| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- Ademuyiwa, Adesoji O., et al.
(författare)
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Determinants of morbidity and mortality following emergency abdominal surgery in children in low-income and middle-income countries
- 2016
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Ingår i: BMJ Global Health. - : BMJ Publishing Group Ltd. - 2059-7908. ; 1:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Child health is a key priority on the global health agenda, yet the provision of essential and emergency surgery in children is patchy in resource-poor regions. This study was aimed to determine the mortality risk for emergency abdominal paediatric surgery in low-income countries globally.Methods: Multicentre, international, prospective, cohort study. Self-selected surgical units performing emergency abdominal surgery submitted prespecified data for consecutive children aged <16 years during a 2-week period between July and December 2014. The United Nation's Human Development Index (HDI) was used to stratify countries. The main outcome measure was 30-day postoperative mortality, analysed by multilevel logistic regression.Results: This study included 1409 patients from 253 centres in 43 countries; 282 children were under 2 years of age. Among them, 265 (18.8%) were from low-HDI, 450 (31.9%) from middle-HDI and 694 (49.3%) from high-HDI countries. The most common operations performed were appendectomy, small bowel resection, pyloromyotomy and correction of intussusception. After adjustment for patient and hospital risk factors, child mortality at 30 days was significantly higher in low-HDI (adjusted OR 7.14 (95% CI 2.52 to 20.23), p<0.001) and middle-HDI (4.42 (1.44 to 13.56), p=0.009) countries compared with high-HDI countries, translating to 40 excess deaths per 1000 procedures performed.Conclusions: Adjusted mortality in children following emergency abdominal surgery may be as high as 7 times greater in low-HDI and middle-HDI countries compared with high-HDI countries. Effective provision of emergency essential surgery should be a key priority for global child health agendas.
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| 3. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Clark, Joseph, et al.
(författare)
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Interchangeability in Left Ventricular Ejection Fraction Measured by Echocardiography and cardiovascular Magnetic Resonance : Not a Perfect Match in the Real World
- 2023
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Ingår i: Current Problems in Cardiology. - : Elsevier BV. - 0146-2806. ; 48:8
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Forskningsöversikt (refereegranskat)abstract
- Comparisons of transthoracic echocardiography (TTE) and cardiovascular magnetic resonance (CMR) derived left ventricular ejection fraction (LVEF) have been reported in core-lab settings but are limited in the real-world setting. We retrospectively identified outpatients from 4 hospital sites who had clinically indicated quantitative assessment of LVEFTTE and LVEFCMR and evaluated their concordance. In 767 patients (mean age 47.6 years; 67.9% males) the median inter-modality interval was 35 days. There was significant positive correlation between the 2 modalities (r = 0.75; P < 0.001). Median LVEF was 54% (IQR 47%, 60%) for TTE and 59% (IQR 51%, 64%) for CMR, (P < 0.001). Normal LVEFTTE was confirmed by CMR in 90.6% of cases. Of patients with severely impaired LVEFTTE, 42.3% were upwardly reclassified by CMR as less severely impaired. The overall proportion of patients that had their LVEF category confirmed by both imaging modalities was 64.4%; Cohen's Kappa 0.41, indicating fair-to-moderate agreement. Overall, CMR upwardly reclassified 28% of patients using the British Society of Echocardiography LVEF grading, 18.6% using the European Society of Cardiology heart failure classification, and 29.6% using specific reference ranges for each modality. In a multi-site “real-worldˮ clinical setting, there was significant discrepancy between LVEFTTE and LVEFCMR measurement. Only 64.4% had their LVEF category confirmed by both imaging modalities. LVEFTTE was generally lower than LVEFCMR. LVEFCMR upwardly reclassified almost half of patients with severe LV dysfunction by LVEFTTE. Clinicians should consider the inter-modality variation before making therapeutic recommendations, particularly as clinical trial LVEF thresholds have historically been guided by echocardiography.
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