Sporocarp δ15N and use of inorganic and organic nitrogen in vitro differ among host-specific suilloid fungi associated with high elevation five-needle pines

Widespread decline of whitebark and limber pines in the northern Rocky Mountains (USA) has created an imperative to understand functional diversity in their ectomycorrhizal associates. Because suilloid fungi are likely important in successful reestablishment of pines the nitrogen-related functional traits of 28 high-elevation suilloid isolates were examined. Radial growth, mass accumulation and mycelial density were measured for isolates on six different nitrogen sources. The δ¹⁵N values of suilloid sporocarps used as sources for pure cultures were compared against growth parameters to investigate a possible link between these N-related functional traits. Isolates grew poorly on nitrate and BSA and grew well on glutamine, alanyl-glutamine and ammonium phosphate, with somewhat slower growth on alanine. Isolates and species varied considerably in their growth response to different nitrogen sources. Effective use of nitrate and BSA was uncommon and associated with isolates with high inherent growth rates. Sporocarp δ¹⁵N was negatively correlated with relative growth on alanine of the corresponding isolates. Our results suggest strong similarities in N source use patterns of suilloid fungi of whitebark pine origin and those of another high-elevation five-needle stone pine, the Swiss stone pine.     

Minimizing outputs: treatment

Many methods are available for the treatment of industrial wastewaters. The pollutant concentrations from aquaculture facilities are often low, but occur in high flow rates. Consequently, much care must be taken to transfer suitable technology. Of the four main types of treatment unit processes, i.e. biological, chemical, mechanical and gravitational, the latter two types are most commonly employed in flow-through aquaculture facilities in Europe. This paper identifies the properties of the wastewater upon which the units operate, the efficiency of selected examples and their suitability for various applications. Relevant strategies are recommended. A combination of screening to remove suspended particles, followed by sedimentation to thicken the resulting sludge appears, at resent, to be the most appropriate primary treatment strategy for flow-through facilities. Various other secondary or even tertiary techniques can be employed to further treat tie main effluent. These can, however, prove prohibitively expensive in high flow situations and can produce negligible improvements in environmental protection.     

Primary rabbit kidney proximal tubule cell cultures maintain differentiated functions when cultured in a hormonally defined serum-free medium

Summary A primary rabbit kidney epithelial cell culture system has been developed which retains differentiated functions of the renal proximal tubule. In addition, the cells have a distinctive metabolism and spectrum of hormone responses. The primary cell were observed to retain in vitro a Na⁺-dependent sugar transport system (distinctive of the proximal segment of the nephron) and a Na⁺-dependent phosphate transport system. Both of these transport processes are localized on the apical membrane of proximal tubule cells in vivo. In addition, probenicid-sensitivep-aminohippurate (PAH) uptake was observed in basolateral membranes of the primary tubule cells, and the PAH uptake by these vesicles occurred at a rate that was very similar to that observed with membranes derived from the original tissue. Several other characteristics of the primary cells were examined, including hormone-sensitive cyclic AMP production and phosphoenolpyruvate carboxykinase (PEPCK) activity. Like the cells in vivo, the primary proximal tubule cells were observed to produce significant cyclic AMP in response to parathyroid hormone, but not in response to arginine vasopressin or salmon calcitonin. Significant PEPCK acivity was observed in the particulate fraction derived from a homogenate of primary rabbit kidney proximal tubule cells. This paper was presented at a Symposium on the Physiology and Toxicology of the Kidney In Vitro co-sponsored by The Society of Toxicology (SOT) and the Tissue Culture Association held at the 27th annual meeting of the SOT in Dallas, Texas in 1988. This work was supported by Grant 9 RO1 DK40286-07 from the National Institutes of Health, Bethesda, MD, and NIH Research Career Development Award 1 K04 CA 0088-01 to M.T.     

Behaviorally conditioned suppression of the immune response by antilymphocyte serum

Previous studies have shown that cyclophosphamide, a drug with a broad spectrum of cytotoxic activity and one that produces noxious gastrointestinal side effects, can elicit taste aversion conditioning when paired with a non-immunosuppressive oral stimulus (saccharin) resulting in immunosuppression after subsequent exposure to the paired stimulus (1). The study reported here indicates that rabbit anti-rat lymphocyte serum (ALS) which is selectively cytotoxic for lymphocytes and does not produce sensory side effects can similarly induce taste aversion conditioning of the immune response. Rats were exposed to oral saccharin paired with ALS injection. Upon subsequent reexposure to saccharin alone the immunosuppressive effects of ALS were reenlisted and the primary mixed lymphocyte culture response of conditioned rats to allogeneic lymphocytes was suppressed by 35% compared to controls. The demonstrated influence of psychologic factors on the immune response has far reaching implications, especially to human medicine, and their role in the course of disease and recovery in man demands further investigation.