Precursors of cytoplasmic RNA in avian cell nucleus

In nucleus of chick embryo four pre-rRNA of molecular weight of 3.43, 2.93, 2.36 and 1.87 X 10(6) were found in addition to the heterogeneous population of "giant" RNA molecules larger than 4.5 X 10(6) daltons, partially polyadenylated, with few methyl groups and numerous double-stranded regions.     

Immunological and cytochemical indices of white blood cells in old age

The group of aged subjects being 66 to 97 years old was compared with the middle-age group with regard to various immunological and cytochemical indices related to lymphocytes and neutrophils. The aged showed a lowered count and percentage of T cells, increased count and percentage of "non-B, non-T" lymphocytes, increased percentage of B cells. These alterations in the composition of lymphocyte subpopulation were associated with characteristic patterns of damage affecting the enzyme-positive lysosomal apparatus of lymphocytes with regard to acid phosphatase, beta-glucuronidase and N-acetyl-beta-D-glucosaminidase. There was a hundredfold smaller number of cells having intact enzyme-positive lysosomes in the aged than in the group of comparison. The changes mentioned above were also associated with the intracellular accumulation of glycogen in lymphocytes, decreased concentration of IgG and IgM in the serum and various changes in IgA concentration. Neutrophils of the aged were fewer in the blood of the aged than in younger subjects. However, an increased activity of myeloperoxidase, alkaline phosphatase, N-acetyl-beta-D-glucosaminidase, and an increased content of glycogen and lipids could be found in these cells. NBT-positive neutrophil numbers in the aged were lowered if the stimulated test was used and if there were no changes of the spontaneous test.