Induction and persistence of suppression of contact hypersensitivity against bystander haptens and alloantigens in rats

The shift of suppression from a tolerizing hapten to a so-called bystander antigen was investigated in this study using contact hypersensitivity to trinitrochlorobenzene (TNCB) and dinitrofluorobenzene (DNFB) and delayed type hypersensitivity (DTH) to alloantigens in the rats as experimental models. Primary suppression of contact hypersensitivity was induced by intravenous injection of the water-soluble forms of TNCB and DNFB. A shift of the suppression to the bystander hapten was found if the tolerizing and bystander hapten were mixed and applied to the same area of skin during the sensitization procedure, but not if they were applied to separate areas of skin. With alloantigens, bystander suppression developed only when the sensitizing allogeneic cells were mixed with hapten-modified syngeneic cells. It was not induced by hapten-modified allogeneic cells. Once induced, such bystander suppression of the response to haptens persisted independently of the primarily tolerizing hapten, and it could be adoptively transferred with spleen cells. These results favour the concept that the bystander suppression is mediated by the non-specific action of suppressor cells generated specifically during the mixed sensitization rather than by an antigen bridge.     

Comparison of Mobilization after Two and Nine Days in Uncomplicated Myocardial Infarction

A total of 189 patients with uncomplicated myocardial infarction were selected at random for early or late mobilization and discharge from hospital. Patients were admitted to the study after 48 hours in a coronary care unit if they were free of pain and showed no evidence of heart failure or significant dysrhythmia. Randomization was achieved by monthly cross-over of the three medical wards to which the patients were discharged. One group of patients was mobilized immediately and discharged home after a total of nine days in hospital, and the second group was mobilized on the ninth day and discharged on the 16th day. Out-patient assessment was carried out six weeks after admission. No significant differences were observed between the groups in terms of mortality or morbidity, as reflected by the incidence of recurrent chest pain or myocardial infarction, heart failure, dysrhythmia, or venous thromboembolism detected either clinically or by ¹²⁵I-labelled fibrinogen scanning.     

Isolation and characterization of a human hepatic epithelial-like cell line (AKN-1) from a normal liver

Summary The isolation and characterization of human liver cell lines are rather difficult due to limited material and poor growth in cell culture. In this report, we present the isolation, culture and characterization of a new epithelial-like liver cell line (AKN-1) with a heterogeneous cell population and many characteristics of the biliary epithelium. The AKN-1 cell line stained positively with antibodies to epithelial cytokeratin polypetides CK 8, 18, and 19. In addition, the cell line expressed the anti-human epithelial-related antigen (MOC-31), the human epithelial antigen (HEA), and the gamma-glutamyl transpeptidase, the hematopoietic growth factor, stem cell factor, and also its receptor, c-kit. The cell line failed to express albumin and factor 8 by immunohistochemistry. It did show, however, a twofold increase in 7-ethoxyresorufin-O-deethylase activity. Cytogenetic characterization revealed rare breakpoints in chromosome 2, which to our knowledge, have not yet been reported in liver cells.     

Dietary practices,site-specific tumors,and age-at-death relationships

When rats are given freedom of dietary choice, the quantity and composition of the diet selected varies from animal to animal, but the risk to the individual of developing a variety of neoplasms is greatly increased over that of rats fed fixed diets. The increase in frequency of tumors cannot be explained on the basis of the amount or the composition of the diet selected. However, the application of “variable selection” statistical procedures shows that there are combinations of temporal-specific interacting dietary and dietary-dependent variables that are closely linked with cancer mortality. The multi-variable statistical model for animals dying with one type of tumor is not applicable to those dying with tumors of other types or sites. In every case, the only data required to characterize the dates of death of tumor-bearing individuals are those describing the dietary practices and growth responses prior to maturity. The model for animals with pancreatic tumors is used to illustrate the extent to which dietary practices of early life are linked with the animals’ survival.