Contact Heat in Magnetoencephalography: A Systematic Review.

BACKGROUND: Contact heat is commonly used in experimental research to evoke brain activity, most frequently acquired with electroencephalography (EEG). Although magnetoencephalography (MEG) improves spatial resolution, using some contact heat stimulators with MEG can present methodological challenges. This systematic review assesses studies that utilise contact heat in MEG, their findings and possible directions for further research. METHODS: Eight electronic databases were searched for relevant studies, in addition to the selected papers' reference lists, citations and ConnectedPapers maps. Best practice recommendations for systematic reviews were followed. Papers met inclusion criteria if they used MEG to record brain activity in conjunction with contact heat, regardless of stimulator equipment or paradigm. RESULTS: Of 646 search results, seven studies met the inclusion criteria. Studies demonstrated effective electromagnetic artefact removal from MEG data, the ability to elicit affective anticipation and differences in deep brain stimulation responders. We identify contact heat stimulus parameters that should be reported in publications to ensure comparisons between data outcomes are consistent. CONCLUSIONS: Contact heat is a viable alternative to laser or electrical stimulation in experimental research, and methods exist to successfully mitigate any electromagnetic noise generated by PATHWAY CHEPS equipment - though there is a dearth of literature exploring the post-stimulus time window.

Estimation of a treatment policy estimand for time to event data using data collected post discontinuation of randomised treatment.

Discontinuation from randomised treatment is a common intercurrent event in clinical trials. When the target estimand uses a treatment policy strategy to deal with this intercurrent event, data after cessation of treatment is relevant to estimate the estimand and all efforts should be made to collect such data. Missing data may nevertheless occur due to participants withdrawing from the study and assumptions regarding the values for data that are missing are required for estimation. A missing-at-random assumption is commonly made in this setting, but it may not always be viewed as appropriate. Another potential approach is to assume missing values are similar to data collected after treatment discontinuation. This idea has been previously proposed in the context of recurrent event data. Here we extend this approach to time-to-event outcomes using the hazard function. We propose imputation models that allow for different hazard rates before and after treatment discontinuation and use the posttreatment discontinuation hazard to impute events for participants with missing follow-up periods due to study withdrawal. The imputation models are fitted as Andersen-Gill models. We illustrate the proposed methods with an example of a clinical trial in patients with chronic obstructive pulmonary disease.

Bayesian joint modelling of benefit and risk in drug development.

To gain regulatory approval, a new medicine must demonstrate that its benefits outweigh any potential risks, ie, that the benefit-risk balance is favourable towards the new medicine. For transparency and clarity of the decision, a structured and consistent approach to benefit-risk assessment that quantifies uncertainties and accounts for underlying dependencies is desirable. This paper proposes two approaches to benefit-risk evaluation, both based on the idea of joint modelling of mixed outcomes that are potentially dependent at the subject level. Using Bayesian inference, the two approaches offer interpretability and efficiency to enhance qualitative frameworks. Simulation studies show that accounting for correlation leads to a more accurate assessment of the strength of evidence to support benefit-risk profiles of interest. Several graphical approaches are proposed that can be used to communicate the benefit-risk balance to project teams. Finally, the two approaches are illustrated in a case study using real clinical trial data.

Biochemical and biophysical characterisation of haloalkane dehalogenases DmrA and DmrB in Mycobacterium strain JS60 and their role in growth on haloalkanes.

Haloalkane dehalogenases (HLDs) catalyse the hydrolysis of haloalkanes to alcohols, offering a biological solution for toxic haloalkane industrial wastes. Hundreds of putative HLD genes have been identified in bacterial genomes, but relatively few enzymes have been characterised. We identified two novel HLDs in the genome of Mycobacterium rhodesiae strain JS60, an isolate from an organochlorine-contaminated site: DmrA and DmrB. Both recombinant enzymes were active against C2-C6 haloalkanes, with a preference for brominated linear substrates. However, DmrA had higher activity against a wider range of substrates. The kinetic parameters of DmrA with 4-bromobutyronitrile as a substrate were Km = 1.9 ± 0.2 mM, kcat = 3.1 ± 0.2 s(-1) . DmrB showed the highest activity against 1-bromohexane. DmrA is monomeric, whereas DmrB is tetrameric. We determined the crystal structure of selenomethionyl DmrA to 1.7 Å resolution. A spacious active site and alternate conformations of a methionine side-chain in the slot access tunnel may contribute to the broad substrate activity of DmrA. We show that M. rhodesiae JS60 can utilise 1-iodopropane, 1-iodobutane and 1-bromobutane as sole carbon and energy sources. This ability appears to be conferred predominantly through DmrA, which shows significantly higher levels of upregulation in response to haloalkanes than DmrB.

Opinions of South Carolina dental students toward tobacco use interventions.

OBJECTIVES: Tobacco use accounts for 75 percent of oral cancer deaths in the United States. One objective of Healthy People 2010 is to increase the percentage of dentists who provide smoking cessation counseling. However, studies of dentists have shown that the majority feel inadequately prepared to do so. The objective of this study was to determine the opinions of dental students at the Medical University of South Carolina (MUSC) regarding the provision of tobacco use interventions for patients. METHODS: In 2002, 163 students were administered a written questionnaire which included questions about tobacco use interventions (response rate=80 percent). Opinion items were analyzed using factor analysis, Fisher's Exact Test, and ANOVA (a < or = 0.025). RESULTS: While 89 percent of students agreed that dentists should be trained to provide tobacco cessation education, only 39 percent thought that they themselves were adequately trained. Students' opinions toward the role and training of dentists in providing tobacco use interventions differed by academic year. Only 14.1 percent of dental students were quite or very confident in their ability to help patients to stop smoking. CONCLUSIONS: This study indicates that although MUSC dental students support tobacco cessation training for dentists, the majority responded that they are not adequately trained and are not comfortable providing tobacco cessation education to patients. A comprehensive tobacco prevention and cessation program is indicated for the objective of Healthy People 2010 to be met.

Assessing oral cancer knowledge among dental students in South Carolina.

BACKGROUND: Because South Carolina has the fourth highest mortality rate for oral cancer among the 50 states, dental students in the state must be knowledgeable about prevention and early detection of the disease. METHODS: In 2002, the authors surveyed 163 students using a written questionnaire (response rate, 79.1 percent). The questionnaire included questions about oral cancer risk and nonrisk factors as well as oral cancer diagnostic signs, symptoms and examination procedures. The authors performed univariate and bivariate analyses (alpha < or = .025). RESULTS: At least 93 percent of the students replied that tobacco, alcohol and previous oral cancer lesions were risk factors. One hundred six students (65 percent) knew that the most likely site for oral cancer is the ventrolateral border of the tongue. Students differed in their overall knowledge of risk factors (P = .002), nonrisk factors (P < .001) and diagnostic procedures (P < .001). CONCLUSION: Although students' level of knowledge increased with academic year, educators and policy-makers need to place greater emphasis on oral cancer education and training in dental schools. PRACTICE IMPLICATIONS: Morbidity and mortality are likely to be reduced if dentists know how to prevent and detect oral cancer.

Healthy practices, social relationships and dental perceptions among US dentate adults.

OBJECTIVE: This study explored and described the effects of healthy practices and social relationships on dental perceptions among U.S. dentate adults. METHODS: Guided by the Alameda County Study: Health and Ways of Living, weighted data from the Third National Health and Nutrition Examination Survey of 8,449 U.S. dentate adults aged 18-64 years were analyzed with SUDAAN 7.5.3. RESULTS: Healthy practices and social relationships showed protective effects against unfavorable dental perceptions after controlling for socio-demographic characteristics, dental access, and related clinical dental status. Besides healthy practices and social relationships, education, family income, having dental visit in the past 12 months, having dental decay, having defective tooth condition, and number of natural teeth helped explain unfavorable dental perceptions in the adjusted model. Compared with persons who had high social relationships and high healthy practices, those who had low social relationships with very low, low and medium healthy practices were about five, times (OR=5.07; 99% CI=3.24, 7.91), almost four times (OR=3.61; 99% CI=2.22, 5.87), and two times (OR=2.24; 99% CI=1.37, 3.67) more likely, respectively, to have unfavorable dental perceptions. In the adjusted model, these odds ratios decreased to three (OR=3.30; 99% CI=2.01, 5.41), two (OR=2.06; 99% CI=1.15, 3.69) and non-significant difference, consecutively. CONCLUSIONS: Influence of healthy practices and social relationships on dental health may encourage dental health professions to participate in general health behavior modifications and social actions to foster social relationships, in addition to preventive dental care.

Use of skin and oral cancer examinations in the United States, 1998.

BACKGROUND: Findings from previous surveys suggest low utilization of oral cancer examinations, even though this examination is noninvasive. The purpose of this analysis is to compare the use of an oral cancer examination (OCE) and a skin cancer examination (SCE) in the past 12 months within the United States. Both exams are noninvasive and include a visual component. METHODS: Weighted data from the Adult Prevention Supplement of the 1998 National Health Interview Survey (NHIS) for adults 40 years of age or older were analyzed using SAS and SUDAAN. A ratio compared the percentage reporting an OCE (%OCE) with the percentage reporting a SCE (%SCE). RESULTS: The percentage having an OCE in the past year (13.8%) was very similar to the percentage having a SCE (13.5%) during that same period. With increasing age group, the %OCE/%SCE ratio varied inversely from 1.60 (C.I. 1.42-1.78) among persons 40-49 years to 0.62 (C.I. 0.55-0.69) among persons 70+ years. The ratio was similar in whites and blacks, males and females, and Hispanics and non-Hispanics. There was a positive gradient in the ratio by education and family income. CONCLUSIONS: Overall, less than 15% of the population is receiving either of these examinations, although the American Cancer Society recommends both of them on an annual basis for individuals 40 years of age and older. To increase detection of these cancers at early stages, extensive educational and media campaigns for the public and providers identifying risk factors and the availability of and the need for these examinations are required.

Oral cancer examinations among U.S. Hispanics in 1998.

BACKGROUND: An oral cancer examination (OCE) is crucial for early detection of oral and pharyngeal cancers. The objectives of this study were: 1) to estimate the percentages of Hispanics and Hispanic subgroups who reported having an OCE in the past 12 months; 2) to compare these groups with various Non-Hispanics; and 3) to evaluate the extents to which having an OCE might be explained by age, gender, education, family income, a recent visit to a dentist, and edentulism. METHODS: Descriptive and logistic regression analyses using data from the 1998 National Health Interview Survey. RESULTS: 6.4% of Hispanics and 14.5% of non-Hispanics had had an OCE in the past 12 months. After adjusting for age, gender, education, income, a dental visit, and edentulism, Hispanics were 1.7 times less likely than non-Hispanics to have had an OCE in the past 12 months. CONCLUSIONS: Fewer Hispanics are receiving OCEs relative to Non-Hispanics.

Attitudes of pediatric dentists towards tobacco intervention for children and adolescents: a pilot survey.

PURPOSE: The purpose of this study was to obtain pilot information concerning the attitudes of pediatric dentists regarding their role in tobacco intervention for children and adolescent patients. METHODS: A 1-page survey, which was adapted and pretested from a previous, comprehensive survey, was distributed to all registrants at the 2001 American Academy of Pediatric Dentistry Annual Meeting in Atlanta, Ga. Descriptive and exploratory multivariable techniques were used to analyze the data. RESULTS: Of the 173 respondents, only 18% had ever received training in tobacco cessation counseling. Although most dentists agreed that they should play a role in tobacco intervention with their young patients, the majority was not comfortable with this task. Pediatric dentists with tobacco counseling training were more likely to accept their role in tobacco prevention and cessation efforts and were more confident in their ability to do so than were their counterparts. Pediatric dentists consider tobacco cessation an important role in their practices, but do not consider themselves well prepared to act on this responsibility. CONCLUSIONS: The results of this pilot survey strongly suggest that a similar, national, comprehensive study should be conducted among pediatric dentists.

Maryland family physicians' knowledge, opinions and practices about oral cancer.

The objective of this study was to assess family physicians' knowledge, opinions and practices regarding oral cancers in the state of Maryland, USA. A 40-item, self-administered questionnaire was mailed to all members of the Maryland Academy of Family Physicians. Unweighted data (n=240) were analyzed using SAS and SUDAAN software; results were evaluated using an alpha < or =0.05. Family physicians (FPs) were aware of the major risk factors for oral cancers, but misinformation existed about the non-risk factors. Approximately 77% asked their patients the eight questions related to risk factors for oral cancer when taking a medical history but less than 24% provided an oral cancer examination to patients 40 years of age and over. Nearly 64% were interested in a continuing education course about oral cancer. This survey identified gaps in knowledge and practices among FPs but it is encouraging that they expressed interest in continuing education courses on this topic.