An Assessment of the Oral and Inhalation Acute Toxicity of Nickel Oxide Nanoparticles in Rats.

Nickel oxide nanoparticles (NiO NPs) have been the focus of many toxicity studies. However, acute toxicity studies that identify toxicological dose descriptors, such as an LC50 or LD50, are lacking. In this paper, the acute toxicity of NiO NPs was evaluated in albino-derived Sprague-Dawley rats through OECD guideline studies conducted by both the oral and inhalation routes of exposure. The animals were assessed for mortality, body weight, behavioral observations, and gross necropsy. Results from previously conducted (unpublished) acute inhalation studies with larger NiO microparticles (MPs) are also included for comparison. Mortality, the primary endpoint in acute toxicity studies, was not observed for rats exposed to NiO NPs via either the oral or inhalation exposure routes, with a determined LD50 of >5000 mg/kg and an LC50 > 5.42 mg/L, respectively. Our results suggest that these NiO NPs do not exhibit serious acute toxicity in rats or warrant an acute toxicity classification under the current GHS classification criteria. This aligns with similar results for NiO MPs from this and previously published studies.

A Case Report Utilizing Ultrasound for the Identification of Traumatic Pulmonary Contusion.

Pulmonary contusions are a common injury in both military and civilian trauma patients. In austere and resource-limited settings common to deployment, military physicians may be limited on their ability diagnose or differentiate this entity from other traumatic injuries. We describe the use of ultrasound for the identification of pulmonary contusion in a patient with a gunshot wound while performing an extended Focused Assessment with Sonography (eFAST). The utility of ultrasound in polytraumatic patients stretches far beyond the initial FAST exam and can drastically inform clinical decision making and treatment.

A coronavirus disease 2019 (COVID-19) patient with bilateral orchitis.

During the development of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2), a myriad of complications has emerged and although rare, several genitourinary complications have been reported. The bulk of these complications have been secondary to hypercoagulable states, such as priapism. Previous SARS family infections have caused orchitis, though no adult cases of orchitis have been reported. We describe a novel case of SARS-CoV2 bilateral orchitis in a previously healthy 37-year-old male who presented for testicular pain with constitutional symptoms. Additionally, there was no epididymitis associated with the bilateral orchitis. Based on both data in SARS-CoV2 infected males and previous data from prior SARS infections, spermatocyte function may be compromised secondary to this infection. With the various symptoms associated with this virulent pathogen, we characterize the potential complications and importance of fertility follow up.

Cholesterol embolization and arterial occlusion from the Heimlich maneuver.

The Heimlich maneuver is a lifesaving bystander intervention to assist an individual with airway obstruction however, cholesterol embolization syndrome is a rare, but serious potential complication of the Heimlich maneuver. We present the case of the 56-year-old female presenting to the emergency department with acute right foot pain following performance of the Heimlich maneuver who was found to have distal arterial occlusion resulting from cholesterol embolization syndrome. The patient underwent right popliteal artery exploration, right popliteal and tibial thrombectomy, and popliteal patch angioplasty resulting in restoration of blood flow to her right foot.

Arthropod Assault: A Case Report of Brown Recluse Envenomation in a Training Environment.

Spider bites are a common emergency department complaint, accounting for ~21% of noncanine bites, injuries, and stings. Military service members, more so than most civilian personnel, are exposed to conditions that place them at increased risk for envenomation, stings, and bites. We present the case of an active duty service member working in a relatively austere environment who presented to a level 1 trauma center with a lesion consistent with a bite from a brown recluse spider, or Loxosceles reclusa.

A prospective study in severely injured patients reveals an altered gut microbiome is associated with transfusion volume.

BACKGROUND: Traumatic injury can lead to a compromised intestinal epithelial barrier and inflammation. While alterations in the gut microbiome of critically injured patients may influence clinical outcomes, the impact of trauma on gut microbial composition is unknown. Our objective was to determine if the gut microbiome is altered in severely injured patients and begin to characterize changes in the gut microbiome due to time and therapeutic intervention. METHODS: We conducted a prospective, observational study in adult patients (n = 72) sustaining severe injury admitted to a Level I Trauma Center. Healthy volunteers (n = 13) were also examined. Fecal specimens were collected on admission to the emergency department and at 3, 7, 10, and 13 days (±2 days) following injury. Microbial DNA was isolated for 16s rRNA sequencing, and α and ß diversities were estimated, according to taxonomic classification against the Greengenes database. RESULTS: The gut microbiome of trauma patients was altered on admission (i.e., within 30 minutes following injury) compared to healthy volunteers. Patients with an unchanged gut microbiome on admission were transfused more RBCs than those with an altered gut microbiome (p < 0.001). Although the gut microbiome started to return to a ß-diversity profile similar to that of healthy volunteers over time, it remained different from healthy controls. Alternatively, α diversity initially increased postinjury, but subsequently decreased during the hospitalization. Injured patients on admission had a decreased abundance of traditionally beneficial microbial phyla (e.g., Firmicutes) with a concomitant decrease in opportunistic phyla (e.g., Proteobacteria) compared to healthy controls (p < 0.05). Large amounts of blood products and RBCs were both associated with higher α diversity (p < 0.001) and a ß diversity clustering closer to healthy controls. CONCLUSION: The human gut microbiome changes early after trauma and may be aided by early massive transfusion. Ultimately, the gut microbiome of trauma patients may provide valuable diagnostic and therapeutic insight for the improvement of outcomes postinjury. LEVEL OF EVIDENCE: Prognostic and Epidemiological, level III.

Moderate Traumatic Brain Injury Alters the Gastrointestinal Microbiome in a Time-Dependent Manner.

The microbiome is defined as the collective genomes of the microbes (composed of bacteria, bacteriophage, fungi, protozoa, and viruses) that colonize the human body, and alterations have been associated with a number of disease states. Changes in gut commensals can influence the neurologic system via the brain-gut axis, and systemic insults such as trauma or traumatic brain injury (TBI) may alter the gut microbiome. The objective of this study was to evaluate the gut microbiome in a preclinical TBI cortical impact model. Male rats underwent craniotomy and randomized to a sham group (n = 4), or a moderate TBI (n = 10) using a pneumatic impactor. MRI and behavioral assessments were performed pre-TBI and on days 2, 7, and 14 days thereafter. Microbiome composition was determined with 16s rRNA sequencing from fecal sample DNA pre-TBI and 2 hrs, 1, 3, and 7 days afterward. Alpha- and ß-bacterial diversity, as well as organizational taxonomic units (OTUs), were determined. Significant changes in the gut microbiome were evident as early as 2 h after TBI as compared with pre-injured samples and sham rats. While there were varying trends among the phylogenetic families across time, some changes persisted through 7 days in the absence of therapeutic intervention. While large structural lesions and behavioral deficits were apparent post-TBI, there were modest but significant decreases in α-diversity. Moreover, both changes in representative phyla and α-diversity measures were significantly correlated with MRI-determined lesion volume. These results suggest that changes in the microbiome may represent a novel biomarker to stage TBI severity and predict functional outcome.

Polytrauma independent of therapeutic intervention alters the gastrointestinal microbiome.

BACKGROUND: This study characterizes the gastrointestinal (GI) microbiome in a pre-clinical polytrauma hemorrhage model. METHODS: Rats (n = 6) were anesthetized, hemorrhaged 20% of their blood volume, and subjected to a femur fracture and crush injuries to the small intestine, liver, and limb skeletal muscle without resuscitation. Fecal samples were collected pre-injury and 2 h post-injury. Purified DNA from the samples underwent 16s rRNA sequencing for microbial quantification. Bacterial diversity analysis and taxonomic classification were performed. RESULTS: Following injury, the gut microbial composition was altered with a shift in beta diversity and significant differences in the relative abundance of taxa. The relative abundance of the families Lachnospiraceae and Mogibacteriaceae was increased at 2 h, while Barnesiellaceae and Bacteroidaceae were decreased. Alpha diversity was unchanged. CONCLUSIONS: The GI microbiome is altered in rats subjected to a polytrauma hemorrhage model at 2 h post-injury in the absence of antibiotics or therapeutic interventions.

A 14-day repeated-dose oral toxicological evaluation of an isothiocyanate-enriched hydro-alcoholic extract from Moringa oleifera Lam. seeds in rats.

A 14-d short-term oral toxicity study in rats evaluated the safety of moringa isothiocyanate-1 (MIC-1)-enriched hydro-alcoholic moringa seeds extract (MSE). Rats (5 males/5 females per group) were gavaged daily for 14 d with the vehicle control or MSE, at 78 (low), 257 (mid-low), 772 (mid-high), or 2571 (high) mg/kg bw/d, standardized to MIC-1 (30, 100, 300, or 1000 mg/kg bw/d, respectively). Toxicological endpoints included body weight and weight gain, food consumption and feed efficiency, clinical observations, hematology, gross necropsy and histopathology, and relative organ weights. Mortality was only observed in the high dose group animals, both male and female, representing decreases in body weight/weight gain and food consumption/feed efficiency. Irregular respiratory patterns and piloerection were major clinical observations found primarily in the mid-high and high dose group animals. In the high dose group, gastrointestinal distention and stomach discoloration were observed in non-surviving males and females, and degeneration and necrosis of the testicular germinal cells and epididymal cells were also observed in a non-surviving male. Increased liver weights were found in females in the mid-high and high dose groups. Animals in the low and mid-low groups did not exhibit adverse effects of MSE (100 mg/kg bw/d MIC-1). A no observed adverse effect level (NOAEL) of the standardized MSE was determined as 257 mg/kg bw/d providing 100 mg/kg bw/d MIC-1.

Biodynamic imaging for phenotypic profiling of three-dimensional tissue culture.

Three-dimensional (3-D) tissue culture represents a more biologically relevant environment for testing new drugs compared to conventional two-dimensional cancer cell culture models. Biodynamic imaging is a high-content 3-D optical imaging technology based on low-coherence interferometry and digital holography that uses dynamic speckle as high-content image contrast to probe deep inside 3-D tissue. Speckle contrast is shown to be a scaling function of the acquisition time relative to the persistence time of intracellular transport and hence provides a measure of cellular activity. Cellular responses of 3-D multicellular spheroids to paclitaxel are compared among three different growth techniques: rotating bioreactor (BR), hanging-drop (HD), and nonadherent (U-bottom, UB) plate spheroids, compared with ex vivo living tissues. HD spheroids have the most homogeneous tissue, whereas BR spheroids display large sample-to-sample variability as well as spatial heterogeneity. The responses of BR-grown tumor spheroids to paclitaxel are more similar to those of ex vivo biopsies than the responses of spheroids grown using HD or plate methods. The rate of mitosis inhibition by application of taxol is measured through tissue dynamics spectroscopic imaging, demonstrating the ability to monitor antimitotic chemotherapy. These results illustrate the potential use of low-coherence digital holography for 3-D pharmaceutical screening applications.

Intracellular Doppler Signatures of Platinum Sensitivity Captured by Biodynamic Profiling in Ovarian Xenografts.

Three-dimensional (3D) tissue cultures are replacing conventional two-dimensional (2D) cultures for applications in cancer drug development. However, direct comparisons of in vitro 3D models relative to in vivo models derived from the same cell lines have not been reported because of the lack of sensitive optical probes that can extract high-content information from deep inside living tissue. Here we report the use of biodynamic imaging (BDI) to measure response to platinum in 3D living tissue. BDI combines low-coherence digital holography with intracellular Doppler spectroscopy to study tumor drug response. Human ovarian cancer cell lines were grown either in vitro as 3D multicellular monoculture spheroids or as xenografts in nude mice. Fragments of xenografts grown in vivo in nude mice from a platinum-sensitive human ovarian cell line showed rapid and dramatic signatures of induced cell death when exposed to platinum ex vivo, while the corresponding 3D multicellular spheroids grown in vitro showed negligible response. The differences in drug response between in vivo and in vitro growth have important implications for predicting chemotherapeutic response using tumor biopsies from patients or patient-derived xenografts.

Hypoxia reduces placental mTOR activation in a hypoxia-induced model of intrauterine growth restriction (IUGR).

Mammalian target of rapamycin (mTOR) is a protein that regulates cell growth in response to altered nutrient and growth factor availability. Our objective was to assess activated mTOR and its intracellular intermediates p70, and 4EBP1 in placental and invasive trophoblast cells in a hypoxia-induced model of intrauterine growth restriction (IUGR) in rats. Rats were treated with hypoxia (9%) for 4 days. Placental and fetal weights, as well as conceptus numbers were recorded at the time of necropsy. Immunohistochemistry was used to determine the level of trophoblast invasion and apoptosis. Western blots were used to determine the activation of mTOR, p70, and 4EBP1 in the placenta and the uterine mesometrial compartment. We observed (1) decreased placental (21%) and fetal (24%) weights (P < 0.05); (2) decreased trophoblast invasion; (3) significantly increased active 4EBP1 (28%; P < 0.05) in invasive trophoblast cells yet no changes in the activation of mTOR and p70 proteins; and (4) a significant decrease in the activation of mTOR (48%; P < 0.05) with no differences in p70 or 4EBP1 activation in the placenta. We conclude that the development of IUGR is correlated with decreased activation of the mTOR protein in the placenta and increased 4EBP1 activity in the invading trophoblast. These results provide important insight into the physiological relevance of these pathways. Furthermore, modification of these and other related targets during gestation may alleviate IUGR severity.

Digital holography of intracellular dynamics to probe tissue physiology.

Digital holography provides improved capabilities for imaging through dense tissue. Using a short-coherence source, the digital hologram recorded from backscattered light performs laser ranging that maintains fidelity of information acquired from depths much greater than possible by traditional imaging techniques. Biodynamic imaging (BDI) is a developing technology for live-tissue imaging of up to a millimeter in depth that uses the hologram intensity fluctuations as label-free image contrast and can study tissue behavior in native microenvironments. In this paper BDI is used to investigate the change in adhesion-dependent tissue response in 3D cultures. The results show that increasing density of cellular adhesions slows motion inside tissue and alters the response to cytoskeletal drugs. A clear signature of membrane fluctuations was observed in mid-frequencies (0.1-1 Hz) and was enhanced by the application of cytochalasin-D that degrades the actin cortex inside the cell membrane. This enhancement feature is only observed in tissues that have formed adhesions, because cell pellets initially do not show this signature, but develop this signature only after incubation enables adhesions to form.

A personalized sensor-controlled microstimulator system for arm rehabilitation poststroke. Part 1: System architecture.

OBJECTIVES: For rehabilitation of the poststroke upper limb in seven subjects, an external sensor-based system controls the timing of five to seven microstimulators implanted near radial nerve branches or their motor points to sequentially extend the elbow, wrist, and fingers with thumb extension and abduction, enabled at the subject's own pace. We hypothesize this system will support sequential activation of affected upper limb muscles intended to improve functional recovery. MATERIALS AND METHODS: Presented here is a personalized sensor-controlled stimulation system, including its architecture, sensor design, and testing of equipment specific to this study, including coils and sensors. RESULTS: All electrical and magnetic tests, and safety tests per International Electrotechnical Commission 60601-1 passed. One sensor type displayed a vulnerability to drop. CONCLUSIONS: The new control system tested safe, met requirements, and allowed each subject to activate the system at their own pace, making the rehabilitation process more acceptable and efficient.

A personalized sensor-controlled microstimulator system for arm rehabilitation poststroke. Part 2: Objective outcomes and patients' perspectives.

OBJECTIVE: To examine the effect of home-based electrical stimulation using closed-loop control of implanted microstimulators on upper limb function and impairment, and subjects' perception of the system. MATERIALS AND METHODS: Six subjects with poststroke hemiparesis, and reduced upper limb function, who had taken part in Phase 1 of the study, were fitted with a personalized closed-loop control system (Phase 2) and used it at home during performance of functional tasks for 12 weeks (Phase 3). Main outcome measures were: Action Research Arm Test (ARAT), Fugl-Meyer upper limb assessment (FMA), and motor control (Tracking Index). Subjects' perception of the system was assessed in a structured interview. RESULTS: Improvement in ARAT (p=0.05), FMA (p=0.02), and Tracking Index (p=0.03) during Phase 3. Five subjects said using the system had changed their lives and improved their function, all performed functional tasks with the system, but external components were inconvenient. CONCLUSIONS: Closed-loop control improved in function. Subjective assessment identified that the external sensors were effective.

Development of an implantable myoelectric sensor for advanced prosthesis control.

Modern hand and wrist prostheses afford a high level of mechanical sophistication, but the ability to control them in an intuitive and repeatable manner lags. Commercially available systems using surface electromyographic (EMG) or myoelectric control can supply at best two degrees of freedom (DOF), most often sequentially controlled. This limitation is partially due to the nature of surface-recorded EMG, for which the signal contains components from multiple muscle sources. We report here on the development of an implantable myoelectric sensor using EMG sensors that can be chronically implanted into an amputee's residual muscles. Because sensing occurs at the source of muscle contraction, a single principal component of EMG is detected by each sensor, corresponding to intent to move a particular effector. This system can potentially provide independent signal sources for control of individual effectors within a limb prosthesis. The use of implanted devices supports inter-day signal repeatability. We report on efforts in preparation for human clinical trials, including animal testing, and a first-in-human proof of principle demonstration where the subject was able to intuitively and simultaneously control two DOF in a hand and wrist prosthesis.

Review of electrical stimulation in cerebral palsy and recommendations for future directions.

Electrical stimulation (ES) for treatment of neuromuscular disorders is introduced. Various forms of ES are defined. Characteristics of cerebral palsy (CP) and treatment options are given. The clinical objectives of ES for CP treatment are stated. A review of the literature for treatment in CP is given. Several common themes within the literature and limitations in prior studies are explored. The majority of studies have used surface stimulation, which has several inherent limitations. To address these limitations, implanted devices may be used. Implanted device systems include percutaneous stimulation systems, and fully implantable leaded systems. While both of these technologies have advantages over surface stimulation, they also have their own limitations. To further address the limitations of percutaneous and fully implantable leaded systems, the Alfred Mann Foundation has developed a completely implantable, telemetered device known as the Radio Frequency Microstimulator (RFM). Results from a study using the RFM for arm rehabilitation in poststroke patients are given. A list of desirable design features for an ES system for CP is given. The next generation microstimulator device under development at the Alfred Mann Foundation is presented. This device may well serve the needs for ES in CP.

Impedance characterization of microarray recording electrodes in vitro.

The mechanisms underlying performance degradation of chronically implanted silicon microelectrode arrays in the central nervous system (CNS) remain unclear. Humoral and cellular components of the brain foreign body response were evaluated to determine whether their presence on the electrode surface results in increased electrical impedance. Iridium oxide microelectrode recording arrays were electrically characterized in saline, culture media with 10% fetal bovine serum, and coated with various CNS cell types isolated from rat brain. Electrochemical impedance spectroscopy and cyclic voltammetry were performed using a three-electrode system. Potential cycling caused an immediate decrease in electrical impedance, which increased with time toward precycling values, with the effect of cycling remaining significant for several days. The addition of serum caused a significant increase in impedance of up to 28% relative to the saline control. Microelectrodes coated with various cell types known to participate in the foreign body response caused a 20%-80% increase in impedance immediately after contact that remained constant or gradually increased for several weeks. Our findings suggest that the attachment of molecular and cellular species following microelectrode implantation into brain tissue likely contribute to increases in impedance, but do not appear sufficient to hinder recording performance.

The military medical school of Mexico: a tradition of excellence.

It is a historical fact that warfare and surgery have been linked together as far back as military history has been recorded. In the 18th century, the tendency of most armies to dismiss their medical services at the end of every major conflict resulted in higher mortality at the beginning of the next war. This became evident in the French and British Armies during the Battle of Waterloo. These countries went to great efforts to mobilize their civilian reserve physicians, only to discover that more than half of the medical personnel declined to serve. The scarcity of physicians and the inexperience of those caring for the wounded resulted in a high casualty rate. The current armed conflicts throughout the world with their high number of victims are living evidence of the need for preparedness of the military medical personnel. In this article, we review the systems of military medical education in several countries, and offer the example of the Escuela Medico Militar (Military Medical School) of Mexico, a prestigious source of military medical physicians for the Mexican armed forces.

Electrical stimulation of excitable tissue: design of efficacious and safe protocols.

The physical basis for electrical stimulation of excitable tissue, as used by electrophysiological researchers and clinicians in functional electrical stimulation, is presented with emphasis on the fundamental mechanisms of charge injection at the electrode/tissue interface. Faradaic and non-Faradaic charge transfer mechanisms are presented and contrasted. An electrical model of the electrode/tissue interface is given. The physical basis for the origin of electrode potentials is given. Various methods of controlling charge delivery during pulsing are presented. Electrochemical reversibility is discussed. Commonly used electrode materials and stimulation protocols are reviewed in terms of stimulation efficacy and safety. Principles of stimulation of excitable tissue are reviewed with emphasis on efficacy and safety. Mechanisms of damage to tissue and the electrode are reviewed.