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1.
J Dent Res ; 99(11): 1262-1269, 2020 10.
Article in English | MEDLINE | ID: mdl-32579872

ABSTRACT

Laboratory studies show that bisphenol A (BPA) leaches from bisphenol A-glycidyl methacrylate (bisGMA)-based dental materials. We aimed to quantify the extent to which children are exposed to BPA from dental treatment with bisGMA materials, by amount of treatment and type of sedation. We hypothesized that posttreatment urinary BPA (uBPA) concentrations would be higher among patients with more surfaces treated with bisGMA-based materials and among patients receiving general anesthesia compared with pretreatment concentrations. We conducted a prospective cohort study in 211 children, 4 to 12 y old, who had no prior resin-based dental treatment. We measured uBPA concentrations twice before treatment and at 2 d and 1, 4, and 16 wk posttreatment. We abstracted treatment data (surfaces treated) from the chart. We generated descriptive statistics and compared pre- and posttreatment uBPA concentrations using generalized estimating equations. Participants were 51% female, 46% non-White, and 74% publicly insured. The median age was 6 y. The mean number of tooth surfaces exposed to BisGMA materials (composites/sealants) was 7.5 (SD 5.3). Overall, uBPA concentrations were 86% higher (95% confidence interval [CI] 42% to 143%, P < 0.001) at 2 d posttreatment compared with pretreatment concentrations. The uBPA concentrations 2 d posttreatment versus pretreatment tended to be higher (112%, 95% CI 53% to 194%) among those receiving treatment on >4 surfaces than those receiving treatment on ≤4 surfaces (50%, 95% CI -2% to 130%). Two days after treatment, uBPA was significantly higher than pretreatment concentrations in children receiving nitrous oxide but not in those receiving general anesthesia. Among all findings, uBPA concentrations returned to baseline by 4 wk. Children experience short-term increases in BPA from dental treatment. The impact of relatively high, short-term BPA exposure on child health is unknown. Given the widespread use of BisGMA-based dental materials and that chronic low-dose BPA exposure may adversely affect child health, strategies that minimize BPA exposure could potentially improve child health.


Subject(s)
Benzhydryl Compounds , Phenols , Benzhydryl Compounds/adverse effects , Bisphenol A-Glycidyl Methacrylate , Child , Female , Humans , Male , Prospective Studies
2.
J Fr Ophtalmol ; 42(3): 262-268, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30879837

ABSTRACT

PURPOSE: To investigate the prevalence and location of optic nerve head drusen and their potential association with other PXE-related ophthalmic abnormalities. MATERIALS AND METHODS: Thirty-eight of the 155 patients (57 male and 98 female aged 49±17 years) included in this retrospective study had optic nerve head drusen. All of the patients underwent a comprehensive ophthalmic examination, including color images using red-free, blue and red filters, autofluorescence imaging and late-phase ICG frames. Comparative analysis of both groups (optic nerve head drusen or not) was conducted using R statistical software. RESULTS: The prevalence of optic nerve head drusen in our cohort was 24.5%. In this study, no evidence of a significant link between optic nerve head drusen and other fundus abnormalities was detected. They were more commonly located in the nasal sector than in the temporal sector of the optic disc (P<0.001). They were more frequently situated superonasally than inferonasally (P<0.004), superotemporally (P<0.001) or inferotemporally (P<0.03). No central visual field defect was observed in OND+ patients who were unaffected by macular disorders. DISCUSSION: We hypothesized this predominantly nasal primary location may result from greater sensitivity in the nasal optic nerve fibers which follow a much more angular path once they arrive in the scleral canal, accounting for accumulation of axoplasmic debris. CONCLUSION: In PXE, optic nerve head drusen are mostly located in the superonasal quadrant, causing progressive optic nerve invasion but probably no central visual field defects.


Subject(s)
Optic Disk Drusen/complications , Optic Disk Drusen/diagnosis , Optic Nerve/diagnostic imaging , Pseudoxanthoma Elasticum/complications , Adolescent , Adult , Aged , Aged, 80 and over , Child , Female , Fundus Oculi , Genotype , Humans , Male , Middle Aged , Optic Disk/diagnostic imaging , Optic Disk Drusen/genetics , Optic Disk Drusen/pathology , Optic Nerve/pathology , Pseudoxanthoma Elasticum/diagnosis , Pseudoxanthoma Elasticum/genetics , Pseudoxanthoma Elasticum/pathology , Retrospective Studies , Tomography, Optical Coherence , Visual Acuity , Visual Field Tests , Young Adult
3.
J Dent Res ; 95(8): 946-52, 2016 07.
Article in English | MEDLINE | ID: mdl-27013641

ABSTRACT

The oral microbial community is the best-characterized bacterial ecosystem in the human host. It has been shown in the mouse that oral commensal bacteria significantly contribute to clinically healthy periodontal homeostasis by influencing the number of neutrophils that migrate from the vasculature to the junctional epithelium. Furthermore, in clinically healthy tissue, the neutrophil response to oral commensal bacteria is associated with the select expression of the neutrophil chemokine CXCL2 but not CXCL1. This preliminary study examined the contribution of commensal bacteria on neutrophil location across the tooth/gingival interface. Tissue sections from the root associated mesial (anterior) of the second molar to the root associated distal (posterior) of the second molar were examined for neutrophils and the expression of the neutrophil chemokine ligands CXCL1 and CXCL2. It was found that both the number of neutrophils as well as the expression of CXCL2 but not CXCL1 was significantly increased in tissue sections close to the interdental region, consistent with the notion of select tissue expression patterns for neutrophil chemokine expression and subsequent neutrophil location. Furthermore, mice gavaged with either oral Streptococcus or Lactobacillus sp. bacteria induced a location pattern of neutrophils and CXCL2 expression similar to the normal oral flora. These data indicate for the first time select neutrophil location and chemokine expression patterns associated with clinically healthy tissue. The results reveal an increased inflammatory load upon approaching the interproximal region, which is consistent with the observation that the interproximal region often reveals early clinical signs of periodontal disease.


Subject(s)
Chemokine CXCL2/physiology , Neutrophils/physiology , Periodontium/physiology , Animals , Cell Movement/physiology , Mice , Mice, Inbred C3H , Periodontium/metabolism , Periodontium/microbiology , Streptococcus/metabolism
5.
Orthop Traumatol Surg Res ; 100(4): 385-8, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24751460

ABSTRACT

BACKGROUND: Anterior cervical fusion is widely used to treat spinal injuries. Radiological evidence of disc abnormalities may develop on either side of the fused segment, raising concern about the potential for inducing adjacent-segment disease. Here, we report the long-term clinical, functional, and radiological outcomes after anterior cervical fusion. HYPOTHESIS: Anterior cervical fusion influences the development of adjacent-segment disease. MATERIALS AND METHODS: In a retrospective study, 15 patients aged 17 to 50 years were re-evaluated more than 5 years after anterior spinal fusion to treat post-traumatic cervical-spine instability. We used the Neck Disability Index (NDI) to assess function. Static and dynamic radiographs of the cervical spine were obtained. RESULTS: NDI values indicated good clinical and functional outcomes, and fusion was achieved consistently. Adjacent-segment disease was a consistent finding at last follow-up but induced no neurological manifestations. Complete fusion of a level adjacent to the treated level was noted in 2 patients. Revision surgery for adjacent-segment disease was not required in any patient. CONCLUSION: The causative factors of adjacent-segment disease are controversial. Disc degeneration is a normal manifestation of the ageing process. Nevertheless, disc disease is more prevalent at levels adjacent to interbody fusion than in the normal population, suggesting accelerated disc degeneration due to increased loading of the adjacent levels. Furthermore, lesions that are missed during the pre-operative work-up may play a role, as the available investigations do not always have high negative predictive values. LEVEL OF EVIDENCE: Level IV, retrospective study.


Subject(s)
Cervical Vertebrae/diagnostic imaging , Intervertebral Disc Degeneration/diagnostic imaging , Joint Instability/surgery , Spinal Fusion/adverse effects , Spinal Injuries/surgery , Adolescent , Adult , Cervical Vertebrae/injuries , Female , Humans , Intervertebral Disc Degeneration/etiology , Joint Instability/diagnosis , Joint Instability/diagnostic imaging , Joint Instability/etiology , Male , Middle Aged , Radiography , Retrospective Studies , Spinal Injuries/complications , Spinal Injuries/diagnostic imaging , Young Adult
6.
Med Mal Infect ; 43(9): 368-73, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23910937

ABSTRACT

INTRODUCTION: An outbreak of shiga-toxin producing Escherichia coli infections occurred in southwest France in June 2012. The outbreak was investigated to identify the source of infection, and guide control measures. METHODS: Confirmed outbreak cases were patients who developed bloody diarrhoea or haemolytic uremic syndrome (HUS) between 28 May and 6 July 2012, with E. coli O157 isolates showing indistinguishable patterns on pulse field gel electrophoresis (PFGE). A standardized questionnaire was administered to patients to document food consumption and other risk exposures. Their purchase was checked through their supermarket shopper card data. RESULTS: Six patients (four with HUS and two with bloody diarrhea) were confirmed outbreak cases. Fresh ground beef burgers from one supermarket were the only common food exposure, identified by interviews and shopper card data. The PFGE profile of shiga toxin-producing E. coli O157 isolated from the suspected beef burgers was identical to those from the human cases. The suspected beef burgers were no longer on sale at the time of investigation but three patients confirmed as outbreak cases had deep-frozen some at home. CONCLUSION: Shopper card data was particularly useful to obtain precise and reliable information on the traceability of consumed food. Despite the expired use-by date, a recall was issued for the beef burgers. This contributed to preventing other cases among consumers who had deep-frozen the beef burgers.


Subject(s)
Disease Outbreaks , Escherichia coli Infections/epidemiology , Escherichia coli O157/isolation & purification , Food Contamination , Food Storage , Hemolytic-Uremic Syndrome/epidemiology , Meat Products/microbiology , Public Health Surveillance/methods , Records , Animals , Bacterial Typing Techniques , Cattle , Cryopreservation , Escherichia coli Infections/etiology , Escherichia coli Infections/microbiology , Escherichia coli O157/genetics , Food Preservation , France/epidemiology , Genes, Bacterial , Hemolytic-Uremic Syndrome/etiology , Hemolytic-Uremic Syndrome/microbiology , Humans
7.
J Dent Res ; 92(7 Suppl): 37S-42S, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23690352

ABSTRACT

One in four adults reports a clinically significant fear of dental injections, leading many to avoid dental care. While systematic desensitization is the most common therapeutic method for treating specific phobias such as fear of dental injections, lack of access to trained therapists, as well as dentists' lack of training and time in providing such a therapy, means that most fearful individuals are not able to receive the therapy needed to be able to receive necessary dental treatment. Computer Assisted Relaxation Learning (CARL) is a self-paced computerized treatment based on systematic desensitization for dental injection fear. This multicenter, block-randomized, dentist-blind, parallel-group study conducted in 8 sites in the United States compared CARL with an informational pamphlet in reducing fear of dental injections. Participants completing CARL reported significantly greater reduction in self-reported general and injection-specific dental anxiety measures compared with control individuals (p < .001). Twice as many CARL participants (35.3%) as controls (17.6%) opted to receive a dental injection after the intervention, although this was not statistically significant. CARL, therefore, led to significant changes in self-reported fear in study participants, but no significant differences in the proportion of participants having a dental injection.


Subject(s)
Computer-Assisted Instruction/methods , Dental Anxiety/prevention & control , Desensitization, Psychologic/methods , Injections/psychology , Patient Education as Topic , Adolescent , Adult , Aged , Dental Care/psychology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Needles/adverse effects , Pamphlets , Relaxation Therapy , Single-Blind Method , Young Adult
8.
Orthop Traumatol Surg Res ; 99(4): 399-404, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23623438

ABSTRACT

BACKGROUND: Intramedullary nailing using long or modular nails is the most reliable mean of achieving femorotibial fusion. Here, we report the operative, clinical, functional, and radiological outcomes of 17 long intramedullary nail arthodeses in patients with infection. HYPOTHESIS: Clinical and functional outcomes after long intramedullary nailing are at least as good as those obtained using other implants. MATERIALS AND METHODS: We retrospectively reevaluated 17 patients after unilateral two-stage knee arthrodesis with a long titanium intramedullary nail and autologous bone grafting. We evaluated satisfaction, leg length discrepancy, and function (Lequesne and WOMAC indices). Radiographs were obtained to assess fusion, time to fusion, and femorotibial angles. RESULTS: No cases of material failure were recorded. One or more complications occurred in seven patients. Mean limb shortening was 27.6mm. Of the 17 patients, 15 were satisfied with the procedure. The mean Lequesne index was 10.5/24 and the mean overall WOMAC score was 26/88. Fusion was achieved in 16 patients, with a mean time to fusion of 5 months. Mean femorotibial angles were 178.6° of varus and 1.9° of flexion. DISCUSSION: This simple and rapid surgical technique provides functional outcomes similar to those obtained using modular nails. The fusion rate is high. Nail extraction is simple and causes minimal damage, in contrast to modular nails. Increased attention to misalignment is needed. LEVEL OF EVIDENCE: Level IV, retrospective study.


Subject(s)
Arthritis, Infectious/surgery , Arthrodesis/instrumentation , Bone Nails , Knee Joint/surgery , Adult , Aged , Aged, 80 and over , Female , Follow-Up Studies , Humans , Knee Joint/physiopathology , Male , Middle Aged , Range of Motion, Articular , Retrospective Studies , Treatment Outcome
9.
Med Phys ; 40(2): 022701, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23387771

ABSTRACT

PURPOSE: To construct a phantom for prostate cancer laser based thermotherapy treatment planning and simulation. METHODS: A realistic and adaptable prostate phantom was designed. It exhibits the following properties: valid and complete description of the prostate anatomy, material with similar optical properties of prostate tissues and compatibility with clinical imaging protocols mainly multiparametric magnetic resonance (MR) and transrectal ultrasound imaging (TRUS). RESULTS: Preliminary experiments with the phantom using an interstitial laser treatment protocol allowed obtaining results similar to those obtained on preclinical model. CONCLUSIONS: These results proved that this phantom could allow a real simulation of laser therapy procedure: target definition and fibers' placement optimization using MR imaging, treatment delivery, and finally treatment monitoring using TRUS imaging.


Subject(s)
Hot Temperature/therapeutic use , Laser Therapy/instrumentation , Phantoms, Imaging , Prostate/anatomy & histology , Prostate/surgery , Humans , Magnetic Resonance Imaging , Male
10.
J Dent Res ; 91(11): 1032-7, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22983408

ABSTRACT

This cluster-randomized pragmatic (effectiveness) trial tested maternal counseling based on Motivational Interviewing (MI) as an approach to control caries in indigenous children. Nine Cree communities in Quebec, Canada were randomly allocated to test or control. MI-style counseling was delivered in test communities to mothers during pregnancy and at well-baby visits. Data on outcomes were collected when children were 30 months old. Two hundred seventy-two mothers were recruited from the 5 test and 4 control communities. Baseline characteristics were comparable but not equivalent for both groups. At trial's end, 241 children had follow-up. The primary analysis outcome was enamel caries with substance loss (d2); no statistically significant treatment effect was detected. Prevalence of treated and untreated caries at the d2 level was 76% in controls vs. 65% in test (p = 0.17). Exploratory analyses suggested a substantial preventive effect for untreated decay at or beyond the level of the dentin, d3 (prevalences: 60% controls vs. 35% test), and a particularly large treatment effect when mothers had 4 or more MI-style sessions. Overall, these results provide preliminary evidence that, for these young, indigenous children, an MI-style intervention has an impact on severity of caries (clinical trial registration ISRCTN41467632).


Subject(s)
Counseling , Dental Caries/prevention & control , Health Education, Dental/methods , Indians, North American , Mothers/education , Child, Preschool , Cluster Analysis , Female , Humans , Motivational Interviewing , Pregnancy , Quebec , Sample Size , Single-Blind Method
11.
Euro Surveill ; 17(30)2012 Jul 26.
Article in English | MEDLINE | ID: mdl-22856510

ABSTRACT

A case of human brucellosis was diagnosed in France in January 2012. The investigation demonstrated that the case had been contaminated by raw milk cheese from a neighbouring dairy farm. As France has been officially free of bovine brucellosis since 2005, veterinary investigations are being conducted to determine the origin of the infection and avoid its spread among other herds. Hypotheses about the source of this infection are discussed.


Subject(s)
Brucella melitensis/isolation & purification , Brucellosis, Bovine/diagnosis , Brucellosis/diagnosis , Cattle Diseases/diagnosis , Animals , Brucella melitensis/genetics , Brucellosis/transmission , Brucellosis, Bovine/transmission , Cattle , Communicable Diseases, Emerging , Dairy Products , Food Contamination , France , Humans , Milk/microbiology , Multilocus Sequence Typing , Population Surveillance , Risk Factors , Tandem Repeat Sequences
12.
Int J Tuberc Lung Dis ; 16(7): 880-5, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22583660

ABSTRACT

OBJECTIVE: To examine neighborhood-level influences on tuberculosis (TB) incidence in a multilevel population-based sample. DESIGN: All incident TB cases in Washington State, United States (n = 2161), reported between 1 January 2000 and 31 December 2008 were identified. Multivariate Poisson analysis was used at the ZIP Code tabulation area (ZCTA) level, which allowed for further exploration of area-specific influences on TB incidence. RESULTS: A significant association was found between indices of socio-economic position (SEP) and TB incidence in Washington State, with a clear gradient of higher rates observed among lower ZCTA socio-economic quartiles. Compared to the wealthiest SEP quartile, the relative incidence of TB in successively lower quartiles was respectively 2.7, 4.1 and 10.4 (P trend <0.001). In multivariate analyses, the addition of area-level race, ethnicity and country of birth significantly attenuated this association (adjusted incidence rate ratios 2.3, 2.6, 5.7; P trend <0.001). CONCLUSION: This study found a significant inverse association between area measures of socio-economic status (SES) and TB incidence across ZCTAs in Washington State, even after adjusting for individual age and sex and area-based race, ethnicity and foreign birth. These results emphasize the importance of neighborhood context and the need to target prevention efforts to low-SES neighborhoods.


Subject(s)
Health Status Disparities , Residence Characteristics , Tuberculosis/epidemiology , Humans , Incidence , Multivariate Analysis , Socioeconomic Factors , United States/epidemiology , Washington/epidemiology
14.
Dentomaxillofac Radiol ; 40(8): 501-5, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22065799

ABSTRACT

OBJECTIVES: The aim of this study was to (1) evaluate the fractal dimension (FD) in regions of the mandible on cone beam CT (CBCT) images of patients with bisphosphonate-associated osteonecrosis of the jaws (BP-ONJ) and (2) to select the most suitable region of interest (ROI) for further study on detection of bone alterations associated with bisphosphonates. METHODS: CBCT images of patients with BP-ONJ were included with matched controls. Values of FD were compared between groups. Selected ROIs were: ROI-1 - below the mandibular foramen; ROI-2 - above the mandibular foramen; ROI-3 - anterior to the mental foramen; ROI-4 - above the mandibular canal. The area of bone exposure was included as ROI-5. The results were analysed using generalized estimating equations and conditional logistic regression. RESULTS: There were 36 patients (67% female) with a mean age of 60.7 years. The mean FDs were: ROI-1 - 1.678 for controls and 1.673 for patients (P = 0.81); ROI-2 - 1.657 for controls and 1.653 for patients (P = 0.78); ROI-3 - 1.661 for controls and 1.684 for patients (P = 0.17); and ROI-4 - 1.670 for controls and 1.698 for patients (P = 0.03). The value of the FD in the area of exposed bone was the highest (1.729). The odds of being a BP-ONJ patient vs being a control was six times as high for individuals with a higher FD score at ROI-4, although the confidence interval was quite wide owing to the small sample size. CONCLUSION: In this preliminary study, BP-ONJ patients had higher FD values than controls at regions close to the alveolar process. The results suggest that FD is a promising tool for detection of bone alterations associated with BP-ONJ.


Subject(s)
Bone Density Conservation Agents/adverse effects , Cone-Beam Computed Tomography/methods , Diphosphonates/adverse effects , Fractals , Mandibular Diseases/chemically induced , Mandibular Diseases/diagnostic imaging , Osteonecrosis/chemically induced , Osteonecrosis/diagnostic imaging , Adult , Aged , Aged, 80 and over , Case-Control Studies , Female , Humans , Logistic Models , Male , Middle Aged , Pilot Projects , Regression Analysis , Retrospective Studies , Single-Blind Method
15.
Ann Fr Anesth Reanim ; 30(2): 113-6, 2011 Feb.
Article in French | MEDLINE | ID: mdl-21282035

ABSTRACT

OBJECTIVE: The aim of this study was to assess airway management by emergency physicians in case of a simulated situation where intubation and ventilation were both impossible. STUDY DESIGN: Observational manikin study. METHODS: A manikin (Airman®; Laerdal) allowing simulating difficult airway situations was used. The scenario assessed concerned a patient needing tracheal intubation for severe traumatic brain injury. The manikin was settled to make tracheal intubation under direct laryngoscopy impossible at the first attempt and to make facemask ventilation impossible after the second attempt. Manikin could initially be ventilated through the intubating laryngeal mask Airway (ILMA) but became impossible few seconds after its insertion. With impossible ventilation through the ILMA, arterial oxygen saturation decreased during 2 minutes before an hypoxic cardiac arrest occurred. Physicians could use classic laryngoscope with Macintosh blade, a Gum Elastic Bougie, an ILMA and a cricothyrotomy set. Adhesion to the national airway management algorithm was assessed. Time to cricothyroidotomy decision after ventilation through ILMA became impossible was measured. RESULTS: Twenty-five emergency physicians were assessed. For 14 of them, national expert conference algorithm was perfectly followed. For ten physicians, cricothyroidotomy decision was taken after hypoxic cardiac arrest occurred. CONCLUSION: Simulation with a manikin is useful to assess the adhesion rate to difficult intubation algorithms. Our study shows that the decision making process for cricothyrotomy is too often delayed as soon as ventilation became impossible and oxygenation compromized.


Subject(s)
Airway Management/methods , Cricoid Cartilage/surgery , Emergency Medical Services/methods , Intubation, Intratracheal , Respiration, Artificial , Tracheostomy/methods , Adult , Algorithms , Brain Injuries/therapy , Clinical Competence , Decision Making , Female , Guideline Adherence , Humans , Laryngeal Masks , Laryngoscopy , Male , Manikins , Middle Aged , Oximetry , Oxygen/blood
16.
J Food Sci ; 75(4): S245-9, 2010 May.
Article in English | MEDLINE | ID: mdl-20546428

ABSTRACT

In this study, the effect on taste due to the addition of air bubbles to a water-based gel was investigated. The gel phase contained either sucrose to give a sweet taste or sodium chloride to give a salty taste. For the sweet gels, taste intensities were evaluated for samples with different volume fractions of the air bubbles (up to 40%, v/v) and different concentrations of the sucrose. For the salty gels, samples were evaluated at 40% volume fraction of air bubbles. It was found that a reduction of the sodium chloride or sucrose by the same weight percentage as the volume fraction of the air bubbles in the samples gave equal taste perception as the nontastant-reduced samples. Moreover, saltiness and sweetness perception were clearly enhanced at 40% volume fractions of air bubbles if the sodium chloride or sucrose was not reduced. Thus, the overall tastes of the samples appeared to depend mainly on the concentration levels of the salt or the sucrose in the aqueous phase irrespective of the volume fraction of the air bubbles. However, the air bubbles were found to change the texture and appearance of the samples. It has been demonstrated that the inclusion of air bubbles offers scope for the reduction of sodium chloride or sucrose in food products.


Subject(s)
Flavoring Agents/chemistry , Food Additives/chemistry , Food Analysis , Taste , Agar/chemistry , Air/analysis , Chemical Phenomena , Diet, Carbohydrate-Restricted/methods , Diet, Sodium-Restricted/methods , Dietary Sucrose , Gels , Humans , Models, Chemical , Osmolar Concentration , Sodium Chloride, Dietary , Water/analysis
17.
Stat Med ; 29(4): 464-73, 2010 Feb 20.
Article in English | MEDLINE | ID: mdl-19904773

ABSTRACT

Multilevel nested, correlated data often arise in biomedical research. Examples include teeth nested within quadrants in a mouth or students nested within classrooms in schools. In some settings, cluster sizes may be large relative to the number of independent clusters and the degree of correlation may vary across clusters. When cluster sizes are large, fitting marginal regression models using Generalized Estimating Equations with flexible correlation structures that reflect the nested structure may fail to converge and result in unstable covariance estimates. Also, the use of patterned, nested working correlation structures may not be efficient when correlation varies across clusters. This paper describes a flexible marginal regression modeling approach based on an optimal combination of estimating equations. Particular within-cluster and between-cluster data contrasts are used without specification of the working covariance structure and without estimation of covariance parameters. The method involves estimation of the covariance matrix only for the vector of component estimating equations (which is typically of small dimension) rather than the covariance matrix of the observations within a cluster (which may be of large dimension). In settings where the number of clusters is large relative to the cluster size, the method is stable and is highly efficient, while maintaining appropriate coverage levels. Performance of the method is investigated with simulation studies and an application to a periodontal study.


Subject(s)
Cluster Analysis , Computer Simulation , Models, Statistical , Alveolar Bone Loss/drug therapy , Doxycycline/therapeutic use , Female , Humans , Osteoporosis, Postmenopausal/drug therapy , Periodontitis/drug therapy , Randomized Controlled Trials as Topic/statistics & numerical data
18.
Emerg Med J ; 26(3): 210-2, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19234017

ABSTRACT

BACKGROUND: Non-invasive arterial blood pressure measurement is often inaccurate in emergency unstable patients. A study was undertaken to assess the feasibility of out-of-hospital intra-arterial catheterisation in haemodynamically unstable patients and to evaluate the correlation between invasive and non-invasive arterial pressure values. METHODS: In this prospective 2-year observational study conducted by mobile emergency medical units, the success rate of arterial catheterisation was calculated and blood pressure values measured invasively and non-invasively after successful catheterisation were compared. RESULTS: 94 patients were included. The success rate for catheterisation (44 radial access, 50 femoral access) was 86% (95% CI 79% to 93%). Bias and precision in invasive versus non-invasive comparisons were -0.1, 38 mm Hg for systolic pressure and 4.2, 27 mm Hg for diastolic pressure. Values differed by more than 20 mm Hg in over 40% of patients. Invasive measurement led to 79 changes in vasoactive treatment in 51 patients. CONCLUSION: Emergency out-of-hospital invasive arterial blood pressure monitoring in haemodynamically unstable patients is highly feasible. Discrepancies between invasive and non-invasive measurements are common and highlight the value of early out-of-hospital monitoring.


Subject(s)
Blood Pressure Determination/methods , Catheterization, Peripheral/methods , Emergency Medical Services/methods , Aged , Brain Injuries/therapy , Chi-Square Distribution , Feasibility Studies , Female , Heart Arrest/therapy , Humans , Male , Middle Aged , Prospective Studies , Sensitivity and Specificity , Stroke/therapy
19.
Int J Dent Hyg ; 6(3): 238-43, 2008 Aug.
Article in English | MEDLINE | ID: mdl-18768029

ABSTRACT

UNLABELLED: Dental hygiene activities were developed as part of a randomized clinical trial designed to assess the safety of low-level mercury exposure from dental amalgam restorations. Along with dental-hygiene clinical work, a community programme was implemented after investigators noticed the poor oral hygiene habits of participants, and the need for urgent action to minimize oral health problems in the study population. OBJECTIVES: Clinical and community activity goal was to promote oral health and prevent new disease. Community activities involved participants and their fellow students and were aimed at providing education on oral health in a school environment. METHODS: Dental hygienists developed clinical work with prophylaxis, sealants application and topical fluoride and implemented the community programme with in-class sessions on oral health themes. Twice a month fluoride mouthrinses and bi-annual tooth brushing instructional activity took place. Participation at dental-hygiene activities, sealed teeth with no need of restoration and dental-plaque-index were measures used to evaluate success of the programme for the participants. RESULTS: Improvement in dental hygiene is shown by the decrease in dental plaque index scores (P < 0.0001); also sealants integrity is achieved in 86.3% of teeth. 888 (13.7%) teeth with sealants had to be restored or were lost. Children participated actively on dental hygiene activities. Teachers became aware of the problem and included oral-health in school curricula. CONCLUSION: Dental hygiene activities have shown to be helpful to promote dental hygiene, promote oral health and to provide school-age children with education on habits that will be important for their future good health.


Subject(s)
Health Education, Dental , Oral Hygiene , School Dentistry , Cariostatic Agents/therapeutic use , Child , Dental Care for Children , Dental Caries/prevention & control , Dental Devices, Home Care , Dental Plaque/prevention & control , Dental Plaque Index , Dental Prophylaxis , Feeding Behavior , Female , Fluorides, Topical/therapeutic use , Follow-Up Studies , Health Education, Dental/methods , Health Promotion , Health Services Accessibility , Humans , Male , Motivation , Mouthwashes/therapeutic use , Patient Education as Topic , Periodontal Diseases/prevention & control , Pit and Fissure Sealants/therapeutic use , Toothbrushing
20.
J Dent Res ; 87(5): 475-9, 2008 May.
Article in English | MEDLINE | ID: mdl-18434580

ABSTRACT

Mercury emitted from dental amalgam may select for increased numbers of antibiotic- or mercury-resistant commensal bacteria in patients and increase their risk for bacterial diseases that are resistant to common therapies. We hypothesized that the presence of dental amalgams would increase the level of mercury-, tetracycline-, ampicillin-, erythromycin-, or chloramphenicol-resistant oral and urinary bacteria as compared with levels in children receiving composite fillings. Samples were collected at baseline, 3-6 months after the initial dental treatment, and annually for 7 years of follow-up. There were no statistically significant differences between treatment groups in the numbers of bacteria growing on antibiotic- or mercury-supplemented plates. This study provided no evidence that amalgam fillings on posterior teeth influenced the level of antibiotic- or mercury-resistant oral or urinary bacteria as detected by culture.


Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Dental Amalgam/pharmacology , Dental Caries/microbiology , Drug Resistance, Microbial , Adolescent , Anti-Bacterial Agents/metabolism , Child , Dental Amalgam/metabolism , Dental Caries/therapy , Dental Restoration, Permanent/methods , Female , Humans , Longitudinal Studies , Male , Mouth/microbiology
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