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At least 271 records · Page 15Linked to original sources
PubMed2005

Topical vitamin C: a useful agent for treating photoaging and other dermatologic conditions.

BACKGROUND: Cosmeceuticals containing antioxidants are among the most popular antiaging remedies. Topically applied antioxidants exert their benefits by offering protection from damaging free radicals produced when skin is exposed to ultraviolet light or allowed to age naturally. Vitamin C is a naturally occurring potent water-soluble antioxidant. Accordingly, it has been incorporated into a variety of cosmeceuticals designed to protect and rejuvenate photoaged skin. OBJECTIVE: This article reviews the scientific data and clinical studies supporting the use of topically applied vitamin C for treating photoaged skin. Other innovative uses for vitamin C cosmeceuticals are also discussed. CONCLUSION: A significant body of scientific research supports the use of cosmeceuticals containing vitamin C. Cutaneous benefits include promoting collagen synthesis, photoprotection from ultraviolet A and B, lightening hyperpigmentation, and improvement of a variety of inflammatory dermatoses. Because of the diverse biologic effects of this compound, topical vitamin C has become a useful part of the dermatologist's armamentarium.

Administration, Topical↗
PubMedDate not supplied

Safety factors and establishment of acceptable daily intakes.

The acceptable daily intake (ADI) of food additives and other foreign compounds is derived usually by the application of a 100-fold safety factor to the 'no observable adverse effect' level in animal experiments. This safety factor is recognized as comprising two 10-fold factors to allow for possible differences between animals and humans, and for possible differences between individual humans. This paper reviews the adequacy of these safety factors in relation to published data on inter-species and inter-individual differences in both the kinetics and dynamics of foreign compounds. Although the 100-fold factor is reasonable, situations can be envisaged where the scientific data base indicates that considerably higher or lower factors would be more appropriate. A scheme is proposed that would allow structured flexibility to be available in the choice of safety factor to be used in the regulation of foreign compounds.

Absorption↗
PubMed1998

Epidemiology of dementias.

The increasing and widespread interest in age-associated dementias originated because of the rapid aging of the world population. Considering the rapid demographic changes and current epidemiologic data indicating a steep increase in the frequency of dementia with advancing age, several authors have introduced the concept of an "epidemic of dementia". Epidemiological research gives the opportunity to provide both scientific data and background information for health policy makers. Information concerning the frequency of dementias, their geographical distribution, as well as related disability, is an essential requirement for cost-effective planning of health care services. At the same time, data from population-based surveys, and in particular from cross-national studies, may give clues to the etiology, diagnosis and treatment of the dementias.

Journal Article↗
PubMed2001

Is diesel the cause for the increase in allergic disease?

LEARNING OBJECTIVES: The purpose of this review is to objectively critique available data regarding the role of diesel exhaust particles (DEPs) in allergic disease. Readers of this review should understand the ways in which diesel particulates can affect human airways and the extent of the scientific data which are currently available. DATA SOURCES: Data were obtained from published studies and reviews. STUDY SELECTION: The specific reviewed studies selected for this review met the following criteria: human and animal in vivo, in vitro, and pulmonary dosimetry studies, as well as epidemiologic studies to examine the role of DEPs and particulates on the airways. RESULTS: The results of the published studies show that although DEPs may play a role in the increased levels of allergic disorders through a number of immunologic mechanisms, it remains to be proven whether it is responsible for the recent rise in the prevalence of asthma and other allergic disorders. CONCLUSIONS: Further studies in humans are needed to elucidate the mechanisms by which DEPs may be responsible for the increased prevalence of allergic disorders.

Animals↗
PubMed1988

NCI dietary guidelines: rationale.

The National Cancer Institute (NCI) believes that the potential for dietary changes to reduce the risk of cancer is considerable and that the existing scientific data provide evidence that is sufficiently consistent to warrant prudent interim dietary guidelines that will promote good health and reduce the risk of some types of cancer. Six interim dietary guidelines and their scientific rationale are discussed herein. The evidence presented for the scientific rationale is based on the 1982 National Academy of Sciences Committee report Diet, Nutrition and Cancer and NCI's own scientific reviews that link long-term dietary patterns with cancer risk. These guidelines to the American public are consistent with other dietary recommendations from the US departments of Agriculture and Health and Human Services, the American Cancer Society, and the American Heart Association.

Diet↗
PubMed2005

The history of beta-carotene and cancers: from observational to intervention studies. What lessons can be drawn for future research on polyphenols?

An important question being raised by nutritionists today is whether available scientific data support an important role for polyphenols in the prevention of pathologic conditions that represent an important public health burden, such as cardiovascular diseases, cancers, and osteoporosis. More broadly, when can we consider scientific knowledge sufficient to allow specific public health implications and recommendations? The history of the relationship between beta-carotene and cancer illustrates the complexity of the research process leading to the demonstration of a causal relationship between nutritional factors and the prevention of disease. The beta-carotene story, which has developed in the past 30 y, is particularly significant and illustrative because of apparent controversies that are far from resolved. This is an extremely interesting example from which many lessons can be learned. For beta-carotene, we need to collect sufficient information from experimental, clinical, and epidemiologic research before we support any specific public health recommendations. The same principles must be applied to recommendations regarding polyphenols (in particular, which polyphenols, at which doses, to achieve which benefits for which populations). If these questions are not answered, then we run the risk of needing to renounce recommendations regarding polyphenols in the future, damaging the credibility of nutritional recommendations for public health.

Animals↗
PubMed1996

Antidepressants for children. Is scientific support necessary?

This article is concerned with issues pertaining to the degree to which clinical therapeutic decisions can reasonably depart from the best available scientific data. There is a tension between the traditions of practitioner autonomy and the boundaries set by research findings. Ambiguity exists as to how much freedom practitioners have to accept or reject the existing scientific paradigm. The nature of the dilemma is explored by analyzing the current problems confronting child psychiatrists and pediatricians who choose to treat depressed children with antidepressants. Despite unanimous literature of double-blind studies indicating that antidepressants are no more effective than placebos in treating depression in children and adolescents, such medications continue to be in wide use. The strategies used to resolve this sort of contradiction are considered, and certain ethical puzzles are appraised.

Adolescent↗
PubMed1995

Survey of critical care management of comatose, head-injured patients in the United States.

OBJECTIVE: This survey was designed to study current practices in the monitoring and treatment of patients with severe head injury in the United States. DATA SOURCES: The collected data represent answers to telephone interviews of nurse managers, clinical specialists, and staff nurses specializing in neurotrauma care at 277 randomly selected hospitals from a total pool of 624 trauma centers. Overall, 261 (94%) centers participated in the survey. Of the participating centers, 219 (84%) were providers of care for severely head-injured patients. In order to assess reliability and account for differences among respondents, personnel from 40 (15%) centers were resurveyed 6 months later and a different nursing professional was interviewed, although the questions remained the same. DATA EXTRACTION: The largest group of respondents came from level I centers (49%), followed by level II (32%) and level III (2%). Thirty-four percent of the surveyed hospitals had a designated neurologic/neurosurgical intensive care unit, and 24% of all units surveyed were under the direction of either a neurosurgeon or a neurologist. Twenty-eight percent of the centers routinely performed intracranial pressure monitoring, while 7% of the centers reported never using this technique. The use of ventriculostomy catheters for intracranial pressure monitoring was employed in 72% of the centers, but cerebrospinal fluid drainage was utilized by only 44% of the hospitals. The percentage of patients who had their intracranial pressure monitored was significantly higher in level I trauma centers and at hospitals that treated larger numbers of severely head-injured patients (15 to 30 patients per month, which represented 15% of the hospitals surveyed). Hyperventilation and osmotic diuretics were used in 83% of centers to reduce intracranial hypertension. The administration of barbiturates was reported in 33% of the units as a treatment for intracranial hypertension. Corticosteroids were used more than half of the time in 64% of trauma centers. Twenty-nine percent of the centers reported aiming for PaCO2 values of < 25 torr (< 3.3 kPa). CONCLUSIONS: The survey data indicate that there is a considerable variation in the management of patients with severe head injury in the United States. The establishment of guidelines for the management of head injury based on available scientific data and moderated by practical and financial considerations may lead to improvement in the standard of care.

Adrenal Cortex Hormones↗
PubMed2000

[Value of hydrodistention and bladder training].

Although hydrodistension of the bladder is generally considered standard therapy for interstitial cystitis, scientific data are largely lacking. With the mechanism of action unknown, prospective studies non-existent and the therapeutic effect at best very short-lived, hydrodistension cannot be regarded as a therapeutic standard concept with scientifically validated efficacy. The value of behavioral therapy and bladder training is equally unclear; success can only be anticipated in the very rare subset of patients without pain.

Cystitis, Interstitial↗
PubMed2001

Graph use in psychology and other sciences.

Since the early 19th century, graphs have been recognised as an effective method of analysing and representing scientific data. However, levels of graph use have varied widely since then, partly due to increasing reliance on inferential statistics in some fields. Recent studies indicate that graph use is closely related to the 'hardness' of scientific disciplines, and that this finding holds for journal articles and textbooks across the subfields of psychology. In the area of animal behaviour, journals devote about one-sixth of their page space to graphs, a level of graph use approximating that of biology and physics. Implications for the training of scientists in the use of visual displays are considered.

Journal Article↗
PubMedDate not supplied

[Variability in working systems in intensive care units].

INTRODUCTION: Patients attended in Intensive Medicine Services (IMS) require a high therapeutic support. To do so, each IMS elaborates a work system (monitoring of constants, insertion of catheters,...) aiming to respond to these high necessities of therapy. The objective of this study is to describe the variability among different IMS. METHODS: The study was performed in 15 hospitals in Catalonia between April and May 1995. In the end two of them did not participate in the study. In each hospital 180 pieces of data were collected referring to their material and human resources, graphics of data collection, monitoring of respiratory system (mechanical ventilator, aspirations of secretions, tracheostomy care), techniques of catheterization of artery and venous via vesical probing, prevention of pressure ulcers , hygiene of patients, nutrition, family treatment and data about medical orders and nursing courses. Similarly, the fact whether the work system was justified by studies from the same IMS, other centres, or whether it was simply unknown, was also evaluated. RESULTS: There was a great variability among the IMS studied, oscillating significatively according to assigned resources, frequency of action and cost. According to the procedure 61% of IMS did not justify the work systems depending on scientific data. CONCLUSION: it is necessary to unify the different work systems. To do so, and in our opinion, scientific societies should establish common norms, guidelines and protocols so as to obtain a higher efficiency of IMS.

Humans↗
PubMed2006

Consumption of historical and current phytotherapeutic agents for urolithiasis: a critical review.

PURPOSE: Recent years have shown a dramatic expansion in the knowledge of molecular mechanism of phytotherapeutic agents used to treat urolithiasis. The discovery and elucidation of the mechanism of action, in particular the clinical role of these herbal remedies, has made an important contribution to treatment for urinary stone disease as an alternative or adjunct therapy. Thus, the potential clinical application of these folk medicines to urolithiasis is discussed. MATERIALS AND METHODS: The literature on phytotherapeutic agents with scientifically determined efficiency and historically consumed agents was reviewed using MEDLINE after 1940 to the present. RESULTS: Although information on the complete mechanism of action of each remedy is lacking, commonly known extracts exert antilithogenic properties by altering the ionic composition of urine or by expressing diuretic activity. Also, some of them contain saponins that can disaggregate suspensions of mucoproteins, which are actually promoters of crystallization and some herbal remedies have antimicrobial properties that protect the anti-adherent layer of the mucosa, which acts as a protective barrier against urinary stone disease. CONCLUSIONS: Although phytotherapeutic extracts are popular in folk culture, because of the absence of scientific data on the exact clinical role, efficacy and side effects of these herbs the potential consumption of this alternative medical therapy as an alternative or adjunct to classic therapy remains to be determined. In this respect scientific research designed to determine the exact mechanism of action of these drugs would be fruitful for willing investigators.

Humans↗
PubMed2006

Epidemiology of crystal arthropathy.

Gout is an inflammatory arthritis mediated by the crystallization of uric acid within the joints and often is associated with hyperuricemia. Data suggest that the overall disease burden of gout remains substantial and may be increasing. Identifying and characterizing modifiable risk factors for gout is a major step in preventing and managing this painful condition. As more scientific data on the risk factors and comorbidities of gout become available, their integration into gout prevention and care strategies may become essential. This article reviews the relevant epidemiologic data, with a focus on recent progress and data on other crystal arthropathies.

Female↗
PubMed1996

What can research contribute to regulatory decisions about the health risks of multiple chemical sensitivity?

Multiple Chemical Sensitivity (MCS), which may not be caused by chemicals at all, is a serious medical problem of unknown origin and uncertain etiology that raises many fundamental science and policy questions. Regulators, for example, are confronted with a dilemma: what, if anything, should be done to protect people from the scientifically uncertain health risks of exposures to extremely low levels of environmental chemicals. Regulatory agencies, such as the Environmental Protection Agency, do not have the luxury of waiting until conclusive scientific evidence is available before making a decision; however, our present lack of scientific understanding about MCS is so acute that it is not possible to ascertain whether the cause of MCS-related symptoms is chemical, biological, physical, psychosocial, or some combination thereof. Nevertheless, many MCS sufferers and advocates for the chemically induced hypothesis are clamoring for regulatory action to reduce putative health risks from very-low-level exposures to chemicals in the environment. Unless steps are taken to improve the quantity and quality of the existing scientific data base, we cannot, with any acceptable degree of certainty, evaluate the extent to which regulatory decisions about MCS are either protective of public health or cost-effective. This article examines how research can strengthen the scientific basis for risk-related decisions about MCS, and proposes a framework for establishing research directions and priorities. It is argued that high-priority research on MCS is distinguishable by four attributes: (1) results are valuable for risk-related decisions; (2) findings significantly advance scientific knowledge and understanding; and the hypothesis being tested is both (3) biologically plausible and (4) readily testable.

Decision Making↗
PubMed2005

Hospital disinfection: efficacy and safety issues.

PURPOSE OF REVIEW: To review recent publications relevant to hospital disinfection (and cleaning) including the reprocessing of medical instruments. RECENT FINDINGS: The key question as to whether the use of disinfectants on environmental surfaces rather than cleaning with detergents only reduces nosocomial infection rates still awaits conclusive studies. New disinfectants, mainly peroxygen compounds, show good sporicidal properties and will probably replace more problematical substances such as chlorine-releasing agents. The safe reprocessing of medical devices requires a well-coordinated approach, starting with proper cleaning. New methods and substances show promising activity for preventing the transmission of prions. Different aspects of virus inactivation have been studied, and the transmissibility, e.g. of norovirus, shows the need for sound data on how different disinfectant classes perform. Biofilms or other forms of surface-adherent organisms pose an extraordinary challenge to decontamination. Although resistance to biocides is generally not judged to be as critical as antibiotic resistance, scientific data support the need for proper use, i.e. the avoidance of widespread application, especially in low concentrations and in consumer products. SUMMARY: Chemical disinfection of heat-sensitive instruments and targeted disinfection of environmental surfaces are established components of hospital infection control. To avoid danger to staff, patients and the environment, prudent use as well as established safety precautions are required. New technologies and products should be evaluated with sound methods. As emerging resistant pathogens will challenge healthcare facilities in the future even more than at present, there is a need for well-designed studies addressing the role of disinfection in hospital infection control.

Disinfection↗
PubMed1984

[Estrogens and the psyche].

Animal experiments have revealed much about location, mode and mechanism of action of oestrogens on the brain. It appears very likely from these experiments that oestrogens affect psychic functions. However, data proving such actions in the human are fragmentary and incomplete. It is generally assumed that physiological concentrations of oestrogens influence sexual and non-sexual behaviour, as well as mental performance in man, but the requisite scientific data are still insufficient in many cases to allow definite conclusions to be reached. Similarly, statements that moderately increased concentrations of oestrogens affect the psyche continue to be a matter of debate. In contrast it is established that both excess and deficiency of oestrogens can influence psychic functions in the human. This has been clearly demonstrated in extensive studies, particularly with regard to the psychic changes in the peri- and postmenopause, whereas little can be said about a cause-effect relationship between oestrogen deficiency and declining mental function with advancing age. The therapeutic value of oestrogen replacement in psychic disturbances associated with oestrogen deficiency states such as hypogonadism, after castration and in the climacteric is well documented by many studies. All other assumed psychic indications in the process of ageing are much less clearly defined and at present of questionable medical importance.

Adult↗
PubMed2000

Lessons learned in applying the U.S. EPA proposed cancer guidelines to specific compounds.

An expert panel was convened to evaluate the U.S. Environmental Protection Agency's "Proposed Guidelines for Carcinogen Risk Assessment" through their application to data sets for chloroform (CHCl3) and dichloroacetic acid (DCA). The panel also commented on perceived strengths and limitations encountered in applying the guidelines to these specific compounds. This latter aspect of the panel's activities is the focus of this perspective. The panel was very enthusiastic about the evolution of these proposed guidelines, which represent a major step forward from earlier EPA guidance on cancer-risk assessment. These new guidelines provide the latitude to consider diverse scientific data and allow considerable flexibility in dose-response assessments, depending on the chemical's mode of action. They serve as a very useful template for incorporating state-of-the-art science into carcinogen risk assessments. In addition, the new guidelines promote harmonization of methodologies for cancer- and noncancer-risk assessments. While new guidance on the qualitative decisions ensuing from the determination of mode of action is relatively straightforward, the description of the quantitative implementation of various risk-assessment options requires additional development. Specific areas needing clarification include: (1) the decision criteria for judging the adequacy of the weight of evidence for any particular mode of action; (2) the role of mode of action in guiding development of toxicokinetic, biologically based or case-specific models; (3) the manner in which mode of action and other technical considerations provide guidance on margin-of-exposure calculations; (4) the relative roles of the risk manager versus the risk assessor in evaluating the margin of exposure; and (5 ) the influence of mode of action in harmonizing cancer and noncancer risk assessment methodologies. These points are elaborated as recommendations for improvements to any revisions. In general, the incorporation of examples of quantitative assessments for specific chemicals would strengthen the guidelines. Clearly, any revisions should retain the emphasis present in these draft guidelines on flexibility in the use of scientific information with individual compounds, while simultaneously improving the description of the processes by which these mode-of-action data are organized and interpreted.

Animals↗
PubMed1998

Vulvovaginal candidiasis: epidemiologic, diagnostic, and therapeutic considerations.

Although it is the second most common vaginal infection in North America, vulvovaginal candidiasis is a non-notifiable disease and has been excluded from the ranks of sexually transmitted diseases. Not surprisingly, vulvovaginal candidiasis has received scant attention by public health authorities, funding agencies, and researchers. Epidemiologic data on risk factors and pathogenic mechanisms remain inadequately studied. Most important, standards of care, including diagnosis and therapy, remain undefined. A conference was held in April 1996 to define and summarize what is known and supported by scientific data in the areas of epidemiology, diagnosis, and treatment of vulvovaginal candidiasis; but, more important, the conference aimed at defining what is not known, poorly studied, and controversial. Guidelines for the treatment and diagnosis of the different forms of vulvovaginal candidiasis are suggested.

Antifungal Agents↗