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Biomedical subjects

H Seibold

Publications and source records attributed to H Seibold.

At least 19 recordsLinked to original sources

Effects of atenolol, slow-release nifedipine, and their combination on respiratory gas exchange and exercise tolerance in stable effort angina.

The effects of atenolol, nifedipine, and their combination on gas exchange and exercise tolerance were studied in 27 patients with effort angina and normal global ventricular function in an open-label and randomized cross-over trial. Symptom-limited semi-supine exercise tests using a ramp protocol (20 W/min) with simultaneous breath-by-breath analysis of gas exchange were carried out after a 4-day wash-out period and after consecutive 2-week treatment periods with atenolol (50 mg b.i.d.), slow-release nifedipine (20 mg b.i.d.), and their combination (b.i.d.). Exercise tolerance was not significantly higher with atenolol than with nifedipine [118(24) vs 113(23) W]. Combination therapy [120(23) W] was more effective than monotherapy with nifedipine (p less than 0.05) but produced no further increase in exercise tolerance over atenolol monotherapy. Maximum oxygen uptake was not significantly different among the treatments. In the range of light to moderate exercise, the slope of the VO2-workload regression line expressed as ml.min-1.W-1 was lower with atenolol than with nifedipine [8.64(1.59) vs 10.28(1.74), p less than 0.005] and intermediate with combination therapy [9.99(1.83)]. The intercept on the VO2 axis was higher with atenolol than with nifedipine [366(111) vs 299(113) ml.min-1, p less than 0.05]. A similar pattern of results was seen when the drug effects on the slope of the VCO2-workload relation were analyzed. VE was higher with nifedipine than with atenolol at all points of the regression analysis [greater than 30 W].(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

An unusual presentation of staphylococcal pericarditis.

An atypical presentation of purulent pericarditis caused by Staphylococcus aureus is described. A bacterial etiology was initially not taken into consideration because the clinical course was torpid and afebrile. Therefore, the appropriate treatment was delayed. The patient recovered after percutaneous pericardial drainage of his purulent pericardial effusion and antimicrobial therapy. The importance of a high index of suspicion of a bacterial cause in patients with pericardial effusion of unexplained etiology is emphasized.

Bacteriuria

"Physiological osteoporosis" and "osteoblast insufficiency" in old age. Comparative radiological-morphometric and statistical studies on the spongy bone of lumbar and cervical vertebral bodies.

To investigate the expectation of general insufficiency of osteoblasts with increasing age, we studied autotopsy material from 105 deceased persons of both sexes who had died between 16 and 91 years and in whom clinically manifest diseases of the bone had been excluded. Quantitative morphometric examination of the structure of the spongy bone of the 3rd-5th lumbar vertebral bodies (LVBs) and of the 5th-7th cervical vertebral bodies (CVBs) was carried out in frontal and sagittal planes, the parameters analysed being volumetric density (Vv), surface density (Sv) and specific surface area (S/V), and the results were subjected to statistical evaluation. The results showed that in the three LVBs, Vv, Sv and S/V behave in a similar manner, Vv and Sv decreasing after the age of 50 years by more than one-third while S/V remains constant throughout life. The three lower CVBs had higher values than the LVBs for all three structural parameters. In the 7th CVB somewhat lower Vv and Sv values and higher S/V values were found than in the 5th and 6th. The age-related changes, by contrast, were very small. This differing behavior of the spongy bone in the two regions of the spinal column is an expression of the different characteristic loading forces in each regions: LVB loading is predominantly static, CVB loading mainly dynamic. Thus, from the functional point of view, what is known as "physiological osteoporosis due to ageing" is nothing more than adaptation by an ageing bone to physical activity, reflecting--like the bone of the young adult--the current loading of the cancellous bone by the actions of the musculoskeletal system. Since such physical activity is often age-related, the performance of the osteoblasts does not depend upon age per se, but merely on the remaining functional adaptive capacities of the ageing organism as whole.

Adaptation, Physiological

Effects of hypothyroidism on bronchial reactivity in non-asthmatic subjects.

The effect of hypothyroidism on non-specific bronchial reactivity was studied in 11 patients without pulmonary disease (mean age 40 (SD 13) years) who had had a total thyroidectomy and radioiodine treatment for thyroid cancer 41 (36) months before the study. All patients when mildly hyperthyroid while having long term thyroxine replacement treatment and once when hypothyroid two weeks after stopping triiodothyronine for the purpose of screening for metastases. Bronchial reactivity was assessed by measuring specific airways conductance (sGaw) after increasing doses of inhaled carbachol (45-1260 micrograms). The dose producing a 35% decrease in sGaw (PD35) was determined from the cumulative log dose-response curve by linear regression analysis. Mean baseline sGaw values were similar when the patients were hypothyroid and when they were hyperthyroid (1.35 (0.36) and 1.41 (0.56) s-1 kPa-1). The interstudy coefficients of variation of baseline sGaw were higher in the thyroid patients than in a euthyroid control group (14% versus 8%). Geometric mean PD35 was lower when the patients were hypothyroid (97 micrograms) than when they were mildly hyperthyroid (192 micrograms). It is concluded that acute hypothyroidism increases non-specific bronchial reactivity in nonasthmatic subjects.

Acute Disease

[Comparative structural analyses of the spongy bone of lumbar and cervical vertebral bodies. Radiological-morphometric and statistical studies].

To investigate the question as to a possible insufficiency of the osteoblasts with increasing age, autopsy material obtained from 105 deceased of both sexes at an age of 16 to 91 in whom clinically manifest bone diseases had been excluded, was studied. The structure of the spongy bone of the 3rd to 5th lumbar vertebral bodies (LVB) and of the 5th to 7th cervical vertebral bodies (CVB) was examined quantitatively-morphometrically, and the results were submitted to a statistical evaluation. In the three LVB, Vv, Sv and S/V behave in a similar manner. Here, Vv and Sv decrease after the age of 50 by more than 1/3, while S/V remains constant throughout live. In all the structural parameters, the three lower CVB have higher values than do the LVB. The age-dependent changes, in contrast, are only very slight. This differing behaviour of the spongy bone in the two regions of the spinal column is an expression of the characteristic loading forces in the respective regions: LVB loading is predominantly static, CVB loading mainly dynamic. Thus, from this functional point of view, physiological osteoporosis due to aging, so-called, is merely an expression of an aging bone adapting - in the same way as the bone of a young adult - to the current loading forces acting upon it.

Adolescent

[Relation of peak flow and spirometry values in patients following bone marrow transplantation].

In about 30% of patients who were subjected to bone marrow transplantation, progressing interstitial and rarely obstructive pulmonary diseases can result in death. Early identification of curable diseases such as pulmonary changes during a "graft versus host reaction" would be desirable. Retrospective evaluation of 159 lung functions in 60 patients after bone marrow transplantation, however, revealed only moderate sensitivity of the peak flow value to vital capacity and FEV1, so that only pathological levels of this parameter will signify noticeable reductions in spirometric values.

Bone Marrow Transplantation

Acute hypothyroidism has no effect on pulmonary vascular resistance.

The effect of acute hypothyroidism on the pulmonary circulation was studied in 9 nonobese athyreotic patients by right heart catheterization at rest and during exercise. The patients were studied while they were hypothyroid 2 weeks after ceasing triiodothyronine treatment and while they were euthyroid on replacement therapy. At rest, pulmonary blood flow [4.0 +/- 0.6 l/min vs 5.8 +/- 1.0 l/min, p less than 0.01] and systolic pulmonary artery pressure [18 +/- 3 mmHg vs 23 +/- 2 mmHg, p less than 0.01] were lower when the patients were hypothyroid than when they were euthyroid. The mean and diastolic pressures in the pulmonary artery and the pulmonary capillary pressures were not different among the groups. Likewise, thyroid hormone levels had no significant effect on pulmonary vascular resistance [100 +/- 25 dyn-s-cm-5 vs 90 +/- 23 dyn-s-cm-5]. With supine exercise, pulmonary blood flow [10.1 +/- 1.6 l/min vs. 13.2 +/- 2.0 l/min, p less than 0.01], mean pulmonary artery pressure [25 +/- 6 mmHg vs 30 +/- 6 mmHg, p less than 0.02], and systolic pulmonary artery pressure [36 +/- 6 mmHg vs 44 +/- 8 mmHg, p less than 0.01] were lower when the patients were hypothyroid. The diastolic pulmonary artery pressure and the pulmonary capillary pressure were similar in both thyroid states. Again, thyroid deficiency had no effect on pulmonary vascular resistance [81 +/- 23 dyn-s-cm-5 vs 76 +/- 24 dyn-s-cm-5]. The lower systolic pressures in the pulmonary artery seen in hypothyroidism are probably due to the decreased systolic volume load of the pulmonary circulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Pathophysiological aspects of predominant preload lowering on pulmonary circulation, gas exchange, and the biventricular function in patients with chronic obstructive lung disease.

A group of 21 patients with various degrees of chronic obstructive pulmonary disease underwent radionuclide ventriculography with hemodynamic monitoring to assess the extent to which pulmonary artery pressures and pulmonary vascular resistance can be lowered by the vasodilator molsidomine. Molsidomine (N-carboxy-3-morpholino-sydnonimin-ethylester) is similar to nitroglycerin in its mode of action. After hemodynamic and radionuclide data acquisition, at rest and during submaximal exercise in the steady state, 2 mg molsidomine was injected intravenously. Rest and exercise measurements were repeated 45 min after molsidomine injection. In patients with mild to moderate disease (group 1), pulmonary artery resting pressures decreased by 12% (p less than 0.05) at rest by 22% (p less than 0.01) during exercise after the administration of the drug. Total pulmonary resistance during exercise decreased significantly (p less than 0.01) as a result of marked decrease of pulmonary artery pressure (PAP) compared with a minimal decrease in cardiac index (CI). In patients with severe disease (group 2), only the resting values of PAP decreased while the relationship between pressure and flow was unchanged. During the exercise period, the preload parameters of the right and left ventricles decreased by an average of 30%. With regard to gas exchange, only the arterial PO2 at rest decreased slightly but significantly (p less than 0.05) after molsidomine, while the coefficient of oxygen delivery was not affected by the drug. However, in four patients arterial PO2 was markedly reduced by the drug. Right ventricular ejection fraction increased significantly (p less than 0.01) both at rest and during exercise in group 1 and during exercise in group 2 after administration of molsidomine.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Relation of pressure and flow of pulmonary circulation in patients with chronic obstructive pulmonary disease.

A series of 31 patients with various degrees of chronic obstructive pulmonary disease underwent right heart catheterization using flow-directed thermodilution catheters. Both rest and supine exercise values were obtained. The patients were divided into two groups on the basis of their reduction in forced expiratory volume in 1 s (FEV1). In patients with FEV1 values of greater than or equal to 1,300 ml (group 1), the arterial oxygen partial pressure (PaO2) did not significantly change with exercise, while in patients with FEV1 of less than or equal to 1,200 ml (group 2) PaO2 significantly (p less than 0.05) fell in response to exercise. In group 2, a significant increase of total pulmonary resistance (TPR) with exercise was found (p less than 0.01). Pulmonary vascular resistance (PVR) remained unchanged in both subgroups. It is suggested that the value of PVR for subgroup 2 is artificially low because an important variable, namely pulmonary artery wedge pressure, is influenced by alveolar pressure in patients with an uneven distribution of perfusion and ventilation at pulmonary venous pressures lower than alveolar pressure. The steeper slope of the pressure-flow relationship in these patients is probably due to an increased vascular tone caused by chronic hypoxia at rest and further fall of PaO2 and rise of arterial CO2 partial pressure in response to exercise.

Adult

[Continuous subcutaneous insulin infusion in the treatment of insulin-dependent diabetes mellitus].

Intensified insulin delivery has attained significant importance in the treatment of insulin-dependent diabetes to avoid microangiopathy involving the retina and kidney. 15 patients have been treated for periods from 2 month to 3 years, 2 years with continuous subcutaneous insulin infusion. All patients have better metabolic control than that achieved with conventional therapy. HbA1c decreased from 7.8% +/- 1.6 (SD) to 6.2% +/- 1.3 (normal value: 3.8-6.5%). Negative features of insulin-pump therapy include hyperglycemias after discontinuation of insulin infusion and cutaneous infection at the catheter site. No severe episodes of hypoglycemia were observed. Acceptability of pump treatment is good in our patients because of improved physical condition and the ability to pursue their usual activities.

Adolescent

Relation of noninvasive parameters and pulmonary artery mean pressure in patients with chronic obstructive lung disease.

A series of 31 patients with various degrees of chronic obstructive pulmonary disease (COPD) underwent radionuclide ventriculography with right heart catheterization. The patients were divided into 2 groups on the basis of their reduction in forced expiratory volume in 1 s (FEV1). In patients with FEV1 greater than or equal to 1,300 ml (group 1) the oxygen partial pressure (PaO2) did not significantly change with exercise, while in patients with FEV1 less than or equal to 1,200 ml (group 2) the PaO2 significantly decreased (p less than 0.05) with exercise. The groups were significantly different from each other as to the correlation between hemodynamic and noninvasive parameters. In the resting state, the correlation between pulmonary artery mean pressure (PAP) and both residual volume to total lung capacity (RV/TLC) and PaO2 was close only in group 2. By contrast, the right ventricular end diastolic wall thickness (RWD) correlated closely with PAP in both groups. With exercise close correlations were observed between PAP and the noninvasive parameters: RWD, PaO2 and right ventricular ejection fraction in both groups. Arterial CO2 partial pressure (PaCO2) was only increased (greater than or equal to 45 mm Hg) in group 2. This parameter correlated moderately closely with PAP both in the resting and the exercise state only in group 2. The predictive value of PaCO2 greater than or equal to 45 mm Hg for estimation of PAP greater than 35 mm Hg during exercise was 100%. We conclude that separation of patients with COPD into groups with different impairments of the lung function parameter FEV1 can improve the correlation coefficients between noninvasive and invasive parameters. The exercise values obviously correlate more closely than the resting values. An increased value of echocardiographically determined RWD seems to be a reliable parameter for prediction of PAP.

Adult

Effect of right ventricular hypertrophy on cardiac performance and the relation between right ventricular systolic peak pressure and end-systolic volume.

To investigate the role of hypertrophy of the right ventricle upon right heart performance and the significance of the peak systolic pressure/end-systolic volume (P/V) ratio in terms of right ventricular systolic performance, simultaneous measurements of radionuclide ventriculograms and central hemodynamics were done in 32 patients with chronic obstructive pulmonary disease. In 26 of the patients (80%) technically adequate two-dimensional echocardiograms could be performed. In the subset of patients with increased (greater than or equal to 6 mm) right ventricular end-diastolic wall thickness no relationship between pulmonary artery pressure and right ventricular ejection fraction (RVEF) existed in comparison with the remaining patients. P/V indices and cardiac output were not decreased. Considering the patients, whose P/V ratio did not increase from rest to exercise, RVEF decreased highly significantly more than in the remaining patients. The ratio of wall thickness and end-diastolic radius as determinant of peak systolic stress was significantly decreased in these patients compared with the remaining patients. In the patients with right ventricular hypertrophy despite significantly higher values of pulmonary artery pressures and resistances, the afterload in terms of systolic wall stress is markedly reduced. We conclude that in the hypertrophic state, right ventricular performance is not impaired despite decreased RVEF values. In the patients whose P/V ratio does not increase from rest to exercise, an inappropriate high peak systolic wall stress may exist both due to inadequate wall thickness and increased diameter of the right ventricle. The role of P/V in terms of prognosis and development of decompensated right heart failure remains undetermined.

Biomechanical Phenomena

[Radionuclide ventriculography--a noninvasive method of diagnosis and quantification of tricuspid valve insufficiency].

The diagnosis of tricuspid regurgitation (TR) is difficult to make by simple clinical methods or by invasive techniques. Contrast echocardiography and Doppler echocardiography have improved diagnostic results, but a golden standard is still not available. Radionuclide ventriculography (RNV) is a well-established method for the detection and quantification of a volume load on the left ventricle: the regurgitation fraction can simply be derived from the regurgitant index as the ratio of enddiastolic-endsystolic count-rate differences between the left and right ventricle. In left heart valvular regurgitation a regurgitant index exceeding the upper normal limit can be expected. This study was performed to evaluate the diagnostic accuracy of an abnormally low regurgitant index in detecting TR, which is accompanied by an isolated volume load on the right ventricle. A series of 33 patients with TR on physical examination and cardiac catheterization underwent RNV and was compared with 48 patients with right ventricular enlargement or pressure load on the right ventricle. In addition, the specificity of the method was evaluated in 470 consecutive patients with various forms of heart disease. In 18 out of 20 subjects with isolated TR a regurgitant index below the lower normal limit was found. The remaining 2 cases with minor TR had a regurgitant index within the normal range, which is 0.89 to 1.97 in this laboratory. In patients with additional volume load on the left ventricle, the sensitivity of the method was found to be low, as could be expected from the principle of the method. The time-activity curve over the liver was usually in phase with that recorded over the atria in subjects with TR. Therefore, the additional examination of a region of interest over the liver was particularly useful in these patients with concomitant aortic or mitral valve regurgitation. None of the 48 patients with right ventricular enlargement or pressure load on the right ventricle had a falsely positive result. A total of 17 out of 470 consecutive patients had a regurgitant index below the normal range; left ventricular function was severely impaired in 9 of these patients. The remaining subjects had a regurgitant index slightly below the lower normal limit. In conclusion, RNV has a high sensitivity in the diagnosis of TR in patients without left heart valvular regurgitation and a high specificity in patients without severely impaired left ventricular function and without left-to-right shunt through an atrial septal defect.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult

Left heart function in chronic obstructive lung disease.

In patients with varying degrees of chronic obstructive pulmonary disease (COPD), simultaneous measurements of central hemodynamics and left ventricular radionuclide ventriculograms at rest and during exercise were made. In 21 of these patients, satisfactory echocardiograms could be performed. In seven of the patients, arterial blood pressure at rest was increased. Decreased compliance of the left ventricle was thought to be present in patients with COPD and additional arterial hypertension. The left ventricular ejection fraction (LVEF) at rest was in the high normal range in all patients. During exercise, no further increase was observed. This pattern of LVEF response seems to be typical in patients with COPD. Because the highest values were observed in the more severe COPD and right ventricular hypertrophy, it is unlikely that an impairment of left ventricular function is caused by COPD. In five of 27 patients, an abnormal decrease of LVEF and regional hypokinesis occurred during exercise, thus suggesting additional coronary heart disease. The fact that at least 30% of the patients with COPD suffered from arterial hypertension and 20% of the patients exhibited unexpected ischemia detected by regional hypokinesis in RNV during exercise, but not in the ECG, may be of practical relevance. Coronary angiography was not indicated because most of these patients were over 65 and the factor limiting the working capacity was ventilatory impairment and not angina pectoris, in all patients. For this reason, a diagnostic uncertainty remains with regard to additional coronary heart disease in the older patients with advanced chronic obstructive pulmonary disease.

Aged

Pulmonary gas exchange and central hemodynamics at rest and during exercise in patients with chronic obstructive pulmonary disease.

Right-heart catheterization and ergometry with arterial and mixed venous blood gas analysis were performed in 27 patients with a wide range of chronic obstructive pulmonary diseases. The purpose of the examination was to evaluate the risk in patients for lung surgery or to detect additional heart diseases. Patients who developed exertional hypoxia (group 1) were compared with others who did not (group 2). In all patients the steady-state maximal workload was determined by ventilatory dysfunction. Both groups had normal values for mixed venous pO2 and normal increase of the circulatory parameters during exercise. The patients with exertional hypoxia differed from the others in that they showed no decrease of venous admixture and alveolar-arterial oxygen gradient. In addition, these patients had increasing pCO2 values at rest compared with exercise, indicating alveolar hypoventilation and ventilation-perfusion mismatching. Because of the good correlation of the absolute values of FEV1 (forced expiratory volume in 1 s) with pulmonary artery pressures, parameters of gas exchange and working capacity, this lung function parameter seems to have a central role in predicting the functional state of patients with chronic obstructive disease. Ergometry and blood gas analysis should be performed in addition because these values cannot be predicted with the calculated postoperative FEV1.

Aged

Right ventricular function in patients with chronic obstructive pulmonary disease.

Simultaneous right heart catheterization and radionuclide ventriculography were performed in 27 patients with a wide range of chronic obstructive pulmonary disease. Central hemodynamics and radionuclide studies were done at rest and during exercise. In the resting state the right ventricular ejection fraction (RVEF) was in the normal range (43.3 +/- 6%). During exercise a significant (p less than 0.001) decrease of RVEF to 38.8 +/- 6.7% occurred. The pulmonary artery mean pressures were 19.9 +/- 3.8 at rest. During exercise a significant (p less than 0.001) increase to 41 +/- 9.8 mm Hg occurred. There was a linear relationship between pulmonary pressures and RVEF during exercise in patients with pulmonary artery pressures not exceeding 35 mm Hg. In patients with right ventricular end-diastolic wall thickness greater than or equal to 6 mm a curvilinear relationship between these parameters could be observed with a flattening of the curve at higher pressures (greater than 35 mm Hg) and lower ejection fractions (less than 35% RVEF). Radionuclide ventriculography cannot substitute for right heart catheterization. Echocardiography is useful for interpretation of right ventricular ejection fractions in advanced chronic obstructive pulmonary disease.

Aged