Mechanisms for controlling symbiont populations are critical for maintaining the associations that exist between a host and its microbial partners. We describe here the transcriptional, metabolic, and ultrastructural characteristics of a diel rhythm that occurs in the symbiosis between the squid Euprymna scolopes and the luminous bacterium Vibrio fischeri. The rhythm is driven by the host's expulsion from its light-emitting organ of most of the symbiont population each day at dawn. The transcriptomes of both the host epithelium that supports the symbionts and the symbiont population itself were characterized and compared at four times over this daily cycle. The greatest fluctuation in gene expression of both partners occurred as the day began. Most notable was an up-regulation in the host of >50 cytoskeleton-related genes just before dawn and their subsequent down-regulation within 6 h. Examination of the epithelium by TEM revealed a corresponding restructuring, characterized by effacement and blebbing of its apical surface. After the dawn expulsion, the epithelium reestablished its polarity, and the residual symbionts began growing, repopulating the light organ. Analysis of the symbiont transcriptome suggested that the bacteria respond to the effacement by up-regulating genes associated with anaerobic respiration of glycerol; supporting this finding, lipid analysis of the symbionts' membranes indicated a direct incorporation of host-derived fatty acids. After 12 h, the metabolic signature of the symbiont population shifted to one characteristic of chitin fermentation, which continued until the following dawn. Thus, the persistent maintenance of the squid-vibrio symbiosis is tied to a dynamic diel rhythm that involves both partners.Euprymna scolopes | microarray | mutualism | Vibrio fischeri | cytoskeleton

The light-organ symbiosis between the squid Euprymna scolopes and the luminous bacterium Vibrio fischeri offers the opportunity to decipher the hour-by-hour events that occur during the natural colonization of an animal's epithelial surface by its microbial partners. To determine the genetic basis of these events, a glassslide microarray was used to characterize the light-organ transcriptome of juvenile squid in response to the initiation of symbiosis. Patterns of gene expression were compared between animals not exposed to the symbiont, exposed to the wild-type symbiont, or exposed to a mutant symbiont defective in either of two key characters of this association: bacterial luminescence or autoinducer (AI) production. Hundreds of genes were differentially regulated as a result of symbiosis initiation, and a hierarchy existed in the magnitude of the host's response to three symbiont features: bacterial presence > luminescence > AI production. Putative host receptors for bacterial surface molecules known to induce squid development are up-regulated by symbiont light production, suggesting that bioluminescence plays a key role in preparing the host for bacteria-induced development. Further, because the transcriptional response of tissues exposed to AI in the natural context (i.e., with the symbionts) differed from that to AI alone, the presence of the bacteria potentiates the role of quorum signals in symbiosis. Comparison of these microarray data with those from other symbioses, such as germ-free/conventionalized mice and zebrafish, revealed a set of shared genes that may represent a core set of ancient host responses conserved throughout animal evolution.Euprymna ͉ fischeri ͉ microarray ͉ symbiosis

WHAT'S KNOWN ON THIS SUBJECT: Research in the aftermath of large-scale terrorist attacks shows that exposed children experience numerous negative psychological sequelae, including increased emotional difficulties, posttraumatic stress, and significant attack-related life disruptions. WHAT THIS STUDY ADDS:Most research on terrorism-exposed youth examines large-scale terrorism. Limited work examines reactions to terrorism of the scope of the marathon attack, and the extraordinary manhunt and shelter-in-place warning was an unprecedented experience. Understanding adjustment after these events is critical.abstract BACKGROUND: The majority of research on terrorism-exposed youth has examined large-scale terrorism with mass casualties. Limited research has examined children' s reactions to terrorism of the scope of the Boston Marathon bombing. Furthermore, the extraordinary postattack interagency manhunt and shelter-in-place warning made for a truly unprecedented experience in its own right for families. Understanding the psychological adjustment of Boston-area youth in the aftermath of these events is critical for informing clinical efforts. METHODS: Survey of Boston-area parents/caretakers (N = 460) reporting on their child's experiences during the attack week, as well as psychosocial functioning in the first 6 attack months. RESULTS: There was heterogeneity across youth in attack-and manhuntrelated experiences and clinical outcomes. The proportion of youth with likely attack/manhunt-related posttraumatic stress disorder (PTSD) was roughly 6 times higher among Boston Marathon-attending youth than nonattending youth. Attack and manhunt experiences each uniquely predicted 9% of PTSD symptom variance, with manhunt exposures more robustly associated than attack-related exposures with a range of psychosocial outcomes, including emotional symptoms, conduct problems, hyperactivity/inattention, and peer problems. One-fifth of youth watched .3 hours of televised coverage on the attack day, which was linked to PTSD symptoms, conduct problems, and total difficulties. Prosocial behavior and positive peer functioning buffered the impact of exposure. CONCLUSIONS: Clinical efforts must maintain a broadened focus beyond simply youth present at the blasts and must also include youth highly exposed to the intense interagency pursuit and manhunt. Continued research is needed to understand the adjustment of youth after mass traumas and large-scale manhunts in residential communities.

During an 18-month period, 6 laparoscopic partial nephrectomies were attempted, 4 of which were successful. The surgical technique was modified and improved between cases aided by new laparoscopic instrumentation, such as the argon beam coagulator and the 7.5 MHz. ultrasonic sector scanning system. In a retrospective comparison between laparoscopic and open partial nephrectomy, estimated blood loss was 525 ml. for the former versus 708 ml. for the latter procedure. However, operating time was more than 2 hours longer with the laparoscopic approach. The major advantages of the laparoscopic procedure appear to be a more rapid return to full diet, less postoperative pain and less requirement for parenteral narcotics. Despite the small size of this series and limited followup data, convalescence may be shortened by 4 weeks after laparoscopic partial nephrectomy. Patients with benign diseases of the kidney, especially with a duplicated collecting system, who require partial nephrectomy may be considered candidates for the laparoscopic approach. The advantages to the patient, however, may be offset by the technical demands on the surgeon.

Background. Imaging biomarkers hold tremendous promise for precision medicine clinical applications. Development of such biomarkers relies heavily on image post-processing tools for automated image quantitation. Their deployment in the context of clinical research necessitates interoperability with the clinical systems. Comparison with the established outcomes and evaluation tasks motivate integration of the clinical and imaging data, and the use of standardized approaches to support annotation and sharing of the analysis results and semantics. We developed the methodology and tools to support these tasks in Positron Emission Tomography and Computed Tomography (PET/CT) quantitative imaging (QI) biomarker development applied to head and neck cancer (HNC) treatment response assessment, using the Digital Imaging and Communications in Medicine (DICOM®) international standard and free open-source software.Methods. Quantitative analysis of PET/CT imaging data collected on patients undergoing treatment for HNC was conducted. Processing steps included Standardized Uptake Value (SUV) normalization of the images, segmentation of the tumor using manual and semi-automatic approaches, automatic segmentation of the reference regions, and extraction of the volumetric segmentation-based measurements. Suitable components of the DICOM standard were identified to model the various types of data produced by the analysis. A developer toolkit of conversion routines and an Application Programming Interface (API) were contributed and applied to create a standards-based representation of the data.Results. DICOM Real World Value Mapping, Segmentation and Structured Reporting objects were utilized for standards-compliant representation of the PET/CT QI analysis results and relevant clinical data. A number of correction proposals to the standard were developed. The open-source DICOM toolkit (DCMTK) was improved to simplify the task of DICOM encoding by introducing new API abstractions. Conversion and visualization tools utilizing this toolkit were developed. The encoded objects were validated for consistency and interoperability. The resulting dataset was deposited in the QIN-HEADNECK collection of The Cancer Imaging Archive (TCIA). Supporting tools for data analysis and DICOM conversion were made available as free open-source software.Discussion. We presented a detailed investigation of the development and application of the DICOM model, as well as the supporting open-source tools and toolkits, to accommodate representation of the research data in QI biomarker development. We demonstrated that the DICOM standard can be used to represent the types of data relevant in HNC QI biomarker development, and encode their complex relationships. The resulting annotated objects are amenable to data mining applications, and are interoperable with a variety of systems that support the DICOM standard.