| 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. |
- Denfeld, Quin E., et al.
(författare)
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Assessing and managing frailty in advanced heart failure: An International Society for Heart and Lung Transplantation consensus statement
- 2024
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Ingår i: The Journal of Heart and Lung Transplantation. - : Elsevier. - 1053-2498 .- 1557-3117. ; 43:1
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Tidskriftsartikel (refereegranskat)abstract
- Frailty is increasingly recognized as a salient condition in patients with heart failure (HF) as previous studies have determined that frailty is highly prevalent and prognostically significant, particularly in those with advanced HF. Definitions of frailty have included a variety of domains, including physical performance, sarcopenia, disability, comorbidity, and cognitive and psychological impairments, many of which are common in advanced HF. Multiple groups have recently recommended incorporating frailty assessments into clinical practice and research studies, indicating the need to standardize the definition and measurement of frailty in advanced HF. Therefore, the purpose of this consensus statement is to provide an integrated perspective on the definition of frailty in advanced HF and to generate a consensus on how to assess and manage frailty. We convened a group of HF clinicians and researchers who have expertise in frailty and related geriatric conditions in HF, and we focused on the patient with advanced HF. Herein, we provide an overview of frailty and how it has been applied in advanced HF (including potential mechanisms), present a definition of frailty, generate suggested assessments of frailty, provide guidance to differentiate frailty and related terms, and describe the assessment and management in advanced HF, including with surgical and nonsurgical interventions. We conclude by outlining critical evidence gaps, areas for future research, and clinical implementation. J Heart Lung Transplant 2024;43:1-27 (c) 2023 International Society for Heart and Lung Transplantation. All rights reserved.
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| 3. |
- Liu, Bin, et al.
(författare)
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Structure and genetics of Escherichia coli O antigens
- 2020
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Ingår i: FEMS Microbiology Reviews. - : Oxford University Press (OUP). - 0168-6445 .- 1574-6976. ; 44:6, s. 655-683
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Forskningsöversikt (refereegranskat)abstract
- Escherichia coli includes clonal groups of both commensal and pathogenic strains, with some of the latter causing serious infectious diseases. O antigen variation is current standard in defining strains for taxonomy and epidemiology, providing the basis for many serotyping schemes for Gram-negative bacteria. This review covers the diversity in E. coli O antigen structures and gene clusters, and the genetic basis for the structural diversity. Of the 187 formally defined O antigens, six (O31, O47, O67, O72, O94 and O122) have since been removed and three (O34, O89 and O144) strains do not produce any O antigen. Therefore, structures are presented for 176 of the 181 E. coli O antigens, some of which include subgroups. Most (93%) of these O antigens are synthesized via the Wzx/Wzy pathway, 11 via the ABC transporter pathway, with O20, O57 and O60 still uncharacterized due to failure to find their O antigen gene clusters. Biosynthetic pathways are given for 38 of the 49 sugars found in E. coli O antigens, and several pairs or groups of the E. coli antigens that have related structures show close relationships of the O antigen gene clusters within clades, thereby highlighting the genetic basis of the evolution of diversity.
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