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Biomedical subjects

M Hulme

Publications and source records attributed to M Hulme.

9 recordsLinked to original sources
PubMed1982

Properties of intact and univalent (Fab) antibodies raised against isolated, solubilized, mouse zonae pellucidae.

Intact and univalent antibodies were prepared against mechanically isolated mouse zonae pellucidae solubilized in a variety of ways (heat, low pH, SDS, urea and trypsin). The antisera bound avidly and specifically to solubilized iodinated zona antigens and the intact zona structure. When the concentrations of immunoreactive Fab material in the intact and univalent antibody preparations were equalized and compared for their ability to block the sperm-binding stage of fertilization, only the intact gamma-globulin preparations possessed antifertility activity. These results indicate that antibodies raised against intact solubilized zonae pellucidae block fertilization by cross-linking antigens on the outer zona surface, thereby indirectly masking the sperm receptor sites. The integrity of these surface components did not appear to be affected by solubilization procedures that disrupt non-covalent bonds (heating, low pH, SDS and urea) although they did appear to be adversely affected by trypsin treatment. None of the antisera tested contained antibodies directed against the sperm receptor site indicating that these critical components lack immunogenicity.

Animals↗
PubMed1980

Amylobarbitone and forgetting.

In an earlier report (Hulme et al. 1979), we argued that sodium amylobarbitone (SAB) affects the acquisition of information. That conclusion was based on the finding that SAB produces rates of forgetting that are similar to control, thereby ruling out storage (and possibly retrieval) deficiencies which would predict dissimilar rates. However, it is possible that the rate of forgetting is itself influenced by the amount of information that actually entered store in the first place, and SAB reduces this by affecting acquisition. The possibility that both acquisition and storage could therefore have been affected was explored by equating control and drug zero delay performance, which was achieved by lowering the performance of control subjects. Nonetheless, subsequent rates of forgetting remained similar, thereby strengthening the acquistion hypothesis.

Amobarbital↗
PubMed1979

Effects of sodium amylobarbitone on memory processes in the pigeon.

An experiment was carried out in the pigeon to assess the effects of sodium amylobarbitone (SAB) on memory, using a delayed pair comparison task. Performance was disrupted at all delays by doses of 10 and 20 mg/kg SAB and it was concluded that this effect was not due to perceptual impairment or stereotyped responding, which the drug might have caused, since performance on a visual discrimination task was unaffected by the same doses of SAB. Two further experiments assessed proactive and retroactive effects by varying the inter-trial interval and by introducing an irrelevant orange stimulus at various stages of the delay interval. Although these manipulations disrupted performance, there was no evidence to suggest that the drug potentiated their effects in a specific manner. The results are discussed in terms of an encoding hypothesis, and some reference is made to the possible neuropharmacological basis of action of this drug.

Amobarbital↗
PubMed1979

Characterisation of the immunological response in marmoset monkeys immunised against hCG beta-subunit and its relationship with their subsequent fertility.

Female marmoset monkeys that are actively immunised against hCG beta-subunit remain infertile while antibody titres are high. With declining antibody levels the animals experience recurrent abortions that occur progressively later as the levels continue to wane. After booster immunisations the animals become infertile once more. The affinity and total binding sites of antibodies to beta-hCG were monitored after booster injections in marmosets and the values were correlated with subsequent reproductive events. The relationship between antibody amount and affinity varied considerably and the affinity was the important factor in producing the biological effects, pregnancies being often associated with a fall in antibody affinity. The antisera were also biologically active in inhibiting hCG-induced ovulation and increase in uterine weight in mice. There was no apparent cross-reaction between the antisera and human luteinizing hormone as tested by indirect immunofluorescence on adult human pituitary sections.

Abortion, Incomplete↗