Biomedical subjects
Publications and source records attributed to D W Weiss.
Explore the source record for details and available documents.
Administration to inbred mice of the methanol extraction residue fraction of tubercle bacilli by some, but not by all, routes affected markedly the in vitro phagocytic and antibacterial capacities of their peritoneal macrophages harvested several days to weeks after treatment. Phagocytosis of living [3H]thymidine- labeled Staphylococcus albus and Staphylococcus aureus organisms, but not of Listeria monocytogenes, was markedly enhanced. Uptake of the deoxyribonucleic acid precursor thymidine by the phagocytized staphylococci was consistently and significantly inhibited in macrophages taken from methanol extraction residue-treated donors. Such macrophages also displayed a significant facility to reduce the viability of intracellular S. albus and L. monocytogenes, but not of S. aureus, under the present experimental conditions.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The immunoprophylactic effects of the methanol extraction residue (MER) of BCG were investigated in Strain 2 guinea-pigs injected with cells of the transplantable, diethylnitrosamine-induced, Line 10 hepatocarcinoma. Pretreatment with MER at times ranging from 18 to 182 days prior to tumour implantation protected approximately 40% of guinea-pigs from progressive neoplastic disease. In addition, MER-treated animals developed specific cell-mediated anti-tumour immunity both more rapidly and at higher levels than did non-MER-treated tumour-bearing controls. It was not possible, however, to prognosticate from the results of such laboratory studies to the outcome of immunoprophylaxis.
Explore the source record for details and available documents.
Isografts of two mammary carcinomas, one spontaneously arising in a BALB/cfC3H female infected with MTV and one free of MTV (tumor D7T4S), were removed surgically from Balb/c (MTV free) female hosts, and fragments of each tumor were immediately reimplanted in situ (simulated local recurrence challenge). The animals were then subjected to treatment with the MER fraction of tubercle bacilli, with one of three chemotherapeutic drugs (5-FU, cyclophosphamide, and methotrexate), or with both MER and one of the chemotherapeutic agents (chemoimmunotherapy). The incidence of progressively developing recurrence tumors and the longevity of the animals were determined. The therapeutic effects of treatment with MER alone were ascertained by comparing groups of mice that received the fraction by various schedules with saline-injected control groups; the efficacy of chemoimmunotherapy was assassed by comparing groups that received MER plus one of the drugs with groups subjected to drug intervention by itself. MER administered alone did not reduce the incidence of recurrent tumors but was consistently efficacious in prolonging the lives of animals challenged with the MTV (+) carcinoma, although considerably less so in animals tested with the weakly immunogenic tumor D7T4S. A negative effect by MER on tumor frequency did not occur and was seen only once with regard to host life duration. Combined intervention with MER and 5-FU proved to be significantly and consistently superior to similar treatment with only 5-FU in animals challenged with the MTV(+) carcinoma. No such additive action by MER plus 5-FU was seen in mice challenged with D7T4S, however, nor did the other two chemoimmunotherapeutic regimens differ significantly in therapeutic efficacy from the corresponding chemotherapy alone in most of the trials with both tumors.
Experiments employing two new methods for the in vitro assessment of cell-mediated immunity against neoplastic target cells are indicated. Both methods offer the advantage of rapid and quantifiable determination of very early events in cell-cell confrontations. One technique measures the incorporation of precursors of proteins, RNA, and DNA synthesis by neoplastic cells incubated with effector cells during the first hours of contact. It was found that exposure of BALB/c plasmacytoma (PCT) cells to splenocytes from PCT-sensitized donors failed to bring about inactivation of the target cells or their release of 51Cr during several hours of interaction. However, inhibition of 3H-thymidine incorporation was almost instantaneous and pronounced. This observation suggests that cytostatic events may transpire in cell-cell interactions in the absence, or before the onset, of lethal changes. The second method assays the specific adherence of 51Cr-labeled lymphoid cells from Rous sarcoma (RS)-bearing chickens to RS target cells. This immunoadherence test revealed perferential, specific reactivity in autochthonous as compared with allogeneic interactions, which indicated recognition of individual-specific tumor-associated antigens against a background of strongly expressed group antigenicities.
Neoplasia is considered within the biologic framework of host-parasite relationships, and the arguments favoring this perspective are discussed. By viewing neoplastic processes as dynamic interactions between transformed clones, host defense mechanisms, and the environmental circumstances impinging directly on the neoplastic event, the experimentalist and clinician are better prepared conceptually for a balanced assessment of all factors determining the development and outcome of confrontations with neoplastic clones. The frame of reference placing progressive neoplasia into the category of host-parasite associations also prepares the ground for techinical approaches to the study and observation of oncologic phenomena appropriate to their essential nature. The correct evaluation and most promising future development of the current emphasis on immunologic parameters of neoplasia demands especially an awareness of the role of immunologic variables in other host-parasite relationships.
Complement-medicated cytotoxicity and indirect immunofluorescence assays showed that sera from random-bred chickens bearing Rous sarcoma (RS) tumors are usually more reactive in vitro against RS cells of autochthonous than of allogeneic origin. Absorption of such sera with autochthonous, but not with allogeneic, RS cells abrogated the fluorescence staining capacity. Sera from tumor-bearing birds did not stain normal chicken embryo cells (CEC), but reacted with a higher proportion of CEC transformed by the RS virus than with cultured PS tumor cells. Tumor cells incubated at 37 degrees C with autochthonous serum and fluorescent horse anti-chicken immunoglobulin conjugate displayed cell surface fluorescence patching.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Strain BALB/c female mice bearing syngeneic implants of 2 mammary adenocarcinomata were treated with MER, x-irradiation or both. MER was administered either subcutaneously at a site contralateral to the neoplastic growth or both into such a site and directly at the tumour location. None of the treatments effected cures but many of the treated animals survived significantly longer than did the saline injected controls. There was no evidence that introduction of MER into, or directly adjacent to, a tumour is a generally more efficacious route of administration than application at only a distal site and there was, indeed, the strong contrary impression that distal treatment alone bestowed survival protection more often and to a greater extent. In no instance was there a shortening of survival time following administration of MER at a location away from the tumour implant.