Designing criterion measures for physically demanding jobs.

The Bureau of Labor Statistics reported that 39.1% of the civilian workforce in the United States performs physically demanding jobs that require lifting, carrying, pushing/pulling, kneeling, stooping, crawling, and climbing activities in varied environmental conditions. United States military occupations are similar to those in the civilian sector involving equipment installation, emergency rescues, and maintenance, along with combat arms occupations. This article provides an overview of the types of criterion measures used to assess the physical domain and approaches for designing and evaluating the criteria. It also includes a method for generating criterion measures that are applicable across multiple jobs.

Evaluation of the Strength Aptitude Test and Other Fitness Tests to Qualify Air Force Recruits for Physically Demanding Specialties.

The Air Force uses the Strength Aptitude Test (SAT) to determine whether recruits meet the fitness levels needed to perform the duties of various Air Force specialties with physical strength requirements. However, the SAT was developed in the early 1980s and has not been revalidated since then. In the interim, the duties associated with many Air Force Specialty Code classifications may have changed, and new ones have been added. These changes require a reevaluation of the SAT's utility and effectiveness for qualifying recruits into these specialties. This study evaluates the status and validity of the SAT in a series of studies and summarizes the studies RAND has completed independently and one study conducted in conjunction with HumRRO, which provided the additional data necessary to develop some courses of action for the Air Force to follow to ensure airmen can meet job-related physical requirements.

U.S. Army Physical Demands Study: Development of the Occupational Physical Assessment Test for Combat Arms soldiers.

OBJECTIVES: The United States Army sought to create a legally defensible, scientifically validated physical pre-employment screening test. The purpose of this study was to identify a single combination of predictor tests that would predict physical performance on all of the criterion measure task simulations relevant to the Combat Arms military occupational specialties. DESIGN: Concurrent validation. METHODS: Data from 838 (608 males, 230 females) soldiers who completed both the criterion measure task simulations of a military occupational specialty and up to 14 predictor tests were used in the development of the test batteries. Stepwise regressions were used to identify test batteries that significantly predicted performance on the criterion measure task simulations of the military occupational specialties. RESULTS: Three test batteries were developed based on different subsets of the predictor tests: Test Battery 1 consisted of the medicine ball put, squat lift, beep test, standing long jump, and arm ergometer (adjusted R2=0.80-0.85, p<0.01); Test Battery 2 consisted of the medicine ball put, squat lift, beep test, and standing long jump (adjusted R2=0.79-0.80, p<0.01); and Test Battery 3 consisted of the standing long jump, 1-minute push-ups, 1-minute sit-ups, 300m sprint, and Illinois agility test (adjusted R2=0.55-0.71, p<0.01). CONCLUSIONS: Test Battery 2 was selected as the Army's Occupational Physical Assessment Test. It was highly predictive of performance of the Combat Arms military occupational specialties, required no complex equipment, and covered a range of physical fitness domains.

Age as a Risk Factor in Abdominoplasty.

Background: Recent studies reviewing large patient databases suggested that age may be an independent risk factor for abdominoplasty. However, these investigations by design considered only short-term major complications. Objectives: The purpose of this investigation was: (1) to compare the safety of abdominoplasty in an elderly and younger patient population; (2) to determine the complication rates across all spectrums: major, minor, local, and systemic; and (3) to evaluate complications occurring both short and long term. Methods: Abdominoplasty procedures performed from 2010 to 2015 were retrospectively reviewed. Subjects were divided into two groups: ≤59 years old and ≥60 years old. Major, minor, local, and systemic complications were analyzed. Patient demographics, comorbidities, perioperative details, adjunctive procedures were also assessed. Results: A total of 129 patients were included in the study: 43 in the older and 86 in the younger age group. The median age of The elderly and young groups was 65.0 and 41.5 years, respectively (P < .001). No statistically significant differences in major, minor, local, or systemic complications were found when both age groups were compared. Major local, major systemic, minor local, and minor systemic in the elderly were 6.9%, 2.3%, 18.6%, and 2.3%, while in the younger patients were 9.3%, 4.7%, 10.5%, and 0.0%, respectively (P > .05). Median follow-up time of the elderly (4.0 months) was no different than the younger (5.0 months) patients (P > .07). Median procedure time in the elderly (4.5 hours) was no different than the younger group (5.0 hours) (P = .4). The elderly exhibited a greater American Society of Anesthesiologist score, median body mass index (28.7 vs 25.1 kg/m2), and number of comorbidities (2.7 vs 0.9) (P < .001). Conclusions: There was no significant difference in either major or minor complications between the two groups. This suggests that with proper patient selection, abdominoplasty can be safely performed in the older age patient population. Level of Evidence: 2.

Ubiquitin Urine Levels in Burn Patients.

The objective of this study was to determine whether urine ubiquitin levels are elevated after burns and to assess whether urine ubiquitin could be useful as a noninvasive biomarker for burn patients. Forty burn patients (%TBSA: 20 ± 22; modified Baux scores: 73 ± 26) were included (control: 11 volunteers). Urine was collected in 2-hour intervals for 72 hours, followed by 12-hour intervals until discharge from the intensive care unit. Ubiquitin concentrations were analyzed by enzyme linked immunosorbent assay and Western blot. Total protein was determined with a Bradford assay. Patient characteristics and clinical parameters were documented. Urine ubiquitin concentrations, renal ubiquitin excretion, and excretion rates were correlated with patient characteristics and outcomes. Initial urine ubiquitin concentrations were 362 ± 575 ng/ml in patients and 14 ± 18 ng/ml in volunteers (P < .01). Renal ubiquitin excretion on day 1 was 292.6 ± 510.8 µg/24 hr and 21 ± 27 µg/24 hr in volunteers (P < .01). Initial ubiquitin concentrations correlated with modified Baux scores (r = .46; P = .02). Ubiquitin levels peaked at day 6 postburn, whereas total protein concentrations and serum creatinine levels remained within the normal range. Total renal ubiquitin excretion and excretion rates were higher in patients with %TBSA ≥20 than with %TBSA <20, in patients who developed sepsis/multiple organ failure than in patients without these complications and in nonsurvivors vs survivors. These data suggest that ubiquitin urine levels are significantly increased after burns. Renal ubiquitin excretion and/or excretion rates are associated with %TBSA, sepsis/multiple organ failure, and mortality. Although these findings may explain previous correlations between systemic ubiquitin levels and outcomes after burns, the large variability of ubiquitin urine levels suggests that urine ubiquitin will not be useful as a noninvasive disease biomarker.

Laparoscopic cholecystectomy for biliary dyskinesia: Which patients have long term benefit?

PURPOSE: Biliary dyskinesia (BD) is described as biliary colic in the absence of gallstones. The diagnosis relies on imaging studies and decreased excretion of bile in response to cholecystokinin during quantitative cholescintigraphy. The purpose of this study was to evaluate the success of laparoscopic cholecystectomy (LC) for relieving symptoms in patients diagnosed with BD and correlate gallbladder ejection fraction (EF) with symptom relief. METHODS: A retrospective review was performed at a single institution of all patients who underwent LC for BD from January 2005 through January 2012. The diagnosis of BD was determined by a normal gallbladder as viewed with ultrasonography and cholescintigraphy with a gallbladder EF less than or equal to 45%. Data collection included demographics, results of imaging studies, pathologic diagnosis, and early postoperative pain relief. Patients were contacted by phone after being discharged from the surgeon's care for evaluation of symptom relief. Data were analyzed with nonparametric statistical methods, including Mann-Whitney U test, receiver operator characteristic, Fisher exact test, and χ(2) test. All data are expressed as median and 25th and 75th percentile range. RESULTS: There were 126 patients who had a LC for BD during the study period. The median biliary EF was 20% (10-29%). The most common pathologic finding was chronic cholecystitis (n = 95; 75%). Median length of follow-up in the perioperative period was 11 days (8-17), during which time 98 patients (78%) had relief of symptoms. Phone interviews (n = 53; 42%) confirmed 66% (n = 35) of patients remained free of pain. There was no difference in the mean EF among those with resolution of pain 20% (10-29%) compared with patients with persistent pain 23% (11-29%), P = .62. Obese patients were more likely to have persistent symptoms in the perioperative period with a shift to lower body mass index at the time of the phone survey. Receiver operator characteristic characteristic for the association between scintigraphic EF and resolution of postoperative pain demonstrated no association, with the area under the curve equal to 0.47. CONCLUSION: The majority of patients in this series with BD had resolution of symptoms with LC. However, cholescintigraphy EF did not correlate with outcome. Further studies are needed to better identify patients diagnosed with BD who will benefit from LC.

Effects of exogenous ubiquitin in a polytrauma model with blunt chest trauma.

OBJECTIVE: To determine whether treatment with the CXC chemokine receptor 4 agonist ubiquitin results in beneficial effects in a polytrauma model consisting of bilateral femur fractures plus blunt chest trauma (Injury Severity Score 18-25). DESIGN: Treatment study. SETTING: Research laboratory. SUBJECTS: Seventeen Yorkshire pigs. INTERVENTIONS: Intravenous injection of 1.5 mg/kg ubiquitin or albumin (control) at 60 mins after polytrauma. MEASUREMENTS AND MAIN RESULTS: Anesthetized, mechanically ventilated pigs underwent polytrauma, followed by a simulated 60-min shock phase. At the end of the shock phase, ubiquitin or albumin were administered and animals were resuscitated to a mean arterial blood pressure of 70 mm Hg until t=420 mins. After intravenous ubiquitin, ubiquitin plasma concentrations increased 16-fold to 2870±1015 ng/mL at t=90 mins and decreased with t1/2=60 mins. Endogenous plasma ubiquitin increased two-fold in the albumin group with peak levels of 359±210 ng/mL. Plasma levels of the cognate CXC chemokine receptor 4 ligand stromal cell-derived factor-1α were unchanged in both groups. Ubiquitin treatment reduced arterial lactate levels and prevented a continuous decrease in arterial oxygenation, which occurred in the albumin group during resuscitation. Wet weight to dry weight ratios of the lung contralateral from the injury, heart, spleen and jejunum were lower with ubiquitin. With ubiquitin treatment, tissue levels of Interleukin-8, Interleukin-10, Tumor Necrosis Factor α, and stromal cell-derived factor-1α were reduced in the injured lung and of Interleukin-8 in the contralateral lung, respectively. CONCLUSIONS: Administration of exogenous ubiquitin modulates the local inflammatory response, improves resuscitation, reduces fluid shifts into tissues, and preserves arterial oxygenation after blunt polytrauma with lung injury. This study further supports the notion that ubiquitin is a promising protein therapeutic and implies CXC chemokine receptor 4 as a drug target after polytrauma.

Initial assessment of the role of CXC chemokine receptor 4 after polytrauma.

CXC chemokine receptor (CXCR)-4 agonists have been shown to attenuate inflammation and organ injury in various disease models, including trauma/hemorrhage. The pathophysiological role of CXCR4 during the early response to tissue injury, however, remains unknown. Therefore, we investigated the effects of AMD3100, a drug that antagonizes binding of stromal cell-derived factor (SDF)-1α and ubiquitin to CXCR4 during the initial response to polytrauma in pigs. Fifteen minutes before polytrauma (femur fractures/lung contusion; control: sham), 350 nmol/kg AMD3100, equimolar AMD3100 and ubiquitin (350 nmol/kg each) or vehicle were administered intravenously. After a 60-min shock period, fluid resuscitation was performed for 360 min. Ubiquitin binding to peripheral blood mononuclear cells was significantly reduced after intravenous AMD3100. SDF-1α plasma levels increased transiently >10-fold with AMD3100 in all animals. In injured animals, AMD3100 increased fluid requirements to maintain hemodynamics and enhanced increases in peripheral blood granulocytes, lymphocytes and monocytes, compared with its effects in uninjured animals. Cytokine release from leukocytes in response to Toll-like receptor (TLR)-2 and TLR-4 activation was increased after in vitro AMD3100 treatment of normal whole blood and after in vivo AMD3100 administration in animals subjected to polytrauma. Coadministration of AMD3100/ubiquitin reduced lactate levels, prevented AMD3100-induced increases in fluid requirements and sensitization of the tumor necrosis factor (TNF)-α and interleukin (IL)-6 release upon TLR-2/4 activation, but did not attenuate increases in leukocyte counts and SDF-1α plasma levels. Our findings suggest that CXCR4 controls leukocyte mobilization after trauma, regulates leukocyte reactivity toward inflammatory stimuli and mediates protective effects during the early phase of trauma-induced inflammation.

Biplanar flap reconstruction for pressure ulcers: experience in patients with immobility from chronic spinal cord injuries.

BACKGROUND: Surgical therapy for advanced-stage pressure ulcers recalcitrant to healing is a widely accepted practice. The present study examined the incidence of wound recurrence after reconstruction with fasciocutaneous versus combined (biplanar) muscle and fasciocutaneous flaps. METHODS: A retrospective review identified 90 nonambulatory patients with spinal cord injury who underwent reconstruction for persistent decubitus ulcers from 2002 to 2008. Electronic medical records were surveyed for patient comorbidities and postoperative complications. Statistical methods included the Fisher exact test and the Mann-Whitney U test with a 2-sided P value of less than .05. RESULTS: Among 90 patients reviewed, 33% (n = 30) received fasciocutaneous flaps and 66% (n = 60) underwent biplanar reconstruction. Comorbidities were the same between cohorts with the exception of a greater prevalence of diabetes in the biplanar group (27% vs 50%; P < .05). The incidence of recurrence for biplanar flaps (25%) was significantly lower than for fasciocutaneous reconstruction (53%; P < .01). CONCLUSIONS: Biplanar flap reconstruction should be considered for chronically immobilized patients at high risk for recurrent decubitus ulceration.

Ubiquitin and stromal cell-derived factor-1α in bronchoalveolar lavage fluid after burn and inhalation injury.

The objective of the study was to determine whether the CXC chemokine receptor (CXCR) 4 ligands ubiquitin and stromal cell-derived factor (SDF)-1α are detectable in bronchoalveolar lavage fluid (BALF) after burn and inhalation injury and whether their concentrations in BALF are associated with injury severity, physiological variables, or clinical outcomes. BALF was obtained on hospital admission from 51 patients (48 ± 18 years) with burn (TBSA: 23 ± 24%) and inhalation injury (controls: 10 healthy volunteers, 42 ± 8 years). BALF was analyzed for total protein and for ubiquitin and SDF-1α by enzyme-linked immunosorbent assay. Ubiquitin/SDF-1α levels were normalized to total BALF protein content. The extent of inhalation injury was determined during bronchoscopy using a standardized scoring system. Percent TBSA, Baux scores, revised Baux scores, and clinical variables were documented. Ubiquitin and SDF-1α were detectable in 40% of normal BALF specimens. After injury, ubiquitin was detectable in 90% (P < .01 vs control) and SDF-1α in 10% of the specimens (P < .05 vs control). While SDF-1α levels were reduced in patients (P < .01), ubiquitin levels were increased (P < .01). Ubiquitin concentrations correlated inversely with grade of inhalation injury, revised Baux scores, and resuscitation fluid requirements (Spearman correlation coefficients [r]: -.3, -.33, and -.45, respectively). Ubiquitin levels correlated positively with arterial oxygenation at the time of bronchoscopy (r: .35). BALF levels of CXCR4 agonists are differentially regulated after burn and inhalation injury. Increases in BALF ubiquitin after inhalation injury may maintain CXCR4-mediated lung protection and repair processes. The finding that BALF ubiquitin decreased with higher grades of inhalation injury may provide a biological correlate for an insufficient local inflammatory response after severe inhalation injury.

Systemic release of cytokines and heat shock proteins in porcine models of polytrauma and hemorrhage*.

OBJECTIVE: To define systemic release kinetics of a panel of cytokines and heat shock proteins in porcine polytrauma/hemorrhage models and to evaluate whether they could be useful as early trauma biomarkers. DESIGN: Prospective observational study. SETTING: Research laboratory. SUBJECTS: Twenty-one Yorkshire pigs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Pigs underwent polytrauma (femur fractures/lung contusion, P), hemorrhage (mean arterial pressure 25-30 mm Hg, H), polytrauma plus hemorrhage (P/H), or sham procedure (S). Plasma was obtained at baseline, in 5- to 15-min intervals during a 60-min shock period without intervention, and in 60- to 120-min intervals during fluid resuscitation for up to 300 min. Plasma was assayed for interleukin-1ß, interleukin-4, interleukin-5, interleukin-6, interleukin-8, interleukin-10, interleukin-12/interleukin-23p40, interleukin-13, interleukin-17, interleukin-18, interferonγ, transforming growth factor-ß, tumor necrosis factor-α, heat shock protein 40, heat shock protein 70, and heat shock protein 90 by enzyme-linked immunosorbent assay. All animals after S, P, and H survived (n = 5/group). Three of six animals after P/H died. Interleukin-10 increased during shock after P and this increase was attenuated after H. Tumor necrosis factor-α increased during the shock period after P, H, and also after S. P/H abolished the systemic interleukin-10 and tumor necrosis factor-α release and resulted in 20% to 30% increased levels of interleukin-6 during shock. As fluid resuscitation was initiated, tumor necrosis factor-α and interleukin-10 levels decreased after P, H, and P/H; heat shock protein 70 increased after P; and interleukin-6 levels remained elevated after P/H and also increased after P and S. CONCLUSIONS: Differential regulation of the systemic cytokine release after polytrauma and/or hemorrhage, in combination with the effects of resuscitation, can explain the variability and inconsistent association of systemic cytokine/heat shock protein levels with clinical variables in trauma patients. Insults of major severity (P/H) partially suppress the systemic inflammatory response. The plasma concentrations of the measured cytokines/heat shock proteins do not reflect injury severity or physiological changes in porcine trauma models and are unlikely to be able to serve as useful trauma biomarkers in patients.

Prolongation of myocardial viability by proteasome inhibition during hypothermic organ preservation.

Recently, we provided evidence for a possible role of the cardiac proteasome during ischemia, suggesting that a subset of 26S proteasomes is a cell-destructive protease, which is activated as the cellular energy supply declines. Although proteasome inhibition during cold ischemia (CI) reduced injury of ischemic hearts, it remains unknown whether these beneficial effects are maintained throughout reperfusion, and thus, may have pathophysiological relevance. Therefore, we evaluated the effects of epoxomicin (specific proteasome inhibitor) in a rat heterotopic heart transplantation model. Donor hearts were arrested with University of Wisconsin solution (UW) and stored for 12 h/24 h in 4 °C UW±epoxomicin, followed by transplantation. Efficacy of epoxomicin was confirmed by proteasome peptidase activity measurements and analyses of myocardial ubiquitin pools. After 12hCI, troponin I content of UW was lower with epoxomicin. Although all hearts after 12hCI started beating spontaneously, addition of epoxomicin to UW during CI reduced cardiac edema and preserved the ultrastructural integrity of the post-ischemic cardiomyocyte. After 24hCI in UW±epoxomicin, hearts did not regain contractility. When hearts were perfused with epoxomicin during cardioplegia, the cardiac proteasome was inhibited immediately, all of these hearts started beating after 24hCI in UW plus epoxomicin and cardiac edema and myocardial ultrastructure were comparable to hearts after 12hCI. Epoxomicin did not affect markers of lipid peroxidation or neutrophil infiltration in post-ischemic hearts. These data further support the concept that proteasome activation during ischemia is of pathophysiological relevance and suggest proteasome inhibition as a promising approach to improve organ preservation strategies.

A subset of 26S proteasomes is activated at critically low ATP concentrations and contributes to myocardial injury during cold ischemia.

Molecular mechanisms leading to myocardial injury during warm or cold ischemia are insufficiently understood. Although proteasomes are thought to contribute to myocardial ischemia-reperfusion injury, their roles during the ischemic period remain elusive. Because donor hearts are commonly exposed to prolonged global cold ischemia prior to cardiac transplantation, we evaluated the role and regulation of the proteasome during cold ischemic storage of rat hearts in context of the myocardial ATP content. When measured at the actual tissue ATP concentration, cardiac proteasome peptidase activity increased by 225% as ATP declined during cold ischemic storage of hearts in University of Wisconsin (UW) solution for up to 48h. Addition of the specific proteasome inhibitor epoxomicin to the UW solution inhibited proteasome activity in the cardiac extracts, significantly reduced edema formation and preserved the ultrastructural integrity of the cardiomyocyte. Utilizing purified 20S/26S proteasome enzyme preparations, we demonstrate that this activation can be attributed to a subset of 26S proteasomes which are stable at ATP concentrations far below physiological levels, that ATP negatively regulates its activity and that maximal activation occurs at ATP concentrations in the low mumol/L range. These data suggest that proteasome activation is a pathophysiologically relevant mechanism of cold ischemic myocardial injury. A subset of 26S proteasomes appears to be a cell-destructive protease that is activated as ATP levels decline. Proteasome inhibition during cold ischemia preserves the ultrastructural integrity of the cardiomyocyte.

Role of interventional radiology in the management of complications after pancreaticoduodenectomy.

BACKGROUND: This study evaluated the role of interventional radiology (IR) procedures to manage complications after pancreaticoduodenectomy. METHODS: A retrospective review was made of the records of patients with postsurgical complications managed with IR. RESULTS: Among the 440 patients reviewed, the mortality, morbidity and reoperation rates were 1.6%, 36%, and 2%, respectively. Complications occurred in 159 patients, of which 39 (25%) required > or = 1 IR procedures. Of those 39 patients, 72% underwent percutaneous drainage of an intra-abdominal abscess, 18% underwent percutaneous biliary drainage, and 10% underwent angiography for gastrointestinal bleeding or pseudoaneurysm. The reoperation rate among the 159 patients with complications was 6% (n = 9). Reoperation was avoided in 90% of patients receiving IR. Four patients underwent reoperation despite IR for persistent abscess, pancreatic fistula, anastomotic disruption, or mesenteric venous bleeding. CONCLUSIONS: The majority of complications occurring after pancreaticoduodenectomy can be managed effectively using IR, thus minimizing morbidity and the need for reoperation.