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

Clinical Characteristics, Racial Inequities, and Outcomes in Patients with Breast Cancer and COVID-19: A COVID-19 and Cancer Consortium (CCC19) Cohort Study

BACKGROUND: Limited information is available for patients with breast cancer (BC) and coronavirus disease 2019 (COVID-19), especially among underrepresented racial/ethnic populations. METHODS: This is a COVID-19 and Cancer Consortium (CCC19) registry-based retrospective cohort study of females with active or history of BC and laboratory-confirmed severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection diagnosed between March 2020 and June 2021 in the US. Primary outcome was COVID-19 severity measured on a five-level ordinal scale, including none of the following complications, hospitalization, intensive care unit admission, mechanical ventilation, and all-cause mortality. Multivariable ordinal logistic regression model identified characteristics associated with COVID-19 severity. RESULTS: 1383 female patient records with BC and COVID-19 were included in the analysis, the median age was 61 years, and median follow-up was 90 days. Multivariable analysis revealed higher odds of COVID-19 severity for older age (aOR per decade, 1.48 [95% CI, 1.32-1.67]); Black patients (aOR 1.74; 95 CI 1.24-2.45), Asian Americans and Pacific Islander patients (aOR 3.40; 95 CI 1.70-6.79) and Other (aOR 2.97; 95 CI 1.71-5.17) racial/ethnic groups; worse ECOG performance status (ECOG PS ≥2: aOR, 7.78 [95% CI, 4.83-12.5]); pre-existing cardiovascular (aOR, 2.26 [95% CI, 1.63-3.15])/pulmonary comorbidities (aOR, 1.65 [95% CI, 1.20-2.29]); diabetes mellitus (aOR, 2.25 [95% CI, 1.66-3.04]); and active and progressing cancer (aOR, 12.5 [95% CI, 6.89-22.6]). Hispanic ethnicity, timing, and type of anti-cancer therapy modalities were not significantly associated with worse COVID-19 outcomes. The total all-cause mortality and hospitalization rate for the entire cohort was 9% and 37%, respectively however, it varied according to the BC disease status. CONCLUSIONS: Using one of the largest registries on cancer and COVID-19, we identified patient and BC-related factors associated with worse COVID-19 outcomes. After adjusting for baseline characteristics, underrepresented racial/ethnic patients experienced worse outcomes compared to non-Hispanic White patients. FUNDING: This study was partly supported by National Cancer Institute grant number P30 CA068485 to Tianyi Sun, Sanjay Mishra, Benjamin French, Jeremy L Warner; P30-CA046592 to Christopher R Friese; P30 CA023100 for Rana R McKay; P30-CA054174 for Pankil K Shah and Dimpy P Shah; KL2 TR002646 for Pankil Shah and the American Cancer Society and Hope Foundation for Cancer Research (MRSG-16-152-01-CCE) and P30-CA054174 for Dimpy P Shah. REDCap is developed and supported by Vanderbilt Institute for Clinical and Translational Research grant support (UL1 TR000445 from NCATS/NIH). The funding sources had no role in the writing of the manuscript or the decision to submit it for publication. CLINICAL TRIAL NUMBER: CCC19 registry is registered on ClinicalTrials.gov, NCT04354701

Reversal of inappropriate peripheral vascular responses in hypertrophic cardiomyopathy

We assessed the frequency of abnormal forearm vasodilator responses during lower body negative pressure (LBNP) in 21 non-obstructive hypertrophic cardiomyopathy (HCM) patients (31 +/- 8 [20 to 43] years) with abnormal blood pressure response (ABPR) to exercise and the effects of three drugs used to treat vasovagal syncope (propranolol, clonidine, and paroxetine) in a double-blind crossover study

Human distal airways contain a multipotent secretory cell that can regenerate alveoli

The human lung differs substantially from its mouse counterpart, resulting in a distinct distal airway architecture affected by disease pathology in chronic obstructive pulmonary disease. In humans, the distal branches of the airway interweave with the alveolar gas-exchange niche, forming an anatomical structure known as the respiratory bronchioles. Owing to the lack of a counterpart in mouse, the cellular and molecular mechanisms that govern respiratory bronchioles in the human lung remain uncharacterized. Here we show that human respiratory bronchioles contain a unique secretory cell population that is distinct from cells in larger proximal airways. Organoid modelling reveals that these respiratory airway secretory (RAS) cells act as unidirectional progenitors for alveolar type 2 cells, which are essential for maintaining and regenerating the alveolar niche. RAS cell lineage differentiation into alveolar type 2 cells is regulated by Notch and Wnt signalling. In chronic obstructive pulmonary disease, RAS cells are altered transcriptionally, corresponding to abnormal alveolar type 2 cell states, which are associated with smoking exposure in both humans and ferrets. These data identify a distinct progenitor in a region of the human lung that is not found in mouse that has a critical role in maintaining the gas-exchange compartment and is altered in chronic lung disease

A randomized controlled trial to investigate the use of acute coronary syndrome therapy in patients hospitalized with COVID-19: the COVID-19 Acute Coronary Syndrome trial.

BackgroundPatients hospitalized with COVID-19 suffer thrombotic complications. Risk factors for poor outcomes are shared with coronary artery disease.ObjectivesTo investigate the efficacy of an acute coronary syndrome regimen in patients hospitalized with COVID-19 and coronary disease risk factors.MethodsA randomized controlled, open-label trial across acute hospitals (United Kingdom and Brazil) added aspirin, clopidogrel, low-dose rivaroxaban, atorvastatin, and omeprazole to standard care for 28 days. Primary efficacy and safety outcomes were 30-day mortality and bleeding. The key secondary outcome was a daily clinical status (at home, in hospital, on intensive therapy unit admission, or death).ResultsThree hundred twenty patients from 9 centers were randomized. The trial terminated early due to low recruitment. At 30 days, there was no significant difference in mortality (intervention vs control, 11.5% vs 15%; unadjusted odds ratio [OR], 0.73; 95% CI, 0.38-1.41; p = .355). Significant bleeds were infrequent and were not significantly different between the arms (intervention vs control, 1.9% vs 1.9%; p > .999). Using a Bayesian Markov longitudinal ordinal model, it was 93% probable that intervention arm participants were more likely to transition to a better clinical state each day (OR, 1.46; 95% credible interval [CrI], 0.88-2.37; Pr [beta > 0], 93%; adjusted OR, 1.50; 95% CrI, 0.91-2.45; Pr [beta > 0], 95%) and median time to discharge to home was 2 days shorter (95% CrI, -4 to 0; 2% probability that it was worse).ConclusionAcute coronary syndrome treatment regimen was associated with a reduction in the length of hospital stay without an excess in major bleeding. A larger trial is needed to evaluate mortality

A randomized controlled trial to investigate the use of acute coronary syndrome therapy in patients hospitalized with COVID-19: the COVID-19 Acute Coronary Syndrome trial.

BACKGROUND: Patients hospitalized with COVID-19 suffer thrombotic complications. Risk factors for poor outcomes are shared with coronary artery disease. OBJECTIVES: To investigate the efficacy of an acute coronary syndrome regimen in patients hospitalized with COVID-19 and coronary disease risk factors. METHODS: A randomized controlled, open-label trial across acute hospitals (United Kingdom and Brazil) added aspirin, clopidogrel, low-dose rivaroxaban, atorvastatin, and omeprazole to standard care for 28 days. Primary efficacy and safety outcomes were 30-day mortality and bleeding. The key secondary outcome was a daily clinical status (at home, in hospital, on intensive therapy unit admission, or death). RESULTS: Three hundred twenty patients from 9 centers were randomized. The trial terminated early due to low recruitment. At 30 days, there was no significant difference in mortality (intervention vs control, 11.5% vs 15%; unadjusted odds ratio [OR], 0.73; 95% CI, 0.38-1.41; p = .355). Significant bleeds were infrequent and were not significantly different between the arms (intervention vs control, 1.9% vs 1.9%; p > .999). Using a Bayesian Markov longitudinal ordinal model, it was 93% probable that intervention arm participants were more likely to transition to a better clinical state each day (OR, 1.46; 95% credible interval [CrI], 0.88-2.37; Pr [beta > 0], 93%; adjusted OR, 1.50; 95% CrI, 0.91-2.45; Pr [beta > 0], 95%) and median time to discharge to home was 2 days shorter (95% CrI, -4 to 0; 2% probability that it was worse). CONCLUSION: Acute coronary syndrome treatment regimen was associated with a reduction in the length of hospital stay without an excess in major bleeding. A larger trial is needed to evaluate mortality