Histomorphometrical aspects of the postnatal development of masticatory muscle in the muscular dystrophic mouse.

Histomorphological and histomorphometrical observations were used to describe the development of masticatory muscles from normal and muscular dystrophic mice. The masseter and the digastric muscle were described from the birth to 35-40 week of age. It has not been possible by histomorphological criteria to separate dystrophic muscles from normal muscles at birth.

Os penis of the rat. VI. Scanning electron microscopy of the surfaces of the mature bone.

Observations on the ultrastructural appearance of the surfaces of the mature os penis in the rat reveal that a majority of its surfaces may be classified as prolonged resting surfaces on very slow growing surfaces. Although a vast majority of the bone consists of bone tissue types which usually only form a small part of human and laboratory animal bones, their surface appearances resemble to a high degree surface appearances described for ordinary bone tissue types. Thus, surface morphology need not reflect tissue type variance.

Presence of alpha-naphthyl acetate esterase enzymes in dental and oral epithelium of guinea pig embryos.

This study examines the distribution of alpha-naphthyl acetate esterase enzymes in reduced enamel epithelium, i.e., post secretory ameloblasts (PSA) and external cells of reduced enamel epithelium (ERE) of continuously growing incisor and molar tooth germs and in the covering oral epithelium (OE).

Histomorphometrical analysis of the influence of soft diet on masticatory muscle development in the muscular dystrophic mouse.

The known difference in the severity of dystrophy between the masseter and the digastric muscle of the mouse (dy/dy C57BL/J6) may be attributed to the differences in muscle work load. This possibility was tested by subjecting 3-week-old mice (normal and dystrophic) to a soft diet for 4 weeks. Microscopic examination of haematoxylin-eosin stained sections of these muscles showed that the fibre size dispersion (a measure of disease severity) decreased slightly but significantly in the masseters of mice on a soft diet.

Skull development in the muscular dystrophic mouse.

Roentgencephalometric tracings of skulls of 7-week-old normal and muscular dystrophic mice were compared. A marked size reduction of the dystrophic skulls relative to the normal ones was observed. However, the visceral parts of the dystrophic skull were more reduced in size than the neural parts.