Single-molecule live-cell imaging reveals RecB-dependent function of DNA polymerase IV in double strand break repair

© The Author(s) 2020. Published by Oxford University Press on behalf of Nucleic Acids Research. Several functions have been proposed for the Escherichia coli DNA polymerase IV (pol IV). Although much research has focused on a potential role for pol IV in assisting pol III replisomes in the bypass of lesions, pol IV is rarely found at the replication fork in vivo. Pol IV is expressed at increased levels in E. coli cells exposed to exogenous DNA damaging agents, including many commonly used antibiotics. Here we present live-cell single-molecule microscopy measurements indicating that double-strand breaks induced by antibiotics strongly stimulate pol IV activity. Exposure to the antibiotics ciprofloxacin and trimethoprim leads to the formation of double strand breaks in E. coli cells. RecA and pol IV foci increase after treatment and exhibit strong colocalization. The induction of the SOS response, the appearance of RecA foci, the appearance of pol IV foci and RecA-pol IV colocalization are all dependent on RecB function. The positioning of pol IV foci likely reflects a physical interaction with the RecA* nucleoprotein filaments that has been detected previously in vitro. Our observations provide an in vivo substantiation of a direct role for pol IV in double strand break repair in cells treated with double strand break-inducing antibiotics

Objects of Correction: Literature and the Birth of Modern Punishment

In England in the sixteenth and seventeenth centuries, the impact of humanist education, the changes of the Reformation, and the emergence of capitalism and colonialism all gave rise to an equally momentous revolution in carceral technology. This was the birth of “correction,” or the argument that punishments for minor crimes ought to go beyond retribution, and beyond deterrence, to aim at reintegrating offenders into society as well. This idea was first institutionalized in the “house of correction,” beginning in the 1550s with London’s Bridewell, which became the first prison anywhere in early modern Europe to combine short sentences with punitive work-training. By the 1630s a network of houses of correction extended across England, offering an institutional model and a culture of work discipline that could be exported, along with its convicts, to the American colonies. Objects of Correction charts the surprising extent to which imaginative literature was involved in this carceral revolution. Bridewell, the original house of correction, was located next door to Shakespeare’s indoor theater at Blackfriars—a gallery bridge connected the two—and workshops in the prison made puppets for the stage. The first English translations of More’s Utopia, with its famous ideas about penal reform, were commissioned and promoted by some of Bridewell's strongest propagandists. Milton pushed reading as a means of self-discipline, while his associates in the Hartlib Circle re-imagined houses of correction as “Literary work-houses.” Objects of Correction recast the so-called “Golden Age” entirely, by showing how English literature defined itself against the carceral institutions of its time. Working upward from the practices, institutions, philosophy, rhetoric, and even the syntax of early modern culture, Objects of Correction also offers a provocative account of "correction" itself, in the centuries before this argument became modernity’s most powerful justification for punishment

AMPK-mediated potentiation of GABAergic signalling drives hypoglycaemia-provoked spike-wave seizures.

Metabolism regulates neuronal activity and modulates the occurrence of epileptic seizures. Here, using two rodent models of absence epilepsy, we show that hypoglycaemia increases the occurrence of spike-wave seizures. We then show that selectively disrupting glycolysis in the thalamus, a structure implicated in absence epilepsy, is sufficient to increase spike-wave seizures. We propose that activation of thalamic AMP-activated protein kinase, a sensor of cellular energetic stress and potentiator of metabotropic GABAB-receptor function, is a significant driver of hypoglycaemia-induced spike-wave seizures. We show that AMP-activated protein kinase augments postsynaptic GABAB-receptor-mediated currents in thalamocortical neurons and strengthens epileptiform network activity evoked in thalamic brain slices. Selective thalamic AMP-activated protein kinase activation also increases spike-wave seizures. Finally, systemic administration of metformin, an AMP-activated protein kinase agonist and common diabetes treatment, profoundly increased spike-wave seizures. These results advance the decades-old observation that glucose metabolism regulates thalamocortical circuit excitability by demonstrating that AMP-activated protein kinase and GABAB-receptor cooperativity is sufficient to provoke spike-wave seizures

Clinical decision support tools for paediatric sepsis in resource-poor settings: an international qualitative study

Objective New paediatric sepsis criteria are being developed by an international task force. However, it remains unknown what type of clinical decision support (CDS) tools will be most useful for dissemination of those criteria in resource-poor settings. We sought to design effective CDS tools by identifying the paediatric sepsis-related decisional needs of multidisciplinary clinicians and health system administrators in resource-poor settings.Design Semistructured qualitative focus groups and interviews with 35 clinicians (8 nurses, 27 physicians) and 5 administrators at health systems that regularly provide care for children with sepsis, April–May 2022.Setting Health systems in Africa, Asia and Latin America, where sepsis has a large impact on child health and healthcare resources may be limited.Participants Participants had a mean age of 45 years, a mean of 15 years of experience, and were 45% female.Results Emergent themes were related to the decisional needs of clinicians caring for children with sepsis and to the needs of health system administrators as they make decisions about which CDS tools to implement. Themes included variation across regions and institutions in infectious aetiologies of sepsis and available clinical resources, the need for CDS tools to be flexible and customisable in order for implementation to be successful, and proposed features and format of an ideal paediatric sepsis CDS tool.Conclusion Findings from this study will directly contribute to the design and implementation of CDS tools to increase the uptake and impact of the new paediatric sepsis criteria in resource-poor settings