The kappa-opioid U-50,488H suppresses the initiation of nocturnal spontaneous drinking in normally hydrated rats

The effect of a systemic (IP) treatment with 1.0, 3.0 and 9.0 mg/kg U-50,488H (U50), a highly selective kappa-agonist, on spontaneous, nocturnal ingestive behavior of the rat was studied using a microcomputer controlled data acquisition system. The latency to initiate drinking was increased and drinking behavior was suppressed in the first hour after injection in a dose-dependent manner. The consummatory indices of drinking were not affected. After this period of adipsia, a phase of polydipsia, that was probably due to the diuretic effect of U50, was evident. The prophagic effect of U50 was evident only at the dose of 3 mg/kg and was accompanied by an increased duration of feeding episodes but not by a reduced latency to feed. These results suggest that kappa-receptors play a pivotal role in modulating spontaneous drinking in the normally hydrated rat and that this control is mainly exerted on the motivational aspect of drinking.     

Characteristics of Contraceptive Use in Sao Paulo State, Brazil

Objective To know the characteristics of contraceptive use in Sao Paulo State collected by the Demographic and Health Survey （DHS） conducted in 1996. Methods Data of Sao Paulo in 1996 were analyzed compared with the previous DHS carried on in 1986focusing on Sao Paulo State. Contraceptive use among married or cohabiting women by age, number of children and schooling was closely examined. Age and timing of female sterilization were also analyzed. Results The results showed that unlike Brazil there was a stability of female sterilization in Sao Paulo State during 1986 and 1996. There was a pattern in Sao Paulo： up to 30 years old the pill was the most used contraceptive, after 30 there was a predominance of female sterilization, which increased with the number of children and decreased with schooling. The use of male methods had also increased in the 1986 and 1996 period, being greater in Sao Paulo than in Brazil. Sao Paulo also presented more diversity in the use of reversible contraceptives. Conclusions The predominant two contraceptive methods in Brazil and Sao Paulo changed from 1986 to 1996, i.e..from pill to female sterilization.     

The role of contextual versus discrete drug-associated cues in promoting the induction of psychomotor sensitization to intravenous amphetamine

The environmental context in which psychostimulant drugs are administered can have a large effect on both their acute psychomotor activating effects and their ability to induce the psychomotor sensitization associated with repeated drug administration. For example, the acute effects of amphetamine and the development of psychomotor sensitization to amphetamine and cocaine are enhanced when they are administered in a distinct and relatively novel test environment, relative to when they are given in the home cage, in the absence of any environmental stimuli predictive of drug administration. The experiments reported here were designed to further examine this phenomenon and to test the hypothesis that the ability of a distinct context to promote robust psychomotor sensitization is due to its ability to reliably signal (cue) drug administration. Specifically, we compared the ability of contextual cues (a distinct test environment) and discrete cues (light, tone and/or odor), which both reliably predict drug administration, to promote the induction of sensitization. The psychomotor stimulant effects (rotational behavior) of repeated intravenous infusions of 0. 5 mg/kg amphetamine were assessed in rats for whom drug treatments were signaled either: (1) by placement into a distinct test environment; (2) by presentation of discrete cues; or (3) rats for whom drug treatments were given in the home environment in the absence of any environmental cues. Amphetamine produced robust sensitization when given in association with placement into a distinct test environment. The same treatment failed to produce sensitization when the drug was given unsignaled in the animal's home cage. Most importantly, signaling drug administration by presenting discrete cues was not sufficient to promote the robust sensitization seen when treatments were given in a distinct test environment. These results confirm that the induction of psychomotor sensitization can be powerfully modulated by environmental context and further establish that, although contextual stimuli associated with a distinct test environment promote robust sensitization, discrete cues that merely predict drug administration do not have this property. Possible reasons for the difference in the ability of contextual versus discrete environmental cues to promote sensitization are discussed.     

Environmental modulation of the interoceptive effects of amphetamine in the rat

The aim of the present study was to investigate the effect of environmental novelty on amphetamine discrimination. Two groups of rats (home group and novelty group) were trained to perform water-reinforced operant behavior in cages equipped with two levers and a retractable liquid dipper (0.1cc cup). The experimental procedures for the two groups were identical except for the fact that home rats were housed and tested in the operant cages whereas novelty rats were transferred daily to these cages for the testing sessions (25min). The rats were trained to discriminate one of two doses of amphetamine (0.25 and 0.5mg/kg) from saline. Saline and amphetamine were administered intraperitoneally immediately before each daily session according to a semi-random schedule for a total of 50 sessions. Reinforcements were delivered according to a fixed ratio that was increased daily from 2 to 30. Successful drug discrimination was achieved when activity on the appropriate lever before the first reinforcement was greater than 80% of total activity, on at least seven out of eight consecutive sessions. When training was conducted with 0.25mg/kg of amphetamine, no home rat acquired drug discrimination whereas 56% of novelty rats reached criterion. When training was conducted with 0.5mg/kg of amphetamine, drug discrimination was achieved by 50% of home rat versus 86% of novelty rats. These findings indicate that environmental novelty can alter the ability of amphetamine to produce interoceptive cues.     

Modulation of morphine sensitization in the rat by contextual stimuli

Rationale: The repeated administration of addictive drugs, such as amphetamine, cocaine, and morphine, produces a progressive enhancement (sensitization) of their psychomotor activating effects. We have previously shown that administration of amphetamine or cocaine in a distinct test environment promotes more robust psychomotor sensitization than if they are given at home. No information is available, however, on whether this environmental manipulation has a similar effect on sensitization to morphine, a drug that enhances dopamine (DA) release in the striatum indirectly by disinhibiting midbrain DA neurons. Objectives: The main goal of present study was to determine whether exposure to a distinct environmental context facilitates morphine sensitization. Methods: As an index of psychomotor activation, we used rotational behavior in rats with a uni- lateral 6-hydroxydopamine lesion of the mesostriatal DA system. There are inconsistencies in the literature regarding the ability of morphine to elicit rotational behavior. Therefore, in experiment 1 we determined the effect of 2.0, 3.0, 4.0, 6.0, and 8.0 mg/kg, IP, of morphine on rotational behavior. In experiment 2, we studied the effect of five consecutive IV infusions of saline or morphine (2.0 mg/kg) in rats treated either in their home cage or in a distinct and relatively novel test environment. After 5 days of withdrawal, all rats received an IV infusion of 2.0 mg/kg morphine (Morphine challenge). The following day all rats received an IV infusion of saline (Saline challenge). Results: Morphine produced a dose-dependent increase in rotational behavior. Environmental novelty enhanced both the acute psychomotor response to morphine and its ability to induce psychomotor sensitization. Furthermore, a conditioned rotational response was seen only in animals treated in the novel environment. Conclusions: Environmental novelty can facilitate the development of sensitization to the psychomotor activating effects of major addictive drugs, such as amphetamine, cocaine, and morphine. Received: 29 November 1999 / Accepted: 14 March 2000     

Is whole colonic imaging necessary for symptoms of change in bowel habit and/or rectal bleeding?

Aim Following the introduction of a 2-week-wait (2ww) cancer pathway, many units are triaging patients with change in bowel habit (CIBH) and/or rectal bleeding (RB) straight to colonoscopy. Evidence suggests that right-sided colonic cancer does not present with these symptoms, hence imaging the left colon only is satisfactory. If this were substantiated, patients could be offered a flexible sigmoidoscopy (FS) alone. This study aimed to review presenting symptoms of patients diagnosed with a right-sided colonic malignancy and assess whether their tumours would be missed based on this practice. Method This is a retrospective analysis of patients who underwent curative resection for a proximal colonic malignancy over a 4-year period. Two-week-wait referral proforma and case notes were analysed for mode of presentation. Results Of 206 elective right hemicolectomies performed, 20/206 (9.7%) patients presented in the absence of either iron deficiency anaemia or palpable abdominal mass. Twelve patients had polyposis identified in the left colon and eight patients had no left-sided colonic pathology. One patient had a strong family history of colon cancer (two first-degree relatives) in the group absent of left-sided pathology. Conclusion Twelve patients who had left-sided polyposis and one patient with a strong family history would have undergone whole colonic imaging based on current colorectal cancer management guidelines. The remaining seven patients with right-sided cancer would have been missed if FS were the only investigation used. Patients presenting on the 2ww with symptoms of a CIBH and/or RB can be adequately investigated with a FS with a 3% chance of missing a proximal cancer.     

Injection of the protein kinase C inhibitor Ro31-8220 into the nucleus accumbens attenuates the acute response to amphetamine: tissue and behavioral studies

The ability of amphetamine to produce heightened locomotor activity is thought to be due to its ability to enhance dopamine release from mesolimbic dopamine neurons. The mechanism by which amphetamine increases dopamine release is not well understood, but is thought to involve exchange diffusion with synaptosomal dopamine through the dopamine transporter. We recently reported that amphetamine-mediated dopamine release in the striatum is also dependent on protein kinase C activity. In the current study, we investigated the role of protein kinase C activity in the acute neurochemical and behavioral response to amphetamine in the nucleus accumbens. Consistent with previous results in the striatum, amphetamine-stimulated dopamine release from nucleus accumbens tissue was inhibited by the specific protein kinase C inhibitor Ro31-8220, but not by the relatively inactive analog bisindoylmaleimide V. In addition, the effects of protein kinase C activity on the acute behavioral response to amphetamine was examined by injecting Ro31-8220 into the nucleus accumbens 15 min prior to intra-accumbens amphetamine. Pretreatment with Ro31-8220 attenuated the motor-stimulant effects of intra-accumbens amphetamine relative to control subjects pretreated with vehicle. Bisindoylmaleimide V did not significantly inhibit the motor-stimulant effects of intra-accumbens amphetamine. These results suggest that the action of amphetamine in the nucleus accumbens in increasing dopamine release and locomotor activity is dependent on protein kinase C activity.     

CT结肠成像对有临床症状的结直肠癌病人的排除诊断

目的 CT结肠成像技术已经越来越多地用于有结直肠症状病人的影像学评价。本研究的目的是评价CT结肠成像技术对有临床症状的老年病人在排除结直肠癌的诊断中的作用。方法对2002年3月—2007年12月间进行CT结肠成像的1359例病人进行回顾性分析。金标准是一年内的内镜检查结果和(或)至数据分析时临床、内镜及影像学检     

Environmental modulation of amphetamine-induced c-fos expression in D1 versus D2 striatal neurons.

We have reported previously that exposure to environmental novelty enhances the behavioral activating effects of amphetamine and its ability to induce the immediate early gene c-fos in the striatum and in other brain regions. In the present study, we used double in situ hybridization histochemistry to study the effect of amphetamine and/or novelty on c-fos expression in two populations of striatal neurons that preferentially express either D1 or D2 dopamine receptor mRNA. When given intraperitoneally to rats in their home cage, amphetamine (2.0 mg/kg) increased c-fos expression only in D1 neurons. In contrast, when the same dose of amphetamine was administered to rats in a novel environment, c-fos was increased in both D1 and D2 neurons. We conclude that the neural populations engaged by amphetamine vary as a function of the circumstances surrounding its administration.     

Metabolomics as a powerful tool for molecular quality assessment of the fish Sparus aurata

The molecular profiles of perchloric acid solutions extracted from the flesh of Sparus aurata fish specimens, produced according to different aquaculture systems, have been investigated. The (1)H-NMR spectra of aqueous extracts are indicative of differences in the metabolite content of fish reared under different conditions that are already distinguishable at their capture, and substantially maintain the same differences in their molecular profiles after sixteen days of storage under ice. The fish metabolic profiles are studied by top-down chemometric analysis. The results of this exploratory investigation show that the fish metabolome accurately reflects the rearing conditions. The level of many metabolites co-vary with the rearing conditions and a few metabolites are quantified including glycogen (stress indicator), histidine, alanine and glycine which all display significant changes dependent on the aquaculture system and on the storage times.