[The anesthesia of anesthesia].

Viewed from a cultural-ethical perspective, anesthesiology can be understood as a comprehensive concept of medicine in general. As such it contains two dilemmas: very often pain must be inflicted in order to alleviate pain and this can only be done by somebody who is himself relatively free of pain. The necessary apathy or anesthesia of the anesthetist is correlated with a general twentieth century-type of perception: the cool observer.

Limited proteolysis of lactate dehydrogenase from porcine heart with trypsin: characterization and reactivation of the fragments.

The ternary complex formed by native lactate dehydrogenase (LDH) from porcine heart, NAD+ and sulfite, was digested with trypsin over a period of 12-16 h3. After removal of the ligands and residual native lactate dehydrogenase by ion exchange chromatography dimers were obtained which were almost inactive. The dimers were lacking a hexapeptide at the N-terminus; however, the secondary structure was the same as that of native lactate dehydrogenase.

Glucose dehydrogenase from Bacillus subtilis expressed in Escherichia coli. I: Purification, characterization and comparison with glucose dehydrogenase from Bacillus megaterium.

Escherichia coli containing the Bacillus subtilis glucose dehydrogenase gene on a plasmid (prL7) was used to produce the enzyme in high quantities. Gluc-DH-S was purified from the cell extract by (NH4)2SO4-precipitation, ion-exchange chromatography and Triazine-dye chromatography to a specific activity of 375 U/mg. The enzyme was apparently homogenous on SDS-PAGE with a subunit molecular mass of 31.

The differentiation of normal and transformed human fibroblasts in vitro is influenced by electromagnetic fields.

We studied the effect of symmetric, biphasic sinusoidal electromagnetic fields (EMF) (20 Hz, 6 mT) on the differentiation of normal human skin fibroblasts (HH-8), normal human lung fibroblasts (WI38), and SV40-transformed human lung fibroblasts (WI38SV40) in in vitro cultures. Cells were exposed up to 21 days for 2 x 6 h per day to EMF. Normal mitotic human skin and lung fibroblasts could be induced to differentiate into postmitotic cells upon exposure to EMF.

Acidic and basic forms of glutathione S-transferases from human placenta and comparison with human kidney glutathione S-transferase.

Glutathione S-transferase (GSH-transferase) was purified from human placenta and kidney by affinity chromatography on S-glutathione-carbamidomethyl-epsilon-aminolysyl-Sepharose CL 4B and gel filtration chromatography on Sephades G-75. Electrophoretically pure enzyme with the specific activities of 50.7 and 55.

The amount of Tamm-Horsfall-protein in the human kidney, related to its daily excretion.

1. The amount of Tamm-Horsfall-protein in the human kidney was determined using zonal-immunoelectrophoresis. 2.

Reversible pH-induced dissociation of glucose dehydrogenase from Bacillus megaterium. II. Kinetics and mechanism.

Glucose dehydrogenase from Bacillus megaterium exists as a stable, active tetramer at pH 6.5. By shifting the pH to 9, the enzyme is, completely and reversibly, dissociated into four inactive protomers.

An integrated prediction of secondary, tertiary and quaternary structure of glucose dehydrogenase.

Based on homology of partial sequences, on physico-chemical evidence and on studies using chemical modification, we came to the tentative conclusion that tetrameric glucose dehydrogenases from Bacillus megaterium and B. subtilis should have a structure closely related to that of lactate dehydrogenase. The overall homology of primary structures was found to be very low, however, and independent predictions of secondary structure produced a clearly different pattern of beta-strands and alpha-helices.

[Isoenzymes].

Isoenzymes, especially non-allelic forms, are enzyme variants with different primary structure, apparently adapted during phylogeny to distinct physiological conditions. They are ideal research objects either for studies of structure-function relationship and morphogenesis in vertebrates or as diagnostic indicators for pathological processes.

Colour development of immunogold-labelled antibodies for light microscopy.

We describe an improvement of the immunogold technique, which is based on the colour development of silver-intensified immunogold signals. This method (referred to as the coloured-SIG technique) was found to be as sensitive as the silver-intensified immunogold method and more sensitive (in two of the three tested systems) than immunoenzymatic procedures, such as the peroxidase/antiperoxidase technique or the avidin-biotin system. The coloured SIG-method results in either a magenta-red or a cyan-blue final reaction product.

[Alkaline phosphatase in human lymphocytes. II. A method for ultracytochemical detection of alkaline phosphatase in lymphocytes].

For the ultracytochemical identification of alkaline phosphatase in lymphocytes gained from the peripheral blood of healthy individuals a sensitive method is described which allows the low enzyme activity of these cells to be determined. This was possible because the authors succeeded in stabilizing lead ions in the alkaline medium by forming a complex directly between tris-(hydroxymethyl) aminomethan and lead (II) citrate. AP localized ultrachemically in lymphocytes in particular formations similar to phosphasomes of neutrophilic granulocytes.

[Alkaline phosphatase in human lymphocytes. I. Cytochemical detection of alkaline phosphatase in normal human peripheral blood lymphocytes].

The present paper deals with a sensitive cytochemical method of identifying alkaline phosphatase (AP) in rosette-forming lymphocytes gained from the peripheral blood of healthy human beings. The percentage of AP-positive lymphocytes amounts to 5%, with all cells comprising B- and O-lymphocyte population and with T-lymphocytes being negative. In a group of healthy test persons, recently, however, having undergone various inflammatory processes or virus diseases, the number of AP-positive lymphocytes is significantly higher, from 41-73% in B- and O-lymphocytes and from 6-38% in T-lymphocytes.

An ultracentrifuge study on the self-association of glucose dehydrogenase from Bacillus megaterium.

The self-association of glucose dehydrogenase (beta-D-glucose:NAD(P) 1-oxidoreductase, EC 1.1.1.

Placental alkaline phosphatase in tumour tissue and serum.

Using immunochemical techniques, alkaline phosphatase isoenzymes were determined in tissue samples of breast carcinomas and carcinomas of the gastrointestinal tract. In breast carcinomas only 19% of the patients expressed significant placental alkaline phosphatase activity, compared with 78% in gastrointestinal tumours. The intestinal isoenzyme was found in 50% of the breast carcinomas and in nearly all of the other examined tissues.

[pH-induced inactivation of glycerol dehydrogenase from Bacillus megaterium].

The kinetic of the reversible dissociation of glycerol dehydrogenase from Bacillus megaterium in slightly alkaline medium was measured by biochemical, chemical and physical methods. The dissociation is followed by changes in the secondary structure and can be prevented by addition of NAD or increased potassium chloride concentration. Crosslinking by suberimidate, but not by monofunctional imido esters, shows a high stabilization against alkali, urea or heat inactivation caused by hindrance of dissociation.

Synthesis and properties of 5-membered heterocyclic disulfides: application for enzyme modification.

Synthesis of the disulfides 2,2'-dithiodithiazole, 2,2'-dithiobis(4-methylthiazole), and 5,5'-dithiobis(3-methylisothiazole), which are thiol-specific reagents, is described and the uv-absorption spectra of the disulfides and corresponding thiols and/or thiones are presented. The utility of these and several other reagents for the modification of thiol groups in enzymes has been demonstrated with lactate dehydrogenase and malate dehydrogenase and compared with the frequently applied modification reagents 5,5'-dithiobis(2-nitrobenzoic acid) and 2,2'-dithiodipyridine. The 5-membered heterocyclic disulfides permit the spectrophotometric determination of all sulfhydryl groups of malate dehydrogenase and lactate dehydrogenase without requiring their prior denaturation.

Complete amino acid sequence of glucose dehydrogenase from Bacillus megaterium.

The amino acid sequence of glucose dehydrogenase from Bacillus megaterium has been determined. The enzyme consists of 4 identical subunits, each containing 262 amino acid residues. Its structure was established using manual Edman degradation procedures after modification of the enzyme in the native form with reagents specific to the amino acids histidine, tyrosine, tryptophan and lysine in order to identify residues involved in catalysis or located in the subunit binding area.

Alkaline phosphatase isoenzymes in human kidney and urine, immunohistochemical, immunological and biochemical characterization.

Human kidney contains two antigenetically distinct isoenzymes of alkaline phosphatase (AP): a liver type and an intestinal type. The intestinal type AP is a minor component (1%-4%) of the total AP activity: it is found only in the cytoplasm. Both isoenzymes are located, found by an immunohistochemical technique, in the proximal convoluted tubules.

Synthesis and application of a fluorescent imido ester for specific labelling of amino groups in proteins.

2-(5'-Dimethylaminonaphthalene-1'-sulfonamido)methylimidic acid methyl ester has been synthesized for fluorescence labelling of amino groups in proteins. The incorporation of the dansyl group serving as an extrinsic fluorescent probe is determined spectrophotometrically. Glucose dehydrogenase (beta-D-glucose: NAD(P+) 1-oxidoreductase, EC 1.

[Isolation and characterization of glycerol dehydrogenase from bacillus megaterium].

Glycerol dehydrogenase of high purity was isolated from Bacillus megaterium. The enzyme has a pH optimum of 9 and dehydrogenizes in presence of NAD+ glycerol as well as 1,2-propanediol and, to a smaller extent, erythritol. The Michaelis constant for glycerol is 1.

Solid-phase direct immunoassay for serum intestinal and placental alkaline phosphatase.

Antibodies against placental alkaline phosphatase (PAP) share antigenic determinants with the intestinal isoenzyme (IAP) and vice versa. Both isoenzymes can be found as part of the total activity of alkaline phosphatase (AP) in the serum. Using antibody-coated polystyrene tubes, a simple and sensitive immunoassay was developed which allows the quantitative determination of IAP or PAP without interference of the cross-reacting isoenzyme.

Amino acid sequence of an insect chymotrypsin from the larvae of the hornet, Vespa orientalis.

The complete amino acid sequence of the endopeptidase II from the larvae of the hornet, Vespa orientalis, has been determined. The enzyme is a single polypeptide chain of 216 residues. The protease is a serine endopeptidase.

Importance of tyrosine for structure and function of mitochondrial malate dehydrogenases.

Mitochondrial malate dehydrogenase from pig and chicken both contain one tyrosine/subunit with highly red-shifted spectrum, most probably involved in a hydrogen bond with a carboxylate group. The spectral changes of this tyrosine can be used as an indicator for alkaline denaturation, acid transition and coenzyme binding. Acid transition is coupled with breaking of this bond by protonation as monitored by loss of absorbance at 290 nm.