Chemiluminescence associated with phagocytosis of foreign particles in rabbit alveolar macrophages

Rabbit alveolar macrophages exhibit a chemiluminescent response which is associated with phagocytosis of zymosan and polystyrene-butadiene particles. The chemiluminescence reaches a peak in 15 to 25 minutes and then gradually diminishes over the next 1 to 3 hours. During the time of maximal light emission there appears to be no actual uptake of particles, but the response is dependent upon the particle concentration. The metabolic inhibitor, DNP (2,4-dinitrophenol), causes a rapid inhibition of the chemiluminescent response. The addition of ATP to the medium prior to exposure of the cells to particles causes the chemiluminescent response to be greatly diminished, i.e., 0.3mM ATP virtually abolishes the response. These experiments suggest that some metabolic response of the cell to phagocytosis is responsible for the chemiluminescence.     

Alteration of the Pathogenicity of Pasteurella pneumotropica for the Murine Lung Caused by Changes in Pulmonary Antibacterial Activity

Pasteurella pneumotropica is a potential pulmonary pathogen in mice. In healthy animals, this organism was killed rapidly by the normal function of the intrapulmonary phagocytic defense mechanisms. Impairment of this bactericidal activity by the acute renal failure of nephrectomy resulted in multiplication of the Pasteurella in the lung, both when the animals were nephrectomized first and then infected, and when the animals were infected first and nephrectomized several hours after the infection. The study demonstrates that the pathogenicity of the Pasteurella organisms is governed by the functional state of these pulmonary antibacterial mechanisms.     

Dietary vitamin E and the response of rainbow trout, Oncorhynchus mykiss (Walbaum), to infection with Yersinia ruckeri

Rainbow trout fed diets containing 7, 86 or 806 mg vitamin E kg⁻¹ for 22 weeks were exposed to virulent Yersinia ruckeri by bath or injection. Mortalities were always least among those fed the highest concentration of vitamin E but serum antibody production was not affected by vitamin E levels.     

Role of plasminogen, plasmin, and plasminogen activators in the migration of fibroblasts into plasma clots

Human diploid fibroblasts were seeded onto or into plasma clots and different aspects of cell adhesion and migration were measured. The roles of plasminogen activators and plasmin were studied by either the removal of plasminogen from plasma prior to clotting or by the addition of 10 mM epsilon-aminocaproic acid, which brings about an inhibition of plasmin in this system. When cells were seeded onto the surface of plasma clots, rates of attachment, spreading, and migration were unaffected by plasminogen depletion or plasmin inhibition. In contrast, when cells were seeded into plasma clots, then, although the rates of cells spreading were unaffected, cell migration was abolished by plasminogen depletion or by plasmin inhibition. When cells were seeded onto the surface of plasma clots and the rate of migration into the clots was measured, there was an absolute requirement for plasmin activity; while fibroblasts migrated rapidly into the fibrin lattice of control clots, in the case of plasminogen-depleted clots, cells failed to penetrate the lattice. Focussing through a plasma clot revealed that fibroblasts do not migrate through the fibrin lattice but instead, localized areas of fibrinolysis are generated and cells migrate over the surface of the area of lysis.     

Crystallization and preliminary X-ray and optical spectroscopic characterization of the photochemical reaction center from Rhodobacter sphaeroides strain 2.4.1

The photochemical reaction center from Rhodobacter sphaeroides 2.4.1 has been crystallized. The crystals were obtained in a solution of beta-octylglucoside by the vapor diffusion technique using polyethylene glycol 4000 as the precipitant at 22 degrees C. The orthorhombic crystals (space group P2(1)2(1)2(1)) have cell constants a = 142.5 A, b = 136.1 A, c = 78.5 A, and diffract to 3.7 A. The crystals display pronounced linear dichroism in the carotenoid absorption spectral region.     

The effect of monofunctional or difunctional platinum adducts and of various other associated DNA damage on the expression of transfected DNA in mammalian cell lines sensitive or resistant to difunctional agents

The effects of introducing various DNA damage into pSV2gpt DNA on the subsequent expression of xanthine guanine phosphoribosyltransferase (XGPRT), after its transfection into two Walker 256 cell lines, one which is inherently sensitive only to difunctional agents while the other shows a normal sensitivity, have been examined. Both the sensitive (WS) and the relatively resistant (WR) cell lines were shown to be equally capable of both ligation of DNA double-strand breaks (although the efficiency varied with the actual site of the break) introduced into pSV2gpt and homologous recombination of pSV2gpt fragments (recombination events are thought to be important in the repair of DNA-DNA interstrand crosslinks). Reacting the plasmid with either the difunctional platinum compound, Cisplatin, or the monofunctional reacting Pt(Dien) caused a dose-dependent decrease in the subsequent expression of XGPRT. This decrease was about the same with either agent in either cell line when expressed as a function of dose of drug. However, when the actual binding of platinum to DNA by these compounds was measured, a large difference (due to the higher specific binding of Pt(Dien) to DNA) in the effects of the difunctional, as opposed to the monofunctional agent, was apparent and this was a reflection of the relative cytotoxicities of these compounds towards mammalian cells. Although at doses of Cisplatin equitoxic to WS and WR cells 20-fold less Pt is bound to the DNA of WS cells, no significant difference was seen on the expression of pSV2gpt, reacted with this agent, between WS or WR cells. Based upon a knowledge of the proportions of adducts formed in DNA reacted with Cisplatin, the lesion that inactivates expression of XGPRT was probably the intrastrand crosslink and it was calculated that due to the size of the plasmid, the interstrand crosslink was unlikely to be present at these inactivating doses. It is suggested that the inherent sensitivity of WS cells only to difunctional agents is due to their response to such relatively rare lesions such as a DNA-DNA interstrand crosslink.     

Production of butanol by Clostridium puniceum in batch and continuous culture

Summary The pink-pigmented, amylolytic and pectinolytic bacterium Clostridium puniceum in anaerobic batch culture at pH 5.5 and 25–30°C produced butan-1-ol as the major product of fermentation of glucose or starch. The alcohol was formed throughout the exponential phase of growth and surprisingly little acetone was simultaneously produced. Furthermore, acetic and butyric acids were only accumulated in low concentrations, and under optimal conditions were completely re-utilised before the fermentation ceased. Thus, in a minimal medium containing 4% w/v glucose as sole source of carbon and energy, after 65 h at 25°C, pH 5.5 all of the glucose had been consumed to yield (g product/100 g glucose utilised) butanol 32, acetone 3 and ethanol 2. Butanol was again the major product of glucose fermentation during phosphate-limited chemostat culture wherein, although the organism eventually lost its capacity to sporulate and to synthesize granulose, production of butanol continued for at least 100 volume changes. Under no growth condition was the organism capable of producing more than 13.3 g l^-1 of butanol. At pH 5.5, growth on pectin was slow and yielded a markedly lesser biomass concentration than when growth was on glucose or starch; acetic acid was the major fermentation product with lower concentrations of methanol, acetone, butanol and butyric acid. At pH 7, growth on all substrates produced virtually no solvents but high concentrations of both acetic and butyric acids.     

Antibodies to pollen exines

A polyclonal antiserum and monoclonal antibodies have been prepared to purified pollen exines of Calocedrus decurrens Florin. The location of the antigen is in the exine, as shown by light-and electron-microscopic immunocytochemistry. The greatest reduction in antibody binding follows treatment of the exine with chemicals known to alter sporopollenin. These results provide evidence that sporopollenin is antigenic. Exines of ten species of gymnosperms and angiosperms also bound the polyclonal antiserum, indicating similarity of sporopollenin structure.