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Biomedical subjects

G Sauer

Publications and source records attributed to G Sauer.

At least 109 records · Page 6Linked to original sources
PubMed1981

[The effect of molsidomin on the arterial windkessel (author's transl)].

The antianginal effect of Molsidomin is due to a reduction of preload. The decrease of aortic pressure is interpreted by the diminuation of the cardiac output. It is not yet known whether there is an additional primary reduction of afterload, caused by a change of the elastic properties of the arterial windkessel. Therefore in ten patients the effects of Molsidomin were investigated. After Molsidomin the pulmonary capillary pressure decreased by 58%, and the cardiac index by 12%. Mean aortic pressure was diminished by 12%, too, The capacity of the windkessel C was determined from the diastolic pressure decay in the thoracic descending aorta. After Molsidomin there was a decrease of C by 21%. This decrease was due to a reduction in the filling-state but not to altered elastic properties of the arterial windkessel.

Angina Pectoris↗
PubMed1980

Changes in left ventricular diastolic function in coronary artery disease with and without angina pectoris assessed from exercise ventriculography.

In 11 normals and 43 patients with coronary artery disease left ventricular (LV) diastolic pressure-volume (P-V) curves were obtained from biplane ventriculograms and simultaneous high fidelity pressure measurements. During exercise ventriculography 20 patients had angina pectoris (group B), and 16 patients were asymptomatic (group A). At rest there were no akinetic segments in 28 patients (group C), and an akinetic segment was found in 15 (group D). With different total work loads (951 +/- 134 and 2100 +/- 245 kpm in groups B and A), LV minimal and end-diastolic pressures and corresponding ventricular volumes increased to a similar extent in patients with and without angina during exercise ventriculography. With comparable work loads (1,296 +/- 221 and 1,494 +/- 195 kpm in groups C and D) the mean increase in diastolic pressure and volume was larger in group D, which corresponded to the more depressed LV resting function.

Adolescent↗
PubMed1980

Growth dynamics of a latent primate papovavirus.

The stumptailed macaque papovavirus strain HD was discovered in a persistently infected cell line of primate origin designated Vero 76 (K. Bosslet and G. Sauer, J. Virol. 25:596--607, 1978; W. Waldeck and G. Sauer, Nature [London] 269:171--173, 1977). In clonal derivatives of Vero 76 cells a minor and variable proportion of cells is engaged in the productive synthesis of the HD virus strain. A combination of immunofluorescence using simian virus 40 polyoma subgroup-specific antiserum and in situ hybridization with HD complementary RNA revealed that only those cells which harbor discernible amounts of HD DNA also contain the subgroup-specific antigen. Treatment with arabinofuranosylcytosine caused irreversible disappearance of the antigen, whereas actinomycin D, in contrast, reversibly inhibited both HD DNA replication and synthesis of the subgroup-specific antigen. The proportion of HD DNA and subgroup-specific antigen-synthesizing cells in Vero 76 clonal lines could be either decreased or increased by the mode of passaging of the cell cultures. When cell cultures were split every 3 to 7 days at a 1:4 ratio, the amount of HD DNA sequences as revealed by DNA-DNA reassociation and by the Southern blotting technique fell below the level of detection after only a few passages. Furthermore, expression of the viral subgroup-specific antigen was no longer discernible. However, viral DNA persists in such latently infected cells, because a change in the splitting protocol to a 2-week passaging rhythm led to reinitiation of both viral DNA replication and expression of the subgroup-specific antigen. The HD DNA is perpetuated in a restricted state in latently infected cells in an episomal, unintegrated form as shown by Southern blot analysis. This finding complies with the fact that HD DNA-free subclones could be derived from persistently infected clonal Vero 76 cells. Such subclones have lost the viral genomes, probably owing to segregation during cell division.

Animals↗
PubMed1980

Equine connective tissue tumors contain unintegrated bovine papilloma virus DNA.

Bovine papilloma virus (BPV) appears to be the etiological agent of common equine connective tissue tumors. We investigated the physical state of the viral DNA within such tumors and found no indication for integration into the host genome. The BPV genomes were present as free circular episomes. Two equine sarcoids were shown to contain multiple copies of free circular BPV type 1 (BPV-1) DNA. When the tumors were digested with several single-cut restriction enzymes, there were only form III BPV-1 DNA sequences could be revealed. One of the sarcoids contained, apart from wild-type BPV-1 DNA, a class of smaller BPV-1 circular DNA molecules bearing a deletion of approximately 9% of the BPV-1 genome. This deletion is located in the physical map between the relative units 0 and 0.32.

Animals↗
PubMed1980

[Maximum rate of left ventricular volume change--a parameter of ventricular function (author's transl)].

Peak left ventricular ejection rate (dV/dtsyst) and peak left ventricular filling rate (dV/dtdiast) were determined from biplane cineangiographies in patients with normal left ventricular function (n = 8), pressure overload (n = 11), aortic regurgitation (n = 7), mitral regurgitation (n = 9), mitral stenosis (n = 6), hypertrophic obstructive cardiomyopathy (n = 10), congestive cardiomyopathy (n = 9) and coronary heart disease (n = 17). dV/dtsyst (normal 642 +/- 187 ml s-1) was reduced in mitral stenosis (447 +/- 77 ml s-1) and was increased significantly in aortic regurgitation (1085 +/- 162 ml s-1) and mitral regurgitation (744 +/- 232 ml s-1). dV/dtsyst/EDV was correlated linearly with ejection fraction and was reduced significantly in mitral stenosis, aortic and mitral regurgitation, congestive cardiomyopathy and coronary heart disease. Ventricles with pressure overload and coronary heart disease could be separated better from normal ventricles by dV/dstsyst/EDV than by ejection fraction. dV/dtdiast (normal 549 +/- 205 ml s-1) was decreased significantly in mitral stenosis and increased in aortic regurgitation (1141 +/- 557 ml s-1) and mitral regurgitation (946 +/- 349 ml s-1). Peak left ventricular filling rate and diastolic stiffness were correlated by a hyperbolic function. The results show that peak left ventricular ejection and filling rates allow a more detailed analysis of ventricular function than the usually applied parameters. Quantification of the factors which determine the rate of change of left ventricular volume was only partially possible.

Aortic Valve Insufficiency↗
PubMed1979

The influence of growth temperature on the heat stability of inorganic pyrophosphatase from crude extracts of Bacillus stearothermophilus.

Inorganic pyrophosphatase activity of crude extracts from Bacillus stearothermophilus adapts its thermostability to the growth temperature of the cells. Magnesium ions increase the stability of the enzyme in all cases. Depending on the growth temperature of the cells two pyrophosphatase species differing in their molecular weights and heat stabilities have been detected.

Drug Stability↗
PubMed1979

[Evaluation and habits of wearing model cast prostheses--results of an inquiry among patients].

An evaluation was made of 1246 questionnaires. A difference could be established between patients wearing prostheses for the first time and patients wearing prostheses over a long period of time. No differences were demonstrable between men and women. Age-related differences could not be determined, the treated jaw did not influence the evaluation, and there was no relationship between the type of prosthesis and the subjective statements given by the patients.

Denture Retention↗
PubMed1978

Origin of DNA replication in papovavirus chromatin is recognized by endogenous endonuclease.

Isolated simian virus 40 (SV40) and polyoma nucleoprotein complexes contain endonuclease that, under in vitro conditions, converts part (up to 30%) of the covalently closed superhelical DNA to full-length linear rods. The positions of the cleavage sites within the genomes of SV40 and polyoma were determined by digestion with various single-cut restriction endonucleases and subsequent agarose gel electrophoresis of the cleavage products. Both SV40 and polyoma covalently closed superhelical DNA were cleaved open at their respective origins of DNA replication (+/- 75 base pairs). The full-length linear DNA rods whose ends map adjacent to the origin of DNA replication could also be isolated by sodium dodecyl sulfate/phenol extraction both from SV40-infected permissive cells and from purified SV40 virions. These data reveal the presence of a unique structure of the papovavirus chromatin close to the initiation site of DNA replication.

Chromatin↗
PubMed1978

Biological properties and physical map of the genome of a new papovavirus, HD virus.

The superhelical DNA of the HD papovavirus is heterogeneous and consists of two discrete size classes with molecular weights of 3.45 X 10(6) and 3.25 X 10(6). Both size classes of DNA are encapsidated into HD virion particles. Their relative intracellular amounts differ, depending on the cell system. Vero-76 carrier cultures in which HD virus was detected contain both size classes of DNA, with the larger molecules prevailing by a factor of 10. Five clonal lines derived from Vero-76 cell cultures contain exclusively the larger DNA. On the other hand, after cocultivation of Vero-76 with CV-1 cells for several passages, minicircular DNA is accumulated such that both size classes are synthesized in equal amounts. Any of the originally viral DNA-producing cell lines may, upon subcultivation, cease yielding virus. The RITA cell line of Cercopithecus aethiops origin is the only cell line among numerous ones tested which upon infection permits the establishment of a one-step growth cycle. However, between 6 and 8 days after infection, viral DNA synthesis is discontinued, and a persistent viral infection cannot be established. Physical maps of the genomes were constructed, and it could be shown that the smaller, minicircular DNA had originated from the larger DNA as the result of a deletion. The sequences missing in the minicircular DNA are confined to the relative map position 0.15 to 0.21.

Cell Line↗