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- Beal, Jacob, et al.
(author)
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Robust estimation of bacterial cell count from optical density
- 2020
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In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Journal article (peer-reviewed)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. |
- Bhat, Saiuj, et al.
(author)
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A Systematic Review of the Sources of Dietary Salt Around the World.
- 2020
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In: Advances in nutrition (Bethesda, Md.). - : Elsevier BV. - 2156-5376 .- 2161-8313. ; 11:3, s. 677-686
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Journal article (peer-reviewed)abstract
- Excess salt intake contributes to hypertension and increased cardiovascular disease risk. Efforts to implement effective salt-reduction strategies require accurate data on the sources of salt consumption. We therefore performed a systematic review to identify the sources of dietary salt around the world. We systematically searched peer-reviewed and gray literature databases for studies that quantified discretionary (salt added during cooking or at the table) and nondiscretionary sources of salt and those that provided information about the food groups contributing to dietary salt intake. Exploratory linear regression analysis was also conducted to assess whether the proportion of discretionary salt intake is related to the gross domestic product (GDP) per capita of a country. We identified 80 studies conducted in 34 countries between 1975 and 2018. The majority (n = 44, 55%) collected data on dietary salt sources within the past 10 y and were deemed to have a low or moderate risk of bias (n = 75, 94%). Thirty-two (40%) studies were judged to be nationally representative. Populations in Brazil, China, Costa Rica, Guatemala, India, Japan, Mozambique, and Romania received more than half of their daily salt intake from discretionary sources. A significant inverse correlation between discretionary salt intake and a country's per capita GDP was observed (P < 0.0001), such that for every $10,000 increase in per capita GDP, the amount of salt obtained from discretionary sources was lower by 8.7% (95% CI: 5.1%, 12%). Bread products, cereal and grains, meat products, and dairy products were the major contributors to dietary salt intake in most populations. There is marked variation in discretionary salt use around the world that is highly correlated with the level of economic development. Our findings have important implications for the type of salt-reduction strategy likely to be effective in a country.
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3. |
- Greer, Raquel C, et al.
(author)
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Potassium-Enriched Salt Substitutes as a Means to Lower Blood Pressure : Benefits and Risks.
- 2020
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In: Hypertension. - 0194-911X .- 1524-4563. ; 75:2, s. 266-274
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Journal article (peer-reviewed)abstract
- Use of salt substitutes containing potassium chloride is a potential strategy to reduce sodium intake, increase potassium intake, and thereby lower blood pressure and prevent the adverse consequences of high blood pressure. In this review, we describe the rationale for using potassium-enriched salt substitutes, summarize current evidence on the benefits and risks of potassium-enriched salt substitutes and discuss the implications of using potassium-enriched salt substitutes as a strategy to lower blood pressure. A benefit of salt substitutes that contain potassium chloride is the expected reduction in dietary sodium intake at the population level because of reformulation of manufactured foods or replacement of sodium chloride added to food during home cooking or at the dining table. There is empirical evidence that replacement of sodium chloride with potassium-enriched salt substitutes lowers systolic and diastolic blood pressure (average net Δ [95% CI] in mm Hg: -5.58 [-7.08 to -4.09] and -2.88 [-3.93 to -1.83], respectively). The risks of potassium-enriched salt substitutes include a possible increased risk of hyperkalemia and its principal adverse consequences: arrhythmias and sudden cardiac death, especially in people with conditions that impair potassium excretion such as chronic kidney disease. There is insufficient evidence regarding the effects of potassium-enriched salt substitutes on the occurrence of hyperkalemia. There is a need for additional empirical research on the effect of increasing dietary potassium and potassium-enriched salt substitutes on serum potassium levels and the risk of hyperkalemia, as well as for robust estimation of the population-wide impact of replacing sodium chloride with potassium-enriched salt substitutes.
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4. |
- Marklund, Matti, et al.
(author)
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Estimated population wide benefits and risks in China of lowering sodium through potassium enriched salt substitution : modelling study
- 2020
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In: The BMJ. - : BMJ Publishing Group Ltd. - 1756-1833. ; 369
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Journal article (peer-reviewed)abstract
- OBJECTIVES: To estimate the effects of nationwide replacement of discretionary salt (used at table or during cooking) with potassium enriched salt substitute on morbidity and death from cardiovascular disease in China.DESIGN: Modelling study.SETTING: China.POPULATION: Adult population in China, and specifically individuals with chronic kidney disease (about 17 million people).INTERVENTIONS: Comparative risk assessment models were used to estimate the effects of a nationwide intervention to replace discretionary dietary salt with potassium enriched salt substitutes (20-30% potassium chloride). The models incorporated existing data and corresponding uncertainties from randomised trials, the China National Survey of Chronic Kidney Disease, the Global Burden of Disease Study, and the Chronic Kidney Disease Prognosis Consortium.MAIN OUTCOME MEASURES: Averted deaths from cardiovascular disease, non-fatal events, and disability adjusted life years from a reduction in blood pressure were estimated after implementation of potassium enriched salt substitution. In individuals with chronic kidney disease, additional deaths from cardiovascular disease related to hyperkalaemia from increased intake of potassium were calculated. The net effects on deaths from cardiovascular disease were estimated as the difference and ratio of averted and additional deaths from cardiovascular disease.RESULTS: Nationwide implementation of potassium enriched salt substitution could prevent about 461 000 (95% uncertainty interval 196 339 to 704 438) deaths annually from cardiovascular disease, corresponding to 11.0% (4.7% to 16.8%) of annual deaths from cardiovascular disease in China; 743 000 (305 803 to 1 273 098) non-fatal cardiovascular events annually; and 7.9 (3.3 to 12.9) million disability adjusted life years related to cardiovascular disease annually. The intervention could potentially produce an estimated 11 000 (6422 to 16 562) additional deaths related to hyperkalaemia in individuals with chronic kidney disease. The net effect would be about 450 000 (183 699 to 697 084) fewer deaths annually from cardiovascular disease in the overall population and 21 000 (1928 to 42 926) fewer deaths in individuals with chronic kidney disease. In deterministic sensitivity analyses, with changes to key model inputs and assumptions, net benefits were consistent in the total population and in individuals with chronic kidney disease, with averted deaths outweighing additional deaths.CONCLUSIONS: Nationwide potassium enriched salt substitution in China was estimated to result in a substantial net benefit, preventing around one in nine deaths from cardiovascular disease overall. Taking account of the risks of hyperkalaemia, a substantial net benefit was also estimated for individuals with chronic kidney disease.
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