Effects of dopamine D?-like and D?-like agonists in rats trained to discriminate cocaine from saline: Influence of experimental history.

Effects of D?-like and D?-like agonists were compared in rats (Rattus norvegicus) with differing levels of experience (24 or 9 mo) in a cocaine discrimination procedure (5.6 mg/kg cocaine; fixed-ratio 20 schedule of food presentation). Cocaine d-amphetamine, and D?-like agonists (quinelorane, 7-OH-DPAT) dose-dependently substituted cocaine in both groups of rats. In contrast D?-like agonists (SKF 82958, SKF 7734) substituted for cocaine only in rats with less discrimination experience. Pretreatment with D?-like agonists increased the stimulus effects of low cocaine-doses in both groups, whereas D?-like agonists produced these effects only in rats with less discrimination experience. The data suggest that the stimulus effects of cocaine overlap with those of D?-like agonists across a broader range of conditions than with those of D?-like agonists. Thus, D?-like receptors may play an especially important role in cocaine's behavioral effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

S-adenosylmethionine generation and prevention of alcoholic fatty liver by betaine

Earlier studies by other investigators have shown that S-adenosylmethionine (SAM) has the capacity to attenuate liver injury in experimental animals. In a recent study in this laboratory, it was shown that when supplemental dietary betaine was given to control and ethanol-fed rats at the level of 0.50% (W/V), SAM levels were doubled in the livers of control animals and increased fivefold in livers of ethanol-fed rats. The increased levels of SAM in the livers of ethanol-fed animals protected the livers from fatty infiltration due to ethanol feeding. In this study, an attempt was made to determine the minimum level of dietary betaine that protects against the fatty infiltration. Levels of betaine at 0.05%, 0.10%, 0.25%, and 0.50% in semiliquid control and alcohol diets were tested in rats for 30 days. When hepatic betaine, SAM, and triglyceride levels were determined, it was demonstrated that only the dietary level of betaine at 0.50% supplied enough hepatic betaine to generate the level of SAM that was required to protect against the alcoholic steatosis resulting from the dietary ethanol. These results suggest that betaine, when given in sufficient amounts, may be a promising therapeutic agent in the treatment of liver disease.     

Psychomotor stimulation by dopamine D?-like but not D?-like agonists in most mouse strains.

Many neurological and psychiatric disorders are treated with dopamine modulators. Studies in mice may reveal genetic factors underlying those disorders or responsiveness to various treatments, and species and strain differences both complicate the use of mice and provide valuable tools. We evaluated psychomotor effects of the dopamine D?-like agonist R-6-Br-APB and the dopamine D?-like agonist quinelorane using a locomotor activity procedure in 15 mouse strains (inbred 129S1/SvImJ, 129S6/SvEvTac, 129X1/SvJ, A/J, BALB/cByJ, BALB/cJ, C3H/HeJ, C57BL/6J, CAST/EiJ, DBA/2J, FVB/NJ, SJL/J, SPRET/EiJ, outbred Swiss Webster, and CD-1) and Sprague–Dawley rats, using groups of both females and males. Both D? and D? stimulation produced hyperactivity in the rats, and surprisingly, only two mouse strains were similar in that regard (C3H/HeJ, SPRET/EiJ). In contrast, the majority of mouse strains exhibited hyperactivity only with D? stimulation, whereas D? stimulation had no effect or decreased activity. BALB substrains, A/J and FVB/NJ mice showed only decreased activity after either D? or D? stimulation. CAST/EiJ mice exhibited hyperactivity exclusively with D? stimulation. Sex differences were observed but no systematic trend emerged: For example, of the five strains in which a main factor of sex was identified for the stimulant effects of the D? agonist, responsiveness was greatest in females in three of those strains and in males in two of those strains. These results should aid in the selection of mouse strains for future studies in which D? or D? responsiveness is a necessary consideration in the experimental design. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Changes in interleukin-1 beta and soluble interleukin-2 receptor levels in CSF and serum of schizophrenic patients

Some evidence points towards a possible autoimmune role in the aetiology of schizophrenia. Experimental findings provide contradictory results regarding abnormalities in cytokine production in this disorder. In the present study we tested the production of cytokines in CSF and serum in 16 schizophrenic patients and 10 healthy controls (tumor necrosis factor alpha - TNF alpha; interleukins IL-1 beta, IL-2, IL-6, soluble IL-2 receptor). Cytokine levels were evaluated by radioactively-labeled antibodies (IL-1 beta, IL-2, IL-6), by enzyme-linked immunoassay (TNF) and by a sandwich enzyme immunoassay (soluble IL-2 receptor). No significant differences were found in either CSF fluid or serum levels of TNF and IL-2 or IL-6. Interleukin-1 beta was significantly decreased in patients' CSF and serum as compared to controls. Soluble interleukin-2 receptor levels were decreased in CSF of patients, but highly increased in their serum in comparison with controls. Changes in various cytokine levels in CSF fluid and serum of schizophrenic patients probably reflect interrelated process of growth, degeneration or neuroimmunological abnormalities, which may all play a role in the pathophysiology of schizophrenia. The present study supports evidence for change in immune activation, probably of peripheral origin, in schizophrenic patients.     

Aggregation pheromones of the flat grain beetle,Cryptolestes pusillus (Coleoptera: Cucujidae)

Aggregation pheromones were isolated fromCryptolestes pusillus (Schönherr), a coleopteran pest of stored products. Porapak Q-captured beetle and frass volatiles were fractionated by preparative gas-liquid chromatography. The fractions were bioassayed with an arena olfactometer and/or with a two-choice, pitfall olfactometer. Three biologically active, male-produced compounds eliciting aggregation behavior from adultC. pusillus were isolated and identified by spectroscopic methods as (Z)-3-dodecenolide (I), (Z)-5-tetradecen-13-olide (II), and (Z,Z)-3,6-dodecadienolide (III). Compound I was the major volatile produced and was active alone. Compound II was not active alone, but synergized the response to I. Compound III was active alone at higher concentrations, but did not significantly increase the response when added to the most active mixture of I and II, and so it is probably not part of the aggregation pheromone. Pheromone production increased dramatically when the insects were aerated on a food source.Research supported in part by the Natural Sciences and Engineering Research Council of Canada, Operating Grants A3881 and A3785, Strategic Grant 60958, and a Graduate Scholarship to J. G. Millar.     

Fuzzy control of environmentally conscious refrigeration systems

This paper introduces the reader to the concepts of fuzzy sets and fuzzy logic and to their capabilities in the area of control systems. To understand the capabilities of fuzzy logic in real-time controller design, a controller for an environmentally conscious refrigeration system was designed and implemented. Initial results show that a fuzzy logic controller is easy to implement, does not need an exact system model, does not need precise and expensive hardware, and deals with human concepts in a fairly natural and obvious way. This would be, hopefully, a potential avenue for future production of intelligent manufactured products.     

A black body mutation of Attagenus elongatulus Casey (Coleoptera: Dermestidae)

Reported here is black body mutation of Attagenus elongatulus Casey, governed by a single autosomal gene, which shows incomplete dominance. There was no difference in the number of larvae produced by normal females when mated to black or normal males. Black males appear to be more responsive to pheromone extracts of both black and normal females.     

Fostering empowerment in online support groups

Online support groups have been used extensively, in numerous areas of distress, for 15 years. Researchers have presented conflicting findings and ideas about their effectiveness in helping people cope with respective problems. Our review of quantitative studies and our qualitative exploration of the nature of the experiences that occur in such groups show that several factors operate to potentially affect participants. Personal and interpersonal dynamics, which are central in producing effects in these groups, are induced and accelerated by the powerful online disinhibition effect. These factors, including the very impact of writing, expressions of emotions, collecting information and thereby improving understanding and knowledge, developing social relationships, and enhancing decision-making skills and consequent behavioral actions all serve as possible generators of a sense of personal empowerment for people in distress. This view may explain why empirical research has frequently found little or no specific outcomes from participating in online support groups; however, it has found much support for nonspecific personal impacts of this means of intervention. Thus, we contend that online support groups are designed to foster, and many of them actually do, well-being, a sense of control, self-confidence, feelings of more independence, social interactions, and improved feelings—all nonspecific but highly important psychological factors. As such, participating in an online support group could foster personal empowerment, which is much needed in handling specific conditions of distress. Nonetheless, this participation has potential costs, too, especially developing dependence, distancing from in-person contacts, and exposure to unpleasant experiences typical of social engagement in cyberspace.