Draft Genome Sequence of Cellulophaga sp. E6, a Marine Algal Epibiont That Produces a Quorum-Sensing Inhibitory Compound Active against Pseudomonas aeruginosa.

The genus Cellulophaga is composed of obligate aerobic Gram-negative bacteria commonly found in association with marine algae. We report the approximately 4.42-Mbp draft genome sequence of Cellulophaga sp. E6, which inhibits N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C12-HSL)-mediated quorum sensing (QS), lasB transcription, and biofilm formation by Pseudomonas aeruginosa.

Acetazolamide and exercise hypoxia.

Acetazolamide is useful for acclimatizing to high altitude. How long it should be taken, and the physiological consequences of stopping it have not been thoroughly studied. We investigated the effect of acetazolamide cessation on exercise oxygenation at different altitudes and durations of use. Three groups were studied: group 1 acclimatized to 4,060 m for 6 days while taking acetazolamide 250 mg three times a day. On day 7 acetazolamide was stopped, then resumed on day 8. Standardized exercise oximetry was performed each day. The protocol for group 2 was identical to group 1, except acclimatization occurred over 14 days to 4 120 m. The protocol for group 3 was identical to group 2, except subjects acclimatized to 4,770 m. Multivariate regression revealed a negative effect of stopping acetazolamide on exercise oxygenation (p=0.028). At 4,100 m cessation of acetazolamide after one week resulted in a 11% drop in exercise oxygenation (p=0.008); after two weeks acclimatization to this altitude there was an non-significant drop in exercise oxygenation (2.5% p=0.064). At 4 770 m acetazolamide cessation resulted in an increase in exercise oxygenation (7% p=0.027). We conclude that exercise oxygenation after acetazolamide cessation is dependent both on duration of acclimatization/drug administration, and acclimatization altitude.

Localization of the site of the bronchoconstrictor effects of leukotriene C4 compared with that of histamine in asthmatic subjects.

Although the sulfidopeptide leukotrienes are known to be potent bronchoconstrictors, the relative aerodynamic site of response to these compounds is controversial. We determined the decrease in maximal expiratory flow rates (Vmax) from partial and maximal flow-volume curves in seven asthmatic subjects after inhalation of aerosols of histamine or leukotriene C4 (LTC4) while breathing air or a mixture of 80% helium and 20% oxygen (He/O2). Density dependence (DD) of maximal expiratory flow was determined from partial expiratory flow volume curves by an isovolumic comparison of maximal expiratory flows with subjects breathing He/O2 with those obtained while breathing air. Measurements were made before and after inhalation of aerosols generated from graded concentrations of each constrictor agent. An aerodynamic site of response to LTC4 more central than for histamine was indicated by a significant (p less than 0.02) increase in DD with the former but not with the latter agonist. The ratio of Vmax at 30% vital capacity determined from maximal and partial maneuvers (M/P) was routinely higher at baseline while breathing He/O2 compared to the corresponding values with air, suggesting a degree of peripheral obstruction that was reversed by a deep inhalation. Obstruction induced by LTC4 inhalation resulted in a greater increase in M/P compared with baseline when air was the test gas (p less than 0.02). This was not observed when He/O2 was the test gas. Similar effects on M/P were not induced by histamine aerosol inhalation, consistent with a central airway response to LTC4 that was not affected by volume history.(ABSTRACT TRUNCATED AT 250 WORDS)