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Biomedical subjects

J Richardson

Publications and source records attributed to J Richardson.

At least 289 records · Page 16Linked to original sources
PubMed1988

Role of indomethacin in ductus closure: an update evaluation.

Patent ductus arteriosus (PDA) in premature infants is a current challenge to pediatricians. Pharmacological closure of PDA with indomethacin, a prostaglandin synthetase inhibitor is an effective drug therapy, along with usual medical treatment. Administration of indomethacin may decrease mortality and morbidity (e.g. bronchopulmonary dysplasia) among very small premature infants (less than 1,000 g). Co-administration of furosemide with indomethacin may lessen the transient renal side effects of indomethacin. The therapeutic efficacy of indomethacin in closure of PDA depends largely on understanding and manipulation of the pharmacokinetic characteristics of the drug in preterm infants. Maintaining a therapeutic level of the drug in plasma is essential to achieve an optimal therapeutic response. Compared to surgical ligation, indomethacin is a noninvasive, less expensive and safer therapy for ductus closure.

Ductus Arteriosus, Patent↗
PubMed1987

Quality of life survey of urinary diversion patients: comparison of ileal conduits versus continent Kock ileal reservoirs.

There has been a recent marked increase in interest in continent urinary diversions. While considerable time has been spent on the technical aspects of these diversions the psychological impact has not yet been fully explored. We describe an extensive survey that was conducted among 100 consecutive adults (87 respondents) who had undergone urinary diversion via an ileal conduit and 100 consecutive adults (85 respondents) in whom a continent Kock ileal reservoir was created during the last 3 to 5 years at our university by the same surgeons. The Kock pouch patients were stratified further into 63 with primary diversion and 22 who underwent conversion from previous conduit diversions. The survey consisted of a questionnaire that included a social and sexual survey, the Beck Depressive Inventory, the Profile of Mood States and a physical impact study. The results revealed that all patients surveyed generally were satisfied with the diversions and they had adapted reasonably socially, physically and psychologically. The key to adaptation seemed to be a detailed, realistic preoperative education about the type of diversion used. Patients with ileal conduit diversions had the lowest expectations of the form of diversion as defined by the preoperative awareness of the need to wear an external ostomy appliance with its associated inconveniences and change in the external body image. Postoperatively, ileal conduit patients also had the poorest self images as defined by a decrease in sexual desire and in all forms of physical contact (sexual and nonsexual). The subset of patients who underwent conversion from conduit diversions to Kock pouches, however, were statistically the most satisfied, and they were the most physically and sexually active. We conclude that the Kock continent urostomy offers an important alternative to noncontinent forms of diversion.

Adaptation, Psychological↗
PubMed1986

Reticular elicitation of hippocampal slow waves: common effects of some anxiolytic drugs.

Anxiolytic drugs share many of the common behavioural effects of septal and hippocampal lesions in animals. Gray attributes this to changes which the anxiolytics produce in septal generation of hippocampal rhythmical slow activity. However, lesions of the dorsal ascending noradrenergic bundle reproduce this electrophysiological effect of the anxiolytics while only reproducing part of the behavioural profile of the anxiolytics. The present paper reports what appears to be a second common effect of anxiolytic drugs on the generation of hippocampal slow waves which could underlie their behavioural effects. Freely moving rats, previously implanted with electrodes, received high frequency electrical stimulation of the midbrain reticular formation to elicit hippocampal rhythmic slow activity. The frequency of the slow waves produced increased linearly with increasing stimulation intensity as has been reported previously. A barbiturate (amylobarbitone, 15 mg/kg, i.p.) and three benzodiazepines (chlordiazepoxide, 5 mg/kg; diazepam, 5 mg/kg; alprazolam, 1 mg/kg) all decreased the slope of the voltage-frequency function and decreased overall frequency of slow waves produced. Two antipsychotic drugs (haloperidol, 0.2 mg/kg; chlorpromazine, 2 mg/kg) produced similar behavioural sedation to the anxiolytics but did not decrease either the slope of the voltage-frequency function nor the overall frequency of slow waves. The results show that these barbiturates and benzodiazepines produce a common reduction in the frequency of hippocampal rhythmical slow activity. Given the importance attached to slow waves in current theories of hippocampal function, it is possible that this electrophysiological effect could have some relation to the behavioural effects of these anxiolytic drugs. If the effect can be shown to generalize to other classes of anxiolytic drug it could reflect changes in the substrate for the common effects of anxiolytic drugs on behaviour.

Amobarbital↗
PubMed1986

Vitamin C and immunosuppression.

Large daily doses of vitamin C resulted in severe lymphocytopenia in stressed mice. A characteristic biochemical expression of stress is an abrupt increase in adrenal corticosteroids in blood plasma which is always preceeded by a release of vitamin C by the adrenals. It is hypothesized that large doses of vitamin C maintain high levels of plasma corticosteroids which inturn may reduce the organism's immune response when stress is present.

Adrenal Cortex Hormones↗
PubMed1986

Chondrogenesis in peripheral fibromas of the gingiva. Histochemical demonstration of oxytalan fibers and mucopolysaccharides.

Five lesions were studied to elucidate the histogenesis of cartilage in peripheral fibromas. Cytological features suggested direct transformation from fibroblast-like cells to chondrocytes (cartilaginous metaplasia). Supportive evidence for such differentiation was the presence of neutral and acid mucopolysaccharides in the loose stroma of the lesions as well as in the ground substance of the cartilaginous centers. In one instance, the metaplastic cartilage showed bone formation. An increased number of oxytalan fibers could be demonstrated in the fibroma and in the cartilage.

Adult↗
PubMed1986

Retinal macroaneurysm: natural history and guidelines for treatment.

This report describes the features and clinical significance of retinal macroaneurysm. Two groups can be defined: those with acute aneurysmal decompensation, Group I; and those with chronic aneurysmal decompensation, Group II. Haemorrhage is the main feature of the former group and exudates of the latter. Systemic and local associations are noted, and guidelines for treatment by phototherapy are discussed.

Aged↗