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Background and aims: Healthcare workers (HCWs) throughout the world have been exposed to economic and existential stress during the Covid-19 pandemic. The American Medical Association (AMA) has documented that increased healthcare burden correlates with increased stress, burnout, and psychological burden in HCWs. However, limits on personnel, time, and in person interactions make it challenging to assess mental health outcomes during a pandemic. This pilot study used virtual technology to efficiently assess these outcomes. Setting: Data were collected based on voluntary participation in the Coping with Covid-19 for Caregivers Survey created by AMA. The survey was sent out to approximately 300 participants who included local physicians, medical residents, medical students, and allied health professionals and students who attended a virtual Mental Health Summit. Methods: The AMA developed survey included questions about demographics, overall stress, fear of infection and transmission of the virus, perceived anxiety or depression due to Covid-19, work overload, childcare issues, and sense of meaning and purpose. The AMA allows for up to five additional questions to be added to their survey, therefore five questions regarding support service utilization, perseverance, and resilience during the Covid-19 pandemic, and two items to further understand students' areas of medical interest. The survey was administered using an online platform through the AMA. The data were analyzed using descriptive statistics. Results: There were 81 survey respondents. Based on the results of the survey, "high stress" was found in 52 (64%) participants. 66 (81%) were afraid (moderately or to a great extent) of exposure or transmission, 61 (75%) described high levels of anxiety or depression, and 67 (84%) noted work overload. Despite this increase in stress, most respondents (77%) said they were not likely to reduce their devoted hours to clinical care or research in the next 12 months, and 81% answered that they would not leave their practice or research within two years. Conclusion: Covid-19 has negatively affected the well-being of HCWs. This is a similar trend seen during other times of healthcare strain. Mental health support, work modulation, and various provisions should be explored as means to reduce Covid-19-related negative impacts. The use of an online summit and online data collection methods were appropriate for collecting data on the impact of the Covid-19 pandemic on mental health. This pilot study supports the larger scale implementation of this technology for health informatics research.

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In this paper, the scalings incorporating the Prandtl number (Pr) dependence have been obtained by a scaling analysis for the unsteady natural convection boundary layer of an initially quiescent isothermal Newtonian fluid of Pr>1 produced by the sudden imposition of a higher temperature on a vertical plate. It is shown that the transient flow behavior of the resulting boundary layer can be described by a three-region structure and at the start-up stage the boundary layer development is one dimensional and independent of height due to the dominance of pure conduction; however, at steady state it becomes two dimensional and height dependent as the flow becomes dominated by convection. Numerical results demonstrate that the scalings representing the thermal boundary layer development accurately represent their Pr dependence over the whole stage of flow development. The scalings representing the viscous boundary layer development are generally in good agreement with the numerical results with the Pr variation over the whole stage of flow development, although there are small deviations from the numerical results with the Pr variation that are within acceptable limits for scaling.

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The onset of dementia is often recognized to some extent by those affected with this slow, degenerative process. Patients often have comorbid mood and/or anxiety disorders as a result of or in addition to this recognition. The author describes an unusual presentation for dementia, in both its onset and its correlation with regional changes in cerebral and cerebellar blood flow, as detected with whole-brain, voxel-by-voxel analysis. This patient's ultra-rapid cycling from severe disability to a state of near-normalcy was associated with a normalization of a flow deficit in the right posterior-parietal region, in addition to striking increases in the already over-perfused cerebellum. The author summarizes possible mechanisms for these flow changes and gives a brief review of recent literature on the involvement of the cerebellum in cognition.

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BACKGROUND: The U.S. Air Force has developed +Gz-protective equipment that will provide most pilots protection to +9 Gz with minimal-to-no straining. This equipment includes a pressure breathing system called COMBAT EDGE (CE), which is currently operational, and the Advanced Technology Anti-G Suit (ATAGS), which is not yet operational. For future high-performance aircraft design it is important to know the upper limit of various protective equipment and techniques. METHODS: Six subjects were randomly exposed to a 12-cell matrix composed of +Gz and the following combinations of protective equipment at three seat-back angles (13 degrees, 30 degrees and 55 degrees from the vertical): 1) the standard CSU-13B/P anti-G suit (STD); 2) the STD suit with CE; 3) the ATAGS; and 4) the ATAGS with CE. Relaxed, followed by straining +Gz tolerance was determined using 15-s rapid onset runs to a maximum of +12 Gz. A comprehensive battery of baseline and post-exposure medical surveillance studies was performed to evaluate the medical consequences of these high +Gz exposures. RESULTS: All 6 subjects were able to achieve +12 Gz with various combinations of +Gz-protective equipment, seat-back angle, and various amounts of straining, from none to maximum. When the data were collapsed over all protective equipment there was a significant (p < 0.05) seat effect. Relaxed tolerance to ROR increased with seat-back angle from 13 degrees to 30 degrees to 55 degrees. There was also a significant protective equipment effect when the data were collapsed over all seat-back angles. CONCLUSIONS: These data confirm that effortless protection to +9 Gz is available using ATAGS/CE with the 13 degree and 30 degree seat-back angle (F-15, F-16 and F-22) and to +10.5 Gz with a 55 degree seat-back angle. Moreover, with ATAGS/CE, and a moderate degree of straining, +12 Gz is definitely achievable at 55 degrees, even with reduced anti-G suit pressure at 55 degrees. With additional straining +12 GC is also achievable at the 13 degree and 30 degree seat-back angles.

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BACKGROUND: Little has been published about the aeromedical management and disposition of aviators who attempt suicide, and almost no such information about military aviators exists in the open literature. The few available data are scattered and frequently anecdotal. METHODS: The authors reviewed all case reports of fliers evaluated at the USAF School of Aerospace Medicine's Aeromedical Consultation Service (ACS) between 1981-96 for possible return to flying duties after a suicide attempt, and prepared a representative case report. RESULTS: Between 1981 and 1996, the ACS evaluated 14 trained aviators (pilots and other aircrew members, excluding flight surgeons) who had attempted suicide. Of these, 11 (79%) ultimately received a recommendation for return to flying duties. CONCLUSIONS: In most instances the underlying stressors included failed intimate interpersonal relationships, administrative or legal problems, psychiatric disorders, death of spouse, or job conflicts. Evidence of abuse of alcoholor other substances was found in 54% of an earlier, larger data set of attempters. Some data on aircrew suicide completion were available and are reported. The top medical priorities after such attempts should be to diagnose what is wrong, and to treat it. In spite of the common assumption that a suicide attempt inevitably ends a military flying career, some attempters can return to safe and effective flying duty after appropriate psychotherapy. If the flier regains physical and mental health and maintains them for at least 6 mo after treatment, then that flier may be evaluated by an outside aeromedical psychiatric consultant such as the ACS (to avoid transference issues between flier and therapist) for possible return to flying duties. Waiver action should be based on the underlying psychiatric diagnosis, not the suicidal attempt itself. Follow-up may be accomplished through periodic mental health evaluations in conjunction with routine physical examination procedures. Issues involving substance abuse and security clearances must be handled through the appropriate channels.

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UNLABELLED: The goal of this study was to examine the apparent differences in regional cerebral blood flow (rCBF) between two groups of normal individuals who received either of the two tracers, 99mTc-D,L-hexamethylpropylene amine oxide (99mTc-HMPAO, or exametazime) or 99mTc-ethylene-dicysteine diethylester (99mTc-ECD, or bicisate). METHODS: Individuals were screened for drug use, head injury, medication status and other psychiatric and medical illnesses. The two groups were matched for age, sex and race. SPECT measurement of brain perfusion was performed in 35 individuals who received 99mTc-HMPAO and in 55 who received 99mTc-ECD. Subsequent analysis of these scans was done using computer software including Statistical Parametric Mapping and Analyze. Images were intensity-thresholded and spatially normalized to a standardized stereotactic (Talairach) space. This allowed for the objective, quantitative analysis of these data, demonstrating the extent and magnitude of rCBF changes. RESULTS: Our results showed significant changes between these two groups of normal individuals, presumably due to differences in pharmacokinetics between the two radiolabeled tracers. Specifically, large areas of the parietal, occipital and superior temporal cortices were significantly lower in the 99mTc-HMPAO group than in the 99mTc-ECD group. Increases were seen in the subcortical nuclei, parts of the brain stem, hippocampus and small areas of the cerebellum in the 99mTc-HMPAO group as compared to the 99mTc-ECD group. CONCLUSION: We present a method of image analysis to semiquantitatively measure rCBF in SPECT images and the changes seen due to differences between the two radiotracers.

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UNLABELLED: Structural and functional neuroimaging techniques have consistently demonstrated that abnormal lateralization of temporal lobes may be important in identifying the pathophysiologic processes in schizophrenia. The exact nature of these reported abnormalities has not been consistent. METHODS: We examined temporal lobe perfusion using HMPAO-SPECT in 22 individuals with schizophrenia in an effort to establish whether temporal lobe perfusion asymmetry is seen in these individuals, as compared to a group of 22 age- and sex-matched controls. RESULTS: We found that the asymmetry index, a measure of perfusion differences between two homologous compared areas, was lower (more negative) in schizophrenic individuals. The asymmetry indices of patients considered with the results from globally corrected ROI means indicated that the left temporal lobes of individuals with schizophrenia were significantly hypoperfused when compared to controls. This finding does not appear to be caused by medication effects, demographic variables, handedness, imaging artifacts or analysis techniques. CONCLUSION: In our sample, patients with schizophrenia appear to have significant left hypoperfusion relative to right of their temporal lobes. Abnormal lateralization of temporal lobe blood flow may have important clinical implications by assisting with diagnosis and appropriate treatment for individuals with schizophrenia.

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Smoking among commercial and military aviators is a health hazard in the cockpit. Pilots who are required to abstain before and during flight may suffer cockpit performance decrements. This study reviews the physiological, cognitive, behavioral, and psychological effects of smoking withdrawal as they relate to flying performance. The variety of research designs, methodologies, and subject groups is discussed. Findings suggest that heart rate, arousal, vasoconstriction, vigilance, concentration, and energy increase with nicotine use; stress and irritability are reduced with smoking. Withdrawal, on the other hand, produces a decrease in carboxyhemoglobin, digit recall, serial addition/subtraction, and job satisfaction; blood pressure, depression, absenteeism, caloric intake, craving, aggressiveness, confusion, and impulsivity increase with withdrawal. Severity of withdrawal symptoms varied, but most studies report psychological, and/or physiological responses to nicotine withdrawal. The conflict between health and performance is discussed and suggestions for future directions are offered.

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beta-Nerve Growth Factor (NGF) is a 26-kilodalton protein that has, in recent years, been discovered to have functions beyond that of its classical neurotrophic actions. It has been linked to both the neuroendocrine and the immune systems, and NGF-like bio- and immunoreactivities have been found in the anterior pituitary (AP) gland. The purpose of this study was to assay for NGF immunoreactivity in the AP and to identify the cell type(s) by their hormone content. We also wanted to determine if the AP was a target for NGF action, by looking for the p75 (low affinity) and gp140trkA (high affinity) NGF receptors. Immunoreactivity was detected by immunolabeling with the avidin-biotin-peroxidase complex protocol. Immunolabelling showed NGF immunoreactivity in 31 +/- 5% of AP cells. For the NGF receptors, we found that AP cells were p75 negative, but gp140trkA positive (23 +/- 2%). We found NGF immunoreactivity in 10% of cells containing ACTH, 64% of cells with TSH, 75% of cells with LH, 51% of cells containing GH, and 42% of cells with PRL antigens. Expression of gp140trkA immunoreactivity was also found in 33% of ACTH-containing cells, 45% of TSH-containing cells, 44% of LH-containing cells, 23% of cells with GH, and 41% of cells containing PRL. This evidence demonstrates the presence of NGF immunoreactivity in specific hormone-containing AP cells that contain hormones. The presence of gp140trkA receptors suggests that some of these cells could be targets for NGF action, possibly through autocrine or paracrine pathways.

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beta-Nerve growth factor (NGF) is a 26-kilodalton protein that may have a broader distribution and set of functions than its name implies. Its functions are now linked to both the neuroendocrine and the immune systems. NGF immunoreactivity has been found in specific cell types in the anterior pituitary (AP) gland. The purpose of this study was to characterize further the NGF activity in AP cells, learn if it can be secreted, and determine the factors that may control secretion. NGF bioactivity was detected with assays of neurite outgrowth in PC12 tumor cells, and immunoreactivity was detected by an enzyme-linked immunoassay. AP cells secreted both bioactive and immunoreactive NGF at basal levels in vitro. In the enzyme-linked immunoassay, the anti-NGF recognized 2.5S NGF at a concentration of 0.10 pM, but it did not recognize brain-derived neurotrophic factor, neurotrophin-3 (NT-3), or NT-4, at concentrations as high as 10 nM. AP cells cultured for 6 days at 10(5) cells/200 microliters in DME plus 10% fetal calf serum secreted 1.5 +/- 0.16 pM NGF. Tests of substances that might regulate NGF secretion showed that interleukin-1 beta (IL-1 beta) at a concentration of 1 nM caused up to a 2.5 fold increase in NGF secretion. In addition, GH releasing hormone, tumor necrosis factor-alpha, basic fibroblast growth factor, and forskolin all caused an inhibition of NGF secretion below basal levels. The evidence demonstrates the presence and secretion of authentic NGF from AP cells. The fact that secretion is enhanced by IL-1 beta suggests that AP NGF may be a regulatory factor in the neuroendocrine-immune circuit.

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The association of hostility and coronary artery disease was evaluated in a case-control study of aircrew members who had been referred for coronary angiography on the basis of noninvasive tests or risk factor status. The asymptomatic status of the sample and the structured nature of the referral process minimize the methodologic problems normally associated with studies of patients undergoing angiography. Cases (n = 24) had some angiographic evidence of coronary artery disease, whereas controls (n = 25) were found to have no evidence of occlusion. An interaction was observed between smoking history and a measurement of hostility based on observations of the respondent's behavior during a standard interview. Among nonsmokers, cases had higher hostility scores than did controls (p = 0.004). This association was not present among smokers. Self-reported hostility did not discriminate cases from controls. These findings support the notion that hostility plays a role in the pathogenesis of coronary atherosclerosis and point to the potential importance of interactions between hostility and other risk factors.

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This exploratory retrospective multi-case study investigates marital discord in USAF pilots as part of an overall concern with mission safety. Seventeen USAF School of Aerospace Medicine (USAFSAM) cases involving marital distress were reviewed, using a standardized format. Duration of martial discord ranged from 1-10 years with an average of 2.25 years. The most frequent problem noted was one of communication, with authoritarian or controlling styles predominating. The second most frequent conflict concerned occupational demands; both pilots and spouses complained about frequent work-related separations. Nine of ten distressed outcomes (i.e., separated or divorced) were initiated by the wife. We speculate that a pilot with an inflexible communication style who is not cognizant of his or her spouse's emotional needs is likely to exacerbate marital problems. The notion that marital distress may adversely affect a pilot's attention, generating performance decrements, underscores the importance of investigating elements of marital harmony in the pilot population. Based on our study and review of the literature, we suggest the USAF employ programs that: a) recognize the spouse's contribution to mission safety; b) increase spouse's awareness of mission requirements; c) enhance couple's communication; and d) improve stress management skills.

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T cell lines with a novel phenotype (CD3+ TCR-alpha/beta+ CD4- CD8-) were developed from the peripheral blood of a patient with a combined immunodeficiency and tissue injury resembling graft-vs-host disease. One of these IL-2-dependent T cell lines demonstrated non-MHC-restricted cytolytic function against tumor targets, syngeneic and allogeneic fibroblasts, and PHA blasts from allogeneic donors. The other cell line only became cytotoxic in the presence of lectin or anti-CD3 antibody. The two cell lines also differed in their expression of the T-200 gene products CD45RO (gp180) and CD45RA (gp220). Both cell lines produced tumor necrosis factor-alpha and -beta and IFN-gamma activity when activated with mitogens or PMA and IL-1. The in vitro functions of these T-cell lines suggest a potential role for alpha/beta double-negative T lymphocytes in tissue injury resembling graft-vs-host disease.

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We have previously shown that both IFN-gamma and IFN-beta are produced in vivo and in vitro by spleen cells obtained from mice experiencing a chronic form of graft vs host disease (GVHD). Further, we have shown that in vitro production of IFN-beta by spleen cells from GVHD mice may play a role in the suppressed in vitro mitogen responsiveness of these cells. This study was undertaken to investigate if treatment of such mice with mAb to IFN-gamma or IFN-beta could alter the immunosuppression or lymphoid hypoplasia associated with chronic GVHD. GVHD was induced across minor histocompatibilities by the i.v. injection of B10.D2 spleen cells into sublethally irradiated BALB/c mice. These mice were given daily injections for 20 days of one of the following: 1) mAb to IFN-gamma, 2) mAb to IFN-beta, or 3) control IgG. Histologic examination of these mice at 21 to 22 days post transplantation revealed that mice treated with mAb to IFN-beta or control IgG had dramatic hypoplasia of the thymus, spleen, and lymph nodes which was similar to untreated GVHD mice. Mice given mAb to IFN-gamma, however, had no lymphoid hypoplasia and had a near normal gross and histologic appearance of their thymus, spleen, and lymph node tissue when compared with syngeneic controls. In vitro mitogen-induced proliferative responses of spleen and lymph node cells obtained from GVHD mice or GVHD mice treated with mAb to IFN-beta were severely suppressed or absent. In contrast, spleen and lymph node cells from GVHD mice given mAb to IFN-gamma were capable of giving a significant in vitro proliferative response to Con A, PHA, and LPS. Further, natural suppressor cell activity and spontaneous production of IFN-beta, a characteristic of this form of GVHD, was absent in spleen cells obtained from GVHD mice treated with mAb to IFN-gamma. These results further identify the IFN as playing critical roles in the pathogenesis of GVHD.

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Thirty-seven healthy untrained males (age = 21 +/- 1 yr; range = 19 to 35 yr) were studied to determine the effects of 10 wk of low- and high-repetition resistive training on lipoprotein-lipid profiles. Subjects were assigned to 1 of 3 groups: a low-repetition group (N = 15) that trained using 4 to 6 repetitions maximum or a high-repetition group (N = 14) that used 14 to 16 repetitions maximum in their training or to an inactive control group (N = 8). The number of sets was adjusted to equalize workloads. Muscular strength increased significantly in both training groups as indicated by the increase in the one-repetition maximum test (P less than 0.05). VO2max, body weight, and percent body fat did not change in either of these groups. However, fat-free weight increased significantly in both training groups (both P less than 0.05). The low-repetition training program resulted in no significant changes in the plasma concentrations of triglycerides (104 +/- 15 vs 89 +/- 8), total cholesterol (150 +/- 7 vs 141 +/- 6), high-density lipoprotein (HDL)-cholesterol (40 +/- 1 vs 41 +/- 2), and HDL2-cholesterol (7 +/- 1 vs 7 +/- 1). A similar pattern was observed for the high-repetition group ([i.e., no significant changes in the concentrations of triglycerides (87 +/- 10 vs 89 +/- 8), total cholesterol (148 +/- 6 vs 162 +/- 6), HDL-cholesterol (40 +/-2 vs 40 +/- 2), and HDL2-cholesterol (6 +/- vs 1 vs 7 +/- 2)]. All lipid values were expressed in milligrams per deciliter (mean +/- SE).(ABSTRACT TRUNCATED AT 250 WORDS)

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Investigators of the Neuropsychiatry Branch, Clinical Sciences Division, U.S. Air Force School of Aerospace Medicine (USAFSAM), provided biofeedback-moderated behavioral treatment to 53 fliers grounded for chronic, severe motion sickness, and followed each flier for 2 years after treatment completion. Success was defined as returning to and maintaining satisfactory operational flying status. Of these, 42 fliers (79%) met this criterion; 3 (6%) were partially successful, and 8 (15%) were subsequently grounded for recurrent airsickness. Follow-on studies will investigate psychophysiological mechanisms through which this method of treatment works.

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Monoamine oxidase (EC 1.4.3.4; MAO) is the primary enzyme responsible for the intraneuronal degradation of biogenic amines in the central nervous system. An understanding of the physiological significance of the functional and regulatory differences between the two forms of the enzyme, MAOs A and B, would be facilitated by the availability of antibodies specific for the two forms of the enzyme. We previously isolated and characterized a monoclonal antibody (MAO B-1C2, previously designated MAO-1C2) which binds human MAO B but not A. We describe here four new monoclonal antibodies (designated MAO A-3C9, A-4F10, A-7B10, and A-7E10) which were elicited to highly purified MAO A from human placenta and which, in the presence of antimouse IgG and Staphylococcus aureus, immunoprecipitate greater than 90% of the catalytically active purified MAO A. MAO A-3C9 appears to have a lower affinity for purified MAO A than the other three antibodies and does not immunoprecipitate either MAO A or MAO B from human platelets or from Triton X-100 extracts of human placental and liver mitochondria. MAO A-4F10, A-7B10, and A-7E10 immunoprecipitate catalytically active MAO A from Triton X-100 extracts of human placental and liver mitochondria, but not catalytically active MAO B from either pletelets or from Triton X-100 extracts of human liver mitochondria. Collectively, these anti-MAO monoclonal antibodies reveal unique epitopes on human MAO A not shared by MAO B, and at least one epitope on MAO B not shared by MAO A. These immunochemical differences support the hypothesis that MAO A and MAO B are different proteins, presumably isozymes.

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"From the aerospace medicine residents' teaching file: toxic peripheral neuropathy, sacroiliitis, and mitral valve prolapse." The clinical presentation, evaluation and diagnosis of an aviator exposed to N-Hexane and Butanone are discussed. The aeromedical disposition of this patient, who also had mitral valve prolapse and subclinical sacroiliitis, is also presented.

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During the past 2 years we have studied eighty-nine biopsy specimens from nineteen patients with Cowden's syndrome. Among fifty-three facial lesions, twenty-nine were trichilemmomas. Twenty-three of the others were consistent with trichilemmoma, showed a non-specific benign verrucous acanthoma, or were not diagnostic; one was a blue naevus. All fourteen oral mucosal biopsy specimens were benign fibromas. Nineteen of twenty-two biopsy specimens from the hands and feet showed the pattern of benign keratosis. Multiple trichilemmomas were found in all patients with Cowden's syndrome, but at times several biopsy specimens were required before a diagnostic picture was uncovered. All patients with multiple facial trichilemmomas were found to have Cowden's syndrome. The combination of multiple facial trichilemmomas, oral fibromas, and benign acral keratoses enables one to diagnose Cowden's syndrome at a stage before serious internal complications develop.

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