Search PubMed⌕ Search

Biomedical subjects

H Simon

Publications and source records attributed to H Simon.

At least 343 records · Page 19Linked to original sources
PubMed1977

[Local ventricular wall motion, local myocardial flow, and blood flow distribution in a poststenotic myocardial region in patients with coronary heart disease (author's transl)].

In 10 patients with coronary heart disease, local ventricular wall motion, local poststenotic flow, and distribution of myocardial perfusion were determined in the underperfused myocardium before and after 8 mg of Oxyfedrin intravenously. In 8 of the 10 patients there was a uniform reaction consisting of an improvement of wall motion, increase in flow, and homogeneity of flow distribution. These parallel changes of local wall movement and local blood flow in a poststenotic underperfused part of the myocardium can most probably be explained by the positively inotropic action of Oxyfedrin with a consecutive increase in blood flow. The results show that a therapeutic affect in patients with a coronary stenosis less than 60% in the left descending artery can be obtained with a positively inotropic substance.

Adult↗
PubMed1976

Silver impregnation of dopaminergic systems after radiofrequency and 6-OHDA lesions of the rat ventral.

Nauta and Fink-Heimer silver impregnation techniques were used to study the anterior degeneration produced by radiofrequency (RF) or 6-OHDA lesions in the medial and lateral ventral mesencephalic tegmentum (VMT), substantia nigra and dorsalis tegmental decussation (DTD) in rats. Both Nauta and Fine-Heimer impregnating methods showed that RF lesion of the VNT produced degeneration in three major pathways: a ventral pathway corresponding to the fasciculus medialis prosencephali (FMP), an intermediate pathway projecting to the ventral thalamus, and a dorsal pathway to the medio-dorsal thalamus and to the nucleus lateralis habenulae. In addition, the Fink-Heimer method demonstrated prejections of the dopaminergic A10 and A9 cell group in the VMT to the nucleus caudatus after RF or 6-OHDA lesions. Projections to nucleus accumbens, tuberculum olfactorium, stria terminalis, and cortex frontalis were observed only after 6-OHDA lesion of the A10 cell group. Degeneration in cortex cinguli and entorhinalis was seen mainly after 6-OHDA lesion of the A9 cell group. The limbic forebrain cortical projections of the A10 group provide a coherent anatomical basis for the behavioral syndrome provoked by RF and 6-OHDA lesions in the VMT.

Animals↗
PubMed1976

[Pathological perfusion scintigram of the myocardium in angina pectoris patients with normal coronary angiograms (author's transl)].

In patients aged 24 to 45 years with angina pectoris, pathological changes in the exercise electrocardiogram and a normal coronary angiogram, a disturbance of the pattern of myocardial perfusion could be demonstrated in addition by scintigraphy. The cause of this disturbance of myocardial perfusion is unknown. Myocardial scintigraphy is indicated (1) to demonstrate an otherwise undetectable disturbance in the blood flow of the myocardium with a morphologically normal coronary system, (2) in subtotal coronary stenosis before the decision to perform a coronary bypass operation is made, (3) in cases of anginal syndrome with normal coronary angiograms.

Adult↗
PubMed1976

[The reliability of myocardial scintigraphy with thallium201, A comparison with lacvocardiography and perfusion scintigraphy (author's transl)].

Eighteen patients were investigated by laevocardiography, perfusion scintigraphy and with a 201thallium scan. In four patients with normal contractility of the left ventricle, normal uptake of 202thalium was found in every patient. Hypokinesia of the anterior wall or apex of the ventricle showed normal uptake on the 201thallium scintigram in four out of five patients. It follows that it is not usually possible to diagnose hypokinetic mural portions on 201thallium scintigrams without quantitative analysis. Our experience up to date with areas of akinesia has shown that it is possible to demonstrate areas of scarring (as negative contrast) in seven out of nine cases.

Angiocardiography↗
PubMed1976

On the mechanism and some properties of vinylacetyl-CoA delta-isomerase of Clostridium kluyveri.

Vinylacetyl-CoA delta-isomerase from Clostridium kluyveri grown on ethanol/acetate was purified 32-fold. The enzyme is rather labile. All experiments were conducted with the substrate analog thioester of vinylacetic acid and N-acetylchysteamine (vinylacetyl-SEtNAc (1 f)). 3-Butinoyl-SEtNAc is a strong inhibitor of the isomerase. The hydrogen transfer from the alpha-position of vinylacetyl-SEtNAc to the gamma-position of 2-butenoyl-SEtNAc (1f leads to 2 f) occurs partially intramolecularly (40-50%) as shown by experiments in 3HOH/H2O, 2H2O and 3HOH/2H2O as well as by experiments with [2,3-3H]vinylacetyl-SEtNAc. Only 0.07 atoms of tritium are incorporated into the gamma-position of 2f when the isomerisation takes place in 3HOH/H2O. The extent of intramolecularity is in agreement with results of experiments conducted in 2H2O with whole cells [4]. The reaction 1f leads to 2f shows no or only negligiebl reversibility and at least no considerable isotope effect.

Clostridium↗
PubMed1976

On the mechanism and stereochemistry of the malate-lactate fermentation of Leuconostoc mesenteroides.

During the transformation of (2S, 3R) [3-3H]malate to (S) lactate no tritium exchange takes place. The stereochemical course of the decarboxylation studied with (2S, 3R) [3-2H]-malate in 3HOH/H2O and (2S, 3R) [3-3H]malate in 2H2O occurs with retention and is therefore the same as that determined by other authors for malic enzyme from vertebrates and from Escherichia coli. The malate-lactate fermentation is a useful procedure to prepare chiral methyl groups on a preparative scale starting from (2S, 3R) [3-H]malate.

Decarboxylation↗
PubMed1976

[Studies on the specificity of an antiserum against denaturated DNA from Sarcina maxima].

An antiserum against denatured DNA from Sarcina maxima (71% (A + T)) reacted in complement fixation tests with denatured DNA's of various sources. The serological activity of the antibodies is in correlation with the (adenine + thymine)-content of the DNA's used as antigens. Haptene inhibition tests demonstrate a preferable reaction of the antibodies with T2-sequences. The heterogeneity of DNA-antisera and the increasing specificity of such antisera, if DNA with high (A + T) or (G + C)-content served as immunogen, are discussed.

Antibodies, Bacterial↗
PubMed1976

[A clinical method of testing the humidifying capicity of the human nose (author's transl)].

At the beginning attention is drawn to the fact that there is a lack of suitable clinical tests for the measurement of the humidifying and warming capacity of the nose. The great number of testing methods which have been published so far, have been either too complicated to be applied in routine checks or they were too physically strenous, so that this could not be reasonably demanded of the patients. With the help of the clinical method of testing introduced by us one can find out about norm data for the quantitiy of water needed for humidifying the inspired air in healthy persons, as well as examine the influence of pharmacons on the secretion capacity of the nose. In addition to this, pathological states such as atrophic rhinitis, vasomotoric and allergic rhinitis, patients operated with a partial maxillectomy or with total laryngectomy can also be tested as far as the humidifying and warming capacity of the nose ist concerned. In our testing method extremely dry air streams out of a compressed air cylinder with a flow of 8 1/min through a small silicone catheter at the choanal end of one nasal part and is sucked out of the other nostril with a suction flow of 5 1/min, the air passing through a psychrometer modified by us. The excess flow of 3 1/min streams from the naso- into the oropharynx most effectively preventing the air which is to be measured from mixing with the expiratory air saturated with water-vapor. A gas analyzer sensitive to carbon dioxide measures the error possible in this open system which amounts to only one percent of an average mixture with expiratory air. With the help of a psychrometer-normogramme the absolute humidity is determined from the data of the wet and both the dry thermometers. We were testing 22 healthy persons, average age 34, the norm data were established. The result is that for the hole 10 minute measurement period one nasal part needs 1.58 g water for the humidifying of the inspired air. From this it can be calculated that 456 g of water are necessary for humidifying the inspired air through both nasal parts during 24 hours. Compared with other exact methods, which, however, are not suitable for clinical tests (Ingelstedt et al.) our simple and easily workable method correlate very well.

Adult↗
PubMed1976

[Activity distribution of SDH in liver of mice. A histophotometrical study (author's transl)].

The paper presents histophotometrical measurements of the histochemical SDH reaction with INT as redoxindicator in comparison with biochemical techniques of the determination of SDH activity (with K3[Fe(CN)6] and INT as indicators) and a histochemical method of elution (with INT as indicator). The measurements were performed on liver of mice. For each method absolute values of activity (10(-9) mol substrat/min-mg liver) are calculated as relative values of activity [%]. The standard deviation of the biochemical methods is approximate +/- 4%, of the histochemical methods +/- 8%. The smallest value of detection is 2.5-10(-14) mol formazan of histophotometrical measurement. The correspondence between the measurements of the relative values of activity by the described methods was secured by statistical tests. A statistically significant proportion of activities between periportal zone and central zone like 100:82 was determinated by histophotometrical measurement.

Animals↗
PubMed1975

[Non-invasive myocardial scanning with thallium-201: basic principles and methods (author's transl)].

201Tl scanning demonstrated viable myocardium in the area supplied by the anterior interventricular branch (on frontal scanning) and viable myocardium in the interventricular septum and left ventricular lateral wall (scanning in the second oblique position) in 9 of 11 patients. Akinetic myocardial segments in the left ventricular anterior wall and left ventricular apex could be recognized by absent activity when scanning from in front. But hypokinetic segments, which contrary to the appearance with akinesia cannot be equated with myocardial scar, could not according to present experience be recognized by 201TL scanning. The special advantage of 201Tl scanning is is that, except for its intravenous injection, no further invasive procedure has to be undertaken, and it can be repeated. No side effects of complications have been observed.

Angiocardiography↗
PubMed1975

[Ventilation and pulmonary perfusion in chronic obstructive airways disease under Fominoben author's transl].

In 20 patients with chronic obstructive airways disease the distribution of ventilation and perfusion was measured by means of scintigraphy before and after giving Fominoben, a new respiratory stimulant substance. Perfusion and ventilation which in most patients were preferentially distributed to the apices of the lung could be redistributed to a considerable degree to the lower lung zones in 17 patients (perfusion) and 13 patients (ventilation) respectively. In 4 of the 7 patients where the recaudalisation of both perfusion and ventilation was not observed both parameters remained unchanged or moved both further to the apex. The reasons for the preferential perfusion and ventilation in patients with chronic obstructive airways disease and the mechanism of the redistribution under Fominoben are discussed. The question of autoregulation of ventilation and perfusion is shortly dealt with.

Aged↗