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Biomedical subjects

S Mattila

Publications and source records attributed to S Mattila.

At least 73 records · Page 4Linked to original sources
PubMed1987

Reappearance of Hering-Breuer reflex after bilateral autotransplantation of the lungs.

In combined heart-lung transplantation the afferent nerve pathways inevitably are transsected. In previous studies with en bloc heart-lung transplantation in dogs, we found altered regulation of breathing-abolition of Hering-Breuer reflex and response to hypercapnia inhalation stimulus consisting of augmented tidal volume with no change in respiratory rate-shortly after the operation. The long-term effects of pulmonary denervation on breathing regulation were now studied in dogs after staged bilateral pulmonary autotransplantation. Mechanical and electrical activities of the respiratory muscles were recorded during spontaneous breathing and after deflation and inflation with varying volumes of air. Five months postoperatively the duration of the respiratory cycle increased 2.5 times on inflation with 600 ml of air and occlusion of the airways, compared with tenfold prolongation in intact control dogs, indicating a partial return of the Hering-Breuer reflex after the autotransplantation. The duration of the EMG bursts in respiratory muscles increased in intact dogs and in those with bilateral lung autotransplants. In impulse frequency the response to stretching was less evident after autotransplantation. The mechanism mediating reappearance of Hering-Breuer reflex warrants further study.

Animals↗
PubMed1987

Cardiorespiratory function after correction of tetralogy of Fallot. Modifying effect of previous shunt operation.

Of 28 patients with total surgical correction of tetralogy of Fallot in adult life, 22 had previously undergone Blalock-Taussig shunt operation. Possible modifying effects of the shunt on pulmonary ventilation and perfusion and on exercise tolerance were investigated with spirometry, radiospirometry and bicycle ergometry. The observed ventilatory volumes and capacities and diffusing capacity were significantly lower than the predicted values. Vital capacity was significantly reduced in patients with adverse NYHA or haemodynamic classification. Between the various NYHA or haemodynamic groups no statistically significant difference was demonstrable in pulmonary function or diffusing capacity or in airway resistance. Ventilatory obstruction was found also in patients without previous shunt. Other lung function tests showed no significant difference between the shunt and the non-shunt group. Nor was distribution of lung perfusion significantly affected by shunt. No correlation was seen between lung function and bicycle ergometric findings. However, in non-shunt patients who had ventilatory obstruction or impaired diffusing capacity, exercise tolerance was significantly higher than in patients who had had palliative shunt.

Adult↗
PubMed1987

Correlation of NYHA classification, bicycle ergometry and right heart haemodynamics after total correction of tetralogy of Fallot in adults.

Thirty-two patients who had undergone correction of Fallot's tetralogy in adult life were examined on average 6.3 years postoperatively, at mean age 25.8 years. Palliative shunt operation had been performed in childhood in 28 cases. The clinical condition was good in 25 patients (78%). 13 of whom had mean gradient between right ventricle and pulmonary artery 16.0 +/- 4.2 mmHg and systolic right ventricular pressure 39.0 +/- 10.0 mmHg, while 12 had right ventricular pressure 62.6 +/- 16.3 mmHg. In these groups the maximum exercise capacity was, respectively, 136.7 +/- 36.1 and 106.1 +/- 30.8 W/min. Three other patients were in satisfactory, and four in poor clinical condition, with right ventricular systolic pressure, respectively, 74.3 +/- 10.9 and 91.5 +/- 60.0 mmHg. The gradient from right ventricle to pulmonary artery averaged 58.5 +/- 10.4 mmHg in the latter group but, despite the obstructed pulmonary outflow tract, the exercise capacity (116.7 +/- 28.9 W/min) was similar to that in the groups with better clinical results. It is concluded that in most patients with palliative surgery in childhood, tetralogy of Fallot can be successfully corrected in adult life. The causes of right ventricular impairment do not significantly reduce the exercise capacity.

Adult↗
PubMed1987

Coronary endothelium and cardioplegic solutions.

Using surface and transmission electron microscopy in eight isolated sheep hearts it was noted that cold crystalloid cardioplegic solution produced coronary endothelial damage which could be prevented if homologous blood or albumin was added into the preservation fluid. Similar endothelial damage was observed in the endothelium of aorto-coronary saphenous vein bypasses and in the endothelium of the proximal aorta after infusion with cold crystalloid cardioplegic fluid. No endothelial changes were seen after infusion of the grafts with cold blood. There was no correlation between the preservation of the high energy phosphates of the myocardium and the endothelial changes of the coronary arteries.

Albumins↗
PubMed1986

Prolonged survival with a thrombotically occluded tricuspid valve prosthesis.

A 49-year-old man who had undergone tricuspid valve replacement with a Björk-Shiley prosthesis in November 1974 was reoperated on in January 1985 due to prosthesis malfunction. The operation revealed a totally occluded prosthetic valve and a paravalvular defect which had served as the channel for atrioventricular blood flow. In retrospect, all evidence indicated that the valve had stuck as early as six months after the primary operation, when the patient had first noticed the loss of audible valve clicks and the reappearance of effort intolerance. Due to the gradual progression of the patient's symptoms and misinterpretation of the significance of absent valve clicks, the correct diagnosis was not made until a follow-up study 10 years after the first operation when contrast echocardiography showed the absence of both disc movements and transvalvular contrast flow. Our experience indicates that thrombosis of a tricuspid valve prosthesis may present highly insidiously and that the loss of audible valve clicks should be relied on as a sign of prosthesis malfunction.

Adult↗
PubMed1986

Failure of mechanical valves in Ebstein's malformation.

Five patients with Ebstein's malformation were operated on with closure of the atrial septal defect and implantation of a mechanical prosthesis at the right atrioventricular junction. The 4 patients who survived showed an excellent early recovery. Three of the patients noticed the disappearance of the valve clicks 6 months after the operation. At re-examination using echophonocardiography, peripheral dye dilution curves and catheterization, these valves were found to be stuck in the open position in 2 patients and in the closed position in 1 patient. The last patient had a paravalvar channel supplying blood into the right ventricle. One patient who had a St. Jude prosthesis was doing excellently 4 years postoperatively and the valve was functioning well. Two years after the operation, the other patient with a St. Jude valve again noticed valve clicks after over 1 year of silence. Examination revealed the prosthesis to be functioning normally. The totally occluded Björk-Shiley prosthesis (10 years postoperatively) was excised at re-operation and replaced by an Ionescu-Shiley bioprosthesis. The patient with a jammed Björk-Shiley prosthesis (10 years postoperatively) declined a re-operation and is doing well, albeit under close observation.

Adult↗
PubMed1986

The effect of inhaled carbon dioxide and hypoxia mixtures on the electrical and mechanical activities of respiratory muscles in dogs.

The effects of hypercapnia and hypoxia on the regulation of breathing was studied in six mongrel dogs during pentobarbital anaesthesia with special reference to their action on the respiratory muscles. Carbon dioxide (5.5% in air) inhalation produced an increase of minute volume due to augmentation of respiratory frequency and tidal volume. The number of electrical impulses per breath remained unaffected despite the increase tidal volume. Therefore the mechanical ventilation increased more than the electrical output to the respiratory muscles indicating that the efficiency of the muscles increased. The tidal volume increased more than the pressure impulse (mechanical work by the respiratory muscles) suggesting that the airway conductance was increased during hypercapnia. During hypoxic stimulus (11% oxygen in nitrogen) the increase of minute volume was due to increase in respiratory frequency. The ratio of tidal volume to the number of electrical impulses in the respiratory muscles remained unaltered. During combined carbon dioxide and hypoxia stimulus the responses were similar to those of carbon dioxide stimulus alone. However, the increase of minute volume and the increase in the ratio of tidal volume and pressure impulse to the number of electrical impulses in the respiratory muscles were more pronounced. These findings suggest that carbon dioxide affects the regulation of breathing above the respiratory muscles and in the muscles themselves. Hypoxic stimulus seems not to have any direct effect on the respiratory muscles in dogs during pentobarbital anaesthesia.

Animals↗
PubMed1986

Auscultatory characteristics of normally functioning Lillehei-Kaster, Björk-Shiley, and St Jude heart valve prostheses.

Auscultatory and echocardiographic and phonocardiographic studies were performed on 26 patients who had a total of 11 Lillehei-Kaster, 16 Björk-Shiley, and 18 St Jude heart valve prostheses functioning normally in the aortic or mitral positions or both. With all types and positions of prostheses a distinct closing sound was always detected. It was frequently heard in two parts which, according to echocardiographic and phonocardiographic studies, resulted from the onset and completion of the valve closure. An opening sound could be heard from all Björk-Shiley and St Jude valves but from only four of the 11 Lillehei-Kaster valves. The opening sounds due to mitral prostheses consisted of two to three closely spaced clicks detected as a faint early diastolic crackle on auscultation. Echocardiography with phonocardiography indicated that they were related to the onset and termination of the disc opening excursion. In the aortic position the valves always produced early to mid-systolic murmurs, and a soft early diastolic murmur was also heard in seven of 23 patients. A mid-diastolic rumble was heard in 12 of 22 patients with mitral prostheses. Normally functioning tilting disc valve prostheses produce characteristic auscultatory findings, and familiarity with these findings will be useful in clinical evaluation of patients with these prostheses.

Adult↗
PubMed1986

Effects of synthetic blood combined with contrast medium on coronary endothelium: an experimental study.

The study described was carried out to evaluate endothelial injury following incubation of coronary material in contrast medium and in contrast medium diluted with fluorocarbon solution. Six porcine hearts were excised and isolated. Immediately thereafter, pieces of the main coronary arteries and ascending aortas were incubated in four different solutions: 1) blood, 2) contrast medium, 3) fluorocarbon solution, 4) fluorocarbon--contrast medium (1:1). Flow surfaces and coronary endothelial morphology were evaluated by scanning electron microscopy (SEM). Porcine blood (at room temperature) preserved endothelial structures intact but, in two samples, small patchy areas of denuded surface were found. Four minutes' immersion in contrast medium resulted in easily visible changes in the endothelial lining and individual cells. Denuded flow surface areas were common, the intact surface morphology was flattened. After 7 minutes, destruction was total. The addition of fluorocarbon solution to contrast medium (1:1) diminished the changes, which also occurred later than after incubation in pure contrast medium. After 7 minutes, separate endothelial cells were still identifiable but the microvilli had disappeared. Fluorocarbon solution preserved the endothelial lining well during a 10-minute follow-up period. The experimental protocol described confirmed the deleterious effect of contrast medium on coronary endothelial lining, which could be reduced to some extent by adding fluorocarbon solution to contrast medium.

Animals↗
PubMed1986

Comparative analysis of tilting disc and ball valve prosthesis in aortic position.

In a retrospective analysis, comparison was made between the Cutter-Smeloff ball valve (n = 63) and the Lillehei-Kaster tilting disc valve (n = 256) in the aortic position. No significant intergroup difference was found as regards rate of thromboembolism (0.6/100 patient years for both valve types), endocarditis (0.2 for Cutter-Smeloff and 0.5 for Lillehei-Kaster/100 patient years) and paraprosthetic leak (0.9 and 0.5, respectively/100 patient years). The actuarial curve of cumulative survival was similar for both valves until 6 years postoperatively. Thereafter the outcome was less favourable for the patients with Cutter-Smeloff valve (actuarial survival 79 +/- 5% than for those with Lillehei-Kaster valve (91.2 +/- 2%). The reason for this, statistically significant, difference may be associated with the difference in valve profiles.

Actuarial Analysis↗
PubMed1986

Long-term follow-up of Björk-Shiley mitral valve replacement. 10 years' experience.

Retrospective analysis was made of 176 patients who received a Björk-Shiley mitral valve replacement in the period 1973 through 1982. Actuarial cumulative curves showed the 10-year and 5-year survival rates to be 79 +/- 3.4%. The functional status at follow-up was better than preoperatively in 77.1% of the patients. The hospital mortality was 9.1% and the late mortality was 3.6/100 patient years. Early complications included disc entrapment against the ventricular wall in three cases, wedging of chorda between disc and valve rim in two and posterior perforation of the left ventricle in three patients. There was no structural valve damage. Calculated per 100 patient years, the incidence of thromboembolism was 2.5, endocarditis 1.4 and prosthetic leak 1.8. One thrombosed valve was successfully replaced by a new prosthesis 11 years after the initial implantation. Jamming of the disc by tissue over-growth necessitated a new valve implantation in one case. The incidence of early valve-related complications was high, but the long-term results were comparable with those from other mechanical valves. One early complication--disc entrapment against the ventricular wall--may be avoided by use of a sufficiently small valve if the ventricle is small and thickened.

Actuarial Analysis↗
PubMed1986

Substance P- and leu-enkephalin-immunoreactive nerves before and after myocardial ischaemia, hypothermic chemical cardioplegia and reperfusion injury during open-heart surgery.

During open-heart surgery, myocardial biopsies were obtained before the start of extracorporeal circulation (from the right auricular appendage) and after weaning from the pump (from the right atrium), and processed for immunocytochemical demonstration of substance P- and leu-enkephalin-immunoreactive nerve fibres and for electron microscopy. Substance P-immunoreactive nerves were seen around blood vessels, between myocardial cells and forming large glomerulus-like loops, but were not numerous. Leu-enkephalin-immunoreactive nerves were very sparse. We therefore believe that both nerve types primarily are modulatory axons. In the post-weaning specimens, nerves of both types were more numerous (attributable to the different site of biopsy), and no change was seen in the immunofluorescence reaction. The ultrastructure (all types) of nerve terminals was well preserved, although myocardial damage was obvious in many specimens. Cardiac nerves, including peptidergic nerves, thus seem to be relatively resistant to ischaemia, hypothermic chemical cardioplegia and reperfusion injury.

Biopsy↗
PubMed1986

Mediastinal neurogenic tumours. Early and late results of surgical treatment.

Early and late results of surgery for neurogenic mediastinal tumour were evaluated in 66 cases with a mean follow-up of 12 years. The series comprised 48 neurilemmomas, 8 neurofibromas, 7 ganglioneuromas, and neurinoma, neurofibrosarcoma and ganglioneuroblastoma each in one case. There were two early deaths (3%), one due to peroperative bleeding from the left subclavian artery and the other to acute myocardial infarction. Operative complications arose in 12 cases (18%), the most common being wound infection (3 cases). There were 17 late deaths (26.6%). In the neurilemmoma group, 3 of the 13 late deaths were related to the tumour or its treatment, and both deaths in the neurofibroma group were related to malignant transformation. Recurrence of tumour appeared in 3 of the 48 patients with neurilemmoma and also in the single patient with neurinoma as tumour classification. One neurilemmoma was a dumb-bell tumour, and operation in this case resulted in paraplegia. Malignant transformation appeared in 2 of the 8 neurofibromas 5 and 13 years postoperatively. Because of the risks of malignant degeneration and of recurrence, patients operated on for neurogenic mediastinal tumour should be carefully followed up for many years.

Adolescent↗
PubMed1986

Plasma cell granuloma of lung and pleura.

A report is presented of seven patients with plasma cell granuloma of the lung or pleura. Two were operated on in 1970, three in 1971, one in 1973 and one in 1984. None of the patients had smoked cigarettes. Five had a history of infection. Most of the patients were young, healthy and working. The surgical treatment was lobectomy in four cases, bilobectomy in one case and resection of tumour in two cases. The histology of the tumours was re-evaluated, and was similar in all cases. They were composed mainly of plasma cells, lymphocytes and granulocytes, and small foci of calcification were also seen. No recurrence of tumour was found in observation up to 13 years postoperatively. One patient died of pancreatic carcinoma after 6 years. The others are doing well.

Adolescent↗
PubMed1986

Residual carcinoma in bronchial resection line.

Microscopic residual tumour growth was found postoperatively in the bronchial resection lines in 44 out of a total of 1069 patients who underwent resection for pulmonary carcinoma. Bronchopleural fistula developed in six of these patients (13.6%). The incidence of bronchopleural fistula in the material overall was 4.2% (45 patients). Residual carcinoma therefore seemed to impair healing of the bronchial stump (p less than 0.01). Routine intraoperative frozen sections of the bronchial resection line can be recommended in order to reveal the residual carcinoma and thus lower the incidence of bronchopleural fistula. The five-year survival rate of these patients with microscopic residual carcinoma in their bronchial resection lines was similar to that in patients with the same TNM staging who had undergone resection for pulmonary carcinoma. Residual carcinoma in the bronchial resection line therefore did not worsen prognoses. The survival rate in our patients was better than survival rates reported for other series. Most of our patients had received postoperative radiotherapy. Previous reports relate to patients treated only surgically. Postoperative radiotherapy may therefore improve the prognosis in patients with residual tumour growth in their bronchial resection lines.

Adenocarcinoma↗
PubMed1986

Carcinoembryonic antigen (CEA) and gastrointestinal cancer associated antigen CA 19-9 in bronchioloalveolar carcinomas and pulmonary adenocarcinomas.

The concentrations of carcinoembryonic antigen (CEA) and the gastrointestinal cancer associated antigen CA 19-9 were studied by radioimmunoassay in serum samples from patients with malignant and benign pulmonary tumours. Elevated levels of either markers were found in 14% of patients with malignant tumours and in none of the cases with benign lesions. Following removal of the tumour, a decline in high CA 19-9 levels was found. The advanced tumours produced the highest serum CA 19-9 concentrations but elevated values were also found in small bronchioloalveolar carcinomas and pulmonary adenocarcinomas. Immunohistochemical staining for CEA and CA 19-9 was performed on routine histopathological specimens. About half of the cases of bronchioloalveolar carcinomas and pulmonary adenocarcinomas were CA 19-9 positive and about 90% were CEA positive. No correlation between intensity of tissue expression and serum levels of CA 19-9 could be demonstrated. However, the bronchioloalveolar carcinomas and pulmonary adenocarcinomas which produced high serum levels of CA 19-9 also stained positively.

Adenocarcinoma↗
PubMed1985

Multifactorial primary prevention of cardiovascular diseases in middle-aged men. Risk factor changes, incidence, and mortality.

In a randomized five-year multifactorial primary prevention trial of vascular diseases, hyperlipidemias, hypertension, smoking, obesity, and abnormal glucose tolerance of the high-risk test group (n = 612 men) were treated with dietetic-hygienic measures and hypolipidemic (mainly probucol and clofibrate) and antihypertensive (mainly diuretics and beta-blockers) agents. A matched high-risk control group (n = 610) and a low-risk control group (n = 593) were not treated. The program markedly improved the risk factor status, yet the five-year coronary incidence tended to be higher in the intervention group than in the control group (3.1% vs 1.5%), while the stroke incidence was significantly reduced (1.3% vs 0%). The coronary events tended to be accumulated in subgroups treated with beta-blocking agents or clofibrate, but there were few in those receiving probucol or diuretics. Thus, the intervention program significantly reduced development of stroke, but the occurrence of cardiac events was not prevented. Possible adverse drug effects offsetting the probable benefit of improved risk profile are not excluded.

Antihypertensive Agents↗