SEARCH · Search PubMed

Results for “Reality Testing”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,297 records · Page 72Linked to original sources

PubMed1989

Model systems for defining initiation, promotion, and progression of skin neoplasms.

A number of items that must be considered in designing and choosing a suitable model for initiation and promotion testing have been described. Although these items may seem complex, tests for initiation and promotion are, in reality, quite simple and provide a rational approach to carcinogen testing. Several tests have been described here and Eastin, elsewhere in this book, describes the validation of a simple and highly recommended test. The processes involved in initiation and promotion are qualitatively different. The criteria for concern about possible human hazards as well as for regulation of initiators and promoters should be based on these qualitative differences. Realistic appraisal of the risk must be based on the level and nature of the potential hazard. In particular, it must be recognized that promoting action is reversible, that a threshold exists, and that promotion is readily inhibited. Therefore, animal tests that differentiate between potential initiators and promoters are essential to enable a logical assessment of human risk and the implementation of appropriate protective measures based on scientific facts.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed2006

High-level virtual reality simulator for endourologic procedures of lower urinary tract.

OBJECTIVES: To analyze the limitations of existing simulators for urologic techniques, and then test and evaluate a novel virtual reality (VR) simulator for endourologic procedures of the lower urinary tract. Surgical simulation using VR has the potential to have a tremendous impact on surgical training, testing, and certification. Endourologic procedures seem to be an ideal target for VR systems. METHODS: The URO-Trainer features genuine VR, obtained from digital video footage of more than 400 endourologic diagnostic and therapeutic procedures, as well as data from cross-sectional imaging. The software offers infinite random variations of the anatomy and pathologic features for diagnosis and surgical intervention. An advanced haptic force feedback is incorporated. Virtual cystoscopy and resection of bladder tumors were evaluated by 24 medical students and 12 residents at our department. RESULTS: The system was assessed by more than 150 international urologists with varying experience at different conventions and workshops from March 2003 to September 2004. Because of these evaluations and constant evolutions, the final version provides a genuine representation of endourologic procedures. Objective data are generated by a tutoring system that has documented evident teaching benefits for medical students and residents in cystoscopy and treatment of bladder tumors. CONCLUSIONS: The URO-Trainer represents the latest generation of endoscopy simulators. Authentic visual and haptic sensations, unlimited virtual cases, and an intelligent tutoring system make this modular system an important improvement in computer-based training and quality control in urology.

Computer Simulation↗

PubMed1999

On sex, mate selection and the red queen.

The widespread occurrence of sexual reproduction despite the two-fold disadvantage of producing males, is still an unsolved mystery in evolutionary biology. One explanatory theory, called the "Red Queen" hypothesis, states that sex is an adaptation to escape from parasites. A more recent hypothesis, the mate selection hypothesis, assumes that non-random mating, possible only with sex, accelerates the evolution of beneficial traits. This paper tests these two hypotheses, using an agent-based or "micro-analytic" evolutionary algorithm where host-parasite interaction is simulated adhering to biological reality. While previous simpler models testing the "Red Queen" hypothesis considered mainly haploid hosts, stable population density, random mating and simplified expression of fitness, our more realistic model allows diploidy, mate selection, live history constraints and variable population densities. Results suggest that the Red Queen hypothesis is not valid for more realistic evolutionary scenarios and that each of the two hypotheses tested seem to explain partially but not exhaustively the adaptive value of sex. Based on the results we suggest that sexual populations in nature should avoid both, maximizing outbreeding or maximizing inbreeding and should acquire mate selection strategies which favour optimal ranges of genetic mixing in accordance with environmental challenges.

Animals↗

PubMed2006

Effectiveness of virtual reality for pediatric pain distraction during i.v. placement.

The objective of this study was to test the efficacy and suitability of virtual reality (VR) as a pain distraction for pediatric intravenous (i.v.) placement. Twenty children (12 boys, 8 girls) requiring i.v. placement for a magnetic resonance imaging/computed tomography (MRI/CT) scan were randomly assigned to two conditions: (1) VR distraction using Street Luge (5DT), presented via a head-mounted display, or (2) standard of care (topical anesthetic) with no distraction. Children, their parents, and nurses completed self-report questionnaires that assessed numerous health-related outcomes. Responses from the Faces Pain Scale-Revised indicated a fourfold increase in affective pain within the control condition; by contrast, no significant differences were detected within the VR condition. Significant associations between multiple measures of anticipatory anxiety, affective pain, i.v. pain intensity, and measures of past procedural pain provided support for the complex interplay of a multimodal assessment of pain perception. There was also a sufficient amount of evidence supporting the efficacy of Street Luge as a pediatric pain distraction tool during i.v. placement: an adequate level of presence, no simulator sickness, and significantly more child-, parent-, and nurse-reported satisfaction with pain management. VR pain distraction was positively endorsed by all reporters and is a promising tool for decreasing pain, and anxiety in children undergoing acute medical interventions. However, further research with larger sample sizes and other routine medical procedures is warranted.

Attention↗

PubMed2002

Stroke rehabilitation at home using virtual reality, haptics and telemedicine.

The objective of this pilot study is to identify the level of difficulty in which subjects with left hemisphere damage in the acute phase after stroke can start practicing in a virtual environment. Second, to test an application of Virtual Reality technology to existing occupational treatment methods in stroke rehabilitation and develop a platform for home rehabilitation controlled telemedically. The findings indicate that the system shows potential as an assessment and training device. The feasibility study setup is working well likewise the assessment method. Developing and increasing the complexity of the tasks must be based on the patient individual neurology, and that the cinematic motion patterns of the patient's are the basis for exercise design.

Adult↗

PubMed1999

Evaluation of a testing method for the fatigue performance of total knee tibial trays.

Catastrophic failure of tibial baseplates due to fatigue fracture have occurred in patients. The International Standards Organisation (ISO) have proposed an endurance test to ensure a safety level for trays with respect to this problem. At present the magnitude of the applied load has not been defined. The purpose of this study is to evaluate the ISO test by comparing the results of two tibial trays: one with a clinical history of fracture of the tibial baseplate in some cases (Kinematic) and one without such a record (Kinemax). A load of 2000 N was selected, representing the peak force during the normal walking cycle. Finite element analysis (FEA) predicted that both the Kinematic and Kinemax trays would rapidly fail for two defined contact positions. Mechanical testing performed on both these components confirmed the FEA predictions. However, under service conditions, the Kinematic tray has been reported to have a failure of only 1-2%, the failure occurring at a mean of 54 months for early fracture and 7 years for late fracture. There are no published reports of failed Kinemax trays. It is concluded that the ISO test is an exaggeration of reality when a physiological load is used. As a result of our study we propose that a load of 500 N would effectively screen components with respect to the ISO test conditions for the likelihood of fracture.

Bone Plates↗

PubMed2001

Detecting differentially expressed genes in multiple tag sampling experiments: comparative evaluation of statistical tests.

The comparison of several statistical methods currently used for detection of differentially expressed genes was attempted both by a simulation approach and by the analysis of data sets of human expressed sequence tags, obtained from UniGene. In the simulated mixed case, mimicking a situation close to reality, the general chi(2) test was unexpectedly the most efficient in multiple tag sampling experiments, especially when dealing with variations affecting weakly expressed genes. On the other hand, Audic and Claverie's method proved the most efficient for detecting differences in gene expression when dealing with pairwise comparisons. By applying the above methods on UniGene-based data sets concerning two human kidney tumours compared with normal kidney tissue, three novel genes overexpressed in these tumours were identified. Software and additional information on statistical methodologies, simulation approach and data are available at http://telethon.bio.unipd.it/bioinfo/IDEG6/.

Animals↗

PubMed2000

Positive symptomatology and source-monitoring failure in schizophrenia--an analysis of symptom-specific effects.

Recent research has suggested that certain positive symptoms in patients with schizophrenia are linked to self monitoring/reality-monitoring deficits. We wished to investigate the association between such deficits and three specific symptoms: hallucinations, delusions and thought disorganisation. Forty patients with schizophrenia and 40 normal controls were administered a source-monitoring task. Twenty-four items were produced, either verbally by the experimenter, or verbally by the subject, or presented as pictures. Then, subjects were read a recognition list including the produced target items mixed with distractors. They were required to recognise the target items and to remember their source of production. The pattern of memory deficits has previously been reported (Brébion, G., Smith, M., Gorman, J., Amador, X., 1997. Discrimination accuracy and decision biases in different types of reality monitoring in schizophrenia. Journal of Nervous and Mental Disease 185, 247-253). The current analyses focussed on the false recognition of distractors, and on the errors in the source attribution of the recognised target items. Results showed that higher hallucination scores were associated with an increased tendency towards false recognition of non-produced items. In addition, hallucinators were more prone than control subjects to misattribute to another source the items they had produced themselves. Furthermore, hallucinators and delusional patients were more prone than the other patients to report that spoken items had been presented as pictures. This latter finding suggests that both hallucinations and delusions are associated with confusion between imagined and perceived pictures. Our previous report stated that only one of the three investigated types of response bias was associated with global positive symptomatology. However, this finer-grained analysis revealed that the three of them were in fact associated with hallucinations and/or delusions. On the other hand, thought disorganisation appeared to be independent from these mechanisms.

Adult↗

PubMed1998

Current susceptibility patterns of anaerobic bacteria.

While antibiotic resistance among anaerobes continues to increase, the frequency of antimicrobial susceptibility testing for anaerobes is declining. Because anaerobic infections are often mixed and detailed bacteriology of the organisms involved may take some time, physicians must institute empiric therapy before susceptibility testing results are available. Also, economic realities and prudent use of resources mandate that careful consideration be given to the necessity for routine susceptibility testing of anaerobic bacteria. Determination of appropriate therapy can be based on published antibiograms; however, since patterns may vary within geographic regions and even within hospitals, it is strongly recommended that each hospital center periodically test their isolates to determine local patterns and detect any pockets of resistance. As a general guide, antibiograms from the last several years of susceptibility testing at the Wadsworth Anaerobe Laboratory are reported.

Bacteria, Anaerobic↗

PubMed1997

[The role of Hühner's direct post-coital test in the evaluation of conjugal sterility in the African environment in Senegal. (Apropos of 2593 post-coital tests performed by the clinical cytology, cytogenetic and reproduction biology laboratory at the University Hospital Center in Dakar, Senegal) 1983-1993].

About 2593 post-coïtal tests (PCT) or Hühner direct tests were realised in the laboratory of clinical cytology, cytogenetics and reproductive biology of the University medical Centre of Dakar, Senegal from 1983 to 1993. Analysing the results, the authors showed the importance of the infectious factor in women and also the role of male deficiency in conjugal sterility in black African environment. These realities have been confirmed cytospermiologic test deficient results. These sperm exams have shown among other things, the prevailing number of azoospermia (25%) and of oligo-asthénotératozoospermia (44%) in husbands of sterile women in the black African environment of Senegal. Pap's Tests have been jointly realised at the same time as 1902 PCT. The results have enabled us to track down 120 cervix with precancerous and cancerous cell alterations; 81 condylomas (HPV), 25 CIN1, 11 CIN2 and 3 CIN3 (CIN: cervical intra-epithelial Neoplasia). These facts suggest a cautious technics, and a prudent interpretation of the results and taking into account the competence and the subjectivity of the practitioner. We have learnt from the study that we must give as much as possible to biologists of Reproduction in southern countries, where conjugal sterility and cervix precancerous and cancerous cell alterations are high, a polyvalent training so that they can practise jointly the post-coïtal or Hühner direct test (PCT) and the Papanicolaou Colpocytologic Test (TP), provided that one owes a microscope.

Adolescent↗

PubMed1987

The maternity blues: exploration of a psychological hypothesis.

Previous studies of the maternity blues have failed to identify a consistent factor discriminating between the group of women who experienced the phenomenon and those who did not. The present study hypothesized that the maternity blues are a hormonally-assisted grief reaction which will occur predominantly in women whose antenatal expectation of baby or delivery fails to be fulfilled by the reality events. The hypothesis was tested in a prospective study of 89 women. The phenomenology of the blues was not found to be associated with the hypothesized sense of disappointment or anti-climax despite many womens' experiences falling short of expectation. Rather, the most powerful predictor of the blues was a sense of "pessimism" in late pregnancy which was actually fulfilled by postpartum reality. In addition, the triad comprising of severity of pre-menstrual tension, unplanned pregnancy and consideration given to elective termination in early pregnancy was associated with increased incidence of the blues.

Abortion, Induced↗

PubMed1984

Seeing and believing: children's understanding of the distinction between appearance and reality.

When young children are asked questions about objects with misleading appearances, they make two kinds of errors: (1) phenomenism--they report appearance when asked to report reality; and (2) intellectual realism--they report reality when asked to report appearance. Two studies with 3-year-old children tested the hypothesis that phenomenism errors predominate when children are asked about objects' real and apparent properties, whereas intellectual realism errors predominate when children are asked about objects' real and apparent identities. The results of these studies provided some support for the property-identity hypothesis; children's appearance-reality judgments about properties tended to differ from those about identities. More phenomenism errors were elicited when the stimuli were described to the children in terms of their properties than when the very same stimulus objects were described in terms of their identities. Identity tasks were not found to elicit predominantly intellectual realism errors, although the data showed trends in this direction. The implications of these results for theories about young children's tendency to accept things in terms of their perceptual characteristics were briefly discussed.

Child Development↗

PubMed1983

Reality orientation therapy--a controlled trial.

Sixty long-stay patients who were demented or withdrawn or both were randomly allocated to reality orientation or diversional occupational therapy and were assessed blind on two scales. Owing to a high drop-out rate only 19 organic and 19 functional patients satisfied reasonable criteria for inclusion in the analyses. Those treated by reality orientation therapy fared better than the controls but not significantly so. Initial test scores were no guide to outcome. The results suggested that both organic and functional patients benefited cognitively, but hardly at all behaviourally, from both types of treatment.

Adult↗

PubMed2000

Circumventing multiple testing: a multilocus Monte Carlo approach to testing for association.

Advances in marker technology have made a dense marker map a reality. If each marker is considered separately, and separate tests for association with a disease gene are performed, then multiple testing becomes an issue. A common solution uses a Bonferroni correction to account for multiple tests performed. However, with dense marker maps, neighboring markers are tightly linked and may have associated alleles; thus tests at nearby marker loci may not be independent. When alleles at different marker loci are associated, the Bonferroni correction may lead to a conservative test, and hence a power loss. As an alternative, for tests of association that use family data, we propose a Monte Carlo procedure that provides a global assessment of significance. We examine the case of tightly linked markers with varying amounts of association between them. Using computer simulations, we study a family-based test for association (the transmission/disequilibrium test), and compare its power when either the Bonferroni or Monte Carlo procedure is used to determine significance. Our results show that when the alleles at different marker loci are not associated, using either procedure results in tests with similar power. However, when alleles at linked markers are associated, the test using the Monte Carlo procedure is more powerful than the test using the Bonferroni procedure. This proposed Monte Carlo procedure can be applied whenever it is suspected that markers examined have high amounts of association, or as a general approach to ensure appropriate significance levels and optimal power.

Alleles↗

PubMed1981

Emotional reactions of expectant fathers to their wives' first pregnancy.

A group of 51 expectant fathers, whose wives were in the last three months of their first pregnancy, was compared to a control group of 51 married men without children. On the Anxiety Scale Questionnaire the expectant fathers were significantly higher in overall anxiety (both overt and covert), as well as in tension and apprehensiveness. The Blacky Picture Test indicated stronger Oedipal intensity, sibling rivalry and guilt feelings in the experimental group than in the control group. Clinical interviews with six of the subjects revealed considerable ambivalence, frequently related to re-aroused infantile fantasies, feminine identifications, castration fears and Oedipal themes, as well as attempt to defend against the ambivalent feelings through negation, denial, isolation, repression, intellectualization and reaction formation. While the higher levels of anxiety could be understood as a reaction to a reality stress situation, the Blacky Test results and the interview material point to more specific dynamic factors, and support several psychoanalytic hypothesis about significance of pregnancy for the prospective father. The inner conflict aroused contributes to the intensified anxiety, which is likely to be overdetermined.

Adult↗

PubMed1994

'Cognitive inhibition' and positive symptomatology in schizotypy.

The negative priming paradigm (Tipper, 1985) was used to investigate the relationship between 'cognitive inhibition' and symptoms of reality distortion in schizotypy, after previous findings that the negative priming effect is reduced in both acute schizophrenics and high schizotypes (Beech, Powell, McWilliam & Claridge, 1989; Beech, Baylis, Smithson & Claridge, 1989). Following Frith's (1979) model, which suggests that the positive symptoms of schizophrenia are due to a failure of the inhibitory processes which normally limit the contents of consciousness, it was predicted that negative priming would be inversely correlated with levels of positive symptomatology, as measured by the CSTQ (Bentall, Claridge & Slade, 1989). The results supported the hypothesis, which confirms the usefulness of a symptom-oriented approach as well as providing some validation for the concept of schizotypy. It was concluded that high schizotypes, similarly to acute schizophrenics, show a reduction in 'cognitive inhibition', as was predicted by Frith's (1979) model.

Adult↗

PubMed1997

Card-sort performance and syndromes of schizophrenia.

The performance of subgroups of schizophrenic patients on the Wisconsin Card Sort Test was investigated. Factor analyses of positive and negative symptom ratings confirmed that ratings described three groups similar to those reported by several other researchers. These symptom groups were labeled psychomotor poverty, cognitive disorganization, and reality distortion. Coaching and incentives resulted in significant improvement in the card-sort performance for patients characterized by symptoms of psychomotor poverty and reality distortion. Patients with symptoms of disorganization, however, had impaired ability to improve card-sort performance after coaching and incentives. Results indicate that symptoms of disorganization appear to differentiate learners from nonlearners on the Wisconsin Card Sorting Test and may be correlated with different underlying deficits.

Adult↗

PubMed2002

Evaluation of the efficiency of chemotherapy in in vivo orthotopic models of human glioma cells with and without 1p19q deletions and in C6 rat orthotopic allografts serving for the evaluation of surgery combined with chemotherapy.

BACKGROUND: Malignant gliomas of the central nervous system remain associated with dismal prognoses because of their diffuse invasion of the brain parenchyma. Very few experimental models that mimic clinical reality are available today to test potentially new therapies. The authors set up experimental in vivo glioma models of anaplastic astrocytomas of human and rat origins and anaplastic oligodendroglioma of human origin. Standard hospital chemotherapies were employed to test the validity of these models. METHODS: Three glioma cells lines obtained from the American Type Culture Collection (i.e., human Hs683 and U373 cells and rat C6 cells) were implanted into nude mouse brains (Hs683 and U373 cells) and rat brains (C6 cells). The astrocytic nature, as opposed to the oligodendrocytic nature, of the Hs683 and U373 models was investigated by using quantitative (computer-assisted microscopy) immunohistochemical characterizations of nestin, vimentin, glutathione-S-transferase alpha (GSTalpha), GSTmu, GSTpi, and p53 expression. Comparative genomic hybridization (CGH) was employed to investigate 1p19q losses. Chronic administrations of carmustine (BCNU), fotemustin, or temozolomide were assayed in the xenografted U373 and Hs683 models. Both BCNU-related chemotherapy and surgery were assayed in the C6 model. RESULTS: The quantitative phenotypic analyses pointed to the oligodendroglial nature of the Hs683 cell line and the astrocytic nature of the U373 cell line. The Hs683 cells exhibited 1p19q losses, whereas the U373 cells did not. BCNU, fotemustin, and temozolomide dramatically increased the time of survival of the Hs683 oligodendroglioma-bearing mice, whereas temozolomide only induced a weak but nevertheless statistically significant increase in the U373 glioma-bearing mice. In the C6 rat glioma model, surgery and BCNU chemotherapy were more efficient than either treatment alone. CONCLUSIONS: The in vivo models of gliomas of the central nervous system developed in the current work best mimicked clinical reality. They can be used either to identify new therapies against human gliomas or to optimize existing therapies.

Animals↗