Enhanced Hydrocarbons Biodegradation at Deep-Sea Hydrostatic Pressure with Microbial Electrochemical Snorkels

In anaerobic sediments, microbial degradation of petroleum hydrocarbons is limited by the rapid depletion of electron acceptors (e.g., ferric oxide, sulfate) and accumulation of toxic metabolites (e.g., sulfide, following sulfate reduction). Deep-sea sediments are increasingly impacted by oil contamination, and the elevated hydrostatic pressure (HP) they are subjected to represents an additional limitation for microbial metabolism. While the use of electrodes to support electrobioremediation in oil-contaminated sediments has been described, there is no evidence on their applicability for deep-sea sediments. Here, we tested a passive bioelectrochemical system named ”oil-spill snorkel” with two crude oils carrying different alkane contents (4 vs. 15%), at increased or ambient HP (10 vs. 0.1 MPa). Snorkels enhanced alkanes biodegradation at both 10 and 0.1 MPa within only seven weeks, as compared to nonconductive glass controls. Microprofiles in anaerobic, contaminated sediments indicated that snorkels kept sulfide concentration to low titers. Bulk-sediment analysis confirmed that sulfide oxidation by snorkels largely regenerated sulfate. Hence, the sole application of snorkels could eliminate a toxicity factor and replenish a spent electron acceptor at increased HP. Both aspects are crucial for petroleum decontamination of the deep sea, a remote environment featured by low metabolic activity.

Time from diagnosis to treatment initiation in advanced non-small cell lung cancer (NSCLC): Time trends and racial differences

6037 Background: Historical survival evaluation of clinical trials for advanced NSCLC suggests that median survival improved by 0.4 months over a 22 year period. Survival in clinical trails is evaluated from treatment initiation and not from diagnosis. If treatment is initiated earlier over time, this may create a lead-time effect on survival analysis and thus may explain the apparent discrepancy between trial findings and outcomes in the community. Objective: Investigate if, over time, there has been a shortening of the time between the diagnosis of NSCLC and the initiation of chemotherapy. Methods: We evaluated patients with NSCLC stages IIIB and IV between 01/01/1994 and 12/31/1999. Date of diagnosis was obtained from Surveillance, Epidemiology, and End Results (SEER). Treatment data was obtained from Medicare claims and is restricted to patients above age 65. Differences were compared using analysis of variance (ANOVA). Results: A total of 11,995 patients were identified. Patient’s characteristics: median age 74 years; 57% of patients were males; racial distribution: white (82.4%), black (9.4%), Asian (3.2%), Hispanics (1.2%), others (3.8%); stage distribution: IIIB (38%), IV (62%). Chemotherapy was given to 3,377 (28%) patients. There was an increase in chemotherapy utilization over time: 10% in 1994 to 35% in 1999. Over time there was a shortening from diagnosis to chemotherapy initiation from 1.6 months in 1994 to 1.3 months in 1999 (p = 0.0004). Among those receiving chemotherapy, median survival from diagnosis did not change over this time period. Black patients had a longer time between diagnosis and treatment initiation: 1.7 months vs. 1.4 months (p < 0.01). Conclusions: Over time, there has been a shortening of the time between diagnosis and chemotherapy initiation. This difference, although small, seems to account for much of the apparent historical survival benefit observed. This finding puts additional limitation on the historical comparisons of survival between trials. Racial differences may help explain, in part, observed differences in outcome. No significant financial relationships to disclose.

Some Implications of Listening Level for Speech Reception by Sensorineural Hearing-Impaired Children

The benefits of amplification for sensorineural hearing-impaired persons listening at low levels were investigated. Eleven college students were tested, and the results suggest that the level above threshold at which a person listens to speech may ultimately influence the benefits obtained from amplification. The data indicate the possibility of an additional limitation to the potential for auditory speech communication when these persons cannot listen comfortably at levels above threshold of 20 to 30 dB or more.