| 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. |
- Welch, Robert D, et al.
(författare)
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Ability of Serum Glial Fibrillary Acidic Protein, Ubiquitin C-Terminal Hydrolase-L1, and S100B to Differentiate Normal and Abnormal Head Computed Tomography Findings in Patients with Suspected Mild or Moderate Traumatic Brain Injury.
- 2016
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Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert Inc. - 1557-9042 .- 0897-7151. ; 33:2, s. 203-214
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Tidskriftsartikel (refereegranskat)abstract
- Head Computed Tomography (CT) imaging is still a commonly obtained diagnostic test for patients with minor head injury despite availability of clinical decision rules to guide imaging use and recommendations to reduce radiation exposure resulting from unnecessary imaging. This prospective multi-center observational study of 251 patients with suspected mild to moderate traumatic brain injury (TBI) evaluated three serum biomarkers' (Glial Fibrillary Acidic Protein [GFAP], Ubiquitin C-Terminal Hydrolase-L1 [UCH-L1] and S100B measured within 6-hours of injury) ability to differentiate CT negative and CT positive findings. Of the 251 patients, 60.2% were male and 225 (89.6%) had a presenting Glasgow Coma Scale score of 15. A positive head CT (intracranial injury), was found in 36 (14.3%). UCH-L1 was 100% sensitive and 39% specific at a cutoff value > 40 pg/ml. To retain 100% sensitivity, GFAP was 0% specific (cutoff value 0 pg/ml) and S100B had a specificity of only 2% (cutoff value 30 pg/ml). All three biomarkers had similar values for areas under the receiver operator characteristic curve; 0.79 (95% CI; 0.70 to 0.88) for GFAP, 0.80 (0.71 to 0.89) for UCH-L1, and 0.75 (0.65 to 0.85) for S100B. Neither GFAP nor UCH-L1 curve values differed significantly from S100B (p=0.21 and p=0.77 respectively). In our patient cohort, UCH-L1 outperformed GFAP and S100B when the goal was to reduce CT use without sacrificing sensitivity. UCH-L1 values < 40 pg/ml could potentially have aided in eliminating 83 of the 215 negative CT scans. These results require replication in other studies before the test is used in actual clinical practice.
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| 3. |
- Welch, Robert D., et al.
(författare)
-
Ability of serum glial fibrillary Acidic Protein, Ubiquitin C-Terminal Hydrolase-L1, and S100B to differentiate normal and abnormal head computed tomography findings in patients with suspected mild or moderate traumatic brain injury
- 2016
-
Ingår i: Journal of Neurotrauma. - : Mary Ann Liebert. - 0897-7151 .- 1557-9042. ; 33:2, s. 203-214
-
Tidskriftsartikel (refereegranskat)abstract
- Head computed tomography (CT) imaging is still a commonly obtained diagnostic test for patients with minor head injury despite availability of clinical decision rules to guide imaging use and recommendations to reduce radiation exposure resulting from unnecessary imaging. This prospective multicenter observational study of 251 patients with suspected mild to moderate traumatic brain injury (TBI) evaluated three serum biomarkers' (glial fibrillary acidic protein [GFAP], ubiquitin C-terminal hydrolase-L1 [UCH-L1] and S100B measured within 6 h of injury) ability to differentiate CT negative and CT positive findings. Of the 251 patients, 60.2% were male and 225 (89.6%) had a presenting Glasgow Coma Scale score of 15. A positive head CT (intracranial injury) was found in 36 (14.3%). UCH-L1 was 100% sensitive and 39% specific at a cutoff value >40 pg/mL. To retain 100% sensitivity, GFAP was 0% specific (cutoff value 0 pg/mL) and S100B had a specificity of only 2% (cutoff value 30 pg/mL). All three biomarkers had similar values for areas under the receiver operator characteristic curve: 0.79 (95% confidence interval; 0.70-0.88) for GFAP, 0.80 (0.71-0.89) for UCH-L1, and 0.75 (0.65-0.85) for S100B. Neither GFAP nor UCH-L1 curve values differed significantly from S100B (p = 0.21 and p = 0.77, respectively). In our patient cohort, UCH-L1 outperformed GFAP and S100B when the goal was to reduce CT use without sacrificing sensitivity. UCH-L1 values <40 pg/mL could potentially have aided in eliminating 83 of the 215 negative CT scans. These results require replication in other studies before the test is used in actual clinical practice.
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