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Biomedical subjects

R Bell

Publications and source records attributed to R Bell.

At least 253 records · Page 14Linked to original sources
PubMed1987

Acquisition of a brief behavioral experience in the presence of neuron-specific and D2-CAM/N-CAM-specific antisera.

The effect of intraventricular infusion of D2-CAM/N-CAM directed antibodies prior to the acquisition of a passive-avoidance paradigm is described. The antisera used in this study were the neuron specific anti-BPM and a D2-CAM/N-CAM specific serum, anti-D2. Anti-BPM reliably inhibited paradigm acquisition when recall was ascertained at 24 and 48 hours and no effect was noted with absorbed anti-BPM or in sham-operated animals. This effect was time-dependent and no inhibition of memory formation was noted when the antiserum was administered at 6 and 10 hours after training. In contrast, infusion of anti-D2 had no effect on paradigm acquisition. These findings are discussed in relation to the potential synaptogenic events associated with memory formation.

Animals↗
PubMed1987

Catecholamines and aggression in animals.

This paper assesses the evidence for the role of catecholamines in the aggressive behaviour of animals. The effects of manipulating dopamine and noradrenaline function, either alone or in combination, are considered with respect to two categories of aggression, predatory and affective. Affective aggression is further subdivided into shock-induced defensive fighting, isolation-induced aggression and irritable aggression. The results indicate that catecholamines may not have a specific role in aggressive behaviour. Rather, they may act more to excite or inhibit general behavioural systems, although certain treatments do have a specific influence on aggressive behaviour. The review also highlights certain problems concerning the psychopharmacology of aggression; different species may make varying responses to the same treatment, whilst treatments exerting a similar pharmacological action may result in diverse behavioural effects.

Aggression↗
PubMed1987

Friedreich's disease: V. Variant form with vitamin E deficiency and normal fat absorption.

A 30-year-old woman was thought to have Friedreich's disease because of progressive ataxia, dysarthria, and titubation from age 3 years. Her diet was normal, and there were neither symptoms nor laboratory evidence of liver disease or fat malabsorption. Serum vitamin E content and the ratio of serum vitamin E to total serum lipid were very low, but serum vitamin A, cholylglycine, and lipid levels were normal, as was an oral vitamin E tolerance test. Muscle biopsy showed the lysosomal inclusions of vitamin E deficiency. Mitochondria had normal oxidative phosphorylation using polarographic assays. The cause of her vitamin E deficiency was unknown.

Adult↗
PubMed1987

Reactivation of cytoplasmic actomyosin in Physarum plasmodia extracted with glycerol and dimethylsulphoxide.

Thin-spread plasmodia of Physarum were subjected to extraction procedures using 50% glycerol or DMSO (dimethylsulphoxide) followed by labelling of actin with fluorescent phallotoxins. During the reactivation of the actomyosin system by 2 mM-MgATP fluorescent actin fibres contract isotonically, which results in numerous fluorescent 'contraction beads'. After short-term extraction 1 mM-Ca2+ has an inhibitory effect on the reactivation. This calcium sensitivity is abolished after long-term extraction with glycerol. Calcium at 10 mM irreversibly inhibits reactivation, irrespective of the duration of extraction. The inhibitory effect of 10 mM-calcium is prevented by phallotoxin labelling prior to incubation in Ca2+. The DMSO model shows an improvement in structural preservation when compared with the glycerol models. However, reactivation is inhibited by prolonged treatment with DMSO.

Actomyosin↗
PubMed1987

Amiodarone-associated pulmonary fibrosis. Evidence of an immunologically mediated mechanism.

A case of pulmonary fibrosis attributed to amiodarone was studied immunologically and morphologically. A specific antibody of the IgG class was identified in the serum of this patient which reacted with the patient's own lung tissue. The immunoglobulin did not react with normal lung tissue nor was there evidence of reaction with lung tissue from patients with pulmonary fibrosis but without a history of amiodarone therapy. The patient probably developed a humoral antibody response to a lung-amiodarone complex with the amiodarone acting as a hapten which bound in vivo to the lung tissue. The subsequent antibody-antigen reaction stimulated a proliferation of pulmonary fibroblasts and probably enhanced the fibro-collagen deposition in the lung.

Amiodarone↗
PubMed1986

13-cis-retinoic acid in the treatment of oral leukoplakia.

13-cis-Retinoic acid has been reported to be effective in treating oral leukoplakia. We randomly assigned 44 patients with this disease to receive 13-cis-retinoic acid (24 patients) or placebo (20), 1 to 2 mg per kilogram of body weight per day for three months, and followed them for six months. There were major decreases in the size of the lesions in 67 percent (16 patients) of those given the drug and in 10 percent (2 patients) of those given placebo (P = 0.0002); dysplasia was reversed in 54 percent (13 patients) of the drug group and in 10 percent (2 patients) of the placebo group (P = 0.01). The clinical response to the drug correlated with the histologic response in 56 percent (9 of 16) of the patients evaluated. Relapse occurred in 9 of 16 patients two to three months after treatment ended. The toxic effects of the drug were acceptable in all but two patients. Cheilitis, facial erythema, and dryness and peeling of the skin were common; conjunctivitis and hypertriglyceridemia also occurred. All adverse reactions could be reversed by reducing the dose or temporarily discontinuing the drug. We conclude that 13-cis-retinoic acid, even in short-term use, appears to be an effective treatment for oral leukoplakia and has an acceptable level of toxicity.

Aged↗
PubMed1986

Intracranial histiocytosis X: a case report.

A case of intracranial histiocytosis X that presented radiologically with thickening of the pituitary stalk is presented. The radiologic findings, including a blush seen on angiography, are described.

Adult↗
PubMed1986

Spurious detection of terminal deoxynucleotidyl transferase in phytohemagglutinin-stimulated lymphocytes.

Expression of terminal transferase (TdT) is believed to be restricted to primitive lymphoid cells; recently, however, indirect immunofluorescent (IF) assays have been used to demonstrate the apparent presence of TdT in phytohemagglutinin (PHA)-stimulated peripheral blood lymphocytes and in various nonlymphoid malignancies. Using an IF assay, we found that a heteroantiserum to TdT reacted with cultured and PHA-stimulated human peripheral blood mononuclear cells, but we were unable to confirm the presence of TdT in these cells using immunoblotting and biochemical assays. We conclude that the IF results are spurious and most likely represent recognition by the heteroantiserum of inducible protein(s) other than TdT.

Clinical Enzyme Tests↗
PubMed1985

Perceptions of facial profile and their influence on the decision to undergo orthognathic surgery.

Eighty patients, who had previously been evaluated by an oral surgeon and an orthodontist as requiring orthognathic surgery, completed questionnaires rating their perceptions of their own profiles. Half of the patients had decided to undergo surgical correction of their jaw deformities, while the other half had decided against surgical treatment. In addition, booklets containing pretreatment photographs of all 80 patients were mailed to 37 oral surgeons, 46 orthodontists, and 43 lay persons. These three groups of evaluators rated the patients' profiles, using the same rating scales that the patients had used. Cephalometrically, the two patient groups were statistically the same in all skeletal and soft-tissue measures except for ANB (mean difference = 1.8 degrees) and soft-tissue AN-pogonion (mean difference = 2.4 degrees). Differences in these dimensions were considered in subsequent data analyses. Results of this study support the following conclusions: In spite of the fact that surgical treatment may be recommended by dental specialists and indicated by cephalometric measurements, self-perceptions of profile are more important in the patient's decision to elect surgical correction; the perception by others that the profiles of patients deciding against surgery are closer to ideal may have some influence on their decision against surgical correction of their jaw deformities; oral surgeons and orthodontists evaluate facial profiles similarly, but surgeons are more likely to recommend surgical correction; lay persons are more likely to rate an individual's profile as being normal than are dental specialists in orthodontics and oral surgery; in contrast, individuals perceive their own profiles differently than orthodontists, oral surgeons, and lay persons, particularly with respect to the mandibular and dentoalveolar dimensions.

Adolescent↗
PubMed1985

Raising the orphan foal.

Orphan foals are best reared by fostering them onto a brood mare of appropriate size. If no foster mother is available, they can be reared on 2 per cent fat skimmed cow's milk fortified with dextrose at the rate of 20 gm per L. This should be slowly increased from 10 per cent of body weight at 1 day of age to 25 per cent of body weight at 10 days of age. The amount should then be held constant until weaning. Alternatively, foals can be reared on milk replacers. Manufacturers' feeding instructions rarely mimic the milk intake obtained by a foal nursing her dam, and problems have been observed in milk replacer fed foals. It may be better to feed milk replacers at 1- to 2-hour intervals as a 12.5 per cent solution. The volume fed can be slowly increased from 5 per cent of body weight at day 1 to 20 per cent of body weight at day 10. Fresh water, hay, and good-quality creep feed with at least an 18 per cent crude protein should be offered from 2 weeks of age. Foals can be weaned at 8 to 12 weeks of age.

Animal Nutritional Physiological Phenomena↗
PubMed1985

Hemodialysis clearance of pentobarbital during continuous infusion.

The hemodialysis clearance of pentobarbital during continuous infusion was determined in a 34-year-old man in acute renal failure. Pentobarbital specimens were obtained simultaneously from arterial blood entering and leaving the dialysis machine at five 1-h intervals. The mean hemodialysis clearance of pentobarbital was 22.3 ml/min. Pentobarbital concentration was relatively unaffected throughout the dialysis period, because of the high dose and continuous infusion of a drug with low hepatic intrinsic clearance and a short dialysis period. A large contribution to total body clearance was not evident, and dosage adjustment would have been unwarranted.

Acute Kidney Injury↗
PubMed1985

Digital subtraction angiography of the extremities using table translation.

Digital subtraction angiography (DSA) of the extremities has been performed with both intravenous and intraarterial injections of contrast material. Intravenous studies are usually site specific and are limited by contrast material load; a complete intraarterial study with multiple injections of contrast material may be time consuming. A feasibility study to evaluate a DSA technique that would allow table translation and imaging of two contiguous regions following a single injection of contrast material--bolus-chase DSA--was performed. Forty-five examinations were performed, 13 intravenously and 32 intraarterially. Twelve intravenous and 16 intraarterial DSA examinations were totally satisfactory. Inadequate studies were predominantly caused by slow arterial clearance of contrast material in the distal calf and by operator error. Compared with conventional DSA, anatomic studies of lower-extremity vessels could be obtained faster and with lower contrast material loads using bolus-chase DSA.

Adult↗
PubMed1985

Drugs as research tools in psychology: cholinergic drugs and aggression.

A review of studies using cholinergic drugs as tools to investigate the neural mechanisms mediating affective and predatory aggressive behaviour reveals that the same two cholinergic systems are involved with both sorts of behaviour. There is a brain muscarinic system initiating aggression and a nicotinic system which inhibits aggressive behaviour. This evidence suggests that there could be two possible forms of cholinergic therapy for aggression, cholinolytics and nicotinic agonists. These possibilities are discussed.

Aggression↗