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E Seidler

Publications and source records attributed to E Seidler.

At least 19 recordsLinked to original sources
PubMed1992

Calibration of a flow cytometric assay of glucose-6-phosphate dehydrogenase activity.

The reduction of tetrazolium salts to colored formazans is a reaction which has been exploited both in histo- and cytochemistry. Tetrazolium salts forming fluorescent formazans prove suitable for measuring defined cellular dehydrogenase activities in automated processes. This study considers an important aspect of formazan measurement in flow cytometry, namely, calibration. Calibration is performed by correlating the number (and fluorescence intensity) of formazan-bearing cells measured by flow cytometry with simultaneously performed biochemical analyses of the same material. The method is demonstrated by an example of glucose-6-phosphate dehydrogenase. Using the data of a typical experiment, the enzyme activity is expressed in femtomol of hydrogen transferred per cell during incubation time. Furthermore, through spatially resolved double excitation of formazan and nuclear DAPI fluorescence, an independent analysis of cell cycle and cellular enzymatic activity is established.

Breast Neoplasms↗
PubMed1991

The tetrazolium-formazan system: design and histochemistry.

Our increasing knowledge about the chemistry and the correlations between chemical structure and histochemical properties of the tetrazolium/formazan system is resulting in: a better understanding of existing histochemical tetrazolium techniques; the selection of optimal tetrazolium salts for qualified use in histochemistry, cytochemistry and biochemistry; both qualitative and quantitative improvements in histochemical techniques for purposes demonstrating the activities of various dehydrogenating enzymes; an extended insight into the "state" of the tested biological object by means of tetrazolium indicators with special properties; and the combination of histochemical enzyme determination with further morphological techniques. This article has attempted to illustrate the progress in the use of the tetrazolium/formazan-system for histochemical purposes.

Formazans↗
PubMed1991

[Histochemical model investigations of the action mechanisms of lathyrogenic substances].

In histochemical model studies, aminoacetonitrile and 3-aminopropionitrile can form hydrolysis-stable azomethines (Schiff bases) with periodate-induced aldehyde groups of tissue slices. Both substances and triethylentetramine do not inhibit the histochemical monoaminoxidase activity, they even can act as substrates of this enzyme. These substances cause an inhibition of the histochemical aminopeptidase M activity, but this inhibition was recognized as a methodological error due to the formation of complexes between diazonium salts and aliphatic amines. The results indicate that the inhibition of the lysyl oxidase will not be the only mechanism of action of lathyrogenic substances.

Aminoacetonitrile↗
PubMed1989

Histophotometry--the method of choice in quantifying dehydrogenase histochemistry.

Succinate, malate, and lactate dehydrogenase were demonstrated histochemically and measured histophotometrically in the heart and skeletal muscle (m. extensor digitorum longus and m. soleus) of rats at different ages. To prove the value of histophotometry, the enzymes of the tissues were estimated biochemically. The gel film technique cannot sufficiently prevent the diffusion of the soluble enzymes (malate-, lactate dehydrogenase) out of the tissue sections. Because of the different mobility, various isoenzymes, histophotometry cannot give reliable results. But, as far as membrane-bound dehydrogenases (succinate dehydrogenase) are concerned, histophotometry is the method of choice for basic measurements as in routine practical work, especially with tissues where the enzyme activities are heterogeneously distributed, e.g. in different types of muscle fibres in skeletal muscles.

Aging↗
PubMed1989

[Functional morphology of the human placenta].

An account is given of latest knowledge on the structure of the human placenta. Reference is made to the early stages of development as well as to maturation under both normal and pathological conditions. The paper is intended to contribute to better understanding of the pathogenesis of chronic placental insufficiency.

Chorionic Villi↗
PubMed1988

[Model studies in the histochemical investigation of hydrolases using tetrazolium salts].

As a model alkaline phosphatase and non-specific esterase were investigated with indoxyl substrates and 11 tetrazolium salts of different reducible substances in livers and kidneys of rat. Besides their localizing qualities, the reducibility of the used tetrazolium salts is the most important parameter for their use in histochemistry of hydrolases. The composition of the reaction products depends on the reducibility of the indicator and the pH of the reaction. The of phenazine methosulphate improves the indoxyl-tetrazolium techniques above all in the neutral and acid range.

Alkaline Phosphatase↗
PubMed1987

[Naphthotriazolium salts as histochemical reduction indicators].

6 mono- and 2 ditriazolium salts [1,2-diaryl-(naphtho-1',2':4,5-triazolium salts) were synthesized and tested histochemically. As in tetrazolium salts, the histochemical qualities of the triazolium salts correlate to their chemical structure. The results show that histochemical use of these indicators has no advantages in comparison with the well-known tetrazolium salts. Their use will be restricted to special cases.

Histocytochemistry↗
PubMed1986

Histophotometric evaluation of glutamate dehydrogenase activity of the rat hippocampal formation during postnatal development, with special reference to the glutamate transmitter metabolism.

Transmitter glutamate/aspartate synthesis is known to proceed along different metabolic pathways. In this light, the functional relevance of glutamate dehydrogenase in postnatally maturing glutamatergic/aspartatergic structures was studied by means of quantitative enzyme histochemistry. The basic requirements concerning the kinetics and calibration of the histochemical glutamate dehydrogenase reaction used were proved to be met in order to obtain valid quantitative data. The histochemically demonstrable activity of glutamate dehydrogenase (EC 1.4.1.3) in the hippocampal formation of the rat increased markedly during postnatal development. On day 30, the distribution pattern observed was similar to that in adult animals. While the enzyme activity rose within cell body layers from day 0 to day 30 by 240-285%, the increase in neuropil layers was found to be up to 830%. Maximum values were seen in the stratum lacunosum-moleculare of CA1 and CA3 and the stratum moleculare of the dentate fascia on day 30. Since the hippocampal neuropil is supposed to be copiously provided with glutamatergic (and aspartatergic?) structures which become functional in rats during the first weeks of postnatal life, the increase in enzyme activity is discussed to be primarily a consequence of maturing synaptic systems using glutamate and/or aspartate as transmitters.

Animals↗
PubMed1986

[Relation between chemical structure and histochemical qualities of tetrazolium salts].

For ascertaining correlations between the chemical structure of tetrazolium salts and their histochemical qualities, 97 of these indicators (72 monotetrazolium salts and 25 ditetrazolium salts) were used to demonstrate histochemically the succinic dehydrogenase activity in organs of rat. The nitro-derivatives of tetrazolium salts are of special value for histochemical use.

Animals↗
PubMed1986

[Enzyme histochemical demonstration of sodium-dependent glutamate uptake in glutamatergic brain structures in the rat].

Using a special tetrazolium salt technique, a striking correlation was observed between Na+ concentration of the incubation medium and the activity of glutamate dehydrogenase (GDH) in glutamatergic neuropil areas of the hippocampal formation, cerebellum, and other brain regions. Na+ concentration of 130 to 150 mmol/l caused maximal formazan production. The histochemical enzyme reaction in neuronal perikarya as well as biochemically estimated GDH activity were found to be rather inhibited by such Na+ concentrations. The GDH catalyzed sodium dependent increase in formazan production is discussed to be a consequence of the sodium dependence of glutamate uptake in glutamatergic brain structures supplying the enzyme with substrate.

Animals↗
PubMed1985

Biomedicine and naturopathic healing in West Germany. A historical and ethnomedical view of a stormy relationship.

We trace the history of medical pluralism in Germany from the perspective of a clinically oriented medical anthropology. The continuation of naturopathic medicine in both formal and informal health care illumines fundamental epistemological issues. Cultural and social forces in Germany shaped the scientific and technical development of medicine, which continues in a form distinctly different from that of medicine in North America. The construction of clinical reality in German practice is distinctive and edifying for a cross-cultural understanding of medical systems of knowledge and praxis.

Germany, West↗
PubMed1985

[Differences in the effects of laser radiation on the myocardium and liver induced by a combination of histochemical succinate dehydrogenase demonstration and acridine orange fluorochromy (MS-AO-technic)].

In laser induced wounds of myocardium and liver of rats, 1 reversible zone and 3 irreversible zones of damage can be separated in dependence of time until 24 h by a combined enzyme-histochemical and fluorescence microscopical technique. Besides these zones, another carbonized zone is also detectable. A mainly reversible zone of contraction can be seen for a short time in the myocardium. The results indicate different types of manifestation of laser and ischemic induced tissue necroses.

Acridine Orange↗
PubMed1979

The teaching of medical ethics in the Federal Republic of Germany.

Eduard Seidler sets his discussion of the teaching of medical ethics in the Federal Republic of Germany against an historical background. Immediately after the Second World War the freshness of the memory of the 'Nuremberg Medical Trials' influenced the way in which moral dilemmas were treated in Germany. At the present time no systematic instruction in medical ethics is provided in either undergraduate or postgraduate or continuing medical education. As a result of this, an inquiry was set up in 1977/78. Questionnaires were sent out with a view to collecting information on how subjects referring to medical ethics are treated during medical training. The inquiry showed that no special discipline can claim to be the only competent one for medical ethics, but that everyone has something to contribute. Dr Seidler concludes by stating that basic curricula related to the problems of medical ethics would have to be developed and should be carried on continuously within the training programme.

Curriculum↗
PubMed1979

[The mechanism of the tetrazolium reduction and the effect of phenazinmethosulfate (author's transl)].

Modern results of the literature form the basis for the presentation of a scheme which shows the reduction of tetrazolium salts and the action of phenazine methosulfate under histochemical conditions. The reduction of tetrazolium salts passes the radical state and it hapens principally on the niveau of the flavin proteins and the ubiquinone. The importance of the superoxide radical for the reduction of tetrazolium salts under aerobic conditions is emphasized.

Aerobiosis↗