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Biomedical subjects

J Randall

Publications and source records attributed to J Randall.

At least 55 records · Page 3Linked to original sources
PubMed1986

Haemorrhage and perforation of gastrointestinal neoplasms during chemotherapy.

Gastrointestinal haemorrhage and perforation are known complications of cytotoxic therapy for chemosensitive tumours involving the wall of the gut, in particular non-Hodgkin's lymphoma. These complications can be avoided by aggressive surgery before chemotherapy is started. When they do occur, early operative intervention is essential to reduce morbidity and mortality. We report 4 cases in whom delay in diagnosis and surgery led to 3 deaths and suggest a policy for the management of such cases in the future.

Adult↗
PubMed1985

Naloxone potentiates the depressant effect of chlordiazepoxide on spontaneous activity in mice.

Recent reports suggest that at least some of the behavioural effects of benzodiazepines may involve interaction with endogenous opioid mechanisms. In the present study, chlordiazepoxide (CDP, 10-20 mg/kg, i.p.) induced dose-dependent reductions in spontaneous locomotor activity and rearing in mice. Although naloxone (1 mg/kg) was itself without effect, and did not alter behavioural changes induced by the lower dose of CDP, it enhanced the depressant effects of 20 mg/kg CDP on locomotor activity. Results are discussed in relation to previous studies in which opiate antagonists have been found to block or to have no effect upon behavioural actions of benzodiazepines.

Analysis of Variance↗
PubMed1985

Hot-plate learning in mice is unaltered by immediate post-training administration of naloxone, naltrexone or morphine.

Repeated exposure to the hot-plate assay results in shorter response latencies in both rats and mice. In view of the postulated role of endorphins in memory processes, the present study examined the effects of immediate post-trial opiate-induced manipulations on this phenomenon of hot-plate learning. In experiment 1, adult male mice were injected with naloxone (0.1-10.0 mg/kg, i.p.) immediately after initial hot-plate testing and were reassessed 24 and 48 hr later. In experiment 2, mice were similarly treated with either naltrexone (0.1-10.0 mg/kg) or morphine (0.5-5.0 mg/kg) and retested 48 and 72 hr later. Results indicated a potent training effect in all groups but failed to reveal any significant effects of drugs. These data are inconsistent with a role for endorphins in hot-plate learning and, further, may question the generality of the involvement of opioids in memory processes.

Animals↗
PubMed1984

Shoulder reconstruction following disarticulation for ruptured mycotic aneurysm.

A method of wound management following shoulder disarticulation is described. In this report, the primary lesion is a mycotic aneurysm of the axillary artery. The pectoralis major muscular flap provides satisfactory coverage and maintains shoulder contour. It can be performed in a single procedure. Preoperative arteriography is important to determine the extent of arterial damage as well as the vascular anatomy of the proposed flap.

Adult↗
PubMed1982

The measurement and interpretation of Brillouin scattering in the lens of the eye.

Brillouin scattering from hypersonic waves in the eye lenses of many animals has been observed with a multipass Fabry Perot interferometer. The measured values of speed and attenuation range widely among the different species and in different parts of any one lens. These variations correlate broadly with the observed stiffness and the densities that have been measured with a graded column. From the spectroscopic and density measurements high-frequency elastic moduli may be derived. The results are also evaluated at a macromolecular level in terms of scattering of hypersonic waves from spherical entities composed of the crystallins and their aggregates. Reasonable agreement is obtained for the hypersonic speed for lower protein concentration; the hypersonic attenuation and variation with scattering vector are consistent with the presence of large aggregates (of order 100 nm radius) in certain of the materials.

Animals↗
PubMed1981

Small-angle neutron scattering studies of the conformation of myeloma protein MOPC315 and its Fab fragment, and the interaction with a monovalent dinitrophenyl hapten.

The first small-angle scattering study of an immunoglobulin A is reported. Neutron measurements have been made to determine conformational parameters of the mouse myeloma protein MOPC315 and to relate these to previous immunoglobulin G results. Use of the contrast method shows that the MOPC315 IgA molecule is not simply globular, that it has a dry volume of 220.0 +/- 4.5 nm3 corresponding to a mass density of 1.275 +/- 0.025 g cm-3 and that its full and cross-sectional radii of gyration, corrected for concentration dependence, are 7.97 +/- 0.07 nm, 2.40 +/- 0.08 nm and 1.33 +/- 0.07 nm respectively. Similar study of its Fab fragment gives a dry molecular volume of 69.0 +/- 0.7 nm3, a mass density of 1.285 +/- 0.015 g cm-3 and uncorrected radii of gyration that are consistent with those of the parent and support an overall "T" or "Y" conformation in solution. Addition to saturation of a small monovalent dinitrophenyl hapten leaves the dry volume of the whole molecule unaltered, but may slightly lower one or more of its radii of gyration. The significance of this finding is discussed. Comparative studies with rabbit anti-dinitrophenyl immunoglobulin G antibody suggest a different initial conformation but similar consequences of hapten binding, which, if real, are probably unrelated to classical complement fixation.

Amino Acid Sequence↗
PubMed1977

Serotonin levels in the blood and central nervous system of a patient with sudanophilic leukodystrophy.

A case report is presented of a boy with the infantile spasm syndrome beginning at eight months of age. He had a clinical course marked by increasingly severe seizures and neurological regression. After death at twenty-one months of age, autopsy of the central nervous system revealed demyelination of white matter with sparing of arcuate fibers. An earlier born male sibling had had a similar clinical pattern but died without an autopsy. During his lifetime, the patient had markedly elevated levels of 5-hydroxyindoles (a measure of serotonin) in his blood. At autopsy, the level of 5-hydroxytryptamine (serotonin) in four grey matter areas of the brain was lower than those of a control who died on the same day. This is the first case reporting a comparison of blood and central nervous system levels of 5-hydroxytrypamine in a child.

Age Factors↗