Expression of gastric-associated antigens by human premalignant and malignant colonic epithelial cells.

A rabbit antiserum prepared to 2nd-trimester fetal organ extracts and absorbed with adult tissue (anti-STFa) was used to detect antigens common to 2nd-trimester fetal large bowel, normal adult stomach, several colon carcinoma cells (in primary and established cultures) and epithelial cells cultured from benign colonic polyps. The frequency of anti-STFa-positive cells was highest in cultures derived from benign tumors known to be associated with a greater degree of premalignancy. Thus, the percentage of antigen-positive cells increased from 18 and 43% to 70% of cultures from tubular, villotubular and villous adenomas, respectively. Considerable heterogeneity in the distribution of antigen-containing cells was evident within any given area of a positive culture. Absorption experiments, using a spectrum of fetal and normal adult tissue extracts, indicated that the adenoma-carcinoma specificity resides in fetal, but not adult, large bowel and normal adult stomach.

Impact of cancer therapy on survival.

Survival rates improved significantly for 28,036 lymphoma and leukemia patients studied between 1950 and 1973. Nine cancers reviewed demonstrated increased one, three and five year survival rates. Greatest improvement was acute lymphocytic leukemia survival. Least improvement was for chronic granulocytic leukemia. Analyses of age-specific trends in U.S. cancer mortality since 1960 indicates death rates decreased 20% for all ages up to 45 years. This included 70% of the population, but less than 10% of all cancer deaths. Age groups over 55 experienced an 8% increase in cancer mortality. Accurate determination of national cancer incidence trends is not presently possible. Available data, representing approximately 15 million population, indicate that cancer incidence rates increased between 1960 and 1973. Age-specific trend analyses indicate unusual divergences. For the group 15 to 29-years-old, incidence increased 28% in 13 years and there was a concomitant decrease of 20% in mortality.

Chromosomal mapping by means of mutational induction in synchronous populations of Streptococcus faecalis.

Stonehill, E. H. (Sloan-Kettering Institute for Cancer Research, New York, N.Y. and Dorris J. Hutchison. Chromosomal mapping by means of mutational induction in synchronous populations of Streptococcus faecalis. J. Bacteriol. 92:136-143. 1966.-A new method for mapping genetic loci on the bacterial chromosome, based on the linear progression of the deoxyribonucleic acid-replicating enzyme (replicase) in synchronous cultures of Streptococcus faecalis, is described. Ultraviolet irradiation was used to induce mutations to drug and to bacteriophage resistance at various intervals during the progress of the replicase along the chromosome. The time of duplication of the gene in synchronous populations was determined from reductions in the rates of irradiation-induced mutation. After the replication of various genes, the rates fell to half their former values. The resulting data made possible the construction of a 1-hr time-map indicating the sequence of replication of five genes in S. faecalis.