PubMed HealthSearch

Biomedical subjects

P Finnegan

Publications and source records attributed to P Finnegan.

At least 19 recordsLinked to original sources

Immunoglobulin G subclasses and spirometry in patients with chronic obstructive pulmonary disease.

Immunoglobulin G (IgG) subclass levels were measured in 58 patients with chronic obstructive pulmonary disease (COPD) and in 125 healthy controls. Total IgG values were significantly lower in the 27 COPD patients on steroid therapy compared with patients not taking steroids (8.31 (0.14) vs 9.80 (0.14), p less than 0.05), geometric mean (log SD). Total IgG (9.80 (0.14) vs 12.18 (0.16), p less than 0.005), IgG1 (5.87 (0.19) vs 6.68 (0.12), p less than 0.05) and IgG2 levels (2.75 (0.21) vs 3.70 (0.20), p less than 0.005) were significantly reduced in the COPD patients not taking steroids compared with the controls. IgG3 values were significantly elevated in smokers compared with nonsmokers in both the control and COPD groups. Fifteen COPD patients (25.9%) had a low level of one or more subclasses. IgG2 subclass deficiency was the most common, being present in 9 patients. A significant correlation was found between forced expiratory volume in one second (FEV1) and IgG2 subclass levels (r = 0.415; p less than 0.005). IgG subclass deficiencies may contribute to the development and progression of respiratory disease in COPD patients.

Adult

Retrotracheal goiter: a diagnostic and therapeutic problem.

A patient with chronic cough and recent dysphagia was found to have a retrotracheal mass extending into the visceral mediastinum on chest roentgenogram. A computed tomographic scan confirmed a retrotracheal lesion, which was believed to be of lymphatic origin. A thyroid scan demonstrated downward displacement of the left lobe but little uptake in the mass. Histological findings of mediastinal biopsies were inconclusive. A large retrotracheal thyroid adenoma was easily excised through a right thoracotomy. The approach to diagnosis and, in cases of doubt, the safety of surgical access through thoracotomy for thyroid lesions in this unusual site is discussed.

Adenoma

Difference in metabolic profile of potassium canrenoate and spironolactone in the rat: mutagenic metabolites unique to potassium canrenoate.

The metabolic fates of potassium canrenoate (PC) and spironolactone (SP) were compared for the rat in vivo and in vitro. Approximately 18% of an in vivo dose of SP was metabolized to canrenone (CAN) and related compounds in the rat. In vitro, 20-30% of SP was dethioacetylated to CAN and its metabolites by rat liver 9000 g supernatant (S9). Thus, the major route of SP metabolism is via pathways that retain the sulfur moiety in the molecule. PC was metabolized by rat hepatic S9 to 6 alpha, 7 alpha- and 6 beta, 7 beta-epoxy-CAN. The beta-epoxide was further metabolized to its 3 alpha- and 3 beta-hydroxy derivatives as well as its glutathione (GSH) conjugate. Both 3 alpha- and 3 beta-hydroxy-6 beta, 7 beta-epoxy-CAN were shown to be direct acting mutagens in the mouse lymphoma assay, whereas 6 alpha, 7 alpha- and 6 beta, 7 beta-epoxy-CAN were not. These mutagenic metabolites, their precursor epoxides and their GSH conjugates were not formed from SP under identical conditions. The above findings appear to be due to inhibition of metabolism of CAN formed from SP by SP and/or its S-containing metabolites, since the in vitro metabolism of PC by rat hepatic microsomes was appreciably reduced in the presence of SP. The hypothesized mechanism(s) for this inhibition is that SP and its S-containing metabolites specifically inhibit an isozyme of hepatic cytochrome P-450 or SP is a preferred substrate over PC/CAN for the metabolizing enzymes. Absence of the CAN epoxide pathway in the metabolism of SP provides a possible explanation for the observed differences in the toxicological profiles of the two compounds.

Animals

Effect of intravenous terbutaline on arterial blood gas tensions, ventilation, and pulmonary circulation in patients with chronic bronchitis and cor pulmonale.

Terbutaline sulphate was given intravenously to 10 patients with pulmonary vascular disease secondary to chronic hypoxia. The resting cardiac index increased after terbutaline in all the patients between 5 and 74% above the control level. The greatest change was seen in patients who had received the largest total dose. The rise in cardiac index was associated with a fall in pulmonary vascular resistance although mean pulmonary artery pressure remained unaltered. There was a significant increase in the venous admixture but this did not adversely affect the arterial oxygen tension. The peak expiratory flow rate did not change significantly but there was an increase in ventilation from a mean value of 4.36 1/min/m2 to 4.67 1/min/m2. The results show that terbutaline has little adverse effect on the pulmonary circulation or gas exchange in patients with irreversible airways disease who are in a stable state.

Aged

Evaluation of pressure-derived indices of right ventricular contractility.

Myocardial function was studied in 23 subjects using indices of contractility based on the right ventricular pressure pulse. Pressure-velocity curves were plotted during early systole and contractile element velocity was derived. The pressure-velocity curves varied in shape and curves with single, linear descending slopes occurred in only 7 subjects. The other pressure-velocity curves were either biphasic or hyperbolic in form. The derivation of Vmax and Vpm and beat-to-beat analysis of these indices was therefore difficult. The effects of a number of physiological variables, e.g. right ventricular enddiastolic pressure, respiration and the infusion of isoprenaline were examined. It was demonstrated that Vmax and Vpm were not independent of the loading conditions of the ventricle. The infusion of isoprenaline changed the shape of the pressure-velocity curves and increased the problems of analysis. The theoretical and practical difficulties involved in this type of analysis are discussed.

Blood Flow Velocity

Results of total correction of the tetralogy of Fallot. Long-term haemodynamic evaluation at rest and during exercise.

Postoperative haemodynamic evaluation was performed on 15 patients 7 to 14 years (mean, 11 years) after total intracardiac repair of Fallot's tetralogy. The average age of the patients at the time of postoperative catheterization was 20 years (range 12 to 29) and they were all asymptomatic. Before operation 11 patients were severely cyanosed and disabled and 4 had mild cyanosis with anoxic spells. The cardiac output and right heart pressures were measured at rest and after 5 minutes of submaximal exercise on a bicycle ergometer. It was shown that the degree of residual obstruction of the pulmonary outflow tract was slight and that the right ventricular/pulmonary arterial systolic gradient (RV/PA gradient) exceeded 20 mmHg (2-6 kPa) at rest in only 3 patients. The mean cardiac index at rest was 5-4 l min-1 m-2 which increased to 8-3 l min-1 m-2 during exercise. The response of the cardiac output during exercise was either normal or supranormal in 14 of the 15 patients. In the remaining patient the response was marginally below the normal range. Pulmonary valvular regurgitation was present in 8 patients but there was no detectable difference in the cardiac function of these patients compared with patients with competent pulmonary valves. Six of the patients investigated had also had cardiac catheterizations performed 1 to 4 years after operation. The results of the present study show that remarkably little change has occurred in their haemodynamic status in the intervening years. Though these results are encouraging, further studies are required to determine the eventual outcome of the RV pressure and volume overload.

Adolescent

Pulmonary sarcoidosis: A clinico-pathological study.

The light and electron microscopic changes in biopsy tissue from the lung of a 30-year-old housewife severeley incapacitated by diffuse pulmonary sarcoidosis with pulmonary hypertension are presented. The lung tissue was distorted by numerous granulomas in the interstitial tissues and within alveoli. Many pulmonary blood vessels including arteries were damaged by the granulomas. The ultrastructural features of the epithelioid cells were found to be distinctive and probably specific. The giant cells which accompanied the epithelioid cells contained two types of inclusion body: one appeared to be related to the Schaumann body but the nature and origin of the second type was not clear. Many of the granulomas were surrounded by avascular fibrous tissue which contained, in addition to mature fibroblasts, myofibroblasts and a primitive form of cell that appeared to be a fibroblast precursor. It was conjectured that the myofibroblasts, through their contractile powers, might increase the distortion of the lung architecture and thereby the patient's disability. The alveolar walls were thickened by a diffuse infiltrate of macrophages and epithelioid cells but there was no excess of collagen and elastic fibres. The evidence suggested that the epithelioid cells developed from macrophages. From the cellular nature of the diffuse infiltration of the alveolar walls and the absence of fibrosis it seemed that the disease was still at an early and active stage, a conclusion strengthened by the fact that treatment with corticosteroids led to marked and sustained clinical improvement.

Adult

Long-term domiciliary oxygen in chronic bronchitis with pulmonary hypertension.

Five patients with chronic bronchitis and pulmonary hypertension were treated with oxygen in their homes for periods of between 6 and 24 months. Oxygen was supplied for 15 hours daily from cylinders or from an oxygen concentrator and few practical difficulties arose. After 23 to 59 weeks of treatment there were significant decreases in pulmonary arterial pressure and vascular resistance, and four of the five patients no longer had pulmonary hypertension at rest. Two of these patients had shown little response after three weeks of treatment. There was a reduction in the number of episodes of congestive cardiac failure compared with the corresponding period before treatment. Two of the patients improved enough to return to work. These results are encouraging enough to justify a controlled trial of the treatment in a large number of patients.

Adult

Daily requirement of oxygen to reverse pulmonary hypertension in patients with chronic bronchitis.

We have shown previously in patients with chronic bronchitis that correction of the hypoxaemia by continuous administration of oxygen substantially reduced the pulmonary hypertension by reversal of structural changes in the pulmonary resistance vessels. We have now demonstrated that such improvements may occur with less than continuous oxygen. Treatment with oxygen for 18 hours daily significantly decreased pulmonary arterial pressure and pulmonary vascular resistance. Oxygen therapy for 15 hours a day also decreased pulmonary vascular resistance; such a regimen is practicable in the home, is consistent with a working day free from the constraints of an oxygen supply, and should reduce the number of episodes of congestive cardiac failure.

Adult