Ratio of fetal choroid plexus to head size: simple sonographic marker of open spina bifida at 11-13 weeks' gestation

OBJECTIVES

To measure the ratio of choroid plexus (CP) size to head size in normal fetuses and to compare it to that in fetuses with open spina bifida (OSB) and quantify the subjective sign of a 'dry brain'.

METHODS

This was a retrospective study of ultrasound images, obtained during first-trimester screening between 11 and 13 weeks of gestation, from 34 fetuses with OSB and 160 normal fetuses. From the hospital databases, we retrieved images of the fetal head in the transventricular axial plane. We measured the areas of both CPs and the head and calculated the ratio between them. We also measured the longest diameter of each CP and calculated their mean (CP length), and measured the occipitofrontal diameter (OFD) and calculated the ratio of CP length to OFD. Measurements from the OSB fetuses were plotted on crown-rump length (CRL) reference ranges constructed using data from the normal fetuses, and Z-scores were calculated.

RESULTS

In the normal fetuses, the CP area increased, while the ratios of CP area to head area and CP length to OFD decreased, with increasing CRL. In 30 of the 34 (88%) fetuses with OSB, both ratios were increased significantly and the CPs filled the entirety of the head, giving the impression of a dry brain. In these cases, the borders of the lateral ventricles could not be identified.

CONCLUSIONS

At 11-13 weeks, the majority of fetuses with OSB have reduced fluid in the lateral ventricles such that the CPs fill the head. The dry brain sign is easily visualized during routine first-trimester ultrasound examination while measuring the biparietal diameter, and can be quantified by comparing the size of the CPs to the head size. Until prospective data confirm the usefulness of this sign in screening for OSB, it should be considered as a hint to prompt the examiner to assess thoroughly the posterior fossa and spine. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Outcome of intrahepatic portosystemic shunt diagnosed prenatally

We analyzed the characteristics of the population with congenital portosystemic shunt diagnosed during the antenatal period and the organization of their perinatal care. This multicentric retrospective study included all the patients with a prenatal diagnosis of congenital portosystemic shunt. Between 1999 and 2015, 12 patients were included. Prenatal diagnosis was done at a median 26.5 weeks of gestation (21-34). All the patients presented intrahepatic CPSS, three of them had associated congenital cardiopathy, and one a Bannayan-Zonana syndrome. Ten patients had simple outcome on conservative treatment, eight of them having a spontaneous closure of their portosystemic shunt within the first 2 years of life. One patient had surgical treatment which failed and he developed a focal nodular hyperplasia. Another patient had radiological interventional closure of his shunt which was complicated by a venal portal thrombosis.

CONCLUSION

Outcome of intrahepatic portosystemic shunt diagnosed prenatally is good in the majority of cases. What is known: • Multiples studies exist on congenital porto systemic shunt but when the diagnosis is done after birth. • The evolution, management, and complication are well known. What is new: • There is very few studies with only patients diagnosed in antenatal and it is a large series of cases. • Outcome of intrahepatic portosystemic shunt diagnosed prenatally is good in the majority of cases.

Neurophysiological assessment of acute pain in infants: a scoping review of research methods

A systematic scoping search to describe the neurophysiological methods used in infant acute pain assessment research was conducted. Of the 2411 abstracts screened, 19 articles were retained. Nine studies utilised near-infrared spectroscopy (NIRS), two utilised functional magnetic resonance imaging (fMRI), and eight utilised electroencephalography (EEG). There was methodological variability in studies utilising NIRS, whereas EEG and fMRI studies reported consistent methods. Of the eight EEG studies, six identified a nociceptive-specific event-related potential.

CONCLUSION

While more methodologically rigorous studies are needed, ERPs appear to hold some promise as indicators of infant nociception during clinical procedures to supplement existing measures.

Heterotopic ossification following total hip replacement for acetabular fractures

Early total hip replacement (THR) for acetabular fractures offers accelerated rehabilitation, but a high risk of heterotopic ossification (HO) has been reported. The purpose of this study was to evaluate the incidence of HO, its associated risk factors and functional impact. A total of 40 patients with acetabular fractures treated with a THR weres retrospectively reviewed. The incidence and severity of HO were evaluated using the modified Brooker classification, and the functional outcome assessed. The overall incidence of HO was 38% (n = 15), with nine severe grade III cases. Patients who underwent surgery early after injury had a fourfold increased chance of developing HO. The mean blood loss and operating time were more than twice that of those whose surgery was delayed (p = 0.002 and p < 0.001, respectively). In those undergoing early THR, the incidence of grade III HO was eight times higher than in those in whom THR was delayed (p = 0.01). Only three of the seven patients with severe HO showed good or excellent Harris hip scores compared with eight of nine with class 0, I or II HO (p = 0.049). Associated musculoskeletal injuries, high-energy trauma and head injuries were associated with the development of grade III HO.

The incidence of HO was significantly higher in patients with a displaced acetabular fracture undergoing THR early compared with those undergoing THR later and this had an adverse effect on the functional outcome.

Cite this article: Bone Joint J 2013;95-B:95–100.

New first-trimester crown-rump length equations from a French general population

INTRODUCTION

The purpose of this study was to obtain precise knowledge of fetal biometric measurements, in particular crown-rump length (CRL). Our results have been carefully compared to equations found in the literature.

MATERIALS AND METHODS

Single-operator measurements of 2,123 spontaneous pregnancies from a general French population provided new statistical relationships between fetal age (FA) and CRL. Comparisons were made with measurements obtained from 402 in vitro fertilizations (IVFs) for which FA were known. Heteroskedastic and robust regressions were compared by cross-validation, and prediction errors were studied. All ultrasound measurements were taken during standard follow-ups of pregnancies, without any additional features.

RESULTS

From a cleaned subsample of 513 spontaneous pregnancies, we reported good modeling of first-term embryonic growth, with equations and predictions of standard deviations agreeing with objective datations for IVFs. Most precise CRL measurements were predicted for FA of 49 days.

DISCUSSION

Our results allow future detection of fetal growth abnormalities using Z-scores throughout the first trimester.

Small biparietal diameter in fetuses with spina bifida on 11-13-week and mid-gestation ultrasound

OBJECTIVES

To assess whether, at 11-13-week and mid-trimester ultrasound examinations, the biparietal diameter (BPD) in fetuses with open spina bifida is smaller than the reference range.

METHODS

In a multicenter retrospective analysis of data from 23 fetuses with open spina bifida diagnosed at 16-24 weeks, BPD at diagnosis was compared with that measured at 11-13 weeks, before diagnosis. Z-scores were calculated for comparison of BPD deviations from the reference range within the groups at 11-13 weeks and 16-24 weeks, and between these two time intervals.

RESULTS

BPD Z-scores at 11-13 weeks and 16-24 weeks were significantly lower (P < 0.0001) in fetuses with open spina bifida when compared to the reference range, with mean values of - 1.29 and - 2.14, respectively, corresponding to the 10(th) and 1.5(th) centiles, respectively. At 11-13 weeks only six of the 23 (26%) fetuses with open spina bifida had BPD below the 5(th) centile, in comparison to 16 (69%) at mid-gestation. This was confirmed by paired t-test comparing the first-trimester with the second-trimester BPD measurements, which showed significantly slower growth of the BPD in fetuses with spina bifida.

CONCLUSION

In fetuses with open spina bifida, BPD is smaller not only in the second trimester, as previously reported, but also in the first trimester. This is most likely due to loss of cerebrospinal fluid. We suggest that a BPD value < 10(th) centile in an otherwise normally grown fetus at 11-13 weeks' gestation should be considered as a potential subtle early marker for open spina bifida.

Prospective detection of open spina bifida at 11-13 weeks by assessing intracranial translucency and posterior brain

We describe a case series of six fetuses with open spina bifida (OSB) from four different prenatal units, where the anomaly was detected at the routine 11-13-week ultrasound examination. Crown-rump length ranged from 49 to 78 mm. All cases were first suspected during nuchal translucency thickness measurement in the mid-sagittal plane of the face. OSB was lumbosacral in five fetuses and cervical in one. The intracranial translucency (IT) was obliterated in two cases, but some fluid was found in the other four cases. However, in all cases the typical landmarks of a normal posterior brain and normal IT were absent. In all six cases the ratio of brainstem diameter to brainstem-occipital bone distance was increased (≥ 1). This detection of an abnormal posterior brain led to a targeted examination and detection of the spinal lesion during the same examination in five cases, whereas in one suspicious case the patient was recalled at 17 weeks, when the abnormality was detected. Two fetuses had both multiple anomalies and trisomy 18. These prospective cases demonstrate the feasibility of using the standard mid-sagittal plane commonly used for NT measurement to assess the IT and the posterior brain and to determine the presence of OSB during NT screening.

Internal fixation of osteopenic acetabular fractures involving the quadrilateral plate

BACKGROUND

Older patients tend to have acetabular fractures with medial displacement patterns and associated comminution, particularly of the quadrilateral surface. Our goal was to investigate the appropriateness of open reduction and internal fixation using an infra-pectineal buttress plate for osteopenic acetabular fractures.

MATERIALS AND METHOD

We conducted a retrospective review involving twenty one consecutive patients over the course of 4 years with an acetabular fracture in an academic level 1 trauma centre. We performed the modified Stoppa approach with buttress plating of the quadrilateral surface. Clinical examination radiographs was done using criteria described by Matta. Functional outcome was evaluated using surveys including SF-12, WOMAC, Harris Hip score and modified Postel Merle D'Aubigne.

RESULTS

Average follow-up was 4.2 years with a minimum of 2 years. Mean age for patients was 64.3 years. We obtained anatomic reduction in 52.4% (11/21) of cases, imperfect reduction in 38.1% (8/21) of cases and poor reduction in 9.5% (2/21) of cases. Significant loss of reduction was seen in 2 patients. A superior dome impaction (a Gull sign) was correlated to arthroplasty (p=0.02) and reduced quality of initial reduction (p=0.02). Two patients required re-intervention with a total hip arthroplasty. There was one traumatic injury to the obturator nerve and 2 patients were noted to have temporary weakness of the hip adductors postoperatively.

CONCLUSION

Internal fixation using the modified Stoppa approach to buttress the quadrilateral plate should be considered a viable alternative to total hip arthroplasty for the initial treatment of acetabular fractures in the elderly.

Fetal interlens distance: normal values during pregnancy

OBJECTIVES

The aims of this study were to establish normal ranges of values for interlens distance (ILD) during gestation, and to assess the correlation between ILD and growth of the orbits and other fetal biometric parameters.

METHODS

A cross-sectional study of morphologically normal, singleton fetuses was carried out in low-risk pregnant women. We measured the distance between the centers of the fetal lenses from 12 to 37 completed weeks of gestation. An oblique anterior coronal section was used to measure the ILD. The biorbital diameter (BOD) was measured in the same plane. We analyzed the correlation between the ILD and gestational age (GA), BOD, biparietal diameter (BPD), head circumference (HC), femur length (FL) and abdominal circumference (AC). Fetal gender was assessed to evaluate possible significant differences.

RESULTS

Four hundred and fifty normal fetuses were recruited for the study. In 427 fetuses appropriate ILD measurements were obtained, and complete evaluation of all parameters was accomplished in 377 of these. ILD demonstrated a high positive correlation with GA (r(2) = 0.969), BPD (r(2) = 0.959), HC (r(2) = 0.962), AC (r(2) = 0.949) and FL (r(2) = 0.956) as pregnancy advanced. The mean BOD : ILD ratio was 1.50 +/- 0.08, remaining constant throughout pregnancy (linear regression r(2) = 0.006). No statistically significant differences were found between genders for mean ILD and GA of the study population (P = 0.604 and 0.595, respectively).

CONCLUSIONS

The results of this study confirm previous hypotheses regarding the close relationship between eyeball growth and growth of the surrounding bony structures. Measurement of fetal ILD, which can be used interchangeably with BOD measurement in either the axial or coronal plane, can be taken to reflect the expected development of the fetal orbits whilst simultaneously providing valuable information on eyeball development. It is likely that ILD could be used as a complementary tool in the elaboration of various severe abnormalities, mainly related to craniofacial and nervous system malformations.

Assessment of intracranial translucency (IT) in the detection of spina bifida at the 11-13-week scan

OBJECTIVE

Prenatal diagnosis of open spina bifida is carried out by ultrasound examination in the second trimester of pregnancy. The diagnosis is suspected by the presence of a 'lemon-shaped' head and a 'banana-shaped' cerebellum, thought to be consequences of caudal displacement of the hindbrain. The aim of the study was to determine whether in fetuses with spina bifida this displacement of the brain is evident from the first trimester of pregnancy.

METHODS

In women undergoing routine ultrasound examination at 11-13 weeks' gestation as part of screening for chromosomal abnormalities, a mid-sagittal view of the fetal face was obtained to measure nuchal translucency thickness and assess the nasal bone. In this view the fourth ventricle, which presents as an intracranial translucency (IT) between the brain stem and choroid plexus, is easily visible. We measured the anteroposterior diameter of the fourth ventricle in 200 normal fetuses and in four fetuses with spina bifida.

RESULTS

In the normal fetuses the fourth ventricle was always visible and the median anteroposterior diameter increased from 1.5 mm at a crown-rump length (CRL) of 45 mm to 2.5 mm at a CRL of 84 mm. In the four fetuses with spina bifida the ventricle was compressed by the caudally displaced hindbrain and no IT could be seen.

CONCLUSION

The mid-sagittal view of the face as routinely used in screening for chromosomal defects can also be used for early detection of open spina bifida.

Abnormal number of fetal ribs on 3-dimensional ultrasonography: associated anomalies and outcomes in 75 fetuses

OBJECTIVE

The purpose of this study was to describe the clinical importance of an abnormal number of fetal ribs.

METHODS

A retrospective study of all fetuses that were found to have an abnormal number of ribs during routine ultrasonographic examinations was performed. Volume data sets of the fetal ribs were acquired by either static 3- or 4-dimensional volume contrast imaging in plane C. In all cases, a meticulous survey of the fetal anatomy was performed, and prenatal and postnatal records were reviewed.

RESULTS

Seventy-five fetuses were found retrospectively to have an abnormal number of ribs. Ultrasonographic examinations were done between 14 and 31 weeks' gestation (mean, 21.8 weeks; median, 23 weeks). More than 24 ribs were found in 28 fetuses (37%), and fewer than 24 ribs were found in 47 (63%). Additional anomalies were found in 22 fetuses (29%). Cardiovascular anomalies were detected in 10 fetuses. Seven fetuses had renal anomalies. Two fetuses had mild ventriculomegaly, and 1 fetus had holoprosencephaly. Lung dysplasia was found in 2 cases. One fetus had enlarged nuchal translucency with wormian bones. Termination of pregnancy was performed in 3 cases because of major malformations. The other 19 fetuses with associated abnormalities and the 53 without associated anomalies were born alive with only minor anomalies.

CONCLUSIONS

An abnormal number of fetal ribs is an isolated finding in most cases. It may also be seen with major anomalies; however, more frequently the anomalies are minor, and the overall prognosis is good.

Long-term outcome of surgically-treated habitual patellar dislocation in children with coexistent patella alta. Minimum follow-up of 11 years

We retrospectively reviewed the operative treatment carried out between 1988 and 1994 of eight patients with habitual patellar dislocation. In four the condition was bilateral. All patients had recurrent dislocation with severe functional disability. The surgical technique involved distal advancement of the patella by complete mobilisation of the patellar tendon, lateral release and advancement of vastus medialis obliquus. The long-term results were assessed radiologically, clinically and functionally using the Lysholm knee score, by an independent observer. The mean age at operation was 10.3 years (7 to 14) with a mean follow-up of 13.5 years (11 to 16). One patient required revision. At the latest follow-up, all patellae were stable and knees functional with a mean Lysholm knee score of 98 points (95 to 100). In those aged younger than ten years at operation there was a statistically significant improvement in the sulcus angle at the latest follow-up (Student's t-test, p = 0.001). Two patients developed asymptomatic patella infera as a late complication. This technique offers a satisfactory treatment for the immature patient presenting with habitual patellar dislocation associated with patella alta. If performed early, we believe that remodelling of the shallow trochlea may occur, adding intrinsic patellofemoral stability.

Three-dimensional sonographic evaluations of embryonic brain development

OBJECTIVE

The purpose of this presentation is to show 3-dimensional development of the ventricles of the brain in early pregnancy, from 6 to 13 weeks, and to provide a reference for early diagnosis of central nervous system anomalies such as hydrocephalus and holoprosencephaly.

METHODS

From March 2007 to August 2007, 46 patients were included. All patients had routine first-trimester 2- and 3-dimensional sonographic examinations at the same time. All cases were examined with a Voluson 730 Expert or Voluson E8 ultrasound scanner (GE Healthcare, Milwaukee, WI) using a 4- to 8- or 6- to 12-MHz transvaginal probe. Volumes were reviewed and analyzed with GE 4DView release 6 software. After the inversion-rendering mode was selected, volumes were dissected by the MagicCut function to show the ventricles.

RESULTS

A total of 34 volumes from 7 to 12 complete gestational weeks were successfully dissected. Those before 7 and after 12 weeks could not be dissected properly. The crown-rump length ranged from 12.7 to 68 mm. Twelve representative images of the rendered volumes in chronologic order are shown. The brain volume dissections of 2 fetuses with ventriculomegaly and alobar holoprosencephaly are shown for comparison.

CONCLUSIONS

Early human brain ventricular structures could be evaluated in vivo with 3-dimensional sonography. This presentation shows the timeline of brain development and provides reference images to compare possible anomalies of development.

Acrocallosal syndrome in fetus: focus on additional brain abnormalities

Acrocallosal syndrome (ACS) is an autosomal recessive disorder characterized by craniofacial dysmorphism, agenesis or hypoplasia of the corpus callosum, duplication of the phalanges of the hallux, more rarely the thumbs, post-axial polydactyly, syndactyly and severe mental retardation. Here we report the two first descriptions of acrocallosal syndrome in fetus with extensive neuropathological study and provide new data regarding additional brain abnormalities in ACS. The first case was a 25-gestational week male fetus displaying craniofacial and limb abnormalities, with bilateral syndactyly of the fourth and fifth fingers, preaxial polydactyly of the left foot and an inter-frontal extra-bone. The second fetus was a 33-gestational week male fetus. His left hand displayed a broad thumb and 4/5 syndactyly. In both cases, gross examination of the brain showed an absence of corpus callosum associated with interhemispheric cysts. The cerebral cortex in front of the cysts was nodular. Upon microscopic examination, the nodular masses corresponded to large dysplastic areas represented by clusters of undifferentiated neurons in the white matter. The cyst wall showed arachnoidal and ependymal covering and contained numerous choroid plexus, suggesting a developmental abnormality of the ventricles. The pons and the cerebellum were hypoplastic. The dentate nuclei were fragmented. Numerous neuronal heterotopias associated with ectopic ependymal cavities were observed in the vermis in one case. The olivary nuclei were severely dysplastic too. We hope that these new data will make both the ante- and post-natal diagnosis easier, facilitate comparisons with animal models and encourage the identification of the genes responsible for this syndrome.

Intrathoracic fluid may be a normal finding at around 8 gestational weeks

OBJECTIVE

To describe the observation of embryonic thoracic fluid at around 8 weeks' gestation and to discuss the likely etiology.

METHODS

This was a retrospective study of patients referred between August 2005 and May 2006 to our units in France and in the USA for a dating scan between 6 and 10 weeks. Included in our series were all embryos presenting with an ultrasound finding suggestive of an early pericardial fluid collection, i.e. a large anechoic fluid collection surrounding the heart. The gestational age, fetal heart rate and maternal age at this first scan were recorded, along with nuchal translucency thickness as measured at the 12-week scan and the second-trimester anomaly scan results.

RESULTS

Five cases were included in this study. In all five patients, the anechoic fluid collection was visualized at 8 weeks, and by the time of the nuchal scan it had disappeared completely. The nuchal translucency thickness was normal in all cases and all five embryos had normal cardiac examinations during the second trimester and were normal at birth.

CONCLUSIONS

The observation on ultrasound at 8 weeks' gestation of a large anechoic fluid collection surrounding the heart that disappears by week 12 is suggestive of a transient pericardial collection.

Standardization of three-dimensional images in obstetrics and gynecology: consensus statement

Standardization of the display of ultrasound images has so far only been achieved in transabdominal two-dimensional (2D) sonography. In contrast, there is a lack of uniformity in the demonstration of transvaginal 2D ultrasound images. The described non-uniformity frequently leads to confusion in the assessment of an image, in particular with regard to the accurate anatomical assignment of left/right and dorsal/ventral. Three-dimensional (3D) sonography offers a unique opportunity to avoid this confusion in the interpretation of ultrasound images, because, independent of primary volume acquisition, the volume can always be rotated so that the stored object can at all times be visualized in a known anatomical position, rendering it of no importance whether the image acquired transvaginally is demonstrated from above or from below. This will also be important in allowing fusion of ultrasound image data with computed tomographic, magnetic resonance and/or positron emission tomography images. In this article we suggest that standardization of transabdominal and transvaginal 3D images does not only provide the inexperienced physician/sonographer with a guide to spatial orientation, but also serves to avoid erroneous topographical interpretations.

Prise en charge des kystes ovariens

Ovarian cysts occur frequently in women of reproductive age. These are usually functional cysts which resolve spontaneously and whose evolution can be followed with ultrasound. Non-functional cysts have diverse histologic origins. The most common are serous and mucinous cystadenomas which arise from the epithelial wall of the ovary, endometriomas which arise in the setting of pelvic endometriosis, and dermoid cysts which arise from the germinal cells of the ovary. Endovaginal ultrasound with Doppler enhancement is the best imaging technique to establish the nature of cysts and to distinguish cysts suspicious for malignancy which require more invasive investigation. Pelvic laparoscopy is the surgical approach of choice for the treatment of non-functional benign ovarian cysts. Conservative treatment to shell out the cyst and preserve functional ovarian tissue should be reserved for women desirous of future pregnancies. The risk of ovarian cancer remains a major preoccupation of the surgeon. Where malignancy is suspected, laparoscopy is contraindicated and a median laparotomy is appropriate for radical extirpative surgery. This article describes the diagnostic techniques which allow a laparoscopic approach to presumably benign cysts and discusses surgical techniques specifically adapted to their different histologic nature of ovarian cysts.

Metopic suture in fetuses with trisomy 21 at 11 + 0 to 13 + 6 weeks of gestation

OBJECTIVE

To investigate the development of the frontal bones and metopic suture in fetuses with trisomy 21 at 11 + 0 to 13 + 6 weeks of gestation.

METHODS

Three-dimensional (3D) ultrasound was used to measure the height of and gap between the frontal bones in 75 fetuses with trisomy 21 and these were compared to the measurements in 200 normal fetuses at 11 + 0 to 13 + 6 (median, 12 + 6) weeks of gestation.

RESULTS

In the fetuses with trisomy 21, compared to the normal fetuses, there was no significant difference in either the height of the frontal bones (mean difference 0.16 SD, range -1.78 to 2.17 SD; P = 0.369) or the gap between them (mean difference 0.012, 95% CI -0.073 to 0.097; P = 0.780). Additionally, within the group of trisomy 21 fetuses there were no significant differences in the development of the frontal bones and metopic suture between those with absent (n = 46) and those with present (n = 29) nasal bone.

CONCLUSIONS

In trisomy 21 the development of the frontal bones and metopic suture is as normal and is independent from the development of the nasal bones.

Pregnancy after embolization therapy for uterine arteriovenous malformation

OBJECTIVE

To describe childbearing prognosis following embolization therapy for uterine arteriovenous malformation (AVM).

DESIGN

Case report and review.

SETTING

University hospital.

PATIENT(S)

Thirteen patients, including our case, who underwent pregnancy after embolization therapy for arteriovenous malformation.

INTERVENTION(S)

Two successive embolization procedures.

MAIN OUTCOME MEASURE(S)

Childbearing prognosis following embolization therapy for uterine AVM.

RESULT(S)

Bilateral embolization was performed in seven patients. In four cases, including ours, two successive embolization procedures were required to treat the uterine AVM. The longest delay between embolization and pregnancy was 5 years and the shortest was six weeks. Two patients presented with postpartum hemorrhage which was treated medically. One neonate required resuscitation after delivery in the context of Listeria infection.

CONCLUSION(S)

Conservative management of uterine AVMs using embolization therapy is being increasingly developed. New embolization agents and hyperselective technical procedures aim at reducing morbidity related to such treatments and preserving reproductive capacity in women of childbearing age.

Metopic suture in fetuses with holoprosencephaly at 11 + 0 to 13 + 6 weeks of gestation

OBJECTIVE

To investigate the development of the metopic suture in fetuses with holoprosencephaly at 11 + 0 to 13 + 6 weeks of gestation.

METHODS

Three-dimensional (3D) ultrasound was used to measure the height and gap between the frontal bones in 200 normal fetuses and in nine fetuses with holoprosencephaly at 11 + 0 to 13 + 6 (median, 12) weeks of gestation.

RESULTS

In the 200 normal fetuses, the height of the frontal bones increased significantly with gestation from a mean of 2.5 mm (5(th) and 95(th) centiles: 1.9 mm and 3.3 mm) at 11 weeks to 6.1 mm (5(th) and 95(th) centiles: 4.6 mm and 8.1 mm) at 13 + 6 weeks. The gap between the two frontal bones did not change significantly with gestation (mean: 1.5 mm; 5(th) centile: 1.0 mm; 95(th) centile: 2.0 mm). In fetuses with holoprosencephaly, the height of the frontal bones was significantly larger (mean difference, 5.6 SDs; range, 3.9-7.7 SDs; P < 0.0001) and the gap was significantly smaller (mean 0.2 mm, range 0-0.8 mm; P < 0.0001) than those in normal fetuses.

CONCLUSIONS

Holoprosencephaly is associated with an accelerated development of the frontal bones and premature closure of the metopic suture.

Metopic suture in fetuses with Apert syndrome at 22-27 weeks of gestation

OBJECTIVES

To examine the possible association of skull deformity and the development of the cranial sutures in fetuses with Apert syndrome.

METHODS

Three-dimensional (3D) ultrasound was used to examine the metopic and coronal sutures in seven fetuses with Apert syndrome at 22-27 weeks of gestation. The gap between the frontal bones in the transverse plane of the head at the level of the cavum septi pellucidi was measured and compared to findings in 120 anatomically normal fetuses undergoing routine ultrasound examination at 16-32 weeks.

RESULTS

In the normal group, the gap between the frontal bones in the metopic suture at the level of the cavum septi pellucidi, decreased significantly with gestation from a mean of 2.2 mm (5th and 95th centiles: 1.5 mm and 2.9 mm) at 16 weeks to 0.9 mm (5th and 95th centiles: 0.3 mm and 1.6 mm) at 32 weeks. In the seven cases with Apert syndrome, two-dimensional ultrasound examination demonstrated the characteristic features of frontal bossing, depressed nasal bridge and bilateral syndactyly. On 3D examination there was complete closure of the coronal suture and a wide gap in the metopic suture (15-23 mm).

CONCLUSION

In normal fetuses, cranial bones are believed to grow in response to the centrifugal pressure from the expanding brain and proximity of the dura to the suture is critical in maintaining its patency. In Apert syndrome, the frontal bossing may be a mere consequence of a genetically predetermined premature closure of the coronal suture. Alternatively, there is a genetically predetermined deformation of the brain, which in turn, through differential stretch of the dura in the temporal and frontal regions, causes premature closure of the coronal suture and impaired closure of the metopic suture.

Three-dimensional sonographic description of abnormal metopic suture in second- and third-trimester fetuses

OBJECTIVE

To describe patterns of abnormal development of the metopic suture in association with fetal malformations during the second and third trimesters of pregnancy.

METHODS

This was a cross-sectional study of the frontal bones and metopic suture in 11 fetuses at 17-32 weeks of gestation. Cases were selected because there were obvious abnormalities in the metopic sutures. In each case, a malformation was detected by two-dimensional (2D) ultrasound and the abnormality of the metopic suture was detected and evaluated on three-dimensional (3D) ultrasound, using transparent maximum mode.

RESULTS

There were essentially four patterns of abnormality in the metopic suture: firstly, delayed development with a V- or Y-shaped open suture, which is found in normal fetuses at 12-16 weeks; secondly, a U-shaped open suture, presumably due to upward growth of the frontal bones with delayed closure; thirdly, premature closure of the suture, which is normally observed after 32 weeks; fourthly, the presence of additional bone between the frontal bones. Premature closure of the suture or additional bone between the frontal bones was observed in fetuses with holoprosencephaly and abnormalities of the corpus callosum, whereas the V-, Y- and U-shaped metopic sutures were observed in fetuses with facial defects involving the orbits, nasal bones, lip, palate and mandible, in the absence of holoprosencephaly and abnormal corpus callosum.

CONCLUSIONS

This preliminary study describes the pattern of possible abnormalities of the metopic suture and should stimulate further investigation to establish the prevalence and evolution of abnormal sutures as well as the incidence and pattern of other associated defects.

Three-dimensional sonographic description of the fetal frontal bones and metopic suture

OBJECTIVE

To describe the morphology of the frontal bones and metopic suture at 9-34 weeks of gestation using three-dimensional (3D) ultrasonography.

METHODS

This was a cross-sectional study of the frontal bones and metopic suture in 16 fetuses at 9-34 weeks of gestation. 3D ultrasonography was used to obtain volumes of the whole fetal skull in the mid-sagittal plane. The volumes were analyzed using the rendering mode and transparent maximum mode in order to achieve a clear view of the frontal bones and the metopic suture.

RESULTS

At 9 weeks, a small ossification center was visible in the middle of each supraorbital part of the frontal bones and by 11 weeks the frontal bones appeared as 'thick eyebrows'. In the second trimester there was progressive radial bone expansion and delineation of the metopic suture and in the third trimester there was closure of the metopic suture, starting from the glabella and moving upwards towards the anterior fontanelle.

CONCLUSIONS

This study provides 3D ultrasound images that illustrate the process of ossification of the frontal bones and the subsequent development of the metopic suture during prenatal life.

In vivo haematopoietic potential of human neural stem cells

The fetal sheep model was used to compare the in vivo haematopoietic potential of human neural stem cells (NSC) versus bone marrow (BM)-derived haematopoietic stem cells (HSC). To this end, sheep were transplanted with either 8 x 10(5) NSC (n = 11) or HSC, CD34(+)Lin(-) (n = 5), and subsequently analysed for haematopoietic chimaerism. While HSC-transplanted sheep displayed robust donor-derived haematopoiesis starting at less than 2 months post-transplant, NSC recipients exhibited haematopoietic engraftment at much later time points. Nevertheless, chimaerism persisted in both groups throughout the course of this study. Transplantation of secondary recipients with human CD45(+)/HLA-DR(+) cells from the BM of NSC primary recipients at 14 and 16 months post-transplant demonstrated that long-term engrafting HSC were present in these animals. At 6 months post-transplant, both NSC- and HSC-transplanted sheep were mobilised with granulocyte colony-stimulating factor. In contrast to HSC-transplanted animals, levels of human blood cells in peripheral blood of NSC-transplanted sheep remained low throughout mobilisation. Our results show that, although human NSC were able to give rise to multilineage haematopoiesis in our model, the levels, timing of blood cell production and the ability to respond to cytokine mobilisation were different, suggesting that human NSCs latent haematopoietic potential is inherently different from that of true HSC.

Early prenatal diagnosis of oculoauriculofrontonasal syndrome by three-dimensional ultrasound

Oculoauriculofrontonasal syndrome is a rare developmental field defect that represents an abnormal morphogenesis of the frontonasal eminence. It consists of features of both oculoauriculovertebral spectrum and frontonasal malformation. A few cases in the literature have described this syndrome, but to the best of our knowledge the present case is the first early prenatal diagnosis of this severe condition using three-dimensional ultrasonography.

Three-dimensional ultrasound with maximal mode rendering: a novel technique for the diagnosis of bilateral or unilateral absence or hypoplasia of nasal bones in second-trimester screening for Down syndrome

OBJECTIVE

Three-dimensional (3D) ultrasound of the fetal face with maximal mode rendering allows accurate visualization of the bony face and the distinct demonstration of both nasal bones in second-trimester fetuses. The aim of this study was to analyze the feasibility of assessing nasal bones spatially on prenatal ultrasound in second- and third-trimester fetuses with present and absent nasal bones.

METHODS

The faces of 38 fetuses between 17 and 33 weeks' gestation were examined with 3D ultrasound and volumes were stored for offline evaluation. Eighteen fetuses had normal karyotype and an apparently normal nasal bone on 2D ultrasound; these were examined to standardize the 3D rendering technique. Twenty fetuses had trisomy 21.

RESULTS

In all 18 healthy fetuses both nasal bones could be demonstrated on 3D ultrasound. Nine of the 20 Down syndrome fetuses had a hypoplastic or absent nasal bone on two-dimensional ultrasound. On 3D ultrasound three of the nine had discrepant findings between left and right nasal bones with evidence of absence of one side, and hypoplasia (n = 2) or normal length (n = 1) of the other.

CONCLUSIONS

Unilateral absence or hypoplasia of nasal bones is an important and new observation in fetuses with Down syndrome. This differentiation is best demonstrated on 3D ultrasound with maximal mode rendering. This observation of unilaterality of findings could explain some discrepant findings on absence of nasal bones on two-dimensional ultrasound but their "presence" on lateral postmortem radiographs.

Prenatal Sonographic Patterns in Six Cases of Wolf-Hirschhorn (4p–) Syndrome

This multicentric study presents 6 cases of Wolf-Hirschhorn syndrome (deletion of 4p) detected after a sonographic prenatal diagnosis of early intrauterine growth retardation with fetal abnormalities. Standard karyotyping on regular G-banding during pregnancy was normal in half of the cases. Fortunately, the associated sonographic signs of a typical face, cystic cerebral lesions, midline fusion defects and bilateral renal hypoplasia may help to refine specific indications for high-resolution banding and molecular analysis by in situ hybridization.

The value of three-dimensional ultrasonography in the screening of the fetal skeleton

3D ultrasound is a new technical advance that gives complementary information to that provided by the 2D ultrasound. It may help to correctly diagnose fetal anomalies. VALUE OF 3D ULTRASOUND: Its major advantages are as follows: any section plane can be created within the volume, making it possible to realize sections perpendicular to the ultrasound beam; multiplanar view; storage of volumes that can be reviewed afterward and may be useful for educational purposes.

Three-dimensional sonoembryology

Three-dimensional (3D) ultrasound plays an important role in obstetrics, predominantly for assessing fetal anatomy. Presenting volume data in a standard anatomic orientation valuably assists both ultrasonographers and pregnant patients to recognize the anatomy more readily. Three-dimensional ultrasound is advantageous in studying normal embryonic and/or fetal development, as well as providing information for families at risk for specific congenital anomalies by confirming normality. This method offers advantages in assessing the embryo in the first trimester due to its ability to obtain multiplanar images through endovaginal volume acquisition. Rotation allows the systematic review of anatomic structures and early detection of fetal anomalies. Three-dimensional ultrasound imaging in vivo compliments pathologic and histologic evaluation of the developing embryo, giving rise to a new term: 3D sonoembryology. Rapid technological development will allow real-time 3D ultrasound to provide improved and expanded patient care on the one side, and increased knowledge of developmental anatomy on the other.

Harlequin fetus: three-dimensional sonographic findings and new diagnostic approach

Congenital ichthyosis, otherwise known as harlequin fetus, is a severe, generally lethal, anomaly. Prenatal diagnosis is usually possible in families at risk but requires invasive fetoscopy for skin biopsy. The application of three-dimensional ultrasound enables a greatly improved analysis of the facial morphology and thus provides an important contribution to prenatal diagnosis. Although such three-dimensional diagnostic procedures are performed in specialized centers, sonographers should be aware of the signs observed at routine two-dimensional ultrasound examination in order to ensure appropriate referral for diagnosis. We describe two consecutive pregnancies of the same parents in which two- and three-dimensional ultrasound were used in the prenatal diagnosis of harlequin fetus.

Detection of clonal T-cell receptor gamma gene rearrangements using fluorescent-based PCR and automated high-resolution capillary electrophoresis

BACKGROUND

Analysis of T-cell receptor gamma (TCR gamma) gene rearrangements by PCR is a powerful tool for detecting clonal T-cell populations for the diagnosis of lymphoid neoplasms. We report a method for TCR gamma PCR analysis using capillary electrophoresis (CE).

METHODS AND RESULTS

To define the threshold for identification of a predominant monoclonal population within a polyclonal background, we developed a novel objective parameter of the peak height ratio (Rn) of the peak of interest and the average of the two immediate flanking peaks. After evaluation of monoclonal, reactive, and normal T-cell populations, an Rn of 3.0 or greater was determined to be consistent with a monoclonal population, whereas an Rn between 1.9 and 3.0 was considered an intermediate range. This CE method was compared with the standard denaturing gradient gel electrophoresis (DGGE) method using previously evaluated clinical specimens. Eleven of 12 clinical specimens (92%) with a definitive diagnosis of T-cell lymphoma were monoclonal by CE, with 100% concordance with the DGGE method. Of nine specimens morphologically suspicious for T-cell lymphoma, five specimens were positive by CE analysis compared with four specimens by DGGE. In addition, 14 specimens for staging from patients with known T-cell lymphoma were studied using both the CE and DGGE methods, with a concordance of 86%.

CONCLUSION

CE is a powerful and efficient method for analysis of clonality by TCR gamma PCR.

Influence of timing of administration of 5-fluorouracil to donors on bone marrow engraftment in nonmyeloablated hosts

We evaluated the engraftment and the cell cycle status of marrow cells at various times after 5-fluorouracil (5-FU) administration. 5-FU (150 mg/kg) was given to donor male BALB/c mice at 1, 2, 6, or 12 days prior to marrow harvest. The donor cells were then assessed in host nonmyeloablated female mice. Bone marrow engraftment of marrow treated with 5-FU was evaluated and compared to marrow treated with diluent (phosphate-buffered saline) at 3 and 10 weeks after marrow infusion. Our data show a rapid induction of an engraftment defect 1 day after 5-FU, persistence of this defect through day 6, and a recovery by day 12. Experiments using hydroxyurea (which selectively kills cells in the S phase) to determine the cell cycle status indicated that cells that engrafted in post-5-FU marrow were noncycling at days 1, 2, and 12 but cycling at day 6. Post-5-FU bone marrow was also analyzed in vitro by colony assays and its cycling status determined by 3H-thymidine suicide assay. High-proliferative-potential colony-forming cells (HPP-CFCs) and low-proliferative-potential colony-forming cells (LPP-CFCs) decreased rapidly 1 day after 5-FU, with a nadir observed at day 6 for HPP-CFCs and day 2 for LPP-CFCs. By day 12, LPP-CFCs showed a total recovery, but HPP-CFCs were still defective. Significant numbers of HPP-CFCs were cycling, mostly at days 6 and 8 after 5-FU, whereas LPP-CFCs appeared quiescent except at day 2. These results emphasize the importance of timing if post-5-FU marrow is used for gene therapy or marrow transplantation.

Molecular characterization and phylogenetic analysis of a human T cell leukemia virus type 2 strain from French Guiana

Extensive studies have been carried out on native Amerindian populations living in French Guiana in an attempt to detect human T cell leukemia virus type 2 (HTLV-2). However, the first strain of this virus identified in this region was not detected in these populations, but in a Brazilian woman of Amerindian origin. Comparative analyses of the nucleotide sequences of 589 bp of the gp21 env gene and of 625 bp of the long terminal repeat (LTR) showed that this new HTLV-2 strain (HTLV-2 GUY) was of subtype A. Sequence comparison and phylogenetic analyses demonstrated that HTLV-2 GUY was closely related to a group of distinct variants of HTLV-2 subtype A strains originating mostly from Brazilian inhabitants and formerly called HTLV-2 subtype C. As there is a high level of immigration from Brazil in French Guiana, we carried out a seroepidemiological study of 175 Brazilians, mostly women (obtained from a serum databank) and 72 female Brazilian prostitutes living in French Guiana to determine whether HTLV-2 is likely to become an emerging infection in this area. No HTLV-2 infection was detected, indicating that this virus is unlikely to become prevalent in the near future.

Halo structure of (14)Be

The two-neutron halo nucleus (14)Be has been investigated in a kinematically complete measurement of the fragments ((12)Be and neutrons) produced in dissociation at 35 MeV/nucleon on C and Pb targets. Two-neutron removal cross sections, neutron angular distributions, and invariant mass spectra were measured, and the contributions from electromagnetic dissociation (EMD) were deduced. Comparison with three-body model calculations suggests that the halo wave function contains a large nu(2s(1/2))(2) admixture. The EMD invariant mass spectrum exhibited enhanced strength near threshold consistent with a nonresonant soft-dipole excitation.

Tissue-specific autoregulation of Drosophila suppressor of forked by alternative poly(A) site utilization leads to accumulation of the suppressor of forked protein in mitotically active cells

The Suppressor of forked protein is the Drosophila homolog of the 77K subunit of human cleavage stimulation factor, a complex required for the first step of the mRNA 3'-end-processing reaction. We have shown previously that wild-type su(f) function is required for the accumulation of a truncated su(f) transcript polyadenylated in intron 4 of the gene. This led us to propose a model in which the Su(f) protein would negatively regulate its own accumulation by stimulating 3'-end formation of this truncated su(f) RNA. In this article, we demonstrate this model and show that su(f) autoregulation is tissue specific. The Su(f) protein accumulates at a high level in dividing tissues, but not in nondividing tissues. We show that this distribution of the Su(f) protein results from stimulation by Su(f) of the tissue-specific utilization of the su(f) intronic poly(A) site, leading to the accumulation of the truncated su(f) transcript in nondividing tissues. Utilization of this intronic poly(A) site is affected in a su(f) mutant and restored in the mutant with a transgene encoding wild-type Su(f) protein. These data provide an in vivo example of cell-type-specific regulation of a protein level by poly(A) site choice, and confirm the role of Su(f) in regulation of poly(A) site utilization.

The Drosophila poly(A)-binding protein II is ubiquitous throughout Drosophila development and has the same function in mRNA polyadenylation as its bovine homolog in vitro

The poly(A)-binding protein II (PABP2) is one of the polyadenylation factors required for proper 3'-end formation of mammalian mRNAs. We have cloned Pabp2, the gene encoding the Drosophila homolog of mammalian PABP2, by using a molecular screen to identify new Drosophila proteins with RNP-type RNA-binding domains. Sequence comparison of PABP2 from Drosophila and mammals indicates that the most conserved domains are the RNA-binding domain and a coiled-coil like domain which could be involved in protein-protein interactions. Pabp2 produces four mRNAs which result from utilization of alternative poly(A) sites and encode the same protein. Using an antibody raised against Drosophila PABP2, we show that the protein accumulates in nuclei of all transcriptionally active cells throughout Drosophila development. This is consistent with a general role of PABP2 in mRNA polyadenylation. Analysis of Drosophila PABP2 function in a reconstituted mammalian polyadenylation system shows that the protein has the same functions as its bovine homolog in vitro : it stimulates poly(A) polymerase and is able to control poly(A) tail length.