[Comparison of ergometer and dipyridamole echocardiography in patients with suspected coronary heart disease]. / Vergleich von Ergometer- und Dipyridamol-Echokardiographie bei Patienten mit vermuteter koronarer Herzkrankheit.

To compare exercise echocardiography (EE) and dipyridamole echocardiography (DE), echocardiographically assessable wall motion abnormalities were examined in 80 patients with suspected coronary artery disease. Issues of the study were the evaluation of feasibility, sensitivity, specificity, and the necessity of recordings under dynamic maximal stress (peak exercise) on a bicycle. DE had a better feasibility than EE (95% vs. 84%, p < 0.05). Eleven percent of patients had no interpretable echocardiograms during peak exercise. However, after peak exercise all patients had adequate images. In order to calculate sensitivity of the methods, coronary stenoses of at least 70% on coronary angiograms were considered. Sensitivity of DE (73%) was similar to that of EE (75%). In patients with single-vessel disease both methods were less sensitive (63% and 67%) than in patients with multi-vessel disease (86% each). However, compared with stress ECG both methods proved to be superior (p < 0.05). In 31% of patients with coronary artery disease only recordings during peak exercise led to pathological findings. By not applying the EE during peak exercise the results of these patients would have been falsely negative i.e. regarded as normal. The specificity of DE (87%) was similar to that of EE (80%). In conclusion, there are no significant differences between DE and EE except feasibility and side-effects. Both methods are superior to stress ECG in terms of sensitivity regarding detection of ischemic myocardium. However, their precision needs to be evaluated differentially: Sensitivity was higher among patients with multi-vessel disease compared with those with single-vessel disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Intermittent obstruction of the Omnicarbon-valve prosthesis in the mitral position due to interference by papillary muscle. Diagnostic and surgical considerations.

The frequency of prosthetic heart valve malfunction caused by intrinsic factors has been markedly decreased by refinements of prosthetic design and by improved quality of the prosthetic material. Nevertheless, a variety of extrinsic factors, i.e. thrombus formation, bacterial endocarditis, inadequate suture technique and papillary muscle entrapment, are known to be responsible for mechanical malfunctions of prosthetic heart valves, occasionally leading to sudden cardiac death. In this report, a case of intermittent entrapment of papillary muscle in the Omnicarbon valve is presented; diagnostic and surgical aspects are discussed.

[Diagnosis and classification of tricuspid valve insufficiency with dynamic magnetic resonance tomography: comparison with right ventricular angiography]. / Diagnose und Klassifizierung der Trikuspidalinsuffizienz mit dynamischer Magnetresonanztomographie: Vergleich mit rechtsventrikulärer Angiographie.

To evaluate the diagnostic potential of magnetic resonance imaging (MRI) to diagnose and evaluate tricuspid incompetence (TI), right ventricular angiography (RVA) and MRI were compared in 51 patients. For angiographic semi-quantification a 4-grade modified Sellers classification was used. Several MRI-parameters (jet volume, jet area, number of slices with visible jet, duration of the regurgitation and volume of the right atrium) were examined concerning their validity to evaluate TI and compared to the angiographic data. Limits for MRI jet areas and volumes for each angiographic group were defined to obtain the best agreement with angiographic results. Thirty of 34 patients with angiographically visible TI (sensitivity = 88%) were diagnosed correctly with MRI. The 4 remaining patients also showed a small regurgitant jet which was, however, interpreted as physiologic. One of the 17 patients without angiographic TI was diagnosed as mild TI by MRI (specificity = 94%). MRI classification using jet volume (46/51 = 90% correct classifications) was not significantly better than the easier and faster MRI classification using jet area (43/51 = 84%). The other parameters (number of slices, duration of regurgitation and volume of the right atrium) showed considerable overlap between angiographic groups and did therefore not allow a classification into 4 grades. However, simple classification into hemodynamic relevant and irrelevant TI was possible. Thus MRI is able to diagnose TI with good sensitivity and specificity. Classifications based on jet volume and jet area showed good agreement with angiographic results. However, both parameters depend on the magnet and the pulse sequence used and must therefore be specifically determined for each imaging routine.

The sequence of IS4.

IS-elements are devoid of easily recognizable transacting functions and exert their visible effects in the position cis only (recent reviews Calos and Miller 1980; Starlinger 1980). It has been a matter of debate, whether these elements encode functions for their own transposition. In the case of the E. coli IS-elements this could not easily be determined by genetic methods, because most of these elements are present in several copies (Saedler and Heiss 1973; Deonier et al. 1979). In the case of the IS-elements flanking transposons, evidence has recently been brought forward that these carry the transposition specificity (Rothstein et al. 1980; Kleckner 1980; Grindley 1981). IS4 is present in one copy only in several E. coli K12 strains and should, therefore, be suitable for genetic and physiological studies (Chadwell et al. 1979). It has been cloned from several sites on the E. coli chromosome in pBR322 (Klaer and Starlinger 1980). Here we report the DNA sequence of IS4 which contains an open reading frame for 442 amino acids, and of the junctions of this element with surrounding DNA at three different sites in the E. coli chromosome.

IS4 at its chromosomal site in E. coli K12.

IS4 DNA has been isolated in pure form. Hybridization of this DNA against restricted DNA of several E. coli K12 strains by Southern's blotting technique has shown that, in most strains, only one copy of IS4 is present. Though the restriction fragments around this site differ in size, IS4 can be shown always to be located at the same site. In one strain, one additional copy has been found in a new location. In this strain, IS4 in its original location has been retained.

IS4 is still found at its chromosomal site after transposition to galT.

IS4-DNA has been hybridized to separated DNA fragments of E. coli K12 strain M28 and to three mutants caused by transposition of IS4 to galT. The parental strain shows one band hybridizing to IS4 representing one copy of IS4 in the chromosome. The mutants have this copy retained and show in addition a second band corresponding to the IS4 copy in galT. The experiments support the hypothesis that transposition of IS4 is accompanied by replication of the element.

IS4 is found between eleven or twelve base pair duplications.

Three mutations caused by the integration of IS4 in galT in both possible orientations were shown by DNA sequence analysis to be integrated between a duplication of eleven base pairs of gene galT. IS4 has been cloned from its single position on the E. coli K12 chromosome. Here, 12 base pairs are duplicated adjacent to IS4. This sequence is unrelated to the duplicated sequence in galT.