Comparison of injuries between US Army paratroopers and their non-paratrooper soldier counterparts.

INTRODUCTION: Military studies have investigated acute injuries associated with parachute jumps, but the literature does not address paratroopers' cumulative microtraumatic (CMT) injury risk, nor does it compare injury risks between paratroopers and the rest of the military population. This study determined whether US active duty Army paratroopers experienced greater injury risks than their non-paratrooper soldier counterparts and whether their injuries cost more to treat suggesting greater injury severity. METHODS: This retrospective study evaluated electronic medical records (2016-2018) for 31 621 paratroopers and a randomly selected comparison group of 170 715 non-paratrooper soldiers. Analyses included univariate and multivariate regression to quantify odds of injuries associated with risk variables and additional descriptive statistics. RESULTS: Paratroopers had a 57% increase in the odds of experiencing one or more injuries (OR=1.57, 95% CI: 1.52 to 1.62) after controlling for sex, race and age, with a greater proportion of acute injuries (OR=1.38, 95% CI: 1.34 to 1.42), relative to comparison group soldiers. Injury types proportionally higher among paratroopers included head trauma and shoulder injuries. Average injury cost among paratroopers was 13% lower than for non-paratroopers ($2470 vs $2830 per injury). Among both populations, acute injury costs were notably higher than for CMT injuries (paratroopers, $1710/$630; non-paratroopers, $1860/$880 per injury). CONCLUSIONS: Paratroopers were more likely to incur injury, especially an acute injury, than non-paratroopers. However, paratroopers' average injury costs were less. This may be due to higher return-to-duty motivations, fitness levels, and/or facility-specific cost of care. Future studies should investigate causes of injuries found to be proportionally higher among paratroopers.

Activities and risk factors associated with fall-related injuries among US Army soldiers.

INTRODUCTION: Falls/near falls are the second leading cause of hospitalisation and outpatient visits among US Army soldiers. While numerous studies have evaluated fall-related or near fall-related injuries among elderly adults, few have evaluated this association among young adults. The objective of this study is to describe the characteristics and risk factors associated with fall-related or near fall-related injuries among male US Army soldiers. METHODS: This is a cross-sectional study of male US Army Airborne Division soldiers (n=5187). Electronic surveys captured demographic, lifestyle, physical training (PT), fitness and injury data during spring/summer of 2016. Multiple logistic regression was used to identify independent risk factors of fall-related or near fall-related injuries, adjusting for potential confounders. RESULTS: Primary findings indicated that activities and risk factors associated with fall-related or near fall-related injuries among soldiers included younger age (≤35 years), holding a job that required minimal lifting activities, slower 2-mile run times and not running during personal PT. CONCLUSIONS: The findings from this study suggest that male US Army soldiers and other physically active men may benefit from (1) obtaining and/or maintaining higher aerobic endurance and muscular strength, and (2) training focused on preventing fall-related injuries during PT, road marching and sports/recreational activities. Moreover, prevention strategies and education should further target younger soldiers (≤35 years old), as younger age is not modifiable.

Pectoralis major injuries in the military: a surveillance approach to reduce an underestimated problem.

INTRODUCTION: Multiple studies report increasing cases of surgically treated pectoralis major (PM) muscle and tendon ruptures in military populations. Studies associate this with a growing popularity of weight-training and bench press exercises. Mild-to-moderate non-surgical PM traumas and overuse injuries have not been included in these studies despite evidence that these types of outpatient injuries account for the majority of the military's injury medical burden. METHODS: To assess rates of all PM injuries (ruptures, tears, strains, overuse), regardless of form of treatment, a PM injury surveillance definition was derived from International Classification of Disease (ICD) diagnostic codes used in routine US Army injury surveillance. A detailed clinical examination of 2016 Active Duty Army medical records was used to identify ICD codes commonly associated with PM injuries. Cost data were calculated and the definition applied to medical data from 2016 through 2018to assess trends. RESULTS: The estimated incidence of PM cases among soldiers was over 95% greater than if only considering severe surgical cases. Over 96% of army annual PM injury costs (direct medical and indirect from lost labour) were for outpatient services. PM injury incidence rates were not statistically different from 2016 to 2018. CONCLUSIONS: The PM injury surveillance definition provides a consistent means to monitor trends over time and evaluate the effectiveness of prevention efforts. PM injuries have a larger military impact than previously recognised and prioritised prevention strategies are needed to reduce them. Future interventions could focus on the bench press given its observed association with PM injuries.

Expanding the injury definition: evidence for the need to include musculoskeletal conditions.

OBJECTIVES: The objectives of the study are to quantify the proportion of cumulative microtraumatic overuse injuries in a physically active population, evaluate their impact in terms of lost work time, and link them to precipitating activities to inform prevention initiatives. STUDY DESIGN: The study design is retrospective cohort study. METHODS: For a population of U.S. Army Soldiers, diagnoses from medical records (International Classification of Diseases [ICD]-9 800-999 and selected ICD-9 710-739) were matched with self-reported injury information. Common diagnoses, limited duty days, and activities and mechanisms associated with the injuries were summarized. RESULTS: Most self-reported injuries (65%) were classified by providers with diagnoses that described cumulative microtraumatic tissue damage, and these injuries led to a higher incidence of limited duty (85%) than acute traumatic injury diagnoses. Reported mechanisms and activities often indicated repetitive physical training-related onset. CONCLUSIONS: Because many diagnoses for cumulative microtraumatic musculoskeletal tissue damage are categorized as diseases to the musculoskeletal system in the International Classification of Diseases, they are often not included in definitions of injury. However, reported injury activities and mechanisms in this population provide evidence that cumulative microtraumatic injuries often arise from identifiable and preventable events. This finding confirms that these diagnoses should be classified as injuries in epidemiologic evaluations and surveillance to accurately represent injury burden.

Occupation and other risk factors for injury among enlisted U.S. Army Soldiers.

OBJECTIVE: To investigate injury risk associated with occupation and occupational physical demand levels among U.S. Army Soldiers. STUDY DESIGN: Retrospective cohort study. METHODS: Personal characteristics, physical fitness, military occupational specialty (MOS), and injury data were obtained by survey from Soldiers in an Army light infantry brigade (n = 2101). Odds ratios (OR) and 95% confidence intervals (95% CI) from a multivariate analysis assessing injury risk were calculated. RESULTS: Injury incidence for the prior 12 months was 43%. Physical fitness and behavioral factors associated with injury risk included age 21-29 (OR [age 21-29/age ≤ 20] = 1.37, 95% CI 1.00-1.90), BMI 27.5-29.9 (high-overweight) (OR high-overweight/normal = 1.62, 95% CI 1.20-2.18); BMI >29.9 (obese) (OR obese/normal = 1.73, 95% CI 1.23-2.44), cigarette smoking (OR Smoker/Nonsmoker = 1.34, 95% CI 1.11-1.63), and poor APFT two mile run performance (OR (Q4/Q1) = 1.61, 95% CI 1.19-2.19). Higher risk of injury was associated with some MOSs (OR (Chemical, Explosives & Ammunition/Infantry) = 2.82, 95% CI 1.19-6.68; OR (Armor/Infantry) = 1.53, 95% CI 1.13-2.07). CONCLUSION: This study identified a number of potentially modifiable risk factors for injuries including: maintenance of healthy weight, improved aerobic endurance, and reduction in smoking. Results also indicate certain Army occupations may be at higher risk of injury. Further investigation into reasons for their higher risk is warranted.

Stress fracture risk factors in basic combat training.

This study examined demographic and physical risk factors for stress fractures in a large cohort of basic trainees. New recruits participating in US Army BCT from 1997 through 2007 were identified, and birth year, race/ethnicity, physical characteristics, body mass index, and injuries were obtained from electronic databases. Injury cases were recruits medically diagnosed with inpatient or outpatient stress fractures. There were 475 745 men and 107 906 women. Stress fractures incidences were 19.3 and 79.9 cases/1 000 recruits for men and women, respectively. Factors that increased stress fracture risk for both men and women included older age, lower body weight, lower BMI, and race/ethnicity other than black. Compared to Asians, those of white race/ethnicity were at higher stress fractures risk. In addition, men, but not women, who were taller or heavier were at increased stress fracture risk. Stress fracture risk generally increased with age (17-35 year range) at a rate of 2.2 and 3.9 cases/1 000 recruits per year for men and women, respectively. This was the largest sample of military recruits ever examined for stress fractures and found that stress fracture risk was elevated among recruits who were female, older, had lower body weight, had lower BMI, and/or were not of black race/ethnicity.

Injuries before and after deployments to Afghanistan and Iraq.

OBJECTIVE: To examine outpatient injuries before and after deployments of elements of the 10th Mountain Division to Afghanistan (n = 505 men) and the 1st Cavalry Division to Iraq (n = 3242 men). STUDY DESIGN: Observational. METHODS: The military units provided a list of deployed soldiers, and soldiers' outpatient medical encounters were obtained from the Defense Medical Surveillance System. Cumulative injury incidence was examined for two consecutive 90-day periods before the deployments (Periods 1-2) and two consecutive 90-day periods after the deployments (Periods 3-4). RESULTS: Both groups showed post-deployment increases in the overall incidence of injury (Afghanistan group = 14.1%, 14.1%, 16.4, 23.4%; Iraq Group = 15.1%, 12.4%, 35.4%, 43.4%; Periods 1-4, respectively). Soldiers with pre-deployment injuries were 1.4-3.0 times more likely to experience post-deployment injuries. CONCLUSIONS: This study found a post-deployment increase in the incidence of outpatient injury. Also, soldiers with pre-deployment injuries were more likely to experience post-deployment injuries.

Risk factors associated with self-reported training-related injury before arrival at the US army ordnance school.

OBJECTIVE: This study examined risk factors for self-reported injury incurred before arrival at Ordnance School for advanced individual training (AIT). STUDY DESIGN: During AIT in-processing, soldiers (n=27,289 men and 3856 women) completed a questionnaire that collected demographic and lifestyle information, and asked if the soldier currently had an injury that would affect their AIT performance. METHODS: Potential risk factors for self-reported injury were explored using logistic regression. RESULTS: For men, self-reported injury was associated with older age [odds ratio (OR) >or=30 years/17-19 years=1.9], race (OR Black/Caucasian=1.2), basic combat training (BCT) site (OR Fort Benning/Fort Jackson=1.7; OR Fort Leonard Wood/Fort Jackson=1.6, OR Fort Knox/Fort Jackson=1.3), smoking on 20 or more days in the 30 days prior to BCT (OR smoker/non-smoker=1.2) and current illness (OR ill/not ill=6.2). For women, increased self-reported injury was associated with older age (OR>or=30 years/17-19 years=2.0), BCT site (OR Fort Leonard Wood/Fort Jackson=1.5) and current illness (OR ill/not ill=5.8). CONCLUSIONS: Certain demographic characteristics and lifestyle behaviours may be identified as injury risk factors on arrival at Ordnance AIT.

Intradermal reactivity to various insect and arachnid allergens among dogs from the southeastern United States.

OBJECTIVE: To compare cutaneous reactivity to insect and arachnid allergens in clinically normal (control) and allergic dogs in the southeastern United States. DESIGN: Prospective, controlled study. ANIMALS: 26 clinically normal dogs and 82 allergic dogs from the southeastern United States. PROCEDURE: Intradermal skin testing with various dilutions of 13 insect and arachnid allergens was performed on control dogs to establish skin threshold concentrations (ie, concentrations to which < 25% of the dogs had positive reactions). These established threshold concentrations were then used to test allergic dogs for reactivity. Prevalence of single and multiple insect and arachnid reactions were determined. RESULTS: Flea allergen was the only allergen that caused a significantly higher prevalence of positive reactions in allergic dogs than in control dogs. CLINICAL IMPLICATIONS: Flea hypersensitivity is the most important arthropod hypersensitivity in dogs. The importance of reactivity to insect and arachnid allergens other than flea allergen can be determined only when prevalence of positive reactivity has been determined in an appropriate regional control group of dogs.

Allergenic cross-reactivities in flea-reactive canine serum samples.

OBJECTIVES: To determine whether flea extract could be determined (via ELISA) to share allergenic epitopes with other insects, and to determine whether sera with different reactivities to insect extracts have different cross-reactivity patterns. SAMPLE POPULATION: 69 canine serum samples that were selected from samples submitted for routing ELISA allergy testing and had previously been found to have high reactivities to flea. PROCEDURE: Each serum sample was assessed by means of a direct ELISA for IgE binding to 11 common insects. Samples that were reactive primarily to flea extract alone were designated pool 1, samples that were reactive to small numbers of insects were designated pool 2, and samples that were reactive to all or almost all insects were designated pool 3. Samples that did not have any apparent patterns of cross-reactivity were not included in the rest of the study. Inhibition ELISA techniques were used with the 3 serum pools to determine whether multiple insect extracts inhibited reactivity on flea-coated ELISA plates. Those extracts were used to coat ELISA plates, and reciprocal inhibition studies were then performed. RESULTS: Black fly, black ant, and cockroach extracts were capable of > 50% inhibition of flea solid-phase IgE binding with all 3 serum pools. In the ELISA inhibition studies, flea extract was able to inhibit IgE binding to each extract with all pools, confirming reciprocal inhibition. CONCLUSIONS: Inhibition of IgE binding to solid-phase flea antigen by black ant, black fly, and cockroach extracts suggested sharing of allergenic epitopes among these species. Reciprocal inhibition studies further confirmed these findings. These results indicated in vitro cross-reactivity between flea, black ant, black fly, and cockroach extracts. These results need to be further investigated in vivo. CLINICAL RELEVANCE: It is possible that dogs may become sensitized to fleas via exposure to other insects, and flea allergenic dogs may have signs of pruritus, in the absence of fleas, if exposed to cross-reactive insects.

TestPack Chlamydia, a new rapid assay for the direct detection of Chlamydia trachomatis.

TestPack Chlamydia (Abbott Laboratories) is a rapid enzyme immunoassay for the direct antigen detection of Chlamydia trachomatis in endocervical specimens. The assay is self-contained, requires no specialized equipment, and yields results in less than 30 min. The clinical performance of TestPack Chlamydia versus chlamydial cell culture was evaluated with a total of 1,694 paired endocervical specimens. Discordant samples were further investigated by immunofluorescent staining and by Chlamydiazyme immunoassay, with confirmatory procedures. The sensitivity of TestPack Chlamydia with less-than-48-h-old specimens was 76.5%, while culture sensitivity was 86.7%. TestPack Chlamydia specificity was determined to be 99.5%. These results indicate that TestPack Chlamydia is an accurate test for chlamydial infection, with a positive predictive value of 96.2%. This assay is suitable for low-volume chlamydial testing in physician offices, clinics, and smaller laboratories.

The role of C-4-substituted mannose analogues in protein glycosylation. Effect of the guanosine diphosphate esters of 4-deoxy-4-fluoro-D-mannose and 4-deoxy-D-mannose on lipid-linked oligosaccharide assembly.

The effects of the guanosine diphosphate esters of 4-deoxy-4-fluoro-D-mannose (GDP-4FMan) and 4-deoxy-D-mannose (GDP-4dMan) on reactions of the dolichol pathway in chick-embryo cell microsomal membranes were investigated by studies with chick-embryo cell microsomal membranes in vitro and in baby-hamster kidney (BHK) cells in vivo. Each nucleotide sugar analogue inhibited lipid-linked oligosaccharide biosynthesis in a concentration-dependent manner. GDP-4FMan blocked in vitro the addition of mannose to Dol-PP-(GlcNAc)2Man from GDP-Man (where Dol represents dolichol), but did not interfere with the formation of Dol-P-Man, Dol-P-Glc and Dol-PP-(GlcNAc)2. Although GDP-4FMan and Dol-P-4FMan were identified as metabolites of 4FMan in BHK cells labelled with [1-14C]4FMan, GDP-4FMan was a very poor substrate for GDP-Man:Dol-P mannosyltransferase and Dol-P-4FMan could only be synthesized in vitro if the chick-embryo cell membranes were primed with Dol-P. It therefore appears that the inhibition of lipid-linked oligosaccharide formation in BHK cells treated with 4FMan [Grier & Rasmussen (1984) J. Biol. Chem. 259, 1027-1030] is due primarily to a blockage in the formation of Dol-PP-(GlcNAc)2Man2 by GDP-4FMan. In contrast, GDP-4dMan was a substrate for those mannosyltransferases that catalyse the transfer of the first five mannose residues to Dol-PP-(GlcNAc)2. In addition, GDP-4dMan was a substrate for GDP-Man:Dol-P mannosyltransferase, which catalysed the formation of Dol-P-4dMan. As a consequence of this, the formation of Dol-P-Man, Dol-P-Glc and Dol-PP-(GlcNAc)2 may be inhibited through competition for Dol-P. In BHK cells treated with 10 mM-4dMan, Dol-PP-(GlcNAc)2Man9 was the major lipid-linked oligosaccharide detected. Nearly normal extents of protein glycosylation were observed, but very little processing to complex oligosaccharides occurred, and the high-mannose structures were smaller than in untreated cells.

4-Deoxy-4-fluoro-D-mannose inhibits the glycosylation of the G protein of vesicular stomatitis virus.

The effect of 4-deoxy-4-fluoro-D-mannose (4F-Man), a synthetic analog of D-mannose, on the synthesis of the glycoprotein (G) of vesicular stomatitis virus was examined. Nearly confluent monolayers of cultured BHK21 cells infected with vesicular stomatitis virus were incubated for 2 h with 4F-Man (0-10 mM) or for 1 h with tunicamycin (2 micrograms/ml) and then pulse-labeled with [35S]methionine or [3H]glucosamine. After a 90-min chase period, the cells were lysed and the viral proteins were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. The 35S-labeled G protein from cells exposed to greater than or equal to 1 mM 4F-Man migrated more rapidly than G protein isolated from control cells and with the same electrophoretic mobility as the glycoprotein produced by cells treated with tunicamycin. When infected cells were labeled with [3H]glucosamine, little or no radioactivity was associated with G protein synthesized in the presence of greater than or equal to 1 mM 4F-Man. The conclusion that 4F-Man blocks the glycosylation of the G protein was supported by experiments which demonstrated that the fluorosugar inhibits the synthesis of lipid-linked oligosaccharides.

Metabolism of 3-deoxy-3-fluoro-D-mannose and 4-deoxy-4-fluoro-D-mannose by Saccharomyces cerevisiae S288C.

Incubation of Saccharomyces cerevisiae S288C with 4-deoxy-4-fluoro-D-[1-14C]-mannose resulted in the formation of three metabolites that were characterized as 4-deoxy-4-fluoro-D-[1-14C]mannose 1,6-bisphosphate, 4-deoxy-4-fluoro-D-[1-14C]-mannose 6-phosphate and GDP-4-deoxy-4-fluoro-D-[1-14C]mannose. In addition, radioactive material was incorporated into a particulate fraction composed primarily of cell-wall polysaccharides. Compared with the 4-fluoro sugar, 3-deoxy-3-fluoro-D-[1-14C]mannose was not transported into yeast cells as well, and its conversion into sugar nucleotide was much less efficient. Metabolites that were isolated after incubation with the 3-fluoro analogue were identified as 3-deoxy-3-fluoro-D-[1-14C]mannose 1,6-bisphosphate, 3-deoxy-3-fluoro-D-[1-14C]mannose 6-phosphate and GDP-3-deoxy-3-fluoro-D-[1-14C]mannose. Little radioactivity was transferred into the cell-wall fraction.

Epidemiologic studies of coronary heart disease and stroke in Japanese men living in Japan, Hawaii and California: distribution of biochemical risk factors.

Distributions of serum cholesterol, glucose, uric acid and triglycerides are examined among Japanese men living in Japan, Hawaii and California. Laboratory methods are described in detail and efforts to assure comparability of these methods. In every age group studied, the mean, median and percentile for each of the biochemical variables are lower for men in Japan than in Hawaii and California.