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PubMed1988

Interactions of ethanol with benzodiazepine receptor ligands in tests of exploration, locomotion and anxiety.

The ability of benzodiazepine receptor ligands to modify the behavioral effects of ethanol in tests of exploration, locomotion and anxiety are reviewed. Drugs with inverse agonist activity appear capable of consistently antagonizing the reductions in exploration and anxiety caused by ethanol. In contrast, the locomotor stimulant action of ethanol has appeared relatively insensitive to inverse agonists, suggesting that this effect may not be mediated primarily by an action of ethanol at the benzodiazepine/GABA receptor complex.

Animals↗

PubMed1992

Scopolamine suppresses both locomotion and object contact in a free-exploration situation.

It was recently reported by Buhot et al. that presession cholinergic disruption with scopolamine decreases time spent in proximity to novel objects while increasing locomotor behavior. Male Long-Evans rats (Rattus norvegicus, 80 days old) were given low-light access to an arena containing objects but were not forced to remain in the arena. On day 1, each subject was injected with saline (SAL). This session was used for familiarization with the apparatus and procedure. On days 2 and 3, four groups were given saline (SAL) or scopolamine (SCO, 1 mg/kg or 0.25 mg/kg), resulting in SAL-SAL, SAL-SCO, SCO-SAL, and SCO-SCO groups. Videotapes of these sessions were scored according to a standard protocol that allows separate quantification of locomotion, general activity, and object interaction behaviors. Scopolamine suppressed object investigation (both gross contact measures and indices of interaction character) whenever present. In contrast to Buhot et al. (using a forced-exploration situation), in this free-exploration context SCO also suppressed locomotor behavior. This study supports the conclusion that anticholinergics impair information gathering instead of affecting memory directly, which calls into question memory-related explanations of cholinergic treatments.

Acetylcholine↗

PubMed1990

Correlations between behavior of mice in Porsolt's swim test and in tests of anxiety, locomotion, and exploration.

This study examined whether the behavior of male NIH Swiss mice in a putative animal model of depression, Porsolt's swim test, is related to that in other behavioral tests. The other tests were the plus-maze test of anxiety, the holeboard test of exploration and locomotor activity, and a test of seizure threshold to bicuculline. The immobility of the mice in the swim test did not correlate with their behavior in any of the other tests used. The only significant correlations found occurred between individual measures in the holeboard and plus-maze tests. The data suggest that immobility in the swim test is not related to behavior in the tests of anxiety, directed exploration, locomotor activity, or seizure threshold.

Animals↗

PubMed1982

Behavior during hippocampal microinfusions. I. Norepinephrine and diversive exploration.

Adult male Sprague-Dawley rats were surgically implanted with guide cannulas in the anterodorsal hippocampal formation. After recovery from surgery they were administered bilateral infusions into the dentate gyrus of D,L-norepinephrone (NE) at the rate of 0.025 microliter/min throughout a 40-min session in a holeboard/activity apparatus. The computerized holeboard system measured the animals' locomotor activity, stimulus responsivity, and response to novelty, and permitted the reconstruction and analysis of their sequential patterns of movement. The NE infusions failed to affect overall locomotion or holepoking, although group means were slightly elevated. Rearing frequency and duration were significantly increased, as were the number of different holes poked per 5-min epoch and the amount of time in and number of entries into the center region of the holeboard. The novel object reaction of NE-infused rats, measured as the increase in poke duration into holes with novel stimuli, was indistinguishable from that of saline-infused rats. The NE-infused rats exhibited more varied, widespread spatial distributions of sequential patterns of locomotor activity. A dose of the beta-adrenergic antagonist propranolol that was minimally effective when infused by itself blocked all of NE's affects when co-infused in the same solution. Infusions of the noradrenergic releasing agent tyramine mimicked NE's actions, whereas infusions of NE's relatively inactive stereoisomer D-NE or infusions into the overlying lateral ventrical failed to do so. Histological examination of dye-infused brains and microspectrofluorimetry of NE-infused brains treated using the Falck-Hillarp technique for the formaldehyde-induced fluorescence of monoamines indicated that spread of the infusate was confined to the dentate gyrus of the anterodorsal hippocampal formation. The behavioral profile of the NE-infused rats suggests a role for the noradrenergic input to the hippocampal formation in spontaneous environmental reconnaissance and the diversification of stimulus sampling-'diversive' exploration, as opposed to the inspection or 'specific' exploration of unfamiliar stimuli.

Animals↗

PubMed1992

The playground maze: a new method for measuring directed exploration in the rat.

A new test, called the 'playground maze', is described. Rat exploratory responses to a single novel object are measured in the context of responses to 7 familiar objects in a familiar environment. Responses are measured as time spent in areas around the objects on a circular open field. These times are expressed as percentages of the total time spent exploring all the objects and a value which is significantly greater than the expected chance level (12.5%) indicates a novelty response. The paths traversed by the animals on the maze are also recorded and the lengths of these give a measure of locomotion. Preliminary experiments on the effects of chlordiazepoxide (CDP) (1-5 mg/kg) and amphetamine (1.5-4 mg/kg) are reported. CDP significantly increased the novelty response but had no effect on locomotion. Amphetamine treatment at 4 mg/kg abolished the response to novel objects while lower doses (1.5 and 2 mg/kg) did not affect it. All 3 doses of amphetamine significantly increased locomotion. This test provides a new way of measuring the exploratory response to novelty under low stress conditions and allows the separation of drug effects on directed exploration and locomotion.

Amphetamine↗

PubMed1992

An exploration of issues relating to feminism and nurse education.

This paper explores the issue of feminism in relation to nursing and nurse education. As a result of this exploration, the authors suggest there is a need for a move away from traditional patriarchal approaches to nurse education, towards an educational programme based on empowerment principles that maximises the potential of feminine patterns of thinking.

Education, Nursing↗

PubMed1993

'But we're doing it already!' Exploring a response to the concept of reflective practice in order to improve its facilitation.

The paper uses the stimulus of a personal reflection to explore how the concept of reflective practice can be facilitated. The thoughts on facilitation combine the use of recognised knowledge, experience and reflection to offer a way of reducing the risk of rejection of reflective practice. In setting the context for such an exploration, reflective practice is defined and its potential contribution to nursing considered.

Clinical Competence↗

PubMed1993

Exploring the process of learning in human ecology.

The process of learning phenomenon has been and is still widely discussed in nursing education especially in relation to adult learning. In this paper, the author reflects upon and analyses his own specific learning activity in the human ecology perspective to construct a conceptual framework of how learning takes place. He begins by briefly defining human ecology within which this learning process takes place and explores in general terms the existing definitions of 'learning' before arriving at his working definition. He then relates, and explores his learning experience as a basis for analysing how learning actually takes place and uses the identified learning characteristics within this mode of learning to support its relevance and implications for nurse education.

Cultural Characteristics↗

PubMed1989

Planetary protection issues in advance of human exploration of Mars.

Current planetary quarantine considerations focus on robotic missions and attempt a policy of no biological contamination. The presence of humans on Mars, however, will inevitably result in biological contamination and physical alteration of the local environment. The focus of planetary quarantine must therefore shift toward defining and minimizing the inevitable contamination associated with humans. This will involve first determining those areas that will be affected by the presence of a human base, then verifying that these environments do not harbor indigenous life nor provide sites for Earth bacteria to grow. Precursor missions can provide salient information that can make more efficient the planning and design of human exploration missions. In particular, a robotic sample return mission can help to eliminate the concern about returning samples with humans or the return of humans themselves from a planetary quarantine perspective. Without a robotic return the cost of quarantine that would have to be added to a human mission may well exceed the cost of a robotic return mission. Even if the preponderance of scientific evidence argues against the presence of indigenous life, it must be considered as part of any serious planetary quarantine analysis for missions to Mars. If there is life on Mars, the question of human exploration assumes an ethical dimension.

Bacteria↗

PubMed1992

On the negligible role of manned missions for the geological exploration of Mars: a commentary.

At the 28th Plenary Meeting of the Committee on Space Research (COSPAR) in The Hague, The Netherlands, there was on June 28, 1990, a session of commission MF.1 on Impact of Human Expeditions to Mars, in which, among others, the benefits of manned Mars missions for the geological survey of Mars were discussed. The present commentary does not intend to discuss the pros and cons of manned space flight or of Mars exploration at large, but will reiterate some of the points made in that discussion concerning the justification of manned versus automated Mars exploration in the context of geologic sciences.

Exobiology↗

PubMed1994

Long-term modulation of Galactic Cosmic Radiation and its model for space exploration.

As the human exploration of space has received new attention in the United States, studies find that exposure to space radiation could adversely impact the mission design. Galactic Cosmic Radiation (GCR), with its very wide range of charges and energies, is particularly important for a mission to Mars, because it imposes a stiff mass penalty for spacecraft shielding. Dose equivalent versus shielding thickness calculations, show a rapid initial drop in exposure with thickness, but an asymptotic behavior at a higher shielding thickness. Uncertainties in the radiobiology are largely unknown. For a fixed radiation risk, this leads to large uncertain ties in shielding thickness for small uncertainties in estimated dose. In this paper we investigate the application of steady-state, spherically-symmetric diffusion-convection theory of solar modulation to individual measurements of differential energy spectra from 1954 to 1989 in order to estimate the diffusion coefficient, kappa (r,t), as a function of time. We have correlated the diffusion coefficient to the Climax neutron monitor rates and show that, if the diffusion coefficient can be separated into independent functions of space and time: kappa (-r,t)=K(t)kappa 0 beta P kappa 1(r), where beta is the particle velocity and P the rigidity, then (i) The time dependent quantity 1/K(t), which is proportional to the deceleration potential, phi(r,t), is linearly related to the Climax neutron monitor counting rate. (ii) The coefficients obtained from hydrogen or helium intensity measurements are the same. (iii) There are different correlation functions for odd and even solar cycles. (iv) The correlation function for the Climax neutron monitor counting rate for given time, t, can be used to estimate mean deceleration parameter phi(t) to within +/- 15% with 90% confidence. We have shown that kappa(r,t) determined from hydrogen and/or helium data, can be used to fit the oxygen and iron differential energy spectra with a root mean square error of about +/- 10%, and essentially independent of the particle charge or energy. We have also examined the ion chamber and 14C measurements which allow the analysis to be extended from the year 1906 to 1990. Using this model we have defined reference GCR spectra at solar minimum and solar maximum. These can be used for space exploration studies and provide a quantitative estimate of the error in dose due to changes in GCR intensities.

Carbon Radioisotopes↗

PubMed1979

Heart-rate correlates of childhood activities: play, exploration, problem-solving and day-dreaming.

Heart-rate was monitored while children were engaged in different activities. The first study examined the hypothesis that the behavioural distinction between exploration and play would be supported by the psychophysiological measure. Two-year-olds showed suppression of heart rate variability (HRV) during exploration, and even more during solution of a puzzle, suggesting that the task demands these two activities were greater than those during play. The second study demonstrated a relationship between HRV during daydreaming and during problem solving in 9-year-old children which was similar to that obtained between play and problem solving in younger children. The correlative use of HRV thus strengthened functional interpretations of behaviour.

Child↗

PubMed1987

Exploration of the fetal cerebral blood flow by duplex Doppler--linear array system in normal and pathological pregnancies.

The umbilical circulation can be investigated by Doppler ultrasound techniques very easily. The Doppler frequency spectrum from the umbilical arteries provides information on the placental circulation. The diastolic flow amplitude is directly related to the vascular resistances of the placenta (Rp). In cases of pathological pregnancies with hypertension the decrease of the diastolic flow and the increase of the resistance index Rp have been correlated with intrauterine fetal growth retardation. Fetal cerebral arteries have also been explored during normal pregnancies (n = 40). The index of cerebral resistance (Rc) as defined by Pourcelot is Rc = S-D/S (with S systolic amplitude and D diastolic amplitude) and shows variations similar to the placental index. During normal pregnancy, the cerebral index is higher than the placental index and the cerebro-placental ratio (Rc/Rp) is greater than 1. This preliminary study of both umbilical and cerebral circulation seems to demonstrate that during pathological pregnancies with hypertension (n = 21), with fetal growth retardation one of the indices, Rc or Rp may be out of the normal range but the cerebro-placental ratio (CPR) is always less than 1. However a larger number of patients should be explored in order to evaluate the clinical usefulness of such an observation.

Cerebral Arteries↗

PubMedDate not supplied

Behavioral consequences in animal tests of anxiety and exploration of exposure to cat odor.

Rats exposed to a cloth impregnated with cat odor showed a decreased number of contacts with the cloth and time in contact with it and increased time sheltering from it. Exposure to the odor of rat blood produced similar, though less marked, changes and also increased the number of occasions the rat sought shelter. Exposure to the odor of disinfectant changed only the time in contact with the cloth. Exposure to cat odor also resulted in anxiogenic responses in the social interaction and elevated plus-maze tests that could be detected up to 1 h, but not 24 h, after odor exposure. Decreased exploration in the holeboard could also be detected up to 1 h, but not 24 h, after exposure to cat odor. The time in contact with the cloth, the incidence of, and time spent sheltering did not decrease over five successive exposures to the odor of a cat. The number of contacts with the control odor cloth increased over successive exposures, but contacts with the cat odor cloth did not change over successive exposures. The decreased exploration in the holeboard, as a result of prior exposure to cat odor, showed rapid habituation, as did the anxiogenic response detected in the social interaction test, whereas that detected in the plus-maze persisted for up to five odor exposures.

Animals↗

PubMed1985

Local wound exploration of anterior abdominal stab wounds.

At least 25% of stab wounds of the abdomen are superficial. This can be determined in the ED by local wound exploration. If there is no penetration of the posterior fascia as determined by the technique herein described, the patient can be discharged from the emergency department after adequate local wound care is given. Because the patient is not admitted if exploration is negative, this is a safe and cost-effective method of managing superficial stab wounds of the abdomen.

Abdominal Injuries↗

PubMed1993

Laparoscopic approaches to the common bile duct stone: transcystic bile duct exploration, choledochotomy and stone fragmentation.

It has been illustrated that a convergence of new technologies, including advanced laparoscopic techniques, flexible video endoscopy, coaxial balloon dilators and biliary lithotripsy, has allowed the modern laparoscopic surgeon to address a pressing issue: how to deal with choledocholithiasis. A variety of techniques and methods have been described; each has their advocates, philosophical advantages and potential drawbacks. The definitive decision as to which technique is the best awaits the results of future prospective studies. Until then, the three techniques outlined will allow the majority of surgeons to extend the advantages of minimally invasive surgery to patients with choledocholithiasis. There is no doubt that this is desirable. These procedures, however, are not without their failure rate and complications, and they remain technically demanding. Increased education and training of surgeons is needed and further improvement of existing technology is demanded. This includes improved fibreoptic choledochoscopes with better optics, more flexibility and larger working channels; better stone baskets and better mechanical graspers, and safer and more effective stone lithotriptors. Other questions remain unanswered, such as the relative and absolute contraindications to performing laparoscopic common duct explorations. Can patients with multiple common duct stones or very small ducts be safely handled using these methods? Is there a size of common duct stone that is safe to leave behind, and are there safe antegrade methods of treating distal duct stenosis? The new interest in avoiding the placement of T-tubes for common duct drainage also needs close scrutiny. All these questions need well-constructed studies to answer them; but in the meantime, laparoscopic common duct exploration is undoubtedly here to stay, and this new approach to an old problem is inducing biliary surgeons to question many traditionally held dicta, which can in the long run only be in the patients' best interest.

Endoscopy, Digestive System↗

PubMedDate not supplied

Pathological findings in 165 patients explored for malignant hyperthermia susceptibility.

The pathological findings in 165 patients explored for malignant hyperthermia (MH) susceptibility are reported. The first group of 120 subjects were patients investigated for MH. These patients had suffered an attack of MH under anaesthetic or were members of families in which a subject had died of MH. In vitro contracture tests revealed 25 malignant hyperthermia susceptible (MHS) subjects, with positive contracture tests for halothane and caffeine, 5 malignant hyperthermia subjects with reaction to caffeine only (MHC), 3 malignant hyperthermia subjects with reaction to halothane only (MHH) and 87 malignant hyperthermia negative (MHN) subjects with normal contracture tests. The second group of 45 subjects had exertional heat stroke. In vitro contracture tests performed at least 3 months after the exertional heat stroke revealed 11 MHS, 6 MHC, 2 MHH subjects and 26 MHN. In both groups, whatever the in vitro contracture test results, pathological findings were heterogeneous and revealed various changes: rhabdomyolysis, mitochondrial myopathy, denervation, type II atrophy, AMPase deficiency, non-specific findings or normal features. Central core myopathy was only observed in the first subgroup and was the only disease significantly associated with MH. In contrast to previous reports, this study demonstrates the absence of a specific malignant hyperthermia or exertional heat stroke myopathy. Furthermore, the discovery of MHS subjects among the EHS group of patients highlights the need for systematic exploration of all these patients.

Genetic Predisposition to Disease↗

PubMed1995

Synthesis of 4'-iodo-5-methoxy-valerophenone O-(2-aminoethyl)oxime as an agent for exploration of serotoninergic transporter.

The serotonin reuptake process is observed in the central nervous system and in cells derived from the neural crest. It would therefore be of great interest to visualize this reuptake for brain exploration and to visualize the tumors derived from these cells (Apudome). Fluvoxamine has been described as a specific uptake inhibitor for serotonin uptake and we therefore supposed that an iodinated derivative of this compound would be a suitable tracer for this purpose. We had shown by computer-assisted investigation that the trifluoromethyl group of fluvoxamine can be replaced by iodine without changing the steric hindrance of the structure. We therefore expected that this result would allow the development of a new iodinated ligand for human exploration by SPECT which would inhibit for the serotoninergic transporter. This new ligand is 4'-iodo-5-methoxyvalerophenone O-(2-aminoethyl)oxime in its E configuration. In vitro binding studies demonstrated that this iodinated ligand has a weaker affinity for the serotonin uptake sites than fluvoxamine. Steric hindrance is not sufficient to predict affinity, other structural factors such as electronic density and dipole moment must be considered to explain the biological difference between fluvoxamine and its iodinated analog.

Animals↗