Preventing fat embolism syndrome (FES) in implantation of cemented hip endoprosthesis shafts with a trans-prosthetic drainage system (TDS)]

In vitro studies with the transprosthetic drainage system (TDS) have revealed a reduction in intrafemoral pressure in cemented total hip prosthesis. The aim of the present study was to establish whether the incidence of fat embolic syndrome (FES) is also reduced. Ten patients underwent standardized cemented total hip replacement using TDS under standardized general anaesthesia. The usual peri-operative monitoring measures were extended to include cardiopulmonary monitoring (pulmonary artery catheter, intra-arterial blood pressure) and two-dimensional transoesophageal echocardiography. Previous studies had reported an increased risk for fat embolic syndrome with conventional, and even with vacuum cementing techniques. Our recorded cardiopulmonary data and the data provided by two-dimensional transoesophageal echocardiography show a significant reduction in pulmonary embolism with TDS. This technique can be recommended in particular for high-risk patients (osteoporosis, elderly patients) and the implantation of long femoral stems. On the basis of the clinical data, a new femoral stem allowing the use of the TDS technique is being developed.     

Differential expression of a cell wall-localized peroxidase isoenzyme capable of oxidizing 4-hydroxystilbenes during the cell culture of grapevine (Vitis vinifera cv. Airen and Monastrell)

Differential expression and localization of peroxidase isoenzymes capable of oxidizing 4-hydroxystilbenes was studied during establishment of callus cultures from Vitis vinifera Airen (anthocyanin-non accumulating) and Monastrell (anthocyanin-accumulating) berries. Callus formation from mesocarp tissues was accompanied by differential expression of several peroxidase isoenzyemes located in cell walls, among which only peroxidase isoenzyme A₁ was capable of oxidizing 4-hydroxystilbene to any great extent. Likewise, grape cell cultures were capable of accumulating the grape stilbene phytoalexin, resveratrol. However, -viniferin, the most powerful phytoalexin in grapevines and previously considered as the product of peroxidase-mediated oxidative coupling of two resveratrol moieties, was only detectable in trace amounts. Since grapevine suspension cell cultures were unable to produce H₂O₂ as revealed by the luminol test, H₂O₂ production by the cultured cells appears to be one of the main factors which limits resveratrol oxidation in the cell walls of grapevine cells cultured in suspension.     

Constitutive expression of extracellular peroxidase isoenzymes capable of oxidizing 4-hydroxystilbenes during the growth cycle of grapevine suspension cell cultures

The constitutive expression of peroxidase isoenzymes which are capable of oxidizing 4-hydroxystilbenes was studied during the growth cycle of suspension cell cultures from grapevine (Vitis vinifera L. cv. Monastrell) berries. the results showed that the growth of suspension cell cultures is accompanied by the constitutive expression of the peroxidase isoenzymes HSPrx 1 and HSPrx 2, previously characterised by their properties for oxidizing 4-hydroxystilbene, the expression of these isoenzymes being characteristic of Monastrell vines brought to a resistant state. However, although the differential catalytic properties of these grapevine isoenzymes are also shown by the horseradish peroxidase, no immunological relationships have been found between the peroxidases from either source. Communicated by I. MACHáČKOVá     

CYANIDIA (CYANIDIALES) POPULATION DIVERSITY AND DYNAMICS IN AN ACID‐SULFATE‐CHLORIDE SPRING IN YELLOWSTONE NATIONAL PARK1

The unicellular eukaryotic algae Cyanidium, Galdieria, and Cyanidioschyzon (herein referred to as “cyanidia”) are the only photoautotrophs occurring in acidic (pH<4.0) geothermal environments at temperatures above 40°C. In Yellowstone National Park (YNP), we examined an annual event we refer to as “mat decline,” where cyanidial mats undergo a seasonably defined color fading. Monthly sampling of chemical, physical, and biological features revealed that spring aqueous chemistry was essentially invariant over the 1‐year sampling period. However, multiple regression analysis suggested that a significant proportion of algal most probable number (MPN) count variation could be explained by water temperature and UV–visible (VIS) light exposure. Irradiance manipulations (filtering) were then coupled with ¹⁴CO₂ incorporation experiments to directly demonstrate UV inhibition of photosynthesis. Population dynamics were also evident in 18S rDNA PCR clone libraries, which were different in composition at MPN maxima and minima, and again evident in PCR‐amplified chloroplast genomic short sequence repeat (SSR) analysis. PCR‐cloned SSRs of the YNP isolates and mats were very similar to Cyanidioschyzon merolae Luca, Taddei et Varano, although distance analysis could distinguish the YNP cyanidia from the genome sequenced C. merolae that was isolated in Italy. Unexpectedly, while phylogenetic analysis of 18S rDNA sequences and SSR sequences derived from YNP cyanidial mats and pure cultures suggested these algae are most closely related to C. merolae (99.7% identity), cell morphology was consistent with the genera Galdieria and Cyanidium.     

THE GROWTH AND MORPHOLOGY OF THE SILICOFLAGELLATE DICTYOCHA FIBULA EHRENBERG IN CULTURE1,2

Dictyocha fibula was cultured in an enriched seawater medium from collections taken at Edmonds, Washington. The optimum temperature for growth is 10 C at salinity 24% and 160 ft-c illumination in Provasoli enriched seawater at the concentration of 7.5 ml/liter seawater. Average generation time is 49 hr. In addition to swimming cells with skeletons, swimming cells without skeletons and nonswimming coenocytes were observed in clonal cultures at 15 C.     

Reversal of hydroxyproline-induced inhibition of elongation of Avena coleoptiles

Hydroxy-l-proline-induced inhibition of elongation of Avena coleoptile segments was measured in water and in indole-3-acetic acid. This inhibition was completely reversed by l-proline.     

UNUSUAL PHENOMENA IN THE LIFE HISTORIES OF FLORIDEAE IN CULTURE1

Several Florideae grown in natural seawater media under defined laboratory conditions have interesting and unusual life histories. Antithamnion occidentale males of one generation produced tetraspores that gave rise to nonsporangiate males. The functional females of A. pygmaeum developed spermatangia and tetrasporangia; the tetraspores formed new females. Antithamnion defectum tetrasporophytes of one generation bore spermatangia in addition to tetrasporangia; the tetraspores gave rise to typical gametophytes. Tetraspores from successive generations of Callitham-nion sp. developed into tetrasporophytes and males but no females were produced. Functional female gametophytes of Platythamnion sp. bore abortive tetrasporangia. Field-collected plants of two species of Fauchea produced tetraspores that yielded additional sporangiate plants: those of F. pygmaea being bispo-rangiate and tetrasporangiate, and those of F. lacini-ata being strictly tetrasporangiate. Male plants of Pleonosporium vancouverianum from a running seawater table bore spermatangia and polysporangia when collected. The same plants in unialgal culture produced only spermatangia.     

Ecology,environment and evolutionary history influence genetic structure in five mammal species from the Italian Alps

The identification and evaluation of the ecological and environmental factors shaping patterns of natural genetic variation are fundamental goals of population and conservation genetics. Many studies focus on factors affecting single species, but it is also important to test whether some influential biotic and abiotic factors are common drivers of genetic diversity across species, or if species or species groups are each affected by different forces; a multi‐species analysis is necessary for this. Here we analysed the molecular variation from five mammal species (roe deer, red deer, chamois, mountain hare and European brown hare) at mtDNA and microsatellite loci from the eastern Italian Alps. We use phylogeographical and landscape‐level analyses to test the relative influence of large‐scale geographical history and contemporary environmental characteristics of the landscape on genetic diversity and differentiation. We found: (1) all study species except brown hare are strongly differentiated into two main groups, located west and east of a major river valley; (2) significant correlations between levels of within‐population diversity at both mtDNA and microsatellite loci, and several landscape features such as alpine grassland, water courses and anthropized areas. We conclude that heterogeneous landscape has some influence on within‐population diversity, but biogeographical history has probably had the stronger influence on current genetic patterns, despite an apparently large dispersal potential of certain species. However, our results for brown hare show that management actions such as stocking may alter these large‐scale patterns.