Polysaccharopeptide (PSP) is a substance produced by an edible mushroom, Coriolus versicolor which has been claimed to possess antitumor activity. However, neither tumoricidal activity nor cytotoxicity was observed when five tumor cell lines and mouse peritoneal macrophages were cultured in vitro in the presence of 2.5-10 micrograms/ml PSP. An increase in the production of reactive nitrogen intermediates, reactive oxygen intermediates (superoxide anions) and tumor necrosis factor was measured in peritoneal macrophages collected from inbred C57 mice which had received PSP in the drinking water for 2 weeks. Northern blot analysis also demonstrated that PSP activated the transcription of tumor necrosis factor gene in these cells, indicating that PSP exerted an immunomodulatory effect on the defensive cells.

Adjuvants, Immunologic↗

PubMedDate not supplied

Alzheimer neurofibrillary lesions: molecular nature and potential roles of different components.

Neurofibrillary lesions found in Alzheimer disease (AD) are known to react with antibodies raised against different molecules. At least 20 components have been detected in neurofibrillary tangles. These components can be roughly categorized into five groups, which include structural proteins, kinases and other cytosolic enzymes, stress-related molecules, amyloid and amyloid binding proteins, and others. Among them, an abnormal form of microtubule associated protein tau, PHF-tau, is a major component of Alzheimer NFT. Kinases associated with NFT, especially those belonging to the family of proline-directed Ser/Thr kinases, are considered to be important for PHF-tau hyperphosphorylation. A potentially significant kinase is a Cdc2-related kinase, which is associated tightly with paired helical filaments, has a molecular weight of 33kDa and is different from other known Cdc2-related kinases. The possibility that some of the NFT-associated elements may play an active role in the pathogenesis of Alzheimer's disease was supported by recent studies, in which advanced glycated products and markers of oxidant stress were located in NFT. In addition, PHF-tau was found to be glycated, and in vitro glycated tau was capable of inducing oxidant stress. Further characterization of different components of NFT by biochemical and other approaches will be important for understanding the mechanisms involved in the supramolecular aggregation of PHF within NFT.

Alzheimer Disease↗

PubMedDate not supplied

Scanning electron microscopic study of invasiveness between normal and neoplastic cells and fibroblasts in monolayer culture.

Normal cells are non-invasive except for a few cell types such as leukocytes and macrophages, while neoplastic cells are active in both migration and invasion. In the present investigation, the confrontations of normal rat hepatocytes, lung macrophages and B16 melanoma cells with monolayers of fibroblasts grown on collagen gel have been studied. When monolayers of fibroblasts were confronted with melanoma cells, there was obvious retraction of the fibroblasts. When hepatocytes or macrophages were seeded onto monolayers of fibroblasts, infiltration always occurred at intercellular contacts and no retraction of fibroblasts was seen. Therefore it would appear that normal and neoplastic cells penetrate into monolayers of fibroblasts by different mechanisms.

Animals↗

PubMedDate not supplied

Actions of lectins from the mushroom Tricholoma mongolicum on macrophages, splenocytes and life-span in sarcoma-bearing mice.

Two lectins isolated from the mushroom Tricholoma mongolicum stimulated the production of nitrite ions by macrophages in normal and tumor-bearing mice. Both lectins exhibited negligible mitogenic activity toward T-cells or splenocytes from normal mice in vitro when compared with Con A. Similarly, T-cells from sarcoma-bearing mice treated with the lectins did not exhibit a mitogenic response different from that of the control. However, T-cells from normal lectin-treated mice demonstrated a reduced mitogenic response when compared with the control. In mice the growth of sarcoma 180 cells in the peritoneal cavity was inhibited and the life-span was prolonged by the two lectins.

Animals↗