Terminal 6.9 Mb deletion of chromosome 15q, associated with a structurally abnormal X chromosome in a patient with congenital diaphragmatic hernia and heart defect

We report the case of a female patient exhibiting multiple congenital malformations including diaphragmatic hernia and heart defect. Cytogenetic studies (including karyotype, FISH and array-CGH) showed a de novo terminal deletion (6.9 Mb) on chromosome 15 in association with a recombinant X chromosome bearing a 9-Mb Xp duplication and a 46-Mb Xq deletion distal to XIST. The recombinant X chromosome was caused by a maternal inv(X)(p22.31q22.3). The X chromosome inactivation pattern was skewed in the patient suggesting a possible inactivation of the recombinant X chromosome. Considering these results, the phenotype was linked to the de novo terminal 15q deletion. These results strengthen the assumption that array-CGH should be applied to each fetus/newborn with multiple congenital malformations.     

Monte Carlo studies of the exit photon spectra and dose to a metal/phosphor portal imaging screen

The energy spectra and the dose to a Cu plate/Gd2O2S phosphor portal imaging detector were investigated for monoenergetic incident beams of photons (1.25, 2, and 5 MeV). The Monte Carlo method was used to characterize the influence of the patient/detector geometry, detector material and design, and incident beam energy on the spectral distribution and the dose, at the imaging detector plane, of a photon beam scattered from a water phantom. The results show that radiation equilibrium is lost in the air gap and that, for the geometries studied, this effect led to a reduction in the exit dose of up to 40%. The finding that the effects of the air gap and field size are roughly complementary has led to the hypothesis that an equivalent field size concept may be used to account for intensity and spectral changes arising from air gap variations. The copper plate preferentially attenuates the low-energy scattered photons incident on it, while producing additional annihilation, bremsstrahlung, and scattered photons. As a result, the scatter spectra at the copper surface entrance of the detector differs significantly from that at the Cu/phosphor interface. In addition, the mean scattered photon energy at the interface was observed to be roughly 0.4 MeV higher than the corresponding effective energy for 2 MeV incident beams. A comparison of the dose to various detector materials showed that exit dosimetry errors of up to 24% will occur if it is assumed that the Cu plate/Gd2O2S phosphor detector is water equivalent.     

Disruption of Conscious Access in Psychosis Is Associated with Altered Structural Brain Connectivity

According to global neuronal workspace (GNW) theory, conscious access relies on long-distance cerebral connectivity to allow a global neuronal ignition coding for conscious content. In patients with schizophrenia and bipolar disorder, both alterations in cerebral connectivity and an increased threshold for conscious perception have been reported. The implications of abnormal structural connectivity for disrupted conscious access and the relationship between these two deficits and psychopathology remain unclear. The aim of this study was to determine the extent to which structural connectivity is correlated with consciousness threshold, particularly in psychosis. We used a visual masking paradigm to measure consciousness threshold, and diffusion MRI tractography to assess structural connectivity in 97 humans of either sex with varying degrees of psychosis: healthy control subjects (n = 46), schizophrenia patients (n = 25), and bipolar disorder patients with (n = 17) and without (n = 9) a history of psychosis. Patients with psychosis (schizophrenia and bipolar disorder with psychotic features) had an elevated masking threshold compared with control subjects and bipolar disorder patients without psychotic features. Masking threshold correlated negatively with the mean general fractional anisotropy of white matter tracts exclusively within the GNW network (inferior frontal-occipital fasciculus, cingulum, and corpus callosum). Mediation analysis demonstrated that alterations in long-distance connectivity were associated with an increased masking threshold, which in turn was linked to psychotic symptoms. Our findings support the hypothesis that long-distance structural connectivity within the GNW plays a crucial role in conscious access, and that conscious access may mediate the association between impaired structural connectivity and psychosis.     

Relationship between prolactin secretion, and plasma risperidone and 9-hydroxyrisperidone concentrations in adolescents with schizophreniform disorder

BACKGROUND: Treatment with the atypical antipsychotic risperidone can result in elevated prolactin levels. To date, the relationships between plasma concentrations of prolactin, risperidone and its active 9-hydroxy-metabolite have been little investigated in adolescents with psychosis. METHODS: Prolactin levels were determined at baseline in 16 hospitalized drug-na?ve adolescents meeting DSM-IV criteria for schizophreniform disorder. Prolactin, risperidone, 9-hydroxyrisperidone levels were subsequently determined after 3 weeks of oral risperidone treatment. RESULTS: Compared with pretreatment values, prolactin levels at endpoint were significantly increased (p<0.00001) and correlated with risperidone doses (r=0.58, N=16, p<0.02), and plasma levels of risperidone (r=0.60, N=16, p<0.02) and 9-hydroxyrisperidone (r=0.54, N=16, p=0.03). CONCLUSIONS: These data suggest that risperidone's effect on prolactin release is dose-dependent in adolescents and is linked to both plasma risperidone and 9-hydroxyrisperidone concentrations.     

Five-year follow-up of clinical and radiological outcomes of LP-ESP elastomeric lumbar total disc replacement in active patients

Background context

The surgical treatment of degenerative disc disease at the lumbar spine may involve fusion. Total disc replacement (TDR) is an alternative treatment to avoid fusion-related adverse events, specifically adjacent segment disease. New generation of elastomeric non-articulating devices has been developed to more effectively replicate the shock absorption and flexural stiffness of native disc.

Treatment goals: response and nonresponse

Psychiatric symptomatology is often subjective, but it can be partly made more objective for the purposes of evaluation. Esquirol was the first modern psychiatrist to stress the need for a scientific approach to treatment evaluation. The kinetics of treatment is complex because different components of the clinical picture improve at a different pace. Assessment of treatment requires prior definition of end point, response, and nonresponse. Response is influenced by several factors, such as placebo effect, diagnostic category and subtypes, and patient heterogeneity. Treatment response may be predicted from clinical and biological parameters. This article lists the main causes of nonresponse, and suggests how to remedy them.     

Instant centre frequency at anaesthetic induction--a new way to analyse sympathovagal balance

The instant centre frequency (ICF) of RR interval has been proposed as a global index to analyse the sympathovagal interaction in the heart. The aim of this study was to assess the ICF during anaesthesia to test if it can reliably capture the neural control of the cardiovascular system. Twenty-four ASA II or III patients scheduled for cardiac surgery were included in the study. They were allocated in two groups: control, no treatment (group 1, n = 12), and beta-adrenergic blockade by atenolol (group 2, n = 12). Spectra of pulse interval series were computed with a time-frequency method and they were divided into: very low frequency (VLF, 0.000-0.040 Hz), low frequency (LF, 0.050-0.150 Hz) and high frequency (HF, 0.160-0.500 Hz). Normalized power was obtained by dividing the cumulative power within each frequency band (LF or HF) by the sum of LF and HF; the ratio of LF/HF was also calculated. Instant centre frequency is a time-varying parameter that the evolution along time of the gravity centrum of a local spectrum. All spectral indexes were recorded at the following time points: before induction, after induction and before intubation, during intubation, and after intubation. The atenolol group had lower normalized LF and the LF/HF ratio (P < 0.05) higher HF before induction; and lower LF/HF ratio after induction and before intubation (P < 0.05). The ICF was higher in atenolol group at all times. The ICF shifted towards HF frequency after induction and before intubation and shifted towards LF during intubation in both groups. The autonomic nervous system control on the heart through the interaction of sympathetic and parasympathetic reflex mechanisms could be studied by the ICF. The ICF may assess the autonomic cardiac modulation and may provide useful information for anaesthetic management.     

Dosimetric investigation and portal dose image prediction using an amorphous silicon electronic portal imaging device.

A two step algorithm to predict portal dose images in arbitrary detector systems has been developed recently. The current work provides a validation of this algorithm on a clinically available, amorphous silicon flat panel imager. The high-atomic number, indirect amorphous silicon detector incorporates a gadolinium oxysulfide phosphor scintillating screen to convert deposited radiation energy to optical photons which form the portal image. A water equivalent solid slab phantom and an anthropomorphic phantom were examined at beam energies of 6 and 18 MV and over a range of air gaps (approximately 20-50 cm). In the many examples presented here, portal dose images in the phosphor were predicted to within 5% in low-dose gradient regions, and to within 5 mm (isodose line shift) in high-dose gradient regions. Other basic dosimetric characteristics of the amorphous silicon detector were investigated, such as linearity with dose rate (+/- 0.5%), repeatability (+/- 2%), and response with variations in gantry rotation and source to detector distance. The latter investigation revealed a significant contribution to the image from optical photon spread in the phosphor layer of the detector. This phenomenon is generally known as "glare," and has been characterized and modeled here as a radially symmetric blurring kernel. This kernel is applied to the calculated dose images as a convolution, and is successfully demonstrated to account for the optical photon spread. This work demonstrates the flexibility and accuracy of the two step algorithm for a high-atomic number detector. The algorithm may be applied to improve performance of dosimetric treatment verification applications, such as direct image comparison, backprojected patient dose calculation, and scatter correction in megavoltage computed tomography. The algorithm allows for dosimetric applications of the new, flat panel portal imager technology in the indirect configuration, taking advantage of a greater than tenfold increase in detector sensitivity over a direct configuration.