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H HERRMANN

Publications and source records attributed to H HERRMANN.

At least 19 recordsLinked to original sources
PubMed1965

BIOSYNTHESIS OF COLLAGEN AND NON-COLLAGEN PROTEIN DURING DEVELOPMENT OF THE CHICK CORNEA.

The relationship between the rates of increase of corneal protein fractions and incorporation of labeled precursors has been examined during embryonic and early posthatching development of the chick corneal stroma. Non-collagen protein increased gradually from 9 through 20 days of incubation. Collagen accumulated approximately logarithmically through the 19th day, the most rapid rate occurring between 13 and 20 days of incubation. The rates at which labeled amino acids are incorporated into collagen in vivo and in vitro undergo marked changes during the last week of embryonic development, corresponding closely to the rate of collagen accumulation in vivo; whereas incorporation into non-collagen protein changes much less markedly. Changes in the rate of incorporation of precursors into collagen are not due to changes in the rate of conversion of collagen from the soluble to insoluble form, or to changes in the endogenous amino acid pool size. Chick embryo corneal stroma collagen turns over very slowly, if at all. Non-collagen protein turns over more rapidly. An increase in cell number, as indicated by DNA content, does not account for the increased rate of collagen synthesis between the 9th and 16th day of incubation. It is concluded that the observed changes in collagen synthesis reflect changing activities in the individual cornea fibroblasts. These activities are comparable in the intact tissue in vivo and in isolated corneas in vitro.

Animals↗
PubMed1964

CHROMATOGRAPHY OF RIBONUCLEASE-TREATED MYOSIN EXTRACTS FROM EARLY EMBRYONIC CHICK MUSCLE.

Chromatography, on diethylaminoethyl cellulose, of leg muscle extracts from older chick embryos yields three myosin-containing fractions, whereas material from muscle extracts of 11-day embryos cannot be eluted under the same conditions. A major fraction having the adenosine triphosphotase activity characteristic of myosin can be eluted when 11-day-old embryo muscle extracts are given prior treatment with ribonuclease.

Animals↗
PubMed1964

IN VITRO CULTURE OF MUSCLE TISSUE FROM NORMAL HETEROZYGOUS, AND DYSTROPHIC CHICKS.

The degree of histological deterioration of the original explant and the extent of cell spreading was evaluated in cultures of pectoralis muscle from 11-day chicks. Although the frequencies of these two parameters varied with the amounts of horse serum and embryo extract added to the medium, cultures from dystrophic chicks, in comparison to those from either normal or heterozygous animals, consistently showed the largest number of explants with the most extreme forms of histological deterioration and cell spreading. At 20 per cent horse serum the cultures from heterozygous chicks showed greater frequencies of the more extensive forms of deterioration and spreading than the normal muscle explants, but at 5 per cent horse serum these two groups appeared similar. Regardless of genetic background, cultures of the pectoralis muscle from 18-day embryos and of the latissimus dorsi muscle from 11-day chicks exhibited comparable high frequencies for the maximal degrees of deterioration and spreading.

Animals↗