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Biomedical subjects

M Randall

Publications and source records attributed to M Randall.

7 recordsLinked to original sources
PubMed1978

Opiates, catecholamines, behavior, and mood.

Indirect evidence has linked opioid reinforcement with changes in noradrenergic metabolism secondary to drug administration. Methodological precedents for biobehavioral correlations in depressive illness have suggested an important association between changes in mood and biogenic amine excretion patterns in the urines of patients during depression and recovery. This paper presents preliminary data on the possible relationship between changes in catecholamine excretion that were observed and the changes in behavior, mood, psychiatric status, and cardiorespiratory physiology secondary to heroin administration and methadone-assisted withdrawal. This study focuses on the urinary excretion of MHPG, since an appreciable fraction of this metabolite is probably derived from norepinephrine originating in the brain. The subjective changes in mood associated with heroin use, the decrease in respiratory rate, and the behavioral and mental status effects associated with opiate intoxication were observed only in the individuals whose MHPG excretion increased during the period of opiate administration.

Adult↗
PubMed1976

Changes in shape, ossification and quality of bones in children with spina bifida.

Changes in the cross-sectional shape, size, bone mass and amount of unmineralised osteoid tissue were studied in 17 dissected tibiae from spina-bifida babies who died with paralysis and foot deformities and in 14 tibiae from non-spina bifida controls of matching age. In addition, 12 tibiae from young experimental rats with myotomy of foot dorsiflexors and foot plantiflexors were double-labelled with bone-seeking markers and studied in order to find the role of experimental muscle imbalance in the dynamic remodelling of the developing long bones. It was found that in tibiae from spina-bifida children with paralysis the total area of cortical bone, its thickness, number of Haversian systems and number of large remodelling cavities are diminished. Significant changes in the cross-sectional shape of the midshaft of the tibia were found, ranging from the triangular shape seen in normal babies and in those with spina bifida and calcaneus-type foot deformity, to the circular shape of tibiae from babies with spina-bifida paralysis and no foot deformity or with spina bifida and equinovarus-type of deformity. Results of experimental myotomy on growing rats showed the direct influence of working muscles on the remodelling process of growing tibiae. On the side of myotomy the flat cortex resumed a bulging convex shape and the centre of gravity shifted towards the myotomised side. These principles cannot on their own explain the specific changes in the shape of human tibiae found during anatomical studies. There is, however, a common denominator in these apparently contradictory findings. This is the combined action of two factors previously reported: the combination of paralysis of the growing limb and mechanical intra-uterine pressure acting on it. The findings in the present study also indicate that they played a major role in the production of deformities. The total amount of osteoid tissue in spina-bifida paralysed bone is increased. This delay of mineralisation of newly laid-down bone matrix would lead to softening of the new bone matrix and osteoid-rich subepiphyseal and metaphyseal regions. This 'paralytic rickets', together with the diminished total bone mass found, could probably be the cause of the common spina-bifida fractures in these regions.

Animals↗
PubMed1976

Aftercare on narcotic antagonists: prospects and problems.

This study examines the problems and prospects of aftercare of the multiple treatment failure opiate addict who is being treated with narcotic antagonists (primarily naltrexone). At the time of this paper, 21 patients had been admitted to the Drug Addiction Research Project at McLean Hospital, with a retention rate of 42%. "Completers," "noncompleters," and "dropouts" could not be differentiated on the basis of demographic or psychiatric variables, thus making it impossible to define the population most suited for antagonist treatment. The degree of carry-over into the first month in the community, for those who successfully completed the inpatient segment of the program, disappeared over time. The nonreinforcing (lack of euphoric effect) properties of the antagonists and the resultant high level of motivation necessary for the continuation of its use by the patient make this form of treatment suitable for only a small percentage of the "hard core" addict population.

Adult↗