An integrated assessment of sediment remediation in a midwestern U.S. stream using sediment chemistry, water quality, bioassessment, and fish biomarkers.

A comprehensive biological, sediment, and water quality study of the lower Little Scioto River near Marion, Ohio, USA, was undertaken to evaluate the changes or improvements in biotic measurements following the removal of creosote-contaminated sediment. The study area covered 7.5 river miles (RMs), including a remediated section between RMs 6.0 and 6.8. Fish and macroinvertebrate assemblages, fish biomarkers (i.e., polycyclic aromatic hydrocarbon [PAH] metabolite levels in white sucker [Castostomus commersoni] and common carp [Cyprinus carpio] bile and DNA damage), sediment chemistry, and water quality were assessed at five locations relative to the primary source of historical PAH contamination-upstream (RM 9.2), adjacent (RM 6.5), and downstream (RMs 5.7, 4.4, and 2.7). Overall, the biomarker results were consistent with the sediment PAH results, showing a pattern of low levels of PAH bile metabolites and DNA damage at the upstream (reference or background location), as well as the remediated section, high levels at the two immediate downstream sites, and somewhat lower levels at the furthest downstream site. Results show that remediation was effective in reducing sediment contaminant concentrations and exposure of fish to PAHs and in improving fish assemblages (60% increase in index of biotic integrity scores) in remediated river sections. Additional remedial investigation and potentially further remediation is needed to improve the downstream benthic fish community, which is still heavily exposed to PAH contaminants.

Obstructive sleep apnea in sleepy pediatric psychiatry clinic patients: polysomnographic and clinical correlates.

STUDY OBJECTIVES: To assess the incidence of polysomnographically defined obstructive sleep apnea (OSA) in pediatric psychiatric clinic patients reporting daytime sleepiness on questionnaire, and to identify diagnostic correlates for OSA in this grouping. DESIGN: Prospective and observational. SETTING: Outpatient pediatric psychiatry clinic, outpatient sleep medicine clinic, AASM-accredited hospital-based sleep laboratory. SUBJECTS: Children aged 3 to 16 years, reporting daytime sleepiness on questionnaire (N = 74); exclusions: adenotonsillectomy and trisomy 21. INTERVENTIONS: Parents and children completed a questionnaire designed and validated for identifying pediatric patients with OSA at the pediatric psychiatry clinic. Patients with at least one positive response as to daytime sleepiness (N = 74) were referred for a history and physical by a board-certified sleep medicine physician before in-hospital polysomnography utilizing a routine apnea montage with parent or legal guardian sleeping in room. RESULTS: Mean apnea-hypopnea index (AHI) for this pediatric psychiatry clinic grouping was 5.5. Of these patients, 39.2% had an AHI > 5.0. Mean AHI for patients with attention deficit/hyperactivity disorder (AD/HD) was 7.1; without AD/HD it was 4.5 (p < 0.05). Mean AHI for patients with tonsillar hypertrophy was 6.5 compared with 4.4 for those without tonsillar hypertrophy (p < 0.05). CONCLUSION: In a clinical grouping of pediatric psychiatry patients reporting daytime sleepiness by questionnaire, polysomnographically defined OSA is common. Both AD/HD as diagnosed using DSM-IV criteria and tonsillar hypertrophy based on clinical exam by a sleep medicine physician are diagnostic correlates for polysomnographically defined OSA in this pediatric psychiatry clinic grouping of patients.

Evaluation of a virtual reality simulator for arthroscopy skills development.

We evaluated a virtual reality shoulder arthroscopy simulator using a standardized skills-assessment algorithm in 3 specific groups with various degrees of surgical expertise. The simulator (Mentice Corp, Gothenberg, Sweden) consists of a computer-based, dual-force feedback system with video monitor. Modeled structures include cartilage, labrum, ligaments, biceps tendon, and rotator cuff. The study included 3 groups of volunteers: group 1, medical students interviewing for orthopaedic residency (n = 35); group 2, orthopaedic residents interviewing for sports medicine fellowship (n = 22); and group 3, experienced faculty at a shoulder surgery course (n = 21). Data were collected anonymously and subjects completed a standardized test protocol designed to assess accuracy and efficiency. Subjects used the probe to "touch" a sphere that appeared at various locations within the joint (11 positions total). The sphere changed location immediately on contact with the tip of the probe. The following parameters were calculated by the computer: time (from touching the first ball until touching the eleventh ball), path ratio (percent of measured path length relative to the ideal path), collisions (number of times the probe / arthroscope contacted any tissue), and injuries (collisions beyond a threshold force). Test time and path ratio differed significantly as a function of surgical experience. There was no significant difference in probe collisions between the groups. Arthroscope collisions and injuries averaged 2 or less in all of the groups. There was significant correlation between path ratio and time to complete the test in groups 1 and 2 (r =.527 and r =.827, respectively, P <.001), but not in group 3 (r =.376, P =.10). There was essentially normal distribution of time performance in groups 1 and 2. Time was shorter and more consistent in group 3, suggesting greater consistency in the experienced surgeons. These data suggest that this arthroscopy simulator facilitates discrimination of arthroscopic skills. Computer-based simulation technology provides a major opportunity for surgical skills development without morbidity and operating room inefficiency.