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A novel cyclopentenedione, asterredione (1), two new terrecyclic acid A derivatives, (+)-5(6)-dihydro-6-methoxyterrecyclic acid A (2) and (+)-5(6)-dihydro-6-hydroxyterrecyclic acid A (3), and five known compounds, (+)-terrecyclic acid A (4), (−)-quadrone (5), betulinan A (6), asterriquinone D (7), and asterriquinone C-1 (8), were isolated from Aspergillus terreus occurring in the rhizosphere of Opuntia versicolor, using bioassay-guided fractionation. Acid-catalyzed reaction of 2 under mild conditions afforded 4, whereas under harsh conditions 2 yielded 5 and (−)-isoquadrone (9). Catalytic hydrogenation and methylation of 4 afforded 5(6)-dihydro-terrecyclic acid A (10) and (+)-terrecyclic acid A methyl ester (11), respectively. The structures of 1−11 were elucidated by spectroscopic methods. All compounds were evaluated for cytotoxicity in a panel of three sentinel cancer cell lines, NCI-H460 (non-small cell lung cancer), MCF-7 (breast cancer), and SF-268 (CNS glioma), and were found to be moderately active. Cell cycle analysis of 2, 4, and 5 using the NCI-H460 cell line indicated that 4 is capable of disrupting the cell cycle through an apparent arrest to progression at the G1 and G2/M phases in this p53 competent cell line. A pathway for the biosynthetic origin of asterredione (1) from asterriquinone D (7) is proposed.

We have measured the in vivo protein turnover for the major calcium regulatory proteins of the sarcoplasmic reticulum from the skeletal muscle of young adult (7 months) and aged (28 months) Fischer 344 rats. From the time course of the incorporation and decay of protein-associated radioactivity after a pulse injection of [14C]leucine and correcting for leucine reutilization, in young rats, the apparent half-lives for calsequestrin, the 53-kDa glycoprotein, and ryanodine receptor are 5.4 +/- 0.4, 6.3 +/- 1.3, and 8.3 +/- 1.3 days, respectively. A half-life of 14.5 +/- 2.5 days was estimated for the Ca-ATPase isolated from young muscle. Differences in protein turnover associated with aging were determined using sequential injection of two different isotopic labels ([14C]leucine and [3H]leucine) to provide an estimate of protein synthesis and degradation within the same animal. The Ca-ATPase and ryanodine receptor isolated from aged muscle exhibits 27 +/- 5% and 25 +/- 3% slower protein turnover, respectively, relative to that from young muscle. In contrast, the 53-kDa glycoprotein exhibits a 25 +/- 5% more rapid turnover in aged SR, while calsequestrin exhibits no age-dependent alteration in turnover. Statistical analysis comparing the sensitivity of various methods for discriminating different rates of protein turnover validates the approach used in this study and demonstrates that the use of two isotopic labels provides at least a 6-fold more sensitive means to detect age-related differences in protein turnover relative to other methods.

Spin-trapping with 5,5-dimethyl-1-pyrroline 1-oxide (DMPO) was used to demonstrate that 3-nitrotyrosine (nitrotyrosine) promotes the formation of substantial amounts of reactive oxygen species (O2^•- and ^•OH), when incubated with NAD(H)−cytochrome c reductase and a corresponding electron donor. Spin adduct formation is strongly inhibited by the presence of superoxide dismutase (SOD); spin adduct formation requires aerobic conditions. Nitration of leucine enkephalin, a tyrosine-containing pentapeptide, results in a similar generation of O2^•- and ^•OH species. Both nitrotyrosine and nitrated leucine enkephalin stimulate acetylated ferricytochrome c reduction in the presence of NAD(H)−cytochrome c reductase with typical Michaelis−Menten kinetics and Km's of 104 ± 14 and 0.78 ± 0.11 μM, respectively. No stimulation of acetylated ferricytochrome c reduction is observed in the presence of SOD. Catalase and the metal chelators DTPA and deferoxamine mesylate do not influence observed stimulation of acetylated ferricytochrome c reduction by nitrotyrosine. Nitration of two tyrosines (of four) within the sequence of the 6.5-kDa globular protein bovine pancreas trypsin inhibitor (BPTI) fails to stimulate O2^•- generation implying steric restrictions for BPTI−reductase interactions. However, nitrated BPTI subjected to trypsin digestion stimulated reduction of acetylated ferricytochrome c. These results suggest that, as with other nitroaromatic compounds, nitrotyrosine may be enzymatically reduced to the corresponding nitro anion radical (ArNO2^•-) which is then oxidized by molecular oxygen to yield O2^•- and regenerate ArNO2. Thus, once formed in vivo, nitrotyrosine may act to promote oxidative stress by means of repetitive redox cycling.

We have developed a quantitative and relatively model-independent measure of lipid fluidity using EPR and have applied this method to compare the temperature dependence of lipid hydrocarbon chain fluidity, overall protein rotational mobility, and the calcium-dependent enzymatic activity of the Ca-ATPase in sarcoplasmic reticulum. We define membrane lipid fluidity to be T/eta, where eta is the viscosity of a long chain hydrocarbon reference solvent in which a fatty acid spin label gives the same EPR spectrum (quantitated by the order parameter S) as observed for the same probe in the membrane. This measure is independent of the reference solvent used as long as the spectral line shapes in the membrane and the solvent match precisely, indicating that the same type of anisotropic probe motion occurs in the two systems. We argue that this empirical measurement of fluidity, defined in analogy to the macroscopic fluidity (T/eta) of a bulk solvent, should be more directly related to protein rotational mobility (and thus to protein function) than are more conventional measures of fluidity, such as the rate or amplitude of rotational motion of the lipid hydrocarbon chains themselves. This new definition thus offers a fluidity measure that is more directly relevant to the protein's behavior. The direct relationship between this measure of membrane fluidity and protein rotational mobility is supported by measurements in sarcoplasmic reticulum. The overall rotational motion of the spin-labeled Ca-ATPase protein was measured by saturation-transfer EPR. The Arrhenius activation energy for protein rotational mobility (11-12 kcal/mol/degree) agrees well with the activation energy for lipid fluidity, if defined as in this study, but not if more conventional definitions of lipid fluidity are used. This agreement, which extends over the entire temperature range from 0 to 40 degrees C, suggests that protein mobility depends directly on lipid fluidity in this system, as predicted from hydrodynamic theory. The same activation energy is observed for the calcium-dependent ATPase activity under physiological conditions, suggesting that protein rotational mobility (dependent on lipid fluidity) is involved in the rate-limiting step of active calcium transport.

This DataWatch examines an outpatient capitated payment system, in the state of Oregon, designed to enhance community services for persons with chronic mental illness who had repeatedly been hospitalized involuntarily. Special state funds and Medicaid dollars were used to pay providers prospectively on a risk-adjusted basis for the delivery of outpatient mental health services. During the three-year study period clients were able to be discharged from the state hospital. Although the data are not straightforward, capitated clients' use of the state mental hospital seems to have declined somewhat more than that of comparison subjects. Outpatient service use was modest and appeared to have little relationship to a client's level of illness severity. Indeed, it was not possible to predict prospectively these clients' outpatient mental health services expenditures.

The phenotypes of seed progeny (R2generation) of Oryza sativaL. cv. Taipei 309, which carried the neomycin phosphotransferase II (nptII) gene, were compared with those of non-transformed, protoplast-derived plants of the same generation and non-transformed, seed-derived plants under field and glasshouse conditions. Under both conditions the transgenic plants were generally smaller, took longer to flower and had reduced fertility. Significant differences were observed between individuals within the group of transgenic plants. The nptII gene was present in most of the transgenic plants, but NPT II activity was only detected in a minority of individuals.

We have investigated the role of lipid and protein dynamics in the activation of the Ca2+-dependent ATPase in sarcoplasmic reticulum (SR) by diethyl ether. Conventional and saturation-transfer electron paramagnetic resonance (EPR) were used to probe rotational motions of spin labels attached either to fatty acid hydrocarbon chains or to the Ca-ATPase in SR. We confirm previous studies (Salama, G., and Scarpa, A. (1980) J. Biol. Chem. 255, 6525-6528; Salama, G., and Scarpa, A. (1983) Biochem. Pharmacol. 32, 3465-3477; Kidd, A., Scales, D., and Inesi, G. (1981) Biochem. Biophys. Acta 65, 124-131) reporting that addition of diethyl ether to SR results in an approximately 2-fold enzymatic activation, without loss of coupling. Diethyl ether progressively fluidizes the SR membrane with respect to lipid hydrocarbon chain dynamics probed at several depths in the bilayer. Digital substractions, used to analyze two-component lipid spin label spectra, reveal that a 2-fold mobilization occurs in the population of lipid probes motionally restricted by the protein, while the remaining more mobile population is less affected. The microwave saturation properties of lipid probes also indicate that restricted motions of these probes are mobilized in maximally activated SR membranes. Saturation-transfer EPR, applied to maleimide spin-labeled Ca-ATPase, demonstrates that a 2-fold increase in microsecond rotational motion of the Ca-ATPase correlates with the maximal enzymatic activation. Effects of diethyl ether on both the enzymatic activity and molecular dynamics are completely reversible by dilution with buffer. We propose that ether activates by selectively mobilizing lipid chains adjacent to the enzyme, thus facilitating protein motions that are essential for calcium transport.

Coniophora eremophila and Antrodia sinuosa cause brown heartrot in living lemon trees in southern Arizona and California. They can be distinguished in the field by differences in rot characteristics. Both have a high optimum growth temperature of approximately 35°C. Coniophora eremophila has a cultural morphology typical of other Coniophora species and did not fruit in culture. Antrodia sinuosa cultures were morphologically similar to previous reports and fruited readily under laboratory conditions. Mating tests with homokaryotic single spore isolates showed it to have a heterothallic bipolar mating system. The decay capacity of C. eremophila on lemon wood test blocks under laboratory conditions was low compared to that of A. sinuosa, five other brown rot fungi, and three white rot fungi.