Characterization of Avian-like Influenza A (H4N6) Virus Isolated from Caspian Seal in 2012

正Dear Editor Marine mammals are widely distributed and can be found almost in all coastal waters and coastlines around the world. The interface areas between marine and terrestrial environments provide natural habitats for aquatic and semiaquatic mammals as well as for reservoir species of avian influenza viruses (AIV)(Runstadler et al. 2013). Previous     

Effect of linker length on the photomodification process of tyrosine residues in N-(tyrosyl)-N'-(5-azido-2-nitrobenzoyl)diaminoalkanes]

N-(Tyrosyl)-N'-(5-azido-2-nitrobenzoyl)-1,4-diaminobutane, containing a Tyr residue connected with the photoreactive aryl azide group through the diaminobutylene linker, was synthesized as a model for studying the photomodification of Tyr residues in proteins. This compound and the compound with a shorter, 1,2-diaminoethylene linker, obtained previously, were subjected to computer modeling to find their minimal-energy conformations. The aromatic rings of Tyr and 5-azido-2-nitrobenzoic acid residues in the latter compound were localized in parallel planes at a distance of approximately 0.3 nm between them and were shown to be implicated in stacking interactions. On the contrary, the planes of aromatic rings of the former compound with a longer, diaminobutylene linker were found to be situated perpendicularly to each other, with the distance between the centers of the rings being approximately 0.6 nm. The computer analysis was confirmed by experimental results: when studying the photomodification of the compound with the diaminobutylene linker, neither stable products of the Tyr photomodification nor unstable products capable of transformation into stable products in the dark were found. On the contrary, such products were previously identified in the case of the compound with diaminoethylene linker. The formation of amino, nitro, azoxy, and azo derivatives was common for the photomodification of both compounds.     

Transformation of clay minerals caused by an alkaliphilic cyanobacterial community

Transformation of clay minerals (smectite-zeolite, illite, kaolinite, and bentonite) and admixtures of iron oxides (hydroxides) under the action of an alkaline cyanobacterial community was studied. The results demonstrate that the processes of transformation of clay minerals such as intensification of removal of exchange bases and dissolution of silicates and iron oxides occurred in the presence of the alkaliphilic cyanobacterial community. The main factor that determines resistance of a mineral to biochemical weathering is its composition. Transformations of clay minerals in the course of active cyanobacterial photosynthesis (up to 14 days) and at decomposition of organic matter (OM) (28–60 days) are different. For smectite-zeolite and illite, these processes are dissolution of silicates and oxides (removal of Si and Fe) and removal of exchange bases (K), which were observed at both the of biomass production and OM destruction stages. For two other clays, the processes of neosynthesis are more typical: formation of carbonates (most probably siderite for bentonite clay and Mg-calcite for kaolin clay) and transformation of ferrihydrite into the more thermodynamically stable goethite.     

Enhanced absorption of millimeter wave energy in murine subcutaneous blood vessels

The aim of the present study was to determine millimeter wave (MMW) absorption by blood vessels traversing the subcutaneous fat layer of murine skin. Most calculations were performed using the finite-difference time-domain (FDTD) technique. We used two types of models: (1) a rectangular block of multilayer tissue with blood vessels traversing the fat layer and (2) cylindrical models with circular and elliptical cross-sections simulating the real geometry of murine limbs. We found that the specific absorption rate (SAR) in blood vessels normally traversing the fat layer achieved its maximal value at the parallel orientation of the E-field to the vessel axis. At 42 GHz exposure, the maximal SAR in small blood vessels could be more than 30 times greater than that in the skin. The SAR increased with decreasing the blood vessel diameter and increasing the fat thickness. The SAR decreased with increasing the exposure frequency. When the cylindrical or elliptical models of murine limbs were exposed to plane MMW, the greatest absorption of MMW energy occurred in blood vessels located on the lateral areas of the limb model. At these areas the maximal SAR values were comparable with or were greater than the maximal SAR on the front surface of the skin. Enhanced absorption of MMW energy by blood vessels traversing the fat layer may play a primary role in initiating MMW effects on blood cells and vasodilatation of cutaneous blood vessels.     

Shotgun microbial profiling of fossil remains

Millions to billions of DNA sequences can now be generated from ancient skeletal remains thanks to the massive throughput of next‐generation sequencing platforms. Except in cases of exceptional endogenous DNA preservation, most of the sequences isolated from fossil material do not originate from the specimen of interest, but instead reflect environmental organisms that colonized the specimen after death. Here, we characterize the microbial diversity recovered from seven c. 200‐ to 13 000‐year‐old horse bones collected from northern Siberia. We use a robust, taxonomy‐based assignment approach to identify the microorganisms present in ancient DNA extracts and quantify their relative abundance. Our results suggest that molecular preservation niches exist within ancient samples that can potentially be used to characterize the environments from which the remains are recovered. In addition, microbial community profiling of the seven specimens revealed site‐specific environmental signatures. These microbial communities appear to comprise mainly organisms that colonized the fossils recently. Our approach significantly extends the amount of useful data that can be recovered from ancient specimens using a shotgun sequencing approach. In future, it may be possible to correlate, for example, the accumulation of postmortem DNA damage with the presence and/or abundance of particular microbes.     

Channelopathies of inwardly rectifying potassium channels.

Mutations in genes encoding ion channels have increasingly been identified to cause disease conditions collectively termed channelopathies. Recognizing the molecular basis of an ion channel disease has provided new opportunities for screening, early diagnosis, and therapy of such conditions. This synopsis provides an overview of progress in the identification of molecular defects in inwardly rectifying potassium (Kir) channels. Structurally and functionally distinct from other channel families, Kir channels are ubiquitously expressed and serve functions as diverse as regulation of resting membrane potential, maintenance of K(+) homeostasis, control of heart rate, and hormone secretion. In humans, persistent hyperinsulinemic hypoglycemia of infancy, a disorder affecting the function of pancreatic beta cells, and Bartter's syndrome, characterized by hypokalemic alkalosis, hypercalciuria, increased serum aldosterone, and plasma renin activity, are the two major diseases linked so far to mutations in a Kir channel or associated protein. In addition, the weaver phenotype, a neurological disorder in mice, has also been associated with mutations in a Kir channel subtype. Further genetic linkage analysis and full understanding of the consequence that a defect in a Kir channel would have on disease pathogenesis are among the priorities in this emerging field of molecular medicine.     

Millimeter waves thermally alter the firing rate of the Lymnaea pacemaker neuron

The effects of millimeter waves (mm-waves, 75 GHz) and temperature elevation on the firing rate of the BP-4 pacemaker neuron of the pond snail Lymnaea stagnalis were studied by using microelectrode techniques. The open end of a rectangular waveguide covered with a thin Teflon film served as a radiator. Specific absorption rates (SARs), measured in physiological solution at the radiator outlet, ranged from 600 to 4200 W/kg, causing temperature rises from 0.3 to 2.2 °C, respectively. Irradiation at an SAR of 4200 W/kg caused a biphasic change in the firing rate, i.e., a transient decrease in the firing rate (69 ± 22% below control) followed by a gradual increase to a new level that was 68 ± 21% above control. The biphasic changes in the firing rate were reproduced by heating under the condition that the magnitude (2 °C) and the rate of temperature rise (0.96 °C/s) were equal to those produced by the irradiation (for an SAR of 4030 W/kg). The addition of 0.05 mM of ouabain caused the disappearance of transient responses of the neuron to the irradiation. It was shown that the rate of temperature rise played an important role in the development of a transient neuronal response. The threshold stimulus for a transient response of the BP-4 neuron found in warming experiments was a temperature rise of 0.0025 °C/s. Bioelectromagnetics 18:89–98, 1997. © 1997 Wiley-Liss, Inc.     

Effects of millimeter waves on ionic currents of Lymnaea neurons

The effects of mm‐waves 60.22–62.22 GHz and 75 GHz on A‐type K⁺ currents and the effects of 61.22 GHz on Ca²⁺ currents of Lymnaea neurons were investigated using a whole‐cell voltage‐clamp technique. The open end of a rectangular waveguide covered with a thin Teflon film served as a radiator. Specific absorption rates at the waveguide outlet, inserted into physiological solution, were in the range of 0–2400 W/kg. Millimeter wave irradiation increased the peak amplitudes, activation rates, and inactivation rates of both ion currents. The changes in A‐type K⁺ current were not dependent on the irradiation frequency. It was shown that the changes in the amplitudes and kinetics of both currents resulted from the temperature rise produced by irradiation. No additional effects of irradiation on A‐type K⁺ current other than thermal were found when tested at the phase transition temperature or in the presence of ethanol. Ethanol reduced the thermal effect of irradiation. Millimeter waves had no effect on the steady‐state activation and inactivation curves, suggesting that the membrane surface charge and binding of calcium ions to the membrane in the area of channel locations did not change. Bioelectromagnetics 20:24–33, 1999. © 1999 Wiley‐Liss, Inc.