IL-1 secretion by macrophages. Enhancement of IL-1 secretion and processing by calcium ionophores

In the present study we have demonstrated that the murine IL-1 alpha precursor lacks a cleavable signal sequence and does not undergo cotranslational translocation across microsomal membranes in vitro. Culture supernatants of the murine macrophage cell line, P388D, or from normal peritoneal macrophages collected within 0.5 to 3 h after stimulation contained the 33,000 m.w. precursor as the predominant form of IL-1 alpha. Over an 18-h period, the level of low m.w. IL-1 alpha increased as the secreted precursor was processed by extracellular and/or cell surface-associated proteolytic enzymes. The calcium ionophores A23187 and ionomycin were found to dramatically enhance the release and processing of murine and human IL-1. The rapid release of IL-1 in response to a change in the intracellular level of calcium does not appear to be caused by release of a membrane-bound form of the protein, nor is there evidence that IL-1 is packaged and released from cytoskeletal associated secretory granules. In marked contrast, calcium ionophores do not induce secretion of IL-1 from a nonmacrophage cell line that synthesizes but does not normally secrete IL-1. Our results suggest that activated macrophages possess a novel processing independent, possibly calcium-dependent, mechanism that allows for the release of the precursor forms of IL-1 alpha and IL-1 beta.     

Identification of IL-1 receptors on human monocytes

The expression and functional analysis of IL-1 beta R on human monocytes were investigated. Binding of 125I-IL-1 to human monocytes was found to be specific and saturable. Scatchard plot analysis revealed a single class of receptors with a binding constant of 600 pM and a receptor density of approximately 100 binding sites per cell. At 37 degrees C 54% of the labeled ligand was internalized over 2 h of incubation. Addition of 0.2% sodium azide to the cells reduced ligand internalization to 9% of total bound. Cross-linking studies revealed that the IL-1R in human monocytes had a Mr of 80 kDa. The addition of IL-1 to monocytes caused changes in membrane Ag expression as assessed by flow cytometric analysis. The results of this study identify IL-1 receptors on monocytes and suggest that IL-1 may act as an effector molecule for monocytes by enhancing expression of Ag correlated with cell differentiation and immune function.     

Tracing paternal ancestry in mice, using the Y-linked, sex-determining locus, Sry

The molecular evolution of mammalian Y-linked DNA sequences is of special interest because of their unique mode of inheritance: most Y- linked sequences are clonally inherited from father to son. Here we investigate the use of Y-linked sequences for phylogenetic inference. We describe a comparative analysis of a 515-bp region from the male sex- determining locus, Sry, in 22 murine rodents (subfamily Murinae, family Muridae), including representatives from nine species of Mus, and from two additional murine genera--Mastomys and Hylomyscus. Percent sequence divergence was < 0.01% for comparisons between populations within a species and was 0.19%-8.16% for comparisons between species. Our phylogenetic analysis of 12 murine taxa resulted in a single most- parsimonius tree that is highly concordant with phylogenies based on mitochondrial DNA and allozymes. A total evidence tree based on the combined data from Sry, mitochondrial DNA, and allozymes supports (1) the monophyly of the subgenus Mus, (2) its division into a Palearctic group (M. musculus, M. domesticus, M. spicilegus, M. Macedonicus, and M. spretus) and an Oriental group (M. cookii++, M. cervicolor, and M. caroli), and (3) sister-group relationships between M. spicilegus and M. macedonicus and between M. cookii and M. cervicolor. We argue that Y- chromosome DNA sequences represent a valuable new source of characters for phylogenetic inference.      

Effect of stocking density on growth and survival of Clarias batrachus (Linn.) larvae and fry during hatchery rearing

Experiments were conducted to determine optimum stocking density for Clarias batrachus larvae and fry during hatchery rearing. The increase in stocking density decreased the total weight, specific growth rate (SGR) and percent weight gain of Clarias larvae during a 13‐day experiment. Survival rate was highest at a stocking density of 1000 m^?2 and lowest at 5000 m^?2. Stocking density did not influence the total biomass production of larvae. Clarias batrachus fry performance was studied during a 28‐day hatchery rearing experiment whereby fry stocked at a density of 100 m^?2 attained the highest total body weight (P < 0.05). The survival rate greatly declined to 59–61% by a density increase to 300 m^?2 and above. Stocking density influenced growth and survival of C. batrachus larvae and fry during hatchery rearing. The best performance was obtained when larvae were stocked at 2000 m^?2; survival was highest with C. batrachus fry stocked at 200 m^?2.     

The dialectic between globalization and localization: Economic restructuring,women and strategies of cultural reproduction

Dialectical Anthropology -     

Sister chromatid exchange and chromosome aberrations induced by curcumin and tartrazine on mammalian cells in vivo

Sister chromatid exchanges (SCEs) and chromosomal aberrations induced by curcumin (a natural dye) and tartrazine (a synthetic dye) were studied on bone marrow cells of mice and rats following acute and chronic exposure via the diet. Except for two low concentrations in the curcumin and one low concentration in the tartrazine treated series a significant increase in SCEs was observed in all the concentrations of the two dyes tested. Except for two high concentrations during the 9 months treatment no significant increase in chromosomal aberrations was observed in the curcumin treated series, whereas tartrazine showed a significant increase in chromosomal aberrations in some of the higher concentrations in all the series tested. The results indicate that tartrazine is more clastogenic than curcumin.     

Behavior,net reproduction,longevity, and mummy-stage survival ofAphidius matricariae [Hym. Aphidiidae]

The courtship, mating and ovipositional behavior ofA. matricariae Haliday were studied. UsingMyzus persicae (Sulzer) as the host, the production of progeny per female parasite and survival from mummy stage to the adult were studied at constant temperatures of 10°, 12.8°, 15.6°, 18.3°, 21°, 24°, 26.7°, 29.5° and 32°C. The longevity of male and female parasites was determined at temperatures of 7°, 10°, 15.6°, 21°, 26.7°, 29.5° and 32°C. The greatest number of progeny (392) was produced at 21°C. The optimal temperatures for production of progeny and survival of the parasites during the mummy stage were from 12.8°C to 21°C. The longevity of male and female adult parasites decreased as temperatures increased and male parasites lived significantly (P<0.05) longer than females at 10° and 15.6°C.     

Shapes of proteins L1, L9, L25, and L30 from the 50S subunit of the Escherichia coli ribosome, determined by hydrodynamic studies.

Proteins L1, L9, L25, and L30, purified by a nondenaturing method from the 50S ribosomal subunit of Escherichia coli A19, have been characterized. The four proteins were studied under conditions which resemble those used for reconstitution experiments. These proteins have S020,W values of 2.0 S, 1.8 S, 1.8 S, and 1.0 S and D20,W values of 8.4 X 10(-7), 9.0 X 10(-7), 14.0 X 10(-7), and 15.0 X 10(-7) cm2/S. Apparent specific volumes at 20 degrees C are 0.738, 0.733, 0.700, and 0.735 mL/g for the four proteins. The respective molecular weights determined by sedimentation equilibrium are 25 000, 17 300, 12 000, and 6500. The intrinsic viscosity values for the four proteins are 4.0, 5.5, 3.6, and 3.2 mL/g. From these hydrodynamic parameters L1 and L9 appear to have globular or at most only slightly elongated shapes, whereas L25 and L30 appear to be definitely globular.