Bernard N. Jaroslow

Age-associated decline in theta antigen on spleen thymus-derived lymphocytes of b6cf1 mice.

Abstract The proportion of theta-bearing cells in spleen cell suspensions of normal B6CF 1 mice of both sexes, from 1 to 900 days of age, was determined using indirect immunofluorescence. By 25 days of age theta positive cells constituted ~32% of the population, and this proportion remained constant to 183 days of age. Between 183 and 650 days of age the proportion of theta positive cells declined linearly. The amount of theta antigen per cell also decreased with age. Theta was visualized as a continuous ring on cells from young mice and changed to a patchy distribution to faintly visible incomplete rings by 600 days of age. The age-associated decline in theta antigen suggests that the amount of theta on the cell surface is an indicator of, and perhaps a contributor to, the functional capability of the thymus-derived cell.

Blood catalase polymorphism. Some immunological aspects.

The immunological properties of the erythrocyte catalase of mice—normal (wild type) strain, one lacking catalase (acatalasemic), and four with only slight catalase activity (hypocatalasemic strains)—have been investigated. Agardiffusion tests and antigen titration of red-cell lysates against rabbit antiserum to catalase from normal mouse blood showed that immunologically identical catalase protein was present in large amounts in the acatalasemic as well as in the hypocatalasemic mutant strains. Despite lack of catalatic activity, the erythrocytes lacking catalase as well as those with only a little catalase contain catalase protein that has been modified at the site of enzyme activity, although the antigenic determinants are identical with those of normal catalase protein. This mutation is purely structural, being characterized by modification of the enzyme active site but not of the antigenic site.

Clearance of foreign red cells from the blood of aging mice

The blood clearance system, which is important in protection against infection, was studied in young, adult and senescent B6CF1 mice. We found that the blood clearance mechanism distinguishes between different degrees of foreignness, as shown by increasing blood clearance rates for 51Cr-labelled red cells from other mouse strains, rats, non-Murid mice, and pigeons. Our findings indicate that there is a decline in clearance rate between 14 and 150 days but no decline from maturity to senescence. These results were the same for isologous or heterologous cells and confirm the findings reported by other workers; but they refute generalizations to the effect that the clearance rate declines in aging animals.

Hydroxyurea and cell-cycle kinetics of cultured antibody-forming cells

Abstract Cell-cycle kinetics of precursors to antibody-forming cells was studied in mouse spleen cell cultures immunized with sheep red cells. Hydroxyurea (0.5 m M ) added on the day of culture did not interfere with the response if removed within 24 hr. When it was added on Day 4 of culture, during log growth, 76% of the antibody-forming cells were killed with treatment lasting 8 hr or less. Treatment of 12 hr or more resulted in death for 98% of the cells. The shape of the survival curve showed the proportion of cells killed in S (.74), the duration of S (6–7.5 hr), and generation time 8.5–10 hr. This technique is particularly useful for the study of a very small population of differentiating cells at a time prior to the expression of the unique character by which they are detected.

Influence of poly A-poly U on early events in the immune response in vitro

Abstract Adjuvant action of artificial homopolyribonucleotides and nucleic acid digests was studied in mouse spleen-cell cultures, stimulated with sheep red cells by the technique of Mishell and Dutton. Assays of antibody-forming cells were performed according to the Jerne and Nordin technique. Doublestranded poly A-poly U, and RNA digests had adjuvant activity over a wide dose range (0.01–100 μg/ml). DNA digests, single stranded polynucleotides (poly A, poly U, poly C) and mixtures of ribonucleosides and ribonucleotides had little or no enhancing effect at comparable doses. From our study of the kinetics of increase of plaque-forming cells in cultures treated with poly A-poly U, in conjunction with in vivo studies of others, we concluded that adjuvant action, during induction, indirectly increased the number of bone marrow-derived cells that responded to antigenic stimulation by increasing the effectiveness of the thymus-derived cells in the culture.

Antigen disappearance in hibernating ground squirrels.

The rate of antigen disappearance was studied in hibernating ground squirrels (Citellus tridecemlineatus) injected with I131-labeled bovine serum albumin. There was no detectable disappearance of antigen during 14 days of hibernation. The induction period, however, ended 5 days after arousal as compared to a 7-day induction period in nonhibernating ground squirrels.

Survival of hibernating ground squirrels (Citellus tridecemlineatus) after single and fractionated doses of cobalt-60 gamma radiation.

The effects of hibernation on survival after irradiation was studied in thirteen-lined ground squirrels (Citellus tridecemlineatus). The

Molecular location of the genetic lesion in the acatalasemic mouse

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Nucleic Acids and Induction of Antibody Synthesis in Inhibited Systems

for a single dose of60 Co gamma radiatio...

[22] Production of antibodies to catalase and their effect on enzyme activity

Antibody to normal mouse catalase will stabilize blood and liver catalase of the acatalasemic mouse against a variety of agents which damage protein tertiary structure (urea, guanidine, trypsin) but not against agents which affect the heme group (azide, hydroxylamine). The antibody will also stabilize catalase against inhibition by 3-amino 1,2,4-triazole (AT), the specific site of action of which is known. The antibody is able also to protect normal mouse catalase from urea denaturation, but it is without effect on AT inhibition of normal catalase. A hypothesis is proposed which explains these results and which helps localize the site of the mutation on the catalase molecule.