Genetically encoded barcodes for correlative volume electron microscopy.

While genetically encoded reporters are common for fluorescence microscopy, equivalent multiplexable gene reporters for electron microscopy (EM) are still scarce. Here, by installing a variable number of fixation-stable metal-interacting moieties in the lumen of encapsulin nanocompartments of different sizes, we developed a suite of spherically symmetric and concentric barcodes (EMcapsulins) that are readable by standard EM techniques. Six classes of EMcapsulins could be automatically segmented and differentiated. The coding capacity was further increased by arranging several EMcapsulins into distinct patterns via a set of rigid spacers of variable length. Fluorescent EMcapsulins were expressed to monitor subcellular structures in light and EM. Neuronal expression in Drosophila and mouse brains enabled the automatic identification of genetically defined cells in EM. EMcapsulins are compatible with transmission EM, scanning EM and focused ion beam scanning EM. The expandable palette of genetically controlled EM-readable barcodes can augment anatomical EM images with multiplexed gene expression maps.

Efficiency evaluation of leaded glasses and visors for eye lens dose reduction during fluoroscopy guided interventional procedures.

PURPOSE: Fluoroscopy guided interventional procedures guarantee high benefits for patients, but are associated with high levels of radiation exposure for the medical staff. Their increasing use and complexity results in even higher radiation exposures, with a risk to exceed the annual dose limit of 20 mSv for the eye lens. The aim of the study was to evaluate the potential dose reduction of eye lens exposure for lead glasses and for two types of visors (half and full), used by physicians performing interventional procedures. METHODS: Eye lens dose measurements were carried out on an anthropomorphic phantom simulating a physician performing a fluoroscopy guided interventional procedure. Dose reduction factors were calculated using high sensitivity thermoluminescent dosimeters. Moreover, a spatial dose distribution was generated for the two visors. RESULTS: The dose reduction coefficient was found to be 1.6 for the glasses, 1.2 for the half visor and 4.5 for the full visor. CONCLUSIONS: Optimal radiation protection requires a combination of different radiation protection equipment. Full visors that cover all the face of the operator are recommended, as they absorb scattered radiation reaching the eyes from all directions. Full visors should be prioritized over radiation protection glasses for cases where other protective equipment such as ceiling shielding cannot be used.

Quality assurance of dose management systems.

BACKGROUND AND AIM: Dose management systems (DMS's) have been widely used for radiation dose data collection and analysis, and have been proven useful for optimization. Although DMS's are used for patient dosimetry, a quality assurance (QA) program has not yet been developed. The aim of this work was to propose vendor neutral quality tests and discuss how QA can be established for DMS's to ensure robustness and quality of patient dose data. MATERIALS & METHODS: Different DMS's functions were organized in three groups according to their complexity. As basic functions, we defined those that depend on simple data collection and require data verification. Intermediate functions provide calculations such as effective dose or higher dose alerts, while the advanced group aims to address complicated analyses, such as peak skin dose calculations. RESULTS: An Excel file was developed that includes quality tests on basic and intermediate functions for different modalities (radiography, interventional radiology, CT and mammography) and is provided as Annex. For advanced functionalities, tests are discussed to guide medical physics experts to design their QA program as appropriate. CONCLUSIONS: The QA program is intended to ensure the trustworthy functioning for applications in normal circumstances and patient outliers. As DMS's are systems with regular upgrades, the associated QA program should be a dynamic process that takes into account the functionalities of the DMS and its application in the clinics. Medical physics experts should ensure the safety and accuracy of DMS's, as an essential component in patient dosimetry - part of their mission.

Systematic literature review on the benefit of patient protection shielding during medical X-ray imaging: Towards a discontinuation of the current practice.

PURPOSE: Patient shielding during medical X-ray imaging has been increasingly criticized in the last years due to growing evidence that it often provides minimal benefit and may even compromise image quality. In Europe, and as also shown in a short assessment in Switzerland, the use of patient shielding is inhomogeneous. The aim of this study was to systematically review recent literature in order to assess benefits and appraise disadvantages related to the routine use of patient shielding. METHODS: To evaluate benefits and disadvantages related to the application of patient shielding in radiological procedures, a systematic literature review was performed for CT, radiography, mammography and fluoroscopy-guided medical X-ray imaging. In addition, reports from medical physics societies and authorities of different countries were considered in the evaluation. RESULTS: The literature review revealed 479 papers and reports on the topic, from which 87 qualified for closer analysis. The review considered in- and out-of-plane patient shielding as well as shielding for pregnant and pediatric patients. Dose savings and other dose and non-dose related effects of patient shielding were considered in the evaluation. CONCLUSIONS: Although patient shielding has been used in radiological practice for many years, its use is no longer undisputed. The evaluation of the systematic literature review of recent studies and reports shows that dose savings are rather minimal while significant dose- and non-dose-related detrimental effects are present. Consequently, the routine usage of patient protection shielding in medical X-ray imaging can be safely discontinued for all modalities and patient groups.

Adaption and validity of the “Physical Activity Class Satisfaction Questionnaire» (PACSQ) in Greek educational dancing context / Adaptación y validez del "Cuestionario de Satisfacción de La Clase de Actividad Física" (PACSQ) en el contexto de baile educativo griego / Adaptação e validade do "Questionário de Satisfação da Classe de Atividade Física" (PACSQ) no contexto de dança educacional grega

Satisfaction is a contributing factor to increasing participation in sports activities, especially since it is linkedto behavioural procedures responsible for causing positive feelings to people involved. The aim of this study was to confirm the “Physical Activity Class Satisfaction Questionnaire”in a Greek educational dancing context. The internal consistency of the questionnaire has also been examined. The sample of the study consisted of 482 participants, 184 male and 298 females. All participants have attended Greek traditional dance courses in dancing associations among Greece. The scale consists of 45 questions which constitute nine factors. The following statistical analyses were carried out: Questionnaire’s validity and reliability were examined via an exploratory factor analysis and a confirmatory factor analysis. Reliability analysis was conducted to examine the internal cohesion of the factors. Descriptive statistics have been calculated to broadly examine the degree of satisfaction. Results’ analysis arrived at the following conclusion:a. The Greek version of the questionnaire has shown stablestationary psychometric properties, which partially support its use in the Greek dancing context. b. Correlations among subscales indicated a related factor model supporting the construct validityof the scale. (AU)

La satisfacción es un factor que contribuye a aumentar la participación en las actividades deportivas, principalmente porque está vinculada a procedimientos conductuales responsables de generar sentimientos positivos en las personas involucradas. El objetivo de este estudio fue confirmar el "Cuestionario de Satisfacción de La Clase de Educación Física" en un contexto educativo de danza griega. También se examinó la coherencia interna del cuestionario. La muestra del estudio consistió en 482 participantes, 184 de los cuales eran hombres y 298 eran mujeres. Todos los participantes asistieron a cursos de danza tradicional griega en diferentes asociaciones de danza en Grecia. La escala consta de 45 preguntas que constituyen nueve factores. Se realizaron los siguientes análisis estadísticos: La validez y fiabilidad del cuestionario se examinaron mediante un análisis de factores exploratorios y un análisis de factores confirmatorios. Se llevó a cabo un análisis de fiabilidad para examinar la cohesión interna de los factores. Se calcularon estadísticas descriptivas para examinar ampliamente el grado de satisfacción. El análisis de los resultados llegó a la siguiente conclusión: a) La versión griega del cuestionario mostró propiedades psicométricas estacionarias estables, que apoyan parcialmente su uso en el contexto de la danza griega. b) Las correlaciones entre las subescalas indicaban un modelo de factor relacionado que soporta la validez de la construcción de escalas. (AU)

A satisfação é um fator que contribui para aumentar a participação nas atividades desportivas, principalmentepor estar ligada a procedimentos comportamentais responsáveis por gerarem sentimentos positivos nas pessoas envolvidas. O objetivo deste estudo foi confirmar o “Questionário de Satisfação da Aula de Educação Física” num contexto educacional grego de dança. A consistência interna do questionário também foi examinada. A amostra do estudo foi composta por 482 participantes, sendo que 184 eram homens e 298 eram mulheres. Todos os participantes frequentaram cursos de dança tradicional grega em diferentes associações de dança na Grécia. A escala é composta por 45 questões que constituem nove fatores. Foram realizadas as seguintes análises estatísticas: A validade e confiabilidade do questionário foram examinadas através de uma análise de fatores exploratória e uma análise de fatoresconfirmatória. A análise de confiabilidade foi conduzida para examinar a coesão interna dos fatores. Foram calculadas estatísticas descritivas para examinaramplamente o grau de satisfação. A análise dos resultados chegou à seguinte conclusão: a) A versão grega do questionário mostrou propriedades psicométricas estacionárias estáveis, que suportam parcialmente o seu uso no contexto da dança grega. b) As correlações entre as subescalas indicaram um modelo de fator relacionado que suporta a validade de construção da escala. (AU)

Exogenous oxytocin modulates human myometrial microRNAs.

OBJECTIVE: MicroRNAs (miRNAs) play a modulatory role in pathways that lead to labor onset, although oxytocin is known to modulate gene expression within the myometrium. We aimed to identify miRNAs whose expression is regulated by oxytocin in pregnant human myometrium. STUDY DESIGN: Myometrial miRNA expression profiles were compared between samples collected from women at term before the onset of labor (no labor; n = 8) and after labor onset after early exogenous oxytocin treatment (n = 8). Multivariate modelling was used to assess differences in miRNA profiles. Biologic validation was undertaken on 3 independent patient cohorts (no labor, n = 10; labor induced with oxytocin, n = 8; and spontaneous labor with no oxytocin treatment, n = 10). In vitro studies that used primary myocytes were undertaken to assess target miRNA expression after oxytocin treatment. Target genes of candidate miRNAs were identified in silico and cross-referenced with genes that are known to be associated with labor or expressed in myometrium. RESULTS: In total, 1309 miRNAs were analyzed by microarray, of which 494 were detected in human myometrium. Multivariate modeling identified 12 target miRNAs the differential expression of which was most responsible for the observed separation of the 2 patient populations in the primary discovery cohorts. Biologic validation in the independent secondary sample cohorts showed that oxytocin independently regulated 5 miRNAs (hsa-miR-146b-3p, hsa-miR-196b-3p, hsa-miR-223-3p, hsa-miR-873-5p, and hsa-miR-876-5p). Additionally, hsa-miR-146b-3p was increased both in labor that was induced with oxytocin and in myometrium from spontaneous labor with no oxytocin treatment compared with no labor samples. Four of the validated miRNAs (hsa-miR-146a-5p, hsa-miR-146b-3p, hsa-miR-196b-3p, and hsa-miR-876-5p) were expressed in primary human myocytes; oxytocin treatment of these cells replicated the directional changes that were observed in vivo. CONCLUSION: Oxytocin alters the expression of a unique set of myometrial miRNAs. These results suggest a further role for oxytocin as a signaling molecule that is involved in the regulation of gene expression during parturition.

Exposure of the Swiss population to computed tomography.

BACKGROUND: The frequency of CT procedures has registered a significant increase over the last decade, which led at the international level to an increasing concern on the radiological risk associated with the use of CT especially in paediatrics. This work aimed at investigating the use of computed tomography in Switzerland, following the evolution of CT frequency and dose data over a decade and comparing it to data reported in other countries. METHODS: The frequency and dose data related to CT are obtained by means of a nationwide survey. National frequencies were established by projecting the collected data, using the ratio of the number of CT units belonging to the respondents to the total number of CT units in the country. The effective doses per examination were collected during an auditing campaign. RESULTS: In 2008 about 0.8 Million CT procedures (~100 CT examinations/1000 population) were performed in the country, leading to a collective effective dose of more than 6000 man.Sv (0.8 mSv/caput). In a decade the frequency of CT examinations averaged over the population and the associated average effective dose per caput increased by a factor of 2.2 and 2.9 respectively. CONCLUSIONS: Although the contribution of CT to the total medical X-rays is 6% in terms of the frequency, it represents 68% in terms of the collective effective dose. These results are comparable to those reported in a number of countries in Europe and America with similar health level.

Swiss population exposure to radiation by interventional radiology in 2008.

The aim of this study was to investigate the radiation exposure of the Swiss population to interventional procedures. A nationwide survey was conducted in Switzerland. The annual effective dose per capita due to interventional procedures was found to be 0.14 mSv, corresponding to 12% of the total dose. Coronary angiography and percutaneous coronary interventions were found to be the most frequent and the most irradiating interventional procedures, accounting for 52% of the total examination frequency and 64% of the dose delivered to the population. Switzerland stands at the same level as other countries in terms of effective dose per capita due to interventional radiology.

Exposure of the Swiss population by medical x-rays: 2008 review.

Nationwide surveys on radiation dose to the population from medical radiology are recommended in order to follow the trends in population exposure and ensure radiation protection.The last survey in Switzerland was conducted in 1998,and the annual effective dose from medical radiology was estimated to be 1 mSv y j(-1) per capita. The purpose of this work was to follow the trends in diagnostic radiology between 1998 and 2008 in Switzerland and determine the contribution of different modalities and types of examinations to the collective effective dose from medical x-rays. For this reason, an online database(www.raddose.ch) was developed. All healthcare providers who hold a license to run an x-ray unit in the country were invited to participate in the survey. More than 225 examinations, covering eight radiological modalities, were included in the survey. The average effective dose for each examination was reassessed. Data from about 3,500 users were collected (42% response rate). The survey showed that the annual effective dose was 1.2 mSv/capita in 2008. The most frequent examinations are conventional and dental radiographies (88%). The contribution of computed tomography was only 6% in terms of examination frequency but 68% in terms of effective dose. The comparison with other countries showed that the effective dose per capita in Switzerland was in the same range as in other countries with similar healthcare systems, although the annual number of examinations performed in Switzerland was higher.

Predictors of mortality of Acinetobacter baumannii infections: A 2-year prospective study in a Greek surgical intensive care unit.

BACKGROUND: Nosocomial infections are a frequent and continuously increasing problem worldwide, have a rapidly increasing multidrug resistance to antibiotics, and are associated with significant morbidity and mortality. OBJECTIVE: Our objectives were to evaluate Acinetobacter baumannii infection incidence in our surgical intensive care unit (SICU), the clinical features and outcome of these patients, and, particularly, to investigate predictors of A baumannii infection-related mortality. METHODS: Ours was a prospective study of all patients with ICU-acquired A baumannii infection from January 1, 2006, to December 31, 2007. RESULTS: Among 680 patients, 60 (8.8%) sustained A baumannii infection. Mean age was 68.4 ± 6.2 years, Acute Physiology and Chronic Health Evaluation (APACHE) II score on SICU admission 20.6 ± 8.1 and Sequential Organ Failure Assessment (SOFA) score on infection day 9.5 ± 4.2 (women: 50%). Multidrug resistance, morbidity, and mortality were 45%, 65%, and 46.6% (n = 28), respectively. In multivariate analysis, age (P = .03; odds ratio [OR], 1.13; 95% confidence interval [CI]: 1.018-1.259), acute renal failure (P = .001; OR, 17.9; 95% CI: 6.628-75.565), and thrombocytopenia (P = .03; OR, 26.4; 95% CI: 1.234-56.926) complicating the infection and subsequent Enterococcus faecium bacteremia (P = .01; OR, 3.5; 95% CI: 1.84-6.95) were mortality predictors. CONCLUSION: A baumannii infections are frequent and associated with high drug multiresistance, morbidity, and mortality. Age, renal failure, thrombocytopenia, and subsequent E faecium bacteremia were predictors of A baumannii infection-associated mortality.

Therapeutic ERCP and pregnancy: is the radiation risk for the conceptus trivial?

BACKGROUND: Symptomatic choledocholithiasis can be treated during pregnancy. Conceptus doses ranged from 0.1 mGy to 3 mGy in previous studies. OBJECTIVE: The objectives of the current study were to investigate whether the conceptus dose may exceed the threshold of 10 mGy in the case of a pregnant patient undergoing ERCP, and to provide data for the accurate assessment of a conceptus dose. DESIGN: Monte Carlo methodology and mathematical anthropomorphic phantoms were used to determine normalized conceptus dose data. Phantoms simulated pregnant patients of different body sizes and gestational stages. Monte Carlo simulations were performed to estimate the efficiency of external shielding. SETTING: University hospital. PATIENTS: Twenty-four consecutive patients. INTERVENTIONS: All patients underwent therapeutic ERCP. Exposure parameters and dose-area product were recorded during the procedures. MAIN OUTCOME MEASUREMENTS: The total dose-area product recorded during ERCP procedures ranged between 62 x 10(3) and 491 x 10(3) mGy . cm(2). RESULTS: Monte Carlo normalized conceptus dose data are presented as a function of kV(p), total filtration, gestational stage, and body mass index. The conceptus dose may exceed 10 mGy when the total dose-area product surpasses 130 mGy . cm(2). LIMITATIONS: Variations of conceptus location and size from the average. CONCLUSIONS: Conceptus dose from ERCP may occasionally exceed 10 mGy, the dose above which the analytical dose calculation is recommended. The use of external shielding is unnecessary because the associated dose reduction is negligible. The normalized dose data may be used for the accurate estimation of conceptus dose from an ERCP procedure performed on a pregnant patient, regardless of body size, gestational stage, operating parameters, and equipment used.

Infections in a surgical intensive care unit of a university hospital in Greece.

OBJECTIVES: We aimed to evaluate the clinical and microbiological characteristics of the patients who developed an infection in our surgical intensive care unit (SICU). METHODS: This was a prospective study of all patients who sustained an ICU-acquired infection from 2002 to 2004. RESULTS: Among 683 consecutive SICU patients, 123 (18.0%) developed 241 infections (48.3 infections per 1000 patient-days). The mean age of patients was 66.7+/-3.8 years, the mean APACHE II score (acute physiology and chronic health evaluation) on SICU admission was 18.2+/-2.4, and the mean SOFA score (sepsis-related organ failure assessment) at the onset of infection was 8.8+/-2. Of the study patients, 51.2% were women. Infections were: bloodstream (36.1%), ventilator-associated pneumonia (VAP; 25.3%, 20.3/1000 ventilator-days), surgical site (18.7%), central venous catheter (10.4%, 7.1/1000 central venous catheter-days), and urinary tract infection (9.5%, 4.6/1000 urinary catheter-days). The most frequent microorganisms found were: Acinetobacter baumannii (20.3%), Pseudomonas aeruginosa (15.7%), Candida albicans (13.2%), Enterococcus faecalis (10.4%), Klebsiella pneumoniae (9.2%), Enterococcus faecium (7.9%), and Staphylococcus aureus (6.7%). High resistance to the majority of antibiotics was identified. The complication and mortality rates were 58.5% and 39.0%, respectively. Multivariate analysis identified APACHE II score on admission (odds ratio (OR) 4.63, 95% confidence interval (CI) 2.69-5.26, p=0.01), peritonitis (OR 1.85, 95% CI 1.03-3.25, p=0.03), acute pancreatitis (OR 2.27, 95% CI 1.05-3.75, p=0.02), previous aminoglycoside use (OR 2.84, 95% CI 1.06-5.14, p=0.03), and mechanical ventilation (OR 3.26, 95% CI: 2.43-6.15, p=0.01) as risk factors for infection development. Age (OR 1.16, 95% CI 1.01-1.33, p=0.03), APACHE II score on admission (OR 2.53, 95% CI 1.77-3.41, p=0.02), SOFA score at the onset of infection (OR 2.88, 95% CI 1.85-4.02, p=0.02), and VAP (OR 1.32, 95% CI 1.04-1.85, p=0.03) were associated with mortality. CONCLUSIONS: Infections are an important problem in SICUs due to high incidence, multi-drug resistance, complications, and mortality rate. In our study, APACHE II score on admission, peritonitis, acute pancreatitis, previous aminoglycoside use, and mechanical ventilation were identified as risk factors for infection development, whereas age, APACHE II score on admission, SOFA score at the onset of infection, and VAP were associated with mortality.