Receptor-mediated and receptor-independent activation of G-proteins in rat brain membranes

High-affinity GTPase activity intrinsic to G-proteins, which serves as an index of G-protein activation elicited through agonist-stimulated receptors as well as by receptor-independent direct G-protein activators like mastoparan, was measured in rat brain membranes. Receptor-mediated high-affinity GTPase activity was detectable preferentially for the Gi subfamily associated with adenylyl cyclase inhibition mediated by group II metabotropic glutamate, pirenzepine-insensitive muscarinic acetylcholine, GABA(B), adenosine A1, dopamine D2-like (striatum), and serotonin 5-HT1A (hippocampus) receptors. The pharmacological characteristics of such receptor-mediated high-affinity GTPase activities were presented. Mastoparan, a tetradecapeptide from wasp venom which has been shown to directly activate Gi and Go, inhibited low-affinity GTP hydrolyzing activity, probably due to its activating effect on nucleoside diphosphokinase (NDPK). When NDPK activity was inhibited completely by UDP, mastoparan stimulated high-affinity GTPase activity in a concentration-dependent manner. There are many compounds other than mastoparan with apparently diverse structural properties which have been shown to directly activate G-proteins. The relevance and possible participation of receptor-independent mode of G-protein activation for some neuropeptides were discussed.     

Comments on "Determination of matrix transfer function in the form of matrix fraction from input-output observations"

-Furuta and Paquet have proposed an algorithm for determining coefficients of an input-output relation from input-output observations. The purpose of this note is to point out that these coefficients can be obtaiined by a simpler algorithm which requires less computation and that there are other algorithms for minimal realization from these coefficients.     

A case report of incomplete endocardial cushion defect with mitral stenosis in an elderly patient

The following paper describes a mitral valve replacement (SJM 27 mm), the patch closure (EPTFE) of an ostium primum atrial septal defect and tricuspid annuloplasty (De Vega's method) in a 64-year-old female patient with an incomplete endocardial cushion defect and mitral stenosis. Surgery revealed thickened, mitral valve leaflets and the presence of a cleft, findings similar to those observed in case of rheumatic degeneration. Investigation of patient hemodynamics confirmed a diagnosis of Lutembacher syndrome and a lower with left ventricle volume. After surgery, the volume of left ventricle increased and the patients clinical course was uneventful.     

Comparison of Urinary Scents of Two Related Mouse Species, <Emphasis Type="Italic">Mus spicilegus</Emphasis> and <Emphasis Type="Italic">Mus domesticus</Emphasis>

Whereas the house mouse (Mus domesticus) has been studied extensively in terms of physiology/behavior and pheromonal attributes, the evolutionarily related mound-building mouse (Mus spicilegus) has received attention only recently due to its divergent behavioral traits related to olfaction. To date, no chemical studies on urinary volatile compounds have been performed on M. spicilegus. The rationale for our investigations was to determine if there are differences in urinary volatiles of intact and castrated M. spicilegus males and to explore further whether this species could utilize the same or structurally similar pheromones as the male house mouse, M. domesticus. The use of capillary gas chromatography/mass spectrometry (GC-MS) together with sorptive stir bar extraction sampling enabled quantitative comparisons between the intact and castrated M. spicilegus urinary profiles. Additionally, through GC-MS and atomic emission (sulfur-selective) detection, we identified qualitative molecular differences between intact M. spicilegus and M. domesticus. A series of volatile and odoriferous lactones and the presence of coumarin were the unique features of M. spicilegus, as was the notable absence of 2-sec-butyl-4,5-dihydrothiazole (a prominent M. domesticus male pheromone) and other sulfur-containing compounds. Castration of M. spicilegus males eliminated several substances, including δ-hexalactone and γ-octalactone, and substantially decreased additional compounds, suggesting their possible role in chemical communication. Some other M. domesticus pheromone components were also found in M. spicilegus urine. These comparative chemical analyses support the notion of metabolic similarities as well as the uniqueness of some volatiles for M. spicilegus, which may have a distinct physiological function in reproduction and behavior.     

Early construction and operation of the highly contaminated water treatment system in Fukushima Daiichi Nuclear Power Station (III) – a unique simulation code to evaluate time-dependent Cs adsorption/desorption behavior in column system

A simulation code was developed to evaluate the performance of the cesium adsorption instrument operating in Fukushima Daiichi Nuclear Power Station. Since contaminated water contains seawater whose salinity is not constant, a new model was introduced to the conventional zeolite column simulation code to deal with the variable salinity of the seawater. Another feature of the cesium adsorption instrument is that it consists of several columns arranged in both series and parallel. The spent columns are replaced in a unique manner using a merry-go-round system. The code is designed by taking those factors into account. Consequently, it enables the evaluation of the performance characteristics of the cesium adsorption instrument, such as the time history of the decontamination factor, the cesium adsorption amount in each column, and the axial distribution of the adsorbed cesium in the spent columns. The simulation is conducted for different operation patterns and its results are given to Tokyo Electric Power Company (TEPCO) to support the optimization of the operation schedule. The code is also used to investigate the cause of some events that actually occurred in the operation of the cesium adsorption instrument.     

The effect of thiophene sequence separation on air-stable organic thin-film transistor materials

The relationship between thiophene sequences and organic thin-film transistor (OTFT) characteristics was studied to determine their effect on ionization potential, molecular orientation, and air stability. Two types of molecular structures were used: continuous sequence and divided sequence thiophenes. The length of thiophene sequence did not affect FET characteristics but did affect ionic potential and air stability. Furthermore, materials with divided thiophene sequences showed no change in OTFT characteristics when exposed to air. These results suggest that separation of thiophene sequences can improve air stability, which is a problem of thiophene-based materials.     

Colour-odour correspondences in women during the menstrual cycle: Comparative analysis between the menstrual and ovulation phases

Women might experience modulation in their perception and cognition of colours and odours during the menstrual cycle, but how women's impressions of and correspondence between colours and odours differ according to the cycle changes remains unknown. Here, we experimentally examined women's performance of several tasks, including evaluation of impressions of colours and odours, matching/nonmatching of colours with odours, and identification of odours, comparing two phases: the beginning of menstruation and ovulation. The results showed that participants had similar impressions of colours and odours and made similar colour choices for odours in both the menstrual and ovulation phases, while “pleasant-unpleasant” impressions of colour and odour might vary according to the menstrual cycle. We found no significant differences in odour identification between the phases. The findings imply that hormonal changes during the menstrual cycle might affect “pleasant-unpleasant” impressions of colour and odour but not other features regarding impressions or crossmodal correspondence. In future studies, examination with a large number of participants is necessary.