bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two case reports of rare fetal tumors: an indication for surface rendering?
Authors: Hösli I. , Holzgreve W. , Danzer E. , Tercanli S. 
Published: March 2003

AbstractFetal tumors are rare and can be difficult to diagnose in utero. This report describes one case of an extrarenal rhabdoid tumor and one case of a giant congenital melanocytic nevus. Both presented with moderate polyhydramnios and were prenatally detected at 31 weeks of gestation with two‐dimensional ultrasound. The application of the surface mode of three‐dimensional ultrasound improved the visualization of these tumors especially for the parents and the multidisciplinary team. Three‐dimensional sonography proved to be a valuable addition to the prenatal armamentarium for the evaluation of these fetal tumors although it is not mandatory for their assessment and clinical management. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
The clivus–supraocciput angle: a useful measurement to evaluate the shape and size of the fetal posterior fossa and to diagnose Chiari II malformation
Authors: D'Addario V. , Pinto V. , Del Bianco A. , Di Naro E. , Tartagni M. , Miniello G. , Serio G. 
Published: March 2003

AbstractObjectiveTo obtain a nomogram of the clivus–supraocciput angle as a basis for the diagnosis of Chiari II malformation in fetuses with ventriculomegaly.MethodsA cross‐sectional study was undertaken on 310 normal pregnant women of 16–34 weeks' gestation. A mid‐sagittal section of the fetal skull was obtained and the angle between the clivus and the supraocciput was measured. Forty‐four fetuses with ventriculomegaly due to various causes (13 Chiari II malformation, 12 dysgenesis of the corpus callosum, 7 aqueductal stenosis, 6 borderline ventriculomegaly, 3 Dandy–Walker malformation, 2 porencephaly, 1 schizencephaly) were also included in the study and the values of the angle found in the pathological cases were compared with those found in the normal population.ResultsThe clivus–supraocciput angle did not change during gestation and was almost constant with an average value of 79.3 ± 6°. All cases of Chiari II malformation showed a value below the 5th centile of our nomogram.ConclusionsThe evaluation of the posterior fossa and particularly the measurement of the clivus–supraocciput angle is a useful parameter to differentiate the various causes of fetal ventriculomegaly and particularly to recognize Chiari II malformation. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Fetal heart rate and umbilical artery velocity variability in fetuses with congenital cardiac defects: a preliminary study
Authors: Ursem N. T. C. , Clark E. B. , Pagotto L. T. , Wladimiroff J. W. 
Published: March 2003

AbstractObjectiveTo examine whether variabilities in fetal heart rate and umbilical artery flow velocity are possible markers for hemodynamic dysfunction in fetuses with a congenital heart defect.MethodsDoppler studies of the umbilical artery velocity waveform were performed at 20–35 weeks of gestation in 13 patients with a congenital heart defect. We determined absolute and variability values for heart rate and flow velocities from umbilical artery velocity waveforms of a least 18 s duration. We compared these findings with normal controls matched for gestational age.ResultsFetuses with a congenital heart defect displayed decreased umbilical artery peak systolic and time‐averaged velocities. However, variability in peak systolic and time‐averaged velocities and fetal heart rate variability were increased compared with normal controls. Absolute fetal heart rates were similar between the two groups.ConclusionsMarked cardiovascular changes occur in the fetus with a congenital heart defect compared with the normal healthy fetus. We propose that variability in fetal heart rate and umbilical artery blood flow velocity could be additional markers for impaired homeostasis in the presence of fetal congenital heart disease. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Diagnosis of low‐lying placenta: can migration in the third trimester predict outcome?
Authors: Oppenheimer L. , Holmes P. , Simpson N. , Dabrowski A. 
Published: March 2003

AbstractObjectivesTo investigate the relationship between the rate of migration of a low‐lying placenta during the third trimester and the eventual route of delivery.MethodsAll patients with a placenta lying within 3 cm of the internal cervical os or overlapping it on transvaginal ultrasound at ≥ 26 weeks' gestation were included in the study. The exact distance between the center of the internal cervical os and the leading edge of the placenta was measured by transvaginal sonography, repeated at approximately 4‐week intervals until delivery.ResultsThe mean rates of migration in patients who had (n = 7) and who did not have (n = 29) Cesarean section for placenta previa were +0.3 mm/week and +5.4 mm/week, respectively (P < 0.0001). When the placental edge was initially > 20 mm from the internal os, migration occurred in all cases and no Cesarean section for placenta previa was performed. For those between −20 mm and +20 mm, sufficient migration to avoid Cesarean section occurred in 88.5% of cases. Beyond a 20 mm overlap, significant placental migration did not occur and all patients required Cesarean section.ConclusionPlacental migration may occur progressively throughout the third trimester. The initial position of the placental edge and the subsequent rate of migration can be used to predict the eventual route of delivery. Copyright © 2001 International Society of Ultrasound in Obstetrics and Gynecology
Persistent right umbilical vein: incidence and significance
Authors: Wolman I. , Gull I. , Fait G. , Amster R. , Kupferminc M. J. , Lessing J. B. , Jaffa A. J. 
Published: March 2003

AbstractObjectivesTo conduct a prospective evaluation of the incidence and neonatal outcome of fetuses with persistent right umbilical vein. This condition had traditionally been considered to be extremely rare and to be associated with a very poor neonatal prognosis, but later evidence has raised some doubts about the veracity of these contentions.MethodsBetween August 1995 and November 1998, 8950 low‐risk patients were prospectively evaluated at two medical centers. The sonographic diagnosis of a persistent right umbilical vein was made in a transverse section of the fetal abdomen when the portal vein was curved toward the stomach, and the fetal gall bladder was located medially to the umbilical vein.ResultsPersistent right umbilical vein was detected in 17 fetuses during the study. Four of them had additional malformations, of which three had been detected antenatally.ConclusionsWe established that the incidence of persistent right umbilical vein in a low‐risk population is 1 : 526. We believe that the sonographic finding of this anomaly is an indication for conducting targeted fetal sonography and echocardiography. When the persistent right umbilical vein is connected to the portal system and other anomalies are ruled out, the prognosis can generally be expected to be favorable. Copyright © 2002 ISUOG
Placenta accreta diagnosed at 9 weeks' gestation
Authors: Chen Y.‐J. , Wang P.‐H. , Liu W.‐M. , Lai C.‐R. , Shu L.‐P. , Hung J.‐H. 
Published: March 2003

AbstractThe majority of cases of placenta accreta are unanticipated and initially identified intraoperatively. Although color Doppler ultrasound is adequate for the evaluation of placenta accreta in the third trimester, ultrasound diagnosis in the first trimester has never been reported. To our knowledge, this is the first case of placenta accreta detected at 9 weeks' gestation by ultrasound. Placenta accreta with intraplacental lacunae can be identified together with a loss of the hypoechogenic retroplacental myometrial zone. Based on this case, we found that early diagnosis of placenta accreta in the first trimester by ultrasound is possible. Copyright © 2002 ISUOG
Two‐dimensional ultrasound is accurate in the diagnosis of fetal craniofacial malformation
Authors: Ghi T. , Perolo A. , Banzi C. , Contratti G. , Valeri B. , Savelli L. , Morselli G. P. , Bovicelli L. , Pilu G. 
Published: March 2003

AbstractObjectiveTo assess the accuracy of antenatal ultrasound in the diagnosis of craniofacial malformations and to compare two‐dimensional with three‐dimensional ultrasound.MethodsThis was a retrospective study in which the archives of our ultrasound laboratory were searched for cases with an ultrasound diagnosis of craniofacial malformation in the period 1986–2001. No attempt was made to look for false‐negative diagnoses.ResultsSixty cases with an antenatal diagnosis of a craniofacial malformation were found: 37 with cleft lip/palate; 17 with heterogeneous dysmorphisms (including mostly micrognathia and craniosynostosis) and 6 with miscellaneous craniofacial malformations. Associated anomalies were present in 48/60 (80%) cases, and holoprosencephaly (25 cases) was the most frequent of these. In 43 (72%) cases the diagnosis was made before 24 weeks' gestation. Postnatal follow‐up was available for 43 cases and there was always complete correlation between antenatal and postnatal diagnoses. Cleft lip/palate was always accurately differentiated from cleft lip. Three‐dimensional ultrasound was performed in 12 cases and was successful in 11. However, it did not provide further diagnostic information with regard to the two‐dimensional scan.DiscussionCurrent two‐dimensional ultrasound in expert hands allows an accurate diagnosis of craniofacial abnormalities from early gestation. In our hands, three‐dimensional ultrasound did not add any valuable diagnostic information. Three‐dimensional ultrasound may facilitate the understanding of the lesion by the parents and facilitate communication with the plastic surgeons. However, these potential benefits need to be carefully weighed against the costs of the ultrasound instrumentation, increased examination time and training of personnel. Copyright © 2002 ISUOG
Three‐dimensional prenatal diagnosis of frontonasal malformation and unilateral cleft lip/palate
Authors: Shipp T. D. , Mulliken J. B. , Bromley B. , Benacerraf B. 
Published: March 2003

AbstractFrontonasal malformation includes a spectrum of anomalies involving the eyes, nose, lips, forehead and brain. We present a case in which a fetal labial cleft was initially identified using traditional two‐dimensional sonography. Three‐dimensional sonography with multiplanar reconstruction and surface‐rendering were essential to establish the diagnosis of frontonasal malformation with severe nasal hypoplasia and unilateral complete cleft lip/palate. Copyright © 2002 International Society of Ultrasound in Obstetrics and Gynecology
Impaired baroreflex function during pregnancy is associated with stiffening of the carotid artery
Authors: Visontai Z. , Lenard Z. , Studinger P. , Rigo J. , Kollai M. 
Published: March 2003

AbstractObjectiveThe baroreflex sensitivity and the distensibility of the carotid artery were measured during normotensive pregnancy to test the hypothesis that changes in baroreflex sensitivity are related to carotid artery stiffening.DesignData were obtained from pregnant subjects during each trimester (T1, T2, T3; n = 23) and postpartum (n = 11). End‐diastolic diameter and pulsatile distension of the carotid artery were measured with an ultrasound wall‐tracking system, and the distensibility coefficient was calculated. Spontaneous fluctuations in cardiac interval and systolic pressure were used to determine baroreflex sensitivity.ResultsBoth distensibility coefficient and baroreflex sensitivity were reduced from T1 to T3 (5.1 ± 1.6 vs. 3.7 ± 0.9 10−3/mmHg and 10.1 ± 2.9 vs. 5.7 ± 1.8 ms/mmHg, respectively). Baroreflex sensitivity and carotid distensibility coefficient were linearly related in each subject (r = 0.62 ± 0.12). Augmentation index and return time changes indicated a global increase in arterial distensibility.ConclusionsStiffening of the carotid artery significantly contributes to the impairment of baroreflex sensitivity during pregnancy, and represents a region specific change as global arterial distensibility was found to increase during pregnancy. Copyright © 2002 International Society of Ultrasound in Obstetrics and Gynecology
Fetal learning: a prospective randomized controlled study
Authors: James D. K. , Spencer C. J. , Stepsis B. W. 
Published: March 2003

AbstractObjectivesTo examine whether prenatal exposure to a music stimulus alters fetal behavior and whether this continues into the newborn period.Subjects and methodsA prospective randomized control trial was conducted using an exposure learning model in 20 normal term pregnancies. Music was played to ten fetuses via a headphone on the maternal abdomen. Ten controls had the headphone without sound. All fetal studies took place within 72 h prior to elective delivery. All 20 newborns were exposed to the same music on days 3–5. Computerized assessment of fetal heart rate and activity was documented and neonatal behavioral states were recorded. Nonparametric statistical analysis was used.ResultsFor the first hour of study, exposed fetuses had higher mean heart rates (FHR) and spent more time exhibiting high FHR variation compared to unexposed fetuses, but neither of these differences was statistically significant. However, by the fourth hour the exposed fetuses not only demonstrated these two features but also exhibited more state transitions (P = 0.01) and higher FHR variation (P = 0.04) compared to unexposed fetuses. These effects were carried over into the neonatal period with prenatally exposed newborns manifesting more state transitions (P = 0.01) and spending a higher proportion of time in awake states (P = 0.05) when exposed to the same music stimulus.ConclusionPrenatal music exposure alters the fetal behavioral state and is carried forward to the newborn period. This suggests that a simple form of fetal programming or learning has occurred. Copyright © 2002 International Society of Ultrasound in Obstetrics and Gynecology
Anastomosis at the level of the elbow joint connecting the deep, or normal, brachial artery with major arterial variations of the upper limb
Authors: RODRÍGUEZ‐NIEDENFÜHR M. , SAÑUDO J. R. , VÁZQUEZ T. , NEARN L. , LOGAN B. , PARKIN I. 
Published: March 2003

Major variations of the principal arteries of the upper limb have long received the attention of anatomists. These variations can be summarised as the presence of 2 main arteries traversing the cubital fossa, a deep (or normal) brachial artery in coexistence with a superficial brachial, radial or ulnar artery. Anastomosis between these arterial trunks at elbow level has been reported in 1–6% of cases as an incidental finding in studies on the major arterial variations of the upper limb (Quain, 1844; Müller, 1903; Poynter, 1922; Adachi, 1928; McCormack et al. 1953; Wankoff, 1962; Rodríguez‐Baeza et al. 1995). Only a single report (Ljubomudroff, 1927) has dealt specifically with the anastomosis.The anatomical pattern of the anastomosis has been classified into 2 or 3 types depending on different morphological details. Three types have been described, taking into account its length, calibre and form (Quain, 1844) or the positions of the origin and number of recurrent radial arteries (Ljubomudroff, 1927). Two types have been described on the basis of whether the anastomosis coursed anterior or posterior to the bicipital tendon (McCormack et al. 1953). The aim of this study was to revisit these specific morphological details in a statistically reliable sample in order to catalogue the variations of the anastomosis and to provide an embryological explanation.
Surface antigens of human embryonic stem cells: changes upon differentiation in culture*
Authors: Draper Jonathan S. , Pigott Christine , Thomson James A. , Andrews Peter W. 
Published: March 2003

AbstractWe have analysed the surface antigen phenotype of a human embryonic stem (hES) cell line (H7) and the changes that occur upon differentiation induced by retinoic acid, hexamethylene bisacetamide and dimethylsulphoxide. The undifferentiated stem cells expressed Stage Specific Embryonic Antigen‐3 (SSEA3), SSEA4, TRA‐1‐60, and TRA‐1‐8 but not SSEA1. In these characteristics they closely resemble human embryonal carcinoma (EC) cells derived from testicular teratocarcinomas, and are distinct from murine EC and ES cells. The undifferentiated cells also expressed the liver/bone/kidney isozyme of alkaline phosphatase detected by antibody TRA‐2‐54, the class 1 major histocompatability antigens, HLA‐ABC, and the human Thy1 antigen. Differentiation of hES cells was induced by retinoic acid, HMBA and DMSO with the appearance of various cell types including neurons and muscle cells. The surface antigens characteristically expressed by hES cells were down‐regulated following induction of differentiation and other antigens appeared, notably several ganglioside glycolipids detected by antibodies VIN‐IS‐56 (GD3 and GD2), VIN‐2PB‐22 (GD2), A2B5 (GT3) and ME311 (9‐O‐acetyl‐GD3). Whereas the expression of HLA was slightly down‐regulated upon differentiation, its expression was strongly induced by interferon‐γ in both the undifferentiated and the differentiated cells, although the induction in the differentiated cultures was considerably stronger than in the stem cells. In all of these features the human ES cells, and their pattern of differentiation, resembled the pluripotent human EC cell line NTERA‐2 although clearly the range of cells generated by the hES cells was considerably greater.
A background to nuclear transfer and its applications in agriculture and human therapeutic medicine*
Authors: Campbell Keith H. S. 
Published: March 2003

AbstractThe development of a single celled fertilized zygote to an animal capable of reproduction involves not only cell division but the differentiation or specialization to numerous cell types forming each tissue and organ of the adult animal. The technique of nuclear transfer allows the reconstruction of an embryo by the transfer of genetic material from a single donor cell, to an unfertilized egg from which the genetic material has been removed. Successful development of live offspring from such embryos demonstrates that the differentiated state of the donor nucleus is not fixed and can be reprogrammed by the egg cytoplasm to control embryo and fetal development. Nuclear transfer has many applications in agriculture and human medicine. This article will review some of the factors associated with the success of embryo development following nuclear transfer and outline the potential uses of the technology.
Signals that determine Schwann cell identity*
Authors: Jessen K. R. , Mirsky R. 
Published: March 2003

AbstractWhile the signals that direct neural crest cells to choose the glial lineage and generate Schwann cell precursors are still obscure, studies bothin vivoandin vitroindicate that the survival and differentiation of these cells to form Schwann cells is regulated by at least two signals, neuregulin‐1 and endothelin. We know little about the signals that cause some immature Schwann cells to choose myelin differentiation, while other cells form non‐myelinating cells. Three transcription factors, Sox‐10, Oct‐6 and Krox‐20, have been shown to play key roles in the Schwann cell lineage. The transcription factor Krox‐20 has been identified as a major target of the signals that induce myelin differentiation. Gene transfer experimentsin vitroshow that this protein has a remarkable ability to promote a large number of phenotypic changes in immature Schwann cells that characterize the transition of these cells to myelinating cells. Furthermore, Krox‐20 shows important functional interactions with neuregulin and transforming growth factor β (TGFβ), two factors that have been implicated in the regulation of myelination in postnatal nerves. Another signal of importance in developing peripheral nerves, Desert Hedgehog, secreted by Schwann cells directs formation of the peripheral nerve connective tissue sheaths. Ongoing gene screening experiments are likely to reveal new genes of interest in this system.
Improved digital SEM of cancellous bone: scanning direction of detection, through focus for in‐focus and sample orientation
Authors: Boyde Alan 
Published: March 2003

AbstractThree‐dimensional (3D) study of cancellous bone tissue organization is necessary to understand how modelling and remodelling processes regulate bone structure and connectivity. It requires imaging methods that have both sufficient resolution power and width and depth of field. Since clinical imaging methods fall far short of the first requirement, we can only study prepared tissue in isolation from the body. Scanning electron microscopy (SEM) of macerated plane parallel slices is the most productive method, but we meet special technical problems in imaging porous bone because samples need to be relatively thick to maintain both continuity and context. Problems due to charging under the electron beam can be controlled by imaging with only high‐energy backscattered electrons (BSE). This gives an important additional benefit that the direction of apparent illumination can be manipulated by positioning the detector, and multiple detector positions can be employed strategically to generate images in which colour is used to help in coding surface morphology. However, we next confront the difficulty of the limited depth of field. This can be improved by taking series of images, moving the sample along the electron optic axis, and combining these to generate a single extended‐focus image. SEM imaging geometry gives a change in magnification with change of working distance, and it is shown that this must be corrected for each image of the through‐focus sequence. Colour coding the lighting direction and increasing the depth of field are approaches that can be combined, and are well matched to the possibilities offered by communication by digital data projection. Finally, the latter means also offer another powerful technique for 3D representation through the display of through tilt image sequences. The novel routines considered here are generally applicable to all classes of microanatomical SEM sample.
Immunocytochemical investigation of neurovascular relationships in human tooth pulp
Authors: Rodd Helen D. , Boissonade Fiona M. 
Published: March 2003

AbstractThis study sought to explore the anatomical relationships between peptidergic nerves and blood vessels within human primary and permanent teeth. Extracted primary and permanent molars (n = 120) were split longitudinally, placed in Zamboni's fixative and the coronal pulps were processed for indirect immunofluorescence. Ten‐micrometre‐thick serial frozen pulp sections were triple‐labelled using combinations of the following antisera: (1) protein gene‐product 9.5 (PGP 9.5), a general neuronal marker; (2) one of the neuropeptides, calcitonin gene‐related peptide (CGRP), substance P (SP), vasoactive intestinal polypeptide (VIP) or neuropeptide Y (NPY); and (iii) the lectin Ulex europeus, a label for vascular endothelium. The mid‐coronal pulp region was examined, using fluorescence microscopy, to determine the proportion of blood vessels showing a positive innervation (recorded when PGP 9.5‐labelled nerves appeared to intersect the vessel wall). In addition, the percentage of these vascular‐related nerves expressing each of the above neuropeptides was recorded. Overall, 20% of pulpal blood vessels appeared to have a positive innervation. In the main these were thick‐walled arterioles. Capillaries, venules and lymphatics were mostly devoid of an associated innervation. Ninety‐two per cent of vascular‐related nerves expressed CGRP, 87% expressed SP, 15% expressed VIP and 80% expressed NPY. There were no significant differences in overall innervation or peptide‐related innervation between primary and permanent teeth (P < 0.05, anova), indicating that pulpal blood flow is likely to be subject to similar neurological control mechanisms in both dentitions.