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Judith D. Goldberg Arnold I. Weiss Kenneth J. Koury 《Journal of clinical periodontology》1986,13(5):411-414
In order to make effective use of the statistical theory of design of clinical trials for chronic diseases such as periodontal disease, certain issues must be considered. Any clinical trial requires that the disease definition be well-specified; that patient eligibility be explicit; that the observation times be explicit; that the duration and endpoint of therapy be specified; that the duration of subsequent followup observation be specified; and that the unit of observation (e.g., tooth, set of teeth, patient) be defined. In a chronic disease, the potential biases that can readily be introduced by self-selection of patients who enter the trial and/or who return for subsequent observation become more important, because subjects are required to remain on treatment and/or observation for prolonged periods. Further, the cyclical nature of some chronic diseases may require special attention to baseline definitions of active disease and disease outcome. These issues are illustrated with examples from clinical trials of hypertension, breast cancer screening, and Polycythemia Vera. Implications for periodontal disease are discussed. 相似文献
24.
Failure of corollary discharge, a mechanism for distinguishing self-generated from externally generated percepts, has been posited to underlie certain positive symptoms of schizophrenia, including auditory hallucinations. Although originally described in the visual system, corollary discharge may exist in the auditory system, whereby signals from motor speech commands prepare auditory cortex for self-generated speech. While associated with sensorimotor systems, it might also apply to inner speech or thought, regarded as our most complex motor act. In this paper, we describe the results of a series of studies in which we have shown that: (1) event-related brain potentials (ERPs) can be used to demonstrate the corollary discharge phenomenon during talking, (2) corollary discharge is abnormal in patients with schizophrenia, (3) EEG gamma band coherence between frontal and temporal lobes is greater during talking than listening and is disrupted by distorted feedback during talking in normals, and (4) patients with schizophrenia do not show this pattern for EEG gamma coherence. While these studies have identified ERPs and EEG gamma coherence indices of the efference copy/corollary discharge system and documented abnormalities in these systems in patients with schizophrenia, we have so far had limited success in establishing a relationship between these neurobiologic indicators of corollary discharge abnormality and reports of hallucinations in patients. 相似文献
25.
In addition to the rhodopsin crystal structure, high-resolution crystal structures of ligand-mediated G-protein-coupled receptors (GPCRs) have recently become available, and these have become attractive templates for developing homology models of several GPCRs of therapeutic interest. These crystal structures and the homology models derived from them have provided significant insights into ligand–receptor interactions. Moreover, several studies have demonstrated that the structural models are indeed suitable for virtual screening of compound databases to identify new ligands for various GPCRs. Recent examples of such virtual screening against GPCRs are discussed in this review. 相似文献
26.
Stanley J. Bigos John Holland Carole Holland John S. Webster Michele Battie Judith A. Malmgren 《The spine journal》2009,9(2):147-168
Background contextBack problems (BPs), with their cost and disability, are a substantial burden for individuals, employers, and society.PurposeThis systematic review of controlled trials evaluates the effectiveness of interventions to prevent BP episodes in working age adults.Data sourcesWe searched MEDLINE/EMBASE through May 2007, and COCHRANE/Trials Registry through August 22, 2008 using search terms of back pain, back injuries or sciatica, linked to prevention, control, workplace interventions, or ergonomics and searched article bibliographies.Study selectionFor systematic review inclusion, articles had to describe prospective controlled trials of interventions to prevent BPs in working-age adults, with intervention assignment either to individual participants or preexisting groups. Of 185 articles identified as potentially relevant, 20 trials (11%) met inclusion criteria.Data extractionResearchers extracted relevant information from controlled trials and graded methodological quality. Because of heterogeneity of trials, meta-analysis was not performed.ResultsOnly exercise was found effective for preventing self-reported BPs in seven of eight trials (effect size 0.39 to >0.69). Other interventions were not found to reduce either incidence or severity of BP episodes compared with controls. Negative trials included five trials of education, four of lumbar supports, two of shoe inserts, and four of reduced lifting programs.ConclusionsTwenty high-quality controlled trials found strong, consistent evidence to guide prevention of BP episodes in working-age adults. Trials found exercise interventions effective and other interventions not effective, including stress management, shoe inserts, back supports, ergonomic/back education, and reduced lifting programs. The varied successful exercise approaches suggest possible benefits beyond their intended physiologic goals.Level of evidenceSystematic review Level I evidence. 相似文献
27.
Robert H. EckelAuthor Vitae Penny Kris-EthertonAuthor Vitae Alice H. LichtensteinAuthor Vitae Judith Wylie-RosettAuthor Vitae Allison Groom Author Vitae Kimberly F. StitzelAuthor Vitae Shirley Yin-PiazzaAuthor Vitae 《Journal of the American Dietetic Association》2009,109(2):288-296
In recent years, epidemiologic and clinical studies, public and regulatory policy activity, and media coverage have focused on issues related to trans fats. To help increase awareness and understanding of trans fats and other fats, the American Heart Association (AHA) launched the “Face the Fats” national consumer education campaign in April 2007. The AHA commissioned a quantitative tracking survey between 2006 and 2007 to measure changes in consumer awareness, knowledge, and behaviors related fats and oils and their perceived impact on heart disease. The survey was conducted by Cogent Research. Data were collected during March 2006 and May 2007. At both time points, the survey included a representative sample of the American population age 18 to 65 years (n=1,000). The sampling plan for the survey was designed based on the 2000 and 2003 US Census. The margin of error was ±3.10 percentage points. Awareness of trans fats increased during the 1-year study period. In 2007, 92% of respondents were aware of trans fats, an increase from 84% in 2006 (P<0.05). The 2007 level was similar to the awareness of saturated fats (93%). Perceptions that certain fats and oils heighten the risk of heart disease increased for trans fats (73% in 2007 vs 63% in 2006; P<0.05), saturated fats (77% in 2007 vs 73% in 2006; P<0.05), and partially hydrogenated oils (56% in 2007 vs 49% in 2006; P<0.05). Knowledge about food sources of different fats remained low. On an unaided basis, 21% could name three food sources of trans fats in 2007, up from 17% in 2006 (P<0.05). Knowledge of food sources of saturated fat remained unchanged at 30% in 2007. Significantly more respondents in 2007 reported behavioral changes related to trans fat information, such as buying food products because they show “zero trans fat” on labels or packages (37% in 2007 vs. 32% in 2006; P<0.05). Between 2006 and 2007, consumer awareness about trans fats increased and attained awareness levels similar to saturated fats. The increased awareness is associated with improved self-reported behaviors in grocery shopping. Nonetheless, overall knowledge, especially regarding food sources of saturated and trans fats, remains relatively low, underscoring the need for heightened consumer education activities. The positive change in consumer awareness about trans fats is likely attributable to the wide range of messages available to them, including the AHA “Face the Fats” national consumer education campaign. 相似文献
28.
Marc J. P. M. van Veldhoven Judith K. Sluiter 《International archives of occupational and environmental health》2009,82(9):1065-1075
Objectives
Recovery opportunities allow employees to recuperate from work and diminish load effects. The aims of this study are to present a scale for measuring recovery opportunities, study its psychometric properties and its relationship with health. 相似文献29.
Charles H Henry Judith A Whittum-Hudson Gregory T Tull Larry M Wolford 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(1):e22-e26
OBJECTIVE: The objective of this study was to determine if temporomandibular joint (TMJ) samples positive for Chlamydia trachomatis have a greater presence of tumor necrosis factor-alpha (TNFalpha) or interleukin-6 (IL-6) when compared with Chlamydia-negative samples. STUDY DESIGN: Posterior bilaminar tissue samples removed during TMJ surgery from 70 patients were evaluated. Cryosections were stained using monoclonal antibody that identifies C. trachomatis. The presence of IL-6 and TNFalpha were evaluated by immunostaining in 15 samples positive and in 25 samples negative for the presence of C. trachomatis. RESULTS: Of the 70 TMJ samples, 32 (46%) were positive for C. trachomatis. In 15 samples positive for C. trachomatis, 10 (67%) were positive for TNFalpha and 7 (47%) for IL-6. In 25 samples negative for C. trachomatis, only 4 (16%) were positive for TNFalpha and only 2 (8%) for IL-6. Differences in C. trachomatis-positive samples versus negative were significant for both TNFalpha (P < .002) and IL-6 (P < .008). CONCLUSION: The presence of C. trachomatis in the TMJ is associated with a significantly increased presence of TNFalpha and IL-6. 相似文献
30.
Barbara A. Laraia Author Vitae Judith B. BorjaAuthor Vitae Margaret E. BentleyAuthor Vitae 《Journal of the American Dietetic Association》2009,109(6):1042-1047
African Americans experience household food insecurity, ie, the limited availability of nutritionally adequate and safe food, or ability to acquire acceptable foods in socially acceptable ways, at three times the rate of non-Hispanic whites. Thirty percent of all African-American children live in food-insecure households. The purpose of this study was to identify characteristics associated with household food insecurity among a high-risk postpartum population. Two-hundred six low-income, African-American mother−infant dyads were recruited through the Special Supplemental Nutrition Program for Women, Infants, and Children clinics. The six-item US Department of Agriculture food security scale was used to classify households as food secure, marginally food secure, or food insecure. Multinomial logistic regression was used to estimate the association between selected maternal/household characteristics and household food-security status. Fifty-three percent of households were food secure, 34% were marginally food secure, and 13% were food insecure. Maternal education less than college (relative risk ratio [RRR]=0.46; 95% confidence interval [CI]: 0.22 to 0.98) was inversely associated with marginal food security. Depressive symptoms (RRR=1.09; 95% CI: 1.02 to 1.16) and having the baby's father in the household (RRR=3.46; 95% CI: 1.22 to 9.82) were associated with household food insecurity, while having a grandmother in the household (RRR=0.15; 95% CI: 0.03 to 0.80) was inversely associated with experiencing household food insecurity. Findings from this study suggest that young, low-income, African-American families with only one child are particularly susceptible to experiencing household food insecurity. Intergenerational support and transfer of knowledge can be a key protective attribute among low-income African-American households. 相似文献