Robust estimation of bacterial cell count from optical density

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

Preventing foot ulceration in diabetes:systematic review and meta-analyses of RCT data

Aims/hypothesis: Foot ulceration is a serious complication for people with diabetes that results in high levels of morbidity for individuals and significant costs for health and social care systems. Nineteen systematic reviews of preventative interventions have been published, but none provides a reliable numerical summary of treatment effects. The aim of this study was to systematically review the evidence from RCTs and, where possible, conduct meta-analyses to make the best possible use of the currently available data. Methods: We conducted a systematic review and meta-analysis of RCTs of preventative interventions for foot ulceration. OVID MEDLINE and EMBASE were searched to February 2019 and the Cochrane Central Register of Controlled Trials to October 2018. RCTs of interventions to prevent foot ulcers in people with diabetes who were free from foot ulceration at trial entry were included. Two independent reviewers read the full-text articles and extracted data. The quality of trial reporting was assessed using the Cochrane Risk of Bias tool. The primary outcome of foot ulceration was summarised using pooled relative risks in meta-analyses. Results: Twenty-two RCTs of eight interventions were eligible for analysis. One trial of digital silicone devices (RR 0.07 [95% CI 0.01, 0.55]) and meta-analyses of dermal infrared thermometry (RR 0.41 [95% CI 0.19, 0.86]), complex interventions (RR 0.59 [95% CI 0.38, 0.90], and custom-made footwear and offloading insoles (RR 0.53 [95% CI 0.33, 0.85]) showed beneficial effects for these interventions. Conclusions/interpretation: Four interventions were identified as being effective in preventing foot ulcers in people with diabetes, but uncertainty remains about what works and who is most likely to benefit

Robust estimation of bacterial cell count from optical density

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

Robust estimation of bacterial cell count from optical density

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 &lt;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

Patients&rsquo; Expectations of Evidence-Based Service at the Pharmacy Regarding Information on Self-Care of the Feet for Persons with Diabetes at Risk of Developing Foot Ulcers &ndash; A Cross-Sectional Observational Study in Sweden

Ulla Hellstrand Tang,1,2 Isabella Scandurra,3 Leif Sundberg,4 Magdalena Annersten Gershater,5 Roland Zügner2 1Department of Prosthetics and Orthotics, Sahlgrenska University Hospital, Gothenburg, Sweden; 2Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy,University of Gothenburg, Sahlgrenska University Hospital, Gothenburg, Sweden; 3Centre of Empirical Research in Information Systems, Örebro University, Örebro, Sweden; 4Gothenburg Diabetes Association, Gothenburg, Sweden; 5Department of Care Science, Faculty of Health and Society, Malmö University, Malmö, SwedenCorrespondence: Ulla Hellstrand Tang, Department of Prosthetics and Orthotics, Sahlgrenska University Hospital, Falkenbergsgatan 3, Gothenburg, SE-412 85, Sweden, Tel +46 70 6397913, Fax +46 31 40 81 62, Email [email protected]: Self-care of the feet is one of the cornerstones in the prevention of diabetic foot ulcers (DFU). Often, individuals with diabetes seek help at the pharmacy, but it is still unclear whether the service meets their expectations and needs. The aims were to explore patients’ expectations of support from the pharmacy regarding self-care of their feet and explore how patients with diabetes felt that they managed the self-care of their feet.Patients and Methods: The included participants (n = 17), aged 70 ± 9 years, answered surveys regarding their expectations of support from the pharmacy related to self-care of the feet and how they felt that they managed the self-care of their feet. By using software, MyFoot Diabetes, they assessed their risk of developing DFU (ranging from 1 = no risk to 4 = DFU). In addition, a healthcare professional assessed the risk grade.Results: Sixteen patients had not received any information from the pharmacy regarding how to take care of their feet. Several suggestions for ways the pharmacy could help patients with diabetes to take care of their feet were registered. They included having the necessary skills and competence, giving advice regarding self-care, giving information regarding the products they market and have for sale and giving advice on ointments/creams. The participants gave several examples of how they self-managed their feet: by wearing shoes indoors and outdoors, wearing socks and compression stockings as often as possible, being physically active, inspecting their feet, being aware of the fact that their feet have no problems, washing, moisturising their feet, cutting their nails and finally seeking help to prevent DFU.Conclusion: The participants thought that they should receive competent information from the personnel at the pharmacy to improve the self-care of their feet, eg, being given information about which ointments/creams to use.Clinical Trial: NCT05692778.Plain Language Summary: Persons living with diabetes have better opportunities to be physically active, keep on walking and participate in social activity if the feet are in good health. Besides getting support from healthcare, on how to promote good foot health, the pharmacies offer services and products aimed for self-care of the feet. Seventeen persons living with diabetes in the western region of Sweden answered a survey regarding their expectations of support from the pharmacy related to self-care of the feet and how they felt that they managed the self-care of their feet. The study found that persons living with diabetes self-managed their feet in different ways. The services being available from the pharmacies should be improved, promoting good foot health for persons living with diabetes, and in its prolongation prevent the development of diabetic foot ulcers.Keywords: diabetic foot, prevention, diabetes type 1, diabetes type 2, self-care, self-management, self-monitorin

The C-glycosylation of flavonoids in cereals

Flavonoids normally accumulate in plants as O-glycosylated derivatives, but several species, including major cereal crops, predominantly synthesize flavone-C-glycosides, which are stable to hydrolysis and are biologically active both in planta and as dietary components. An enzyme (OsCGT) catalyzing the UDP-glucose-dependent C-glucosylation of 2-hydroxyflavanone precursors of flavonoids has been identified and cloned from rice (Oryza sativa ssp. indica), with a similar protein characterized in wheat (Triticum aestivum L.). OsCGT is a 49-kDa family 1 glycosyltransferase related to known O-glucosyltransferases. The recombinant enzyme C-glucosylated 2-hydroxyflavanones but had negligible O-glucosyltransferase activity with flavonoid acceptors. Enzyme chemistry studies suggested that OsCGT preferentially C-glucosylated the dibenzoylmethane tautomers formed in equilibrium with 2-hydroxyflavanones. The resulting 2-hydroxyflavanone-C-glucosides were unstable and spontaneously dehydrated in vitro to yield a mixture of 6C- and 8C-glucosyl derivatives of the respective flavones. In contrast, in planta, only the respective 6C-glucosides accumulated. Consistent with this selectivity in glycosylation product, a dehydratase activity that preferentially converted 2-hydroxyflavanone-C-glucosides to the corresponding flavone-6C-glucosides was identified in both rice and wheat. Our results demonstrate that cereal crops synthesize C-glucosylated flavones through the concerted action of a CGT and dehydratase acting on activated 2-hydroxyflavanones, as an alternative means of generating flavonoid metabolites