The Effect of Dietary Energy Restriction on Body Weight Gain and the Development of Noninsulin-Dependent Diabetes Mellitus (NIDDM) in Psammomys obesus

Food intake was restricted to 75% of ad libitum levels in 37 male Psammomys obesus (Israeli Sand Rats) from the ages of 4 (weaning) to 10 weeks. Energy restriction reduced the mean body weight at 10 weeks by 29% compared with 44 ad libitum fed controls. Hyperglycemia was prevented completely in the food-restricted group, and mean blood glucose concentrations were significantly reduced (3.8 ± 0.2 vs. 5.5 ± 0.4 μmol/L; p<0.05) compared with control animals. Plasma insulin concentrations were also decreased significantly compared with ad libitum fed controls (105 ± 13 vs. 241 ± 29 mU/L;p<0.05). Although energy restriction prevented hyperglycemia from developing in 10-week-old P. obesus, 19% of the food restricted animals still developed hyperinsu-linemia. We concluded that hyperphagia between the ages of 4 to 10 weeks may be essential for the development of noninsulin-dependent diabetes mellitus in P. obesus, but that hyperinsulinemia may still occur in the absence of hyperphagia and hyperglycemia, suggesting a significant genetic influence on the development of hyperinsulinemia in this animal model.     

Characterization of the Subunit Structure of the Ribonucleic Acid Genome of Influenza Virus

Ribonucleic acid extracted from influenza virus was labeled at the 3' termini with (3)H and analyzed by polyacrylamide gel electrophoresis. Influenza virus was found to contain a minimum of seven and possibly as many as 10 polynucleotide chains, most of which appear to terminate at the 3' end in uridine.     

Induction of cytochrome P-450 isozymes by mirex and chlordecone

The effect of the insecticides, mirex and chordecone (Kepone), on the cytochrome P-450 monooxygenase system in C57BL/6N mouse liver microsomes was studied. Mice were treated intraperitoneally with low (6 mg/kg) and high (30 mg/kg) doses of mirex and chlordecone in corn oil for 2 days. For comparison, mice were also treated with either phenobarbital (PB) or 3-methylcholanthrene (3-MC). All treatments significantly increased the hepatic microsomal P-450 content over that of controls. Benzphetamine N-demethylase, ethoxyresorufin O-deethylase, benzo[a]pyrene hydroxylase, and acetanilide hydroxylase activities were also determined. Mirex and chlordecone resembled phenobarbital with respect to the induction of monooxygenase activities. Immunoquantitation with antibodies to purified P-450 IIB1 (Pb-induced P-450) and P-450 IA1 (3-MC-induced P-450) indicated that mirex and chlordecone induced P-450 IIB1 in a dose-dependent manner. The high dose of mirex also induced a small amount of a protein cross reacting with the antibody to IA1. The induction of this isozyme did not, however, contribute significantly to the monooxygenase activities measured.     

Differences in induction of hepatic cytochrome p450 isozymes by mice in eight methylenedioxyphenyl compounds

Eight methylenedioxyphenyl (MDP) compounds were examined for their ability to induce cytochrome P450 (P450) in mouse liver. Induction by safrole, isosafrole, and dihydrosafrole was studied in both C57BL/6N (Ah-responsive) and DBA/2N (Ahnonresponsive) male mice after IP administration of 200 mg/kg/day MDP compound for 3 days. Hepatic P450 content, ethylmorphine N-demethylase, ethoxy-resorufin O-deethylase, and acetanilide hydroxylase activities were induced to the same extent in both strains of mice. Benzo(a)pyrene hydroxylase activity, however, was not induced in either C57 or DBA mice. The similarity of results in both strains of mice indicated induction of these P450 isozymes by these three MDP compounds is not mediated by the Ah receptor. Induction of P450 by butylbenzodioxole (n-butyl-BD), tertiarybutylbenzodioxole (t-butyl-BD), methylbenzodioxole (methyl-BD), nitrobenzodioxole (nitro-BD), and bromobenzodioxole (bromo-BD) was examined only in C57BL/6N mice. Methyl-BD, nitro-BD, and bromo-BD did not induce hepatic microsomal proteins or selected P450 monooxygenase activities. In contrast, n-butyl-BD, and t-butyl-BD induced P450 content, ethylmorphine N-demethylase, acetanilide hydroxylase, and ethoxyresorufin O-deethylase activities. Benzo(a)pyrene hydroxylase was not induced by any of the treatments. Induction of these P450 activities is consistent with induction of P450 IIB1 and P450 IA2, but not induction of P450 IA1. Western blot analysis with antibodies to P450 isozymes induced with either phenobarbital (Pb) or 3-methylcholanthrene (3-MC) confirmed that both IIB1 and IA2 were induced, but that IA1 was not induced.     

Liquid flow in heterogeneous biofilms

Liquid flow was studied in aerobic biofilms, consisting of microbial cell clusters (discrete aggregates of densely packed cells) and interstitial voids. Fluorescein microinjection was used as a qualitative technique to determine the presence of flow in cell clusters and voids. Flow velocity profiles were determined by tracking fluorescent latex spheres using confocal microscopy. Liquid was flowing through the voids and was stagnant in the cell clusters. Consequently, in voids both diffusion and convection may contribute to mass transfer, whereas in cell clusters diffusion is the dominant factor. The flow velocity in the biofilm depended on the average flow velocity of the bulk liquid. The velocity profiles in biofilms were linear and the velocity was zero at the substratum surface. The velocity gradients within biofilms were 50% of that near walls without biofilm coverage. The influence of the biofilm roughness on the flow velocity profiles was similar to that caused by rigid roughness elements. (c) 1994 John Wiley & Sons, Inc.     

Comparative LCA studies of simulated HMF biorefineries from maize and miscanthus as an example of first- and second-generation biomass as a tool for process development

5-Hydroxymethylfurfural (HMF) is a versatile platform chemical for a fossil free, bio-based chemical industry. HMF can be produced by using fructose as a feedstock. Using edible, first-generation biomass to produce chemicals has been questioned in terms of potential competition with food supply. Second-generation biomass like miscanthus could be an alternative. However, there is a lack of information if second-generation lignocellulosic biomass is a more sustainable feedstock to produce HMF. Therefore, a life cycle assessment was performed in this study to determine the environmental impacts of HMF production from miscanthus and to compare it with HMF from high-fructose corn syrup (HFCS). HFCS from either Hungary or Baden-Württemberg (Germany) was considered. Compared to the HFCS biorefineries the miscanthus concept is producing less emissions in all impact categories studied, except land occupation. Overall, the production and usage of second-generation biomass could be especially beneficial in areas where the use of N fertilizers is restricted. Besides, conclusions for the further development of the on-farm biorefinery concept were elaborated. For this purpose, process simulations from a previous study were used. Results of the previous study in terms of TEA and the current LCA study in terms of environmental sustainability indicate that the lignin depolymerization unit in the miscanthus biorefinery has to be improved. The scenario without lignin depolymerization performs better in all impact categories. The authors recommend to not further convert the lignin to products like phenol and other aromatic compounds. The results of the contribution analyses show that the major impact in the HMF production is caused by the auxiliary materials in the separation units and the required heat. Further technical development should focus on efficient heat as well as solvent use and solvent recovery. At this point further optimizations will lead to reduced emissions and costs at the same time.     

Novel Miscanthus hybrids: Modelling productivity on marginal land in Europe using dynamics of canopy development determined by light interception

New biomass crop hybrids for bioeconomic expansion require yield projections to determine their potential for strategic land use planning in the face of global challenges. Our biomass growth simulation incorporates radiation interception and conversion efficiency. Models often use leaf area to predict interception which is demanding to determine accurately, so instead we use low-cost rapid light interception measurements using a simple laboratory-made line ceptometer and relate the dynamics of canopy closure to thermal time, and to measurements of biomass. We apply the model to project the European biomass potentials of new market-ready hybrids for 2020–2030. Field measurements are easier to collect, the calibration is seasonally dynamic and reduces influence of weather variation between field sites. The model obtained is conservative, being calibrated by crops of varying establishment and varying maturity on less productive (marginal) land. This results in conservative projections of miscanthus hybrids for 2020–2030 based on 10% land use conversion of the least (productive) grassland and arable for farm diversification, which show a European potential of 80.7–89.7 Mt year⁻¹ biomass, with potential for 1.2–1.3 EJ year⁻¹ energy and 36.3–40.3 Mt year⁻¹ carbon capture, with seeded Miscanthus sacchariflorus × sinensis displaying highest yield potential. Simulated biomass projections must be viewed in light of the field measurements on less productive land with high soil water deficits. We are attempting to model the results from an ambitious and novel project combining new hybrids across Europe with agronomy which has not been perfected on less productive sites. Nevertheless, at the time of energy sourcing issues, seed-propagated miscanthus hybrids for the upscaled provision of bioenergy offer an alternative source of renewable energy. If European countries provide incentives for growers to invest, seeded hybrids can improve product availability and biomass yields over the current commercial miscanthus variety.     

Kinetic analysis of dynamic 13C NMR spectra: metabolic flux, regulation, and compartmentation in hearts.

Control of oxidative metabolism was studied using 13C NMR spectroscopy to detect rate-limiting steps in 13C labeling of glutamate. 13C NMR spectra were acquired every 1 or 2 min from isolated rabbit hearts perfused with either 2.5 mM [2-13C]acetate or 2.5 mM [2-13C]butyrate with or without KCl arrest. Tricarboxylic acid cycle flux (VTCA) and the exchange rate between alpha-ketoglutarate and glutamate (F1) were determined by least-square fitting of a kinetic model to NMR data. Rates were compared to measured kinetics of the cardiac glutamate-oxaloacetate transaminase (GOT). Despite similar oxygen use, hearts oxidizing butyrate instead of acetate showed delayed incorporation of 13C label into glutamate and lower VTCA, because of the influence of beta-oxidation: butyrate = 7.1 +/- 0.2 mumol/min/g dry wt; acetate = 10.1 +/- 0.2; butyrate + KCl = 1.8 +/- 0.1; acetate + KCl = 3.1 +/- 0.1 (mean +/- SD). F1 ranged from a low of 4.4 +/- 1.0 mumol/min/g (butyrate + KCl) to 9.3 +/- 0.6 (acetate), at least 20-fold slower than GOT flux, and proved to be rate limiting for isotope turnover in the glutamate pool. Therefore, dynamic 13C NMR observations were sensitive not only to TCA cycle flux but also to the interconversion between TCA cycle intermediates and glutamate.     

Immunologic reactivity to incompatible blood group substances of the ABO system in scleroderma.

The immunization with incompatible blood groups substances of the ABO system yielded distinct increases in the isohemagglutinin titers and their scores in 16 patients suffering from systemic sclerosis (scleroderma) and in 16 controls. The difference between these two groups was not statistically significant, which suggests an intact humoral immunological reactivity of these antigens. However, investigations with further antigens would be necessary to judge the immunological factors supposed to be involved in the pathogenesis of systemic sclerosis. The method may be recommended for testing the humoral immunological response in similar problems.