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T Dick

Publications and source records attributed to T Dick.

81 records · Page 5Linked to original sources
PubMed1980

Laryngeal and diaphragmatic responses to airway occlusion in sleep and wakefulness.

Under anesthesia, electrodes were implanted in 5 adult cats for chronically recording sleep parameters. In the same operation, a tracheal fistula was created that allowed tracheal intubations for recordings of breathing (pneumotachography) and tracheal occlusions in subsequent experiments conducted during the spontaneous sleep-waking cycle. After a recovery period of at least 3 months, electrodes were placed, under ether anesthesia, in the laryngeal abductors. Two days later, electrodes were inserted into the diaphragm, and the responses of the diaphragm and laryngeal abductor muscles to airway occlusion in sleep and wakefulness were studied. Total airway occlusion at end-expiration in NREM sleep caused a progressive augmentation of both laryngeal adductor and diaphragmatic activity. Increases in laryngeal abductor activity exceeded for increases in diaphragmatic activity. The greatest augmentations between one breath and the next were seen when occluded breath "n" occurred in sleep and occluded breath "n + 1" occurred in wakefulness. This augmentation of activity at the transition from sleep to wakefulness was greater for the laryngeal abductors than for the diaphragm, and it signifies an immediate wakefulness stimulus to the response to an occlusion. Occlusions in REM sleep caused a variable augmentation in laryngeal inspiratory activity, but, across animals, there was no clear augmentation of either tonic (expiratory) laryngeal abductor or diaphragmatic activity. In addition, arousal in response to occulusion was delayed in REM sleep.

Airway Obstruction↗
PubMedDate not supplied

The Antibacterial activity in vitro and beta-lactamase stability of the new cephalosporin HR 810 in comparison with five other cephalosporins and two aminoglycosides.

The antibacterial activity of the cephalosporin antibiotic HR 810 was evaluated in comparison with cefoperazone, cefotaxime, ceftazidime, ceftriaxone, latamoxef, gentamicin and amikacin against 1500 clinical isolates. HR 810 is the antibiotic with the broadest antimicrobial spectrum. It is also highly active against isolates of the genera Pseudomonas, Enterobacter, Staphylococcus and enterococci. HR 810 is very stable against hydrolysis by plasmid-coded and chromosomally coded beta-lactamases.

Acinetobacter↗
PubMedDate not supplied

Incidence and abundance of mycotoxins in maize in Rio Grande do Sul, Brazil.

The levels of aflatoxins B1, B2, G1, and G2, ochratoxin A, zearalenone and sterigmatocystin were determined by thin-layer chromatography in 36 samples of stored maize in the state of Rio Grande do Sul; the samples were obtained from May to September 1988, 23 samples were from silos and 13 samples were collected directly from farms. In 34.8% of the samples from silos aflatoxin B1+G1 was detected in concentrations that varied from 12 to 906 micrograms/kg. In 13% of the samples from silos aflatoxin B2 was detected in concentrations that varied from 48 to 180 micrograms/kg. In 9% of the samples from silos aflatoxin G2 was detected in concentrations that varied from 6 to 11 micrograms/kg. In 23% of the samples collected directly from farms aflatoxin B1+G1 was detected in concentrations that varied from 10 to 14 micrograms/kg. Ochratoxin A, zearalenone and sterigmatocystin were not detected at any time.

Aflatoxin B1↗
PubMedDate not supplied

Inducibility of the Streptomyces traRts107-Ptra expression cassette in Mycobacterium smegmatis.

An inducible Streptomyces expression cassette utilising the Ptra promoter and a temperature-sensitive allele of the TraR repressor from S. nigrifaciens plasmid pSN22 was tested in Mycobacterium smegmatis. Using reporter assays and Northern blot analysis, a marked increase of Ptra-directed transcription was observed upon a temperature shift from 28 to 37 degrees C. These results show that the S. nigrifaciens promoter-repressor cassette is functional in M. smegmatis. However, comparison of the level of induced Ptra-directed transcription with the level of transcription directed by the strong mycobacterial promoter Phsp60 indicated that the relative strength of the Ptra promoter was low. Considering the severe limitation of inducible expression systems for mycobacteria, this Streptomyces cassette might be a useful starting point for the development of a compact and fully portable inducible mycobacterial expression cassette.

Bacterial Proteins↗