A Deep Learning Approach to Antibiotic Discovery.

Due to the rapid emergence of antibiotic-resistant bacteria, there is a growing need to discover new antibiotics. To address this challenge, we trained a deep neural network capable of predicting molecules with antibacterial activity. We performed predictions on multiple chemical libraries and discovered a molecule from the Drug Repurposing Hub-halicin-that is structurally divergent from conventional antibiotics and displays bactericidal activity against a wide phylogenetic spectrum of pathogens including Mycobacterium tuberculosis and carbapenem-resistant Enterobacteriaceae. Halicin also effectively treated Clostridioides difficile and pan-resistant Acinetobacter baumannii infections in murine models. Additionally, from a discrete set of 23 empirically tested predictions from >107 million molecules curated from the ZINC15 database, our model identified eight antibacterial compounds that are structurally distant from known antibiotics. This work highlights the utility of deep learning approaches to expand our antibiotic arsenal through the discovery of structurally distinct antibacterial molecules.

Long-term tolerance to skin commensals is established neonatally through a specialized dendritic cell subgroup.

Early-life establishment of tolerance to commensal bacteria at barrier surfaces carries enduring implications for immune health but remains poorly understood. Here, we showed that tolerance in skin was controlled by microbial interaction with a specialized subset of antigen-presenting cells. More particularly, CD301b+ type 2 conventional dendritic cells (DCs) in neonatal skin were specifically capable of uptake and presentation of commensal antigens for the generation of regulatory T (Treg) cells. CD301b+ DC2 were enriched for phagocytosis and maturation programs, while also expressing tolerogenic markers. In both human and murine skin, these signatures were reinforced by microbial uptake. In contrast to their adult counterparts or other early-life DC subsets, neonatal CD301b+ DC2 highly expressed the retinoic-acid-producing enzyme, RALDH2, the deletion of which limited commensal-specific Treg cell generation. Thus, synergistic interactions between bacteria and a specialized DC subset critically support early-life tolerance at the cutaneous interface.

COVID-19 tissue atlases reveal SARS-CoV-2 pathology and cellular targets.

COVID-19, which is caused by SARS-CoV-2, can result in acute respiratory distress syndrome and multiple organ failure1-4, but little is known about its pathophysiology. Here we generated single-cell atlases of 24 lung, 16 kidney, 16 liver and 19 heart autopsy tissue samples and spatial atlases of 14 lung samples from donors who died of COVID-19. Integrated computational analysis uncovered substantial remodelling in the lung epithelial, immune and stromal compartments, with evidence of multiple paths of failed tissue regeneration, including defective alveolar type 2 differentiation and expansion of fibroblasts and putative TP63+ intrapulmonary basal-like progenitor cells. Viral RNAs were enriched in mononuclear phagocytic and endothelial lung cells, which induced specific host programs. Spatial analysis in lung distinguished inflammatory host responses in lung regions with and without viral RNA. Analysis of the other tissue atlases showed transcriptional alterations in multiple cell types in heart tissue from donors with COVID-19, and mapped cell types and genes implicated with disease severity based on COVID-19 genome-wide association studies. Our foundational dataset elucidates the biological effect of severe SARS-CoV-2 infection across the body, a key step towards new treatments.

Barriers and facilitators to exclusive breastfeeding among Black mothers: A qualitative study utilizing a modified Barrier Analysis approach.

Breastfeeding has health benefits for both infants and mothers, yet Black mothers and infants are less likely to receive these benefits. Despite research showing no difference in breastfeeding intentions by race or ethnicity, inequities in breastfeeding rates persist, suggesting that Black mothers face unique barriers to meeting their breastfeeding intentions. The aim of this study is to identify barriers and facilitators that Black women perceive as important determinants of exclusively breastfeeding their children for at least 3 months after birth. Utilizing a Barrier Analysis approach, we conducted six focus group discussions, hearing from Black mothers who exclusively breastfed for 3 months and those who did not. Transcripts were coded starting with a priori parent codes based on theory-derived determinants mapped onto the Socioecological Model; themes were analysed for differences between groups. Facilitators found to be important specifically for women who exclusively breastfed for 3 months include self-efficacy, lactation support, appropriate lactation supplies, support of mothers and partners, prior knowledge of breastfeeding, strong intention before birth and perceptions of breastfeeding as money-saving. Barriers that arose more often among those who did not exclusively breastfeed for 3 months include inaccessible lactation support and supplies, difficulties with pumping, latching issues and perceptions of breastfeeding as time-consuming. Lack of access to and knowledge of breastfeeding laws and policies, as well as negative cultural norms or stigma, were important barriers across groups. This study supports the use of the Socioecological Model to design multicomponent interventions to increase exclusive breastfeeding outcomes for Black women.

Identifying Social Media Competencies for Health Professionals: An International Modified Delphi Study to Determine Consensus for Curricular Design.

STUDY OBJECTIVE: The use of social media by health professionals is widespread. However, there is a lack of training to support the effective use of these novel platforms that account for the nuances of an effective health and research communication. We sought to identify the competencies needed by health care professionals to develop an effective social media presence as a medical professional, with the goal of building a social media curriculum. METHODS: We conducted a modified Delphi study, utilizing Kraiger's Knowledge, Skills, and Attitudes framework to identify appropriate items for inclusion in a social media curriculum targeted at health care professionals. Experts in this space were defined as health care professionals who had delivered workshops, published papers, or developed prominent social media tools/accounts. They were recruited through a multimodal campaign to complete a series of 3 survey rounds designed to build consensus. In keeping with prior studies, a threshold of 80% endorsement was used for inclusion in the final list of items. RESULTS: Ninety-eight participants met the expert criteria and were invited to participate in the study. Of the 98 participants, 92 (94%) experts completed the first round; of the 92 experts who completed the first round, 83 (90%) completed the second round; and of the 83 experts who completed the second round, 81 (98%) completed the third round of the Delphi study. Eighteen new items were suggested in the first survey and incorporated into the study. A total of 46 items met the 80% inclusion threshold. CONCLUSION: We identified 46 items that were believed to be important for health care professionals using social media. This list should inform the development of curricular activities and objectives.

Space Microgravity Alters Neural Stem Cell Division: Implications for Brain Cancer Research on Earth and in Space.

Considering the imminence of long-term space travel, it is necessary to investigate the impact of space microgravity (SPC-µG) in order to determine if this environment has consequences on the astronauts' health, in particular, neural and cognitive functions. Neural stem cells (NSCs) are the basis for the regeneration of the central nervous system (CNS) cell populations and learning how weightlessness impacts NSCs in health and disease provides a critical tool for the potential mitigation of specific mechanisms leading to neurological disorders. In previous studies, we found that exposure to SPC-µG resulted in enhanced proliferation, a shortened cell cycle, and a larger cell diameter of NSCs compared to control cells. Here, we report the frequent occurrence of abnormal cell division (ACD) including incomplete cell division (ICD), where cytokinesis is not successfully completed, and multi-daughter cell division (MDCD) of NSCs following SPC-µG as well as secretome exposure compared to ground control (1G) NSCs. These findings provide new insights into the potential health implications of space travel and have far-reaching implications for understanding the mechanisms leading to the deleterious effects of long-term space travel as well as potential carcinogenic susceptibility. Knowledge of these mechanisms could help to develop preventive or corrective measures for successful long-term SPC-µG exposure.

How do breastfeeding workplace interventions work?: a realist review.

BACKGROUND: Women are representing an increasing share of the labor force, thus, raising the need to accommodate breastfeeding working mothers at the workplace. While there is an emerging body of evidence supporting the positive influence of workplace lactation programs on breastfeeding outcomes, there is a lack of literature on the mechanisms underlying those interventions. Aims of this realist review were three-fold: to uncover underlying mechanisms, determine who benefits the most from such interventions and important contextual factors influencing uptake. METHODS: Purposive bibliographic searches on Medline, Web of Science Core Collection, CINAHL, Global Health, LILACS, Global Index Medicus, Business Source Complete, Proquest Dissertations and Theses and Open Access Theses and Dissertations were conducted to identify relevant publications. Included publications (qualitative and quantitative) described interventions aiming to improve the breastfeeding behavior of working mothers, that were initiated by the employer, reported on breastfeeding outcomes and had a clearly defined workplace. Publications only focusing on maternity leave or that were not published in English, Spanish, Portuguese or German were excluded. A realist approach was followed to identify how workplace interventions work, who benefits the most and the important contextual factors. RESULTS: The bibliographic search yielded a total of 4985 possible publications of which 37 publications were included in the realist analysis. Effective workplace breastfeeding interventions activate three mechanisms: 1) awareness of the intervention, 2) changes in workplace culture, manager/supervisor support, co-worker support and physical environments, and 3) provision of time. Contextual factors such as the distance between the workplace and the infant and the type of workplace may influence the degree of activation of the underlying mechanisms for programs to positively impact breastfeeding outcomes. CONCLUSIONS: In order to be effective, workplace breastfeeding interventions need to: raise awareness of the intervention(s) available among working mothers as well as their work environment, change the workplace culture, foster manager/supervisor support and co-workers support, provide enough time and adequate space and facilities for women to breastfeed or express breastmilk during the workday.

Patterns of esophageal dysmotility elicited by multiple rapid swallows.

BACKGROUND: High-resolution manometry (HRM) is a gastrointestinal motility diagnostic system that measures intraluminal pressures using closely aligned sensors. Multiple rapid swallows (MRS) are used in conjunction with HRM to assess esophageal physiology prior to anti-reflux and hiatal hernia procedures. METHODS: A retrospective, qualitative study was conducted on 90 patients who underwent HRM with MRS in a single community clinic. 80 patients met the inclusion criteria. MRS testing consisted of rapid 2 mL swallows in 2-3 s intervals with patients in a seated, upright position. Clinical information was reviewed including indications for HRM, prior diagnostic workup, manometry, distal contractile integral (DCI), and integrated residual pressure (IRP). HRM studies were visualized using Manoview Analysis Software v3.0 (Medtronic). RESULTS: Certain esophageal dysmotility and pressurization manometry patterns were previously undetected on HRM alone. In our study, the addition of MRS was clinically helpful in (1) assessing contraction reserve, (2) highlighting features of jackhammer, (3) stimulating esophageal spasm, and (4) visualizing distal esophageal pressurization pattern with mechanical obstruction. Additionally, abnormal pathophysiology such as (5) paradoxical LES contraction (achalasia) and (6) loss of deglutition inhibition were identified. MRS had a diagnostic utility of 21.25% (n = 17) among the 80 patients. An intolerance rate of 7.7% (n = 7) was observed in patients unable to complete the protocol. CONCLUSIONS: Augmentation of HRM with MRS produces unique manometric features that have clinical utility in uncovering esophageal disorders. MRS provocation testing is a practical, inexpensive, well-tolerated addition to HRM that may yield useful clinical information to guide complicated diagnoses and medical management.

High Mannose N-Glycans Promote Migration of Bone-Marrow-Derived Mesenchymal Stromal Cells.

For hundreds of indications, mesenchymal stromal cells (MSCs) have not achieved the expected therapeutic efficacy due to an inability of the cells to reach target tissues. We show that inducing high mannose N-glycans either chemically, using the mannosidase I inhibitor Kifunensine, or genetically, using an shRNA to silence the expression of mannosidase I A1 (MAN1A1), strongly increases the motility of MSCs. We show that treatment of MSCs with Kifunensine increases cell migration toward bone fracture sites after percutaneous injection, and toward lungs after intravenous injection. Mechanistically, high mannose N-glycans reduce the contact area of cells with its substrate. Silencing MAN1A1 also makes cells softer, suggesting that an increase of high mannose N-glycoforms may change the physical properties of the cell membrane. To determine if treatment with Kifunensine is feasible for future clinical studies, we used mass spectrometry to analyze the N-glycan profile of MSCs over time and demonstrate that the effect of Kifunensine is both transitory and at the expense of specific N-glycoforms, including fucosylations. Finally, we also investigated the effect of Kifunensine on cell proliferation, differentiation, and the secretion profile of MSCs. Our results support the notion of inducing high mannose N-glycans in MSCs in order to enhance their migration potential.

Local Mechanical Perturbation Provides an Effective Means to Regulate the Growth and Assembly of Functional Peptide Fibrils.

Mucin 1 (MUC1) peptide fused with Q11 (MUC1-Q11) having 35 residues has previously been shown to form amyloid fibrils. Using time-dependent and high-resolution atomic force microscopy (AFM) imaging, it is revealed that the formation of individual MUC1-Q11 fibrils entails nucleation and extension at both ends. This process can be altered by local mechanical perturbations using AFM probes. This work reports two specific perturbations and outcomes. First, by increasing load while maintaining tip-surface contact, the fibrils are cut during the scan due to shearing. Growth of fibrils occurs at the newly exposed termini, following similar mechanism of the MUC1-Q11 nucleation growth. As a result, branched fibrils are seen on the surface whose orientation and length can be controlled by the nuclei orientation and reaction time. In contrast to the "one-time-cut", fibrils can be continuously fragmented by modulation at sufficiently high amplitude. As a result, short and highly branched fibrils accumulate and pile on surfaces. Since the fibril formation and assembly of MUC1-Q11 can be impacted by local mechanical force, this approach offers a nonchemical and label-free means to control the presentation of MUC1 epitopes, and has promising application in MUC1 fibril-based immunotherapy.

Förster resonance energy transfer to impart signal-on and -off capabilities in a single microRNA biosensor.

Many studies have found that over- or under-expression of biomolecules called microRNAs (miRNA) regulates several diseases. Biosensors are in need to visually identify the relative expression level of miRNA to determine the direction these miRNA change in cells and tissues. Our established reporter+probe miRNA biosensor design requires that miRNA outcompete and displace the reporter from the probe. Once displaced, the reporter folds into a hairpin structure to force together a pair of Förster Resonance Energy Transfer (FRET) dyes. The donor and acceptor signal changes can be used to indicate the over-/under-expression of miRNA. The bright signal from the donor will indicate miRNA under-expression; the bright acceptor signal will indicate miRNA over-expression. Since close proximity of the dyes to each other and nucleic acids often quench fluorescence, polyethylene glycol spacers were added in-between the dyes and nucleic acids. We compared reporter designs with and without spacers to investigate the effects on the following analytical metrics: (1) extent of signal change, (2) limits of detection and quantitation, and (3) sensitivity. Systematic errors and amount of reporter+probe biosensor formed were evaluated for one of the biosensors. Cy3|Cy5 and 6-carboxyfluorescein (6-FAM)|ATTO 633 dye pairs on reporters containing spacers showed an increase in the acceptor signal change by ∼190 and ∼484%, respectively, compared to no spacers. Transduction mechanisms that enhance and quench the signal both showed LODs that ranged from 3-17 nanomolar (nM) with 100 nM of the biosensor.

Detection of miRNA using a double-strand displacement biosensor with a self-complementary fluorescent reporter.

Design of rapid, selective, and sensitive DNA and ribonucleic acid (RNA) biosensors capable of minimizing false positives from nuclease degradation is crucial for translational research and clinical diagnostics. We present proof-of-principle studies of an innovative micro-ribonucleic acid (miRNA) reporter-probe biosensor that displaces a self-complementary reporter, while target miRNA binds to the probe. The freed reporter folds into a hairpin structure to induce a decrease in the fluorescent signal. The self-complementarity of the reporter facilitates the reduction of false positives from nuclease degradation. Nanomolar limits of detection and quantitation were capable with this proof-of-principle design. Detection of miRNA occurs within 10 min and does not require any additional hybridization, labeling, or rinsing steps. The potential for medical applications of the reporter-probe biosensor is demonstrated by selective detection of a cancer regulating microRNA, Lethal-7 (Let-7a). Mechanisms for transporting the biosensor across the cell membrane will be the focus of future work.

Targeting p21-activated kinase 1 (PAK1) to induce apoptosis of tumor cells.

p21-activated kinases (PAKs) are serine/threonine protein kinases that serve as important mediators of Rac and Cdc42 GTPase function as well as pathways required for Ras-driven tumorigenesis. PAK1 has been implicated in signaling by growth factor receptors and morphogenetic processes that control cell polarity, invasion, and actin cytoskeleton organization. To better understand the role of PAK1 in tumorigenesis, PAK1 genomic copy number and expression were determined for a large panel of breast, lung, and head and neck tumors. PAK1 genomic amplification at 11q13 was prevalent in luminal breast cancer, and PAK1 protein expression was associated with lymph node metastasis. Breast cancer cells with PAK1 genomic amplification rapidly underwent apoptosis after inhibition of this kinase. Strong nuclear and cytoplasmic PAK1 expression was also prevalent in squamous nonsmall cell lung carcinomas (NSCLCs), and selective PAK1 inhibition was associated with delayed cell-cycle progression in vitro and in vivo. NSCLC cells were profiled using a library of pathway-targeted small-molecule inhibitors, and several synergistic combination therapies, including combination with antagonists of inhibitor of apoptosis proteins, were revealed for PAK1. Dual inhibition of PAK1 and X chromosome-linked inhibitor of apoptosis efficiently increased effector caspase activation and apoptosis of NSCLC cells. Together, our results provide evidence for dysregulation of PAK1 in breast and squamous NSCLCs and a role for PAK1 in cellular survival and proliferation in these indications.

Space Flight Enhances Stress Pathways in Human Neural Stem Cells.

Mammalian cells have evolved to function under Earth's gravity, but how they respond to microgravity remains largely unknown. Neural stem cells (NSCs) are essential for the maintenance of central nervous system (CNS) functions during development and the regeneration of all CNS cell populations. Here, we examined the behavior of space (SPC)-flown NSCs as they readapted to Earth's gravity. We found that most of these cells survived the space flight and self-renewed. Yet, some showed enhanced stress responses as well as autophagy-like behavior. To ascertain if the secretome from SPC-flown NSCs contained molecules inducing these responses, we incubated naïve, non-starved NSCs in a medium containing SPC-NSC secretome. We found a four-fold increase in stress responses. Proteomic analysis of the secretome revealed that the protein of the highest content produced by SPC-NSCs was secreted protein acidic and rich in cysteine (SPARC), which induces endoplasmic reticulum (ER) stress, resulting in the cell's demise. These results offer novel knowledge on the response of neural cells, particularly NSCs, subjected to space microgravity. Moreover, some secreted proteins have been identified as microgravity sensing, paving a new venue for future research aiming at targeting the SPARC metabolism. Although we did not establish a direct relationship between microgravity-induced stress and SPARC as a potential marker, these results represent the first step in the identification of gravity sensing molecules as targets to be modulated and to design effective countermeasures to mitigate intracranial hypertension in astronauts using structure-based protein design.

Polymorph driven diversification of photosalient responses in a zinc(II) coordination complex.

A novel crystallographic form of a Zn(II) coordination complex [Zn(4-ohbz)2(4-nvp)2] (1-Form-III) (H4-ohbz = 4-hydroxybenzoic acid and 4-nvp = (E)-4-(1-naphthylvinyl)pyridine), undergoes a solid-state photochemical [2+2] cycloaddition reaction accompanied by a moderate photosalient effect, whereby single-crystals show cracking and splitting. This UV-induced cycloaddition accompanies a single-crystal to single-crystal transformation, allowing for continuous monitoring of the unit cell parameters. The new polymorph represents an intermediate form of the two previously reported crystallographic forms of [Zn(4-ohbz)2(4-nvp)2], and provides novel insight into moderating the magnitude of photosalient responses across polymorphic materials.

Oligodendrocyte Progenitors Display Enhanced Proliferation and Autophagy after Space Flight.

Intracranial hypertension (ICP) and visual impairment intracranial pressure (VIIP) are some of the consequences of long-term space missions. Here we examined the behavior of oligodendrocyte progenitors (OLPs) after space flight using time-lapse microscopy. We show that most OLPs divided more than ground control (GC) counterparts did. Nonetheless, a subpopulation of OLPs flown to space presented a significant increase in autophagic cell death. Examination of the proteomic profile of the secretome of space flown OLPs (SPC-OLPs) revealed that the stress protein heat shock protein-90 beta "HSP-90ß" was the 5th most enriched (6.8 times) and the secreted protein acidic and rich in cysteine "SPARC" was the 7th most enriched (5.2 times), with respect to ground control cells. SPARC induces endoplasmic reticulum stress, which leads to autophagy. Given the roles and importance of these two proteins in mammalian cells' metabolism, their upregulation may hold the key to modulating cell proliferation and autophagy, in order to mitigate ICP and VIIP during and after space missions.

Ohio School Nurses´ Perceptions of School Absences for Dental Care.

Purpose: To evaluate the knowledge, practices and attitudes of Ohio school nurses regarding school absenteeism (SA) for dental treatment. Methods: A 40-item questionnaire was generated and distributed to 246 attendees at an annual conference for Ohio school nurses in December 2019. Results: The response rate was 65.9 percent (n=162 out of 246 attendees) and 136 surveys were eligible for inclusion. The sample was female (100 percent), worked at public schools (86.0 percent, n=117) and trained as registered nurses (83.8 percent, n=114). Nurses reported no change in concerns over children missing school for dental appointments in the last five years (69.9 percent, n=95) and most agreed that SA for dental visits "almost never" negatively impacted the educational needs of children. The medical history of the patient was the most common factor when determining the duration of a school excuse (81.6 percent, n=111) and the potential for pain was the most common dental consideration (93.4 percent, n=127). Nurses reported that they "sometimes" had problems with a child after a dental visit (44.9 percent, n=61) and pain was the most reported problem (83.8 percent, n=114). Conclusion: Nurses did not feel that SA for dental treatment negatively impacted the educational needs of children.

Correction: Tran et al. Delayed Maturation of Oligodendrocyte Progenitors by Microgravity: Implications for Multiple Sclerosis and Space Flight. Life 2022, 12, 797.

The authors wish to make the following corrections to Figure 10 of this paper [...].

Loss of function mutation in Ank causes aberrant mineralization and acquisition of osteoblast-like-phenotype by the cells of the intervertebral disc.

Pathological mineralization of intervertebral disc is debilitating and painful and linked to disc degeneration in a subset of human patients. An adenosine triphosphate efflux transporter, progressive ankylosis (ANK) is a regulator of extracellular inorganic pyrophosphate levels and plays an important role in tissue mineralization. However, the function of ANK in intervertebral disc has not been fully explored. Herein we analyzed the spinal phenotype of Ank mutant mice (ank/ank) with attenuated ANK function. Micro-computed tomography and histological analysis showed that loss of ANK function results in the aberrant annulus fibrosus mineralization and peripheral disc fusions with cranial to caudal progression in the spine. Vertebrae in ank mice exhibit elevated cortical bone mass and increased tissue non-specific alkaline phosphatase-positive endplate chondrocytes with decreased subchondral endplate porosity. The acellular dystrophic mineral inclusions in the annulus fibrosus were localized adjacent to apoptotic cells and cells that acquired osteoblast-like phenotype. Fourier transform infrared spectral imaging showed that the apatite mineral in the outer annulus fibrosus had similar chemical composition to that of vertebral bone. Transcriptomic analysis of annulus fibrosus and nucleus pulposus tissues showed changes in several biological themes with a prominent dysregulation of BMAL1/CLOCK circadian regulation. The present study provides new insights into the role of ANK in the disc tissue compartments and highlights the importance of local inorganic pyrophosphate metabolism in inhibiting the mineralization of this important connective tissue.