Methyleholanthrene tumors: Methylcholanthrene tumors were obtained after instillation

The results of our study underline the importance of risk estimation for possible postoperative urological dysfunction by means of preoperative urologic evaluation in this patient collective. Of patients with postoperative bladder dysfunction, 90% improved within 6 months after surgery and only 10% continued to have bladder dysfunction beyond 6 months, indicating irreversible nerve damage.

No abstract

Lipoteichoic acids (LTAs) from various bacterial species, including Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Enterococcusfaecalis, and Listeria monocytogenes, were examined for the ability to induce secretory and cellular responses in a pure population of bone marrow-derived mononuclear phagocytes. Some of the highly purified LTAs, in particular LTAs from Bacilus subtilis, S. pyogenes, E. faecalis, and Enterococcus hirae, were able to affect each of the macrophage parameters measured, i.e., reductive capacity, secretion of tumor necrosis factor and nitrite, and tumoricidal activity. As after stimulation with whole organisms or other bacterial products, secretion of tumor necrosis factor induced by these LTAs reached its maximum within the first few hours of the interaction, while secretion of nitrite and tumoricidal activity required 24 to 36 h for full expression. Other purified LTAs, i.e., LTAs from Streptococcus sanguis, S. pneumoniae, and L. monocytogenes, as well as lipomannan from Micrococcus luteus affected only some of these parameters, while native LTA from S. aureus was inactive. There was no obvious correlation between biological activity and chain length, kind of glycosyl substituents, glycolipid structures, or fatty acid composition of LTAs. Deacylation of LTAs resulted in a complete loss of activity, and deacylated LTAs did not impair the activity of their acylated counterparts, suggesting that acyl chains may be essential for binding of LTA to the cell surface. The results demonstrate that some LTA species are potent inducers of macrophage secretory and cellular activities.

ABSTRACT-Various attempts were made to assess the role of the mononuclear phagocyte system in tumor resistance of rats in vivo. The growth of sc inoculated, weakly immunogenic, carcinogen-induced, syngeneic tumor cells was modestly reduced by ip injection and, more impressively, by local injection of peptoneinduced, activated, nonimmune macrophages. A single iv injection of silica particles or carrageenan on the day of sc tumor cell inoculation greatly enhanced tumor growth. When these agents had been given a few days before or after tumor cell inoculation, the tumor-promoting efficiency was distinctly diminished or even cancelled. The enhancing effects of silica and carrageenan on tumor growth were nullified by the macrophage-stabilizing agent, poly-2-vinylpyridine N-oxide. To assess the in vivo consequences of silica administration, various cellular, biochemical, and functional macrophage parameters were determined at different intervals. Results indicated the complexity of events elicited after the mononuclear phagocyte system was damaged, which made the interpretation of such results difficult.-J Natl Cancer Inst 57: 1355-1361,1976. Many in vitro studies indicate that, in addition to the basic role that is assigned to lymphocytes (in tumor resistance), macrophages activated by specific or nonspecific means also contribute to tumor resistance (1). Since presently no direct or effective way exists of depleting the host of macrophages, their function in tumor resistance in vivo remains obscure. However, considerable evidence, admittedly indirect, implies such a capacity for the macrophage (2). For example, in the Nippostrongylus brasiliensis-infected rat, tumor growth can either be suppressed or enhanced, depending on the timing of inoculation of tumor cells in relation to the parasite infection (3). In this (4) and other in vivo model systems (5, 6), suppression of tumor growth seems attributable to AM, and enhancement of tumor growth seems due to a macrophage-inactivating factor arising after a nematode infection (7). Moreover, the use of adjuvants of microbial derivation such as BCG, Corynebacterium parvum, or Listeria monocytogenes has been considerably expanded, and recent evidence attests to intralesional injection of the adjuvant being particularly effective in producing regression of established syngeneic tumors (8)(9)(10)(11). As the responsiveness of tumors to these adjuvants does not parallel their immunogenicity, this effect is now considered more likely to reflect the extent to which tumors are infiltrated by macrophages. Still other observations imply an inverse relationship between the macrophage content of tumors and tumor regression (12) or metastases (13). Despite these distinctive approaches and the expanding magnitude of the effort, no convincing evidence exists that macrophages are directly involved in tumor resistance.The function of macrophages in tumor resistance is explored further in the present study. Various measures known to diminish the functional capacities of macrophages in vi...