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Biomedical subjects

K Richter

Publications and source records attributed to K Richter.

At least 235 records · Page 13Linked to original sources
PubMed1989

[Differential assessment of myocardial diseases: hemodynamic-angiocardiography studies and etiologic classification].

Subject of our study are 293 patients with diseases of the myocardium, 212 males and 81 females at the average age of 45.2 years who were examined invasively including biopsy of the endomyocardium on account of clinical symptoms and changes of the ECG. Patients with hypertension, vitia, coronary stenoses as well as with hypertrophic cardiomyopathy were excluded. The aims of our study were a precised assessment of the degree of severity by a score from invasive parameters, the characterization of so-called latent or beginning cardiomyopathies and their relations to the dilatative cardiomyopathy as well as the aetiological classification by the biopsy of the endomyocardium. The score resulted from the number and the degree of individual pathological parameters, in which case the degree of the deviation was confirmed with points between 0 and 3. By summarizing of the score three degrees of severity were defined, to which clinical, electrocardiographic and bioptic results were coordinated. In the degree of severity 1 were 170 patients, in the degree of severity 2 42 patients, in the degree of severity 3 81 patients. In the higher degree of severity dyspnoea was significantly more frequently stated. In all degrees of severity the decrease of function was nearly of the same frequency. Of the degree of severity 3 died 28 patients, of the degree of severity 2 1 patient. In the degree of severity 1 by the biopsy of the endomyocardium in greater than 80% aetiological clues were detected, only in 35% in the degree of severity 3. Inflammatory changes were relatively frequently observed in all degrees of severity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Glutaminase in the postnatally developing rat cerebellum: comparison of staining and immunocytochemistry activity.

Distribution patterns and developmental profiles of phosphate activated glutaminase (PAG) in the cerebellar cortex of the rat were demonstrated by enzyme activity staining (tetrazolium salt technique) and immunolabeling. Histochemical evaluation of enzyme activity stained sections revealed in the molecular and granular layer (i.e. premigratory zone and external germinal zone in neonate rats) an increase from postnatal day 2 to day 50 by 350 and 400%, respectively. The smallest elevation was found in Purkinje cell bodies (140%). Maximum rise of PAG-activity was observed for all of the areas examined between day 12 and 15. The immunocytochemical visualisation of PAG-like immunoreactivity resulted in spatial and developmental patterns which differed from those of PAG-activity staining and displayed, to some extent, dependency on the way of tissue preparation, especially the fixation procedure.

Animals↗
PubMed1989

[Doppler sonography determination of flow ratios Qp/Qs and resistance ratios Rp/Rs in isolated ventricular septal defect].

We present a model based on an electric analogon that describes the haemodynamic situation of an isolated ventricular septal defect. The model shows a way to estimate the ratio of pulmonary to systemic vascular resistance by Doppler sonographic measurements of pulmonary to systemic flow ratio (Qp/Qs) and the ratio between the size of the defect and the cross-sectional area of the aorta (Av/Aa). The ratio of pulmonary to systemic vascular resistance is theoretically given by: Rp/Rs = Qs/Qp + log (Av/Aa) * (1-Qs/Qp). Systemic to pulmonary flow ratio can be measured by Doppler echocardiography as well as Av/Aa; therefore, Rp/Rs can be estimated noninvasively by the equation given above. The values estimated noninvasively by Doppler echocardiography showed a good correlation with the haemodynamic data obtained at cardiac catheterisation.

Aorta, Thoracic↗
PubMed1989

The biliary elimination of the selective beta-receptor blocking drug talinolol in man.

The biliary elimination of the beta-1-receptor blocking agent talinolol was investigated after intravenous administration of 30 mg in 6 patients with a T-tube drain after cholecystectomy. Serum concentration decreased in a biexponential manner with a median terminal half-life time of 4.4 h (range: 3.0-6.2 h). In some patients a second peak of the serum level was found. Concentration-time curves in bile paralleled serum profiles. The bile:serum concentration ratio (b:s-ratio) ranged from 24 to 98. The biliary clearance amounted to 43 ml/h.kg (range: 13-212 ml/h.kg). The median of the amount of talinolol eliminated by bile was 2.8 mg (range: 1.1-7.4 mg). It is concluded that talinolol undergoes an enterohepatic circulation. However, the amount eliminated cannot provide a sufficient explanation for the second peak, observed in some patients.

Adrenergic beta-Antagonists↗
PubMed1988

Determination of clozapine in human serum by capillary gas chromatography.

A gas chromatographic method using a fused-silica wide-bore capillary column and a nitrogen-specific detector for the determination of the antipsychotic agent clozapine in human serum is described. This method was found to be suitable for the determination of serum levels down to 1-2 ng/ml. The sensitivity, precision and accuracy of this method are adequate for studies on pharmacokinetics and bioavailability.

Chromatography, Gas↗
PubMed1988

Hypercalcemia associated with rodenticide poisoning in three cats.

Hypercalcemia (12.0 to 18.3 mg/dl) was detected in 3 cats that had eaten a rodenticide that contained cholecalciferol. Clinical signs included lethargy, anorexia, vomiting, and polydipsia. Treatment with furosemide and fluids administered IV resulted in normalization of the serum calcium concentration and in remission of the clinical signs in 2 cats. One cat with a serum calcium concentration of 18.3 mg/dl did not have clinical signs, was not treated, and was reportedly normal 9 months after initial examination. We attributed the uniformly favorable outcome of exposure to the rodenticide in these cats to the small quantity of the toxin ingested.

Animals↗
PubMed1988

[Effectiveness of various forms of therapy in chronic cardiovascular diseases--a vector analysis of the transition probabilities of degrees of severity].

The present findings result from a check of probationers representative for approx. 280,000 inhabitants of defined territories, who had been designated as suspects of heart and vessel disease on grounds of X-ray-morphological criterions (classification by Richter). Those about 3,000 suspects, subdivided into 3 comparable patient groups A, B and C, underwent different regimes of treatment of outpatient medical practice after standardized and noninvasive diagnostics in a follow-up during 5 years and had been valued by means of a problem-specific grading. The comparative analysis about the distribution of severe degrees concerning hypertension and coronary heart disease after the conclusion of the intervention showed significant differences concerning the results of treatment to the credit of the patient group A (treated by specialists) contrary to the patient group B (treated by family doctors) and patient group C (principle of announcing the patients themselves). Also the patient group B showed significantly better results of therapy compared with the patient group C. In addition to the concluding rating the estimation of yearly transition of severe degrees gave an insight into the therapeutical decision of the person who looks after as well as the different distribution of severe degrees of special heart diseases in dependence on the starting severe degree in the special period of intervention conditioned on the therapy. The results gain exceptional importance for practice on the grounds of methodics of the study-automatable classification of dv-thorax-X-ray pictures, problem-specific grading of noninvasive, simple parameters, variants of therapy in dependence on the graduated system of medical care.

Coronary Disease↗
PubMed1988

[Description and evaluation of diagnostic measures in German-language clinical journals].

A literature study was performed in four German-language medical journals of 1985 and 1986 on the methodology of published diagnostic studies. A total of 93 papers was investigated. The results showed that fundamental requirements for the evaluation of diagnostic tests, such as blindness of judgement, were met only in 5% of the papers. In more than half of the publications the use of test parameters (sensitivity, specificity) was insufficient and the relationship between pretest and posttest probability was considered only in isolated cases. It is concluded that the methodologic criteria for the evaluation of diagnostic tests do not seem to be widely known and that a significant improvement is desirable.

Austria↗
PubMed1988

[Principles for evaluating simple, diagnostic tests].

The fundamental terms in the evaluation of diagnostic tests are described and the differences to corresponding test parameters in clinical chemistry are emphasized. The derivation of a two-by two contingency table is explained in detail and basic characteristics of diagnostic tests, i.e. sensitivity and specificity as well as their independence of the prevalence (in the sense of a-priori-probability) is pointed out. The importance of the so-called predictive values is shown graphically, also the problem of selecting a cut-off-level (discrimination value) for the evaluation of quantitative data. The various attempts to find a single value for the description of a diagnostic test are discussed and it is stressed that there is no principal necessity to use other terms than those mentioned above. Nevertheless it is possible to give a prevalence-independent measure which has some additional advantages in rating and comparing simple diagnostic tests.

Diagnostic Tests, Routine↗
PubMed1988

Histochemically demonstrable activity of phosphate-activated glutaminase in the postnatally developing rat hippocampus.

Phosphate-activated glutaminase (PAG) mediating the conversion of glutamine to glutamate and ammonia, appears to be the major glutamate metabolizing enzyme in brain. The functional relevance of PAG in postnatally maturing glutamatergic/aspartatergic structures of the rat hippocampus was studied by means of quantitative enzyme histochemistry as an alternative to immunocytochemical techniques. The calibration of the histochemical PAG reaction as well as several control experiments for specificity were carried out to ensure reliability of findings. PAG activity increased markedly during the first weeks of life with a drastic rise between postnatal days 12 and 15. On the other hand, activity of NADH diaphorase involved in the histochemical PAG assay as an auxiliary enzyme, showed a different distribution pattern as well as a different developmental sequence with high levels early in ontogenesis. The topographical and temporal parallelisms of PAG activity to several other parameters which are putatively associated with postnatally maturing glutamatergic/aspartatergic transmission processes, mutually indicate their significance in such a functional context.

Aging↗
PubMed1988

[Acute changes in global and regional systolic heart function caused by pentoxifylline in patients with and without coronary sclerosis].

In 36 patients with angina pectoris during complex invasive diagnostic procedure the changes of global and regional systolic heart function by intravenous application of 200 mg pentoxifylline were examined. We observed a significant decrease of preload (reduction of LVEDP and MCS, LVEDV was not influenced) and an improvement of myocardial pump function, possibly combined with a favourable influence on alterated myocardial blood supply. In case of perfusion disturbances of the LV anterior wall the pentoxifylline injection was followed by signs of coronary-steal-mechanism in the LV posterior wall region. We did not found significant changes of afterload. Thus the acute hemodynamic effects of an intravenous application of pentoxifylline are comparable with those of nitrates and non-glycoside-cardiotonic substances with a predominant myocardial effect.

Coronary Artery Disease↗
PubMed1988

[Assessment of prognosis with Markov chains in chronic cardiovascular diseases in relation to various therapies].

On the basis of 5-years intervention results concerning chronic heart and vessel diseases of a check, which is representative for approx. 280.000 inhabitants of defined territories (EBMO-Cor Berlin), the prognose for the time of 5 and 10 years were estimated. It refers to ambulantories with the diagnosis hypertension and coronary heart disease, who were treated in a different way. The fundamental idea was to extract a prognostic index to make possible a choice of the treatment, adequate to the specific disease and its severe degrees, free of chance. The basic requirement of the application of the "Markoff-model" was the evidence of homogeneity concerning transition of severe degrees, used as reference, which was proved by means of the 2-k-chi 2-Felder-test. By using a starting vector of 1000 patients in each case inquiries about the distribution to the severe degrees had been made. The so achieved results illustrate a therapy-dependent susceptibility of these (morphologically defined) population suffering from a heart disease and allow a forecast, estimated also for a longer period, about the extent of the transition of a respecting and with the possibilities of the outpatient practice defined severe degrees of a heart and circulation disease and with that about chance and risk of a patient. By means of the epidemiological reference of the study the result gains special importance for outpatient practice.

Cardiovascular Diseases↗
PubMed1988

[Methodology and organization of a laboratory diagnostic study program within the scope of epidemiologic cardiovascular studies exemplified by the Berlin EMBO-Cor research project].

With reference to the high prevalence of heart and vessel disease and the necessity of its early detection procedure and consideration concerning a laboratory-diagnostic program within the framework of the follow-up examination after x-ray screening (research project EBMO-Cor Berlin) in special consideration of efficient methods within the territorial Public Health are depicted and also conclusions for similar epidemiological examinations and for practice are formulated.

Berlin↗