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.

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.

Contrasting Effects of Local Environmental and Biogeographic Factors on the Composition and Structure of Bacterial Communities in Arid Monospecific Mangrove Soils.

Mangrove forests are important biotic sinks of atmospheric CO2 and play an integral role in nutrient-cycling and decontamination of coastal waters, thereby mitigating climatic and anthropogenic stressors. These services are primarily regulated by the activity of the soil microbiome. To understand how environmental changes may affect this vital part of the ecosystem, it is key to understand the patterns that drive microbial community assembly in mangrove forest soils. High-throughput amplicon sequencing (16S rRNA) was applied on samples from arid Avicennia marina forests across different spatial scales from local to regional. Alongside conventional analyses of community ecology, microbial co-occurrence networks were assessed to investigate differences in composition and structure of the bacterial community. The bacterial community composition varied more strongly along an intertidal gradient within each mangrove forest, than between forests in different geographic regions (Australia/Saudi Arabia). In contrast, co-occurrence networks differed primarily between geographic regions, illustrating that the structure of the bacterial community is not necessarily linked to its composition. The local diversity in mangrove forest soils may have important implications for the quantification of biogeochemical processes and is important to consider when planning restoration activities. IMPORTANCE Mangrove ecosystems are increasingly being recognized for their potential to sequester atmospheric carbon, thereby mitigating the effects of anthropogenically driven greenhouse gas emissions. The bacterial community in the soils plays an important role in the breakdown and recycling of carbon and other nutrients. To assess and predict changes in carbon storage, it is important to understand how the bacterial community is shaped by its environment. Here, we compared the bacterial communities of mangrove forests on different spatial scales, from local within-forest to biogeographic comparisons. The bacterial community composition differed more between distinct intertidal zones of the same forest than between forests in distant geographic regions. The calculated network structure of theoretically interacting bacteria, however, differed most between the geographic regions. Our findings highlight the importance of local environmental factors in shaping the microbial soil community in mangroves and highlight a disconnect between community composition and structure in microbial soil assemblages.

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.

The role of seagrass vegetation and local environmental conditions in shaping benthic bacterial and macroinvertebrate communities in a tropical coastal lagoon.

We investigated the influence of seagrass canopies on the benthic biodiversity of bacteria and macroinvertebrates in a Red Sea tropical lagoon. Changes in abundance, number of taxa and assemblage structure were analyzed in response to seagrass densities (low, SLD; high, SHD; seagrasses with algae, SA), and compared with unvegetated sediments. Biological and environmental variables were examined in these four habitats (hereafter called treatments), both in the underlaying sediments and overlaying waters, at three randomly picked locations in March 2017. Differences between treatments were more apparent in the benthic habitat than in the overlaying waters. The presence of vegetation (more than its cover) and changes in sedimentary features (grain size and metals) at local scales influenced the observed biological patterns, particularly for macroinvertebrates. Of note, the highest percentage of exclusive macroinvertebrate taxa (18% of the gamma diversity) was observed in the SHD treatment peaking in the SA for bacteria. Benthic macroinvertebrates and bacteria shared a generally low number of taxa across treatments and locations; approximately, 25% of the gamma diversity was shared among all treatments and locations for macrofauna, dropping to 11% for bacteria. Given the low overlap in the species distribution across the lagoon, sustaining the connectivity among heterogeneous soft sediment habitats appears to be essential for maintaining regional biodiversity. This study addresses a current scientific gap related to the relative contributions of vegetated and unvegetated habitats to biodiversity in tropical regions.

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.

Coral reef degradation affects the potential for reef recovery after disturbance.

The loss of coral cover is often accompanied by an increase of benthic algae, a decline in biodiversity and habitat complexity. However, it remains unclear how surrounding communities influence the trajectories of re-colonization between pulse disturbance events. Over a 12-month field experiment in the central Red Sea, we examined how healthy (hard-coral dominated) and degraded (algae-dominated) reef areas influence recruitment and succession patterns of benthic reef foundation communities on bare substrates. Crustose coralline algae and other calcifiers were important colonizers in the healthy reef area, promoting the accumulation of inorganic carbon. Contrary, substrates in the degraded area were predominantly colonized by turf algae, lowering the accumulation of inorganic carbon by 178%. While coral larvae settlement similarly occurred in both habitats, degraded areas showed 50% fewer recruits. Our findings suggest that in degraded reefs the replenishment of adult coral populations is reduced due to recruitment inhibition through limited habitat complexity and grazing pressure, thereby restraining reef recovery.

Biodiversity patterns of plankton assemblages at the extremes of the Red Sea.

The diversity of microbial plankton has received limited attention in the main basin of the Red Sea. This study investigates changes in the community composition and structure of prokaryotes and eukaryotes at the extremes of the Red Sea along cross-shelf gradients and between the surface and deep chlorophyll maximum. Using molecular methods to target both the 16S and 18S rRNA genes, it was observed that the dominant prokaryotic classes were Acidimicrobiia, Alphaproteobacteria and Cyanobacteria, regardless of the region and depth. The eukaryotes Syndiniophyceae and Dinophyceae between them dominated in the north, with Bacillariophyceae and Mamiellophyceae more prominent in the southern region. Significant differences were observed for prokaryotes and eukaryotes for region, depth and distance from shore. Similarly, it was noticed that communities became less similar with increasing distance from the shore. Canonical correspondence analysis at the class level showed that Mamiellophyceae and Bacillariophyceae correlated with increased nutrients and chlorophyll a found in the southern region, which is influenced by the input of Gulf of Aden Intermediate Water.

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.

Interleukin (IL)-17A, F and AF in inflammation: a study in collagen-induced arthritis and rheumatoid arthritis.

Interleukin (IL)-17 plays a critical role in inflammation. Most studies to date have elucidated the inflammatory role of IL-17A, often referred to as IL-17. IL-17F is a member of the IL-17 family bearing 50% homology to IL-17A and can also be present as heterodimer IL-17AF. This study elucidates the distribution and contribution of IL-17A, F and AF in inflammatory arthritis. Neutralizing antibody to IL-17A alone or IL-17F alone or in combination was utilized in the mouse collagen-induced arthritis (CIA) model to elucidate the contribution of each subtype in mediating inflammation. IL-17A, F and AF were all increased during inflammatory arthritis. Neutralization of IL-17A reduced the severity of arthritis, neutralization of IL-17A+IL-17F had the same effect as neutralizing IL-17A, while neutralization of IL-17F had no effect. Moreover, significantly higher levels of IL-17A and IL-17F were detected in peripheral blood mononuclear cells (PBMC) from patients with rheumatoid arthritis (RA) in comparison to patients with osteoarthritis (OA). IL-17A and AF were detected in synovial fluid mononuclear cells (SFMC) in RA and OA, with IL-17A being significantly higher in RA patients. Enriched CD3(+) T cells from RA PBMCs produced singnificantly high levels of IL-17A and IL-17AF in comparison to OA peripheral blood CD3(+) T cells. IL-17A, F and AF were undetectable in T cells from SFMCs from RA and OA. While IL-17A, F, and AF were all induced during CIA, IL-17A played a dominant role. Furthermore, production of IL-17A, and not IL-17F or IL-17AF, was elevated in PBMCs, SFMCs and enriched peripheral blood CD3(+) T in RA.

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.

Ambulatory physical activity during United States Army basic combat training.

Electronic pedometers were used to quantify locomotor physical activity during an entire 9-week United States Army Basic Combat Training (BCT) cycle. Pedometers were worn on the hips of 4 trainees in each of 10 BCT companies during all BCT activities. Investigators obtained pedometer readings (steps) on a daily basis, and estimated travel distances were obtained by multiplying steps by the average individual step length. A short questionnaire was administered daily to assure trainees wore the pedometers and trained with their companies all day. Trainees performed an average +/- SD of 16 311 +/- 5826 steps/day and traveled an estimated 11.7 +/- 4.4 kilometers/day. The highest daily locomotor activity was during the field training exercise in which trainees took an average +/- SD of 22 372 +/- 12 517 steps/day traveling an estimated 16.2 +/- 9.7 kilometers/day. Differences among the 10 companies ranged from 14 720 +/- 6649 steps/day to 18 729 +/- 6328 steps/day. This survey provided the first examination of locomotor physical activity during an entire BCT cycle.

Temporal and spatial variability of fecal indicator bacteria in the surf zone off Huntington Beach, CA.

Fecal indicator bacteria concentrations measured in the surf zone off Huntington Beach, CA from July 1998-December 2001 were analyzed with respect to their spatial patterns along 23 km of beach, and temporal variability on time scales from hourly to fortnightly. The majority of samples had bacterial concentrations less than, or equal to, the minimum detection limit, but a small percentage exceeded the California recreational water standards. Areas where coliform bacteria exceeded standards were more prevalent north of the Santa Ana River, whereas enterococci exceedances covered a broad area both north and south of the river. Higher concentrations of bacteria were associated with spring tides. No temporal correspondence was found between these bacterial events and either the timing of cold water pulses near shore due to internal tides, or the presence of southerly swell in the surface wave field. All three fecal indicator bacteria exhibited a diel cycle, but enterococci rebounded to high nighttime values almost as soon as the sun went down, whereas coliform levels were highest near the nighttime low tide, which was also the lower low tide.

Interventions to prevent softball related injuries: a review of the literature.

OBJECTIVES: To examine the published evidence on interventions to prevent softball related injuries among adults, and to encourage more epidemiologic research as a foundation for future softball injury prevention efforts. METHODS: The authors reviewed literature identified from six electronic databases for studies on softball related injuries. The search was limited to studies written in the English language, published between 1970 and 2002, and involving adult populations. Research was excluded that evaluated baseball ("hard ball") related injuries or was aimed at injury treatment. Identified studies were categorized by study design. Intervention/prevention papers were evaluated further and described in detail. RESULTS: The search strategy identified 39 studies specifically related to softball. Most studies were case reports/case series (n=13) or descriptive studies (n=11); only four were analytic or intervention/prevention studies. Studies collected data in a variety of ways, often without denominator data to permit calculation of injury rates. Studies also did not differentiate between slow or fast pitch softball activities and most did not mention the type of softball that was used. CONCLUSIONS: Surprisingly few studies exist on interventions to reduce injuries during softball, one of the most popular recreational sports in the US. Of the existing literature, much attention has been on sliding related injuries, which comprise only a segment of softball injuries. Basic epidemiologic studies describing the nature, severity, and risk factors for softball injuries in a variety of populations are needed, followed by additional intervention evaluation studies aimed at modifiable risk factors.

Histological quality of polyps resected using the cold versus hot biopsy technique.

BACKGROUND AND STUDY AIMS: The monopolar hot biopsy technique is a widespread method of removing and cauterizing small colonic polyps. Due to the insulated cups of the biopsy forceps, it also allows adequate histological interpretation of the resected specimen. In our experience, polyps removed using the monopolar hot biopsy technique have been less histologically interpretable in comparison with polyps removed using cold biopsy forceps. The aim of this study was to assess and compare the diagnostic quality of polyps obtained using the hot biopsy and cold biopsy techniques. PATIENTS AND METHODS: This was a prospective study of consecutive patients undergoing colonoscopy with removal of polyps using either hot biopsy or cold biopsy techniques. One experienced endoscopist using the same techniques carried out the biopsies. An experienced gastrointestinal pathologist, blinded to the technique used, evaluated the specimens for diameter, artifacts, cautery damage, tissue fragmentation, and general histological and diagnostic quality. Statistical analysis was carried out using the chi-squared test, Fisher's exact test, and Student's t-test. RESULTS: Forty-three consecutive patients (84 % men; mean age 63.8 +/- 15 years) underwent 88 biopsies (45 hot biopsies and 43 cold biopsies). There were no statistically significant differences between the two study groups with regard to demographic data, indications for colonoscopy, endoscopic findings, or polyp size. Cautery damage, architectural distortion, and tissue fragmentation occurred more frequently in polyps resected using the hot biopsy technique ( P < 0.001). CONCLUSIONS: The quality of the specimens removed by cold biopsy was generally better than when using hot biopsy technique. Histological evaluation is more difficult in polyps resected with the hot biopsy technique in comparison with the cold biopsy technique. When the nature of polyps affects the patient's management, a biopsy may be obtained before polyp coagulation.

Influence of an injury reduction program on injury and fitness outcomes among soldiers.

OBJECTIVE: This study evaluated the influence of a multiple injury control intervention on injury and physical fitness outcomes among soldiers attending United States Army Ordnance School Advanced Individual Training. METHODS: The study design was quasiexperimental involving a historical control group (n = 2559) that was compared to a multiple intervention group (n = 1283). Interventions in the multiple intervention group included modified physical training, injury education, and a unit based injury surveillance system (UBISS). The management responsible for training independently formed an Injury Control Advisory Committee that examined surveillance reports from the UBISS and recommended changes to training. On arrival at school, individual soldiers completed a demographics and lifestyle questionnaire and took an army physical fitness test (APFT: push-ups, sit-ups, and two mile run). Injuries among soldiers were tracked by a clinic based injury surveillance system that was separate from the UBISS. Soldiers completed a final APFT eight weeks after arrival at school. RESULTS: Cox regression (survival analysis) was used to examine differences in time to the first injury while controlling for group differences in demographics, lifestyle characteristics, and physical fitness. The adjusted relative risk of a time loss injury was 1.5 (95% confidence interval 1.2 to 1.8) times higher in the historical control men and 1.8 (95% confidence interval 1.1 to 2.8) times higher in the historical control women compared with the multiple intervention men and women, respectively. After correcting for the lower initial fitness of the multiple intervention group, there were no significant differences between the multiple intervention and historical control groups in terms of improvements in push-ups, sit-ups, or two mile run performance. CONCLUSIONS: This multiple intervention program contributed to a reduction in injuries while improvements in physical fitness were similar to a traditional physical training program previously used at the school.

Automated high-throughput probe production for DNA microarray analysis.

DNA microarrays have become an established tool for gene expression profiling. Construction of these microarrays using immobilized cDNAs is a common experimental strategy. However, this is extremely laborious, requiring the preparation of hundreds or thousands of cDNA probes. To minimize this initial bottleneck, we developed a comprehensive high-throughput robotic system to prepare DNA probes suitable for microarray analysis with minimal user intervention. We describe an automated system using the MultiPROBE Nucleic Acid Purification Workstation to provide the liquid handling and other functions needed to optimize this process. We were able to carry out fully automated plasmid cDNA isolation, PCR assay setup, and PCR purification and also to direct the characterization and tracking of DNA probes during processing. Protocols began with the initial preparation of a plasmid DNA archive of bacterial stocks in parallel 96-well plates (192 samples/run) and continued through to the dilution and reformatting of chip-ready DNA probes in 384-well format. These and other probe production procedures and additional instrument systems were used to process fully a set of mouse cDNA clones that were then validated by differential gene expression analysis.

Effects of fatty (fa) allele and high-fat diet on adipose tissue leptin and lipid metabolism.

Leptin is an adipocyte-secreted hormone that binds hypothalamic receptors and potently decreases food intake. Leptin receptor defects in homozygous mutant Zucker fatty ( fa/fa) rats lead to massive obesity, hyperphagia, decreased energy expenditure, and insulin resistance, while the phenotype of heterozygous ( Fa/fa) lean rats lies between lean ( Fa/Fa) and obese ( fa/fa) rats. Whether heterezygotes exhibit specific changes in lipid metabolism in a diet-responsive manner is not clear. Thus, the specific aim of this study was to test whether the presence of one fa allele modulates lipid metabolism and leptin, and whether these effects are exacerbated by high-fat diet. We demonstrate that the presence of one fa allele significantly increases lipogenesis in adipose tissue assessed by glycerol-3-phosphate dehydrogenase (GPDH) and fatty acid synthase (FAS) activities. FAS is more responsive to high-fat diets than GPDH in Fa/fa rats. Adipose tissue leptin levels are significantly higher in fat pads of Fa/fa compared to Fa/Fa rats. Moreover, Fa/fa rats fed high-fat diet show an additional two-fold increase in leptin levels compared to wild type rats on the same diet. Collectively, these results indicate that the presence of one fa allele increase adipocyte lipogenic enzyme activities, which results in hyperleptinemia concurrent with increased adiposity.