Fibrillation of the Cortex of Merino Wool Fibers by Freezing-Thawing Treatment

Ito, Harumi; Sakabe, Hiroshi; Miyamoto, Takeaki; Inagaki, Hiroshi

doi:10.1177/004051758405400607

Cited by 16 publications

(16 citation statements)

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“…Mercer reported that such an ortho-para effect could still be observed after cuticle removal [ 19], but in this study, we reexamined the staining behavior using wool fibers completely decuticled by a mild method [ 1,11]. A light micrograph of the decuticled wool fibers dyed with methylene blue is shown in Figure 2, clearly illustrating the bilateral staining.…”

Section: Summary Of Prior Investigatiorimentioning

confidence: 93%

“…Decuticled wool fibers were prepared by ultrasonic irradiation in aqueous 80% dichloroacetic acid in the same way as reported previously [ 1 ]. Cortical cell particles were prepared according to the procedure of Ito et al [11] ] from decuticled wool fibers by a freezing-thawing treatment in formic acid.…”

Section: Summary Of Prior Investigatiorimentioning

confidence: 99%

“…Figure 3 shows the staining result on the cortical cell particles obtained by fibrillation of decuticled wool fibers. These particles, which consist of aggregates of either orthocortical or paracortical cells, were prepared by a freezing-thawing treatment of decuticled wool fibers in formic acid [ 11 ]. There is little difference in the intensity of staining between the particles.…”

Section: Summary Of Prior Investigatiorimentioning

confidence: 99%

“…The arrangement of this structure is much more regular in the paracortex than in the orthocortex, and the density of the paracortex is higher than that of the orthocortex [ 11,13]. Furthermore, the relative amount of matrix to microfibrils is larger in the paracortex than in the orthocortex [2].…”

Section: Summary Of Prior Investigatiorimentioning

confidence: 99%

“…In a previous paper [ 11 ], we reported on the amino acid composition of the isolated orthocortical and paracortical cells. The results showed that there is little difference in the relative content of the charged groups except for cystine.…”

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Mechanism of Bilateral Staining of Merino Wool Fibers with Basic Dyes

Sakabe

Ito

Miyamoto

et al. 1986

Textile Research Journal

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The mechanism of bilateral staining of the cortex of wool fibers by basic dyes has been investigated in detail. Merino wool fibers were treated with formic acid and pronase, and their behavior in staining with basic dyes such as methylene blue and janus green was examined using light and electron microscopy. Formic acid is known to remove intercellular cement, one of the nonkeratinous proteins, from the cell membrane complex, while pronase removes all nonkeratinous proteins. Bilateral staining was still distinctly observed after cuticle removal, but not for wool fibers treated with pronase, for fiber fragments obtained by treatment with formic acid with stirring, or for cortical cell particles recovered after fibrillation of the cortex in formic acid. The microfibril-matrix structure of the cortex remained unchanged, however, even after treatment with formic acid and with pronase. These results imply that bilateral staining with basic dyes occurs because of the difference in the network structure of nonkeratinous proteins, especially the intercellular cement of the cell membrane complex between the orthocortex and paracortex.The cortex of fine wool fibers consists of two major segments, the orthocortex and the paracortex, and the bilateral arrangement of these two cortices is closely associated with the crimped structure of wool fibers [2,3,12]. Since its discovery by Horio and Kondo [9] and Mercer [ 18], many researchers have studied the differences in the responses of each component of the bilateral cortex to various dyes and metal ions [2]. These differences have been interpreted in terms of differences in the fine structure or the reactivity between orthocortex and paracortex [2,4,9,10,14,18,19,21 ]. There are several possible differences between the two cortices, however, and their behavior in staining is different with ,dyes and metal ions [2]. The detailed mechanism of bilateral staining of the cortex is still open for discussion to some extent. The pioneer works by Horio et al. [9,10] were done with ionic dyes. The staining mechanism with dyes is relatively simple compared to that with metal ions, which is specific to individual ions. A possible interpretation is that the content of charged groups is different for the orthocortex and paracortex. Wool fibers are composed of a number of ceU components, however, and the accessibility of dye molecules to the charged groups is different for different cell components. There is insufficient experimental evidence to explain why large dye molecules can produce a remarkable contrast in staining between the two cortical components.In a previous paper [ 11 ], we reported on the amino acid composition of the isolated orthocortical and paracortical cells. The results showed that there is little difference in the relative content of the charged groups except for cystine. During the course of this study, we also found that bilateral staining does not occur alter fibrillation of the cortex. These results suggest that the nonkeratinous materials [2,24], which may be remove...

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Section: Summary Of Prior Investigatiorimentioning

confidence: 93%

Section: Summary Of Prior Investigatiorimentioning

confidence: 99%

Section: Summary Of Prior Investigatiorimentioning

confidence: 99%

Section: Summary Of Prior Investigatiorimentioning

confidence: 99%

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