications. Advances in treatment have necessitated more detail in some T4 categories. Developments in multimodality therapy have increased the importance of the “y” symbol and the R (residual tumor) classification. New surgical techniques have resulted in the elaboration of the sentinel node (sn) symbol. The use of immunohistochemistry has resulted in the classification of isolated tumor cells and their distinction from micrometastasis. The most important challenge facing users of the TNM Classification is how it should interface with the large number of non‐anatomic prognostic factors that are currently in use or under study. As non‐anatomic prognostic factors become widely used, the TNM system provides an inviting foundation upon which to build a prognostic classification; however, this carries a risk that the system will be overwhelmed by a variety of prognostic data. An anatomic extent‐of‐disease classification is needed to aid practitioners in selecting the initial therapeutic approach, stratifying patients for therapeutic studies, evaluating non‐anatomic prognostic factors at specific anatomic stages, comparing the weight of non‐anatomic factors with extent of disease, and communicating the extent of disease data in a uniform manner. Methods are needed to express the overall prognosis without losing the vital anatomic content of TNM. These methods should be able to integrate multiple prognostic factors, including TNM, while permitting the TNM system to remain intact and distinct. This article discusses examples of such approaches. Semin. Surg. Oncol. 21:3–7, 2003. Published 2003 Wiley‐Liss, Inc.
Patient management scenario: A framework for clinical decision and prognosis
Authors: Gospodarowicz Mary , O'Sullivan Brian
Published: August 2003

The depiction of prognosis is one of the main activities and a mainstay in medical practice. In cancer, as in other diseases, the prognosis differs for a variety of situations and evolves with time and with medical interventions. Although most commonly described at diagnosis, prognosis may be defined at any time during the course of the disease and for any endpoint including response to therapy, failure of treatment, survival, or preservation of function, and so forth. To facilitate the accurate portrayal of the future, the prognosis should be defined within a specific setting, referred to as a ‘management scenario’. In the concept of a management scenario, the prognosis is defined using systematically considered prognostic factors, interventions and the outcome of interest. A deliberate and careful determination of prognosis is essential to clinical decision making and patient care. We illustrate the use of the concept of management scenario in several clinical examples. Semin. Surg. Oncol. 21:8–12, 2003. © 2003 Wiley‐Liss, Inc.
Prognostic factors in cancer
Authors: Gospodarowicz Mary , O'Sullivan Brian
Published: August 2003

Diagnosis, prognosis, and treatment are the three core elements of the art of medicine. Modern medicine pays more attention to diagnosis and treatment but prognosis has been a part of the practice of medicine much longer than diagnosis. Cancer is a heterogeneous group of disease characterized by growth, invasion and metastasis. To plan the management of an individual cancer patient, the fundamental knowledge base includes the site of origin of the cancer, its morphologic type, and the prognostic factors specific to that particular patient and cancer. Most prognostic factors literature describes those factors that directly relate to the tumor itself. However, many other factors, not directly related to the tumor, also affect the outcome. To comprehensively represent these factors we propose three broad groupings of prognostic factors: ‘tumor’‐related prognostic factors, ‘host’‐related prognostic factors, and ‘environment’‐related prognostic factors. Some prognostic factors are essential to decisions about the goals and choice treatment, while others are less relevant for these purposes. To guide the use of various prognostic factors we have proposed a grouping of factors based on their relevance in everyday practice; these comprise ‘essential,’ ‘additional,’ and ‘new and promising factors.’ The availability of a comprehensive classification of prognostic factors assures an ordered and deliberate approach to the subject and provide safeguard against skewed approaches that may ignore large parts of the field. The current attention to tumor factors has diminished the importance of ‘patient’ (i.e., ‘host’), and almost completely overshadows the importance of the ‘environment’. This ignores the fact that the latter presents the greatest potential for immediate impact. The acceptance of a generic prognostic factor classification would facilitate communication and education about this most important subject in oncology. Semin. Surg. Oncol. 21:13–18, 2003. © 2003 Wiley‐Liss, Inc.
TNM, sixth edition: New developments in general concepts and rules
Authors: Sobin Leslie H.
Published: August 2003

This article describes changes and clarifications in the 6th edition of TNM that concern site‐independent rules, regarding such aspects as sentinel lymph node biopsy, methods to distinguish between micrometastasis and isolated tumor cells, classification of tumors undergoing treatment, tumor deposits in lymph drainage beds, the number of lymph nodes needed for pathologic classification, and classification of residual tumor. These changes mainly reflect advances in diagnosis and treatment, and modulate rather than change the basic rules of classification. Semin. Surg. Oncol. 21:19–22, 2003. Published 2003 Wiley‐Liss, Inc.
TNM staging for malignancies of the digestive tract: 2003 changes and beyond
Authors: Greene Frederick L.
Published: August 2003

In preparation for the 6th edition of the UICC and AJCC publications on TNM staging, all data regarding sites of the digestive system (gastrointestinal and hepatobiliary) were reviewed by expert site teams. Although the information for several sites (esophagus, small bowel, and anal canal) required no change from the 5th editions, significant changes were recommended for the pancreas, liver, extrahepatic biliary system, colon, and rectum. Minor but important changes were made regarding gastric and peri‐ampullary malignancies. The changes were made based on new prognostic information and analysis of available data sets. The importance of large national registries, such as the National Cancer Data Base (NCDB; American College of Surgeons Commission on Cancer), is stressed. Semin. Surg. Oncol. 21:23–29, 2003. © 2003 Wiley‐Liss, Inc.
New TNM staging criteria for head and neck tumors
Authors: O'Sullivan Brian , Shah Jatin
Published: August 2003

Cancers of the head and neck have always represented a unique perspective in cancer staging. Not only are these lesions numerous in terms of anatomic sites of origin, but, unlike most other major cancers, they frequently and readily lend themselves to adequate clinical assessment by visual inspection and palpation, which greatly facilitates documentation by the trained clinician. In addition, their location often involves treatment programs that focus on nonsurgical organ‐preservation strategies, and thus anatomic and histological data for comprehensive pathologic staging are often not available. Nevertheless, the processes involved in surgical decision‐making and radiotherapy treatment planning require meticulous assessment and documentation of the extent of locoregional disease. For all these reasons it is especially important to perform reliable and accurate pretreatment clinical staging of head and neck cancers. Also, many patients who succumb to head and neck cancer do so as a result of locoregional disease. Therefore, the staging system must take into account detailed local anatomic features that dictate management, since the degree of involvement of these structures by tumor may be as important as distant metastasis in threatening survival. For this reason the most recent cancer staging classification (6th edition) of the International Union Against Cancer (UICC) and the American Joint Committee on Cancer (AJCC) includes new criteria for the more advanced cases (e.g., T4 categories and stage IV disease). These criteria reflect the fact that in heterogeneous populations there is a realistic opportunity for cure in some patients but not in others. This review summarizes the criteria used in the new TNM for head and neck tumors, and outlines the rationale behind the current changes. It also provides some guidance regarding optimal source data to facilitate classification in the registry setting. In addition, the need for additional changes in the future is recognized. Semin. Surg. Oncol. 21:30–42, 2003. © 2003 Wiley‐Liss, Inc.
New TNM melanoma staging system: Linking biology and natural history to clinical outcomes
Authors: Balch Charles M. , Buzaid Antonio C. , Soong Seng‐Jaw , Atkins Michael B. , Cascinelli Natale , Coit Daniel G. , Fleming Irvin D. , Gershenwald Jeffrey E. , Houghton Alan , Kirkwood John M. , McMasters Kelly M. , Mihm Martin F. , Morton Donald L. , Reintgen Douglas S. , Ross Merrick I. , Sober Arthur , Thompson John A. , Thompson John F.
Published: August 2003

The American Joint Committee on Cancer (AJCC) implemented major revisions of the melanoma TNM and stage grouping criteria in the recently published 6th edition of the Staging Manual. The new staging system better reflects independent prognostic factors that are used in clinical trials and in reporting the outcomes of various melanoma treatment modalities. Major revisions include: 1) melanoma thickness and ulceration but not level of invasion to be used in the T classification, 2) the number of metastatic lymph nodes rather than their gross dimensions and the delineation of microscopic vs. macroscopic nodal metastases to be used in the N classification, 3) the site of distant metastases and the presence of elevated serum lactic dehydrogenase (LDH) to be used in the M classification, 4) an upstaging of all patients with Stage I, II, and III disease when a primary melanoma is ulcerated, 5) a merging of satellite metastases around a primary melanoma and in transit metastases into a single staging entity that is grouped into Stage III disease, and 6) a new convention for defining clinical and pathological staging so as to take into account the new staging information gained from intraoperative lymphatic mapping and sentinel node biopsy. Semin. Surg. Oncol. 21:43–52, 2003. © 2003 Wiley‐Liss, Inc.
Revision of breast cancer staging: The 6th edition of the TNM classification
Authors: Singletary S. Eva , Greene Frederick L.
Published: August 2003

A Breast Task Force comprised of nationally known experts in the field of breast cancer treatment was charged with recommending additions and changes for the 6th edition of the TNM Classification that were based on published evidence and/or were consistent with widespread clinical consensus. Additions made to the staging system were designed to facilitate the uniform collection of clinically relevant information about new techniques for the detection of metastatic cells. These additions include quantitative criteria to distinguish micrometastases from isolated tumor cells, and specific identifiers to record the use of sentinel lymph node biopsy, immunohistochemical (IHC) staining, and molecular biology techniques. Revisions of the previous staging system are related to the number of affected axillary lymph nodes and to the classification of level III axillary lymph nodes and lymph nodes outside of the axilla. Semin. Surg. Oncol. 21:53–59, 2003. © 2003 Wiley‐Liss, Inc.
Seismic response of a cable‐stayed bridge: active and passive control systems (Benchmark Problem)
Authors: Bontempi Franco , Casciati Fabio , Giudici Massimo
Published: August 2003

This paper describes the Benchmark Problem for controlled cable‐stayed bridges. The benchmark in question is the first to be related directly to bridges. It follows on from past experience and experimentation, devoted to buildings, developed at an international level. These past experiences focused upon buildings subjected to wind and earthquake excitation. In this paper seismic excitation is explored in relation to bridges.

Three different schemes of active control are compared with each other. Their performance is also compared with the two most widely used passive control systems which summarize present energy dissipation practice. Copyright © 2003 John Wiley & Sons, Ltd.
H2‐based control strategies for civil engineering structures
Authors: Yang Jann N. , Lin Silian , Jabbari Faryar
Published: August 2003

Two H2‐based control strategies are proposed and their applications to civil engineering benchmark structures are presented. The first strategy deals with a class of excitations with a specified ‘energy’ bound, referred to as the H2‐based controller with energy‐bounded excitations (H2B‐EB), whereas the second strategy addresses a class of excitations with a specified peak bound, referred to as the H2‐based controller with peak‐bounded excitations (H2B‐PB). Both control strategies are derived by minimizing an upper bound of the H2 performance with the constraints (or penalties) on the peak values of another set of quantities, such as the control resources. State feedback and dynamic output feedback controllers are derived and presented. The design syntheses of these control strategies are developed and formulated within the framework of linear matrix inequalities (LMIs), so that the LMI toolbox in MATLAB can be used effectively and conveniently. These control strategies are applied to the Phase I long‐span cable‐stayed benchmark bridge subject to earthquakes and a wind‐excited 76‐storey benchmark building to illustrate their applicability to practical problems. Simulation results indicate that the performances of these proposed controllers for structural responses are better than that of the LQG sample controller. It is shown that these new control strategies are viable and effective for applications to civil engineering structures. Copyright © 2003 John Wiley & Sons, Ltd.
Hybrid control systems for seismic protection of a phase II benchmark cable‐stayed bridge
Authors: Park Kyu‐Sik , Jung Hyung‐Jo , Spencer Billie F. , Lee In‐Won
Published: August 2003

This paper presents hybrid control systems for seismic protection of a phase II benchmark cable‐stayed bridge. Because multiple control devices are operating, a hybrid control system could alleviate some of the restrictions and limitations that exist when each system is acting alone. In this study, two types of hybrid control system are considered to protect the cable‐stayed bridge under seismic events. Lead–rubber bearings are used as passive control devices to reduce the earthquake‐induced forces in the bridge and hydraulic actuators or magnetorheological fluid dampers are used as additional control devices to further reduce the bridge responses, especially deck displacements. Numerical simulation results show that the performances of the proposed hybrid control systems are superior to those of the passive control system, and slightly better than those of the active or semi‐active control system alone. Furthermore, it is verified that the hybrid control systems are robust to mass or stiffness parameter perturbation, and there is no sign of instability in the overall system due to the passive control part. Therefore, the proposed hybrid control systems could effectively be applied to seismically excited cable‐stayed bridges. Copyright © 2003 John Wiley & Sons, Ltd.
Politeness and the clash of interaction orders in cross‐cultural communication
Authors: Morand David A.
Published: August 2003

This conceptual article suggests that crosscultural variation in politeness behaviors, that is, differential culture‐specific norms for
treatment of face, comprises an important dimension of crosscultural organizational behavior. The gentle and respectful handling of others' face
is a vital social behavior in any cultural context. However, research shows that cultures have evolved differential norms for treating face. These
differential norms are at the heart of many crosscultural communication problems. This article provides a conceptual framework explicating the above,
reviews empirical literature on crosscultural variation of politeness norms, and suggests important implications for organizational theorists and for
managers interested in crosscultural communication. © 2003 Wiley Periodicals, Inc.
Political risks as firm‐specific (dis)advantages: Evidence on transnational oil firms in Nigeria
Authors: Frynas Jedrzej George , Mellahi Kamel
Published: August 2003

The international business literature has recognized that political risk can be firm‐specific, but it has so far focused almost exclusively on the national business environment rather than the firm itself. Scholars have still largely confined firms to the role of relatively passive bystanders who, at best, can forecast political risks with some precision or guard against risk (e.g., through insurance). The basic premise of this article, however, is that transnational corporations (TNCs) can be active actors capable of acquiring and upgrading firm‐specific resources and capabilities for coping with or even benefiting from political risk. The research is based on the case of the Nigerian oil industry. The research provides evidence to suggest that the same political events can have varying effects on different transnational firms depending on their strategic resources and capabilities, and can benefit specific firms under certain circumstances. © 2003 Wiley Periodicals, Inc.
Indonesia
Authors: Sitorus Sihar , Budhwar Pawan S.
Published: August 2003

Indonesia's long stability of over three decades came to a sudden end after the regional economic crisis of 1997–1998. The economic
crisis not only shattered the Indonesian economy but also resulted in political turmoil. The national leadership has changed three times over the last
five years. In such conditions, the confidence of foreign investors is very low. The present government has initiated a number of steps to restore
political stability and economic recovery. This article provides useful information on the complex business environment, aimed to help foreign
investors to develop a good understanding on key background knowledge for being successful in Indonesia. It reviews Indonesian historical development,
political structure and climate, regional relations, and economy and foreign trade. Indonesia's infrastructure, legal framework, sociocultural
setup, as well as market structure and potential, are also analyzed. © 2003 Wiley Periodicals, Inc.
Research note: Synergies between export channels in mature and emerging markets
Authors: Li Lee
Published: August 2003

This study identifies and assesses synergies between export channels in emerging and mature markets. The results indicate that exporters'
performance determinants in emerging markets are different from those in mature markets. Exporters transfer funds between export channels. Experienced
exporters' channels in fast‐growing emerging markets and their channels in mature markets where they have developed product or brand
advantages require heavy funding. Other channels will be used as the fund sources to support and control these export channels. © 2003 Wiley
Periodicals, Inc.
An approach to change management
Authors: Calvez Vincent , Guénette Alain Max
Published: August 2003

François Pichault and Jean Nizet. 2000. Les Pratiques de Gestion des Ressources Humaines. Approches Contingente et Politique.
Paris: Editions du Seuil (Points). 332 pages, 2000. ISBN 2020347709, 9 EUR.
Financial Intermediation in the 21st Century
Authors: Lhabitant François‐Serge
Published: August 2003

Zuhayr Mikdashi. 2001. London: Palgrave Macmillan. hardcover, 344 pages; ISBN: 0333802012.
An analysis of the global position of U.S. manufacturing
Authors: Czinkota Michael R.
Published: August 2003

This article provides an overview of the changing export and import flows of U.S. manufactured goods in the global economy, offers some thoughts
on the repercussions of these changes, and outlines possible outcomes. © 2003 Wiley Periodicals, Inc.
Qualitative venous Doppler waveform analysis improves prediction of critical perinatal outcomes in premature growth‐restricted fetuses
Authors: Baschat A. A. , Gembruch U. , Weiner C. P. , Harman C. R.
Published: August 2003

Background

Our aim was to test the hypothesis that qualitative ductus venosus and umbilical venous Doppler analysis improves prediction of critical perinatal outcomes in preterm growth‐restricted fetuses with abnormal placental function.

Methods

Patients with suspected intrauterine growth restriction (IUGR) underwent uniform fetal assessment including umbilical artery (UA), ductus venosus (DV) and umbilical vein (UV) Doppler. Absent or reversed UA end‐diastolic velocity (UA‐AREDV), absence or reversal of atrial systolic blood flow velocity in the DV (DV‐RAV) and pulsatile flow in the umbilical vein (P‐UV) were examined for their efficacy to predict critical outcomes (stillbirth, neonatal death, perinatal death, acidemia and birth asphyxia) before 37 weeks' gestation.

Results

Seventeen (7.6%) stillbirths and 16 (7.1%) neonatal deaths were observed among 224 IUGR fetuses. Forty‐one neonates were acidemic (19.8%) and seven (3.1%) had birth asphyxia. Logistic regression showed that UA‐AREDV had the strongest association with perinatal mortality (R2 = 0.49, P < 0.001), stillbirth (R2 = 0.48, P < 0.001) and acidemia (R2 = 0.22, P = 0.002) while neonatal death was most strongly related to DV‐RAV and P‐UV (R2 = 0.33, P = 0.007). UA waveform analysis offered the highest sensitivity and negative predictive value and DV‐RAV and P‐UV had the best specificity and positive predictive values for outcome prediction. Overall, DV‐RAV or P‐UV offered the best prediction of acidemia and neonatal and perinatal death irrespective of the UA waveform. In fetuses with UA‐AREDV, prediction of asphyxia and stillbirth was significantly enhanced by venous Doppler.

Conclusion

Prediction of critical perinatal outcomes is improved when venous and umbilical artery qualitative waveform analysis is combined. The incorporation of venous Doppler into fetal surveillance is therefore strongly suggested for all preterm IUGR fetuses. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Turner's syndrome in fetal life
Authors: Surerus E. , Huggon I. C. , Allan L. D.
Published: August 2003

Objective

To compare the incidence and type of heart disease found in association with 45X karyotype in fetal life with postnatal life and to examine the outcome after fetal diagnosis.

Methods

Fifty‐three fetuses with a 45X karyotype were examined echocardiographically over a 4‐year period between 1999 and 2002. Of these, 47 were referred because of increased nuchal translucency (NT).

Results

A cardiac abnormality was detected in 33/53 (62.2%) fetuses. The most common diagnosis was coarctation of the aorta in 24/53 (45.3%) fetuses, followed by the hypoplastic left heart syndrome (HLHS) in 7/53 (13.2%) fetuses. The mean NT was significantly higher in fetuses with a heart defect than in those with normal echocardiography. Termination of pregnancy was carried out in 45/53 (84.9%) fetuses and intrauterine death occurred in six cases. Two of four fetuses with a mosaic karyotype are currently alive.

Conclusion

Turner's syndrome is associated with a higher incidence of heart defects detected prenatally when compared to postnatal reports. The commonest associated heart defects detected prenatally are HLHS and coarctation of the aorta, in contrast to postnatal life where a bicuspid aortic valve is the most common diagnosis. The typical intrauterine presentation of Turner's syndrome with a markedly increased NT or with hydrops and with a typical 45X karyotype has an extremely poor prognosis for intrauterine survival. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Pelvic ultrasound and color Doppler findings in different isosexual precocities
Authors: Battaglia C. , Mancini F. , Regnani G. , Persico N. , Iughetti L. , De Aloysio D.
Published: August 2003

Objective

To evaluate the role of ultrasound and color Doppler analyses in improving the differential diagnosis of pubertal precocities.

Methods

Sixty‐nine girls with premature (<8 years old) breast development and/or pubic hair growth underwent: auxological (height, weight, body mass index, skeletal maturation), hormonal (basal, gonadotropin releasing hormone (GnRH)‐test, adrenocorticotropic hormone test), and sonographic (uterine and ovarian volume and endometrial echo) including color Doppler (uterine arteries) evaluations.

Results

The uterine size was greater in girls with a pubertal response to the GnRH test (Group II, n = 16; 7.48 ± 4.18 mL) than in those with a prepubertal response to the GnRH test (Group I, n = 17; 3.02 ± 1.36 mL; P = 0.006), an isolated pubarche (Group III; n = 20; 2.58 ± 1.32 mL; P < 0.001) or an isolated thelarche (Group IV, n = 16; 1.82 ± 1.07 mL; P < 0.001). Endometrial echo was observed in 87.5%, 29.4% and 5% of girls, respectively, in Groups II, I and III. The Doppler analysis of the uterine arteries showed the lowest impedance to be in patients with a pubertal response to the GnRH test (Group II).

Conclusions

Sonographic and color Doppler parameters may improve the diagnosis of GnRH‐dependent precocious puberty and may be useful to determine which girls need treatment. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Customizing fetal biometric charts
Authors: Pang M. W. , Leung T. N. , Sahota D. S. , Lau T. K. , Chang A. M. Z.
Published: August 2003

Objective

To study the effects of maternal and pregnancy characteristics on fetal biometric size using longitudinal ultrasound measurements and to construct customized models for fetal biometric size charts.

Methods

A cohort of 533 healthy pregnant women with normal singleton pregnancies were recruited for regular ultrasound examination for fetal biometry between 24 and 40 weeks' gestation. Multilevel modeling was used to construct models of fetal head size, femur length and abdominal circumference. Variables of maternal and pregnancy characteristics including booking weight and height, age, parity and fetal sex were included in the construction of the customized fetal biometric size charts.

Results

Increased fetal head size and abdominal circumference were significantly associated with extremes of maternal age. Maternal height had a statistically significant influence on biparietal diameter. Maternal booking weight had an influence on fetal abdominal circumference and femur length. Fetal sex was found to have a statistically significant influence on the final regression models of biparietal diameter, head circumference and femur length. Parity had an influence on fetal head circumference and abdominal circumference.

Conclusions

Maternal and pregnancy characteristics have a significant influence on in‐utero fetal biometry. We produced models to construct customized fetal biometric size charts. Further validation studies are necessary to evaluate the clinical usefulness of such customized fetal biometric size charts. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Accuracy of cervical transvaginal sonography in predicting preterm birth: a systematic review
Authors: Honest H. , Bachmann L. M. , Coomarasamy A. , Gupta J. K. , Kleijnen J. , Khan K. S.
Published: August 2003

This review investigates the accuracy with which transvaginal cervical sonography predicts spontaneous preterm birth. Published studies were identified without language restrictions through nine different databases and manual searching of bibliographies of known primary and review articles. Studies were selected if they undertook antenatal transvaginal sonographic cervical assessment among a population of pregnant women with known gestational age of delivery. There were 46 primary articles, which included a total of 31 577 women, consisting of 33 studies in asymptomatic and 13 studies in symptomatic women. Data were extracted for the studies' characteristics and quality. Accuracy data were used to form 2 × 2 contingency tables for various cervical length measurements with birth before 32, 34 and 37 weeks' gestation as the reference standards. Data were stratified according to singleton or twin pregnancy, gestational age at testing, cervical length threshold, and the various reference standards, and were pooled to produce summary estimates of likelihood ratios (LRs). Our review showed that transvaginal cervical sonography identifies women who are at higher risk of spontaneous preterm birth, although there was a wide variation amongst studies with respect to gestational age at testing, definition of threshold of abnormality and definition of reference standard. The most commonly reported sub‐group was testing of asymptomatic women at < 20 weeks' gestation using a threshold cervical length of 25 mm with spontaneous preterm birth before 34 weeks' gestation as the reference standard. The summary LR+ for this group was 6.29 (95% CI, 3.29–12.02), with corresponding LR− of 0.79 (95% CI, 0.65–0.95). Both cervical length measurement and funneling, whether alone or in combination, appear to be useful (depending on the threshold chosen to define the abnormality) in predicting spontaneous preterm birth in asymptomatic women. For symptomatic women there was a paucity of data, although the degree of funneling appeared to be predictive of spontaneous preterm birth. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Effect of fetal gender on first‐trimester ductus venosus blood flow
Authors: Prefumo F. , Venturini P. L. , De biasio P.
Published: August 2003

Objectives

Recent reports have suggested that nuchal translucency (NT) measurements in the first trimester may be influenced by fetal gender. Since both NT and central venous blood flow are considered to be related to fetal cardiac function, we investigated gender‐related differences in first‐trimester ductus venosus Doppler indices.

Methods

A total of 73 male and 79 female normal fetuses at 10–14 weeks of gestation were included in the study. The pulsatility index for veins (PIV), peak velocity during ventricular systole (S‐wave), time‐averaged maximum velocity (TAMV) and A‐wave velocity (A‐wave) were recorded in each case and converted to the corresponding Z‐scores.

Results

The mean Z‐score values of PIV, S‐wave and TAMV were significantly lower in male fetuses compared to female fetuses (P < 0.01 for all three indices). By contrast, A‐wave velocities were not different in the two groups. The correlation between S‐wave velocity and TAMV was significant in both male (P < 0.001) and female (P < 0.001) fetuses, while PIV did not appear to be related to TAMV either in males (P = 0.90) or in females (P = 0.49). A‐wave velocity had a significant negative correlation with PIV in both groups. Finally, PIV was significantly correlated with S‐wave velocity in female fetuses (P < 0.01) but not in males (P = 0.14).

Conclusion

These findings suggest that early cardiovascular development may be different in male and female fetuses. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
A new successful therapy for fetal chylothorax by intrapleural injection of maternal blood
Authors: Parra J. , Amenedo M. , Muñiz‐Díaz E. , Ormo F. , Simó M. , Vega C. , FernÁndez J. G. , Senosiain R. , Moliner E. , Guinovart G.
Published: August 2003

We present two cases of fetal chylothorax and hydrops diagnosed at 20 weeks' gestation, both of which underwent successful intrauterine treatment. In Case 1, a transient, near total resolution began 2 weeks after an iatrogenic hemothorax following a second thoracocentesis performed at 24 + 6 weeks. Because of pleural fluid reaccumulation, a Cesarean section was performed at 36 weeks. The 3805‐g female neonate was admitted to neonatal intensive care but was discharged 50 days later in a healthy condition. In Case 2, resolution occurred after a third thoracocentesis and a second pleural injection of maternal blood, performed at 26 weeks. A 2660‐g female neonate was delivered vaginally at 38 weeks. The infant remained asymptomatic and was discharged aged 4 days. Our experience suggests a possible useful role of intrapleural blood injection for the treatment of fetal chylothorax. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Ductus venosus blood flow velocity characteristics of fetuses with single umbilical artery
Authors: Raio L. , Ghezzi F. , Di Naro E. , Cromi A. , Buttarelli M. , Sonnenschein M. , Dürig P.
Published: August 2003

Objectives

Sonographic Doppler evaluation of the fetal ductus venosus has been proved to be useful in the evaluation of fetal cardiac function. The aim of this study was to investigate the ductus venosus blood flow profile in fetuses with single umbilical artery and to correlate it with the umbilical cord morphology.

Methods

Fetuses at >20 weeks' gestation with single umbilical artery who were otherwise healthy were consecutively enrolled into the study. The sonographic examination included evaluation of the following Doppler parameters: umbilical artery resistance index, maximum blood flow velocity of the ductus venosus during ventricular systole (S‐peak) and atrial contraction (A‐wave), ductus venosus time‐averaged maximum velocity (TAMXV), and pulsatility index for veins (PIV). The cross‐sectional area of the umbilical cord and its vessels were measured in all cases. The Doppler and morphometric values obtained were plotted on reference ranges.

Results

A total of 88 fetuses with single umbilical artery were scanned during the study period. Of these 52 met the inclusion criteria. The S‐peak velocity, A‐wave velocity, and TAMXV were below the 5th centile for gestational age in 57.7%, 59.6%, and 57.7% of cases, respectively. The PIV was within the normal range in 80.1% of cases. The umbilical vein cross‐sectional area of fetuses with single umbilical artery was above the 95th centile for gestational age in 34.6% cases.

Conclusions

The ductus venosus blood flow pattern is different in fetuses with single umbilical artery from that in those with a three‐vessel cord. This difference may be caused in part by the particular morphology of umbilical cords with a single artery. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.
Frequency and type of adnexal lesions in autopsy material from postmenopausal women: ultrasound study with histological correlation
Authors: Valentin L. , Skoog L. , Epstein E.
Published: August 2003

Objective

To determine the prevalence and histology of adnexal cysts in autopsy material from postmenopausal women.

Methods

The study included 104 adnexa from 52 consecutive women with a mean age of 79 (range, 64–96) years, who underwent autopsy and died from causes other than gynecological cancer or intraperitoneal cancer of extragenital origin. The adnexa were removed, put in sterile saline in separate plastic containers and examined sonographically using an 8‐MHz transvaginal transducer. Each lesion detected at ultrasound examination was measured with calipers on the frozen ultrasound image and was classified according to its ultrasound morphology. The adnexa were then put in 4% formaldehyde solution and sent for histological examination.

Results

At ultrasound examination, 56% (29/52) of the women had adnexal lesions, cysts being detected in 54% (28/52) and solid lesions in 12% (6/52). At least one adnexal cyst with a largest diameter of 2–10 mm, > 10 mm, > 20 mm, > 30 mm and > 40 mm, respectively, was found in 33% (17/52), 21% (11/52), 12% (6/52), 8% (4/52) and 4% (2/52) of the women. The largest lesion measured 65 mm in diameter. At ultrasound examination we found 36 intra‐ovarian cysts (26 inclusion cysts, three cystically degenerated corpora albicantia, five simple cysts, one serous cystadenoma and one 3‐mm cyst not confirmed by the pathologist), 19 extra‐ovarian cysts (all simple cysts according to the pathologist), five solid intra‐ovarian lesions (two fibromas, one cystadenofibroma, one Brenner tumor and one case of dystrophic calcification), and one solid extra‐ovarian lesion (fibroma). In addition, the pathologist detected one 20‐mm solid corpus albicans, eight extra‐ovarian simple cysts of 1–8 mm, and 77 intra‐ovarian inclusion cysts of 1–4 mm.

Conclusion

Small (≤ 50 mm) benign adnexal cysts and small benign solid tumors are so common in postmenopausal women that their presence may be regarded as normal. Our results support conservative management of adnexal lesions with benign ultrasound morphology incidentally detected at ultrasound examination in postmenopausal women. Copyright © 2003 ISUOG. Published by John Wiley & Sons, Ltd.