Adriamycin-induced inhibition of melanoma cell invasion is correlated with decreases in tumor cell motility and increases in focal contact formation.

Tumor cell adhesion to the extracellular matrix (ECM) is closely linked with tumor cell invasion and metastasis. In this study, we demonstrate that low levels of adriamycin, a widely used anticancer drug, can inhibit the invasion of highly metastatic K1735-M2 mouse melanoma cells in vitro through a reconstituted basement membrane extract. Adriamycin-induced inhibition of melanoma cell invasion occurred at levels of the drug (i.e. 1 ng/ml) that did not inhibit tumor cell growth, suggesting that the observed inhibition in tumor cell invasion was not due to the well-documented ability of adriamycin to interfere with DNA and/or RNA synthesis. Rather, these studies indicated that adriamycin-induced inhibition of melanoma cell invasion was accompanied by a corresponding decrease in the ability of adriamycin-treated tumor cells to migrate in response to several isolated ECM components including fibronectin, laminin and basement membrane (type IV) collagen. The decreased migration of adriamycin-treated tumor cells was not accompanied by a decrease in the adhesion or spreading of the adriamycin-treated cells on substrata coated with these ECM components. Instead, adriamycin-treated cells actually exhibited a slightly increased propensity (compared to untreated control cells) to adhere on fibronectin-, laminin-, and type IV collagen-coated substrata. Additionally, adriamycin treatment caused a dramatic increase in focal contact formation by these melanoma cells, as assessed by fluorescent microscopy of actin and vinculin. In addition to providing a useful model for which to study the molecular and cellular basis for focal contact formation, these results further emphasize the results of several other investigators that have suggested an important role for focal contacts in modulating tumor cell motility, invasion and metastasis.

Control of Epistylis on channel catfish in raceways.

An Epistylis outbreak occurred on channel catfish in raceways during two growing seasons. Bioassays of potential control chemicals were conducted. Based on the bioassay results, salt (NaC1) plus formalin and salt alone were the most effective treatment chemicals.

Effects of fixation, dehydration and staining on dimensions of myxosporidan.

The effects of fixation, dehydration and staining on the morphological dimensions of myxo- and microsporidan spores were tested. Seven fixatives, two dehydrants and five stains were tested. Ten % formalin produced the least shrinkage and provided the best cytological detail of fixed material in both types of spores. All fixatives caused shrinkage of myxosporidan spore length and polar capsule length. Spore capsule width and polar capsule width were unaffected by 10% formalin. Ethyl alcohol caused no significant change in spore width. Microsporidan spore length shrunk with all fixatives, but spore width was generally unaffected. Dehydration, with either isopropyl alcohol or acetone, produced additional, significant shrinkage. The influence of stains on spore size was negligible. Heidenhains iron hematoxylin followed by eosin, and Mallory's analine-blue collagen stain, effectively stained myxo- and microsporidan spores.

Geographical distribution and host-parasite relationships of Plistophora ovariae (Microsporida, Nosematidae) in Notemigonus crysoleucas.

Plistophora ovariae undergoes schizogony and sporogony in developing ova of the golden shiner. Destruction of the ova greatly reduces fecundity and causes spawning failures. The incidence and intensity of infection is described in 49 commercial fish farms from 12 states. The parasite was found in fish from 45 of 49 sources and in a farm pond and creek from Oklahoma. Overall incidence of infection was 48% of 2759 fish. No significant difference was found in the incidence of disease from fish propagated by either intensive or extensive culture methods. There was a significant difference in incidence of infection with host age. Incidence increased from 30% in age class 0 to 75% in age class 4. Intensity of infection decreased with age and varied with season; it was greatest in May and June. Thus, the maximum number of spores and infected ova occurred during the spawning season of the host. Infected fish were generally larger and heavier than uninfected fish. Reduced egg production (partial parasitic castration) allowed nutrients and energy to be used for faster growth.