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Biomedical subjects

W Bommer

Publications and source records attributed to W Bommer.

At least 37 records · Page 2Linked to original sources
PubMed1983

Accuracy of echocardiography versus electrocardiography in detecting left ventricular hypertrophy: comparison with postmortem mass measurements.

The accuracy of electrocardiography, M-mode echocardiography and two-dimensional echocardiography in predicting left ventricular hypertrophy was compared in 50 patients who came to autopsy within 6 months after the studies were performed. Several methods for determining left ventricular hypertrophy were examined for each of the three techniques. M-mode echocardiography was technically adequate to evaluate the presence or absence of left ventricular hypertrophy more often than either electrocardiography or two-dimensional echocardiography. Measurements from M-mode echocardiography also correlated best with autopsy measurements. Both echocardiographic techniques had a higher sensitivity than electrocardiographic criteria in diagnosing left ventricular hypertrophy. Two-dimensional echocardiography was not shown to improve the M-mode assessment of left ventricular hypertrophy. In an attempt to simplify both M-mode left ventricular mass calculations and the diagnosis of left ventricular hypertrophy for the clinician, a left ventricular mass nomogram was constructed, enabling quick insertion of standard M-mode echocardiographic measurements.

Adult↗
PubMed1980

Cross-sectional echocardiography: physical principles, anatomic planes, limitations and pitfalls.

Although M mode echocardiography has achieved a prominent role in the diagnosis and management of patients with cardiovascular disease, the limited area of view afforded by M mode techniques has restricted the application of ultrasound in many areas. The development of two dimensional echocardiography has obviated many of the limitations inherent in the narrow view of the M mode technique. It has enabled imaging of the heart from additional transducer locations, permitted determination of shape and anatomy and provided the ability to determine motion along two axes. Several types of two dimensional echocardiographs have been developed, and each type offers both advantages and disadvantages. Although two dimensional echocardiography has provided a larger area of view with ultrasound, it has also introduced new limitations including a larger and bulkier transducer, a much reduced sampling rate and a difficult display medium (videotape). In addition, new considerations regarding ultrasonic resolution have been raised. Two dimensional techniques have resulted in new pitfalls in ultrasonic diagnosis related to instrument artifacts as well as to performance and interpretation of the examination. The spurious appearance of cardiac masses because of these ultrasonic artifacts represents a particularly prominent diagnostic pitfall that must be avoided in daily practice. It is anticipated that the new wider field of view provided by two dimensional echocardiography combined with a standard high resolution capability of ultrasound (2 to 4 mm) will result in an increasingly large role for echocardiography in the management of patients with heart disease.

Cardiovascular Diseases↗
PubMed1980

Value and limitations of two dimensional echocardiography in assessment of cardiomyopathy.

Primary myocardial diseases have traditionally been classified into congestive, hypertrophic and restrictive varieties. M mode echocardiography has proved extremely valuable in distinguishing congestive cardiomyopathy with major ventricular dilation and poor contractile performance from hypertrophic cardiomyopathy with predominant left ventricular hypertrophy (septum greater than posterior wall) and normal pump performance, and restrictive disorders with symmetric ventricular wall thickening and normal or diminished contractile function. The contributions of two dimensional echocardiography to the evaluation of patients with congestive or restrictive cardiomyopathy have been limited to certain specific situations, such as the recognition of left ventricular mural thrombi. Twenty-five patients with hypertrophic cardiomyopathy were studied to assess two dimensional echocardiography in the evaluation of patients with this disorder. Two dimensional echocardiography indicated that hypertrophy of the interventricular septum is not uniform from apex to base in all patients but may be greatest in the apical, mid or basal third. In addition, the anterior free wall of the left ventricle was involved in the hypertrophic process in approximately 50 percent of patients. Two dimensional echocardiography documented that the location of systolic anterior motion of the mitral valve in patients with hypertrophic cardiomyopathy is most often at the junction of the mitral valve leaflets and chordae tendineae, although the chordae themselves and even th papillary muscles may be involved in this movement. The heterogeneity of these characteristics may enable patients with hypertrophic cardiomyopathy to be classified into subsets of patients in whom meaningful therapeutic and prognostic implications may be derived. Finally, data derived from two dimensional echocardiography have shown that, although the left ventricle in hypertrophic cardiomyopathy conforms in some degree to the configuration of a catenoid, this geometric conformation is unlikely to account for the genesis of this order.

Cardiomegaly↗
PubMed1980

Toxoplasma gondii: membrane properties of active energy-dependent invasion of host cells.

The energy-dependence and the significance of membrane stability for the active invasion of host cells by Toxoplasma gondii has been examined in vitro. The penetration of Toxoplasma as measured by the infection rate can be significantly decreased by blocking the parasitic respiratory chain with CN-. The infection rate of blocked parasites is nearly normalized when glucose is present during the infection period. This suggests a strong energy-dependence for the active infection mechanism. DMSO (dimethylsulfoxide) known to increase membrane stability is able to lower the infection rate if either the target or the effector cell is pretreated. Ca2+ was shown to exhibit a similar effect. Procain, which destabilizes the cell membrane, stimulates the invasion of host cells by Toxoplasma parasites. The possible modes of action on the invasion schedule for the different effectors are discussed.

Animals↗
PubMed1979

Determination of right atrial and right ventricular size by two-dimensional echocardiography.

No data are available on determining right atrial and right ventricular size by two-dimensional echocardiography. We performed two-dimensional echocardiograms on eight human right-heart casts obtained at autopsy and on 50 patients who underwent complete left- and right-heart catheterization. Measurement of individual dimensions of the long and short axes of the right atrium and ventricle from right heart casts closely correlated with the volume of these structures as determined by water displacement. Further, individual dimensions by cross-sectional echo correlated well with actual casts dimensions. Subsequently, echocardiographic measurements of right atrial and ventricular long and short axes were obtained in the apical four-chambered view in a group of normals and compared with a group of patients with right ventricular volume overload states. Mean values for right atrial short-axis and long-axis measurements were greater in right ventricular volume overload patients than in normals: 6.5 +/- 0.3 vs 3.6 +/- 0.1 cm, and 6.0 +/- 0.3 vs 4.2 +/- 0.1 cm, respectively (both p less than 0.001). In addition, measurements of both individual dimensions as well as planed area of the right ventricle were greater in right ventricular volume overload patients than in normals: maximal short axis 6.1 +/- 0.3 vs 3.5 +/- 0.2 cm, mid-short axis 6.1 %/- 0.4 vs 2.8 +/- 0.2 cm, and area 40 +/- 2.6 vs 18 +/- 1.2 cm2 (all p less than 0.001). There were no differences in right ventricular long-axis measurement. Two-dimensional echocardiography provided better separation of normals from right ventricular volume overload patients than did M-mode techniques. Thus, two-dimensional echocardiography, with the apical four-chambered view, enables accurate visualization of the right atrium and ventricle in almost all patients. Futher, measurements of right atrial and right ventricular size by two-dimensional echocardiography readily distinguish normal patients from those with right ventricular volume overload.

Adolescent↗
PubMed1979

Left ventricular thrombi identified by cross-sectional echocardiography.

We studied 25 patients with anterior myocardial infarction and two with congestive cardiomyopathy to evaluate two-dimensional echocardiography in the diagnosis of left ventricular thrombi. Five coronary patients had systemic emboli. Four of these patients manifested apical filling defects on cineangiogram, while a levophase cine was equivocal for clot in the fifth patient. Neither echocardiography nor cineangiography visualized ventricular thrombi in the nonembolus coronary patients. Echoes from a distinct apical mass, however, were visualized in all five patients in the embolus group by two-dimensional echocardiography at the cardiac apex. Apical thrombi were confirmed in all four patients in the embolus group undergoing surgery. The irregular configuration of recent thrombi in the coronary patients differed from the circumscribed appearance of chronic thrombi in the cardiomyopathy patients on two-dimensional echocardiogram. Thus, two-dimensional echocardiography can be used to detect and characterize left ventricular thrombi.

Adult↗
PubMed1978

[Toxoplasmosis transmission by blood transfusion? (author's transl)].

T-cells of the chicken tumour HPRS-1, mouse mastocytoma cells, Friend virus-transformed erythroleukaemia cells as well as normal human, mouse and chick erythrocytes were tested for their receptivity to toxoplasma infection. The studies indicate that T-cells and mastocytoma cells, which may be counted as part of the white blood cell series, have the highest invasion rate after incubation with toxoplasma. Friend-erythroleukaemia cells were less often affected; mature human, mouse and chick erythrocytes were refractory. The results suggest that cells of the white blood cell series are receptive to toxoplasma infection but that nucleated precursors of the red series may also be so, while mature erythrocytes cannot be infected. The possibility of transmission of toxoplasmosis by blood transfusion can no longer be doubted.

Animals↗