Thermo-search: lifestyle and thermostability analysis

Thermo-search is an online web tool for the analysis of proteomes and individual proteins according to the ratio of two couplets of preferred and avoided amino acids in hyperthermophiles, thermophiles and mesophiles. It displays the ratio between glutamic acid plus lysine (E+K) and glutamine plus histidine (Q+H), which is higher in thermophilic proteomes and thermostable proteins than in mesophilic proteomes and thermo labile proteins. Thermo-search allows a rapid screen of the CRM database for thermostable proteins in their functional categories and a visualization of the (E+K)/(Q+H) average ratio between organisms, allowing a comparison of their lifestyles.     

Characterization of an endogenous retrovirus class in elephants and their relatives

Background  

Endogenous retrovirus-like elements (ERV-Ls, primed with tRNA leucine) are a diverse group of reiterated sequences related to foamy viruses and widely distributed among mammals. As shown in previous investigations, in many primates and rodents this class of elements has remained transpositionally active, as reflected by increased copy number and high sequence diversity within and among taxa.     

Tracking the mind's image in the brain II: transcranial magnetic stimulation reveals parietal asymmetry in visuospatial imagery

The functional relevance of brain activity during visuospatial tasks was investigated by combining functional magnetic resonance imaging with unilateral repetitive transcranial magnetic stimulation (rTMS). The cognitive tasks involved visuospatial operations on visually presented and mentally imagined material ("mental clock task"). While visuospatial operations were associated with activation of the intraparietal sulcus region bilaterally, only the group which received rTMS to the right parietal lobe showed an impairment of performance during and immediately after rTMS. This functional parietal asymmetry might indicate a capacity of the right parietal lobe to compensate for a temporary suppression of the left. This is compatible with current theories of spatial hemineglect and constitutes a constraint for models of distributed information processing in the parietal lobes.     

The G-protein beta-subunit GPB-2 in Caenorhabditis elegans regulates the G(o)alpha-G(q)alpha signaling network through interactions with the regulator of G-protein signaling proteins EGL-10 and EAT-16

The genome of Caenorhabditis elegans harbors two genes for G-protein beta-subunits. Here, we describe the characterization of the second G-protein beta-subunit gene gpb-2. In contrast to gpb-1, gpb-2 is not an essential gene even though, like gpb-1, gpb-2 is expressed during development, in the nervous system, and in muscle cells. A loss-of-function mutation in gpb-2 produces a variety of behavioral defects, including delayed egg laying and reduced pharyngeal pumping. Genetic analysis shows that GPB-2 interacts with the GOA-1 (homologue of mammalian G(o)alpha) and EGL-30 (homologue of mammalian G(q)alpha) signaling pathways. GPB-2 is most similar to the divergent mammalian Gbeta5 subunit, which has been shown to mediate a specific interaction with a Ggamma-subunit-like (GGL) domain of RGS proteins. We show here that GPB-2 physically and genetically interacts with the GGL-containing RGS proteins EGL-10 and EAT-16. Taken together, our results suggest that GPB-2 works in concert with the RGS proteins EGL-10 and EAT-16 to regulate GOA-1 (G(o)alpha) and EGL-30 (G(q)alpha) signaling.     

Flooding tolerance of Carex species in relation to field distribution and aerenchyma formation

The flooding tolerance of Carex species was studied in relation to their field distribution and their capacity to form root aerenchyma under controlled conditions. In an alpine meadow, six Carex species were selected which were distributed in a clear zonation correlating with water content of the soil. Carex sempervirens and C. ferruginea were only found on nonflooded soil, the latter species preferring moister conditions. Carex davalliana and C. nigra were both associated with water-saturated soil, whereas C. limosa and C. rostrata preferred partially submerged conditions. Carex davalliana and C. limosa were bound to flooded soils with a relatively high redox potential and horizontally flowing groundwater. Carex rostrata and C. nigra grew in stagnant soil-flooded conditions with low soil redox potentials. The amount of aerenchyma in the roots of all species increased when grown in oxygen-deficient stagnant agar. This increase in root porosity, combined with increased root diameter, presumably improved internal aeration of the roots. Although all species survived experimental soil flooding, partial submergence was lethal to C. sempervirens and, surprisingly, also to the wetland species C. davalliana. Carex ferruginea showed a reduced growth rate during partial submergence. The three other species, all wetland plants, reached highest biomass production under soil-flooded and partially submerged conditions, with slower growth on free-draining soil. It is concluded that aerenchyma is not constitutive in the Carex species under study, and is best developed in Carex species from wetlands. Species with less aerenchyma perform poorly when soil-flooded, but conditions of partial submergence could even affect species with a considerable amount of root aerenchyma.     

Diagnosis of Deep Vein Thrombosis with 99mTc-streptokinase: A Clinical Comparison with Phlebography

Nineteen patients with signs of deep vein thrombosis in the legs were investigated with a new technique using ^{9 9m}Tc-streptokinase. This compound is probably superior to iodine-labelled fibrinogen in detecting established thrombi. The ratio between the activity in the leg with suspected thrombosis and the other leg was calculated. The results were compared with those obtained with phlebography. A pathologically high activity ratio was found in 11 out of 13 patients in whom phlebography showed a thrombus, while the ratio was normal in the remaining six patients who showed no thrombus on phlebography. No negative correlation was found between the activity ratio and the titrated initial dose of streptokinase. The activity ratio as well as diagnosing the presence of a thrombus may also provide a guide for therapy.