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Biomedical subjects

M F Sullivan

Publications and source records attributed to M F Sullivan.

At least 55 records · Page 3Linked to original sources

Lytic spondylolisthesis above the lumbosacral level.

The syndrome produced by lytic spondylolisthesis depends on the level at which it occurs. Above the lumbosacral level the incidence of neurologic signs and spinal stenosis increases, and further forward slip in adult life is not uncommon. Twenty-seven patients with lesions above the fifth lumbar vertebra and symptoms severe enough to warrant surgery were studied. Some radiologic observations are made. The patients were divided into two groups for assessment of the results of surgery. Patients with no neurologic signs obtained satisfactory results after a fusion procedure alole. Patients with a neurologic deficit fared less well after surgery, and the importance of decompression in this group is stressed.

Adolescent↗

Sustained administration of cyclazocine for antagonism of morphine.

The plasma levels, distribution and excretion of tritium were determined after administration of a single or sustained dose of 3H-cyclazocine to naive and morphine-addicted rats. The plasma levels reached and maintainat animals tolerant to morphine were cross-tolerant to cyclazocine. Although only half the administered radioactivity was excreted after either a single dose or a continuous administration, no appreciable concentration was found in any of the organs studied. The behavior of a single or sustained dose of cyclazocine was also determined in rabbits to evaluate the effect of the implant site on the drugs release rate and tissue biocompatibility. The release-rate of 3H-cyclazocine from a glyceride matrix implanted subcutaneously or intramuscularly could be controlled by modification of the matrix itself or by manipulation of the drug concentration within the matrix. Durations of action between a few days and a month were obtained by these means from devices that were both biodegradable and tissue compatible. The results indicate that the procedures used here may provide a practical means for administering narcotic antagonists to addicts.

Animals↗

Sustained release of naltrexone from glyceride implants.

Solid dispersions of naltrexone in natural glycerides were used to form injectable implants which continuously release narcotic antagonists in vivo. The dispersions were formed and tested either as small cylindrical pellets, e.g. l x 3.0 mm in size, or as particles with diameters in size ranges between 125-250 mu, that are suspended in an aqueous methyl cellulose solution. Both types of implants delivered naltrexone to mice at rates that were effective in blocking the antiociceptive action of morphine for at least one month. The rate of naltrexone release was controlled by altering its concentration in the dispersion and by varying the glyceride composition. Degradation and absorption of the implants were found to depend on their composition, dimensions and location in the body. No appreciable tissue incompatibility was seen in mice, rats, rabbits, monkeys and swine, even when long-lasting preparations were removed a year after treatment.

Animals↗

Sustained release of naltrexone from glyceride implants.

Solid dispersions of naltrexone in natural glycerides were used to form injectable implants which continously release narcotic antagonists in vivo. The dispersions were formed and tested either as small cylindrical pellets, e.g. 1x3.0 mm in size, or as particles with diameters in size ranges between 125-250 mu, that are suspended in an aqueous methyl cellulose solution. Both types of implants delivered naltrexone to mice at rates that were effective in blocking the antiociceptive action of morphine for at least one month. The rate of naltrexone release was controlled by altering its concentration in the dispersion and by varying the glyceride composition. Degradation and absorption of the implants were found to depend on their composition, dimensions and location in the body. No appreciable tissue incompatibility was seen in mice, rats, rabbits, monkeys and swine, even when long-lasting preparations were removed a year after treatment.

Animals↗