A132 ENDOSCOPIC ULTRASOUND-GUIDED GASTROENTEROSTOMY USING A NOVEL DOUBLE BALLOON DEVICE IN THE MANAGEMENT OF MALIGNANT GASTRIC OUTLET OBSTRUCTION

Background

EUS-gastroenterostomy (EUS-GE) is a novel modality in the management of malignant gastric outlet obstruction (MGOO). It is, however, technically challenging limiting its widespread application. To facilitate EUS-GE, a double balloon catheter has been developed in Japan. While this tool is not available outside of Asia, we have conceived a similar device using a widely available vascular balloon catheter. We aim to determine the clinical efficacy and safety of EUS-GE using this double balloon device (DBD).

Aims

We aim to determine the clinical efficacy and safety of EUS-GE using this double balloon device (DBD).

Methods

This is a single-centre, retrospective study of consecutive patients who underwent DBD assisted EUS-GE for MGOO from January 2019-June 2020 (IRB approved). The DBD consists of two 60 mm vascular balloons (Coda, Cook Medical, USA) fashioned together with the balloons 10 cm apart (Figure 1). It is inserted across the obstruction over a wire to the ligaments of Treitz. Both balloons are then inflated followed by saline and contrast infusion into the occluded small bowel segment to facilitate EUS-guided insertion of a 15 mm cautery assisted lumen apposing metal stent (AxiosTM, Boston Scientific Inc, USA). The primary endpoint is the rate of technical success defined as adequate deployment of the stent. Secondary endpoints include rate of clinical success and adverse events.

Results

A total of 11 patients were included in this study. 45% were female with a mean age of 64.9 ± 8.6 years old. The etiology of MGOO was 73% pancreatic cancer, 9% gastric cancer, 9% duodenal cancer, and 9% metastatic cervical cancer. Procedures were performed under general anesthesia and conscious sedation in 82% and 18%, of patients respectively. The mean procedure time was 64.8 ± 25.8 minutes. Technical and clinical success (intention to treat) was 91%. The only technical failure was due to poor patient tolerance of the procedure under conscious sedation. There was one adverse event (9%) due to stent migration rated as severe. Two patients (18%) required re-intervention for stent obstruction secondary to food impaction associated with non-compliance to a low-residue diet. Following re-enforced instructions, no further obstruction occurred.

All patients started a clear liquid diet within 1 day of the procedure with a mean time to a low residue diet of 3.25 days ± 2.5. The median length of hospital stay following the procedure was 5 days ± 13. The median follow-up time was 84 days (IQR 152).

Conclusions

DBD assisted EUS-GE is clinically effective and safe. This balloon device may greatly facilitate the technical aspect of EUS-GE while potential enhancing its safety and clinical use. Larger studies are needed to validate this approach to EUS-GE.

Funding Agencies

None

The BioGRID database: A comprehensive biomedical resource of curated protein, genetic, and chemical interactions

The BioGRID (Biological General Repository for Interaction Datasets, thebiogrid.org) is an open-access database resource that houses manually curated protein and genetic interactions from multiple species including yeast, worm, fly, mouse, and human. The ~1.93 million curated interactions in BioGRID can be used to build complex networks to facilitate biomedical discoveries, particularly as related to human health and disease. All BioGRID content is curated from primary experimental evidence in the biomedical literature, and includes both focused low-throughput studies and large high-throughput datasets. BioGRID also captures protein post-translational modifications and protein or gene interactions with bioactive small molecules including many known drugs. A built-in network visualization tool combines all annotations and allows users to generate network graphs of protein, genetic and chemical interactions. In addition to general curation across species, BioGRID undertakes themed curation projects in specific aspects of cellular regulation, for example the ubiquitin-proteasome system, as well as specific disease areas, such as for the SARS-CoV-2 virus that causes COVID-19 severe acute respiratory syndrome. A recent extension of BioGRID, named the Open Repository of CRISPR Screens (ORCS, orcs.thebiogrid.org), captures single mutant phenotypes and genetic interactions from published high throughput genome-wide CRISPR/Cas9-based genetic screens. BioGRID-ORCS contains datasets for over 1,042 CRISPR screens carried out to date in human, mouse and fly cell lines. The biomedical research community can freely access all BioGRID data through the web interface, standardized file downloads, or via model organism databases and partner meta-databases.

The BioGRID interaction database: 2019 update

The Biological General Repository for Interaction Datasets (BioGRID: https://thebiogrid.org) is an open access database dedicated to the curation and archival storage of protein, genetic and chemical interactions for all major model organism species and humans. As of September 2018 (build 3.4.164), BioGRID contains records for 1 598 688 biological interactions manually annotated from 55 809 publications for 71 species, as classified by an updated set of controlled vocabularies for experimental detection methods. BioGRID also houses records for >700 000 post-translational modification sites. BioGRID now captures chemical interaction data, including chemical-protein interactions for human drug targets drawn from the DrugBank database and manually curated bioactive compounds reported in the literature. A new dedicated aspect of BioGRID annotates genome-wide CRISPR/Cas9-based screens that report gene-phenotype and gene-gene relationships. An extension of the BioGRID resource called the Open Repository for CRISPR Screens (ORCS) database (https://orcs.thebiogrid.org) currently contains over 500 genome-wide screens carried out in human or mouse cell lines. All data in BioGRID is made freely available without restriction, is directly downloadable in standard formats and can be readily incorporated into existing applications via our web service platforms. BioGRID data are also freely distributed through partner model organism databases and meta-databases.

The BioGRID interaction database: 2017 update

The Biological General Repository for Interaction Datasets (BioGRID: https://thebiogrid.org) is an open access database dedicated to the annotation and archival of protein, genetic and chemical interactions for all major model organism species and humans. As of September 2016 (build 3.4.140), the BioGRID contains 1 072 173 genetic and protein interactions, and 38 559 post-translational modifications, as manually annotated from 48 114 publications. This dataset represents interaction records for 66 model organisms and represents a 30% increase compared to the previous 2015 BioGRID update. BioGRID curates the biomedical literature for major model organism species, including humans, with a recent emphasis on central biological processes and specific human diseases. To facilitate network-based approaches to drug discovery, BioGRID now incorporates 27 501 chemical-protein interactions for human drug targets, as drawn from the DrugBank database. A new dynamic interaction network viewer allows the easy navigation and filtering of all genetic and protein interaction data, as well as for bioactive compounds and their established targets. BioGRID data are directly downloadable without restriction in a variety of standardized formats and are freely distributed through partner model organism databases and meta-databases.

BioGRID: A Resource for Studying Biological Interactions in Yeast

The Biological General Repository for Interaction Datasets (BioGRID) is a freely available public database that provides the biological and biomedical research communities with curated protein and genetic interaction data. Structured experimental evidence codes, an intuitive search interface, and visualization tools enable the discovery of individual gene, protein, or biological network function. BioGRID houses interaction data for the major model organism species--including yeast, nematode, fly, zebrafish, mouse, and human--with particular emphasis on the budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe as pioneer eukaryotic models for network biology. BioGRID has achieved comprehensive curation coverage of the entire literature for these two major yeast models, which is actively maintained through monthly curation updates. As of September 2015, BioGRID houses approximately 335,400 biological interactions for budding yeast and approximately 67,800 interactions for fission yeast. BioGRID also supports an integrated posttranslational modification (PTM) viewer that incorporates more than 20,100 yeast phosphorylation sites curated through its sister database, the PhosphoGRID.

The BioGRID interaction database: 2015 update

The Biological General Repository for Interaction Datasets (BioGRID: http://thebiogrid.org) is an open access database that houses genetic and protein interactions curated from the primary biomedical literature for all major model organism species and humans. As of September 2014, the BioGRID contains 749 912 interactions as drawn from 43 149 publications that represent 30 model organisms. This interaction count represents a 50% increase compared to our previous 2013 BioGRID update. BioGRID data are freely distributed through partner model organism databases and meta-databases and are directly downloadable in a variety of formats. In addition to general curation of the published literature for the major model species, BioGRID undertakes themed curation projects in areas of particular relevance for biomedical sciences, such as the ubiquitin-proteasome system and various human disease-associated interaction networks. BioGRID curation is coordinated through an Interaction Management System (IMS) that facilitates the compilation interaction records through structured evidence codes, phenotype ontologies, and gene annotation. The BioGRID architecture has been improved in order to support a broader range of interaction and post-translational modification types, to allow the representation of more complex multi-gene/protein interactions, to account for cellular phenotypes through structured ontologies, to expedite curation through semi-automated text-mining approaches, and to enhance curation quality control.

Multidisciplinary department of "Return to Work After a Cancer": a French experience of support groups for vocational rehabilitation

This qualitative pilot exploratory study focuses on support groups for vocational rehabilitation after cancer implemented in a French and innovative multidisciplinary department of "Return to Work after a Cancer." Sixty-three patients were invited to participate to constitute two support groups of 20 participants. Questionnaires are sent to assess their benefit according to the participants' point of view. For 58% of participants, support groups helped the return to work, and for 70% it provided personal, family, and relational support. Support groups are a relevant response to expectations and specific issues of patients experiencing return to work after cancer.

The BioGRID interaction database: 2013 update

The Biological General Repository for Interaction Datasets (BioGRID: http//thebiogrid.org) is an open access archive of genetic and protein interactions that are curated from the primary biomedical literature for all major model organism species. As of September 2012, BioGRID houses more than 500 000 manually annotated interactions from more than 30 model organisms. BioGRID maintains complete curation coverage of the literature for the budding yeast Saccharomyces cerevisiae, the fission yeast Schizosaccharomyces pombe and the model plant Arabidopsis thaliana. A number of themed curation projects in areas of biomedical importance are also supported. BioGRID has established collaborations and/or shares data records for the annotation of interactions and phenotypes with most major model organism databases, including Saccharomyces Genome Database, PomBase, WormBase, FlyBase and The Arabidopsis Information Resource. BioGRID also actively engages with the text-mining community to benchmark and deploy automated tools to expedite curation workflows. BioGRID data are freely accessible through both a user-defined interactive interface and in batch downloads in a wide variety of formats, including PSI-MI2.5 and tab-delimited files. BioGRID records can also be interrogated and analyzed with a series of new bioinformatics tools, which include a post-translational modification viewer, a graphical viewer, a REST service and a Cytoscape plugin.

The BioGRID Interaction Database: 2011 update

The Biological General Repository for Interaction Datasets (BioGRID) is a public database that archives and disseminates genetic and protein interaction data from model organisms and humans (http://www.thebiogrid.org). BioGRID currently holds 347 966 interactions (170 162 genetic, 177 804 protein) curated from both high-throughput data sets and individual focused studies, as derived from over 23 000 publications in the primary literature. Complete coverage of the entire literature is maintained for budding yeast (Saccharomyces cerevisiae), fission yeast (Schizosaccharomyces pombe) and thale cress (Arabidopsis thaliana), and efforts to expand curation across multiple metazoan species are underway. The BioGRID houses 48 831 human protein interactions that have been curated from 10 247 publications. Current curation drives are focused on particular areas of biology to enable insights into conserved networks and pathways that are relevant to human health. The BioGRID 3.0 web interface contains new search and display features that enable rapid queries across multiple data types and sources. An automated Interaction Management System (IMS) is used to prioritize, coordinate and track curation across international sites and projects. BioGRID provides interaction data to several model organism databases, resources such as Entrez-Gene and other interaction meta-databases. The entire BioGRID 3.0 data collection may be downloaded in multiple file formats, including PSI MI XML. Source code for BioGRID 3.0 is freely available without any restrictions.

A global protein kinase and phosphatase interaction network in yeast

The interactions of protein kinases and phosphatases with their regulatory subunits and substrates underpin cellular regulation. We identified a kinase and phosphatase interaction (KPI) network of 1844 interactions in budding yeast by mass spectrometric analysis of protein complexes. The KPI network contained many dense local regions of interactions that suggested new functions. Notably, the cell cycle phosphatase Cdc14 associated with multiple kinases that revealed roles for Cdc14 in mitogen-activated protein kinase signaling, the DNA damage response, and metabolism, whereas interactions of the target of rapamycin complex 1 (TORC1) uncovered new effector kinases in nitrogen and carbon metabolism. An extensive backbone of kinase-kinase interactions cross-connects the proteome and may serve to coordinate diverse cellular responses.

Still stratus not altocumulus: further evidence against the date/party hub distinction

Analysis of multi-validated protein interaction data reveals networks with greater interconnectivity than the more segregated structures seen in previously available data. To help visualize this, the authors draw comparisons between continuous stratus clouds and altocumulus clouds.

Nucleophosmin/B23 negatively regulates GCN5-dependent histone acetylation and transactivation

Nucleophosmin/B23 is a multifunctional phosphoprotein that is overexpressed in cancer cells and has been shown to be involved in both positive and negative regulation of transcription. In this study, we first identified GCN5 acetyltransferase as a B23-interacting protein by mass spectrometry, which was then confirmed by in vivo co-immunoprecipitation. An in vitro assay demonstrated that B23 bound the PCAF-N domain of GCN5 and inhibited GCN5-mediated acetylation of both free and mononucleosomal histones, probably through interfering with GCN5 and masking histones from being acetylated. Mitotic B23 exhibited higher inhibitory activity on GCN5-mediated histone acetylation than interphase B23. Immunodepletion experiments of mitotic extracts revealed that phosphorylation of B23 at Thr 199 enhanced the inhibition of GCN5-mediated histone acetylation. Moreover, luciferase reporter and microarray analyses suggested that B23 attenuated GCN5-mediated transactivation in vivo. Taken together, our studies suggest a molecular mechanism of B23 in the mitotic inhibition of GCN5-mediated histone acetylation and transactivation.

The BioGRID Interaction Database: 2008 update

The Biological General Repository for Interaction Datasets (BioGRID) database (http://www.thebiogrid.org) was developed to house and distribute collections of protein and genetic interactions from major model organism species. BioGRID currently contains over 198 000 interactions from six different species, as derived from both high-throughput studies and conventional focused studies. Through comprehensive curation efforts, BioGRID now includes a virtually complete set of interactions reported to date in the primary literature for both the budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe. A number of new features have been added to the BioGRID including an improved user interface to display interactions based on different attributes, a mirror site and a dedicated interaction management system to coordinate curation across different locations. The BioGRID provides interaction data with monthly updates to Saccharomyces Genome Database, Flybase and Entrez Gene. Source code for the BioGRID and the linked Osprey network visualization system is now freely available without restriction.

Stratus not altocumulus: a new view of the yeast protein interaction network

Systems biology approaches can reveal intermediary levels of organization between genotype and phenotype that often underlie biological phenomena such as polygenic effects and protein dispensability. An important conceptualization is the module, which is loosely defined as a cohort of proteins that perform a dedicated cellular task. Based on a computational analysis of limited interaction datasets in the budding yeast Saccharomyces cerevisiae, it has been suggested that the global protein interaction network is segregated such that highly connected proteins, called hubs, tend not to link to each other. Moreover, it has been suggested that hubs fall into two distinct classes: “party” hubs are co-expressed and co-localized with their partners, whereas “date” hubs interact with incoherently expressed and diversely localized partners, and thereby cohere disparate parts of the global network. This structure may be compared with altocumulus clouds, i.e., cotton ball–like structures sparsely connected by thin wisps. However, this organization might reflect a small and/or biased sample set of interactions. In a multi-validated high-confidence (HC) interaction network, assembled from all extant S. cerevisiae interaction data, including recently available proteome-wide interaction data and a large set of reliable literature-derived interactions, we find that hub–hub interactions are not suppressed. In fact, the number of interactions a hub has with other hubs is a good predictor of whether a hub protein is essential or not. We find that date hubs are neither required for network tolerance to node deletion, nor do date hubs have distinct biological attributes compared to other hubs. Date and party hubs do not, for example, evolve at different rates. Our analysis suggests that the organization of global protein interaction network is highly interconnected and hence interdependent, more like the continuous dense aggregations of stratus clouds than the segregated configuration of altocumulus clouds. If the network is configured in a stratus format, cross-talk between proteins is potentially a major source of noise. In turn, control of the activity of the most highly connected proteins may be vital. Indeed, we find that a fluctuation in steady-state levels of the most connected proteins is minimized.

Analysis of multi-validated protein interaction data reveals networks with greater interconnectivity than the more segregated structures seen in previously available data. To help visualize this, the authors draw comparisons between continuous stratus clouds and altocumulus clouds.

Development of a database: DACTARI for a radiotoxic element ranking methodology

Dosimetric impact studies aim at evaluating potential radiological effects of chronic or acute releases from nuclear facilities. A methodology for ranking radionuclides (RN) in terms of their health-related impact on the human population was first developed at CEA with specific criteria for each RN that could be applied to a variety of situations. It is based, in particular, on applying physico-chemical criteria to the complete RN inventory (present in the release or in the source term) and on applying norms related to radiation protection and chemical toxicology. The initial step consisted in identifying and collecting data necessary to apply the methodology, with reference to a previous database of long-lived radionuclides (LLRN, with half-lives ranging from 30 to 10(14) y) containing 95 radionuclides. The initial results have allowed us to identify missing data and revealed the need to complete the study for both toxic and radiotoxic aspects. This led us to the next step, developing a specific database, DAtabase for Chemical Toxicity and Radiotoxicity Assessment of RadIonuclides (DACTARI), to collect data on chemical toxicity and radiotoxicity, including acute or chronic toxicity, the chemical form of the compounds, the contamination route (ingestion, inhalation), lethal doses, target organs, intestinal and maternal-foetal transfer, drinking water guidelines and the mutagenic and carcinogenic properties.

Structural and Functional Analysis of Saccharomyces cerevisiae Mob1

The Mob proteins function as activator subunits for the Dbf2/Dbf20 family of protein kinases. Human and Xenopus Mob1 protein structures corresponding to the most conserved C-terminal core, but lacking the variable N-terminal region, have been reported and provide a framework for understanding the mechanism of Dbf2/Dbf20 regulation. Here, we report the 2.0 A X-ray crystal structure of Saccharomyces cerevisiae Mob1 containing both the conserved C-terminal core and the variable N-terminal region. Within the N-terminal region, three novel structural elements are observed; namely, an alpha-helix denoted H0, a strand-like element denoted S0 and a short beta strand denoted S-1. Helix H0 associates in an intermolecular manner with a second Mob1 molecule to form a Mob1 homodimer. Strand S0 binds to the core domain in an intramolecular manner across a putative Dbf2 binding site mapped by Mob1 temperature-sensitive alleles and NMR binding experiments. In vivo functional analysis demonstrates that Mob1 mutants that target helix H0 or its reciprocal binding site are biologically compromised. The N-terminal region of Mob1 thus contains structural elements that are functionally important.

Comprehensive curation and analysis of global interaction networks in Saccharomyces cerevisiae

BACKGROUND

The study of complex biological networks and prediction of gene function has been enabled by high-throughput (HTP) methods for detection of genetic and protein interactions. Sparse coverage in HTP datasets may, however, distort network properties and confound predictions. Although a vast number of well substantiated interactions are recorded in the scientific literature, these data have not yet been distilled into networks that enable system-level inference.

RESULTS

We describe here a comprehensive database of genetic and protein interactions, and associated experimental evidence, for the budding yeast Saccharomyces cerevisiae, as manually curated from over 31,793 abstracts and online publications. This literature-curated (LC) dataset contains 33,311 interactions, on the order of all extant HTP datasets combined. Surprisingly, HTP protein-interaction datasets currently achieve only around 14% coverage of the interactions in the literature. The LC network nevertheless shares attributes with HTP networks, including scale-free connectivity and correlations between interactions, abundance, localization, and expression. We find that essential genes or proteins are enriched for interactions with other essential genes or proteins, suggesting that the global network may be functionally unified. This interconnectivity is supported by a substantial overlap of protein and genetic interactions in the LC dataset. We show that the LC dataset considerably improves the predictive power of network-analysis approaches. The full LC dataset is available at the BioGRID (http://www.thebiogrid.org) and SGD (http://www.yeastgenome.org/) databases.

CONCLUSION

Comprehensive datasets of biological interactions derived from the primary literature provide critical benchmarks for HTP methods, augment functional prediction, and reveal system-level attributes of biological networks.

BioGRID: a general repository for interaction datasets

Access to unified datasets of protein and genetic interactions is critical for interrogation of gene/protein function and analysis of global network properties. BioGRID is a freely accessible database of physical and genetic interactions available at . BioGRID release version 2.0 includes >116 000 interactions from Saccharomyces cerevisiae, Caenorhabditis elegans, Drosophila melanogaster and Homo sapiens. Over 30 000 interactions have recently been added from 5778 sources through exhaustive curation of the Saccharomyces cerevisiae primary literature. An internally hyper-linked web interface allows for rapid search and retrieval of interaction data. Full or user-defined datasets are freely downloadable as tab-delimited text files and PSI-MI XML. Pre-computed graphical layouts of interactions are available in a variety of file formats. User-customized graphs with embedded protein, gene and interaction attributes can be constructed with a visualization system called Osprey that is dynamically linked to the BioGRID.

Uncovering novel cell cycle players through the inactivation of securin in budding yeast

Budding yeast securin/Pds1p, an inhibitor of the anaphase activator separase/Esp1p, is involved in several checkpoint pathways and in promoting Esp1p's nuclear localization. Using a modified synthetic genetic array (SGA) screen for genes that become essential in the absence of Pds1p, we uncovered roles for uncharacterized genes in cell cycle processes, including Esp1p activation.

Phenotypic and Transcriptional Plasticity Directed by a Yeast Mitogen-Activated Protein Kinase Network

The yeast pheromone/filamentous growth MAPK pathway mediates both mating and invasive-growth responses. The interface between this MAPK module and the transcriptional machinery consists of a network of two MAPKs, Fus3 and Kss1; two regulators, Rst1 and Rst2 (a.k.a. Dig1 and Dig2); and two transcription factors, Ste12 and Tec1. Of 16 possible combinations of gene deletions in FUS3, KSS1, RST1, and RST2 in the Σ1278 background, 10 display constitutive invasive growth. Rst1 was the primary negative regulator of invasive growth, while other components either attenuated or enhanced invasive growth, depending on the genetic context. Despite activation of the invasive response by lesions at the same level in the MAPK pathway, transcriptional profiles of different invasive mutant combinations did not exhibit a unified program of gene expression. The distal MAPK regulatory network is thus capable of generating phenotypically similar invasive-growth states (an attractor) from different molecular architectures (trajectories) that can functionally compensate for one another. This systems-level robustness may also account for the observed diversity of signals that trigger invasive growth.

CHD1 associates with NCoR and histone deacetylase as well as with RNA splicing proteins

CHD1 is one of a family of nuclear proteins containing two chromodomains, a SWI/SNF-like helicase/ATPase domain and a DNA binding domain. We found that CHD1 co-immunoprecipitates with histone deacetylase (HDAC) activity and that CHD1 also associates with NCoR, a transcriptional corepressor, in yeast two-hybrid and in vitro pull-down assays. NCoR is known to associate with HDACs to effect its repressive activity, suggesting that the predicted chromatin remodeling activity of CHD1 plays a role in this repression. Yeast two-hybrid assays also showed that CHD1 interacts with splicing proteins mKIAA0164, Srp20, and SAF-B. Splicing assays show that CHD1 overexpression can affect alternative splicing. These results suggest that CHD1 may function in both chromatin mediated transcriptional repression and RNA splicing.

A genome-wide survey of RS domain proteins

Domains rich in alternating arginine and serine residues (RS domains) are frequently found in metazoan proteins involved in pre-mRNA splicing. The RS domains of splicing factors associate with each other and are important for the formation of protein-protein interactions required for both constitutive and regulated splicing. The prevalence of the RS domain in splicing factors suggests that it might serve as a useful signature for the identification of new proteins that function in pre-mRNA processing, although it remains to be determined whether RS domains also participate in other cellular functions. Using database search and sequence clustering methods, we have identified and categorized RS domain proteins encoded within the entire genomes of Homo sapiens, Drosophila melanogaster, Caenorhabditis elegans, and Saccharomyces cerevisiae. This genome-wide survey revealed a surprising complexity of RS domain proteins in metazoans with functions associated with chromatin structure, transcription by RNA polymerase II, cell cycle, and cell structure, as well as pre-mRNA processing. Also identified were RS domain proteins in S. cerevisiae with functions associated with cell structure, osmotic regulation, and cell cycle progression. The results thus demonstrate an effective strategy for the genomic mining of RS domain proteins. The identification of many new proteins using this strategy has provided a database of factors that are candidates for forming RS domain-mediated interactions associated with different steps in pre-mRNA processing, in addition to other cellular functions.

Afferent delays and the mislocalization of perisaccadic stimuli

Determining the precise moment a visual stimulus appears is difficult because visual response latencies vary. This temporal uncertainty could cause localization errors to brief visual targets presented before and during eye movements if the oculomotor system cannot determine the position of the eye at the time the stimulus appeared. We investigated the effect of varying neural processing time on localization accuracy for perisaccadic visual targets that differed in luminance. Although systematic errors in localization were observed, the effect of luminance was surprisingly small. We explore several hypotheses that may explain why processing delays are not more disruptive to localization performance.

MAPK specificity in the yeast pheromone response independent of transcriptional activation

The mechanisms whereby different external cues stimulate the same mitogen-activated protein kinase (MAPK) cascade, yet trigger an appropriately distinct biological response, epitomize the conundrum of specificity in cell signaling. In yeast, shared upstream components of the mating pheromone and filamentous growth pathways activate two related MAPKs, Fus3 and Kss1, which in turn regulate programs of gene expression via the transcription factor Ste12. As fus3, but not kss1, strains are impaired for mating, Fus3 exhibits specificity for the pheromone response. To account for this specificity, it has been suggested that Fus3 physically occludes Kss1 from pheromone-activated signaling complexes, which are formed on the scaffold protein Ste5. However, we find that genome-wide expression profiles of pheromone-treated wild-type, fus3, and kss1 deletion strains are highly correlated for all induced genes and, further, that two catalytically inactive versions of Fus3 fail to abrogate the pheromone-induced transcriptional response. Consistently, Fus3 and Kss1 kinase activity is induced to an equivalent extent in pheromone-treated cells. In contrast, both in vivo and in an in vitro-reconstituted MAPK system, Fus3, but not Kss1, exhibits strong substrate selectivity toward Far1, a bifunctional protein required for polarization and G(1) arrest. This effect accounts for the failure to repress G(1)-S specific transcription in fus3 strains and, in part, explains the mating defect of such strains. MAPK specificity in the pheromone response evidently occurs primarily at the substrate level, as opposed to specific kinase activation by dedicated signaling complexes.

Interferon regulatory factor expression in human breast cancer

OBJECTIVE

To investigate the expression of interferon regulatory factors 1 and 2 (IRF-1 and IRF-2) in human breast cancer.

SUMMARY BACKGROUND DATA

Interferon regulatory factors 1 and 2 are transcription factors in the interferon gamma signal transduction pathway. IRF-1 acts as the effector arm of the interferon gamma response; IRF-2 binds to the same DNA consensus sequence and opposes IRF-1 activity. Previous work in the authors' laboratory has shown the tumor suppressor activity of IRF-1 expression and the oncogenic effect of IRF-2 in human and murine tumor models, including human breast cancer cell lines. The authors' hypothesis is that this pathway is involved in human tumor development, and alterations in the expression of IRF-1 and IRF-2 may occur in breast cancer tissue compared with normal breast tissue, and between more and less differentiated breast cancers.

METHODS

Formalin-fixed paraffin-embedded human archival tissue specimens were obtained from 33 patients with pure ductal carcinoma in situ (DCIS) and 49 women with invasive ductal cancer. Adjacent areas of normal breast tissue were assayed in 31 women. These specimens were stained with polyclonal IRF-1 and IRF-2 antibodies using an avidin-biotin-peroxidase complex technique after epitope retrieval.

RESULTS

Most normal breast tissue showed expression of IRF-1 and no expression of IRF-2 by immunohistochemistry. High-grade DCIS or node-positive invasive ductal cancers were less likely to express the tumor suppressor IRF-1 than normal tissue. More strikingly, high-grade DCIS and invasive ductal cancers were much more likely to express the oncogenic IRF-2 protein than was normal tissue.

CONCLUSIONS

Expression of IRF-1 and IRF-2 is altered in human breast cancer compared with normal adjacent tissue. The loss of IRF-1 expression is consistent with tumor suppressor loss and the development of IRF-2 expression with oncogenic activation. These data support the hypothesis that this pathway is involved in human breast oncogenesis, which warrants further investigation regarding prognostic and therapeutic implications.

Fluorine-18 fluorodeoxyglucose positron emission tomography correlated with computed tomographic scan and magnetic resonance imaging in a case of hematometrocolpos

A 12-year-old girl had intense abdominal pain that had increased in the past 3 months and was accompanied by weight loss. An ultrasound examination revealed large cystic masses in the abdomen. A computed tomographic scan could not conclusively rule out a malignant condition. The hymen was normal on physical examination, but magnetic resonance imaging confirmed that the abnormalities corresponded to dilated cavities of the vagina, uterus, and fallopian tubes, with an appearance suggestive of hematometrocolpos. Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography was requested concurrently with the magnetic resonance image to assess the metabolic activity of the lesions and to exclude the presence of distant metastases. Large defects without FDG accumulation were noted in the areas corresponding to the cystic masses. Vaginal atresia with hematometrocolpos was confirmed at surgery. This rare case involving F-18 FDG positron emission tomographic imaging in hematometrocolpos illustrates that this diagnosis should be considered in the presence of symmetric hypometabolic masses in the pelvis.

Effect of tamoxifen on sexual functioning in patients with breast cancer

PURPOSE

To define the incidence of sexual dysfunction in a population of women with breast cancer treated with tamoxifen.

PATIENTS AND METHODS

Breast cancer patients with a performance status of 0 to 2 who had been treated with tamoxifen for 2 to 24 months completed the following measures: the Center for Epidemiologic Studies-Depression Scale, the Sexual History Form, and the Breast Cancer Prevention Trial Symptom Checklist. Forty-nine of the participants underwent gynecologic examinations with vaginal smears for determination of estrogen effect.

RESULTS

Fifty-seven women were entered onto the trial. Sexual desire, arousal, and ability to achieve orgasm were comparable to norms established in participants in the Tamoxifen Prevention Trial (National Surgical Adjuvant Breast and Bowel Project P-01). Pain, burning, or discomfort with intercourse was reported in 54% of patients and did not correlate with age, surgical treatment of the primary cancer, or chemotherapy. Estrogen effect was seen on the vaginal smears of 34 of 49 participants and was more common in older patients (P = .054). The presence of estrogen effect correlated with negative reactions during sex (P = .02) and vaginal dryness or tightness (P = .046).

CONCLUSION

Women treated with tamoxifen in the adjuvant setting experienced symptoms of sexual dysfunction. The individual contributions of chemotherapy and tamoxifen to sexual dysfunction warrant prospective study.

Osmunda (Osmundaceae) from the Triassic of Antarctica: an example of evolutionary stasis

Compressed specimens of the fern Osmunda are described from the Triassic of the Allan Hills, Antarctica. The specimens consist of a once pinnate, deeply pinnatifid fertile frond as well as several sterile specimens. Six pinnae are present on the partial fertile rachis, with two sterile pinnae above four fertile pinnae. Both sterile and fertile specimens are virtually identical to the modern species Osmunda claytoniana. Entire fronds are fragmentary; the longest is 21 cm in length. Sterile pinnae are alternate and deeply pinnatifid, with slightly toothed pinnules and dichotomous venation. Fertile pinnae are 1-1.3 cm long, once pinnate, and lack vegetative lamina. Sporangia are clustered, each 300-375 um in diameter, and possess a transverse annulus 6-8 cells long; dehiscence is by a vertical slit. Fronds arise from a rhizome 4 cm long by 1 cm wide; two croziers are present on the rhizome. Two frond segments up to 6 cm long and three deeply pinnatifid pinnae are present on the uppermost part of one rachis. Pinnules are ~4 mm long and 2-3 mm wide. The presence of this Osmunda species in the Triassic demonstrates stasis of frond morphology, both fertile and vegetative, for the genus.

Internalization and distribution of inositol hexakisphosphate in red blood cells

Inositol hexakisphosphate (InsP6), an allosteric effector of haemoglobin, is able to modify the oxyhaemoglobin dissociation curve. The rightwards shift of the curve increases the in vivo oxygen delivery to tissues. Such an exogenous substance may be internalized into red blood cells (RBC) using a reversed lysis-resealing process following a hypoosmotic shock, resulting in InsP6-RBC with modified oxygen transport capacity. The efficacy of the process depends on various physicochemical parameters which can be fixed during the experimental protocol. The variability of InsP6 internalization from one sample to another appeared to be mainly due to the natural variation in osmotic fragility of RBC. This factor was also modified during the storage of RBC units before the lysis-resealing process. The separation of InsP6-RBC on a density gradient revealed a wide heterogeneity of internalized InsP6 concentration, varying with the degree of osmotic shock. The control of these various parameters will result in resealed InsP6-RBC in reproducible conditions suitable for in vivo use.

Cognitively impaired spouses as primary caregivers for demented elderly people

OBJECTIVE

To describe problems of dementia patients whose spousal caregivers are also cognitively impaired.

DESIGN

Retrospective chart review.

SETTING

The geriatric assessment clinic at University of California, San Diego, which is one center for the California State sponsored Alzheimer's Disease Diagnosis and Treatment Center Program.

PATIENTS

During the period from January 1992 through May 1994, 65 patients completed the assessment and met the entry criteria of being demented and having a spousal caregiver. Twelve of the spouses scored six or more error points on the Katzman Short Orientation-Memory-Concentration Test.

MEASUREMENTS

Patient data included age, living situation, other caregivers, use of formal and informal support systems, profiles of medical, cognitive, and functional ability, caregivers interactions, and recommendations from the evaluation.

MAIN RESULTS

Dementia patients with cognitively impaired spouses utilized fewer community resources (P = .021) and experienced difficulty with medication compliance (P = .041) more often than those with cognitively normal spousal caregivers.

CONCLUSIONS

Older caregivers of patients suffering from dementia should be screened for cognitive problems.

Technetium-99m antimyosin antibody (3-48) myocardial imaging: human biodistribution, safety and clinical results in detection of acute myocardial infarction

Technetium-99m antimyosin (99mTc-AM) antibody imaging may have significant advantages over indium-111 antimyosin in clinical practice. The purpose of this study was to determine the human biodistribution, the safety profile and the sensitivity of 99mTc-AM (3-48) imaging in the detection of both Q-wave and non-Q-wave myocardial infarction (MI). Biodistribution and safety parameters were mainly determined in 12 normal healthy volunteers while 40 patients with proven MI (22 Q-wave, 18 non-Q-wave) were injected with 99mTc-AM (20-25 mCi) between 5 h and 7 days after the onset of acute chest pain. Three standard planar views were performed at 6 h and at 24 h post injection. Both sets of images were completed in 33 patients while two patients were imaged only at 6 h, three patients only at 18 h and one at 18 and 24 h. One patient was not imaged. Vital signs and ECG were recorded and blood samples for haematology, biochemistry and human antimurine antibodies (HAMA) and urinalysis were obtained in all volunteers and patients. No serious adverse reactions or side-effects attributable to 99mTc-AM have been reported. No volunteers or patients developed allergic reactions or significant increases in HAMA titres. Reading of 99mTc-AM imaging was performed by two blinded experienced observers. The sensitivity of 99mTc-AM in the detection of MI was 100% (21/21) for Q-wave and 83.3% (15/18) for non-Q-wave infarctions. The overall sensitivity was 92.3% (36/39). The three false-negative cases were inferoposterior MI. A certain degree of uptake focalization was seen in 26 out of 35 (74.2%) at 6 h. At 24 h, two patients (5.8%) did not show 99mTc-AM uptake while 22 (64.7%) showed intense focal uptake, seven (20.6%) moderate uptake and 3 (8.9%) slight uptake. It is concluded that 99mTc-AM (3-48) imaging is safe and shows high sensitivity in the detection of both Q-wave and non-Q-wave MI even with early imaging (6 h post injection). These promising results warrant further clinical investigation.

Comparison of the effects of captopril and nicardipine on insulin sensitivity and thrombotic profile in patients with hypertension and android obesity. CaptISM Study Group. Captopril Insulin Sensitivity Multicenter Study Group

Hypertension is often related to metabolic disorders, such as android obesity, glucose intolerance, dyslipidemia, and hyperinsulinism (X syndrome). Insulin resistance (IR), described as the common link among these disorders, could contribute to an increase in coronary risk. The euglycemic insulin clamp technique has been used to show that different classes of antihypertensive agents have different effects on IR. The purpose of this multicenter study was to compare the effects of captopril to those of nicardipine on insulin profile using the oral glucose tolerance test (OGTT), a routine-feasible test. After a 1-month single-blind placebo period, 154 patients with hypertension and android obesity were randomized to 3 months of double-blind therapy with either 50 mg captopril twice daily (n = 77) or 50 mg nicardipine twice daily n = 77). An OGTT with an assay of insulin was performed before and after active treatment. Lipid parameters, Factor VII (F VII), fibrinogen, plasminogen activator inhibitor 1 (PAI-1), and insulin-like growth factor I (IGF-I) were measured at the same time. After 3 months of treatment, the changes from baseline in mean +/- SD values for the insulin area under the curve (AUC) were -24.8 +/- 107.4 microIU x h/mL (-15.2%) for captopril v 6.1 +/- 98.6 microIU x h/mL (4.8%) for nicardipine (P = .072). Changes in peak insulin values were -18.3 +/- 86.2 microIU/mL (-14%) for captopril v 6.7 +/- 79.4 microIU/mL (6.6%) for nicardipine (P = .070).(ABSTRACT TRUNCATED AT 250 WORDS)

Monoclonal antibody against a tumor-associated sialoglycoprotein of superficial papillary bladder tumors and cervical condylomas

A mouse IgG1 monoclonal antibody (MAb), 19A211, defining a tumor-associated cell-surface antigen of superficial papillary bladder tumors, was generated by immunizing with fresh bladder tumor cells mice neonatally injected with normal human urothelial cells. The reactivity of the antibody with cell lines was examined by indirect immunofluorescence staining and was restricted to 3/14 bladder cancer lines and 3/31 cancer cell lines of non-bladder origin, including HeLa cervical cancer. No normal fibroblast, kidney cells, EBV-lymphocytes, erythrocytes or leukocytes expressed the antigen. Reactivity of MAb 19A211 was well preserved on tissue paraffin sections. Immunoperoxidase staining of normal adult or fetal tissues showed no reactivity except for a patchy or uniform staining of umbrella cells in 6/23 adult and 1/4 fetal urothelium samples. Positive and often heterogeneous staining was observed on 24/38 papillary superficial tumors (Ta) and 4/5 carcinoma in situ bladder lesions but on only 4/20 infiltrating tumors. It was also observed on 5/6 cervical condylomas and one bladder condyloma, but none of 6 penile or vulvar condylomas. All other tumors tested were negative. The antigenic determinant is present on a heterogeneous group of proteins with molecular weights ranging from 90 to 200 kDa. It is sensitive to periodate treatment and to neuraminidase but only partially sensitive to proteases. MAb 19A211 is different from other reported MAbs with similar reactivity to superficial bladder tumors and umbrella cells of normal urothelium. When tested in competition assays, several of these MAbs, but not 19A211, were found to react with Lewis X blood group determinant. Our results suggest that 19A211 may be useful for detection and stratification of bladder tumors.

Estimation of fractional changes in peak gNa, -gNa, ENa, and h infinity (V) of cardiac cells from Vmax of the propagating action potential

Fractional changes in the peak sodium conductances of the cardiac cell membrane during the action potential are often estimated from fractional changes in Vmax. The present model study shows, in reasonable accord with experimental evidence, that this approach is valid for propagating action potentials provided that the membrane capacitance does not change and that the nonsodium current is small at the time of Vmax. When the maximum conductance of the sodium channel (gNa) and the sodium equilibrium potential (ENa) are varied independently of one another, fractional changes in either of them can be predicted from fractional changes in Vmax if a reasonable estimate of the initial value of ENa is available. Manipulations which modify the resting membrane potential without changing gNa allow to calculate fractional changes in the steady-state Na+ inactivation [h infinity (V)] when ENa is known. Simulation runs were carried out for a continuous cable and a discontinuous cable with either a low (1 omega.cm2) or a high (10 omega.cm2) junctional resistance. The predictions of the model are valid in the discontinuous cable provided that the recording point remains strictly the same throughout the series of measurements. Because the high-resistance discontinuous cable provides conditions which reduce further the nonsodium current at the time of Vmax, the accuracy of the predictions are better in this case. It is concluded that properly designed experimental approaches based on Vmax measurements can yield important information on manipulations affecting gNa, ENa, and h infinity (V) during propagation, and that a better accuracy is possible in cardiac muscle when measurements are made during transverse propagation.

Model study of the spread of electrotonic potential in cardiac tissue

This model study describes the electrotonic response of a cable model of cardiac tissue stimulated at one point. The stimulus is applied intracellularly in the form of a 2 ms pulse of current of near threshold amplitude. The attenuation of the electrotonic potential with distance and its mode of propagation along the cable are compared for equivalent passive, continuous and discontinuous cables. The three structures have the same basic physical and electrical characteristic and they differ either with respect to being active or passive or to the presence or absence of intercellular gap junctions. In the continuous cable a just subthreshold stimulus produces a local active response which propagates more slowly and is attenuated less rapidly with distance than in a passive cable. The spatial decrement of the local response in a discontinuous cable is faster than in a continuous cable of equal average resistivity. It is suggested that the larger time constant of the foot of the action potential observed in the longitudinal direction in cardiac muscle could be due in part to the electrotonic spread of the local response from the site of stimulation.

Comparaison de critères utilisables pour l'étude de la structure des populations du polychète Nereis virens (Sars)

The various biometrical criteria used in the study of the population structure of the annelid polychaete Nereis virens (Sars) are reviewed. This type of study, which requires the examination of large numbers of specimens representing all size classes, is sometimes complicated by the occurrence of autotomy, a phenomenon quite frequent in this species, and by mechanical breaks during sampling and sieving. Measurements such as total length, width of an anterior segment, and total weight are not good criteria. We have used a new biometrical criterium developed at the Laboratoire maritime de Dinard (France). This criterium is based on a partial weight of animals that have been put in formaldehyde and wiped; the weight is determined from an histogram in which breaking points are "ranked". This ponderal measurement has been compared with the linear measurement of the jaw length. The new method allows the manipulation of a larger number of individuals and it is easier and faster to use than the method based on jaw measurements.[Journal translation]

Polymorphic expression of a human superficial bladder tumor antigen defined by mouse monoclonal antibodies

Three mouse monoclonal antibodies (mAbs), which define a highly restricted antigen, were obtained by simultaneous immunizations with superficial papillary bladder tumor cells and mouse polyclonal serum against normal urothelium. The antigen was detected by the avidin/biotin/peroxidase method in 30/44 superficial bladder tumors (68%) but in only 4/27 infiltrating urothelial cancers (with much less intensity). No normal adult or fetal tissues tested expressed the antigen, including normal urothelium from 40 individuals, 13 of whom had a bladder tumor positive for the antigen. Only 1 of 45 nonbladder tumors showed some reactivity with one of the three mAbs. Serological tests on a large panel of human cancer cell lines and normal cultured cells were negative. The antigen is highly stable and well preserved on paraffin-embedded tissues. Electrophoretic transfer blot experiments with fresh tumor extracts showed that all three mAbs react with a determinant on a component of 300,000 Mr (pI 9.5) and 62,000 Mr (pI 6.5). The antigen shows polymorphic expression at the cellular level on tissue sections and also at a molecular level on immunoblots where the two bands are differentially detected on extracts of a series of tumors but are not visualized on normal urothelium extracts. The characteristics of this antigenic system suggest that it may provide some insights about the biology of bladder cancer. Specific detection of the antigen on 70% of superficial bladder tumors with normal cytology may be useful for their diagnosis and follow-up.