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1.
Int Endod J ; 53(2): 145-153, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31306506

RESUMO

AIM: To investigate the effect of magnesium sulphate used as an adjuvant to lidocaine with epinephrine local anaesthetic on the success of inferior alveolar nerve blocks (IANB) in patients with symptoms of irreversible pulpitis undergoing root canal treatment. METHODOLOGY: In a double-blind clinical trial, following power calculation, 124 patients with symptoms of irreversible pulpitis in mandibular molar teeth were selected, and initial pain data were collected using a Heft-Parker (Pain, 19, 1984 and 153) visual analogue scale. The first group (control) received IANB with 1.8 mL of a local anaesthetic solution containing 1.8% lidocaine with 1 : 88 000 epinephrine while the second group (test) received IANB with 1.8 mL of an anaesthetic solution containing 1% magnesium sulphate, and 1.8% lidocaine with 1 : 88 000 epinephrine. Pain data were collected after access cavity and penetration of files in the canals using a Heft-Parker visual analogue scale. Two patients were not included in the study as they did not consent, and a further 54 patients were excluded as they did not report lip numbness within 15 min after IANB administration; thus, the data presented in this study are related to 68 patients. The data were analysed using chi-square and t-test (α = 0.05). RESULTS: The success of pulpal anaesthesia with IANB was 82% for the magnesium sulphate group and 53% for the control group. There was a significant difference in the effectiveness of the IANB between the two groups (P < 0.001). There was no significant difference between the magnesium sulphate and control groups regarding gender (P = 0.598) or age (P = 0.208) or initial pain scores (P = 0.431). CONCLUSIONS: The addition of 1% magnesium sulphate to 1.8% lidocaine with 1 : 88 000 epinephrine resulted in a positive impact for the success of IANB in patients with a diagnosis of irreversible pulpitis related to mandibular molar teeth undergoing root canal treatment. Thus magnesium sulphate may be used as adjuvant for achieving profound pulpal anaesthesia in challenging cases. However, more studies with larger sample size and different concentration doses must be carried out to establish an appropriate conclusion before its routine clinical use.


Assuntos
Anestesia Dentária , Bloqueio Nervoso , Pulpite , Anestésicos Locais , Método Duplo-Cego , Humanos , Lidocaína , Sulfato de Magnésio , Nervo Mandibular , Estudos Prospectivos
2.
Int Endod J ; 53(7): 986-997, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32163598

RESUMO

AIM: To establish whether irrigant activation techniques, namely manual dynamic activation (MDA), passive ultrasonic irrigation (PUI) and sonic irrigation (SI), improve the tubular penetration of sodium hypochlorite (NaOCl) into root dentine when compared with conventional needle irrigation (CNI). Secondly, investigate if increasing NaOCl concentration and/or contact time improves the performance of these techniques. METHODOLOGY: A total of 83 extracted human maxillary permanent canines were decoronated to 15 mm, and root canals prepared to a size 40, .10 taper. Root dentine was stained with crystal violet for 72 h and embedded in silicone. Eighty specimens were randomly distributed into 16 groups (n = 5) according to the irrigant activation technique, NaOCl concentration (2%; 5.25%) and irrigant contact time (10 min; 20 min). All activation techniques were used for 60 s in the last minute of irrigation. Additionally, three teeth were not exposed to NaOCl to confirm adequate dentine staining had occurred (i.e. negative control). All specimens were subsequently dissected, observed under a light microscope and NaOCl penetration depth (µm) determined by measuring the average width of bleached dentine using ImageJ software. Statistical comparisons were made with paired and unpaired t-tests, anovas followed by post hoc Tukey's and Dunnett's tests, and a general linear model (α < 0.05). RESULTS: Overall, NaOCl penetration ranged from 38.8 to 411.0 µm with MDA, PUI and SI consistently resulting in significantly greater tubular infiltration than CNI (P < 0.05). The deepest measurements in the coronal, middle and apical segments were all recorded in the MDA; 5.25%; 20 min group and the least in the CNI; 2%; 10 min group. Increasing either irrigant concentration or contact time resulted in significantly greater NaOCl penetration depths for all techniques and segments of the canal (P < 0.05). However, when irrigant concentration and contact time were increased together, a significant interaction effect between these two independent variables was observed on overall NaOCl penetration (P < 0.05). CONCLUSIONS: Agitating irrigants with MDA, PUI or SI, as well as using greater irrigant concentrations or contact times, potentiated NaOCl penetration into root dentine. However, longer durations of NaOCl exposure at lower concentrations resulted in similar depths of tubular penetration as those achieved at higher concentrations.


Assuntos
Irrigantes do Canal Radicular , Hipoclorito de Sódio , Cavidade Pulpar , Dentina , Humanos , Técnicas In Vitro , Preparo de Canal Radicular , Irrigação Terapêutica
3.
Community Dent Health ; 36(3): 229-236, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31437389

RESUMO

OBJECTIVE: To determine the prevalence and severity of dental caries (at dentine and enamel levels of diagnosis) amongst Malaysian children and to investigate determinant factors associated with caries detection at these different thresholds. METHODS: This study involved life-long residents aged 12 years-old in fluoridated and non-fluoridated areas in Malaysia (n=595). The survey was carried out in 16 public schools by a calibrated examiner, using ICDAS-II criteria. A questionnaire on socio-demographic and oral hygiene practices was self-administered by parents/guardians. Data were analysed using Mann-Whitney U tests and logistic regression. RESULTS: The overall response rate was 74.4%. Caries prevalence at the dentine level or at the dentine and enamel level was significantly (p⟨0.001) higher among children in the non-fluoridated area (D1₋6MFT⟩0 = 82.4%, D4₋6MFT⟩0 = 53.5%) than in the fluoridated area (D1₋6MFT⟩0 = 68.7%, D4₋6MFT⟩0 = 25.5%). Considering only the decayed component of the index, no significant differences were observed between the two areas when the detection threshold was set at enamel caries (D1₋3) (p=0.506). However, when the detection criteria were elevated to the level of caries into dentine (D4₋6) there were clear differences between the fluoridated and non-fluoridated areas (p=0.006). Exposure to fluoridated water proved a significant predictor for lower caries prevalence in the statistical model. Children whose father and mother had a low monthly income had a significantly higher dentine caries prevalence. CONCLUSION: Results confirmed existing evidence of the benefit of water fluoridation in caries prevention. Detection criteria set at caries into dentine shows clear differences between fluoridated and non-fluoridated areas. Exposure to fluoridated water and socio-economic status were associated with caries prevalence.


Assuntos
Cárie Dentária , Fluoretação , Criança , Índice CPO , Cárie Dentária/epidemiologia , Cárie Dentária/prevenção & controle , Dentina , Humanos , Malásia/epidemiologia , Prevalência , Abastecimento de Água
4.
Int Endod J ; 51(6): 605-621, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29178166

RESUMO

AIMS: To establish whether irrigant activation techniques (IATs) result in greater intracanal smear layer and debris removal than conventional needle irrigation (CNI). METHODOLOGY: Six electronic databases were searched to identify scanning electron microscopy studies evaluating smear layer and/or debris removal following the use of manual dynamic activation (MDA), passive ultrasonic irrigation (PUI), sonic irrigation (SI) or apical negative pressure (ANP) IATs in mature permanent teeth. Meta-analyses were performed for each canal segment (coronal, middle, apical and apical 1 mm) in addition to subgroup analyses for individual IATs with respect to CNI. Outcomes were presented as standardized mean differences (SMD) alongside 95% confidence intervals (95% CI) and chi-squared analysis. RESULTS: From 252 citations, 16 studies were identified. The meta-analyses demonstrated significant improvements in coronal (SMD: 1.15, 95% CI: 0.72-1.57 / SMD: 0.54, 95% CI: 0.29-0.80), middle (SMD: 1.30, 95% CI: 0.59-2.53 / SMD: 0.8, 95% CI: 0.58-1.13) and apical thirds (SMD: 1.22, 95% CI: 0.83-1.62 / SMD: 1.86, 95% CI: 0.76-2.96) for smear layer and debris removal, respectively. In the apical 1 mm IATs improved cleanliness; however, differences were insignificant (SMD: 1.15, 95% CI: -0.47-2.77). Chi-squared analysis revealed heterogeneity scores of 79.3-92.8% and 0.0-93.5% for smear layer and debris removal, respectively. CONCLUSIONS: IATs improve intracanal cleanliness across a substantial portion of the canal, and therefore, their use is recommended throughout root canal preparation. However, current data is too heterogeneous to compare and identify superiority of an individual technique highlighting the need to standardize experimental protocols and develop a more representative research model to investigate the in vivo impact of IATs on clinical outcomes and periapical healing following root canal treatment.


Assuntos
Cavidade Pulpar/ultraestrutura , Dentição Permanente , Irrigantes do Canal Radicular/administração & dosagem , Camada de Esfregaço/prevenção & controle , Irrigação Terapêutica/métodos , Humanos , Microscopia Eletrônica de Varredura , Preparo de Canal Radicular/métodos , Sonicação/métodos , Irrigação Terapêutica/instrumentação
5.
Int Endod J ; 51(7): 717-728, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29319894

RESUMO

AIM: To evaluate the views of final year dental surgery students (BDS; G1) at Cardiff University and general dental practitioners (GDPs; G2) within the geographic area of Cardiff, Wales, on antibiotic prescribing for endodontic conditions, and investigate the potential differences between the two groups. METHODS: A cross-sectional online questionnaire-based survey of 12 qualitative and quantitative questions was distributed to 76 final year BDS Cardiff University students and 55 dental practices within Cardiff, UK. Six questions recorded general information, and the remaining questions included a series of hypothetical clinical scenarios, where the participants were asked to state whether they would or would not prescribe antibiotics. The data were analysed using spss version 23 to produce descriptive statistics, contingency tables and to run chi-square (χ²) tests, Fisher's exact tests and relative risk calculations. RESULTS: The response rate was 60% (n = 79). All G1 participants were aware of the consequences of antibiotic overuse. Approximately 60% of responders were aware of guidelines for antibiotic use in endodontic therapies, and 83% would only use antibiotics for a limited selection of patients (e.g. patients with systemic complications). G1 responses to clinical scenarios indicated overall that they were comparable to the ideal answers except for acute apical abscess (64% believed that antibiotics were indicated). The majority of G2 were aware of the consequences of antibiotic overuse. Only 28% of G2 were aware of guidelines for antibiotic use in endodontic therapies. Overall responses revealed that antibiotics would be prescribed for: systemic complications (78%), acute apical abscess (72%) and symptomatic apical periodontitis (28%). The clinical scenarios revealed G1 were more likely to prescribe antibiotics compared to G2 for cases of necrotic pulp with symptomatic apical periodontitis without systemic complications (incorrect answer) and less likely to other clinical scenarios such as necrotic pulp and asymptomatic apical periodontitis for patients with a history of rheumatic fever (ideal answers), symptomatic irreversible/reversible pulpitis, failure to achieve anaesthesia, chronic apical abscess for patients with diabetes. The recognition of antibiotic prescription for cases with signs of spreading infection was more evident in G2. CONCLUSION: Final year undergraduate students were aware of the antibiotic resistance crisis, although a third was not aware of guidelines for use of antibiotics in endodontic conditions; their responses to clinical scenario were generally compatible with the guidelines. General dentists were less aware of the implications of overuse of antibiotics and the existence of guidelines, and their responses were occasionally incompatible with antibiotic guidelines for endodontic therapies.


Assuntos
Antibioticoprofilaxia/estatística & dados numéricos , Odontólogos/estatística & dados numéricos , Endodontia/estatística & dados numéricos , Padrões de Prática Odontológica/estatística & dados numéricos , Estudantes de Odontologia/estatística & dados numéricos , Antibacterianos/uso terapêutico , Estudos Transversais , Humanos , Inquéritos e Questionários , País de Gales
6.
Int Endod J ; 52(4): 554, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30864224
7.
J Dent ; 114: 103813, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34530058

RESUMO

OBJECTIVES: To synthesise evidence on structural failures and prevalence of post-treatment endodontic disease (PTD) in anterior and posterior root filled teeth with a single crown and adhesively bonded fibre post with regards to the number of axial walls. DATA: An electronic search was performed, no language constraints or restriction on the year of publication were applied. SOURCES: PubMed, Medline, Cochrane and Scopus on 13th of July 2021. STUDY SELECTION: Clinical studies that reported the remaining number of axial walls for permanent anterior and posterior root filled teeth (RFT) restored with single crowns and adhesively bonded fibre posts with a minimum of 1 year follow-up were included. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines [1] were used. The number of axial walls and the success/failures were analysed as follows: fibre post and/or core decementation, post and/or core fracture and post treatment endodontic disease, and root fracture. CONCLUSIONS: A total of 811 studies were identified with 5 meeting the inclusion criteria. The two randomized controlled trials included had 'some concerns' as determined by the Cochrane risk-of-bias 2 tool while the Newcastle-Ottawa scale found low risk of bias for the remaining three studies. The random effects model for subgroup meta-analysis revealed failures for posterior RFT increased with decreasing numbers of remaining walls. Failures for 0 remaining walls were 23% (95% CI = 10% - 36%) and for one remaining wall 15% (CI: 3% -26%), irrespective of follow-up times. Fibre post debonding and PTD increased with decreasing numbers of walls. Relative & catastrophic failure of posterior teeth restored with a fibre post and single crown after root canal treatment increased with decreasing numbers of remaining axial walls. CLINICAL SIGNIFICANCE: This synthesis is unique as it minimizes the presence of confounding factors by reviewing evidence of failures and post-treatment endodontic disease associated with teeth restored with single crowns. Therefore, it provides valuable predictive evidence of potential coronal restoration catastrophes and post-treatment endodontic disease associated with root filled teeth.


Assuntos
Técnica para Retentor Intrarradicular , Dente não Vital , Coroas , Falha de Restauração Dentária , Humanos , Obturação do Canal Radicular , Coroa do Dente
8.
Comput Methods Programs Biomed ; 200: 105935, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33485077

RESUMO

BACKGROUND AND OBJECTIVES: Multilevel statistical models represent the existence of hierarchies or clustering within populations of subjects (or shapes in this work). This is a distinct advantage over single-level methods that do not. Multilevel partial-least squares regression (mPLSR) is used here to study facial shape changes with age during adolescence in Welsh and Finnish samples comprising males and females. METHODS: 3D facial images were obtained for Welsh and Finnish male and female subjects at multiple ages from 12 to 17 years old. 1000 3D points were defined regularly for each shape by using "meshmonk" software. A three-level model was used here, including level 1 (sex/ethnicity); level 2, all "subject" variations excluding sex, ethnicity, and age; and level 3, age. The mathematical formalism of mPLSR is given in an Appendix. RESULTS: Differences in facial shape between the ages of 12 and 17 predicted by mPLSR agree well with previous results of multilevel principal components analysis (mPCA); buccal fat is reduced with increasing age and features such as the nose, brow, and chin become larger and more distinct. Differences due to ethnicity and sex are also observed. Plausible simulated faces are predicted from the model for different ages, sexes and ethnicities. Our models provide good representations of the shape data by consideration of appropriate measures of model fit (RMSE and R2). CONCLUSIONS: Repeat measures in our dataset for the same subject at different ages can only be modelled indirectly at the lowest level of the model at discrete ages via mPCA. By contrast, mPLSR models age explicitly as a continuous covariate, which is a strong advantage of mPLSR over mPCA. These investigations demonstrate that multivariate multilevel methods such as mPLSR can be used to describe such age-related changes for dense 3D point data. mPLSR might be of much use in future for the prediction of facial shapes for missing persons at specific ages or for simulating shapes for syndromes that affect facial shape in new subject populations.


Assuntos
Face , Imageamento Tridimensional , Adolescente , Criança , Face/diagnóstico por imagem , Feminino , Humanos , Análise dos Mínimos Quadrados , Masculino , Análise de Componente Principal , Software
9.
Comput Methods Programs Biomed ; 188: 105272, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31865094

RESUMO

BACKGROUND AND OBJECTIVES: The study of age-related facial shape changes across different populations and sexes requires new multivariate tools to disentangle different sources of variations present in 3D facial images. Here we wish to use a multivariate technique called multilevel principal components analysis (mPCA) to study three-dimensional facial growth in adolescents. METHODS: These facial shapes were captured for Welsh and Finnish subjects (both male and female) at multiple ages from 12 to 17 years old (i.e., repeated-measures data). 1000 "dense" 3D points were defined regularly for each shape by using a deformable template via "meshmonk" software. A three-level model was used here, namely: level 1 (sex/ethnicity); level 2, all "subject" variations excluding sex, ethnicity, and age; and level 3, age. The technicalities underpinning the mPCA method are presented in Appendices. RESULTS: Eigenvalues via mPCA predicted that: level 1 (ethnicity/sex) contained 7.9% of variation; level 2 contained 71.5%; and level 3 (age) contained 20.6%. The results for the eigenvalues via mPCA followed a similar pattern to those results of single-level PCA. Results for modes of variation made sense, where effects due to ethnicity, sex, and age were reflected in modes at appropriate levels of the model. Standardised scores at level 1 via mPCA showed much stronger differentiation between sex and ethnicity groups than results of single-level PCA. Results for standardised scores from both single-level PCA and mPCA at level 3 indicated that females had different average "trajectories" with respect to these scores than males, which suggests that facial shape matures in different ways for males and females. No strong evidence of differences in growth patterns between Finnish and Welsh subjects was observed. CONCLUSIONS: mPCA results agree with existing research relating to the general process of facial changes in adolescents with respect to age quoted in the literature. They support previous evidence that suggests that males demonstrate larger changes and for a longer period of time compared to females, especially in the lower third of the face. These calculations are therefore an excellent initial test that multivariate multilevel methods such as mPCA can be used to describe such age-related changes for "dense" 3D point data.


Assuntos
Face/fisiologia , Imageamento Tridimensional , Desenvolvimento Maxilofacial , Análise de Componente Principal , Adolescente , Fatores Etários , Criança , Feminino , Finlândia , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Análise Multivariada , Reconhecimento Automatizado de Padrão , Fatores Sexuais , Software , País de Gales
10.
Clin Transl Radiat Oncol ; 21: 98-103, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32072031

RESUMO

There is an increasing need to measure treatment-related side effects in normal tissues following cancer therapy. The ALERT-B (Assessment of Late Effects of RadioTherapy - Bowel) questionnaire is a screening tool that is composed of four items related specifically to bowel symptoms. Those patients that respond with a "yes" to any of these items are referred on to gastroenterologist in order to improve the long-term consequences of these side effects of radiological treatment. Here we wish to test the ability of this questionnaire to identify these subsequent gastroenterological complications by tracking prostate cancer patients that were positive with respect to ALERT-B. We also carry out receiver-operator curve (ROC) analysis for baseline data for an overall ALERT-B questionnaire score with respect to subscale data for the Gastrointestinal Symptom Rating Scale (GSRS) and the Expanded Prostate Cancer Index Composite (EPIC-26) questionnaire. 84.4% and 95.7% of patients identified by the ALERT-B questionnaire demonstrated complications diagnosed at 6 and 12 months post-treatment, respectively. ROC curve analysis of baseline data showed that ALERT-B detected clinically relevant levels of side effects established at baseline by the GSRS diarrhoea subscale (AUC = 0.867, 95% CI = 0.795 to 0.926) and at the minimally important level of side effects for the EPIC bowel subscale (AUC = 0.765, 95% CI = 0.617 to 0.913). These results show that ALERT-B provides a simple and effective screening tool for identifying gastroenterological complications after treatment for prostate cancer.

11.
Br J Cancer ; 100(10): 1558-65, 2009 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-19384297

RESUMO

The aims of this study were to assess changes in quality of life (QoL) scores in relation to radical radiotherapy for gynaecological cancer (before and after treatment up to 3 years), and to identify the effect that late treatment effects have on QoL. This was a prospective study involving 225 gynaecological cancer patients. A QoL instrument (European Organisation for the Research and Treatment of Cancer QLQ-C30) and late treatment effect questionnaire (Late Effects Normal Tissues - Subjective Objective Management Analysis) were completed before and after treatment (immediately after radiotherapy, 6 weeks, 12, 24 and 36 months after treatment). Most patients had acute physical symptoms and impaired functioning immediately after treatment. Levels of fatigue and diarrhoea only returned to those at pre-treatment assessment after 6 weeks. Patients with high treatment toxicity scores had lower global QoL scores. In conclusion, treatment with radiotherapy for gynaecological cancer has a negative effect on QoL, most apparent immediately after treatment. Certain late treatment effects have a negative effect on QoL for at least 2 years after radiotherapy. These treatment effects are centred on symptoms relating to the rectum and bowel, for example, diarrhoea, tenesmus and urgency. Future research will identify specific symptoms resulting from late treatment toxicity that have the greatest effect on QoL; therefore allowing effective management plans to be developed to reduce these symptoms and improve QoL in gynaecological cancer patients.


Assuntos
Neoplasias dos Genitais Femininos/radioterapia , Qualidade de Vida , Lesões por Radiação/fisiopatologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Terapia Combinada/efeitos adversos , Feminino , Neoplasias dos Genitais Femininos/tratamento farmacológico , Neoplasias dos Genitais Femininos/reabilitação , Neoplasias dos Genitais Femininos/cirurgia , Humanos , Pessoa de Meia-Idade , Cooperação do Paciente , Lesões por Radiação/diagnóstico , Inquéritos e Questionários , Fatores de Tempo , Adulto Jovem
12.
Comput Methods Programs Biomed ; 87(2): 93-103, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17576020

RESUMO

The aim of this study was to provide numerical evidence that latanoprost induced iris darkening (LIID) can be caused by changes to the melanin granule size distribution in the anterior segment of the iris. Iridectomies from two patients were used, where both had undergone unilateral treatment with latanoprost and had exhibited LIID. The untreated eye provided the comparative control. Micrographs from the iris samples were analysed to determine the number and size of the mature melanin granules. Monte Carlo (MC) simulation of light propagation in the iris was performed to examine the changes in reflectance and absorption with varying particle size and density. The reflected intensity of light was obtained as a function of wavelength. CIE colour theory was employed in order to estimate a perceived colour from the reflectance data. MC simulations showed that the reflectance was reduced for the LIID irises compared to the control irises for both subjects and for all wavelengths of light. The MC simulated colours were in good agreement with the in vivo photography of the eye colour. Hence, we have demonstrated that increases in melanin granule size causes iris darkening, and can explain LIID.


Assuntos
Cor de Olho/efeitos dos fármacos , Doenças da Íris/induzido quimicamente , Doenças da Íris/fisiopatologia , Iris/fisiopatologia , Modelos Biológicos , Transtornos da Pigmentação/induzido quimicamente , Transtornos da Pigmentação/fisiopatologia , Prostaglandinas F Sintéticas/efeitos adversos , Anti-Hipertensivos/administração & dosagem , Simulação por Computador , Relação Dose-Resposta a Droga , Humanos , Iris/efeitos dos fármacos , Latanoprosta , Melaninas/metabolismo , Método de Monte Carlo
13.
Radiography (Lond) ; 23(4): 305-309, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28965893

RESUMO

INTRODUCTION: Panoramic radiography is a common radiographic examination carried out in the UK. This study was carried out to determine if acquisition site has an impact on image quality. METHODS: An image quality audit was carried out in South Wales across a number of dental and general radiology settings. The image quality was assessed retrospectively against national standards. A total of 174 radiographs were assessed from general radiology departments and 141 from dental radiology units. Chi-squared analysis was used to investigate whether there were differences in the grading between dental radiology units and general radiology departments. Differences between the two settings in terms of the number of errors in the radiographs was analysed using the Mann-Whitney test. Chi-squared analysis was used to see if there were differences between the types of errors in the two clinical settings. RESULTS: There was a significant association (p = 0.021) between the quality of the radiograph grading and type of radiology department. However when excellent and diagnostically acceptable radiographs were grouped together there was no significant difference between the two clinical settings. Although the vast majority of radiographs were diagnostic (89% for general radiology and 92% for dental radiology units), neither reached the required standards. The most common errors were patient positioning errors (54.6% radiographs affected) and preparation/instructional errors (47.9% radiographs affected). CONCLUSION: Errors in panoramic radiography are relatively high and further instruction to staff undertaking these procedures is required to ensure the targets are reached.


Assuntos
Erros de Diagnóstico/estatística & dados numéricos , Radiografia Panorâmica/métodos , Humanos , Posicionamento do Paciente , Fatores de Risco , País de Gales
14.
J Natl Cancer Inst ; 74(4): 927-31, 1985 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3857386

RESUMO

Because hormones of pregnancy are thought to alter the mammary gland such that the epithelial cells are less susceptible to future carcinogenic insults, the present study was conducted to determine the ability of short-term treatment with 17 beta-estradiol and/or progesterone, administered immediately after puberty, to prevent mammary cancers in rats subsequently exposed to N-nitroso-N-methylurea [(NMU) CAS:684-93-5]. Beginning at 40 days of age, female outbred Sprague-Dawley rats received 20 micrograms 17 beta-estradiol and/or 4 mg progesterone for 5 weeks. NMU (50 mg/kg body wt) was administered at 96 and 103 days of age (3 and 4 wk, respectively, after the last hormone injection). Pretreatment of rats with 17 beta-estradiol plus progesterone was highly effective in preventing mammary cancer induction (88% fewer cancers compared to the cancer incidence in rats pretreated with the hormone vehicle). Wholemounts of the mammary glands of rats treated with 17 beta-estradiol plus progesterone revealed that the gland was stimulated to a highly differentiated state (similar to that observed in late pregnancy). At the time of NMU treatment, the gland had involuted but was quite different from controls; i.e. an absence of terminal end buds and terminal ducts was noted. The short-term treatment with hormones did not induce tumors and did not interfere with subsequent reproductive and lactational performance. It is apparent that stimulation of the mammary gland to a highly differentiated state early in life can provide protection against future carcinogen exposure.


Assuntos
Adenocarcinoma/prevenção & controle , Estradiol/uso terapêutico , Neoplasias Mamárias Experimentais/prevenção & controle , Metilnitrosoureia/toxicidade , Compostos de Nitrosoureia/toxicidade , Progesterona/uso terapêutico , Adenocarcinoma/induzido quimicamente , Animais , Quimioterapia Combinada , Feminino , Glândulas Mamárias Animais/efeitos dos fármacos , Glândulas Mamárias Animais/patologia , Neoplasias Mamárias Experimentais/induzido quimicamente , Ratos
15.
Cancer Res ; 61(10): 3961-8, 2001 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-11358813

RESUMO

Exisulind (Aptosyn) is a novel antineoplastic drug being developed for the prevention and treatment of precancerous and malignant diseases. In colon tumor cells, the drug induces apoptosis by a mechanism involving cyclic GMP (cGMP) phosphodiesterase inhibition, sustained elevation of cGMP, and protein kinase G activation. We studied the effect of exisulind on bladder tumorigenesis induced in rats by the carcinogen, N-butyl-N-(4-hydroxybutyl) nitrosamine. Exisulind at doses of 800, 1000, and 1200 mg/kg (diet) inhibited tumor multiplicity by 36, 47, and 64% and tumor incidence by 31, 38, and 61%, respectively. Experiments on the human bladder tumor cell line, HT1376, showed that exisulind inhibited growth with a GI(50) of 118 microM, suggesting that the antineoplastic activity of the drug in vivo involved a direct effect on neoplastic urothelium. Exisulind also induced apoptosis as determined by DNA fragmentation, caspase activation, and morphology. Analysis of phosphodiesterase (PDE) isozymes in HT1376 cells showed PDE5 and PDE4 isozymes that were inhibited by exisulind with IC(50)s of 112 and 116 microM, respectively. Inhibition of PDE5 appears to be pharmacologically relevant, because treatment of HT1376 cells increased cGMP and activated protein kinase G at doses that induce apoptosis, whereas cyclic AMP levels were not changed. Immunocytochemistry showed that PDE5 was localized in discrete perinuclear foci in HT1376 cells. Immunohistochemistry showed that PDE5 was overexpressed in human squamous and transitional cell carcinomas compared with normal urothelium. The data lead us to conclude that future clinical trials of exisulind for human bladder cancer treatment and/or prevention should be considered and suggest a mechanism of action involving cGMP-mediated apoptosis induction.


Assuntos
Anticarcinógenos/farmacologia , Sulindaco/farmacologia , Neoplasias da Bexiga Urinária/prevenção & controle , 3',5'-AMP Cíclico Fosfodiesterases/antagonistas & inibidores , 3',5'-AMP Cíclico Fosfodiesterases/metabolismo , 3',5'-GMP Cíclico Fosfodiesterases/antagonistas & inibidores , 3',5'-GMP Cíclico Fosfodiesterases/metabolismo , Animais , Apoptose/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , AMP Cíclico/metabolismo , GMP Cíclico/metabolismo , Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4 , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5 , Relação Dose-Resposta a Droga , Ativação Enzimática/efeitos dos fármacos , Feminino , Humanos , Concentração Inibidora 50 , Microscopia de Fluorescência , Ratos , Ratos Endogâmicos F344 , Sulindaco/análogos & derivados , Células Tumorais Cultivadas , Neoplasias da Bexiga Urinária/induzido quimicamente , Neoplasias da Bexiga Urinária/metabolismo
16.
Comput Methods Programs Biomed ; 129: 149-59, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26830379

RESUMO

BACKGROUND AND OBJECTIVE: Methods used in image processing should reflect any multilevel structures inherent in the image dataset or they run the risk of functioning inadequately. We wish to test the feasibility of multilevel principal components analysis (PCA) to build active shape models (ASMs) for cases relevant to medical and dental imaging. METHODS: Multilevel PCA was used to carry out model fitting to sets of landmark points and it was compared to the results of "standard" (single-level) PCA. Proof of principle was tested by applying mPCA to model basic peri-oral expressions (happy, neutral, sad) approximated to the junction between the mouth/lips. Monte Carlo simulations were used to create this data which allowed exploration of practical implementation issues such as the number of landmark points, number of images, and number of groups (i.e., "expressions" for this example). To further test the robustness of the method, mPCA was subsequently applied to a dental imaging dataset utilising landmark points (placed by different clinicians) along the boundary of mandibular cortical bone in panoramic radiographs of the face. RESULTS: Changes of expression that varied between groups were modelled correctly at one level of the model and changes in lip width that varied within groups at another for the Monte Carlo dataset. Extreme cases in the test dataset were modelled adequately by mPCA but not by standard PCA. Similarly, variations in the shape of the cortical bone were modelled by one level of mPCA and variations between the experts at another for the panoramic radiographs dataset. Results for mPCA were found to be comparable to those of standard PCA for point-to-point errors via miss-one-out testing for this dataset. These errors reduce with increasing number of eigenvectors/values retained, as expected. CONCLUSIONS: We have shown that mPCA can be used in shape models for dental and medical image processing. mPCA was found to provide more control and flexibility when compared to standard "single-level" PCA. Specifically, mPCA is preferable to "standard" PCA when multiple levels occur naturally in the dataset.


Assuntos
Diagnóstico por Imagem , Radiografia Panorâmica , Estudos de Viabilidade , Humanos , Método de Monte Carlo , Análise de Componente Principal
17.
Br Dent J ; 221(1): 21-4, 2016 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-27388086

RESUMO

Objective To determine general dental practitioners' (GDPs) confidence in managing orthodontic emergencies.Design Cross-sectional study.Setting Primary dental care.Subjects and methods An online survey was distributed to dentists practicing in Wales. The survey collected basic demographic information and included descriptions of ten common orthodontic emergency scenarios.Main outcome measure Respondents' self-reported confidence in managing the orthodontic emergency scenarios on a 5-point Likert scale. Differences between the Likert responses and the demographic variables were investigated using chi-squared tests.Results The median number of orthodontic emergencies encountered by respondents over the previous six months was 1. Overall, the self-reported confidence of respondents was high with 7 of the 10 scenarios presented scoring a median of 4 indicating that GDPs were 'confident' in their management. Statistical analysis revealed that GDPs who saw more orthodontic emergencies in the previous six months were more confident when managing the presented scenarios. Other variables such as age, gender, geographic location of practice and number of years practising dentistry were not associated with self-reported confidence.Conclusions Despite GDPs encountering very few orthodontic emergencies in primary care, they appear to be confident in dealing with commonly arising orthodontic emergency situations.


Assuntos
Emergências , Odontologia Geral , Autorrelato , Estudos Transversais , Humanos , Atenção Primária à Saúde , Inquéritos e Questionários , País de Gales
18.
Clin Oncol (R Coll Radiol) ; 28(10): e139-e147, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27369458

RESUMO

AIMS: Although pelvic radiotherapy is an effective treatment for various malignancies, around half of patients develop significant gastrointestinal problems. These symptoms often remain undetected, despite the existence of effective treatments. This study developed and refined a simple screening tool to detect common gastrointestinal symptoms in outpatient clinics. These symptoms have a significant effect on quality of life. This tool will increase detection rates and so enable access to specialist gastroenterologists, which will in turn lead to improved symptom control and quality of life after treatment. MATERIALS AND METHODS: A literature review and expert consensus meeting identified four items for the ALERT-B (Assessment of Late Effects of RadioTherapy - Bowel) screening tool. ALERT-B was face tested for its usability and acceptability using cognitive interviews with 12 patients experiencing late gastrointestinal symptoms after pelvic radiotherapy. Thematic analysis and probe category were used to analyse interview transcripts. Interview data were presented to a group of experts to agree on the final content and format of the tool. ALERT-B was assessed for reliability and tested for validity against the Gastrointestinal Symptom Rating Scale in a clinical study (EAGLE). RESULTS: Overall, the tool was found to be acceptable in terms of wording, response format and completion time. Participant-reported experiences, including lifestyle modifications and the psychological effect of the symptoms, led to further modifications of the tool. The refined tool includes three questions covering rectal bleeding, incontinence, nocturnal bowel movements and impact on quality of life, including mood, relationships and socialising. ALERT-B was successfully validated against the Gastrointestinal Symptom Rating Scale in the EAGLE study with the tool shown broadly to be internally consistent (Cronbach's α = 0.61 and all item-subscale correlation [Spearman] coefficients are > 0.6). CONCLUSION: The ALERT-B screening tool can be used in clinical practice to improve post-treatment supportive care by triggering the clinical assessment of patients suitable for referral to a gastroenterologist.


Assuntos
Gastroenteropatias/diagnóstico , Programas de Rastreamento/métodos , Neoplasias/radioterapia , Radioterapia/efeitos adversos , Idoso , Doença Crônica , Feminino , Gastroenteropatias/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Pelve/efeitos da radiação , Qualidade de Vida , Reprodutibilidade dos Testes , Inquéritos e Questionários , Sobreviventes
19.
J R Soc Interface ; 2(2): 79-88, 2005 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-16849167

RESUMO

We provide initial evidence that a structure formed from an articulated series of linked elements, where each element has a given stiffness, damping and driving term with respect to its neighbours, may 'swim' through a fluid under certain conditions. We derive a Lagrangian for this system and, in particular, we note that we allow the leading edge to move along the x-axis. We assume that no lateral displacement of the leading edge of the structure is possible, although head 'yaw' is allowed. The fluid is simulated using a computational fluid dynamics technique, and we are able to determine and solve Euler-Lagrange equations for the structure. These two calculations are solved simultaneously by using a weakly coupled solver. We illustrate our method by showing that we are able to induce both forward and backward swimming. A discussion of the relevance of these simulations to a slowly swimming body, such as a mechanical device or a fish, is given.


Assuntos
Simulação por Computador , Natação/fisiologia , Animais , Peixes/fisiologia , Modelos Biológicos
20.
Toxicol Sci ; 45(1): 113-27, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9848118

RESUMO

Combination therapy with anti-HIV drugs and opportunistic infection drugs is a common practice in treatment of AIDS patients. Although toxic effects of most individual therapies are known, the toxic potential of most combination therapies has not been established. To understand the toxic consequences of combination therapies, the commonly used anti-HIV drug 3'-azido-3'-deoxythymidine (AZT) and tuberculosis infection therapies pyrazinamide, isoniazid, and rifampicin were evaluated by 13-week gavage studies in B6C3F1 mice, either alone or AZT in combination with one of the antituberculosis drugs. The doses include AZT 100, 200, and 400; pyrazinamide 1000 and 1500; isoniazid 50, 100, and 150; and rifampicin 100, 200, and 400 mg/kg/day. AZT alone caused hematopoietic toxicity with dose-related bone marrow suppression, macrocytic anemia, and thrombocytosis. Pyrazinamide or isoniazid alone at the doses tested did not cause significant toxicity. Rifampicin alone caused hematopoietic toxicity and possibly mild hepatic toxicity. Pyrazinamide below 10 times the therapeutic dose when given with AZT did not increase the hematological toxicity of AZT. Isoniazid markedly increased the hematological toxicity of AZT and contributed to mortality at 3 to 4 times the therapeutic dose combinations. Administration of rifampicin with AZT at the calculated therapeutic doses resulted in toxicity of far greater magnitude than that caused by AZT or rifampicin alone. Combination treatment with AZT and rifampicin caused severe anemia with mortality at 2 to 4 times the therapeutic dose combinations. However, AZT did not enhance the hepatotoxicity of rifampicin. Increased hematopoietic toxicity of AZT when given in combination with the above antituberculosis drugs may be due to changes in the metabolism of AZT. Results of these studies indicate that toxicological effects of combination therapies could be considerably more severe than and different from the toxicity of individual therapies.


Assuntos
Fármacos Anti-HIV/toxicidade , Antibióticos Antituberculose/toxicidade , Medula Óssea/efeitos dos fármacos , Isoniazida/toxicidade , Pirazinamida/toxicidade , Rifampina/toxicidade , Zidovudina/toxicidade , Animais , Plaquetas , Medula Óssea/patologia , Interações Medicamentosas , Eritrócitos , Feminino , Hemoglobinas , Masculino , Camundongos , Testes de Toxicidade
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