Revolutionizing Combat Casualty Care: The Power of Digital Twins in Optimizing Casualty Care Through Passive Data Collection.

The potential impact of large-scale combat operations and multidomain operations against peer adversaries poses significant challenges to the Military Health System including large volumes of critically ill and injured casualties, prolonged care times in austere care contexts, limited movement, contested logistics, and denied communications. These challenges contribute to the probability of higher casualty mortality and risk that casualty care hinders commanders' forward momentum or opportunities for overmatch on the battlefield. Novel technical solutions and associated concepts of operation that fundamentally change the delivery of casualty care are necessary to achieve desired medical outcomes that include maximizing Warfighter battle-readiness, minimizing return-to-duty time, optimizing medical evacuation that clears casualties from the battlefield while minimizing casualty morbidity and mortality, and minimizing resource consumption across the care continuum. These novel solutions promise to "automate" certain aspects of casualty care at the level of the individual caregiver and the system level, to unburden our limited number of providers to do more and make better (data-driven) decisions. In this commentary, we describe concepts of casualty digital twins-virtual representations of a casualty's physical journey through the roles of care-and how they, combined with passive data collection about casualty status, caregiver actions, and real-time resource use, can lead to human-machine teaming and increasing automation of casualty care across the care continuum while maintaining or improving outcomes. Our path to combat casualty care automation starts with mapping and modeling the context of casualty care in realistic environments through passive data collection of large amounts of unstructured data to inform machine learning models. These context-aware models will be matched with patient physiology models to create casualty digital twins that better predict casualty needs and resources required and ultimately inform and accelerate decision-making across the continuum of care. We will draw from the experience of the automotive industry as an exemplar for achieving automation in health care and inculcate automation as a mechanism for optimizing the casualty care survival chain.

Reversible Suppression of Fear Memory Recall by Transient Circadian Arrhythmia.

We tested the hypothesis that a temporary period of circadian arrhythmia would transiently impair recall of an aversive memory in Siberian hamsters (Phodopus sungorus). Unlike mice or rats, circadian arrhythmia is easily induced in this species by a one-time manipulation of their ambient lighting [i.e., the disruptive phase shift (DPS) protocol]. Hamsters were conditioned to associate footshocks with a shock chamber (context) and with a predictive auditory tone (cue), and then exposed to the DPS protocol. Following DPS, animals either became arrhythmic (ARR), reentrained to the light-dark cycle (ENT), or became arrhythmic for < 14 days before their circadian locomotor rhythms spontaneously recovered and reentrained (ARR-ENT). Tests for contextual memory showed that freezing was decreased 9-10 days post-DPS when both ARR and ARR-ENT groups were arrhythmic. Once ARR-ENT animals reentrained (day 41), however, freezing was elevated back to Pre-DPS levels and did not differ from those observed in ENT hamsters. ENT animals maintained high levels of freezing at both time points, whereas, freezing remained low in ARR hamsters. In contrast to contextual responses, cued responses were unaffected by circadian arrhythmia; all three groups exhibited elevated levels of freezing in response to the tones. The differential impact of circadian arrhythmia on contextual versus cued associative memory suggests that arrhythmia preferentially impacts memory processes that depend on the hippocampus.

The utilization of Blaptica dubia cockroaches as an in vivo model to test antibiotic efficacy.

Insects are now well recognized as biologically relevant alternative hosts for dozens of mammalian pathogens and they are routinely used in microbial pathogenesis studies. Unfortunately, these models have yet to be incorporated into the drug development pipeline. The purpose of this work was to begin to evaluate the utility of orange spotted (Blaptica dubia) cockroaches in early antibiotic characterization. To determine whether these model hosts could exhibit mortality when infected with bacteria that are pathogenic to humans, we subjected B. dubia roaches to a range of infectious doses of Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, and Acinetobacter baumannii to identify the medial lethal dose. These results showed that lethal disease did not develop following infection of high doses of S. aureus, and A. baumannii. However, cockroaches infected with E. coli and K. pneumoniae succumbed to infection (LD50s of 5.82 × 106 and 2.58 × 106 respectively) suggesting that this model may have limitations based on pathogen specificity. However, because these cockroaches were susceptible to infection from E. coli and K. pneumoniae, we used these bacterial strains for subsequent antibiotic characterization studies. These studies suggested that ß-lactam antibiotic persistence and dose was associated with reduction of hemolymph bacterial burden. Moreover, our data indicated that the reduction of bacterial CFU was directly due to the drug activity. Altogether, this work suggests that the orange-spotted cockroach infection model provides an alternative in vivo setting from which antibiotic efficacy can be evaluated.

Changes in the gut microbiome community of nonhuman primates following radiation injury.

BACKGROUND: Composition and maintenance of the microbiome is vital to gut homeostasis. However, there is limited knowledge regarding the impact of high doses of radiation, which can occur as a result of cancer radiation therapy, nuclear accidents or intentional release of a nuclear or radioactive weapon, on the composition of the gut microbiome. Therefore, we sought to analyze alterations to the gut microbiome of nonhuman primates (NHPs) exposed to high doses of radiation. Fecal samples were collected from 19 NHPs (Chinese rhesus macaques, Macaca mulatta) 1 day prior and 1 and 4 days after exposure to 7.4 Gy cobalt-60 gamma-radiation (LD70-80/60). The 16S V4 rRNA sequences were extracted from each sample, followed by bioinformatics analysis using the QIIME platform. RESULTS: Alpha Diversity (Shannon Diversity Index), revealed no major difference between pre- and post-irradiation, whereas Beta diversity analysis showed significant differences in the microbiome after irradiation (day + 4) compared to baseline (pre-irradiation). The Firmicutes/Bacteriodetes ratio, a factor known to be associated with disruption of metabolic homeostasis, decreased from 1.2 to less than 1 post-radiation exposure. Actinobacillus, Bacteroides, Prevotella (Paraprevotellaceae family) and Veillonella genera were significantly increased by more than 2-fold and Acinetobacter and Aerococcus genus were decreased by more than 10-fold post-irradiation. Fifty-two percent (10/19) of animals exposed to radiation demonstrated diarrhea at day 4 post-irradiation. Comparison of microbiome composition of feces from animals with and without diarrhea at day 4 post-irradiation revealed an increase in Lactobacillus reuteri associated with diarrhea and a decrease of Lentisphaerae and Verrucomicrobioa phyla and Bacteroides in animals exhibiting diarrhea. Animals with diarrhea at day 4 post-irradiation, had significantly lower levels of Lentisphaere and Verrucomicrobia phyla and Bacteroides genus at baseline before irradiation, suggesting a potential association between the prevalence of microbiomes and differential susceptibility to radiation-induced diarrhea. CONCLUSIONS: Our findings demonstrate that substantial alterations in the microbiome composition of NHPs occur following radiation injury and provide insight into early changes with high-dose, whole-body radiation exposure. Future studies will help identify microbiome biomarkers of radiation exposure and develop effective therapeutic intervention to mitigate the radiation injury.

Biomechanics of suprachoroidal drug delivery: From benchtop to clinical investigation in ocular therapies.

INTRODUCTION: As research in suprachoroidal drug delivery advances, and therapeutic candidates, ranging from small molecule suspensions to gene therapy, progress through clinical trials, an understanding of  suprachoroidal space (SCS) biomechanics assumes increasing importance.Areas covered:Numerous anatomic features play an important role in therapeutic access to the SCS. Methods of access include a catheter, a standard hypodermic needle, and a microinjector with microneedle. Physical and fluidic properties of injectates into the SCS, such as volume, viscosity, particle size, osmotic pressure, and ionic charge of formulation can impact the spread and extent of opening of the SCS. Pharmacokinetic data of several small molecule suspensions yielded favorable ocular distribution and pharmacokinetic profiles. Phase 2 and 3 clinical trials have been completed with a suprachoroidally injected corticosteroid; results and information on procedural details with the microinjector are discussed. EXPERT OPINION: Suprachoroidal drug delivery has been demonstrated to be a reliable and consistent drug delivery method for targeted treatment of retinal and choroidal disorders to potentially maximize efficacy, while compartmentalizing therapies away from the unaffected tissues to potentially enhance safety. These delivery attributes, along with fluid transport properties and formula customization for pharmacological agents, may allow for more tailored treatment of diseases affecting chorio-retinal tissues.

COVID-19 Airway Management Isolation Chamber.

OBJECTIVE: During the coronavirus pandemic (COVID-19), health care workers are innovating patient care and safety measures. Unfortunately, many of these are not properly tested for efficacy. The objective of this study was to determine the efficacy of the novel COVID-19 Airway Management Isolation Chamber (CAMIC) to contain and evacuate particulate. STUDY DESIGN: Multi-institutional proof-of-concept study. SETTING: Two academic institutions: Walter Reed National Military Medical Center (WRNMMC) and Madigan Army Medical Center (MAMC). SUBJECTS AND METHODS: Smoke, saline nebulizer, and simulated working port models were developed to assess the efficacy of the CAMIC to contain and remove ultrafine particles. Particulate counts were collected at set time intervals inside and outside the system. RESULTS: With the CAMIC on, smoke particulate counts inside the chamber significantly decreased over time: r(18) = -0.88, P < .001, WRNMMC; r(18) = -0.91, P < .001, MAMC. Similarly, saline nebulizer particulate counts inside the chamber significantly decreased over time: r(23) = -0.82, P < .001, WRNMMC; r(23) = -0.70, P < .001, MAMC. In the working port model, particulate counts inside the chamber significantly decreased over time: r(23) = -0.95, P < .001, WRNMMC; r(23) = -0.85, P < .001, MAMC. No significant leak was detected in the smoke, saline nebulizer, or working port model when the CAMIC was turned on. CONCLUSIONS: The CAMIC system appears to provide a barrier that actively removes particles from within the chamber and limits egress. Further studies are necessary to determine clinical applicability. The CAMIC may serve as an adjunct to improve health care worker safety and patient outcomes.

Loss of Circadian Timing Disrupts Theta Episodes during Object Exploration.

This study examined whether theta oscillations were compromised by the type of circadian disruption that impairs hippocampal-dependent memory processes. In prior studies on Siberian hamsters, we developed a one-time light treatment that eliminated circadian timing in the central pacemaker, the suprachiasmatic nucleus (SCN). These arrhythmic animals had impaired hippocampal-dependent memory whereas animals made arrhythmic with SCN lesions did not. The current study examined whether theta oscillations are compromised by the same light treatment that produced memory impairments in these animals. We found that both methods of inducing circadian-arrhythmia shortened theta episodes in the EEG by nearly 50%. SCN-lesioned animals, however, exhibited a 3-fold increase in the number of theta episodes and more than doubled the total time that theta dominated the EEG compared to SCN-intact circadian-arrhythmic animals. Video tracking showed that changes in theta were paralleled by similar changes in exploration behavior. These results suggest that the circadian-arrhythmic SCN interferes with hippocampal memory encoding by fragmenting theta oscillations. SCN-lesioned animals can, however, compensate for the shortened theta episodes by increasing their frequency. Implications for rhythm coherence and theta sequence models of memory formation are discussed.

Progress or Pathology? Differential Diagnosis and Intervention Criteria for Meditation-Related Challenges: Perspectives From Buddhist Meditation Teachers and Practitioners.

Studies in the psychology and phenomenology of religious experience have long acknowledged similarities with various forms of psychopathology. Consequently, it has been important for religious practitioners and mental health professionals to establish criteria by which religious, spiritual, or mystical experiences can be differentiated from psychopathological experiences. Many previous attempts at differential diagnosis have been based on limited textual accounts of mystical experience or on outdated theoretical studies of mysticism. In contrast, this study presents qualitative data from contemporary Buddhist meditation practitioners and teachers to identify salient features that can be used to guide differential diagnosis. The use of certain existing criteria is complicated by Buddhist worldviews that some difficult or distressing experiences may be expected as a part of progress on the contemplative path. This paper argues that it is important to expand the framework for assessment in both scholarly and clinical contexts to include not only criteria for determining normative fit with religious experience or with psychopathology, but also for determining need for intervention, whether religious or clinical. Qualitative data from Buddhist communities shows that there is a wider range of experiences that are evaluated as potentially warranting intervention than has previously been discussed. Decision making around these experiences often takes into account contextual factors when determining appraisals or need for intervention. This is in line with person-centered approaches in mental health care that emphasize the importance of considering the interpersonal and cultural dynamics that inevitably constitute the context in which experiences are evaluated and rendered meaningful.

Suprachiasmatic lesions restore object recognition in down syndrome model mice.

The Ts65Dn mouse is a well-studied model of trisomy 21, Down syndrome. This mouse strain has severe learning disability as measured by several rodent learning tests that depend on hippocampal spatial memory function. Hippocampal long-term potentiation (LTP) is deficient in these mice. Short-term daily treatment with low-dose GABA receptor antagonists rescue spatial learning and LTP in Ts65Dn mice leading to the hypothesis that the learning disability is due to GABAergic over-inhibition of hippocampal circuits. The fact that the GABA receptor antagonists were only effective if delivered during the daily light phase suggested that the source of the excess GABA was controlled directly or indirectly by the circadian system. The central circadian pacemaker of mammals is the suprachiasmatic nucleus (SCN), which is largely a GABAergic nucleus. In this study we investigated whether elimination of the SCN in Ts65Dn mice would restore their ability to form recognition memories as tested by the novel object recognition (NOR) task. Full, but not partial lesions of the SCN of Ts65Dn mice normalized their ability to perform on the NOR test. These results suggest that the circadian system modulates neuroplasticity over the time frame involved in the process of consolidation of recognition memories.

Sporulation and Germination of Paenibacillus larvae Cells.

Endospores are metabolically dormant cells formed by a variety of Gram-positive bacteria within the phylum Firmicutes in response to nutrient limiting or otherwise unfavorable growth conditions. American foulbrood disease (AFB) is a serious disease of honeybees that is caused by the introduction of Paenibacillus larvae endospores into a honeybee colony. Progression to fulminant disease and eventual collapse of the colony requires multiple rounds of endospore germination, vegetative replication, endospore formation, and subsequent spread within the colony. This unit includes protocols for the in vitro sporulation and germination of P. larvae to assist investigators in the study of these processes. © 2018 by John Wiley & Sons, Inc.

Growth and Laboratory Maintenance of Paenibacillus larvae.

Paenibacillus larvae is a Gram-positive, spore-forming bacterium and the causative agent of American foulbrood disease (AFB), a highly contagious, fatal disease affecting managed honeybee (Apis mellifera) colonies. As the etiological agent of American foulbrood disease, P. larvae is the most economically significant bacterial pathogen infecting honeybees. This unit includes protocols for the in vitro growth and laboratory maintenance of P. larvae. © 2018 by John Wiley & Sons, Inc.

The Madagascar Hissing Cockroach as an Alternative Non-mammalian Animal Model to Investigate Virulence, Pathogenesis, and Drug Efficacy.

Many aspects of innate immunity are conserved between mammals and insects. An insect, the Madagascar hissing cockroach from the genus Gromphadorhina, can be utilized as an alternative animal model for the study of virulence, host-pathogen interaction, innate immune response, and drug efficacy. Details for the rearing, care and breeding of the hissing cockroach are provided. We also illustrate how it can be infected with bacteria such as the intracellular pathogens Burkholderia mallei, B. pseudomallei, and B. thailandensis. Use of the hissing cockroach is inexpensive and overcomes regulatory issues dealing with the use of mammals in research. In addition, results found using the hissing cockroach model are reproducible and similar to those obtained using mammalian models. Thus, the Madagascar hissing cockroach represents an attractive surrogate host that should be explored when conducting animal studies.

Scheduled feeding restores memory and modulates c-Fos expression in the suprachiasmatic nucleus and septohippocampal complex.

Disruptions in circadian timing impair spatial memory in humans and rodents. Circadian-arrhythmic Siberian hamsters (Phodopus sungorus) exhibit substantial deficits in spatial working memory as assessed by a spontaneous alternation (SA) task. The present study found that daily scheduled feeding rescued spatial memory deficits in these arrhythmic animals. Improvements in memory persisted for at least 3 weeks after the arrhythmic hamsters were switched back to ad libitum feeding. During ad libitum feeding, locomotor activity resumed its arrhythmic state, but performance on the SA task varied across the day with a peak in daily performance that corresponded to the previous daily window of food anticipation. At the end of scheduled feeding, c-Fos brain mapping revealed differential gene expression in entrained versus arrhythmic hamsters in the suprachiasmatic nucleus (SCN) that paralleled changes in the medial septum and hippocampus, but not in other neural structures. These data show that scheduled feeding can improve cognitive performance when SCN timing has been compromised, possibly by coordinating activity in the SCN and septohippocampal pathway.

The varieties of contemplative experience: A mixed-methods study of meditation-related challenges in Western Buddhists.

Buddhist-derived meditation practices are currently being employed as a popular form of health promotion. While meditation programs draw inspiration from Buddhist textual sources for the benefits of meditation, these sources also acknowledge a wide range of other effects beyond health-related outcomes. The Varieties of Contemplative Experience study investigates meditation-related experiences that are typically underreported, particularly experiences that are described as challenging, difficult, distressing, functionally impairing, and/or requiring additional support. A mixed-methods approach featured qualitative interviews with Western Buddhist meditation practitioners and experts in Theravada, Zen, and Tibetan traditions. Interview questions probed meditation experiences and influencing factors, including interpretations and management strategies. A follow-up survey provided quantitative assessments of causality, impairment and other demographic and practice-related variables. The content-driven thematic analysis of interviews yielded a taxonomy of 59 meditation-related experiences across 7 domains: cognitive, perceptual, affective, somatic, conative, sense of self, and social. Even in cases where the phenomenology was similar across participants, interpretations of and responses to the experiences differed considerably. The associated valence ranged from very positive to very negative, and the associated level of distress and functional impairment ranged from minimal and transient to severe and enduring. In order to determine what factors may influence the valence, impact, and response to any given experience, the study also identified 26 categories of influencing factors across 4 domains: practitioner-level factors, practice-level factors, relationships, and health behaviors. By identifying a broader range of experiences associated with meditation, along with the factors that contribute to the presence and management of experiences reported as challenging, difficult, distressing or functionally impairing, this study aims to increase our understanding of the effects of contemplative practices and to provide resources for mediators, clinicians, meditation researchers, and meditation teachers.

The orange spotted cockroach (Blaptica dubia, Serville 1839) is a permissive experimental host for Francisella tularensis.

Francisella tularensis is a zoonotic bacterial pathogen that causes severe disease in a wide range of host animals, including humans. Well-developed murine models of F. tularensis pathogenesis are available, but they do not meet the needs of all investigators. However, researchers are increasingly turning to insect host systems as a cost-effective alternative that allows greater increased experimental throughput without the regulatory requirements associated with the use of mammals in biomedical research. Unfortunately, the utility of previously-described insect hosts is limited because of temperature restriction, short lifespans, and concerns about the immunological status of insects mass-produced for other purposes. Here, we present a novel host species, the orange spotted (OS) cockroach (Blaptica dubia), that overcomes these limitations and is readily infected by F. tularensis. Intrahemocoel inoculation was accomplished using standard laboratory equipment and lethality was directly proportional to the number of bacteria injected. Progression of infection differed in insects housed at low and high temperatures and F. tularensis mutants lacking key virulence components were attenuated in OS cockroaches. Finally, antibiotics were delivered to infected OS cockroaches by systemic injection and controlled feeding; in the latter case, protection correlated with oral bioavailability in mammals. Collectively, these results demonstrate that this new host system provides investigators with a new tool capable of interrogating F. tularensis virulence and immune evasion in situations where mammalian models are not available or appropriate, such as undirected screens of large mutant libraries.

Genetic Manipulation of Stenotrophomonas maltophilia.

Stenotrophomonas maltophilia is a Gram-negative, aerobic, motile, environmental bacterium that is emerging as an important nosocomial pathogen with high rates of attributable mortality in severely ill patients. S. maltophilia is of particular concern to patients suffering from cystic fibrosis (CF) as it has been shown to colonize airway epithelial and establish a chronic infection. Here we describe several molecular techniques for the genetic manipulation of this bacterium, including DNA extraction, RNA extraction, conjugation of plasmids from Escherichia coli and allelic exchange.

Immune Defense Varies within an Instar in the Tobacco Hornworm, Manduca sexta.

Research on how insect immunity changes with age as insects develop within an instar, or larval developmental stage, is limited and contradictory. Insects within an instar are preparing for the next developmental stage, which may involve changes in morphology or habitat. Immunity may also vary accordingly. To determine how immunity varies in the fifth instar, we tested humoral immune responses, antimicrobial peptide activity, and phenoloxidase activity using the tobacco hornworm, Manduca sexta. We determined that while M. sexta have more robust antimicrobial peptide and phenoloxidase responses at the beginning of their fifth instar, this did not translate into better survival of bacterial infection or lower bacterial load in the hemolymph. We also determined that M. sexta injected with bacteria early in the fifth instar experience lower growth rates and longer development times than caterpillars of the same age injected with sham. This could indicate a shift in energy allocation from growth and development to metabolically costly immune responses. Because of the importance of insects as pests and pollinators, understanding how immunity varies throughout development is critical.

A randomized controlled pilot trial of classroom-based mindfulness meditation compared to an active control condition in sixth-grade children.

The current study is a pilot trial to examine the effects of a nonelective, classroom-based, teacher-implemented, mindfulness meditation intervention on standard clinical measures of mental health and affect in middle school children. A total of 101 healthy sixth-grade students (55 boys, 46 girls) were randomized to either an Asian history course with daily mindfulness meditation practice (intervention group) or an African history course with a matched experiential activity (active control group). Self-reported measures included the Youth Self Report (YSR), a modified Spielberger State-Trait Anxiety Inventory, and the Cognitive and Affective Mindfulness Measure -Revised. Both groups decreased significantly on clinical syndrome subscales and affect but did not differ in the extent of their improvements. Meditators were significantly less likely to develop suicidal ideation or thoughts of self-harm than controls. These results suggest that mindfulness training may yield both unique and non-specific benefits that are shared by other novel activities.

Laboratory culture and maintenance of Stenotrophomonas maltophilia.

Stenotrophomonas maltophilia is a ubiquitous soil bacterium that is increasingly recognized as an emerging nosocomial pathogen. This unit includes protocols for the in vitro growth and maintenance of S. maltophilia.