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Biomedical subjects

H Dittrich

Publications and source records attributed to H Dittrich.

At least 91 records · Page 5Linked to original sources
PubMed1983

Radionuclide analysis of sequential changes in central circulatory volumes: inspiration, expiration, and the Valsalva maneuver.

We evaluated the effects of deep inspiration, expiration, and the Valsalva maneuver on composite cardiac (left and right ventricular) and pulmonary volumes using equilibrium radionuclide angiography in 15 adult males without left or right ventricular dysfunction. The additional effects of nitroglycerin during these maneuvers were also examined. Midexpiration was used as the control point and data analyzed as a ratio (e.g., inspiration counts divided by midexpiration counts). Left ventricular volume (LVV) declined with inspiration (0.90 +/- 0.08 inspiratory/midexpiration) and with the Valsalva maneuver (0.89 +/- 0.08 Valsalva/midexpiration). Similar changes occurred after nitroglycerin, although the effects of the Valsalva maneuver on LVV were exaggerated when compared to the initial control intervention (0.79 +/- 0.09, vs 0.88 +/- 0.07, p less than .05). Right ventricular volume (RVV) increased with inspiration and decreased with the Valsalva maneuver; these changes were similar after nitroglycerin. Pulmonary blood volume (PBV) was greater with inspiration than expiration (1.02 +/- 0.10 vs 0.95 +/- 0.05, p less than .05), and was reduced with the Valsalva maneuver. Nitroglycerin reduced significantly all volumes and the reduction was similar for each compartment when respiratory interventions were compared. We conclude that blood pool imaging can be used to characterize abrupt fluxes in central circulatory volumes. Blood pool imaging of the heart and lungs should be considered a technique for monitoring the distribution of blood volume during acute pharmacologic and physiologic alterations.

Adult↗
PubMed1983

[Catheter tip force probe: a paraclinical development for per- and postoperative monitoring in heart surgery].

Local intramyocardial "one-point" force measurement is well adapted to the myocardial architecture. The dense three-dimensional muscle network does not permit direct measurement of longitudinal tension in a particular bundle of muscle fibers. However, measurements on the skeletal muscle have shown changes in tendon stress to be strictly proportional to changes in local force measured simultaneously at different sites on the gastrocnemial muscle. In the heart in situ the response to inotropic and pre- and afterloads changes is extremely sensitive. However, in comparison to left ventricular pressure, local force measurements at different sites and in different ventricular layers show distinct force gradients and phase dislocation, indicating a wide range of inhomogeneities in ventricular dynamics. The method is suitable for clinical application in cardiac surgery: the probe may be implanted directly on the exposed heart or during ventricular catheterization using a pointed catheter tip force probe.

Cardiac Catheterization↗
PubMed1982

Comparison of single-plane and biplane contrast analyses of right ventricular function and size.

To evaluate the utility of single and biplane right ventricular (RV) contrast angiograms, we evaluated 25 canine RV casts and 31 cineangiograms performed in patients during standard contrast ventriculograms. Both standard single and biplane formulae were utilized. In the 25 canine RVs, absolute volume was determined by water displacement. Both biplane (r = 0.96) and single-plane (r = 0.86) volumes correlated well with cast data. These formulae were then applied to contrast ventriculograms in the 31 patients (30-degree right anterior oblique and 60-degree left anterior oblique projections). The ejection fractions (EFs) calculated from the single-plane technique provided fair correlation with EFs derived from the biplane data (r = 0.81, y = 0.81X + 0.05). Similar correlations were noted when end-diastolic volume results were compared (r - 0.78, y - 0.57X + 56.4). However, while single-plane contrast right ventriculograms correlate with estimates of global RV function and size by biplane methods, considerable scatter of the data may limit its application in individual cases.

Aged↗
PubMed1982

Mineralization of human aortas with coarctation: quantitative electron probe microanalysis.

Aortas with coarctation (isthmus stenosis) are obviously an ideal model to investigate pressure dependent changes of the aorta, as one can compare the proximal region (high pressure) with the distal region (low pressure). 7 aortas of patients aged from 2 months to 54 years were investigated. The concentrations of Na, Mg, P, S, C1, K, and Ca were determined by electronprobe microanalysis. Ca and P are constituent parts of the developing mineral and are mainly discussed. The Ca/P ratio (by weight) is about 0.3 in the unmineralized and about 2 in the mineralized tissue. Mineralization is demonstrated by a parallel increase of Ca, P, and the Ca/P ratio. Enrichments of Ca and P are found above all in a subintimal band. Usually they occur proximally and distally, but are much more pronounced proximally. Even in the aorta of a 2 month old infant enrichments were found proximally, but not distally. Thus mineral deposits occur very early in regions of hypertension. The differences between the proximal and distal region may demonstrate the influence of blood pressure on vascular mineralization. The mineralization starts in small compartments, which increase in size and number in the process of mineralization. Mineralized regions could often be localized by cathodoluminescence. But to demonstrate and localize the initial mineral deposits and to quantify element contents, electronprobe microanalysis became indispensable.

Adolescent↗
PubMed1981

[Electron probe x-ray microanalysis of human aorta with isthmus stenosis].

Aortas with isthmus stenosis (coarctation) can be regarded as a model for those changes of the vessel wall, that depend on blood pressure, as one can compare the proximal region (high pressure) with the distal one (low pressure). The Na, Mg, P, S, Cl, K, and Ca content of the vessel walls of 5 patients (age: 2 months to 34 years) were determined by electron probe microanalysis. We have used cryostat sections and measured the element concentrations from the lumen to the outer media. In this paper we discuss especially the measurements of Ca and P, as the mineral being deposited in the vessel wall, e.g. in arteriosclerosis, contains Ca and P. Up to 18 years Ca and P enrichments are found only in a subintimal band parallel to the lumen. The proximal region of the aorta of a 34 years old patient, however, demonstrated Ca and P enrichments in the whole media with a high peak in the subintimal band. The enrichments are proximally always higher than distally. Only in the distal region of the 2 months old infant no Ca or P enrichments were found, but they appeared proximally. Thus high blood pressure causes an enrichment of Ca and P in a subintimal band very rapidly and promotes the mineralization of the vessel wall. The quantitative electron probe microanalysis demonstrated these pathological alterations.

Adult↗
PubMed1981

[Hepatitis B antigen in patients undergoing gastroscopy (author's transl)].

497 patients undergoing gastroscopy were tested for RIA for HBs antigen, HBs antibody and HBc antibody. In 21.9% of these patients (women 19.6%, men 23.3%) one of these tests was positive. The high frequency of positive HBc antibody is remarkable. 7% of our patients (women 7.8%, men 6.3%) were HBs antigen positive and, therefore, a source of infection for doctors and nurses of an endoscopic unit. The results are comparable with studies from other units reported in the literature.

Adult↗
PubMed1981

Coarctation of the aorta. A risk factor in children for the development of arteriosclerosis.

Pressure recordings in 120 patients, aged 0-35 years, undergoing operation for coarctation of the aorta, show a slow but steady rise in both systolic and diastolic peak pressures, the highest peak registered being in patients aged 16-18 years. The finding of significant morphological changes in the aorta in this age group is the rule and these arteriosclerotic changes become more severe as the patients get older. In long-standing coarctation, the degree of mineralisation proximally is up to 10 times higher than distally. The microscopic and ultrastructural changes in the proximal segment are essentially arteriosclerotic. In conclusion, the role of coarctation of the aorta in the pathogenesis of arteriosclerosis is essentially that of hypertension, a most important risk factor of arteriosclerosis. Since arteriosclerosis also develops in the region of low blood pressure, other factors are operative. We suppose that the reduced pulse and volume pressures, which in turn diminish the "windkessel" function of the aorta may effect a change in the blood flow patterns to favour the development of arteriosclerosis.

Adolescent↗
PubMed1981

[Scoring system for indication for operative correction of funnel chest (author's transl)].

Based on 50 consecutive patients whom we operated for funnel chest, we tried to work out the indications for operative correction by developing a scoring system. In this scoring system we considered not only the depth of of the funnel respectively the depth of the impression, but also all the other disturbances of the organs of the chest resulting from the malformation. The possible accompanying deformities of the thoracic cage were taken into account too. The scoring system demands a more stringent indication.

Adolescent↗
PubMed1981

[The behaviour of the granular alveocytes in chronic pulmonary congestion, pulmonary fibrosis and after extracorporeal circulation (author's transl)].

The granular alveocytes, known to be the site of the production of the surfactant, undergo characteristic changes following chronic pulmonary congestion and the succeeding fibrosis, and after extracorporeal circulation. Congestion is accompanied by cell edema and the breakdown of the lamellar bodies. With fibrosis the cells are shrunken and present with little if any lysosomes. The nuclei are pyknotic or demonstrate karyolysis. Vacuolar degeneration of the lamellar bodies and progressive degeneration of the mitochondria are observed. The extracorporeal circulation damages many granular alveocytes. The degree of damage correlates with the duration of the cardiopulmonary bypass and with the degree of the prepump pathological changes present in the lungs. On the other and the extracorporeal circulation induces in the intact cells enhanced surfactant production, during which the different developmental stages of the lamellar body increasingly accumulate within the cell. In conclusion, pulmonary congestion and fibrosis reduce the activity of the granular alveocytes. The extracorporeal circulation enhances structurally favourable conditions in the granular alveocytes for the increased release of the surfactant in the immediate post-operative phase - a process which could be regarded as an autoregulatory mechanism.

Adult↗
PubMed1980

[The influence of therapy with silymarin on the survival rate of patients with liver cirrhosis (author's transl)].

A randomized double-blind study about the therapy of the cirrhosis of the liver shows a significant higher surviving rate of the alcoholic cirrhosis in the group treated with Silymarin. This result can be well explained by the protective influence of this substance against toxic injuries. The etiology of many chronic liver diseases is uncertain and therefore it is advisable to try the therapy also in other cases. The conditions of the study are exactly reported. The influence on the clinic of the disease and on the laboratory data obtained in many controls will be published later, because the statistical analysis needs some more time.

Clinical Trials as Topic↗