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Biomedical subjects

J Evans

Publications and source records attributed to J Evans.

At least 361 records · Page 20Linked to original sources
PubMed1990

Transesophageal echocardiography in the awake elderly patient: its role in the clinical decision-making process.

To assess the impact on the management and safety of transesophageal echocardiography (TEE) in the elderly population, the results and limitations of this technique were retrospectively analyzed in 88 patients. TEE was indicated whenever the transthoracic approach was not diagnostic or was inconsistent with the clinical setting. The most frequent clinical indications were to investigate the source of emboli, assess valvular regurgitation, and identify valvular vegetations. In 72 patients (82%) TEE significantly influenced management decisions. In selected patients TEE avoided the use of more invasive diagnostic procedures. Adverse effects included occasional premature atrial or ventricular beats (11 patients), sinus bradycardia (six patients), and protracted nausea (one patient). We conclude that in elderly patients with cardiovascular diseases, TEE plays a significant role in the decision-making process without adding a significant risk.

Aged↗
PubMed1990

A new protocol for the treatment of stage I cutaneous malignant melanoma; interim results of the first 806 patients treated.

A protocol is described which has been used in a prospective study of 806 patients with stage I malignant melanoma. Excisional biopsies are performed as soon as possible and Breslow thickness and Clark's levels determined. Patients are allocated to low, medium and high risk groups and definitive excision is carried out with a clearance of 2, 20 and 50 mm respectively. Preliminary results are reported on the 806 patients treated over 7 years in three plastic surgery units. No local recurrences have occurred so far in the low and medium risk groups, which suggests that the protocol is safe.

Adolescent↗
PubMed1990

Survival and disinfection of parainfluenza viruses on environmental surfaces.

Three dilutions of each of three parainfluenza strains were placed on nonabsorptive (stainless steel, laminated plastic, skin) and absorptive (hospital gown, facial tissue, laboratory coat) surfaces to assess persistence of virus recovery at 0, 0.5, 1, 2, 4, 6, 8, and 10 hours. Virus persisted longest on stainless steel. Additionally, the ability to recover virus was enhanced by increasing the initial concentration of virus in the initial inoculum. Drying of the inoculum on surfaces reduced but did not immediately eliminate the ability to recover virus. Cleaning the contaminated surface with a number of commonly available disinfectant or antiseptic agents reduced or eliminated virus with only short exposure times. It is likely that removal of contaminated material by vigorous cleaning was as important as the actual disinfecting substance. In general, all three strains of parainfluenza virus responded similarly. Persistence of all three strains of parainfluenza virus for up to 10 hours on nonabsorptive surfaces and up to 4 hours on absorptive surfaces suggests a need to consider fomites a possible source of transmission of the parainfluenza viruses inside and outside the hospital.

Clothing↗
PubMed1990

Influence of alterations in loading produced by lower body negative pressure on aortic blood flow acceleration.

The objectives of this study were to evaluate the effects of alterations in loading induced by lower body negative pressure on aortic blood flow velocity and acceleration. Twenty-seven normal men were studied during various levels of lower body negative pressure (0 to -60 mm Hg) during which echocardiographic, Doppler and hormonal measurements were obtained. Lower body negative pressure induced a decrease in left ventricular diastolic diameter from 5.18 +/- 0.08 to 4.41 +/- 0.1 cm (p less than 0.0001) and in left ventricular systolic diameter from 3.33 +/- 0.09 to 2.84 +/- 0.1 cm (p less than 0.0001). Shortening fraction remained unchanged. The decrease in diastolic diameter resulted in a reduction in flow velocity integral from 13.8 +/- 0.8 to 7.5 +/- 0.4 cm (p less than 0.0001) and, therefore, in stroke volume from 89.6 +/- 4.7 to 49.5 +/- 2.8 ml (p less than 0.0001). Heart rate reflexly increased from 62.5 +/- 1.9 to 82.2 +/- 2.3 beats/min (p less than 0.0001) as did systemic vascular resistance from 1,280.8 +/- 69.5 to 1,863.4 +/- 121.4 dyne.s.cm-5 (p less than 0.0001). The increase in heart rate was insufficient to maintain cardiac output, which decreased from 5.53 +/- 0.29 to 3.99 +/- 0.21 liters/min (p less than 0.0001). Systolic, diastolic and mean arterial blood pressure was maintained. The negative pressure resulted in a concomitant significant increase in norepinephrine levels from 1.46 +/- 0.09 to 2.056 +/- 0.2 nmol/liter (p = 0.0019) but no change in plasma epinephrine: 0.845 +/- 0.22 to 0.78 +/- 0.11 nmol/liter (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Reduction of left ventricular preload by lower body negative pressure alters Doppler transmitral filling patterns.

The objective of this study was to evaluate the effect of alterations in preload induced by lower body negative pressure on Doppler transmitral filling patterns. Echocardiograms and Doppler recordings were performed in 18 normal young men (aged 23 to 32 years) during various levels of lower body negative pressure (0, -20 and -50 mm Hg). Lower body negative pressure induced a reduction in diastolic velocity integral (from 12.17 +/- 0.79 to 8.42 +/- 0.71 cm, p = 0.0067) and consequently left ventricular diastolic diameter (from 5.11 +/- 0.09 to 4.45 +/- 0.1 cm, p less than 0.0001). There was a significant reflex increase in heart rate from 59.9 +/- 1.9 to 77.1 +/- 2.4 beats/min (p less than 0.0001), but blood pressure was unchanged. This reduction in preload altered Doppler transmittral filling patterns as follows: 1) peak early velocity (E) decreased from 59.2 +/- 3.8 to 39.1 +/- 1.7 cm/s (p less than 0.0001); 2) atrial filing velocity (A) was unchanged (35.58 +/- 1.5 to 33.52 +/- 1.4 cm/s, p = 0.517); 3) E/A ratio decreased from 1.7 +/- 0.13 to 1.19 +/- 0.08 (p = 0.0087); 4) mean acceleration (from 482 +/- 37 to 390 +/- 27 cm/s2, p = 0.03) and mean deceleration (from 327 +/- 31 to 169 +/- 21 cm/s2, p less than 0.001) of the early filling wave were significantly reduced; and 5) peak acceleration (from 907 +/- 42 to 829 +/- 29 cm/s2) and peak deceleration (from 771 +/- 94 to 547 +/- 76 cm/s2) also decreased, but not significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Methylprednisolone acetate does not cause inflammatory changes in the epidural space.

Few studies have examined the possible adverse effects that epidural injection of depot corticosteroid preparations may have on meningeal membranes and nervous tissue. Thirty-six healthy adult white rabbits received 0.3 ml/kg epidural injections of either lactated Ringer's solution (negative control group), 1% lidocaine containing methylprednisolone acetate (study group), or normal saline containing talc (positive control group). Animals were killed either 4 or 10 days after injection and stained sections of the spinal cord and meningeal membranes were examined by light microscopy. In all animals that received either lactated Ringer's solution or lidocaine with methylprednisolone acetate, microscopic examination of specimens taken from the L5-L6 interspace revealed no white cell infiltrates and no fibroblastic activity. All animals that received epidural injections of normal saline containing talc had marked infiltration of tissue macrophages in the epidural space. There was no thickening of the meningeal membranes or nerve roots in any animal. The complete lack of inflammatory changes and meningeal thickening demonstrated in this pilot study helps to confirm the safety of methylprednisolone acetate when injected into the epidural space.

Animals↗
PubMed1990

Hirsutism in a gynaecological context.

Investigation of patients presenting with hirsutism to a gynaecological endocrine clinic revealed a high incidence of anovulation, obesity and elevated androgen levels. The underlying abnormality was polycystic ovarian syndrome (PCOS) in the majority of patients. Low levels of sex hormone binding globulin were common; these increased with oestrogen treatment. Treatment with a combined oral contraceptive pill and low dose spironolactone was often effective in reducing symptoms.

Adult↗
PubMed1990

Farmer's lung in Northern Ireland.

A total of 381 farmers in Northern Ireland were studied using a questionnaire, pulmonary function tests, and antibody levels to Micropolyspora faena to assess the incidence of farmer's lung. Twenty (4.9%) had a history of a previous diagnosis of farmer's lung by their doctor. Forty four (10.4%) had delayed onset symptoms compatible with farmer's lung, 32 (7.9%) had precipitant antibody, and 61 (15%) had raised antibody by the enzyme linked immunosorbent (ELISA) method. Restricted lungs were present physiologically in 40 (9.8%). A confirmation of delayed symptoms and precipitant antibody was present in seven (1.7%) whereas delayed symptoms and ELISA antibody was present in nine (2.2%). Using either antibody method only two (0.5%) had a combination of antibody to M faenae, delayed onset symptoms, and restricted pulmonary physiology.

Antibodies, Bacterial↗
PubMed1990

[Long-term effects of indapamide in left ventricular hypertrophy in patients with hypertension].

Left ventricular hypertrophy is a major and independent cardiovascular risk factor in hypertension. The effects of a diuretic, indapamide, on the regression of left ventricular hypertrophy were studied in a group of 9 patients with mild hypertension treated in an open therapeutic trial over a 12 month period. At the end of the trial, the left ventricular mass index decreased significantly from 172 +/- 11 to 147 +/- 11 g/m2 (p less than 0.001). Therefore, in contrast to the other diuretics which have been studied, indapamide seems able to induce regression of the left ventricular hypertrophy complicating hypertension.

Adult↗
PubMed1990

Psychological impact of osseointegrated dental implants.

This longitudinal study of 39 patients who underwent treatment involving osseointegrated implants examined problems in oral and psychosocial functioning, expectations and experiences of difficulties with surgery, satisfaction with surgery, body image, neuroticism, self-concept, and extroversion. Patients completed six questionnaires from before phase 1 surgery to the final recall appointment for the new prosthesis (12 to 18 months after phase 1 surgery). The most common problems reported before treatment were those associated with eating; esthetics was less of a concern. Significant improvements in all problem areas were observed immediately after phase 2 surgery. Expectations of surgery-related problems were generally consistent with experiences immediately after phase 1 surgery, but more negative than experiences following phase 2 surgery. Body image before treatment was most negative vis-à-vis teeth. Significant improvements were found not only regarding teeth, but also on facial, mouth, and even overall body image. Satisfaction scores were generally high, but showed continued improvements through the final assessment. The only group experiencing negative outcomes consisted of patients scoring high on neuroticism.

Adult↗
PubMed1989

Dermatofibromas and arthropod bites: is there any evidence to link the two?

30 patients with dermatofibromas were questioned closely about contacts with stinging or blood-sucking arthropods before the development of their lesions. Their responses were not significantly different from those of a matched control group. 100 dermatofibromas were examined by dissection, histology, and after acid digestion of the collagenous material; no traces of arthropod skeletal tissues were found. These data are not consistent with the theory that the mechanical presence of arthropod tissues is necessarily, or even usually, a cause of dermatofibromas.

Animals↗
PubMed1989

Substance P and somatostatin coexist within neuritic plaques: implications for the pathogenesis of Alzheimer's disease.

In recent years the present authors and others have sought to determine the neurochemical composition of the dilated neuronal processes found within neuritic plaques of patients with Alzheimer's disease. To date a number of neurotransmitter and neuropeptide systems have been observed within different plaques, yet at present it is unclear whether individual human plaques contain more than one transmitter substance. In the present study a highly sensitive dual-immunolabeling procedure was employed and it was demonstrated that substance P and somatostatin-immunoreactive profiles coexist within single senile plaques of patients with Alzheimer's disease. Coexistence of somatostatin and substance P immunoreactivity within plaques was observed in the hippocampus and amygdala but not in the neocortex, although the latter region contained plaques within which somatostatin and substance P existed alone. The frequency with which we observed one or more neuropeptide within plaques was relatively low and in fact most plaques contained neither substance P nor somatostatin immunoreactivity. In addition, a large number of swollen peptidergic processes were observed outside of plaques. The significance of these observations with respect to the pathogenesis of Alzheimer's disease is discussed.

Aged↗