Significant Increase In Exposure Research Articles

RADIATION EXPOSURE IN INTERVENTIONAL CARDIOLOGY: STRATEGIES FOR REDUCTION AND PROTECTION

Occupational radiation exposure is a significant concern among healthcare professionals, particularly those in interventional radiology and cardiology procedures. This study aims to comprehensively investigate radiation exposure and its health effects among 200 healthcare professionals, including 100 physicians, 50 nurses, and 50 technicians, across five hospitals. The study employed a controlled, multi-center, observational design, with 100 participants in the experimental group exposed to enhanced radiation protection strategies, while 100 participants in the control group adhered to standard safety protocols. The interventions included additional lead barriers, radiation-absorbent pads, real-time dose monitoring systems, and continuous staff training on radiation safety. Exposure levels were measured using personal dosimeters at regular intervals before and after the interventions. Subgroup analysis was conducted based on professional roles and procedure types, categorized into simple and complex interventions. The results showed a statistically significant reduction in annual radiation exposure in the experimental group compared to the control group, with substantial effect sizes. Subgroup analysis revealed varying degrees of exposure reduction among different professional roles. Notably, complex interventions demonstrated the most substantial reductions in radiation exposure. Furthermore, an analysis of X-ray beam angles indicated a statistically significant increase in exposure at steep angles (≥30°). However, no significant interaction between the control and experimental groups was observed, suggesting that other variables may influence the relationship between steep angles and exposure. The findings of this study emphasize the effectiveness of enhanced protection strategies in reducing occupational radiation exposure among healthcare professionals. The nuanced effects observed across different professional roles and procedure types underscore the importance of tailored safety measures. These results contribute to the ongoing efforts to optimize radiation safety in medical settings and promote the well-being of healthcare professionals. Ethical considerations, adherence to international standards, and the potential implications for policy and guidelines further underscore the significance of this study's findings.

The Effect of Pre-Operative Verbal Confirmation for Interventional Radiology Physicians on Their Use of Personal Dosimeters and Personal Protective Equipment.

Interventional radiology (IR) physicians must be equipped with personal passive dosimeters and personal protective equipment (PPE); however, they are inconsistently used. Therefore, we aimed to explore practical measures to increase PPE usage and ascertain whether these measures could lead to an actual decrease in exposure doses to IR physicians. Dosimeters and PPE were visually inspected. Then, a pre-operative briefing was conducted as a direct intervention, and the use of dosimeters and PPE was verbally confirmed. Finally, the intervention effect was verified by measuring the use rates and individual exposure doses. Because of the intervention, the use rate markedly improved and was almost 100%. However, both the effective dose rate (effective dose/fluoroscopy time) and the lens equivalent dose rate (lens equivalent dose/fluoroscopy time) showed that the intervention led to a statistically significant increase in exposure (effective dose rate: p = 0.033; lens equivalent dose rate: p = 0.003). In conclusion, the proper use of dosimeters and PPE raised the radiation exposure values for IR physicians immediately after the intervention, which was hypothesized to be due to the inclusion of exposure overlooked to date and the changes in the dosimeter management method from a single- to a double-dosimeter approach.

Implementation and Outcomes of a Comprehensive Tobacco Free Workplace Program in Opioid Treatment Centers.

Tobacco use is exceedingly high among individuals receiving care for opioid addiction, but not commonly addressed by clinicians in treatment settings. Taking Texas Tobacco Free (TTTF) is a comprehensive tobacco-free workplace (TFW) program that builds treatment centers’ capacity to address tobacco use with evidence-based tobacco cessation policies and practices. Here, we examine the process and outcomes of TTTF’s implementation within 7 opioid addiction centers. Program goals were structured according to the RE-AIM framework. Pre- and post-implementation data were collected from client facing and non-client facing employees to assess changes in education, training receipt, knowledge, and intervention behaviors, relative to program goals. Centers reported tobacco screenings conducted and nicotine replacement therapy (NRT) delivered through 6 months post-implementation. Overall, 64.56% of employees participated in TTTF-delivered tobacco education, with a 54.9% gain in tobacco control and treatment knowledge (p < 0.0001), and significant increases in exposure to education about tobacco use and harms among individuals with opioid use disorder (p = 0.0401). There were significant gains in clinicians’ receipt of training in 9/9 tobacco education areas (ps ≤ 0.0118). From pre- to post-implementation, there were mean increases in the use of the 5A’s (ask, advise, assess, assist, and arrange) and other evidence-based interventions for tobacco cessation, with statistically significant gains seen in NRT provision/referral (p < 0.0001). Several program goals were achieved or exceeded; however, 100% center participation in specialized clinical trainings was among notable exceptions. One program withdrew due to competing pandemic concerns; all others implemented comprehensive TFW policies. Overall, TTTF may have improved participating opioid treatment centers’ capacity to address tobacco use, although study limitations, including lower post-implementation evaluation response rates, suggest that results require replication in other opioid addiction treatment settings.

Predictive In Vitro-In Vivo Extrapolation for Time Dependent Inhibition of CYP1A2, CYP2C8, CYP2C9, CYP2C19, and CYP2D6 Using Pooled Human Hepatocytes, Human Liver Microsomes, and a Simple Mechanistic Static Model.

Inactivation of Cytochrome P450 (CYP450) enzymes can lead to significant increases in exposure of comedicants. The majority of reported in vitro to in vivo extrapolation (IVIVE) data have historically focused on CYP3A, leaving the assessment of other CYP isoforms insubstantial. To this end, the utility of human hepatocytes (HHEP) and human liver microsomes (HLM) to predict clinically relevant drug-drug interactions was investigated with a focus on CYP1A2, CYP2C8, CYP2C9, CYP2C19, and CYP2D6. Evaluation of IVIVE for CYP2B6 was limited to only weak inhibition. A search of the University of Washington Drug-Drug Interaction Database was conducted to identify a clinically relevant weak, moderate, and strong inhibitor for selective substrates of CYP1A2, CYP2C8, CYP2C9, CYP2C19, and CYP2D6, resulting in 18 inhibitors for in vitro characterization against 119 clinical interaction studies. Pooled human hepatocytes and HLM were preincubated with increasing concentrations of inhibitors for designated timepoints. Time dependent inhibition was detected in HLM for four moderate/strong inhibitors, suggesting that some optimization of incubation conditions (i.e., lower protein concentrations) is needed to capture weak inhibition. Clinical risk assessment was conducted by incorporating the in vitro derived kinetic parameters maximal rate of enzyme inactivation (min-1) (kinact) and concentration of inhibitor resulting in 50% of the maximum enzyme inactivation (KI) into static equations recommended by regulatory authorities. Significant overprediction was observed when applying the basic models recommended by regulatory agencies. Mechanistic static models, which consider the fraction of metabolism through the impacted enzyme, using the unbound hepatic inlet concentration lead to the best overall prediction accuracy with 92% and 85% of data from HHEPs and HLM, respectively, within twofold of the observed value. SIGNIFICANCE STATEMENT: Coupling time-dependent inactivation parameters derived from pooled human hepatocytes and human liver microsomes (HLM) with a mechanistic static model provides an easy and quantitatively accurate means to determine clinical drug-drug interaction risk from in vitro data. Optimization is needed to evaluate time-dependent inhibition (TDI) for weak and moderate inhibitors using HLM. Recommendations are made with respect to input parameters for in vitro to in vivo extrapolation (IVIVE) of TDI with non-CYP3A enzymes using available data from HLM and human hepatocytes.

A phase 1, randomized study to evaluate safety, tolerability, and pharmacokinetics of GDC-3280, a potential novel anti-fibrotic small molecule, in healthy subjects

BackgroundIdiopathic pulmonary fibrosis (IPF) is a chronic progressive lung disease. Although anti-fibrotic treatments, such as pirfenidone, are available that reduce the rate of disease progression, these medications have limitations in tolerability, and IPF patients still have poor prognoses. GDC-3280, an orally available small molecule that was designed to improve upon pirfenidone's activity, has anti-fibrotic activity in animal models. This first-in-human, phase 1 trial evaluated GDC-3280 to determine its safety, tolerability, and pharmacokinetics (PK). MethodsSingle and multiple ascending-doses of GDC-3280 were administered to healthy volunteers in two parts. Part A consisted of 6 treatment groups, each receiving a single, oral dose of GDC-3280 (25–1600 mg) or placebo in the fasted state. Part A also assessed the effect of food and coadministration of a proton pump inhibitor (rabeprazole) on the tolerability and PK of single doses of 400- and 800-mg GDC-3280. Part B consisted of 3 treatment groups who received either 200- or 275-mg GDC-3280 twice daily or 525-mg once daily after a low-fat meal for 7 days. The trial monitored treatment-emergent adverse events (TEAEs) and assessed the pharmacokinetics of GDC-3280 in blood and urine samples. ResultsFifty-six subjects (42 GDC-3280, 14 placebo) in Part A and 24 subjects (18 GDC-3280, 6 placebo) in Part B received treatment. No deaths, serious adverse events, or dose-limiting adverse events occurred, and no subjects withdrew due to a TEAE. In both Parts A and B, most TEAEs were mild. The most frequent TEAEs in Part A were headache and nausea. TEAEs occurred more often when GDC-3280 was administered with food. Pretreatment and coadministration with rabeprazole had no effect on GDC-3280 tolerability. In Part B, the most frequent TEAEs were nausea, dizziness, nasal congestion, and cough. Transient, treatment-related increases in serum creatinine occurred at doses greater than 400 mg in Part A (12%–18% from baseline) and after multiple doses in each group in Part B (20%–34% from baseline). GDC-3280 was generally readily absorbed with a median tmax < 4.0 h following single- or repeat-dose oral administration. In Part A, less-than-dose-proportional increases in systemic exposure occurred, and in Part B, dose-proportional increases occurred within the dose range tested. At doses of 200 mg or lower, more than 50%–70% of orally administered doses were recovered in urine as unchanged GDC-3280 when subjects received a single dose of GDC-3280, suggesting renal excretion is one of the major routes of elimination. Administration of single doses of 400- and 800-mg GDC-3280 after a meal caused statistically significant increases in exposure due to increased rates of absorption compared to the fasted state. Pretreatment and coadministration of rabeprazole dosing led to decreases in exposure compared to GDC-3280 alone, indicating a weak drug-drug interaction. Following repeat dose administration, steady-state plasma concentrations of GDC-3280 were achieved within 2 days with an apparent terminal half-life (t1/2) between 5 and 6 h. ConclusionsSingle and multiple doses of GDC-3280 were generally well tolerated, with acceptable safety and pharmacokinetic profiles that support twice-daily, oral administration with food in future clinical trials.

Factor investing: alpha concentration versus diversification

Despite extensive research support, the role of diversification in current factor investing strategies remains neglected. This paper investigates whether well-designed multifactor portfolios should not only be based on firm characteristics, but should also include portfolio diversification effects. While the alpha concentration approach mainly considers factor-specific firm characteristics, the diversified approach utilizes covariance estimators in addition to firm characteristics to account for portfolio diversification. The corresponding out-of-sample results show that including an efficient covariance estimator improves the performance of long-only multifactor portfolios compared to the pure alpha concentration approach. A particular advantage of diversified factor investing strategies can be identified in the significant increase in exposure to the low-volatility factor represented by firm characteristics with high informational content. No significant performance differences are observed for long-short portfolios where the factor exposures of the alpha concentration and diversification approaches are similar with respect to the low-volatility factor.

Crop-specific exposure to extreme temperature and moisture for the globe for the last half century

Global assessments of climate extremes typically do not account for the unique characteristics of individual crops. A consistent definition of the exposure of specific crops to extreme weather would enable agriculturally-relevant hazard quantification. To this end, we develop a database of both the temperature and moisture extremes facing individual crops by explicitly accounting for crop characteristics. To do this, we collate crop-specific temperature and moisture parameters from the agronomy literature, which are then combined with time-varying crop locations and high-resolution climate information to quantify crop-specific exposure to extreme weather. Specifically, we estimate crop-specific temperature and moisture shocks during the growing season for a 0.25∘ spatial grid and daily time scale from 1961 to 2014 globally. We call this the Agriculturally-Relevant Exposure to Shocks (ARES) model and make all ARES output available with this paper. Our crop-specific approach leads to a smaller average value of the exposure rate and spatial extent than does a crop-agnostic approach. Of the 17 crops included in this study, 13 had an increase in exposure to extreme heat, while 9 were more exposed to extreme cold over the past half century. All crops in this study show a statistically significant increase in exposure to both extreme wetness and dryness. Cassava, sunflowers, soybeans, and oats had the greatest increase in hot, cold, dry, and wet exposure, respectively. We compare ARES model results with the EM-DAT disaster database. Our results highlight the importance of crop-specific characteristics in defining weather shocks in agriculture.

Clopidogrel Dosing: Current Successes and Emerging Factors for Further Consideration

This review aimed to evaluate the clinical success of clopidogrel dosing based on CYP2C19 genotype and to identify the relevant additional factors that may be useful for consideration by the clinician when dosing individuals with clopidogrel. The results indicated that genotype-guided dosing in individuals with acute coronary syndrome undergoing percutaneous coronary intervention is frequently practiced, although the advantages remain controversial. Demographic factors, such as age, ethnicity, and some comorbidities, such as diabetes mellitus, can potentially contribute to further refinement of clopidogrel dosage but additional clinical studies to guide these practices are required. Drugs that are CYP2C19 or CYP3A4 inhibitors may reduce the effectiveness of clopidogrel and should be carefully considered during co-administration. In particular, as stated in the clopidogrel label, concomitant use with strong or moderate CYP2C19 inhibitors, such as omeprazole, should be avoided. Increased exposure and response to clopidogrel has been observed in smokers. Noteworthy, a very recent study has shown that smoking cessation in clopidogrel patients may result in reduced response and carries the risk of high on-clopidogrel platelet reactivity. Recent studies have shown clinically significant increases in exposure to CYP2C8 substrates (repaglinide, dasabuvir, and desloratadine) and a CYP2B6 substrate (s-sibutramine) following co-administration with clopidogrel, indicating that therapeutic strategies with clopidogrel should avoid these drugs.

COVID-19 öncesi ve sonrası torasik bilgisayarlı tomografi analizi

Aim: The aim of this study is to describe the changes in the number of Thoracic Computed Tomographs (TCT) taken from the emergency department (ED) and the general characteristics of the patients concerned. Material and Methods: The patients were examined in two periods as before and after March 10 (Period 1: January 1, 2020 - March 9, 2020; Period 2: March 10-31, 2020), the date COVID-19 first occurred in our country. Furthermore, if COVID-19 findings were present, the severity of the findings, the side involved (right lung, left lung, bilateral), the number of lobes involved, the type of the finding observed, the localization of the lesions were identified. Results: The daily number of TCT scans increased by approximately two-folds after March 10. A total of 400 TCT scans were performed in Period 1. In a total of 69 days, the average daily TCT number was 5.8, and the number of cases consistent with viral pneumonia was 21 (5.25% of the TCT scans on these dates). A total of 243 TCT scans were performed in Period 2. In a total of 22 days, the daily number of TCT scans was 11.04, and the number of patients consistent with viral pneumonia (COVID-19 included) was 44 (18.1% of the TCT scans on these dates). Conclusion: During this period, while it is still being debated whether COVID-19 is a biological attack or not, the significant increase in exposure to ionizing radiation with known risks is a matter worthy of discussion.

Disseminating the Foundations of Knowledge Translation and Patient Engagement Science Through the KnowledgeNudge Blog and Twitter Profile: Quantitative Descriptive Evaluation.

BackgroundThere is a documented need to build capacity for theory- and evidence-informed knowledge translation (KT) and patient engagement (PE) practice in health research. Dissemination of foundational content online coupled with social media promotion may build capacity by increasing awareness, knowledge, and positive attitudes.ObjectiveThis retrospective study sought to (1) describe exposure and engagement of the KnowledgeNudge KT and PE dissemination strategy (online blog and Twitter profile) over 2 years and (2) identify and compare characteristics of individual posts with the most and least exposure and reach.MethodsExposure was assessed by blog site views per month and Twitter profile impressions per month. Engagement was assessed by Twitter profile interactions per month. Descriptive statistics were calculated for 6-month blocks and compared using one-way analysis of variance or Student t test. Individual post exposure was assessed by average post views per week. Individual post reach was assessed by average post reads per week. High- and low-profile blog posts with the highest and lowest 10th percentile for exposure and reach were identified.ResultsA total of 99 posts and 755 tweets were published during the study period. There was a significant increase in exposure (P=.004) and reach (P<.001) during the final 6 months. Seven high-profile and 6 low-profile posts were identified. High-profile posts had a significantly greater average word count than low-profile posts (P=.003). There were no other significant differences between posts.ConclusionsThe increases in KnowledgeNudge exposure and engagement offer preliminary evidence in support of this dissemination strategy for the practice of KT and PE. Variation in individual post exposure and reach warrants further exploration to tailor content to user needs. Future work will include a prospective evaluation strategy to explore the effect of KnowledgeNudge on awareness, knowledge, attitudes, and behavior.

Extended endoscopic approaches to the maxillary sinus.

Treatment of inflammatory and neoplastic disease in the maxillary sinus, pterygopalatine and infratemporal fossae requires appropriate surgical exposure. As modern rhinology evolves, so do the techniques available. This paper reviews extended endoscopic approaches to the maxillary sinus and the evidence supporting each technique. A literature search of the Ovid Medline and PubMed databases was performed using appropriate key words relating to endoscopic approaches to the maxillary sinus. Mega-antrostomy and medial maxillectomy have a role in the surgical treatment of refractory inflammatory disease and sinonasal neoplasms. The pre-lacrimal fossa approach provides excellent access but can be limited because of anatomical variations. Both the transseptal and endoscopic Denker's approaches were reviewed; these appear to be associated with morbidity, without any significant increase in exposure over the afore-described approaches. A range of extended endoscopic approaches to the maxillary sinus exist, each with its own anatomical limitations and potential complications.

Meeting Proceedings of the “Phase I: Where Science Becomes Medicine” Conference, Manchester, UK

Meeting Proceedings of the “Phase I: Where Science Becomes Medicine” Conference, Manchester, UK

800P - A phase Ib study of oraxol in combination with ramucirumab in patients with gastric or esophageal cancers who failed previous chemotherapy

BackgroundOraxol consists of oral paclitaxel administered with the novel P-glycoprotein inhibitor HM30181A which enables the oral absorption of paclitaxel. Ramucirumab (RAM) + intravenous paclitaxel is FDA approved 2nd line treatment of gastric cancer. Oraxol 200mg/m2 days 1-3, weekly has similar exposure to weekly paclitaxel 80/m2 intravenously. This study was to determine the maximum tolerated dose (MTD) of Oraxol + RAM. Methods17 patients with gastric or esophageal cancers who failed prior fluoropyrimidine or platinum containing chemotherapies were studied. Dose escalation followed the standard 3+3 design: Cohort 1: Oraxol 200mg/m2 days 1-3, weekly. Cohort 2: Oraxol 250mg/m2 days 1-3, weekly. Cohort 3: Oraxol 300mg/m2 days 1-3, weekly. RAM 8mg/kg IV every 2 weeks was co-administered in all patients. Dose limiting toxicity (DLT) were assessed by week 4. Adverse events (AEs) were assessed per CTCAE v4.03 and response by RECIST v1.1. ResultsCohort 1: One febrile neutropenia (DLT) occurred in 6 patients. Partial response (PR)=2/6, stable disease (SD)=1/6 and progressive disease (PD)=3/6. Cohort 2: One grade-3 neutropenia with treatment delay (DLT) occurred in 7 pts. PR=3/6 and PD=3/6 in 6 evaluable patients. Cohort 3: Two DLT (febrile neutropenia and grade-3 gastric hemorrhage) occurred in 3 patients. The MTD of Oraxol was 300mg/m2 days 1-3, weekly in combination with RAM. All patients in this study had complete recovery of their DLT. Oraxol PK did not increase significantly in Cohort-2 and Cohort-3. ConclusionsBased on the lack of significant increase in exposure to Oraxol at higher doses, with similar efficacy and DLT in Cohorts 1 and 2, an extension study using Oraxol 200mg/m2 Days 1-3, weekly + Ramucirumab 8mg/kg every 2 weeks as in Cohort-1 is initiated. Clinical trial identificationNCT02970539. Legal entity responsible for the studyAthenex Inc. FundingAthenex Inc. DisclosureAll authors have declared no conflicts of interest.

Intervention Reach and Sexual Risk Reduction of a Multi-level, Community-Based HIV Prevention Intervention for Crack Users in San Salvador, El Salvador.

This article examines the effects of a multi-level, community-based HIV prevention intervention for crack users residing in low-income neighborhoods in San Salvador, El Salvador conducted between August 2011 and June 2016. The intervention consisted of three components introduced sequentially: (1) rapid HIV testing in community settings; (2) a social network HIV testing intervention; and (3) small group interventions with crack users who were members of the same social network. The intervention was evaluated with an interrupted time series design in which we used respondent-driven sampling to conduct 7 cross-sectional surveys with crack users along a 3-4month period for each assessment (total n = 1597). Results revealed a significant increase in exposure to the intervention over time with 50% of the participants reporting exposure to one or more of the three components. Getting an HIV test at the community site was associated with reductions in total times each individual had sex without a condom (p < 0.05) compared to those who had been exposed to no intervention components. Being referred by another crack user through the Social Network HIV intervention was also associated with reductions in total numbers of condomless sex (p < 0.05) The cumulative effect of being exposed to more than one intervention component was associated with reductions in total number of times individuals had condomless sex (p < 0.05). In spite of the high level of intervention reach and that self-reported exposure to intervention components was associated with lower sexual risk, reductions in sexual risk over time were not observed in the full sample, indicating that the penetration of HIV prevention components was not sufficient to produce population level change.

Survival and reproductive costs of repeated acute glucocorticoid elevations in a captive, wild animal

Organisms are continuously encountering both predictable and unpredictable ecological stressors within their environment. The activation of the hypothalamic-pituitaryadrenal (stress) axis is a fundamental process allowing animals to cope with and respond to such encounters. A main consequence of HPA axis activation is the release of glucocorticoid hormones. Although short-term glucocorticoid elevations lead to changes in physiological and behavioral processes that are often adaptive, our understanding of fitness consequences of repeated acute elevations in glucocorticoid hormones over a longer time period is largely lacking. This is of particular current importance as animals are facing a significant increase in exposure to stressors including those associated with human-induced rapid environmental change. Here, we test fitness-relevant consequences of repeated exposure to glucocorticoids in the absence of natural challenges, by treating wild-caught gravid female eastern fence lizards (Sceloporus undulatus) with a daily transdermal dose of a glucocorticoid hormone until laying. This treatment causes an increase in plasma glucocorticoids that mimics the natural response lizards have when they encounter a stressor in the wild, without confounding effects associated with the encounter itself. This treatment reduced females’ reproductive success (hatching success) and survival. Further, glucocorticoid-induced reductions in reproductive success were greater when females had experienced higher temperatures the previous winter. This demonstrates the potential significant consequences of repeated exposure to acute elevations in glucocorticoid hormones. Additionally, the costs of repeated glucocorticoid elevation may be further exaggerated by an individual’s previous experience, such as the potential compounding effects of winter warming increasing animals’ vulnerability to increased glucocorticoid levels during spring breeding.

Challenges in assessing the health risks of consuming vegetables in metal-contaminated environments

A great deal of research has been devoted to the characterization of metal exposure due to the consumption of vegetables from urban or industrialized areas. It may seem comforting that concentrations in crops, as well as estimated exposure levels, are often found to be below permissible limits. However, we show that even a moderate increase in metal accumulation in crops may result in a significant increase in exposure. We also highlight the importance of assessing exposure levels in relation to a regional baseline. We have analyzed metal (Pb, Cd, As) concentrations in nearly 700 samples from 23 different vegetables, fruits, berries and mushrooms, collected near 21 highly contaminated industrial sites and from reference sites. Metal concentrations generally complied with permissible levels in commercial food and only Pb showed overall higher concentrations around the contaminated sites. Nevertheless, probabilistic exposure assessments revealed that the exposure to all three metals was significantly higher in the population residing around the contaminated sites, for both low-, median- and high consumers. The exposure was about twice as high for Pb and Cd, and four to six times as high for As. Since vegetable consumption alone did not result in exposure above tolerable intakes, it would have been easy to conclude that there is no risk associated with consuming vegetables grown near the contaminated sites. However, when the increase in exposure is quantified, its potential significance is harder to dismiss – especially when considering that exposure via other routes may be elevated in a similar way.

Seasonal differences in household air pollutants and determinants of personal air pollution exposure in rural women cooking and heating with biomass fuels in the Tibetan Plateau

Cooking and heating with traditional biomass stoves impacts climate and population health. The very limited information on personal exposures to biomass smoke and its major determinants limits intervention evaluation and the estimation of dose-response relationships and attributable disease burden We enrolled 204 Chinese women in Sichuan, China who cooked with biomass, and measured their seasonal 48-h personal exposures to PM2.5 and CO and 48-h kitchen PM2.5, elemental and organic carbon (EC/OC), and CO and NOx concentrations in the baseline assessment of an energy intervention study. We measured daily outdoor PM2.5 and collected information on demographics, household energy use and ventilation, among others. Multivariate regression models were used to assess the environmental, household, and individual determinants of women’s PM2.5 exposure. Women’s geometric mean 48-h exposure to PM2.5 was 80 μg/m3 (95% CI: 74, 87) in summer and twice as high in winter (169 μg/m3, 95% CI: 150, 190). OC/EC and NOx ratios also differed by season (summer: OC/EC = 9.4 (7.9, 11.1), NO/NO2 = 40 (12, 140); winter: OC/EC = 14.8 (11.6, 18.8); NO/NO2 = 86 (44, 165)). In winter, the most significant decreases in personal PM2.5 exposures were for women heating with electricity or wood-charcoal (-25% (-52, 1) and who used frequent kitchen ventilation (-37% (-78, -3)), while the most significant increase in exposure was for women with a barrier separating the fuel loading area from the kitchen (73% (31, 114)). In summer, primary use of a gaseous fuel or electricity for cooking (-37% (-67, -7)) and outdoor PM2.5 (11 (6, 16)) had the largest impacts on personal PM2.5 exposure. Outdoor and household air pollution were significant predictors of women’s PM2.5 exposure. Use of cleaner-burning fuels could lower PM2.5 exposures in this region and may impact levels of climate-relevant pollutants (EC, OC).

Évaluation de l’exposition aux radiations du chirurgien lors d’un TLIF mini-invasif : comparaison entre fluoroscopie et navigation O-arm

IntroductionTransforaminal lumbar interbody fusion with a minimally invasive approach (MIS TLIF) has become a very popular technique in the treatment of degenerative diseases of the lumbar spine, as it allows a decrease in muscle iatrogenic. However, iterative radiological controls inherent to this technique are responsible for a significant increase in exposure to ionizing radiation for the surgeon. New techniques for radiological guidance (O-arm navigation-assisted) would overcome this drawback, but this remains unproven. ObjectivesTo analyze the exposure of the surgeon to intraoperative X-ray during a MIS TLIF under fluoroscopy and under O-arm navigation-assisted. Materials and methodsThis prospective study was conducted at the University Hospital of Lille from February to May 2013. Twelve patients underwent a MIS TLIF for the treatment of low-grade spondylolisthesis; six under standard fluoroscopy (group 1) and six under O-arm system (group 2). Passive dosimeters (rings and glasses) and active dosimeters for thorax were used to measure the radiation exposure of the surgeon. ResultsFor group 1, the average time of fluoroscopy was 3.718minutes (3.13–4.56) while no radioscopy was perform on group 2. For the first group, the average exposure dose was 12μSv (5–20μSv) on the thorax, 1168μSv (510–2790μSv) on the main hand and 179μSv (103–486μSv) on the lens. The exposure dose was measured zero on the second group. ConclusionThe maximum recommended doses can be reached, mainly for the lens. In addition to the radioprotection measures, O-arm navigation systems are safe alternatives to significantly reduce surgeon exposure.

A quantitative analysis of posterolateral approaches to the ventral thoracic spinal canal

Background contextVarious posterolateral approaches exist to access ventral thoracic spinal canal pathologies. Selecting the optimal surgical approach requires sound understanding of the exposure and working angle afforded by each approach. PurposeThe purpose of this study was to quantify exposure of the ventral spinal canal with various posterolateral thoracic spinal approaches and to determine how regional anatomical differences affect measurements. Study designThis is a quantitative anatomical cadaveric study. MethodsFour fresh cadaveric C7–L1 specimens were used with a saline infusion model to mimic in vivo thecal sac dimensions. Using stereotactic navigation, we measured exposure (expressed as percentage of total width) and maximum approach angle of the ventral spinal canal without thecal sac retraction after each surgical condition: laminectomy (L), 50% medial facetectomy (MF), transpedicular (TP), costotransversectomy (CTV), and lateral extracavitary (LE). The thoracic spine was divided into four regions (T1–T2, T3–T6, T7–T10, and T9–T12). A two-sided paired t test was used. ResultsAt T1–T2, visualized exposures were 25.8%, 31.5%, 42.3%, 45.1%, and 46.8%, respectively, after each surgical condition. Costotransversectomy and LE did not provide significant increase in exposure compared with the preceding condition. At T3–T6, exposures were 19.1%, 29.6%, 38.7%, 44.4%, and 44.5%, respectively. Only LE did not provide significant increase in exposure compared with the preceding condition. At T7–T10, visualized exposures were 17.9%, 30.6%, 39.9%, 44.9%, and 53.3%, respectively. All successive surgical conditions provided a significant increase in exposure. At T11–T12, visualized exposures were 14.2%, 25.8%, 43.1%, 47.7%, and 52.7%, respectively. Only LE did not provide a significant increase in exposure compared with the preceding condition. Each successive surgical condition provided a significantly increased lateral approach angle compared with the preceding condition, except LE at T1–T2. Maximum approach angle was more favorable at T1–T2 for L, MF, TP, and CTV compared with other thoracic regions. ConclusionsMedial facetectomy and TP approaches provide significantly increased exposure of the ventral spinal canal at all thoracic regions. Costotransversectomy provided significantly increased exposure compared with TP at T3–T12. Lateral extracavitary only provided significantly increased exposure compared with CTV at T7–T10. The results of this study can be used preoperatively to determine the optimal approach based on quantitative measurements and region-specific anatomical differences.

The Clinical Education Partnership Initiative: an innovative approach to global health education.

BackgroundDespite evidence that international clinical electives can be educationally and professionally beneficial to both visiting and in-country trainees, these opportunities remain challenging for American residents to participate in abroad. Additionally, even when logistically possible, they are often poorly structured. The Universities of Washington (UW) and Nairobi (UoN) have enjoyed a long-standing research collaboration, which recently expanded into the UoN Medical Education Partnership Initiative (MEPI). Based on MEPI in Kenya, the Clinical Education Partnership Initiative (CEPI) is a new educational exchange program between UoN and UW. CEPI allows UW residents to partner with Kenyan trainees in clinical care and teaching activities at Naivasha District Hospital (NDH), one of UoN’s MEPI training sites in Kenya.MethodsUW and UoN faculty collaborated to create a curriculum and structure for the program. A Chief Resident from the UW Department of Medicine coordinated the program at NDH. From August 2012 through April 2014, 32 UW participants from 5 medical specialties spent between 4 and 12 weeks working in NDH. In addition to clinical duties, all took part in formal and informal educational activities. Before and after their rotations, UW residents completed surveys evaluating clinical competencies and cross-cultural educational and research skills. Kenyan trainees also completed surveys after working with UW residents for three months.ResultsUW trainees reported a significant increase in exposure to various tropical and other diseases, an increased sense of self-reliance, particularly in a resource-limited setting, and an improved understanding of how social and cultural factors can affect health. Kenyan trainees reported both an increase in clinical skills and confidence, and an appreciation for learning a different approach to patient care and professionalism.ConclusionsAfter participating in CEPI, both Kenyan and US trainees noted improvement in their clinical knowledge and skills and a broader understanding of what it means to be clinicians. Through structured partnerships between institutions, educational exchange that benefits both parties is possible.Electronic supplementary materialThe online version of this article (doi:10.1186/s12909-014-0246-5) contains supplementary material, which is available to authorized users.