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Biomedical subjects

J D Gray

Publications and source records attributed to J D Gray.

68 records · Page 4Linked to original sources
PubMed1980

Decreased elimination of theophylline after influenza vaccination.

The elimination of theophylline is decreased after vaccination against influenza. In three patients receiving 200 mg of oxtriphylline (equivalent to 128 mg of theophylline) every 6 hours by mouth the serum theophylline levels rose after vaccination, and in four healthy volunteers given the same dose of oxtriphylline 24 hours after vaccination the half-life of theophylline increased by an average of 122%. Two of the three patients showed signs of a toxic reaction to the drug. These results suggest that the elimination of theophylline is impaired to a clinically important degree after influenza vaccination and that the resulting levels of the drug can be toxic even when conventional therapeutic doses of theophylline are given.

Aged↗
PubMed1969

The emission of corrosive vapours by wood. Sweet-chestnut (Castanea stiva) and wych-elm (Ulmusglabrau) O-acetyl-4-O-methylglucuronoxylans extracted with dimethyl sulphoxide.

1. O-Acetylated 4-O-methylglucuronoxylans were isolated from sweet chestnut and wych elm, either green or incubated at 48 degrees and 100% relative humidity for 36 weeks. 2. The chlorine-ethanolamine method of delignification resulted in a 50% loss of O-acetyl groups from green wych elm compared with an 18% loss from green sweet chestnut. 3. The acid-chlorite method gave an acceptable loss of O-acetyl groups in three cases, but incubated sweet chestnut showed a 44.6% loss. However, it is believed that this is due to the loss of simple O-acetylated xylose sugars resulting from glycosidic hydrolysis, rather than removal of O-acetyl groups by direct hydrolysis. Assuming that this occurs in a random manner, it is unlikely to have much structural significance. 4. Dimethyl sulphoxide extraction of chestnut holocellulose and elm holocellulose, green and incubated, yielded O-acetyl glucuronoxylans containing 10.2, 3.8, 13.1 and 7.7% O-acetyl groups respectively. 5. The location of these O-acetyl groups was determined by Bouveng's method in which phenyl isocyanate is used as a blocking group.

Acetates↗
PubMed1969

The emision of corrosive vapours by wood. Hot-water-extracted O-acetylated hemicelluloses from sweet chestnut (Castnaea sativa) and wych elm (Ulmus glabrau) and a discussion of O-acetyl-group changes occurring in these woods during incubation at 48 degrees and 100 per cent relative humidity.

1. O-Acetylated polysaccharides were obtained from green wood of both sweet chestnut and wych elm by treatment of the residue remaining after dimethyl sulphoxide extraction with water at 98 degrees . This gives a mixture of polysaccharides containing xylose, galactose, glucose and uronic acids. Analysis of these and their fractionated products suggest that only xylans in green sweet chestnut and green wych elm are O-acetylated. 2. The isolated O-acetylated xylans are not representative of the total O-acetylated xylans occurring in sweet chestnut and wych elm. 3. Application of the method developed by Bouveng for the location of O-acetyl groups to all four O-acetylated xylans obtained in this series of investigations by dimethyl sulphoxide extraction showed that those from sweet chestnut and wych elm, under the same conditions of incubation, lost: 74.2 and 43.4% of acetyl groups respectively, at C-2; 58.0 and 28.5% of acetyl groups respectively at C-3; 41.8 and 82.2% of acetyl groups respectively at C-2 and C-3. 4. A consideration of electronic and steric factors indicates that there does not appear to be a purely chemical reason for the difference in loss of O-acetyl groups between sweet chestnut and wych elm. It is suggested that the location of O-acetylated xylans in the wood cell walls and the presence of extractive may play some part in this difference.

Acetates↗
PubMedDate not supplied

Generation of natural killer-like cytotoxicity from human thymocytes with interleukin-2.

Human thymocytes cultured in the presence of an interleukin-2 (IL-2) source (the supernatant of the MLA 144 cell line) that contains no lectin or interferon (IFN) activity become cytotoxic to K562 target cells. Inclusion of allogeneic lymphoblastoid cells in these cultures results in the earlier detection of cytotoxic activity. Addition of IFN to the thymocyte cultures has no effect on the development of cytotoxic activity. In contrast, the cytotoxic activity of IL-2 activated thymocytes can be augmented by subsequent exposure to IFN. The specificity and cell surface phenotype of the cytotoxic thymocytes are similar to that of peripheral blood natural killer cells.

Adjuvants, Immunologic↗