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Biomedical subjects

R Lange

Publications and source records attributed to R Lange.

At least 397 records · Page 22Linked to original sources
PubMed1978

[Report of a case of primary abdominal pregnancy (author's transl)].

A case of primary abdominal pregnancy is described. The diagnosis was suspected by laparoscopy and confirmed by the laparotomy in the same operative session. The microscopic examination corroborated the diagnosis. The patient was discharged in good condition on the 12. post-operative day.

Adult↗
PubMed1978

[Receptors for complement on rat mast cells and release of histamine].

Using rat complement-treated zymosan particles a rosetting of purified rat peritoneal mast cells could be demonstrated. The question was investigated whether the binding of activated complement could be a trigger of histamine release. Varying the degree of complement label on the zymosan particles, the time and temperature of incubation and the dependence on Ca2+ ions, we could not induce a release of histamine in any case. The addition of labeled zymosan increased slightly the mediator release induced by ATP. The immunologic significance of the complement receptors on mast cells is still unclear.

Animals↗
PubMed1977

The low-spin/high-spin transition equilibrium of camphor-bound cytochrome P-450. Effects of medium and temperature on equilibrium data.

The spin state of camphor-bound cytochrome P-450 is shown to depend largely on medium and temperature in aqueous as well as in mixed organic buffer. At sub-zero temperatures a variation of paH, ionic strength or camphor concentration modifies the spin equilibrium from nearly pure high-spin form to nearly pure low-spin form. Since the apparent pKa of transition is a linear function of log I, the spin state seems to be controlled by the electrostatic potential in the heme proximity. K+ is found to have a specific effect on the spin state. The change of enthalpy, deltaH, of the spin transition depends on the same parameters as the equilibrium constant, in the organic cosolvent as well as in aqueous buffer. As the cosolvent effect is reflected by higher deltaH values, and KCl and pH tend to lower deltaH, the cosolvent effect can easily be compensated. Therefore kinetic studies of the spin conversion might well be undertaken at sub-zero temperature in this solvent.

Camphor↗
PubMed1977

Ionization dependence of camphor binding and spin conversion of the complex between cytochrome P-450 and camphor. Kinetic and static studies at sub-zero temperatures.

The kinetic rate constants of formation and dissociation of the cytochrome-P-450 - camphor complex (Fe3+-RH) have been obtained by low-temperature (+ 5 degrees C to -20 degrees C) stopped-flow experiments. Simiarly the high-spin/low-spin equilibrium of this complex has been studied as a function of temperature and protonic activity. Both the camphor-binding mechanism and the high-spin/low-spin thermodynamic parameters of Fe3+-RH depend on the protonic activity of the medium in the physiological pH range. The binding rate constants are shown to depend on the ionization of a residue of the protein, probably a histidine. Linear enthalpy-entropy compensation is observed for the camphor binding as well as for the spin-state transition. A camphor-binding-induced change of the electrostatic potential is discussed.

Calorimetry↗
PubMed1977

[Demonstration of the surface values of spheroid cell nuclei, determined in natural size order, in relation to the large and small diameters of the nuclear incision surface, as a measurement value; a further contribution to the statistics of nuclear variation].

The paper explains how the formulas for calculating the surface area of the prolate spheroid, which a nucleus resembles, can be changed by suitable substitutions into formulas based on measured diameters l and k [mm] of the nucleus approach side surface, magnified 3.000 times, and on a mixed cyclometric function dependent on the axial ratio. Their values established for distinct axial ratios are compiled in a table. The values of the mixed cyclometric function are to be calculated for any other axial ratio according to a formula based on linear interpolation. The nucleus surface Omu is obtained in the natural order of magnitude [micron2]. In case of constant axial ratio, the surface area values form a second-order arithmetic progression, and a recursion formula has been developed to check the values of its terms. In case of nuclei of spherical shape or constant small diameter k, the surface area formulas may be simplified. Numeral examples serve for explanation. For all measured-value combinations involved, a second part, which is being prepared, will contain a complete table of function values, which is referred to in the Appendix and from which the values of the natural surface areas of spheroid nuclei can be gathered.

Cell Nucleus↗
PubMed1976

Cotransfer of two linked human genes into cultured mouse cells.

Two linked human genes which code for the expression of cytosol thymidine kinase (ATP:thymidine 5'-phosphotransferase, EC 2.7.1.75) and galactokinase (ATP:D-galactose 1-phosphotransferase, EC 2.7.1.6) have been cotransferred via purified metaphase chromosomes from the human lymphoblastoid cell line WI-L2a, into mouse L-cells [B82 and LM(TK-)]. Both genes have previously been shown to be closely linked on the human chromosome E17, band q21-22. Coexpression of both human enzyme markers was detected in two out of eight gene transfer clones, whilst the remaining six clones contained only human cytosol thymidine kinase, as shown by electrophoretic techniques. A further 23 human enzyme markers corresponding to 15 different human chromosomes were found to be absent in these gene transfer clones. No human chromosome or chromosomal fragment could be detected by karyotype analyses. Some of the gene transfer clones rapidly lost the transferred donor material when grown in nonselective medium, whereas others expressed a stable phenotype under these conditions. Prolonged maintenance in selective medium favors the survival of gene transfer cells expressing a stable phenotype. Possibly these cells harbor the donor genes integrated into a recipient chromosome.

Cells, Cultured↗
PubMed1976

[Methods for approximate and exact complanation of spheroidal-cell nuclei as an aid for statistical karyometric studies on nuclear variation].

After short mathematical explanations on exact formulas for surface area calculation of the three-axis ellipsoid and the spheroid, approximation formulas, which for the most part are modified formulas of the spherical surface area, are developed. By application of of Jacobj's linear method and Lange's curvimeter-planimeter method, these approximation formulas are used to calculate the surface areas with identical semi-axis and diameter values being inserted, and the results are compared with each other and the true values. If the design procedure is extended to other axial rations, numeric and per cent surveys result in the form of tables. The approximation formulas, whose results differ only a little from the true value and which require only a minimum of computing effort are selected. For the three-axis ellipsoid as well as for the spheroid, the true surface area values can be determined from the approximate value, with help of tabulated percentages and by interpolation of intermediate values are required. Interpolation formulas have been formulated, for that purpose, in addition. In the last part an exact formula for the nucleus surface area, if it has the shape of a spheroid, has been developed. According to the formula there exists a dependence of nucleus volume and axial ratio as the basis of a mixed cyclometric function. A further detailed table contains these surface area values, arranged in groups of equal axial ratios. In addition two other formulas have been evolved for exact computing of the nucleus surface area. For one it is dependent on the two diameters and the mixed cyclometric function which is based on the axial ratio; for the other it depends on the large diameter, the axial ratio and the mixed cyclometric function. Numerical examples have been worked out for all representations. For u = n = const, the surface values from terms of an arithmetical second-order procession. In case of equal axial ratios a recurrence formula can be worked out, according to which the succeeding term can be calculated from its predecessor.

Karyometry↗
PubMed1975

Competent Bacillus subtilis cultures synthesize a denatured DNA binding activity.

A protein activity has been detected in soluble extracts of competent cultures of bacillus subtilis which protects denatured DNA from nuclease solubilization. Both binding activity and competence development occur simultaneously but not coordinately, since the peak of binding activity appears 3 hr after the peak of competence. The binding activivity is not detected in physiologically noncompetent cultures, in an isogenic noncompetent cultures, in an isogenic noncompetent mutant grown through the competence regimen, or in early sporulating cells. The activity is included on Sephadex G-100 gel filtration columns but elutes in a broad nonhomogeneous peak. This binding activity may play a role in uptake of DNA and/or integration of exogenous DNA into the genome of competent B. subtilis cells.

Bacillus subtilis↗
PubMed1974

C4-dicarboxylate transport in Bacillus subtilis studied with 3-fluoro-L-erythro-malate as a substrate.

Bacillus subtilis cells grown in yeast extract medium accumulated 3-fluoro-l-erythro-[1,2-(14)C(2)]malate more than 30-fold from the surrounding medium. No metabolic products derived from 3-fluoro-l-erythro-malate could be detected in these cells. l-Malate competitively inhibited transport of 3-fluoro-l-erythro-malate. This malate analogue was itself a competitive inhibitor of l-malate uptake. Cells that had been grown in yeast extract supplemented with 5 mM l-malate showed a 10-fold increased affinity towards 3-fluoro-l-erythro-malate relative to cells grown in yeast extract medium with no added malate. Our results suggest that two transport systems for l-malate can be induced in B. subtilis. The first of these systems seems to effect uptake of C(4)-dicarboxylates (l-malate, succinate, and fumarate) in yeast extract medium. The second transport system (or possibly a modification of the first transport system) seems to be induced by addition of l-malate to this medium and is also functioning in malate minimal medium.

Autoradiography↗