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Biomedical subjects

K Bauer

Publications and source records attributed to K Bauer.

At least 271 records · Page 15Linked to original sources
PubMed1978

Small-angle X-ray studies of a human immunoglobulin M.

The conformation of a Waldenström immunoglobulin M (IgM) with antibody-like activity for X-ray contrast media, based on 3-amino-2,4,6-triiodobenzoic acid, was studied by small-angle X-ray scattering. The radius of gyration was determined as 12.1 nm, the maximum distance 35 nm, the volume 1900 nm3. A flat star-shaped model was found to be equivalent in scattering. Aggregation of IgM molecules seems to take place as side-by-side combinations of single molecules, manifesting itself as a relatively large increase of the radius of gyration and unchanged thickness of the flat aggregates.

Humans↗
PubMed1977

[Severe accidental acrolein intoxication in the home (author's transl)].

In a private household overheated fat-containing food emitted vapours which caused severe intoxication in a previously healthy man. The resulting pulmonary changes presented a grave threat to the patient's life for several days. The origin and properties of the vapours led to the conclusion that acrolein was their major toxic component.

Accidents, Home↗
PubMed1977

Degradation of hypothalamic hormones.

The enzymatic fragmentation of TRH (pyroGlu-His-Pro-NH2) by serum, hypothalamic and hypophyseal tissue was investigated. As primary cleavage product only His-Pro-NH2 was detected when TRH was incubated with serum while with the tissue preparations the formation of His-Pro-NH2, deamido-TRH and prolineamide could be detected as enzymatically formed primary fragments.

Animals↗
PubMed1977

[Connatal malaria (author's transl)].

A case of connatal malaria due to Plasmodium vivax in a newborn of turkish origin is presented. Most likely the infection was acquired by materno - fetal transfusion during labor. Pathophysiological aspects and mode of transmission of this rare disease are discussed.

Adult↗
PubMed1976

Protamines, histones and the genetic code. New evidence for code evaluations.

A new approach is presented to give evidence for the theories of Jukes and Crick (1-3) that at a more primitive stage the genetic code consisted of doublets separated by "comma-bases" rather than true triplets and that G and C or A and U are the exclusive bases used by the primordial code. This approach makes use of the conservation of the histone IV sequence over extremely long periods of time by comparing the amino acid composition of the average vertebrate protein with the one of histone IV, a reconstructed ancestral polypeptide and various nuclear proteins, homologous or otherwise related to it. All protamines studied and the majority of histones show deviations from the average vertebrate protein which are statistically highly significant if the amino acids sufficiently coded for by the first two bases are compared. A similar result is obtained for those amino acids which are sufficiently coded for by the first two bases of the codon and have codons composed of G and C only.

Amino Acid Sequence↗
PubMed1976

The reconstruction of a fragment of primordial genetic information from modern proteins: PGI-FI (AHAP).

In a continuation of earlier studies the connection between a reconstructed ancestral histone IV peptide and various sequences from non-histone proteins was investigated. This peptide, AHAP, was found to be related to partial peptides from the human encephalitogenic protein, immunoglobulin L-chains, fibrinopeptide A, glyceraldehyde-3-phosphate-dehydrogenase, TMV coat protein and several other proteins and protein families; for comparison, nodal sequences were employed wherever possible. The widespread occurrence of genetic information expressed in AHAP caused us to rename the peptide PGI-FI (primordial genetic information-fragment 1) since this peptide is apparently part of a very primitive and ancient genetic information, and may be called "protogene".

Amino Acid Sequence↗
PubMed1976

Attempts toward biosynthesis of the thyrotropin-releasing hormone and studies on its breakdown in hypothalamic tissue preparations.

Attempts were made to study the reported biosynthesis of the thyrotropin-releasing hormone (TRH = pyroGlu-His-Pro-amide) by incubating extracts of freeze-dried hypothalamic tissue with radioactively labeled precursor amino acids. Chromatographic analysis indicated a fast incorporation of radioactivity into many metabolites, including one that initially co-migrated with TRH. However, on two-dimensional chromatography, such coincidence disappeared and thus a biosynthesis of TRH could not be confirmed. A very fast degradation of TRH by serum, as well as by brain tissue preparations, was observed and was studied in detail because it could be a cause of difficulties encountered in detecting an in vitro synthesis. In hypothalamic and cortical tissue preparations, on incubation with TRH labeled with [3H]proline, fast formation of radioactively labeled deamido-TRH and liberation of prolineamide and free proline were found. On incubation of serum with labeled TRH there was a similar rapid breakdown, but different products were yielded. Degradation of TRH by serum has been reported to be strongly inhibited by pyroGlu-His-OCH3, a dipeptide analogue of TRH (10). The peptidolytic cleavage of TRH by brain enzymes, yielding proline and prolineamide as split products, was also effectively reduced using comparatively high concentrations of the dipeptide ester without, however, preventing TRH deamidation. Presuming deamido-TRH to be a biosynthetic intermediary, we decided to continue studying the synthesis of TRH with hypothalamic tissue preparations in the presence of inhibitory concentrations of the dipeptide ester, aiming at the isolation of deamido-TRH. Using [14C]proline as the label, it appeared that rather large amounts of radioactively labeled deamido-TRH, which was identified as such by vigorous purification, could be isolated from such incubates. However, only proline was incorporated, but labelled histidine or glutamic acid were not, and ATP addition was, if anything, inhibitory. Therefore, this proline incorporation could not have been due to de novo synthesis. Since the inhibiting pyroGlu-His-methyl ester was rapidly split during incubation, and, therefore, presumably inhibited the tissue peptidase by competition, we have concluded that ester-derived peptidase-bound dipeptide had reacted with [3H]proline in reverse to form the radioactive deamido-TRH in a process unrelated to biosynthesis.

Animals↗
PubMed1976

Attempts at potency testing of foot-and-mouth disease vaccines by evaluation of the complement fixing capacity of eluates.

A method has been developed to evaluate the amount of antigen in foot-and-mouth disease vaccines by complement fixation after elution from aluminum hydroxide. The 12 S antigen is eliminated by treatment with Arcton 119 so that only the 140 S antigen may be determined. The concentration of 140 S antigen eluted from the vaccine is compared with the degree of protection conferred to cattle. 333 heads of cattle were vaccinated with 111 vaccines containing detectable amounts of 140 S antigen. Only one animal was not protected. In a repeated test of the questionable vaccine with 6 animals all were found to be protected. From 32 vaccines the amount of eluted 140 S antigen was compared with the PD50 in guinea pigs. Ten vaccines from 11 without detectable 140 S antigen had a PD50 value in guinea pigs lower than the limit indicating a satisfying potency for cattle.

Animals↗