Sepsis Associated Encephalopathy Studied by MRI and Cerebral Spinal Fluid S100B Measurement

The pathogenesis of sepsis associated encephalopathy (SAE) is not yet clear: the blood–brain barrier (BBB) disruption has been indicated among the possible causative mechanisms. S100B, a calcium binding protein, originates in the central nervous system but it can be also produced by extra-cerebral sources; it is passively released from damaged glial cells and neurons; it has limited passage through the BBB. We aimed to demonstrate BBB damage as part of the pathogenesis of SAE by cerebral spinal fluid (CSF) and serum S100B measurements and by magnetic resonance imaging (MRI). This paper describes four septic patients in whom SAE was clinically evident, who underwent MRI and S100B measurement. We have not found any evidence of CSF-S100B increase. Serum S100B increase was found in three out of four patients. MRI did not identify images attributable to BBB disruption but vasogenic edema, probably caused by an alteration of autoregulation, was diagnosed. S100B does not increase in CSF of septic patients; S100B increase in serum may be due to extracerebral sources and does not prove any injury of BBB. MRI can exclude other cerebral pathologies causing brain dysfunction but is not specific of SAE. BBB damage may be numbered among the contributors of SAE, which aetiology is certainly multifactorial: an interplay between the toxic mediators involved in sepsis and the indirect effects of hyperthermia, hypossia and hypoperfusion.     

The effects of elevated atmospheric CO<Subscript>2</Subscript> and nitrogen amendments on subsurface CO<Subscript>2</Subscript> production and concentration dynamics in a maturing pine forest

Profiles of subsurface soil CO₂ concentration, soil temperature, and soil moisture, and throughfall were measured continuously during the years 2005 and 2006 in 16 locations at the free air CO₂ enrichment facility situated within a temperate loblolly pine (Pinus taeda L.) stand. Sampling at these locations followed a 4 by 4 replicated experimental design comprised of two atmospheric CO₂ concentration levels (ambient [CO₂]^a, ambient + 200 ppmv, [CO₂]^e) and two soil nitrogen (N) deposition levels (ambient, ambient + fertilization at 11.2 g_N m⁻² year⁻¹). The combination of these measurements permitted indirect estimation of belowground CO₂ production and flux profiles in the mineral soil. Adjacent to the soil CO₂ profiles, direct (chamber-based) measurements of CO₂ fluxes from the soil–litter complex were simultaneously conducted using the automated carbon efflux system. Based on the measured soil CO₂ profiles, neither [CO₂]^e nor N fertilization had a statistically significant effect on seasonal soil CO₂, CO₂ production, and effluxes from the mineral soil over the study period. Soil moisture and temperature had different effects on CO₂ concentration depending on the depth. Variations in CO₂ were mostly explained by soil temperature at deeper soil layers, while water content was an important driver at the surface (within the first 10 cm), where CO₂ pulses were induced by rainfall events. The soil effluxes were equal to the CO₂ production for most of the time, suggesting that the site reached near steady-state conditions. The fluxes estimated from the CO₂ profiles were highly correlated to the direct measurements when the soil was neither very dry nor very wet. This suggests that a better parameterization of the soil CO₂ diffusivity is required for these soil moisture extremes.     

Characterization of the first dominant dwarf maize mutant carrying a single amino acid insertion in the VHYNP domain of the <Emphasis Type="Italic">dwarf8</Emphasis> gene

The “green revolution” involving mainly wheat and rice was based on the use by breeders of semidominant mutations involved in the signal transduction pathway of Gibberellin (GA). In particular, mutations in the Reduced height (Rht) gene of wheat have been used to reduce plant height and consequently to avoid storm damage and lodging. These genes have been cloned and they encode for DELLA proteins which contain an N-terminal DELLA and a VHYNP domain essential for GA-dependent degradation of these proteins. In maize several mutations have been isolated which affect gibberellin biosynthesis and perception and in particular, mutations in Dwarf8 (D8) gene cause a severe dwarfing phenotype. D8 gene has been identified as an orthologue of Rht (Reduced height), Slr1(Slender rice 1) and Gibberellic Acid Insensitive (GAI) genes, this latter is a negative regulator of GA response in Arabidopsis. In this work, for the first time, we isolated and characterized a single amino acid insertion in the VHYNP domain of D8 maize gene causing the appearance of a dominant dwarf mutation. This spontaneous mutation, named D8-1023, showed a phenotype which is less severe in comparison with the other D8 mutants previously isolated which have modifications in the DELLA domain. This mutant appears to be an useful tool either to study the mechanism of GA-modulated growth in plants or to lower the height of maize tropical germplasm for breeding purposes.     

Effect of the Environmental Factors on the Caloric Content of Benthic and Phytophilous Invertebrates in Neotropical Reservoirs in the Paraná State,Brazil

The complexity of the relations between the organisms and the environment are reflected through the energy content. So we tested the hypothesis on body energy content variation in invertebrates and its relation with some environmental factors (season, habitat type, trophic status and trophic guild). We expected higher energy values for phytophilous fauna, rainy season, in reservoirs with higher trophic levels and for herbivorous invertebrates. The results showed the influence of seasonality and trophic status of the reservoir on the energy content of invertebrates, which was higher in the rainy season and in the mesotrophic reservoirs, due to the input of allochthonous material during this season, confirming our initial prediction. A higher caloric content was recorded for carnivorous and detritivorous invertebrates. The differences between the trophic guilds were primarily related to the opportunistic feeding behavior, which may be considered as one of the main factors controlling the energy flow of benthic and phytophilous invertebrates. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The Novel PMCA2 Pump Mutation Tommy Impairs Cytosolic Calcium Clearance in Hair Cells and Links to Deafness in Mice

The mechanotransduction process in hair cells in the inner ear is associated with the influx of calcium from the endolymph. Calcium is exported back to the endolymph via the splice variant w/a of the PMCA2 of the stereocilia membrane. To further investigate the role of the pump, we have identified and characterized a novel ENU-induced mouse mutation, Tommy, in the PMCA2 gene. The mutation causes a non-conservative E629K change in the second intracellular loop of the pump that harbors the active site. Tommy mice show profound hearing impairment from P18, with significant differences in hearing thresholds between wild type and heterozygotes. Expression of mutant PMCA2 in CHO cells shows calcium extrusion impairment; specifically, the long term, non-stimulated calcium extrusion activity of the pump is inhibited. Calcium extrusion was investigated directly in neonatal organotypic cultures of the utricle sensory epithelium in Tommy mice. Confocal imaging combined with flash photolysis of caged calcium showed impairment of calcium export in both Tommy heterozygotes and homozygotes. Immunofluorescence studies of the organ of Corti in homozygous Tommy mice showed a progressive base to apex degeneration of hair cells after P40. Our results on the Tommy mutation along with previously observed interactions between cadherin-23 and PMCA2 mutations in mouse and humans underline the importance of maintaining the appropriate calcium concentrations in the endolymph to control the rigidity of cadherin and ensure the function of interstereocilia links, including tip links, of the stereocilia bundle.     

Molecular identification of Korean Trichinella isolates

Muscle larvae of Trichinella isolates from two outbreaks in Korea were analyzed by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and multiple-PCR. All of the muscle larvae showed a band similar to that of T. spiralis larvae of the reference strain. The two Korean Trichinella isolates (isolate code ISS623 and ISS1078) might be classifiable to Trichinella spiralis.     

A micrite-dominated norian carbonate platform from Northern Calabria (Southern Italy)

Summary  This paper is focused on the facies associations of an Early-Middle Norian stratigraphic succession cropping outin the Northern Calabria (Buonvicino, Cosenza). These carbonate deposits, pertaining to the Verbicaro Unit, represent a dolomitized platform characterized by a clear dominance of automicrites over skeletal metazoans. On the basis of the chronostatigraphic data and sedimentary evolution, two stratigraphic units have been distinguished: the Lower Unit (object of the present paper) and the Upper Unit. The Lower Unit consists of an Early-Middle Norian high-relief prograding carbonate platform. The Upper Unit is represented by Middle p.p.-Upper Norian basinal deposits. Three main facies associations, indicative of different depositional settings, have been identified. The inner platform facies association is characterized by automicrite (cauliflower-columnar subordinate planar stromatolites) associated with detrital carbonates (intraclastic breccia, bioclastic grainstone and packstone). Apeculiar facies is represented by megalodontid-bearing beds. Mud-cracked horizons and low-developed teepees occur quite frequently. The margin facies association is dominated by automicrite (planar to low relief stromatolites associated with thrombolitic fenestral boundstone) and detrital carbonates with subaerial exposure features. The slope facies association includes detrital carbonates (breccia/megabreccia) associated with serpulid/sphinctozoan bioconstructions and automicrite (planar stromatolites/thrombolitic boundstone). The whole carbonate body is completely dolomitized; nevertheless the morphology and microarchitecture of carbonate components (cements, grains and automicrite) is still clearly recognizable. The dolomite Mg content ranges from 40 to 48 mole%, sometimes reaching the stoichiometric value. Cements, primary and late, represent a minor component of the rock volume; they occur more frequently on the margin and upper slope setting. Quantitative tacies analyses lead to the following conclusions: