Kamal Eldin Hashem Abdalla

Identification of morphological markers of sarcopenia at early stage of aging in skeletal muscle of mice

The gastrocnemius muscle (GM) of young (3months) and aged (12months) female wild-type C57/BL6 mice was examined by light and electron microscopy, looking for the presence of structural changes at early stage of the aging process. Morphometrical parameters including body and gastrocnemius weights, number and type of muscle fibers, cross section area (CSA), perimeter, and Ferets diameter of single muscle fiber, were measured. Moreover, lengths of the sarcomere, A-band, I-band, H-zone, and number and CSA of intermyofibrillar mitochondria (IFM), were also determined. The results provide evidence that 12month-old mice had significant changes on skeletal muscle structure, beginning with the reduction of gastrocnemius weight to body weight ratio, compatible with an early loss of skeletal muscle function and strength. Moreover, light microscopy revealed increased muscle fibers size, with a significant increase on their CSA, perimeter, and diameter of both type I and type II muscle fibers, and a reduction in the percentage of muscle area occupied by type II fibers. Enhanced connective tissue infiltrations, and the presence of centrally nucleated muscle fibers, were also found in aged mice. These changes may underlie an attempt to compensate the loss of muscle mass and muscle fibers number. Furthermore, electron microscopy discovered a significant age-dependent increase in the length of sarcomeres, I and H bands, and reduction on the overlapped actin/myosin length, supporting contractile force loss with age. Electron microscopy also showed an increased number and CSA of IFM with age, which may reveal more endurance at 12months of age. Together, mice at early stage of aging already show significant changes in gastrocnemius muscle morphology and ultrastructure that are suggestive of the onset of sarcopenia.

Morphological study of the hard palate in the Egyptian goats (Capra hircus) : a scanning electron microscopic study

The aim of this study was to investigate the morphology of the goat hard palate by light and scanning electron microscopy (SEM), in addition to gross and morphometric analysis. A total of twelve goat heads, from normal adult and apparently healthy goats of both sexes, were collected from local slaughterhouses in Qena province, Egypt. Samples were subjected to gross examination, morphometric analysis, light microscopy and SEM. The hard palate in the goats was long and could be divided into a rostral narrow part and a caudal wide part with about 12–15 transverse palatine ridges from which the rostral palatine ridges were serrated on their free caudal edges. The dental pad replaced the upper incisors; its caudal border had a serrated appearance. At higher magnification, the epithelial surface of the palatine rugae and incisive papilla revealed a variety in the shape of the microplicae and the pattern of the micropits. These adaptations of the goats hard palate might increase its efficiency during ingestion and mastication of coarse roughages and in directing the food backwards. To our knowledge, this is the first study showed the detailed anatomical description of the hard palate of the goat with SEM.