Comparative equilibration has been proposed as a methodological approach for determining the hydrogen isotopic composition (deltaD) of non-exchangeable hydrogen in complex organic materials, from feathers to blood and soils. This method depends on using homogenized standards that have been previously calibrated for their deltaD values of non-exchangeable H, that are compositionally similar to u...

To elucidate the role of keratin modification in tumor pro motion, we investigated the keratin polypeptide patterns of mouse epidermis, papillomas, and carcinomas throughout an initiation-promotion experiment. The epidermal keratin modifi cations induced by repetitive 12-O-tetradecanoylphorbol-13acetate treatments in both initiated and noninitiated mouse skin were essentially identical to those...

We have investigated keratin and keratin mRNA expression during (1) differentiation of stem cells into epidermis and hair follicles and (2) morphogenesis of follicles. Our results indicate that a type I keratin K14 is expressed early in embryonal basal cells. Subsequently, its expression is elevated in the basal layer of developing epidermis but suppressed in developing matrix cells. This diffe...

The expression of distinct keratin pairs during epidermal differentiation is assumed to fulfill specific and essential cytoskeletal functions. This is supported by a great variety of genodermatoses exhibiting tissue fragility because of keratin mutations. Here, we show that the loss of K10, the most prominent epidermal protein, allowed the formation of a normal epidermis in neonatal mice withou...

Electrophoretically homogeneous keratin A and keratin B were studied in the ultracentrifuge. Both preparations revealed two fractions: one which sedimented rapidly and another which sedimented slowly. This indicated that both preparations are heterogeneous with respect to particle size.

It is generally accepted that cementoblasts originate in the process of differentiation of the mesenchymal cells of the dental follicle. Recently, a different hypothesis for the origin of cementoblasts has been proposed. Hertwig's epithelial root sheath cells undergo the epithelial-mesenchymal transformation to differentiate into cementoblasts. To elucidate whether the epithelial-mesenchymal tr...

AIMS To investigate differences in expression of keratin 20, a cytoskeletal protein in gastrointestinal epithelial cells, in completely differentiated intestinal metaplasia (type I) and incomplete metaplasia (types II and III). METHODS Gastric biopsy specimens from 66 patients with intestinal metaplasia were analysed immunohistochemically. Expression of keratin 20 was quantified as the percen...

To elucidate the role of keratin modification in tumor promotion, we investigated the keratin polypeptide patterns of mouse epidermis, papillomas, and carcinomas throughout an initiation-promotion experiment. The epidermal keratin modifications induced by repetitive 12-O-tetradecanoylphorbol-13-acetate treatments in both initiated and noninitiated mouse skin were essentially identical to those ...

We conducted two-dimensional (2D) discrete Fourier analyses of the spatial variation in refractive index of the spongy medullary keratin from four di¡erent colours of structurally coloured feather barbs from three species of bird: the rose-faced lovebird, Agapornis roseicollis (Psittacidae), the budgerigar, Melopsittacus undulatus (Psittacidae), and the Gouldian ¢nch, Poephila guttata (Estrildi...

Candida parapsilosis is an increasingly important human pathogen. However, little is known about its potential to cause disease. The aims of the present study were to analyse the production of acid proteinases by clinical isolates of C. parapsilosis in the presence of different keratinous substrates from human sources (stratum corneum, nail and hair) and to verify the capability of yeast cells ...