Effect of 5-HT3 antagonists and a 5-HT(1A) agonist on fluoxetine-induced conditioned gaping reactions in rats.

Rationale: The effect of manipulation of the serotonin (5-HT) system on conditioned gaping (presumably reflective of nausea in rats) was evaluated.

Objective: The potential of the selective serotonin reuptake inhibitor (SSRI), fluoxetine (which produces nausea in the clinic), to produce conditioned gaping in rats and of the 5-HT(3) antagonists (ondansetron and palonosetron) and the 5-HT(1A) autoreceptor agonist (8-OH-DPAT) to reverse this effect were evaluated.

Materials And Methods: In each of four experiments, rats received three pairings of intraorally delivered 17% sucrose solution and fluoxetine (0, 2, 10 or 20 mg/kg) and 72 h later were given a drug-free test trial.

Lipopolysaccharide dose dependently impairs rapid toxin (LiCl)-induced gustatory conditioning: a taste reactivity examination of the conditioned taste aversion.

There is much debate on how immune activation affects cognitive processing. Research has shown that stimulation of the immune system can significantly impair, have no adverse effects, or enhance learning and memory processes in animals. The present experiment evaluated the effects of the bacterial endotoxin, lipopolysaccharide (LPS) on the acquisition of a rapidly acquired conditioned taste aversion using a toxin-containing food.

Potential of the rat model of conditioned gaping to detect nausea produced by rolipram, a phosphodiesterase-4 (PDE4) inhibitor.

Rolipram, a phosphodiesterase-4 (PDE4) inhibitor, is of current interest as a cognitive enhancer and as a treatment for inflammatory diseases. Originally developed as an anti-depressant, rolipram's efficacy was limited due to its side effects of nausea and vomiting. The experiments reported here evaluated the potential of rolipram to produce conditioned gaping (a selective measure of nausea in rats) to a flavor in the taste reactivity test (Experiment 1) and to a context (Experiment 2).

Conditioned nausea in rats: assessment by conditioned disgust reactions, rather than conditioned taste avoidance.

The terms conditioned taste avoidance and conditioned taste aversion are often used interchangeably in the literature; however, considerable evidence indicates that they may represent different processes. Conditioned taste avoidance is measured by the amount that a rat drinks in a consumption test that includes both appetitive phases and consummatory phases of responding. However, conditioned taste aversion is more directly assessed using the taste reactivity (TR) test that includes only the consummatory phase of responding.

QUADOMICS: an adaptation of the Quality Assessment of Diagnostic Accuracy Assessment (QUADAS) for the evaluation of the methodological quality of studies on the diagnostic accuracy of '-omics'-based technologies.

Objectives: To adapt the Quality Assessment of Diagnostic Accuracy Assessment (QUADAS) to the particular methodological challenges posed by research on '-omics'-based diagnostic tests.

Design And Methods: We generated new guidelines by appraising the suitability of each criterion from QUADAS to '-omics'-based diagnostic research, and by adding new items that addressed specific sources of error. In addition, we defined four phases in the evaluation of a diagnostic test.

Differential effects of neurotoxin-induced lesions of the basolateral amygdala and central nucleus of the amygdala on lithium-induced conditioned disgust reactions and conditioned taste avoidance.

When rats are intraorally exposed to saccharin solution that has previously been paired with lithium chloride (LiCl), they display Pavlovian conditioned disgust reactions. When exposed to LiCl-paired saccharin solution by bottle, they display suppressed instrumental approach to the bottle resulting in suppressed consumption. The present experiments demonstrated that while neither neurotoxin-induced lesions of the basolateral amygdala (BLA) nor the central nucleus of the amygdala (CeA) attenuated the display of Pavlovian conditioned disgust reactions, lesions of the BLA (but not the CeA) attenuated instrumental conditioned avoidance of the taste.

Helical computed tomography inaccuracy in the detection of pulmonary metastases: can it be improved?

Background: In thoracic surgery, manual lung palpation for detection of pulmonary metastases during resection is the standard of care, despite improvements in computed tomography (CT) imaging. In our previous study based on chart review alone, the accuracy of helical CT in the detection of pulmonary metastases was surprisingly low, with a sensitivity of 78%. We hypothesized that this may be improved by scan interpretation with adequate clinical history and focused documentation of all pulmonary lesions, and may be influenced by the training of the reader.

The effect of cannabidiol and URB597 on conditioned gaping (a model of nausea) elicited by a lithium-paired context in the rat.

Rationale: Anticipatory nausea (AN) experienced by chemotherapy patients is resistant to current anti-nausea treatments. In this study, the effect of manipulation of the endocannabinoid (EC) system on a rat model of nausea (conditioned gaping) was determined.

Objective: The potential of cannabidiol (CBD) and the fatty acid amide hydrolase (FAAH) inhibitor, URB597 (URB) to reduce conditioned gaping in rats were evaluated.

Exposure to a context previously associated with nausea elicits conditioned gaping in rats: a model of anticipatory nausea.

Following one or more chemotherapy treatments, many patients report that they experience anticipatory nausea. This phase of nausea has been interpreted as a classically conditioned response where a conditional association develops between the contextual clinic cues and the nausea and/or vomiting that developed following treatment. Although rats do not vomit, they display a distinctive gaping reaction when exposed a flavored solution previously paired with a toxin.

The novel cannabinoid CB1 receptor neutral antagonist AM4113 suppresses food intake and food-reinforced behavior but does not induce signs of nausea in rats.

Drugs that interfere with cannabinoid CB1 transmission suppress various food-motivated behaviors, and it has been suggested that such drugs could be useful as appetite suppressants. Biochemical studies indicate that most of these drugs assessed thus far have been CB1 inverse agonists, and although they have been shown to suppress food intake, they also appear to induce nausea and malaise. The present studies were undertaken to characterize the behavioral effects of AM4113, which is a CB1 neutral antagonist, and to examine whether this drug can reduce food-reinforced behaviors and feeding on diets with varying macronutrient compositions.

Cannabinoid CB1 receptor inverse agonists and neutral antagonists: effects on food intake, food-reinforced behavior and food aversions.

Drugs that interfere with cannabinoid CB1 receptor transmission suppress a number of food-related behaviors, and these compounds are currently being assessed for their potential utility as appetite suppressants. In addition to rimonabant (SR141716A), several other compounds have been evaluated, including AM251 and AM1387. Biochemical studies indicate that most of the drugs assessed thus far have been CB1 inverse agonists, and these drugs all act to suppress food intake and disrupt food-reinforced behavior.

Effect of prior exposure to a lithium- and an amphetamine-paired flavor on the acoustic startle response in rats.

The experiments reported here evaluated the hypothesis that an amphetamine-paired flavor elicits conditioned fear-arousal, whereas a lithium-paired flavor elicits conditioned nausea-disgust by examining the effect of prior flavor exposure on an acoustic startle reaction (ASR). Exposure to a lithium-paired flavor by intraoral infusion, either immediately prior to a startle session (Experiment 1) or during a startle session (Experiments 2 and 3), resulted in a blunted ASR. In contrast, intraoral infusion of an amphetamine-paired flavor resulted in a potentiated ASR.

Effect of delta9-tetrahydrocannabinol on quinine palatability and AM251 on sucrose and quinine palatability using the taste reactivity test.

Here we provide evidence that the cannabinoid agonist, Delta9-tetrahydrocannabinol (Delta9-THC) enhances quinine palatability and the CB1 antagonist/inverse agonist, AM251, reduces sucrose and quinine palatability using the taste reactivity test, which provides a direct measure of palatability independently of appetitive behavior. In Experiment 1, rats were treated with a low dose of Delta9-THC (0.5 mg/kg) or Vehicle 30 min, 60 min, 120 min or 240 min prior to a 5-min intraoral infusion of a highly unpalatable 0.

Effects of the FAAH inhibitor, URB597, and anandamide on lithium-induced taste reactivity responses: a measure of nausea in the rat.

Rationale: The endogenous cannabinoid system plays a vital role in the control of nausea and emesis. Because of the rapid breakdown and hydrolysis of endocannabinoids, such as anandamide, the therapeutic effects may be enhanced by prolonging their duration of action.

Objective: The present experiment evaluated the potential of various doses of URB597, a fatty acid amide hydrolase (FAAH) inhibitor, alone and in combination with systemic administration of anandamide to modulate the establishment of lithium-induced conditioned taste reactivity responses in rats.

Conditioned gaping in rats: a selective measure of nausea.

When intraorally infused with a flavored solution previously paired with an emetic drug, rats display a characteristic gaping reaction that reflects conditioned nausea in this species that is unable to vomit. The commonly used conditioned taste avoidance measure, is not a selective measure of nausea because nearly every drug tested (even rewarding drugs) is capable of producing a conditioned taste avoidance. In contrast, only emetic drugs produce conditioned gaping reactions in rats, and anti-emetic drugs interfere with the establishment and the expression of conditioned gaping reactions but do not interfere with conditioned taste avoidance.

Effect of conditioning method and testing method on strength of lithium-induced taste aversion learning.

Here the authors evaluated the effect of the method of conditioning (bottle or intraoral [IO] infusion) on the strength of a flavor-drug association when measured in a standard 1-bottle consumption test or when measured by IO infusion in a taste reactivity test. When tested with the bottle test in Experiment 1, rats conditioned by bottle displayed stronger taste avoidance than those conditioned by IO infusion. When tested for rejection reactions with the taste reactivity test in Experiment 2, rats conditioned by infusion displayed a stronger aversion than did rats conditioned by bottle.

Chronic treatment with Delta-9-tetrahydrocannabinol alters the structure of neurons in the nucleus accumbens shell and medial prefrontal cortex of rats.

The potential of repeated exposure to Delta(9)-tetrahydrocannabinol (Delta(9)-THC) to produce long-lasting changes in synaptic connections in a manner similar to other drugs of abuse was evaluated in Sprague-Dawley rats. For 12 days, rats received two i.p.

Renewal effect: context-dependent extinction of a cocaine- and a morphine-induced conditioned floor preference.

Rationale: Extinction of fear conditioning has been demonstrated to be context dependent. The experiments in this study evaluate whether extinction of a drug-cue association is also context dependent, using a conditioned floor preference procedure.

Methods: A drug (cocaine or morphine)-floor association was established in a specific context (black or white box).

Extinction of a saccharin-lithium association: assessment by consumption and taste reactivity.

Extinction of a conditioned palatability shift preceded extinction of conditioned taste avoidance whether rats were tested using a within-subjects design or a between-subjects design. In each of two experiments, consumption of 0.1% saccharin was paired with either 20 ml/kg of 0.

Exposure to a lithium-paired context elicits gaping in rats: A model of anticipatory nausea.

Chemotherapy patients report anticipatory nausea and vomiting upon re-exposure to the cues previously associated with the treatment. Although rats do not vomit, they display a distinctive gaping reaction when exposed to a toxin-paired flavored solution. Here we report that rats also display gaping reactions during exposure to a context previously paired with the illness-inducing effects of lithium chloride (Experiment 1).

Artificial rearing alters the response of rats to natural and drug-mediated rewards.

Artificial rearing (AR) of infant rats permits precise control over key features of the early environment without maternal influence. The present study examined the behavioral response of AR rats towards natural and drug-mediated rewards, as well as their exploratory and affective behaviors. Adolescent AR rats showed increased preference for sucrose consumption relative to chow and demonstrated greater activity in the open field and in the elevated plus-maze compared to maternally reared (MR) rats.

The role of nausea in taste avoidance learning in rats and shrews.

When paired with a novel flavoured solution, the injection of an emetic drug, such as lithium chloride, produces avoidance of that solution in both non-emetic rats and in emetic shrews. On the other hand, the pairing of a novel flavour with a drug with rewarding properties results in conditioned taste avoidance in rats, but in conditioned taste preference in shrews. It, therefore, appears that nausea may be necessary for the establishment of conditioned taste avoidance in the emetic shrew, but not in the non-emetic rat.

Part 2: Birth trauma: injuries to the intraabdominal organs, peripheral nerves, and skeletal system.

Part 1 of this 2-part article, "Early Recognition and Treatment of Birth Trauma: Injuries to the Head and Face" provided readers with basic concepts related to birth trauma to the head and face. Part 2 focuses on the pathophysiology, etiology, diagnosis, treatment, and prognosis of birth injuries to the intraabdominal organs, the peripheral nerves, the spinal cord, and the skeletal system. Risk factors for birth injury to these areas are discussed along with key issues related to the nursing care of affected infants.

Part 1: early recognition and treatment of birth trauma: injuries to the head and face.

The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) Sentinel Event Alert from July 21, 2004 states that there have been 47 cases of birth trauma-related perinatal death or permanent disability reported for JCAHO review since 1996. This report clearly illustrates the importance of birth trauma in clinical practice for neonatal and perinatal nurses. Estimates suggest that birth trauma occurs in 2% to 7% of all deliveries and is associated with an increase in both mortality and morbidity.

Delta-9-tetrahydrocannabinol and cannabidiol, but not ondansetron, interfere with conditioned retching reactions elicited by a lithium-paired context in Suncus murinus: An animal model of anticipatory nausea and vomiting.

Chemotherapy patients report not only acute nausea and vomiting during the treatment itself, but also report anticipatory nausea and vomiting upon re-exposure to the cues associated with the treatment. We present a model of anticipatory nausea based on the emetic reactions of the Suncus murinus (musk shrew). Following three pairings of a novel distinctive contextual cue with the emetic effects of an injection of lithium chloride, the context acquired the potential to elicit conditioned retching in the absence of the toxin.