In 1948, Rinehart and Greenberg reported on the arteriosclerosis in pyridoxine-deficient monkeys. In this paper, authors investigated the recovery of monkeys, kept on the pyridoxine-deficient diet for 12 months, during the period of being switched back to the control diet. The weight of monkeys rapidly increased for three or four months after being discontinued the deficient diet, and then reached gradually of the weight of the control animals. Animals were killed after maintaining 2 months, 6 months and 12 months of the control diet. Their organs were weighed and compared with those in the deficient monkeys. Marked atrophy of the thymus and the increase in weight of the adrenal gland were observed in the deficient monkeys. After changing into the control diet, the atrophied thymus was most remarkably recovered, while some of the plaque in the abdominal aorta and renal artery remained after 12 months. Scarcely any sclerotic change was found in the coronary artery of the animals recovering from changes induced by deficient diet, indicating a pronounced reversibility of the sclerotic changes in pyridoxine-deficient animals.
Simple reaction time to light was determined in 627 healthy subjects between the ages of 7 to 80 (221 males, 406 females). Mean and standard deviation in each sex and age group was compared. 1) The mean reaction time and its standard deviation in the subjects of both sexes decreased with age up to the 15-19 age group and then increased with age. 2) The mean reaction time and its standard deviation were greater in female than in male. 3) The mean reaction time and its standard deviation were smaller in the aged subjects living in normal society than in that in the institution. 4) There was no significant difference in the mean reaction time and its standard deviation between normal subjects and patients with hypertension.
Using human autopsy skin specimens from 144 Caucasian males, 172 Japanese males and 103 Japanese females at different ages ranging from infants to 94 years old, age changes in cellularity, vascularity and proportions of several cell types in connective tissue of the dermis were studied. In the youngest age group, cellularity of the dermis was high, and the cells were constituted almost entirely by fibroblasts and macrophages. Cellularity in the dermis decreased with age. The number of fibroblasts with dark nuclei increases in older age groups. The number of demonstrable mast cells also increases. The number of papillae in a given area decreases remarkably in the later decades. There is an apparent increase in percentage of lymphocyts with age. However, the increase is not significant according to analysis by the Tukey methods. With the exception of the number of fibroblasts with dark nuclei, the difference in number of all types of cells between Japanese males and females are not significant. However, difference between two races (Caucasian males and Japanese males) are significant statistically with a few exceptions. The difference in the age change in number of several types of cells, as between the two races, are significant.