Anthony A. Billings

Influence of mast production on black bear non-hunting mortalities in West Virginia

Abstract Food availability influences movements, population dynamics, and harvest of black bears (Ursus americanus) in the Appalachian Mountains. We compared combinations of hard and soft mast indices to black bear non-hunting mortalities in West Virginia, USA, 1980–2004. Mast conditions were inversely related to non-hunting black bear mortalities. We constructed regression equations to predict non-hunting bear mortalities and used Akaikes Information Criterion (AIC) to compare fit of each model to the data. Oak (Quercus spp.; ΔAICc  =  0.000), oak + hickory (Carya spp.; ΔAICc  =  0.251), all hard mast (ΔAICc  =  6.41), and hard mast + black cherry (Prunus serotina; ΔAICc  =  7.06) were considered the best competing models for explaining non-hunting black bear mortalities. Managers may use this data to help explain and predict the importance of hard mast conditions on non-hunting black bear mortalities.

Comparison of Early versus Late Use of Antibiotic Locks in the Treatment of Catheter-Related Bacteremia

BACKGROUND AND OBJECTIVES This retrospective study compared the effectiveness of the timing of the antibiotic locks to clear catheter-related bacteremia in children on chronic hemodialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS The early antibiotic lock group received antibiotic locks along with systemic antibiotics from the very beginning of catheter-related bacteremia. The late antibiotic lock group was given only systemic antibiotics initially, and antibiotic locks were used late in the infection if the catheter-related bacteremia could not be cleared after resolution of symptoms. RESULTS There were 264 catheter-related bacteremias in 79 children during 6 yr of observation. Early antibiotic locks were able to clear catheter-related bacteremia and resolve the symptoms more effectively without the need for catheter exchange when compared with late antibiotic locks. A total of 84 catheter-related bacteremias required wire-guided exchange of the catheters. Late antibiotic locks required wire-guided catheter exchange more frequently than the early antibiotic locks. The post-catheter-related bacteremia infection-free survival of the catheters after wire-guided exchange were significantly longer than those of both antibiotic lock groups. Recurrence of catheter-related bacteremia within 45 d after wire-guided exchange occurred at similar rates compared with the antibiotic lock groups. CONCLUSION Antibiotic locks are significantly more effective in clearing catheter-related bacteremia when used early in infection, diminishing the need for catheter exchange. Wire-guided exchange has a late-onset advantage for infection-free survival compared with catheter in situ treatment. The recurrence rates in the first 45 d after catheter-related bacteremia are similar regardless of the treatment strategy.

Differences between actual and expected leisure activities after total knee arthroplasty for osteoarthritis.

This prospective cohort study determined the type, frequency, intensity, and duration of actual vs expected leisure activity among a cohort undergoing total knee arthroplasty. Data on actual and expected participation in 36 leisure activities were collected preoperatively and at 12 months in 90 patients with knee osteoarthritis. Despite high expectations, there were statistically and clinically significant differences between actual and expected activity at 12 months suggesting that expectations may not have been fulfilled. The differences were equivalent to walking 14 less miles per week than expected, which is more than the amount of activity recommended in national physical activity guidelines. Perhaps an educational intervention could be implemented to help patients establish appropriate and realistic leisure activity expectations before surgery.

Antibiotic lock solutions allow less systemic antibiotic exposure and less catheter malfunction without adversely affecting antimicrobial resistance patterns.

There are current concerns that antibiotic lock solutions (ABL) can induce antimicrobial resistance in long‐term hemodialysis patients. Retrospective chart review of 157 children on hemodialysis between January 1997 and June 2006 was performed. In ERA I, only systemic antibiotics were used. In ERA II, ABL were added to systemic antibiotics when needed. In ERA III, ABL were used for treatment of all cases of catheter‐related bacteremia (CRB) and for CRB prophylaxis in high‐risk patients. The study includes 111,325 catheter days. The CRB incidence was 3.9 CRB/1000 catheter days. There was significant decrease for the total systemic antibiotic exposure (P = 0.0484) and the percentage of catheters lost to malfunction (P = 0.001) in ERA III. Protocol ABL exposure was associated with a trend to increased tobramycin‐gentamicin resistance for gram‐positive CRBs (P = 0.2586) but with improved tobramycin‐gentamicin resistance for gram‐negative (P = 0.0949) and polymicrobial CRBs (P = 0.1776) and improved vancomycin resistance for gram‐positive CRBs (P = 0.0985). This retrospective analysis does not support the premise that ABL use will promote antimicrobial resistance in the hemodialysis population. The decreased exposure to systemic antibiotics by vigorous ABL use may even improve the antimicrobial resistance patterns in this population in the long term.

Early weight bearing after complete tibial shaft fractures in children.

This study determined the prevalence of complications related to early weight bearing and the factors associated with time to healing in children after a complete tibial shaft fracture. Radiographs and medical records were reviewed from patients with unilateral, closed, complete tibial shaft fractures who were treated nonoperatively with a long leg cast. There were 55 males (68.8%) and 25 females (31.2%) with a mean±SD age of 6.0±4.0 years (range 1–16). There were few complications (2.5%) and patients healed faster if they bore weight earlier (0.3 days faster for each day earlier to weight bearing, P=0.02), were younger (2.3 days faster per year younger, P<0.001), were female (2.7 days faster than males, P=0.02), or did not have a closed reduction (3.8 days faster, P=0.002) (R2=0.63). Time to weight bearing after complete tibial shaft fracture was not associated with an increased risk of complications. Earlier weight bearing was associated with a shorter time to healing. This study provides support for treatment with early weight bearing in children with closed, complete tibial shaft fractures.

Spatial and Temporal Distribution of Imidacloprid Within the Crown of Eastern Hemlock

Systemic imidacloprid is the most widely used insecticide to control the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), an exotic pest of eastern hemlock, Tsuga canadensis (L.) Carriére in the United States. This study was conducted to 1) determine the effect of treatment timing (spring vs. fall) and application method (trunk injection vs. soil injection) on the spatial and temporal distribution of imidacloprid within the crown of A. tsugae-free eastern hemlock using a competitive enzyme-linked immunosorbent assay (ELISA), 2) compare ELISA to gas chromatography-mass spectrometry (GC/MS) for the detection of imidacloprid in xylem fluid, and 3) determine the concentration of imidacloprid in leaf tissue using high performance liquid chromatography with tandem mass spectrometric (LC/MS/MS) detection methods. Xylem fluid concentrations of imidacloprid were found to be significantly higher for spring applications than for fall applications and for trunk injections than soil injections in the first year posttreatment. A total of 69% of samples analyzed by ELISA gave 1.8 times higher concentrations of imidacloprid than those found by GC/MS, leading to evidence of a matrix effect and overestimation of imidacloprid in xylem fluid by ELISA. A comparison of the presence of imidacloprid with xylem fluid and in leaf tissue on the same branch showed significant differences, suggesting that imidacloprid moved intermittently within the crown of eastern hemlock.