Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Deception”

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.

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

At least 1,279 records · Page 71Linked to original sources
PubMed2003

Chemistry and the hydrogenases.

The reversible reduction protons to dihydrogen: 2H+ + 2e [symbol: see text] H2 is deceptively the simplest of reactions but one that requires multistep catalysis to proceed at practical rates. How the metal-sulfur clusters of the hydrogenases catalyse this interconversion is currently the subject of extensive structural, spectroscopic and mechanistic studies of the enzymes, of synthetic assemblies and of in silico models. This is driven both by curiosity and by the view that an understanding of the underlying chemistry may inform the design of new electrocatalytic systems for hydrogen production or uptake, pertinent to energy transduction technology in an 'Hydrogen Economy'. Can chemists design materials that replace the expensive platinum metal catalysts of fuel cells with metal-sulfur cluster assemblies utilising abundant Ni, Fe and S as in the natural systems? Here we review the state of the art.

Bacteria↗
PubMed1997

The DNA damage-recognition problem in human and other eukaryotic cells: the XPA damage binding protein.

The capacity of human and other eukaryotic cells to recognize a disparate variety of damaged sites in DNA, and selectively excise and repair them, resides in a deceptively small simple protein, a 38-42 kDa zinc-finger binding protein, XPA (xeroderma pigmentosum group A), that has no inherent catalytic properties. One key to its damage-recognition ability resides in a DNA-binding domain which combines a zinc finger and a single-strand binding region which may infiltrate small single-stranded regions caused by helix-destabilizing lesions. Another is the augmentation of its binding capacity by interactions with other single-stranded binding proteins and helicases which co-operate in the binding and are unloaded at the binding site to facilitate further unwinding of the DNA and subsequent catalysis. The properties of these reactions suggest there must be considerable conformational changes in XPA and associated proteins to provide a flexible fit to a wide variety of damaged structures in the DNA.

Animals↗
PubMed2001

Amoebiasis: diagnosis by aspiration and exfoliative cytology.

The present study was undertaken to evaluate the use of fine needle aspiration and exfoliative cytology in the identification of amoebic cysts/trophozoites, and to characterize amoebiasis. The subjects consisted of 15 patients, 11 diagnosed by fine needle aspiration cytology (FNAC) as amoebic abscesses (14 liver and one pulmonary) and four women whose cervical smears contained Entamoeba histolytica cysts or trophozoites. Of 128 ultrasonographically guided FNAC of hepatic lesions over a four year period, 17 were abscesses of which 10 were diagnosed as amoebic. A single case of pulmonary amoebiasis was detected in an 18-year-old male. The case was initially diagnosed as tubercular due to deceptive symptomatology. Three cases of amoebic cysts and one trophozoite were reported on routine cervical smear screening. All four cases were unsuspected for amoebic infection. The disease may easily go undetected unless meticulous screening is exercised, and the search for cysts or trophozoites is made with clear concepts of the morphological characteristics of E. histolytica in mind.

Adolescent↗
PubMed2002

Endocervical adenocarcinoma and its variants: their morphology and differential diagnosis.

Adenocarcinoma of the uterine cervix and its variants account for a much greater number of cases in routine practice of histopathology than they did several decades ago. The varied morphology of these tumours results in diverse problems in differential diagnosis. The overall area of glandular pathology of the cervix, of which invasive adenocarcinoma is only one subset, is further complicated by the fact that there are many benign glandular proliferations of the cervix that can potentially be misinterpreted as adenocarcinoma. In this review the histopathology of endocervical adenocarcinoma and its variants is presented with the emphasis on evaluation of routinely stained sections, still the bedrock of routine practice, relatively little aid being provided by immunohistochemistry or other new techniques, contrary to what is sometimes implied in the literature. Description of the appearance of each subtype of adenocarcinoma or variant thereof is followed by a section on their differential diagnosis. Eighty percent of endocervical carcinomas are of the so-called usual type being characterized by cells with eosinophilic cytoplasm and generally brisk mitotic activity. It is sometimes stated that endocervical adenocarcinomas are mucinous but the usual form just noted often has little or no mucin. Pure or almost pure mucinous adenocarcinoma do occur, however, and have an important subtype, the so-called adenoma malignum (minimal deviation adenocarcinoma). Although treacherous because of its bland cytological features and sometimes deceptive pattern, a cone biopsy or hysterectomy specimen showing this neoplasm typically has easily recognizable features that indicate the presence of an infiltrative adenocarcinoma. An important variant of usual endocervical adenocarcinoma is the well differentiated villoglandular papillary adenocarcinoma, a designation that should be reserved for tumours with grade 1 cytologic features as usual endocervical adenocarcinoma, which is typically grade 2, may have papillae. In our opinion all other variants of pure adenocarcinoma, including endometrioid, are rare and include in addition to the latter clear cell, serous and mesonephric neoplasms. Tumours with a glandular and nonglandular component are also reviewed: adenosquamous carcinoma, glassy cell carcinoma, adenoid basal carcinoma, 'adenoid cystic' carcinoma and adenocarcinoma admixed with a neuroendocrine tumour.

Adenocarcinoma↗
PubMed2003

Endometrioid adenocarcinoma of the uterus with a minimal deviation invasive pattern.

AIMS: Minimal deviation adenocarcinoma of endometrioid type is a rare pathological entity. We describe a variant of typical endometrioid adenocarcinoma associated with minimal deviation adenocarcinoma of endometrioid type. METHODS AND RESULTS: One 'pilot' case of minimal deviation adenocarcinoma of endometrioid type associated with typical endometrioid adenocarcinoma was encountered at our institution in 2001. A second case of same type was received in consultation. We reviewed 168 consecutive hysterectomy specimens diagnosed with 'endometrioid adenocarcinoma' specifically to identify areas of minimal deviation adenocarcinoma of endometrioid type. Immunohistochemistry was done with the following antibodies: MIB1, p53, oestrogen receptor (ER), progesterone receptor (PR), cytokeratin 7 (CK7), cytokeratin 20 (CK20), carcinoembryonic antigen (CEA), and vimentin (VIM). Four additional cases of minimal deviation adenocarcinoma of endometrioid type were identified. All six cases of minimal deviation adenocarcinoma of endometrioid type were associated with superficial endometrioid adenocarcinoma. In two cases with a large amount of minimal deviation adenocarcinoma of endometrioid type, the cervix was involved. The immunoprofile of two representative cases was ER+, PR+, CK7+, CK20-, CEA-, VIM+. MIB1 immunostaining of four cases revealed little proliferative activity of the minimal deviation adenocarcinoma of endometrioid type glandular cells (0-1%) compared with the associated 'typical' endometrioid adenocarcinoma (20-30%). The same four cases showed no p53 immunostaining in minimal deviation adenocarcinoma of endometrioid type compared with a range of positive staining in the associated endometrioid adenocarcinoma. CONCLUSIONS: Minimal deviation adenocarcinoma of endometrioid type more often develops as a result of differentiation from typical endometrioid adenocarcinoma than de novo. Due to its deceptively benign microscopic appearance, minimal deviation adenocarcinoma of endometrioid type may be overlooked and may lead to incorrect assessment of tumour depth and pathological stage. There was a tendency for tumour with a large amount of minimal deviation adenocarcinoma of endometrioid type to invade the cervix.

Aged↗
PubMed1993

The role of denial in clinical practice.

Denial is typically viewed as maladaptive in clinical practice, despite ample evidence of its adaptive role in personal and health crises. The failure of health professionals to embrace the positive aspects of denial lies deeply rooted in cultural beliefs, which have been reinforced in more recent times by misapplication of clinical theory. Denial is a form of self-deception that protects the individual from threats to the self and involves exaggerated perceptions of control and self-efficacy. Social-psychological research suggests that such biases in cognitive appraisal are the norm and not exclusive reactions to crises. It is proposed that denial has the following functions during crises: denial protects the integrity of the self-concept by distorting reality in a self-enhancing way, promoting a sense of mastery and control; this in turn leads to lower levels of anxiety, which may enhance decision-making under conditions of stress. Psychological health appears to be contingent, at least in part, on an ability to see the world through 'rose-tinted glasses'. Health professionals should be aware, therefore, that whilst trying to promote psychological well-being we do not ask patients to be unrealistically realistic.

Adaptation, Psychological↗
PubMed2001

Development and evaluation of a moral distress scale.

AIM OF THE STUDY: This methodological research developed and evaluated the moral distress scale from 1994 to 1997. BACKGROUND/RATIONALE: Although nurses confront moral questions in their practice daily, few instruments are available to measure moral concepts. The methodological design used a convenience sample consisted of 214 nurses from several Unites States hospitals. The framework guiding the development of the moral distress scale (MDS) included Jameton's conceptualization of moral distress, House and Rizzo's role conflict theory, and Rokeach's value theory. Items for the MDS were developed from research on the moral problems that nurses confront in hospital practice. The MDS consists of 32 items in a 7-point Likert format; a higher score reflects a higher level of normal distress. RESULTS: Mean scores on each item ranged from 3.9 to 5.5, indicating moderately high levels of moral distress. The item with the highest mean score (M=5.47) was working where the number of staff is so low that care is inadequate. Factor analysis yielded three factors: individual responsibility, not in the patient's best interest, and deception. No demographic or professional variables were related to moral distress. Fifteen percent of the nurses had resigned a position in the past because of moral distress. CONCLUSION: The results support the reliability and validity of the MDS.

Adult↗
PubMed2002

Caring as a slave morality: Nietzschean themes in nursing ethics.

BACKGROUND: Sceptical arguments about 'caring' can be divided into three categories. First, it is suggested that, while caring is no doubt an admirable thing in itself, it is just one ideal among others. Secondly, it is claimed that caring is not really a virtue at all, and that it should be regarded as more of a vice, because it promotes favouritism, injustice, and self-deception. Thirdly, there is a worry that caring is not politically realistic, and that its advocates underestimate the powerful organizational and social structures which conspire to subvert nursing. AIM: This paper outlines a fourth, and more radical, type of scepticism, which explains why caring is subject to these drawbacks. In doing so, it considers the relation between caring, phenomenology and holism in nursing discourse, and the way in which all three fit together to form the 'caring paradigm'. METHODS: The paper adopts a genealogical approach, borrowed directly from Nietzsche's Genealogy of Morality. That book argues that the values associated with caring are the expression of a profound resentment, harboured by the slaves (weak, powerless, timorous) against the nobles (strong, powerful, self-confident). Caring represents an inversion, a sort of 'fantasy revenge', in which the nobles can be portrayed as 'evil', while the slaves portray their own weakness as 'good'. Taking its cue from Nietzsche, the paper shows that the Genealogy narrative can be transposed into a modern health care context, with nurses as the 'slaves' and the medical profession as the 'nobles'. CONCLUSIONS: The ideology of caring is, in the Genealogy's terms, a slave morality. It represents an attack on the 'medical-scientific model', motivated by resentment, and designed to establish nursing's superiority. Its effects have been debilitating, and it has prevented nursing from becoming a 'noble' (that is, a properly scientific) discipline.

Christianity↗
PubMed2003

Manipulation: description, identification and ambiguity.

The word manipulation is frequently applied to some of the difficult-to-manage behaviours of the personality-disordered patient. However, the term is rarely defined, and a review of both the clinical and research literature shows that little has been written about its definition and identification, let alone its clinical management in both in- and outpatient settings. Recent empirical work conducted with nurses in forensic settings has demonstrated the range of behaviours that professionals refer to as 'manipulative', thus clarifying the use of the term and allowing the provision of a more precise definition. The scope of manipulation in everyday life, management practice and politics is perhaps relatively small, although manipulation can occur in all areas of human activity. Social behaviour is doubly ambiguous with respect to judgements of manipulation, as such judgements involve a moral evaluation combined with the identification of deception on the basis of little or partial evidence. The implications of this social ambiguity for clinical psychiatric practice are that professionals need to guard themselves from two polar faults: seeing manipulation everywhere; or being blind to its presence. In order to achieve a cautious moderation, staff need to hold both alternatives in mind at all times.

Attitude of Health Personnel↗
PubMed2000

Molecular analysis of orchid pollinaria and pollinaria-remains found on insects.

Direct observations of pollinator visits to orchids are often difficult and time consuming, especially in orchids with a deceptive pollination system where seed set is typically pollinator-limited. This lack of direct observations greatly inhibits our understanding of orchid-pollinator relationships and especially the degree of pollinator-specificity. Here we describe a molecular approach to the study of orchid-pollinator relationships based on the analysis of DNA recovered from pollinaria found on insects. The insects were collected from nectar-rich plants flowering near natural orchid populations, or taken from museum collections. Sequence analysis of the nuclear ribosomal ITS region allowed the identification of the orchid species or species-group from which the pollinaria originated. Four out of eight orchid-pollinator relationships established with this approach have not been reported previously, which highlights the value of molecular tools for the study of orchid pollination biology.

Animals↗
PubMed2002

Psychiatrists as a moral community? Psychiatry under the Nazis and its contemporary relevance.

OBJECTIVE: In Nazi-occupied Europe, substantial numbers of psychiatrists murdered their patients while many other psychiatrists were complicit with their actions. This paper addresses their motivations and actions, and with particular reference to Australia, explores issues of contemporary relevance. METHODS: The events are reviewed in their historical context using mainly secondary sources. RESULTS: The assumption that the term "Nazi" denotes a closed and unrepeatable chapter is questioned. As with the Holocaust that followed, medical killing of psychiatric patients was an open secret with gradations of collective knowing. Perpetrators were impelled by pressure from peers and superiors, unquestioning obedience, racist ideology and careerism. Perpetrators and bystanders' denial was facilitated by use of deceptive language, bureaucratic and technical proficiency, and notions such as "a greater cause" or "sacred mission". Dissociation and numbing were common. Psychiatrists were the main medical specialty involved because Nazi race and eugenic ideology (accepted by many psychiatrists) targeted mentally ill people for sterilization and euthanasia, and because psychiatrists were state-controlled and tended to objectify patients. Few psychiatrists resisted. IMPLICATIONS: Nazi psychiatry raises questions about medical ethics, stigma and mental illness, scientific "fashions", psychiatry's relations with government, and psychiatrists' perceived core business. Psychiatric resistance to future similar threats should be based on commemoration, broad-based education and reflection on cultural values, strong partnerships between psychiatrists and patients, and willingness to question publicly policies and attitudes that disadvantage and stigmatize groups. The principle fundamental to all these practices is an orientation to people as subjects rather than objects.

Euthanasia↗
PubMed2002

Nutrition labelling: purpose, scientific issues and challenges.

Nutrition labels describe the nutrient content of a food and are intended to guide the consumer in food selection. The nutrition information provided must be selected on the basis of consistency with dietary recommendations. Selection of the specific nutrients or food components to be listed should further take into account label space, the analytical feasibility of measuring the particular nutritional component within the food matrix, and the relative costs of such analyses. Nutrition information provided on labels should be truthful and not mislead consumers. At the same time, labelling regulations should provide incentives to manufacturers to develop products that promote public health and assist consumers in following dietary recommendations. It is likely that in many countries, there would be some segments of the population that would benefit from information about the composition of foods. In these cases, countries should consider the need to provide for appropriate labelling and its presentation relative to existing guidelines and approaches. As nutrition-labelling efforts have evolved, different approaches and legal requirements have been established. These create difficulties in developing and harmonizing nutrition information listings, which have broad international applications. For these reasons, the Codex Guidelines on Nutrition Labeling play an important role to provide guidance to member countries when they want to develop or update their national regulations and to encourage harmonization of national standards with international standards. These Guidelines are based on the principle that no food should be described or presented in a manner that is false, misleading or deceptive. The Guidelines include provisions for voluntary nutrient declaration, calculation and presentation of nutrient information. The Guidelines on Claims establish general principles to be followed and leave the definition of specific claims to national regulations. Definitions are provided for a number of claims (nutrient content, comparative claims, nutrient function claims) as well as general requirements concerning consumer information in relation with claims. Nutrition labelling by itself cannot solve nutrition problems. It should be seen as one of the elements of nutrition policy and should be envisaged in the larger perspective of consumer education, which in its turn is part of an overall development policy. Exchange of information at the regional and subregional level is important, as each country can learn from the experience of others and regional co-ordination and co-operation can be developed.

Food Labeling↗
PubMed2002

Nutrition labelling: perspectives of a bi-national agency for Australia and New Zealand.

Australia New Zealand Food Authority (ANZFA) is a bi-national government agency forming a partnership between all of Australia's States and Territories and the New Zealand government. Australia New Zealand Food Authority employs scientific, legal policy, communication and administrative staff in our Australia and New Zealand offices. Prior to 1991 each of Australia's States and Territories had their own food standards; however, in 1991 Commonwealth legislation was introduced to consolidate responsibility for developing food standards in one specialist agency and to ensure the uniformity of Standards across all States and Territories in Australia. This was extended to New Zealand in 1995 when we became a bi-national agency following the signing of a Treaty between Australia and New Zealand to develop joint food standards for both countries. Australia New Zealand Food Authority's objectives in setting food standards are to: protect public health and safety; provide adequate information to enable consumers to make informed choices; and prevent misleading or deceptive conduct. Health Ministers have recently approved a new Joint Food Standards Code for Australia and New Zealand. This is the result of over 6 year's work and many rounds of public consultation. The new Code has had extensive input from government agencies, industry and consumers. In drafting the new code our emphasis has been on making decisions based on sound science and the most up-to-date information available. We also recognized the need for Standards to be practical in not imposing unnecessary costs on food manufacturers with an inevitable flow on effect to consumer prices. The Joint Code will replace both the existing Australian Food Standards Code and the New Zealand Food Regulations after a 2-year transition period. During the development of the Joint Code a wide range of matters were considered in relation to labelling. Amongst these were consumer needs, costs to industry, voluntary versus mandatory, enforcement issues, relationship to advertising and exemptions. A number of features of the new Code relate specifically to labelling and include: warning and advisory statements; ingredients lists; date marking; directions for use and storage; nutrition information; legibility requirements; and percentage labelling. One of the key features of the Joint Code is the requirement for most packaged foods to bear a nutrition information panel (NIP). Information must be presented on the amount of fat, saturated fat, protein, energy, carbohydrates, sugars and sodium. For the majority of foods the label is the first and only source of information regarding the nutritional content of food purchased. Mandatory nutrition labelling will ensure that consumers are provided with key nutritional information about foods. Single ingredient produce such as fruit and vegetables, and some other foods such as spices, tea and coffee will be exempt. The new requirements will give consumers more nutritional information to allow product comparison. All products will be required to provide information on these nutrients on both a per 100 g basis and in terms of an average serving. In addition to the mandatory nutrient declarations NIP are also required to carry additional data for any substance for which a nutrition claim is made. During the 2-year transition period to December 2002 ANZFA will be working with industry, enforcement agencies and consumers to help to ensure that there is a smooth transition to the Joint Food Standards Code.

Australia↗
PubMed2002

High-pressure water injection injury: emergency presentation and management.

Presentations of high-pressure water blaster injuries to the emergency department are varied. Though these injuries are sometimes described as a 'benign variant' of high-pressure injection injuries, external appearances can be deceptive. These injuries can produce an unexpected pattern of severe internal injury and infectious complications. Such injuries are surgical emergencies and must be evaluated quickly and thoroughly in the emergency department. We review the current literature of these injuries and present the first reported case involving a forearm injury.

Accidents, Occupational↗
PubMed2003

Analytic quantification of solar lentigines lightening by a 2% hydroquinone-cyclodextrin formulation.

BACKGROUND: The innate melanin pigmentation of skin is modulated during lifetime by a series of factors, including ageing and chronic ultraviolet light exposure. Actinic lentigines may be of particular concern from a cosmetic point of view. Conventional hypopigmenting agents are usually deceptive. Using cyclodextrins to form inclusion compounds with these agents might represent a more active drug delivery system. OBJECTIVE: To assess sensitive and objective methods predicting the effects of a 2% hydroquinone-cyclodextrin formulation on solar lentigines. STUDY DESIGN: Thirty Asian adults applied a 2% hydroquinone-cyclodextrin formulation once daily on solar lentigines of a forearm for 2 months. The other untreated forearm served as a control. Monthly assessments were performed using skin colorimetry and fluorescence video recording combined with image analysis. Corneomelametry following photodensitometry of cyanoacrylate skin surface strippings was performed after melanin staining of the samples. RESULTS: The control untreated solar lentigines showed no significant variations in the biometrological parameters. By contrast, the test formulation induced lightening of the solar lentigines. Corneomelametry disclosed improvement after 1 months' treatment, whereas the other assessments only reached significance after 2 months. CONCLUSIONS: A 2% hydroquinone-cyclodextrin formulation proved to be effective in lightening actinic lentigines. Corneomelametry predicted the effects discernible at a later stage by in vivo colour assessments of the melanin content.

Administration, Topical↗
PubMed2000

Inadequate diagnosis and therapy of arterial hypertension as causes of left ventricular hypertrophy in uremic dialysis patients.

BACKGROUND: Left ventricular hypertrophy (LVH) is highly prevalent in the dialyzed population, possibly because of inadequate diagnosis and therapy of arterial hypertension. The purpose of this study was to ascertain the adequacy of our approach in correctly identifying and treating arterial hypertension in our dialysis center. METHODS: Fifty-five dialyzed uremics were studied by continuous ambulatory blood pressure (BP) monitoring, which started before a single hemodialysis (HD) session, continued for 24 hours after HD ended, and was repeated for 15 minutes before the beginning of the next HD. Clinical pre-HD and post-HD routine BP measurements taken the month preceding BP monitoring were retrieved, and echocardiography was performed. RESULTS: LVH was present in 46 out of 55 patients, and clinical pre-HD arterial hypertension was present in 36 out of 55. There were discrepancies between clinical and monitored BPs, mostly concerning diastolic pre-HD BP since BP readings were lower than monitored BP records (P < 0.0002). Although both clinical and monitored BPs bore strong direct correlations with the left ventricular mass (LVM), the closest correlations were those for monitored BP. Four groups of patients were identified by BP monitoring: group A (N = 14), with persistently normal BP, and group D (N = 13), with persistently supranormal BP levels. There were also two other groups (group B, N = 19; and group C, N = 9), whose BP values were high before HD, normalized after HD, and then increased again either soon after HD (group C) or later on following HD (group B). Monthly averaged clinical pre-HD mean BP values differed significantly among the four groups [91 +/- 10 (SD) mm Hg in group A, 101 +/- 7 in group B, 106 +/- 6 in group C, and 106 +/- 7 in group D; P < 0.0001, analysis of variance], as did their corresponding LVMs [132 +/- 27 g/m2 body surface area (BSA), 156 +/- 26, 201 +/- 51, and 200 +/- 36; P < 0.0001]. There were also differences in dialytic age, which was significantly longer in group A patients (109 +/- 54 months), who also tended to have higher, although not significantly higher, Kt/V(urea) values. No differences, however, were detected among the groups as far as type, dosages, and number of antihypertensive drugs given to each individual patient. CONCLUSIONS: The high prevalence of LVH in the dialysis population might be the result of inadequate diagnosis and therapy of arterial hypertension. Arterial hypertension, in fact, was insufficiently treated in our dialysis center, since patients with varying degrees of severity of both arterial hypertension and LVH were kept on antihypertensive therapy of similar strength. Undertreatment may have resulted from not having recognized and/or from having underestimated the severity of arterial hypertension since some clinical BPs were measured incorrectly. Reluctance to use more aggressive antihypertensive therapy might also result from the deceptive feeling of "normalized" BP that one has following volume unloading with dialysis. This causes both the BP to run out of control between dialyses and LVH to worsen.

Adult↗
PubMedDate not supplied

Mixed choriocarcinoma in a postmenopausal patient.

Gestational trophoblastic disease rarely presents in patients beyond the reproductive years. To our knowledge, this is the first case of mixed trophoblastic disease in a postmenopausal woman. We present here a case of a 60-year-old woman with evidence of a pelvic mass and pulmonary metastasis. Surgery revealed an 8 x 6 x 6 cm multinodular uterine tumor involving the right adnexa. Histologic review was consistent with choriocarcinoma with intermediate trophoblastic features. Postoperative beta-hCG was 381 561 mIU/ml. We conclude that maintaining a high index of suspicion facilitates the identification of postmenopausal patients with metastatic gestational trophoblastic disease. This case reconfirms the deceptive presentation of the "great masquerader".

Choriocarcinoma↗
PubMed2001

Placebos, placebo effect, and the response to the healing situation: the evolution of a concept.

In spite of its impressive progress, medicine has been strongly criticized for relying on its modern biomedical tradition to the neglect of the psychosocial aspects of health. This neglect may account for patients' dissatisfaction and eventual use of alternative health approaches. The concept of placebo has sustained dramatic "protean" metamorphoses through the ages. For centuries, placebos have been regarded as powerful deceptive therapies. From the middle of the twentieth century, however, conventional medicine has used placebos as methodologic tools to distinguish the specific from the nonspecific ingredients in treatments. In modern medical research, the double-blind, placebo-controlled, randomized clinical trial has been established as the gold standard for the assessment of any new treatment. Recently a new trend regarding placebos seems to have emerged. The placebo and other nonspecific effects elicited by the "healing situation" have been independently subjected to scientific study. Progress in this area may promote useful clinical applications, enabling physicians to broaden their perspectives on the healing process. We present the historical changes of the concept of placebo and the ethical issues raised by their use.

Attitude to Health↗