Serrano (sano) functions with the planar cell polarity genes to control tracheal tube length.

Epithelial tubes are the functional units of many organs, and proper tube geometry is crucial for organ function. Here, we characterize serrano (sano), a novel cytoplasmic protein that is apically enriched in several tube-forming epithelia in Drosophila, including the tracheal system. Loss of sano results in elongated tracheae, whereas Sano overexpression causes shortened tracheae with reduced apical boundaries. Sano overexpression during larval and pupal stages causes planar cell polarity (PCP) defects in several adult tissues. In Sano-overexpressing pupal wing cells, core PCP proteins are mislocalized and prehairs are misoriented; sano loss or overexpression in the eye disrupts ommatidial polarity and rotation. Importantly, Sano binds the PCP regulator Dishevelled (Dsh), and loss or ectopic expression of many known PCP proteins in the trachea gives rise to similar defects observed with loss or gain of sano, revealing a previously unrecognized role for PCP pathway components in tube size control.

An image score inference system for RNAi genome-wide screening based on fuzzy mixture regression modeling.

With recent advances in fluorescence microscopy imaging techniques and methods of gene knock down by RNA interference (RNAi), genome-scale high-content screening (HCS) has emerged as a powerful approach to systematically identify all parts of complex biological processes. However, a critical barrier preventing fulfillment of the success is the lack of efficient and robust methods for automating RNAi image analysis and quantitative evaluation of the gene knock down effects on huge volume of HCS data. Facing such opportunities and challenges, we have started investigation of automatic methods towards the development of a fully automatic RNAi-HCS system. Particularly important are reliable approaches to cellular phenotype classification and image-based gene function estimation. We have developed a HCS analysis platform that consists of two main components: fluorescence image analysis and image scoring. For image analysis, we used a two-step enhanced watershed method to extract cellular boundaries from HCS images. Segmented cells were classified into several predefined phenotypes based on morphological and appearance features. Using statistical characteristics of the identified phenotypes as a quantitative description of the image, a score is generated that reflects gene function. Our scoring model integrates fuzzy gene class estimation and single regression models. The final functional score of an image was derived using the weighted combination of the inference from several support vector-based regression models. We validated our phenotype classification method and scoring system on our cellular phenotype and gene database with expert ground truth labeling. We built a database of high-content, 3-channel, fluorescence microscopy images of Drosophila Kc(167) cultured cells that were treated with RNAi to perturb gene function. The proposed informatics system for microscopy image analysis is tested on this database. Both of the two main components, automated phenotype classification and image scoring system, were evaluated. The robustness and efficiency of our system were validated in quantitatively predicting the biological relevance of genes.

Cellular phenotype recognition for high-content RNA interference genome-wide screening.

Genome-wide, cell-based screens using high-content screening (HCS) techniques and automated fluorescence microscopy generate thousands of high-content images that contain an enormous wealth of cell biological information. Such screens are key to the analysis of basic cell biological principles, such as control of cell cycle and cell morphology. However, these screens will ultimately only shed light on human disease mechanisms and potential cures if the analysis can keep up with the generation of data. A fundamental step toward automated analysis of high-content screening is to construct a robust platform for automatic cellular phenotype identification. The authors present a framework, consisting of microscopic image segmentation and analysis components, for automatic recognition of cellular phenotypes in the context of the Rho family of small GTPases. To implicate genes involved in Rac signaling, RNA interference (RNAi) was used to perturb gene functions, and the corresponding cellular phenotypes were analyzed for changes. The data used in the experiments are high-content, 3-channel, fluorescence microscopy images of Drosophila Kc167 cultured cells stained with markers that allow visualization of DNA, polymerized actin filaments, and the constitutively activated Rho protein Rac(V12). The performance of this approach was tested using a cellular database that contained more than 1000 samples of 3 predefined cellular phenotypes, and the generalization error was estimated using a cross-validation technique. Moreover, the authors applied this approach to analyze the whole high-content fluorescence images of Drosophila cells for further HCS-based gene function analysis.

The relationship between measures of unprofessional behavior during medical school and indices on the California Psychological Inventory.

BACKGROUND: Research studies on physicians disciplined by state medical boards showed specific types of unprofessional behavior were predictive of later disciplinary action. Similarly, law enforcement officers who received disciplinary action scored lower on certain scales of the California Psychological Inventory (CPI). METHOD: This study used a case-control descriptive design and independent t tests to examine differences in scores on six psychological indices (CPI scales) by level of unprofessional behavior during medical school. RESULTS: Physicians who demonstrated unprofessional behavior during medical school versus those who did not scored significantly lower on four CPI scales. Results are consistent with findings in which general unprofessional behavior during medical school can be further characterized to domains of irresponsibility, lack of self-improvement, and poor initiative. CONCLUSIONS: The psychological indices of the CPI scales differed by level of unprofessional behavior, which leads one to wonder whether the use of personality measures should be considered during the admissions process to medical school.

A questionnaire survey of students' perceptions of nurse tutor teaching in a clinical skills learning programme.

Changes in medical education and in the environments in which students learn have brought about new ways of learning in undergraduate medical curricula. Amongst these have been the establishment of courses in clinical skills learning to address concerns of deficient skills amongst newly qualified doctors. Curriculum reform at Liverpool, UK, included extensive and early learning of clinical skills. Nurse tutors provide full-time teaching support in a single Clinical Skills Resource Centre. They work alongside medically qualified tutors in delivering a clinical skills learning programme. This study aimed to explore students' opinion of nurses teaching clinical skills and to compare that to their opinion of teaching by medically qualified clinicians. A questionnaire survey was used to gain the views of 206 first-year medical students. Overall, students were strongly supportive in their opinion of nurse tutors. Some small statistically significant differences are probably of little or no educational significance. This role for nurses stresses the importance of interprofessional teachers in undergraduate healthcare education.

Psychological issues related to the use of spiral CT for lung cancer early detection.

Although the NCI is presently investigating whether enhanced detection of lung tumors via spiral CT reduces lung cancer mortality, use of this technology for lung cancer screening is already widespread in the US. Few data are available concerning level of interest in, or awareness of, spiral CT for lung cancer screening, correlates of participation in screening, or potential reactions to screening results (i.e. smoking cessation) among high-risk individuals. One-hundred-and-seventy-two current or former smokers with no personal cancer history were queried about their awareness of spiral CT for lung cancer screening, received information about the procedure, and completed a survey that assessed interest in screening, correlates of screening interest (i.e. demographic, health, psychological), and expected effects of screening results on smoking. Seventy-seven percent of respondents were unaware of spiral CT for lung cancer screening and 62% expressed high interest in screening. Screening interest was positively related to screening self-efficacy, knowledge of asymptomatic illness, and perceived lung cancer risk. In the face of a positive scan, 52% of smokers said that they would quit, 43% said they would consider quitting, and 3% would continue smoking. If the scan was negative, 19% of smokers said that they would quit, 61% said they would consider quitting, and 20% would continue smoking. Finally, 59% of smokers were interested in smoking cessation counseling, with screening. These findings can help guide the design of psychological interventions to promote the utilization of spiral CT for early lung cancer detection as well as the development of protocols to promote behavior change within lung cancer screening programs, should future studies indicate that spiral CT screening can effectively reduce the overall lung cancer mortality rate.

Characteristics of female smokers attending a lung cancer screening program: a pilot study with implications for program development.

Anticipating the development of lung cancer early detection programs, we examined the: (1) feasibility of a lung cancer early detection program; (2) characteristics of enrollees (e.g. motivation to quit smoking); (3) correlates of enrollee motivation to quit smoking; and (4) rates of smoking cessation following screening. Brief surveys were completed before and after screening, which involved sputum cytology, chest X-ray, bronchoscopy, spiral CT, and a meeting with an oncologist to discuss smoking cessation. Of the 168 eligible women who were heavy smokers recruited via newspaper and cancer center advertisements, 55 agreed to undergo screening. Enrollees showed low-to-moderate levels of quit motivation and high levels of nicotine addiction; enrollees were interested in a range of smoking cessation treatments; 20% of enrollees exhibited clinical-levels of emotional distress; 64% of enrollees reported low levels of self-efficacy (i.e. self-confidence) to quit; 24% of enrollees reported low levels of quitting pros and 25% reported high levels of quitting cons; 31% of enrollees showed high levels of fatalistic beliefs about cancer; and all enrollees recognized their elevated lung cancer risk. Greater motivation to quit smoking was related to: greater age, lower nicotine addiction, fewer health symptoms, and higher quitting self-efficacy and quitting pros. Finally, 16% of enrollees quit smoking after screening. Overall, many women eligible for screening refused to undergo comprehensive screening that included bronchoscopy and spiral CT. Screening may represent an opportunity for quitting smoking, although more intensive smoking cessation interventions that target nicotine addiction and self-efficacy may be needed to maximize the health benefits of an early detection program.

Organ positioning in Drosophila requires complex tissue-tissue interactions.

Positioning an organ with respect to other tissues is a complex process necessary for proper anatomical development and organ function. The local environment surrounding an organ can serve both as a substrate for migration and as a source of guidance cues that direct migration. Little is known about the factors guiding Drosophila salivary gland movement or about the contacts the glands establish along their migratory path. Here, we provide a detailed description of the spatial and temporal interactions between the salivary glands and surrounding tissues during embryogenesis. The glands directly contact five other tissues: the visceral mesoderm, gastric caecae, somatic mesoderm, fat body, and central nervous system. Mutational analysis reveals that all of the tissues tested in this study are important for normal salivary gland positioning; proper differentiation of the visceral and somatic mesoderm is necessary for the glands to attain their final correct position. We also provide evidence that the segment-polarity gene, gooseberry (gsb), controls expression of signals from the developing fat body that direct posterior migration of the glands. These data further the understanding of how organ morphology and position are determined by three-dimensional constraints and guidance cues provided by neighboring tissues.

Posterior migration of the salivary gland requires an intact visceral mesoderm and integrin function.

The final overall shape of an organ and its position within the developing embryo arise as a consequence of both its intrinsic properties and its interactions with surrounding tissues. Here, we focus on the role of directed cell migration in shaping and positioning the Drosophila salivary gland. We demonstrate that the salivary gland turns and migrates along the visceral mesoderm to become properly oriented with respect to the overall embryo. We show that salivary gland posterior migration requires the activities of genes that position the visceral mesoderm precursors, such as heartless, thickveins, and tinman, but does not require a differentiated visceral mesoderm. We also demonstrate a role for integrin function in salivary gland migration. Although the mutations affecting salivary gland motility and directional migration cause defects in the final positioning of the salivary gland, most do not affect the length or diameter of the salivary gland tube. These findings suggest that salivary tube dimensions may be an intrinsic property of salivary gland cells.