Cesium and rubidium salts: effects on voluntary intake of ethanol by the rat

The effects of RbCl and CsCl on voluntary intake of ethanol solution by rats preferring ethanol solution 5% (w/w) over water as the drinking fluid was studied as a function of the dose given and the vehicle injected. Administration of RbCl or CsCl, 0.5 mEq/kg/day or 1.5 mEq/kg/day for three consecutive days, did not alter amounts of ethanol consumed. Repeated administration of RbCl or CsCl, 3.0 mEq/kg/day for three days, produced some moderate reduction in ethanol consumption. Simultaneous injection of RbCl (1.5 mEq/kg) and CsCl (1.5 mEq/kg) resulted in greater and profound lasting decrease in ethanol drinking. The later treatment did not alter specific activities of rat liver alcohol- and aldehyde dehydrogenase from saline treated controls. In general, dissolving the chloride salt of the alkali metals in saline resulted in greater effects on ethanol drinking than that determined after identical dose injected with water as the vehicle. The possible mechanism(s) underlying the effects of alkali metal salts used are suggested.     

Learning selectively increases protein kinase C substrate phosphorylation in specific regions of the chick brain

The effect of imprinting, an early form of exposure learning, on the phosphorylation state of the protein kinase C substrates myristoylated alanine-rich C-kinase substrate (MARCKS) and protein F1/43-kDa growth-associated protein (F1/GAP-43) was studied in two regions of the chick forebrain. One region, the intermediate and medial part of the hyperstriatum ventrale (IMHV), is probably a site of long-term memory; the other, the wulst, contains somatic sensory and visual projection areas. After imprinting, a significant increase in MARCKS protein phosphorylation was observed in the left IMHV but not the right IMHV. No significant alteration in F1/GAP-43 was observed in IMHV. MARCKS was resolved into two acidic components of pI approximately 5.0 and approximately 4.0. Phosphorylation of the pI approximately 5.0 MARCKS but not the pI approximately 4.0 MARCKS was significantly altered by imprinting. The partial correlation between preference score (an index of learning) and phosphorylation, holding constant the effect of approach activity during training, was significant only for the pI approximately 5.0 MARCKS in the left IMHV. A significant negative partial correlation between preference score and F1/GAP-43 phosphorylation in the right wulst was observed. Because the imprinting-induced alteration in MARCKS is selective with respect to phosphoprotein moiety, hemispheric location, and brain region, we propose that these alterations may be central to the learning process.     

Carbide lime and industrial hydrated lime characterization

This paper focuses on the characterization of carbide lime (CL) - a by-product of acetylene production, composed mainly of calcium hydroxide with minor parts of carbonate - and compares its features to those of “dry” hydrated lime (HL) commonly used as a building material. Chemical, thermogravimetric and X-ray diffraction analyses indicated that the limes are similar in chemical and mineralogical compositions, except for the presence of carbon in the waste. Morphological and elemental chemical analyses by SEM and EDS revealed that CL particles differ from HL ones in their morphology and by the presence of carbon formations. Physical characterization included density and BET surface area of the materials, as well as, their particle size distributions in deionized water at diverse time periods. CL underwent agglomeration after approximately 60 min in water, whereas HL progressively became finer with time as determined by laser diffraction. In addition, water retention and squeeze flow tests were used to assess the pastes' fresh properties.     

Proton and neutron excitations in superdeformed 150Tb

To determine which of two treatments for reducing ischemic injury after temporal focal ischemia is more effective, the effects of mild (33 degrees C) intraischemic hypothermia were compared with those of mannitol, the most commonly used neuroprotective agent. Four groups of Sprague-Dawley rats underwent 1 hour of endovascular middle cerebral artery occlusion followed by 23 hours of normothermic reperfusion. The four experimental groups were as follows: Group A, saline control; Group B, mannitol (25%, 1 g/kg); Group C, hypothermia; and Group D, hypothermia plus man-nitol. Laser-Doppler estimates of cortical blood flow showed that hypothermia did not affect blood flow during ischemia or reperfusion. Mannitol increased cortical blood flow during ischemia and reperfusion under both normothermic and hypothermic conditions (p < 0.05). Neurological deficit was significantly less severe in treated rats (Group B, p < 0.05; Group C or D, p < 0.01) than in controls (Group A). Infarct volume, measured on semiserial Nissl-stained sections, was significantly smaller in treated rats (p < 0.01) than in controls. Infarct volume was also significantly smaller in rats treated with hypothermia than in those treated with mannitol (Group C vs. Group B, p < 0.05); there was no difference between rats treated with mannitol and those treated with mannitol and hypothermia. All three treatments reduced infarct area in the ischemic penumbra; hypothermia with or without mannitol also reduced infarct area in the ischemic core. These results demonstrate that both mild intraischemic hypothermia and mannitol reduce infarct size and neurological deficit: hypothermia reduces infarct size more effectively than mannitol, and mannitol adds no significant protection to hypothermia, whereas hypothermia adds significant protection beyond that afforded by mannitol after brief focal ischemia followed by reperfusion in rats. The results suggest that mild intraischemic hypothermia alone, or in combination with mannitol, may be useful in avoiding ischemic injury from temporary vessel occlusion during cerebrovascular surgery.