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Research seeking to explain intraspecific variations in plant phenolics has focused on two general paradigms, the resource availability (carbon/nutrient balance) and induced-defense models. We experimentally tested both hypotheses to explain changes in phlorotannin concentrations in the brown alga Fucus vesiculosus. Fucus was collected monthly from two estuarine sites (Cape Cod, Massachusetts, USA) differing in nitrogen availability, and analyzed for polyphenolic levels and tissue-nitrogen concentrations. In situ nutrient enrichment experiments were conducted to measure changes in polyphenolic levels related to N availability. Simulated grazing experiments examined the possibility of induced increases in polyphenolic concentrations in Fucus vesiculosus. Paired choice ex- periments conducted in the laboratory examined feeding selectivity by the snail Littorina littorea for either Fucus population. Field measurements and experiments revealed temporal and site-related changes in tissue constituents. Polyphenolic concentrations were consistently, sometimes two times, higher in Fucus vesiculosus from the low-N site compared with algae from the high-N site; tissue-N content was higher in the population from the high-N site. For both populations, tissue N was inversely correlated with polyphenolic concentrations. Only Fucus from the low-N site showed a significant reduction in polyphenolic concentrations under experi- mental enrichment. Regression analysis revealed a significant inverse relationship (R2 = 0.71) between phenolic concentrations and growth rates for Fucus at the high-N, but not the low-N site. This suggests a growth cost associated with phlorotannin production for this phenolic-poor population due, perhaps, to C-limited growth. Phlorotannin concentra- tions increased significantly in clipped Fucus at the low-N site in two of three simulated grazing experiments, indicating an inducible response. We did not find a significant in- ducible response for the high-N, phenolic-poor population, and our choice experiments revealed a clear preference for this population by Littorina littorea. Our results offer support for both the induced-defense and carbon/nutrient balance hypotheses as explanation for variations in phlorotannin concentrations in Fucus vesiculosus. We suggest that within- species variation in polyphenolics is due to a complex interaction of environmental (nutrient availability, irradiance levels) and defense-related (grazing activity) factors.

Understanding how lung immunity develops against pulmonary pathogens should lead to more rational approaches in vaccine design and to the use of recombinant cytokines in lung disease. T lymphocytes are central to the development of effective immune responses; therefore, understanding how lung immunity develops will require a study of how and where T cells respond to respiratory antigens. Our laboratory has helped define the phenotype and function of lung dendritic cells, which likely play an essential role in stimulating naive T cells to respond to antigens. We found that both interstitial and alveolar macrophages can regulate the function of these cells, the former to enhance activity, the latter to suppress. In addition, we developed a murine pulmonary infection model using the fungus, Cryptococcus neoformans, in which T-cell-mediated immunity is essential for effective host clearance of the organism. The role of T cells in this model is to recruit and activate effector cells to resolve the lung infection; both CD4 and CD8 T-cell subsets are required for optimal effector cell recruitment. These studies are summarized as examples of current approaches to understanding pulmonary immunity.

The publication at this time of the result of our endeavors to cultivate an organism from the tissues of patients with Hodgkin's disease is occasioned by the publication by Negri and Mieremet 1 of the successful cultivation from two cases of Hodgkin's disease of a diphtheroid organism which they designate as the Corynebacterium granulomatis maligni . While Hodgkin's disease, or malignant granuloma of the lymphatic apparatus, has of late years come to be generally regarded as of infectious nature, the etiological agent has remained undetermined. The work in this country of Reed 2 and of Longcope 3 showed definitely that the condition was independent of tuberculosis, and that the theory supported by Sternberg 4 that it was a manifestation of the activity of the tubercle bacillus could not be maintained. In 1900 Fraenkel and Much 5 reported that by treating Hodgkin's nodes with a strong alkalin solution of sodium hypochlorid

Pure cultures of diphtheroid organisms apparently identical with or closely related to the Bacillus hodgkini have recently been obtained by us from two spleens removed surgically in the treatment of splenic anemia. Case 1 was under the care of Dr. J. J. Bellin of Green Bay, Wis., who kindly submitted blood-smears for examination before operation and sent the spleen immediately after its removal. The spleen was carefully sterilized externally by boiling before cultures were made from its interior. Case 2 was a patient in the Milwaukee County Hospital, where the blood was studied before and after splenectomy and where part of the bacteriologic and experimental observations were made. Histologic studies of the two spleens confirmed the clinical diagnosis of splenic anemia or the early stage of Banti's disease. Inoculation of dogs and rabbits was made with cultures of the organism obtained from Case 2 and with a culture obtained from

In this summary of our clinical experience in treating sixty-three cases of Hodgkin's disease of certain diagnosis over a period of eight years, we shall exclude, so far as practicable, hypotheses and technical details. We offer an interpretation of the effects of our therapy that is to some extent both incomplete and unsatisfactory. Many of our patients began treatment comparatively recently, and approximate accuracy in the estimation of results depends on a series of well controlled observations extending over a period of at least five years. On the other hand, this is the largest series of cases reported from one group of observers, the only one that has been followed at frequent intervals by coordinated workers, consecutive records thus being obtained of variation in the blood picture, general physical condition and roentgenographic evidence. These observations, so far as possible, have been made independently in an effort to eliminate bias. Pending

In a preliminary note recently published,1we reported that by repeated injection of the diphtheroid organism cultivated by us from cases of Hodgkin's disease, there had been produced in monkeys lesions of the lymphnodes showing all the essential features of early Hodgkin's disease in man. Up to that time we had been unable to demonstrate that the organism could survive in the monkey for any great length of time, and therefore we felt that we could not assert that we had produced Hodgkin's disease in the monkey, or that we had even demonstrated any great pathogenicity of the diphtheroid organism for that species. Since making that report, however, the course of our experimental work has demonstrated fully the pathogenicity of the culture we were using, and has further shown that the virulence of the organism to the monkey may easily be increased even to the point of producing death

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