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Biomedical subjects

H Bentz

Publications and source records attributed to H Bentz.

27 records · Page 2Linked to original sources
PubMed1979

The covalent structure of calf skin type III collagen. III. The amino acid sequence of the cyanogen bromide peptide alpha 1(III)CB4 (positions 403--551).

The cyanogen bromide peptide alpha 1(III)CB4 comprises the sequence region from position 403 to 551 of the alpha 1(III) chain. Almost the entire sequence of this region was elucidated using two hydroxylamine- and one chymotrypsin-derived fragments for automated Edman degradation. The sequence analysis of alpha 1(III)CB4 was completed with the help of trypsin and one protease V8-derived peptide. Comparison with the corresponding region of the alpha 1(I) chain revealed a striking homology between the two chains in this region which is higher than for the entire alpha chains.

Amino Acid Sequence↗
PubMed1978

Physical evidence for the assembly of A and B chains of human placental collagen in a single triple helix.

Native collagen molecules containing A and B chains were isolated from pepsin-solubilised human chorionic and amniotic membrane extracts by fractional salt precipitation and DEAE-cellulose chromatography. They exhibited a circular dichroism spectrum, and a melting curve, characteristic for a triple-helical structure. Electron microscopical investigations of their segment-long-spacing crystallites revealed a molecule similar to those of the interstitial types I, II and III collagens. After denaturation, the A and B chains were separated by DEAE-cellulose chromatography and were consistently recovered in a ratio of 1:2. Renaturation experiments indicated that only the B chains are able to reform triple-helical molecules which are stable under conditions in vivo. The data support a molecular formula A(B)2 for the native collagen molecule.

Amino Acids↗
PubMedDate not supplied

Systemic administration of recombinant transforming growth factor beta 2 (rTGF-beta 2) stimulates parameters of cancellous bone formation in juvenile and adult rats.

Transforming growth factor beta is a multifunctional protein with known actions on bone and bone cells. The ability of TGF-beta to stimulate osteogenic parameters in vitro and osteogenesis adjacent to injection sites in vivo is well established. The purpose of this study was to determine if systemic administration of recombinant TGF-beta 2 (rTGF-beta 2) could stimulate bone formation in rats of different ages. Juvenile (25-day-old) and adult (160-day-old) rats were treated daily for 5 days and 14 days, respectively, with rTGF-beta 2 given by subcutaneous injection. Bone formation was measured in cancellous bone of the lumbar vertebrae in juvenile rats and the femoral epiphysis in adult rats. Endochondral bone growth rates were measured in the distal femurs from both juvenile and adult rats using histomorphometric methods. Systemic administration of rTGF-beta 2 resulted in substantial increases in bone formation rates (both surface and volume referent) in both juvenile and adult rats. In the juvenile rats, rTGF-beta 2 increased the percent double labeled surface and the mineral appositional rate. In the adult rats, TGF-beta 2 treatment increased the double labeled surface and also endochondral (longitudinal) growth parameters without changing the number of osteoclasts or the number of osteoclast nuclei per cell. These results demonstrate that short-term systemic administration of rTGF-beta 2 substantially increases cancellous bone formation rate in rats.

Aging↗
PubMedDate not supplied

[The use of a methanol bacterial mass in multigenerational studies in the hen. 2. Laying period].

In a multi-generation trial with 120 or 96 hens of the breed White Leghorn per group the effect of diets containing 7.5% or 15.0% of methanol-grown dried bacterial cells was examined. The hens were kept in conventional three-stage battery. In two of the three experiments the feed intake was decreased if it was used methanol-grown bacterial cells as a protein source. The period of intensive laying (50% egg production) started later and the egg production has been decreased by using the bacterial cells. For the traits egg weight and mortality no relation to the nutrition could be found. The feeding of methanol-grown bacterial cells showed in two incubatory trials no negative effects on reproductive ability of the hens. The cock's sperm quality was not influenced in two experiments. In one trial the sperm volume was reduced and the sperm concentration was raised if diets contained methanol-grown dried bacterial cells. Indications of toxic influences of the methanol-grown bacterial cells were not found.

Animals↗