Systems biology perspectives on minimal and simpler cells

The concept of the minimal cell has fascinated scientists for a long time, from both fundamental and applied points of view. This broad concept encompasses extreme reductions of genomes, the last universal common ancestor (LUCA), the creation of semiartificial cells, and the design of protocells and chassis cells. Here we review these different areas of research and identify common and complementary aspects of each one. We focus on systems biology, a discipline that is greatly facilitating the classical top-down and bottom-up approaches toward minimal cells. In addition, we also review the so-called middle-out approach and its contributions to the field with mathematical and computational models. Owing to the advances in genomics technologies, much of the work in this area has been centered on minimal genomes, or rather minimal gene sets, required to sustain life. Nevertheless, a fundamental expansion has been taking place in the last few years wherein the minimal gene set is viewed as a backbone of a more complex system. Complementing genomics, progress is being made in understanding the system-wide properties at the levels of the transcriptome, proteome, and metabolome. Network modeling approaches are enabling the integration of these different omics data sets toward an understanding of the complex molecular pathways connecting genotype to phenotype. We review key concepts central to the mapping and modeling of this complexity, which is at the heart of research on minimal cells. Finally, we discuss the distinction between minimizing the number of cellular components and minimizing cellular complexity, toward an improved understanding and utilization of minimal and simpler cells.J.C.X. is sponsored by grant SFRH/BD/81626/2011 from the Fundacao para a Ciencia e Tecnologia, Portugal

We must harness the power of social and behavioural science against the growing pandemic of antimicrobial resistance

Social and behavioural science offers a valuable toolkit for combating pandemics, but has not been broadly applied to tackle the rising pandemic of antimicrobial resistance

We must harness the power of social and behavioural science against the growing pandemic of antimicrobial resistance

Antimicrobial resistance occurs when microorganisms (such as bacteria, fungi and viruses) adapt to survive exposure to medicines that normally kill them or inhibit their growth, which in turn makes these medicines less effective over time. Left unmitigated, antimicrobial resistance will reverse previous gains in modern medicine and increase global mortality from currently treatable diseases. According to the World Health Organization (WHO), antimicrobial resistance is one of the most important threats to global health, food security and development today1. In 2019, antimicrobial resistance is estimated to have contributed to the deaths of approximately 4.95 million people: 1.27 million deaths were directly attributed to it2. By comparison, the WHO estimated that — on the basis of excess deaths statistics — COVID-19 was associated with 3 million deaths in 2020 (ref. 3). If no immediate measures are taken to reduce the spread of antimicrobial resistance, by 2050 it could contribute to up to 10 million deaths annually4. The burden is not distributed equally, as it disproportionally affects people from low- and middle-income countries2

Performance of indirect immunofluorescence assay, immunochromatography assay and reverse transcription-polymerase chain reaction for detecting human respiratory syncytial virus in nasopharyngeal aspirate samples

Comparison of the use of indirect immunofluorescence assay (IFA), immunochromatography assay (ICA-BD) and reverse transcription-polymerase chain reaction (RT-PCR) for detecting human respiratory syncytial virus (HRSV) in 306 nasopharyngeal aspirates samples (NPA) was performed in order to assess their analytical performance. By comparing the results obtained using ICA-BD with those using IFA, we found relative indices of 85.0% for sensitivity and 91.2% for specificity, and the positive (PPV) and negative (NPV) predictive values were 85.0% and 91.2%, respectively. The relative indices for sensitivity and specificity as well as the PPV and NPV for RT-PCR were 98.0%, 89.0%, 84.0% and 99.0%, respectively, when compared to the results of IFA. In addition, comparison of the results of ICA-BD and those of RT-PCR yielded relative indices of 79.5% for sensitivity and 95.4% for specificity, as well as PPV and NPV of 92.9% and 86.0%, respectively. Although RT-PCR has shown the best performance, the substantial agreement between the ICA-BD and IFA results suggests that ICA-BD, also in addition to being a rapid and facile assay, could be suitable as an alternative diagnostic screening for HRSV infection in children

Antioxidant and DNA methylation-related nutrients and risk of distal colorectal cancer

OBJECTIVE: To investigate the relationship between antioxidant nutrients (vitamins C and E, β-carotene, selenium) and DNA methylation-related nutrients (folate, vitamins B6 and B12) and distal colorectal cancer risk in whites and African Americans and to examine intakes from food only versus total (food plus dietary supplements) intakes. METHODS: Data are from the North Carolina Colon Cancer Study-Phase II, a case–control study of 945 distal colorectal cancer (including sigmoid, rectosigmoid, and rectum) cases and 959 controls. In-person interviews captured usual dietary intake and various covariates. Multivariate logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (95% CI). RESULTS: High intakes of each antioxidant and DNA methylation-related nutrient were significantly associated with lower risk in whites. In African Americans, the highest category of selenium from food only had a marginally significant inverse association with distal colorectal cancer risk (Q4 vs. Q1 OR: 0.55, 95% CI 0.29–1.02). Supplements did not provide additional risk reduction beyond intakes from food. CONCLUSIONS: Our findings provide evidence that antioxidant and DNA methylation-related nutrients may lower the risk of distal colorectal cancer in whites, and selenium may lower risk in African Americans. Optimal micronutrient intakes from food alone may be more beneficial than supplementation