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Biomedical subjects

D Locker

Publications and source records attributed to D Locker.

At least 37 records · Page 2Linked to original sources
PubMed2001

DSP1, an HMG-like protein, is involved in the regulation of homeotic genes.

The Drosophila dsp1 gene, which encodes an HMG-like protein, was originally identified in a screen for corepressors of Dorsal. Here we report that loss of dsp1 function causes homeotic transformations resembling those associated with loss of function in the homeotic genes Sex combs reduced (Scr), Ultrabithorax (Ubx), and Abdominal-B. The expression pattern of Scr is altered in dsp1 mutant imaginal discs, indicating that dsp1 is required for normal expression of this gene. Genetic interaction studies reveal that a null allele of dsp1 enhances trithorax-group gene (trx-G) mutations and partially suppresses Polycomb-group gene (Pc-G) mutations. On the contrary, overexpression of dsp1 induces an enhancement of the transformation of wings into halteres and of the extra sex comb phenotype of Pc. In addition, dsp1 male mutants exhibit a mild transformation of A4 into A5. Comparison of the chromatin structure at the Mcp locus in wild-type and dsp1 mutant embryos reveals that the 300-bp DNase I hypersensitive region is absent in a dsp1 mutant context. We propose that DSP1 protein is a chromatin remodeling factor, acting as a trx-G or a Pc-G protein depending on the considered function.

Alleles↗
PubMed2001

Toothbrushing competency among high-risk grade one students: an evaluation of two methods of dental health education.

OBJECTIVE: To evaluate the effectiveness of two methods of dental health education (DHE) for improving toothbrushing competency among grade one students at high risk for dental diseases. METHODS: Fifty elementary schools in the former city of North York, Ontario, Canada, were assigned to one of two groups. In one group, students received a classroom-based DHE lesson that was reinforced by two small group sessions (n = 243). In the other group, students received only a single classroom-based DHE lesson (n = 206). Trained examiners assessed 11 toothbrushing skills at pre- and postintervention. RESULTS: At the preintervention test, few significant differences were found between the groups and many students did not display competency in fundamental oral health skills, such as placing a toothbrush at the gum line. Following DHE interventions, students in both groups demonstrated improvements in most skills. A significantly higher proportion of students who received both classroom and small group sessions displayed gains in competency in three skills, compared to students receiving only a classroom lesson. These skills were brushing anterior lingual surfaces, brushing posterior lingual surfaces, and brushing all areas in a routine fashion. Students receiving only a classroom session did not display greater improvements in any skill areas compared to "classroom plus small group" students. Some students in both groups still lacked fundamental skills at the end of the DHE program. CONCLUSIONS: While one must exercise caution in interpreting the results due to several methodologic limitations, findings suggest that for high-risk grade one students, a classroom-based lesson combined with small group sessions is a more effective method of improving toothbrushing skills compared to a single classroom-based lesson.

Child↗
PubMed2001

Psychological disorder, conditioning experiences, and the onset of dental anxiety in early adulthood.

Most studies examining the origins of dental fear and anxiety have relied on cross-sectional data. These are subject to several problems, such as recall and uncertainty concerning temporal relationships. This paper uses longitudinal data from the Dunedin Multidisciplinary Health and Development Study to assess risk factors for the development of dental anxiety in persons between the ages of 18 and 26 years. It was hypothesized that psychological factors would be as important as conditioning experiences in the genesis of dental anxiety over this period. The eight-year incidence of dental anxiety was 16.5%. Five variables entered models predicting onset: multiple fears, symptoms of substance dependence, previous experience of invasive dental treatment, dental visiting pattern, and the extraction of one or more teeth. Separate analyses for those avoiding and those using dental services resulted in different explanatory models. These results indicated that both psychological and conditioning variables contributed to the development of dental anxiety in this population of young adults.

Adolescent↗
PubMed2001

Sensory and affective components of orofacial pain: is it all in your brain?

In this paper, we shall review several chronic orofacial pain conditions with emphasis on those that are essentially refractory to treatment. We shall present a review of current and past literature that describes the various pain phenomena as well as their underlying central mechanisms. New data concerning refractory pain will be used to underscore the importance of central processing of pain, with particular emphasis on neuropsychological and cognitive function and capacity that may play important roles in pain processing and maintenance of the pain state. Further, neurophysiological data showing that the anterior cingulate cortex (ACC) and other structures in the brain may play key roles in modulation of chronic pain will also be discussed. Although peripheral triggering events surely play an important role in initiating pain, the development of chronic and, in particular, refractory pain may depend on changes or malfunctions in the central nervous system. These changes may be quite subtle and require sophisticated approaches, such as functional MRI, to study them, as is now being done. New findings obtained therefore may lead to more rational and reliable treatment for orofacial pain.

Accidents, Traffic↗
PubMed2001

The mouth-body split: conceptual models of oral health and their relationship to general health among ethnic minorities in South Thames Health Region.

OBJECTIVE: To identify and describe conceptual models of oral health shared by people from different minority ethnic groups, in particular the relationship between 'oral health' and 'general health'. To identify how these conceptions vary across social factors. BASIC RESEARCH DESIGN: In-depth interviews. Analysis of the interview data to identify the conceptual models used by participants in discussing oral health and its relationship to general health. PARTICIPANTS: Ninety-five individuals from different ethnic groups. RESULTS: Two models of 'health' were identified. The first reflected a traditional model which related health to the absence of disease. The second encompassed a broad definition of health including not only physical but social and psychological well-being and the ability to carry out everyday functions. The model within which an individual operated was influenced by ethnicity and gender. Additionally, two models of the relationship between oral health and general health were identified: one in which the two concepts were seen as separate but related; the other in which oral health and general health were viewed as inseparable aspects of a single dimension. CONCLUSIONS: People from minority ethnic groups vary in their understanding of oral health and its relationship to general health. This variation can be explained in part by ethnic and cultural factors. This finding has important implications both for the design of measures which seek to assess oral health related quality of life, and for the development of health promotional materials.

Activities of Daily Living↗
PubMed2001

Does dental care improve the oral health of older adults?

OBJECTIVE: To assess the relationship between self-perceived change in oral health status and the provision of dental treatment in an older adult population. DESIGN: A longitudinal study with data collection at baseline and after three years. Information on change in oral health was obtained by interviews with study subjects and information on dental treatment over three years was obtained from subjects' dentists. SUBJECTS: Nine hundred and seven subjects took part at baseline and 611 at follow-up. Of the latter, 495 reported at least one dental visit during the three-year observation period and dental treatment information was available for 408. Outcome measures Global transition judgements and change scores derived from four oral health indexes were used to assess change in oral health status. RESULTS: Over the three-year period, one-tenth of subjects reported that their oral health had improved and one-fifth that it had deteriorated. Those who improved made significantly more dental visits and received significantly more dental services that those who deteriorated or did not change (P<0.0001). They also received a broader range of diagnostic, preventive and therapeutic services. The association between change and dental service provision remained after controlling for other potential determinants of oral health. CONCLUSION: The study suggests that improvements in the oral health of older adults depend upon access to comprehensive dental treatments which can address fully their clinical and self-perceived needs.

Aged↗
PubMed2001

Onset of and patterns of change in dental anxiety in adolescence and early adulthood: a birth cohort study.

OBJECTIVE: To assess the onset of and patterns of change in dental anxiety during adolescence and early adulthood. DESIGN: A birth cohort study of 1,037 individuals born in Queen Mary Hospital, Dunedin, New Zealand between 1 April 1972 and 31 March 1973. Data were collected from these individuals at birth, every two years between the ages of 3 and 15 and at 18, 21 and 26 years. STUDY MEMBERS: Data on dental anxiety were obtained at the 15, 18 and 26-year assessments from 678 study members. OUTCOMES: Dental anxiety was assessed using the Dental Anxiety Scale. Study members with a score of 13 or over were classified as being dentally anxious. RESULTS: The prevalence of dental anxiety increased from 10.6% at age 15 years to 13.3% at 18 years and 21.1% at 26 years. Of the 31.2% who were anxious at one or more data collection periods, approximately one third were anxious by the age of 15, one third became anxious between 16 and 18 years and one third between 18 and 26 years. High rates of remission were observed. Of 72 study members who were dentally anxious at 15 years, 22% were persistent cases, anxious at all three data collection points; 24% were recurrent cases, anxious at 26 but not anxious at 18 years; and 54% were remitted cases, no longer anxious at 26 years. There were no gender differences in the onset and course of dental anxiety over the developmental periods observed. CONCLUSIONS: The period of observation was one of instability with respect to anxiety about dental treatment. Early adulthood in particular appeared to be a life stage during which this population was vulnerable to the onset of dental anxiety. This may be related to dental disease and treatment factors, or changing psychological states during significant life transitions.

Adolescent↗
PubMed2001

Reduced neuropsychologic measures as predictors of treatment outcome in patients with temporomandibular disorders.

AIMS: To determine via a prospective investigation whether the presence of neuropsychologic or cognitive deficiencies could be identified in patients with temporomandibular disorders (TMD) and used to predict treatment outcome. This was based on the theory that measurable reductions in neuropsychologic and cognitive function might have a negative impact on treatment outcome in patients with essentially nontraumatic TMD, as has been shown for patients with posttraumatic TMD. METHODS: Various neuropsychologic, psychosocial, and clinical parameters (including but not limited to the Peterson-Peterson Consonant Trigram Test and the California Verbal Learning Test) were used to pretest patients suffering from TMD prior to treatment. Patients were then entered into treatment, after which determination of treatment success was made both by the use of visual analog scales for pain and global transitional outcome measures (e.g., "better," responders versus "same/worse," nonresponders). After determination of treatment success was made, treatment response was correlated with the various clinical, cognitive, and neuropsychologic test scores. RESULTS: Overall, the nonresponders did worse in both the neuropsychologic and psychosocial assessments, with greater memory deficits, sleep disturbances, depression, and fatigue and lower energy levels as compared to responders. Among the best predictors of treatment outcome were the Peterson-Peterson Consonant Trigram Test scores, as well as the scores on the California Verbal Learning Test (i.e., poorer test outcomes predicted nonresponse). Neither responders nor nonresponders could be distinguished from one another based on clinical parameters of maximum interincisal opening or muscle tenderness. Three psychosocial variables were also found to be predictors of poor outcome: sleep disturbance, fatigue, and income. Pretreatment pain on chewing was also found to be a reliable predictor of poor treatment outcome. CONCLUSION: We conclude that various neuropsychologic, psychosocial, and some clinical parameters may provide pretreatment prediction of treatment outcome in an idiopathic TMD population.

Adolescent↗
PubMed2000

HMG boxes of DSP1 protein interact with the rel homology domain of transcription factors.

Formation of the dorsoventral axis in Drosophila melanogaster is mediated through control of the expression of several genes by the morphogen Dorsal. In the ventral part of the embryo Dorsal activates twist and represses zen amongst others. Recently, several proteins have been shown to assist Dorsal in the repression of zen, one of which is DSP1, a HMG box protein that was isolated as a putative co-repressor of Dorsal. In this report we used a DSP1 null mutant to ascertain in vivo the involvement of DSP1 in Dorsal-mediated repression of zen but not in the activation of twist. We show that Dorsal has the ability to interact with DSP1 in vitro as well as with rat HMG1. Using truncated versions of the proteins we located the domains of interaction as being the HMG boxes for DSP1 and HMG1 and the Rel domain for Dorsal. Finally, studies of the zen DNA binding properties of Dorsal and another related Rel protein (Gambif1 from Anopheles gambiae) revealed that their DNA binding affinities were increased in the presence of DSP1 and HMG1.

Amino Acid Sequence↗
PubMed2000

Oral hygiene knowledge of high-risk Grade One children: an evaluation of two methods of dental health education.

The effectiveness of two methods of dental health education (DHE) for improving oral hygiene knowledge among high-risk Grade One students was evaluated. Fifty elementary schools in the former City of North York, Canada were assigned to one of two groups. In one group, students received a classroom-based DHE lesson which was reinforced by two small-group sessions (n=243). In the other group, students received only a single classroom-based DHE lesson (n=206). After DHE interventions, students in both groups displayed improved knowledge for most oral hygiene questions (e.g., when should you throw your toothbrush away?). However, for several questions, a significantly higher proportion of "classroom plus small-group sessions" students displayed improved knowledge compared to students receiving only a classroom lesson. These items included: awareness that cavity prevention and removal of germs are two purposes of oral hygiene; and knowledge that teeth help people to eat and talk. Results suggest a classroom-based lesson combined with small-group sessions is a more effective method of improving oral hygiene knowledge among high-risk Grade One students compared to a single classroom-based lesson.

Child↗
PubMed2000

Dental neglect and dental health among 26-year-olds in the Dunedin Multidisciplinary Health and Development Study.

OBJECTIVES: To test a modification of a previously-reported six-item dental neglect scale and examine its association with dental health and service-use among young adults. METHODS: Of the 980 26-year-old participants in the Dunedin Multidisciplinary Health and Development Study, 973 completed the scale and 930 underwent dental examination. Sociodemographic and dental service-use data were collected using a self-report questionnaire. RESULTS: Factor analysis showed that five of the original six items loaded on the scale, and responses to those items were summed to give a dental neglect scale score for each participant. Scale scores were normally distributed (mean=13.0; SD=3.6; range 5 to 25), and a median split created higher and lower dental neglect groups. A higher proportion of the higher neglect group group: (i) were male; (ii) rated their dental health and dental appearance as below average; (iii) brushed their teeth infrequently; (iv) had extensive plaque deposits; (v) used dental services only when they had a problem; (vi) had not recently seen a dentist; (vii) had lost at least one permanent tooth because of caries, and (viii) had a greater number of decayed tooth surfaces. CONCLUSIONS: Although further examination of its validity and reliability is indicated, the dental neglect scale appears to hold promise for use in dental health promotion, not only in highlighting population groups or individuals who would benefit from intensive health promotion efforts, but also in the evaluation of health promotion interventions.

Adult↗
PubMed2000

Deprivation and oral health: a review.

The link between socioeconomic status and health, including oral health, is well established. The conventional measures of socioeconomic status used in these studies, such as social class and household income, have a number of weaknesses so that alternatives, in the form of area-based measures of deprivation, are increasingly being used. This paper reviews epidemiological research linking deprivation and oral health. Four types of study are identified and described: simple descriptive, comparative, analytic and explanatory. These studies confirm that deprivation indices are sensitive to variations in oral health and oral health behaviours and can be used to identify small areas with high levels of need for dental treatment and oral health promotion services. As such, they are likely to provide a useful administrative tool. In terms of research, the studies demonstrate that these measures provide a ready way of controlling for socioeconomic status in studies examining the association between oral health and other variables. However, this research, in largely replicating previous studies using social class, does not address fundamental issues concerning the mechanisms which link social inequality and health. Deprivation measures have a major role to play in research that examines features of people and places, and how they promote and/or damage both oral and general health.

Adolescent↗
PubMed2000

Incidence of dental anxiety in young adults in relation to dental treatment experience.

OBJECTIVES: To document the incidence of dental anxiety among individuals aged 18 years at baseline and 26 years at follow-up, and to determine if dental treatment experience continues to play a significant etiological role with respect to the onset of dental anxiety in young adults. METHODS: Dental anxiety scale (DAS; Corah, 1969) scores at ages 15, 18 and 26 were obtained for Study members in the Dunedin Multidisciplinary Health and Development Study. Dental examinations were conducted, and sociodemographic and dental service-use data were collected using a self-report questionnaire. Using a case definition of a DAS score of 13 or more, age 18-26 incident cases were identified and their dental treatment experience and service-use characteristics compared with the remainder. RESULTS: DAS scores at 18 and 26 were available for 792 (80.8%) of the 980 26-year-old Study members. An increase in dental anxiety prevalence was observed over the eight-year period, with an annualized incidence of 2.1%. Fewer incident cases had visited a dentist in the previous eight years, and there were no differences between incident cases and others in their eight-year DFS, FS or tooth-loss increments. A subgroup of "recurrent" cases was identified who were dentally anxious at 15 and 26 but not at 18, and their eight-year incidence of tooth loss due to caries was substantially higher than non-cases. CONCLUSIONS: Aversive conditioning experiences appear to be unrelated to the adult onset of dental anxiety, and it may be that particular temperamental or psychological traits are associated with the condition.

Adolescent↗
PubMed2000

Response and nonresponse bias in oral health surveys.

Oral health surveys are undertaken to provide estimates of the dental health and behaviors of populations or population subgroups. However, the integrity of the data from sample surveys may be compromised by one or more sources of sampling and nonsampling error. An important source of nonsampling error is the failure to collect data from some of the individuals comprising the sample. Consequently, the response to a sample survey, and the direction and magnitude of bias induced by nonresponse, need to be taken into account when using estimates derived from sample surveys. Although the response rate to a survey is usually used as an indicator of the quality of the data it provides, nonresponse error is a function of nonresponse and the extent of differences in the characteristics of responders and nonresponders. Nonresponse may be managed in two ways. The first is to reduce nonresponse to a minimum using response-enhancement strategies. The second is the post-survey adjustment of data using weighting or imputation techniques to produce estimates that correct for nonresponse. This paper discusses issues concerning response and nonresponse bias in oral health surveys and provides guidelines on the management and reporting of nonresponse. It describes response-enhancement strategies to reduce noncontacts and refusals, sources of data to facilitate the comparison of responders and nonresponders, methods of assessing the degree of bias induced by nonresponse, techniques for producing adjusted survey estimates, and the assumptions on which these procedures and processes are based.

Bias↗
PubMed2000

Replacement of an NH(3) by an iminoether in transplatin makes an antitumor drug from an inactive compound.

To investigate the modifications of antitumor activity and DNA binding mode of transplatin after replacement of one nonleaving group NH(3) by an iminoether group, trans-[PtCl(2)(Z-HN=C(OMe)Me)(NH(3)] and trans-[PtCl(2)(E-HN=C(OMe)Me)(NH(3)] complexes (differing in the Z or E configuration of iminoether, and abbreviated mixed Z and mixed E, respectively), have been synthesized. In a panel of human tumor cell lines, both mixed Z and mixed E show a cytotoxic potency higher than that of transplatin, the mean IC(50) values being 103, 37, and 215 microM, respectively. In vivo mixed Z is more active and less toxic than mixed E in murine P388 leukemia and retains its efficacy against SK-OV-3 human cancer cell xenograft in nude mice. In the reaction with naked DNA, mixed Z forms monofunctional adducts that do not evolve into intrastrand cross-links but close slowly into interstrand cross-links between complementary guanine and cytosine residues. The monofunctional mixed Z adducts are removed by thiourea and glutathione. The interstrand cross-links behave as hinge joints, increasing the flexibility of DNA double helix. The mixed Z, transplatin, and cisplatin interstrand cross-links, as well as mixed Z monofunctional adducts are not specifically recognized by HMG1 protein, which was confirmed to be able to specifically recognize cisplatin d(GpG) intrastrand cross-links. These data demonstrate that the DNA interaction properties of the antitumor-active mixed Z are very similar to those of transplatin, thus suggesting that clinical inactivity of transplatin could not depend upon its peculiar DNA binding mode.

Animals↗
PubMed2000

Self-perceived oral health status, psychological well-being, and life satisfaction in an older adult population.

Numerous studies have demonstrated that many older adults have problems chewing, pain, difficulties in eating, and problems in social relationships because of oral disorders. However, it is not clear if these functional and psychosocial outcomes affect broader psychological well-being and life satisfaction. Consequently, this paper begins to address the question, 'Does poor oral health compromise the quality of life?'. Initial cross-sectional analyses used data derived from the seven-year follow-up of the Ontario Study of the Oral Health of Older Adults. As at baseline and three-year follow-up, oral health was measured by self-ratings of oral health and five oral health indices. Psychological well-being and life satisfaction were assessed according to the Morale Index, the Perceived Life Stress Questionnaire, The Life Satisfaction Scale, and the General Health Questionnaire. All oral health variables were significantly associated with scores from the first three of these measures in the expected direction. These associations remained after we controlled for other potential influences on the quality of life. In addition, prospective analysis indicated that self-perceived oral health at three years had a significant independent effect on psychological well-being and life satisfaction at seven years. These results suggest that poor self-perceived oral health and relatively poor quality of life co-exist in the same subgroup of older adults.

Aged↗
PubMed2000

Measuring the effect of intra-oral implant rehabilitation on health-related quality of life in a randomized controlled clinical trial.

The importance of assessing the impact of treatments for chronic conditions on an individual's quality of life has been well-established. In this randomized clinical trial, oral-health-related quality of life, measured with the Oral Health Impact Profile (OHIP), was compared between two groups of edentulous patients. One group (n = 54) received mandibular implant-supported overdentures, and the other group (n = 48) received conventional dentures. Assessments were performed pre-treatment and two months after the prostheses were delivered. The multivariate model showed that implant treatment was significantly associated with lower post-treatment OHIP scores (p = 0.0002), indicating a better quality of life. In addition, pretreatment OHIP scores, treatment allocation, age, sex, and marital status explained 31% of the variation in post-treatment OHIP scores (F = 0.0001). These results suggest that implant treatment provides significant short-term improvement over conventional treatment in oral-health-related quality of life.

Adult↗