Influenza virus-specific human cytotoxic T cell clones: Heterogeneity in antigenic specificity and restriction by class II MHC products

Human cytotoxic T lymphocytes specific for A/JAP/57 (H2N2) influenza virus were cloned from in vitro stimulations of peripheral blood lymphocytes. Analysis of the viral specificity in cytotoxic function revealed one clone that killed all type A influenza-infected targets, another clone that was specific for the hemagglutinin subtype of the immunizing influenza virus, and the third clone that demonstrated cytotoxicity restricted to the hemagglutinin of A/JAP/57 and A/JAP/62 (H2N2) and not other type A influenza strains with the H2N2 subtypes. The phenotype of these three clones was Leu 2^?, Leu 3⁺, Leu 4⁺; MHC restriction of their cytotoxic function was mapped to HLA-DR by a panel of target cells as well as by inhibition of cytotoxicity with monoclonal antibodies. Proliferation of these clones, examined in a tritiated thymidine incorporation assay, was found to be driven by antigen in the absence of exogenous lymphokines. For all three clones antigen-dependent production and secretion of lymphokines with IL-2 activity was demonstrated. The antigen specificity of proliferation and factor production was shown to be identical to the pattern that each clone revealed in its cytotoxic function.     

Morphogenesis of bone ornamentation in extant and extinct crocodilians

Summary Histological study of bone in the skull and osteoscutes of extant and extinct Crocodylia reveals that the skeletal ornamentation of crocodiles is caused by a process of differential, superficial resorption of bone. A partial reconstruction follows the resorption, and several resorption-reconstruction cycles are necessary to suit pit dimensions to overall bone growth. Bone ornamentation is a dynamic structure during ontogeny: the shape and the location of a given pit or groove vary in accordance with the instantaneous regional trends of skeletal growth. This supports the contention that bone oranmentation can be used as a reliable indicator of regional bone growth trends.     

Partial Purification of Nuclear Protein Kinase from Small Dense Nuclei of Mouse Brain and the Effect of Chronic Morphine Treatment

Abstract: To deduce whether or not the nuclear protein kinase activity may be responsible for the change in phosphorylation of chromatin proteins during morphine tolerance-dependence, the nuclear protein kinases from small dense nuclei of mouse brain have been partially purified by ammonium sulfate fractionation and phosphocellulose column chromatography. Two peaks of cyclic AMP-independent nuclear protein kinase activity are eluted from the phosphocellulose column by a linear NaCl gradient. During morphine tolerance-dependence, the specific activity of peak I, but not of peak 11, is increased significantly relative to placebo controls. This increase in nuclear protein kinase activity may partially account for the elevated chromatin protein phosphorylation in small dense nuclei of mouse brain seen during morphine tolerance-dependence.     

Control of sporulation in yeast: SAD1-a mating-type specific, unstable alteration that uncouples sporulation from mating-type control

Summary Normally, in order to sporulate, a diploid yeast cell must be heterozygous (MAT a/MAT) at the mating-type locus. In a new mutant, this requirement is circumvented by SAD1. This alteration is mating-type specific; it allows sporulation of MAT/ MAT. MAT/mat a-1, and MAT/mat-2 diploid cells, but not MAT a/MAT a or MAT a/0 (monosomic) strains. Other than acquiring the ability to sporulate, SAD1 cells behave as wild-type MAT/MAT strains; they exhibit medial budding, normal mating factor production and response and mate with normal mating efficiencies and kinetics. The segregation of SAD1 is often bizarre; for example, MAT/MAT strains which were constructed to be heterozygous SAD1/+ often segregate 4 SAD1:0+progeny and strains which were constructed to be homozygous SAD1/ SAD1 sometimes segregated 1 SAD1:3+progeny. The genetic analyses of SAD1 suggest that it is dominant and is located 30 cM from MAT on chromosome III.     

Photosynthetic parameters of the entire euphotic phytoplankton of the Bransfield Strait,Summer 1985

Summary The photosynthetic parameters ^B, P^Bm, and I_k were derived from the relationship between primary productivity (P) and irradiance (I) for mixed samples, each mixture consisting of seven samples of phytoplankton collected from different depths, between the surface and 35 m at eight different sampling stations in the Bransfield Strait in January–February 1985. The ^B values obtained in this study were considerably higher than those generally reported for phytoplankton from a single depth in polar waters. These higher values may be attributed to the fact that most of the phytoplankton in the mixed samples came from depths with limiting irradiances, which had a greater yield than surface phytoplankton. The P^Bm value we obtained was lower than that reported by other authors, possibly because the mixed sample phytoplankton have saturation points at low light intensity. Our I_K values confirmed the ability of phytoplankton in these latitudes to reach maximum photosynthesis rates with low densities of photonic flux. When treated as independent parameters, the ^B and P _m ^B values showed a significant correlation for each sampling station. The efficiency of the entire euphotic phytoplankton of the water column, estimated as ₀ ^eu Pdz/ ₀ ^eu Bdz or Integral Assimilation Number (IAN), showed a predictable significant correlation with the ^B values calculated from the entire euphotic phytoplankton. Areas with high surface biomass were as productive as those with low surface phytoplankton biomass. Areas with low surface phytoplankton biomass showed higher ^B values than areas with high surface biomass, which suggests, that, the ^B values for the entire photosynthesizing phytoplankton in the water column may have greater predictive value than the ^B values for the phytoplankton from a single depth. This finding should be taken into account when satellites are used for studying marine production processes, especially in areas with very different euphotic depths and surface phytoplankton concentrations.This research was made possible by grants from Chilean Antarctic Institute (INACH); Chilean National Commission for Science and Technology (FONDECYT 0854-1989); and University of Chile (DTI N-2449-88)     

Nutritional copper deficiency does not affect sponge granuloma formation in the rat

Sponge granuloma formation was compared in copper-deficient and copper-sufficient rats following feeding of respective diets for 20, 40, or 60 d. Body weight, total blood hemoglobin, and activities of ceruloplasmin and Cu, Zn-superoxide dismutase in plasma were monitored to ascertain copper deficiency. Mean granuloma weights (mg +/- SEM) in copper-deficient and copper-sufficient groups of rats, respectively, were as follows: 37 +/- 2 and 38 +/- 2 after 20 d, 22 +/- 2 and 23 +/- 2 after 40 d, and 19 +/- 1 and 21 +/- 1 after 60 d on respective diets. Thus, nutritional copper deficiency did not have an effect on sponge granuloma formation in the rat.     

Cyclic AMP-stimulated protein kinase activity in rabbit peripheral myelin

Cyclic AMP-sensitive protein kinase activity has been found in suspensions of purified rabbit peripheral myelin. The enzyme phosphorylated the P₀, Y, X, P₁, and P₂ myelin proteins. Kinase activity, which was maximal at physiological pH, 2.5 mM Mg²⁺, and 2 M cAMP, was stimulated three-fold over basal levels by cyclic AMP. Addition of calcium or EGTA had no effect on the enzyme activity in the presence or absence of cyclic AMP. Cyclic GMP also did not stimulated endogenous or exogenous protein phosphorylation. Theophylline, an inhibitor of 3,5-cyclic nucleotide phosphodiesterase activity, increased protein kinase activity in the presence of cyclic AMP. These data show that PNS myelin proteins can be phosphorylated in situ by a protein kinase system whose activity is stimulated selectively by cyclic AMP.