In 10 volunteers, the pharmacokinetics of ofloxacin {HOE 280, DL 8280; (+)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H-pyrido-[1,2,3-deI [1,4] 1.4 liters/kg of body weight) suggested effective diffusion into the extravascular space. High total and renal clearances indicated primarily renal excretion with additional elimination pathways, such as tubular secretion and extrarenal elimination. After oral administration, absorption was excellent, and the absolute bioavailability following 200 mg of ofloxacin could be calculated at >0.95. Maximal concentrations in serum were attained 1.2 to 1.9 h after dosing; areas under the curve increased in proportion to dose between 200 and 400 mg of oral ofloxacin. The amount of known metabolites (demethyl and N-oxide compounds) excreted in urine reached only 4.3% (intravenously) and 4.0% (orally). Transient headaches in some volunteers were the only side effects registered.6-Fluoro-7-piperazino-4-quinolones are noteworthy both for the wide range and intensity of activities against gramnegative bacilli and cocci in vitro and the capacity to control experimentally induced systemic infections with selected bacteria when administered orally in well-tolerated doses (9,15,27).Ofloxacin {HOE 280, DL 8280; (±)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl) -7-oxo-7H-pyrido[1,2,3-de] [1,4]benzoxacine-6-carboxylic acid} is a new quinolone carboxylic acid derivative showing a broad antimicrobial spectrum against gram-positive and gram-negative bacteria (1,11,17,22,27). This substance was found to be more active than norfloxacin and pipemidic acid (22), its in vitro antibacterial activity being almost comparable to those of gentamicin, tobramycin, and newer cephalosporins (9,11,27). When first introduced, ofloxacin could only be administered orally, but recently a parenteral form was developed.The purpose of this study was to investigate the pharmacokinetic properties of this quinolone after oral and intravenous (i.v.) administration of various doses to determine the bioavailability and metabolism of this drug.(Part of this study was presented at the 24th Interscience

In ten volunteers the pharmacokinetics of ofloxacin and ciprofloxacin were determined after crossover administration of 100 and 200 mg intravenously (30 min constant infusion). Concentrations in serum and urine were measured by HPLC. Concentrations in serum following parenteral ofloxacin dosages demonstrated dose dependency with long biological half-lives. Pharmacokinetic parameters were calculated on the basis of an open three-compartment model, which resulted in a high volume of distribution for both substances (166-246 1 for ofloxacin, 178-2611 for ciprofloxacin). AUC for ofloxacin was three times higher than that for ciprofloxacin. Approximately 80% of ofloxacin and 57% of ciprofloxacin were eliminated through the kidneys. Ciprofloxacin had a considerable amount of extrarenal clearance, whereas only 19% of ofloxacin were eliminated by extrarenal mechanisms. Only 4.3% of ofloxacin after iv dosing could be detected as metabolites in urine.

<p>In the last two decades, acreage for biomass production has strongly increased in Germany due to the Renewable Energy Act. Recently, discussion about soil, climate, and biodiversity protection is receiving more and more public attention throughout broad parts of the society. The project BESTLAND focuses on the effect of land use change from the common annual maize cropping system to a perennial cropping system, as a measure against increasing environmental constraints in biomass production. A suitable perennial biomass crop as an alternative for maize is S. perfoliatum (cup plant). On one hand, the yellow flowering plant produces high biomass yields and on the other hand it provides a variety of ecosystems services. Field experiments were carried out in the Saar-Nahe mountain range in the state of Saarland on a fine textured planosol. The experimental sites are characterized by temporal waterlogging and slopes and therefore these sites are prone for soil compaction and soil erosion. Under these conditions perennial crops are assumed to have soil preserving benefits. Maize was compared to cup plant by establishing four paired sites, where each pair consisted of a maize and a cup plant field in close vicinity (< 500 meters) to each other. All sites are grower fields and were managed by the farmers according best management practices. Nitrous oxide and methane fluxes were measured weekly using the static chamber technique all year round. Besides greenhouse gas measurement, soil samples for determination of soil mineral nitrogen were taken at each gas sampling date. Furthermore, soil temperature and water content were continuously monitored using sensors. Biomass yields at each site were determined at harvest. In the first year average nitrous oxide emissions from cup plant fields were lower than from maize fields by more than 70 % on area and dry matter yield basis. These results indicate that perennial bioenergy crops not only offer a wider range of ecosystem services but can also decrease GHG emissions from bioenergy production.</p>