Mitochondrial protection impairs BET bromodomain inhibitor-mediated cell death and provides rationale for combination therapeutic strategies.

Inhibitors of the bromodomain and extraterminal domain family (BETI) have recently entered phase I clinical trials. In patients with advanced leukemia's, potent antileukemia activity was displayed with minimum dose-limiting toxicity. In preclinical models of hematological malignancies, including aggressive B-cell lymphomas, BETI induced cell-cycle arrest and apoptosis. However, the underlying cell death mechanisms are still not well understood. Dissecting the mechanisms required by BETI to mediate cell death would provide strong direction on how to best utilize BETI to treat patients with aggressive hematological malignancies. Herein, we provide understanding of the molecular mechanisms underlying BETI-mediated cell death using I-BET762. Induction of cell death occurred in primary murine and human B-cell lymphomas through apoptosis. Genetic dissection using Eµ-myc B-cell lymphoma compound mutants demonstrated that I-BET762-induced apoptosis does not require the p53 pathway. Furthermore, deletion of Apaf1, and thus the absence of a functional apoptosome, is associated with a delayed drug response but do not provide long-term resistance. Prolonged treatment of this model in fact fails to suppress the therapeutic efficacy of the drug and is associated with biochemical features of autophagy. However, lack of mitochondrial permeability completely inhibited I-BET762-mediated tumor cell death, indicating mitochondrial damage as key events for its activity. Combination of I-BET762 with BH3-only mimetics ABT-263 or obatoclax, restored sensitivity to I-BET762 lymphoma killing; however, success was determined by expression of Bcl-2 family antiapoptotic proteins. Our study provides critical insight for clinical decisions regarding the appropriate strategy for using BETI as a single agent or in combination to treat patients with aggressive B-cell lymphomas.

Vasa previa: prenatal diagnosis, natural evolution, and clinical outcome.

OBJECTIVE: To describe the prenatal ultrasonographic diagnosis, natural evolution, and clinical outcomes of vasa previa in a large population at a single institution. METHODS: We attempted to view the internal cervical os of 93,874 women with second- and third-trimester pregnancies during an 8-year period. Echogenic parallel or circular lines near the cervix, seen by gray-scale ultrasonography, raised the possibility of vasa previa. Diagnosis was confirmed by Doppler and endovaginal studies if aberrant vessels over the internal cervical os were suspected. Abnormal placental morphology and velamentous cord insertion were documented if they were identified during prenatal scans. Ultrasonographic findings were correlated with clinical courses, perinatal outcomes, and placental pathology examinations. RESULTS: Eighteen cases of vasa previa were suspected at a mean (+/- standard deviation) gestational age of 26.0 +/- 6.3 weeks; the earliest diagnosis was at 15.6 weeks' gestation. Eight of those cases initially showed placental edge over the internal os and later developed vasa previa after the placenta "receded" from the cervix. Six women had mild vaginal bleeding at a mean gestational age of 31.3 weeks. Three women had normal late third-trimester scans and were allowed to have uncomplicated vaginal deliveries. The remaining subjects delivered by cesarean. There were two deaths (one fetal and one neonatal), and minor preterm complications slightly prolonged infant hospitalizations. One set of preterm twins needed neonatal transfusions. Pathology findings included ten cases of velamentous insertion and three cases each of bilobed placentas, succenturiate lobes, and marginal cord insertion. CONCLUSION: Vasa previa was detected in asymptomatic women as early as the second trimester. Perinatal outcome was generally favorable, although several infants had slightly extended newborn nursery admissions due to mild complications of prematurity.

Fetal cleft lip and palate detection by three-dimensional ultrasonography.

OBJECTIVES: To demonstrate a standardized approach for the evaluation of cleft lip and palate by three-dimensional (3D) ultrasonography. DESIGN: This was a retrospective study of seven fetuses with confirmed facial cleft anomalies. Post-natal findings were compared to a blinded review of 3D volume data from abnormal fetuses with seven other normal fetuses that were matched for gestational age. Upper lip integrity was examined by 3D multiplanar imaging. Sequential axial views were used to evaluate the maxillary tooth-bearing alveolar ridge contour and anterior tooth socket alignment. Alveolar ridge disruption suggested cleft palate. Premaxillary protrusion, either by multiplanar imaging or surface rendering, indicated bilateral cleft lip and palate. RESULTS: Post-natal findings confirmed bilateral cleft lip and palate (four cases), unilateral cleft lip and palate (one case), and unilateral cleft lip (two cases). Multiplanar review identified all three fetuses with unilateral cleft lip, three of four fetuses with bilateral cleft lip, one fetus with unilateral cleft palate, and three of four fetuses with bilateral cleft palate. Surface rendering correctly identified all cleft lips, with the exception of one fetus, who was thought to have a unilateral cleft lip and palate, despite the actual presence of a bilateral lesion. One cleft palate defect was directly visualized by 3D surface rendering. No false-positives occurred. CONCLUSION: Interactive review of standardized 3D multiplanar images allows one to evaluate labial defects, abnormalities of the maxillary tooth-bearing alveolar ridge, and presence of premaxillary protrusion for detecting cleft lip and palate anomalies. Surface rendering may increase diagnostic confidence for normal or abnormal studies. This technology provides an array of visualization tools that may improve the prenatal characterization of facial clefts, particularly of the palate.

Vasa previa: prenatal detection by three-dimensional ultrasonography.

OBJECTIVE: To describe three-dimensional (3D) ultrasonography (US) for the antepartum diagnosis of vasa previa. DESIGN: This was a descriptive study of two pregnant women who were suspected to have vasa previa by conventional gray-scale ultrasonography. Three-dimensional studies were also performed during the early third trimester to further investigate the possibility of this condition. RESULTS: In the first case, 3D US provided gray-scale multiplanar and surface-rendered views of an aberrant vessel over the internal cervical os. For the second case, a 'flight-path' technique allowed the examiner to follow axial views of the endocervical canal toward the internal os until an aberrant vessel was verified. The 'niche-mode' analysis, with and without color power Doppler ultrasonography, was also used to confirm the diagnosis. CONCLUSION: Three-dimensional ultrasonography offers several additional imaging tools that are not currently provided by more conventional ultrasonography for the detection of vasa previa. It represents an important adjunct to two-dimensional (2D) studies, especially when this diagnosis is questionable.

Fetal cardiac asymmetry: a marker for congenital heart disease.

OBJECTIVE: To determine the sensitivity of prenatally detected fetal cardiac asymmetry as a sonographic marker for congenital heart disease. METHODS: The normal ratios of pulmonary artery to aorta diameters and of right ventricle to left ventricle diameters were derived from normal fetuses scanned at 17 weeks or more in a 65-month period. Cross-sectional diameters of cardiac ventricles and great arteries were measured at the level of the valves at the time of the scan. Fetuses with confirmed cardiac anomalies detected prenatally during the study were examined to identify how many had cardiac asymmetry, determined by abnormal ratios. RESULTS: Linear regression analysis of the group of 881 normal fetuses showed the normal pulmonary artery to aorta diameter ratio remained constant throughout pregnancy and the normal right ventricle to left ventricle ratio increased slightly with progressing gestational age. The 90% confidence intervals were 0.79, 1.24 for the right ventricle to left ventricle ratio and 0.84, 1.41 for the pulmonary artery to aorta ratio. Of the 73 fetuses with abnormal hearts, 66% had either ventricular or great artery asymmetry (at least one of the two ratios was abnormal). However, if no asymmetry was present, the cardiac defect was more likely to be a minor one. CONCLUSION: Cardiac asymmetry was present in two-thirds of fetuses with cardiac anomalies diagnosed prenatally. If cardiac asymmetry is found, a more thorough examination of the fetal heart is indicated.

Double-outlet right ventricle: an antenatal diagnostic dilemma.

OBJECTIVE: The purpose of this study was to describe the antenatal ultrasonographic findings of fetuses with double-outlet right ventricle (DORV). DESIGN: The records were reviewed of all fetuses scanned in our ultrasound unit which were suspected of having DORV during a 6-year period ending in April 1996. A medical record search for all infants with a postnatal diagnosis of DORV was also undertaken to identify cases that were not detected antenatally. Records were examined to determine the accuracy of antenatal diagnosis and the reasons for diagnostic errors. Fetuses without follow-up were excluded. RESULTS: There were 20 fetuses with antenatally detected conotruncal defects that had DORV included in the differential diagnosis. Three fetuses were excluded, seven did not have DORV and ten were confirmed postnatally as having DORV. Two additional infants were found to have DORV from the medical record search, producing a total of 12 cases. Antenatal sonographic cardiac findings included malpositioned (overriding or transposed) great arteries (n = 11), ventricular septal defect (n = 11) and small pulmonary artery suggesting stenosis (n = 4). Confirmed postnatal cardiac findings that were missed antenatally included aortic coarctation (n = 2), right-sided aortic arch (n = 2) and pulmonary stenosis (n = 1). Seven of the 12 fetuses had extracardiac findings. Nine of the 12 fetuses tested had a normal karyotype. Eleven of the 12 infants were liveborn. Nine of these 11 survived the neonatal period and underwent surgical repair within the first year of life; two subsequently died. In total, seven fetuses survived and five did not. CONCLUSIONS: Most fetuses with DORV can be identified antenatally as having an abnormal heart. However, it is very difficult to distinguish this particular defect from other conotruncal abnormalities.

Right fetal cardiac axis: clinical significance and associated findings.

OBJECTIVE: To ascertain the clinical significance of right fetal cardiac axis. METHODS: Fetal cardiac axis was assessed prospectively in ultrasound examinations of 16,562 fetuses over a 6-year period. RESULTS: Twenty-two fetuses had a right cardiac axis. When classified by ventricular and atrial configuration, six fetuses had mirror-image hearts with situs inversus, 12 had rotation of the heart axis alone, and four had inversion of the ventricles. Fourteen of the 22 had underlying structural cardiac defects, most of which were atrioventricular septal defects, double outlet right ventricles, or common atria. The chromosomes and/or phenotypes of all 22 were normal. All four fetuses with polysplenia and asplenia died. Major extracardiac defects were few (two) but lethal. CONCLUSION: Right cardiac axis in the fetus is associated with a high incidence of structural cardiac defects. In the absence of severe extracardiac defects, polysplenia, or asplenia, neonatal outcome was good.

Birthweight prediction by three-dimensional ultrasonographic volumes of the fetal thigh and abdomen.

Our validation study examined a three-dimensional ultrasonographic phantom that contained irregularly shaped volume targets ranging from 0.5 to 76.1 milliliters. Four different examiners made blinded measurements from volume datasets that were acquired by 4 and 7 MHz transducers. Birthweight predictions using abdominal and thigh volumes from 18 term fetuses also were compared with two-dimensional ultrasonographic methods. In vitro volume measurements were accurate, precise, and repeatable despite a small systematic overestimation with increasing object size. Mean systematic error and precision for birthweight predictions by three-dimensional ultrasonography (-0.03% +/- 6.1%) were not significantly different from those by two-dimensional ultrasonography (-0.60% +/- 8.8%). Conventional prediction methods yielded three birthweights with greater than 15% error. By comparison, except for one infant whose birthweight indicated an 11% error, all predictions based on fetal volume parameters were within 10% of true values. Accurate birthweight predictions by fetal volume parameters appear to be technically feasible at term gestation although their practical clinical application requires further investigation. Birthweight predictions in this manner may allow remote consultants to evaluate the fetus over wide-area computer networks despite the physical absence of the patient.

Maternal diabetes mellitus: which views are essential for fetal echocardiography?

OBJECTIVE: To determine which fetal echocardiography views are essential to detect the majority of cardiac defects in fetuses of women with diabetes mellitus. METHODS: Fetal echocardiograms performed from February 1990 through May 1996 on insulin-requiring women with diabetes were reviewed. Individual component views of the examination were analyzed for the detection of fetal congenital heart defects. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated. Multiple gestations and patients with additional risk factors for congenital heart defects were excluded. RESULTS: A total of 223 patients were included in the study. There were 11 (4.9%) congenital heart defects, eight of which were conotruncal. When the four-chamber view and outflow tracts appeared normal, additional views such as the ductal and aortic arches did not detect a cardiac defect. The sensitivity of the four-chamber view for detecting an abnormal heart increased from 73% to 82% with the addition of the aortic outflow tract. There were two false-negative and no false-positive diagnoses. CONCLUSION: The four-chamber and outflow tracts are the essential views that will detect most cardiac defects in fetuses of women with insulin-requiring diabetes mellitus.

Sonographic screening to detect fetal cardiac anomalies: a 5-year experience with 111 abnormal cases.

OBJECTIVE: To determine whether there is a difference between the types of cardiac lesions detected as abnormal prenatally and those that are not detected. METHODS: Consecutive fetuses at 14 weeks' gestation or more were scanned in our unit from February 1990 through July 1995 and later were delivered at our hospital. Outcome information was obtained from neonatal echocardiograms and autopsies. Our results were compared to sensitivities for individual cardiac lesions based on pooled data from studies published previously. RESULTS: There were 111 fetuses with cardiac anomalies, of which 73 (66%) were identified correctly as abnormal prenatally. Sensitivities for the most common cardiac lesions were as follows: 87% atrioventricular septal (endocardial cushion) defects, 65% tetralogy of Fallot, 63% transposition of the great arteries, 50% aortic coarctation, and 44% isolated ventricular septal defects. The lesions that went undetected most frequently were isolated septal defects (n = 17); most of these were ventricular and small or moderate in size. Based on our sensitivities and those calculated from previous studies, the fetal cardiac lesions with the highest detection rates involve hypoplastic ventricles and atrioventricular septal defects, followed by lesions of the great arteries and finally by isolated septal defects. CONCLUSIONS: The sensitivity of sonographic screening to defect fetal cardiac anomalies varies with the type of lesion. Isolated septal defects are the most difficult lesions to detect.

Transvaginal ultrasonography for all placentas that appear to be low-lying or over the internal cervical os.

The purpose of this study was to determine in what percentage of cases the assessment of placental localization using transabdominal sonography (TAS) was changed after transvaginal sonography (TVS) was applied. TVS was prospectively performed on all pregnant women of at least 15 weeks' gestation, when the placental edge using TAS appeared to be over or within 2 cm (low-lying) of the internal cervical os. The time required for the TVS scan and the distance of the placental edge from the internal cervical os were recorded. Of the 168 patients entered into the study, 131 were analyzed. Landmarks were poorly seen in 50% of the cases when using TAS. In 66 cases, the placenta appeared low or possibly over the internal cervical os using TAS, but a definitive diagnosis could not be made due to suboptimal visualization. In the remaining 65 cases, visualization of the internal os and placental edge was possible using both TAS and TVS. In this group, there was a change in the diagnosis in 26% of the cases after TVS was performed. Our results suggest that optimal visualization of the placental edge and internal cervical os is usually difficult with TAS when the placenta appears low-lying or over the internal cervical os. The assessment of placental localization was changed in over one-quarter of cases (26%) after transvaginal sonography was performed. The use of transvaginal ultrasound should be seriously considered when the placenta appears to be low or over the internal cervical os by transabdominal ultrasound.

The use of second-trimester transvaginal sonography to predict placenta previa.

Our objective was to determine the incidence and rate of persistence of placenta previa diagnosed at 15-20 weeks' gestation by using transvaginal sonography (TVS), and to describe the characteristics of TVS that predict placenta previa at delivery. Patients having placental tissue within 20 mm of the cervical os were prospectively identified by transabdominal ultrasound and underwent TVS. The distance of the placental edge from the cervical os was measured in millimeters. Characteristics of TVS predicting placenta previa at delivery were analyzed by logistic regression. The incidence of placenta previa diagnosed by TVS at 15-20 weeks was 1.1%; 14% persisted until delivery. Gestational age at the time of TVS and the distance of the placental edge to the cervical os helped predict placenta previa at delivery. Between 15 and 24 weeks' gestation, placenta overlapping the internal os by > or = 10 mm identified patients at risk of placenta previa at delivery with 100% sensitivity and 85% specificity. The use of TVS in the second trimester to diagnose placenta previa resulted in a lower incidence than was historically reported with the use of transabdominal ultrasound. The distance of the placental edge from the cervical os helps identify patients at risk of previa at delivery.

The significance of ultrasonographically diagnosed fetal wrist position anomalies.

OBJECTIVE: Our purpose was to determine the clinical significance of ultrasonographically diagnosed fetal wrist position anomalies. STUDY DESIGN: The relationship of the fetal hand to the forearm was prospectively evaluated in all second- and third-trimester scans over a 5-year period. If an abnormal wrist position was detected, a targeted scan, including echocardiography, was performed. The outcomes of abnormal pregnancies were obtained. RESULTS: An abnormal relationship of the hand to the forearm was found in 22 fetuses in 27,467 scans. Nine had a normal karyotype, and 13 had an abnormal karyotype. Among the nine with normal chromosomes, three had evidence of a movement disorder. Three with normal karyotypes are alive; two of these are the only normally functioning survivors. They had no other major anomalies and were shown prenatally to have normal movement of the limbs. CONCLUSIONS: An abnormal fetal wrist position is associated with a high incidence of karyotype and movement abnormalities.

Tetralogy of Fallot: prenatal diagnosis and postnatal survival.

OBJECTIVES: To correlate prenatal echocardiographic findings with infant outcome in a large screening population affected by tetralogy of Fallot. METHODS: Inclusion criteria required confirmed postnatal cardiac diagnosis, at least one fetal ultrasound examination with satisfactory heart visualization, and infant delivery at our institution. Aortic and pulmonary artery diameters were measured from real-time ultrasound or videotaped scans and compared against published nomograms. The pulmonary artery to aorta ratio was also evaluated in a similar manner. Infant survival was assessed 1 year after delivery. RESULTS: Seventeen fetuses were confirmed to have a ventricular septal defect and an overriding aorta with varying degrees of right ventricular outflow obstruction after delivery. All karyotypes were normal. Ultrasound screening identified 12 of 17 abnormal hearts at a mean gestational age of 22.9 +/- 5.1 weeks; two of these fetuses were thought to have only ventricular septal defect before delivery. Five fetuses had enlarged aortic roots during the initial scan. Only two of the ten fetuses with a measurable pulmonary artery had initial sonographic evidence for valve stenosis. Six other pulmonary arteries became abnormally small with advancing pregnancy. The pulmonary artery to aorta ratio was decreased in six of the ten fetuses with a measurable pulmonary artery. Sixteen infants survived at least 1 year after birth and successfully completed either corrective or palliative cardiac surgery. CONCLUSION: Fetuses with tetralogy of Fallot may present with only a ventricular septal defect and aortic septal override by prenatal ultrasound examination. Pulmonary artery stenosis is not always present at initial ultrasound examination, but this finding can develop or worsen during pregnancy. Furthermore, a normal aortic diameter does not exclude tetralogy of Fallot. Infant survival appears to be favorable in the absence of other major structural or chromosomal anomalies.

Ultrasonographic left cardiac axis deviation: a marker for fetal anomalies.

OBJECTIVE: To determine if a relation exists between left cardiac axis deviation and fetal anomalies. METHODS: Estimation of cardiac axis was attempted prospectively as part of the cardiac examination in approximately 41,500 second- and third-trimester fetuses scanned between 1987-1993. Those with heart axes greater than 75 degrees to the left were considered to have left axis deviation. Only cases with postnatal follow-up were included. RESULTS: Thirty-four fetuses with left cardiac axis deviation had postnatal follow-up; eight were normal and 26 abnormal (positive predictive value 76%). Twenty-one fetuses had cardiac abnormalities (ten of these had additional extracardiac findings), and five had extracardiac findings only. CONCLUSION: Although left cardiac axis deviation can occur as an isolated sonographic finding in an otherwise normal fetus, most cases will demonstrate abnormalities of cardiac and/or extracardiac anatomy. Left cardiac axis deviation is largely associated with cardiac abnormalities, especially conotruncal anomalies, which may not be detectable by a four-chamber view alone. Therefore, the cardiac axis should be examined routinely as part of the four-chamber view of the fetal heart.

Interactive multimedia for prenatal ultrasound training.

This demonstration project examines the utility of interactive multimedia for prenatal ultrasound training. A laser-disc library was linked to a three-dimensional (3-D) heart model and other computer-based training materials through interactive multimedia. A testing module presented ultrasound anomalies and related questions to house-staff physicians through the image library. Users were asked to evaluate these training materials on the basis of perceived instructional value, question content, subjects covered, graphics interface, and ease of use; users were also asked for their comments. House-staff physicians indicated that they consider interactive multimedia to be a helpful adjunct to their core fetal imaging rotation. During a 9-month period, 16 house-staff physicians correctly diagnosed 78 +/- 4% of unknown cases presented through the testing module. The 3-D heart model was also perceived to be a useful teaching aid for spatial orientation skills. Our findings suggest that interactive multimedia and volume visualization models can be used to supplement traditional prenatal ultrasound training. The system provides a broad exposure to ultrasound anomalies, increases opportunities for postnatal correlation, emphasizes motion video for ultrasound training, encourages development of independent diagnostic ability, and helps physicians understand anatomic orientation. We hypothesize that interactive multimedia-based tutorials provide a better overall training experience for house-staff physicians. However, these supplementary methods will require formal evaluation of effectiveness to better understand their potential educational impact.

Prenatal screening for cardiac anomalies: the value of routine addition of the aortic root to the four-chamber view.

OBJECTIVE: To determine whether the addition of the aortic-root view would detect more congenital cardiac anomalies than a standard four-chamber view alone. METHODS: The study included fetuses of 14 weeks' gestation or more who were scanned in our unit during a 28-month period. Outcome information was obtained from postnatal echocardiograms and autopsies. Abnormal hearts were classified as to whether the four-chamber or aortic-root view was abnormal. RESULTS: There were 5967 fetuses in whom a four-chamber view could be obtained. In 5111 of these, an aortic-root view could also be obtained. The four-chamber view detected 24 (47%) of the 51 fetuses with abnormal hearts. Adding the aortic-root view increased the sensitivity to 78%. CONCLUSIONS: Visualization of the aortic root is a quick and easy means of evaluating the aortic outflow tract during routine scanning. Adding the aortic-root view to the standard four-chamber view will result in the detection of most cardiac anomalies prenatally.

Time-domain ultrasonography during pregnancy.

Time-domain ultrasonography is an alternative to Doppler analysis of blood flow direction and velocity. The technique uses timing information between successive echo pulses to measure flow velocities directly through a color display map. Volume flow quantification also can be achieved by combining time-domain methods with M-mode ultrasonography. This report describes our preliminary experiences with fetal vascular imaging by time-domain ultrasonography, compares Doppler peak velocity correlation to time-domain sonography, and examines the in vitro accuracy of time-domain sonography combined with M-mode volume flow measurements. Excellent agreement was found between peak Doppler velocity measurements and time-domain ultrasonography for a variety of maternal and fetal vessels (N = 29). Close volume-flow correlation was observed between a flow pump and time-domain ultrasonography under constant and pulsatile conditions. Time-domain ultrasonography appears to be a useful alternative to Doppler techniques for imaging small fetal vessels and also may provide the basis for accurate volume flow measurements during pregnancy.

Transverse cerebellar diameter: a useful predictor of gestational age for fetuses with asymmetric growth retardation.

There have been conflicting reports regarding the ability of cerebellar diameter to satisfactorily predict the gestational age of growth-retarded fetuses. Gestational age prediction intervals were derived from 270 normal fetuses between 14 and 40 weeks' gestation for biparietal diameter, head circumference, abdominal circumference, femur length, and transverse cerebellar diameter. We evaluated the ability of these parameters to predict gestational age for 19 small-for-gestational-age fetuses. The cerebellar diameter regression model led to the smallest differences between observed and predicted gestational age for all growth-retarded fetuses. Transverse cerebellar diameter satisfactorily predicted gestational age for all six fetuses with asymmetric intrauterine growth retardation and was associated with the least amount of underestimation bias when compared with other ultrasonographic parameters. However, transverse cerebellar diameter appeared to be no better than biparietal diameter, head circumference, or femur length for accurately predicting gestational age of fetuses with symmetric intrauterine growth retardation (n = 13) despite the finding that cerebellar growth was also relatively spared under these circumstances. We conclude that transverse cerebellar diameter can be used to reliably approximate gestational age in fetuses with asymmetric intrauterine growth retardation. However, caution is warranted when using it to predict the gestational age of fetuses affected by symmetric intrauterine growth retardation.