PubMed Health⌕ Search

Biomedical subjects

M Schleyer

Publications and source records attributed to M Schleyer.

At least 55 records · Page 3Linked to original sources
PubMed1981

Comparative investigations of human and porcine somatotropin.

Human and porcine somatotropin were compared by different methods. Both hormones show biological activity in the Greenspan assay. Molecular masses, N- and C-terminal amino acids as well as the chromatographic patterns on ion exchange cellulose at room temperature are identical. Chromatography in the cold results in different behaviour of the two hormones. Polyacrylamide gel electrophoresis and electrofocusing also show characteristic differences. The quantitative amino acid analyses of the two hormones are different. The N-terminal amino acid sequences estimated up to position 20 show identity only in 13 positions.

Amino Acid Sequence↗
PubMed1980

The influence of culture conditions on the production of colony-stimulating activity by human placenta.

The growth of human granulopoietic progenitor cells (CFUc) in vitro is stimulated by supernatants of human placental tissue cultures. The placenta culture was the subject of systematic experiments with the aim of improving the concentration of colony-stimulating activity (CSA) in the crude material. Different culture parameters were varied and analyzed separately on the basis of dose-response studies. Maximum levels of CSA in human placental conditioned medium (HPCM) were obtained from 7-day cultures with a tissue-to-medium ratio of 1 to 20 and a depth of the culture fluid of 3 mm. Moreover, these modifications of the placenta culture resulted in a considerable reduction of inhibitors. HPCM stimulation of colony growth in agar unfailingly equaled feeder layer stimulation both in terms of colony number and size, each placenta producing enough material for maximum stimulation of 30,000 cultures.

Colony-Stimulating Factors↗
PubMed1979

Preparation and characteristics of porcine growth hormone.

A recently published method for preparation of porcine growth hormone resulted in a highly purified protein with good biological activity. However, after storing for some months the originally homogeneous hormone separated again into several fractions when rechromatographed on ion exchange columns. The biological activity, found in one of these fractions, was clearly diminished compared with the activity of a freshly prepared hormone. In the present paper a modified procedure is described for the isolation of a more stable porcine growth hormone. The influence of ions, involved in buffers of the same molarity and the same pH, upon ion exchange chromatography of porcine growth hormone is discussed. The purified hormone shows high biological activity in the tibia test and is free of activities of other pituitary hormones. The molecular weight is about 20 000; only phenylalanine is found as N-terminal as well as C-terminal amino acid; the amino acid composition resembles neither that of porcine growth hormone described in literature nor that of human growth hormone.

Amino Acids↗
PubMed1978

Studies on the pituitary "Fettstoffwechselhormon". VIII. Radioimmunoassay of the lipolytic factor P-LF II D.

A radioimmunoassay of the lipolytic peptide P-LF II D from porcine pituitaries is described. The assay is performed with 125-iodine labeled P-LF II D and with antisera either from guinea pigs or from rabbits. Bound antigen is separated from the free by double antibody technique. No cross reaction is observed with gamma lipotropin, peptide B, secretin, glucagon, isoproterenol. Due to contamination P-LF II C, beta lipotropin and human growth hormone displace the tracer when added at large doses. Complete cross reaction is observed between porcine 1-39 ACTH and P-LF II D. Specificity of this reaction is demonstrated by the increase of cross reaction, when ACTH fragments of increasing length of the polypeptide chain are used (1-23 ACTH, 1-24 ACTH and 1-28 ACTH).

Adrenocorticotropic Hormone↗
PubMed1977

Preparation of highly purified human somatotropin (growth hormone).

A method for preparation of highly purified human somatotropin on large-scale basis is described. Starting from deep-frozen pituitary gland, less time is needed to obtain highly purified hormone than with other published methods for preparation of human somatotropin. The hormone obtained in this fasion is chromatographically and electrophoretically homogeneous; it shows high biological and radioimmunological growth hormone activity and is free of other pituitary hormone activities. The effects of various experimental conditions upon aggregation of somatotropin are critically evaluated.

Animals↗
PubMed1976

Studies on the pituitary "fettstoffwechselhormon". VII. Analytical studies on two lipolytically high active peptides from hog pituitary glands.

First results of analytical studies on the highly purified lipolytic active hog pituitary fractions P-LF II C and P-LF II D are reported. Electrophoresis and end-group determinations indicate homogeneity for both peptides. The molecular weights, amino acid compositions, and the N- and C-terminal sequences of these peptides have been established and are compared with the corresponding results of other laboratories. The relation between biological activity and the structure of lipolytic active peptides is discussed.

Amino Acid Sequence↗
PubMed1976

Studies on the pituitary "fettstoffwechselhormon". VI. Preparation of two highly purified lipolytic active peptides from hog pituitary glands.

The preparation of two highly purified lipolytically active hog pituitary peptides, called P-LF II C and P-LF II D is described. The two peptides are free of other pituitary hormone activities. In isolated rat and porcine adipose tissue, both fractions are lipolytically much more active than every other lipolytic active pituitary peptide described to date. By fraction P-LF II D, the first pituitary peptide was isolated which has lipolytic activity in isolated rat adipose tissue than corticotropin, the lipolytically most active pituitary hormone known so far. On isolated porcine adipose tissue, fraction P-LF II D as well as P-LF II C showed without doubt higher activity than corticotropin.

Adipose Tissue↗
PubMed1976

Growth hormone radiologand assay unresponsive to human prolactin.

A specific and sensitive radioligand assay for growth hormone with female rat liver plasma membranes is presented. Growth hormones of different species are able to displace labelled human growth hormone from membrane binding sites with parallel standard curves. Human prolactin V-L-S is not equal to 1 and the international human prolactin standard MRC 71/222 do not affect the assay. Human prolactin preparations with different growth hormone content displace human growth hormone tracer only to the same extent as they contain growth hormone when measured by radioimmunoassay.

Animals↗
PubMed1975

Calcium-binding protein in the duodenal mucosa of uremic patients and normal subjects.

In the present study we measured the content and determined the localization of a calcium-binding protein (CaBP) in the intestinal biopsy specimen of ten patients with severe renal insufficiency and in eight healthy individuals. In each patient a biopsy specimen of the iliac crest was obtained for evaluation of the degree of osteodystrophy. The CaBP was isolated from human kidneys. Its identity with human intestinal CaBP was suggested by acrylamid gel electrophoresis. Specific antibodies against it were developed in rabbits. The content of CaBP in duodenal mucosa biopsy material was measured by quantitative radial immunodiffusion. Its mean value in the duodenum of patients with renal insufficiency was 3.65 +/- 1.14 mug; in that of normal persons, 10.80 +/- 3.20 mug/mg of protein in the supernatant. There was neither a correlation between the type and duration of renal insufficiency and the CaBP content of the specimens nor between the degree of renal osteodystrophy and CaBP content. In normal persons the specific immunohistological activity indicating the presence of CaBP was found uniformly along the brush border and basement membrane of duodenal epithelial and the goblet cells. In uremic patients the fluorescence was markedly reduced in the typical locations, especially in the brush border area.

Adult↗
PubMed1975

Immunological relatedness of human and porcine growth hormones.

The immunological relatedness of human and porcine growth hormones is examined by means of labelled human growth hormone and guinea pig antiserum. 1) Labelled human growth hormone is found in the precipitate after reaction with antiserum against porcine growth hormone. Parallel dilution curves are obtained with antisera against human and porcine growth hormones. 2) After addition of antiserum against porcine growth hormone, all the radioactivity is eluted from Sephadex G-100 with the void volume. 3) The addition of an excess of porcine hormone displaces labelled human growth hormone from antibodies against human growth hormone to the same extent as an excess of non-labelled human growth hormone does. 4) The standard radioimmunoprecipitation curves for porcine and human growth hormones obtained in the assay system for the human hormone are parallel in slope, provided that the human hormone and our preparation of the porcine hormone are introduced at a proportion of 1 to 560. 5) In a double diffusion test in agarose gel layers, with human and porcine growth hormones diffusing against guinea pig anti-porcine serum, cross reaction is observed. The conclusion is drawn that with guinea pig antisera, human and porcine growth hormones behave immunologically in a similar fashion. Labelled human growth hormone seems to have only such immunodeterminants as are also found in porcine growth hormone.

Animals↗
PubMed1975

Immunological identity of human and porcine growth hormones. Application to determination of growth hormone in porcine serum.

In two radioimmunoassay systems with iodinated human growth hormone as tracer and anti-human growth hormone or anti-porcine growth hormone as binding site, the standard curves for human and for porcine growth hormone were parallel. In both systems the porcine growth hormone preparation had to be added in about the same excess as compared to the human hormone. It was concluded that the human and the porcine hormones behave in an identical way and that the values obtained in radioimmunoassay for human growth hormone represent the amount of immunologically active molecules in the porcine growth hormone preparation. As parallel standard curves were obtained with porcine serum, the concentration of growth hormone is porcine serum may be determined by radioimmunoassay for human growth hormone.

Animals↗