bluuebunny/crossref_metadata_2025_split huggingface dataset:
Down–up sequential separation of the placenta
Authors: Herman A. , Zimerman A. , Arieli S. , Tovbin Y. , Bezer M. , Bukovsky I. , Panski M. 
Published: March 2003

AbstractObjectiveTo characterize the patterns of placental separation during the third stage of labor.MethodsContinuous real‐time ultrasound was performed during the third stage of labor in 101 normal deliveries. The sequence of placental separation was recorded for determining whether the process was multiphasic, the site from which separation commenced and the mode of its progression.ResultsSeparation in 97 cases was multiphasic. Monophasic separation in which all parts of the placenta appeared to separate simultaneously occurred in two cases only. Pathological prolongation of the third stage precluded determination of separation in two cases. Ninety‐two cases had a uterine wall placenta (anterior or posterior); the separation commenced at one pole and progressed sequentially towards the opposite side in 89 of them. The process started at the lower pole (down–up separation) in 83/92 cases (90.2%) and began from the upper pole (up–down separation) in only 6/92 cases (6.5%). Nine cases had a fundal placenta; of these the separation was also multiphasic but began sequentially from either the anterior or posterior pole, or simultaneously from both, in 8 (88.9%) cases so that the fundal part was separated last (bipolar separation).ConclusionsPlacental separation is usually an orderly multiphasic phenomenon that begins mostly from the lower pole of the placenta and propagates sequentially upwards. Fundal placentae, however, separate first at their poles with the fundal part being separated last. Recognition of the sequence of events and understanding of the mechanism of placental separation may aid in detecting cases prone to third‐stage complications and in managing pathological ones. Copyright © 2002 ISUOG
Cerebral hemodynamics and fetal behavioral states
Authors: Clerici G. , Luzietti R. , Cutuli A. , Di Renzo G. C. 
Published: March 2003

AbstractObjectiveThis study aimed to evaluate the hemodynamic patterns of the proximal (M1) and distal (M2) portions of the middle cerebral artery, during different fetal behavioral states.DesignThe study included 20 normal singleton pregnancies at between 36 and 40 weeks of gestation. After identification of the fetal behavioral state (FBS), flow velocity evaluation was performed on the proximal and distal segments of the middle cerebral artery during ‘quiescence’ (FBS‐1F) and ‘activity’ (FBS‐2F).ResultsA statistically significant decrease of pulsatility index, reflecting a decrease of impedance to flow values, was identified in both segments of the middle cerebral artery (MCA) during ‘activity’, with a more marked decrease in the MCA‐M2 than in MCA‐M1 (M1, P = 0.0028; M2, P = 0.00000085). The mean fetal heart rate during ‘quiescence’ was significantly lower than during ‘activity’ (P = 0.0047). However, there was no significant correlation between the pulsatility index of both segments of the middle cerebral artery and the fetal heart rate during different fetal behavioral states.ConclusionsThe results of this study provide evidence of the influence of different fetal behavioral states on fetal cerebral hemodynamic patterns. We believe it is better to sample the proximal segment in clinical practice because it is less influenced by fetal behavioral state. This information should be considered when evaluating fetal cerebral hemodynamics. Copyright © 2002 ISUOG
Antenatal prediction of intraventricular hemorrhage in fetal growth restriction: what is the role of Doppler?
Authors: Baschat A. A. , Gembruch U. , Viscardi R. M. , Gortner L. , Harman C. R. 
Published: March 2003

AbstractObjectiveTo evaluate relationships between neonatal intraventricular hemorrhage and altered brain blood flow in preterm growth‐restricted fetuses.MethodsOne hundred and thirteen growth‐restricted fetuses (birth weight <10th centile and umbilical artery pulsatility index > two standard deviations above gestational age mean) which delivered prematurely (<34.0 weeks) were studied. Three expressions of altered brain blood flow were defined: ‘brain sparing’ = middle cerebral artery pulsatility index > two standard deviations below the gestational age mean, ‘centralization’ = ratio of middle cerebral artery/umbilical artery pulsatility indices (cerebroplacental ratio) > two standard deviations below the gestational age mean, and ‘redistribution’ = absent or reversed umbilical artery end‐diastolic velocity. Intraventricular hemorrhage was graded after Papile (I–IV) by cranial ultrasound performed within 7 days of delivery.ResultsSixty‐seven (59.3%) fetuses had brain sparing, 84 (74.3%) had centralization and 51 (45.1%) had redistribution. Fifteen (13.3%) neonates had intraventricular hemorrhage and were more likely to have a biophysical profile <6, earlier delivery for fetal indications, lower cord artery pH, HCO3, hemoglobin, and platelets, a 10‐min Apgar score <7 and high perinatal mortality (5/15; 33.3%). No associations between intraventricular hemorrhage and brain sparing or centralization were identified. However, neonates with intraventricular hemorrhage had significantly higher umbilical artery pulsatility index deviations from the gestational age mean and a relative risk of 4.9‐fold for intraventricular hemorrhage with redistribution (95% confidence interval, 1.5–16.3; P < 0.005). Multiple logistic regression revealed significant associations between intraventricular hemorrhage and a low 10‐min Apgar score (r = 0.30, P < 0.005) and low hemoglobin (r = 0.28), gestational age at delivery (r = 0.25) and birth‐weight centiles (r = 0.23) (P < 0.05). No Doppler parameter was identified as an independent contributor to intraventricular hemorrhage.ConclusionWhile loss of umbilical artery end‐diastolic velocity early in gestation significantly increases the risk for neonatal intraventricular hemorrhage, prematurity and difficult transition to extrauterine life remain the most important determinants of intraventricular hemorrhage. Copyright © 2002 ISUOG
Ultrasound imaging of paravaginal defects in women with stress incontinence before and after paravaginal defect repair
Authors: Martan A. , Mašata J. , Halaška M. , Otčenášek M. , Svabik K. 
Published: March 2003

AbstractObjectiveThe aim of our study was to analyze whether transabdominal and introital sonography can identify paravaginal defects and to determine changes that occur following paravaginal defect repair and Burch colposuspension.MethodsTwenty women with genuine stress incontinence took part in this prospective study. The mobility of the bladder neck was assessed transperineally with a curved array probe following instillation of 300 mL saline. The same probe was used transabdominally to determine the presence of paravaginal defects. Introital examination using a transvaginal probe was then performed to determine the presence of paravaginal defects. The same measurements were performed following Burch colposuspension and paravaginal defect repair.ResultsThere were significant differences in bladder neck position and mobility before and after surgical intervention. In 18 women before surgery, transabdominal ultrasound identified unilateral or bilateral paravaginal defects. Eight unilateral defects were found on the right side but only two were found on the left side. In eight women, the defect was bilateral. The introital approach obtained similar results apart from in two patients with a bilateral defect in whom it indicated a unilateral right defect. Between the first and second weeks following the operation transabdominal ultrasound found no paravaginal defects in 16 women and introital ultrasound found no paravaginal defects in 18 women. We were unable to visualize the region of the paravaginal defect in two women using transabdominal ultrasound because the abdominal wall was edematous after surgery. Five to 6 weeks after the operation, our results were confirmed by abdominal and introital ultrasound in all cases. No paravaginal defects were found in any of the patients after paravaginal defect repair.ConclusionOur clinical study suggests that ultrasound scanning should be performed to confirm the presence of paravaginal defects and that paravaginal defect repair may be added to Burch colposuspension for the treatment of genuine stress incontinence, as an operation to correct cystourethrocele and the posterior urethrovesical angle. Copyright © 2002 ISUOG
Prenatal diagnosis of parasitic twins using three‐dimensional ultrasound: a case report
Authors: Tan A. , Lee S.‐L. 
Published: March 2003

AbstractParasitic twins are a rare form of monochorionic, monoamniotic conjoined twins. Early prenatal ultrasound is essential for their diagnosis and assists in determining their eventual outcome; the use of three‐dimensional ultrasound may enhance diagnostic capabilities in the presence of this severe condition. Copyright © 2002 International Society of Ultrasound in Obstetrics and Gynecology
Two‐dimensional and M‐mode echocardiography of the fetal coronary sinus
Authors: Abello K. C. , Stewart P. A. , Baschat A. A. 
Published: March 2003

AbstractObjectiveTo document fetal coronary sinus dimensions in normal pregnancy.MethodsTwo hundred and sixty‐five normal fetuses in which congenital cardiac defects had been excluded were examined cross‐sectionally between 21 and 38 weeks of gestation. From the apical or basal four‐chamber view the transducer was tilted towards the inferior cardiac surface in order to visualize the coronary sinus by real‐time ultrasound. Maximum systolic and diastolic diameters were measured using M‐mode. Reference ranges were constructed and the ratio of systolic and diastolic diameters calculated. Data from two fetuses, one with supraventricular tachycardia and a second one with hydrops secondary to anemia, were also compared.ResultsVisualization and measurement of the coronary sinus were successful in 258 (97.4%) patients. The coronary sinus systolic and diastolic diameters increased significantly with gestational age (maximum systolic diameter, 1.6 mm at 21 weeks to 4 mm at 38 weeks; maximum diastolic diameter, 0.9 mm at 20 weeks to 2.2 mm at 38 weeks). The ratio of systolic to diastolic diameters remained relatively constant (range, 1.7–2.1) and therefore was unrelated to gestational age. In the fetuses with supraventricular tachycardia and hydrops, both diameters of the coronary sinus were increased and diminished fluctuation in size during the cardiac cycle was observed.ConclusionsThe described sonographic approach provides an effective method for measurement of coronary sinus dimensions. The normative data may facilitate the detection of coronary sinus dilation as an indirect marker for abnormalities in venous return to the heart.
Quantitative transvaginal two‐ and three‐dimensional sonography of the ovaries: reproducibility of antral follicle counts
Authors: Scheffer G. J. , Broekmans F. J. M. , Bancsi L. F. , Habbema J. D. F. , Looman C. W. N. , Te Velde E. R. 
Published: March 2003

AbstractObjectiveTo assess the intra‐ and interobserver reproducibilities in addition to the between‐method reliability of antral follicle counts using two (2D)‐ and three (3D)‐dimensional transvaginal sonography (TVS).MethodsTwo groups of women with regular menstrual cycles were studied. One group consisted of healthy volunteers with proven fertility and the other group consisted of patients visiting the general infertility clinic. In each woman, 2D or 3D TVS was performed in the early follicular phase (day 2, 3 or 4) of the menstrual cycle to measure the number of antral follicles (2–10 mm).ResultsIntraobserver reproducibility was calculated from follicle counts using 3D TVS in 41 women. The intraclass correlation coefficient was 0.99 and the 95% coverage interval of the difference (CID) was −3.2 to +3.2. Interobserver reproducibility was assessed from both 2D (n = 37) and 3D (n = 49) TVS‐based follicle counts. An interclass correlation coefficient of 0.98 was found for both methods. The 95% CID was −5.0 to +4.1 for 2D and −5.6 to +5.7 for 3D measurements. The latter CID appeared to increase in the higher range of counts. Finally, the degree of agreement between 2D and 3D TVS counts (n = 76) was characterized by a 95% CID of −5.3 to +8.3. This coverage interval widened when higher numbers of follicles were counted. With the exception of the between‐method analysis, kappa values indicated overall that follicle counts will hardly change from one category to another when repeatedly carried out.ConclusionsDetermination of antral follicle numbers by both 2D and 3D TVS is adequate with regard to the intra‐ and interobserver reproducibility. The between‐method reproducibility of follicle counts measured both by 2D and 3D ultrasound is moderate. When higher follicle counts are observed both interobserver and between‐method reproducibilities tend to decline. If used in categorical classifications, ultrasound‐based follicle counts appear to have a high level of agreement between and within observers. Copyright © 2002 International Society of Ultrasound in Obstetrics and Gynecology
Splenic artery Doppler in the prediction of the small‐for‐gestational age infant
Authors: Oz U. , Kovanci E. , Jeffress A. , Mendilicioglu I. , Mari G. , Bahado‐Singh R. O. 
Published: March 2003

AbstractObjectivesWe hypothesized that, as with other areas of the peripheral circulation, fetal splenic artery blood flow undergoes changes in small‐for‐gestational age (SGA) fetuses due to a redistribution of cardiac output, and that the Doppler peak systolic velocity (PSV) reflects such changes and thus may be used to predict fetuses being SGA.MethodsSplenic artery Doppler PSV, end‐diastolic velocity (EDV), resistance index (RI) and umbilical artery RI were measured prospectively in fetuses at risk for being SGA at birth. Normal reference data were generated from appropriately grown fetuses delivering at ≥ 37 weeks without complications, and SGA was defined as birth weight < 10th percentile. The Doppler indices were expressed as multiples of the normal median (MoM) for gestational age. Using receiver operating characteristic curves, optimal Doppler thresholds for the detection of SGA cases were determined and the areas under the curves calculated. The analysis was limited to singleton pregnancies delivered within 2 weeks of the last Doppler examination.ResultsThere were 88 study patients of which 60 had SGA babies. The mean gestational age at Doppler examination was 31.4 weeks with a mean interval of 5.6 days from Doppler to delivery. The splenic artery PSV was lower in SGA, compared to normal cases: mean PSV (MoM), 0.93 vs. 1.09, respectively (P = 0.0001). The sensitivity, specificity and area under the curve were 70.0%, 72% and 0.734, respectively (P < 0.003), for the PSV in the prediction of delivery of a SGA fetus. For the splenic artery RI, values were 70%, 46% and 0.539, respectively (not significantly different), and for umbilical artery RI these were 70%, 61% and 0.689, respectively (P < 0.01). Splenic artery EDV was significantly reduced in SGA vs. normally grown fetuses (0.924 MoM vs. 1.145 MoM, P = 0.007).ConclusionsFetal splenic artery PSV decreases in SGA infants, and is a strong predictor of the delivery of a SGA infant. It appears to be superior to the standard Doppler index, the RI, in predicting this outcome. Copyright © 2002 International Society of Ultrasound in Obstetrics and Gynecology
Compartmentalisation of the developing trigeminal ganglion into maxillary and mandibular divisions does not depend on target contact
Authors: SCOTT LISA , ATKINSON MARTIN E. 
Published: March 2003

During development axons contact their target tissues with phenomenal accuracy but the mechanisms that control this homing behaviour remain largely elusive. A prerequisite to the study of the factors involved in hard‐wiring the nervous system during neurogenesis is an accurate calendar of developmental events. We have studied the maxillary and mandibular components of the trigeminal system to determine the stages during embryogenesis when a gross somatotopic order is first established within the trigeminal ganglion and the axons projecting to the brainstem. The retrograde transganglionic fluorescent tracers DiO and DiI were injected into the maxillary and mandibular arches or their derivatives in fixed mouse embryos staged between 13 and 40 somites (E9–E11). After 1–4 wk, the distribution of the 2 tracers was determined using confocal laser scanning microscopy. The first maxillary nerve cell bodies and their developing axons were labelled at the 30 somite stage (E10). This was 2 somite stages earlier than the mesencephalic nucleus and the ganglion cell bodies of the mandibular nerve. The gross somatotopic division of cells within the trigeminal ganglion projecting to the maxillary and mandibular targets was established by the 32 somite stage (E10). This arrangement was evident as 2 groups of cell bodies occupying adjacent but separate regions of the trigeminal ganglion. The central branches of the maxillary and mandibular cell bodies entered the metencephalon as 2 distinct bundles at the same stage. The trigeminal motor nucleus was first detected at the 38 somite stage (E10.5).Gross somatotopy in the major divisions of the trigeminal ganglion is established before outgrowing axons have contacted their peripheral target tissue at E10.5. This suggests that target tissues do not induce somatotopy.
Endothelial barriers: from hypothetical pores to membrane proteins*
Authors: Firth J. A. 
Published: March 2003

AbstractThe anatomical counterpart of the physiologically defined small pore system of capillary endothelia has proved difficult to establish. In non‐brain continuous capillaries, the contributions of caveolar and transmembrane pathways are likely to be small and paracellular clefts are probably the dominant routes. Analogy with epithelial paracellular pathways suggests that tight junctions may be the most restrictive elements. However, structural features of tight junction‐based models are incompatible with physiological data; it is more likely that the tight junction acts as a shutter limiting the available cleft area. Proposed molecular sieves elsewhere in the paracellular pathway include the glycocalyx and the cadherin‐based complexes of the adherens junctions. The molecular architecture of tight junctions and adherens junctions is moderately well defined in terms of molecular species, and there are differences at both sites between the endothelial and epithelial spectra of protein expression. However, definition of the size‐restricting pore remains elusive and may require structural biology approaches to the spatial arrangements and interactions of the membrane molecular complexes surrounding the endothelial paracellular clefts.
Complementary actions of VEGF and Angiopoietin‐1 on blood vessel growth and leakage*
Authors: Thurston Gavin 
Published: March 2003

AbstractVascular endothelial growth factor (VEGF) and Angiopoietins are families of vascular‐specific growth factors that regulate blood vessel growth, maturation and function. To learn more about the effects of these factors in vivo, we have overexpressed VEGF‐A or Angiopoietin‐1 (Ang1) in two systems in mice, and examined the effects on blood vessel growth and function. In one set of studies, VEGF, Ang1, or both factors, were transgenically overexpressed in the skin under the keratin‐14 (K14) promoter. The skin of mice overexpressing VEGF (K14‐VEGF) had numerous tortuous, capillary‐sized vessels which were leaky to the plasma tracer Evans blue under baseline conditions. In contrast, the skin of mice overexpressing Ang1 (K14‐Ang1) had enlarged dermal vessels without a significant increase in vessel number. These enlarged vessels were less leaky than those of wild‐type mice in response to inflammatory stimuli. In double transgenic mice overexpressing VEGF and Ang1, the size and number of skin vessels were both increased; however, the vessels were not leaky. In a second set of studies, VEGF or Ang1 was systemically delivered using an adenoviral approach. Intravenous injection of adenovirus encoding VEGF (Adeno‐VEGF) resulted in widespread tissue oedema within 1–2 days after administration, whereas injection of Adeno‐Ang1 resulted in the skin vessels becoming less leaky in response to topical inflammatory stimuli or local injection of VEGF. The decreased leakage was not accompanied by morphological changes. Thus, overexpressing VEGF appears to promote growth of new vessels accompanied by plasma leakage, whereas overexpressing Ang1 promotes the enlargement of existing vessels and a resistance to leakage. Further understanding of the interrelationship of these factors during normal development could lead to their application in the treatment of ischaemic diseases.
Rheological and ultrastructural properties of bovine vaginal fluid obtained at oestrus
Authors: Rutllant J. , López‐Béjar M. , Santolaria P. , Yániz J. , López‐Gatius F. 
Published: March 2003

AbstractThe properties of cervical–vaginal fluid are under strict hormonal control: and in mammals in which semen is deposited in the anterior vagina, changes produced in these properties can result in a lower or higher resistance to sperm motion. The aim of this study was to determine whether the structural organization of bovine vaginal fluid is related to its rheological properties. Vaginal fluid samples were collected from 41 cows at oestrus: 20 at the middle of oestrus (between 8 and 12 h after starting) and 21 at the end of oestrus (between 18 and 22 h). Flow behaviour was determined using a viscosimeter, and the ultrastructural analysis was performed by scanning electron microscopy. Six samples showed newtonian behaviour: three collected at the middle and three collected at the end of oestrus. Newtonian samples had dense and compact matrices arranged as membranes with rough, irregular surfaces, and sparse, thin filaments (< 150 nm). Non‐newtonian samples collected at the end of oestrus (n = 18) had a higher (P = 0.016) consistency index (K = 944 ± 229 mPa.sn) than those collected at the middle of oestrus (n = 17; K = 237 ± 84 mPa.sn). Thick filaments (> 700 nm) that were either randomly arranged with thinner filaments forming a mesh or heavily cross‐linked by thin filaments (50–150 nm) were observed in all non‐newtonian samples collected at the end of oestrus, while medium‐diameter filaments (between 200 and 500 nm) forming loose networks were observed in non‐newtonian samples collected at the middle of oestrus. These findings indicate a close relationship between the molecular organization of the structural elements of bovine vaginal fluid and its rheological behaviour. Vaginal fluid dramatically reduces its mechanical barrier effect during the course of oestrus but always appears to maintain its three‐dimensional filamentous structure. The images of vaginal fluid showing newtonian behaviour would appear to support previous results, suggesting that this property may be related to bovine infertility.