Organochlorine pesticides and mercury in cottonmouths (Agkistrodon piscivorus) from northeastern Texas, USA

Despite their ecological importance and global decline, snakes remain poorly studied in ecotoxicology. In this study, we examined organochlorine (OC) pesticide and mercury accumulation in cottonmouths (Agkistrodon piscivorus) living on a contaminated site in northeastern Texas (USA). Mercury and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) were detected in all snakes examined. Other OCs, including p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT), methoxychlor, aldrin, and heptachlor, also were detected, but less frequently. Concentrations of p,p'-DDE were higher in fat than in liver, while mercury concentrations were highest in liver, followed by kidney and tail clips. One animal contained the highest mercury concentration yet reported for a snake (8,610 ng/g). Mercury concentrations in liver and kidney were higher in males than females, while no intersex differences in p,p'-DDE concentrations were observed. Concentrations of p,p'-DDE in fat were correlated positively with body size in male cottonmouths but not females, suggesting a slower rate of accumulation in females. Body size strongly predicted mercury concentrations in liver, kidney, and tail clips of both sexes. Tail clips were strong predictors of mercury in liver and kidney in males but not females, suggesting possible sex-dependent differences in mercury toxicokinetics. Both long-term field studies and controlled laboratory investigations are needed to adequately assess the response of cottonmouths to chronic contaminant exposure.     

Hormonal contraceptive use and the effectiveness of highly active antiretroviral therapy

The role of hormonal contraceptive use in the effectiveness of highly active antiretroviral therapy (HAART) was examined among participants in the Women's Interagency HIV Study who were followed from HAART initiation to 2001. Propensity score selection was used to match 77 hormonal contraceptive users with 77 nonusers on age, race, and pre-HAART CD4-positive T-lymphocyte (CD4+ cell) count and viral load. The authors compared hormonal contraceptive users and nonusers with regard to the CD4+ cell count and viral load responses to HAART upon initiation. Proportional hazards analyses were used to assess the effect of hormonal contraceptive use on times to increases in CD4+ cell count of 50 cells/mm(3) and 100 cells/mm(3) and achievement of an undetectable viral load. There were no statistically significant differences in CD4+ cell counts and log viral load responses by hormone use after HAART initiation, except in log viral load at the third visit after initiation (p = 0.047). Time-dependent hormonal contraceptive use was not a statistically significant predictor of achieving increases in CD4+ cell count of 50 cells/mm(3) and 100 cells/mm(3) or an undetectable viral load (p = 0.517, p = 0.751, and p = 0.218, respectively) after HAART initiation. In conclusion, the authors did not find substantial evidence that use of hormonal contraceptives strongly affected responses to HAART.     

Music and anxiety in Williams syndrome: a harmonious or discordant relationship?

In this two-part study, we assessed musical involvements in two samples of persons with Williams syndrome compared to others with mental retardation and also related musicality to anxiety and fears in Study 2. Relative to others with mental retardation, those with Williams syndrome were more likely to take music lessons, play an instrument, and have higher ratings of musical skills. In the Williams syndrome groups only, fewer externalizing symptoms were associated with listening to music, whereas less anxiety and fewer fears were associated with the frequency, duration, and skill in producing music as well as emotional responses to negatively toned music. Implications are discussed for future research on musical processing, musical interventions, and well-being in Williams syndrome and other groups.     

High-frequency pulsed electromagnetic energy in tinnitus treatment

OBJECTIVES/HYPOTHESIS: Electromagnetic therapy has been used with reported success in multiple clinical settings, including the treatment of seizure disorders, brain edema, migraine headaches, revascularization of burn wounds, and diabetic ulcers. The purpose of the study was to investigate the effect of pulsed high-frequency electromagnetic therapy on chronic tinnitus. STUDY DESIGN: A randomized, prospective, double-blind, placebo-controlled pilot study was conducted to evaluate the effectiveness of high-frequency pulsed electromagnetic energy using the Diapulse device in the treatment of chronic tinnitus. Thirty-seven adult patients with chronic tinnitus of at least 6 months' duration were recruited and randomly assigned to either a treatment or a placebo group. METHODS: Patients received 30-minute treatments with the Diapulse device three times a week for 1 month. The unit was set to deliver electromagnetic energy at a frequency of 27.12 MHz at a repetition rate of 600 pulses per second. All subjects had pretreatment and post-treatment audiological testing, including tinnitus frequency and intensity matching. They responded to a tinnitus rating questionnaire and the Tinnitus Handicap Inventory before and after treatment. RESULTS: There was no significant change in the pretreatment and post-treatment audiometric thresholds in either group. There were no significant differences between the pretreatment and post-treatment Tinnitus Handicap Inventory scores or the tinnitus rating scores in either subject group (Student t test). No diagnosis-specific differences were identified. CONCLUSION: High-frequency pulsed electromagnetic energy (Diapulse) at the settings used in the study showed no role in the therapy of patients with chronic tinnitus.