PubMed Health⌕ Search

Biomedical subjects

W Henkel

Publications and source records attributed to W Henkel.

At least 37 records · Page 2Linked to original sources
PubMed1979

Investigations on the effectiveness of cefazedone in experimental E. coli pyelonephritis.

The therapeutic effectiveness of (6R,7R)-7-(2-[3,5-dichloro-4-oxo-1(4H)-pyridyl]-acetamido)-3-([(5-methyl-1,3,4-thiadiazol-2-yl)-thio]methyl)-8-oxo-5-thia-1-azabicyclo[4,2,0]oct-2-ene-2-carboxylic acid (cefazedone, Refosporen), cephazolin, cephacetrile and cephalothin was compared in the test model of estradiol-induced E. coli pyelonephritis in the rat. Cefazedone and cephazolin were similar in effect. The relations between results of treatment and microbiological and pharmacokinetic characteristics of the cephalosporins tested are discussed.

Animals↗
PubMed1978

[Therapeutic studies on two different models of experimental pyelonephritis (author's transl)].

By transurethral instillation of a suspension of a serum resistant E. coli strain (serotype O25:19:12), chronic pyelonephritis is induced in rats, if systemic and local defense mechanisms are impaired by estradiol application. Without hormonal treatment a similar infection can be achieved with a more virulent E. coli strain (serotype O2:1:4). Due to the chronic course of the renal infection in either model, beginning of therapy may be delayed (e.g., 10 days after infection) thus imposing difficult therapeutic conditions on the efficacy of antibiotics to be tested. Evaluation of antibiotics in both models produced differential therapeutic results. In spite of equal MIC's for the applied E. coli strains, gentamicin and particularly cefazolin treatment was less effective in the estradiol treated rats than in those without hormone application. Cefuroxime therapy produced favourable results in either model. The different therapeutic efficacy in both models is to be explained by differences in host resistance to infection. It is suggested that by simultaneans testing of antibiotics in either model, it will be possible to estimate to what extent the therapeutic efficacy of antibiotics depends on the support of intact host defense mechanisms.

Animals↗
PubMed1977

[Rapidly fatal myocarditis due to group B streptococci (author's transl)].

The case of acute purulent group B streptococcal myocarditis in a 29-year-old Turk is described, no similar case having previously been published. He fell ill suddenly with gastro-intestinal symptoms, high fever and pain in arms and legs. The ECG had low voltage in the limb leads and signs of a large acute myocardial infarct. The sedimentation rate was slightly raised, an initial leukopenia was followed by leukocytosis and high enzyme activity. He died in cardiogenic shock on the third day of illness. The post-mortem examination revealed acute purulent myocarditis, and numerous group B streptococci (Strept. agalactiae) were found in the myocardium.

Adult↗
PubMed1976

Isolation of a crosslinked cyanogen-bromide peptide from insoluble rabbit collagen. Tissue differences in hydroxylation and glycosylation of the crosslink.

A radioactive peptide has been isolated from cyanogen bromide digests of sodium boro[3H]-hydride-reduced collagen from rabbit bone, tendon and skin. It was identified as a crosslinked peptide linking the short C-terminal cyanogen bromide peptide alpha1-CB6B (17 amino acid residues) to alpha1-CB5 (37 residues) from the helical part of the chain of an adjacent molecule. Both peptides could be separated after cleaving the crosslink with periodate. Thus the crosslinked peptide alpha1-CB5 X alpha1-CB6B originates from an intermolecular crosslink between quarter-staggered molecules within collagen fibrils previously assigned as 'head-to-tail' link. The chemical nature of the reduced crosslinking component was identified and was shown to differ between peptides derived from different tissues: alpha1-CB6B X alpha1 CB5 from bone contains hydroxylysinohydroxynorleucine [o5Lys(o5omegaNle)] whereas the skin peptide contains hydroxylysinonorleucine [o5Lys(omegaNle)]. The peptide derived from tendon contains both components. The relation of o5Lys(omegaNle) to o5Lys(o5omegaNle) in the peptides corresponds to that of the original tissue. On the other hand, histidino-hydroxymerodesmosine which is a major reduced cross-linking component in skin and tendon, is completely absent in the isolated peptides. The crosslinking component in the skin peptide is completely glycosylated, mainly by glucosylgalactosyl residues and to a smaller extent by galactosyl residues. o5Lys(o5omegaNle) from the bone peptide is only partly glycosylated, containing equal amounts of the disaccharide and monosaccharide. Only slight glycosylation was found in the tendon peptide.

Amino Acid Sequence↗
PubMed1976

Isolation and characterization of CNBr derived peptides of the alpha1 (III) chain of pepsin-solubilized calf skin collagen.

Fetal calf skin was solubilized by limited pepsin digestion and type III collagen separated from type I collagen by fractional salt precipitations. Cleavage of the type III collagen with CNBr gave rise to ten peptides, which were isolated by molecular sieve and ion exchange chromatography. The peptides were characterized by determination of their molecular weights and amino acid compositions. Together they account for all the amino acids and total molecular weight of the alpha1 (III) chain. Six of the peptides contain more hydroxyproline than proline residues. The two cysteinyl residues of the alpha1 (III) chain which provide sites for interchain disulfide bonding were localized in the C-terminal CNBr peptide. In addition to the ten CNBr peptides, three double peptides were isolated which still contained one methionine residue. About 0.1 residue Gal-Hyl monosaccharide and 0.8 Glc-Gal-Hyl residue disaccharide were found per alpha1 (III) chain. Almost all hydroxylysine-bound carbohydrate was located on peptide 7.

Alkylation↗
PubMed1975

Purification and properties of UDP-glucose galactosylhydroxylysine collagen glucosyltransferase (EC 2.4.1.?) from bovine arterial tissue.

The glucosyltransferase (UDP-glucose galactosylhydroxylsine collagen glucosyltransferase, EC 2.4.1.?.) was purified 50-fold from calf arterial tissue by ammonium sulfate precipitation, gel filtration and electrofocusing. The purified enzyme has a molecular weight of 72 000 and a requirement for Mn2. It resolves into two activity peaks when submitted to electrofocusing (isoelectric point at pH 4.2 and 8.1) or disc electrophoresis and exhibits a double pH optimum (pH 8.3 and 9.9). The enzyme was found to transfer glucose from UDP-glucose to the denatured forms of citrate-soluble calf skin collagen (I), the alphal chain (II) and the beta12 component (III) derived from it, and of an acetic-acid-souble collagen preparation (IV) obtained from alkali-treated calf arterial tissue. The Km values for the substrates were 1.67 X 10(-4) (I), 6.3 X 10(-4) (II), 3.3 X 10(-4) (III) and 2.8 X 10(-4) mol/l (IV), indicating that the enzyme has the greatest affinity for the calf skin collagen. The glucose transferred to hydroxylysine-linked galactose residues may be released subsequently by the action of a specific alpha-glucosidase purified from bovine spleen. The results support the assumtion that the glucosylation step in the course of the (pro-)-collagen biosynthesis depends on special structural features of the substrate and may be controlled by a specific alpha-glucosidase.

Animals↗
PubMed1975

[Isolation and properties of a preparation of arterial collagen solubilized by pretreatment with alkali (author's transl)].

The acid-soluble, highly cross-linked aorta collagen, of which about 30% can be converted into a soluble form by alkali treatment, followed by extraction with aetic acid, was obtained predominantly in the form of monomeric, helical molecules, as indicated by the value for the intrinsic viscosity and its behaviour in sodium dodecylsulphate disc electrophoresis. Apart from decreased values for tyrosine (0.26%), arginine (4.4%) and aspartic acid (3.9%), the amino acid composition of the aorta collagen fraction was similar to that of the acid-soluble calf skin collagen. This finding, together with the cyanogen bromide peptide pattern, shows that the collagen extracted from the artery is predominantly type I. Treatment with alkali probably shortens the alpha1-CB6-peptide by about 45 amino acids. The collagen extracted from artery was compared with acid soluble skin collagen by sodium dodecylsulphate polyacrylamide electrophoresis. The arterial collagen showed a marked increase in the rations alpha1 to alpha2 (4:1), alpha to beta (3:1) and beta11 to beta12 (2.5:1). Compared with acid soluble skin collagen, the aorta collagen contained twice as much galactose and glucose (13.5 and 9.6 nmol/mg protein respectively), which are bound to hydroxylysine. 50% of the hydroxylysine residues are unsubstituted, 15% are present as galactosyl hydroxylysine, and 35% as glucosyl-galactosyl hydroxylysine. On the basis of its reported properties, arterial collagen obtained by the method of Fujii appears to be a suitable substrate for the study of the enzymic synthesis and enzymic degradation of hydroxylysine glycosides of native arterial collagen.

Amino Acids↗