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Biomedical subjects

H F Hansen

Publications and source records attributed to H F Hansen.

34 records · Page 2Linked to original sources
PubMed1985

Binding of epidermal growth factor from man, rat and mouse to the human epidermal growth factor receptor.

Human, rat and mouse epidermal growth factors (EGF) bind to the same receptor on human placenta, but the binding characteristics differ. The apparent affinity constant (KA) for human EGF is higher (15 X 10(9) l/mol) than KA for rat EGF (10 X 10(9) l/mol). Mouse EGF binds with the lowest KA (5 X 10(9) l/mol). The pH optimum differs so that human and rat EGF bind with a pH optimum of 8.0, whereas mouse EGF binds with an optimum of pH 7.4. Half maximal dissociation is 130, 50 and 25 min for human, rat and mouse EGF, respectively. The structures of human, rat and mouse EGF differ somewhat. At least 11 of the first 24 residues differ. The N-terminal sequence of rat EGF is: Ala/Ser-Gly-X-Pro-Pro-Ser-Tyr-Asp-Gly-Tyr-X-Lys-Asp-Gly-Gly-Val-X-Met-Ty r-Val -Glu.

Amino Acid Sequence↗
PubMed1985

Evidence that the medium-chain acyltransferase of lactating-goat mammary-gland fatty acid synthetase is identical with the acetyl/malonyltransferase.

Competitive binding experiments with malonyl-CoA and [1-14C]acetyl-CoA, [1-14C]butyryl-CoA or [1-14C]decanoyl-CoA indicate that all these substrates are transferred to lactating-goat mammary-gland fatty acid synthetase by the same transferase. Isolation and determination of the amino acid sequence of [1-14C]decanoyl-labelled CNBr-cleavage peptide from the decanoyltransferase site showed that this transferase is identical with the acetyl/malonyltransferase.

Acetyl Coenzyme A↗
PubMed1985

Primary structure of glucagon and a partial sequence of oxyntomodulin (glucagon-37) from the guinea pig.

Two glucagon-like peptides have been isolated from guinea pig pancreas and their primary structures determined. A 29-residue peptide is identical to the glucagons from all other mammals yet studied in the N-terminal region (residues 1-20) but the C-terminal region [Gln-Phe-Leu-Lys-Trp-Leu-Leu-Asn-Val] contains five substitutions. A 37-residue peptide probably represents guinea pig glucagon extended from the C-terminus by [Lys-Arg-Asn-Arg-Asn-Asn-Ile-Ala] and is analogous to human oxyntomodulin (glucagon-37). The structures suggest evolutionary pressure to conserve the N-terminal region of glucagon and the C-terminal region of oxyntomodulin. The biological activity of guinea pig glucagon has not yet been determined but it is speculated that changes in the C-terminal region of glucagon may have produced a molecule with reduced biological potency that is appropriate to the reduced potency of guinea pig insulin.

Amino Acid Sequence↗
PubMed1984

Renal origin of rat urinary epidermal growth factor.

The origin of rat urinary epidermal growth factor (EGF) has been investigated. Unilateral nephrectomy decreased the concentration, total output of EGF and EGF/creatinine ratio by approximately 50%, while the output of creatinine was unchanged. Removal of the submandibular glands and duodenal Brunner's glands, organs known to produce EGF, had no influence on the output of EGF in urine. Renal clearance of EGF exceeded that of creatinine, and after bilateral nephrectomy or bilateral ligation of the ureters, the concentration of creatinine in serum increased, while the concentration of EGF was below the detection limit of the assay. Renal production of EGF was confirmed by immunohistochemistry demonstrating EGF immunoreactivity in the afferent arteriole of the juxtaglomerular apparatus. EGF in the submandibular glands and in urine was found to differ with chromatofocusing and reverse-phase HPLC. At isoelectric focusing the pI of submandibular EGF was 4.8 and 5.4 while that of urinary EGF was 5.3 and 6.4. In conclusion, this study demonstrates that urinary EGF mainly originates from the kidneys and is localized to the renal juxtaglomerular apparatus.

Animals↗
PubMed1984

Human pancreatic icosapeptide: isolation, sequence, and immunocytochemical localization of the COOH-terminal fragment of the pancreatic polypeptide precursor.

In dogs, the COOH-terminal part of the pancreatic polypeptide precursor gives rise to a stable icosapeptide product against which an antiserum has been raised. By immunohistochemistry, icosapeptide immunoreactivity was localized in human pancrease exclusively to cells that also stored pancreatic polypeptide. Analytical peptide chemistry demonstrated that a peptide corresponding to the canine icosapeptide could be extracted from the pancreatic polypeptide-rich duodenal part of the human pancreas. The human pancreatic icosapeptide was isolated by acid ethanol extraction, gel filtration, anion-exchange chromatography, and reverse-phase high-performance liquid chromatography. The COOH-terminal sequence of the human icosapeptide is very similar to that of the canine icosapeptide, whereas none of the first nine amino acid residues are identical. When the primary structure of peptides from three different species are compared, it is apparent that the pancreatic polypeptide part of the common precursor is a well-conserved sequence as compared to the icosapeptide part, although 8 out of 11 residues in the COOH-terminal sequence of the icosapeptide are identical in all three species.

Amino Acid Sequence↗
PubMed1984

Gastrin and cholecystokinin in pituitary neurons.

Gastrins occur in the hypothalamo-hypophyseal neurons of all mammalian species examined. In addition, human, bovine, and murine hypothalamo-hypophyseal neurons contain the homologous cholecystokinins (CCKs). CCK also occurs in neurons innervating bovine melanotrophs. Although the concentration of gastrin is of the same magnitude (15-30 pmol/g) in all neural lobes, the concentration of CCK varies from undetectable in pig and cat to 1 nmol/g in the cow. The constant occurrence of neurohypophyseal gastrin suggests a role different from that of the species-dependent CCK.

Animals↗
PubMedDate not supplied

Solid-phase synthesis of peptide nucleic acids.

Peptide nucleic acids (PNA) were synthesized by a modified Merrifield method using several improvements. Activation by O-[benzotriazol-1-yl]-1,1,3,3-tetramethyluronium hexafluorophosphate in combination with in situ neutralization of the resin allowed efficient coupling of all four Boc-protected PNA monomers within 30 min. HPLC analysis of the crude product obtained from a fully automated synthesis of the model PNA oligomer H-CGGACTAAGTCCATTGC-Gly-NH2, indicated an average yield per synthetic cycle of 97.1%. N1-benzyloxycarbonyl-N6(3)-methylimidazole triflate substantially outperformed acetic anhydride as a capping reagent. The resin-bound PNAs were successfully cleaved by the 'low-high' trifluoromethanesulphonic acid procedure.

Base Sequence↗
PubMedDate not supplied

Increased susceptibility of bobwhites (Colinus virginianus) to Histomonas meleagridis after exposure.

Bobwhites given heterakid eggs but no Sevin became infected with cecal histomonads, but there was no pathological histomoniasis. Quail given 50 microgram of Sevin (10 microgram/day) behaved normally, but at necropsy they had slightly discolored livers. Quail given various doses of heterakid eggs and Sevin (Sevin increasing from 2.5 to 50 microgram) and those given various doses of heterakid eggs and 10 microgram/day of Sevin developed pathological histomoniasis and mortality rates of 36 and 63%, respectively.

Animals↗