Sepsis: Current Dogma and New Perspectives

Sepsis, a clinical syndrome occurring in patients following infection or injury, is a leading cause of morbidity andmortality worldwide. Current immunological mechanisms do not explain the basis of cellular dysfunction and organ failure, the ultimate cause of death. Here we review current dogma and argue that it is time to delineate novel immunometabolic and neurophysiological mechanisms underlying the altered cellular bioenergetics and failure of epithelial and endothelial barriers that produce organ dysfunction and death. These mechanisms might hold the key to future therapeutic strategies

Drop-on-demand microdroplet generation: a very stable platform for single-droplet experimentation

This paper reports the performance of drop-on-demand piezo-activated microdroplet generation investigated using microdroplet cavity enhanced fluorescence spectroscopy. Aqueous microdroplets, doped with a fluorescent dye, exhibit fluorescence spectra that are dominated by cavity resonances (termed whispering gallery modes) that, when analysed using Mie theory, allow for the determination of the radius of each microdroplet. The effect of controlled changes in the square-wave droplet generator voltage waveform on droplet size is investigated as well as the size reproducibility of successive microdroplets. Furthermore, using custom square-wave waveforms, microdroplet radii spanning ∼10 to 30 μm are produced from the same droplet dispenser. These non-standard waveforms do not sacrifice the reproducibility of microdroplet generation with \u3c1% size variation. Tuning the single square-wave pulsewidths induces predictable changes in the microdroplet radius and steps on the order of tens of nanometers are detectable. With finer voltage adjustments the microdroplet size is essentially tunable. These results confirm the extremely high stability and reproducibility of on-demand microdroplet generation and that precise size control is possible, rendering them suitable platforms for many applications in fundamental and applied research in areas including mass spectrometry, aerosol investigations and liquid-phase chemistr

Opioids depress cortical centers responsible for the volitional control of respiration

Respiratory depression limits provision of safe opioid analgesia and is the main cause of death in drug addicts. Although opioids are known to inhibit brainstem respiratory activity, their effects on cortical areas that mediate respiration are less well understood. Here, functional magnetic resonance imaging was used to examine how brainstem and cortical activity related to a short breath hold is modulated by the opioid remifentanil. We hypothesized that remifentanil would differentially depress brain areas that mediate sensory-affective components of respiration over those that mediate volitional motor control. Quantitative measures of cerebral blood flow were used to control for hypercapnia-induced changes in blood oxygen level-dependent (BOLD) signal. Awareness of respiration, reflected by an urge-to-breathe score, was profoundly reduced with remifentanil. Urge to breathe was associated with activity in the bilateral insula, frontal operculum, and secondary somatosensory cortex. Localized remifentanil-induced decreases in breath hold-related activity were observed in the left anterior insula and operculum. We also observed remifentanil-induced decreases in the BOLD response to breath holding in the left dorsolateral prefrontal cortex, anterior cingulate, the cerebellum, and periaqueductal gray, brain areas that mediate task performance. Activity in areas mediating motor control (putamen, motor cortex) and sensory-motor integration (supramarginal gyrus) were unaffected by remifentanil. Breath hold-related activity was observed in the medulla. These findings highlight the importance of higher cortical centers in providing contextual awareness of respiration that leads to appropriate modulation of respiratory control. Opioids have profound effects on the cortical centers that control breathing, which potentiates their actions in the brainstem

Comparing Psychosocial Adjustment Across the College Transition in a Matched Heterosexual and Lesbian, Gay, and Bisexual Sample

We compared a matched sample of heterosexual and lesbian, gay, and bisexual (LGB) students on 5 psychosocial adjustment composites, longitudinally across the transitional first year of college. Both LGB and heterosexual students experienced a significant increase in psychological distress over the first semester, along with significant decreases in psychological well-being and cognitive-affective strengths. Across the entire first year, LGB students demonstrated consistently greater psychological distress, greater cognitive-affective vulnerabilities, and less social well-being compared to heterosexual peers. This research indicates specific challenges that LGB students experience during the first year of university, suggesting opportunities for promoting successful transitions through this developmental milestone

High-mobility Group Box 1 Protein Initiates Postoperative Cognitive Decline by Engaging Bone Marrow-derived Macrophages

Background: Aseptic trauma engages the innate immune response to trigger a neuroinflammatory reaction that results in postoperative cognitive decline. The authors sought to determine whether high-mobility group box 1 protein (HMGB1), an ubiquitous nucleosomal protein, initiates this process through activation and trafficking of circulating bone marrow-derived macrophages to the brain. Methods: The effects of HMGB1 on memory (using trace fear conditioning) were tested in adult C57BL/6J male mice; separate cohorts were tested after bone marrow-derived macrophages were depleted by clodrolip. The effect of anti-HMGB1 neutralizing antibody on the inflammatory and behavioral responses to tibial surgery were investigated. Results: A single injection of HMGB1 caused memory decline, as evidenced by a decrease in freezing time (52 11% vs. 39 +/- 5%; n = 16-17); memory decline was prevented when bone marrow-derived macrophages were depleted (39 +/- 5% vs. 50 +/- 9%; n = 17). Disabling HMGB1 with a blocking monoclonal antibody, before surgery, reduced postoperative memory decline (52 +/- 11% vs. 29 +/- 5%; n = 15-16); also, hippocampal expression of monocyte chemotactic protein-1 was prevented by the neutralizing antibody (n = 6). Neither the systemic nor the hippocampal inflammatory responses to surgery occurred in mice pretreated with anti-HMGB1 neutralizing antibody (n = 6). Conclusion: Postoperative neuroinflammation and cognitive decline can be prevented by abrogating the effects of HMGB1. Following the earlier characterization of the resolution of surgery-induced memory decline, the mechanisms of its initiation are now described. Together, these data may be used to preoperatively test the risk to surgical patients for the development of exaggerated and prolonged postoperative memory decline that is reflected in delirium and postoperative cognitive dysfunction, respectively

ABC transporter FtsABCD of Streptococcus pyogenes mediates uptake of ferric ferrichrome

BACKGROUND: The Streptococcus pyogenes or Group A Streptococcus (GAS) genome encodes three ABC transporters, namely, FtsABCD, MtsABC, and HtsABC, which share homology with iron transporters. MtsABC and HtsABC are believed to take up ferric (Fe(3+)) and manganese ions and heme, respectively, while the specificity of FtsABCD is unknown. RESULTS: Recombinant FtsB, the lipoprotein component of FtsABCD, was found to bind Fe(3+ )ferrichrome in a 1:1 stoichiometry. To investigate whether FtsABCD transports Fe(3+ )ferrichrome, GAS isogenic strains defective in lipoprotein gene ftsB and permease gene ftsC were generated, and the effects of the mutations on uptake of Fe(3+ )ferrichrome were examined using radioactive (55)Fe(3+ )ferrichrome. FtsB was produced in the wild-type strain but not in the ftsB mutant, confirming the ftsB inactivation. While wild-type GAS took up 3.6 × 10(4 )Fe(3+ )ferrichrome molecules per bacterium per min at room temperature, the ftsB and ftsC mutants did not have a detectable rate of Fe(3+ )ferrichrome uptake. The inactivation of ftsB or ftsC also decreased (55)Fe(3+ )ferrichrome uptake by >90% under growth conditions in the case of limited uptake time. Complementation of the ftsB mutant with a plasmid carrying the ftsB gene restored FtsB production and (55)Fe(3+ )ferrichrome association at higher levels compared with the parent strain. The inactivation of mtsA and htsA and Fe-restricted conditions enhanced the production of FtsB and Fe(3+ )ferrichrome uptake. CONCLUSION: The FtsB protein bound Fe(3+ )ferrichrome, and inactivation of ftsB or ftsC, but not htsA or mtsA, diminished Fe(3+ )ferrichrome uptake, indicating that FtsABCD, but not HtsABC and MtsABC, is the transporter that takes up Fe(3+ )ferrichrome in GAS. Fe acquisition systems are virulence factors in many bacterial pathogens and are attractive vaccine candidates. The elucidation of the FtsABCD specificity advances the understanding of Fe acquisition processes in GAS and may help evaluating the GAS Fe acquisition systems as vaccine candidates

Residential Water Meters as Edge Computing Nodes: Disaggregating End Uses and Creating Actionable Information at the Edge

We present a new, open source, computationally capable datalogger for collecting and analyzing high temporal resolution residential water use data. Using this device, execution of water end use disaggregation algorithms or other data analytics can be performed directly on existing, analog residential water meters without disrupting their operation, effectively transforming existing water meters into smart, edge computing devices. Computation of water use summaries and classified water end use events directly on the meter minimizes data transmission requirements, reduces requirements for centralized data storage and processing, and reduces latency between data collection and generation of decision-relevant information. The datalogger couples an Arduino microcontroller board for data acquisition with a Raspberry Pi computer that serves as a computational resource. The computational node was developed and calibrated at the Utah Water Research Laboratory (UWRL) and was deployed for testing on the water meter for a single-family residential home in Providence City, UT, USA. Results from field deployments are presented to demonstrate the data collection accuracy, computational functionality, power requirements, communication capabilities, and applicability of the system. The computational node’s hardware design and software are open source, available for potential reuse, and can be adapted to specific research needs

Monoclonal Antibodies Capable of Binding SARS-CoV-2 Spike Protein Receptor Binding Motif Specifically Prevent GM-CSF Induction.

A severe acute respiratory syndrome (SARS)-like coronavirus (SARS-CoV-2) has recently caused a pandemic COVID-19 disease that infected more than 25.6 million and killed 852,000 people worldwide. Like the SARS-CoV, SARS-CoV-2 also employs a receptor-binding motif (RBM) of its envelope spike protein for binding the host angiotensin-converting enzyme 2 (ACE2) to gain viral entry. Currently, extensive efforts are being made to produce vaccines against a surface fragment of a SARS-CoV-2, such as the spike protein, in order to boost protective antibody responses. It was previously unknown how spike protein-targeting antibodies would affect innate inflammatory responses to SARS-CoV-2 infections. Here we generated a highly purified recombinant protein corresponding to the RBM of SARS-CoV-2, and used it to screen for cross-reactive monoclonal antibodies (mAbs). We found two RBM-binding mAbs that competitively inhibited its interaction with human ACE2, and specifically blocked the RBM-induced GM-CSF secretion in both human monocyte and murine macrophage cultures. Our findings have suggested a possible strategy to prevent SARS-CoV-2-elicited cytokine storm , and provided a potentially useful criteria for future assessment of innate immune-modulating properties of various SARS-CoV-2 vaccines. One Sentence Summary: RBM-binding Antibodies Inhibit GM-CSF Induction