Search PubMed⌕ Search

Biomedical subjects

S Iversen

Publications and source records attributed to S Iversen.

At least 91 records · Page 5Linked to original sources
PubMed1982

Therapeutic effect of tolbutamide in non-insulin dependent diabetes mellitus (NIDDM). Relation to beta-cell function.

The therapeutic effect of tolbutamide (1.5 g daily) in a random sample of patients with non-insulin dependent diabetes mellitus (NIDDM), was studied in a controlled, double-blind cross-over trial of 13 women and 6 men, aged 40-65 years and of 85-155% ideal body weight. The trial comprised C-peptide determinations during a standard carbohydrate rich meal followed by four periods of 3 months in which alternating tolbutamide and placebo were given. From the beginning to the end of the treatment periods fasting blood glucose was reduced from 11.9 +/- 1.1 (mean +/- SEM) to 10.0 +/- 0.8 mmol/l (P less than 0.025), glycohaemoglobin from 12.8% +/- 0.7 to 11.3% +/- 0.5 (P less than 0.02) with a close correlation between fasting blood glucose and glycohaemoglobin (r = 0.87, P less than 0.001). The observations during the first 3 months of study was not included in the calculations. Fasting C-peptide and fasting insulin concentrations were not significantly altered by tolbutamide treatment. The effect of tolbutamide was inversely correlated to the C-peptide response to the standard test meal at the start of the trial (r = 0.76, P less than 0.01), so that patients with the most pronounced beta-cell failure had the greatest therapeutical effect. The beta-cell response to the test meal could not identify patients, whose fasting blood glucose would be normalized by tolbutamide treatment.

Adult↗
PubMed1981

Re-excitation of the cardioplegic heart. A possible hazard in clinical cardioplegic arrest.

Clinical cardioplegic arrest may coincide with a washout of cardioplegic agents by varying amounts of extracoronary collateral blood flow. This may shorten the duration of electromechanical arrest. Furthermore, even in the absence of electromechanical cardiac activity, washout may influence the cardioprotective properties of cardioplegic methods. The present study was designed to quantify the effects of cardioplegic washout. In a standardized isolated paracorporeal dog heart model, the St. Thomas's Hospital solution (ST-CP) and the Bretschneider histidine buffered solution (B-CP) were compared under the condition of washout by arterial blood. An inverse relationship was found between the amount of blood flowing through the coronary system and the duration of electromechanical arrest. Flow rates compatible with a 100 min period of complete electromechanical arrest were less than 0.41 ml/100 gr heart weight . min in ST-CP arrest and less than 0.21 ml/100 gr . min in B-CP arrest. This would indicate a greater safety against washout-induced re-excitation in ST-CP arrest. Postarrest myocardial function after 2 hours of complete electromechanical arrest at 20 degrees C was distinctly influenced by washout with arterial blood (20 degrees C) even in the absence of cardiac activity. A 100-min period of 0.2 ml/100 gr . min blood flow during arrest improved postarrest recovery of left ventricular developed pressure by 10% (76% versus 66%) after ST-CP arrest. By contrast, after B-CP arrest at equal rates of washout, recovery was diminished by 20% (79% versus 99%). It is concluded, that ST-CP, as compared to B-CP, provides longer periods of electromechanical arrest under the same washout conditions. Whereas postarrest recovery in the B-CP group is clearly superior to ST-CP in totally ischemic hearts, i.e. in hearts without collateral blood supply (99% versus 66%), this advantage may vanish in the presence of cardioplegic washout.

Animals↗
PubMedDate not supplied

Detection of central pulmonary artery thromboemboli by transesophageal echocardiography in patients with severe pulmonary embolism.

Transthoracic echocardiography generally provides only indirect signs of pulmonary embolism. In contrast, with transesophageal echocardiography the thromboembolus itself can be visualized in the central parts of the pulmonary artery. The aims of our study were to evaluate, first, the incidence of central pulmonary artery thromboemboli in patients with severe pulmonary embolism, and second, the accuracy of the echocardiographic diagnosis. Our study group comprised 60 patients with proved severe pulmonary embolism. All patients were examined by transthoracic and transesophageal echocardiography. The echocardiographic findings concerning the absence or presence of central pulmonary artery thromboemboli were compared with the results of different reference methods. Central pulmonary thromboemboli were found in 35 patients (58.3%) by echocardiography. Two types of thrombus were differentiated. Type A is a long, highly mobile thrombus, and type B is an immobile wall-adherent thrombus. In comparison with the reference methods, we determined a sensitivity of 96.7% and a specificity of 88% for the echocardiographic detection of central pulmonary artery thromboemboli in patients with severe pulmonary embolism. Transesophageal echocardiography seems to be a useful method for the diagnosis of severe pulmonary embolism. In our series, central pulmonary artery thromboemboli were present in more than half of the patients. In these cases, transesophageal echocardiography can clarify the diagnosis within a few minutes without further invasive diagnostic procedures.

Adult↗
PubMedDate not supplied

Value and limitations of transesophageal echocardiography in the evaluation of aortic prostheses.

Results of 34 transesophageal (TEE) studies in patients with suspected aortic prosthetic dysfunction were compared with transthoracic echocardiographic (TTE) results and to anatomic findings. Mass lesions noted at surgery (autopsy) were correctly described in 93% by TEE versus 43% by TTE. Abscesses were detected in 88% by TEE versus 18% by TTE. Bioprosthetic degeneration was visualized in 88% versus 38% and prosthetic obstruction correctly identified in 75% versus 50% by TEE and TTE, respectively. Anatomic aortic regurgitant lesions were identified in 96% by TEE versus 77% by TTE, whereas the correct origin was detected in 88% of cases by TEE versus 54% of cases by TTE. TEE provides valuable additional information on morphologic conditions and flow pathology in aortic valve prostheses.

Aortic Valve↗