Regeneration of muscle following cryosurgery of the tongue

Regeneration of muscle following low-temperature destruction of tissue has not been extensively studied. Using light and transmission electron microscopy an investigation of this phenomenon was made in hamster tongue. Healing commenced 1 week after the operation and was of the continuous regeneration type in the least damaged muscle fibers. Healing was of the discontinuous or embryonic type in severely damaged muscle and myoblasts formed either within old intact endomysial tubes or separate from them. Healing with minimal scarring was well advanced 6 weeks after the operation.     

SURFACE AREA RELATIONS OF WOODY PLANTS AND FOREST COMMUNITIES

Surface area of wood and bark is an important dimension of forests, with implications for respiration rate, energy exchange, and water and mineral budgets. Surface area of stem wood and bark can be estimated effectively from linear regressions on conic surface (one-half basal circumference times tree height) or from regressions of the logarithm of area on the logarithm of diameter at breast height. Branch surface can be estimated from a formula using branch basal diameter, length, and number of current twigs, and from logarithmic regressions of branch bark surface on basal diameter of branches and breast-height diameter of trees. In temperate deciduous forests several square meters of plant surface occur above each square meter of ground surface; these plant surfaces include 0.3–0.6 m² of stem bark, 1.2–2.2 m² of branch bark, and 3.0–6.0 m² of leaf blades. Branch bark surface increases more rapidly than leaf surface with increasing size of branches and trees. Growth and aging of trees, and maturation of forests, imply increasing ratios of bark (and wood) surface to the photosynthetic leaf surface which supports its growth and respiration.     

Segregation of the E1j gene for plasma cholinesterase in family studies

Four families are reported in which the E1j gene is segregating. Two E1jE1k and one E1jE1f genotypes have been recognised by genetic analysis. The biochemical characteristics of several E1j genotypes are presented.     

A Yaba-like condition in a young baboon (Papio anubis)

A rapidly developing proliferation of subcutaneous nodules on the leg of a young baboon is described. Histologically the nodules consisted of plump round cells, many of which contained intracytoplasmic eosinophilic viral-like inclusions.