Preliminary Promising Findings for Manganese Chloride as a Novel Radiation Countermeasure Against Acute Radiation Syndrome.

INTRODUCTION: Military members and first responders may, at moment's notice, be asked to assist in incidents that may result in radiation exposure such as Operation Tomadachi in which the U.S. Navy provided significant relief for the Fukushima Daiichi Nuclear Reactor accident in Japan after an earthquake and tsunami in 2011. We are also currently facing potential threats from nuclear power plants in the Ukraine should a power disruption to a nuclear plant interfere with cooling or other safety measures. Exposure to high doses of radiation results in acute radiation syndrome (ARS) characterized by symptoms arising from hematopoietic, gastrointestinal, and neurovascular injuries. Although there are mitigators FDA approved to treat ARS, there are currently no FDA-approved prophylactic medical interventions to help protect persons who may need to respond to radiation emergencies. There is strong evidence that manganese (Mn) has radiation protective efficacy as a promising prophylactic countermeasure. MATERIALS AND METHODS: All animal procedures were approved by the Institutional Animal Care and Use Committee. Male and female B6D2F1J mice, 10 to 11 weeks old, were used for neurotoxicity studies and temporal effects of Mn. Four groups were evaluated: (1) vehicle injection, (2) dose of 4.5 mg/kg for 3 days, (3) dose of 13.5 mg/kg, and (4) sham. Irradiated mice were exposed to 9.5 Gy whole body Co60 γ-radiation. MRI was performed with a high dose of manganese chloride (MnCl2) (150 mg/kg) to assess the distribution of the MnCl2. RESULTS: The mice have promising survival curves (highest survival-13.5 mg/kg dose over 3 days of MnCl2 at 80% [87% female, 73% male] P = 0.0004). The complete blood count (CBC) results demonstrated a typical hematopoietic response in all of the irradiated groups, followed by mildly accelerated recovery by day 28 in the treated groups. No difference between groups was measured by Rota Rod, DigiGait, and Y-maze. Histologic evaluation of the bone marrow sections in the group given 13.5 mg/kg dose over 3 days had the best return to cellularity at 80%. MRI showed a systemic distribution of MnCl2. DISCUSSION: The preliminary data suggest that a dose of 13.5 mg/kg of MnCl2 given over 3 days prior to exposure of radiation may have a protective benefit while not exhibiting the neurobehavioral problems. A countermeasure that can prophylactically protect emergency personnel entering an area contaminated with high levels of radiation is needed, especially in light that nuclear accidents are a continued global threat. There is a need for a protective agent with easy long-term storage, easy to transport, easy to administer, and low cost. Histologic evaluation supports the promising effect of MnCl2 in protecting tissue, especially the bone marrow using the dose given over 3 days (4.5 mg/kg per day) of MnCl2. CONCLUSIONS: Initial experiments show that MnCl2 is a promising safe and effective prophylactic countermeasure against ARS. MRI data support the systemic distribution of MnCl2 which is needed in order to protect multiple tissues in the body. The pathology data in bone marrow and the brain support faster recovery from radiation exposure in the treated animals and decreased organ damage.

Transcriptomic Signatures of Neuronally Derived Extracellular Vesicles Reveal the Presence of Olfactory Receptors in Clinical Samples from Traumatic Brain Injury Patients.

Traumatic brain injury (TBI) is defined as an injury to the brain by external forces which can lead to cellular damage and the disruption of normal central nervous system functions. The recently approved blood-based biomarkers GFAP and UCH-L1 can only detect injuries which are detectable on CT, and are not sensitive enough to diagnose milder injuries or concussion. Exosomes are small microvesicles which are released from the cell as a part of extracellular communication in normal as well as diseased states. The objective of this study was to identify the messenger RNA content of the exosomes released by injured neurons to identify new potential blood-based biomarkers for TBI. Human severe traumatic brain injury samples were used for this study. RNA was isolated from neuronal exosomes and total transcriptomic sequencing was performed. RNA sequencing data from neuronal exosomes isolated from serum showed mRNA transcripts of several neuronal genes. In particular, mRNAs of several olfactory receptor genes were present at elevated concentrations in the neuronal exosomes. Some of these genes were OR10A6, OR14A2, OR6F1, OR1B1, and OR1L1. RNA sequencing data from exosomes isolated from CSF showed a similar elevation of these olfactory receptors. We further validated the expression of these samples in serum samples of mild TBI patients, and a similar up-regulation of these olfactory receptors was observed. The data from these experiments suggest that damage to the neurons in the olfactory neuroepithelium as well as in the brain following a TBI may cause the release of mRNA from these receptors in the exosomes. Hence, olfactory receptors can be further explored as biomarkers for the diagnosis of TBI.

Leadership perspectives on osteopathic medical school applicants to pathology residency training.

The number of graduating allopathic (MD) medical students matching into pathology has declined in recent years, while the number of osteopathic (DO) medical students has increased modestly, given the rapid expansion of osteopathic medical schools. Nonscholarly publications and materials on the internet often perpetuate negative perceptions of osteopathic physicians. Anecdotally, perspectives exist that some pathology residency programs are not DO-friendly; however, the reasons and how widespread an effect this might be are unclear. Our survey queried pathology chairs and residency program directors about their perceptions of osteopathic applicants and their knowledge of osteopathic medical school/training in general. This study utilized two similar, parallel surveys of pathology chairs and residency program directors with general questions structured around the perceptions and knowledge of both allopathic and osteopathic physicians, their medical training, and the consideration of osteopathic applicants to pathology residency. Pathology residency leaders acknowledge some negative perceptions of osteopathic physicians in the medical profession, the news, and social media. They also have some knowledge and perception gaps regarding osteopathic training and applicants, although experience with training osteopathic physicians as residents has been equivalent to that with allopathic physicians, and consideration appears to be fairly equal for osteopathic applicants. Even though negative perceptions of osteopathic physicians persist in news and social media, our surveys demonstrate that the leadership of pathology residency programs does not hold the same degree of bias and that DOs perform well in allopathic pathology residency programs without evidence of inferior outcomes.

Pathology Competencies in Medical Education and Educational Cases: Update 2023.

Pathology is a core component of medical school curricula because understanding the pathogenesis of the disease is foundational both for diagnostic efficiency and optimal use of ancillary resources in patient care. The Pathology Competencies for Medical Education (PCME) were developed as a national resource of expectations of pathology knowledge for medical students. The PCME are composed of three competencies: disease mechanisms and processes, organ system pathology, and diagnostic pathology and therapeutic pathology. The learning goals and learning objectives of the PCME that were first published in 2017 have been carefully revised and updated. Significant additions were made to fill gaps of the original PCME objectives, and some learning objectives have been retired or moved to more appropriate locations within the competencies. As curricula and the practice of medicine change, the PCME will continue to be revised and updated periodically. They have and will continue to serve as the organizing principle for the growing number of educational cases published by Academic Pathology. Nomenclature in the original and revised PCME will allow for continued linking of previous and new educational cases to the revised learning objectives. PCME and the educational cases can be adapted into any type of curricula. Having a widely accepted resource of learning objectives in pathology will help students and medical educators focus on essential components of pathology for the future practice of medicine.

Experiential exposure as the key to recruiting medical students into pathology.

Medical student interest and pursuit of a career in pathology have been steadily declining since 2015. We conducted three separate surveys of medical students to better understand these trends. In our first survey, we focused on assessing U.S. allopathic medical students understanding and perceptions of pathology. We later surveyed U.S. osteopathic medical students as a companion to the allopathic medical student survey, in which many similarities were discovered with some key differences. In our final survey, we specifically looked at curriculum differences between the U.S. allopathic medical schools that graduate the most students who enter pathology training programs (Group 1) versus those schools that graduate the fewest future pathologists (Group 2) to determine if the curriculum had an impact on medical student matriculation into pathology. Together, through these surveys, we were able to identify several remarkable recurring trends, presenting areas of targetable action. Here, we summarize themes from the three studies as well as a review of pertinent literature to offer best practices for exposing and engaging medical students to pathology and possibly recruiting students to consider pathology as a career.

How influential are medical school curriculum and other medical school characteristics in students' selecting pathology as a specialty?

There has been a significant decline in the number of United States allopathic medical students matching to pathology residency programs. Data acquired from the American Association of Medical Colleges (AAMC) show sustained variation in the medical school production of students who go on to pathology residency. When divided into groups based on the medical school's historical volume of graduates entering pathology, the schools in groups labeled Group 1 and Group 2 produced significantly higher and lower proportions of pathology residents, respectively. This study aimed to identify what medical school curriculum elements and other medical school characteristics might explain the differences observed in the AAMC data. The Dean or another undergraduate medical education contact from the Group 1 and Group 2 schools was invited to participate in an interview. Pathology Program Directors and Pathology Department Chairs were also included in communications. Thirty interviews were completed with equal numbers from each group. Interview questions probed pathology experiences, existence, and structure of a pathology interest group, options for post-sophomore fellowships, recent curriculum changes, and the extent of mentoring programs. Surprisingly, the curriculum does not appear to be a predictor of a medical school's production of students who enter pathology residency. A significantly greater percentage of Group 1 schools are public institutions compared to Group 2 schools. Other factors that may increase the number of students who go into pathology include mentoring, active learning versus observation, and post-sophomore fellowships or other opportunities to work in the capacity of a new pathology resident.

Essential laboratory tests for medical education.

Medical practice requires physicians to have a broad understanding of the basic sciences, have competent clinical skills, and have an ability to practice in evolving health systems in a cost-effective and evidence-based manner. Essential to the practice of medicine is an understanding of the common laboratory tests and the ability to use them effectively. The Essential Laboratory Tests for Medical Education (ELTME) is a concise document explaining the pathophysiology of common laboratory tests and clinical context for each test and was developed in response to an expressed need from medical students, residents and fellows, and medical educators. The ELTME is linked to the Pathology Competencies in Medical Education and its third competency of diagnostic medicine and therapeutic pathology. The ELTME table is a document of common laboratory tests in alphabetical listing. Laboratory tests may be easily queried by name or organ system, and with simple editing tools, new tables may be constructed to fit the needs of individual curricula or learners. Furthermore, the table may be easily expanded by educators who wish to add specific tests to complement their curricula.

Factors influencing US osteopathic medical students to choose pathology as a specialty.

The decline in the number of US allopathic (Medical Doctor or M.D.) medical students matching to pathology residency has been a topic of much discussion at national pathology professional society meetings and in recent publications. A recent survey of fourth-year allopathic medicals students was conducted to better understand the rationale behind students' interest or lack thereof in pathology as a specialty. This study utilizes a similar survey tool gauging osteopathic (Doctor of Osteopathy or D.O.) student knowledge and interest in pathology, and offers insight into a possible growth market for the specialty. Similar to allopathic students, osteopathic students noted that clinical or research opportunities in pathology during medical school, autopsy observation/participation, and participation in pathology interest groups correlated with a greater likelihood of selecting pathology as a specialty. However, some key differences in osteopathic medical school curricular elements including microscope use, gross pathology specimen demonstrations, case-based learning by pathologists, exposure to pathology during other rotations, awareness of a pathology interest group, as well as an overall understanding of the everyday work of a pathologist were noted. Experiential exposure to pathology, and direct mentorship from pathologists may present an opportunity for pathology professional organizations, and pathology residency programs to partner with osteopathic medical schools to increase interest in the field, and aid in pipeline development.

Association of Peripheral Serum MicroRNAs With Persistent Phantom Limb Pain in Individuals With Amputation.

OBJECTIVE: Individuals with major limb amputation(s) frequently experience phantom limb sensations, which are described as vivid impressions of either parts or entire missing limb(s). Despite the high incidence and prevalence of phantom limb pain, the underlying pathophysiology of phantom limb pain remains poorly understood. The objective of this study was to evaluate a possible role of microRNAs in the pathophysiology of phantom limb pain. DESIGN: Adults with acquired limb amputation and varying degrees of phantom limb pain consented to provide clinical data and blood samples. One hundred forty participants with single or multiple limb amputation(s) were enrolled. The Visual analog scale and neuropathic pain symptom inventory were administered to evaluate the pain. Serum samples were analyzed for microRNA expression and bioinformatic analysis was performed. RESULTS: Sixty-seven participants did not experience phantom limb pain, whereas 73 participants experienced varying severities of phantom limb pain measured on a pain scale. Linear regression analysis suggested that the time since amputation is inversely related to severity of the pain. A significantly increased expression of 16 microRNAs was observed in participants experiencing phantom limb pain. Bioinformatic analysis shows a possible role of these microRNAs in regulating genes expressed in peripheral neuropathy. CONCLUSIONS: This study provides the first evidence of association of microRNA in phantom limb pain.

Decreases in Dorsal Cervical Spinal Cord White Matter Tract Integrity Are Associated with Elevated Levels of Serum MicroRNA Biomarkers in NCAA Division I Collegiate Football Players.

This prospective, controlled, observational cohort study assessed the performance of a novel panel of serum microRNA (miRNA) biomarkers relative to findings on cervical spinal cord magnetic resonance imaging (MRI) in collegiate football players. There were 44 participants included in the study: 30 non-athlete control subjects and 14 male collegiate football athletes participating in a Division I Football Bowl Subdivision of the National Collegiate Athletic Association. Diffuse tensor MRI and blood samples were acquired within the week before the athletic season began and within the week after the last game of the season. All miRNAs were significantly higher in athletes regardless of their fractional anisotropy (FA) values (p < 0.001), even those considered to be in the "normal" range of FA for white and gray matter integrity in the cervical spinal cord. miRNA biomarkers were most significantly correlated with FA of the white matter (WM) tracts of the dorsal (posterior) spinal cord; particularly, the fasciculus gracilis, fasciculus cuneatus, lateral corticospinal tract, rubrospinal tract, lateral reticulospinal tract, spinal lemniscus, and spinothalamic and -reticular tracts. Areas under the curve for miRNA biomarkers predicting lower FA of WM dorsal (posterior) cervical spinal tracts, therefore lower white matter integrity (connectivity), were miR-505* = 0.75 (0.54-0.96), miR-30d = 0.74 (0.52-0.95), and miR-92a = 0.75 (0.53-0.98). Should these findings be replicated in a larger cohort of athletes, these markers could potentially serve as measures of neuroimaging abnormalities in athletes at risk for concussion and subconcussive injuries to the cervical spinal cord.

MicroRNAs in Basolateral Amygdala Associated with Stress and Fear Memories Regulate Rapid Eye Movement Sleep in Rats.

Stress-related sleep disturbances are distressing clinical symptoms in posttraumatic stress disorder patients. Intensely stressful events and their memories change rapid eye movement (REM) sleep in animal models. REM sleep varies with individual differences of stress resilience or vulnerability. The basolateral amygdala (BLA) is a primary mediator of the effects of stress and fear memories on sleep. However, the molecular mechanisms in BLA regulating the effects of fear conditioning, shock training (ST) and context re-exposure (CTX) on REM sleep are not well known. MicroRNAs (miRNAs) are small, non-coding RNAs and posttranscriptional gene regulators of diverse biological processes. The aim of this study is to investigate ST- and CTX-altered miRNAs in the BLA of resilience and vulnerable animals and on REM sleep regulation. MiRNAs expression profiles in BLA were generated following ST and CTX using the Taqman Low Density rodent microRNA array. The altered BLA miRNAs expression and REM sleep reduction observed in ST and CTX vulnerable animals. AntagomiR-221 microinjection into BLA for one of the upregulated miRNAs, miR-221 in BLA, attenuated the REM sleep reduction. This study suggests that miRNAs in the BLA may play a significant role in mediating the effects of stress and fear memories on REM sleep.

Magnetic bead purification of enveloped alphavirus and flavivirus.

Virus production is an essential part of virology. The quality of virus preparation, in terms of purification and yield, can affect the outcome of experiments. Purified virus is critical for assays, as contamination from cell culture supernatants may affect results. Purified virus is also needed for vaccine preparations. The traditional process of gradient purification of virus is time consuming, with multiple steps spanning over days, and produces significant amounts of biohazard waste. Developing a more efficient alternative that provides a purified virus product is highly desirable. In this study, we performed magnetic bead purification of Zika virus (ZIKV) and Mayaro virus (MAYV) with the Mag4C LV kit from OZ Biosciences. Currently, this kit is only indicated for use with lentiviruses and retroviruses. We found that we were able to successfully concentrate and purify both ZIKV and MAYV using the kit. Therefore, we concluded that the Mag4C LV kit provides a quick and simple alternative to traditional virus purification methods.•Our protocol is customized by using an alphavirus (MAYV) and flavivirus (ZIKV). This method has not been previously used for these viruses.

Educational Case: Point-of-Care Testing.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040. 1.