Electrophoretic evaluation of the taxonomic status of two species of sea anemone

Puerto Rican populations of two species of sea anemones (Bunodosoma cavernata and B. granulifera) which had previously been considered one were assayed electrophoretically for enzymes encoded by 12 loci. The two species shared no common allozymes at 6 of the 12 loci. Genetic distance and identity values based on these allozymes were computed for the Puerto Rican populations and for B. cavernata from Florida and B. granulifera from Panama. The Puerto Rican populations of both species had much higher genetic identities for their geographically distant conspecifics than for each other. These results indicate that the two species are reproductively isolated and should be considered as separate valid species. Average heterozygosities are presented which are the first published for coelenterate species.     

Deadly liaisons: fatal attraction between CCN matricellular proteins and the tumor necrosis factor family of cytokines

Recent studies have revealed an unexpected synergism between two seemingly unrelated protein families: CCN matricellular proteins and the tumor necrosis factor (TNF) family of cytokines. CCN proteins are dynamically expressed at sites of injury repair and inflammation, where TNF cytokines are also expressed. Although TNFα is an apoptotic inducer in some cancer cells, it activates NFκB to promote survival and proliferation in normal cells, and its cytotoxicity requires inhibition of de novo protein synthesis or NFκB signaling. The presence of CCN1, CCN2, or CCN3 overrides this requirement and unmasks the apoptotic potential of TNFα, thus converting TNFα from a proliferation-promoting protein into an apoptotic inducer. These CCN proteins also enhance the cytotoxicity of other TNF cytokines, including LTα, FasL, and TRAIL. Mechanistically, CCNs function through integrin α₆β₁ and the heparan sulfate proteoglycan (HSPG) syndecan-4 to induce reactive oxygen species (ROS) accumulation, which is essential for apoptotic synergism. Mutant CCN1 proteins defective for binding α₆β₁-HSPGs are unable to induce ROS or apoptotic synergism with TNF cytokines. Further, knockin mice that express an α₆β₁-HSPG-binding defective CCN1 are blunted in TNFα- and Fas-mediated apoptosis, indicating that CCN1 is a physiologic regulator of these processes. These findings implicate CCN proteins as contextual regulators of the inflammatory response by dictating or enhancing the cytotoxicity of TNFα and related cytokines.     

Separation and Identification of the Polar Lipids of Chromatium Strain D

The polar lipids of the autotrophically grown, obligately anaerobic, photosynthetic bacterium Chromatium strain D were separated by paper chromatography. Four major phospholipids were identified: lysophosphatidylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin. In addition, three glycolipids were observed and characterized, namely, monoglucosyldiglyceride, which is found in other biological systems, and (mannosyl, glucosyl)-diglyceride and (dimannosyl, glucosyl)-diglyceride, which heretofore have not been observed in nature.     

Factors affecting biomass attachment during startup and operation of anaerobic fluidized beds

Three anaerobic fluidized bed reactors at 37 degrees C were utilized to observe the effects of startup and operational procedures on biomass attachment. Using a meat-based synthetic waste and stepped-loading regime, the influences of synthetic polymer addition and maintenance of anaerobiosis during startup were investigated. Subsequently, increasing bed expansions were applied to assess shear effects. Synthetic polymer addition enhanced biomass retention but did not improve process performance. Maintenance of a reduced environment ameliorated fluctuating process parameters during start up and aided biomass retention and substrate removal. A bed expansion of 5% was detrimental to biomass attachment and COD removal but system stability was maintained at expansions between 10% and 30%. Startup was achieved in 56 days. Anaerobiosis appeared to enhance the initial evolution of a stable, well-adapted microbial population, whereas polymer addition interfered with this. Moderate bed expansions had negligible effects on attachment and performance.     

Theophylline-induced protection in myoglobinuric acute renal failure: further characterization

We have reported previously that aminophylline has an ameliorating effect on the course and severity of glycerol-induced myoglobinuric acute renal failure in rats. Since aminophylline dissociates into theophylline in biological fluids and since theophylline is an adenosine receptor antagonist, we attributed the ameliorating effects to antagonism of the hemodynamic effects of endogenous adenosine. However, theophylline blocks tubuloglomerular feedback and produces natriuresis, and either of these effects might have accounted for the beneficial effects in acute renal failure. Therefore, this study was designed to further characterize the effects of theophylline in glycerol-induced acute renal failure in rats. Aminophylline had dose-dependent beneficial effects, as judged by the peak serum creatinine during the 3 days following induction of acute renal failure, by the number of animals with peak serum creatinine greater than 1 mg/dL, and by the mortality rate. Both furosemide and theophylline block tubuloglomerular feedback and produce natriuresis, but aminophylline had protective effects, whereas furosemide actually increased mortality, compared with aminophylline, following induction of myoglobinuric acute renal failure. Therefore, aminophylline's protective effects are independent of tubuloglomerular feedback and natriuresis. These results offer further support for the hypothesis that adenosine-induced hemodynamic changes play a pathogenic role in glycerol-induced acute renal failure in rats.     

Characterization of the cytochrome c oxidase in isolated and purified plasma membranes from the cyanobacterium Anacystis nidulans

Functionally intact plasma membranes were isolated from the cyanobacterium (blue-green alga) Anacystis nidulans through French pressure cell extrusion of lysozyme/EDTA-treated cells, separated from thylakoid membranes by discontinuous sucrose density gradient centrifugation, and purified by repeated recentrifugation. Origin and identity of the chlorophyll-free plasma membrane fraction were confirmed by labeling of intact cells with impermeant protein markers, [35S]diazobenzenesulfonate and fluorescamine, prior to membrane isolation. Rates of oxidation of reduced horse heart cytochrome c by purified plasma and thylakoid membranes were 90 and 2 nmol min-1 (mg of protein)-1, respectively. The cytochrome oxidase in isolated plasma membranes was identified as a copper-containing aa3-type enzyme from the properties of its redox-active and EDTA-resistant Cu2+ ESR signal, the characteristic inhibition profile, reduced minus oxidized difference spectra, carbon monoxide difference spectra, photoaction and photodissociation spectra of the CO-inhibited enzyme, and immunological cross-reaction of two subunits of the enzyme with antibodies against subunits I and II, and the holoenzyme, of Paracoccus denitrificans aa3-type cytochrome oxidase. The data presented are the first comprehensive evidence for the occurrence of aa3-type cytochrome oxidase in the plasma membrane of a cyanobacterium similar to the corresponding mitochondrial enzyme (EC 1.9.3.1).     

Identification of protein kinase C and its potential substrate in Entamoeba histolytica

1. Protein kinase C (PKC) activity has been identified in various strains of the human parasite, Entamoeba histolytica. 2. An amoebic protein of mol. wt 78,000 was recognized by polyclonal antibodies raised against the 82,000 mol. wt rat brain protein kinase C. 3. A partially purified PKC preparation from E. histolytica phosphorylated histone I in the presence of calcium, phospholipids and diacylglycerol, and specifically bound tritiated phorbol ester at an apparent KD of 9 nM. 4. A relocalization of the amoebic PKC activity from the cytosol to the membrane fraction was observed when trophozoites were actively phagocytising bacteria. Under these conditions, a labelled phosphoprotein of mol. wt 68,000 was identified. 5. Similar to what was found during macrophage activation, a myristoylated mol. wt 68,000 protein was detected in amoebae grown in the absence of bacteria, but not in amoebae which were active in phagocytosis.