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Biomedical subjects

M J Sullivan

Publications and source records attributed to M J Sullivan.

At least 145 records · Page 8Linked to original sources
PubMed1986

Autoimmune thyroiditis: pathophysiology and relationship to thyroid cancer.

Autoimmune thyroiditis (Hashimoto's disease) is one of a myriad of clinical entities associated with the endocrine system. The disease is thought to be a defect in the immune regulatory system. The following report is a study of 112 cases of Hashimoto's thyroiditis treated over a 10-year period. The incidence of malignancy associated with autoimmune thyroiditis in this study was 6.3%, which correlates well with the incidence of thyroid cancer seen in the general population at autopsy. We have concluded from this study that patients with autoimmune thyroid endocrinopathy are at no greater risk for the development of thyroid malignancy than the general population. A review of the pathophysiology of autoimmune disorders is discussed and recommendations for treatment of patients with Hashimoto's disease is provided.

Adolescent↗
PubMed1986

Heightened pressor effect and dipsogenicity to intracerebroventricularly applied angiotensin II and III in spontaneously hypertensive rats.

The effect of acute intracerebroventricular (i.c.v.) injections of angiotensin II and III (ANG II and ANG III; 0, 1, 10 and 100 pmol in 2 microliters artificial cerebrospinal fluid (CSF) on blood pressure and water consumption was investigated in Okamoto-Aoki spontaneously hypertensive rats (SHR), and Wistar-Kyoto (WKY) and Sprague-Dawley (SD) normotensive controls. Heightened sensitivity to i.c.v. ANG II and ANG III was observed in the SHR compared with the WKY and SD strains (P less than 0.001), for both pressor and drinking responses. In addition, i.c.v. treatment with an aminopeptidase B inhibitor, bestatin (20 nmol in 1 microliter artificial CSF) significantly potentiated the heightened pressor response to i.c.v.-injected ANG II and ANG III (100 pmol) in SHR and to a lesser degree in WKY animals compared with SD controls (P less than 0.001). These results suggest that a dysfunction in central aminopeptidase activity results in an extended life of endogenous angiotensins, and perhaps other peptides that may contribute to the high blood pressure seen in this animal model of human essential hypertension.

Angiotensin II↗
PubMed1985

Brain angiotensin II and III binding and dipsogenicity in the rabbit.

The rabbit brain evidenced low or non-detectable levels of [125I]angiotensin II binding but considerable [125I]angiotensin III specific binding in agreement with distributions reported for the primate brain. The rabbit was dispsogenically responsive to the intracerebroventricular infusions of angiotensin II and III; however, no elevations in blood pressure were measured for either peptide. Thus, members of this species appear to have limited usefulness as a primate model for central angiotensin-induced cardiovascular changes.

Angiotensin II↗
PubMed1985

Dysfunction of central angiotensinergic aminopeptidase activity in spontaneously hypertensive rats.

Alert spontaneously hypertensive (SH) rats, prepared with indwelling carotid artery catheters, demonstrated heightened and prolonged blood pressure (BP) responses to intracerebroventricular (i.c.v.) injections of 10 and 100 pmol angiotensin II and III (AII and AIII) as compared with Wistar-Kyoto (WKY) and Sprague-Dawley normotensive animals. Pretreatment with the aminopeptidase B inhibitor bestatin (10 nmol, i.c.v.) potentiated and prolonged the heightened pressor response to AIII (100 pmol, i.c.v.) in SH rats. These results suggest that dysfunction of angiotensin peptidase activity may be contributing to the progressive and sustained elevations in blood pressure noted to occur in the SH rat model of human essential hypertension.

Angiotensin II↗
PubMed1985

The 6-minute walk: a new measure of exercise capacity in patients with chronic heart failure.

Cycle and treadmill exercise tests are unsuitable for elderly, frail and severely limited patients with heart failure and may not reflect capacity to undertake day-to-day activities. Walking tests have proved useful as measures of outcome for patients with chronic lung disease. To investigate the potential value of the 6-minute walk as an objective measure of exercise capacity in patients with chronic heart failure, the test was administered six times over 12 weeks to 18 patients with chronic heart failure and 25 with chronic lung disease. The subjects also underwent cycle ergometer testing, and their functional status was evaluated by means of conventional measures. The walking test proved highly acceptable to the patients, and stable, reproducible results were achieved after the first two walks. The results correlated with the conventional measures of functional status and exercise capacity. The authors conclude that the 6-minute walk is a useful measure of functional exercise capacity and a suitable measure of outcome for clinical trials in patients with chronic heart failure.

Aged↗
PubMed1985

How should we measure function in patients with chronic heart and lung disease?

To elucidate the characteristics of measures of function in patients with chronic heart failure and chronic lung disease we administered four functional status questionnaires, a 6-min walk test and a cycle ergometer exercise test, to 43 patients limited in their day to day activities as a result of their underlying heart or lung disease. Correlations between these measures were calculated using Spearman's rank order correlation coefficient. The walk test correlated well with the cycle ergometer (r = 0.579), and almost as well with the four functional status questionnaires (r = 0.473-0.590) as the questionnaires did with one another (0.423-0.729). On the other hand, correlations between cycle ergometer results and the questionnaires was in each case 0.295 or lower, and none of these correlations reached statistical significance. These results suggest that exercise capacity in the laboratory can be differentiated from functional exercise capacity (the ability to undertake physically demanding activities of daily living) and that the walk test provides a good measure of function in patients with heart and lung disease.

Activities of Daily Living↗
PubMed1985

Prevention of bedrest-induced physical deconditioning by daily dobutamine infusions. Implications for drug-induced physical conditioning.

The effects of intermittent infusions of dobutamine were studied in young normal male subjects during a period of bedrest deconditioning to determine whether this synthetic catechol affects physical conditioning processes in humans. 24 volunteers were placed at bedrest and randomized to daily 2-h treatments of saline infusions (control), dobutamine infusions, or maintenance exercise (control). Exercise, hemodynamic, and metabolic studies were performed at base line and at the termination of the 3-wk treatment period. Maximal exercise (duration, oxygen consumption, and workload) fell for the saline group and remained unchanged for the dobutamine and exercise groups. Hemodynamics during exercise were maintained the same as pretreatment base line for the dobutamine and exercise groups, whereas stroke volume and cardiac output dropped and heart rate rose for the saline group. The metabolic profile showed an increased blood lactate response at rest and during submaximal exercise after 3 wk of bedrest for the saline group, and essentially no change for the exercise and the dobutamine groups. Extraction of oxygen across the exercising lower limb rose for the dobutamine group, as did the activity of the skeletal muscle oxidative enzymes, citrate synthetase, and succinate dehydrogenase. In contrast to the exercise control group, the saline and dobutamine groups developed orthostatic hypotension, tachycardia, and accentuation of the renin-aldosterone response over the 3-wk treatment period; for the saline group, this is best explained by the observed fall in blood volume and for the dobutamine group, by the blunting of vascular vasoconstrictive responses. During a period of bedrest deconditioning in humans, infusions of dobutamine maintain many of the physiologic expressions of physical conditioning.

Adult↗
PubMed1984

Effect of encouragement on walking test performance.

Walking tests, frequently used to document effects of treatment on exercise capacity, have never been standardised. We studied the effects of encouragement on walking test performance in a randomised study that controlled for the nature of the underlying disease, time of day, and order effects. We randomised 43 patients with chronic airflow limitation or chronic heart failure or both to receive or not receive encouragement as they performed serial two and six minute walks every fortnight for 10 weeks. Simple encouragement improved performance (p less than 0.02 for the six minute walk), and the magnitude of the effect was similar to that reported for patients in studies purporting to show beneficial effects of therapeutic manoeuvres. Age and test repetition also affected performance. These results demonstrate the need for careful standardisation of the performance of walking tests, and suggest caution in interpreting studies in which standardisation is not a major feature of the study design.

Chronic Disease↗
PubMed1984

Unilateral pruritus and Nocardia brain abscess.

We studied a patient with unilateral itching associated with Nocardia brain abscess. Pruritus without a primary cutaneous eruption often indicates an underlying medical disorder, but has rarely been described in cerebral disease such as MS or infarctions. Our patient also had sensory loss and motor findings contralateral to the cerebral lesion, suggesting that itching may have cerebral representation contiguous to other sensations.

Adult↗
PubMed1983

Peripheral arterial thrombosis due to the nephrotic syndrome: the clinical spectrum.

We reviewed the literature concerning arterial thromboses associated with the nephrotic syndrome and the hypercoagulable state. An illustrative case of peripheral arterial thrombosis and pulmonary emboli attributed to the hypercoagulable state of the nephrotic syndrome is included. In our patient, serum levels of antithrombin III, plasminogen, factor VII activity, factor VIII activity, and factor VIII antigen were abnormal. Arterial thromboses in patients with the nephrotic syndrome are often associated with steroid and diuretic use. In pediatric patients, a predisposing factor may be femoral venipuncture.

Adolescent↗