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Angiotensin II (AII) has been implicated as an important factor in the pathophysiology of heart diseases. Following the recent identification of two subtypes of the AII receptor in cardiac tissue of animals, we investigated the possible occurrence of these, or similar, subtypes in human atrial tissue. In right-atrial tissue from patients undergoing heart surgery, we determined the AII-receptor profile in receptor binding studies, using [125I]-angiotensin as radioligand and subtypes to identify and quantify AII-receptor subpopulations. In 35 patients (23 requiring coronary bypasses, 10 valvular surgery and two combined coronary and valvular surgery), the left-ventricular ejection fraction was determined in the preoperative phase, and right- and left-atrial pressure during surgery. In membranes of human right atria, AII receptors are present in high density (median: Bmax = 294 fmol.mg-1 protein, range: 111-2073) and two different subtypes can be distinguished. Type-1 receptors (AT1) accounted for 33 +/- 10% of the population whereas type-2 receptors (AT2) made up 67 +/- 10% of the population. There was no correlation between any of the measured cardiac functions and total AII-receptor density or receptor affinity. However, the percentage of AT1 receptors was higher in the atria of patients with normal right-atrial pressure; left-ventricular ejection fraction was positively and right-atrial pressure inversely correlated with the percentage of AT1 receptors (r = 0.740 and -0.901, respectively; P < 0.001, for both). Moreover, the percentage of AT2 receptors was directly correlated with the levels of left-atrial pressure (r = 0.853; P < 0.001). It is concluded that the ratio of AT1 to AT2 receptors correlates well with right-atrial pressure and left-ventricular function. This is a first indication of a possible involvement of AII-receptor subtypes in the pathophysiology of cardiac dysfunctions.

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Twenty-one consecutive patients with traumatic rupture of the thoracic aorta were treated at the University Hospital of Basel, Switzerland. The patients were divided into two groups according to their clinical status at the time of surgery. Six patients with unstable vital functions underwent immediate surgery (group 1), while 15 patients were operated upon semi-urgently because of delayed diagnosis or electively (group 2). Five of 6 patients undergoing immediate repair in group 1 died intraoperatively, 3 of 15 patients with deferred surgery expired postoperatively after a period of 6 weeks to 3 months. All 13 survivors underwent follow-up for 10 months to 20 years. NMR imaging of the aorta in 12 patients revealed neither pseudoaneurysms nor stenosis at the anastomoses. The results indicate that the timing of the surgical intervention in stable contained aortic rupture with serious associated injuries should preferably be deferred until after stabilization of the clinical status.

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Transesophageal echocardiography is a new, semi-invasive technique for the examination of the heart and the aorta. Within 10-15 minutes it is possible to obtain good pictures of the anatomy and function of the heart. Diagnostic indications are native and prosthetic valvular heart disease; the method is particularly suitable for visualization of endocarditic vegetations, evaluation of embolic events or congenital heart disease and assessment of aortic dissection. In the intensive care unit transesophageal echocardiography is a new window to the heart, yielding instantaneous information on cardiac status. For the anesthetist it is the first method to provide perioperative beat to beat analysis of ventricular function.

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In bronchial carcinoma the assessment of operability requires an accurate evaluation of the regional and mediastinal lymph nodes. For this, both mediastinoscopy and computed tomography are often used on a routine basis today. The present work considers the relative value of these two methods of investigation. Fifty-seven patients with bronchial carcinoma, in whom both investigations were carried out prior to surgery, were included in this prospective study. In the computed tomogram, lymph nodes with a diameter of more than 1 cm were defined as positive (i.e. suspected malignant infiltration). Sixteen of the 57 patients had histologically confirmed lymph node metastases; in 13 cases the metastases were detected by computed tomography, in 12 cases also by mediastinoscopy and in 3 cases only at thoracotomy. In 41 of the thoracotomized patients, no mediastinal metastases were found. As was to be expected, mediastinoscopy also proved negative in these cases. In 9 of these cases, however, the preoperative computed tomography findings were false-positive. For computed tomography the specificity was 78% and the sensitivity 81%; for mediastinoscopy, on the other hand, the specificity was 100% and the sensitivity 75%. The specificity of computed tomography is too low. Also, lymph nodes which are only inflamed may be considerably enlarged and cannot be differentiated in the computed tomogram from those with malignant infiltration. Mediastinal lymph nodes which appear enlarged in the computed tomogram therefore have to be further investigated by mediastinoscopy. However, in this prospective study, mediastinoscopy provided no additional information in those cases in whom the computed tomography findings were negative (lymph node diameter less than or equal to 1 cm); it did not detect the metastases in the 3 patients with false-negative computed tomography findings. Therefore, in the case of a negative computed tomogram, thoracotomy may be performed immediately, without previous mediastinoscopy.

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Vein bypass grafts in 8 patients were examined by light microscopy (LM) only or, in addition, by transmission electron microscopy (TEM) and scanning electron microscopy (SEM) before stretching, after stretching and immediately before implantation. Before stretching, the endothelium showed only discrete changes and detachment of the endothelium was rare. After stretching severe endothelial damage was evident, including loss of large areas of endothelium and extensive endothelial tears. Before implantation there had been an extension of the tears and the endothelial detachment in individual preparations. The most important factor causing damage is stretching of the vein. The incubation medium may also play a significant role. Damage incurred before operation or during removal, and hypoxia are of lesser importance. By avoiding endothelial damage it should be possible to limit the occurrence of early postoperative thrombosis and possibly severe late changes as well.

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The evidence of considerable damage caused by stretching to the vein transplants for aorto-coronary bypasses led us to a modified technique of vein dilation that allows control and limitation of the pressure to which the veingraft is exposed. The efficiency of this procedure in terms of reduced damage to the vascular wall was investigated by microscopic and electronmicroscopic methods. It could be shown that the integrity of the intimal layer of vein grafts can be maintained to a high degree. Clinically this implies that the long-term patency rate of aorto-coronary veingrafts may be improved. This will be subject to further coronarographic studies during the follow-up of a present series of patients.

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90 out of 202 lung cancer patients hospitalized for preoperative investigations were scheduled for radical surgery. 15 patients were not operated on because of insufficient lung function data. The operation was performed in 75 patients. The complication rate was 11% and mortality 8%. 7 out of 8 patients who subsequently developed severe complications had fulfilled the criteria for lung resection only after intensive antibronchitic treatment. Nearly all the survivors showed the predicted preoperative minimal lung function values after the operation. The limit of 1000 ml for postoperative FEV1 is justified, since patients with these or larger functional reserves nearly all had a favourable early and late postoperative course, and also because lung function values continuously deteriorate in chronic obstructive lung disease.

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A case of chronic constrictive uraemic pericarditis successfully treated by pericardectomy is reported together with the pre- and postoperative haemodynamic data.

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