La supervision, un élément central pour la sécurisation de la prise en charge des patients infectés par le SARS-CoV-2

Introduction

Notre hôpital a pris en charge dès janvier 2020 des patients infectés par le SARS-CoV-2 et organisé une prise en charge (PEC) des cas possibles en ambulatoire. Nous rapportons ici l’organisation paramédicale, centrée sur le principe de la supervision.

Matériels et méthodes

Trois patients ont été hospitalisés en maladies infectieuses (SMIT) et 1 en réanimation médicale. Un patient du SMIT a été secondairement transféré en réanimation. Au SMIT les patients sont dans l’unité de risque épidémique et biologique (REB) dans des chambres à pression négative avec sas et, en réanimation dans une partie cloisonnée, avec pression négative ou traitement d’air mobile. La supervision a été développée en 2014 avec les alertes Ebola, elle consiste à former les cadres des 3 services concernés (EOH, SMIT, réanimation) pour : anticiper l’arrivée des cas, vérifier l’habillage et le déshabillage, suivre la PEC et les examens biologiques, veiller à l’organisation logistique, transport des patients…Les alertes Ebola puis MERS-CoV, avec une vingtaine de patients admis par an, ont permis d’améliorer la supervision. L’ensemble des services de 1^re ligne (SMIT, SAU et réanimation) est régulièrement formé aux mesures de prévention. Des exercices avec le SMIT, la réanimation et le SAMU ont été organisés pour tester les circuits et les procédures.

Résultats

En situation de crise, un superviseur est mobilisable 24 h/24. Il accompagne les équipes dans la PEC des patients, de l’accueil à la sortie ou décès. Il s’assure du bon fonctionnement des circuits logistiques, de la mise à disposition du matériel et de la gestion des stocks. Il coordonne et accompagne la réalisation des examens hors du service (5 scanners pour le SARS-CoV-2) en collaboration avec les services de brancardage et de sécurité. Il encadre les visites auprès des patients infectés. Il participe aussi à l’information des services de 2^e ligne. Cette organisation est très rassurante pour les équipes soignantes, le superviseur servant de « tour de contrôle » du dispositif, et assurant la liaison opérationnelle entre tous les partenaires. Comme pour les autres acteurs impliqués dans cette épidémie, se pose la question de la pérennité de cette organisation en situation de crise prolongée, compte tenu de la charge technique et psychologique qu’il supporte.

Conclusion

Les organisations de PEC des patients REB sont variables d’un établissement à l’autre. La supervision, menée par un cadre qui maîtrise les procédures REB, semble être de nature à assurer la sécurité et la coordination entre tous les partenaires pour une prise en charge optimale des patients et la protection des personnels.

Microscale light management and inherent optical properties of intact corals studied with optical coherence tomography

Coral reefs are highly productive photosynthetic systems and coral optics studies suggest that such high efficiency is due to optimized light scattering by coral tissue and skeleton. Here, we characterize the inherent optical properties, i.e. the scattering coefficient, μ_s, and the anisotropy of scattering, g, of eight intact coral species using optical coherence tomography (OCT). Specifically, we describe light scattering by coral skeletons, coenoarc tissues, polyp tentacles and areas covered by fluorescent pigments (FP). Our results reveal that light scattering between coral species ranges from μ_s = 3 mm^-1 ( Stylophora pistillata) to μ_s = 25 mm^-1 ( Echinopora lamelosa) . For Platygyra pini, μ_s was 10-fold higher for tissue versus skeleton, while in other corals (e.g. Hydnophora pilosa) no difference was found between tissue and skeletal scattering. Tissue scattering was threefold enhanced in coenosarc tissues ( μ_s = 24.6 mm^-1) versus polyp tentacles ( μ_s = 8.3 mm^-1) in Turbinaria reniformis. FP scattering was almost isotropic when FP were organized in granule chromatophores ( g = 0.34) but was forward directed when FP were distributed diffusely in the tissue ( g = 0.96). Our study provides detailed measurements of coral scattering and establishes a rapid approach for characterizing optical properties of photosynthetic soft tissues via OCT in vivo.

Modeling subdiffusive light scattering by incorporating the tissue phase function and detector numerical aperture (Erratum)

This erratum corrects an error in "Modeling subdiffusive light scattering by incorporating the tissue phase function and detector numerical aperture."

Simultaneous Multicolor Single-Molecule Tracking with Single-Laser Excitation via Spectral Imaging

Single-molecule tracking (SMT) offers rich information on the dynamics of underlying biological processes, but multicolor SMT has been challenging due to spectral cross talk and a need for multiple laser excitations. Here, we describe a single-molecule spectral imaging approach for live-cell tracking of multiple fluorescent species at once using a single-laser excitation. Fluorescence signals from all the molecules in the field of view are collected using a single objective and split between positional and spectral channels. Images of the same molecule in the two channels are then combined to determine both the location and the identity of the molecule. The single-objective configuration of our approach allows for flexible sample geometry and the use of a live-cell incubation chamber required for live-cell SMT. Despite a lower photon yield, we achieve excellent spatial (20-40 nm) and spectral (10-15 nm) resolutions comparable to those obtained with dual-objective, spectrally resolved Stochastic Optical Reconstruction Microscopy. Furthermore, motions of the fluorescent molecules did not cause loss of spectral resolution owing to the dual-channel spectral calibration. We demonstrate SMT in three (and potentially more) colors using spectrally proximal fluorophores and single-laser excitation, and show that trajectories of each species can be reliably extracted with minimal cross talk.

Portable, low-cost multispectral imaging system: design, development, validation, and utilization

Optical spectral images can be used to estimate the amount of bulk absorbers in tissues, specifically oxy- and deoxyhemoglobin, as well as scattering parameters. Most systems that capture spectral image data are large, heavy, and expensive. This paper presents a full end-to-end analysis of a low-cost reflectance-mode multispectral imaging system operating in the visible and near-infrared spectra. The system consists of 13 LEDs mounted on a printed circuit board, a monochrome machine vision camera, and a tablet computer to control the hardware. The bill of materials for the system is less than $1000. Hardware design and implementation are detailed. Calibration, image capture, and preprocessing are also discussed. In validation experiments, excellent agreement is observed in diffuse reflectance measurements between the spectral camera setup and a spectrometer. To demonstrate that such spectral image data can yield meaningful optical measurements in vivo, the forearms of eight volunteers are imaged in the system. Their data are then analyzed to estimate the tissue optical properties of different skin layers using a Monte Carlo lookup table. In three volunteers, spectral images are captured before and after inducing erythema using a warm wet towel. Across the three subjects, a clear increase in the blood content of the superficial plexus layer was observed as a result of the erythema. Collectively, these findings suggest that a low-cost system can capture accurate spectral data and that clinically meaningful information can be derived from it.

Neuropsychological Functioning following Fetal Striatal Transplantation in Huntington's Chorea: Three Case Presentations

Neurotransplantation has been proposed as a potential treatment for the neurodegenerative disorder of Huntington's disease (HD), which currently has no effective therapy. While patients with Parkinson's disease have received neurotransplantation, until recently no HD patients have undergone transplantation for HD with standardized evaluations of their progress following surgery. The current report presents the cognitive changes in three patients with HD who underwent bilateral transplantation of human fetal striatal tissue. As part of the pre- and postsurgical evaluation, all three patients were administered a neuropsychological battery sensitive to the cognitive effects of HD within 2 mo prior to surgery and at 4-6 mo following transplantation. Four to 6 mo subsequent to surgery, all patients demonstrated increased scores on some measures of cognitive functioning. However, the pattern of changes was not uniform across subjects. These findings suggest that fetal striatal transplantation may improve some of the cognitive symptoms associated with HD in the three reported patients.

Aneuploidy: the impact of chromosome imbalance on nuclear organization and overall genome expression

The organization and dynamics of chromatin within the interphase nucleus as chromosome territories (CTs) and the relationship with transcriptional regulation are not fully understood. We studied a natural example of chromosomal disorganization: aneuploidy due to trisomies 13, 18 and 21. We hypothesized that the presence of an extra copy of one chromosome alters the CT distribution, which perturbs transcriptional activity. We used 3D-FISH to study the position of the chromosomes of interest (18 and 21) in cultured amniocytes and chorionic villus cells from pregnancies with a normal or aneuploid karyotype. We studied the volumes of nuclei and CTs in both conditions and performed a compared transcriptome analysis. We did not observe any differences between euploid and aneuploid cells in terms of the radial and relative CT positions, suggesting that the same rules govern nuclear organization in cases of trisomy. We observed lower volumes for CTs 18 and 21. Overall genome expression profiles highlighted changes in the expression of a subset of genes in trisomic chromosomes, while the majority of transcriptional changes concerned genes located on euploid chromosomes. Our results suggest that a dosage imbalance of the genes on trisomic chromosomes is associated with a disturbance of overall genomic expression.

Application of circularly polarized light for non-invasive diagnosis of cancerous tissues and turbid tissue-like scattering media

Polarization-based optical techniques have become increasingly popular in the field of biomedical diagnosis. In the current report we exploit the directional awareness of circularly and/or elliptically polarized light backscattered from turbid tissue-like scattering media. We apply circularly and elliptically polarized laser light which illuminates the samples of interest, and a standard optical polarimeter is used to observe the polarization state of light backscattered a few millimeters away from the point of incidence. We demonstrate that the Stokes vector of backscattered light depicted on a Poincaré sphere can be used to assess a turbid tissue-like scattering medium. By tracking the Stokes vector of the detected light on the Poincaré sphere, we investigate the utility of this approach for characterization of cancerous and non-cancerous tissue samples in vitro. The obtained results are discussed in the framework of a phenomenological model and the results of a polarization tracking Monte Carlo model, developed in house. Schematic illustration of the experimental approach utilizing circularly and elliptically polarized light for probing turbid tissue-like scattering media.

Quantitative analysis of transcranial and intraparenchymal light penetration in human cadaver brain tissue

BACKGROUND AND OBJECTIVE

Photobiomodulation (PBM) also known as low-level light therapy has been used successfully for the treatment of injury and disease of the nervous system. The use of PBM to treat injury and diseases of the brain requires an in-depth understanding of light propagation through tissues including scalp, skull, meninges, and brain. This study investigated the light penetration gradients in the human cadaver brain using a Transcranial Laser System with a 30 mm diameter beam of 808 nm wavelength light. In addition, the wavelength-dependence of light scatter and absorbance in intraparenchymal brain tissue using 660, 808, and 940 nm wavelengths was investigated.

STUDY DESIGN/MATERIAL AND METHODS

Intact human cadaver heads (n = 8) were obtained for measurement of light propagation through the scalp/skull/meninges and into brain tissue. The cadaver heads were sectioned in either the transverse or mid-sagittal. The sectioned head was mounted into a cranial fixture with an 808 nm wavelength laser system illuminating the head from beneath with either pulsed-wave (PW) or continuous-wave (CW) laser light. A linear array of nine isotropic optical fibers on a 5 mm pitch was inserted into the brain tissue along the optical axis of the beam. Light collected from each fiber was delivered to a multichannel power meter. As the array was lowered into the tissue, the power from each probe was recorded at 5 mm increments until the inner aspect of the dura mater was reached. Intraparenchymal light penetration measurements were made by delivering a series of wavelengths (660, 808, and 940 nm) through a separate optical fiber within the array, which was offset from the array line by 5 mm. Local light penetration was determined and compared across the selected wavelengths.

RESULTS

Unfixed cadaver brains provide good anatomical localization and reliable measurements of light scatter and penetration in the CNS tissues. Transcranial application of 808 nm wavelength light penetrated the scalp, skull, meninges, and brain to a depth of approximately 40 mm with an effective attenuation coefficient for the system of 2.22 cm(-1) . No differences were observed in the results between the PW and CW laser light. The intraparenchymal studies demonstrated less absorption and scattering for the 808 nm wavelength light compared to the 660 or 940 nm wavelengths.

CONCLUSIONS

Transcranial light measurements of unfixed human cadaver brains allowed for determinations of light penetration variables. While unfixed human cadaver studies do not reflect all the conditions seen in the living condition, comparisons of light scatter and penetration and estimates of fluence levels can be used to establish further clinical dosing. The 808 nm wavelength light demonstrated superior CNS tissue penetration.

Continence and micturition: an anatomical basis

Urinary incontinence remains an important clinical problem worldwide, having a significant socio-economic, psychological, and medical burden. Maintaining urinary continence and coordinating micturition are complex processes relying on interaction between somatic and visceral elements, moderated by learned behavior. Urinary viscera and pelvic floor must interact with higher centers to ensure a functionally competent system. This article aims to describe the relevant anatomy and neuronal pathways involved in the maintenance of urinary continence and micturition. Review of relevant literature focusing on pelvic floor and urinary sphincters anatomy, and neuroanatomy of urinary continence and micturition. Data obtained from both live and cadaveric human studies are included. The stretch during bladder filling is believed to cause release of urothelial chemical mediators, which in turn activates afferent nerves and myofibroblasts in the muscosal and submucosal layers respectively, thereby relaying sensation of bladder fullness. The internal urethral sphincter is continuous with detrusor muscle, but its arrangement is variable. The external urethral sphincter blends with fibers of levator ani muscle. Executive decisions about micturition in humans rely on a complex mechanism involving communication between several cerebral centers and primitive sacral spinal reflexes. The pudendal nerve is most commonly damaged in females at the level of sacrospinous ligament. We describe the pelvic anatomy and relevant neuroanatomy involved in maintaining urinary continence and during micturition, subsequently highlighting the anatomical basis of urinary incontinence. Comprehensive anatomical understanding is vital for appropriate medical and surgical management of affected patients, and helps guide development of future therapies.

"Trophoblast islands of the chorionic connective tissue" (TICCT): a novel placental histologic feature

INTRODUCTION

We found isolated or clustered trophoblasts in the chorionic connective tissue of the extraplacental membranes, and defined this novel histologic feature as the "trophoblast islands of the chorionic connective tissue" (TICCT). This study was conducted to determine the clinical significance of TICCT.

METHODS

Immunohistochemistry for cytokeratin-7 was performed on the chorioamniotic membranes (N = 2155) obtained from singleton pregnancies of 1199 uncomplicated term and 956 preterm deliveries. The study groups comprised 1236 African-American and 919 Hispanic women. Gestational age ranged from 24(+0) weeks to 41(+6) weeks. Multiple logistic regression analysis was performed to investigate the magnitude of association between patient characteristics and the presence of TICCT.

RESULTS

The likelihood of TICCT was significantly associated with advancing gestational age both in term (OR: 1.29, 95% CI: 1.16-1.45, p < 0.001) and preterm deliveries (OR: 1.19, 95% CI: 1.07-1.32, p = 0.001) . Hispanic women were less likely than African-American women to have TICCT across gestation in term (OR: 0.23, 95% CI: 0.18-0.31, p < 0.001) and preterm pregnancies (OR: 0.41, 95% CI: 0.29-0.58, p < 0.001). Women with a female fetus were significantly more likely to have TICCT than women with a male fetus, in both term (OR: 1.64, 95% CI: 1.28-2.11, p < 0.001) and preterm gestations (OR: 2.04, 95% CI: 1.46-2.85, p < 0.001). TICCT was 40% less frequent in the presence of chronic placental inflammation [term (OR: 0.60, 95% CI: 0.45-0.81, p = 0.001) and preterm gestations (OR: 0.58, 95% CI: 0.40-0.84, p = 0.003)] and in parous women at term (OR: 0.60, 95% CI: 0.44-0.81, p = 0.001).

CONCLUSIONS

Our findings suggest that the duration of pregnancy, fetal sex, and parity may influence the behavior of extravillous trophoblast and placental mesenchymal cells.

SU-E-T-06: A Mathematical Explanation to Tumor's Response to Perfusion and Hypoxic Fraction after Radiation

PURPOSE

To develop a dynamic model that explains oxygen dynamics between the microvascular perfusion and the hypoxic cell population inside a tumor.

METHODS

Bussink et al (Radiat Res 153(4), p.398 (2000)) observed fast oxygen dynamics, faster than cell-death. Based on a simplified three-compartment-model: the microvasculature, well-oxygenated, and hypoxic tumor cell populations. We applied a first-order differential model for the tumor's transient response as a function of oxygen content within the blood vessels. The sink terms in our model for each compartment are fast changing parameters because radiation rapidly changes the oxygen consumption of the tumor cell in a time scale which is much faster than the population changes of the tumor. Transportation balance condition is also applied for each compartment.

RESULTS

Our simulation results can explain the experimental data in Bussink et al's (Radiat Res 153(4), p.398 (2000)) paper. We provide an explanation for the relative complex behavior of the microvascular perfusion after radiation that emphasizes the role of dynamic metabolic changes in addition to population changes.

CONCLUSIONS

A newly developed dynamic model leads our understanding to the interrelationship between microvascular oxygen content within the blood vessels and the hypoxia state of the tumor to a deeper level, which has the potential to provide the theoretical foundation for the patient' specific adaptive radiotherapy.

SU-E-J-197: A Novel Optical Interstitial Fiber Spectroscopic System for Real-Time Tissue Micro-Vascular Hemodynamics Monitoring

PURPOSE

To demonstrate a novel interstitial optical fiber spectroscopic system, based on diffuse optical spectroscopies with spectral fitting, for the simultaneous monitoring of tumor blood volume and oxygen tension. The technique provides real-time, minimally-invasive and quantification of tissue micro-vascular hemodynamics.

METHODS

An optical fiber prototype probe characterizesthe optical transport in tissue between two large Numerical Aperture (NA) fibers of 200μm core diameter (BFH37-200, ThorLabs) spaced 3-mm apart. Two 21-Ga medical needles are used to protect fiber ends and to facilitate tissue penetration with minimum local blunt trauma in nude mice with xenografts. A 20W white light source (HL-2000-HP, Ocean Optics) is coupled to one fiber with SMA adapter. The other fiber is used to collect light, which is coupled into the spectrometer (QE65000 with Spectrasuite Operating software and OmniDriver, Ocean Optics). The wavelength response of the probe depends on the wavelength dependence of the light source, and of the light signal collection that includes considerable scatter, modeled with Monte-Carlo techniques (S. Jacques 2010 J. of Innov. Opt. Health Sci. 2 123-9). Measured spectra of tissue are normalized by a measured spectrum of a white standard, yielding the transmission spectrum. A head-and-neck xenograft on the flank of a live mouse is used for development.

RESULTS

The optical fiber probe delivers and collects light at an arbitrary depth in the tumor. By spectral fitting of the measured transmission spectrum, an analysis of blood volume and oxygen tension is obtained from the fitting parameters in real time.

CONCLUSIONS

A newly developed optical fiber spectroscopic system with an optical fiber probe takes spectroscopic techniques to a much deeper level in a tumor, which has potential applications for real-time monitoring hypoxic cell population dynamics for an eventual adaptive therapy metric of particular use in hypofractionated radiotherapy.

SU-E-J-196: In-Vivo Tumor Blood-Oxygen Content Measurement via Interstitial Optical Transmission Spectroscopy

PURPOSE

To demonstrate the application of in-vivo diffuse optical transmission spectroscopy in quantifying oxygen saturation in interstitial tissue, and to use this technique to examine reoxygenation dynamics in real-time as tumors responds to radiotherapy.

METHODS

Two 200 micron core fiber optics were threaded through two 21 gauge hypodermic needles: one coupled to an OceanOptics QE65000 spectrometer, and the other to an Ocean Optics HL-2000-HP 20W light source. These needles were fixed approximately 3 mm apart, and inserted into nude mice with human head- and-neck tumor xenografts. The oxygen saturation was then measured as a function of time after irradiation at intervals of 0.5, 1, 2, 6, 12, and 24, to measure the tumors' prompt oxygen saturation response to radiation.

RESULTS

Blood volume, deoxy and oxy-hemoglobin concentrations were measured through least-squares fitting of transmission spectra. Furthermore, various configurations of interstitial fiber optic probes were explored to optimize signal strength. Improvement of the optical coupling to the biological system and a concurrent increase in source intensity are the main two focuses for boosting signal strength.

CONCLUSIONS

This work has the potential to give an understanding of the time-scales of hypoxia and reoxygenation in vivo as tumors respond to radiation injury. This technique is of particular interest for hypofractionated therapies particularly treatments of only two or three treatments, where optimizing treatment timing can increase the tumorcidal effect of the remaining fractions.

Pixellated Cd(Zn)Te high-energy X-ray instrument

We have developed a pixellated high energy X-ray detector instrument to be used in a variety of imaging applications. The instrument consists of either a Cadmium Zinc Telluride or Cadmium Telluride (Cd(Zn)Te) detector bump-bonded to a large area ASIC and packaged with a high performance data acquisition system. The 80 by 80 pixels each of 250 μm by 250 μm give better than 1 keV FWHM energy resolution at 59.5 keV and 1.5 keV FWHM at 141 keV, at the same time providing a high speed imaging performance. This system uses a relatively simple wire-bonded interconnection scheme but this is being upgraded to allow multiple modules to be used with very small dead space. The readout system and the novel interconnect technology is described and how the system is performing in several target applications.

Immune profile and Epstein-Barr virus infection in acute interstitial nephritis: an immunohistochemical study in 78 patients

BACKGROUND

Acute interstitial nephritis (AIN) is a common cause of acute kidney injury and is characterised by a dense interstitial cellular infiltrate, which has not been well defined. Previous studies have demonstrated a correlation between Epstein-Barr virus (EBV) infection and AIN. The purpose of our study was to define the nature of the interstitial immune infiltrate and to investigate the possibility of renal infection with EBV.

METHODS

Seventy-eight patients with AIN were identified from renal biopsy reports in a single centre over an 18-year period. Immunohistochemical staining was performed to define the cellular infiltrate. In situ hybridization and immunohistology were used to detect EBV.

RESULTS

A positive correlation between CD68 macrophage infiltration and serum creatinine concentration at presentation was identified. IL-4, eotaxin, CCR3, CCR5 and VCAM-1 were all expressed in biopsies of AIN. Using in situ hybridization and immunohistochemistry, EBV was not detected in any of the AIN sections analysed.

CONCLUSION

This study has assessed the nature of the interstitial infiltrate in AIN. EBV was not detected in the renal biopsies, suggesting that EBV is not a pathogenetic factor in AIN.

A synchrotron tomographic energy-dispersive diffraction imaging study of the aerospace alloy Ti 6246

A titanium alloy sample (#6246) containing a linear friction weld has been imaged nondestructively using tomographic energy-dispersive diffraction imaging (TEDDI). The diffraction patterns measured at each point of the TEDDI image permitted identification of the material and phases present (±5%). The image also showed the preferred orientation and size–strain distribution present within the sample without the need for any further sample preparation. The preferred orientation was observed in clusters with average dimensions very similar to the experimental spatial resolution (400 µm). The length scales and preferred orientation distributions were consistent with orientation imaging microscopy measurements made by Szczepanski, Jha, Larsen & Jones [Metall. Mater. Trans. A(2008),39, 2841–2851] where the microstructure development was linked to the grain growth of the parent material. The use of a high-energy X-ray distribution (30–80 keV) in the incident beam reduced systematic errors due to the source profile, sample and air absorption. The TEDDI data from each voxel were reduced to an angle-dispersive form and Rietveld refined to a mean χ2of 1.4. The mean lattice parameter error (δd/d) ranged from ∼10−4for the highly crystalline regions to ∼10−3for regions of very strong preferred orientation and internal strain. The March–Dollase preferred orientation errors refined to an average value of ±2%. A 100% correlation between observed fluorescence and diffraction peak broadening was observed, providing further evidence for vicinal strain broadening.

Pleural and pericardial effusion: a potential ultrasonographic marker for the prenatal differential diagnosis between congenital diaphragmatic eventration and congenital diaphragmatic hernia

OBJECTIVES

To determine whether or not the presence of pleural and/or pericardial effusion can be used prenatally as an ultrasonographic marker for the differential diagnosis between diaphragmatic eventration and diaphragmatic hernia.

METHODS

We present two case reports of non-isolated diaphragmatic eventration associated with pleural and/or pericardial effusion. Additionally, we reviewed the literature for all cases of congenital diaphragmatic hernia (CDH) and diaphragmatic eventration that met the following criteria: (1) prenatal diagnosis of a diaphragmatic defect and (2) definitive diagnosis by autopsy or surgery. The frequencies of pleural effusion, pericardial effusion and hydrops were compared between the two conditions using Fisher's exact test. A subanalysis was conducted of cases with isolated diaphragmatic defects (i.e. diaphragmatic defects not associated with hydrops and other major structural or chromosomal anomalies).

RESULTS

A higher proportion of fetuses with diaphragmatic eventration had associated pleural and pericardial effusions compared with fetuses with diaphragmatic hernia (58% (7/12) vs. 3.7% (14/382), respectively, P < 0.001). This observation remained true when only cases of diaphragmatic defects not associated with hydrops and other major structural or chromosomal anomalies were compared (29% (2/7) with eventration vs. 2.2% (4/178) with CDH, P < 0.02).

CONCLUSIONS

The presence of pleural and/or pericardial effusion in patients with diaphragmatic defects should raise the possibility of a congenital diaphragmatic eventration. This information is clinically important for management and counseling because the prognosis and treatment for CDH and congenital diaphragmatic eventration are different. Published by John Wiley & Sons, Ltd.

Poliovirus persistence in human cells in vitro

Poliovirus (PV) can persist in vivo in the intestine of immunocompromised hosts for years. Moreover, immunocompetent individuals who have survived paralytic poliomyelitis sometimes develop the post-poliomyelitis syndrome (PPS), consisting of a variety of symptoms including new muscular atrophies. PPS may be due to PV persistence. We have developed models of PV persistence in neural cells and epidermoid cells. Cell determinants are of crucial importance for the establishment of persistent infections in human neuronal cells, whereas viral determinants play the primary role in human epidermoid HEp-2 cells. The results obtained with these in vitro models show the capacity of PV to persist and reveal a virus and cell co-evolution involving PV-receptor interactions. In addition, they suggest that several mechanisms are used by PV to establish and maintain persistent infections.

The Flexible Item Selection Task (FIST): a measure of executive function in preschoolers

Abstraction and cognitive flexibility were assessed in 197 preschool children at 2, 3, 4, and 5 years of age using the Flexible Item Selection Task, a task adapted from the Visual-Verbal Test (Feldman & Drasgow, 1951). On this new inductive task, children were shown a set of 3 cards and required to select 2 cards that matched each other on 1 dimension (Selection 1) and then to select a different pair of cards that matched each other on another dimension (Selection 2). Thus, 1 of the 3 cards always had to be selected twice according to different dimensions. Two-year-olds failed to understand basic task requirements as assessed by a criterial measure. Three-year-olds did more poorly on Selection 1 than 4- and 5-year-olds (who performed near ceiling), suggesting that 3-year-olds had difficulty with the abstraction component of the task. Four-year-olds did worse than 5-year-olds on Selection 2, suggesting that they had difficulty with the cognitive flexibility component (i.e., difficulty selecting the same card on more than 1 dimension). Results are discussed in terms of the development of executive function.

Time- and space-resolved dynamic studies on ceramic and cementitious materials

A review is given of the results and lessons arising from a sustained in situ diffraction study of the structure and performance of functional ceramic/cementitious materials in which synchrotron-based energy-dispersive diffraction has been the central under-pinning technique. Five particular points of discussion emerge: the demands on time resolution; the use of penetrating radiation for the in situ mode; the need for complementary techniques; re-analysing of data; spatially resolved diffraction: a new tomography. These aspects are discussed in turn using illustrative examples taken from the fields of cement hydration, clay intercalation, cation-exchanged zeolites, and particulate/fluid invasion into building and archaeological objects.

Activation of neurotransplants in humans

Clinical studies report symptomatic benefit in most fetal neurotransplantation treated Parkinson's disease patients. The underlying mechanism is incompletely explained. We investigated whether neural connections between host and transplanted tissue are established. Two Parkinson's disease patients with clinically excellent outcome after transplantation were studied with functional magnetic resonance imaging. A repetitive motor task that provided robust stimulation in the contralateral putamen in volunteers activated graft bearing regions of putamen in patients. In response to contralateral motor tasks, activation was recorded consistently in left putamen in patient 1 and in right putamen in patient 2. Functional magnetic resonance imaging suggests that neuronal rewiring contributes to the functioning of neurotransplants in vivo in humans.

Rule selection versus rule execution in preschoolers: an error-detection approach

In 2 experiments, an error-detection approach was used to determine whether 3-year-olds' perseverative errors on the postswitch phase of the Dimensional Change Card Sort (DCCS) are due to lack of response control or representational inflexibility. In Experiment 1, 3-, 4-, and 5-year-olds watched a puppet sort perseveratively on the postswitch phase and evaluated its responses. Most 4- and 5-year-olds detected the puppet's perseverative errors, whereas most 3-year-olds failed to do so despite detecting errors on a simpler card sort. Experiment 2 revealed that 3-year-olds who failed to correctly evaluate the puppet's behavior tended to fail their own DCCS. Results imply that perseveration on the DCCS cannot be attributed to difficulty inhibiting prepotent motor responses. Instead, changes in rule use between 3 and 5 years of age are interpreted in terms of the development of representational flexibility.

Safety of intrastriatal neurotransplantation for Huntington's disease patients

Fetal neural transplantation has been shown to be a feasible, safe, and according to a number of recent reports, effective treatment for Parkinson's disease (PD). Fetal striatal transplantation may be as feasible, safe, and effective a treatment for Huntington's disease (HD), a disorder for which there is currently no effective treatment. This report describes our experience with fetal striatal transplantation to adult striatum in three HD patients. Three moderately advanced, nondemented HD patients received transplantation of fetal striatal tissue. The striatal precursor was selectively obtained from the lateral ganglionic eminence. Each patient received bilateral grafts from five to eight donors, placed into the caudate nucleus (one graft on each side) and the putamen (four grafts on each side). All three patients had HD as documented by family history, DNA heterozygosity (17-20 and 48-51 repeats), magnetic resonance imaging (MRI) revealing striatal atrophy, and 2-deoxyglucose positron emission tomography revealing striatal hypometabolism. All patients had been evaluated using the Unified Huntington's Disease Rating Scale and appropriate neuropsychological tests for at least 3 months prior to transplantation. One year following transplantation, MRI of all three patients revealed that the grafts survived and grew within the striatum without displacing the surrounding tissue. No patients demonstrated adverse effects of the surgery or the associated cyclosporin immunosuppression, nor did any patient exhibit deterioration following the procedure. The limited experience provided by these three patients indicates that fetal tissue transplantation can be performed in HD patients without unexpected complications.

Neuropsychological functioning following fetal striatal transplantation in Huntington's chorea: three case presentations

Neurotransplantation has been proposed as a potential treatment for the neurodegenerative disorder of Huntington's disease (HD), which currently has no effective therapy. While patients with Parkinson's disease have received neurotransplantation, until recently no HD patients have undergone transplantation for HD with standardized evaluations of their progress following surgery. The current report presents the cognitive changes in three patients with HD who underwent bilateral transplantation of human fetal striatal tissue. As part of the pre- and postsurgical evaluation, all three patients were administered a neuropsychological battery sensitive to the cognitive effects of HD within 2 mo prior to surgery and at 4-6 mo following transplantation. Four to 6 mo subsequent to surgery, all patients demonstrated increased scores on some measures of cognitive functioning. However, the pattern of changes was not uniform across subjects. These findings suggest that fetal striatal transplantation may improve some of the cognitive symptoms associated with HD in the three reported patients.

Crystal structures of peptide complexes of the amino-terminal SH2 domain of the Syp tyrosine phosphatase

BACKGROUND

Src homology 2 (SH2) domains bind to phosphotyrosine residues in a sequence-specific manner, and thereby couple tyrosine phosphorylation to changes in the localization or catalytic activity of signal transducing molecules. Current understanding of SH2 specificity is based on the structures of SH2-peptide complexes of the closely-related Src and Lck tyrosine kinases. The tyrosine phosphatase Syp contains two SH2 domains that are relatively divergent from those of the tyrosine kinases, with distinct target specificities, and is thus well suited for structural studies aimed at extending our understanding of SH2 specificity.

RESULTS

Crystal structures of the amino-terminal SH2 domain of Syp in separate complexes with two high-affinity peptides, in complex with a non-specific peptide and in the uncomplexed form have been determined at between 2 A and 3 A resolution. The structure of the SH2 domain and the mode of high-affinity peptide binding is essentially similar to that seen in the Src and Lck structures. However, the binding interface is more extensive in Syp.

CONCLUSIONS

Most SH2 targets have hydrophobic residues at the third position following the phosphotyrosine, and the Syp structure confirms that the peptide is anchored to the SH2 surface by this residue and by the phosphotyrosine. In addition, the Syp structure has revealed that sequence specificity can extend across the five residues following the phosphotyrosine, and has shown how the SH2 domain's surface topography can be altered with resulting changes in specificity, while conserving the structure of the central core of the domain.

Cerebral metabolic changes induced by MK-801: a 1D (phosphorus and proton) and 2D (proton) in vivo NMR spectroscopy study

The dynamic effects of the non-competitive NMDA receptor antagonist, MK-801 on brain metabolism were investigated over 105 minutes in unanesthetized rats by proton and phosphorus NMR spectroscopy. MK-801 (0.5 and 5 mg/kg, i.p) induced no changes in intracellular pH, and in phosphocreatine, ATP, and inorganic phosphate levels, indicating that the drug preserved energy and intracellular pH homeostasis. There were transient increases in lactate after both doses of MK-801, suggesting early activation of glycolysis, which was not immediately matched by enhanced oxidative metabolism or by enhanced blood flow. Thereafter, lactate control level was not restored after 0.5 mg/kg whereas it was restored after 5 mg/kg in spite of a sustained metabolic activation. The low dose of MK-801 also caused a continuous decrease in cerebral aspartate level (-38%) which is thought to match the enhanced energy demand, whereas the high dose caused shorter and smaller changes. The intracerebral glucose level rose after MK-801 injection, indicating that brain tissue had an adequate or even excessive supply of glucose. Glucose time course seemed to closely match the changes in blood flow elicited by MK-801. This is the first study giving the metabolic pattern of a pharmacological activation. We demonstrate an excess of glycolysis over oxidative metabolism in the early time similar to that following physiological and pathophysiological states such as photic stimulation and seizures. The difference between the effects of the two doses of MK-801 suggests that the adjustment of cerebral metabolism to MK-801 activation is faster and greater with the high dose than with the low dose.

Therapy of recurrent high grade gliomas with surgery, and autologous mitogen activated IL-2 stimulated killer (MAK) lymphocytes: I. Enhancement of MAK lytic activity and cytokine production by PHA and clinical use of PHA

Nineteen patients with recurrent high grade gliomas were treated in a phase I/II trial with aggressive debulking of the tumor, mitogen activated IL-2 stimulated peripheral blood lymphocytes (MAK cells), and rIL-2. Phytohemagglutin (PHA) was introduced into the tumor site in 16 patients prior to implanting MAK cells and IL-2 in an attempt to trigger more effective lysis of the tumor in vivo. In vitro both TNF bioactivity and cytolytic activity of long term cultured MAK (LMAK) cells were dramatically enhanced by adding PHA to the cultures of these activated PBL. Three of eleven patients (27%) had a decrease in size of the enhancing lesion on CT and/or MRI. Seven (37%) patients clinically improved. Median survival after therapy was 30 weeks. PHA was shown to be safe in vivo and more effective than IL-2 triggering enhanced effector function in vitro.