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Biomedical subjects

R J Collins

Publications and source records attributed to R J Collins.

7 recordsLinked to original sources
PubMed1979

Dose and physical dependence as factors in the self-administration of morphine by rats.

Groups of naive rats were offered morphine sulfate for self-admininstration in doses of 0.0032-10 mg/kg for 6 days. On day 7 saline was substituted for morphine. Loss of weight was taken as physiological evidence of dependence. Rats that did not lose weight formed a single population whose mean injection rate did not differ from control rats receiving only saline injections. Injection rates for rats losing weight were log-normally distributed, and the mean of the logarithms of the injection rates was linearly related to the logarithm of the dose. Mean daily injection rates averaged 12 for controls, 23 at 10 mg/kg, and 411 at 0.01 mg/kg. A transient increase in morphine intake after an injection of nalorphine was taken as behavioral evidence of dependence. Nalorphine increased morphine intake when rats were self-injecting 0.32 and 1.0 mg/kg of morphine, but not 0.032 or 0.1 mg/kg. The reinforcing property of morphine may occur without behavioral evidence of dependence.

Animals↗
PubMed1978

Drug labelling.

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Adult↗
PubMed1978

Pharmacology of some metabolites of triazolam, alprazolam, and diazepam prepared by a simple, one-step oxidation of benzodiazepines.

A simple, one-step chemical oxidation of triazolam (7) to its 4-hydroxy analogue, 7a, has been developed and applied to other triazolo- and imidazobenzodiazepines. The reaction may be used to convert diazepam to temazepam. 4-Hydroxytriazolo[4,3-a][1,4]benzodiazepines have low central nervous system sedative and anticonvulsant activity in sharp contrast to metabolites of diazepam which remain active. While 10, an alpha-hydroxy metabolite of triazolam, retains much of the activity of 7, 10a, and alpha,4-dihydroxy metabolite of triazolam, is 250 times less potent than 7 on the nicotine-antagonism assay and over 300 times less potent on the traction assay.

Animals↗
PubMed1977

A population of lymphocytes in human blood distinctive in morphology and other characteristics.

Evidence is presented that lymphocytes characterised by being large and having abundant feebly staining, and usually profusely granulated cytoplasm ('pale' cells) are a group which is distinct from the other small basophilic ('dark') cells. In patients with genetic storage disorders characterised by abnormalities of lymphocyte structure, the structural peculiarites were confined to the basophilic cells, and cytochemical differences were found between the 'pale' and 'dark' cells in normal subjects.

Adolescent↗
PubMed1975

Specificity and sensitivity of skin test reactions to extracts of Toxocara canis and Ascaris suum II. Homologous 48-hour passive cutaneous anaphylaxis tests with sera from infected guinea pigs.

The specificity and sensitivity of adult and larval somatic antigens and perienteric fluid of Toxocara canis and Ascaris suum were investigated by using a modified passive cutaneous anaphylaxis procedure in guinea pigs. Pooled sera from animals infected with low doses (0.01, 0.1, or 1.0 egg/g) were most reactive with the homologous larval antigen preparation. However, the Toxocara antisera were highly reactive with this antigen only, whereas the Ascaris antisera reactions could not be interpreted as being clearly positive with any of the antigen preparations. Sera from hyperinfected animals were also reactive with the homologous larval antigen. In addition, Ascaris larval antigen was reactive with Toxocara antiserum. The reciprocal relationship, i.e., reactivity of Toxocara larval antigen with Ascaris antiserum, was no apparent. In no instance did adult antigens induce reactions that could be interpreted as specific or sensitive indicators of antibody.

Animals↗