Use of inlet radiographs in the assessment of reduction after the surgical treatment of developmental dysplasia of the hip.

AIMS: This pilot study aimed to evaluate prospectively the use of inlet radiographs of the hip as an alternative method of the assessment of reduction after the surgical treatment of developmental dysplasia of the hip (DDH). PATIENTS AND METHODS: The children in this study underwent surgery between January 2013 and January 2015. All had inlet radiographs and CT scans post-operatively. Data were analysed by determining inter-observer reliability and intra-observer reproducibility, using the kappa value (K). Differences were settled by discussion between the two observers until a consensus was reached. The sensitivity and specificity of the radiographic and CT results were compared. A total of 26 radiographs were obtained from 23 children, with a mean age of 2.38 years (one to five). RESULTS: Similar high levels of intra- and inter-observer agreement were observed (K = 0.834, 95% confidence interval (CI)). There was a high agreement between the radiographic and CT results (K = 0.834, 5% CI), with excellent sensitivity and a specificity of 95.5%. CONCLUSION: These results suggest that inlet radiographs may be a reliable method of assessing the reduction of the hip after the surgical treatment of DDH. Cite this article: Bone Joint J 2017;99-B:697-701.

Enhanced Transverse Magneto-Optical Kerr Effect in Magnetoplasmonic Crystals for the Design of Highly Sensitive Plasmonic (Bio)sensing Platforms.

We propose a highly sensitive sensor based on enhancing the transversal magneto-optical Kerr effect (TMOKE) through excitation of surface plasmon resonances in a novel and simple architecture, which consists of a metal grating on a metal magneto-optical layer. Detection of the change in the refractive index of the analyte medium is made by monitoring the angular shift of the Fano-like resonances associated with TMOKE. A higher resolution is obtained with this technique than with reflectance curves. The key aspect of the novel architecture is to achieve excitation of surface plasmon resonances mainly localized at the sensing layer, where interaction with the analyte occurs. This led to a high sensitivity, S = 190° RIU-1, and high performance with a figure of merit of the order of 103, which can be exploited in sensors and biosensors.

Velamentous cord insertion in dichorionic and monochorionic twin pregnancies - Does it make a difference?

OBJECTIVE: To estimate the prevalence of velamentous cord insertion (VCI) in dichorionic (DC) and monochorionic (MC) twins with and without twin-twin transfusion syndrome (TTTS), and to study the associated outcomes. METHODS: We recorded the type of umbilical cord insertion in all consecutive DC and MC placentas examined in two European tertiary medical centers. The association between VCI and perinatal outcomes was estimated and compared. RESULTS: A total of 1498 twin placentas were included in this study (DC placentas n = 550, MC placentas without TTTS n = 513 and MC placentas with TTTS n = 435). The prevalence of VCI in DC, MC without TTTS and MC with TTTS groups was 7.6%, 34.7% and 36.1%, respectively (P < 0.001). In MC twins (non-TTTS and TTTS groups), VCI was associated with severe birth weight discordance (odds ratio [OR] 4.76 95% CI 2.43, 10.47 and OR 4.52 95% CI 1.30, 28.59, respectively). In MC twins without TTTS, VCI was associated with small for gestational age (OR 1.66, 95% CI 1.12, 2.50). VCI was significantly associated with increased risk of intrauterine fetal demise in MC twins, and this effect was greater in the non-TTTS group (OR 2.71 95% CI 1.38, 5.47). These associations did not occur in DC group. Gestational age at birth was lower in the presence of VCI in the DC and MC twins without TTTS. CONCLUSION: Our findings confirm that the prevalence of VCI is higher in MC twins than in DC twin pregnancies. VCI is an important indicator of adverse perinatal outcome, particularly in MC twins.

Revisiting amniotic band sequence: a wide spectrum of manifestations.

OBJECTIVE: To describe the spectrum of clinical deformities related to amniotic band sequence (ABS), ranging from mild to severe. METHODS: Retrospective evaluation of 9 cases of ABS managed during a 4-year period (February 2006 to April 2010) in a tertiary hospital. RESULTS: The median gestational age at prenatal diagnosis was 15 weeks (range 11-26). Only 2 patients had clinical prenatal evidence of amnion rupture. In the other 5 cases the diagnosis of ABS was established prenatally based on fetal structural abnormalities. These abnormalities included: (1) upper limb defects: syndactyly, amputation at the level of phalanges or first metacarpal or forearm; (2) inferior extremities defects: tallus equinovarus and flexed knee, and constriction ring; (3) umbilical cord strangulation, and (4) acrania. CONCLUSION: ABS is a polymorphous syndrome and recognizing its various manifestations can be of help in prenatal identification.

Velamentous cord insertion in monochorionic twins with or without twin-twin transfusion syndrome: Does it matter?

OBJECTIVE: To study the association between velamentous cord insertion (VCI) and different outcomes in monochorionic twins with and without twin-twin transfusion syndrome (TTTS). METHODS: We recorded the cord insertion type in all consecutive monochorionic placentas examined in two tertiary medical centers. The association between VCI and several outcomes was estimated. RESULTS: A total of 630 monochorionic placentas with TTTS (n = 304) and without TTTS (n = 326) were studied. The incidence of VCI in the TTTS and non-TTTS group was 36.8% and 35.9%, respectively (P = 0.886). The presence of VCI in one twin was significantly associated with small for gestational age (SGA) status (odds ratio [OR] 1.45, 95% CI 1.13, 1.87) and severe birth weight discordance (OR 3.09, 95% CI 1.93, 4.96). Our results also showed significant interaction between TTTS and VCI when we considered intrauterine fetal demise (IUFD) and gestational age (GA) at birth. The prevalence of IUFD in monochorionic pregnancies without TTTS increased from 4.6% to 14.1% in the presence of VCI (P = 0.027). In the TTTS group, the prevalence of IUFD was comparable in the absence or presence of VCI. Similarly, GA at birth was significantly lower in the presence of VCI only in the non-TTTS group. CONCLUSION: Our findings suggest that VCI is not associated with the development of TTTS but increases the risk of adverse outcomes. Both VCI and TTTS independently increase the prevalence of IUFD and lower GA at birth in a similar way, showing that VCI is an important indicator of adverse perinatal outcome in monochorionic twins.

Lateral ventricles in fetuses with aneuploidies at 11-13 weeks' gestation.

OBJECTIVE: To examine the possible association between aneuploidies and fetal lateral cerebral ventriculomegaly in the first trimester of pregnancy. METHODS: Three-dimensional brain volumes were acquired by transvaginal ultrasound examination at 11-13 weeks' gestation in 410 euploid fetuses and 63 fetuses with trisomy 21, 34 with trisomy 18 and seven with trisomy 13. Lateral ventricles were assessed in a transverse view, just above the roof of the third ventricle and measurements of the areas of the lateral ventricles and choroid plexuses were obtained. The ratio between choroid plexus and lateral ventricle areas (CLR) was calculated. Measurements in aneuploid fetuses were compared to those in euploid fetuses. RESULTS: In euploid fetuses the lateral ventricle and choroid plexus areas increased, whereas the CLR decreased with fetal biparietal diameter. In fetuses with trisomy 21, lateral ventricle and choroid plexus areas were smaller but CLR was not significantly different from that in euploid fetuses. In trisomy 18 and 13 fetuses, CLR was significantly smaller than in euploid fetuses. The CLR was below the 5(th) centile of normal range in 11 (32.4%) fetuses with trisomy 18 and in six (85.7%) with trisomy 13. CONCLUSION: There is evidence of ventriculomegaly at 11-13 weeks' gestation in most fetuses with trisomy 13 and one third of fetuses with trisomy 18.

Cerebral ventricular system in fetuses with open spina bifida at 11-13 weeks' gestation.

OBJECTIVE: To determine if in fetuses with open spina bifida at 11-13 weeks' gestation there are alterations in the cerebral ventricular system. METHODS: In this study we selected 10 cases of open spina bifida and 410 normal singleton pregnancies which subsequently resulted in the delivery of phenotypically normal neonates. In all cases transvaginal sonography was carried out at 11-13 weeks' gestation and three-dimensional (3D) brain volumes were acquired. The fetal head was systematically assessed in a series of transverse views and measurements were obtained of the area of the lateral ventricles, the diameter of the roof of the third ventricle, the diameter of the aqueduct of Sylvius and the diameter of the fourth ventricle. The measurements obtained on the normal and affected fetuses were compared. RESULTS: In normal fetuses the area of the lateral ventricles and the diameter of the roof of the third ventricle increased, the diameter of the aqueduct of Sylvius decreased and the diameter of the fourth ventricle did not change significantly with biparietal diameter (BPD). In fetuses with open spina bifida, compared with normal fetuses, the measurements of the lateral ventricle area, the diameter of the roof of the third ventricle, the diameter of the aqueduct of Sylvius and the diameter of the fourth ventricle were significantly decreased (P < 0.01). CONCLUSION: In fetuses with open spina bifida at 11-13 weeks' gestation the intracranial collection of cerebrospinal fluid is substantially reduced.

Phenotypic variability in fetuses with down syndrome: a case-control pathological evaluation.

OBJECTIVES: Evaluation of morphological and morphometric characteristics of fetuses with Down syndrome based on a detailed postmortem examination and comparison of these fetuses with a control group of fetuses with normal karyotype to improve the prenatal knowledge of Down syndrome characteristics. MATERIAL AND METHODS: A case-control study was undertaken in a tertiary referral hospital. The Down syndrome fetuses (50) were compared with chromosomally normal fetuses (47) matched for gestational age. Biometric and morphological parameters were compared. RESULTS: The biometry of fetuses with Down syndrome differs from control fetuses only in the occipitofrontal diameter and in the nasal bone length. There were craniofacial anomalies in 96% of fetuses with Down syndrome and in 51% of fetuses with normal karyotype. With the exception of small ears, all craniofacial features analyzed were significantly different between Down syndrome fetuses and control fetuses. All extremity features of fetuses with Down syndrome were significantly different from fetuses without Down syndrome. There were 31 fetuses with Down syndrome (62%) with 55 internal anomalies. Nineteen fetuses (38.8%) showed 27 cardiac anomalies. Six fetuses had more than one anomaly. There were 18 fetuses (36%) with 28 noncardiac anomalies. DISCUSSION: The importance of studying the morphological characteristics of fetuses with Down syndrome is the contribution to a better knowledge of fetal characteristics and probably to optimize prenatal diagnosis.

Zero-(n) non-Bragg gap plasmon-polariton modes and omni-reflectance in 1D metamaterial photonic superlattices.

A theoretical study of the photonic band structure and transmission spectra for 1D periodic superlattices with an elementary cell composed of two layers of refractive indices n(a) and n(b), which may take on positive as well as negative values, has been performed within the transfer-matrix approach. The dependence on the angle of incidence of the electromagnetic wave for excitation of plasmon-polaritons as well as the properties of the (n) = 0 gap were thoroughly investigated. Results are found for the generalized conditions that must be satisfied by the ratio a/b of the layer widths of metamaterial photonic superlattices, for both transverse electric and transverse magnetic polarizations, in order to have an omnidirectional (n) = 0 gap. The present study indicates new perspectives in the design and development of future optical devices.

Coupling-barrier and non-parabolicity effects on the conduction electron cyclotron effective mass and Landé [Formula: see text] factor in GaAs double quantum wells.

We have performed a theoretical study of the effects of the non-parabolicity and coupling barrier in between GaAs quantum wells on the conduction electron cyclotron effective mass and Landé [Formula: see text] factor under the action of a growth-direction applied magnetic field. Numerical calculations are performed within the effective mass approximation and taking into account the non-parabolicity effects for the conduction-band electrons, by means of the Ogg-McCombe effective Hamiltonian. The system consists of two GaAs quantum wells connected by a Ga(1 - x)Al(x)As barrier and surrounded by Ga(1 - y)Al(y)As material. We have found that both the [Formula: see text] factor and the cyclotron effective mass are sensitive to the coupling strength, that is the height and width of the barrier in between the GaAs quantum wells. This behavior is similar for every Landé [Formula: see text] factor and the cyclotron effective mass calculated for different Landau levels. It is noticeable that the splitting between the [Formula: see text] and [Formula: see text] cyclotron effective mass increases with the central barrier width and the growth-direction applied magnetic field. As in a single quantum well, we found that the electron Landé [Formula: see text] factor increases with the growth-direction applied magnetic field, comparing quite well with the experimental reports, and that the magnetic field plays an important role in decoupling the quantum wells of the system. Additionally, we have studied the electron cyclotron effective mass and Landé g factor as functions of the Landau levels, depending on the non-parabolicity. From this result one can infer that their population must be taken into account for a complete study of the band parameters as has been proposed in previous works. The present theoretical results are in very good agreement with previous experimental reports in the limiting geometry of a single quantum well.

Systematic fetal autopsy in cases of medical termination of pregnancy due to chromosomal abnormalities: improving the quality of perinatal care?

OBJECTIVES: Evaluation of the clinical utility of systematically performing autopsy after termination of pregnancy (TOP) due to chromosomal abnormalities. METHODS: A retrospective study of cases of TOP due to chromosomal abnormalities was performed between 1 January 2002 and 30 September 2007, in a tertiary referral hospital. A comparative study between prenatal ultrasonographic findings and postmortem findings was performed. RESULTS: There were 57 cases of TOP due to chromosomal abnormalities. The median gestational age at TOP was 17 (range 14-24 weeks). There were 46 trisomies, 4 monosomies, 4 triploidies and 3 cases of structural anomalies. In 25 cases (43.9%) there was at least one major anomaly detected by ultrasound. In 15 cases (26.3%) additional information was obtained after fetal autopsy: in 7 cases further major structural anomalies were detected, and in 8 cases the presence of a major abnormality was not confirmed by the autopsy. CONCLUSION: Fetal autopsy may provide additional information to the ultrasonographic morphological evaluation of the fetus submitted to TOP due to chromosomal abnormalities. The combination of prenatal ultrasound and pathological examination can broaden our knowledge of the natural history of chromosomal anomalies in the earlier stages of development and eventually contribute to improve the quality of perinatal care.

Screening for twin-twin transfusion syndrome at 11-14 weeks of pregnancy: the key role of ductus venosus blood flow assessment.

OBJECTIVES: A discrepancy in crown-rump length (CRL) and/or nuchal translucency thickness (NT) between monochorionic twins has been found to be associated with an increased risk of twin-twin transfusion syndrome (TTTS). As one of the most plausible mechanisms for increased NT is hemodynamic imbalance and cardiac dysfunction, indirectly manifested by abnormal blood flow in the ductus venosus (DV), we aimed to clarify the role of DV blood flow assessment in identifying those monochorionic twins more prone to develop TTTS. METHODS: We present 99 cases of monochorionic diamniotic twin pregnancies in which CRL, NT and DV blood flow were evaluated at 11-14 weeks' gestation. RESULTS: Discrepant values of CRL were not predictive of TTTS development. Intertwin NT discrepancy >or= 0.6 mm had a sensitivity of 50.0% and a specificity of 92.0%. The presence of at least one abnormal blood flow waveform in the DV was associated with a relative risk for developing TTTS of 11.86 (95% CI, 3.05-57.45), with a sensitivity of 75.0% and a specificity of 92.0%. The combination of abnormal DV blood flow with NT discrepancy >or= 0.6 mm yielded a relative risk for the development of TTTS of 21 (95% CI, 5.47-98.33). CONCLUSIONS: Both intertwin discrepancy in NT and abnormal flow in the DV in monochorionic twins may represent early manifestations of hemodynamic imbalance between donor and recipient. In these pregnancies, in addition to NT measurement at 11-14 weeks, the Doppler assessment of DV blood flow significantly increases the performance of screening for those at risk of developing TTTS.

Concordance for bilateral congenital diaphragmatic hernia in a monozygotic dichorionic twin pair - first clinical report.

The authors present a clinical case of concordance for bilateral congenital diaphragmatic hernia in a monozygotic twin pair diagnosed in the early second trimester.

Laser-dressing and magnetic-field effects on shallow-donor impurity states in semiconductor GaAs-Ga(1-x)Al(x)As cylindrical quantum-well wires.

The influence of an intense laser field on shallow-donor states in cylindrical GaAs-Ga(1-x)Al(x)As quantum-well wires under an external magnetic field applied along the wire axis is theoretically studied. Numerical calculations are performed in the framework of the effective-mass approximation, and the impurity energies corresponding to the ground state and 2p(±) excited states are obtained via a variational procedure. The laser-field effects on the shallow-donor states are considered within the extended dressed-atom approach, which allows one to treat the problem 'impurity + heterostructure + laser field + magnetic field' as a renormalized 'impurity + heterostructure + magnetic field' problem, in which the laser effects are taken into account through a renormalization of both the conduction-band effective mass and fundamental semiconductor gap.

Quantum confinement and magnetic-field effects on the electron g factor in GaAs-(Ga, Al)As cylindrical quantum dots.

We have performed a theoretical study of the quantum confinement (geometrical and barrier potential confinements) and axis-parallel applied magnetic-field effects on the conduction-electron effective Landé g factor in GaAs-(Ga, Al)As cylindrical quantum dots. Numerical calculations of the g factor are performed by using the Ogg-McCombe effective Hamiltonian-which includes non-parabolicity and anisotropy effects-for the conduction-band electrons. The quantum dot is assumed to consist of a finite-length cylinder of GaAs surrounded by a Ga(1-x)Al(x)As barrier. Theoretical results are given as functions of the Al concentration in the Ga(1-x)Al(x)As barrier, radius, lengths and applied magnetic fields. We have studied the competition between the quantum confinement and applied magnetic field, finding that in this type of heterostructure the geometrical confinement and Al concentration determine the behavior of the electron effective Landé [Formula: see text] factor, as compared to the effect of the applied magnetic field. Present theoretical results are in good agreement with experimental reports in the limiting geometry of a quantum well, and with previous theoretical findings in the limiting case of a quantum well wire.

Recipient's vascular doppler pattern immediately following death of the donor in a case of untreated severe twin-to-twin transfusion syndrome.

In a stage III twin-to-twin transfusion syndrome, death of the donor at 31 weeks was followed by unusual umbilical artery (UA) doppler findings in the recipient, with a high diastolic peak velocity and a low S/D ratio. Besides, middle cerebral artery waveforms could not be obtained in the recipient. The recipient was delivered by emergency cesarean section, weighed 1,230 g, was strikingly pale and had a cord hemoglobin concentration of 15 g/dl. Neonatal blood average pressure was of 29 mm Hg, immediately after delivery, and ranged from 33 to 43 mm Hg in the first 12 h of life. Neonatal heart function returned to normal on day 2. We hypothesize that death of the donor twin induced an acute decrease in placental resistance. This phenomenon, combined with decreased systolic blood flow due to the recipient's systolic function impairment, could account for the umbilical artery flow pattern we observed. The acute decrease in volemia and the presence of systemic hypertension and cardiomyopathy may explain the inability to obtain middle cerebral artery doppler. This complex hemodynamic disturbance in the recipient may be responsible for morbidity unrelated to anemia in case of donor's demise, as acute fetal distress.