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Biomedical subjects

S Jost

Publications and source records attributed to S Jost.

At least 55 records · Page 3Linked to original sources
PubMed1991

Angioplasty of subacute and chronic total coronary occlusions: success, recurrence rate, and clinical follow-up.

Angioplasty of single total, subacute, or chronic coronary occlusions was performed in 90 patients. It was successful in 54 occlusions (60%), in 77% of those less than 6 weeks old, and in 44% of those of greater than 6 weeks' duration (p less than 0.005). All procedures were uneventful. Control angiography was performed in 53 (98%) patients with successful angioplasty after an average interval of 97 +/- 53 days. Stenosis had recurred in 16 patients (30%). During a follow-up period of 36 +/- 13 months, three patients died, five patients underwent coronary bypass operation, and 10 had reangioplasty. Despite an additional late angiographic recurrence of stenosis in seven patients, 36 patients revealed angiographic long-term success. In the 46 nonoperated patients, angina pectoris and exercise stress tests were substantially improved. Thus angioplasty of subacute and chronic total coronary occlusions is an uneventful procedure, the success rate depending on the duration of the occlusions. Despite a high angiographic recurrence rate, the angiographic and clinical long-term results are favorable.

Adult↗
PubMed1991

Ventricular fluid neuropeptides in Parkinson's disease. II. Levels of substance P-like immunoreactivity.

Substance P-like immunoreactivity (SPLI) was determined in cerebrovascular fluid of patients with extrapyramidal motor diseases. Patients with Parkinson's disease (PD) showed a SPLI concentration decreased by 30% compared with patients without extrapyramidal disease. No differences were apparent for patients with dystonia. Fluid obtained from the foramen Monro showed higher SPLI concentrations than fluid from a lateral ventricle, indicating that hypothalamic sources are important for ventricular substance P. Lateral ventricular SPLI was particularly low in parkinsonian patients which raises the possibility of a decreased SPergic activity in basal ganglia occurring in PD.

Adult↗
PubMed1991

Increased thrombin levels during thrombolytic therapy in acute myocardial infarction. Relevance for the success of therapy.

BACKGROUND: It has been suggested that thrombolysis in a feedback reaction may generate pro-coagulant activities. METHODS AND RESULTS: Fifty-five patients were treated with urokinase-preactivated prourokinase (n = 35) or tissue-type plasminogen activator (n = 20) for acute myocardial infarction and underwent coronary angiography at 90 minutes and at 24-36 hours into thrombolysis, and fibrinogen (Ratnoff-Menzie), D-dimer (ELISA) and thrombin-antithrombin III complex levels (ELISA) were measured. Primary patency was achieved in 39 patients (70.9%), 13 of whom (33.3%) suffered early reocclusion. Nonsignificant decreases in fibrinogen levels were observed while D-dimer levels increased +3,008 +/- 4,047 micrograms/l (p less than 0.01), differences not being significant in respect to the thrombolytic agents or to the clinical course. In contrast, while thrombin-antithrombin III complex levels decreased -4.4 +/- 13.0 micrograms/l in patients with persistent patency, they increased +7.5 +/- 13.6 micrograms/l in case of nonsuccessful thrombolysis (p less than 0.02) and +11.9 +/- 23.8 micrograms/l in case of early reocclusion (p less than 0.001). For patients with thrombin-antithrombin III complex levels greater than 6 ng/l 120 minutes into thrombolysis, the unfavorable clinical course was predicted with 96.2% sensitivity and 93.1% specificity. CONCLUSION: Generation of thrombin, occurring during thrombolysis, is a major determinant for the success of therapy and thrombin-antithrombin III levels may serve as predictors for the short-term prognosis.

Antithrombin III↗
PubMed1991

[Percutaneous, transluminal angioplasty of aortocoronary venous bypass grafts--acute success, angiography and clinical follow-up].

In 41 consecutive patients with 49 stenoses of aorto-coronary venous bypass (ACVB) grafts percutaneous transluminal angioplasty (PTA) was attempted. PTA was successful, i.e., the percent area stenosis was reduced by greater than 20% to less than 70% (quantitative measurement with a precision magnifying lens from two orthogonal angiographic views) in 46 stenoses (94%) of 38 patients (93%). In 35 patients (92%) with 42 stenoses control coronary angiography was performed after a mean interval of 189 +/- 186 days. Recurrence, defined as an increase of percent area stenosis to greater than or equal to 70%, was found in nine stenoses (21%) of nine patients (26%). Recurrence correlated with a stenosis length greater than 10 mm before PTA (5/8 vs 4/32 stenoses: p less than 0.01). In recurrent stenoses, the average diameter of the grafted native coronary artery was significantly smaller than in recurrence-free stenoses (1.92 +/- 0.52 mm vs 2.45 +/- 0.50 mm; p less than 0.01). Clinical data were collected from all 38 patients with successful PTA after an average of 30 +/- 17 months following PTA. In this interval, 11 patients had undergone re-angioplasty and eight patients were re-operated; in addition, there were three cardiac deaths. In the 27 surviving patients without re-operation (71%), angina pectoris had improved from a mean of 3.0 +/- 0.7 before PTA to 1.8 +/- 1.0 (CCS-classification) (p less than 0.001). In 19 of the 27 patients (70%) the exercise stress test was negative, in contrast to only three patients (11%) before PTA. Thus, in the majority of patients PTA of ACVB-graft stenoses improves quality of life.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Retardation of angiographic progression of coronary artery disease by nifedipine. Results of the International Nifedipine Trial on Antiatherosclerotic Therapy (INTACT). INTACT Group Investigators.

425 patients showing mild coronary artery disease (CAD) on arteriography were enrolled in a multicentre trial and randomised to treatment with nifedipine (80 mg/day) or placebo. The two groups were well matched for age, sex, and risk factors. 348 patients (82%) underwent repeat arteriography 3 years later; 282 (134 nifedipine, 148 placebo) had received treatment throughout, but treatment had been stopped in 39 nifedipine-treated and 27 placebo-treated patients after average periods of 354 and 467 days. Computer-assisted measurements of arteriograms from all restudied patients (175 placebo, 173 nifedipine) showed no significant differences in the number or severity of lesions on initial arteriograms, or in the progression or regression of existing lesions over 3 years. In contrast, the number of new lesions per patient was significantly lower in the nifedipine group than in the placebo group (0.59 vs 0.82 lesions per patient, a 28% reduction). Thus in patients with mild CAD nifedipine substantially suppresses disease progression as shown by the appearance of new lesions detectable by quantitative coronary arteriography.

Administration, Oral↗
PubMed1990

Reproducible uniform coronary vasomotor tone with nitrocompounds: prerequisite of quantitative coronary angiographic trials.

In quantitative analysis of repeated coronary angiograms, a variable vasomotor tone of the epicardial coronary arteries may influence the accuracy of the results. Therefore, we evaluated the extent and reproducibility of coronary artery dilation with nitrocompounds. In 32 patients with coronary artery disease, the vasodilatory response of angiographically normal coronary segments to different nitrocompounds was analyzed with the computer-assisted contour detection system CAAS. Twenty patients received 5 mg or 10 mg of isosorbide dinitrate sublingually. After 10 to 15 min, a maximal diameter increase was measured with an average of 16 +/- 11% (5 mg: P less than 0.01) and 28 +/- 13% (10 mg: P less than 0.001) from control. Another 12 patients received 0.025 mg per kg body weight of SIN-1, the active metabolite of molsidomine, as an intravenous infusion over 5 min. A comparable maximal dilation (29 +/- 5%; P less than 0.001) occurred after 10 to 15 min and could not be enhanced further with 0.8 mg nitroglycerin administered sublingually (28 +/- 7%; n.s.). One hour after square root of Sin-1, coronary dilation was still 24 +/- 8% (P less than 0.001 compared with control), and 0.8 mg of nitroglycerin sublingually reestablished the previous maximal dilation of 28 +/- 8%. We conclude that high doses of nitrocompounds induce a reproducible maximal coronary dilation that eliminates a substantial source of error in quantitative analysis of repeated coronary angiograms. At present, sublingual administrations of either 10 mg isosorbide dinitrate once or 0.8 mg nitroglycerin repeatedly seem to represent the easiest practicable modes to achieve maximal coronary vasodilation for an adequate period.

Angiography↗
PubMed1990

Coronary vasomotor tone in large epicardial coronary arteries with special emphasis on beta-adrenergic vasomotion, effects of beta-blockade.

Changes in coronary vasomotor tone of large epicardial coronary arteries today can be assessed quite accurately by exact measurements of coronary diameters applying computer assisted systems. The effect of various vasodilators (nitrates, calcium antagonists, EDRF-dependent compounds) was tested in this way. It appears that normal coronary artery segments reach a maximum of dilator reserve with an increase of luminal diameter of approximately 30-40%; different patterns of kinetics were, however, encountered. beta-Blocking agents, both non-selective (propranolol) and selective (atenolol), were found to lead to a gradual vasoconstriction, i.e., a decrease in diameter by approximately 20-25% over 20 min, an effect which is overcome by nitrates. New beta-blocking compounds with vasodilator properties, such as celiprolol, show no constriction. The vasoconstrictor effect of propranolol and atenolol may not only be due to the decrease of flow following the drop in myocardial oxygen consumption, but could also reflect an unopposed alpha-adrenergic tone. The clinical aspects of this observation are discussed.

Adrenergic beta-Antagonists↗
PubMed1990

Elimination of variable vasomotor tone in studies with repeated quantitative coronary angiography.

In quantitative coronary angiographic studies, unintentional changes of coronary vasomotor tone may have a significant influence on the coronary artery diameters, thereby increasing the variability in the measurements. To obtain objective data on these measurement variabilities, two protocols were designed to assess the influences of ionic and nonionic radiographic contrast media on the mean diameters of angiographically normal coronary arteries. The vessel sizes were determined with the CAAS using automated edge detection techniques. In 21 patients (study no. I), coronary angiograms were taken in identical angiographic projections before (control), and immediately following several (at average 7) subsequent diagnostic dye injections administered over a period of about 7 min. The ionic contrast agent diatrizoate 76% induced a coronary dilation of 19 +/- 7% (mean +/- s.d., p less than 0.001; n = 10); the nonionic agent iopromide 370 increased the coronary artery diameters by only 6 +/- 4% (p less than 0.01; n = 11). In another 11 patients (study no. II) coronary angiograms were obtained using the nonionic contrast medium iopamidol 300 at 5, 8, 10 and 11 min after the control acquisition; this protocol was repeated in the same patients with diatrizoate 76%. With iopamidol, coronary diameter changes were not significant at any time; with diatrizoate, however, coronary dilation was measured at 10 min (2 +/- 2%; p less than 0.01) and at 11 min (10 +/- 3%; p less than 0.001). In a third study it was tested, whether standardization of coronary vasomotor tone (e.g. in coronary angiographic follow-up studies) is possible by the induction of a reproducible maximum coronary dilation with nitrocompounds. In 12 patients, the mean diameters of angiographically normal coronary segments were analyzed before and at various times after i.v. administration (over 4 min) of 0.025 mg SIN-1/kg bodyweight. Coronary dilation was maximal at 10 or 15 min after the onset of the SIN-1-infusion (29 +/- 5%; p less than 0.001). 0.8 mg nitroglycerin given s.l. at 15 min did not further dilate the coronary arteries (28 +/- 7%). One hour after SIN-1, coronary dilation still amounted to an average of 24 +/- 8% (p less than 0.001) and became 'maximal' again, when 0.8 mg nitroglycerin was again administered sublingually (28 +/- 8%; p less than 0.001). In conclusion, short-term variability of coronary vasomotor tone induced by ionic radiographic contrast media can be eliminated by the use of nonionic contrast agents and observation of injection intervals of at least 2 min. In quantitative coronary angiographic follow-up studies, as well as during acute interventions (e.g., PTCA), identical baseline vasomotor tone can be achieved by induction of the maximal coronary dilation using nitrocompounds.

Adult↗
PubMed1990

Vasodilatory effects of nisoldipine on coronary arteries--correlation with plasma levels.

Vasomotion of angiographically normal and stenotic epicardial coronary arteries was analyzed up to 15 minutes after the onset of an intravenous infusion (4 minutes) of 0.5 mg (13 patients, group A) or 1 mg nisoldipine (13 patients, group B). After both doses the maximal increase of the mean diameters of normal coronary segments was achieved not before the 15th minute, averaging 11 +/- 6% in group A (p less than 0.001) and 18 +/- 9% in group B (p less than 0.001). Eleven of 15 and 8 of 9 coronary stenoses in groups A and B dilated to 5-80% and 15-70%, respectively. The nisoldipine concentration reached maximal levels at the end of the infusion (fourth minute) with an average of 8 +/- 4 ng/ml and 17 +/- 7 ng/ml in groups A and B, respectively. A significant correlation between nisoldipine plasma levels and dilation of normal coronary segments was obtained only with the individual maxima of these parameters and only in group A (p less than 0.01). The hysteresis of the coronary dilation in relation to the drug plasma levels may be due to the high receptor affinity of nisoldipine. In either group nisoldipine provoked a persistent increase in coronary sinus oxygen saturation (p less than 0.01) and a substantial and prolonged drop in systolic and diastolic aortic pressure (p less than 0.001). Both doses of nisoldipine induced a rise in heart rate (p less than 0.01) and a slight drop in the rate-pressure product (p less than 0.05).

Adult↗
PubMed1990

Features of the angiographic evaluation of the INTACT study. International Nifedipine Trial on Antiatherosclerotic Therapy.

INTACT (International Nifedipine Trial on Antiatherosclerotic Therapy) is a prospective, placebo-controlled, randomized, double-blind, multicenter trial analyzing the influence of 80 mg nifedipine/day on the angiographic progression of early stage coronary atherosclerosis. Coronary angiograms were taken in identical projections before and after a treatment period of 3 years. Quantitative analysis of the angiograms was performed with the computer-assisted contour detection system CAAS. For definition purposes, the coronary artery system was subdivided into 25 different segments, including all anatomic variants. Measurement parameters of segments were mean and minimal diameter, and of stenoses minimal diameter, percentage diameter reduction (at least 20%), length, and plaque area. The variable extent of the changes of these parameters in the different projections analyzed per patient in the two study angiograms was considered by separate computation of the maximal, mean, and minimal changes over these projections; the comparison of the parameter changes between the two treatment groups was performed separately according to these three modes. For all parameters, this comparison was performed on the basis of the individual 25 segments, as well as after aggregation of individual segments to arteries (RCA, LAD, and LCX), to groups of large and small segments, and to the entire coronary artery system. Assessment of changes of the coronary (patho)morphology by quantitative analysis of coronary angiograms is associated with a number of methodical limitations, which may lead to a certain variability of the results. However, due to the double-blind feature of INTACT, this variability should be comparable in the two groups of this study, allowing for a conclusive comparison.

Angiography↗
PubMed1990

Retardation of coronary artery disease in humans by the calcium-channel blocker nifedipine: results of the INTACT study (International Nifedipine Trial on Antiatherosclerotic Therapy).

Experimental studies have demonstrated a 30-50% reduction in the development of atheromatous lesions of the aorta in rabbits fed a diet rich in cholesterol when they were treated with nifedipine. Based on these favorable results, we designed a multicenter, placebo (PL)-controlled, randomized, double-blind study, to test the effect of 80 mg nifedipine (NIF) per day versus placebo on the progression of mild coronary artery disease (CAD) (further development of existing stenoses, especially formation of new stenoses and occlusions) over a duration of 3 years. Progression of CAD was assessed by coronary angiograms performed at entrance and at completion of the study, using a computer-assisted analysis system (CAAS) to quantitate various stenosis parameters (percent degree of stenosis and minimal stenosis diameter). Of the 425 patients enrolled, 348 (82%) underwent a second angiogram; 66 of them, however, terminated treatment prematurely after an average of 359 (placebo) and 467 days (nifedipine). A total of 282 patients (148 on placebo, 134 on nifedipine) completed the trial with full-length treatment. There were no differences between the two groups in the progression of the existing stenoses. Patients on nifedipine, however, demonstrated significantly fewer new lesions (stenoses greater than 20% or occlusions) than those on placebo: In the 282 patients undergoing the full-length treatment, there were 73 patients on placebo (49%) with 118 new lesions (0.8/patient) and 54 patients on nifedipine (40%) with 78 new lesions (0.58/patient), a difference of -27% (p = 0.031 by Cochran's linear trend test). The difference was greatest in the left anterior descending branch, with 28 patients on placebo developing 33 new lesions (0.22/patient), versus 16 patients on nifedipine with 18 new lesions (0.13/patient) (-40%; p = 0.045); and in the left circumflex branch, where 34 patients on placebo exhibited 39 new lesions (0.26/patient) versus 23 patients on nifedipine with 22 new lesions (0.16/patient) (-38%, p = 0.033). No differences were observed in the right coronary artery, the vessel with the highest number of existing and new lesions [PL] versus 0.27 [NIF] new lesions/patient) (-7.6%, p = 0.381). Hence, INTACT confirmed the previous experimental studies and demonstrates a significant reduction in newly formed coronary lesions in patients on nifedipine when compared with those on placebo, especially in the presence of early coronary artery disease.

Adult↗
PubMed1990

Ventricular fluid neuropeptides in Parkinson's disease. I. Levels and distribution of somatostatin-like immunoreactivity.

We have measured somatostatin-like immunoreactivity SLI in cerebroventricular fluid of patients with Parkinson's disease (PD) and other extrapyramidal disorders with hyperkinesia. Patients with PD showed a significantly lower concentration of SLI when compared with levels in control patients with chronic stable multiple sclerosis or temporal lobe epilepsy. Less markedly decreased levels of SLI were also noted in patients with torsion dystonia. Of two patients with Huntington's disease one showed a high and one a medium concentration of SLI. According to the site of the stereotactic cannula, verified by ventriculopathy, SLI concentrations in CSF specimen obtained from the foramen Monro tended to be higher than in specimen from a supraforaminal level. Of 5 other patients with lateral and third ventricle being accessible during the passage of the stereotactic cannula, 4 showed higher SLI concentrations in the third ventricle compared to the lateral ventricle. High performance liquid chromatographic analysis combined with radioimmunoassay showed molecular heterogeneity of SLI in CSF. The ratio of SST-14 to SST-28 was higher in the third ventricle than in the lateral ventricle.

Adult↗
PubMed1990

Role of thrombolysis and thrombin in patients with acute coronary occlusion during percutaneous transluminal coronary angioplasty.

In a series of 447 patients with single vessel angioplasty, 27 (6.0%) had acute thrombotic occlusion early after the procedure. They were treated with combined intracoronary (20 mg)/intravenous (50 mg) thrombolysis with recombinant tissue-type plasminogen activator (rt-PA) and repeat mild balloon inflations. Reopening of the vessel was achieved in 22 patients (81.5%). Follow-up coronary angiography 24 to 36 h later revealed reocclusion in 12 patients (54.5%). Thrombin levels measured as thrombin-antithrombin-III complex in patients with successful thrombolysis and persistent patency decreased from 8.5 +/- 11.4 micrograms/liter at baseline to 3.5 +/- 1.4 micrograms/liter 120 min after the start of thrombolysis; these levels increased from 9.4 +/- 15.0 micrograms/liter at baseline to 15.7 +/- 13.5 micrograms/liter 120 min after the start of thrombolysis in the patients with unsuccessful thrombolysis or early reocclusion (p less than 0.05). When a borderline value for thrombin-antithrombin-III complex level of 6 micrograms/liter was selected to separate the two groups of patients, patients with an unfavorable clinical course were identified 120 min after the start of thrombolysis by levels greater than 6 micrograms/liter (sensitivity 100%, specificity 92.8%). Thus, after abrupt thrombotic vessel closure during coronary angioplasty, the short-term results of thrombolysis seem to be governed by the release of thrombin. In two thirds of patients, however, the thrombin release cannot be suppressed by concomitant aspirin and heparin therapy. Even after successful reopening of the vessel these patients should therefore undergo immediate aortocoronary bypass grafting.

Angioplasty, Balloon, Coronary↗
PubMed1990

Coronary dilation with nitrocompounds and calcium antagonists.

The vasodilatory effects of nitrocompounds and calcium antagonists on epicardial coronary arteries represent substantial antianginal mechanisms in the presence of coronary vasospasm or eccentric coronary stenoses. With high doses of nitrocompounds, angiographically normal coronary segments can be dilated by an average of approx. 30%, some coronary stenoses even by up to 100%, usually without severe reduction of blood pressure. With calcium antagonists, a similar extent of dilation of normal coronary arteries and eccentric stenoses can be obtained. Our own group demonstrated an average dilation of normal coronary arteries of about 20% after intravenous administration of dihydropyridine calcium antagonists; however, the average systolic blood pressure dropped below 100 mmHg after these compounds. Hence, although in isolated human coronary arteries high concentrations of calcium antagonists were shown to induce a considerably greater vasodilation than nitrocompounds, the early drop in blood pressure prohibits a higher dosage of calcium antagonists in vivo. In the presence of coronary artery disease, particularly when associated with coronary vasospasm, a combination of the two groups of compounds might be recommendable, since an addition of the effects of coronary vasomotor tone is likely. Furthermore, the antianginal effects of a reduction of preload and afterload are complementary.

Angina Pectoris↗
PubMed1990

[Relationship between arrhythmia profile, left ventricular function and sudden death in the post-infarct period of patients resuscitated from heart arrest].

In order to determine the relationship among ventricular arrhythmias, left ventricular dysfunction and sudden cardiac death (SCD), 75 consecutive patients with myocardial infarction, 38 of whom resuscitated from SCD, were studied retrospectively by 48 hour Holter electrocardiographic monitoring (ECGD), cardiac catheterization and radionuclide angiography (ACRD). The patients were divided in 3 groups, related to SCD occurrence and to the interval between acute myocardial infarction (AMI) and SCD: Group I (37 patients-control group) no cardiac arrest occurred; Group II (26 patients) resuscitated less than or equal to 48 hours after AMI; Group III (12 patients) resuscitated 6-12 weeks after AMI. ECGDs were recorded with an average of 2 (ECGD 1), 16 (ECGD 2) and 36 months (ECGD 3) after AMI. In ECGD 1, there were no differences in the frequency and complexity of ventricular arrhythmias among the 3 groups, whereas in ECGD 2 and 3 the incidence of complex ventricular arrhythmias was significantly higher in Group III than in the other 2 groups (p less than 0.05). In Group III, the complexity and frequency of ventricular arrhythmias increased both in ECGD 2 and 3 compared to ECGD 1 (p less than 0.05). Furthermore, between patients of Group II and III higher grade arrhythmias and more frequent ventricular premature beats (VPB) were noted in sudden death patients than in survivors. There was no statistical difference in mean cardiac index, left ventricular end-diastolic pressure and ejection fraction among the groups. In the ACRD 1 performed an average of 8 months after AMI, a slight decrease of ejection fraction in Group III compared to the other groups was noted (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Coronary vasodilation with dihydropyridines--a pharmacokinetic study.

In 26 patients with coronary artery disease, the mean diameters of angiographically 'normal' epicardial coronary arteries were assessed with the aid of a computer-assisted contour detection system (CAAS) before and up to 15 min after onset of a 4-min intravenous-infusion of 2 mg nifedipine (13 patients, group I) or 1 mg nisoldipine (13 patients, group II). Maximal coronary dilation amounted to 20 +/- 9% (4th min) in group I and to 18 +/- 9% (15th min) in group II. In addition, in group II changes of the minimal diameters of 9 coronary obstructions were measured; the maximum increase averaged 28 +/- 15% (7th min). In order to compare the pharmacokinetic properties of these compounds the dilation of the 'normal' coronary segments was correlated with the respective drug plasma levels; maximal plasma concentrations averaged 62 +/- 21 ng ml-1 (7th min) in group I and 17 +/- 7 ng ml-1 (4th min) in group II respectively. A positive, linear correlation between coronary dilation and plasma levels was only found with nifedipine (P less than 0.05); with nisoldipine, however, coronary dilation developed in form of a hysteresis curve, when plotted against plasma levels, probably due to the high receptor affinity of this substance. The prolonged efficacy of nisoldipine could be favourable in oral long-term treatment of patients with coronary artery disease.

Adult↗