Effect of ascorbic acid, sodium salicylate, and caffeine on the serum interferon level in response to viral infection

The ability of ascorbic acid, sodium salicylate, and caffeine to alter the circulating serum level of interferon was investigated in mice. The animals were singly injected subcutaneously with one of the compounds, 4-8 h later again singly injected intraperitoneally with poly I:C, and bled 6-8 h afterward. The sera from the mice were assayed for interferon titer by the use of the plaque inhibition method utilizing vesicular stomatitis virus. Ascorbic acid, sodium salicylate, and caffeine increased the serum level of interferon; however, the increase produced by sodium salicylate was dose-dependent, i.e. low doses increased interferon titers, high doses decreased the titers. Caffeine produced minimal increases in the interferon titer. These observations suggest that a potential prophylactic result may occur in virus infections from administration of the three compounds either singly or in combination at the proper concentration.

Age-related refractoriness of PHA-induced lymphocyte transformation. I. Comparable sensitivity of spleen cells from young and old mice to culture conditions

The decline in phytohemagglutinin (PHA) responsiveness of spleen cells from aged mice was studied in an effort to determine the nature of the depressed PHA reactivity. The reduced response of DNA synthesis (thymidine incorporation) to PHA stimulation could not be attributed to a decreased viability of spleen lymphocytes from old mice in in vitro culture conditions, to different PHA dose requirements, or to longer periods of culture time for old mouse spleen cells to reach maximal activity. Culture of cells for 24-48 h prior to addition of PHA gave patterns of thymidine incorporation similar to those of freshly prepared spleen cells. The elimination of red blood cells by a brief hypotonic shock significantly increased thymidine incorporation in spleen lymphocytes from both yound and old mice.

Symmetric and Asymmetric Mitosis and Cytokinesis in the Root Tip of Hydrocharis Morsus-Ranae L

In the roots of Hydrocharis morsus-ranae, certain cells of the protoderm divide asymmetrically to form a small, highly cytoplasmic trichoblast proximally, and a larger, more vacuolate epidermal cell distally. The former develops as a root hair without further division; the latter divides several times to form ordinary epidermal cells. During mitosis, presumed dictyosome vesicles and fragments or sections of reticulated or serrate sheets of ER, aligned with the spindle microtubules, were observed among the chromosomes as early as metaphase, suggesting that the portions of ER were involved in formation of the cell plate or in some other function in the equatorial region. A pre-prophase band of microtubules was not observed. Asymmetric divisions differ from symmetric ones in the skewed orientation of the metaphase plate, the formation of a curved, rather wavy cell wall and the slightly greater vacuolation of one daughter cell. Less difference in the ultrastructure of the daughter cells resulting from an asymmetric division was observed in this rather slowly growing material than in other examples previously described in the literature.