Extent Of Irritation Research Articles

Comparative studies on the usefulness of phosphate versus glycerin enema in preparation for colon examinations

Fifty of 100 persons who had undergone health screening received phosphate enema while the other 50 received glycerin enema prior to proctoscopy and barium enema, and their usefulness for preparation for colon examination was compared by a double-blind test. There was no significant difference in the degree of colonic cleansing achieved by proctoscopy and barium enema. In the subjects who received phosphate enema, the incidence of abdominal pain was less than that in those who received glycerin enema, while the effect of phosphate enema on defecation appeared later than that of glycerin enema, indicating prolonged stool retention in the subjects given phosphate enema. To study the safety of the two enemas, either phosphate enema, glycerin enema or physiological saline solution as a control was administered at 0.35 ml/animal in the rectum by 4-h closure of the anus in 10 male 7-week-old Wistar rats, and the rectal mucosa was observed for irritation macroscopically and histopathologically. Glycerin enema produced less irritation than phosphate enema diffusely in the entire area of the rectum, while phosphate enema produced more local irritation at the end of the rectum than glycerin enema. The differences in the extent of irritation and injury between phosphate and glycerin enemas were considered to be derived from differences in the pharmacologic actions of these drugs. If the extent of injury were included in the extent of irritation, the difference in irritation between phosphate and glycerin enemas would not be significant. As described above, no specific difference seem to exist in the usefulness of phosphate and glycerin enemas as preparation for colon examination.

The Respective Rôles of Heredity and Somatic Mutation in the Origin of Malignancy

In their studies of induced Cysticercus sarcoma the authors found that an increase in the number of cysts, that is, an increase in the surface area exposed to the irritant, decreased directly the time interval necessary for the onset of the malignant process and increased directly the probability of its occurrence until it became inevitable. They therefore concluded (1) that chance was an important factor in the change of a normal cell to a cancer cell. They have shown further that in the case of Cysticercus sarcoma hereditary factors influenced the occurrence of malignancy only in so far as they determined the longevity of the individual and its susceptibility to Cysticercus disease. The Cysticercus cysts and the tumors showed (2) a fortuitous distribution to the several lobes of the liver, and the type of Cysticercus tumors observed represented the types of cells found in the cyst wall, each being represented by a number consistent with the expectation that the change of a normal to a cancer cell results from the chance action of an irritant. It would seem, therefore, that with the use of a carcinogenic agent which is more rapidly effective and can be distributed mechanically, differences resulting from the hereditary control of the duration and extent of irritation might be eliminated. The induced tumors would be expected to show a chance distribution to the injected loci in individuals of any genetic constitution or species, the type of tumor and the time from the injection of the irritant to the onset of the malignant change depending upon the character and the number of cells exposed.