Civil Aerospace Medical Institute

Increasing evidence indicates widespread occurrence of pharmaceuticals and personal care products (PPCPs) in municipal effluent discharges and surface waters. Studies that characterize the fate and effects of PPCPs in aquatic systems are limited, and to our knowledge, data regarding pharmaceutical accumulation in fish of effluent-dominated ecosystems have not been previously reported. In the present study, fish populations were sampled from a reference stream and an effluent-dominated stream in north Texas, USA. Lepomis macrochirus, Ictalurus punctatus, Cyprinus carpio, and Pomoxis nigromaculatus were killed; the liver, brain, and lateral filet tissues dissected; and the tissues stored at -80 degrees C until analysis. Fish tissues were extracted using solid-phase extraction and then analyzed by gas chromatography-mass spectrometry in the negative chemical ionization mode. The selective serotonin reuptake inhibitors (SSRIs) fluoxetine and sertraline and the SSRI metabolites norfluoxetine and desmethylsertraline were detected at levels greater than 0.1 ng/g in all tissues examined from fish residing in a municipal effluent-dominated stream. To our knowledge, the present study is the first report of SSRI residues in fish residing within municipal effluent-dominated systems.

In vivo, platelets associate with neutrophils at sites of hemorrhage or inflammation. In vitro, stimulated platelets bind to neutrophils in a Ca2(+)-dependent manner. GMP-140, an integral membrane glycoprotein found in secretory granules of platelets and endothelium, is rapidly translocated to the cell surface after cellular activation. It shares sequence similarity with two leukocyte adhesion molecules, ELAM-1 and a lymphocyte homing receptor. We have recently shown that neutrophils bind to purified GMP-140 in a Ca2(+)-dependent fashion, and that GMP-140 participates in adhesion of neutrophils to activated endothelium. In this study we demonstrate that GMP-140 also mediates adhesion of neutrophils to stimulated platelets. Fixed thrombin-activated human platelets, but not unstimulated platelets, formed rosettes around neutrophils in the presence of Ca2+. The binding of platelets to neutrophils was inhibited by a monoclonal antibody to GMP-140 and by purified GMP-140. By promoting close cell-cell contact, GMP-140 may recruit both platelets and neutrophils to sites of tissue injury as well as modulate the function of each cell type by the other.

OBJECTIVE: The aim of this study was to extend previous examinations of aviation accidents to include specific aircrew, environmental, supervisory, and organizational factors associated with two types of commercial aviation (air carrier and commuter/ on-demand) accidents using the Human Factors Analysis and Classification System (HFACS). BACKGROUND: HFACS is a theoretically based tool for investigating and analyzing human error associated with accidents and incidents. Previous research has shown that HFACS can be reliably used to identify human factors trends associated with military and general aviation accidents. METHOD: Using data obtained from both the National Transportation Safety Board and the Federal Aviation Administration, 6 pilot-raters classified aircrew, supervisory, organizational, and environmental causal factors associated with 1020 commercial aviation accidents that occurred over a 13-year period. RESULTS: The majority of accident causal factors were attributed to aircrew and the environment, with decidedly fewer associated with supervisory and organizational causes. Comparisons were made between HFACS causal categories and traditional situational variables such as visual conditions, injury severity, and regional differences. CONCLUSION: These data will provide support for the continuation, modification, and/or development of interventions aimed at commercial aviation safety. APPLICATION: HFACS provides a tool for assessing human factors associated with accidents and incidents.

Air traffic control instructors controlled simulated traffic while a variety of techniques for determining situation awareness (SA) were implemented. SA was assessed using a self-report measure (the Situation Awareness Rating Technique, or SART), a query method that removed information on the plan-view display (the Situation Awareness Global Assessment Technique, or SAGAT), a query technique that did not have a memory component (the Situation-Present Assessment Method, or SPAM), and the detection of errors integrated into the scenarios (implicit performance). We used these measures of SA together with a measure of workload, NASA Task Load Index (TLX), to predict two different performance measures: (1) an over-the-shoulder, subjective assessment by a subject matter expert (SME), and (2) a count of the number of control actions remaining to be performed at the end of the scenario. The SME evaluation was predicted by workload and the controller’s appreciation of both the present and the future. The remaining-actions count (RAC) was predicted by the controller’s appreciation of the future. In fact, an appreciation of the present led to poorer RAC scores: the better the participant was at answering questions about the present or the better he or she understood the present situation, the larger the number of actions that remained to be performed. The results have implications for the relationships among workload, SA, and performance, and suggest limitations on several of the measures currently proposed as SA techniques. The results confirm that future versus present is an important conceptual difference in ATC. More important, they suggest that a controller who remains overly focused on the present may do so at the expense of the future.

Brockner and Adsit (1986) found that satisfaction with an exchange relationship was more strongly related to perceptions of equity among men than women. Kahn (1972) reported that men were more likely than women to distribute outcomes to individuals in direct proportion to their input. We evaluated potential gender differences among 12,979 personnel in 30 different organizational systems in (a) correlations between fairness and job satisfaction scores and (b) standardized group differences in the perceived amounts of pay and promotion fairness and expressed levels of facet and global job satisfaction. The fairness-satisfaction relationship was not higher for men, and there were no practical differences in fairness perceptions and job satisfaction between men and women.

The Human Factors Analysis and Classification System (HFACS) is a general human error framework originally developed and tested within the U.S. military as a tool for investigating and analyzing the human causes of aviation accidents. Based upon Reason’s (1990) model of latent and active failures, HFACS addresses human error at all levels of the system, including the condition of aircrew and organizational factors. The purpose of the present study was to assess the utility of the HFACS framework as an error analysis and classification tool outside the military. Specifically, HFACS was applied to commercial aviation accident records maintained by the National Transportation Safety Board (NTSB). Using accidents that occurred between January 1990 and December 1996, it was demonstrated that HFACS reliably accommodated all human causal factors associated with the commercial accidents examined. In addition, the classification of data using HFACS highlighted several critical safety issues in need of intervention research. These results demonstrate that the HFACS framework can be a viable tool for use within the civil aviation arena.

During active intestinal inflammation polymorphonuclear leukocytes (PMN) transmigrate into the lumen and release 5'-AMP (J. Clin. Invest. 1993. 91:2320-2325). 5'-AMP is converted to adenosine by the apical epithelial surface with subsequent activation of electrogenic Cl- secretion (the basis of secretory diarrhea) via apical A2b adenosine receptors (J. Biol. Chem. 1995. 270:2387-2394). Using a polarized human intestinal epithelial monolayer (T84), we now characterize the basis of the observed conversion of 5'-AMP to adenosine required for this paracrine signaling pathway. An inhibitor of the ecto-5'-nucleotidase CD73, alpha, beta-methylene ADP (AOPCP), inhibited epithelial Cl- secretory responses to 5'-AMP, but not to authentic adenosine. Confocal immunofluorescent microscopy revealed CD73 to be surface expressed on both model and natural human intestinal epithelia. Expression was about sixfold greater on the apical cell surface as assessed biochemically by selective cell surface biotinylation, and morphologically by immunofluorescence. Treatment with phosphotidylinositol specific-phospholipase C (PI-PLC) released 95% of apical CD73, indicating that the intestinal CD73 possesses a glycosylphosphatidylinositol (GPI) anchor. Neither adenosine nor 5'-AMP stimulation induced intact T84 cells to shed surface CD73. The bulk of apical CD73 ( approximately 60%) was released from the cell surface by treatment with 1% Triton X-100 (TX-100) at 4 degrees C, but such release was not affected by pretreatment with ligand or by prior, antibody-mediated cross-linking of CD73. Subsequent analyses showed that the subpool of CD73 released by TX-100 at 4 degrees C was not truly solubilized, but rather represented TX-100-induced release of CD73-containing membrane fragments. These membrane fragments displayed light density on sucrose gradients characteristic of detergent insoluble glycosphingolipid-rich membrane domains (DIGs)/ caveolae, were solubilized by n-octyl glucoside (NOG, 1%) at 4 degrees C, and contained caveolin. These data indicate that human intestinal epithelia express CD73, which is apically polarized and targeted to microdomains with DIGs/caveolae characteristics. CD73 likely participates in translating paracrine, PMN-derived 5'-AMP signals to the authentic effector adenosine. These studies define CD73 as central to PMN-mediated intestinal Cl- secretion, the major directacting mechanism by which PMN induce intestinal epithelial Cl- secretion.

Physicians are often asked to provide assistance when symptoms develop in a passenger during a commercial flight. This Review Article identifies the most common problems that develop during air travel. The authors recommend ways to respond to such events and describe the resources that are available to physicians and flight crews while the aircraft is still airborne.

The present study examined the dimensionality and construct validity of the Perceptions of Organizational Politics Scale (POPS) which is comprised of three subscales: (1) General Political Behavior, (2) Going Along to Get Ahead, and (3) Pay and Promotion. Results of analyses conducted on data collected from 1,297 civilian government employees were inconsistent with a multidimensional factor structure of the POPS. Principal components and confirmatory factor analyses failed to confirm the Kacmar and Ferris 3-factor solution. Rather, the results indicated that the POPS was unidimensional. POPS scores were strongly and inversely related to scores on the Survey of Perceived Organizational Support (SPOS). POPS and SPOS scores were not differentially correlated with other job attitude measures.

Boredom and monotony are generally conceded to be negative factors that can have adverse effects on morale, performance, and quality of work. This article examines the evidence for yet another claimed effect of boredom and monotony, viz., that these factors are stressors, and that because they are stressors, they may produce effects even more detrimental than those mentioned above. Both laboratory and field studies are examined for evidence of increased neuroendocrine activity during exposure to conditions determined to be, or generally acknowledged to be, boring or monotonous. It is concluded that the available data offer no support for the belief that boredom or monotony per se produces the syndrome of stress. However, monotony coupled with a need to maintain high levels of alertness could represent a combination capable of eliciting considerable stress.

Approximately 6% of dog platelets are positive for staining with thiazole orange, a dye frequently used to stain ribonucleic acid. In this report, thiazole-orange positivity is shown to mark platelets that are less than 24 hours old. Dog platelets were derivatized in vivo with N-hydroxysuccinimido biotin such that greater than 95% of all platelets were biotinylated. Newly synthesized, nonbiotinylated platelets were then monitored by flow cytometry for their ability to bind thiazole orange. After biotinylation, the percentage of biotin-negative, thiazole-orange-positive platelets increased gradually from 0.72% at 30 minutes to 5.44% at 24 hours. These data indicate that thiazole-orange staining does label newly synthesized platelets.

A growing number of studies have examined alterations in white matter organization in people with posttraumatic stress disorder (PTSD) using diffusion MRI (dMRI), but the results have been mixed which may be partially due to relatively small sample sizes among studies. Altered structural connectivity may be both a neurobiological vulnerability for, and a result of, PTSD. In an effort to find reliable effects, we present a multi-cohort analysis of dMRI metrics across 3047 individuals from 28 cohorts currently participating in the PGC-ENIGMA PTSD working group (a joint partnership between the Psychiatric Genomics Consortium and the Enhancing NeuroImaging Genetics through Meta-Analysis consortium). Comparing regional white matter metrics across the full brain in 1426 individuals with PTSD and 1621 controls (2174 males/873 females) between ages 18-83, 92% of whom were trauma-exposed, we report associations between PTSD and disrupted white matter organization measured by lower fractional anisotropy (FA) in the tapetum region of the corpus callosum (Cohen's d = -0.11, p = 0.0055). The tapetum connects the left and right hippocampus, for which structure and function have been consistently implicated in PTSD. Results were consistent even after accounting for the effects of multiple potentially confounding variables: childhood trauma exposure, comorbid depression, history of traumatic brain injury, current alcohol abuse or dependence, and current use of psychotropic medications. Our results show that PTSD may be associated with alterations in the broader hippocampal network.

The feasibility of a gradational step test for the assessment of work capacity was investigated. A device was constructed on which the level of a stepping platform could be raised between 2.0 and 50 cm as subjects continued work at a prescribed stepping rate. Two test procedures applicable to individuals who vary in their state of health from that of a chronically ill patient to a trained athlete are described. Sixty men performed experiments to establish the minute-by-minute metabolic costs of the work in the two tests. The oxygen expenditures ranged from 12.9 ± 1.2 to 40.8 ± 3.5 ml/min per kg in the 30/min step test and from 10.7 ± 1.1 to 28.8 ± 1.3 ml/min per kg in the 24/min step test. The procedures are well suited for measuring various physiological parameters during stepping and for establishing physiological working limits. The oxygen costs of the “negative” and “positive” work components in stepping were determined. The cost of negative work was approximately one-third of the positive work. An equation was derived for predicting the metabolic costs of stepping at various rates and platform levels. Comparisons of predicted and measured oxygen intake values for the 30-step and 24-step tests approximated one another at all levels of energy expenditure. energy expenditure stepping; cardiorespiratory responses to exercise; work in stepping; negative work; positive work; physical fitness tests Submitted on August 7, 1964

P-selectin, an adhesion receptor for leukocytes, is constitutively expressed by megakaryocytes and endothelial cells. Synthesis of P-selectin is also increased by some inflammatory mediators. We characterized a previously identified kappa B site (-218GGGGGTGACCCC-207) in the promoter of the human P-selectin gene. The kappa B site was unique in that it bound constitutive nuclear protein complexes containing p50 or p52, but not inducible nuclear protein complexes containing p65. Furthermore, the element bound recombinant p50 or p52 homodimers, but not p65 homodimers. Methylation interference analysis indicated that p50 or p52 homodimers contacted the guanines at positions -218 to -214 on the coding strand and at -210 to -207 on the noncoding strand. Changes in the three central residues at -213 to -211 altered binding specificity for members of the NF-kappa B/Rel family. Mutations that eliminated binding to NF-kappa B/Rel proteins reduced by approximately 40% the expression of a reporter gene driven by the P-selectin promoter in transfected bovine aortic endothelial cells. Overexpression of p52 enhanced P-selectin promoter activity, and co-overexpression of Bcl-3 further induced promoter activity in a kappa B site-dependent manner. In contrast, overexpression of p50 repressed promoter activity; this repression was prevented by co-overexpression of Bcl-3. Similar phenomena were observed with reporter gene constructs driven by two tandem P-selectin kappa B sequences linked to the SV40 minimal promoter. These data suggest that Bcl-3 differentially regulates the effects of p50 and p52 homodimers bound to the kappa B site of the P-selectin promoter. This site may be a prototype for kappa B elements in other genes that bind specifically to p50 and/or p52 homodimers.

BACKGROUND: We studied the complications of peripheral intravenous (i.v.) catheters in the hand and forearm in a teaching hospital over a 3-year period. METHODS: The records of 67 patients who developed i.v. catheter-related complications were reviewed. RESULTS: The most common sites for developing complications in order of frequency were the forearm, hand, wrist, and antecubital fossa. There were 56 minor and 11 major complications. More than 50% of minor complications occurred in the hand and wrist, and more than 50% of major complications occurred in the hand. In 68% of minor complications, the patients were aged 50 years or older and 68% were women. Minor complications comprised 26 intravenous infiltrations, 23 cases of thrombophlebitis, and 7 cases of cellulitis. Ninety percent of major complication patients were aged 50 or older and 82% were women. Major complications included septic thrombophlebitis in three; hematomas resulting in skin necrosis in two; and infiltration related complications in six, resulting in skin necrosis in two, compressive nerve lesions in two, digital stiffness in one, and compartment syndrome in one. Ten patients with major complications were over the age of 50 years and nine were women. Two patients receiving anticoagulation developed large dorsal subcutaneous space hematomas. Chemotherapeutic agents contributed to two minor complications and one major complication. CONCLUSION: The hand is a common site for minor and major i.v. catheter complications. Women and older patients are more susceptible to these complications. Peripheral i.v. line complications are not uncommon and can result in morbidity and increased health care costs from prolonged hospitalization, extended use of i.v. antibiotic therapy, and surgical intervention.

Thrombomodulin is an endothelial cell surface protein which complexes with thrombin to accelerate protein C activation. To gain insight into the mechanisms of thrombomodulin-membrane association, limited proteolytic digestions of thrombomodulin with trypsin and elastase were performed. Trypsin digestion resulted in two major fragments (Mr = 54,000 and 27,000), both of which bound to phosphatidylcholine/phosphatidylserine vesicles. Elastase digestion also yielded two major fragments (Mr = 50,000 and 25,000), but only the smaller fragment bound to the phospholipid vesicles. The larger fragment obtained from both enzymatic digestions retained the ability to accelerate protein C activation. The Mr = 54,000 fragment from the trypsin digest retained a high affinity for thrombin (Kd less than or equal to 0.5 nM), a Km for protein C of approximately equal to 8 microM, and a half-maximal Ca2+ dependence of 0.3 mM. The Mr = 50,000 fragment from elastase digestion had a lower affinity for thrombin (Kd approximately equal to 6 nM) than intact thrombomodulin, and the Km for protein C was decreased to 0.3 microM in the presence of 0.3 mM Ca2+. The Ca2+ dependence of protein C activation with the Mr = 50,000 fragment was distinctly different from that of thrombomodulin or the active tryptic fragment. The active elastase fragment exhibited a Ca2+ optimum at 0.3 mM and activity rapidly decreased with further increases in Ca2+. At the Ca2+ optimum, the Km for protein C was similar to that observed on endothelial cell surfaces or with thrombomodulin reconstituted into liposomes. Our data demonstrate that thrombomodulin has one or more membrane-binding domains and that an active soluble form with catalytic activity can be generated by limited proteolytic digestion. Digestion with elastase appears to expose a site on thrombomodulin capable of recognizing the gamma-carboxyglutamic acid domain of protein C (residues 1-44 of the light chain). Whether this is the same site which is exposed on thrombomodulin upon incorporation into phospholipid vesicles (see accompanying manuscript) remains to be determined.

The goal of the Enhancing Neuroimaging Genetics through Meta-Analysis (ENIGMA) Stroke Recovery working group is to understand brain and behavior relationships using well-powered meta- and mega-analytic approaches. ENIGMA Stroke Recovery has data from over 2,100 stroke patients collected across 39 research studies and 10 countries around the world, comprising the largest multisite retrospective stroke data collaboration to date. This article outlines the efforts taken by the ENIGMA Stroke Recovery working group to develop neuroinformatics protocols and methods to manage multisite stroke brain magnetic resonance imaging, behavioral and demographics data. Specifically, the processes for scalable data intake and preprocessing, multisite data harmonization, and large-scale stroke lesion analysis are described, and challenges unique to this type of big data collaboration in stroke research are discussed. Finally, future directions and limitations, as well as recommendations for improved data harmonization through prospective data collection and data management, are provided.

Clinicians who care for patients infected with coronavirus disease 2019 (COVID-19) must wear a full suite of personal protective equipment, including an N95 mask or powered air purifying respirator, eye protection, a fluid-impermeable gown, and gloves. This combination of personal protective equipment may cause increased work of breathing, reduced field of vision, muffled speech, difficulty hearing, and heat stress. These effects are not caused by individual weakness; they are normal and expected reactions that any person will have when exposed to an unusual environment. The physiologic and psychologic challenges imposed by personal protective equipment may have multiple causes, but immediate countermeasures and long-term mitigation strategies can help to improve a clinician's ability to provide care. Ultimately, a systematic approach to the design and integration of personal protective equipment is needed to improve the safety of patients and clinicians.

OBJECTIVES: No satisfactory treatment is available for obesity. Previous animal studies suggested the therapeutic potential of intestinal electrical stimulation for obesity. The aim of this study was to investigate the effects of duodenal electrical stimulation (DES) on gastric emptying and water intake in healthy humans. METHODS: The study was performed in 12 healthy volunteers intubated with a feeding tube in the duodenum under endoscopy. There were three ring electrodes at the end tip of the tube and the two distal electrodes were used for recording and electrical stimulation. On two separate days, each subject underwent a session of DES with various stimulation parameters, a water-intake test with DES or with sham-DES, and a gastric-emptying test with DES or with sham-DES. RESULTS: DES did not induce any noticeable dyspeptic symptoms. The amount of water drunk by the subjects was significantly reduced from 897 +/- 88 ml with sham-DES to 673 +/- 63 ml with DES (p < 0.002). The mean T(50) of gastric emptying was significantly increased from 113.1 +/- 10.0 min with sham-DES to 176.5 +/- 20.8 min with DES state (p < 0.005). The gastric retention at 2 h was increased with DES (42.8 +/- 4.5% vs 61.4 +/- 4.7%; p < 0.02). CONCLUSIONS: DES delays gastric emptying and reduces water intake. It may have a potential application for the treatment of obesity.

The present study examined the hypothesis that procedural justice and distributive justice are positively related. In other words, when individuals perceive fairness in how decisions are made, they are likely to perceive the outcomes as fair. Similarly, when individuals perceive a fair outcome, they are likely to believe that fair procedures led to that outcome. In line with the Tyler group-value model of procedural justice, it was hypothesized that this would hold true primarily when the individual has a long-term view of organization membership, a view influenced by the individual's disposition to delay gratification or reward. Hierarchical-moderated multiple regression analyses on data collected from workers in a small American tooling plant supported this hypothesis. These results have implications for attempts to enhance perceptions of justice.