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.