Trypsin inhibitors from Pisum sativum L exhibit identical epitopes

Pea (Pisum sativum L) trypsin inhibitor, known to be a mixture of at least eight different peptides exhibiting different charges as shown by electrophoresis, was subjected to an immunochemical analysis. By PAGE-SDS analysis, only one large diffuse band was detected showing that pea trypsin inhibitor peptides have a molecular weight between 12000 and 15000 amu. After preparative non-denaturing electrophoresis, four major bands, as judged by Coomassie blue staining, were purified and each of them was used to raise specific antibodies in rabbits. By ELISA test, immunoelectrophoresis and absorption on an immunoaffinity column, it was shown that each antiserum directed against any one of the four bands completely cross-reacted against each other. Thus, it can be concluded that each component of the pea trypsin inhibitor should exhibit a very strong sequence homology.     

Blue light generated by frequency doubling of laser diode light ina lithium niobate channel waveguide

Blue light was generated in a LiNbO₃ channel waveguide by frequency doubling radiation from a laser diode in a guided to guided wave interaction, utilizing first-order quasi-phase-matching in a periodically domain inverted structure. A fabrication method that does not depend on the use of titanium was used. A periodic pattern of silicon oxide on the positive c-face of LiNbO₃ was used in combination with a heat treatment to achieve a periodic outdiffusion and domain reversal in the surface layer. A channel guide was subsequently formed by proton exchange     

Awareness of the response after feedback training for changes in heart rate and sudomotor laterality.

Examined the relation between (a) the ability to control visceral responding on a biofeedback (BFB) task and (b) the ability to report behaviors actually contributing to this performance in 4 experiments with 97 male Ss. Ss received BFB training for unidentified visceral responses and then gave written reports about what they had done to control BFB displays. Independent judges were given these reports and, on the basis of knowledge about activities known to contribute to visceral activity, were asked to determine the visceral responses for which Ss had been trained. The reports of Ss who succeeded at bidirectional control of heart rate (Exp I) or sudomotor laterality (Exp II) showed awareness of behaviors related to BFB as assessed by this procedure, whereas the reports of Ss who failed at bidirectional control did not. Subsequent experiments indicated that these results did not depend on a learning strategy that might have been specific to the initial studies. Findings question the view that people are unaware of what they have done to produce the response after training on BFB tasks. (81 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strain differences in maintenance of cocaine self-administration and their relationship to novelty activity responses.

The authors previously demonstrated that Fischer 344 (F344) and Lewis inbred rats differ in acquisition of cocaine self-administration. Other studies show that acquisition and maintenance of drug self-administration are predicted by locomotor activity in a novel environment among outbred Sprague-Dawley rats. The present study was designed to determine whether this relationship extended to F344 and Lewis rats. In Experiment 1, F344, Lewis, and Sprague-Dawley rats were trained to self-administer cocaine and tested with several doses under fixed- and progressive-ratio schedules of reinforcement. Self-administered infusions and ineffective active lever presses--those emitted during infusion and time-out periods--were assessed. In Experiment 2, separate sets of rats of each strain were examined for locomotor responses (distance traveled and center time) under novelty conditions. Results show that F344 rats self-administer more cocaine than Lewis or Sprague-Dawley rats under both schedules and emit more ineffective lever presses--a possible measure of craving. Strain comparisons of locomotor responses suggest that center time, not activity, relates to self-administration behavior. Maintenance studies of cocaine self-administration rather than acquisition may better reflect vulnerability to addiction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Preclinical Characterization of Acyl Sulfonimidamides: Potential Carboxylic Acid Bioisosteres with Tunable Properties

Herein we present the preclinical characterization of novel compounds containing the linear acyl sulfonimidamide functionality. Specifically, we studied the pK_a, lipophilicity, in vitro metabolic stability, plasma protein binding, Caco‐2 permeability, and aqueous solubility for nine aryl acyl sulfonimidamides. In comparison with widely used carboxylic acid bioisosteres, the acyl sulfonimidamides were found to be less acidic and more lipophilic depending on the substitution pattern in the studied compounds. Importantly, the pK_a values (5.9–7.6) were significantly influenced by substituents on the nitrogen atom and the aryl substituents. Moreover, the acyl sulfonimidamides displayed membrane permeabilities ranging from moderate to very high, which correlated with decreased pK_a and low to negligible efflux ratios. We foresee that the chiral sulfur center and the two handles for structural diversity of linear acyl sulfonimidamides will offer new opportunities for drug design and for improving the oral bioavailability of acidic drug candidates.     

Adrenalectomy reduces peripheral neural responses to gustatory stimuli in the rat.

The adrenalectomized rat, because of excessive body sodium loss, has been an important animal model for studying the physiological mechanisms underlying salt ingestion. To investigate the mediation by peripheral taste responsivity of changes in salt intake, multiunit responses of the chorda tympani nerve to various concentrations of NaCl, KCl, and LiCl, hydrochloric acid, and quinine hydrochloride were recorded from 18 adrenalectomized or intact male Sprague-Dawley rats. To control for a generalized decrease in sensory sensitivity, recordings from this auriculotemporal nerve to tactile stimulation of the pinna were also performed. There were no group differences in amplitude of the integrated neural responses to tactile stimulation. The largest decrease in gustatory responsivity occurred for suprathreshold concentrations of NaCl and LiCl. Data are discussed with reference to possible mechanisms underlying this neural alteration and the role that reductions in salt taste responsivity play in mediating increases in salt intake. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of bolus injection duration on perfusion estimates in dynamic CT and dynamic susceptibility contrast MRI

Estimates of cerebral blood flow (CBF) and tissue mean transit time (MTT) have been shown to differ between dynamic CT perfusion (CTP) and dynamic susceptibility contrast MRI (DSC-MRI). This study investigates whether these discrepancies regarding CBF and MTT between CTP and DSC-MRI can be attributed to the different injection durations of these techniques. Five subjects were scanned using CTP and DSC-MRI. Region-wise estimates of CBF, MTT, and cerebral blood volume (CBV) were derived based on oscillatory index regularized singular value decomposition. A parametric model that reproduced the shape of measured time curves and characteristics of resulting perfusion parameter estimates was developed and used to simulate data with injection durations typical for CTP and DSC-MRI for a clinically relevant set of perfusion scenarios and noise levels. In simulations, estimates of CBF/MTT showed larger negative/positive bias and increasing variability for CTP when compared to DSC-MRI, especially for high CBF levels. While noise also affected estimates, at clinically relevant levels, the injection duration effect was larger. There are several methodological differences between CTP and DSC-MRI. The results of this study suggest that the injection duration is among those that can explain differences in estimates of CBF and MTT between these bolus tracking techniques.