Allometric relationships to estimate seasonal above-ground vegetative and reproductive biomass of Vitis vinifera L.

A procedure is described for obtaining allometric regression equations to estimate non-destructively and in a cost-effective manner the current year's above-ground vegetative and reproductive biomass of Vitis vinifera L. Merlot' throughout the growing season. Significant relationships were obtained over a 3-year period (1998-2000) between the dimensions of an individual shoot per vine (i.e. diameter and length) and dry weights of its primary stem, primary leaves and lateral growth. The dry mass of a grape was best estimated from measurements of the basal diameter of the bunch peduncle. Introducing cumulative degree-days as an additional explanatory variable in the equations allowed them to be used irrespective of year and growth stage. Multi-year regressions were used to quantify in detail the seasonal evolution of mature grapevine biomass under the climatic conditions of the Bordeaux area, France, and for differing levels of soil nitrogen.

Responses of Antioxidative Systems to Drought Stress in Pendunculate Oak and Maritime Pine as Modulated by Elevated CO2.

The aim of the present study was to investigate the effects of an enhanced CO2 concentration alone or in combination with drought stress on antioxidative systems of a deciduous (oak; Quercus robur) and an evergreen (pine; Pinus pinaster) tree species. The seedlings were grown for one season in a greenhouse in tunnels supplied with 350 or 700 [mu]L L-1 CO2. The experiment was repeated in a second year. Antioxidants, protective enzymes, soluble protein, and pigments showed considerable fluctuations in different years. Elevated CO2 caused significant reductions in the activities of superoxide dismutases in both oak and pine. The activities of ascorbate peroxidase and catalase were also reduced in most cases. The activities of dehydroascorbate reductase, monodehydroascorbate radical reductase, glutathione reductase, and guaiacol peroxidase were affected little or not at all by elevated CO2. When the trees were subjected to drought stress by withholding water, the activities of antioxidative enzymes decreased in leaves of pine and oak grown at ambient CO2 and increased in plants grown at elevated CO2 concentrations. The present results suggest that growth in elevated CO2 might reduce oxidative stress to which leaf tissues are normally exposed and enhance metabolic flexibility to encounter increased stress by increases in antioxidative capacity.

[Determination of methylmethacrylate in expired gases after hip prosthesis cementing]. / Dosage du méthacrylate de méthyle dans les gaz expirés après scellement des prothèses de hanche.

Total hip replacement using methylmethacrylate can induce early intraoperative hypoxaemia caused, according to some authors, by alveolar gas dilution by acrylic monomer vapour. In order to test this hypothesis, expired monomer was measured in ten patients undergoing total hip replacement carried out under narconeuroleptanalgesia. Methylmethacrylate was collected by adsorption on activated charcoal and measured by gas chromatography. The quality of expired monomer was 25 +/- 10 micrograms after cotyloid sealing. It is of 264 +/- 396 micrograms after femoral sealing; the most important excretion took place in the first three minutes, and its total duration may exceed 18 min. A simple calculation showed quite convincingly that the volume of expired monomer vapour was not sufficient to explain the hypoxaemia: impaired arterial oxygenation associated with the use of methylmethacrylate is not due to a dilution technique.

[Potentiation of a vitamin K antagonist by a pefloxacin-rifampicin combination]. / Potentialisation d'une antivitamine K par l'association péfloxacine-rifampicine.

The combination of a new quinolone, pefloxacin, with rifampicin seemed of interest in the treatment of staphylococcal osteitis. Interactions of a coumarin anticoagulant (acenocoumarol) and several antibiotics were well known, mostly resulting in a decrease of the anticoagulant activity. A new interaction of this anticoagulant drug with the pefloxacin-rifampicin combination is described which gave an increase in the anticoagulant activity.

[Surgery and the acquired inhibitor of factor VIII coagulant]. / Chirurgie et inhibiteur acquis du facteur VIII coagulant.

A case is reported of an 80 year old woman with old sarcoidosis and acquired factor VIIIc inhibitor undergoing orthopaedic surgery. This was successfully carried out after she had been given a total of 48,420 units of factor VIII concentrate: there were no haemorrhagic complications. The main pathological states in which acquired factor VIIIc inhibitor may be found are related: principal treatments available nowadays are discussed: immunosuppressors, human factor VIII, animal factor VIII, prothrombin complex concentrate, plasma exchange.