A METHOD TO IDENTIFY AND LOCALIZE A SINGLE HOT PARTICLE IN THE LUNGS USING AN ARRAY OF HIGH-PURITY GERMANIUM DETECTORS FOR IMPROVED ESTIMATE OF THE DEPOSITED ACTIVITY

A new method has been developed to identify and localize a single hot particle in the lungs using an array of four high-purity germanium detectors. The method is based upon calculating a set of three count rate ratios (generated by each individual detector in the array) that are evaluated in sequence to designate whether the measured deposition can be associated with a hot particle rather than the default assumption of a uniform activity distribution. Identification and localization of the hot particle are determined from a single in vivo measurement in which detectors are positioned above and below the thorax. The method was tested using an anthropomorphic thorax phantom in which point sources of 241Am, 137Cs and 60Co were individually inserted in the lungs at 15 different locations and were measured using a scanning bed whole-body counter. Depending upon source location and photon energy, a bias of -35% up to +76% could be introduced by falsely assuming a uniform activity distribution in the lungs. This bias would directly translate to an erroneous dose estimate to the lungs. It was demonstrated that by using the appropriate detector efficiencies for the single hot particle, the bias associated with the activity determination is reduced to <10% and ~2% in average.

Long-Term Correction of Albumin Levels in the Nagase Analbuminemic Rat: Repopulation of the Liver by Transplanted Normal Hepatocytes under a Regeneration Response

Numerous studies have reported successful transplantation of hepatocytes with demonstration of function. However, none have shown long-term correction of a liver-related metabolic defect. Male Nagase analbuminemic rats, immunosuppressed with cyclosporin-A, were transplanted with normal hepatocytes (2 × 107 cells/rat) isolated from allogeneic male Sprague–Dawley rat donors. Hepatocytes were selectively transplanted via the portal vein tributary into the posterior liver lobes of Nagase analbuminemic rats. Following 2 wk, to allow engraftment, selected transplanted rats (Group I) were reoperated and the portal venous branch supplying the anterior liver lobes was permanently ligated, resulting in their atrophy and induction of regeneration in the residual transplant-bearing lobes. Control rats consisted of: Group II—transplanted with normal hepatocytes without portal branch ligation; Group III—transplanted with analbuminemic hepatocytes with portal branch ligation; and Group IV—nontransplanted analbuminemic rats with portal branch ligation. The experimental period extended to 3 mo posttransplantation. All rats transplanted with normal hepatocytes demonstrated a significant elevation in serum albumin levels (ELISA). Group I rats had dramatic elevations in serum albumin to near normal levels (1.78 ± 0.20 g/dl), and maintained these levels until the end of the experiment Albumin levels in Group II rats reached 0.26 ± 0.07 g/dl (p < 0.001), whereas Group III and IV rats showed no changes in serum albumin levels throughout the experiment Immunohistology of liver tissue obtained from Group I rats, demonstrated large numbers (22.6 ± 7.5%) of albumin-positive hepatocytes populating the recipient liver. This is the first report of near-total and sustained correction of a genetic defect in liver function in an experimental animal model following allogeneic hepatocyte transplantation.

[Mucinous carcinoma of the breast: Clinical, biological and evolutive profile]

PURPOSE

Mucinous carcinoma of the breast accounts for 1 to 4% of all breast cancer. There are two histological subtypes: mixed mucinous carcinoma, where the ductal carcinoma is associated with the colloid component, and pure mucinous carcinoma, with a favorable prognosis, where the mucus surrounds the tumour tissue and constitutes a mechanical barrier limiting cell invasion and making this form less aggressive. Our study aimed to determine retrospectively the main epidemiological, clinical, biological, and therapeutic features, as well as the prognosis of this rare form of breast carcinoma.

MATERIALS AND METHODS

The authors report 32 cases of mucinous carcinoma of the breast diagnosed in Mohammed-VI centre for cancer treatment in Casablanca.

RESULTS

The average tumour size was 4.5cm (0.5-7cm). We found ten positive lymph node dissections, seven of them were of mixed mucinous carcinoma with a tumour size ranging between 4 and 7cm. Mucinous carcinoma was pure in 16 cases, mixed in 14 and a neuroendocrine differentiation was found in two cases. Most tumours were of an intermediate histological grade (n=19) with positive hormonal receptors (68%). After a mean follow-up of 30 months, complete remission was maintained in 92% of evaluable patients.

CONCLUSION

Mucinous carcinoma is a rare type of breast cancer, with a favourable prognosis for the pure form.

Surface-induced spin state locking of the [Fe(H2B(pz)2)2(bipy)] spin crossover complex

Temperature- and coverage-dependent studies of the Au(1 1 1)-supported spin crossover Fe(II) complex (SCO) of the type [Fe(H2B(pz)2)2(bipy)] with a suite of surface-sensitive spectroscopy and microscopy tools show that the substrate inhibits thermally induced transitions of the molecular spin state, so that both high-spin and low-spin states are preserved far beyond the spin transition temperature of free molecules. Scanning tunneling microscopy confirms that [Fe(H2B(pz)2)2(bipy)] grows as ordered, molecular bilayer islands at sub-monolayer coverage and as disordered film at higher coverage. The temperature dependence of the electronic structure suggest that the SCO films exhibit a mixture of spin states at room temperature, but upon cooling below the spin crossover transition the film spin state is best described as a mix of high-spin and low-spin state molecules of a ratio that is constant. This locking of the spin state is most likely the result of a substrate-induced conformational change of the interfacial molecules, but it is estimated that also the intra-atomic electron-electron Coulomb correlation energy, or Hubbard correlation energy U, could be an additional contributing factor.

Metal nanocluster light-emitting devices with suppressed parasitic emission and improved efficiency: exploring the impact of photophysical properties

Here we investigate the photophysical properties of Au(0)@Au(i)-thiolate nanoclusters by controlling the degree of aggregation, and measure electrochemical energy levels to design a metal nanocluster-based thin film LED (MNC-LED) structure. These efforts allow us to implement MNC-LEDs with luminance exceeding 40 cd m(-2) and external quantum efficiency exceeding 0.1% with clearly visible orange emission. It is also demonstrated that by varying the sizes of nanoclusters, the electroluminescence spectrum of the device can be tuned to the infrared emission, indicating the possibility of exploiting metal nanocluster emitters for use over a wide spectral range.

Lemierre's syndrome: a serious complication of a routine dental procedure

Lemierre's syndrome is the clinical presentation characterized by oropharyngeal or tonsillar infection, anaerobic septicaemia often with distant septic emboli, and clinical or radiological evidence of thrombosis of the internal jugular vein. We report a case of Lemierre's syndrome in a 44-year-old type II diabetic male. This case is unique for two reasons. Firstly, we believe it is the first reported iatrogenic case following a routine dental procedure. Secondly, the internal jugular vein thrombosis was found to occur on the contralateral side to the primary infection.

Chronic inflammatory autoimmune disorders and atherosclerosis

Rheumatoid arthritis (RA), periodontal disease (PD), and coronary artery disease (CAD) are common chronic inflammatory diseases. RA is associated with accelerated vascular risk resulting in an increased prevalence of CAD with attendant early mortality and excess morbidity. RA and PD have a common pathobiology. Accordingly, the aim of this study was to evaluate the association between RA, PD, and CAD and the influence of systemic inflammatory factors. A total of 100 active RA patients of which 50 had established CAD and 50 had no CAD were assessed for PD. All subjects underwent a clinical, cardiac, dental, laboratory, and radiological evaluation. Blood samples were obtained and the level of high-sensitivity C-reactive protein (hs-CRP), total white blood counts (WBC), erythrocyte sedimentation rate (ESR), fibrinogen and tumor necrosis alpha (TNF-alpha), total cholesterol (TC), and high-density lipoprotein (HDL) were assayed. The findings of this study demonstrated an association between RA, PD, and CAD. The RA patients with CAD had significantly more PD than RA patients without CAD, P < 0.001. The inflammatory markers hs-CRP, ESR, WBC, fibrinogen, and TNF-alpha were raised in all patients but were significantly higher in RA patients with CAD who also had PD, that is, in those with more inflammatory disease burden. HDL levels were lower in RA patients with CAD when compared to RA patients without CAD, P < 0.005. Evidence from this study shows an association between RA, PD, CAD, and systemic levels of the inflammatory mediators. The implication is that inflammation may be the central link between the chronic inflammatory autoimmune disorders and atherosclerosis.

Rheumatoid arthritis, periodontal disease and coronary artery disease

Rheumatoid arthritis (RA), periodontal disease (PD), and coronary artery disease (CAD) are common chronic inflammatory diseases. RA is associated with accelerated vascular risk resulting in an increased prevalence of CAD with attendant early mortality and excess morbidity. RA and PD have a common pathobiology. Accordingly, the aim of this study was to evaluate the association between RA, PD, and CAD and the influence of systemic inflammatory factors. A total of 100 active RA patients of which 50 had established CAD and 50 had no CAD were assessed for PD. All subjects underwent a clinical, cardiac, dental, laboratory, and radiological evaluation. Blood samples were obtained, and the level of high sensitivity C-reactive protein (hs-CRP), total white blood counts (WBC), erythrocyte sedimentation rate (ESR), fibrinogen and tumor necrosis factor (TNF) alpha, total cholesterol (TC), and high density lipoprotein (HDL) were assayed. The findings of this study demonstrated an association between RA, PD, and CAD. The RA patients with CAD had significantly more PD than RA patients without CAD. The inflammatory markers, hsCRP, ESR, WBC, fibrinogen, and TNF-alpha, were raised in all patients but were significantly higher in RA patients with CAD who also had PD. HDL levels were lower in RA patients with CAD when compared to RA patients without CAD. Evidence from this study shows an association between RA, PD, CAD, and systemic levels of the inflammatory mediators. The implication is that inflammation may be the central link between the chronic inflammatory, autoimmune disorders, and atherosclerosis.

E-MSD: improving data deposition and structure quality

The Macromolecular Structure Database (MSD) (http://www.ebi.ac.uk/msd/) [H. Boutselakis, D. Dimitropoulos, J. Fillon, A. Golovin, K. Henrick, A. Hussain, J. Ionides, M. John, P. A. Keller, E. Krissinel et al. (2003) E-MSD: the European Bioinformatics Institute Macromolecular Structure Database. Nucleic Acids Res., 31, 458-462.] group is one of the three partners in the worldwide Protein DataBank (wwPDB), the consortium entrusted with the collation, maintenance and distribution of the global repository of macromolecular structure data [H. Berman, K. Henrick and H. Nakamura (2003) Announcing the worldwide Protein Data Bank. Nature Struct. Biol., 10, 980.]. Since its inception, the MSD group has worked with partners around the world to improve the quality of PDB data, through a clean up programme that addresses inconsistencies and inaccuracies in the legacy archive. The improvements in data quality in the legacy archive have been achieved largely through the creation of a unified data archive, in the form of a relational database that stores all of the data in the wwPDB. The three partners are working towards improving the tools and methods for the deposition of new data by the community at large. The implementation of the MSD database, together with the parallel development of improved tools and methodologies for data harvesting, validation and archival, has lead to significant improvements in the quality of data that enters the archive. Through this and related projects in the NMR and EM realms the MSD continues to improve the quality of publicly available structural data.

E-MSD: an integrated data resource for bioinformatics

The Macromolecular Structure Database (MSD) group (http://www.ebi.ac.uk/msd/) continues to enhance the quality and consistency of macromolecular structure data in the Protein Data Bank (PDB) and to work towards the integration of various bioinformatics data resources. We have implemented a simple form-based interface that allows users to query the MSD directly. The MSD 'atlas pages' show all of the information in the MSD for a particular PDB entry. The group has designed new search interfaces aimed at specific areas of interest, such as the environment of ligands and the secondary structures of proteins. We have also implemented a novel search interface that begins to integrate separate MSD search services in a single graphical tool. We have worked closely with collaborators to build a new visualization tool that can present both structure and sequence data in a unified interface, and this data viewer is now used throughout the MSD services for the visualization and presentation of search results. Examples showcasing the functionality and power of these tools are available from tutorial webpages (http://www. ebi.ac.uk/msd-srv/docs/roadshow_tutorial/).

E-MSD: the European Bioinformatics Institute Macromolecular Structure Database

The E-MSD macromolecular structure relational database (http://www.ebi.ac.uk/msd) is designed to be a single access point for protein and nucleic acid structures and related information. The database is derived from Protein Data Bank (PDB) entries. Relational database technologies are used in a comprehensive cleaning procedure to ensure data uniformity across the whole archive. The search database contains an extensive set of derived properties, goodness-of-fit indicators, and links to other EBI databases including InterPro, GO, and SWISS-PROT, together with links to SCOP, CATH, PFAM and PROSITE. A generic search interface is available, coupled with a fast secondary structure domain search tool.

From molecular activities and processes to biological function

This paper describes how biological function can be represented in terms of molecular activities and processes. It presents several key features of a data model that is based on a conceptual description of the network of interactions between molecular entities within the cell and between cells. This model is implemented in the aMAZE database that presently deals with information on metabolic pathways, gene regulation, sub- or supracellular locations, and transport. It is shown that this model constitutes a useful generalisation of data representations currently implemented in metabolic pathway databases, and that it can furthermore include multiple schemes for categorising and classifying molecular entities, activities, processes and localisations. In particular, we highlight the flexibility offered by our system in representing multiple molecular activities and their control, in viewing biological function at different levels of resolution and in updating this view as our knowledge evolves.

Representing and analysing molecular and cellular function using the computer

Determining the biological function of a myriad of genes, and understanding how they interact to yield a living cell, is the major challenge of the post genome-sequencing era. The complexity of biological systems is such that this cannot be envisaged without the help of powerful computer systems capable of representing and analysing the intricate networks of physical and functional interactions between the different cellular components. In this review we try to provide the reader with an appreciation of where we stand in this regard. We discuss some of the inherent problems in describing the different facets of biological function, give an overview of how information on function is currently represented in the major biological databases, and describe different systems for organising and categorising the functions of gene products. In a second part, we present a new general data model, currently under development, which describes information on molecular function and cellular processes in a rigorous manner. The model is capable of representing a large variety of biochemical processes, including metabolic pathways, regulation of gene expression and signal transduction. It also incorporates taxonomies for categorising molecular entities, interactions and processes, and it offers means of viewing the information at different levels of resolution, and dealing with incomplete knowledge. The data model has been implemented in the database on protein function and cellular processes 'aMAZE' (http://www.ebi.ac.uk/research/pfbp/), which presently covers metabolic pathways and their regulation. Several tools for querying, displaying, and performing analyses on such pathways are briefly described in order to illustrate the practical applications enabled by the model.

Long-term correction of albumin levels in the Nagase analbuminemic rat: repopulation of the liver by transplanted normal hepatocytes under a regeneration response

Numerous studies have reported successful transplantation of hepatocytes with demonstration of function. However, none have shown long-term correction of a liver-related metabolic defect. Male Nagase analbuminemic rats, immunosuppressed with cyclosporin-A, were transplanted with normal hepatocytes (2 x 10(7) cells/rat) isolated from allogeneic male Sprague-Dawley rat donors. Hepatocytes were selectively transplanted via the portal vein tributary into the posterior liver lobes of Nagase analbuminemic rats. Following 2 wk, to allow engraftment, selected transplanted rats (Group I) were reoperated and the portal venous branch supplying the anterior liver lobes was permanently ligated, resulting in their atrophy and induction of regeneration in the residual transplant-bearing lobes. Control rats consisted of: Group II-transplanted with normal hepatocytes without portal branch ligation; Group III-transplanted with analbuminemic hepatocytes with portal branch ligation; and Group IV-nontransplanted analbuminemic rats with portal branch ligation. The experimental period extended to 3 mo posttransplantation. All rats transplanted with normal hepatocytes demonstrated a significant elevation in serum albumin levels (ELISA). Group I rats had dramatic elevations in serum albumin to near normal levels (1.78 +/- 0.20 g/dl), and maintained these levels until the end of the experiment. Albumin levels in Group II rats reached 0.26 +/- 0.07 g/dl (p < 0.001), whereas Group III and IV rats showed no changes in serum albumin levels throughout the experiment. Immunohistology of liver tissue obtained from Group I rats, demonstrated large numbers (22.6 +/- 7.5%) of albumin-positive hepatocytes populating the recipient liver. This is the first report of near-total and sustained correction of a genetic defect in liver function in an experimental animal model following allogeneic hepatocyte transplantation.

Masking as a mechanism for evaporative loss of trace analyte, especially after solid-phase extraction

Using a Pasteur pipette plugged with silanized glass wool and packed with C18-silica particles, we attempted to remove K2CO3 from an aqueous acetonitrile solution. In spite of extensive washing of the column with water after the sample was applied, elution with acetonitrile followed by evaporation gave a visible, white residue. It was found that the residue was derived from both the sample and the packing, including particles from the latter. Substitution of a plastic column/polyethylene frit for the Pasteur pipette/glass wool gave a more consistent residue, apparently because this improved the retention of particles. Subsequent experiments were conducted in the plastic hardware. The amount of the residue was observed to vary as much as 19-fold when C18-silica particles were tested from different manufacturers, and the residue could be reduced in amount as much as 9-fold when a column was prepared in the laboratory vs. the use of a comparable, pre-packed column. The water itself contributed some of the residue: even the "purest" water routinely available left a visible residue when 1.0 ml was appropriately evaporated (e.g. on Saran Wrap in a microwave oven). The recovery of an arbitrary trace analyte and internal standard (pentafluorobenzylated nucleobases at the low pg level) was 32% less when they were evaporated in acetonitrile that had been passed through an acetonitrile and water-washed cartridge containing C18-Si vs. evaporation in untreated acetonitrile. Collectively these results reveal that an evaporation can risk some loss of an analyte from masking by even subtle solvent contaminants.(ABSTRACT TRUNCATED AT 250 WORDS)

Galaxies, Human Eyes, and Artificial Neural Networks

The quantitative morphological classification of galaxies is important for understanding the origin of type frequency and correlations with environment. However, galaxy morphological classification is still mainly done visually by dedicated individuals, in the spirit of Hubble's original scheme and its modifications. The rapid increase in data on galaxy images at low and high redshift calls for a re-examination of the classification schemes and for automatic methods. Here are shown results from a systematic comparison of the dispersion among human experts classifying a uniformly selected sample of more than 800 digitized galaxy images. These galaxy images were then classified by six of the authors independently. The human classifications are compared with each other and with an automatic classification by an artificial neural network, which replicates the classification by a human expert to the same degree of agreement as that between two human experts.