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Biomedical subjects

R Morris

Publications and source records attributed to R Morris.

At least 37 records · Page 2Linked to original sources
PubMed1992

Complex cranial base trauma resulting from recreational fireworks injury: case reports and review of the literature.

Two patients who sustained complex skull base trauma secondary to recreational fireworks injuries are reported. Initial assessment and management included axial and coronal computerized tomography, control of hemorrhage, debridement of wound and brain, isolation of brain from external environment, and reconstruction of the cranial base floor. Secondary orbital and facial reconstruction used available bone fragments and iliac bone graft in one patient and vascularized free tissue transfer in the other. In both patients, reconstruction of both the intracranial and extracranial compartments was successful with acceptable cosmetic result. Modification of multiple conventional approaches, along with a multispecialty surgical team, was used to deal effectively with these unique cases.

Adult↗
PubMed1992

Collagen gel contraction by cells associated with proliferative vitreoretinopathy.

The capacities of porcine choroidal fibroblasts, retinal glial cells, and retinal pigment epithelial cells to contract collagen gels in vitro were compared. Experiments with varied cell numbers indicated that glial cells are the most effective, followed by choroidal fibroblasts and retinal pigment epithelial cells. Analysis of the secretory products from cultures of these cell types revealed that retinal pigment epithelial cells synthesize and secrete peptides that promote fibroblast contraction of collagen gels in vitro. The mechanism of action of the retinal pigment epithelial cell-secreted contraction promoter was compared with that found in serum (type A) and secreted by cultured endothelial cells (type B). Like the serum factor, the retinal pigment epithelial cell-secreted factor was not dependent on active protein synthesis by the target cell and must be present continuously to promote contraction.

Animals↗
PubMed1991

The Johannesburg cardiac rehabilitation programme.

Cardiac rehabilitation has become a generally accepted mode of treatment for patients suffering from coronary artery disease. The Johannesburg cardiac rehabilitation programme was started in 1982 and has rapidly grown to become one of the largest programmes in southern Africa. This paper describes the 387 patients admitted to the unit between June 1986 and July 1988 and evaluates the effects of a combined exercise training and lifestyle modification programme. The mean age on admission was 55 years for males and 58 years for females. Most patients were from social classes I and II. Myocardial infarction, coronary artery bypass graft and a combination of both were the most common reasons for admission (35.4%, 23% and 21.2% respectively). On admission 72.9% of patients were smokers, 26.3% had hypertension and 34.3% had hypercholesterolaemia. A 50% drop-out rate within 12 months of starting the programme was noted. An increase in peak oxygen uptake, weight and skinfold thickness reduction, and improvement in the lipogram were seen after 6 months in patients who complied well with the programme. Cardiac rehabilitation is a secondary preventive strategy that can complement traditional medical and surgical therapies.

Adult↗
PubMed1991

Exercise-related cardiac arrest in cardiac rehabilitation. The Johannesburg experience.

Prescribed physical activity plays a major role in the rehabilitation of patients with coronary artery disease, and as with any other form of treatment its benefits must be weighed against its possible risks. This study attempted to establish the safety of cardiac rehabilitation as a medical intervention at the Johannesburg Cardiac Rehabilitation Centre from its inception in September 1982 to July 1988, and analyses the medical status of patients who suffered a cardiac arrest (CA) in order to determine possible factors predictive of sudden death. Between September 1982 and July 1988, 1,574 patients were admitted to the unit; 480,000 man-hours of exercises were accumulated with 4 episodes of CA, giving an incidence of CA of 1/120,000 patient-hours. Three of the 4 episodes were fatal, giving an incidence of fatal CA of 1/160,000 patient-hours. This incidence is acceptably low and comparable with other cardiac rehabilitation programmes, making exercise as prescribed at the Johannesburg Cardiac Rehabilitation Centre a safe form of medical intervention. Patients at risk of CA during exercise were essentially not identifiable, since they did not come from a group currently recognised as at particularly high risk. A combination of inferior infarction with occluded dominant right coronary artery, good collateralisation and asymptomatic ischaemia was present in all CA patients. The likelihood of these pathological features being predictors of exercise-related sudden death requires further investigation.

Coronary Disease↗
PubMed1991

Photic retinal injury from endoillumination during vitrectomy.

We treated a patient who developed a paramacular area of light-induced retinal damage after endoscopic epimacular membrane removal. Postoperative color photographs showed complete absence of the membrane, but fluorescein angiography demonstrated a previously absent superior paramacular lesion consistent with a photic injury. Operative microscope illumination had been eliminated by corneal shielding, which implicated endoillumination as the source of injury. We recommend the following procedures to avoid this complication: careful planning of vitreous surgery for epimacular membrane removal; using filters; minimizing the length of surgery; keeping the light output low; maintaining maximal light pipe distance from the retina; eccentric orientation of the light pipe; and use of intermittent and variable site illumination techniques.

Aged↗
PubMed1991

Effects of six trace metals on calcium fluxes in brown trout (Salmo trutta L.) in soft water.

Calcium fluxes were measured simultaneously in brown trout fry maintained in an artificial soft water medium of [Ca] 20 mumol.1(-1) and pH 5.6, and exposed to each of six trace metals (Al, Cu, Fe, Ni, Pb, and Zn). The trace metal concentrations represented typical and maximum levels found in acid waters experiencing declining fishery status. In the absence of trace metals, evidence is presented which suggests that ca. 91% of Ca taken up from the external medium was by extraintestinal active transport. Calcium efflux was stimulated by both concentrations of Al, Cu, Fe, and Pb. Efflux was also stimulated by [Ni] 170 nmol.1(-1) and [Zn] 3000 nmol.1(-1). In some cases, response to increased efflux was stimulation of influx. Lack of stimulation of influx resulted in negative net Ca fluxes. Net Ca losses were recorded at both concentrations of Al, Pb, and Ni, lower concentrations only of Fe, and higher concentrations only of Cu and Zn.

Aluminum↗
PubMed1991

Mineral content and blood parameters of dying brown trout (Salmo trutta L.) exposed to acid and aluminum in soft water.

1. Whole body mineral content and blood parameters were monitored in dying brown trout exposed to acid (pH 4.5) and aluminium (12 mumol l-1) at low external calcium concentration (20 mumol l-1). 2. Fish surviving the treatment had elevated haematocrit, low plasma sodium levels, and low whole body sodium and potassium content. 3. Dying trout had haematocrit and plasma sodium levels similar to treatment survivors, but whole body mineral content was unaffected and moisture content increased. 4. Death was probably caused by redistribution of fluid from the extracellular compartment to the intracellular compartment.

Acids↗
PubMed1991

DNA flow cytometry of follicular non-Hodgkin's lymphoma.

S-phase fraction, an index of cellular proliferation, and DNA ploidy were measured by DNA flow cytometry in a retrospective study of lymph node biopsy specimens from 83 cases (before treatment) of follicular non-Hodgkin's lymphoma, Working Formulation categories B and C. The correlations between these measures and survival, clinical stage, symptoms and histopathological factors were investigated. Aneuploidy was rare (n = 16) and had no effect on length of survival or transformation to high grade lymphoma. The overall mean S-phase fraction was 3.6%; for the whole series increasing S-phase fraction was associated with decreased survival. A high S-phase fraction (more than 5%) in initial biopsy specimens was also associated with an increased risk of subsequent high grade transformation at relapse. There was no difference between the survival or proliferative activity of tumours composed of mainly small cleaved cells compared with those composed of mixed small and large cells. There was no difference in survival or proliferative activity between tumours showing a pure follicular growth pattern and those with a mixed follicular and diffuse growth pattern. Multifactorial analysis showed that an S-phase fraction of more than 5% and B symptoms were the most important factors determining survival in these follicular non-Hodgkin's lymphomas.

Adult↗
PubMed1991

Cognitive outcome following tricyclic and electroconvulsive treatment of major depression in the elderly.

OBJECTIVE: This study sought to ascertain the affective and cognitive outcome after tricyclic and electroconvulsive treatment of elderly medical-psychiatric patients meeting diagnostic criteria for major depression, some of whom had normal cognitive functioning and some of whom were cognitively impaired before treatment. METHOD: Patients who met criteria for major depression on the basis of a structured diagnostic interview and who scored 17 or more on the Hamilton Rating Scale for Depression were evaluated with the Mattis Dementia Rating Scale. The patients were then treated in a nonrandom manner with either tricyclic antidepressants or ECT (followed by tricyclic maintenance therapy). The majority of the patients treated with ECT had not responded previously to tricyclics. Follow-up psychometric testing was repeated in 6 months. RESULTS: Among the patients with normal pretreatment cognitive functioning, cognition was generally stable. Among the patients with pretreatment cognitive impairment, a substantial number--including those receiving ECT--demonstrated improvement in cognition. While the majority of patients improved with respect to both their affective and cognitive states, certain treatment-refractory subgroups were nevertheless identified. CONCLUSIONS: The data suggest that cognitive dysfunction associated with depression may improve after treatment in a substantial number of elderly patients, including those receiving ECT. Relapse rates, however, may be relatively high, and residual symptoms may persist, which emphasizes the need for optimal initial and long-term antidepressant strategies for this population.

Aged↗
PubMed1991

Consultants' and patients' views about patient access to their general practice records.

Semi-structured interviews were conducted with 24 hospital consultants and 47 general practice patients, asking for their opinions about a proposed policy of partial access to records in one general practice. Eleven consultants were opposed to the policy, 10 were in favour and three were classified as ambivalent. Arguments against access were couched largely in terms of consultants' own interests whereas arguments in favour of access were couched in terms of patients' interests. Although 81% of patients interviewed said that they should in principle be allowed to see their own records, only 51% wanted access to their own records. Fears expressed by consultants on patients' behalf are not necessarily well founded.

Attitude of Health Personnel↗
PubMed1991

The medical-psychiatric unit as a site for outcome research in dementia/depression syndromes.

The era of cross-sectional "snapshot" clinical epidemiology studies in consultation-liaison psychiatry, while still important, do not in themselves yield the critical outcome information needed to document both the clinical efficacy and cost-efficacy of timely psychiatric treatment of patients with concurrent medical-psychiatric illness. As consultation-liaison psychiatry has been plagued by problems regarding reimbursement for clinical services rendered and has only a few systematic outcome studies as yet documenting the effectiveness of treatment interventions, more prospective studies are desperately needed to confirm the value of our efforts. The era of proselytizing the virtues of consultation-liaison psychiatry is over, and as with every other area of psychiatric therapy, governmental policy makers and third party payors are appropriately demanding to see "proof" that our treatments are both clinically- and cost-effective. As may be seen from this brief overview of our research demonstrating the potential reversibility of disabling cognitive dysfunction in depressed medical-psychiatric patients and the efficacy of labetalol in decreasing cardiovascular complications from ECT in high risk medical patients, positive reports from clinical investigations that are strategically planned and implemented on specific populations form strong arguments for the clinical and probable cost efficacy of both consultation-liaison psychiatry and medical-psychiatric units.

Comorbidity↗
PubMed1991

Which deprivation? A comparison of selected deprivation indexes.

A number of indexes of deprivation which have been devised or adopted for use by the health services are examined in relation to their performance in explaining the variation observed in a range of health measures, using data for postcode sectors in Scotland. The Scottish deprivation score and the Townsend index are found to explain most variation, and to adhere most closely to the concept of material disadvantage. The Jarman score is less effective as a result of the inclusion of individual variables which are seen to correlate very weakly, even negatively, with the health indicators. The use of these measures in relation to resource allocation and the new GP contract is discussed.

Chronic Disease↗
PubMed1990

Tissue-specific control elements of the Thy-1 gene.

We have exploited the structural homology, but different patterns of expression of the murine and human Thy-1 genes to map a number of tissue-specific enhancer elements in the genes. All of these are located downstream from the site of transcriptional initiation. The human gene contains separate elements which direct expression to the kidney or spleen epithelium. The murine gene lacks these elements but instead contains a thymocyte specific enhancer in the third intron. Developmentally-regulated expression in nerve cells is directed (at least in part) by an atypical element in the first intron. The latter is active on heterologous promoters, but is position and distance dependent.

Animals↗
PubMed1990

Sensory responses of caudal trigeminal neurons to thermal and mechanical stimuli and their behavioural correlates in the rat.

Behavioural experiments in the freely moving rat were carried out to determine thermal and mechanical nociceptive thresholds to ramp stimuli applied to the face. The mean thermal escape threshold was 43.5 degrees C, and the mean mechanical escape threshold was 179.2 g/mm2. In a parallel set of experiments recordings were made from single neurons in the caudal trigeminal nucleus of the anaesthetized rat. Neurons were classified according to their responses to a range of thermal and mechanical stimuli applied to the face. Three classes of neuron responded exclusively to mechanical stimuli and four classes responded to thermal stimuli (usually in addition to responding to mechanical stimuli). The mean thermal threshold of neurons responsive to warming stimulation was 44.4 degrees C. Neurons responsive to innocuous warming were located in deeper laminae. Many of the neurons responsive to noxious heat appeared to show an exponential relation between temperature and firing rate. An argument is made for a direct role of exponentially responding neurons in thermal nociception. The distribution of all neuronal response thresholds was left-skewed compared with a normal distribution, whereas the behavioural escape thresholds approximated a normal distribution.

Anesthesia↗