Evolutionary patterns of MHC class II B in owls and their implications for the understanding of avian MHC evolution.

Owing to its special mode of evolution and central role in the adaptive immune system, the major histocompatibility complex (MHC) has become the focus of diverse disciplines such as immunology, evolutionary ecology, and molecular evolution. MHC evolution has been studied extensively in diverse vertebrate lineages over the last few decades, and it has been suggested that birds differ from the established mammalian norm. Mammalian MHC genes evolve independently, and duplication history (i.

[Cardiology 1995].

Rapid progress in the field of cardiology calls for an almost continuous update on latest developments. In particular, this is the case with respect to indications for diagnostic and therapeutic interventions. The present contribution deals with some topics in this area.

[Acquired heart diseases and pregnancy].

Understanding of the mechanisms of cardiovascular and hemodynamic adaptation during pregnancy helps to prevent or manage complications in cardiac patients during gestation. Manifestations of coronary heart disease are exceptional during pregnancy and delivery. The same is true of disorders of the pericardium.

[Work load in occupations].

Fewer subjects return to work after acute myocardial infarction or a cardiac surgical procedure than one would expect from the results of their medical examinations and cardiac tests. To decide whether a patient is able to return to work, one has to assess his individual prognosis and measure his maximal physical working capacity without cardiac dysfunction. Psychological and socioeconomic aspects have also to be considered.

The internal mammary artery 'string phenomenon'. Analysis of 10 cases.

The internal mammary artery (IMA) string sign has been described as a narrowing of IMA grafts in the late course after coronary artery bypass grafting. It has been assumed that this phenomenon was due to competitive flow in grafts connected to only mildly stenosed coronary arteries. We analyzed 10 cases of IMA string sign operated on between March 1988 and June 1991.

Hemodynamic performance and myosin light chain-1 expression of the hypertrophied left ventricle in aortic valve disease before and after valve replacement.

Previously, we have reported on the selective accumulation of an atrial-like myosin light chain-1 (ALC1) in different forms of human ventricular hypertrophy. The present study involves the determination of ALC1 content in a control group and in patients with aortic stenosis or insufficiency before and 56 +/- 23 months after valve replacement and compares the hemodynamic and angiographic parameters. ALC1 was quantified densitometrically after two-dimensional electrophoretic resolution of biopsy specimens from the left ventricle and was expressed in percent of total ventricular light chain-1.

[Developments in mitral valve surgery].

Between 1987 and 1990 we operated on 104 patients for mitral valve disease. If possible the valve was reconstructed according to CARPENTIER's technique: 8 of 28 stenotic, 43 of 57 regurgitant and 2 of 7 mixed lesions were repaired. Twelve patients underwent re-replacement of a previously inserted mitral prosthesis.

[Micrococcus luteus: a rare pathogen of valve prosthesis endocarditis].

A rare case of prosthetic valve endocarditis caused by Micrococcus luteus is described and compared with the few cases reported in the literature, as well as the clinical features, microbiological profile, therapy, and prognosis of common prosthetic valve endocarditis. Micrococcus luteus is a constituent of the normal human buccal bacterial flora which forms yellowish colonies and appears as a gram-positive coccus typically arranged in tetrades. Although of low virulence, the germ may become pathogenic in patients with impaired resistance, colonizing the surface of heart valves.

[Emergency surgery for PTCA complications: tactics and results].

Incidence, risk and results of emergency coronary bypass surgery after failed percutaneous transluminal coronary angioplasty (PTCA) have been analyzed in a retrospective study. Failed PTCA has been defined as visible pathology (dissection, occlusion) of the dilated vessel associated with acute chest pain and ECG changes. From 3-1-1987 to 11-30-1990, 23 patients of 433 (5%) underwent emergency surgery for failed PTCA (19 male, 4 female, mean age 55 +/- 8 years).

[Heart center surgery in the private hospital: heart surgery in the hospital with covering physicians].

Based upon the experiences at the "Herzzentrum Hirslanden" Zurich it is demonstrated that heart surgery and invasive cardiology, including cardiac catheterization and PTCA, can readily be performed by surgeons and cardiologists in private practice at a private hospital not receiving any government funds. The needs for additional heart surgical beds in the greater area of Zurich is confirmed. Manpower needed and necessary apparative infrastructure are discussed and present activities at the "Herzzentrum Hirslanden" illustrated.

Effects of ischemia, bypass surgery and past infarction on myocardial contraction, relaxation and compliance during exercise.

Abnormalities of left ventricular function during ischemia have been described in animal models and in humans. Exercise, while a physiologic means of inducing ischemia, has a complex effect on left ventricular function by itself. In addition, patients with coronary artery disease have a diversity of chronic changes in myocardial structure and function.

Determination of the ratio of pulmonary blood flow to systemic blood flow by derivation of amplitude weighted mean velocity from continuous wave Doppler spectra.

Conventional Doppler echocardiographic techniques for the estimation of blood flow ratios depend on the precise measurement of the diameters of the aorta and the pulmonary artery and the mean blood flow velocities in these vessels. A simpler and quicker method is described, based on the calculation of the systolic time integrals of the amplitude weighted mean velocities from continuous wave Doppler spectra within the great arteries. In 30 controls the mean (2 SD) ratio of pulmonary to systemic blood flow averaged 0.